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ANIMAL AND VEGETABLE 
 
 FIXED-OILS, FATS; BUTTERS, 
 -AND WAXES:- 
 
 THEIR PREPARATION AND PROPERTIES, 
 
 AND THE 
 
 0f 
 
 BY 
 
 C. R. ALDER BRIGHT, 
 
 D.Sc. (LOND.), B.Sc. (VicT.), F.R.S., 
 
 LECTURER ON CHEMISTRY IN ST. MARY'S HOSPITAL MEDICAL SCHOOL, LONDON ; EXAMINER IN 
 "SOAP" TO THE CITY AND GUILDS OF LONDON INSTITUTE. 
 
 Witb 144 Illustrations* 
 
 OF THE 
 
 UNIVERSITY 
 
 LONDON: 
 
 CHARLES GRIFFIN & COMPANY, LIMITED; 
 
 EXETER^ STREET, STRAND. 
 
 1894. 
 
 [All Rights Reserved.] 
 
bl 
 
 
OF THE *" Ny 
 
 CVERSITT) 
 OF J 
 
 PREFACE 
 
 The complete discussion of the Sources, Production, and 
 General Technology of the numerous substances included in 
 the term Oils, and of the intimately associated Fats, Butters, 
 and Waxes (all of which are practically oils when melted), 
 would require far more space than is compatible with the 
 limits of the present ^or-k'; it has accordingly been found 
 indispensable to make a selection from this wide field, as 
 the result of which the subjects now dealt with are 
 narrowed down to the Animal and Vegetable Fixed Oils 
 and allied substances ; whilst Mineral Oils, Products of 
 Distillation, Essential Oils, and various analogous materials 
 are only discussed in so far as they are associated with the 
 Fixed Oils in their technological applications. For the 
 same sufficient reason minute details respecting the various 
 special tests employed in the practical examination of oils, 
 &c., for adulterations have, as a rule, been omitted ; as also 
 have the descriptions of the distinctive properties and 
 qualities of the individual oils and fats, excepting in a 
 comparatively small number of typical cases. In short, the 
 object aimed at has rather been to give general descriptions 
 of the methods whereby Animal and Vegetable Oils and Fat 
 are obtained from natural sources, of their leading practical 
 applications and uses, and of their chief physical and 
 chemical properties and reactions, than to enter into special 
 details, and to discuss minutely the analytical tests and 
 processes applicable in each separate case for the detection 
 of adulteration. 
 
VI PREFACE. 
 
 The literature relating to the chemistry and technology 
 of fixed oils arid fats is already voluminous, and yearly 
 increases considerably in magnitude, being mostly dispersed 
 throughout the pages of numerous scientific and technical 
 serials. Amongst the periodicals of this description consulted 
 for the purpose of gathering together to some extent these 
 scattered results and items may be more particularly 
 mentioned : 
 
 The Journal of the Society of Chemical Industry. 
 
 The Journal of the Society of Arts. 
 
 The Journal of the Chemical Society. 
 
 The Analyst. 
 
 The Chemical News. 
 
 Zeitschrift fur angewandte Chemie. 
 
 Berichte der Deutschen Chemischen Gesellschaft. 
 
 Dingler's Polytechnisches Journal. 
 
 Biedermann's Technisch-Chemisches Jahrbuch. 
 
 Moniteur Scientiftque. 
 
 Bulletin de la Societe Chimique de Paris. 
 
 Comptes rcndus. 
 
 Besides many others in which papers bearing on the matters 
 in hand appear from time to time. Various text-books and 
 technical dictionaries previously published in this country 
 or abroad have also been freely consulted with the object of 
 rendering the present work as complete as possible, with 
 due regard to the limits of space. In particular the author 
 desires to express his indebtedness to the following works: 
 
 Schadler, Technologic der Fette und Oele* Berlin, 1883. 
 
 Allen, Commercial Organic Analysis, vol. ii., Second 
 edition. London, 1886. 
 
 Schadler, Untersuchungen der Fette und Oele* Leipzic, 
 1889. 
 
 Benedikt, Analyse der Fette und Wachsarten, Second 
 edition. Berlin, 1892. 
 
 * Whilst the present book was in the press the two works by Schadler 
 above mentioned have been incorporated into a single volume, edited by 
 P. Lohmann after the decease of the original author. 
 
PREFACE. Vll 
 
 To the firm of Kose, Downs, & Thompson, of Hull, the 
 author is greatly indebted for numerous illustrations of the 
 most recent and effective forms of oil mill machinery, as 
 well as for valuable information concerning their use in oil 
 extraction generally. In similar fashion be desires to thank 
 Messrs. Neill & Sons, of St. Helens, for a variety of specially 
 made drawings of appliances used in soap manufacture; 
 Messrs. S. H. Johnson, of Stratford, for drawings of the 
 newest forms of filter presses ; and Messrs. E. Cowles & Co., 
 of Hounslow, for cuts of improved candlemaldng machines. 
 
 C. R. ALDER WRIGHT. 
 
 LONDON, October, 1893. 
 
^E LIBR^PT^ 
 OF THE X 
 
 ;VERSITY) 
 OF J 
 
 TABLE OP CONTENTS 
 
 1. General Composition and Nature of Oils, Butters, Fats, 
 Waxes, and Allied Substances. 
 
 CHAPTER I. 
 
 THE SOURCES AND GENERAL 
 NATURE OF NATURAL AND 
 ARTIFICIAL OILS. 
 
 Meaning of the Terms "Oil," 
 "Fat," "Butter," and "Wax," 
 
 Sources and General Nature of 
 Oils, 
 
 Nature of Sapoiiification Changes, 
 
 Classification of Oils, Fats, 
 Waxes, &c. , according to Chem- 
 ical Composition, 
 
 CHAPTER II. 
 
 ALCOHOLIFORM SAPONIFICATION 
 PRODUCTS OF OILS, FATS, 
 WAXES, &c. 
 
 Glycerol, Glycerides, Hydrolysis 
 
 of Glycerides, .... 7 
 
 Fatty Alcohols, Ethylic Series, &c., 13 
 
 Glycols, 18 
 
 CHAPTER III. 
 
 ACID SAPONIFICATION PRODUCTS 
 OF OILS, FATS, WAXES, &c. 
 
 Fatty A cids- Acetic Family, . 18 
 
 Oleic Family, . . . 24 
 
 Linolic Family, . . 30 
 
 Linolenic Family, . . 36 
 
 Glycollic Family, . . 37 
 
 Ricinoleic Family, . . 39 
 
 Oxystearic Acids, . . 43 
 
 2. Physical Properties of Oils, Fats, Waxes, &e. 
 
 CHAPTER IV. 
 GENERAL PHYSICAL CHARACTERS. 
 
 Phy sical Texture and Consistency ; 
 Cohesion Figures, . 
 
 Taste, Odour, and Colour, . 
 
 Action of Polarised Light; Re- 
 fractive Index, 
 
 Solubility of Oils, Fats, &c., in 
 various Solvents, 
 
 Thermometric Scales, . 
 
 Methods used in the Determina- 
 tion of Fusing and Solidifying 
 Points, ..... 
 
 Freezing and Melting Points of 
 Oils, &c., 
 
 CHAPTER V. 
 SPECIFIC GRAVITY AND VISCOSITY. 
 
 Determination of Specific Gravity, 77 
 Construction of Tables of Errors 
 for Hydrometers and Hydro- 
 static Balances, . . . 82 
 Hydrometer Scales, . . .84 
 Relative Densities of the Principal 
 
 Oils, Fats, &c., . . 86 
 
 Classification of Oils, Fats, &c., 
 according to their Relative 
 Densities, . . . .89 
 Variation of Density of Oils, &c., 
 
 with Temperature, . . .92 
 Viscosimetry ; Mechanical Testing 
 
 Arrangements, . . . .94 
 Efflux Viscosimeters, . .95 
 
 Standards of Efflux Viscosity, . 101 
 Relative Viscosity of Oils, &c., . 102 
 Determination of Viscosity in 
 Absolute Measure, . . . 107 
 
CONTENTS. 
 
 3. Chemical Properties of Oils, Fats, Butters, and Waxes. 
 
 CHAPTER VI. 
 
 PROXIMATE CONSTITUENTS AND 
 THE METHODS USED FOR THEIR 
 EXAMINATION AND DETERMIN- 
 ATION. 
 
 Compound Nature of Oils, Fats, 
 and Waxes ; Variations in Com- 
 position with Circumstances of 
 Natural Formation,. 
 
 110 
 
 Methods Employed for Separa- 
 ting Constituents, . . .112 
 
 Determination of Free Fatty 
 Acids; Free Acid Number, . 116 
 
 Determination of Unsaponifiable 
 Constituents, . . . .119 
 
 Determination of Water, . . 122 
 
 Adulteration of Fats with sus- 
 pended Matters, 
 
 Sulphurised and 
 Constituents, . 
 
 Phosphorised 
 
 123 
 123 
 
 CHAPTER VII. 
 
 CHEMICAL REACTIONS or OILS, 
 FATS, c., AND THEIR, USES AS 
 TESTS OF PURITY, &c. 
 
 Effect of Heat on Oils, &c. ; 
 
 Flashing Point, . . .125 
 Characteristic Oxidation Products, 128 
 Spontaneous Oxidation of Oils, 
 Fats, &c. ; E fleet of Light 
 
 thereon, 129 
 
 Spontaneous Combustion, . .132 
 Film Test; Livache's Test, . . 133 
 Chemical Changes occurring dur- 
 ing drying of Oils, . . . 134 
 Elaidin Reaction ; Legler's Con- 
 sistency Tester, . . .137 
 Nitric Acid Test, , . .139 
 Zinc Chloride Reaction and Colour 
 Test; Action of Zinc Chloride 
 on Oleic Acid, . . . .141 
 
 Action of Sulphuric Acid on Oils 
 and Fats ; Turkey Red Oils, . 143 
 
 Maumene's Sulphuric Acid Ther- 
 mal Test, . . . 147 
 
 Various Colour Reactions, . . 151 
 
 Sulphur Chloride Reaction; Vul- 
 canised Oils, . . . .154 
 
 CHAPTER VIII. 
 
 QUANTITATIVE REACTIONS OF 
 OILS. 
 
 Koettstorfer's Test Total Acid 
 Number, ..... 157 
 
 Classification of Oils, &c., accord- 
 ing to their Saponification Equi- 
 valents, ..... 159 
 
 Practical Determination of Saponi- 
 fication Equivalents of Glycer- 
 ides, &c., .... 
 
 159 
 163 
 
 Proportion of Fatty Acids formed 
 by Saponification, . 
 
 Hehner's Test; Insoluble Acid 
 Number, . . ... . 166 
 
 Practical Determination of the 
 amount of Fatty Acids formed 
 on Saponification, . . . 167 
 
 Corrections for An hydro Deriva- 
 tives, Free Acids, and Unsa- 
 ponifiable Matters, 
 
 170 
 
 172 
 
 Mean Equivalent of Fatty Acids 
 
 contained in Soap, . 
 Reichert's Test and Modifica- 
 tions thereof, . . . .173 
 Bromine and Iodine Absorption ; 
 
 Bromine Process, . . . 176 
 Iodine Process ; Hiibl's Test, . 179 
 Iodine Numbers of Oils, Fats, 
 
 &c., . . . . .180 
 
 Acetylation Test ; Benedikt and 
 
 Ulzer'sTest, . . . .186 
 Methyl Iodide Test; Zeisel's 
 
 Test, 191 
 
 Tabulated results of the various 
 
 Quantitative Tests, . . . 194 
 
 4. Processes Used for Extracting, Rendering, Refining, 
 and Bleaching Oils, Fats, &e. 
 
 CHAPTER IX. 
 
 EXTRACTION OF OILS FROM SEEDS, 
 &c., BY PRESSURE OR SOLVENTS. 
 
 Earlier forms of Press, 
 
 199 
 
 Elbow, Wedge, and Screw 
 
 Presses, 202 
 
 Hydraulic Press, . . . 207 
 
 Composition of Oilcake, . .213 
 Oil Mill Plant ; " Unit " Mill, . 214 
 
CONTENTS. 
 
 XI 
 
 Crushing Rolls and Edge 
 Runners, . . . .218 
 
 Kettle ; Moulding Machine, . 221 
 
 Faring Machine ; Supplementary 
 Appliances, .... 223 
 
 Decortication, .... 224 
 
 Filter Presses, . ' . 
 
 Separation of Solid Stearines from 
 
 226 
 229 
 
 Oils, &c., . 
 
 Manufacture of Lard Oil, and 
 Allied Products, . . .231 
 
 Extraction of Oil from Seeds, Oil- 
 cake, &c., by Solvents, . . 231 
 
 Extraction of Grease from Engine 
 Waste, &c., . . . . 236 
 
 Determination of Fat in Seeds, 
 &c., 237 
 
 Proportion of Fatty Matter Con- 
 tained in Seeds, &c., . . 241 
 
 CHAPTER X. 
 
 A NIMAL FATTY TISSUES : EXTRAC- 
 TION or OILS AND FATS 
 
 THEREFROM. 
 
 Rendering of Fatty Tissues by 
 Dry Fusion, . . . .246 
 
 Rendering of Fatty Tissues by 
 Heating with Water or Steam 
 
 under ordinary Atmospheric 
 Pressure, .... 247 
 
 Rendering under Increased 
 Pressure, . . . .250 
 
 Extraction of Fat from Bones, . 251 
 
 CHAPTER XI. 
 
 REFINING ANDBLEACHING ANIMAL 
 AND VEGETABLE OILS, FATS, 
 WAXES, &c. 
 
 Suspended Matters, . 
 Dissolved Matters, 
 Sulphuric Acid Process for 
 Refining Oils, &c., 
 
 Alkaline Refining Processes, 
 Utilisation of " Foots," 
 Clarification, 
 Bleaching Oils and Fats, 
 Wax Bleaching, . 
 
 CHAPTER XII. 
 
 RECOVERY OF GREASE FROM 
 
 "SUDS," &C. 
 
 Modes of Treating Soap Suds, 
 Analysis of Yorkshire Grease, 
 Distilled Grease, 
 Engine Waste Grease, 
 
 254 
 
 256 
 
 259 
 260 
 261 
 262 
 263 
 268 
 
 270 
 273 
 
 277 
 279 
 
 5. Classification and Uses of Fixed Oils, Fats, Waxes, &e. ; 
 Adulterations. 
 
 CHAPTER XIII. 
 
 CLASSIFICATION. 
 
 Classification according to Tex- 
 ture, Sources, and Essential 
 Chemical Nature. . . .281 
 CLASS I. Olive (Almond) Class; 
 Vegetable Expression 
 Oleines, . . .282 
 II. Rape (Colza) Class, . 284 
 III. Castor Class, . . 284 
 ,, IV. Animal Non-Drjdng 
 
 Oils- Lard Oil Class, 285 
 ,, V. Sesame or Cotton Seed 
 Class Vegetable 
 Semidrying Oils, . 286 
 Lesser Known Vege- 
 table Oils, . . .287 
 ,, VI. Drying Oils Linseed 
 
 O'il Class, . . .290 
 ,, VII. Train, Liver, and Fish 
 
 Oils, . . . .292 
 
 ,, VIII. Vegetable Butters, 
 
 Fats, Waxes, &c., . 295 
 
 Lesser Known Vege- 
 table Butters, &c., . 296 
 
 IX. Animal Fats Tallow, 
 
 Lard, and Butter Class, 298 
 
 ,. X. Animal Oils Sperm 
 
 Oil Class, . . .299 
 
 ,, XI. Vegetable Nonglyce- 
 
 ridic Waxes, . . 301 
 
 ,, XII. Beeswax and Sperma- 
 ceti Class, . . 301 
 
 CHAPTER XIV. 
 
 PRINCIPAL USES OF OILS AND 
 FATS, &c. 
 
 Classification according to Uses, . 302 
 Edible and Culinary Uses of Oils, 
 
 Fats, &c 303 
 
 Cotton Seed Stearine ; Vegetable 
 
 Lards, . . 305 
 
Xll 
 
 CONTENTS. 
 
 Manufacture of Hog's Lard, . 306 
 Manufacture of Artificial Lard 
 
 and Batter, . . . .307 
 Utilisation of Fatty Matter from 
 
 an Ox, 311 
 
 Lamp Oils, 312 
 
 Drying Oils used in making Paints 
 
 and Varnishes, . . . 313 
 Blown Oils Oxygen Process, . 319 
 Miscellaneous Uses of Oils, Fats, 
 &c. ; Manufacture of Lubri- 
 cants, 321 
 
 Analysis of Lubricating Oils and 
 
 Greases, 328 
 
 Turkey Red Oils; Analysis, . 330 
 Currier's Grease, Sod Oils, and 
 
 Degras, 336 
 
 Manufacture of Lanolin, . . 337 
 
 CHAPTER XV. 
 ADULTERATION OF OILS AND FATS. 
 
 Methods employed in Detecting 
 
 Adulterations, . . .340 
 
 Relative Values of Oils, . . 342 
 General Characters of Olive Oil 
 andTests for Adul- 
 terations thereof, . 342 
 ,, Rape Seed and Colza 
 
 Oil, . . .348 
 Linseed Oil, . . 349 
 Sperm Oil, . . 353 
 Tallow, . . . 354 
 Beeswax, . . 357 
 
 Spermaceti, . . 359 
 
 6. The Candle Industry. 
 
 CHAPTER XVI. 
 
 MATERIALS USED IN CANDLE- 
 MAKING. 
 
 Origin of Candles ; Combustible 
 Materials, . . . . 362 
 
 Manufacture of ' ' Stearine ; " the 
 Chevreul-Milly Process, 
 
 Composition and Analysis of 
 "Rock," 
 
 Milly- Autoclave Process, . 
 
 Analysis of Red Oils, Separation 
 Cake, and Similar Products, . 
 
 Sulphuric Acid Process, 
 
 364 
 
 371 
 373 
 
 378 
 
 380 
 
 Hydrolysis of Glycerides by 
 
 Water only, . . . .385 
 Utilisation of Red Oils, . . 386 
 
 CHAPTER XVII. 
 
 MANUFACTURE OF CANDLES, TAPERS, 
 AND NIGHT LIGHTS. 
 
 Basted and Drawn Wax Candles, 
 
 Tapers, &c., . . . .388 
 Dip Caudles; Dipping Machinery, 390 
 Wicks ; Wick Pickling, . . 394 
 Moulded Candles ; Handmade, . 395 
 Continuous Moulding Machines, 398 
 Night Lights and Medicated 
 Candles, 406 
 
 7. The Soap Industry. 
 CHAPTER XVIII. CHAPTER XIX. 
 
 MATERIALS USED IN THE MANU- 
 FACTURE OF SOAP. 
 
 Fatty Matters ; Alkalies, . . 408 
 Causticising Process, . . .411 
 Valuation of Alkalinity of Leys, 414 
 Corrections for Impurities, . .419 
 English, French, and German 
 
 Decrees, 420 
 
 Calculations, . . . .421 
 Formulae, 425 
 
 SOAPMAKING PLANT. 
 
 Heating Appliances ; Free-fired 
 
 Soap Coppers, ... 426 
 
 Morfit's Steam Twirl, . . 429 
 
 Steam-heated Soap Coppers, 432 
 
 Curb and Fan, ... 433 
 
 Soap Pumps, . . . 434 
 
 Soap Frames, . . . 434 
 
 Barring and Slabbing, . 437 
 
 Crutching, 438 
 
CONTENTS. 
 
 Xlll 
 
 Toilet Soap Machinery ; Remelt- 
 
 ing, 441 
 
 Stamping, ..... 444 
 
 Transparent Soaps, . . . 445 
 
 Milling, 446 
 
 Plotting, 448 
 
 CHAPTER XX. 
 
 MANUFACTURE OF SOAP. 
 
 Soapmaking Processes ; Direct 
 
 Neutralisation, . . . 449 
 Calculations, .... 454 
 Processes in which the Free Gly- 
 
 cerol is retained ; Cold Process 
 
 Soaps, ..... 456 
 Soft, Hydrated, and Marine 
 
 Soaps, ..... 459 
 Calculations, .... 464 
 Processes in which the Glycerol 
 
 is separated ; Curd Soaps, . 466 
 Graining, ..... 469 
 Fitted and Mottled Soaps, . . 470 
 Special Varieties of Soap ; Rosin 
 
 Soaps, Silicated Soaps, &c., . 473 
 Toilet and Fancy Soaps; Milled 
 
 Soaps, 478 
 
 Transparent Soaps, &c., . . 481 
 Neutralised Soaps, . . .483 
 
 CHAPTER XXI. 
 
 GENERAL CHEMISTRY OF SOAP 
 SOAP ANALYSIS. 
 
 General Properties of Soaps ; 
 
 Hydrolysis of Soap Solutions, 484 
 Reaction of Soap Solution or of 
 
 Fused Soap on Inorganic and 
 
 other Salts, . . . .488 
 Methods Used in the Analysis of 
 
 Soap, 492 
 
 General Scheme for Analysis, . 506 
 Composition of Manufacturers', 
 
 Laundry, and Toilet Soaps, &c., 508 
 Classification of Toilet Soaps 
 
 according to amount of Free 
 
 Alkali present, . . .512 
 
 CHAPTER XXII. 
 
 GLYCEROL EXTRACTION MANU- 
 FACTURE OF GLYCERINE. 
 
 Sources of Glycerol ; Extraction, . 513 
 Valuation of Commercial Glycer- 
 ine ; Estimation of Glycerol in 
 Watery Solution, . . .516 
 Glycerol in Soap Leys, . . 522 
 
 INDEX, 
 
 525 
 
LIST OF ILLUSTRATIONS. 
 
 FIG. PAGE 
 
 1. Cohesion Figures, ....... 48 
 
 2. Capillary Tubes used for determining Fusing Points. . . 60 
 
 3. Mode of attachment to Thermometer, . . . .61 
 
 4. Mode of heating the arrangement in Water, . . .61 
 
 5. Another Mode, ....... 62 
 
 6. Olberg's Water Bath, ...... 62 
 
 7. Bensemann's Tubes, . . . . . .63 
 
 8. Pohl's Method, ....... 64 
 
 9. Cross and Bevan's Method, ..... 63 
 
 10. Lcewe's Method, . . . . . . .65 
 
 11. Mohr's Hydrostatic Balance, ..... 78 
 
 12. Westphal's do., ..... 79 
 
 13. Lefebre's Oleometer, ...... 80 
 
 14. Hot Air Bath for use with Westphal's Hydrostatic Balance, . 81 
 
 15. Ambuhl's Arrangement, ...... 81 
 
 16. Schiibler's Viscosimeter (Efflux Method), . " . .95 
 
 17. Schmid's do., . . . . . .96 
 
 18. Redwood's do., . . . . . ,97 
 
 19. Do. do., ...... 98 
 
 20. Allen's Modification of Viscosimeter, . . . .98 
 
 "21. Engler's Viscosimeter, ...... 99 
 
 22. Hurst's do., . . . . . .100 
 
 23. Eedwood's Chart of Viscosity of Oils, . . . .103 
 
 24. Do. do. do., .... 104 
 
 25. Lepenau's Leptometer, ...... 107 
 
 26. Traube's Apparatus, . . . . , .109 
 
 27. Chattaway's Tubes, ...... 120 
 
 28. Abel's Flashing Point Apparatus, . . . . .126 
 
 29. Pen sky's Modification of same, ..... 127 
 
 30. Legler's Consistency Tester, . . . . .139 
 
 31. Apparatus for Maumeue's Test, ..... 147 
 
 32. Jean's Thermeleometer, . . . . . .151 
 
 33. Benedikt and Griissner's Apparatus for Zeisel's Test, . . 193 
 
 34. Elbow Press, ....... 202 
 
 35. Wedge Press, Front Elevation, . ; . . | . 203 
 
 36. Do. Side do., . . . . '" :. 203 
 
 37. Do. Longitudinal Section, . . . .204 
 
 38. Screw Press (English), ". . . . . . 205 
 
 39. Do. (German), . ... . .206 
 
 40. Hydraulic Press (German, empty), . . . 208 
 
 41. Do. (after the ram has risen), . . . 209 
 
 42. Do. (English, Handworked), .... 210 
 
 43. Do. (Anglo-American System), . . .211 
 
LIST OF ILLUSTRATIONS. XV 
 
 FKi. PAGK 
 
 44. Hydraulic Press, Plan and Longitudinal Section of Plate, . 212 
 
 45. Do. Cross Section of Plate, .... 212 
 
 46. Oil Mill Plant; Ground Plan of 16- press Installation, . . 216 
 
 47. Crushing Rolls, . . . . . . .218 
 
 48. Edge Runners, ....... '219 
 
 49. Kettle, ........ 220 
 
 50. 51. Envelopes, ....... 221 
 
 52. Paring Machine, ....... 222 
 
 53. Decortication of Cotton Seeds, ..... 224 
 
 54. ,, of Castor Beans, . . . . .224 
 
 55. Disintegrator and Elevator, ..... 225 
 
 56. Filter Press, ....... 226 
 
 57. Do., Front Elevation of Plates, .... 226 
 
 58. Do., Sectional do., . . . . . 226 
 
 59. Do., with Pyramid Drainage Surfaces, . . . 227 
 
 60. Do., do. do., . . . 228 
 
 61. Do., Small Handworked, ..... 229 
 
 62. Apparatus for Oil Extraction by Solvents, . . . 233 
 
 63. Heyl's Distillation Apparatus, ..... 234 
 
 64. Deitz's Extraction Apparatus, ..... 235 
 
 65. Plant for Cleansing Engine Waste, .... 237 
 
 66. 67. Soxhlet's Tube (two forms), . . ... .238 
 
 68. Allihn's Reflux Condenser, . . . . .239 
 
 69. Fruhling's form of Soxhlet Tube, . . . . .239 
 
 70. Reservoir for same, ...... 240 
 
 71. Laboratory Extraction Apparatus, .... 240 
 
 72. Honig and Spitz's Apparatus, ..... 240 
 
 73. Wilson's Digester, ....... 250 
 
 74. Barrel Digester for Extracting Fat from Bones, . . . 252 
 
 75. Leuner's Apparatus, ...... 253 
 
 76. Free-fired Pan for Boiling Oil, ..... 316 
 
 77. Steam-heated Oil Kettles, . . . . .317 
 
 78. Open Pan used in manufacturing Stearine, . . . 366 
 
 79. 80. Crystallising Pans, . . . . . .367 
 
 81. Hot Press, ........ 368 
 
 82. Plant for Saponification by Open Pan Process, . . . 369 
 
 83. Plant for Hydrolysis of Fats by means of Sulphuric Acid, . 381 
 
 84. Knab's Apparatus for Distillation by Superheated Steam, . 382 
 
 85. Plant for Hydrolysis of Glycerides by Superheated Steam, . 386 
 
 86. Basting Wheel, ....... 388 
 
 87. Drawing Tapers, ....... 389 
 
 88. Knife for Cutting off Butt Ends, . . . . .390 
 
 89. Rotating Candle Dipper, ...... 390 
 
 90. Edinburgh Wheel, ....... 391 
 
 91. Wick-holder, ....... 392 
 
 92. 93. Dipper with Movable Cauldron, 393 
 
XVI LIST OF ILLUSTRATIONS. 
 
 PAGK 
 
 FIG. 
 
 94. Candle Mould, ....... 396 
 
 95. Hand Moulding Frame, ...... 396 
 
 96. Mode of fixing Wick, .... 396 
 
 97. 98. Improved Moulding Frame, ..... 396 
 99. Royan's Continuous Wick Moulding Machine, . . . 397 
 
 100. Camp's Moulding Wheel, ..... 398 
 
 101. Piston of Moulding Machine, ..... 399 
 
 102. Moulding Machine and Nippers, ..... 400 
 
 103. Self -fitting Butt End, ...... 402 
 
 104. Machine for Moulding Self-fitting Butt End Candles, . . 403 
 
 105. Turnover Machine, ...... 404 
 
 106. Polishing Machine, ...... 405 
 
 107. Soap Tank for holding Ley, . . . . .412 
 
 108. Free-fired Soap Pan, ...... 427 
 
 109. Another form of do., ...... 427 
 
 110. Steam-heated Pan, ...... 428 
 
 111. Morfit's Steam Twirl, . . . . . .429 
 
 112. Soap Copper, . . . . . . . 430 
 
 113. Morfit's Steam Series, ...... 430 
 
 114. Modern form of Steam-heated Pan, .... 431 
 
 115. Plan of same, ....... 432 
 
 116. Fan, ........ 434 
 
 117. Rotary Soap Pump, ...... 434 
 
 118. Mode of building up Wooden Frames, .... 435 
 
 119. Galvanised Iron Frames, ...... 435 
 
 120. Improved form of Steel Soap Frame, .... 436 
 
 121. Cutting Soap, . ..... 437 
 
 122. Looped Wire used for cutting, ..... 437 
 
 123. Scribe, ........ 438 
 
 124. Slabbing and Barring Machine, ..... 439 
 
 125. Padded Frame, ....... 440 
 
 126. Hand Crutch, ....... 440 
 
 127. Crutching Machine, ...... 440 
 
 128. Jacketted Crutching Machine, ..... 440 
 
 129. 130. Series of Crutching Pans, . . . . .442 
 131, 132. Neill and Son's Remelter, . . . . . 44 
 
 133. Hand Tablet Stamping Machine, .... 444 
 
 134, 135. Steam Stamping Machine, ..... 445 
 
 136. Rutschmann's Stripping Machine, .... 446 
 
 137. Soap Mill, ........ 447 
 
 138. Beyer's Plotting Machine, . . . . .448 
 
 139. Steam Jacketted Pan and Agitator, . . . .452 
 
 140. 141. Hawes' Boilers for Cold Process Soaps, . . .457 
 
 142. Dunn's Plant for making Hydrated Soaps under Pressure, . 463 
 
 143. Alder Wright's Chart of Hydrolysis of Soap Solutions, . 488 
 
 144. Gerlach's Vaporimeter, . . . . .' 518 
 
1. General Composition and Nature of 
 Oils, Butters, Fats, Waxes, and 
 Allied Substances. 
 
 CHAPTER I. 
 
 THE SOURCES AND GENERAL NATURE OF NATURAL 
 AND ARTIFICIAL OILS, &c. 
 
 AMONGST the alchemists the term " oil " had a somewhat wider 
 range of application than is usual at the present day, including 
 various inorganic substances, such as " oil of vitriol." Similarly 
 " butter of antimony " and " butter of tin " were metallic deri- 
 vatives entirely dissimilar from cow's butter in constitution, 
 although resembling it in physical consistency. Even when 
 such wholly inorganic compounds are excluded, the term " oil " 
 has still an extremely elastic meaning, being employed to 
 designate a very large variety of liquid substances, natural 
 and artificial, which have but few features in common beyond 
 the fact that, being all organic in character, they are capable of 
 burning with more or less facility under suitable conditions ; 
 whilst with but very few exceptions they are practically in- 
 soluble in water, so as to be incapable of permanent solution 
 therein ; being as a rule lighter than water, when agitated 
 therewith an emulsion forms, from which the water and oil 
 gradually separate 011 standing, the latter usually floating as a 
 separate layer on the former. 
 
 The term "fatty matter," or more shortly "fat," is applied to 
 substances which are more or less of a soft solid character at 
 the ordinary temperature, but on gently heating pass to liquids 
 closely resembling fluid oils in general characters ; " butters " 
 being specially soft varieties of such fats possessing the peculiar 
 physical texture of cow's butter at the atmospheric temperature 
 of temperate climates. " Waxes," on the other hand, possess a 
 somewhat different and much firmer texture at the ordinary 
 temperature, but when heated melt to fluids which closely 
 resemble ordinary liquid oils and melted fats in their general 
 physical characters. 
 
 1 
 
; 01 LS, FATS, WAXES, ETC. 
 
 Oils proper are derived from animal, vegetable, and mineral 
 sources, being mostly precontained in the tissues, seeds, or strata, 
 &c., from which they are obtained by simple mechanical pro- 
 cesses, such as pressure or pumping, or by means of solvents, 
 or by volatilisation ; certain products of destructive distillation, 
 however, are also ranked amongst oils e.g., the "light oils," 
 " creosote oils," &c., obtained during the rectification of coal tar; 
 and "shale oils," " bone oil " (Dippel's oil, or bone tar), "paraffin 
 oils," " rosin oils, 5 ' and similar substances formed by the breaking 
 up of more complex organic matters under the influence of heat. 
 Somewhat -similar substances (fusel oils) are produced by ana- 
 logous decompositions occurring during fermentative changes. 
 
 Oils capable of being converted into vapour by the application 
 of heat wdthout suffering material decomposition (volatile oils) 
 are for the most part either artificial products of destructive 
 distillation, natural mineral oils (petroleum, very probably 
 formed underground by the long-continued action of intra- 
 terrestrial heat on subterranean organic matter), or " essential " 
 oils i.e., volatile odorous matters extracted from numerous vege- 
 table sources, usually by distillation along with water. Fixed 
 oils, on the other hand, are substances not volatile without 
 decomposition, and are essentially of animal and vegetable 
 origin ; as also are butters, fats, and waxes (which practically 
 become fixed oils on slightly raising the temperature), with 
 the exception of the so-called waxes of mineral origin, paraffin 
 wax, ozokerite, cerasin, &c.* 
 
 From the point of view of general chemical composition, oils, 
 fats, butters, and waxes may be divided into two leading classes- 
 viz., those consisting of carbon and hydrogen only (Jiydro- 
 carbons); and those containing carbon, hydrogen, and oxygen. 
 Oils, &c., of the former class are practically all volatile without 
 decomposition ; those of the second class are in some cases 
 volatile without change (e.g., oxidised essential oils), but, as a 
 rule, are " fixed," undergoing destructive distillation when heated, 
 so that the vapours emitted are produced in consequence of 
 decomposition. 
 
 Hydrocarbon oils include a large number of " essential oils " 
 (in which oxidised substances are often present along with hydro- 
 carbons) ; paraffin and petroleum oils, including the lightest and 
 most volatile distillates of the " benzoline " class, " burning oils " 
 (kerosenes, <fec.) of medium volatility, "lubricating oils" of 
 higher boiling point, and paraffin waxes, Arc.; coaltar oils of 
 
 * The terms " fat " and " butter " are not confined to the fatty matters 
 obtainable from the adipose tissues of animals and the milk of mammalia ; 
 thus, various vegetable fats and butters are known, e.g., Dika fat, Palm 
 butter, Shea butter, vegetable tallow, &c. Similarly, whilst animal waxes 
 are the best known products of the wax class, various forms of vegetable 
 wax occur in nature (e.g., Japanese wax and Carnauba wax). 
 
THE SOURCES AND GENERAL NATURE OF OILS, ETC. 3 
 
 various kinds ; and other analogous products of destructive 
 distillation, from which various "closed chain" hydrocarbons, 
 (benzene, naphthalene, anthracene, &c.) are isolable, along with 
 many other kinds of hydrocarbons, some of the " saturated " 
 class (paraffins, indicated by the general formula C n Ho n + 2 ), some; 
 of the " unsaturated " classes (C m H 2n , where n is not greater 
 than in}. 
 
 Oxidised oils (including fats, butters, and waxes), from the point 
 of view of chemical constitution, are divisible into two classes 
 viz., those that are, and those that are not, of the nature of 
 " compound ethers," or substances capable of undergoing changes, 
 of the character of that known as " saponification." Oils of the 
 first class are again divisible into two groups viz., Glycerides, 
 or oils, &c., developing glycerol by saponification ; and Non- 
 glycerides, or oils not developing glycerol by saponification, but 
 giving rise instead to some other alcoholiform product. As 
 examples of these two groups may be mentioned, olive oil, 
 coker* butter, mutton tallow, cow's butter, Japanese wax, 
 linseed oil, colza oil, cod liver oil, and whale oil, essentially 
 glyceridic in character ; and oil of wintergreen (chiefly methyl 
 salicylate), beeswax (mainly myricyl palmitate), spermaceti 
 (chiefly cetylic palmitate), and sperm and doegling oils, essenti- 
 ally non-glyceridic in character. 
 
 Oils, &c., of the second class (non-saponifiable) include various 
 oxidised essential oils belonging to different organic families 
 e.g., aldehydes, such as oil of bitter almonds (benzoic aldehyde) ;. 
 ketones, like oil of rue (methyl nonyl ketone) and oil of tansy 
 (methyl octyl ketone) ; alcohols, such as oil of geranium 
 (geraniol) ; camphor analogues, such as oil of wormwood (absin- 
 thol) ; and resinoid constituents. Various alcoholiform sub- 
 stances are also contained in the free state in natural oils, 
 greases, &c. ; thus woolgrease contains cholesterol, and amber- 
 gris an allied body ambreol ; whilst similar substances are found 
 in small quantity in many vegetable oils. Higher alcohols (e.g., 
 cetylic alcohol) are often present in the free state in marine 
 cetacean oils ; whilst phenol and its homologues are present in 
 coaltar oils and other products of destructive distillation. 
 
 SAPONIFICATION . 
 
 Originally the term " Saponification " was used to designate 
 the chemical changes taking place when soap is prepared by 
 the action of alkalies on fixed oils and fats ; but subsequently it 
 
 * Although the spelling " coker" at first sight looks inelegant, it is con- 
 venient to employ it instead of " cocoa," in order clearly to distinguish the 
 product of the cokernut palm (Cocos nucifera) from that of the cacao (choco- 
 late plant yielding the beverage cocoa) and the coca (yielding the alkaloid 
 cocaine). 
 
4 OILS, FATS, WAXES, ETC. 
 
 has been extended to include a large number of parallel changes 
 occurring where various classes of " compound ethers " are broken 
 up under the influence of alkalies or other bases, so as to give 
 rise, on the one hand, to the metallic salt of an organic acid, and, 
 on the other, to an alcoholiform complementary product. The 
 following equations represent typical reactions of saponification, 
 according as' the alcoholiform product is an alcohol of the mono- 
 hydric, dihydric, trihydric, or tetrahydric class : 
 
 Ethyl Acetate. 
 
 C 2 H 5 .O.C 2 H 3 
 
 Potassium Potassium 
 
 Hydroxide. Acetate. 
 
 K . OH = K . . C 2 H 3 
 
 Ethylic 
 Alcohol. 
 
 + C 2 H, . OH 
 
 Ethylene Diacetate. 
 
 Potassium 
 Hydroxide. 
 
 Potassium 
 Acetate. 
 
 2K.OH = 2K.O.C 2 H,0 
 
 Glycol. 
 
 r (OH 
 
 Uiyceryl Tristearate 
 (Stearin). 
 
 C 3 H 5 
 
 O.C 1S H 35 
 O.C 18 H 35 
 O.C 18 H 35 
 
 Erythrol Tetrabenzoate. 
 
 O.C 7 H 5 
 O.C 7 H 5 
 O . C 7 H 5 O 
 O.C 7 H 5 
 
 4. C 4 H 
 
 Sodium 
 Hydroxide. 
 
 Sod'um 
 Stearate. 
 
 SNa.OH = 3Xa. 0. C 18 H 35 
 
 Sodium 
 Hydroxide. 
 
 4Na.OH 
 
 Sodium 
 Benzoatc. 
 
 Glycerol. 
 ( OH 
 
 (OH 
 
 Erythrol. 
 
 ( OH 
 
 4Na.O.C 7 H 5 + C 4 H 6 < 
 f OH 
 
 The majority of saponification changes occurring with natural 
 fixed oils and fats, c., belong to the third class ; i.e., these sub- 
 stances are chiefly " glycerides," or compound ethers furnishing 
 glycerol on saponification ; some liquid fixed saponifiable oils, 
 however, are of non-glyceridic character, undergoing saponifica- 
 tion changes of the first kind ; thus sperm oil largely consists of 
 Cetylic pliysetoleate and homologous substances, broken up by 
 saponification, thus 
 
 Cetyl Physetoleate 
 
 C ]6 H 33 .O.Ci C H 29 
 
 Potassium Potassium 
 
 Hydroxide. Physetoleate. 
 
 K.OH = K.O.C 1G H 29 
 
 Cetylic Alcohol. 
 
 C 1C H 33 .OH 
 
 Most waxes possess an analogous constitution; thus the chief 
 constituents of beeswax and spermaceti are respectively myricyl 
 palmitate and cetyl palmitate, decomposable by saponification, 
 thus 
 
 Myricyl Palmitate. 
 ^3oH(;i . . CicH 3 iO 
 
 Sodium 
 Hydroxide. 
 
 Na.OH = Na.O.C 16 H 31 O 
 
 Sodium 
 Palmitate. 
 
 Myricylic 
 Alcohol. 
 
 CsoHgi . OH 
 
 Cetyl Palmitate. 
 
 Potassium Potassium 
 
 Hydroxide. Palmitate. 
 
 K.OH = K.O.C J6 H 31 
 
 Cetylic 
 Alcohol 
 
 C 1C H 33 .OH 
 
THE SOURCES AND GENERAL NATURE OF OILS, ETC. 5 
 
 Some few vegetable waxes, however, are of glyceridic char- 
 acter, e.g., Japanese wax, chiefly consisting of palmitic glyceride, 
 8 H 6 (O.C 16 H 81 0) 8 . 
 
 A considerable number of oxidised essential oils also consist 
 mainly of compound ethers of the first class ; thus oil of winter- 
 green (Gaultheria procumbens) mainly consists of methyl salicylate, 
 and oil of cow parsnep (fferacleum spondylium) ,of octyl acetate : 
 respectively saponified, thus 
 
 Potassium Potassium Methylic 
 
 Methyl Salicylate. Hydroxide. Salicylate. Alcohol. 
 
 CH 3 .O.C7H 5 2 + K.OH = K.O.C r H 5 2 + CH 3 .OH 
 
 Sodium Sodium Octylic 
 
 Octyl Acetite. Hydroxide. Acetate. Alcohol. 
 
 C 8 H U .O.C 2 H 3 + Na.OH = Na . . C 2 H 3 + C 8 H 17 .OH 
 
 Compound ethers of Class II. (furnishing dihydric alcohols on 
 saponification), although not absolutely unknown amongst natural 
 products of the oil, fat, and wax class, are very rare ; carnauba 
 
 {OTT 
 OH 
 
 on saponification (p. 18). Tetrahydric ethers, like those of 
 erythrol, have not as yet been recognised as constituents of oils 
 and fats, &c. ; and the same remark applies to the yet more com- 
 plex pentahydric and hexhydric ethers; mannitol, C 6 H 8 (OH) 6r 
 a hexhydric alcohol, has been found as a constituent of vege- 
 table fruits, &c., accompanying oil e.g., in unripe olives ; but. 
 neither mannitol nor any ethers thereof appear to be contained 
 in purified expressed olive oil. 
 
 CLASSIFICATION OF OILS, FATS, WAXES, &c., 
 ACCORDING TO CHEMICAL COMPOSITION. 
 
 The following table indicates a rough classification of the 
 principal varieties of oils, fats, and waxes in accordance with 
 the general chemical character of their leading constituents : 
 
 DIVISION I. HYDROCARBONS. 
 
 1. Natural essential oils, mostly of vegetable origin. 
 
 2. Natural mineral oils (petroleum), including the crude oils, and the pro- 
 
 ducts thence obtained by distillation, &c. (benzoline, kerosene oils, 
 lubricating oils, <fcc.) 
 
 3. Artificial products of destructive distillation (paraffin oils, shale oils, 
 
 bone oils, coaltar oils, &c.) 
 
 4. Solid hydrocarbons obtainable from natural products (earthwax, &c.) or 
 
 isolated from the two previous sources e.y., paraffin wax and allied 
 substances largely used in candle-making. 
 
6 OILS, FATS, WAXES, ETC. 
 
 DIVISION II. CONTAINING OXYGEN. 
 
 A . Saponifiable. 
 
 1. Essentially compound ethers of monohydric alcohols. 
 
 a. Various natural essential oils mostly of vegetable origin. 
 6. Certain animal fixed oils, especially those of cetacean origin (some- 
 times termed " liquid waxes"). 
 
 c. Most animal and vegetable solid waxes (waxes proper). 
 
 d. Certain artificial essential oils t.g., various compound ethers used 
 
 for perfumery and flavouring purposes. 
 
 2. Essentially glyceride*, or compound ethers of glycerol. 
 
 a. The majority of animal and vegetable fixed oils, fats, and butters. 
 
 b. Some few vegetable waxes. 
 
 JB. Not Saponifiable. 
 
 a. Various essential oils, consisting of aldehydes, ketones, camphora- 
 
 ceous bodies, &c. 
 6. Alcoholiform constituents of natural animal and vegetable oils 
 
 (cholesterol, phytosterol, cetylic alcohol, &c.) 
 
 c. Alcoholiform bodies formed by fermentation (fusel oils). 
 
 d. Phenoloid bodies formed by destructive distillation and contained 
 
 in coaltar, &c. (phenol, cresol, &c. ) 
 
 e. Products formed by oxidation of hydrocarbons e.g., " Sanitas oil'* 
 
 (formed by the atmospheric oxidation of oil of turpentine). 
 
 In the present work a large number of the various substances 
 thus coming into the general category of oils, fats, butters, and 
 waxes are necessarily excluded from minute consideration, fixed 
 animal and vegetable oils and fats, &c., all practically belonging 
 to Division II., Sections 1 and 2. Certain hydrocarbons, how- 
 ever, are intimately connected with the subjects dealt with, 
 more especially mineral oils and products of destructive distilla- 
 tion employed as adulterants of animal and vegetable fixed oils, 
 -and as ingredients in lubricating mixtures, &c. ; and mineral 
 waxes (paraffin wax, ozokerite, and similar substances) employed 
 as candle materials. Various essential oils, moreover, are in use 
 as ingredients in certain kinds of fancy (toilet) soaps as perfuming 
 agents, and in some kinds of sanitary soaps (e.g., eucalyptus oil) ; 
 as also are certain products of destructive distillation (e.g., car- 
 bolic acid and its higher homologues). 
 
 For further classifications of fixed oils, fats, waxes, &c. 
 (apart from other kinds of oils), based either on their physical 
 characters and the chemical nature of their main ingredients, or 
 on their leading technical uses, vide Chap. xin. 
 
SAPONIFICATION PRODUCTS OF OILS, PATS, WAXES, ETC. 
 
 CHAPTER II. 
 
 SAPONIFICATION PRODUCTS OF OILS, FATS, 
 WAXES, &c. 
 
 ALCOHOLIFORM PRODUCTS. 
 
 A SAPONIFIABLE oil, &c., as above stated, gives rise to two pro- 
 ducts under the influence of alkalies viz., an alcoholiform 
 organic substance (which in practice is either glycerol or some 
 kind of monohydric alcohol), and the alkali salt of an organic acid. 
 Under suitable conditions (more especially heating under pres- 
 sure in contact with water) parallel decompositions can be 
 brought about by means of water, the products of the " hydro- 
 lysis " thus effected being the alcoholiform body and a free 
 " fatty acid." Thus in the cases of the glyceride of oleic acid and of 
 cetyl palmitate the hydrolytic actions take place in accordance 
 with the following equations : 
 
 Oleic Glyceride. Water. Oleic Acid. GHycerol. 
 
 O.C 18 H 33 (OH 
 
 C 3 H 5 O.C 18 H 33 + 3H 2 = 3C 18 H 33 O.OH + C 3 H 5 \ OH 
 
 O.C 18 H 33 (OH 
 
 Cetyl Palmitate. Water. Palmitic Acid. Cetylic Alcohol. 
 
 C 1C H 33 .O.C J6 H 31 + H 2 = C JG H 31 O.OH + C 16 H 33 . OH 
 
 Similar reactions occur in many other parallel cases, the nature 
 of the alcoholiform body and of the fatty acid developed only 
 differing in each instance. 
 
 TRIHYDRIC ALCOHOLS FORMED BY SAPONI- 
 FICATION (GLYCEROL). 
 
 Glycerol, the most frequently occurring alcoholiform saponi- 
 fication product of fixed oils and fatty matters, solidifies, when 
 pure, to a crystalline mass by long continued chilling,* the melting 
 point being about + 22 C.; its great hygroscopic character renders 
 it extremely difficult to obtain absolutely free from water, in 
 consequence of which values varying from 1*262 to 1*2653 have 
 
 * Passing a few bubbles of chlorine into concentrated glycerol will often 
 make it crystallise (Werner). Chilled glycerol usually crystallises when 
 stirred up with a few crystals of the previously solidified substance, a 
 method utilised in manufacture (Chap, xxn.) 
 
8 OILS, FATS, WAXES, ETC. 
 
 been stated as its specific gravity at 15. When heated gently 
 under the ordinary atmospheric pressure it volatilises without 
 decomposition, but at higher temperatures it splits up into water 
 and acrolein, thus 
 
 Glycerol. Acrolein. 
 
 C 3 H 8 3 = 2H 2 + C 3 H 4 
 
 In vacuo it boils at about 1 80 C. 
 
 By cautious oxidation with alkaline permanganate it yields 
 oxalic acid in sufficiently accurate proportions for quantitative 
 estimation. By treatment with potassium dichromate and sul- 
 phuric acid it similarly forms CO 2 and water; by treatment with 
 acetic anhydride it forms triacetin, the saponification of which 
 furnishes another means of quantitative determination (vide 
 Chap, xxii.) In the absence of substances carbonised by 
 sulphuric acid, an excellent qualitative test is to heat cautiously 
 to 120 or a little higher a mixture of two drops glycerol, two of 
 fused phenol, and about as much sulphuric acid \ a brown solid 
 mass forms, which after cooling dissolves in ammonia with a 
 beautiful carmine red colour (Reichl) ; if substances becoming 
 carbonised are present they produce a dark brown colouring 
 matter which hides the red tint. 
 
 Polyglycerols. Glycerol heated in contact with hydrochloric 
 acid or certain other dehydrating substances is capable of 
 undergoing reactions of dehydration and condensation, expres- 
 sible by the general equation : 
 
 nC 3 H 8 3 = mH,0 + C 3n H 8n _o m 3u _ m . 
 Thus when n = 2 and m 1, diglycerol results. 
 
 C 3 H 
 
 2C 3 H 5 (OH) 3 = H 2 + 1 
 
 C 3 H 5 
 
 l (OH) 2 
 
 And when n .= 3 and m = 2, triglycerol is produced. 
 
 (OH), 
 
 3C 3 H 6 (OH) 3 = 2H 2 + C 3 H 5 JOH 
 
 r 
 
 C H *\(OH) 2 
 
 It has been supposed by some chemists that bodies of this 
 class are sometimes contained in commercial " glycerines," more 
 especially those formed under high pressure in autoclaves, or 
 purified by distillation; such glycerine, when slowly evaporated 
 at a temperature of about 160 u.,* leaves a non- volatile organic 
 
 * Lewkowitsch, Year Boole of Pharmacy, 1890, p. 380. 
 
ALCOHOLIFORM PRODUCTS OF SAPONIFICATIOX. 9 
 
 residue, from the weight of which (after deducting ash) the 
 proportion of polyglycerols present may be deduced. It does 
 not appear, however, that the residue thus left has been definitely 
 proved to have the character and composition assigned to it, 
 although the formation of polyglycerols is, a priori, highly pro- 
 bable. 
 
 Natural Triglycerides. As a very general, if not abso- 
 lutely invariable, rule, only one acid radicle is contained in any 
 given substance i.e., substances of the types 
 
 CH 2 . OR CH 2 . OR CH 2 . OR 
 
 CH . OR CH .OS CH . OS 
 
 CH 2 . OS CH 2 . OR CH 2 . OT 
 
 (where K, S, and T are not the same) are only extremely rarely- 
 met with. Cow's butter, however, not improbably contains a 
 mixed glyceride of one or other of these classes ; for whilst it 
 forms butyric acid on saponification, no butyrin (tri glyceride of 
 butyric acid) can be dissolved out from it by means of alcohol ; 
 whereas mixtures of butyrin and other triglycerides readily 
 yield the former to that solvent ; hence a mixed glyceride,, 
 oleo palmito butyric glyceride^ 
 
 CH 2 .O.C ]8 H 33 
 
 CH . . C 1C H 31 
 I 
 CH 2 . . C 4 H 7 
 
 (or some analogous substance) has been supposed to be present, 
 breaking up on saponification into glycerol, with formation of 
 salts of oleic, palmitic, and butyric acids. 
 
 Some few other fats have been supposed, on similar grounds, to 
 contain analogous mixed glycerides ; but, as a general rule, when- 
 ever an oil or fat yields on saponification the salts of two or more 
 different fatty acids, it can be shown that the original substance 
 is a mixture of two or more triglycerides of the ordinary type- 
 (i.e., each containing only one acid radicle) ; thus, by chilling an 
 oil yielding palmitic and oleic acids on saponification, a solid fat 
 usually separates, yielding only palmitic acid on saponification ; 
 whilst the liquid portion is substantially olein, giving rise to 
 oleic acid only on similar treatment, the reaction in each case 
 being indicated by the general equation : 
 
 Normal Caustic P,, _ _, Potassium 
 
 Triglyceride. Potash. Salt 
 
 CH 2 . OR CHo . OH 
 
 I I 
 
 CH . OR + 3K . OH = CH .OH + 3K . OR 
 
 CH 2 . OR CH 3 . OH 
 
10 
 
 OILS, FATS, WAXES, ETC. 
 
 the effect of the alkali being always the same, the only differences 
 in different cases being due to the variation in the nature of R. 
 
 Hydrolysis of Glycerides. As a general rule, pure triglyce- 
 rides are acted upon by water only at an elevated temperature, 
 treatment with superheated steam blown through the mass, or 
 digestion with water under considerable pressure being requisite; 
 under such circumstances, the glycerol set free is often more or 
 less decomposed by secondary reactions. With crude unpurified 
 oils continued standing at the ordinary temperature often suffices, 
 the action in such cases being largely due to changes of a fermen- 
 tative character taking place in the mucilaginous or albuminous 
 extractive matters present as impurities ; in extreme cases the 
 action goes on to such an extent as to hydrolyse the larger 
 portion of the glycerides present, so that upwards of 50 per cent, 
 of the mass is free fatty acid. Changes of this description are 
 almost invariably accompanied by the production of bye-products 
 of unpleasant taste and smell, so that the development of " ran- 
 cidity " by this action greatly deteriorates the value of the oil, 
 <fec., for many purposes, more especially culinary and edible ones. 
 
 In all probability the formation of a free fatty acid and glycerol 
 from a glyceride by hydrolytic action takes place in three stages, 
 giving rise to two kinds of intermediate products, diglycerides 
 .and monoglycerides respectively ; thus, it' R be a fatty acid 
 radicle 
 
 Normnl 
 Triglyceride. 
 
 OH 2 . OR 
 CH . OR + 
 CH 2 . OR 
 
 Dislyceride. 
 
 CH 2 . OR 
 
 I 
 CH .OR + 
 
 I 
 
 CH.> . OH 
 
 Waier. 
 
 HoO = 
 
 Fatty 
 D'uzlyceride. 
 
 CH 2 .OR 
 
 CH .OR 
 
 I 
 
 CH 2 . OH 
 
 Fatty Acid. 
 
 H.OR 
 
 Water. Monoglyceride. Fatty Acid. 
 
 CH 2 . OR 
 
 H,,0 = CH .OH + H . OR 
 CHo.OH 
 
 Monojjlyceride. 
 
 CH 3 .OR 
 
 CH .OH + 
 I 
 CHo.OH 
 
 "Water. 
 
 H 2 
 
 Glycerol. 
 
 CHo . OH 
 
 Fatty Acid. 
 
 H . OR 
 
 = CH .OH 
 CH 2 . OH 
 The final action may consequently be expressed by the equation- 
 
 Triglyceride. 
 CHo. OR 
 CH .OR 
 CHo. OR 
 
 Water. 
 3H 2 = 
 
 Glycerol. 
 CH 2 .OH 
 CH .OH 
 CHo . OH 
 
 Fatty Acid. 
 
 3 H.OR 
 
ALCOHOLIFORM PRODUCTS OF SAPONIFICATION. 11 
 
 which may be written somewhat more compactly 
 
 + 3H - OR 
 
 The formation of the intermediate substances by gradual 
 hydrolysis has not been much studied as yet ; in the case of 
 rape oil, however, it has been shown that whilst fresh oil con- 
 tains the triglyceride erucin, 
 
 (C 22 H 41 0) 3 
 the corresponding diglyceride dierucin, 
 
 CTT \ /~^TT /^\ r^ TT /"\ 
 
 3-T15 J l_ylo . U . v^2 l >^Ml^' 
 
 (C 22 H 41 0)., [ 3 = CH . . Co 2 H 41 
 " H I CH 2 . . H 
 
 is sometimes contained in old oil,* probably formed as above by 
 partial hydrolysis. On the other hand, the reverse reactions 
 leading to the successive building up from glycerol of mono- 
 glyceride, diglyceride, and triglyceride are well known laboratory 
 operations : thus 
 
 Glycerol. Fatty Acid. Monoglycf-ride. 
 
 ( OH I OR 
 
 C 3 TlJOH -l- H.OR = C S H 5 OH + H,O 
 (OH (OH 
 
 Monoglycfride. Diglyceride. 
 
 ( OR ( OR 
 
 C 3 H 5 \ OH + H . OR = C 3 H n { OR + H,0 
 
 (OH (OH 
 
 Diglycsride. Triglyceride. 
 
 ( OR ( OR 
 
 CoH 5 OR + H.OR = C 3 H 5 OR + H 2 
 (OH (OR 
 
 In many cases, when it is desired to obtain triglycerides in a 
 state of purity, it is more easy to saponify an oil, separate and 
 purify the resulting fatty acids, and convert them into glycerides 
 in this way than it is to separate the original glycerides them- 
 selves contained in the oil. 
 
 The following boiling and melting points are possessed by 
 some pure triglycerides prepared synthetically in this way : 
 
 Melting Poiut. Boiling Point. 
 Butyrin, . . C 3 H 5 (0 . C 4 H 7 0) 3 Fluid 285 
 
 Laurin, 
 Myristin, . 
 Palmitiii, . 
 Stearin, 
 Olein, 
 
 C 3 Hs(0 . Ci 2 H 23 0) 3 45 
 
 C 3 H 5 (O.C 14 H 27 0) 3 55 
 
 C 3 H 5 (O.C 1C H 31 0) 3 62 
 
 C 3 H 5 (0 . C 18 H 35 0) 3 71-5 
 
 C 3 H 5 (0 . C 18 H 33 0) 3 solidifies at - 6 
 
 *Reimerand Will(Berichte der Deut. Chem. Ges., 1886, xix., p. 3320) found, 
 that a deposit which had slowly formed in a quantity of colza oil was not 
 the triglyceride usually obtained tinder such conditions, but the diglyceride 
 melting at 47. 
 
12 OILS, FATS, WAXES, ETC. 
 
 When oils that have become hydrolysed through rancidity are 
 refined by treatment with alkalies (Chap. XL), the free acids are 
 removed and neutral oils left ; but other kinds of refining pro- 
 cesses do not affect the free acids, which accordingly are apt to 
 be found in commercial oils to varying extents, sometimes only 
 inconsiderable amounts, and sometimes very large percentages 
 being present. According to Thum the free acids do not consist 
 solely of oleic acid, as is often supposed, but of a mixture in 
 exactly the same proportions as that in which they exist in the 
 undecomposed glycerides. Thus palm oil and olive kernel oil 
 containing much free acid yield as much solid free acids relatively 
 to oleic acid when the free acids are removed by agitation with 
 a cold alkaline ley, as are yielded by the neutral unsaponified 
 fats present. 
 
 Just as the glyceridic compound ethers of fatty acids are apt 
 to be hydrolysed under appropriate conditions, so are their 
 alkaline salts (soaps) split up by water with the formation of 
 basic substance (free alkali) and an acid salt (vide p. 23). 
 
 It is a remarkable fact that although a somewhat considerable 
 number of monohydric alcohols are known to be formed by the 
 saponification of fixed oils, essential oils, and similar sub- 
 stances, only one trihydric alcohol, viz., glycerol, has ever been 
 found to be produced from such sources. 
 
 Isoglyceride Theory. Theoretically the existence is possible 
 of various substances possessing the composition of a trihy- 
 droxylated propane, C 3 H 5 (OH) 3 , but not identical with glycerol : 
 these substances would naturally form compound ethers isomeric 
 with ordinary glycerides containing the same acid radicles. 
 Amongst such hypothetical bodies, the compound ethers of ortho- 
 propionic acid, indicated by the general formula 
 
 ( OR 
 
 C ] OR (JH., . OR 
 
 | /OR | 
 
 CH, isomeric with CM . OR 
 
 ! ' I 
 
 CH, CH 2 .01l 
 
 have been supposed by some chemists to be present in certain 
 fatty matters, notably cow's butter ; but the experimental proofs 
 of this supposition are singularly wanting in clearness and 
 cogency. Such compound ethers on saponification should neu- 
 tralise four instead of three equivalents of alkali, generating an 
 alkaline propionate instead of glycerol ; thus 
 
 Hypothetical Sodium 
 
 Isogyceride. Hydroxide. Sodium Propionate. Sodium Salt. Water. 
 
 C 2 H 5 .C(OR) 3 + 4NaOH = C,H 3 . CO . ONa + 3NaOR + 2H 2 O 
 
ALCOHOLIFORM PRODUCTS OF SAPONIFICATION. 13 
 
 MONOHYDRIC ALCOHOLS FORMED BY 
 SAPONIFICATION. 
 
 Numerous families of alcohols (monohydroxylated hydro- 
 carbons) are known to the chemist, derived successively from 
 saturated hydrocarbons of the series C n H 2n + 2, and from the other 
 series of hydrocarbons containing less hydrogen, by the replace- 
 ment of hydrogen by hydroxyl : thus inter alia the following 
 families of alcohols are known : 
 
 Ethylic alcohol homologues ; general formula, C u H-n+i . OH 
 Allylic ,, CaHo^.OH 
 
 Phenol ,, ,, C n H n -7.0H 
 
 Cinnamic alcohol ., ,, CnH2 n -9,OH 
 
 Although representatives of several such families of alcohols 
 are found amongst products of destructive distillation (coaltar 
 oils, c.), and in essential oils and the allied balsams and other 
 aromatic bodies, and in small quantities as natural constituents 
 of fixed oils of various kinds (occurring there in the free state), 
 yet compound ethers derived from alcohols of the first and second 
 of the above families appear to be the only kinds naturally 
 occurring in fixed oils and waxes, etc. ; and of these by far the 
 most frequently occurring substances belong to the first class. 
 
 Ethylic Series of Alcohols. The table on next page indicates 
 the leading alcohols of this family (general formula C n H 2n + i . OH) 
 derived from fixed and essential oils and similar sources ; besides 
 those mentioned numerous isomeric modifications of many of 
 them exist, obtainable artificially by laboratory reactions. 
 
 The higher alcohols of this series, when fused with alkalies, 
 evolve hydrogen with formation of the alkali salt of the corre- 
 sponding fatty acid;* thus 
 
 CVtylic Alcohol. Potassium Palmitate. 
 
 C 15 H 31 .CH 2 .OH + KOH = C 15 H 31 .CO.OK + 2H 2 
 
 Myricylic Alcohol. Potassium Melissate. 
 
 C 29 H 59 .CH 2 .OH + KOH = C 29 H 59 . CO . OK -f 2H 2 
 
 They are readily converted into compound ethers by treatment 
 with organic anhydrides (e.g., acetic anhydride), and in some 
 cases by heating with the acids alone, water being evolved. 
 
 * C. Hell (Liebig's Annalen, pp. 223, 269) has based a method for the quan- 
 titative determination of higher alcohols on this reaction, the substance to 
 be examined being heated to 300-310 in contact with soda lime, and the 
 evolved hydrogen collected and measured. At higher temperatures there 
 is a possibility of hydrogen being also evolved by the action of caustic 
 alkalies on oleic acid (p. 24). This method has been found useful in the 
 examination of beeswax which, when genuine, furnishes about 54 per 
 cent, of myricylic alcohol. 
 
14 
 
 OILS, FATS, WAXES, ETC. 
 
 Name. 
 
 Formula. 
 
 Boil ing Point. 
 
 Melting 
 Point. 
 
 Sources. 
 
 Methylic alcohol, 
 
 CH 3 . OH 
 
 ccc. 
 
 ... 
 
 Saponification of oil of winter- 
 
 
 
 
 
 green ; wood distillation 
 
 
 
 
 
 products. 
 
 Ethylic alcohol, 
 
 C 2 H 5 . OH 
 
 78 
 
 Fermentation of saccharine 
 
 
 
 
 
 matter. 
 
 Propylic alcohol, ) 
 
 
 97 
 
 
 Fermentation fusel oils. 
 
 Isopropylic alco- ' 
 hoi, ) 
 
 C 3 H 7 . OH 
 
 84 
 
 
 Isopropylic iodide from gly- 
 cerol and hydriodic acid. 
 
 Normal Butylic j 
 
 
 117 
 
 ... 
 
 Heavy oils from brandy. 
 
 alcohol, 
 
 C 4 H 9 . OH 
 
 
 
 
 Isobutylic alcohol ) 
 Amylic alcohols 
 
 dHn.OH 
 
 107 
 127-13S 
 
 ... 
 
 Potato and beet fusel oils. 
 Fusel oils from grain spirit, 
 
 (several isomeric ! 
 
 
 
 &c. Saponification of oil 
 
 modifications), 
 
 
 
 of Roman Chamomile. 
 
 Hexylic alcohols 
 
 C C H 13 .OH 
 
 147-157 
 
 
 Sapouification of oil of cow's 
 
 (several modi- 
 
 
 
 
 parsley, oil of Roman Cha- 
 
 fications), 
 
 
 
 momile, &c. 
 
 Normal Primary C 7 Hj 3 . OH 
 
 176 
 
 
 Brandy fusel oils. Hydro- 
 
 Heptylic alcohol, 
 
 
 
 genation of ccnaiithol from 
 
 
 
 
 
 castor oil. 
 
 Octylic alcohols, 
 
 C 8 H ]7 .OH 
 
 180- 192 
 
 
 Saponification of oil of Hera- 
 
 
 
 
 
 deum spondylium and H. 
 
 
 
 
 
 giganteum. Action of hot 
 
 
 
 
 
 alkali on castor oil. 
 
 Nonylic alcohols, 
 
 C 9 H 19 .OH 
 
 ... 
 
 . 
 
 
 Normal Primary 
 
 C 10 H 21 .OH, 
 
 119 at 15 
 
 7C. 
 
 Hydrogenation of capric 
 
 Decy lie alcohol, 
 
 
 millims. 
 
 
 aldehyde. 
 
 
 
 pressure. 
 
 
 
 Secondary Hen- 
 
 C n H 23 .OH 
 
 220 
 
 ... 
 
 Hydrogenation of oil of rue. 
 
 decylic alcohol, 
 
 
 
 
 
 Dodecylic alcohols, C 12 H 25 .OH 
 
 143 at 15 
 
 24 
 
 Hydrogenation of lauric 
 
 
 millims. 
 
 
 aldehyde. 
 
 Tridecylic alcohols, 
 
 C 13 H 27 .OH 
 
 pressure. 
 
 19 
 
 Saponification of sperm oil. 
 
 Normal Primary 
 
 C J4 H 29 .OH 
 
 167 at 15 
 
 38 
 
 Hydrogenation of myristic 
 
 Tetradecylic 
 
 
 millims. 
 
 
 aldehyde. 
 
 alcohol, 
 
 
 pressure. 
 
 
 
 Pentadecylic alco- C 15 H C1 .OH 
 
 ... 
 
 ... 
 
 
 hols, 
 
 
 
 
 Normal Primary \ 
 
 
 lS9'5atl5 
 
 49'5 
 
 Hydrogenation of palmitic 
 
 Hexadecylic al- ' 
 
 C.^Ho* OH 
 
 millims. 
 
 
 aldehyde. 
 
 cohol, ( 
 
 ^1 6^*33 vJi 
 
 pressure. 
 
 
 
 Cetylic alcohol, ) 
 
 
 188- 193 
 
 49 '2 
 
 Saponification of spermaceti. 
 
 
 
 at 15mm. 
 
 ... 
 
 
 
 
 pressure. 
 
 
 
 Heptadecylic al- 
 
 c ]7 H C ;.OH 
 
 ... 
 
 
 ... 
 
 cohols, 
 
 
 
 
 
 Normal Primary 
 
 C 18 H 37 .OH 
 
 2 10 -5 at 
 
 59 
 
 Hydrogenation of stearic 
 
 Octodecylic al- 
 
 
 15millims. 
 
 
 aldehyde. Saponification 
 
 cohol, 
 
 
 pressure. 
 
 
 of spermaceti (in small 
 
 
 
 
 
 quantity). 
 
 Cerylic alcohol, \ 
 Isocerylic alcohol, J 
 
 C 27 H 55 .OH 
 
 ... \ 
 
 79 
 62 
 
 ( Chinese wax. 
 < Carnauba wax. 
 ( Wax of Fkus gummiflua. 
 
 Myricylic alcohol, ) 
 
 
 , 
 
 8 1 ! 
 
 -p 
 
 xSeeswax. 
 
 Isomyricylic alco- > 
 hoi ? \ 
 
 C SO H 61 .OH 
 
 ... ( 
 
 oO 
 
 72 
 
 Carnauba wax. 
 
ALCOIIOLIFORM PRODUCTS OF SAPONIFICATIOX. 15 
 
 Acetic 
 Cetylic Alcohol. Anhydride. Cetyl Acetate. Acetic Acid. 
 
 C ]6 H 33 .OH + (C 2 H 3 0) 2 = C ]0 H 33 .O.CoH 3 + C 2 H 3 O.OH 
 
 Cetylic Alcohol. Acetic Acid. Cetyl Acetate. Water. 
 
 C 16 H 33 .OH + C 2 H 3 O.OH = C 1G H 33 .O.C 2 H 3 + H 2 
 
 The compound ethers thus produced are, in turn, readily 
 saponified by alcoholic potash, and from the amount of potash 
 neutralised during the operation the molecular weight of the 
 alcohol is deducible, due corrections being made for unsaponifi- 
 able matters, &c., if present (Chap, viu.) 
 
 Allylic Series of Alcohols. Alcohols of the series 
 CnHgn.j.OH, derived from the olefine family of hydrocarbons 
 of formula C n H 9n , are only sparsely represented amongst the 
 derivatives from natural products. Acrolein (acrylic aldehyde), 
 C 2 H 3 . CHO, by hydrogenation yields allylic alcohol, C 2 H 3 .CH 2 .OH 
 (also obtainable in various other ways), existing as a thiocyanic 
 ether in the oils of black mustard seed, horse radish, and garlic ; 
 whilst higher homologues are probably contained amongst the 
 alcohols of the previous series obtained on saponifying sperm 
 oil, since in certain cases a deficiency of hydrogen is observed 
 on analysis, coupled with a strongly marked tendency to com- 
 bine directly with iodine, indicating the presence of unsaturated 
 compounds. These higher alcohols, however, have not as yet 
 been isolated from the other bodies accompanying them in a 
 state of sufficient purity to admit of their formulae being exactly 
 determined. Borneol, C 10 H 19 . OH, occurs in the camphor of 
 Dryobalanops camphora, and to a small extent in oil of valerian 
 and oil of rosemary. 
 
 Alcohols of the series C n H 2n _ 3 . OH, derived from the C n H 2n _ 2 . 
 (acetylene) series of hydrocarbons, are found to some extent in 
 certain essential oils e.g., geraniol, C 10 H llr .OH, in Indian gera- 
 nium oil. This appears to be a true analogue of ethylic and 
 allylic alcohols, being capable of yielding by oxidation an alde- 
 hyde and a monobasic acid (geranic acid) C 9 H 15 . COH and 
 C 9 H 15 . CO . OH respectively : no substances of analogous char- 
 acter have as yet been isolated from fixed oils and fats, tfcc. 
 
 Phenol and its Homologues. Alcohols derived from hydro- 
 carbons still poorer in hydrogen are occasionally met with as 
 constituents of natural products of the resinous class, or as sub- 
 stances formed by destructive distillation; thus the hydrocar- 
 bons of the benzene family, C n H 2n _ 6 , give rise to two such classes 
 of alcohols, both indicated by the general formula C u H :n _ 7 .OH 
 and derived from the same parent body, phenol, C G H 5 . OH. In 
 the one class (phenols proper) the hydroxyl group is situated in 
 connection with the " benzene nucleus " of 6 carbon atoms ; and 
 in the other (benzylic alcohol series] the hydroxyl group is not 
 situated in the benzene radicle, but in one of the "side chains " 
 
16 OILS, FATS, WAXES, ETC. 
 
 introduced by the methylation of benzene so as to develop 
 homologous hydrocarbons ; thus 
 
 Phenols. 
 
 Phenol (carbolic acid), . . . C 6 H 5 . OH 
 Cresol (methyl phenol), . . . C C H 4 /^ 3 
 
 ( CH 3 
 
 Xylenol (dimethyl phenol), . . C C H 3 { CH 3 
 
 OH 
 
 Phlorol (ethyl phenol), . . . C G H 4 |p 
 
 Benzylic Alcohol Series. 
 
 Benzylic alcohol, .... C G H 5 .CH 2 .OH 
 
 Xylylic alcohol, ..... C H *{cH2 OH 
 
 Benzyl carbinol, ..... C 6 H 5 . CH 2 2 /CH 2 . OH 
 
 Alcohols of the phenol class are mostly contained in the tars 
 derived from the destructive distillation of coal, wood, &c. : 
 benzylic alcohol is contained as such in the volatile oil of cherry 
 laurel, and in the form of a compound ether in Balsam of Peru 
 and Liquid Storax ; a higher homologue, sycocerylic alcoJwl, 
 C 18 H 29 . OH, is similarly found as an acetic compound ether in 
 the resin of Ficus rubiginosa : a-lactucerol and (3-lactucerol' are 
 two isomerides thereof contained as acetic ethers in lettuce juice. 
 Quebrachol (from Quebracho bark), and cupreol and cinchol 
 (from Cinchona barks) are analogous substances isomeric with 
 one another and indicated by the higher homologous formula, 
 C 20 H 33 . OH ; whilst Pliasol (from Phaseolus vulgaris) is a lower 
 homologue, C ]5 H 23 . OH. All these substances are closely akin 
 to cholesterol, isocJiolesterol, phytosterol and paraphytosterol, alco- 
 holiform substances belonging to the family derived from the 
 hydrocarbons, C n H 2n _ 8 , and occurring in various fixed oils as 
 normal constituents dissolved in the glycerides, <fcc., constituting 
 the bulk of the oils. It is extremely probable that other 
 .analogous substances are also similarly contained in oils, <fec., 
 but as yet this has not been demonstrated to be the case. In 
 the husks of PJiaseolus vulgaris both paraphytosterol and phasol 
 are present ; when such substances occur in the vicinity of oil- 
 containing tissues, obviously any process applicable for the ex- 
 traction of the oil is extremely likely to dissolve out more or 
 less of the accompanying alcoholiform substances, as well as any 
 other substances soluble in oil that may happen to be contained 
 in the seeds, <fcc., operated upon. 
 
 Cholesterol Series and Analogues. Cholesterol and its 
 isomerides appear to be homologues of cinnamic alco/iol, C 9 H 9 .OH 
 (contained in storax as cinnamic ether), indicated by the formula 
 C 9(5 H 43 . OH ; some (cholesterol long known as a bile constituent 
 
ALCOHOLIFORM PRODUCTS OF SAPONIFICATION. 17 
 
 and isocholesterol) chiefly occur in oils, &c., of animal origin, 
 such as whale and fish oils and woolgrease ; others (phytosterol 
 and isophytosterol) are similarly found in vegetable oils, such as 
 olive oil. Ambergris and castoreum (from the Castor beaver) 
 also appear to contain related substances (ambreol and castorol 
 respectively). All these bodies, like the sycocerylic alcohol and 
 its homologues above mentioned, are of alcoholiform character 
 readily yielding acetic and benzoic compound ethers (often of 
 highly crystalline character, and readily purified in consequence), 
 the melting points of which are characteristic. Thus, cholesterol 
 heated with benzoic anhydride (preferably in a sealed tube at 
 200) forms a compound ether almost insoluble in boiling alcohol, 
 but^ crystallisable from ether in right-angled tables, melting at 
 150-151 . The following table illustrates some of the differences 
 between cholesterol and its isomerides : 
 
 
 Melting Point. 
 
 Action on Polarised 
 Light. 
 
 Melting Point of 
 Benzoic Ether. 
 
 Cholesterol, . . 
 Isocholesterol, . 
 Phytosterol, . 
 
 147 
 137- 138 
 132- 133 
 
 Lsevogyrate. 
 Dextrogyrate. 
 Lsevogyrate. 
 
 150-151 
 190-191 
 
 Paraphytosterol, 
 
 149- 150 
 
 Dextrogyrate. 
 
 
 
 When dissolved in chloroform and treated with an equal 
 volume of sulphuric acid, cholesterol yields a blood red colora- 
 tion, soon becoming cherry red and purplish, permanent for 
 several days ; the acid underlying the chloroform solution ex- 
 hibits a strong green fluorescence. Phytosterol gives a similar 
 coloration, becoming a bluish red on standing some days ; whilst 
 isocholesterol gives no colour at all. On treatment with acetic 
 anhydride, compound ethers are produced in each case, the 
 "acetyl number" of which is 135-5 (parts of caustic potash, 
 KOH, neutralised by the acetic acid developed by the saponifica- 
 tion of 1,000 parts of compound ether, Chap, vin.); the corre- 
 sponding values for the similar compound ethers obtained 
 from cetylic, cerylic, and myricylic alcohols being respectively 
 197-5, 128-1, and 116-7. 
 
 Another substance closely akin to phytosterol has been isolated 
 from the seeds of Lupinus luteus, i.e., lupeol* probably indicated 
 by the formula C 26 H 42 O, containing less hydrogen than phyto- 
 sterol ; this melts at 204, is dextrorotatory, and forms benzoic 
 and acetic ethers melting respectively at 250 and 230 ; dissolved 
 in chloroform and treated with acetic anhydride and sulphuric 
 acid, it gives a reddish coloration, becoming intensely violet red 
 on standing. Several other substances of analogous character 
 appear to be contained in various vegetable products e.g., hydro- 
 
 * Likternik, Berich'.e Deut. Chem. Ge. t 1891, xxiv., pp. 183 and 187. 
 
 2 
 
18 OILS, FATS, WAXES, ETC. 
 
 carotin (carrots), paracJwlesterol (E 'thulium septicum), &c., &c. ; 
 but their occurrence in oil-bearing seeds, and the oils thence 
 obtainable, has not yet been substantiated. 
 
 GLYCOLS. 
 
 It has been shown by Stiirke * that when carnauba wax is 
 saponified, and the alcoholiform constituents thus set free frac- 
 tionated by means of petroleum, a glycol is obtained melting at 
 103 '5 to 103-8, and giving numbers on analysis agreeing with 
 
 ( OI-T OTT 
 the formula C 25 H 52 O 2 , or C 23 H 46 < ^-g 2 ' Q-^; this product evolves. 
 
 eight hydrogen atoms on fusion with caustic alkalies, forming 
 an acid of the oxalic series, thus 
 
 (CH 9 .OH ~ ,TT TT fCO.ONa 
 
 H 
 
 2346 CHj. OH 2 2346 CO . ONa 
 
 just as cerylic alcohol and similar bodies evolve four hydrogen 
 atoms (p. 13), forming an acid of the stearic series, thus 
 
 C 26 H 53 . CH 2 . OH + NaOH = 2H 2 + C 26 H 53 . CO . ONa. 
 
 CHAPTER III.1J 
 
 SAPONIFICATION PRODUCTS OF OILS, FATS, 
 WAXES, &c. 
 
 FATTY ACIDS. 
 
 IT is a remarkable fact that all known compound ethers con- 
 tained in natural fixed oils and fats, &c., invariably give rise on 
 saponification to monobasic acids only, dibasic acids (like oxalic 
 acid), and acids of still higher basicity being conspicuous by their 
 absence from the products thus formed, although in many cases 
 readily obtainable from these products by simple operations in 
 the laboratory. 
 
 At least six different families of monobasic acids are repre- 
 sented amongst the saponification products of fixed oils, <fcc., four 
 of which are included in the general formula, C m H 2n +1 . CO . OH; 
 according as in = n, or = n + 1, n + 2, or 11 + 3, this general 
 formula represents the following families : 
 
 Formula of Acid. 
 
 C m H 2m + 1 .CO.OH 
 C m H 2m - j . CO . OH 
 C m H 2m _ 3 CO . OH 
 C m H 2m . 5 .CO.OH 
 
 Family. 
 
 Acetic (or stearic) series. 
 Acrylic (or oleic) series. 
 Propiolic (or linolic) series. 
 Linolenic series. 
 
 * Annalen der Chemie, pp. 223-2S3 ; also in abstract, Journal Soc. Chem. 
 Industry, 1884, p. 448. 
 
FATTY ACIDS. 
 
 19 
 
 Two other families are more highly oxidised, being included in 
 
 ( OTT 
 
 the general formula C m II 0ll -j p.. OH> accor ^i n g as ni = n or 
 
 n + 1 the following two families result : 
 
 C m H 
 
 Formula of Acid. 
 I OH. 
 
 CO . OH. 
 
 C m H 
 
 2m - 2 
 
 fOH. 
 CO . OH. 
 
 I Family. 
 
 Oxyacetic(oxystearic or glycollic) 
 
 series. 
 Ox3*acrylic (oxyoleic or ricinoleic) 
 
 series. 
 
 In addition to these six leading families of monobasic acids, re- 
 presentatives of several others are obtainable by saponification 
 from various essential oils and allied products ; whilst by gentle 
 oxidation processes or other reactions several different kinds of 
 more oxidised monobasic acids are readily formed from the 
 normal "fatty acids" derived from natural fixed oils, &c. Thus 
 for example : 
 
 Formula of Acid. Family. 
 
 Examples and Sonrces. 
 
 
 
 ( Benzoic and toluic acids, &c. ; 
 
 OmH 2m _ 7 . CO . OH 
 
 Benzoic series 
 
 ) from gum benzoin, balsam of 
 j Tolu, dragon's blood, storax, 
 
 
 ( oil of bitter almonds, &c. 
 
 
 ! Cinnamic acid ; from oil -of 
 
 C m H 2 m - 9 CO . OH Cinnamic series 
 
 cinnamon, cassia, storax, 
 
 
 balsam of Tolu, &c. 
 
 r TT /OH 
 wn 2 m - 8 -[cO.OH 
 
 Oxybenzoic (salicylic) 
 series 
 
 f Salicylic acid ; from gaul- 
 \ theria oil, &c. 
 
 (OH 
 C m H 2m . ! \ OH 
 
 Glyceric (dioxystearic) 
 
 ( Oxidation of oleic acid and 
 < isomerides and homologues 
 
 (CO, OH 
 
 series 
 
 f thereof. 
 
 r H /(OH) S 
 
 L^ttsm - 2 | QQ < Q H 
 
 Erythroglucic (tri- 
 oxystearic) series 
 
 i CigH 3(5 05 ; from oxidation of 
 < ricinoleic acid and its iso- 
 / merides. 
 
 c H f(OH) 4 
 
 Tetroxystearic series 
 
 ( CigHsgOe (sativic acid) ; from 
 \ oxidation of liiiolic acid. 
 
 CmH 2m _ 5 | c^oH Hexoxystearic series 
 
 ( CigH 36 08 (linusic acid) ; from 
 ( oxidation of linolenic acid. 
 
 ACETIC FAMILY OF FATTY ACIDS. 
 
 The following table denotes the leading acids of the acetic 
 family (general formula C n H 2n O 2 - C m H 2m +1 . CO . OH) derived 
 from fixed oils, waxes, essential oils, and similar sources : in 
 addition numerous isomeric modifications of many of the acids 
 are known, obtained artificially by synthetic and other laboratory 
 operations : 
 
20 
 
 OILS, FATS, WAXES, ETC. 
 
 Formula. 
 
 Name of Acid. 
 
 Boiling 
 Point. 
 
 Melting 
 Point. 
 
 Source . 
 
 CH 2 2 
 
 Formic, 
 
 ioic 
 
 8C 
 
 Ants ; nettles. 
 
 C 2 H 4 2 
 
 Acetic, 118 
 
 17 
 
 Acetous fermentation ; oil 
 
 
 
 
 of cow parsnep, and 
 
 
 
 
 various other essential 
 
 
 
 oils. 
 
 C 3 H 6 2 
 
 Propionic or ; 140 
 
 ... 
 
 Oxidation of propylic 
 
 
 Tritylic, 
 
 
 
 alcohol from fermen- 
 
 
 
 
 
 tated fusel oil. 
 
 C4H 8 2 Normal Butyric, 
 
 162 
 
 3 
 
 Cow's butter ; perspira- 
 
 
 Isobutyric, 
 
 153 
 
 
 tion ; oil of cow parsnep. 
 Oxidation of isobutylic 
 
 
 
 
 alcohol from fusel oil ; 
 
 
 
 
 
 Roman chamomile oil. 
 
 CsHioOjj 
 
 Valeric or Pen- 
 
 175- 185 
 
 ... 
 
 Several isomerides known. 
 
 
 toic, 
 
 
 
 Valerian root ; Isova- 
 
 
 
 leric acid from fat of 
 
 
 
 Delphinum Phoccena. 
 
 C 6 H 12 O 2 
 
 Caproic or 200 
 
 - 9 ; Isohexoic acid (isobutyl- 
 
 
 Hexoic, 
 
 
 
 acetic acid) from cow's 
 
 
 
 
 butter and cokernut 
 
 
 
 
 
 oil. 
 
 
 
 205 
 
 - 1'5 
 
 Normal hexoic acid, as 
 
 
 
 
 
 octylic ether in oil of 
 
 
 
 
 Heracleum. 
 
 C 7 H 14 2 
 
 (Enanthic or 
 
 222 
 
 -10'o 
 
 Normal acid by oxidation 
 
 
 Heptoic, 
 
 
 
 of cenanthol from castor 
 
 
 
 
 
 oil ; wine fusel oil. 
 
 CgHiflOg 
 
 Caprylic or 
 
 238 
 
 15 
 
 Isoprimary acid from 
 
 Octoic, 
 
 
 
 cokernut oil and butter; 
 
 
 
 Limburg cheese. 
 
 C 9 H J8 2 
 
 Pelargonic or 
 
 254 13 Normal acid from oil of 
 
 
 Ennoic, 
 
 
 Pelargonium roseum; 
 
 
 
 
 and oxidation of oil of 
 
 
 
 
 rue and beetroot fusel oil. 
 
 Ci H vo 2 
 
 Capric orDecoic, 
 
 269 30 
 
 Butter ; cokernut oil ; 
 
 
 
 
 grape fusel oil. 
 
 C H H 22 2 
 
 Hendecoic or 
 Undecylic, 
 
 228 at 1 GO; 28 "5 
 millims. | 
 
 Hydrogenatiou of Hende- 
 cenoic acid from distil- 
 
 
 
 pressure. 
 
 
 lation of castor oil. 
 
 
 
 ... 
 
 35 
 
 Cocinic acid (?) in coker- 
 
 
 
 
 
 nut oil. 
 
 j 
 
 ... 
 
 Near 23 
 
 Umbellulic acid (?) from 
 
 
 
 
 chaulmoogra oil. 
 
 ^12^2402 ! Laurie or Dode- 
 
 225 at 100 
 
 44 
 
 Laurel butter (Laurux 
 
 
 coic, 
 
 millims. 
 
 nobilis) ; Pichurim bean 
 
 
 
 pressure. 
 
 
 fat ; cokernut oil ; 
 
 
 
 
 
 palm kernel oil. 
 
 Ci3H 26 O 2 
 
 Tridecoic, 
 
 ... 
 
 ... 
 
 Supposed to be contained , 
 
 
 
 
 
 in cokernut oil ; doubt- 
 
 
 
 
 
 ful. 
 
 C 14 H 28 2 
 
 Myristic, 
 
 250 at 100 
 
 54 
 
 Nutmeg butter ; coker- 
 
 
 
 millims. 
 
 
 nut oil ; dika fat ; cro- 
 
 
 
 pressure. 
 
 
 ton oil; spermaceti. 
 
 C 15 H 30 2 
 
 Pentadecoic, 
 
 
 55 
 
 (?) Oil of Jatropha curcas. 
 
FATTY ACIDS. 
 
 21 
 
 Formula. 
 
 Name of Acid. 
 
 Boiling 
 Point. 
 
 Melting 
 Point. 
 
 Sources. 
 
 C, 6 H 30 2 
 
 Pentadecoic, 
 
 53 -5 
 
 Cetic acid(?) from sper- 
 
 
 
 ^ 
 
 
 maceti. 
 
 
 
 
 53 
 
 Benomargaric acid (?) 
 
 
 
 
 
 from oil of Ben. Stilli- 
 
 
 
 
 
 stearic acid (?) from 
 
 | C 16 H 32 02 Palmitic, 
 
 271'o 
 
 62 
 
 Stillingia sebifera. 
 Palm oil. One of the 
 
 
 at 100 
 
 
 constituents of most 
 
 
 millims. 
 
 
 animal fats. Sperma- 
 
 
 
 pressure. 
 
 
 ceti ; beeswax ; Japan 
 
 
 
 
 
 wax. 
 
 C, 7 H 34 2 
 
 Marcraric, 
 
 ... 
 
 60 
 
 From cetyl cyanide ; for- 
 
 
 
 
 merly supposed to be 
 
 
 
 
 
 contained in certain 
 
 
 
 
 
 fats. 
 
 
 Daturic, 
 
 ... 
 
 55 
 
 From oil of Datura 
 
 
 
 
 
 Strammonium. 
 
 C 18 H 36 Oo 
 
 Stearic, 
 
 291 at 100 
 
 69 "2 
 
 Tallow, lard, and most 
 
 
 
 millims. 
 
 
 animal solid fats ; Shea 
 
 C,oH 38 02 
 
 Enneadecoic, 
 
 pressure. 
 
 66 
 
 butter; Illipe" fat. 
 From stearyl cyanide (?) 
 
 
 
 
 obtained along with 
 
 
 
 
 
 artificial margaric acid. 
 
 C 2 oH4 2 
 
 Arachic (or Ara- 
 
 ... 
 
 75 
 
 Earthnut oil (Arachis 
 
 
 chidic); Butic, 
 
 
 hypogcea) ; butter (?) 
 
 1 
 
 
 (Heintz). 
 
 C 21 H4o0 2 ! 
 
 72 -5 
 
 Medullic acid (?) from 
 
 
 
 
 beef marrow. 
 
 C 22 H4 4 2 
 
 Benic or Beni- 
 
 76 
 
 Oil of Ben ; black mustard 
 
 
 stearic, 
 
 
 seed oil ; rape oil. 
 
 C^H^Og 
 
 Lignoceric, 
 
 8l" 
 
 Earthnut oil ; beech- 
 
 
 
 
 wood tar. 
 
 
 Carnatibic, 
 
 72 -5 
 
 Carnauba wax. 
 
 ... 
 
 46 
 
 Paraffinic acid (?) from 
 
 
 
 paraffin wax and nitric 
 
 
 
 
 acid. 
 
 C 25 H 50 02 
 
 Hyaenic, 
 
 78 
 
 Hyaena fat. 
 
 Co 6 H 52 2 
 
 
 
 Geoceric acid (?) from dis- 
 
 
 
 
 
 tillation of brown coal. 
 
 C 27 H5 4 Oo 
 
 Cerotic, 
 
 78 
 
 Beeswax; Carnauba wax; 
 
 C 28 B^0 2 
 
 
 
 
 Chinese wax. 
 
 cEnEoi 
 
 
 
 Melissic, 
 
 ... 
 
 88 ; " 
 
 Oxidation of myricylic 
 
 
 
 
 
 alcohol from beeswax. 
 
 <5, 
 
 Theobromic, 
 
 
 72"" 
 
 Cacao butter. 
 
 The formulae ascribed to several of the acids named in the pre- 
 ceding table can hardly be regarded as established with perfect 
 
22 OILS, FATS, WAXES, ETC. 
 
 certainty ; thus the cocinic acid, C U H 22 O 2 , formerly supposed to 
 be contained in cokernut oil, appears from later researches to 
 be in all probability only a mixture of other acids of the series ; 
 and the same remark applies to the tridecoic acid, C 13 H 20 O. 2 , 
 from the same source, which appears to be simply a mixture 
 of lauric and myristic acids. SimilaYly, cetic acid, C ]5 H 30 O 2 , 
 and the isomeric (?) benomaryaric and stillistearic acids are very 
 doubtful bodies ; the last has been stated by later observers to 
 be simply palmitic acid, and benomargaric acid to be a mixture 
 of palmitic and myristic acids. The margaric- acid, C ir H 34 O 2 , 
 formerly regarded as present in animal fats, has been since 
 shown to consist of a mixture of stearic and palmitic acids 
 and more or less oleic acid." 55 " Again, the compositions ascribed 
 to medullic acid, C 01 H 4 . 7 O 9 ; hycenic acid, C 05 H 50 O ; geoceric 
 acid, C 26 H 52 O 2 ; and tkeobromic acid, C 64 H 128 O ,f require con- 
 firmation as regards the individual character and purity of 
 these substances. Of those acids where the carbon present 
 lies between C 1(> and C 2 w, it is noticeable that those of most 
 frequent and widely-spread occurrence, and of which the com- 
 positions are ascertained with certainty, always contain an 
 even number of carbon atoms; so that it has been supposed 
 by some chemists that acids containing an odd number of 
 carbon atoms do not actually occur as glycerides amongst the 
 natural oils and fats, and that the bodies supposed to possess 
 vsuch a composition are really either mixtures of glycerides with 
 even numbers of carbon atoms, or substances rendered otherwise 
 impure. A priori, however, there seems no reason for doubting 
 the possibility of the existence in nature of glycerides of acids 
 containing an odd number of carbon atoms. 
 
 In the case of butter fat, cokernut oil, and some few other 
 substances, fatty acids of low molecular weight (i.e., where n in 
 the general formula C n Hn n O 2 is of low value), are present to 
 some notable extent ; but, as a general rule, natural oils and fats 
 rarely yield fatty acids of this description where n has a smaller 
 value than 12. Inasmuch as the lower members of the acetic 
 acid family are comparatively easily volatile (especially along 
 with water vapour), whilst the higher ones are almost non- 
 volatile with ordinary steam, this practically means that the 
 fatty acids from most fats and oils will not readily distil by the 
 aid of moist steam, whilst a certain proportion of more easily 
 volatile acids, is< contained in the mixture of acids obtained from 
 butter fat and cokernut oil, tfec. This distinction is utilised in 
 certain case& as. a. means of testing the quality of such substances 
 
 * The margarine or oleomargarine used as a butter substitute is es- 
 ssntially a mixture of the glycerides of stearic and palmitic acids with 
 sufficient olein to give it its soft texture. 
 
 t Graf was unable to find any theobromic acid in Cacao butter (Arch. 
 Pharm., 1888, 26, p. 820). 
 
FATTY ACIDS. 23 
 
 as regards adulteration and admixture with cheaper forms of 
 fatty matter (Reichert's test, vide Chap, vin.) 
 
 The fatty acids of the acetic series diifer considerably in their 
 respective degrees of solubility in water ; the lowest members 
 formic, acetic, propionic, and butyric acids are miscible with 
 water in all proportions^ the highest members, including myristic 
 acid and all above it, are quite insoluble in water ; the inter- 
 mediate acids exhibit a degree of solubility the greater the 
 lower the molecular weight ; thus caprylic acid dissolves in 400 
 parts of boiling water, and capric acid in about 1000 parts, both 
 mostly separating out again on cooling; whilst lauric acid is 
 almost insoluble in cold water, though sparingly dissolved by 
 boiling water. 
 
 Alcohol, especially when warm, readily dissolves even the 
 highest members of the series ; inasmuch as the glycerides of 
 these acids are, as a rule, almost insoluble in alcohol, this pro- 
 perty affords a method of separating the free fatty acids con- 
 tained in natural oils, &c., from the glycerides, the oil being 
 simply agitated with alcohol and allowed to stand so as to 
 separate the alcoholic solution of fatty acids from the unaffected 
 glycerides. Alcohol containing only a minute quantity of a free 
 fatty acid exhibits an acid reaction to phenolphthalein, and can 
 accordingly be readily titrated volumetrically by means of a 
 weak standard alkaline solution in presence of that indicator : 
 on this also is based the general method of determining the 
 amount of fatty acid salt formed on saponifying a glyceride or 
 other compound ether by an alkali (Chap, vin.) The highest 
 acids of the series are not extremely soluble in cold alcohol, so 
 that they are readily crystallisable from that menstrum. 
 
 The normal salts of acids of the acetic family are indicated by 
 the general formula C n H 2n+1 . CO . OM, where M is a monad 
 metal : acids salts of formula C tt Hg B . 1 O 2 l^ C n H 0ll O 2 can in some 
 cases be produced e.g., sodium diacetate, C 2 H 3 NaO 2 , C 2 H 4 O 2 ; 
 potassium distearate, C 1S H 35 K0 , C 18 H 36 2 . Salts of this kind 
 when dissolved in hot alcohol react acid with phenolphthalein, 
 and behave toward alkaline solutions on titration with that 
 indicator precisely as mixtures of the free acid and the neutral 
 salt, 
 
 In certain cases the neutral alkali salts are partly hydrolysed 
 by solution in water with formation of acid salt and caustic 
 alkali ; thus with neutral sodium stearate. 
 
 Neutral Sodium Caustic 
 
 Stearate. Water. Soda. Sodium Distearate. 
 
 2C 18 H 35 Na0 2 + H 2 = NaOH + C 18 H 35 Na0 2 , Ci 8 H S6 2 
 
 By adding common salt to the fluid, the latter compound and 
 the unaltered neutral salt are thrown out of solution ; on collec- 
 
24 OILS, FATS, WAXES, ETC. 
 
 tion by filtration and solution in alcohol and titration an amount 
 of acidity is registered precisely equivalent to the alkalinity 
 of the watery fluid. On the occurrence of this phenomenon 
 depends a good deal of the cleansing properties of soaps, the 
 action being also observable with the alkali salts of oleic and 
 ricinoleic acids to approximately the same extent as with those 
 of palmitic and stearic acids (Chap, xxn.)" 
 
 ACRYLIC (OLEIC) FAMILY OF FATTY ACIDS. 
 
 The total number of acids of general formula C n H 2n _i.CO . OH 
 now known is somewhat considerable ; as with the acetic 
 family, only a comparatively small number of them are con- 
 tained in natural fats, &c., and of these but few are of relatively 
 low molecular weight so as to be readily volatile. The table 011 
 page 25 exhibits the more important acids of this class. 
 
 As in the case of the acetic family of acids, the existence of 
 certain members mentioned in the table is not yet established 
 with perfect certainty ; thus damaluric acid is a substance the 
 existence of which requires confirmation ; and similarly with 
 the aldepalmitic acid recently stated by Wanklyn to be a 
 constituent of cow's butter.* The existence of hypogseic 
 acid has been denied by Schon, who found the only acid of 
 the acrylic series present in earthnut oil to be oleic acid. 
 Similarly, moringic acid has been stated by more recent ex- 
 perimenters to be simply impure oleic acid; and the same kind 
 of thing is said by Schadler to apply to doeglic acid this being 
 regarded by him as simply impure physetoleic acid. 
 
 The unsaturated nature of the hydrocarbons from which this 
 group of fatty acids are derived leads to their possession of some 
 peculiar features ; thus, when heated with fused alkali (caustic 
 potash), there is a tendency to undergo a change indicated by 
 the general equation : 
 
 C m + n H 2(m + n _j,0 2 + 2KOH = K. CmH^-iOg + K.C u H 2n .. 1 2 + H 2 
 
 the potassium salts of two acids of the acetic family being formed 
 along with free hydrogen. In virtue of this tendency, oleic acid, 
 when thus treated, forms palmitic and acetic acids, a circumstance 
 utilised in practical manufacture. 
 
 Oleic Acid. Caustic Potash. Potassium Palmitate. Potassium Acetate. 
 
 Ci8H 34 2 + 2KOH = K.C, C H 31 2 + K.C 2 H 3 2 + H 2 
 
 Again, inasmuch as the unsaturated hydrocarbons have a more 
 or less marked tendency to combine directly with halogens (and 
 
 * Journ. Soc. Chem. Ind., Feb. 1891, p. 89. 
 
FATTY ACIDS. 
 
 25 
 
 so pass into the series of substitution derivatives of the satu- 
 rated hydrocarbons), the same tendency is shared by the fatty 
 
 Formula. 
 
 Name of Acid. 
 
 Boiling Point 
 
 Melting 
 Point. 
 
 Sources. 
 
 C 3 H 4 2 
 
 Acrylic, 
 
 140C. 
 
 8C. 
 
 Oxidation of acrole'in from 
 
 
 
 
 
 glycerol. 
 
 C 4 H 6 2 
 
 Crotonic, 
 
 185 
 
 72 
 
 From cyanide of allyl (de- 
 
 
 
 
 
 rived from oil of mustard). 
 
 C 5 H 8 2 
 
 Angelic, 
 
 185 
 
 45 
 
 Angelica root. Sumbul root 
 
 
 
 
 
 resin. 
 
 
 Tiglic, 
 
 196 
 
 64 
 
 Oil of Chamoinile. Croton 
 
 
 
 
 
 oil. 
 
 C 6 H 10 2 
 
 Pyroterebic, 
 
 210 
 
 ... 
 
 Action of heat on terebic acid 
 
 
 
 
 
 from oil of turpentine and 
 
 
 
 
 
 nitric acid. 
 
 C 7 H 12 2 
 
 ... 
 
 ... 
 
 53 
 
 Damaluric acid? (from cow's 
 
 
 
 
 
 and horse's urine). 
 
 CgHi 4 Oo 
 
 Octenoic, 
 
 ... 
 
 ... 
 
 ... 
 
 c 9 H 16 o; 
 
 Ennenoic, 
 
 ... 
 
 liquid. 
 
 (Enanthol (from castor oil) 
 
 
 
 
 
 and acetic anhydride. 
 
 Ci H 18 2 
 
 Phoronic, 
 Decenoic, 
 
 242-269 
 
 169 
 10-86 
 
 Oxidation of sodium camphor. 
 Several isomeric modifica- 
 
 
 
 
 
 tions known ; all of arti- 
 
 
 
 
 
 ficial origin. 
 
 CnH 20 2 
 
 Hendecenoic, 
 
 275 
 
 24 -5 
 
 Castor oil distilled under 
 
 
 
 
 
 diminished pressure. 
 
 C 12 H 22 2 
 
 Petroleumic, 
 Dodecenoic, 
 
 250- 260 
 
 liquid. 
 
 Contained in petroleum. 
 Artificial. 
 
 Ci 3 H 24 2 
 
 Tridecenoic, 
 
 ... 
 
 ... 
 
 ... 
 
 Ci 4 H 26 2 
 
 Tetradecenoic, 
 
 
 
 ... 
 
 
 Moringic, 
 
 
 
 
 Oil of Ben. 
 
 
 Cimicic, 
 
 ... 
 
 44 
 
 Fcetid oil from Raphirjaster 
 
 
 
 
 
 punctipennis. 
 
 CicH 3 o0 2 
 
 Physetoleic, 
 
 
 30 
 
 Sperm oil. 
 
 
 Hypogaeic, 
 
 ... 
 
 34 
 
 Earthnut oil(Arachis Itypo- 
 
 
 
 
 
 gcea). 
 
 
 
 
 50 
 
 Aldepalmitic acid(?) from 
 
 
 
 
 
 butter. 
 
 C 17 H 32 2 
 
 Heptadecenoic, 
 
 .. . 
 
 
 ... 
 
 Ci 8 H 34 2 
 
 Oleic, 
 
 286 at 100 
 millims. 
 
 14 
 
 Contained as glyceride in 
 most animal fats and 
 
 
 
 pressure. 
 
 
 many vegetable oils. 
 
 
 Isoleic, 
 
 
 44-45 
 
 Distillation of oxystearic 
 
 
 
 
 
 acid. 
 
 
 Stearidic, 
 
 ... 
 
 35 
 
 Action of water on silver 
 
 
 
 
 
 bromostearate. 
 
 Cj9H 3G 2 
 
 Doeglic, 
 
 
 A little 
 
 Oil from dcegling (bottle- 
 
 
 
 
 above 
 
 nose whale). 
 
 C 21 H 40 2 
 
 
 ;.'! 
 
 '... 
 
 '.'.'. ... 
 
 C 22 H 42 2 
 
 Erucic, 
 
 254 -5 at 
 
 34 
 
 Colza, grape seed, and 
 
 
 
 10 millims. 
 
 
 mustard oils. 
 
 
 
 pressure. 
 
 
 
26 OILS, FATS, WAXES, ETC. 
 
 acids derived from them ; thus the hydrocarbon ethylene, as has 
 long been known, combines directly with chlorine forming an 
 oily fluid,* originally known as "Dutch liquid," the reaction 
 being 
 
 Ethylene. Chlorine. Ethylene Bichloride. 
 
 H 2 C = CH 2 + C1 2 = H 2 C1C - CC1H 2 
 
 In the same kind of way, oleic acid and its congeners, being 
 derivatives of ethylene of general formula K . CH = CH . S, 
 will directly combine with bromine or iodine in parallel fashion, 
 forming dibromo-, or diiodosubstitution derivatives of acids of 
 the acetic family of form R . CHBr - CHBr . S ; thus 
 
 Oleic Acid. Iodine. Diiodostearic Acid. 
 
 C 18 H 34 2 + I 2 = CjgHsJjOjj 
 
 This reaction is utilised as a convenient method of dis- 
 tinguishing from one another acids derived respectively from 
 saturated hydrocarbons, and from unsaturated hydrocar- 
 bons of the olefine series, the former not combining with 
 halogens, and the latter uniting therewith in the proportion of 
 one molecule of fatty acid to two atoms of halogen. Accord- 
 ingly, the measurement of the quantity of iodine or bromine 
 thus fixed ("iodine absorption equivalent," or "bromine ab- 
 sorption equivalent") often gives useful information as to the 
 nature of the fatty acid or acids present ; and the same remark 
 equally applies to the glycerides themselves, which also combine 
 with halogens in parallel fashion, e.g. : 
 
 Olein. Glyceride of Glyceride of Diiodo- 
 
 Oleic Acid. Iodine. stearic Acid. 
 
 CgJU^CisH-ssO^s + 3I 2 = ^3^-5(^13^53^2^2)3 
 
 In just the same kind of way certain acids of the acrylic family 
 can directly combine with nascent hydrogen produced under 
 appropriate conditions, becoming thereby converted into acids of 
 the acetic family, the general reaction expressing the change 
 being 
 
 CnH 2n . 2 2 + Ho = C n H 2n 2 
 
 Thus oleic acid forms stearic acid, when heated in a sealed 
 tube with fuming hydriodic acid and phosphorus. By reversing 
 the process, an acetic acid becomes transformed into an acrylic 
 acid. In practice the direct removal of hydrogen after this 
 fashion is difficult to accomplish ; but in certain cases it may be 
 effected by acting on the acid of the acetic family with chlorine 
 or iodine or bromine, so as to produce a monochloro-, iodo-, or 
 bromosubstitution derivative; by treating this with alkalies, &c., 
 
 * Whence the old name olefiant gas for ethylene, signifying " oil making" 
 gaa. 
 
FATTY. ACIDS. 27 
 
 the elements of HC1, HI, or HBr are eliminated, leaving an acid 
 of the acrylic series. 
 
 Thus acrylic acid itself is formed from iodopropionic acid thus, 
 
 lodopropionic Acid. Acrylic Acid. 
 
 C 3 H 5 I0 2 - HI = C 3 H 4 2 
 
 the elimination of the elements of hydriodic acid being brought 
 about by treatment with sodium ethylate, lead oxide, or similar 
 basic substances. 
 
 In other cases a dibromo- or dichlorosubstitution derivative of 
 an acid of the acetic family is acted upon with zinc dust, or other 
 substance having a strong tendency to combine with halogens ; 
 thus dibromopropionic acid and zinc dust form acrylic acid. 
 
 Dibromopropionic Acid. Acrylic Acid. 
 
 C-jH^BraOo Br 2 = G'sH^Og 
 
 In this way the dibrominated and diiodised products obtained 
 by adding Br. 2 or I 2 to the higher acrylic acids can be made to 
 reproduce the original acid. This reaction is utilised in the 
 examination of oils, &c., containing the glycerides of unsaturated 
 acids ; bromine addition products are formed and separated from 
 one another by crystallisation, &c., and then debrominated so as 
 to reproduce the original acids, which can thus be indirectly 
 separated from one another in a fashion usually impracticable 
 with the actual acids themselves. 
 
 Acrylic acids, at any rate in certain cases, combine directly 
 with sulphuric acid, forming saturated compound sulphuric acids 
 analogous to ethylsulphuric acid (sulphovinic acid) ; thus 
 
 Oleic Acid. Sulphuric Acid. Oxystearosulphuric Acid. 
 
 C 17 H 33 .CO.OH + S0 2 (OH) 2 = C irH 
 
 By the action of water, &c., on the compounds thus formed, 
 hydrolysis is brought about, with the formation of sulphuric acid 
 and an acid of the oxyacetic (glycollic) family ; thus 
 
 Oxystearosulphuric Acid. Water. Sulphuric Acid. Oxystearic Acid. 
 
 Ci;H 34 - -f H 2 = S0 2 (OH) 2 + Ci 7 H 34 
 
 These reactions, especially the first, are utilised in the pro- 
 duction of certain kinds of "Turkey red oils;" obviously the 
 sum of the two changes is equivalent to the addition to an 
 acrylic acid of the elements of water. 
 
 The dibromides of acids of the oleic series, when treated 
 with silver hydroxide, Ac., form silver bromide together with 
 glyceric acids i.e., dioxy acids of the acetic series : 
 
 + 2AgOH = 2AgBr + C n H. n _ 
 
28 OILS, FATS, WAXES, ETC. 
 
 By the regulated action of caustic potash, they lose successively 
 HBr and 2HBr, forming in the one case bromoleic acid or a 
 homologue thereof, and in the other case a propiolic aqid 
 
 CO. OH HBr = C " Hsn - 3 1 CO. OH 
 
 j* QH - t>HBr = C n H, n _., . CO. OH 
 
 A remarkable property possessed by many acids of the oleic 
 family is that contact with certain reagents, more especially 
 nitrous acid, converts them into isomeric modifications of higher 
 fusing and boiling points, so that acids liquid at the ordinary 
 temperature become transferred into solids. This effect is also 
 produced with the natural glycerides of these acids, forming 
 a reaction largely utilised in testing the purity of certain oils 
 (Chap. vii). Oleic acid, liquid at ordinary temperatures, thus 
 becomes elaidic acid, melting at 45, by contact with nitrous 
 acid ; and its glyceride, olein, fluid at 0, is similarly converted 
 into elaidin, melting at 32; whence the term "Elaidin reaction" 
 applied to this nitrous acid test. In similar fashion erucic 
 acid, melting at 34, is changed into brassaidic or brassic* acid, 
 fusing at 60 ; whilst parallel changes are undergone by hypo- 
 gseic and physetoleic acids. 
 
 Elaidic acid and the similarly altered other acids of this class 
 call be distilled unchanged under diminished pressure, not being 
 thereby converted back again into the original acids ; for a given 
 pressure the boiling point is always slightly higher than that of 
 the original acid : thus Krafft and Noerdlinger f obtained the 
 following numbers. (See Table, p. 29.) 
 
 The nature of the chemical change ensuing during the elaidin 
 reaction is somewhat uncertain. By fusion with caustic potash 
 both oleic and elaidic acids yield acetate and palmitate ; on the 
 other hand, by oxidation with alkaline permanganate they form 
 two different dioxystearic acids, melting respectively at 136 '5 
 (solidifying at 119) and 99-100 (solidifying at S5-86 Saytzeff). 
 Similarly erucic and brassic (brassaidic) acids give rise to two 
 different dioxybenic acids on oxidation, as well as different 
 derivatives of other kinds. 
 
 * The term " brassic acid " (brasxica .mure) was originally applied to the 
 acid, C 2 2H4 2 O2, obtained from various species of Brassica, there being at 
 that time some doubt whether "erucic acid" obtained from other ana- 
 logous sources was or was not identical therewith. Later on the identity 
 was established, and the term " brassaidic acid " (brassidin siiure) was 
 applied to the product of nitrous acid on erucic acid, to indicate its analogy 
 with elaidic acid (Haussknecht, Annalen der Chem. and Pharm., 1867, 
 143, p. 55). Of late years the term " brassic acid " has been mostly substi- 
 tuted in English chemical literature for "brassaidic acid (c. .7., Morley and 
 Muir's Dictionary of Chemistry, vol. i., p. 631, article Brassic Acid}. 
 
 t Berichte der Dent. Chem. Cn<s., 1889, vol. xxii., p. 819. 
 
FATTY ACIDS. 
 
 29 
 
 Millimetres of 
 Mercury. 
 
 Oleic Acid. 
 
 Elaidic Acid. 
 
 100 
 50 
 30 
 15 
 10 
 
 285-5286 
 264 
 249-5 
 232-5 
 223 
 
 287'5288 
 266 
 251-5 
 234 
 225 
 
 
 Erucic Acid. 
 
 Brassic Acid. 
 
 30 
 15 
 10 
 
 281 
 264 
 254-5 
 
 282 
 265 
 256 
 
 From Erucic Acid. 
 
 Melts at 
 
 Dioxybenic acid, . . 132- 133 
 Dibromide of erucic acid, 42-43 
 Bichloride, . . . 46 
 
 Methylester from dichloride, 30 '5 
 
 From Brassic Acid. 
 
 Melts at 
 
 Isodioxybenic acid, . 9S-99 
 
 Dibromide of brassic acid, 54 
 
 Dichloride, . . . 65 
 
 Methylester from dichloride, 42 -5 
 
 According to recent researches * the isomerism of erucic and 
 brassic acids is of the stereochemical order i.e., the "structures" 
 of the two bodies, when expressed in space of three dimensions, 
 are not superposible ; a difference only imperfectly expressible 
 on a flat surface by the formulae 
 
 CigHsj) C H CjgHjjg C H 
 
 II and || 
 
 H - C - C0 2 H C0 2 H - C - H 
 
 Isomerides of Oleic Acid. Besides elaidic acid (formed 
 from oleic acid by contact with nitrous acid), two other acids 
 isomeric with oleic acid are known, viz., isoleic and stearidic 
 acids ; in addition, other isomerides of the anhydride character 
 exist. 
 
 Isoleic acid is obtained by acting on oleic acid with sulphuric 
 acid ; combination takes place with the formation of oxystearo- 
 sulphuric acid (probably two different modifications), thus 
 
 C 17 H 33 .CO.OH + H 2 S0 4 = C 17 H 34 
 
 By hydrolysis the product forms oxystearic acid (again, probably 
 more than one modification), which on distillation under dimin- 
 ished pressure becomes dehydrated, furnishing a mixture of ordi- 
 nary oleic acid and a solid isomeride, isoleic acid. 
 
 f* TT JO. oU 3 U . TT f\ TT O/-V . /~< TT I OJ~I 
 
 OH 
 
 H 2 = H 2 S0 4 + C, 7 
 - H 2 + C I7 H 33 . CO . OH 
 
 A. Holt, Berichte der Deutsch. Chem. Ges., 1891, vol. xxiv., 4120. 
 
30 OILS, FATS, WAXES, ETC. 
 
 By converting the acids into zinc salts and heating with alcohol 
 a solution is obtained from which zinc isoleate separates on cool- 
 ing, the other zinc salt remaining in solution. The acid obtained 
 from the pure zinc salt by decomposition by a mineral acid, 
 crystallises from ether; it melts at 45, but is not identical with 
 elaidic acid which fuses at nearly the same temperature : like 
 oleic and elaidic acids it forms acetate and palmitate on fusion 
 with caustic potash ; but the dibromide formed by combination 
 with bromine when treated with silver hydroxide forms a dioxy- 
 stearicacid melting at 77-78 and solidifying at 65-66, the same 
 substance being also formed by oxidising isoleic acid with alka- 
 line permanganate ; whereas the dioxystearic acids obtained by 
 oxidising oleic and elaidic acids in the same way melt at 136 '5 
 and 99-100, and solidify at 119 and 85-86 respectively.* 
 
 Isoleic acid combines with hydriodic acid, forming an iodo- 
 stearic acid reducible to ordinary stearic acid by means of nascent 
 hydrogen, and reconverted into isoleic acid by alcoholic potash. 
 The dibromide of isoleic acid similarly reproduces isoleic acid on 
 treatment with zinc and hydrochloric acid. 
 
 Stearidic Acid. By the action of water on bromostearic acid 
 (from bromination of stearic acid) Oudemannsf obtained an acid 
 isomeric with oleic acid, together with silver bromide. This 
 product distilled unchanged : melting point 35. 
 
 Two anhydrides of oxystearic acids are also known, isomeric 
 with oleic acid; viz., stearolactone, ^-oxystearic "inner" anhy- 
 dride (p. 39) ; and the body formed by the action of hydrochloric 
 acid on a-oxystearic acid, regarded as 
 
 CO. 
 O. C 
 
 PROPIOLTC (LINOLIC) FAMILY OF FATTY ACIDS. 
 
 But few members of the family of acids of general formula 
 C U H 2I , _ 3 . CO . OH have been as yet isolated from oils and fats, 
 &c., the best known example being linolic acid, C l7 H 3 j . CO . OH^ 
 contained in various drying oils, notably linseed oil ; several 
 other members, however, have been produced from acids of the 
 oleic series by employing the method founded on the same 
 principle as that by means of which oleic acids are obtainable 
 from acids of the acetic acid series viz., by conversion into a 
 chloro- or bromoderivative of an acetic acid and removal of the 
 elements of HC1 or HBr by the action of a base. Thus oleic 
 acid combined with Br 2 and the product treated with alcoholic 
 potash furnishes stearolic acid 
 
 * M. C. and A. Saytzeff, /. prakt. Chem., 1888, 37, p. 269. 
 t/. prakt. Chemie, 89, p. 193. 
 
FATTY ACIDS. 31 
 
 Oleic Acid. Dibromostearic Acid. 
 
 C ]8 H 34 2 + Br 2 C 18 H 34 Br 2 2 
 
 Dibromostearic Acid. Steai-olic Acid. 
 
 C 18 H 34 Br 2 2 2HBr = C 18 H 32 2 
 
 In similar fashion other homologues of stearolic acid (e.g., Jiende- 
 colic, palmitolic, and benolic acids) are obtainable from the corre- 
 sponding homologues of oleic acid, the general reaction being 
 
 CnH 2ll _ 2 Br 2 2 - 2HBr = C u H 2n _ 4 2 
 
 In certain cases propiolic acids may be directly obtained from 
 acids of the acetic family by treatment with chlorine or bromine, 
 so as to produce dichloro- or dibromoderivatives of formula 
 C n H 2 ,, _ Br 2 O 2 , which are then acted upon with alkalies so as to- 
 remove the elements of 2HBr, in accordance with the above 
 equation ; the total change produced being therefore equivalent 
 to the removal of H 4 . In this way, for instance, myristic acid, 
 C 14 H 2S O 2 , forms myristolic acid, C 14 H 24 2 . 
 
 An analogous result is brought about with rnonochloro- or 
 monobromoderivatives of acids of the acrylic series by similar 
 treatment, the elements of HC1 or HBr being removed, thus 
 
 - HC1 = C u H 2n . 4 2 
 CuHo n _ 3 Br0 2 - HBr = C u H 2 n-4O 2 
 
 For instance, chlorocrotonic acid, C 4 H 5 C10 2 , gives rise by this 
 treatment to tetrolic acid, C 4 H 4 O 2 . 
 
 The table on p. 32 includes the chief acids of this series: 
 Just as one molecule of an acrylic acid will combine with I 2 or 
 Br , so will one of a propiolic acid unite with Br 4 or I 4 , this action 
 being substantially the reverse of that above described, where a 
 dibromoacetic acid loses 2 HBr and becomes a propiolic acid; this; 
 reaction is utilised in the practical testing of oils (Chap, viu.) 
 Conversely, by the action of nascent hydrogen, zinc dust, and 
 similar dechlorinising agents, the tetrabrominated or tetra- 
 iodised bodies thus formed become again reduced to the original 
 propiolic acids ; thus linolic acid can be separated from accompany- 
 ing acids (obtained by saponifying the mixture of glycerides con- 
 tained in linseed oil, <fec.) by combining with bromine, separating 
 by crystallisation the tetrabrominated derivative, C 18 H 32 Br 4 O 2 
 (melting at 114-115), and reproducing linolic acid by removing 
 the bromine. 
 
 Tetrabromostearic Acid. Linolic Acid. 
 
 C 18 H 32 Br 4 2 - Br 4 = C 18 H 32 2 
 
 Those propiolic acids that are formed by the bromine reaction 
 above described (loss of 2HBr from dibromoderivatives of acids 
 of the acetic family) possess the power of directly combining 
 with oxygen (from suitable oxidising agents), forming saturated 
 
32 
 
 OILS, FATS, WAXES, ETC. 
 
 Formula. 
 
 Name of Acid. 
 
 Melting 
 Point. 
 
 Boilinc 
 Point. 
 
 Sources. 
 
 C 3 H 2 2 
 
 Propiolic, 
 
 
 
 Chloropropiolic acid, 
 
 
 
 
 
 C 3 HC10 2 , is formed 
 
 
 
 
 . 
 
 by the action of pot- ; 
 
 
 
 
 
 ash on dichloracrylic 
 
 
 
 
 
 acid, C 3 H 2 CL0 2 . 
 
 C 4 H 2 2 
 
 Tetrolic, 
 
 76-5 
 
 203 
 
 Chlorocrotonic acid and 
 
 
 
 
 
 caustic potash. 
 
 C 5 H 6 2 
 
 Pentolic, 
 
 ... 
 
 ... 
 
 ... 
 
 C 6 H 8 2 
 
 Sorbic, 
 
 Liquid 
 
 221 ) 
 
 
 
 
 at 15 
 
 
 Mountain ash berries. 
 
 
 Parasorbic, 
 
 134-5 
 
 ... ) 
 
 
 C 7 H 10 2 
 
 Benzoleic(Hy- 
 
 Liquid 
 
 
 Hydrogenation of ben- 
 
 
 drobenzoic), 
 
 
 
 zoic acid. 
 
 C 8 H 12 2 
 
 Diallyl acetic, 
 
 Liquid 
 
 227 
 
 Artificial. 
 
 cM, 
 
 Camphic, 
 
 ... 
 
 ... 
 
 Formed together with 
 borneol by heating 
 
 
 
 
 
 camphor with alco- 
 
 
 
 
 
 holic soda. 
 
 
 Campholenic, 
 
 ... 
 
 Near 
 
 Dibromcamphor and 
 
 CnHjsO, 
 
 Hendecolic 
 
 59 -5 
 
 260 
 
 sodium amalgam. 
 From undecylenic 
 
 
 (Undecolic or 
 
 
 
 (hendecenoic) acid 
 
 
 Hendecinoic), 
 
 
 
 by bromine reaction. 
 
 C 12 H 20 2 
 
 ... 
 
 ... 
 
 ... 
 
 ... 
 
 CnH^Oo 
 
 Myristolic, 
 
 12" 
 
 ... 
 
 From myristic acid 
 
 
 
 
 
 by chlorination and 
 
 
 
 
 
 action of alcoholic 
 
 
 
 
 
 potash. 
 
 C^HssOj 
 
 Palmitolic, 
 
 42" 
 
 
 From hypogeeic acid 
 
 
 
 
 
 by bromine reaction. 
 
 C 17 H 30 2 
 
 Elceomargaric, 
 
 48 
 
 ... / 
 
 " Wood oil " from 
 
 
 Eloeostearic, 
 
 71 
 
 ... \ 
 
 Elceococca Vernitia. 
 
 Cj8H 3 <>0 2 
 
 Stearolic, 
 
 48 
 
 ... 
 
 From oleic acid by 
 
 
 
 
 
 bromine reaction. 
 
 
 Linolic, 
 
 Fluid 
 
 ... 
 
 Linseed and other dry- 
 
 
 
 
 
 ing oils. 
 
 
 Ricilinolic, 
 
 Fluid 
 
 ... 
 
 Dehydration of ricin- 
 
 
 
 
 
 oleic acid. 
 
 
 Tariric, 
 
 50 -5 
 
 ... 
 
 Seeds of tariri (genus 
 
 
 
 
 
 Picramnia). 
 
 CgoHgeO* 
 
 ... '... 
 
 Fluid 
 
 
 (?) Higher homologue 
 
 
 
 
 
 of linolic acid, sup- 
 
 
 
 
 
 posed to be con- 
 
 
 
 
 
 tained in some drying 
 
 
 
 
 
 oils. 
 
 c! 2 H4oOa 
 
 Behenolic (or 
 
 5T-5 
 
 ... 
 
 From erucic acid, by 
 
 
 Benolic), 
 
 
 
 bromine reaction. 
 
FATTY ACIDS. 33 
 
 compounds by the addition of two oxygen atoms instead of four 
 bromine atoms, thus 
 
 Propiolic Acid. Saturated Compounds. 
 
 C n H 2 n-3' CO . OH + Br 4 = Cii H 2n -3 
 
 ( =0 
 C n H 2u _ 3 .CO.OH + 0, = C u H 2a _ 3 =0 
 
 ( -CO. OH 
 
 In this way stearolic acid, C 18 H 32 O 2 , forms stearoxylic acid, 
 C 18 H 32 O 4 ; and similarly with palmitolic and benolic acids. 
 The general character of the action is indicated by the equation : 
 
 R . CH-CH . S . CH=CH . T + 2 =R . CH-CH . S . CH-CH . T 
 
 Linolic Acid. The earlier researches on the acids derivable 
 from the chief glycerides contained in linseed and other drying 
 oils led to the conclusion that they were identical, and indicated 
 by the formula C 10 H 28 O 2 , and to this body the name linoleic 
 acid was applied ; but later experiments have shown conclusively 
 that a considerably higher molecular weight is possessed by the 
 acid obtained from linseed oil, and have rendered it not impro- 
 bable that different homologous acids exist (related as myristic, 
 palmitic, and stearic acids, for example), and that different 
 drying oils are not always identical as regards the leading acid 
 of this series present. Linolic acid was originally obtained by 
 Schiller by saponifying linseed oil with caustic soda, salting out, 
 dissolving in water, and precipitating with calcium chloride. 
 The precipitate was treated with ether, whereby calcium lino- 
 late was dissolved out, leaving other substances undissolved ; 
 by agitating the ethereal solution with hydrochloric acid, and 
 evaporating at a low temperature in an atmosphere of hydrogen, 
 crude linolic acid was obtained. This was purified by treat- 
 ment with alcoholic ammonia, precipitating as barium salt, 
 and regenerating the acid as before. The analysis of the acid 
 and its salts by Schiller, and subsequent investigators, led to 
 the formula C 1( . ( H 08 O 2 . 
 
 On the other hand, the Koettstorfer values (Chap, viu.) for lin- 
 seed oil and other drying oils obtained by most of the later experi- 
 menters lead to the conclusion that the mean molecular weight of 
 the fatty acids contained therein, is sensibly higher than 252, 
 the value corresponding with C 16 H 28 O 2 ; the saponification 
 equivalents for linseed, poppy, and hemp oils thus deduced 
 mostly lie between 285 and 300, giving an average of 293 or 
 thereabouts for the glycerides, and consequently of about 280 
 for the fatty acids thence derivable (C 1S H 32 O 2 = 280). Further, 
 various later analyses of linolates and other derivatives corro- 
 
 3 
 
34 OILS, FATS, WAXES, ETC. 
 
 borate this formula; whilst Peters* obtained stearic acid (of 
 melting point 69) by acting on linolic acid with strong hydriodic 
 acid and phosphorus, so as to hydrogenise it. 
 
 Still higher molecular weights result from the observations of 
 some chemists. Thus A. H. Allen f found that whilst the linolic 
 acids isolated from several different samples of linseed oil pos- 
 sessed mean equivalent weights varying between 282 and 295, 
 another specimen, prepared with great care in an atmosphere of 
 coal-gas, gave 307 -2 (C 2p H 36 2 = 308). Norton and Eichardson % 
 found that linolic acid from linseed oil, when distilled at 
 about 290 under a pressure of 89 mm., gave a colourless 
 distillate, constituting about three-quarters of the whole ; this 
 was capable of being redistilled unchanged. It consisted of 
 
 15 
 an acid of specific gravity -9108 at - giving numbers on 
 
 analysis corresponding with the formula C 20 H 36 O 2 ; the vapour 
 density was found to be 153, this formula representing 154. 
 Moreover, on heating with hydriodic acid it did not form stearic 
 acid, melting at 69, as in the case of Peter's product, but an 
 acid of considerably higher melting point 83 (arachic acid, 
 C 20 H 40 O 2 , melts at 75). 
 
 Reformatsky on repeating the experiments of Schuler, obtained 
 from linseed oil freshly expressed in the laboratory a crude 
 linolic acid that did not distil unchanged at 292 under 100 mm. 
 pressure. It contained a considerable amount of oleic acid, 
 yielding dioxystearic acid on oxidation with permanganate ; by 
 heating with alcohol and gaseous hydrochloric acid, ethyl linolate 
 was ultimately obtained, distilling at 270-275 under 180 mm. 
 pressure ; from this by saponification linolic acid was regener- 
 ated in a state of comparative purity ; e.g., giving the iodine 
 number 172-65 to 180-3, that calculated being 181-4. When 
 dissolved in glacial acetic acid the product thus prepared formed 
 two compounds on addition of bromine viz., a tetrabromide 
 (addition product), C 18 H 32 Br 4 , as a viscid oil ; and a crystallis- 
 able hexabrominated substance, regarded by him as a bromosub- 
 stitution derivative of the tetrabromide, C 18 H 30 O 2 Br 6 , melting at 
 177-178 and solidifying at 175. Oxidation with alkaline per- 
 manganate yielded tetroxystearic (sativic) acid and a little azelaic 
 acid. 
 
 Whilst it appears exceedingly probable from the preceding re- 
 sults that more than one homologous acid of the series C n H 2n _ 4 O^ 
 exists in ordinary drying oils, it is more than doubtful whether 
 any single substance in a state of purity was examined by 
 
 * Monatsh. f. Chemie, 1886, 7, p. 552. 
 t Commercial Organic Analysis, vol. ii., 1886, p. 117. 
 J Berichte (L Deut. Chem. Ges., 1887, xx., p. 2735. 
 
 Journ. Soc. Chem. Industry, 1890, p. 744 : from /. prakt. Chem., 1890, 
 41, p. 529. 
 
FATTY ACIDS. 35 
 
 any of the various observers, inasmuch as purification by 
 recrystallisatioii of a well marked crystalline derivative was 
 not found readily practicable. On the other hand, Hazura and 
 Griissner obtained from hemp seed oil* a mixture of fatty 
 acids which on solution in acetic acid and treatment with 
 bromine gave more than one brominated product of crystal- 
 lisable character, as well as iioncrystalline ones. One of the 
 crystallisable products was found to melt at 177-178, and 
 to have the composition 18 H 30 O 2 Br 6 ; another melted at 
 114-115, and had the composition C 18 H 32 O 2 Br 4 ; from this latter 
 by the action of zinc and alcoholic hydrochloric acid the bromine 
 was removed, producing linolic acid, C 18 H.> 9 O. 7 , free from ad- 
 mixture with other acids. It was found impracticable to bromi- 
 nate the bromine compound, C 18 H 3 . 2 O 2 Br 4 , so as to obtain from it 
 any substitution derivative, C 3 8 H 30 O 2 Br (3 ; whence it appears that 
 the hexabrominated body, melting at 177-178, was not formed 
 by the further substitutive action of bromine on the tetrabromi- 
 nated addition product (as supposed by Reformatsky), but must 
 have been produced by the direct combination of Br 6 with an 
 acid, C 18 H< ]0 O , contained along with linolic acid, &c., in the 
 original mixture ; this acid, linolenic acid, is in fact easily repro- 
 duced from the hexabromicle by treatment with zinc and alco- 
 holic hydrochloric acid so as to remove the bromine (p. 27) ; 
 conversely, it is again converted into the original hexabromide 
 by direct combination with Br 6 . 
 
 The linolic acid thus obtained from the tetrabromide of fusing 
 point 114-115, C 18 H 32 O 2 Br 4 , reproduced that substance by 
 combination with bromine ; and similarly combined with I 4 , 
 but did not form a hexabrominated derivative ; on oxida- 
 tion with alkaline permanganate it formed a tetroxystearic 
 
 acid, sativic acid, 18 H 3G G == C ir H' 31 I ,Q ^jj , together with 
 
 a little azelaic acid and other secondary products, but no linusic 
 acid (p. 37). Sativic acid fuses at 170 ;f on heating with 
 hydriodic acid and phosphorus, it forms an iodised acid, reduced 
 to stearic acid by means of zinc and hydrochloric acid ; it dis- 
 solves in 1000 parts of boiling water, and is readily soluble in 
 alcohol, but is insoluble in cold water and in ether; by acety- 
 
 lation it forms a tetracetyl derivative, C 17 H 31 < ,Q j^j| ' 4 ; 
 
 hence it obviously possesses the constitution of a quadruply 
 hydroxylated stearic acid. On further oxidation it does not form 
 linusic acid, but produces azelaic acid, C*-H 14 (CO . OH) 2 . 
 
 Isomerides of Linolic Acid. Stea/rolic acid, obtained by 
 combination of oleic acid with Br 2 , and removing the elements of 
 
 * Journal Soc. Clie.m. Industry, 1888, p. 506 : from MonatsJi. d. Chemie> 
 ix..p. 180. 
 
 t According to earlier observations, at 160-162. 
 
36 OILS, FATS, WAXES, ETC. 
 
 2HBr from the product, fuses at 48. By oxidation with alka- 
 line permanganate, this forms stearoxylic acid, C 18 H 82 O 4> melting 
 at 84-86, together with some suberic acid, C 6 H" 12 (CO.OH) 2 , 
 produced by the further oxidation of the stearoxylic acid first 
 formed (Hazura). Nitric acid also directly oxidises it to stear- 
 oxylic acid, with formation also of azelaic acid, C 7 H 14 (CO.OH) 2 
 (Overbeck), and of pelargonic (ennoic) acid (Limpach). 
 
 Tariric Acid. A. Arnaud has recently described* an acid 
 isomeric with linolic acid contained as triglyceride in the 
 seeds of " tariri," a shrub common in Guatemala ; it melts at 
 50 '5 C., and unites with bromine, forming a tetrabromide, 
 C 18 H 32 Br 4 O 2 , melting at 125. 
 
 Ricilinolic Acid. This name may be conveniently applied to 
 the acid obtained by Krafft,f by heating ricinoleic acid under 
 diminished pressure (15 mm.), when an acid distilled, liquid at 
 ordinary temperature, but solidifying on chilling ; this boiled at 
 230 at 15 mm. ; and gave numbers indicating that it was an 
 isomeride of linolic acid,! produced by the dehydration of 
 ricinoleic acid, which might be expected a priori to take 
 place, thus 
 
 Ricinoleic Acid. Dehydrated Derivative. 
 
 C 1' H ^ H2 + C 17 H S i.CO.OH 
 
 LINOLENIC FAMILY OF FATTY ACIDS. 
 
 The existence in drying oils of two isomeric acids of formula 
 C n H. 2n _ 5 .CO.OH (where n= 17) in the form of glycerides has been 
 rendered extremely probable, if not conclusively substantiated, 
 by Hazura and various collaborateurs. When the fatty acids 
 isolated from such oils e.g., hempseed or linseed oil are dis- 
 solved in acetic acid, at least three different brominated 
 compounds are obtainable by the addition of bromine viz., 
 crystallisable linolic acid tetrabromide, C 18 H 32 O 2 Br 4 , melting 
 at 114-115, and the crystallisable hexabromide, C 18 H 30 OoBr 6 , 
 melting at 177-178 above described (p. 35), together with a non- 
 crystallisable liquid bromide, apparently containing an isomeric 
 hexabromide, 18 H 80 O 2 Br 6 . As already stated, the crystallisable 
 hexabromide loses Br 6 by the action of zinc and alcoholic hydro- 
 chloric acid, forming linolenic acid, C 18 H 30 O 9 , from which the 
 same hexabromide can be reproduced by bromination ; by 
 oxidation with alkaline permanganate no sativic acid is pro- 
 
 * Comptes rendus, 114, p. 79. 
 
 t Eerichte d. Deut. Chcm. Ges., 1888, p. 2730. 
 
 + By heating ricinoleic acid in vacno, Norton and Richardson obtained an 
 acid closely resembling linolic acid, regarded by them as C 2 oH 3C 02 (Bcrichte 
 d. Deut. Chem. Ges., 1887, xx. p. 2735). 
 
FATTY ACIDS. 37 
 
 duced, but, instead, linusic acid, a hexoxystearic acid, 
 C 17 H 29 | (^Q 1 ^. This last melts at 203-205, and furnishes a 
 
 hexacetyl derivative, C 17 H 29 j '^Q ^j| ' 6 . Hence the pre- exist- 
 
 ence of linolenic acid in the original mixture of acids, as 
 the source of the crystallisable hexabromide, would seem to be 
 pretty clearly demonstrated. 
 
 The existence of an isomeric modification of linolenic acid, 
 isolinolenic acid, is inferred from the fact of a noncrystalline hexa- 
 bromide being apparently produced by the addition of bromine 
 to the original mixed acids, together with the circumstance 
 that on oxidising the mixture by alkaline permanganate there 
 are formed (in various relative proportions, according to the 
 kind of drying oil operated on) not only dioxystearic acid (due 
 to oleic acid contained), sativic acid (tetroxystearic acid, due 
 to linolic acid, C 18 H 32 O 9 ), and linusic acid (due to linolenic acid), 
 but also another hexahydroxylated stearic acid, isolinusic acid, 
 isomeric with linusic acid; this melts at 173-175, and furnishes 
 
 a hexacetyl derivative, C 17 H., 9 < ^pA jL,4 , resembling that 
 obtained from linusic acid, but less soluble in ether. 
 
 OXYACETIC (GLYCOLLIC) FAMILY OF FATTY 
 ACIDS. 
 
 The members of this family (general formula, C m H 2in < QQ OH/ 
 
 hitherto recognised as normal constituents of fats, oils, waxes, 
 c., are but few in number. Carnauba wax has been found by 
 Stiircke * to contain a small quantity of a substance simultane- 
 ously possessing the properties of an alcohol and an acid, indi- 
 
 f OTT OTT 
 cated by the formula C 19 H 38 ] QQ 2 j) JT ; when this is heated 
 
 with soda lime, it forms an acid of the oxalic family with evolu- 
 tion of hydrogen. 
 
 CHo.OH , ov ^TT n TT fCO.ONa . O TT TT n 
 
 - ^ 
 
 The essential oil of Angelica Arcliangelica contains (probably 
 as some form of compound ether) an acid which appears to be 
 
 ( OTT 
 
 oxymyristic acid,\ C 13 H 26 \ ^ OH , fusing at 51, and yielding 
 
 ( O f TT O 
 
 a benzoyl oxymyristic acid C 13 H 26 < ^A 5^j| , fusing at near 
 
 * Annahn der Chemie., 223, p. 283; also Journal Soc. Chem. Industry, 
 1884, p. 448. 
 t R. Muller, JBerichte Deut. Chem. Ges., 1881, vol. xiv., p. 2476. 
 
38 OILS, FATS, WAXES, ETC. 
 
 68. An oxymyristic acid apparently identical with this is 
 obtainable from myristic acid by brominating and treating the 
 resulting monobromomyristic acid with caustic soda. 
 
 By similar processes palmitic acid yields oxypalmitic acid and 
 stearic acid, oxystearic acid. Of this latter body, moreover, more 
 than one isomeric modification is known ; thus M. C. & A. Say- 
 tzeff found * that a-oxy stearic acid is obtained when isoleic acid 
 (m.p. 45) is combined with hydriodic acid so as to form an 
 iodostearic acid, and the product treated with silver hydroxide ; 
 while fi-oxystearic acid is similarly obtained from ordinary oleic 
 acid ; the reaction in each case being expressed by the equations 
 
 Oleic Acid. Iodostearic Acid. 
 
 Ci 8 H 34 2 + HI C I8 H 35 IOo 
 
 Iodostearic Acid. Oxysteavic Acid. 
 
 C 18 H 35 I0 2 + AgOH = Agl + C 18 H 3a (OH)0 2 
 
 a-oxystearic acid melts at 80-82 and distils unchanged ; 
 Avhilst /3-oxystearic acid breaks up on heating into water and 
 ordinary oleic acid 
 
 Oxystearic Acid. Oleic Acid. 
 
 C 1S H 35 (OH)0 2 = H 2 O + C J8 H 34 2 
 
 The same two acids are also obtainable by treating isoleic acid 
 with sulphuric acid, when combination takes place as the forma- 
 tion of two isomeric oxystearosulphuric acids, which by the 
 hydrolytic action of water are decomposed into sulphuric acid 
 and oxystearic acids, thus 
 
 Sulphuric Oxystearo- 
 
 Isoleic Acid. Acid. sulphuric Acid. 
 
 C 17 H S3 .CO.OH + H 2 S0 4 = GirH 
 
 Oxystearo- Oxystearic Sulphuric 
 
 sulphuric Acid. Water. Acid. Acid. 
 
 Ci7H 3 4 k 3 + H 2 = Ci 7 H 34 + H 2 S0 4 
 
 the two reactions jointly are consequently tantamount to the 
 addition of water 611 to isoleic acid 
 
 Isoleic Acid. Oxystearic Acid. 
 
 r TI PIT PIT rr ryprj-TT f\\ = Ci 5 H 31 -CH 2 ~CH.OH -CO. OH 
 C 15 M 31 -CH lioUj _ Cl5 H 31 -CH.OH-CH 2 -CO.OH 
 
 The a or the (3 acid thus results according as the hydroxyl group 
 
 becomes added to the penultimate or antepenultimate carbon. 
 
 Geitel finds t that when ordinary oleic acid is thus treated 
 
 * Jahresbericht, 1888, p. 1916 : from Journal pr. Chemie, [2] 37, p. 269. 
 t Journal Soc. C/iem. Industry, 1888, p. 218 ; from Journal f. prakt. 
 Chemie, [2] 37, p. 53. 
 
FATTY ACIDS. 39 
 
 with sulphuric acid, besides the a-oxystearic acids above described 
 a y-oxystearic acid, C 14 H 2g - . CH . OH - CH 2 - CH 2 - CO . OH, 
 is produced, which readily forms an " inner " anhydride, stearo- 
 lactone, C U H 29 - CH - CH 2 - CH 2 - CO. This anhydride is 
 produced whenever a salt of y-oxystearic acid is decomposed by 
 .a mineral acid ; if the acid solution be cautiously neutralised in 
 the cold by an alkali, the stearolactone remains unaltered, and 
 may be obtained by dissolving out with ether or benzoline, 
 and thus separated from any other accompanying fatty acids 
 set free by the mineral acid, but retained by the subsequent 
 addition of alkali. When boiled with alcoholic potash, however, 
 potassium /-oxystearate is produced. 
 
 Stearolactone. Potassium Oxystearate. 
 
 C 17 H 34 J~ I + HOK + C 17 H 34 |** 
 
 Processes for detecting and estimating stearolactone in mix- 
 ture with free fatty acids, &c., are founded on these reactions. 
 Stearolactone is readily soluble in alcohol, ether, and light 
 petroleum spirit; it crystallises in needles melting at 51; it 
 is formed in somewhat large quantity when oleic acid is heated 
 with zinc chloride and the product treated with water (Benedikt), 
 probably by reactions analogous to those taking place under the 
 influence of sulphuric acid (vide Chap, vn.) 
 
 An anhydride isomeric with stearolactone is derived from 
 a-oxystearic acid by the action of hydrochloric acid thereon (C. 
 and A. Saytzeff) in accordance with the equation 
 
 OP TT f OH OTJ n r< TT f CO 1 /-i TT 
 
 2C 17 H 34 | CQ QH 2H 2 + C 17 H 34 | Q co | C 17 H 34 
 
 This substance is fluid at the ordinary temperature and does not 
 solidify 011 chilling ; it combines with neither bromine nor iodine 
 (Hiibl's reagent), but on heating with caustic potash becomes 
 wholly converted into potassium oxystearate ; on acidifying the 
 product a-oxystearic acid is set free, and not. an anhydride, as 
 in the case of stearolactone. 
 
 OXYACRYLIC (KICINOLEIC) FAMILY OF 
 FATTY ACIDS. 
 
 f 
 
 The acids of general formula C m H 2m _ 2 -! QQ QJJ obtained by 
 
 the sapoiiification of fixed oils, &c., are not very numerous, 
 
 { OH 
 
 ricinoleic acid, C ir H 32 \ ^ Q OH , being the only one as yet known 
 
40 OILS, FATS, WAXES, ETC. 
 
 with certainty ; castor oil, and to a lesser extent some other oils, 
 contain ricinolein, the glyceride of ricinoleic acid. To isolate 
 the acid, castor oil is saponified with concentrated caustic potash 
 solution, and the resulting soap decomposed by heating for a 
 short time with hydrochloric acid ; the separated acids are 
 washed with water several times, and then cooled to 0, or some- 
 what lower ; the mass solidifies and is subjected to pressure, 
 first gentle then stronger, so as to squeeze out liquid matters, 
 the temperature being gradually raised to 10- 12. If any con- 
 siderable quantity of unsaponified oil is mixed with the free fatty 
 acids, their solidification by chilling is greatly hindered, a result 
 also brought about by the presence of bye -products formed by the 
 action of the air on the free fatty acids ; wherefore the saponify- 
 ing and decomposing operations, <kc., should be conducted as 
 rapidly as possible. Thus purified ricinoleic acid fuses at 
 16-17, the phenomenon of superfusion being strongly shown 
 by the liquid acid, which usually does not solidify again until 
 considerably chilled. 
 
 When castor oil is heated, the ricinoleic acid present therein 
 as glyceride breaks up into oenanthol and hendecenoic acid, 
 thus 
 
 iiicinoleic Acid. (Enanthol. Hendecenoic Acid. 
 
 <- 1 i 8 H 3 40 3 = C 7 H ]4 + C n H 20 2 
 
 Free ricinoleic acid, however, when heated does not split up in 
 this way at all, neither does it distil unchanged even under 
 greatly diminished pressure below 15 rnm. An acid distillate 
 passes over at about 250, which on rectification furnishes aiiacid 
 boiling at about 230 at 15 mm. ; and giving numbers correspond- 
 ing with the formula C ]8 H 32 O 2 (p. 36), whence it would seem that 
 water is thus split off from ricinoleic acid yielding a linolic acid 
 isomeride. Hydriodic acid and phosphorus convert ricinoleic acid 
 into stearic acid ; heating with caustic potash forms a secondary 
 decylic alcohol, C 10 H 21 (OH), and sebacic acid, C 8 H 16 (CO.OH) 2 , 
 from which reactions the structure would seem probable 
 CH 3 - (OH 2 ) 5 - CH . OH - CH = OH - (CH 2 ) S - CO . OH. Alka- 
 line permanganate oxidises ricinoleic acid to trioxystearic acid 
 (Dieff and Reformatsky). 
 
 By the action of nitrous acid ricinoleic acid is converted into 
 ricinelaidic acid melting at 52-53 ; on heating under diminished 
 pressure, this is decomposed much more slowly than ricinoleic 
 acid. Oxidation by means of nitric acid readily converts it 
 into normal heptoic acid, whilst alkaline permanganate forms 
 trioxystearic acid. According to Hazura and Griissner, 
 two different trioxystearic acids are formed when ricin- 
 oleic acid is thus oxidised, respectively melting at 140-142 
 (trioxystearic acid), and at 110-111 (isotrioxy stearic acid); from 
 which they infer the presence in castor oil of two isomeric acids 
 
FATTY ACIDS. 41 
 
 (ricinoleic and isorlcinoleic acids respectively). Both of these 
 trioxy acids form triacetyl derivatives, C lT H. j: , S QQ ()H 3 > 
 
 and both are reducible to ordinary stearic acid by means of 
 hydriodic acid ; the latter is present to the extent of about twice 
 as much as the former. 
 
 Isomerid.es of Ricinoleic Acid. On heating barium ricin- 
 oleate Krafft obtained a residue from which an acid termed by him 
 ricinic acid was isolated,* apparently isomeric with ricinoleic 
 acid; this melted at 81, and distilled unchanged at 250-252 
 under 15 mm. pressure ; by oxidation it yielded normal heptok? 
 acid. 
 
 Rapic Acid. Reimer and Will have obtained from colza oil a 
 liquid acid, C 1S H 34 O 3 , differing considerably from ricinoleic acid r 
 especially in not forming a solid elaidic acid with nitrous acidf 
 and in not yielding sebacic acid on fusion with potash. This is 
 isolated by means of the zinc salt which is soluble in ether, 
 whereas zinc erucate is insoluble therein. ; by decomposing the 
 recrystallised salt (melting at 78) by tartaric acid, and well 
 Avashing with water, rapic acid is obtained as a fluid mass, not 
 solidifying even when considerably chilled. 
 
 Oxyoleic Acid. When the dibromide of oleicacid (dibromo- 
 stearic acid) is treated with silver hydroxide it forms oxyoleie 
 acid, apparently in consequence of the removal of the elements of 
 HBr, forming bromoleic acid, and the action thereon of silver 
 hydroxide, thus 
 
 Eromoleic Acid. Oxyoleic Acid. 
 
 C 17 H, 2 Br.CO.OH + AgOH = AgBr + C 17 H 
 
 The same product results by first converting the dibromide 
 into bromoleic acid by means of potash and then acting upon 
 this with silver hydroxide (Overbeck). Oxyoleic acid is a thick 
 liquid at ordinary temperatures but solidifies on chilling ; by 
 boiling with caustic potash it takes up water, forming a dioxy- 
 stearic acid, melting at 126. J 
 
 r TT /OH p /(OH) 2 
 
 L i7 M 32| co OH Ll7H33 lCO.OH 
 
 {OH 
 C 1 O OH ' * S 
 
 formed when the dibromide of hypogaeic acid is treated with 
 silver hydroxide (Schroder) ; as with oleic dibromide, the action 
 probably takes place in two stages, the elements of HBr being 
 
 * Berichte d. Deut. Chem. Ges., 1888, vol. xxi., p. 2730. 
 
 t Berkhte d. Deul. Chem. Ges., 1887, vol. xx., p. 2385. 
 
 l^ Later experiments by Saytzeff indicate that this acid is identical with 
 the dioxystearic acid melting at 136'5, obtained by him by oxidation of 
 oleic acid by alkaline permanganate (p. 30). 
 
42 OILS, FATS, WAXES, ETC. 
 
 first removed, forming bromohypogseic acid, C 1G H 20 Br0 2 , and this 
 being then converted into the oxyacid, thus 
 
 C l5 H 28 Br . CO . OH + AgOH = AgBr + C lfi H 28 {cO.OH 
 
 It melts at 34, and by boiling with caustic potash solution 
 takes up the elements of water forming dioxypalmitic acid, 
 
 usin at 115 ' 
 
 When oleic acid is heated to 200 and a stream of air blown 
 through (as in the preparation of " blown oils," it absorbs 
 oxygen and becomes largely converted into an oxyoleic acid 
 (Benedikt and Ulzer). The relationships of the oxidised oleins 
 and similar substances contained in blown oils to ricinoleic 
 glyceride (castor oil) have not been fully studied, but appa- 
 rently there is a considerable degree of similarity between 
 them. The same remark applies to the oxidised acids formed 
 when oils and fats are kept for long periods of time, so as to 
 .absorb oxygen largely from the air spontaneously. On the 
 other hand, when drying oils are exposed to the air in thin 
 films, so as to " dry " up to solid varnishes, they absorb oxygen ; 
 when the absorption attains its maximum, the increment in 
 weight is tolerably close to that corresponding with the weight 
 of iodine capable of being taken up by the original oil, 
 whilst the capacity for absorbing iodine decreases pari passu 
 with the oxidation. It would, therefore, seem that the tendency 
 of atmospheric oxidation of drying oils is to produce less " un- 
 saturated " oxidation products than the original substances ; 
 whence by analogy in the case of oleic glyceride, it would 
 seem probable that saturated acids are formed thus, rather 
 than uiisaturated acids like oxyoleic acid. A product has been 
 recently introduced into the market under the name of " oxy- 
 oleate," for use as a " Turkey red oil," obtained by the action 
 of sulphuric acid on certain oils, and decomposition of the 
 compound sulphuric acid formed by heat (vide Chap, vn.) The 
 precise chemical nature of this substance does not seem to 
 have been closely investigated as yet; presumably it chiefly 
 consists of an oxystearic, rather than an oxyoleic acid, since 
 by hydrolysis the former and not the latter results from the 
 sulphuric acid compound of oleic acid (supra, p. 38). 
 
 AnUydrodioxystearic Acid. When dioxystearic acid (melting 
 point 136-5) is distilled under diminished pressure (100 to 
 180 mm.) it breaks up into water, and a monobasic acid, isomeric 
 with ricinoleic acid, melting at 77-79, and solidifying at 
 66-69.* From its mode of formation this product is obviously 
 
 f -= O 
 indicated by the formula, C^Hgg ! _ /-JQ QJT > being a saturated 
 
 -compound, not containing alcoholiform hydroxyl like ricinoleic acid. 
 * A. Saytzeff, /. prakt. Chem. [2], vol. xxxiii., p. 300. 
 
FATTY ACIDS. 
 
 43 
 
 It is not improbable that the rapic acid above mentioned 
 has an analogous constitution, since the low acetyl number pos- 
 sessed by colza oil renders it unlikely that any large quantity 
 of a glyceride of a hydroxylated acid is present therein (Chap, vin.) 
 
 POLYHYDEOXYLATED STEAKIO ACIDS. 
 
 A number of acids are known, related to stearic acid in that 
 they are derived therefrom by the replacement of two or more 
 hydrogen atoms by hydroxyl groups i.e., by a further continu- 
 ance of the action by means of which oxystearic acids may be 
 regarded as derived from stearic acid. These polyhydroxylated 
 derivatives are all expressed by the general formula, 
 
 C ir E 35 _ n (OH) n .CO.OH 
 
 When 11 = 1, some modification of oxystearic acid results ; when 
 n = 2, a dioxystearic acid (higher homologue of glyceric acid) ; 
 similarly, when n = 3, 4, or 6, trioxy-, tetroxy, and hexoxy- 
 stearic acids respectively result. 
 
 The following table gives the principal sources and melting 
 points of these acids, the usual mode of production being gentle 
 oxidation of the acid serving as source with alkaline perman- 
 ganate : * 
 
 Name. 
 
 Formula. 
 
 Source. 
 
 Melting 
 Point. 
 
 Solidifying 
 Point. 
 
 Dioxystearic acid, 
 
 Ci 7 H 33 (OH)2.CO.OH, 
 
 Oleic acid, 
 
 136 -5 
 
 119- 122 
 
 Isodioxy stearic acid, 
 
 Do., 
 
 Elaidic acid, 
 
 99- 100 
 
 85-86 
 
 Do., 
 
 Do., 
 
 Isoleic acid, 
 
 77-78 
 
 64-66 
 
 Trioxystearic acid, 
 
 C 17 H 32 (OH) 3 .CO.OH, 
 
 Castor oil, 
 
 140- 142 
 
 ... 
 
 Isotrioxystearic \ 
 acid, J 
 
 Do., 
 
 Do., 
 
 110-111 
 
 ... 
 
 /3-isotrioxysteario 1 
 acid, J 
 
 Do., { 
 
 Eicinelaidic 
 acid, 
 
 114- 115 
 
 ... 
 
 Sativic acid ) 
 
 
 
 
 
 (Tetroxystearic > 
 
 C l7 H 3l (OH) 4 .CO.OH, 
 
 Linolic acid, 
 
 173 
 
 ... 
 
 acid), ) 
 
 
 
 
 
 Linusic acid j 
 
 
 
 
 
 (Hexoxystearic > 
 
 C 17 H 2 o(OH) 4 .CO.OH, 
 
 Linolenic acid, 
 
 203-205 
 
 ... 
 
 acid), . . ) 
 
 
 
 
 
 
 
 Hemp seed 
 
 
 
 Isolinusic acid i 
 
 
 oil, &c., J 
 
 
 
 (Isohexoxy- 
 stearic acid), ) 
 
 Do., 
 
 (supposed 
 isolinolenic \ 
 acid), 
 
 173-17C 
 
 ... 
 
 
 i 
 
 
 
 * A dioxystearic acid (melting point 136) is also obtainable in small 
 quantity by the action of silver hydroxide on the dibromide of oleic acid 
 (p. 30); also by the hydration of oxyoleic acid (p. 41). Oxyhypog;eic acid 
 
44 OILS, FATS, WAXES, ETC. 
 
 A remarkable rule is uniformly followed in all cases where 
 unsaturated fatty acids are thus oxidised viz., that a number 
 of hydroxyl groups is always taken up sufficient to form a satu- 
 rated polyoxy acid.* Thus in the case of the oxystearic acids, 
 unsaturated acids of form C 17 H 33 .CO:OH (oleic, isoleic, and 
 elaidic acids), take up two hydroxyl groups forming three dif- 
 
 ferent dioxystearic acids, C 17 Ho 3 < /s/-^ OTT '> similarly ricinoleic 
 
 ( OTT 
 
 and riciiielaidic acids of form C 17 H. J2 < ^^ ~TT take up 2 hy- 
 
 droxyl groups, producing two trioxystearic acids, C 17 H 32 < LQ Q\T. 
 
 In the same w r ay hendecenoic, hypogseic, and erucic acids take up 
 2 hydroxyl groups giving rise to dioxyhendecoic, dioxypalmitic, 
 and dioxybenic acids respectively. On the other hand, linolic 
 acid, C- l7 H 31 . CO . OH, takes up 4 hydroxyl groups, producing 
 
 sativic (tetroxystearic) acid, C 17 H. U < X/-\ ATT ', whilst linolenic 
 acid, C l7 H 09 . CO . OH, takes up 6 groups, producing liimsic 
 (hexoxystearic) acid, C 17 IL < 
 
 The above rule appears to be only a particular case of a con- 
 siderably wider principle applying also to hydrocarbons and 
 alcohols, etc., of unsaturated character, which may be put in the 
 form of the following theorem : - 
 
 With substances containing the group CH = CH (or cer- 
 tain groups thence derived, - OR = CH, - and CR = CS , 
 where R and S are monad alkyl radicles), the effect of oxidising 
 agents of not too energetic a character is to cause the addition of tico 
 hydroxyl radicles so as to form the group - CH. OH - CH. OH - 
 (or the derived group - CR.OH - CS.OH - ), this action 
 occurring twice over if two groups CH = CH are present, 
 thrice over if three groups are present, and so on. 
 
 Thus Wagner has found * that olefmes are readily transformed 
 into glycols by means of potassium permanganate in virtue of 
 this reaction; alcohols of unsaturated character (allylic series) 
 similarly become glycerols ; hydrocarbons containing the group 
 CH = CH - twice (e.g., diallyl) become erythrols, and so on. 
 Glycerol itself is thus obtainable from allylic alcohol. 
 
 (from dibromide of hypogseic acid) behaves similarly, forming a dioxy- 
 palmitic acid, melting point 115. A dioxypalmitic acid was obtained by 
 Groger (inter alia) by the direct oxidation of palmitic acid with alkaline 
 permanganate. Two dioxybenic odds are known, respectively derived 
 from the dibromides of erucic and brassic acids (p. 29), and melting at 
 132- 133 and 9S-99. 
 
 * Hazura & Griissner, Journal Soc. Chem. Industry, 1888, p. 506; from 
 Monatsh. Chem., vol. ix., p. 180. 
 
 t Berichte. d. Dent. Chem. Ges., 1888, 21, pp. 1230 and 3343. 
 
FATTY ACIDS. 45 
 
 111 all probability the first action taking place is the direct com- 
 bination of oxygen in the same way as the combination of bro- 
 mine or iodine, thereby forming a substance containing the group 
 CH CE CR X 
 
 O, or the derived groups | j>O or I/O; 
 
 CH CH/ C8 
 
 this product then assimilating water whilst nascent. 
 
 Tims, for example, oleic acid, C 17 H.,., . CO . OH, may be supposed 
 
 to combine with oxygen, forming C 17 H 33 % ~ ~Q QTT ; by tak- 
 ing up water this immediately produces dioxystearic acid, 
 
 (OH 
 C r H 33 lOH ; whilst linolic acid, C.-H.^ . CO . OH, simi- 
 
 (CO.OH 
 
 i =0 
 
 larly first forms C r H, r =O , which by taking up 2H O 
 
 ( -CO. OH 
 
 OH 
 OH 
 
 forms tetroxystearic acid (sativic acid), C l5 .H gl ^ OH 
 
 OH 
 ^CO.OH 
 
 Tn the case of the stearolic acid and its homologues obtained 
 from acrylic acids by the bromine reaction (addition of Br. 7 and 
 removal of 2HBr, p. 31), the effect of oxidation stops short at 
 the first stage, 2 atoms of oxygen being added on forming a satu- 
 rated compound which does not take up water. Thus stearolic 
 
 ( = 
 acid, C r H. n . CO . OH, forms stearoxylic acid, ^-H^ - = O 
 
 ( - CO . OH 
 
 melting at 84-86, by the direct action of nitric acid (Overbeck),^ 
 or by means of alkaline permanganate (Hazura & Griissner). 
 Similarly palmitolic acid (from hvpogseic dibromide), gives the 
 
 * I = 
 
 analogous pal mito.icyl ic acid, C ir H.>-< =O , melting at 67 
 
 " ( - CO . OH 
 
 (Schroeder) ; and benolic acid (from erucic dibromide) gives ben- 
 
 f = 
 oxylic acidj melting at 90-91, C 91 H 80 ^=O (Hauss- 
 
 (-CO. OH 
 
 knecht). 
 
 ; - Overbeck (Annakn. Chem. P/iarm., 1866, 140, p.39) found that the stear- 
 oxylic acid thus prepared would not combine with bromine, and concluded 
 that the 4 affinity units which in stearolic acid are capable of combining 
 with Br 4 , are saturated by oxygen when stearolic acid is converted into 
 stearoxylic acid. 
 
 t Termed " dioxybenolic acid" by its discoverer. 
 
46 OILS, FATS, WAXES, ETC. 
 
 By the action of heat (distillation in vacuo) dioxystearic acid 
 (melting at 136), loses water forming an anhydro derivative still 
 possessing the characters of a monobasic acid (Saytzeff); obviously 
 thus 
 
 (OH ( = O 
 
 C 17 H S8 OH = H 2 + C 17 HoJ 
 
 ( CO . OH ( - CO . OH 
 
 the reaction being the converse of the second stage in the 
 hydroxylation of unsaturated acids as above. 
 
GENERAL PHYSICAL CHARACTERS. 47 
 
 2. Physical Properties of Oils, Fats, 
 Waxes, &c. 
 
 CHAPTER IV. 
 
 GENERAL PHYSICAL CHARACTERS. 
 PHYSICAL TEXTURE AND CONSISTENCY. 
 
 THE physical consistency of a fixed oil butter, fat, or wax 
 depends entirely upon the temperature ; when this is sufficiently 
 raised all are fluid oils ; but at lower temperatures, according to- 
 the nature of the substance, more or less complete solidification 
 is brought about. In many cases, natural fixed oils, &c., are 
 mixtures of different glycerides, &c., the melting points of which 
 are different ; accordingly, at temperatures somewhat below the 
 melting point of the least fusible constituent, this more or less 
 completely solidifies, whilst the other constituents remain liquid, 
 thus giving rise to pastiness or buttery texture. Substances of 
 practically uniform composition (i.e., consisting essentially of only 
 one kind of compound) generally exhibit a fairly sharply defined 
 melting point when the temperature is sufficiently raised; but this 
 is not the case with mixtures ; accordingly, considerably different 
 temperatures will be registered as the fusing points of such sub- 
 stances if different methods be employed, depending, for instance, 
 in one case, upon the production of a considerable degree of 
 softness only ; in another, upon the complete liquefaction of all 
 the constituents ; and so 011 (vide p. 61, 63). 
 
 Even the most fluid oils possess to a greater or lesser extent 
 the property of viscosity, or resistance to flow, due to the greater 
 or lesser degree of cohesion between the constituent particles of 
 the liquid. When the smooth surfaces of two solids are smeared 
 or wetted with a viscous fluid and applied to one another, a, 
 varying degree of force will be requisite, according to circum- 
 stances, in order to enable one surface to glide over the other. 
 The amount of force requisite in any given case largely depends on 
 the viscosity of the fluid employed; to diminish this force is the 
 
4-S OILS, FATS, WAXES, ETC. 
 
 main object of lubrication in the case of machinery, and in conse- 
 quence the determination of the relative lubricating powers of 
 different materials (lubricating oils, &c.) is an important point in 
 the valuation for such purposes of different fixed oils, mixtures 
 of these and mineral oils, and such like substances employed for 
 the purpose. It is found that the rate at which a given fluid 
 flows through an orifice of standard dimensions is in many cases 
 & fair measure of its lubricative powers ; whence the determina- 
 tion is frequently made of the rate of efflux of lubricating oils, 
 foc., as compared with that of a standard fluid (such as rape oil), 
 similarly examined in the same apparatus at the same tempera- 
 ture, the value deduced being generally (but by no means cor- 
 rectly) spoken of as the relative viscosity of the fluid examined 
 (vide Chap, v.) 
 
 Cohesion Figures. When a drop of oil is allowed to fall 
 gently on the surface of water in a basin or large plate, it often 
 
 Fig. 1. 
 
 behaves in a characteristic way, usually first spreading out into 
 ii thin film and then retracting again. It has been suggested 
 that the particular forms assumed by films of various kinds 
 (cohesion figures) are sufficiently well defined and characteristic 
 to be of service in the examination of oils with a view to 
 
GENERAL PHYSICAL CHARACTERS. 4$ 
 
 detecting adulteration ; but as yet little success has attended 
 experiments in this direction. Olive oil thus treated gives a fairly 
 characteristic result, which is more or less modified by various 
 admixtures, especially sesame oil. Fig. 1 (Schadler) represents 
 the different cohesion figures exhibited by colza oil (A, Brassica 
 rapa ; B, Brassica napus) ; poppy seed oil (C and D) ; sesame 
 oil (E) ; arachis oil (F) ; and olive oil (G-). 
 
 Taste and Odour. When in a state of absolute purity, 
 fixed oils have usually little or no odour or taste ; but as met 
 with in commerce, in most cases traces of sapid or odorous 
 matters accompany the oil, so as give a more or less characteristic 
 flavour or smell thereto. Essential oils of the oxidised class, on 
 the other hand, are frequently possessed of most powerful scent, 
 although the hydrocarbons therein contained, when completely 
 separated from all traces of oxidised matter (by heating with 
 sodium or other similar means), are generally odourless or practi- 
 cally so. As regards the edible oils and fats, a considerable 
 amount of their value depends on the delicacy and purity of the 
 flavour ; thus genuine olive oil is esteemed far more highly by 
 connoisseurs than refined cotton seed oil, groundnut oil, and 
 similar substances with which the ordinary commercial article is 
 often largely intermixed, although, from the nutritive point of 
 view, these latter are probably quite equal in value to the pure 
 product of the olive. Similarly, the commercial value of butter 
 is largely affected by its flavour and freedom from all trace of 
 rancidity or rankness ; and analogous remarks apply to lard. 
 The difficulty of removing all matters communicating unpleasant 
 odour or taste to many varieties of fatty or oily matter often 
 prevents these being used for dietetic purposes to any consider- 
 able extent, at any rate by civilised nations ; in the case of 
 some materials e.g., cod liver oil such removal is practically 
 impossible without more or less interfering with the special 
 characters and qualities of the substance. Palm oil has generally 
 a peculiar smell, recalling that of violets, and for certain purposes 
 the possession of this odour is valuable e.g., in the prepara- 
 tion of certain kinds of scented soaps. The development of 
 " rancidity " in fixed oils on keeping is in most cases due to 
 the presence in small quantity of mucilaginous or albuminous 
 matters which undergo chemical changes (oxidation, or decom- 
 position, &c.) in the course of time ; accordingly, the purification 
 and refining of crude oils, &c., for the purpose of removing these 
 ingredients is often a highly important operation. 
 
 Colour. Expressed vegetable fixed oils sometimes possess a 
 greenish shade, due to the presence of chlorophyll ; as a general 
 rule, coldpressed oils of all kinds, prepared from fresh substances, 
 are almost white ; whilst oils subsequently expressed by the 
 aid of heat, especially from materials that have been stored some 
 time, are generally darker in tint, the hue varying from a 
 
 4 
 
50 
 
 OILS, FATS, WAXES, ETC. 
 
 light straw yellow to a light or even dark brown. Palm butter 
 usually contains a dark orange red colouring matter, different 
 from chlorophyll ; similar substances appear to be present in 
 smaller quantity in many other oils, leading to the necessity for 
 bleaching them for certain purposes. The refining processes, 
 whereby mucilaginous extractive matters, &c., are removed, 
 usually serve to lighten the colour also. 
 
 The addition of coloured vegetable expressed oils (containing 
 chlorophyll, &c.) to animal oils, such as sperm oil, may sometimes 
 be detected by means of the absorption spectroscope * when such 
 adulteration has been practised. 
 
 The phenomenon of fluorescence does not appear to be. exhibited 
 by refined vegetable or animal oils free from substances possessed 
 of fluorescent properties (such as aesculin, occasionally found in 
 horse-chestnut oil); on the other hand, products of destructive 
 distillation (coaltar and rosin oils, tfec.) often exhibit this peculi- 
 arity, so that admixtures of such hydrocarbons with more expen- 
 sive vegetable and animal oils may sometimes be thus detected. 
 
 Action of Polarised Light. The majority of the oils and 
 fats in common use have so little action of a marked character 
 on polarised light that little, if any, definite information of prac- 
 tical value is, as a rule, obtainable by means of such light; on 
 the other hand, adulteration with strongly active hydrocarbons 
 (such as some kinds of rosin oils) may sometimes be detected by 
 means of the polariscope. 
 
 Bishop has obtained the following values for a length of 
 200 mm. of various oils in a Laurent polarimeter; the other 
 figures annexed are from Schadler : 
 
 
 
 
 
 
 
 
 Bishop. 
 
 Scbadler. 
 
 
 
 
 Degrees. 
 
 Degrees. 
 
 
 
 {Linseed oil, 
 
 - 0-3 
 
 - 0-2 
 
 
 
 Nut oil, . 
 
 - 0:3 
 
 
 
 La&vogyrate, 
 
 Apricot oil, 
 Arachis oil, 
 
 - 'o-4 
 
 - 0-2 
 
 -o-i 
 
 
 
 Sweet almond oil, 
 
 - 0-7 
 
 - 0-2 
 
 
 
 Colza oil, . 
 
 - 1-6 to - 2-1 
 
 - 0-3 
 
 
 Neutral, or 
 nearly so, 
 
 {Cotton seed oil, 
 Poppy seed oil, 
 Seal oil, . 
 
 
 
 
 
 + o-i 
 
 
 
 
 
 1' Olive oil, . 
 
 + 0-6 
 
 + 0'2 
 
 
 
 Cod liver oil, 
 
 
 + O'o to + 
 
 : 7 
 
 Dextrogyrate, 
 
 Cold pressed sesame oil, 
 
 + '3-1 
 
 I + 1-0 to + 
 
 1-1 
 
 
 Hot 
 
 -r 7 "2 
 
 \ 
 
 
 
 Castor oil, 
 
 
 + 9-8 
 
 
 * A special form of absorption spectrum colorimeter for this sort of 
 examination has been devised by T. L. Paterson ; vide Journ. ticc. Chem. 
 Industry, 1890, p. 36. 
 
GENERAL PHYSICAL CHARACTERS. 
 
 51 
 
 Peter finds most vegetable oils to be slightly laevogyrate, olive 
 oil being an exception, so that admixtures of other oils may some- 
 times be detected by the rotation being left handed instead of 
 right handed. Croton oil and castor oil, however, are compara- 
 tively powerfully dextrogyrate, giving values exceeding + 40. 
 
 Refractive Index. The differences in refractive power 
 exhibited by different oils are in most cases hardly sufficiently 
 marked to render this property of much value in discriminating 
 one from the other, or in detecting admixtures, excepting in the 
 case of a few oils and fats, such as olive oil and cow's butter; 
 thus Strohmer gives the following values for the I) line at 15, 
 and Abbe the annexed values at 20, water being taken as 
 1-3330: 
 
 . 
 
 Strohmer. 
 
 Abbe. 
 
 Olive oil, 
 
 1-4698 to 1-4703 
 
 1 -4690 
 
 
 
 1-4810 
 
 Sesame oil (new), 
 
 1 -4748 
 
 
 ,, nine years old, 
 
 1-4762 
 
 
 Walnut oil, .... 
 
 ... 
 
 1-491 
 
 Cotton seed oil, ... 
 
 1-4732 to 1-4752 
 
 \Crude, 1-4732 
 ) Refined, 1-4748 
 
 Rape and colza oil, 
 
 1-47-20 to 1-4757 
 
 1-472 to 1-475 
 
 Beechnut oil, .... 
 
 
 1 -5000 
 
 Cold drawn castor oil, 
 
 1 -4795 
 
 \ i -/too 
 
 Hot pressed ,, . 
 
 1-4803 
 
 
 Cold drawn linseed oil, 
 
 1-4835 
 
 4780 
 
 Poppy seed oil, .... 
 Cod liver oil, .... 
 
 1-4783 
 1-4800 to 1-4852 
 
 4670 
 4800 
 
 Whale oil 
 
 
 483 . 
 
 Sperm oil, . 
 
 
 470 
 
 From which it appears that olive oil has a sensibly lower re- 
 fractive index than the others, whilst drying oils and castor oil 
 exhibit the highest values. For the direct determination of the 
 refractive index of oils and other substances, Abbe and Pulfrich 
 have devised special " reiractometers." 
 
 Amagat and Jean * have also constructed an " oleorefracto- 
 meter," whereby the refractive power of a given oil is determined 
 by differential comparison with a sample of genuine oil taken as 
 standard', a positive reading denoting increased refractive index 
 and vice versd ; the following comparative differential values have 
 been obtained by de Bruijn and von Leent and by Jean in this 
 way, from which results they infer that the refractive powers of 
 
 * Comptex rendu*, 1889, 109, p. 616 ; see also Journ. Soc. Cliem. Industry, 
 1890, pp. 113 and 218. 
 
52 
 
 OILS, FATS, WAXES, ETC. 
 
 oils, when thus tested, are capable of giving more information as 
 to admixture than is usually supposed. The oil to be examined 
 should be previously shaken with alcohol to dissolve out free 
 fatty acids ; the standard of comparison was a sample of the 
 purest olive oil obtainable : 
 
 
 de Bruijn and v. 
 
 
 
 Leent. 
 
 
 
 Degrees. 
 
 Degrees. 
 
 Horse foot oil, 
 
 
 - 12 
 
 Sperm oil, . 
 Neat's foot oil, .... 
 
 
 - 12 
 3 
 
 Sheep's trotter oil, 
 
 
 
 
 Olive oil, ..... 
 
 to + 2 
 
 + 1 -5 to + 2 
 
 Almond oil, .... 
 
 + 7 
 
 + 6 
 
 Arachis oil, .... 
 
 + 3 to -- 4 
 
 + 4 to -f 5 
 
 Colza oil, ..... 
 
 + 15 to H- 18 
 
 + 16-5 to + 17'5 
 
 Sesame oil, ..... 
 
 + 45 
 
 + 17 
 
 Cotton seed oil, . 
 
 
 + 20 
 
 Maize oil, ..... 
 
 
 + 27 
 
 Poppy seed oil, .... 
 Whale oil, 
 
 ... 
 
 + 30 
 + 30-5 
 
 Hemp seed oil, 
 
 
 + 33 
 
 Castor oil, ..... 
 
 + 37 to + 46 
 
 + 40 
 
 Linseed oil, .... 
 
 + 49 to + 54 
 
 + 53 
 
 Cod liver oil, 
 
 
 + 42 
 
 Whale oil, 
 
 
 + 30-5 
 
 Holde has obtained the following average results with this 
 instrument,* the temperature of the testing-room being close to 
 20 throughout : 
 
 
 Limits of Index of Refraction. 
 
 Mean Index. 
 
 Refined rape oil, 
 Crude rape oil, 
 Olive oil, ..... 
 
 1-4722 to 1-4736 
 1-4735 ,, 1-4760 
 1-4670 ,. 1-4705 
 1-4776 ,, 1-4980 
 
 1-4735 
 1 -4744 
 1 '4698 
 1 -4923- 
 
 Resiu oil, .... 
 
 1-5274 1-5415 
 
 1 -5344 
 
 The presence of rape oil in olive oil can thus be detected when 
 any considerable amount of adulteration has been made. 
 
 In the case of butter, Jean claims that the oleorefractometer 
 is capable of rendering useful service in the laboratory. Even if 
 butter is not sufficiently constant in refractive power to enable a 
 decision to be always arrived at as to the genuineness or other- 
 
 Journ. Soc. Chem. Industry, 1891, p. 166. 
 
SOLUBILITY IN SOLVENTS. 53 
 
 wise of a given sample without further tests, still the oleo- 
 refractometer indications at least enable a rough classification of 
 a variety of samples to be made, viz., those undoubtedly spurious, 
 those doubtful, and those probably genuine. The normal butter 
 deviation is regarded by him as - 29 to 31, averaging 30 ; 
 if higher values (32 36) are observed, admixture with palm or 
 cokernut oil is probable; slightly lower ones (25-29) correspond 
 with doubtful qualities; margarine and oleomargarine give much 
 lower figures, 13- 17.* Genuine butters have been found that 
 give values materially below the normal deviation, but the cause 
 of this is considered by Jean to be that the cows have been fed 
 on oilcake, unaltered oil from which finds its way into the 
 secreted milk in quantity large enough to affect the refraction, 
 though too small to produce any marked effect either on the 
 saponification equivalent, or the Reichert-Meissl-Wollny figure 
 for volatile acids (Chap, vui.) 
 
 Various British analysts also regard the oleorefractometer as 
 useful in preliminary butter examination, but other chemists 
 consider its value in this respect to be overrated ; thus de Bruijn 
 and von Leent obtained very discordant results with Dutch 
 butters, whilst H. O. G. Ellinger found f that genuine Danish 
 butters gave deflections varying between 23 and 35, according 
 to the season of the year. 
 
 Electrical Conductivity. In general, but little information 
 is obtainable by examining the relative electrical conductivities of 
 different oils. Olive oil, however, has a much lower conducting 
 power than most other oils of ordinary occurrence, and hence, 
 attempts to utilise this property as a means of detecting adultera- 
 tion of olive oil have been made, notably by Palmieri, who has 
 constructed a special instrument, or diagometer, for the purpose ; 
 as yet, however, this method does not seem to have come into 
 practical use to any considerable extent. 
 
 SOLUBILITY OF OILS, FATS, &c., IN VARIOUS 
 SOLVENTS. 
 
 The immiscibility of " oil and water " is proverbial ; but some 
 few oils are known where the solubility in water, although far 
 from perfect, is not entirely inconsiderable ; thus the fusel oils of 
 fermentation, and certain oxidised volatile essential oils, and 
 products of distillation (e.g., phenol), dissolve in water to the 
 
 * Journ. Soc. Ghent. Industry, 1892, p. 945; from Monit. Sclent., 1892, 6, 
 p. 91. 
 
 \-The Analyst, 1891, p. 197; from Journ. f. prakt. Chemie,,[2] 44, p. 
 
54 OILS, FATS, WAXES, ETC. 
 
 extent of a few per cents, by weight at ordinary temperatures. 
 As a general rule, however, fixed oils and hydrocarbons are, for 
 practical purposes, entirely insoluble in pure water ; in some few 
 cases dilute alkaline solutions dissolve them somewhat more freely 
 than pure water; in others the presence of acids slightly promotes 
 solubility ; but, as a rule, when neutral salts are present to any 
 extent, their presence prevents the solution of the oil, &c. ; so 
 that on agitating an aqueous solution with solid common salt or 
 with sodium sulphate, as the mineral matter goes into solution, 
 the dissolved oil is more or less thrown out of solution. The 
 same phenomenon is observed with the potash and soda salts of 
 most of the fatty acids, so that when an aqueous solution of such 
 salts (soaps) are treated with neutral saline matters, the organic 
 salts are thrown out of solution ; this property is largely utilised 
 in the ordinary process of soap boiling. 
 
 Strong alcohol does not exert any great degree of solvent action 
 in the cold on most fixed oils, solid fats, or waxes ; whereas, 
 many essential oils, whether hydrocarbons or of oxidised nature, 
 are extremely freely soluble therein. Similarly, resins and free 
 fatty acids are, generally speaking, moderately soluble in alcohol, 
 especially when almost anhydrous and warm. Some few fixed 
 oils, too, are exceptional as regards solubility in alcohol, more 
 especially castor oil and croton oil, and to a lesser extent coker- 
 nut oil, cow's butter, and linseed oil. 
 
 Girard finds that absolute alcohol at 15 dissolves the following 
 proportions of various oils : 
 
 Ra P eoil '| 1-5 to 2-0 per cent. 
 
 Colza oil, J 
 
 Mustard seed oil, .... 2'7 ,, 
 
 Hazelnut oil, . . . . . 3 '3 ,, 
 
 Olive oil, 3-6 
 
 Almond oil, 3 '9 
 
 Sesame oil, ..... 4*1 ,, 
 
 Apricot kernel oil, . . . . 4 '3 ,, 
 
 Nut oil, 4-4 
 
 Beechnut oil, . . . . . 4*4 ,, 
 
 Poppy seed oil, . . . . 4 '7 ,, 
 
 Hemp seed oil 5 '3 
 
 Cotton seed oil, . . . 6*4 
 
 Aracliis oil, ..... 6'6 
 
 Linseed oil, . . . . . 7'0 ,, 
 
 Camelina oil, ..... 7'H 
 
 Schadler gives the following Table representing the quantities 
 of alcohol, of specific gravity '800, required to dissolve 1 part of 
 oil or fat : 
 
SOLUBILITY IN SOLVENTS. 
 
 55 
 
 
 Cold. 
 
 Boiling. 
 
 
 Parts. 
 
 Parts. 
 
 Almond oil, . . . 
 
 60 
 
 15 
 
 Cacao butter, . 
 
 
 4 
 
 Cotton seed oil, . . 
 
 75 
 
 ... 
 
 Croton oil, 
 
 36 
 
 ... 
 
 Camelina oil, . 
 
 68 
 
 t 
 
 Cod liver oil, . 
 
 45 
 
 "G 
 
 Hemp oil, 
 
 30 
 
 Soluble in all proportions. 
 
 Japan wax, 
 
 
 3 
 
 Linseed oil, . 
 
 40 
 
 5 
 
 Lard' (hog's), 
 
 
 27 
 
 Madia oil, . . 
 
 30 
 
 6 
 
 Nut oil (walnut), 
 
 100 
 
 60 alcohol to 100 of oil. 
 
 Nutzneg oil, . 
 
 
 4 
 
 Poppy seed, 
 
 25 
 
 6 
 
 Tallow (sheep), 
 
 
 45 
 
 Suet (ox tallow), 
 
 
 40 
 
 Whale oil (bottlenose), 
 
 ... 
 
 1 
 
 As a general rule, fixed oils are very freely soluble in carbon 
 disulphide, chloroform, carbon tetrachloride, ether, benzene, light 
 petroleum distillate (mostly consisting of pentane and hexane 
 with their homologues), and oil of turpentine; and on this 
 property are based various methods of extracting oleaginous 
 matters from natural and other sources. Castor oil, however, 
 is almost insoluble in light petroleum spirit whilst drying 
 oils, when oxidised to some considerable extent, generally be- 
 come either quite insoluble in these various solvents, or nearly 
 so, the decrease in solubility usually being the more marked the 
 greater the degree of oxidation. The action of nitrous acid on 
 an oil (conversion into elaidin, Chap, vn.) usually diminishes 
 the solubility of the oil thus affected. 
 
 Glacial acetic acid has been found by Yalenta to be a con- 
 venient solvent for certain oils, &c., as a means of separation 
 from one another. Thus, when equal volumes of acid and oil are 
 intermixed, the oil being previously warmed, complete solution, 
 even when cold, occurs with castor oil, rosin oil, and olive kernel 
 oil, whilst rape oil, mustard seed oil, and wild radish seed oil are 
 not completely dissolved even at the boiling point of the mixture. 
 Most other oils give a clear fluid whilst hot, which on cooling 
 becomes turbid, owing to the lesser solubility of the oil in the 
 acetic acid at lower temperatures. It has been proposed * to 
 make use of the temperature at which turbidity is thus brought 
 about as a distinguishing test for oils of various kinds ; but the 
 figures obtained by different authorities who have repeated 
 
 1 * Valenta, Dinyler's Poly tech. Journal, 252, p. 296 ; also, Journal of the 
 Chemical Society, *W, p. 1078. 
 
56. 
 
 OILS, FATS, WAXES, ETC. 
 
 Yalenta's experiments, exhibit so much discrepancy as to render 
 it very doubtful whether the results can be relied upon at all, as 
 affording indications of adulteration or otherwise. Thus, the 
 following values, amongst others, have been obtained by A. H. 
 Allen * and G. H. Hurst : f 
 
 Oil. 
 
 Valenta. 
 
 Allen. 
 
 Hurst. 
 
 Olive (green), 
 (yellow), . 
 
 85 
 111 
 
 c. 
 
 | 28-76 
 
 Almond, .... 
 
 110 
 
 ... 
 
 
 Arachis, .... 
 
 112 
 
 87 
 
 72-92 
 
 Apricot kernel, 
 
 114 
 
 
 
 Neat's foot, .... 
 
 ... 
 
 102 
 
 G5-85 
 
 Sesame, .... 
 
 107 
 
 87 
 
 ... 
 
 Melon seed, 
 
 108 
 
 ... 
 
 ... 
 
 Cotton seed, 
 
 110 
 
 90 
 
 53-63 
 
 Niger seed, .... 
 
 
 49 
 
 
 Linseed, .... 
 
 ... 
 
 57-74 
 
 36-41 
 
 Cod liver, .... 
 
 101 
 
 79 
 
 65 
 
 Menhaden, . ... 
 
 ... 
 
 64 
 
 
 Shark liver, 
 
 
 105 
 
 95 
 
 Porpoise, .... 
 
 ... 
 
 40 
 
 
 
 
 98 
 
 85 
 
 Bottlenose, .... 
 
 ... 
 
 102 
 
 74-84 
 
 Whale, .... 
 
 
 38-86 
 
 48-71 
 
 Palm, 
 
 23 
 
 83 
 
 Not turbid at 13 
 
 Laurelberry, 
 
 26-27 
 
 40 
 
 ... 
 
 Nutmeg butter, . 
 
 27 
 
 39 
 
 
 Cokernut, . 
 
 40 
 
 7'5 
 
 M turbid at 13 
 
 Palm kernel, 
 
 48 
 
 32 
 
 
 Bassia fat (Illipe), 
 
 64'5 
 
 
 ... 
 
 Cacao butter, 
 
 105 
 
 ... 
 
 
 Beef tallow, 
 
 95 
 
 
 
 Pressed tallow (M.P., 55 '8), 
 
 114 
 
 ... 
 
 
 Tallow oil (cold pressed), 
 
 
 ... 
 
 47 
 
 Hog's lard, .... 
 
 ... 
 
 96-5 
 
 ... 
 
 Lard oil, 
 
 ... 
 
 ... 
 
 69-76 
 
 Butter fat, .... 
 
 
 61 '5 
 
 
 Oleomargarine, 
 
 ... 
 
 . 96-5 
 
 
 The practical value of the test, as shown by the above numbers, 
 is obviously not very great ; it is still further diminished by the 
 circumstance that comparatively slight differences in the strength 
 of the glacial acetic acid considerably influence the temperature 
 of turbidity, as also does the presence or otherwise of free fatty 
 acids ; after an extended examination, Allen concludes that the 
 results are too variable and indefinite to be of service in 
 
 * Commercial Organic A naly&is, vol. ii. , p. 2C. 
 t Journ. Soc. Ckem. Industry, 1887, p. 22. 
 
FUSING AND SOLIDIFYING POINTS. 
 
 57 
 
 discriminating the quality of oils ; an opinion also arrived at by 
 G. H. Hurst, by Ell wood,* and by Thomson and Ballantyne,t 
 the latter of whom obtained the following numbers, inter alia, 
 with glacial acids of different strengths : 
 
 
 1 
 
 
 Percentage of 
 Free Acid 
 
 Temperature of Turbidity with Glacial 
 Acetic Acid of 
 
 Name of Oil. 
 
 present 
 
 
 
 (calculated as 
 
 
 
 
 
 Oleic Acid). 
 
 Sp. gr. 1054-2 
 
 Sp. gr. 1055-2. 
 
 Sp.gr. 1056-2. 
 
 
 
 C. 
 
 G. 
 
 C. 
 
 Olive (Syrian), 
 
 23-88 
 
 42 
 
 
 ... 
 
 ,, (Gioja), 
 
 9-42 
 
 65 
 
 80 
 
 91 
 
 Same sample freed from \ 
 free acid, . . . J 
 
 None. 
 
 87 
 
 ... 
 
 ... 
 
 Arachis oil (commercial), 
 
 6-20 
 
 76 
 
 96 
 
 112 
 
 ,, (French ) 
 refined), { 
 
 62 
 
 96 
 
 m i 
 
 Not completely 
 dissolved. 
 
 Eape oil, 
 
 4-54 
 2-43 
 
 105 \ 
 110 / 
 
 Hot completely 
 dissolved. 
 
 ,, 
 
 Linseed oil (Baltic), 
 
 3-74 
 
 42 
 
 59 
 
 71 
 
 (River Plate), 
 
 1-21 
 
 56 - 
 
 ... 
 
 
 ,, (East India), 
 
 79 
 
 57 
 
 
 
 
 
 
 
 In some few cases, however, the comparatively solubility in 
 glacial acetic acid may afford a useful indication e.g., in de- 
 tecting the presence of rape seed oil in linseed oil, and more 
 especially of hydrocarbons in animal and vegetable saponifiable 
 oils ; thus, mineral oils are but sparingly soluble in glacial acetic 
 acid, so that on agitating with that solvent a mixture of mineral 
 oil and other substances freely soluble in acetic acid, the latter 
 are dissolved, leaving the former undissolved ; in this way the 
 presence of rosin oil is easily detected in paraffin and petroleum 
 distillates. 
 
 FUSING AND SOLIDIFYING POINTS. 
 
 It most unfortunately happens that several different thermo- 
 metric scales are in use in different countries ; of these the 
 Celsius or Centigrade scale is by far the most convenient, and 
 is accordingly used almost exclusively for scientific purposes. 
 In England, however, the highly inconvenient Fahrenheit scale 
 is still largely in use for technical and general purposes ; whilst 
 in some parts of the Continent the Reaumur scale is similarly 
 employed. The following formula gives the means of translating 
 the temperature expressed on any one of these systems to the 
 
 * Pharmaceutical Journal, 3, xvii., p. 519. 
 
 t Journ. Soc. Chem. Industry, 1991, x., p. 233. 
 
58 OILS, FATS, WAXES, ETC. 
 
 corresponding value expressed on either of the others, F being 
 the value on the Fahrenheit scale, C that on the Centigrade scale, 
 and R that on the Reaumur scale : 
 
 F_-_32 _ C _ R 
 
 9 ~ 5 ~ 4* 
 
 This formula is based on the system of construction of the 
 three scales respectively ; the distance between the " ice melting 
 point " (sometimes termed the " freezing point ") and the " steam 
 point" (or "boiling point" under normal atmospheric pressure) 
 being divided into 180 degrees on the Fahrenheit scale,* 100 on 
 the Centigrade, and 80 on the Reaumur scale ; so that the rela- 
 tive values of the degree in each scale respectively are T -J- F : 
 TUIT 8"V > or v i T' The Reaumur and Centigrade scales, 
 however, begin with the ice melting point as 0, so that the 
 steam point is at 80 and 100 on the two scales respectively ; 
 w r hilst the Fahrenheit zero is 32 F. below the ice melting point ; f 
 whence that point is 32, and the steam point 32 + 180 = 212, 
 on the Fahrenheit scale. 
 
 From the above formula are derived the following equations, 
 whereby, when requisite, a Centigrade temperature may be trans- 
 lated into the corresponding Fahrenheit value, and so on : 
 
 C - (F - 32). 
 
 F = C + 32. 
 o 
 
 = (F - 32). 
 
 * This particular number is said to have been selected on account of some 
 hazy idea on the part of the inventor that the temperature-range between 
 freezing and boiling of water had some connection with the number of 
 degrees in a semicircle, or two right angles ! 
 
 -f Presumably because M. Fahrenheit noticed that the temperature of a 
 mixture of snow and salt was 32 of his degrees below the freezing point of 
 water, and concluded, for some unknown reason, that this must be the 
 initial temperature, or absolute zero. 
 
FUSING AND SOLIDIFYING POINTS. 
 
 The following table affords a yet simpler means of effecting 
 the translation : 
 
 Centigrade. 
 
 i 
 
 Reaumur. 
 
 Fahrenheit, 
 
 
 Centigrade. 
 
 Rdaumur. 
 
 
 
 Fahrenheit. 
 
 | 
 i Centigrade. 
 
 jiunnrpjj 
 
 j 
 
 Fahrenheit. 
 
 - 40 
 
 - 32 
 
 - 40 
 
 + 7 
 
 + 5-6 
 
 + 44-6 
 
 + 54 
 
 + 43-2 
 
 + 129-2 
 
 - 39 
 
 - 31-2 
 
 - 38-2 
 
 + 8 
 
 + 6-4 
 
 + 46-4 
 
 + 55 
 
 + 44 
 
 + 131 
 
 - 38 
 
 - 30-4 
 
 - 36-4 
 
 + 9 
 
 + 7-2 
 
 + 48-2 
 
 + 56 
 
 + 44-8 
 
 + 132-8 
 
 - 37 
 
 - 29-6 
 
 - 34-6 
 
 + 10 
 
 t 8 
 
 + 50 
 
 + 57 
 
 + 45-6 
 
 + 134-6 
 
 - 36 
 
 - 28-8 
 
 - 32-8 
 
 + 11 
 
 + 8-8 
 
 + 51-8 
 
 + 58 
 
 + 46-4 
 
 + 136-4 
 
 - 35 
 
 - 2S 
 
 - 31 
 
 + 12 
 
 + 9-6 
 
 + 53-6 
 
 + 59 
 
 + 47'2 
 
 + 138-2 
 
 - 34 
 
 - 27-2 
 
 - 29-2 
 
 + 13 
 
 + 10-4 
 
 + 55-4 
 
 + 60 
 
 + 48 
 
 + 140 
 
 - 33 
 
 - 26-4 
 
 - 27-4 
 
 + 14 
 
 + 11-2 
 
 + 57-2 
 
 + 61 
 
 + 48-8 
 
 + 141-8 
 
 - 32 
 
 - 25-6 
 
 - 25-6 
 
 + 15 
 
 i- 12 
 
 + 59 
 
 + 62 
 
 + 49-6 
 
 + 143-6 
 
 - 31 
 
 - 24-8 
 
 - 23-8 
 
 + 16 
 
 + 12:8 
 
 + 60-8 
 
 + 63 
 
 + 50-4 
 
 + 145-4 
 
 - 30 
 
 - 24 
 
 - 22 
 
 + 17 
 
 + 13 6 
 
 + 62-6 
 
 + 64 
 
 + 51-2 
 
 + 147-2 
 
 - 29 
 
 - 23-2 
 
 - 20-2 
 
 4- 18 
 
 + 14-4 
 
 + 64-4 + 65 
 
 + 52 
 
 + 149 
 
 - 28 
 
 - 22-4 
 
 - 18-4 
 
 + 19 
 
 + 15-2 
 
 + 66-2 ! + 66 
 
 + 52-8 
 
 + 150-8 
 
 - 27 
 
 - 21-6 
 
 - 16-6 
 
 + 20 
 
 + 16 
 
 + 68 
 
 + 67 
 
 + 53-6 
 
 + 152-6 
 
 - 26 
 
 - 20-8 
 
 - 14-8 
 
 + 21 
 
 + 16-8 
 
 + 69-8 
 
 + 68 
 
 + 54-4 
 
 + 154-4 
 
 - 25 
 
 - 20 
 
 - 13 
 
 + 22 
 
 + 17-6 
 
 + 71-6 
 
 + 69 
 
 + 55-2 
 
 + 156-2 
 
 - 24 
 
 - 19-2 
 
 - 11-2 
 
 + 23 
 
 + 18-4 
 
 + 73-4 
 
 + 70 
 
 + 56 
 
 + 158 
 
 - 23 
 
 - 18-4 
 
 9-4 
 
 + 24 
 
 + 19-2 
 
 + 75-2 
 
 + 71 
 
 + 56-8 
 
 + 159-8 
 
 - 22 
 
 - 17-6 
 
 - 7-6 
 
 + 25 
 
 + 20 
 
 + 77 
 
 + 72 
 
 + 57-6 
 
 + 161-6 
 
 - 21 
 
 - 16-8 
 
 - 5-8 
 
 + 26 
 
 + 20-8 
 
 + 78-8 
 
 + 73 
 
 + 58-4 
 
 + 163-4 
 
 - 20 
 
 - 16 
 
 4 
 
 + 27 
 
 + 21-6 
 
 + 80-6 
 
 + 74 
 
 + 59-2 
 
 + 165-2 
 
 - 19 
 
 - 15-2 
 
 - 2-2 
 
 + 28 
 
 + 22-4 
 
 + 82-4 
 
 + 75 
 
 + 60 
 
 + 167 
 
 - 18 
 
 - 14-4 
 
 0-4 
 
 + 29 
 
 + 23-2 
 
 + 84-2 
 
 + 76 
 
 + 60-8 
 
 + 168-8 
 
 - 17 
 
 - 13-6 
 
 + 1-4 
 
 -r 30 
 
 + 24 
 
 + 86 
 
 + 77 
 
 + 61-6 
 
 + 170-6 
 
 - 16 
 
 - 12-8 
 
 + 3-2 
 
 + 31 
 
 + 24-8 
 
 + 87-8 
 
 + 78 
 
 + 62-4 
 
 + 172-4 
 
 - 15 
 
 - 12 
 
 + 5 
 
 + 32 
 
 + 25-6 
 
 + 89-6 
 
 + 79 
 
 + 63-2 
 
 + 174-2 
 
 - 14 
 
 - 11-2 
 
 + 6-8 
 
 + 33 
 
 + 26-4 
 
 + 91-4 
 
 + 80 
 
 + 64 
 
 + 176 
 
 - 13 
 
 - 10-4 
 
 + 8-6 
 
 + 34 
 
 + 27-2 
 
 + 93-2 
 
 + 81 
 
 + 64-8 
 
 + 177-8 
 
 - 12 
 
 9-6 
 
 + 10-4 
 
 + 35 
 
 + 28 
 
 + 95 
 
 + 82 
 
 + 65-6 
 
 + 179-6 
 
 - 11 
 
 - 8-8 
 
 + 12-2 
 
 + 36 
 
 + 2S'8 
 
 + 96-8 
 
 + 83 
 
 + 66-4 
 
 + 181-4 
 
 - 10 
 
 8 
 
 + 14 
 
 + 37 
 
 + 29-6 
 
 + 98-6 
 
 + 84 
 
 + 67-2 
 
 + 183-2 
 
 - 9 
 
 - 7-2 
 
 + 15-8 
 
 + 38 
 
 + 30-4 
 
 + 100-4 
 
 + 85 
 
 + 68 
 
 + 185 
 
 - 8 
 
 - 6-4 
 
 + 17-6 
 
 + 39 
 
 + 31-2 
 
 + 102-2 
 
 + 86 
 
 + 68-8 
 
 + 186-8 
 
 _ IT 
 
 5-6 
 
 + 19-4 
 
 + 40 
 
 + 32 
 
 + 104 
 
 + 87 
 
 + 69-6 
 
 + 188-6 
 
 6 
 
 - 4-8 
 
 + 21-2 
 
 + 41 
 
 + 32-8 
 
 + 105-8 
 
 + 88 
 
 + 70-4 
 
 + 190-4 
 
 5 
 
 4 
 
 + 23 
 
 + 42 
 
 + 33-6 + 107 -G 
 
 + 89 
 
 + 71-2 
 
 + 192-2 
 
 4 
 
 - 3-2 
 
 + 24-8 
 
 + 43 
 
 + 34-4 + 109-4 
 
 + 90 
 
 + 72 
 
 + 194 
 
 3 
 
 - 2-4 
 
 + 26-6 
 
 + 44 
 
 + 35-2 +111-2 
 
 + 91 
 
 + 72-8 
 
 + 195-8 
 
 _ 2 
 
 - 1-6 
 
 + 28-4 
 
 + 45 
 
 +36 ; + 113 
 
 + 92 
 
 + 73-6 
 
 + 197-6 
 
 1 
 
 - 0-8 
 
 + 30-2 
 
 + 46 
 
 + 36-8 
 
 + 114-8 
 
 + 93 
 
 + 74-4 
 
 + 199-4 
 
 
 
 
 
 + 32 
 
 i + 47 
 
 + 37-6 
 
 + 116-6 
 
 + 94 
 
 + 75-2 
 
 + 201-2 
 
 + 1 
 
 + 0-8 
 
 + 33-8 
 
 + 48 
 
 + 38-4 
 
 + 118-4 
 
 + 95 
 
 + 76 
 
 + 203 
 
 + 2 
 
 + 1-6 
 
 + 35-6 
 
 + 49 
 
 + 39-2 
 
 + 120-2 
 
 + 96 
 
 + 76-8 
 
 + 204-8 
 
 + 3 
 
 + 2-4 
 
 + 37-4 
 
 + 50 
 
 + 40 
 
 + 122 
 
 + 97 
 
 + 77-6 
 
 + 206-6 
 
 + 4 
 
 + 3-2 
 
 + 39-2 
 
 + 51 
 
 + 40-8 
 
 + 123-8 
 
 + 98 
 
 + 78-4 
 
 + 208-4 
 
 + 5 
 
 + 4 
 
 + 41 
 
 + 52 
 
 + 41-6 
 
 + 125-6 
 
 + 99 
 
 + 79-2 
 
 + 210-2 
 
 + 6 
 
 + 4-8 
 
 + 42-8 
 
 + 53 
 
 + 42-4 
 
 + 127-4 
 
 + 100 
 
 + 80 
 
 + 212 
 
 
 
 
 
 
 
 ! 
 
 
60 OILS, FATS, WAXES, ETC. 
 
 Iii the following pages, whenever a temperature is expressed 
 as a number without the scale used being mentioned, it is always 
 to be understood that the Centigrade value is intended. 
 
 Determination of Fusing and Solidifying Points. Inas- 
 much as most natural oils and fats, itc., are not chemically pure 
 single substances, but generally consist of one or more main 
 ingredients with smaller quantities of other allied bodies, as a 
 general rule no sharply defined temperature exists characteristic 
 of the fusing or solidifying point of any given variety, although 
 in many cases pure unadulterated specimens, even though of 
 widely various origin, do not differ largely in these respects. 
 For the same reason, the point at which incipient solidification 
 on chilling first becomes manifest, often differs considerably from 
 the temperature at which the mass, when once rendered solid by 
 cold, exhibits incipient fusion on gradual heating. Further, a 
 given substance, if heated considerably above its melting point 
 and then cooled quickly so as to solidify it again, will often melt 
 for the second tyne at a temperature materially different from 
 that at which it first fused, although the normal melting point is 
 more or less regained on standing for some time ; accordingly, if 
 the fusing point of a solid fat that has been once melted is to be 
 determined, a sufficient time must be allowed to elapse to enable 
 the normal physical structure to be re-assumed. In practice, it 
 is generally necessary first to melt the substance and then clarify 
 it by subsidence, or, better, by filtration through dry paper, in 
 order to remove suspended matters and, more particularly, water; 
 so that the purified material, after cooling and solidification, must 
 be allowed to stand some time (at least an hour or two, but 
 preferably a much longer period, say till the next day) before 
 further "examination. 
 
 In order to determine the fusing point of a 
 solidified specimen, several different methods are 
 in use, the results of which are not always com- 
 parable with one another; so that, if an accurate 
 comparison of two substances is requisite, it is 
 indispensable that both must be examined by the 
 same process, side by side. One of the most fre- 
 quently used methods consists in preparing a 
 capillary tube by drawing out in a flame a short 
 piece of quill tubing (Fig. 2); the fine end is 
 sealed up, and when cool, the solid to be ex- 
 amined is cut into very fine fragments or pul- 
 verised, and a little dropped in and shaken down 
 into the capillary tube. This is then bound by 
 Fig. 2. wire, string, or an india-rubber ring to the stem 
 
 of a thermometer (Fig. 3), so that the centre of 
 the bulb is about level with the substance ; the whole is then 
 placed in a small vessel of water (or, for higher temperatures, 
 
FUSING AND SOLIDIFYING POINTS. 01 
 
 melted paraffin wax) which is very slowly raised in temperature, 
 either by means of a small flame underneath (Fig. 4), or, pre- 
 ferably, by placing it inside a much larger similar vessel ; a large 
 flask with the neck cut off and a small beaker answer well (-Fig. 
 5). Olberg employs for this purpose the circulatory arrange- 
 ment shown in Fig. 6 ; this is filled with water or oil, the heat 
 being applied at the base of A. 
 
 If circumstances permit, two such capillary tubes (or more) 
 should be provided, one being used to obtain a first rough 
 
 Fig. 3. Fig. 4. 
 
 approximation to the melting point, and the others used sub- 
 sequently to obtain a nearer result, the bath being previously 
 slightly cooled below the first approximate value, and then very 
 slowly heated again, so that several minutes are requisite to 
 produce a rise in temperature of 2 or 3 C. The thermometer 
 and attached tube are used as a stirrer during this heating, and 
 the temperature noted when the fragments first show signs of 
 melting. Frequently this temperature (softening point) is 
 measurably below that requisite to cause the fragments to liquefy 
 entirely, and run down to the bottom of the capillary tube as a 
 clear fluid (temperature of complete fusion). 
 
G2 
 
 OILS, FATS, WAXES, ETC. 
 
 Instead of a capillary tube sealed up at the end, one bent into 
 a U or V shape may be employed, the solid particles being 
 shaken down to the bend or angle. Bensemann * modifies the 
 tube by drawing it out as represented in Fig. 7. A drop or two 
 
 Fig. 5. Fig. 0. 
 
 of melted substance is introduced into the bulbed portion of the 
 tube, A, and fused as indicated by a. After standing for a 
 sufficient time, the tube is placed in water, the temperature of 
 which is very slowly raised ; the temperature of incipient lique- 
 faction is readily observed when the material softens and begins 
 to run ; at a little higher temperature it all runs down as- 
 indicated by b ; when the turbid liquid becomes completely clear, 
 the temperature of complete fusion is attained. 
 
 Another method of operating consists in drawing out the 
 capillary tube as before, but without sealing up the narrow end ; 
 this end is then dipped into the molten substance to be 
 examined and withdrawn, so that half an inch or so of the 
 capillary tube is filled up with the material. After standing at 
 least an hour, but preferably till next day, the capillary tube is 
 attached to the thermometer and placed in the bath as before ; 
 when the temperature rises to the softening point so as to produce 
 incipient fusion, the plug of solid matter in the capillary tube 
 becomes softened where it touches the glass, and is consequently 
 
 * Journ. Soc. Chem. Industry, 1885, iv., p. 5.35 ; from Rep. Anal. Chem., 
 11, p. 165. 
 
FUSING AND SOLIDIFYING POINTS. 
 
 63 
 
 forced upwards by the hydrostatic pressure of the fluid in the 
 bath ; when this occurs the temperature is noted. The former 
 process, as a rule, is to be preferred, not only because it gives 
 both the softening point and the temperature of complete lique- 
 faction, but also, because by withdrawing the source of heat and 
 allowing the completely fluid mass to cool slowly, the temperature 
 at which re-solidification occurs can be more or less accurately 
 determined. With some kinds of mixed substances, the sealed- 
 up capillary tube process enables three different temperatures to 
 be ascertained, viz. : First, the temperature of incipient fusion 
 when the most fusible constituent commences to melt ; second, a 
 temperature when this constituent has become so far melted that 
 
 the solid fragments run down visibly; and third, a still higher 
 temperature when the whole mass becomes' clear and limpid, 
 showing that the whole of the less fusible constituents have also 
 become completely melted. With certain mixtures of free fatty 
 acids, &c., the difference between the lowest and highest fusion 
 temperatures thus determined may amount to upwards of 5 C. 
 
 A convenient method of determining the softening point in 
 certain cases consists in dipping the bulb of the thermometer into 
 the melted material to be examined, and causing a small light 
 
OILS, FATS, WAXES, ETC. 
 
 glass bulb or float to adhere to the thermometer, cemented 
 thereto by the substance as it solidifies. After waiting a sufficient 
 time to enable the mass to attain its normal physical structure, 
 the thermometer and bulb are placed in a bath, which is 
 gradually heated ; when the temperature attains the softening 
 point, the float becomes detached and rises up in the fluid. 
 Instead of a float, a thick coating of the substance itself may be 
 ap'plied to the thermometer by dipping the latter in the just- 
 melted substance for an instant, taking out again until the 
 adherent film has solidified, and repeating the operation two or 
 three times so as finally to obtain a sufficiently thick coating. 
 Fig. 8 represents Pohl's form of bath for the purpose, consisting 
 of a wide test-tube, C, through the cork in the mouth of which 
 passes the thermometer, T, the heat being applied by means of a 
 small flame impinging on a flat metal disc, supported a little 
 distance below the test-tube, so as to furnish an ascending 
 current of warm air. Obviously a vessel of warm water may be 
 substituted for the disc and flame. A modification of this plan 
 has been suggested by Messrs. Cross and Be van,* where a thin 
 
 piece of sheet iron (ferrotype 
 plate) is cut into the shape 
 shown in Fig. 9, about ;f inch 
 long and f or J inch across ; 
 at A the plate is hammered so 
 as to form a minute saucer or 
 depression, and at B a hole is 
 cut of such size as to allow the 
 plate to fit on to the bulb (coni- 
 cal) of a thermometer. The 
 float is made by blowing a bulb 
 on the end of a thin piece of 
 tubing, and fixing a bit of pla- 
 tinum wire therein, bent into 
 an L shape. A drop of melted 
 substance is put in the saucer, 
 and the end of the wire dipped 
 therein, the stem being sup- 
 ported in a vertical position 
 until the substance solidifies, 
 and so holds it firmly. The 
 thermometer and float are 
 
 placed in a bath of water, &c. (preferably mercury), and when 
 the temperature rises to the softening point, the float becomes 
 detached and rises to the surface. 
 
 In many cases the temperatures of incipient fusion and of 
 complete liquefaction may be easily determined by placing small 
 fragments or pinches of powder of the substance examined on the 
 * Journal of the Chemical Society, vol. xli. (1882), p. 111. 
 
 Fi. 9. 
 
FUSING AND SOLIDIFYING POINTS. 
 
 65 
 
 surface of a bowl of perfectly clean mercury, the temperature of 
 which is gradually raised, a thermometer being placed therein. 
 When complete fusion is effected, the substance becomes a minute 
 drop of clear fluid, which usually spreads out film-wise over the 
 surface of the mercury. A n ingenious modification of this method 
 has been proposed by J. Loewe,* where the substance is first applied 
 to the end of a platinum wire (by dipping into the just-fused 
 substance), so as to cover it completely ; the coated wire is then 
 supported by means of an insulating holder of glass, just below 
 the surface of the mercury, and connected with one pole of a 
 small galvanic cell, whilst the mercury is connected with the 
 other pole. As long as the substance is unmelted no contact 
 takes place between the platinum wire and mercury ; but as soon 
 as fusion takes place contact is brought about, and an electric 
 bell included in the circuit is made to ring. Fig. 10 represents 
 
 Fig. 10. 
 
 the general arrangement employed, the mercury being placed in 
 a capsule heated over a small water bath, and the temperature 
 ascertained by means of a thermometer plunged therein. Instead 
 of a platinum wire coated with the substance examined, Christo- 
 manosf employs a drawn-out capillary tube into which the melted 
 substance is sucked or poured, a platinum wire being imbedded 
 in the material. After solidifying and standing sufficiently long 
 to attain the normal texture of the substance examined, the 
 capillary tube is heated in a mercury bath, electrical connections 
 being applied to the bath and platinum wire, so that when the 
 substance fuses contact is made and a bell rung. A. similar 
 arrangement is in. use in the Paris Municipal Laboratory, the 
 substance tested being placed in the bend of a U-shaped tube 
 with a platinum wire in each limb, together with some mercury, 
 which runs down and makes contact when fusion occurs. 
 
 * Dingier 's Polytechnisches Journal, 201, p. 250. 
 
 t Journal Soc. Chem. Industry, 1890, p. 894 ; from Berichte d. Deut. 
 Chem. Gcs., 1890. p. 1093. 
 
 5 
 
66 OILS, FATS, WAXES, ETC. 
 
 If the fusing point of a fluid oil that has been solidified by 
 chilling is to be determined, the bath used must be itself cooled 
 down below the fusing point, and gradually allowed to rise in 
 temperature. Strong brine, giycerol diluted Avith a little water, 
 or calcium chloride solution may be conveniently used for tem- 
 peratures below 0. When the solidification point of a fluid oil 
 or melted fat is to be determined, a rough approximation may 
 often be obtained by placing some in a small narrow test-tube, 
 or dipping into the fluid a loop of platinum wire so as to cause a 
 small drop to adhere, and immersing in a bath of water, brine, 
 &c., which is being cooled down by an external application of 
 broken ice or snow and salt, &c., noting the temperatures when 
 transparency first ceases, and when visible solidification of the 
 whole mass has ensued. In most cases, however, the temperatures 
 thus ascertained are too low, because superfusion is extremely 
 apt to occur with oils and fats. If, however, a moderately large 
 quantity of substance be used (15 to 20 grammes at least), 
 it frequently occurs that as soon as solidification begins a more 
 or less considerable rise in temperature of the mass takes place, 
 just as when water cooled down below in a dustless still 
 atmosphere rises to whenever freezing actually commences ; or 
 just as the temperature of a supersaturated solution of Glauber's 
 salt (sodium sulphate) rises when the fluid sets to a crystalline 
 mass. The higher temperature thus indicated is permanent for 
 a time as solidification goes on, and is usually much more nearly 
 exact than the lower one attained before solidification com- 
 menced ; but even this higher one is often several degrees below 
 the temperature of incipient fusion (and a fortiori below that of 
 complete fusion) indicated when the mass has been solidified 
 completely, allowed to stand some time, and then re-melted in 
 a sealed-up capillary tube. 
 
 Differences of this description are more usually observed when 
 the substances in question are mixtures of different constituents 
 melting at different temperatures ; on the other hand, a single 
 substance in a state of moderate purity (e.g., a well purified 
 sample of a given fatty acid, such as stearic acid) usually shows 
 but little difference between the temperatures of incipient fusion 
 and of complete fusion in a closed capillary tube, and those 
 where the limpid fused mass first shows signs of turbidity, and 
 where visible complete solidification occurs, on slightly cooling 
 the melted substance. 
 
 With some kinds of oils, time is an important factor in the 
 determination of the temperature at which solidification takes 
 place on chilling, inasmuch as frequently no solidification at all 
 is visible on cooling for a short time to a given temperature 
 (e.g., 15 C.), whereas more or less complete solidification takes 
 place on keeping for several hours at a temperature not so low 
 by several degrees (e.g., 5). In most cases, if a fragment of 
 
FUSING AND SOLIDIFYING POINTS. 
 
 67 
 
 oil, previously solidified by chilling, be dropped into a specimen 
 of cooled oil, solidification is brought about much sooner, the 
 particle introduced acting as a "nucleus " and facilitating crystal- 
 lisation in the well-known way observed with other bodies (e.g., 
 supersaturated solution of sodium sulphate superfused metals ; 
 glycerol ; monohydrated sulphuric acid ; water chilled down 
 whilst at rest below 0, &<?.). For determinations of this kind, 
 baths of fairly constant low temperatures, capable of being main- 
 tained for considerable periods, are requisite ; Hoffmeister uses 
 for this purpose various saline solutions cooled externally by a 
 freezing mixture ; by suitably choosing the saline substance and 
 the strength of its solution, baths of constant temperature are 
 obtainable so long as any liquid remains unsolidified or any solid 
 unmelted. Thus the following temperatures correspond with 
 solutions of the respective strengths : 
 
 Temperature. 
 
 Solution. 
 
 Degrees C. 
 
 - 2-85 to - 3-0 
 
 - 5-0 
 
 - 8 '7 to - <)() 
 - 15-4 to - 15-0 
 
 Distilled Water. 
 Potassium nitrate, . 
 \ Potassium nitrate, . 
 I Sodium chloride. 
 Barium chloride, 
 Ammonium chloride, 
 
 13 parts per 
 13 
 3-3 
 35-8 
 25 
 
 100 of water. 
 
 55 
 3 5 
 
 55 
 
 Chilling baths of this description are more especially of use in 
 the examination of lubricating oils with respect to their congeal- 
 ing temperatures. 
 
 The following table, mostly derived from Schadler's Technologic 
 der Fette und Oele, exhibits the average melting and solidifying 
 points of many of the more commonly occurring fats and oils : 
 
 FREEZING AND MELTING POINTS OF OILS, &c. 
 
 Name. 
 
 Arachis oil, 
 
 Almond oil, 
 
 Bassia fat (Galam butter), 
 
 Beechnut oil, 
 
 Ben oil, 
 
 Belladonna seed oil, . 
 
 Butter, 
 
 Bone grease, 
 
 Cacao butter, 
 
 Castor oil, 
 
 Cokernut oil, 
 
 Colza oil, . 
 
 Cotton seed oil, . 
 
 Cress seed oil, 
 
 
 Melting Point 
 after 
 Solidification. 
 
 Solidifying Point 
 when Cooled 
 (after Fusion, if 
 Solid). 
 
 
 Degrees. 
 
 Degrees. 
 
 , 
 
 
 - 3 to - 4 
 
 
 
 - 20 
 
 
 28 to 29 
 
 21 to 22 
 
 
 ... 
 
 -16-5 to -17-5 
 
 m 
 
 
 About 
 
 
 ... 
 
 - 16 
 
 
 29 to 35 
 
 20 to 30 
 
 
 44 to 45 
 
 35 
 
 
 33 to 34 
 
 20-5 
 
 
 ... 
 
 - 18 
 
 
 24*5 
 
 20 to 20-5 
 
 
 
 - 6 
 
 
 
 - 2 
 
 
 ... 
 
 - 15 
 
68 
 
 OILS, FATS, WAXES, ETC. 
 
 FREEZING AND MELTING POINTS OF OILS, &c. Continued. 
 
 Name. 
 
 Melting Poiut 
 Hfter 
 Solidification. 
 
 Solidif 
 whe 
 (after 
 5 
 
 
 Degrees. 
 
 D( 
 
 Goa butter (Brindonia indica), . 
 Goose grease, ..... 
 
 40 
 26 
 
 
 Gourd seed oil, ..... 
 Hazelnut oil, 
 Hemp seed oil, ..... 
 Japanese wax, ..... 
 Laurel berry fat, .... 
 Linseed oil, ..... 
 Madia oil, ..... 
 Nut oil, 
 
 53 to 54 
 38 
 
 43'5 to 44 
 
 - 17 
 
 - 27 
 40 
 
 Oleic acid, ...... 
 Olive oil .... 
 
 
 2 
 
 
 
 - 16 
 
 Palm oil, ...... 
 Pine oil, ...... 
 Rape seed oil (Brassica napus oleifera), 
 Radish seed oil, 
 
 30 to 41 
 
 21 
 
 Spindel oil (Euonymus europseus), 
 Sunflower seed oil, .... 
 Tallow, 
 Tobacco oil, 
 Train oil, ...... 
 Virola fat (Virola sebifera), 
 Wax, 
 Whale oil ... 
 
 46 to 50 
 
 45 
 62 to 64 
 
 36 
 
 01 
 
 Al 
 
 t 
 
 Weld oil. 
 
 
 
 Beloi 
 
 Solid). 
 
 Degrees. 
 
 - 16 
 32 
 18 
 
 - 16 
 
 - 15 
 
 - 18 
 
 27 to - 28 
 40 to 41 
 30 
 
 - 19 
 
 - 15 
 
 - 28 
 33 
 
 - 6 
 
 2 to 4 
 16 to - 18 
 21 to 37 
 
 - 18 
 
 - 3 
 
 - 4 
 
 - 5 
 
 - 10 
 
 - 16 
 36 to 40 
 
 - 25 
 
 to - 2 
 
 40 
 
 About 60 
 to - 2 
 
 WlMMEL. 
 
 
 Melts at 
 
 Becomes 
 Turbid at 
 
 Temperature 
 rises during 
 Solidification to 
 
 Sheep's tallow (fresh), . 
 (old), . . 
 Ox tallow (fresh), 
 (old), . 
 Hog's lard, .... 
 Butter (fresh), 
 
 Degrees. 
 
 47 
 50-5 
 43 
 42-5 
 41 -5 to 42 
 31 to 31 -5 
 
 Degrees. 
 36 
 39-5 
 33 
 34 
 30 
 19 to 20 
 
 Degrees. 
 40 to 41 
 44 to 45 
 36 to 37 
 38 
 32 
 19 -5 to 20 -5 
 
 Cacao butter, 
 Coker butter, 
 Palm butter (fresh), . 
 (old), 
 Nutmeg butter, . 
 
 34 to 35-5 
 24-5 
 30 to 36 
 42 
 43 -5 to 44 
 62 to 62-5 
 
 20-5 
 20 to 20-5 
 21 to 24 
 38 
 33 
 
 27 to 29 5 
 22 to 23 
 21 -5 to 35 
 39-5 
 41 -5 to 42 
 
 Spermaceti, .... 
 
 44 to 44 5 
 
 
 ... 
 
FUSING AND SOLIDIFYING POINTS. 
 RiJDORFF. 
 
 
 
 
 
 
 Melts at 
 
 Solidifies at 
 
 
 
 
 
 
 Degress. 
 
 Degrees. 
 
 Yellow wax, 
 
 
 
 
 
 63-4 
 
 6 1 -5 to 62 -6 
 
 \Vhite wax, 
 
 
 
 
 
 61-8 
 
 61-6 
 
 Spermaceti, 
 
 
 
 
 
 43 -5 to 44 -3 
 
 43-4 to 44-2 
 
 Japanese wax, 
 
 
 
 
 
 50-4 to 51 
 
 ... 
 
 Cacao butter, 
 
 
 
 
 
 33-5 
 
 ... 
 
 Nutmeg butter, 
 
 
 
 
 
 70 to SO 
 
 ... 
 
 Sheep's tallow, 
 
 
 
 
 
 4G-5 to 47 '4 
 
 32 to 36 
 
 Ox tallow, . 
 
 
 
 
 
 43-5 to 45-0 
 
 27 to 35 
 
 The foregoing fusing and solidifying points of various solid 
 fats are given by Wimmel and Eiidorff respectively. 
 
 The fusion point of a pure glyceride, or mixture of glycerides, 
 is often materially altered if, as is often the case, any considerable 
 amount of hydrolysis has taken place, either through develop- 
 ment of " rancidity" through fermentative changes taking place 
 on account of the presence of mucilaginous or albuminous 
 matters, or by the agency of acids during refining, or otherwise. 
 Hence, the numbers obtained with various samples of otherwise 
 pure oils (i.e., unadulterated with cheaper ones) are apt to vary. 
 More nearly concordant figures are obtained if the whole of 
 the glyceride is saponified by means of alkalies (e.g., alcoholic 
 potash), and the fatty acids separated from the resulting soap 
 by evaporating off alcohol, dissolving the residue in hot water, 
 acidulating with a mineral acid in excess, thoroughly agitating 
 till all the soap is decomposed, and finally allowing to cool, and 
 removing the cake of solidified fatty acids that separates and 
 forms on standing. 
 
 By determining the fusing point of the fatty acid cake thus 
 produced side by side with that similarly prepared from a sample 
 of oil of known purity, or from a mixture of known character, 
 useful indications as to purity or otherwise are often attainable ; 
 for example, the fatty acids from genuine olive oil usually fuse 
 at from 22 to 26 C., and those from refined cotton seed oil at 
 35 to 40, so that any considerable admixture of cotton seed oil 
 with olive oil will usually result in yielding a cake of notably 
 raised fusing point. The amount of rise, however, does not give 
 any very clear indication of the amount of admixture, because, as 
 a general rule, mixtures of different substances fuse at a tempera- 
 ture lower than that calculable arithmetically from the relative 
 amounts and fusing points of the ingredients (vide p. 73). 
 
 The following table represents the melting and solidifying 
 points of the mixed fatty acids obtained from various oils and 
 fats, as given by Schadler : 
 
70 
 
 OILS, FATS, WAXES, ETC. 
 
 Name of Oil. &c. 
 
 Melting Point. 
 
 Solidifying Point. 
 
 
 Degrees C. 
 
 Degrees C. 
 
 Apricot kernel, 
 
 4-5 
 
 
 
 Almond, 
 
 14 
 
 5 
 
 Arachis, 
 
 32 to 33 
 
 29 to 30 
 
 Butter, 
 
 37 
 
 33 
 
 Cacao butter, 
 
 49-5 
 
 46 '5 to 47 
 
 Castor, 
 
 13 
 
 3 
 
 Charlock, . 
 
 18 to 19 
 
 13 
 
 Chinese tallow, 
 
 57 
 
 52 
 
 Cotton seed, 
 
 37 to 38 
 
 32-5 
 
 Cokernut, 
 
 24 to 25 
 
 20 to 20-5 
 
 Colza, .... 
 
 20 to 21 
 
 14 to 14-5 
 
 Galam butter, 
 
 35-5 
 
 30 
 
 Hemp, .... 
 
 19 
 
 15 
 
 Lard, .... 
 
 38 to 39 
 
 35 
 
 Linseed, 
 
 17 
 
 13-5 
 
 Lallemantia (Gundschit), 
 
 11 to 12 
 
 
 Malabar tallow, 
 
 56-5 
 
 54-8 
 
 Margarine, . 
 
 42 
 
 39-4 
 
 Nutmeg, 
 
 42-5 
 
 40 
 
 Nut (Walnut), 
 
 20 
 
 16 
 
 . Olive, .... 
 
 26 "5 to 28 
 
 21 -5 to 22 
 
 Poppy, 
 
 20-5 
 
 16-5 
 
 Palm, .... 
 
 45 to 46 
 
 42 to 43 
 
 Rape, .... 
 
 21 
 
 16 
 
 Suet (Ox), . 
 
 45-5 
 
 43 
 
 Sesame, 
 
 35 to 36 
 
 31-5 to 32 
 
 Spermaceti, . 
 
 13-5 
 
 
 Sunflower, 
 
 23 
 
 17 
 
 Tacamahac, . 
 
 36-5 
 
 31 
 
 Tallow (Sheep), . 
 
 49 
 
 46 
 
 Unguadia, 
 
 19 
 
 10 
 
 Wool grease, 
 
 41-8 
 
 40 
 
 Slightly different values have been given by other observers, 
 the variations arising partly from differences between the par- 
 ticular specimens examined and partly from differences in the 
 mode of observation. Thus the figures below given by Hiibl 
 are respectively the temperatures of complete liquefaction (as 
 noticed by melting in a narrow test-tube, stirring with a ther- 
 mometer, and noting the temperature when turbidity disap- 
 peared), and of incipient solidification (as noticed by cooling 
 down after complete melting, and noticing when cloudiness com- 
 menced) ; whilst those of Beiisemann are (A) the temperature of 
 complete liquefaction, when all turbidity disappears, as deter- 
 mined in the above described form of capillary tube, and (B) 
 the somewhat lower temperature when the substance was suffi- 
 ciently liquefied to run down in the capillary tube, but was not 
 thoroughly fused to a limpid fluid : 
 
FUSING AND SOLIDIFYING POINTS. 
 
 71 
 
 
 Fusing Point. 
 
 Solidifying Point. 
 
 
 Hiibl. 
 
 Bensemann. 
 
 Allen. 
 
 HUbl. 
 
 Bach. 
 
 Allen. 
 
 
 
 A B. 
 
 
 
 
 
 
 Dees. 
 
 
 
 
 
 
 
 
 C. 
 
 Degs. 
 
 Degs. 
 
 Degs. 
 
 Degs. 
 
 Degs. 
 
 Degs. 
 
 Olive oil, . . . 
 
 26-0 
 
 26 to 27 
 
 23 to 24 
 
 26 -Q 
 
 21-2 
 
 22-0 
 
 21-0 
 
 Almond oil, . . i 14*0* 
 
 
 ... 
 
 ... 
 
 5-0 
 
 
 
 Arachis oil, . . 27*7 
 
 34 to 35 
 
 31 to 32 
 
 29-5 
 
 23 -8 
 
 31-0 
 
 28-0 
 
 Rape oil, . . . 
 
 20-1 
 
 21 to 22 
 
 18 to 19 
 
 19-5 
 
 12-2 
 
 15-0 
 
 18-5 
 
 Cotton seed oil,. 
 
 377 
 
 42 to 43 
 
 39 to 40 
 
 35-0 
 
 30-5 
 
 35-0 
 
 32-0 
 
 Sesame oil, . . ! 26 '0 
 
 29 to 30 
 
 25 to 26 
 
 23-0 
 
 22-3 
 
 32-5 
 
 18-5 
 
 Linseed oil, . . 17 ; 
 
 ... 
 
 
 24-0 
 
 13-3 
 
 ... 
 
 17-5 
 
 Poppy oil, . . 
 
 20-5 
 
 
 
 .. . 
 
 16-5 
 
 
 
 Hemp seed oil. . 
 
 19-0 
 
 ... 
 
 
 
 15-0 
 
 
 ... 
 
 Walnut oil, . ' . 
 
 20-0 
 
 ... 
 
 
 
 16-5 
 
 ... 
 
 ... 
 
 Castor oil, 
 
 13-0 
 
 
 
 
 3-0 
 
 2-0 
 
 ... 
 
 Palm oil, ... 
 
 47-8 
 
 
 
 50 : 
 
 42-7 
 
 ... 
 
 45-5 
 
 Cokernut oil, 
 
 24-6 
 
 
 
 24-0 
 
 204 
 
 ... 
 
 20-5 
 
 Japan wax, . . 
 
 
 ... 
 
 
 56-0 
 
 
 ... 
 
 53-0 
 
 Myrtle wax, . . 
 
 
 ... 
 
 
 47-5 
 
 
 ... 
 
 46-0 
 
 Lard, .... 
 
 ... 
 
 ... 
 
 
 44-0 
 
 ... 
 
 42 
 
 39-0 
 
 Tallow, . . . 
 
 45-0 
 
 ... 
 
 
 ... 
 
 43 to 50 
 
 44 to 49 
 
 ... 
 
 Shea butter, . . 
 
 395 
 
 
 ... 
 
 
 38-0 
 
 ... 
 
 ... 
 
 The following tables by Heintz * represent the melting points 
 of various definite mixtures of fatty acids : 
 
 MIXTURES OF MYRISTIC AND LAURIC ACIDS. 
 
 
 
 Percentage of 
 
 Melting Point. 
 
 Solidification Point. 
 
 Myristic Acid. 
 
 Laurie Acid. 
 
 Degrees C. 
 
 Degrees C. 
 
 
 
 58-8 
 
 
 100 
 
 
 
 51-8 
 
 47-3 
 
 90 
 
 10 
 
 49-6 
 
 44-5 
 
 80 
 
 20 
 
 46-7 
 
 39-0 
 
 70 
 
 30 
 
 43-0 
 
 39-0 
 
 60 
 
 40 
 
 37-4 
 
 35-7 
 
 50 
 
 50 
 
 36-7 
 
 33-5 
 
 40 
 
 60 
 
 35-1 
 
 32-3 
 
 30 
 
 70 
 
 38-5 
 
 33-0 
 
 20 
 
 80 
 
 41-3 
 
 36-0 
 
 10 
 
 90 
 
 43-6 
 
 ... 
 
 
 
 100 
 
 * Poggendorff Annalen, 92, p. 588. 
 
72 
 
 OILS, FATS, WAXES, ETC. 
 MIXTURES OF PALMITIC AND MYRISTIC ACIDS. 
 
 Melting Point. 
 
 Solidification Point. 
 
 Percentage of 
 
 Palmitic Acid. 
 
 Myristic Acid. 
 
 Degrees C. 
 
 Degrees C. 
 
 
 
 62-0 
 
 ... 
 
 100 
 
 
 
 61-1 
 
 58-0 
 
 95 
 
 5 
 
 60-1 
 
 55-7 
 
 90 
 
 10 
 
 58-0 
 
 53-5 
 
 80 
 
 20 
 
 54-9 
 
 51-3 
 
 70 
 
 30 
 
 51-5 
 
 49-5 
 
 60 
 
 40 
 
 47-8 
 
 45-3 
 
 50 
 
 50 
 
 47-0 
 
 43-7 
 
 40 
 
 60 
 
 46-5 
 
 43-7 
 
 35 
 
 65 
 
 46-2 
 
 44-0 
 
 32-5 
 
 67-5 
 
 46-2 
 
 43-7 
 
 30 
 
 70 
 
 49-5 
 
 41-3 
 
 20 
 
 SO 
 
 51-8 
 
 45-3 
 
 10 
 
 90 
 
 53'8 
 
 
 
 
 100 
 
 MIXTURES OF STEARIC AND PALMITIC ACIDS. 
 
 
 
 Percentage of 
 
 Melting Point. 
 
 Solidification Point. 
 
 Stearic Acid. 
 
 Palmitic Acid. 
 
 Degrees C. 
 
 Degrees C. 
 
 
 
 69-2 
 
 
 100 
 
 
 
 67-2 
 
 62-5 
 
 90 
 
 10 
 
 65-3 
 
 60-3 
 
 80 
 
 20 
 
 62-9 
 
 59-3 
 
 70 
 
 30 
 
 60-3 
 
 56-5 
 
 60 
 
 40 
 
 56-6 
 
 55-0 
 
 50 
 
 50 
 
 56-3 
 
 54-5 
 
 40 
 
 60 
 
 55-6 
 
 54-3 
 
 35 
 
 65 
 
 55-2 
 
 54-0 
 
 32-5 
 
 67'5 
 
 55-1 
 
 54-0 
 
 30 
 
 70 
 
 57-5 
 
 53-8 
 
 20 
 
 80 
 
 60-1 
 
 54-5 
 
 10 
 
 90 
 
 62-0 
 
 ... 
 
 
 
 100 
 
FUSING AND SOLIDIFYING POINTS. 
 MIXTURES OF STEARIC AND MYRISTIC ACIDS. 
 
 73 
 
 
 Percentage of 
 
 Melting Point. 
 
 Stearic Acid. 
 
 Myristic Acid. 
 
 69-2 
 
 100 
 
 
 
 67-1 
 
 90 
 
 10 
 
 65-0 
 
 80 
 
 20 
 
 62\S 
 
 70 
 
 30 
 
 59-8 
 
 60 
 
 40 
 
 54-5 
 
 50 
 
 50 
 
 50-4 
 
 40 
 
 60 
 
 48-2 
 
 30 
 
 70 
 
 47-8 
 
 20 
 
 80 
 
 51-7 
 
 10 
 
 90 
 
 53-8 
 
 
 
 100 
 
 1 
 
 
 
 MIXTURES OF STEARIC AND LAURIC ACIDS. 
 
 Melting Point 
 
 Perc 
 
 
 
 Stearic Acid. 
 
 69-2 
 
 100 
 
 67-0 
 
 90 
 
 64-7 
 
 80 
 
 62-0 
 
 70 
 
 59-0 
 
 60 
 
 55-8 
 
 50 
 
 50-8 
 
 40 
 
 43-4 
 
 30 
 
 38-5 
 
 20 
 
 41-5 
 
 10 
 
 43-6 
 
 
 
 Myristic Acid. 
 
 
 10 
 20 
 30 
 40 
 50 
 60 
 70 
 SO 
 90 
 100 
 
 These tables amply illustrate the peculiarity above referred to 
 in cases where mixtures are heated viz., that the melting point 
 of the mixture is almost invariably lower than that calculated 
 from the relative proportions and fusing points of the ingredients, 
 and in certain cases falls below the melting point of the most 
 
OILS, FATS, WAXES, ETC. 
 
 MIXTURES OF PALMITIC AND LAURIC ACIDS. 
 
 
 Percentage of 
 
 Melting Point. 
 
 Palmitic Acid. 
 
 Laurie Acid. 
 
 
 
 | 
 
 62-0 
 
 100 
 
 
 
 59 -8 
 
 90 
 
 10 
 
 57-4 
 
 80 
 
 20 
 
 54-5 
 
 70 
 
 30 
 
 51-2 
 
 60 
 
 40 
 
 47-0 
 
 50 
 
 50 
 
 40-1 
 
 40 
 
 60 
 
 38-3 
 
 30 
 
 70 
 
 37-1 
 
 20 
 
 80 
 
 41-5 
 
 10 
 
 90 
 
 "?* 
 
 
 
 100 
 
 fusible of the ingredients. Thus, in the case of a mixture of 
 myristic and lauric acids containing equal quantities (50 per 
 cent.) of each, since the ingredients melt respectively at 58-8 
 a-nd 43 -6 C., the melting point of the mixture would a priori be 
 
 .. . 58*8 + 43*6 , , .. n o-o t 
 
 expected to be- T) = 51 '!; whereas it actually is 61 *4, 
 
 or 13 -8 lower than the calculated temperature, and 6*2 lower 
 than the fusing point of the most fusible ingredient. 
 
 Dalican's Method. The following table by Dalican* repre- 
 sents the solidifying points of various mixtures of pure free 
 stearic and oleic acids, analogous to those obtained by saponify- 
 ing tallow completely and separating the fatty acids from the 
 soaps formed ; these were deduced by determining the tempera- 
 ture to which the thermometer rose when some 20 grammes of 
 mixed pure fatty acids were placed in a test-tube at a tempera- 
 ture a little above the solidifying point, and allowed to cool 
 slowly ; when incipient solidification became visible the contents 
 of the tube were stirred with the thermometer immersed therein, 
 giving a rotary movement three times from right to left, and 
 three times in the opposite direction ; during this stirring the 
 thermometer usually slightly fell just at first, but in every case 
 rose again to a point where the temperature remained stationary 
 for about two minutes, the disengagement of latent heat during 
 solidification balancing the loss of heat by radiation and convec- 
 tion, &c. The temperatures quoted are the stationary ones thus 
 observed with the various mixtures examined. The joint per- 
 centages given in the table only add up to 95, the average yield 
 of total fatty acids from tallow being taken as 95 per cent., after 
 
 * Moniteur Scientifique, Paris, 1868. 
 
FUSING AND SOLIDIFYING POINTS. 
 
 allowing for small quantities of water present and loss of weight 
 by elimination of glycerol (vide Chap, vin.) : 
 
 Tf-mporature 
 Centigrade. 
 
 Stearic Acid. 
 
 Oleic Acid. 
 
 Temperature 
 Centigrade. 
 
 Stearic Acid. 
 
 Oleic Acid. 
 
 40 
 
 35-15 
 
 59-85 
 
 45-5 
 
 52-25 
 
 4275 
 
 40%") 
 
 36-10 
 
 58-90 
 
 46 
 
 53-20 
 
 41-80 
 
 41 
 
 38-00 
 
 57-00 
 
 46-5 
 
 55-10 
 
 39-90 
 
 41-5 
 
 38-95 
 
 56-05 
 
 47 
 
 57-95 
 
 37-05 
 
 42 
 
 40-90 
 
 54-10 
 
 47-5 
 
 58-90 
 
 36-10 
 
 42-5 
 
 4275 
 
 52-25 
 
 48 
 
 61-75 
 
 33-25 
 
 43 
 
 43-70 
 
 51-30 
 
 48-5 
 
 66-50 
 
 28-50 
 
 43-5 
 
 44-65 
 
 50-35 
 
 49 
 
 71-25 
 
 23-75 
 
 44 
 
 47-50 
 
 47-50 
 
 49-5 
 
 72-20 
 
 22-80 
 
 44-5 
 
 49-40 
 
 45-60 
 
 50 
 
 75-05 
 
 19-95 
 
 43 
 
 51-30 
 
 43-70 
 
 
 
 
 The method of manipulation thus employed by Dalican is 
 applicable in the case of most other substances the solidifying 
 point of which is required ; but the amount of rise indicated by 
 the thermometer above the temperature of incipient solidification 
 varies considerably in different cases, a constant temperature for 
 two minutes or more not being always attained. Finkener* finds 
 that more concordant valuations are obtainable if the vessel 
 containing the fused fatty matter is enclosed in an envelope of 
 wadding, or jacketted with a wooden envelope, so as to diminish 
 the rate of cooling. 
 
 Solidifying Point 
 of Tallow Fatty 
 
 Percentage of " Stearine " (Solid Fatty Acids) of Solidification Point 
 
 Acids. 
 
 ' 
 
 Degrees C. 
 
 48 Degrees C. 
 
 50 Degrees C. 
 
 52 Degrees C. 
 
 54 S Degrees C. 
 
 10 
 
 3-2 
 
 2-7 
 
 2-3 
 
 2-1 
 
 15 
 
 7-5 
 
 6-6 
 
 5-7 
 
 4-8 
 
 20 
 
 13-0 
 
 11-4 
 
 9-7 
 
 8-2 
 
 25 
 
 19-2 
 
 17-0 
 
 148 
 
 12-6 
 
 30 
 
 27-9 
 
 23-2 
 
 21-4 
 
 18-3 
 
 35 
 
 39-5 
 
 34-5 
 
 30-2 
 
 25-8 
 
 40 
 
 57'8 
 
 49-6 
 
 43-5 
 
 37-0 
 
 42 66-6 
 
 57-6 
 
 50-5 
 
 429 
 
 44 77-0 
 
 66-2 
 
 58-4 
 
 49-8 
 
 46 87-5 
 
 75-8 
 
 67-0 
 
 56-8 
 
 48 100-0 
 
 87-2 
 
 76-6 
 
 65-0 
 
 50 
 
 100-0 
 
 87-0 
 
 74-5 
 
 52 
 
 
 
 100-0 
 
 84-8 
 
 54 
 
 
 
 ... 
 
 95-3 
 
 54-8 
 
 
 
 
 100-0 
 
 * Journal Soc. Chem. Industry, 18S9, p. 423, and 1890, p. 1071. 
 
OILS, FATS, WAXES, ETC. 
 
 De Schepper and Geitel give the foregoing table representing 
 the amounts of mixed solid fatty acids of different solidification 
 points practically obtainable from tallow, when these acids are 
 separated from oleic acid to such an extent as to possess the 
 solidification points named. 
 
 The same authors give the following analogous table for the 
 relative amounts of mixed solid fatty acids practically obtainable 
 from palm oil : 
 
 Solidifying Point 
 
 
 
 of Palm Oil Fatty 
 
 Percentage of " 
 
 Stearine " (Solid Fatty Acid?) of Solidification Point 
 
 Acids. 
 
 
 
 Degrees C. 
 
 48 Degrees C. 
 
 50 Degrees C. 
 
 52 Degrees C. 
 
 55-4 Degrees C. 
 
 10 
 
 4-2 
 
 3-6 
 
 3-2 
 
 2-6 
 
 15 
 
 10-2 
 
 9-8 
 
 7-8 
 
 6-6 
 
 20 
 
 17-4 
 
 150 
 
 14-4 
 
 11-0 
 
 '25 
 
 26-2 
 
 22-4 
 
 19-3 16-2 
 
 30 
 
 34-0 
 
 30-5 
 
 26-6 22-3 
 
 35 
 
 45-6 
 
 40-8 35-8 29-8 
 
 40 
 
 63-0 
 
 55-2 48-6 40-6 
 
 42 70-5 
 
 02-2 552 45-5 
 
 44 79-2 
 
 70-2 
 
 62-0 51-4 
 
 46 
 
 89-4 
 
 78-8 
 
 69-8 
 
 57-8 
 
 48 
 
 100-0 
 
 88-0 78-6 65-0 
 
 50 
 
 
 100-0 89-6 
 
 73-4 
 
 52 
 
 
 
 100-0 82-8 
 
 54 
 
 
 ... 
 
 92 - 2 
 
 55-4 
 
 
 
 ibo-o 
 
 CHAPTER V. 
 
 SPECIFIC GRAVITY AND VISCOSITY. 
 SPECIFIC GRAVITY OF OILS, FATS, &c. 
 
 INASMUCH as the majority of natural oils, fats, and similar sub- 
 stances are mixtures of more than one constituent, the relative 
 proportions, and even the nature of the ingredients being subject 
 to some degree of variation, it results that the general physical 
 characters of any given oil, c., are liable to fluctuation within 
 certain limits. This is particularly the case with the specific 
 gravity of such materials, differences in the climate and soil 
 in which seed-bearing plants are grown, in the degree of culti- 
 vation and the maturity of the crop, and such like causes 
 
SPECIFIC GRAVITY. 77 
 
 often producing measurable differences in the relative density of 
 the oil extracted ; as also, to some extent, does the method 
 of extraction adopted, the first runnings obtained by pres- 
 sure in the cold being often perceptibly lighter bulk for bulk 
 than those obtained later by hot pressure. In similar fashion, 
 variations in the particular breed of animal (e.g., in the case of 
 oxen and sheep), the part of the body from which the fat is 
 extracted, the mode of feeding, &c., often correspond with ana- 
 logous fluctuations in the case of animal fats ; added to which, 
 the method of refinement adopted and the degree of purification 
 effected, cause variations in proportion to the amount of residual 
 mucilaginous or albuminous matters left unremoved ; whilst the 
 age of the sample is often a material point, many kinds of oil 
 having a tendency to absorb oxygen from the air, thereby 
 becoming more dense. 
 
 Notwithstanding these sources of variation, however, it is 
 often possible to obtain useful information as to the freedom or 
 otherwise of oils, tfcc., from admixture with adulterating sub- 
 stances by examining their specific gravity ; or, in many cases, 
 preferably, the specific gravity of the free fatty acids obtainable 
 from them by saponification. This determination is most accur- 
 ately effected by means of the pyknometer* (specific gravity 
 bottle); but since, excepting in comparatively few special cases 
 (e.g., butter analysis), a very high degree of accuracy is unneces- 
 sary on account of the possible natural fluctuations in density, 
 simpler instruments are in most cases sufficient for the purpose 
 in view, more especially when checked or "calibrated,"' as de- 
 scribed below. Thus for most fluid oils the indications of a 
 fairly well made areometer (hydrometer), used at a standard 
 temperature, are sufficiently accurate ; whilst either for ordinary 
 temperatures or for more elevated ones, the hydrostatic balance 
 is extremely convenient. In using this latter instrument at 
 higher temperatures (e.g., near that of boiling water V it should 
 not be forgotten that if the plummet immersed in the liquid to 
 be examined (as shown in Figs. 11 and 12) be made of glass, it 
 will displace more than 0'2 per cent, (or upwards of 2 per mille) 
 more fluid at near the boiling point of water than at 15 f ; so 
 that if originally constructed to give accurate indications at 15, 
 the values indicated at near 100 will be more than 2 per mille 
 too high on account of the greater displacement ; whence, in the 
 
 * For a description of some highly accurate forms of this instrument and 
 their moie of use, together with a discussion of the corrections indispens- 
 able when results are required to be accurate to a unit in the fourth 
 decimal place ( O'OOOl), and a fortiori to one in the fifth place ( O'OOOOl), 
 vide a paper by the author, Journ. Soc. C/iem. Industry, 1892, p. 297. 
 
 t The cubical coefficient of expansion of glass is near '000025 = - ; 
 
 'rL/jUiJiJ 
 
 so that a rise of temperature of 85 represents an increment in volume of 
 
 o~ 
 
 = 2-125 per mille. 
 
78 OILS, FATS, WAXES, ETC. 
 
 Cease of fluid oils, the specific gravity of which is usually from 
 9 to -95, the indications at near 100 will be close to -002 too 
 high. Analogous errors of excess apply to all glass araeometers 
 and pyknometers when graduated at one temperature and used 
 at a higher one. 
 
 Another matter to be remembered is that the numerical value 
 arrived at expresses different things, according as the water with 
 which the instrument is graduated is at one temperature or 
 another ; this applies equally to the indications of the pyk- 
 
 Fig. 11. 
 
 nometer, the araeometer, and the hydrostatic balance. When 
 the indications represent the ratio between the weight of a given 
 volume of substance and that of the same weight of water, both 
 at the same temperature t, the value is the specific gravity at t ; 
 thus the specific gravity at 100 of a given oil or melted wax is 
 the weight of a given volume of substance compared with that of 
 the same weight of water also at 100. If, however, the oil be 
 at t, and the water at a different temperature, T, the value is 
 neither the specific gravity at t nor that at T. If T = 4 C., the 
 value is the weight in grammes attof\ c.c. of oil, since at 4 C. 
 1 c.c. of water weighs 1 gramme ; this value is often considerably 
 different from the specific gravity of the oil at , the more so 
 the higher the value of t ; thus if t = 100 0, since 1 c.c. of water 
 at 100 weighs 0-9586 gramme, the weight of 1 c.c. of oil at 100 
 will be only 0-9586 times the specific gravity of the oil at 100 ; 
 i.e., the latter value is more than 4 per cent, in excess of the 
 
SPECIFIC GRAVITY. 79 
 
 former one. Unfortunately, most observers have recorded their 
 results in neither of these two forms, but have used a mode of 
 expression where T is not 4, and is not = t. Tne result thus 
 expressed is the relative density of water at t referred to water 
 
 at T, sometimes expressed as the relative density at - - ; when 
 
 T = 15 -5 C., a temperature frequently chosen, this value' repre- 
 sents 1-0009 times the weight of 1 gramme of oil at ^ since 
 1 c.c. of water at 15*5 weighs '9991 gramme. 
 
 Fig. 12. 
 
 Lefebre's Oleometer. Fig. 13 represents Lefebre's araeo- 
 meter, especially intended for oils the specific gravity of which 
 at 15 -5 ranges from 0*9 to 0*95 ; the instrument is so graduated 
 that the specific gravity is directly read off when immersed in a 
 fluid at the standard temperature of 15 -5 ; at various points the 
 average specific gravities of normal oils of different kinds are 
 marked off (linseed oil, olive oil, (fee.); usually, to save figures, 
 only the second and third decimal places are given i.e., 35 
 indicates '935, 8 represents -908, and so on. If the tempera- 
 ture differ slightly from the normal one of 15 -5, a correction is 
 
 2 
 made by adding (or subtracting) - x -001 for every degree of 
 
 o 
 
 temperature above (or below) the standard, this correction being 
 based on the fact that most oils expand on heating to nearly the 
 same extent, so that the specific gravity becomes lowered by 
 about -00068 per 1 C. (vide p. 93). 
 
80 
 
 OILS, FATS, WAXES, ETC. 
 
 Fig. 13. 
 
 When it is required to deter- 
 mine the specific gravity of an oil, 
 &c.j at a temperature somewhat 
 elevated (say at near 100), some 
 form of heating arrangement must 
 be employed, whereby the vessel 
 containing the oil, <fcc., can be 
 constantly maintained at the re- 
 quired temperature for some time. 
 Fig. 12 illustrates a form of hot 
 waterbath thus used for a West- 
 phal hydrostatic balance. 
 
 When temperatures other than 
 100, but higher than the ordi- 
 nary atmospheric temperatures 
 are required, the hot air arrange- 
 ment indicated by Fig. 1 4 may be 
 employed ; in this case the vessel, 
 C, containing the oil, tfec., to be 
 examined, is heated by a hot air 
 bath, B, the ascending hot gases 
 from a ring burner being made to 
 circulate as indicated by the 
 arrows. The temperature of the 
 inner hot air space is shown by 
 the thermometer, D, and should 
 not differ much from that of the 
 oil itself, as indicated by a ther- 
 mometer immersed therein (in 
 the figure, as also in Fig. 12, this 
 is enclosed inside the plummet*). 
 A thermostat, or heat regulator 
 where the gas supply is auto- 
 matically regulated, should be 
 employed in addition. 
 
 Fig. 15 represents Ambuhl's 
 arrangement where the vessel 
 containing the oil is heated in a 
 current of vapour (steam from 
 boiling water, or other vapour 
 emitted by a fluid of convenient 
 boiling point). 
 
 * Fletcher has recently constructed a 
 thermohydrometer, consisting of an ordi- 
 nary arteometer with enclosed thermo- 
 meter, so as to read off the temperature 
 of the fluid examined simultaneously 
 with the indicated relative density. 
 
SPECIFIC GRAVITY. 
 
 81 
 
 Fig. 14. 
 
 Fig. 15. 
 
82 
 
 OILS, FATS, WAXES, ETC. 
 
 In the Paris Municipal Laboratory, a peculiar kind of 
 " thermal araeometer," constructed by Langlet, is in use for the 
 examination of olive oil. This is an araeometer with an internal 
 thermometer, so adjusted that when the instrument is placed in 
 pure olive oil, the level of the fluid indicated on the stem and 
 the thermometer reading are practically the same ; if the oil be 
 warmed so as to become lighter, the hydrometer sinks to an in- 
 creased depth, and the thermometer column rises through the 
 same length, so that the two readings always correspond. If, 
 however, the oil be not genuine olive oil, but contain an admixture 
 of other oil of different density, the readings will not agree. Thus, 
 the following pairs of readings correspond with certain oils other 
 than olive oil and various mixtures (Muntz) : 
 
 
 
 Thermometer 
 Reading. 
 
 Reading on 
 Stem. 
 
 
 
 Degrees C. 
 
 Degrees C. 
 
 
 
 18-9 
 
 11-0 
 
 Cotton seed oil, . 
 
 , , . * * 
 
 18-9 
 
 10-5 
 
 3 Parts olive oil to 
 
 1 of cotton seed oil, 
 
 18-1 
 
 16-1 
 
 2 
 
 1 
 
 18-6 
 
 15-8 
 
 3 
 
 1 of sesame oil, 
 
 18-3 
 
 16-5 
 
 2 
 
 1 
 
 18-6 
 
 16-1 
 
 3 
 
 1 of colza oil, 
 
 18-3 
 
 18-5 
 
 3 
 
 1 of earthnut oil, 
 
 18-1 
 
 17-2 
 
 2 
 
 1 
 
 18-7 
 
 17-5 
 
 52 4 
 
 8 ,, 
 
 187 
 
 17-4 
 
 CONSTRUCTION OF TABLES OF ERRORS FOR 
 
 HYDROMETERS AND HYDROSTATIC 
 
 BALANCES. 
 
 Hydrometers, as usually sold, are not infrequently affected by 
 errors of construction and graduation, sufficiently great to render 
 their indications inexact to at least one unit in the third 
 decimal place, and sometimes much more, quite apart from any 
 error arising from the difficulty of reading off the exact level. 
 To do this with as little error as possible, the hydrometer should 
 be floated in a jar with a white strip of enamel at its back, or a 
 strong light so placed that the lowest point of the meniscus 
 formed by the upper part of the fluid can be read off on the 
 hydrometer scale. Unless the fluid examined be excessively 
 dark coloured, this can generally be done pretty readily, the eye 
 being level with the bottom of the meniscus (as in reading a, 
 burette). 
 
 To eliminate, as far as possible, errors of graduation, it is 
 
SPECIFIC GRAVITY. 
 
 83 
 
 necessary to construct for each instrument a table of errors, 
 deduced by directly comparing at the same temperature the 
 values obtained with different fluids simultaneously examined 
 by means of an accurate pyknometer, and with the hydrometer. 
 The following illustration will suffice to indicate the mode of 
 construction of such a table of errors for a hydrometer intended 
 to show at 15 '5 C. values ranging between '900 and "950 ; when 
 such a table is carefully prepared, the corrected reading of a 
 tolerably sensitive hydrometer should be exact within two, 
 or even one unit in the fourth decimal place. The figures are 
 expressed on the thousandfold scale,* three comparisons being 
 made respectively near the top, middle, and bottom of the hydro- 
 meter scale. 
 
 True Specific Gravity 
 at 15 -5 by Pyknometer. 
 
 Hydrometer Reading 
 at 15 5. 
 
 Difference. 
 
 948-4 
 924-7 
 901-1 
 
 947-5 
 925-0 
 902-5 
 
 + 0-9 
 - 0-3 
 - 1-4 
 
 From these comparisons the following table of errors is 
 deduced by interpolation : 
 
 Hydrometer Reading 
 at ii> -5. 
 
 Correction to be added 
 to obtain the True 
 Specific Gravity. 
 
 Corrected Specific 
 Gravity at 15-t;. 
 
 900-0 
 
 - 1-50 
 
 898-5 
 
 905-0 
 
 - 1-25 
 
 903-75 
 
 910-0 
 
 - TOO 
 
 909-0 
 
 915-0 
 
 - 0-75 
 
 914-25 
 
 920-0 
 
 - 0-50 
 
 919-5 
 
 925-0 
 
 - 0-30 
 
 924-7 
 
 930-0 
 
 - 0-05 
 
 929-95 
 
 935-0 
 
 + 0-20 
 
 935-2 
 
 940-0 
 
 + 0-45 
 
 940-45 
 
 945-0 
 
 + 0-75 
 
 945-75 
 
 950-0 
 
 + i-oo 
 
 951-0 
 
 In similar fashion, a table of errors may be constructed for a 
 hydrostatic balance ; thus, the following numbers were obtained 
 with such an instrument of fairly good construction, the values 
 being here expressed on the ordinary scale, and not multiplied 
 by 1,000, the temperature throughout being 15-5: 
 
 * To save decimals, specific gravity values are often quoted after multi- 
 plication by 1,000 : thus, an oil of specific gravity 0'967 is said " to have 
 the gravity 967," and so on. 
 
OILS, FATS, WAXES, ETC. 
 
 True Specific Gravity 
 by Pyknometer. 
 
 Value indicated by 
 Hydrostatic Balance. 
 
 Difference. 
 
 0-9976 
 0-9517 
 0-9098 
 0-8524 
 
 0-9995 
 0-9530 
 0-9100 
 0-8520 
 
 - 0-0019 
 - 0-0013 
 - 0-0002 
 + 0-0004 
 
 From these determinations the following table of errors is 
 calculated by interpolation : 
 
 Speciflc Gravity 
 indicated by 
 Hydrostatic Balance. 
 
 Correction to be added 
 to obtain the True 
 Speciflc Gravity. 
 
 Corrected Speciflc 
 Gravity. 
 
 0-85 
 
 + -0004 
 
 8504 
 
 0-86 
 
 + -0003 
 
 8603 
 
 0'S7 
 
 + -0002 
 
 8702 
 
 0-88 
 
 + -oooi 
 
 8801 
 
 0-89 
 
 
 
 8900 
 
 0-90 
 
 - -oooi 
 
 8999 
 
 0-91 
 
 - -0002 
 
 9098 
 
 0-92 
 
 - -0005 
 
 9195 
 
 093 
 
 - -ooos 
 
 9292 
 
 0-94 
 
 - -0010 
 
 9390 
 
 0-95 
 
 - -0013 
 
 9487 
 
 0-96 
 
 - -0014 
 
 9586 
 
 0-97 
 
 - -0015 
 
 9685 
 
 0-98 
 
 - -0017 
 
 9783 
 
 0-99 
 
 - -0018 
 
 9882 
 
 1-00 
 
 - -0019 
 
 9981 
 
 Considerably larger corrections than most of those indicated in 
 this table have sometimes to be applied to instruments as 
 purchased, in order to deduce the true specific gravities from the 
 direct results of observation. 
 
 Hydrometer Scales. A considerable number of more or 
 less arbitrary scales for araeometers are in use, a circumstance 
 often leading to much practical inconvenience. The simplest or 
 "gravity" scale is that where the specific gravity of the fluid 
 is directly indicated by the level to which the instrument sinks 
 in the fluid (at the normal temperature) e.g., in Lefebre's 
 oleometer (p. 80). Twaddell's scale is not much inferior in 
 simplicity, each degree on that scale representing an alteration 
 of 5 units in gravity on the thousandfold scale (p. 83), and the 
 valuation being given by the formula 
 
 S = 1000 + 5n, 
 
 where S is the specific gravity on the thousandfold scale, and n 
 the hydrometer reading ; thus 10 T represents specific gravity 
 
SPECIFIC GRAVITY. 
 
 85 
 
 1-050; 100 T, specific gravity 1-500; 150 T, specific gravity 
 1*750 ; and so on. The same rule applies in the case of a fluid 
 having a density less than that of water, the value of n being 
 then negative, so that if n = 10 T, the specific gravity would 
 be '950, and so on ; the negative-scale Twaddell hydrometer, 
 however, is but rarely used. A variety of other scales are also 
 in use, more especially in different parts of the Continent ; the 
 following table of formulae is given by Benedikt, expressing the 
 relative values of their degrees, S and n having the same mean- 
 ings as above : 
 
 Araeometer of 
 
 Temperature. 
 
 Fluids Heavier than 
 Water. 
 
 Fluids Lighter than 
 Water. 
 
 Balling, . 
 Beaume, 
 Beaume,* 
 Beaume, t 
 Beck, . 
 Brix, 
 Cartier, . 
 Fischer, . 
 Gay Lussac,+ . 
 E. G. Greiner, 
 Stoppani, 
 
 Degrees. 
 
 17 '5 C. 
 12 -5 C. 
 15-0 C. 
 17 "5 C. 
 
 12 -5 C. 
 
 /12-5R. 
 \15-625C. 
 
 12 -5 C. 
 
 /12-5R. 
 \15-625C. 
 
 4C. 
 
 /12-5R. 
 \15-625C. 
 
 /12-5R. 
 \15-625C. 
 
 200 
 
 200 
 
 200 - n 
 144 
 
 " 200 + M 
 144 
 
 144 - n 
 144-3 
 
 134 + n 
 144-3 
 
 144-3 - n 
 146-78 
 
 134-3 + n 
 s 146-78 
 
 - 146-78 - n 
 
 170 
 = l70"^i 
 
 400 
 
 136-78 + n 
 
 o 170 
 170 + n 
 
 c 400 
 
 ~ 400 - n 
 
 400 
 400 - n 
 
 100 
 
 o = 
 
 n 
 400 
 
 400 + n 
 Q 136-8 
 
 126-1 + n 
 
 400 
 
 400 + n 
 
 s = ioo 
 
 n 
 400 
 
 400 - n 
 166 
 
 400 + n 
 166 
 
 166 - n 
 
 166 + n 
 
 *S= -.70 : for lighter fluids (Schadler). 
 
 -1 44 "> T" ?/ 
 
 f S = ul*7S+ n for H g hter fluids (SchUdler). 
 
 re for heavier fluids, and = jggqp- for lighter ones (Schadler) 
 
 S = j 
 S = ,-7.7, -- - for heavier fluids, and = j^- for lighter ones (Schadler). 
 
 160 n 
 
 160 + n 
 
A) 
 
 o 
 
 and Hurter (Alkali Maker's Pocket-book) regard the 
 
 144-3 
 
 36 OILS, FATS, WAXES, ETC. 
 
 Lunge 
 
 series of values got by means of the formula S = . 
 
 144-3 - n 
 
 as the only " rational " one of the various Beaume scales in 
 use; taking the formula at 15 C., the specific gravity of 
 water at 15 = B. ; whilst 66 B. represents specific gravity 
 144-3 
 
 = 1-8426. 
 
 The following table exhibits the relation- 
 
 144-3 - 66 
 
 ships between the values of " rational " Beaume degrees, Twaddell 
 
 degrees, and true specific gravity : 
 
 Beaume. 
 
 Twaddell. 
 
 Specific Gravity. 
 
 Beaumd. 
 
 Twaddell. 
 
 Specific Gravity. 
 
 
 
 
 
 1-000 
 
 36 -Q 
 
 66-4 
 
 332 
 
 0-7 
 
 1-0 
 
 1-005 
 
 38 
 
 71-4 
 
 357 
 
 1-0 
 
 1-4 
 
 1-007 
 
 40 
 
 76-6 
 
 383 
 
 1-4 
 
 2-0 
 
 1-010 
 
 42 
 
 82-0 
 
 410 
 
 2-0 
 
 2-8 
 
 1-014 
 
 44 
 
 87-6 
 
 438 
 
 2-7 
 
 4-0 
 
 1-020 
 
 46 
 
 936 
 
 468 
 
 4-0 
 
 5-8 
 
 1-029 
 
 48 
 
 99-6 
 
 498 
 
 5-0 
 
 7'4 
 
 1-037 
 
 50 
 
 106-0 
 
 530 
 
 6-7 
 
 10-0 
 
 1-050 
 
 52 
 
 112-6 
 
 563 
 
 80 
 
 12-0 
 
 1-U60 
 
 54 
 
 119-4 
 
 597 
 
 10-0 
 
 15-0 
 
 1-075 
 
 56 
 
 127-0 
 
 635 
 
 14-0 
 
 21-6 
 
 1-108 
 
 58 
 
 134-2 
 
 671 
 
 16-0 
 
 25-0 
 
 1-125 
 
 60 
 
 142-0 
 
 710 
 
 18-8 
 
 30-0 
 
 1-150 
 
 61 
 
 146-4 
 
 732 
 
 20-0 
 
 32-4 
 
 1-362 
 
 62 
 
 150-6 
 
 753 
 
 23-0 
 
 38-0 
 
 1-190 
 
 63 
 
 155-0 
 
 775 
 
 25-0 
 
 42-0 
 
 1-210 
 
 64 
 
 159-0 
 
 795 
 
 27-0 
 
 46-2 
 
 1-231 
 
 65 
 
 164-0 
 
 1-820 
 
 30-0 
 
 52-6 
 
 1-263 
 
 66 
 
 J68-4 
 
 1-842 
 
 33'0 
 
 59-4 
 
 1-297 
 
 67 
 
 173-0 
 
 1-865 
 
 RELATIVE DENSITIES OF THE PRINCIPAL 
 OILS, FATS, <fec. 
 
 Many experimenters have published the results of their deter- 
 minations of the specific gravities of genuine oils, &c. ; in most 
 instances the observed limits of variation in this respect are not 
 very wide, being mainly dependent on the freedom from rancidity 
 and free fatty acids ; the degree of refinement (or freedom from 
 mucilaginous matter, &c.) ; the age of the sample (whether 
 oxygen has been absorbed or not), and so on. In many cases a 
 measurable difference is observable between the density of the 
 oil first expressed, especially when cold drawn, and that of the 
 later portions obtained by the aid of heat, the latter being 
 generally heavier. The following figures are given by Schadler 
 
SPECIFIC GRAVITY. 
 
 87 
 
 as expressing the average values of the specific gravities at 15 
 of a large number of the more commonly occurring vegetable and 
 other oils : 
 
 Name of Oil. 
 
 Oil from Seed of 
 
 Specific 
 Gravity 
 at 15. 
 
 Almond oil, 
 
 Amygdalus communis, 
 
 9190 
 
 Arachis oil (earthnut oil), . 
 
 Arachis hypogsea, 
 
 9202 
 
 Bassia fat (Illipe butter), . 
 
 Bassia longifolia, Roxb., 
 
 9580 
 
 Ben oil, .... 
 
 Moringa oleifera, 
 
 9120 
 
 Belladonna seed oil, . 
 
 Atropa belladonna, 
 
 9250 
 
 Beechnut oil, 
 
 Fagus sylvatica, 
 
 9225 
 
 Camelina oil (gold of pleasure), 
 
 Camelina sativa, 
 
 9328 
 
 Cacao butter, 
 
 Theobroma cacao, 
 
 9000 
 
 Castor oil, .... 
 
 Ricinus communis, 
 
 9667 
 
 Cokernut oil, 
 
 Cocos nucifera, 
 
 9250 
 
 Colza oil, . 
 
 Brassica campestris, 
 
 9150 
 
 Cotton seed oil (raw), 
 
 Gossypium herbaceum, 
 
 9224 
 
 ,, (refined), . 
 
 
 
 9230 
 
 Cro^on oil, 
 
 Croton tiglium, 
 
 9550 
 
 Euonymus oil (spindel oil), 
 
 Euonymus europseus, 
 
 9380 
 
 Grape seed oil, . 
 
 Vitis vinifera, 
 
 9202 
 
 Hemp seed oil, . 
 
 Cannabis sativa, 
 
 9276 
 
 Gourd seed oil, . 
 
 Cucurbita pepo, 
 
 9251 
 
 Hazelnut oil, 
 
 Corylus avellana, 
 
 9154 
 
 Linseed oil (raw), 
 
 Linum usitatissimum, 
 
 9299 
 
 (boiled), . 
 
 99 99 
 
 9411 
 
 Melon seed oil, . 
 
 Cucurbita pepo, 
 
 9251 
 
 Madia oil, .... 
 
 Madia sativa, 
 
 9350 
 
 Mustard oil, 
 
 Sinapis nigra, 
 
 9182 
 
 Maize oil, .... 
 
 Zea mais, 
 
 9210 
 
 Nut oil (walnut oil), . 
 
 Juglans regia, 
 
 9260 
 
 Nutmeg oil, 
 
 Myristica moschata, 
 
 9480 
 
 Olive oil (greenish yellow), 
 
 Olea europsea, 
 
 9144 
 
 (best quality), 
 ,, (Galipoli), . 
 
 > 
 > > 
 
 9177 
 9196 
 
 Pine oil (red pine seed oil ; "1 
 pinaster seed oil), . . / 
 
 Pinus picea, 
 
 9285 
 
 Palm oil, .... 
 
 Elais guinensis, &c., 
 
 9046 
 
 Poppy seed oil, . 
 Yellowhorn poppy oil, 
 
 Papaver somniferum, 
 Papaver glaucium, 
 
 9245 
 9250 
 
 Plum kernel oil, . . Prunus domestica, 
 
 9127 
 
 Radish seed oil, . . 
 
 Raphanus sativus, 
 
 9162 
 
 Rape oil, .... 
 Red rape oil, 
 Winter rape oil, 
 
 Brassica napus oleifera, 
 Hesperis matronalis, 
 Brassica rapa olifera biennis, 
 
 9157 
 9282 
 9154 
 
 ,, (refined), . 
 
 5 > 
 
 9177 
 
 Sesame" oil, 
 
 Sesamum orient/ale, 
 
 9235 
 
 Sunflower seed oil, 
 
 Helianthus annuus, 
 
 9262 
 
 Tobacco seed oil, 
 
 Nicotiana tabacum, 
 
 9232 
 
 Weld seed oil, . 
 
 Reseda luteola, 
 
 9358 
 
88 
 
 OILS, FATS, WAXES, ETC. 
 
 ANIMAL OILS, &c. 
 
 Name of Oil. 
 
 Source. 
 
 Specific 
 Gravity 
 at 15. 
 
 Bone fat, .... 
 Cod liver oil, 
 (purified), 
 ,, (Labrador), 
 Mutton tallow, . 
 Seal oil, .... 
 
 Bones, 
 Gadus morrhua, &c., 
 > > 
 
 Sheep, 
 Phoca vitulina, &c., 
 
 9185 
 9200 
 9270 
 9237 
 9147 
 9246 
 
 ,, (purified), 
 Sperm oil, .... 
 Whale oil (train oil), . 
 ,, (white), 
 
 Physeter macrocephalus, 
 Balsena mysticetus, 
 
 9261 
 9115 
 9250 
 9258 
 
 The following determinations of the specific gravity at 15 of 
 various solid fats, &c., are given by Hager and Dieterich : 
 
 
 Hager. 
 
 Dieterich. 
 
 Beef tallow, 
 
 925 to -929 
 
 952 to -953 
 
 Sheep's tallow, . 
 
 937 to -940 
 
 961 
 
 Hog's lard, . 
 
 931 to -932 
 
 
 Stearine, 
 
 ... 
 
 971 to -972 
 
 Stearic acid (fused), . 
 
 964 
 
 
 ,, (crystallised), 
 
 967 to -969 
 
 m 
 
 Butter fat (clarified), . 
 
 938 to -940 
 
 
 (several months old), 
 
 936 to -937 
 
 
 Artificial butter, 
 
 924 to -930 
 
 
 Cacao butter (fresh), . 
 
 950 to -952 
 
 980 to -9S1 
 
 , , (very old), 
 
 945 to -946 
 
 
 Beeswax (yellow), 
 
 959 to -962 
 
 963 to -964 
 
 (white), 
 
 919 to -925 
 
 973 
 
 Japanese wax, 
 
 977 to -978 
 
 975 
 
 ,, (very old), 
 
 963 to -964 
 
 ... 
 
 Spermaceti, 
 
 ... 
 
 960 
 
 Colophony (American), 
 
 1-100 
 
 1-108 
 
 ,, (French), . 
 
 
 1-104 to 1-105 
 
 Galipot resin (purified), 
 
 
 1-045 
 
 Crude ozokerite, . 
 
 
 952 
 
 Ceresin (yellow), 
 
 925 to -928 
 
 922 
 
 (half white), . 
 
 923 to -924 
 
 920 
 
 ,, (pure white), . 
 
 905 to -908 
 
 918 
 
 
 
 
 
 The following valuations of specific gravity at 37 '8 C. = 100 F. 
 are given by Muter * : 
 
 * Spon's Encyclopaedia of Arts and Manufactures, ii., p. 1,469. The 
 values quoted are the numbers expressing the weights of given volumes of 
 
SPECIFIC GRAVITY. 
 
 89 
 
 Oil. 
 
 Limits of Specific Gravity. 
 
 Average. 
 
 
 8980 to 
 9073 
 9550 
 9103 
 9170 
 9130 
 9114 
 9173 
 9190 
 9076 
 9232 
 9320 
 9052 
 9080 
 9052 
 9150 
 9060 
 9053 
 9136 
 8672 
 9056 
 
 9109 
 9020 
 9576 
 9152 
 9197 
 9140 
 9220 
 9180 
 9 i95 
 9082 
 9300 
 9440 
 9079 
 9090 
 9079 
 9155 
 9077 
 9065 
 9195 
 8963 
 9066 
 
 9056 
 9085 
 9558 
 
 9176 
 9136 
 9176 
 9179 
 9193 
 9078 
 9252 
 9380 
 9070 
 9085 
 9070 
 9154 
 9067 
 9067 
 9179 
 8724 
 9060 
 
 Arachis (groundnut) oil, 
 Castor, 
 
 
 Cotton seed (brown), . 
 ,, (refined salad oil), . 
 Cod fish oil, 
 
 
 Lard oil, ..... 
 
 (boiled) 
 Neat's foot, 
 Nut, 
 
 Olive, 
 
 
 Rape, 
 ,, refined (Colza), . 
 Seal, 
 
 Sperm, 
 Whale, 
 
 
 Since 1 c.c. of water weighs 1-0000 grm. at 4, -99908 at 
 l5-5, and -9933 at 37'8, these values, when reduced to the 
 standard of "specific gravity at 37'8 referred to water at 15'5" 
 
 . . . ., .. -9933 
 
 be ^ ess m the proportion -7^ onQ 
 * 
 
 / . fl .37-8\ 
 
 I specific gravity at -f K'^E ) > 
 \ lo "O/ 
 
 i.e., less by 0'58 per cent. ; that is, less by from -0051 to -0056. 
 If reduced to the standard of " weight at 37'S in grins. 
 
 *9933 
 per c.c.," tney will be less in the proportion y^/^ *' by -67 
 
 per cent. ; that is, less by from -0058 to -0064. 
 
 Classification of Oils and Fats, &c., according to their 
 Relative Densities. The following tables are given by A. H. 
 Allen,* exhibiting the general classification of oils and fats, &c., 
 according to their respective densities ; the relative density at 
 
 99 
 15 '5 being taken in the case of liquid oils and that at pnr~ in 
 
 the case of fats, &c., solid or nearly so at ordinary tempera- 
 tures : 
 
 oil at 37'8, referred to the weight of the same volume of water at the same 
 temperature as unity, and consequently are the true specific gravities at 
 37 "8 (p. 78). Muter, however, prefers to call them " actual densities ;" an 
 unfortunate term, as the figures are very different from the true densities. 
 
 * Commercial Organic Analysis, vol. ii., p. 89, ct seq. 
 
90 
 
 OILS, FATS, WAXES, ETC. 
 
 OILS LIQUID AT 15 C. 
 
 
 Specific Gravity at 15-5 C. = G0 F. 
 
 Class of Oil. 
 
 875 to -884. 
 
 884 to -912. 
 
 912 to '920. 
 
 920 to -937. 
 
 937 to '970. 
 
 Vegetable 
 oils. 
 
 None. 
 
 None. 
 
 Olive. 
 Almond. 
 
 Cotton 
 seed. 
 
 Japanese 
 wood. 
 
 
 
 
 Ben. 
 
 Sesame. 
 
 Croton. 
 
 
 
 
 Arachis. 
 
 Sunflower. 
 
 Castor. 
 
 
 
 
 Rape. 
 
 Hazelnut. 
 
 Linseed 
 
 
 
 
 Colza. 
 Mustard. 
 
 Poppy seed. 
 Hemp seed. 
 
 (boiled). 
 Blown oils 
 
 
 
 
 
 Linseed 
 
 (manufac- 
 
 
 
 
 
 (raw). 
 
 tured). 
 
 
 
 
 
 Walnut. 
 
 
 
 
 
 
 Cokernut 
 
 
 
 
 
 
 oleine 
 
 
 
 
 
 
 (manufac- 
 
 
 
 
 
 
 tured). 
 
 
 
 
 
 Essentially 
 
 More or less 
 
 
 
 
 
 non-drying 
 
 drying oils. 
 
 
 
 
 
 oils. 
 
 
 
 Terrestrial 
 
 None. 
 
 None. 
 
 Neat's foot. 
 
 None. 
 
 None. 
 
 Animal 
 
 
 
 Bone. 
 
 
 
 oils. 
 
 
 
 Lard and 
 
 
 
 
 
 
 tallow 
 
 
 
 
 
 
 oils (manu- 
 
 
 
 
 
 
 factured). 
 
 
 
 Marine 
 
 Sperm. 
 
 None. 
 
 Shark 
 
 Whale. 
 
 None. 
 
 Animal 
 
 Bottlenose. 
 
 
 liver. 
 
 Porpoise. 
 
 
 oils. 
 
 
 
 
 Seal. 
 
 
 
 
 
 
 Menhaden. 
 
 
 
 
 
 
 Cod liver. 
 
 
 
 
 
 
 Shark 
 
 
 
 
 
 
 liver. 
 
 
 Free fatty 
 
 None. 
 
 Oleic acid. 
 
 
 Linolic 
 
 Ricinoleic 
 
 acids. 
 
 
 
 
 acid. 
 
 acid. 
 
 Hydro- 
 carbon 
 
 Shale pro- 
 ducts. 
 
 Shale pro- 
 ducts. 
 
 Heavy 
 Petroleum 
 
 None. 
 
 None. 
 
 oils. 
 
 Petroleum 
 
 Petroleum 
 
 products. 
 
 
 
 
 products. 
 
 products. 
 
 
 
 
SPECIFIC GRAVITY. 
 
 91 
 
 OILS, &c., PASTY OR SOLID AT 15*5C. = GOT. 
 Arranged according to their Specific Gravity when Melted. 
 
 
 Relative Density at ^~ d * 
 
 Class of Oil, Ac. 
 
 
 
 
 
 750 to -800. 
 
 800 to -855. 
 
 8-55 to '863. { G3 to '867. 
 
 Vegetable 
 fats. 
 
 None. 
 
 None. 
 
 Palm oil. 
 Cacao butter. 
 
 Palmnut oil. 
 Cokernut oil. 
 
 
 
 
 
 Japan wax. 
 
 
 
 
 
 Myrtle wax. 
 
 
 
 
 
 Cokernut and 
 
 
 
 
 
 Cotton seed 
 
 
 
 
 
 steariiie 
 
 
 
 
 
 (manufac- 
 
 
 
 
 
 tured). 
 
 Animal fats. 
 
 None. 
 
 None. 
 
 Tallow. 
 
 Butter fat. 
 
 
 
 
 Lard. 
 
 
 
 
 
 Suet. 
 
 
 
 
 
 Dripping. 
 
 
 
 
 
 Bone fat. 
 
 
 
 
 
 Oleomar- 
 
 
 
 
 
 garine 
 
 
 
 
 
 and Butterine 
 
 
 
 
 
 (manufac- 
 
 
 
 
 
 tured). 
 
 
 Vegetable 
 and Animal 
 
 None. 
 
 Spermaceti. 
 Beeswax. 
 
 None. 
 
 None. 
 
 waxes. 
 
 
 Chinese wax. 
 
 
 
 
 
 Carnauba 
 
 
 
 
 
 wax. 
 
 
 
 Free fatty 
 
 None. 
 
 Stearic acid. 
 
 None. 
 
 None. 
 
 acids. 
 
 
 Palmitic acid. 
 
 
 
 
 
 Oleic acid. 
 
 
 
 Hydro- 
 
 Paraffin wax. 
 
 Shale pro- 
 
 Vaseline. 
 
 None. 
 
 carbons. 
 
 Ozokerite. 
 
 ducts. 
 
 
 
 
 
 Petroleum 
 
 
 
 
 
 products. 
 
 
 
 * These relative density values were mostly taken with the plummet 
 apparatus (Westphal's hydrostatic balance) and not corrected for the 
 expansion of the glass plummet used ; many of the values are, therefore, 
 about 0'2 per cent, too high .e., too high by nearly *002 (p. 77). 
 
92 
 
 OILS, FATS, WAXES, ETC. 
 
 Rosin oils and rosin are not included in these tables, these 
 substances having specific gravities mostly higher than. any 
 therein mentioned viz., from '97 to upwards of I'O; similar 
 remarks apply to some of the highest-boiling petroleum and shale 
 hydrocarbons. 
 
 Variation of Density of Oils, &c., with Temperature. 
 Like most other substances, oils and melted fats, ttc., expand 
 
 
 i 
 
 
 Ratio of Weight of a given Volume 
 
 
 of Substance at t, to that of the i Mean 
 
 
 same Volume of Water at 15 5 
 
 Variation 
 
 Name of Oil or Fat, &c. 
 
 considered as 1000. 
 
 perl 
 Alteration in 
 
 
 
 Tempera- 
 
 
 
 
 
 
 ture. 
 
 
 J=15-5. 
 
 * = 40-80. 
 
 /=98-99. 
 
 
 Arachis oil (groundnut oil), . 
 Beeswax, .... 
 
 922 
 
 835-6 at 80 
 
 867-3 
 822-1 
 
 66 
 75 
 
 Butter fat, .... 
 
 
 904-1 at 40 s 
 
 867-7 
 
 62 
 
 Castor oil, .... 
 
 965-5 
 
 ... 
 
 909-6 
 
 65 
 
 Cod liver oil, "... 
 
 927-5 
 
 ... 
 
 874-2 
 
 65 
 
 Cokernut oleine, . . . 
 
 926-2 
 
 ... 
 
 871-0 
 
 67 
 
 Cokernut stearine, 
 
 ... 
 
 895 -9 at 60 
 
 869-6 
 
 67 
 
 Cokernut butter, . 
 
 
 911 '5 at 40 
 
 873-6 
 
 64 
 
 Cotton seed oil, 
 
 925 
 
 
 872-5 
 
 63 
 
 Doegling oil (bottlenose whale), 
 
 880-8 
 
 
 827-4 
 
 64 
 
 Japanese wax, 
 
 
 901 -8 at 60 
 
 875-5 
 
 69 
 
 Lard, 
 
 
 898-5 at 40 
 
 8608 
 
 65 
 
 Linseed oil, .... 
 
 935 
 
 
 880-9 
 
 65 
 
 Menhaden oil, 
 
 932 
 
 
 877-4 
 
 65 
 
 Neat's foot oil, 
 
 914 
 
 
 861-9 
 
 63 
 
 Niger seed oil, 
 
 927 
 
 ... 
 
 873-8 
 
 64 
 
 Palm butter, .... 
 
 
 893-0 at 50 
 
 858-6 
 
 72 
 
 Porpoise oil, .... 
 
 926 
 
 ... 
 
 871-4 
 
 65 
 
 
 915 
 
 
 863-2 
 
 62 
 
 Seal oil, .... 
 
 924 
 
 
 873-3 
 
 62 
 
 Sesame oil, .... 
 
 921 
 
 ... 
 
 867-9 
 
 62 
 
 Spermaceti, .... 
 
 
 835 -Sat 60 
 
 808-6 
 
 72 
 
 Sperm oil, .... 
 
 883-7 
 
 
 830-3 
 
 65 
 
 Tallow, 
 
 
 895'0 at 50 
 
 862-6 
 
 67 
 
 Whale oil, .... 
 
 930-7 
 
 
 872-5 
 
 70 
 
 Paraffin wax, 
 
 
 780-5 at 60 
 
 753-0 
 
 72 
 
 Commercial "stearine" \ 
 (crude stearic acid), . . j 
 
 ... 
 
 859-0 at 60 
 
 8305 
 
 75 
 
 Commercial "oleine" ( im- \ 
 pure oleic acid), . . / 
 
 903-2 
 
 848-4 
 
 66 
 
 on heating ; it is somewhat remarkable that nearly all bodies of 
 this description expand at about the same rate (within not very 
 wide limits of departure from the average), so that 1 c.c. of 
 substance always increases to about 1*00075 c.c. by rise of tem- 
 perature of 1 C. The effect of this on the density is to diminish 
 it in the inverse proportion; so that an oil, &c., the specific 
 
SPECIFIC GRAVITY. 93 
 
 gravity of which at 15 is from '9 to '95, will become diminished 
 
 9 *95 
 
 in specific gravity to i<0uU75 to 1 . QQ()75 by rise of 1 in tempera- 
 ture i.e., the diminution in the specific gravity is -00067 to 
 00071. Thus the preceding values were obtained by A. H. 
 Allen ; * for the sake of convenience, and to avoid decimals, 
 all the figures are multiplied by 1,000. 
 
 From these values it results that whilst glyceridic oils fluid 
 at the ordinary temperature diminish in specific gravity between 
 15 and 98 C. at close to the average rate of -64 per 1 (uncor- 
 rected for plummet expansion ; somewhat more when corrected), 
 glycerides of higher melting point (like Japanese wax and palm 
 butter) and waxes (beeswax, spermaceti, paraffin wax) diminish 
 in specific gravity at a slightly higher rate, averaging about 0*7 
 
 per 1. In all cases, however, the rate is sensibly near to 
 
 2 
 
 ^ x -001 per 1 C., reckoned on the usual specific gravity scale 
 
 (water =1) and not multiplied by 1,000. 
 
 Figures closely concording with these have been subsequently 
 obtained by other experimenters ; thus 0. A. Crampton f found 
 for various samples of lard, lard stearine, beef fat, oleostearine, 
 cotton seed oil, and olive oil, coefficients of expansion between 
 15 and 100 lying between -000715 and '000797, averaging close 
 
 15 
 to -00075. Since the relative density at of these substances 
 
 was found to lie between -9065 and -9220, the average decrement 
 in density per 1 C. rise in temperature was close to - 69 on the 
 thousandfold scale. W. T. Wenzell found J that olive oil, 
 mustard seed oil, castor oil, sperm oil, and cod liver oil expanded 
 to almost exactly the same extent in each case between 16*7 and 
 44 -4 C. (62 and 112 F.) ; the increment in bulk being 2 per 
 cent., all the substances being examined in the same dilatometer. 
 This represents an apparent coefficient of expansion per 1 C. 
 of -00072, which, when corrected for the expansion of the glass, 
 becomes -00075, or practically the same figure as that found by 
 Crampton ; and indicating an average decrement in density 
 per 1 C. rise in temperature of 0-68 to 0-69. On the other 
 hand, Lohmann states that 1,000 volumes of olive oil increase 
 
 * Commercial Organic Analysis, vol. ii., p. 17, et seq. The values at 
 the higher temperatures were mostly obtained by a plummet apparatus 
 (Westphal's hydrostatic balance), and not corrected for the expansion of the 
 glass plummet used, the object being simply to make comparative estima- 
 tions ; hence many of the figures in the last column are somewhat too low 
 by about -01 to -02 (vide p. 77). 
 
 ^Journ. Soc. Chem. Ind., 1889, p. 550 ; from Amer. Chem. J., 11., p. 232. 
 
 J Analyst, 1890, p. 14. 
 
 Schadler's Technologic der Fette und Oele, 2nd edition, edited by 
 Lohmaun, p. 91. 
 
94 OILS, FATS, WAXES, ETC. 
 
 by 0'83 volumes for 1 C. rise of temperature ; whilst the 
 analogous increment for rape oil is 0*89, and for train oil, I'OO; 
 figures perceptibly higher than those found by the other observers 
 above mentioned. 
 
 YISCOSIMETRY. 
 
 In order to obtain valuations of the so-called " viscosity " of 
 oils, &c., as approximate measurements of their relative lubricat- 
 ing powers, two classes of methods are in use viz., those where 
 the measurements are made by observing the mechanical effects 
 produced by applying the oil, &c., between two conveniently 
 arranged surfaces in motion with respect to one another; and 
 those where the oil to be examined is made to pass through a 
 given tube or orifice, and the time of passage of a known quan- 
 tity is noted. From the practical point of view, obviously the 
 most valuable measurements of the kind are those obtainable by 
 imitating as nearly as possible the conditions under which the 
 lubricant is to be used i.e., the power of overcoming friction is 
 best measured by a testing machine precisely similar to that for 
 which the lubricant is required ; quick moving spindles, rapidly 
 revolving axles in journal boxes, or heavy slow moving shaft- 
 ing, &c., being employed as occasion requires. Such measure- 
 ments, however, can only be properly carried out in compara- 
 tively large establishments, and are not at all adapted for use in 
 laboratories where the chemical nature of the oils is investigated 
 and their general characters tested ; accordingly, in these cases, 
 methods of the second kind are now usually employed, since ex- 
 perience has shown that the comparatively small sized mechanical 
 testing machines of various kinds that have been invented for 
 the purpose are apt to give results more discordant amongst 
 themselves, and less faithfully representing the actual lubricating 
 values of the substances examined, than those obtained by 
 apparatus for the determination of " efflux velocity " (incorrectly 
 designated " viscosity "). 
 
 Of the numerous simpler forms of mechanical testing arrange- 
 ments that have been proposed, one of the earliest (M 'Naught's 
 pendulum machine) is also one of the least unsatisfactory ; this 
 consists of two discs, the lower one provided with a raised edge 
 and attached to a vertical spindle revolving in bearings, the 
 upper one resting on a pivot. The space between the two discs 
 is filled with ' the oil to be tested, and the lower one made to 
 revolve at a given speed. The friction due to the oil would in 
 time cause the upper disc to revolve too ; but this motion is 
 prevented by means of a projecting pin in contact with a 
 pendulum. In consequence, more or less pressure on the pen- 
 dulum is produced, diverting it from a vertical position; the 
 degree of displacement affords a measure of the resistance of 
 the oil. 
 
VISCOSIMETRY. 
 
 95 
 
 Efflux Method. The simplest arrangement for making com- 
 parisons between different oils, &c., as regards their efflux 
 velocities, consists of an ordinary pipette 
 filled up to a given mark on the stem 
 with the oil to be tested, the time being 
 noted requisite for the oil to run out 
 either completely, or down to some 
 lower mark. Fig. 16 represents an in- 
 strument on this principle devised by 
 Schiibler, the upper part of the pipette 
 being expanded into a reservoir, with a 
 scale attached indicating the level to 
 which the fluid sinks ; for comparative 
 observations, the reservoir is filled to a 
 given level, and the time determined 
 during which the level sinks to a given 
 extent, (a) in the case of the substance 
 tested, (b) in the case of some other 
 substance taken as standard. 
 
 The time ratio thus deduced does not 
 represent the relative time for equal 
 weights, but that for equal volumes ; so that 
 
 ratio for equal weights the value 
 
 16. 
 
 to deduce the 
 must be multiplied 
 
 
 by -j ? , where d is the relative density of the substance examined,. 
 a l 
 
 and d.j that of the standard substance. Thus if the substances 
 contrasted were sperm and rape oils, and the respective time& 
 requisite for the same volume to flow out were 40 and 120 
 seconds, whilst the relative densities were -880 and -915 re- 
 spectively, the relative efflux rate for. equal weights would 
 be 
 
 h d,_ J0_xj915 _ 
 
 t 2 ~dl 120 x -880 
 
 As the time of efflux varies markedly with the temperature 
 (usually diminishing as the temperature rises), such comparisons. 
 must necessarily be made under constant conditions as to tem- 
 perature. 
 
 In order to ensure uniformity of temperature in different 
 experiments the results of which are to be compared together, 
 the vessel containing the oil may be conveniently surrounded 
 with a jacket containing water or melted paraffin wax. Fig. 17 
 represents an arrangement of the kind described by E. Schmid r 
 also containing a device for maintaining a constant pressure 
 during the outflow, instead of having a continually varying 
 " head," as in Schiibler's instrument. The vessel containing the 
 oil, A, is a sort of pipette, excepting that the upper end consists 
 
96 
 
 OILS, FATS, WAXES, ETC. 
 
 of a tube, B, passing down inwards to a point, F, near the base 
 of the expanded part. The upper end of B is closed by a stopper, 
 
 R 
 
 Fig. 17. 
 
 D, so that when the stopper is in, no air can enter, and, con- 
 sequently, no oil runs out at G ; but on removing the stopper the 
 
VISCOSIMETRY. 
 
 97 
 
 oil flows out. The pipette is filled by removing the stopper, 
 inverting it with the end BD immersed in the oil, and sucking 
 up at the other end, G, until full, when it contains some 50 c.cs. 
 The stopper being replaced, the pipette is fixed in position inside 
 the water jacket, heated to the required temperature in the 
 ordinary way by means of the projecting tube ; a stirrer, R, with 
 an annular plate at the end is provided ; by moving this up and 
 down the temperature is equalised. When the required tem- 
 perature is attained the stopper is withdrawn and the time 
 ascertained requisite for a given volume of oil to run out; as 
 long as the level of the oil in the pipette does not fall below F, 
 the pressure or " head " under which the oil issues at G is mani- 
 
 festly constant, being that due to a column of oil of length, GF. 
 By employing high-boiling paraffin oils, <fec., in the water jacket, 
 the relative efflux times at high temperatures can thus be readily 
 determined for various oils. 
 
 7 
 
98 
 
 OILS, FATS, WAXES, ETC. 
 
 With all instruments of this description a variable amount of 
 friction is brought into play as the oil passes through the efflux 
 pipe, especially when this is conical ; so that varying results are 
 often obtained with different instruments. This source of error 
 is best avoided by doing away with the efflux tube altogether,, 
 substituting for it a hole drilled in a plate of glass or agate. 
 
 Redwood's Efflux Viscosimeter. Figs. 18 and 19 repre- 
 sent Boverton Redwood's form of viscosimeter, consisting of an 
 interior silvered copper cylinder, about 1^ ins. diameter and 
 3^ ins. deep> containing the oil to be examined ; the bottom 
 of this is furnished with an orifice, consisting of a hole bored 
 through an agate plate, the top of which is excavated into a 
 hemispherical cavity, so that a small brass sphere attached to a 
 rod and dropped in forms a sufficiently tight valve. An outer 
 
 Fig. 19, 
 
 jacket is provided with a closed copper tube projecting therefrom 
 downwards at an angle of 45, so that by heating this "tail" in a 
 Bunsen or spirit lamp flame, the temperature of the liquid (water, 
 oil, melted paraffin wax, &c.) in the jacket can be raised as 
 required. A revolving agitator to equalise temperature in the 
 jacket is provided, with a thermometer attached, a second ther- 
 mometer being supported in the oil by a clamp fixed to the 
 cylinder. The whole rests on a tripod stand furnished with 
 levelling screws. The constancy of initial level of oil inside the 
 
VISCOSIMETRY. 
 
 99 
 
 cylinder is assured by means of a gauge consisting of a small 
 internal bracket with upturned point. 
 
 When an observation is to be made the bath is filled with 
 water, or heavy mineral oil, etc., and heated to the required tem- 
 perature. The oil to be tested is also heated to this temperature 
 and poured in until the level of the liquid just reaches the point 
 of the gauge. A narrow-necked flask, holding 50 c.cs., is placed 
 beneath the jet immersed in a liquid at the same temperature 
 as the oil. When all is ready the ball-valve is raised and a 
 stop-watch started, and the number of seconds requisite to fill 
 
 Fig. 21. 
 
 the 50-c.c. flask noted, care being taken that the temperature 
 does not fluctuate during the time, and that the oil is per- 
 fectly free from suspended matter, such as dirt or globules of 
 water. 
 
 In order to obviate the necessity of always using the same 
 volume of oil (indispensable in order to end with the same 
 difference of level, and consequently maintain the same average 
 head or pressure throughout), A. H. Allen makes an addition 
 
100 
 
 OILS, FATS, WAXES, ETC. 
 
 consisting of an airtight cover, Fig. 20, perforated by two holes, 
 one of which, A, is furnished with a tap, B, while the other has 
 another tube screwing airtight into it. This tube, C, is pro- 
 longed on two sides in contact with the agate orifice, whilst the 
 angles of the inverted V-shaped slits cut on each side terminate 
 at D, exactly 1} inches higher. The cylinder is completely 
 filled with oil before commencing an observation, the tap, B, 
 closed, and the orifice opened till the oil sinks to the level of D 
 
 Fig. 2>2. 
 
 in the inner tube. Air then bubbles regularly in at D ; when 
 this happens, the temperature is noted and the oil collected in a 
 graduated receiver. Any volume from 10 to 50 c.c. can thus be 
 run out, as the oil falls in the upper part of the cylinder, but is 
 maintained constantly at the level, D, in the inner tube. Five 
 consecutive valuations of 10 c.c. each may thus be made, whilst 
 50 c.c. run out. 
 
VISCOSIMETRY. 101 
 
 Several other forms of viscosimeter have been constructed by 
 other experimenters, based on the efflux principle. Fig. 21 
 represents in section Engler's instrument ; a slightly modified 
 form of this by Engler and Kiinkler* is largely used on the 
 continent.! Fig. 22 represents a simple form recently constructed 
 by G. H. Hurst.; The oil, &c., to be examined is run into the 
 innermost vessel up to a given height determined by a gauge- 
 pin, and heated up to the required extent by applying a Bunsen 
 burner or spirit lamp to the heater at the side, connected by two 
 tubes with the water reservoir surrounding the oil chamber, so 
 as to heat the water by circulation. The temperature of the oil 
 is observed by means of a thermometer placed therein (usually 
 this registers about 6 F. below the temperature of the water in 
 the jacket); when the required temperature is reached, the 
 central valve is raised, and 50 c.c. of oil allowed to run out into 
 a measuring flask underneath, the time of efflux being noted. 
 Obviously, with this instrument, the head under which the 
 liquid issues is continually diminishing as it flows. 
 
 Standards of Efflux Viscosity. In actual practice, water is 
 too fluid to be a convenient standard substance ;. rape oil is 
 usually chosen in preference, because, notwithstanding the un- 
 avoidable differences that exist between samples from seeds 
 grown in different countries and soils, these differences are 
 usually not extremely wide. Definite mixtures of pure glycerol 
 and water, however, can be readily prepared, possessing almost 
 any required higher degree of " viscosity," and capable of use 
 as standards of comparison of considerably greater uniformity, 
 when prepared by different operators at different times, than is 
 possible with natural products such as rape oil. 
 
 The following tables are selected from the numerous results 
 published by various authorities, as illustrating the general 
 character of the numbers obtained with " viscosimeters " of 
 different kinds for determining the relative efflux rates of 
 different natural oils, &c., and lubricants made therefrom, or 
 from petroleum and other hydrocarbons, and the effect of varia- 
 tions of temperature 011 the values. The figures obtained by 
 
 * Journ. Soc. Chem. Industry, 1890, p. 654; from Dinyler's polyt. Journ., 
 276, p. 42. 
 
 t A still more recent form is described by Engler, with special in- 
 structions for its use (Journ. Soc. C/icm. Ind., 1893, p. 291 ; from Zeits. 
 ang. Chem., 1892, p. 725). 
 
 $ Journ. Soc. Chem. Industry, 1892, p. 418. 
 
 With the viscosimeter above described, Boverton Redwood finds that 
 the relative times requisite for 50 c.c. of water and genuine rape oil to flow 
 out at the temperature of 15 '5 C. (60 F.) are 25'5 and 535 seconds 
 respectively, taking the average of various samples of pure oil. A. H. Allen 
 rinds that glycerol diluted with water until the specific gravity at 15 '5 is 
 1'226, possesses the same degree of viscosity as average rape oil when 
 tested in the same way. 
 
102 
 
 OILS, FATS, WAXES, ETC. 
 
 Schiibler represent the " viscosity degree " (viscositdtsgrad) or 
 " relative viscosity " of the respective oils i.e., the relative 
 times requisite for equal volumes to pass (at 7 0< 5 and 15 C. 
 respectively), the times required by the same volume of water- 
 being taken as unity ; those quoted from the other authorities 
 are not thus reduced, but are simply the actual times directly 
 observed with the particular instruments used : 
 
 ^ ;iine of Oil. 
 
 Relative Time in Seconds (Schiibler). 
 
 
 Plant from which derived. 
 
 At~ c '5C. 
 
 At 15-0 C. 
 
 Castor oil, 
 
 liicinus communis, 
 
 377-0 
 
 203-0 
 
 Olive oil, 
 
 Olea europaea, 31 '5 
 
 21-6 
 
 Hazelnut oil 
 
 Corylus avellana. 24*2 
 
 18-4 
 
 Colza oil, 
 
 Brassica campestris oleifera, 
 
 22-4 
 
 18-0 
 
 Rape oil, 
 
 Brassica rapa oleifera biennis, 
 
 22-0 
 
 17-6 
 
 Beechnut oil 
 
 Fagus sylvatica, 
 
 26-3 
 
 17-5 
 
 White Mustard oil, 
 
 Sinapis alba, 
 
 24-0 
 
 17-4 
 
 Almond oil, . 
 
 Amydalus communis, 
 
 23-3 
 
 16-6 
 
 Spindlenut oil, 
 
 Kuonymus europaeus, 23 '3 15 '9 
 
 Black mustard seed oil, 
 
 Sinapis nigra, 
 
 19-4 
 
 15-6 
 
 Poppy seed oil, . . Papaver somniferum, 
 
 18-3 
 
 13-6 
 
 Camelina seed oil, 
 
 Myagrum sativum, 
 
 17-7 
 
 13-2 
 
 Belladonna seed oil, 
 
 Atropa belladonna, 
 
 17-3 
 
 13 1 
 
 Sunflower oil, 
 
 Helianthus annuus, 16*4 
 
 12-6 
 
 Turpentine oil, 
 
 Pinus sylvestris, 
 
 16-7 
 
 11-8 
 
 Cress oil, 
 
 Lepidimn sativum, 
 
 14-4 
 
 11-4 
 
 Grape seed oil, 
 
 Vitis vinifera, 
 
 14-2 
 
 11-0 
 
 Plum kernel oil, . 
 
 Primus domestica, 
 
 14-7 
 
 10-3 
 
 Tobacco seed oil, 
 
 Nicotiaua tabacum, 
 
 13-5 
 
 10-0 
 
 Walnut oil, . 
 
 Juglans regia, 
 
 11-8 
 
 9-7 
 
 Linseed oil, . 
 
 Linum usitatissimum, 
 
 11-5 
 
 9-7 
 
 Hemp seed oil, 
 
 Cannabis sativa, 
 
 11-9 
 
 9-6 
 
 
 Relative Time in Seconds (Wilson). 
 
 Oils, &.C., Used. 
 
 
 
 
 
 At 15"6 C. 
 
 At 49 C. 
 
 At 82 C. 
 
 
 = eo F. 
 
 = 120 C l'\ 
 
 = I80F. 
 
 Sperm oil, .... 
 
 47 
 
 30-5 
 
 25-75 
 
 
 92 
 
 37'75 28-25 
 
 Lard oil, .... 9(j 
 
 38 
 
 28-5 
 
 Rape oil 
 Neat's foot oil, 
 
 108 
 112 
 
 41-25 
 40-25 
 
 30 
 
 29-25 
 
 Tallow oil, .... 
 
 143 
 
 37 
 
 25 
 
 Engine tallow, 
 
 Solid. 
 
 41 
 
 26-5 
 
YISCOSIMETKY. 
 VISCOSITY IN SECONDS FOR 50cc. 
 
 10; 
 
 ~te 
 
 II 
 
 
 
 t _ 
 
 S * I 
 
104 
 
 OILS, FATS, WAXES, ETC. 
 
 Rifintd Rape Oil 
 
 Sperm Oil 
 
 American Miueitil Oil, sp. gr. -885 . 
 ,. '913 
 923 . 
 
 Kiuritm , -009 . 
 
 . -915 . 
 
 .IM no too too goo aio zso 
 
 230 290 300 itc 
 
 1 Fig. 24. Temperature in Degrees Fahrenheit. 
 
 Oils Employed. 
 
 , Sperm oil, 
 
 Seal oil (pale), 
 , Northern whale oil, 
 
 Menhaden oil, 
 
 Sesame oil, 
 1 Arachis oil, 
 
 Cotton seed oil (refined), 
 
 Niger seed oil, 
 
 Olive oil, 
 
 Rape oil, 
 
 Castor oil, 
 
 Relative Time in Seconds (Allen). 
 
 Spec. Grav. 
 at 15 0> 5C. 
 
 881 
 
 At lnT.C. 
 = 60 F. 
 
 At r>o C. 
 
 = 122 F. 
 
 At 100 C. 
 - 21'-' F. 
 
 so 
 
 I 
 
 47 
 
 38 
 
 924 
 
 131 
 
 56 
 
 43 
 
 931 
 
 186 
 
 65 
 
 46 
 
 932 
 
 172 
 
 40 
 
 
 921 
 
 168 
 
 65 
 
 50 
 
 922 
 
 180 
 
 64 
 
 ... 
 
 925 
 
 180 
 
 62 
 
 40 
 
 927 
 
 176 
 
 59 
 
 43 
 
 916 
 
 187 
 
 62 
 
 43 
 
 915 
 
 261 
 
 80 
 
 45 
 
 965 
 
 2420 
 
 330 
 
 60 
 
 
 
 I 
 
 
VISCOSIMETRY. 
 
 105 
 
 
 Relative Time in Seconds (Redwood). 
 
 50 F. 
 
 70 F. 
 
 100 F. 
 
 140' F. 
 
 200SF. 
 
 260 F. 
 
 300 F. 
 
 Refined rape oil, No. 1, 
 
 712-5 
 
 405 
 
 147 
 
 105-5 
 
 58-5 
 
 4325 
 
 
 2 
 
 ... 
 
 406 
 
 146 
 
 106-5 
 
 57-5 
 
 ... 
 
 
 " ," 
 
 ... 
 
 405-5 
 
 147 
 
 106-5 
 
 57-5 
 
 ... 
 
 
 4, 
 
 ... 
 
 407 
 
 147-5 
 
 106 
 
 58-5 
 
 ... 
 
 
 Beef tallow, 
 
 
 
 
 
 54-75 
 
 40 
 
 
 Sperm oil, 
 
 ... 
 
 136-8 
 
 60-5 
 
 50-75 
 
 42 
 
 34-75 
 
 30 
 
 Neat's foot oil, . 
 
 620 
 
 366 
 
 126 
 
 88-4 
 
 50-4 
 
 44 
 
 38 
 
 American mineral oil, | 
 specific gravity, '885 j 
 
 145 
 
 90 
 
 47 
 
 41 
 
 
 ,,. 
 
 
 American mineral oil, 1 
 specific gravity, '923 \ 
 Russian mineral oil, \ 
 
 1,030 
 2,040 
 
 485 
 820 
 
 126 
 174 
 
 82 
 116 
 
 42 
 
 48-5 
 
 
 ... 
 
 specific gravity, '909 J 
 
 
 
 
 
 
 
 Russian mineral oil, } 
 semisolid, . . J 
 
 ... 
 
 ... 531 
 
 317-5 
 
 99-25 
 
 5925 
 
 42 -G 
 
 Redwood's results are indicated graphically by the curves 
 indicated in Figs. 23 and 24. 
 
 Castor oil, 
 Thickened rape oil, 
 Sperm oil, 
 Colza oil, 
 Whale oil, . 
 Tallow oil, . 
 Cotton oil, 
 American 885 oil, . 
 American 905 oil, . 
 American 915 oil, . 
 Scotch 865 oil, 
 Scotch 885 oil, 
 Scotch 890 oil, 
 Russian 906 oil, 
 Russian 911 oil, 
 Rosin oil, dark, 
 Rosin oil, pale, 
 Cylinder oil, medium, 
 Cylinder oil, pale, 
 Cylinder oil, dark, 
 
 Relative Time in Seconds (Hurst). 
 
 70 F. 
 
 100 F. 
 
 120 F. 
 
 150 F. 
 
 180 F. 
 
 1,248 
 
 487-5 
 
 201-5 
 
 91 
 
 48 
 
 1,370 
 
 331-5 
 
 279-5 
 
 156 
 
 78-5 
 
 58-5 
 
 36-4 
 
 26 
 
 19-5 
 
 17 
 
 131 
 
 56, 
 
 44 
 
 325 
 
 28 
 
 128-7 
 
 61 
 
 44 
 
 28-5 
 
 28 
 
 105 
 
 63, 
 
 45 
 
 30 
 
 20 
 
 100 
 
 55 
 
 40 
 
 25 
 
 20 
 
 68 
 
 3-> 
 
 23 
 
 15 
 
 14 
 
 113 
 
 44 
 
 32-5 
 
 19-5 
 
 18 
 
 140 
 
 47 
 
 36 
 
 21 
 
 19-5 
 
 325 
 
 22 
 
 18 
 
 15-5 
 
 13 
 
 58-5 
 
 26 
 
 22 18 
 
 15-5 
 
 71-5 
 
 39 
 
 26 
 
 195 
 
 17 
 
 292-5 
 
 97-5 
 
 56 
 
 30 
 
 22 
 
 462 
 
 143 
 
 91 
 
 82-5 
 
 26 
 
 1525 
 
 97-5 
 
 38 
 
 22 
 
 18 
 
 136-5 
 
 49-4 
 
 25 
 
 18 
 
 17 
 
 385 
 
 255 
 
 170 
 
 70 
 
 ... 
 
 405 
 
 265 
 
 120 
 
 90 
 
 ... 
 
 890 
 
 495 
 
 230 
 
 100 
 
 As further illustration of the effect of rise of temperature in 
 diminishing the rate of efflux, the following figures may also be 
 
106 
 
 OILS, FATS, WAXES, ETC. 
 
 quoted, obtained by Villavecchia and Fabris, whilst investigating 
 certain lubricating oils* for excise purposes: 
 
 Lubricating oil. 
 
 No. 1 
 
 n 
 
 
 3 
 
 
 4 
 
 
 5 
 
 
 6 
 
 
 7 
 
 Efflux Rate referred to Water at 
 
 At 20 C. 
 
 At 50 C. 
 
 44-39 
 
 6-81 
 
 51-07 
 
 5-94 
 
 40-85 
 
 5-50 
 
 38-77 
 
 6-03 
 
 72-09 
 
 8-35 
 
 67-92 
 
 9-6(5 
 
 56-03 
 
 5-71 
 
 Thus, the effect of a rise in temperature from 20 to 50 is to 
 diminish the efflux rate to -J- - -^ of the original value, the effect 
 being more marked with the more viscous fluids. 
 
 According to experiments by Bender, f when an oil is chilled 
 to - 20 for some time, and then warmed up again, the efflux 
 viscosity value at the ordinary temperature is often considerably 
 increased as compared with what it was previously at the same 
 temperature of observation, thick oils usually showing a greater 
 increment than thinner ones. On the other hand, if oils are 
 heated up to 50 or 100, and then allowed to cool down again 
 to the air temperature, the thicker oils become perceptibly 
 thinner, whilst the thinner oils are less affected. 
 
 Lepenau's Leptometer. This instrument is based on a 
 principle somewhat different from that involved in the above 
 ^described forms of efflux viscosimeter, inasmuch as it depends not 
 only on the rate of flow through a given orifice, but also on the 
 .amount of surface tension called into play when drops are formed 
 in air. It consists essentially of a pair of precisely similar 
 cylinders, B B (Fig. 25), immersed in the same bath, A, one of 
 which contains the oil to be examined, and the other another oil 
 used as standard of comparison ; the relative rates are noted at 
 which drops form as the oil passes through equal sized capillary 
 tubes, r, r, the dimensions of which are too small to permit of 
 continuous streams being produced, the quantities flowing out in 
 a given time being weighed or measured. 
 
 All these various forms of instrument are subject to one 
 constant source of error viz., that the forces coming into play 
 
 * " Report of the Central Laboratory of the Italian Customs' Depart- 
 ment, 1891 ; also Journ Soc. Chem. Industry, 1891, p. 390. 
 
 t Journ. Soc. Chem. Industry, 1891, p. 936; from Mitth. Konig. techn. 
 Versuchs,, Berlin, 1891, p. 100.' 
 
VISCOSIMETRY. 
 
 107 
 
 when a viscous liquid passes through a tube or orifice under 
 given conditions of temperature, &c., are not the same as those 
 obtaining when the liquid is used as a lubricant for shafting, 
 quickly rotating spindles, axles, and the like ; and, consequently, 
 that the figures obtained by means of such testing appliances are 
 only approximations (and not always 
 close ones) to the relative values 
 of the substances examined, when 
 practically applied for lubricating 
 purposes. 
 
 Determination of Viscosity in 
 Absolute Measure.-When liquids 
 are examined possessing a compara- 
 tively low degree of viscous charac- 
 ter, the rate of flow through a narrow 
 orifice does not represent the true 
 physical "viscosity," because a large 
 proportion of the result is due to 
 flow pure and simple without any 
 " shear ; " accordingly, when a com- 
 paratively long narrow accurately 
 calibrated tube is made use of as 
 the jet, figures are obtained not 
 always showing close agreement 
 with those yielded by the ordinary 
 forms of efflux apparatus. Accord- 
 
 Fig. 25. 
 
 ing to mathematical investigations by Poiseuille and others, the 
 coefficient of friction in narrow tubes is given by the formula 
 
 where 75 is the coefficient of friction, t" the time of efflux, v the 
 volume of fluid discharged, p the hydraulic pressure, I the length 
 and r the radius of the capillary tube, and s the specific gravity 
 of the liquid.* Starting from this, E. J. Mills has made some 
 measurements in absolute measure of the coefficients of friction 
 for various liquids, including water, and sperm, olive, lard, and 
 -castor oils.f 
 
 On the C.G.S. system (centimetre, gramme, and second as units 
 of length, mass, and time respectively) Poiseuille's formula becomes 
 
 * Hagenbacli arrives at a formula involving a second term in addition to 
 that given by Poiseuille 
 
 t Joiirn. Soc. Chem. Ind., 188C, p. 148; also, 1887, p. 414. 
 
108 
 
 OILS, FATS, WAXES, ETC. 
 
 where v is given in cubic millimetres, and r, I, and p in milli- 
 metres ; from this formula and his experimental results, Mills 
 deduces the following values at 12 0. : 
 
 
 Specific Gravity. 
 
 Value of j. 
 
 Rehitive Viscosity, 
 Water =1. 
 
 Water, 
 
 1 -000 
 
 011713 
 
 i-oo 
 
 Sperm oil, . 
 
 88789 
 
 68828 5876 
 
 Olive oil, 
 
 1)2043 1-1393 97-27 
 
 Lard oil, 
 
 92051 1-6285 139 '03 
 
 Castor oil, . . . -915541 
 
 21-721 
 
 1854-4 
 
 Obviously these relative viscosity values are very dissimilar 
 from Schiibler's numbers for castor and olive oils compared with 
 water, although the ratios between the values for the oils alone 
 do not differ so widely in the two cases ; this chiefly arisen 
 
 Fig. 20. 
 
 from the error attaching to the viscosity determination in the 
 case of water by the efflux method through a jet, as compared 
 with the true value through a long narrow tube.* 
 
 * The determinations of absolute " viscosity " values of solutions of gum 
 relatively to water made by noting the times required for given volumes to 
 pass through a known capillary tube, show similar differences when compared 
 with the corresponding values obtained with a "jet" apparatus, such as a 
 burette (vide paper by S. Rideal, Journ. Soc. Chem. Ltd., 1891, p. 610). 
 
VISCOS1MKTRY. 
 
 109 
 
 Coefficient of Friction in Capillary Tubes. Traube has 
 constructed an arrangement for determining with considerable 
 accuracy and speed the friction coefficients for oils and other 
 liquids passing through capillary tubes under pressure. Fig. 26 
 represents this apparatus.* A is a Marriotte bottle filled with 
 water, which serves to compress air in the reservoir B, and to 
 keep the pressure constant ; B is connected by means of a pipe 
 and cock to the efflux apparatus H, consisting of the bulb G- 
 (provided with two marks to permit the measurement of volume 
 of liquid to be discharged) and the capillary tube E. The 
 reservoir B is filled by means of a pump attached to branch and 
 stopcock. When the observations are to be made at temperatures 
 above that of the atmosphere a suitable airbath is employed. 
 When required to be cleaned, ether is forced through the tube. 
 With tubes of different diameters, the relative times observed for 
 water and oils of high viscosities are not identical ; but for oils 
 of considerable viscosity the differences are not great ; thus, the 
 following figures were observed with a cylinder lubricating oil 
 and with olive oil as compared with rape seed oil, being the 
 respective times of efflux in seconds : 
 
 Diameter of tube in milli- \ 
 metres, . . . J 
 
 1-5 
 
 0-8 
 
 0-5 
 
 Cylinder oil, . 
 
 155 -5 -100-0 
 
 472=100-0 
 
 2960=1000 
 
 Rape seed oil, . 
 
 79-0= 50-8 
 
 242- 51-3 
 
 1503= 50-8 
 
 Olive oil, .... 
 
 717- 46-1 
 
 222= 47-0 
 
 1364= 46-1 
 
 
 
 
 
 In all probability the conditions existing when oil is forced 
 through a capillary tube are more nearly akin to those obtaining 
 with a film of oil lying between a shaft and its journal box than 
 are those subsisting in the ordinary forms of efflux viscosimeter ; 
 and hence it is probable that the results of valuations on 
 Traube's system would be valuable as determinations more 
 closely approximating to the actual practical lubricative values. 
 Traube s apparatus, however, is far less convenient for ordinary 
 laboratory work than Redwood's or Engler's viscosimeter. 
 
 * Journ. Soc. Chem. Ind., 1887, p. 414. 
 
110 OILS, FATS, WAXES, ETC. 
 
 3. Chemical Properties of Oils, Fats, 
 Butters, and Waxes. 
 
 CHAPTER VI. 
 
 PROXIMATE CONSTITUENTS AND THE METHODS USED 
 FOR THEIR EXAMINATION AND DETERMINATION. 
 
 VERY few, if any, natural oils, fats, and waxes consist of one 
 single chemical substance ; almost invariably two, and often 
 many more constituents are present, the most marked distinc- 
 tion between which is that some are solid at the ordinary tem- 
 perature (when obtained separate), others liquid; the former 
 often deposit in the solid form on chilling, so that a fluid oil y 
 when chilled and pressed, yields a solid so-called " stearine" and 
 a liquid so-called " oleine " * as first proximate constituents. In. 
 similar fashion semisolid butters and hard fats, like tallow, can 
 be show r n to contain a solid and a liquid constituent in each case, 
 the consistency of the material, roughly speaking, depending 
 simply on the relative proportions of the two substances. When 
 "oleine" largely predominates the substance is an oil; when 
 '* stearine," a hard fat ; and when the two are in intermediate 
 
 * The terms "stearine" and "oleine" are practically employed in 
 several different senses, a circumstance apt to lead to considerable con- 
 fusion. In the strict chemical sense, stearine is the glyceride of stearic acid, 
 C 8 H fi (O.Ci8H 35 O) 8j and oleine the glyceride of oleic acid, CaHsCO.CjaHssOJa , 
 but in the oil trade generally the two terms are applied to indicate respec- 
 tively the solid and liquid constituents into which a fat or chilled oil can 
 be mechanically separated, irrespective of the actual chemical composition 
 of these constituents ; whilst in the candle manufacture they are used to 
 denote the analogous solid and liquid fatty acids obtainable from fatty 
 matters by saponification and mechanical pressure, &c. Similar mixtures of 
 free fatty acids and other substances are also obtainable by subjecting to 
 distillation various kinds of grease (e.g., Yorkshire grease Chap, xn.) ; 
 when these are chilled aud pressed they are separable into solid and 
 liquid portions, generally designated as "distilled" stearine and oleine 
 respectively. In the present work the pure chemical triglycerides are dis- 
 tinguished by the terminal "in" (e.g., stearin, olein, &c.) ; whilst the 
 commercial articles are indicated by names ending in "ine" (e.g., " dis- 
 tilled " oleine, candlemakers' stearine, oleomargarine, &c. ). In similar 
 fashion, the pure chemical compound C 3 Hr,(OH)3 is referred to as- 
 " glycerol," whilst the commercial products mainly consisting of this body, 
 but in a varying state of purity, are distinguished as glycerine (vide p. 8). 
 
PROXIMATE CONSTITUENTS. Ill 
 
 proportions, a more or less buttery consistence is possessed at the 
 ordinary temperature (near 15 C.) 
 
 The further investigation of the solid and liquid constituents 
 thus obtainable from a given oil or fat ; of the variations in their 
 relative proportions and natures according to the soil and climate 
 and other conditions under which the plant was grown in the 
 case of vegetable oils or butter, or the species and habitat of the 
 animal in that of an animal oil or fat ; of the eifect of cultivation 
 and domestication, and various similar points, have hitherto 
 received but little attention. There appears, however, to be 
 some reason for supposing that very considerable differences in 
 the relative amounts and even in the chemical nature of the 
 various constituents of a given oil, &c., may, at any rate in some 
 cases, be brought about by such causes ; thus, very different 
 results have been found by various experimenters who have 
 examined different samples of the same kind of oil e.g., in 
 the case of arachis oil (groundnut oil), where several succes- 
 sive chemists have succeeded in isolating considerable amounts 
 of hypogceAc acid for the purpose of studying that substance 
 and its derivatives, whilst more than one other chemist has 
 found either none at all, or practically none, in the oil ex- 
 amined by him ; and where, moreover, some observers have 
 found more or less considerable amounts of palmitic acid, and 
 others none at all. Similar discrepancies in the results obtained 
 by different investigators have been noticed in several other 
 instances, thus leading to the conclusion that marked differences, 
 are apt to exist in the nature of oils and fats prepared from 
 seeds, &c., grown under different conditions, just as is well 
 known to be the case with fruits and other vegetable produce, as- 
 regards the saccharine matter and other constituents present 
 therein. Even without taking into account these natural varia- 
 tions, however, the knowledge at present extant of the proximate 
 constituents of many of the more commonly occurring oily and 
 fatty matters is decidedly scanty ; whilst a very large number of 
 similar substances exist (in many cases of great local importance, 
 although not always materials largely exported or imported or 
 otherwise dealt with commercially) concerning the general com- 
 position of which accurate knowledge is hitherto entirely want- 
 ing. Many such products promise in the near future to be 
 important articles of trade, as soon as their respective values for 
 particular purposes are better ascertained, and the best means, 
 to be adopted of extracting and refining them so as to render 
 them marketable ; in Central and Southern Africa, and in many 
 other parts of the world, the progress of civilisation is continually 
 tending to bring into notice new products of this kind, many of 
 which only require attention being called to them to demonstrate 
 their commercial value. 
 
 The separation from one another of the different glycerides, 
 
112 OILS, FATS, WAXES, ETC. 
 
 <fec., contained in a given " stearine " or " oleine " is, in most 
 cases, a very difficult problem, more especially if required to be 
 performed in such a fashion as to give an approximate idea of the 
 relative proportions in which they are present. As a rule, the 
 best results are obtained by saponifying the mixture, and 
 applying methods for the separation of the resulting fatty acids, 
 either by mechanical means (chilling and pressing out the 
 more liquid portions) or by chemical processes. For example, 
 the lead salt of oleic acid is soluble in ether, whilst lead stearate, 
 palmitate, &c., are practically insoluble in that medium ; so that 
 l)y converting into lead salts the mixture of free fatty acids 
 obtained on saporiification and acidulation, and treating the mix- 
 ture with ether, a partial separation may be effected, lead oleate 
 with comparatively small quantities of stearate, palmitate, &c., 
 being dissolved out, and lead stearate, palmitate, etc., with small 
 quantities of adhering oleate being left. With a mixture of solid 
 iatty acids (palmitic, stearic, arachic, tkc.), fractional crystallisa- 
 tion from alcohol of the mixed free acids ; fractional precipitation 
 .as insoluble salts (of lead, magnesium, &c.); fractional crystal- 
 lisation of certain salts (e.g., magnesium salt) from alcohol or other 
 appropriate menstruum ; and similar processes are applicable in 
 various cases ; but the complete examination of mixtures of fatty 
 iicids in this way is so laborious, that it has been thoroughly 
 carried out in but very few instances. In the case of fractional 
 precipitation, as a general rule, the acid of higher molecular 
 weight precipitates first; thus, with a mixture of arachic, stearic, 
 und palmitic acids in approximately equal proportions, precipi- 
 tated as salts in several fractions, the first fraction will be 
 chiefly a salt of arachic acid, and the last will contain little 
 besides palmitate. 
 
 Some oils and fats contain appreciable quantities of the 
 glycerides of acids of sufficiently low molecular weight to be 
 volatile along with the vapour of water at the ordinary atmo- 
 spheric pressure. In such a case, after sapoiiification and acidula- 
 tion, an acid distillate is obtainable by boiling, preferably by 
 Mowing through the mass a current of steam from a suitable 
 generator. The weakly acid aqueous fluid may then be neutralised 
 with an alkali, evaporated to a small bulk, and decomposed by a 
 mineral acid ; or converted into silver or barium salts, &c., and 
 further examined. If more than one volatile acid be present, a 
 separation may often be effected by fractional precipitation as 
 silver salt, &c. ; or enough mineral acid may be added to liberate 
 a fraction of the total organic acids from the evaporated solution 
 of alkaline salts, and the distillation repeated ; the acid of lowest 
 molecular weight will then pass over. By similarly liberating 
 successive fractions and distilling alternately, a series of distillates 
 will be obtained, the acids of higher molecular weight being 
 contained in the respective later fractions (Liebig). 
 
PROXIMATE CONSTITUENTS. 113 
 
 When a mixture of acids volatile with steam and others not 
 volatile therewith is present, if, instead of blowing steam through 
 the whole mass, the insoluble fatty acids be allowed to float up 
 in a fused condition, and are then removed (after cooling and 
 solidifying), the remaining aqueous liquor is often found to 
 yield perceptibly less volatile acid, a portion having been dis- 
 solved by the insoluble acids, much as ether dissolves out various 
 substances from aqueous solution when agitated therewith. In 
 consequence of this, it is often impossible to obtain a constant 
 weight of the insoluble fatty acids thus obtained on drying at 
 100, unless they have been repeatedly treated with boiling water, 
 so as to remove soluble constituents (vide Chap. VIIL, " Hehner 
 Number"); otherwise, the small quantity of volatile acid present 
 slowly evaporates, giving a continual small loss. In some cases, 
 this by and by becomes balanced by gain in weight through 
 oxidation (by spontaneous absorption of oxygen from the air), 
 and later 011 still the gain from this cause predominates. 
 
 By means of superheated steam the fatty acids of higher 
 molecular weight may be pretty readily distilled; but any- 
 thing like a complete separation of closely related homologous 
 acids (e.g., myristic, palmitic, and stearic acids) in this way by 
 processes of fractional distillation is difficult, if not impossible ; 
 and the same remark applies to distillation under greatly dimin- 
 ished pressure (in a partial vacuum). In some cases fractional 
 saturation with alkali, c., of a mixture of acids will cause a more 
 or less complete separation, one combining with the base to the 
 exclusion of the other: more often the base becomes shared between 
 the two in proportions depending on the relative masses present. 
 Thus Thum found * that when a mixture of equal weights of 
 stearic and oleic acids is dissolved in hot alcohol and treated 
 with a quantity of alcoholic potash sufficient to saturate only 
 one half of the total acids, a mixed soap is obtained, which (when 
 separated from the uncombined excess of fatty acids by means of 
 petroleum ether) consists substantially of equal quantities of 
 potassium stearate and oleate ; the free acids similarly consisting 
 of stearic and oleic acids in sensibly the same proportion.! 
 
 A good deal still remains to be done in the case of a consid- 
 erable number of vegetable oils in the way of identifying and 
 quantitatively estimating their various proximate constituents; 
 and much the same remarks apply to certain animal oils, more 
 especially " train oils " from marine cetaceans, as regards not 
 only the acids present but also the alcoholiform constituents ; 
 
 *Zeit*ch.f. ancjeic. Chemie, 1890, p. 482. 
 
 t A similar state of matters is observed when a given fatty acid acts on 
 a mixture of caustic potash and caustic soda ; both potash and soda soaps 
 result in proportions sensibly near to those in which the two alkalies are 
 present in the mixture ; and not one kind of soap to the exclusion of the 
 other (vide Chap, xxi.) 
 
 8 
 
114 OILS, FATS, WAXES, ETC. 
 
 whilst it is known that certain of these oils are mainly composed 
 of compound ethers of non-glyceridic character, which furnish on 
 saponincation acids mostly of the oleic family, and as comple- 
 mentary products, alcohols of moderately high molecular weight 
 (e.g., dodecatylic alcohol, C 12 H 26 O, from Doegling oil), the complete 
 investigation of the products thus formed has been attempted 
 in very few instances indeed, and much still remains to be done 
 in this field ; it appears, however, that besides alcohols of the 
 ethylic series, others of a non-saturated character are also present 
 in some of these oils, as the alcoholiform constituents extracted 
 are in many cases capable of combining with iodine, leading to 
 the conclusion that higher acrylic alcohols are also contained as 
 compound ethers in addition to cetylic alcohol homologues. 
 
 Free Fatty Acids and Higher Alcohols contained in 
 Natural Oils and Fats, &c. Owing to the presence of mucila- 
 ginous, albuminous, or gelatinous matters in most crude vegetable 
 oils expressed from seeds, or animal fats and oils obtained from 
 animal tissues, it generally happens that a perceptible amount 
 of hydrolysis of glycerides is brought about in the process of 
 extraction, due to the influence of these substances and the 
 fermentative changes rapidly undergone by them ; even when 
 solvents (such as light petroleum oil, carbon disulphide, or ether) 
 are used for the isolation of the oil, &c., it not unfrequently 
 happens that measurable amounts of free fatty acids are con- 
 tained in the product obtained ; leading to the conclusion that 
 hydrolytic actions naturally take place to a greater or lesser 
 extent in the seeds, tissues, &c., during crushing and analogous 
 operations, or even on simply keeping, so that small quantities 
 of free acids are practically always present in the natural 
 products as obtained on a manufacturing scale from the animal 
 after death, or from the seed after detaching from the plant, 
 even when not normally present in the living animal or 
 growing vegetable. The extent to which actions of this sort 
 take place is extremely variable ; in general the " cold drawn " 
 oils expressed from seeds, and the corresponding first runnings, 
 from fresh fish livers, and the more liquid "oleomargarine," 
 obtained by the action of gentle heat on animal fats, contain 
 much smaller proportions of free fatty acids than the later 
 fractions obtained by subsequent hot pressing and analogous 
 operations ; whilst in the case of vegetable oils the maximum 
 amounts of free fatty acids are contained in the oils extracted 
 by solvents from oilcakes, and in those obtained from vegetable 
 pulps (pounded nuts, crushed olives, and such like) by heating 
 with water so that oily matter floats up, separated by skimming 
 i.e., in those cases where contact with fermentible matters has 
 been most intimate and prolonged. Thus, the following figures 
 were obtained by Noerdlinger,* the total fatty matter being 
 * Journ. Soc. Cfiem. Ind., 1890, p. 422, from Zeit*. Anal Chfm., 29, p. 6. 
 
PROXIMATE CONSTITUENTS. 
 
 115 
 
 extracted from the seeds by means of light petroleum spirit, and 
 the free fatty acid (determined by titration with phenolphthalein. 
 as indicator) reckoned as oleic acid (vide p. 117) : 
 
 
 103 Parts 
 
 contain 
 
 
 
 
 
 Free Fatty 
 
 Oils. 
 
 
 
 Acids Reckoned 
 per 100 of Total 
 
 
 Free Fatty 
 Acids. 
 
 Total Fat. 
 
 Fat. 
 
 Rape (jBras.nca rapct), 
 
 0-42 
 
 37'75 
 
 MO 
 
 Cabbage (B. c.ampestris), . 
 Poppy (Papover somni/eritm) , . 
 
 0-32 
 3-20 
 
 41-22 
 46-90 
 
 0-77 
 6-66 
 
 Earthnut (Arachis hypoy<ea) \ 
 
 seed, / 
 
 1--91 
 
 40-09 
 
 4-15 
 
 Earthnut (Arackift hypogcva) \ 
 outside pale husk, . J 
 
 1-91 
 
 4-43 
 
 43-10 
 
 Sesame (Sesamum orientate), . 
 
 2-21 
 
 51-59 
 
 4-59 
 
 Castor (Riclnus communit"), 
 
 1-21 
 
 46-32 
 
 2-52 
 
 Palmnut (Elais guinenxis) } 
 containing 6 per cent, husks, J 
 
 4-19 
 
 49-16 
 
 8-53 
 
 Cokernut (Cocos nucifera), 
 
 2-98 
 
 67-40 
 
 4-42 
 
 Oil Cakes. 
 
 
 
 
 Rape, . ... 
 
 093 
 
 8-81 
 
 10-55 
 
 Poppy, . ... 
 
 5-06 
 
 9-63 
 
 58-89 
 
 Earthnut, 
 
 1-42 
 
 7-65 
 
 18-62 
 
 Sesame, . ... 
 
 6-15 
 
 15-44 
 
 40-29 
 
 Palmnut, . ... 
 
 1-47 
 
 10-39 
 
 14-28 
 
 Cokernut, 
 
 1-31 
 
 13-11 
 
 10-51 
 
 Linseed, . ... 
 
 0-75 
 
 8-81 
 
 9-75 
 
 Castor, . ... 
 
 1-27 
 
 653 
 
 2007 
 
 Obviously, when oil contains any considerable quantity of free 
 fatty acids the use of alkaline refining processes (Chap, xi.) is apt 
 to lead to a considerable diminution in the quantity of refined 
 product obtained, as compared with the raw material employed, 
 because the free fatty acids are removed in the form of soaps, the 
 production of which, moreover, often leads to further loss by 
 the mechanical en tangling of " neutral " oil in .the saponaceous 
 " foots." 
 
 The presence of free fatty acids in any quantity in most 
 kinds of oils is detrimental to their value, more especially in 
 reference to certain applications. Thus, in the case of lubricating 
 oils, corrosion of bearings, etc., is more apt to be brought about 
 when free fatty acids are present than when the oil is practically 
 free therefrom ; and hence in such cases alkaline refining pro- 
 cesses will often give a superior result, the more so that acid 
 processes are apt to communicate to oil refined thereby traces of 
 mineral acid, the corrosive action of which is still more marked. 
 This is notably the case with oils intended for wool spinning and 
 
116 OILS, FATS, WAXES, ETC. 
 
 analogous purposes. Colza oil containing much free fatty acids 
 burns less freely, and is more apt to char the wick than com- 
 paratively neutral oil. On the other hand, the taste of olive oil 
 is said to be considerably improved by the presence therein of 
 small quantities of free acids ; whilst largely hydrolysed oils 
 (kuiles tournantes] are intentionally prepared for certain special 
 purposes in the textile and dyeing industries. 
 
 In the case of blubber oils largely consisting of the compound 
 ethers of higher monatomic alcohols of the ethylic series, the 
 hydrolytic actions taking place during storage before and after 
 extraction, and whilst the "rendering" is taking place, lead to 
 another result viz., that cetylic alcohol and analogous bodies are 
 largely contained in the oils ultimately obtained ; thus, from 30 
 to 40 per cent., and sometimes more, of so-called " unsaponifiable 
 matter " is frequently found to be present in sperm and other 
 blubber oils, chiefly consisting of alcoholiform products of 
 hydrolytic actions of this description. Similar remarks apply 
 to beeswax, and to the various vegetable waxes of analogous 
 constitution ; figures are on record, obtained by various analysts, 
 indicating in extreme cases that from J to of the original 
 compound ethers have been hydrolysed by actions of this 
 description, either occurring naturally during storage, or in con- 
 sequence of the processes adopted in preparing the raw material. 
 
 DETERMINATION OF FREE FATTY ACIDS. 
 FREE ACID NUMBER. 
 
 The most accurate process for determining the amount of free 
 acids contained in a given sample of oil or fat, consists in agitating 
 it with warm alcohol, and dropping in a standard alkaline solu- 
 tion (preferably alcoholic) until a persistent pink coloration 
 appears after continued agitation, phenolphthalein being the 
 indicator ; the temperature must be high enough to render the 
 fat perfectly fluid. Or the oil may be dissolved in cold ether, 
 mixed with a little alcohol, and the solution titrated with 
 standard alcoholic alkali. If the mean equivalent weight of 
 the free fatty acids is known (or assumed) to be E, the pro- 
 portion of fatty acids in the free state is given by the formula, 
 
 x = JL X ^ x 100, 
 w 
 
 where w is the weight in milligrammes of material taken for 
 examination, n the number of c.c. of normal alkali used,* and 
 x the weight of free fatty acids contained in 100 parts of sub- 
 stance (percentage of free fatty acids) ; for since 1 c.c. of normal 
 
 * If seminormal (or decinormal) alkali be used, the value of n will 
 obviously be * (or Y 1 ^) of the number of c.c. used, and so on. 
 
DETERMINATION OF FREE ACID NUMBER. 117 
 
 alkali represents E milligrammes of fatty acids, the^total weight 
 of acids contained in w milligrammes of substance is n x E 
 
 milligrammes, whence 100 parts of substance contain - x 100 
 
 parts of free fatty acids. 
 
 In many instances the value of E is not known accurately, 
 and in such cases it is more convenient to express the amount 
 of fatty acids in terms of the alkali neutralised. This may be 
 done with respect to 100 parts of original substance, thus giving 
 the percentage of potash (or soda) neutralised, according to the 
 alkali employed ; but a more usual practice is to express the 
 value relatively to 1,000 parts of original substance, potash 
 (caustic potash, KOH, equivalent 56'1), being selected as the 
 alkali, thus giving the permillage of potash neutralised, con- 
 veniently referred to as the "free acidity potash permillage," or 
 "free acid neutral' sation number," or, more shortly, as the " free 
 
 acid number," and expressed by the value - x 56,100.* 
 
 Thus, suppose that 10 grammes (10,000 milligrammes) of palm 
 butter neutralise 8 c.c. of seminormal alkali, equivalent to 
 4'0 c.c. of normal alkali ; since 1 c.c. of normal alkali corre- 
 sponds with 56-1 milligrammes of KOH, and with 256 milli- 
 grammes of palmitic acid (i.e., E = 256 j, the result may be stated 
 by saying that the " free acidity potash permillage "or " free 
 
 acid number " is JQ-^K x 56,100 = 22*44; or it may be expressed in 
 
 terms of percentage of palmitic acid by saying that the substance 
 
 4*0 x *^J56 
 contains free acids jointly equivalent to _ ooo" x ^^ = l^'-M 
 
 per cent, of palmitic acid. 
 
 When only small quantities of free acid are present, and 
 extremely sharp valuations are desired, somewhat large quantities 
 of material should be taken for the determination ; 20 or 25 
 grammes, or even more. A less accurate method of determining 
 free fatty acids consists in shaking up the oil, &c., with alcohol, 
 allowing to stand, separating a known fraction of the alcoholic 
 fluid, and titrating with standard alkali ; the result is apt to be 
 somewhat too low on account of incomplete solution of all free 
 acid by the alcohol. 
 
 In some natural oils (e.g., unrefined cotton seed oil) substances 
 are present of an acid character, although not belonging to the 
 
 * Since 1 c.c. of normal alkali represents 56'1 milligrammes of KOH, n c.c. 
 represent n x 56 '1 milligrammes: then if A be the free acid number as 
 above defined, 
 
 w : n x 56'1 : : 1,000 : A 
 
 whence A= x 56,100. 
 
118 OILS, FATS, WAXES, ETC. 
 
 ordinary fatty acid series, but more resembling the acids of pine 
 resin ; these substances neutralise alkali (phenolphthalein being 
 the indicator), and are consequently included in the total of "free 
 fatty acids " determined by titration. Occasionally ordinary 
 rosin (colophony) is intentionally added to oils or the fatty acids 
 thence derived, either as an adulterant or for special reasons 
 e.g., in the manufacture of some kinds of waggon grease and 
 "yellow " soap. For the methods used in determining the amount 
 of resin present in such cases, vide Chap. xxi. 
 
 When it is required to separate the free fatty acids from the 
 neutral fat, this is readily accomplished by adding alcoholic 
 alkali until just neutral to phenolphthalein, diluting with water, 
 and agitating with ether, or better, with light petroleum spirit.* 
 The ethereal liquid on evaporation leaves the neutral fatty 
 matter, which can be weighed and further examined as desired ; 
 the aqueous fluid is acidulated and shaken with petroleum spirit, 
 &c., whereby the free fatty acids are similarly obtained. 
 
 If mucilaginous matter, &c., is also present, the oil may be 
 ground up in a dish with half its weight of solid sodium car- 
 bonate and as much water, and dried on the waterbath ; the 
 residue is again stirred up with coarsely powdered pumice- 
 stone, and exhausted with ether containing no alcohol, whereby 
 the neutral fat is dissolved out. The residue is exhausted with 
 hot alcohol, and the resulting soap solution evaporated and 
 decomposed by a mineral acid, so as to obtain the free fatty 
 acids, originally present as such, free from the other constituents. 
 Or the fat, &c., may be treated with ether, carbon disulphide, or 
 other solvent ; by filtering through a weighed filter and washing 
 the insoluble matter thoroughly, the mucilage, &c., is obtained, 
 whilst the filtrate may be evaporated, and the resulting mixture 
 of neutral fat and free fatty acid further examined as required. 
 
 Burstyn's Method. A physical method of approximately 
 determining the amount of free acid contained in oil (more 
 especially olive oil) has been devised by Burstynf for use in 
 cases where titration by chemical means is inconvenient or 
 impracticable. 100 c.c. of the oil to be tested are placed in a 
 stoppered cylinder capable of holding 200 c.c.; this is then filled 
 up to the mark with alcohol of 88 to 90 per cent., and the whole 
 well shaken, and allowed to stand two or three hours. The alcohol 
 floats up, having dissolved out most of the fatty acids together 
 with a minute amount of oil ; the increase in specific gravity is 
 determined by testing the upper layer with a highly delicate 
 araeometer, a similar cylinder of the original alcohol used being 
 simultaneously examined side by side. By the aid of a table 
 
 * In presence of alcohol ether is apt to take up into solution small 
 quantities of soap, as well as neutral fat. 
 
 t Dingier 's Polyt. Journal, ccxvii., p. 314; also Journal Chem. Soc., 
 vol. i. (1876), p. 769. 
 
DETERMINATION OF UNSAPONIFIABLE CONSTITUENTS. 11-9 
 
 the amount of free fatty acid is deduced from the increment in 
 specific gravity indicated, the table being so constructed as to 
 allow for the solubility in alcohol of the neutral oil, etc. Apart 
 from the error introduced by the possible presence of varying 
 amounts of phytosterol, or other vegetable substances more or 
 less soluble in alcohol, a very slight difference in temperature 
 between the vessels containing the alcoholic oil solution and the 
 pure alcohol used for comparison produces a great effect on the 
 result. The table is usually arranged so as to show the number 
 of " Burstyn degrees " of free acid i.e., the number of c.c. of 
 normal alkali neutralised by the free acid contained in 100 c.c. 
 of the oil examined. "One degree" consequently represents 
 0-282 gramme of oleic acid per 100 c.c., or close to 0'3 per cent, 
 by weight. 
 
 DETERMINATION OF UNSAPONIFIABLE 
 CONSTITUENTS. 
 
 The unsaponifiable matters contained in many oils and fats 
 to the extent of a few tenths per cent., are most conveniently de- 
 termined by saponifying the oil with alcoholic alkali, evaporating 
 off the spirit, and dissolving out matters soluble in such solvents 
 as ether, chloroform, carbon disulphide, light petroleum spirit, 
 fec., either by means of an extraction arrangement, such as the 
 Soxhlet apparatus described in Chap, ix., or by adding water and 
 agitating with the solvent. Ether frequently dissolves a small 
 amount of soap ; on the other hand, small quantities of oil 
 often escape saponification, and are thus extracted ; so that it 
 is always preferable to boil a second time with alcoholic alkali 
 the residue left on evaporating off the solvent, and repeat the 
 extraction process with the product. The extraction by means 
 of a Soxhlet arrangement is generally facilitated by placing some 
 sand or powdered pumice-stone in the evaporating vessel em- 
 ployed, and rubbing up therewith the residual soap left after 
 evaporating off the alcohol ; the solvent thus obtains more easy 
 access to the matters to be dissolved out, and the operation is 
 effected more quickly and thoroughly. 
 
 In the analysis of soaps similar methods are often employed ; 
 the soap to be tested is reduced to thin shavings which are 
 then cautiously dried, first at a comparatively low temperature 
 (50-60 C.), later on at steam heat or a little above, so as to 
 drive off all moisture without fusing the mass. The dried 
 shavings, coarsely powdered, are packed in the Soxhlet tube 
 and exhausted with solvent, preferably light petroleum ether; 
 in this way unsaponified fat contained in the soap, cholesterol 
 and analogous substances derived from the oils and fats em- 
 ployed, waxy matter or hydrocarbons (e.g., paraffin oil) added to 
 
120 OILS, FATS, WAXES, ETC. 
 
 the soap, or contained in the materials (e.g., in distilled oleins), 
 and similar constituents are all dissolved out, giving a solution, 
 the residue left on evaporation of which is further examined ; 
 whilst the purified soap is also subjected to analysis. 
 
 The modification of Soxhlet's extraction apparatus described 
 by Honig and Spitz (Chap, ix.), is often very convenient for dis- 
 solving out the unsaponifiable constituents soluble in ether, light 
 petroleum spirit, &c., after heating with excess of alcoholic alkali, 
 evaporating off the spirit, and dissolving in a minimum of water. 
 The use of petroleum spirit is preferable, as although it often 
 dissolves out a little soap (though usually less than ether), this 
 may be readily removed by agitating with a mixture of equal 
 quantities of alcohol and water (50 per cent, spirit), when the 
 petroleum solution free from soap floats up. Moreover, ethereal 
 liquids often form froths that remain permanent 
 without separating properly for many hours 
 or even days ; petroleum spirit is less liable to 
 this inconvenience. 
 
 In cases where a portion only of the ethereal 
 or other solution is intended to be drawn off, 
 this is readily effected by running the solution 
 and watery fluid into a graduated vessel, into 
 the mouth of which a doubly perforated cork is 
 fitted, with a washbottle-like arrangement of 
 tubes (Fig. 27, Chattaway). The upper and 
 lower levels of the ethereal liquid being read off, 
 the cork and tubes are inserted, and air blown 
 in so as to force out some of the ethereal solu- 
 tion into a weighed dish in which it is sub- 
 sequently evaporated, the quantity thus drawn 
 off being known by withdrawing the tubes and 
 reading off the difference of level of the top of 
 Fig 27 the ether stratum. When sharp results are re- 
 
 quired, about 90 to95per cent, of the ether should 
 thus be withdrawn, and the remainder diluted, say tenfold, by add- 
 ing more ether; the bulk of this is similarly forced out, so that the 
 remaining ether only represents a small percentage of the original 
 ethereal solution. Thus, suppose that the original ethereal fluid 
 measures 58 c.c., of which 52 are removed by the first blowing 
 out, leaving 6. This is diluted to 60, and another 50 c.c. blown 
 out, leaving 10 of the more dilute liquid, representing 1 of the 
 
 original solution, or 1 x = 1'72 per cent, thereof. Then 
 
 Oo 
 
 100 - 1-72 = 98-28 per cent, of the original solution has been 
 blown off, so that the weight of the residue obtained therefrom 
 
 58 100 
 by evaporation must be increased in the proportion -^= = ^T^TT- 
 
 i i/o **jO 
 
 Oils, &c., adulterated with any considerable proportion of 
 
DETERMINATION OF UNSAPONIFIABLE CONSTITUENTS. 121 
 
 hydrocarbons (paraffin, petroleum, rosin oil, &c.), or similar 
 mixtures intentionally prepared for lubricating purposes, fec., are 
 easily separated by the above treatment ; when the fatty acids 
 contained in the saponifiable constituents are required to be 
 further examined, they are readily isolated by dissolving in hot 
 water the soap thus freed from hydrocarbons, and acidulating 
 with a mineral acid. 
 
 Blubber oils containing the glycerides of higher ethylic alcohols 
 (cetylic alcohol, &c.) when thus treated yield to the solvent the 
 alcoholiform constituents set free during saponification ; when 
 these are mixed with hydrocarbons the proportion of alcohol 
 present may be arrived at by means of the hydrogen test (p. 13), 
 or the acetylation test (Chap, viu.) 
 
 When only minute quantities of unsaponifiable matters are 
 contained in a given oil or fat, &c., these are generally either 
 substances akin to cholesterol and phytosterol dissolved in the 
 oil, or else matters of mucilaginous or albuminous character 
 either dissolved in the oil or suspended in a diluted jelly-like 
 form therein. The former, when dissolved out from the soap 
 resulting after saponification by such solvents as ether or benzo- 
 line, may often be obtained in a crystallised condition by 
 dissolving in hot alcohol and cooling, or may be converted 
 into benzoic or acetic ethers, &c., and identified either by the 
 melting point or the " acetyl number." The latter are left un- 
 dissolved ; on decomposing the soaps with a mineral acid they 
 form flocculent masses, from which the pure molten fatty acids 
 are readily separable by filtration through a dry paper filter after 
 separation from the aqueous liquor. Some oleaginous matters,, 
 extracted by solvents (such as carbon disulphide) from certain 
 vegetables, seeds, &c., or from certain kinds of animal fatty 
 matter, contain complex bodies of the nature of lecithin, a sort 
 of compound ether of choline, glycerophosphoric acid, and fatty 
 acids (oleic and stearic) ; phosphorised constituents of this kind 
 are largely contained in the oily matter from the yolks of hens' 
 eggs, and to a lesser extent in that from the seeds of certain 
 leguminous plants, e.g., peas (vide p. 123). 
 
 Matters of a saponaceous character are sometimes contained 
 in commercial oils, owing either to the use of basic sub- 
 stances in refining (especially in boiling drying oils), whereby 
 more or less considerable amounts of metallic soaps are formed 
 and partially dissolved by the oil ; or to other causes, such as the 
 intentional addition of metallic soaps (aluminium, magnesium, 
 zinc, ttc.) for the purpose of increasing the viscosity of lubricating 
 oils ; or simultaneous contact with air and metals, whereby a 
 metallic oxide is formed, which then is either dissolved as 
 metallic soap, in virtue of free fatty acids present, or reacts on 
 the glyceride, forming metallic soap by saponification. Oils that 
 have been in contact with copper or brass are often rendered 
 
122 OILS, FATS, WAXES, ETC. 
 
 green by the formation of copper soap in this way ; similarly, 
 drying oils that have been " boiled " with metallic oxides as 
 driers (e.g., lead oxide) generally contain more or less metallic 
 soap in solution thence derived. Such admixtures, whether 
 intentional or not, can generally be estimated by diluting the oil 
 with ether free from alcohol, and filtering, when the metallic soap 
 is left undissolved ; by decomposing this with dilute nitric acid 
 the metallic constituents are obtained as nitrates. In most 
 <jases prolonged agitation of the oil with highly dilute nitric acid 
 suffices to dissolve out the metallic oxides present as soaps, and 
 in this way errors are avoided due to solubility of metallic soaps 
 in the ethereal solution of oil. 
 
 Oils containing lead or copper are more or less blackened by 
 shaking up with a few drops of sulphuretted hydrogen water, or 
 dilute solution of ammonium sulphide. Preferably a mixture of 
 equal volumes of glycerol and water is used to dissolve the 
 sulphur compound employed, as this then acts more readily on 
 the oil. 
 
 Oils containing potash and soda soaps in solution generally 
 yield these more or less completely to water when shaken up 
 therewith, so that by allowing to stand and separating the 
 aqueous liquid, the soaps dissolved therein can be obtained by 
 evaporation to dry ness. 
 
 Water contained in Oils, &c. Although " oil and water " 
 are conventionally regarded as immiscible substances, still their 
 mutual insolubility is in most cases relative rather than absolute. 
 Water in general dissolves extremely little oil or fat ; but the 
 converse does not hold so closely, as a few tenths per cent, of 
 water can generally be retained in permanent solution by fluid 
 oils, &c., without impairing their transparency. In the case of 
 semisolid substances (e.g., butter and lard), much larger 
 quantities of water can be mechanically intermixed with the fat 
 in the form of minute globules interspersed throughout the mass ; 
 but in this case there is no true solution, and on gently warming 
 the mass so as to melt the fatty matter, the water gradually 
 separates out to the bottom, so that if the operation be effected 
 in a graduated vessel, the volume of water thus separating may 
 be by and by read off. In some cases, the separation of the 
 water in this way is facilitated by adding to the just-fused mass 
 a sufficient quantity of light petroleum spirit to prevent it 
 solidifying on cooling, and setting by the whole in a corked-up 
 graduated tube for some time, so as to allow the water globules 
 to collect and run together. The amount of admixed water may 
 also be determined by heating a known weight of substance to a 
 temperature a little above 100 C. (by means of an airbath, &c.), 
 and noting the loss of weight. 
 
 When the actually dissolved water is to be determined, the 
 same process may be used; preferably, however, the oil, <fcc., to 
 
DETERMINATION OF UNSAPONIFIABLE CONSTITUENTS. 123 
 
 be examined is not heated in contact with air, but is placed in a 
 weighed U tube, through which a current of dry carbon dioxide 
 gas is passed, to prevent oxidation by absorption of oxygen from 
 the atmosphere during the heating. 
 
 Adulteration of Fats with Suspended Matters. Solid and 
 semisolid fats (lard, tallow, Arc.,) are sometimes intentionally 
 adulterated by admixture with white weight-giving substances, 
 such as china-clay, starch, &c. To determine the quantity arid 
 nature of the adulterants present in such cases, the fat, c., is 
 thinned with carbon disulphide or other volatile solvent, and 
 filtered through a dry weighed filter. The filtrate and washings 
 being evaporated to dry ness, and the residue dried in a steam 
 bath, the proportion of actual fat present is known ; the increment 
 in weight of the filter represents the solid adulterant, and the 
 deficiency in weight the water. The residue on the filter turns 
 blue if starch is present (flour, meal, farina, (fee.); cold water 
 dissolves out common salt and such like saline matters (e.g., in 
 salted butters, &c.) ; kaolin and sand are left behind on incinera- 
 tion, whilst albuminoid and caseous matters, cellulose, mucilage, 
 and other vegetable non-fatty extractives are burnt off during the 
 process. Oils that have been refined by means of sulphuric acid 
 and retain minute quantities of free inorganic acid, when thus 
 treated with a solvent and filtration, leave on the filter paper 
 a minute amount of residue soluble in water with acid reaction ; 
 this may be titrated with deciiiormal alkali in the usual way. 
 
 Sulphurised and Phosphorised Constituents. Certain 
 oils, more especially those derived from cruciferous plants (rape, 
 camelina, mustard, horseradish, cress, &c.), contain small quan- 
 tities of sulphurised constituents, such as thiocyanic ethers ; the 
 presence of these may be qualitatively tested by heating the oil 
 with concentrated potash solution, whereby potassium sulphide is 
 formed; the mass, after dilution with water and separation of 
 the aqueous liquor, gives a brown or black coloration with 
 potassium plumbate. In some cases, heating the oil to "boiling" 
 with a bright strip of silver causes the latter to blacken. To 
 determine the amount of sulphur, the oil is dissolved in sulphur- 
 free petroleum or alcohol, and burnt in the manner employed in 
 determining sulphur in coal gas, the flame being enclosed in a 
 chimney connected with an aspirator, and absorbing tubes filled 
 with moistened glass beads being interposed, so as to condense 
 sulphur dioxide and trioxide along with the water formed by 
 the combustion; a tray with fragments of solid ammonium 
 carbonate is fixed over the flame, to furnish an ammoniacal 
 atmosphere ; the condensed liquid is oxidised with bromine 
 water, and precipitated with barium chloride and hydrochloric 
 acid (Allen). Or the oil may be cautiously heated with alcoholic 
 potash, evaporated, and the residue incinerated with addition of 
 potassium nitrate till white, the sulphate formed being determined 
 
124 OILS, FATS, WAXES, ETC. 
 
 as usual. This latter method is also available for the estimation 
 of phosphorus, present in certain oils and fats as a compound of 
 the nature of lecithin, the phosphorus being ultimately weighed 
 as magnesium pyrophosphate (Benedikt). 
 
 The following general scheme for the examination of oils and 
 fats, &c., is applicable in most cases so far as the above mentioned 
 impurities or constituents are concerned : 
 
 Dry a convenient quantity so as to determine the amount of 
 water present (p. 122). 
 
 Melt a known weight of fat and pass it through a hot weighed 
 filter, finally washing out the adherent fat with ether ; the 
 residue left on the filter may contain saline matters, suspended 
 organic impurities, dust, tfec., &c., which may be further ex- 
 amined as occasion requires. On incinerating the filter, the 
 amount of inorganic suspended matter is obtained. Part of the 
 filtered oil, &c., may be shaken successively with water to dis- 
 solve out alkaline soapy matters, and with dilute nitric or 
 sulphuric acid in case any lead, copper, or other metallic soaps 
 are present, the watery and acid liquors being separated and 
 examined. The oil may advantageously be diluted with ether 
 or carbon disulphide, &c., previously to agitation with water, <fec. 
 Another part of the filtered oil is diluted with warm alcohol, and 
 the free acid number determined (p. 116), using phenolphthalein 
 as indicator ; the alcohol is evaporated and the residue taken up 
 with light petroleum spirit, &c. ; the residual soap formed from 
 the free acid is examined as required (Chap, xxi.) for fatty acids, 
 resin acids, <fcc. Aluminium and other metallic soaps may also be 
 here present, precontained in the oil. 
 
 The light petroleum spirit solution 011 evaporation gives a 
 residue containing neutral oil, hydrocarbons, and unsapoiiifiable 
 matters, c. ; this is saponified with alcoholic alkali, and the pro- 
 duct diluted with water and shaken with ether or petroleum 
 spirit; the ethereal solution is evaporated and the treatment 
 with alcoholic alkali repeated to ensure complete saponification ; 
 finally, the hydrocarbons, &c., are dissolved out by ether or 
 petroleum spirit, and the watery solution of glycerol and fatty 
 acid soaps further examined by acidifying and separating the 
 fatty acids ; these usually constitute 95 to 96 per cent, of the 
 original glycerides (Chap, vin.) 
 
EFFECT OF HEAT ON OILS. 125 
 
 CHAPTER VII. 
 
 CHEMICAL REACTIONS OF OILS, FATS, &c., AND 
 THEIR USES AS TESTS OF PURITY, &c. 
 
 EFFECT OF HEAT ON OILS, &c. 
 
 WHEN fixed oils, &c., are subjected to heat, decomposition is 
 sooner or later brought about ; if the oil is a glyceride, acroleiri 
 (acrylic aldehyde, C 2 ~H 3 .COH) is generally evolved, so named on 
 account of the acrid character of its vapour. In some cases the 
 fatty acid originally present as glyceride is also volatilised un- 
 changed in greater or less quantity ; but in general, destructive 
 distillation only takes place. If the heating be carried out in 
 presence of water vapour, as when superheated steam is blown 
 through the mass, in many cases hydrolysis takes place, fatty 
 acids and glycerol being produced, which more or less completely 
 pass off along with the water vapour ; on this action are based 
 certain processes for the manufacture of free fatty acids for candle 
 making, c., and for preparing pure glycerol. 
 
 When drying oils, more especially linseed, poppy, and walnut 
 oils, are heated for the purpose of preparing " boiled " oil for the 
 manufacture of paint, ttc., and particularly when the action is 
 pushed to a great length, as in the manufacture of printing 
 ink, the glyceridic portion of the compounds appears to be 
 almost completely decomposed, the linolic acid or anhydride 
 developed being more or less dehydrated (and probably poly- 
 merised) in such fashion as to form a highly viscid or rubber-like 
 mass. Oxidation by direct addition of oxygen so as to form 
 oxylinolic acid and derivatives thereof usually occurs simul- 
 taneously, more especially in the " blowing " process of preparing 
 boiled oils. 
 
 Flashing Point. The determination of the temperature at 
 which inflammable vapours are given oif (whether by simple 
 volatilisation, or in consequence of decomposition) in sufficient 
 quantity to take fire by the application of a light to the mixture 
 of air and vapour contained in the upper part of the heating 
 vessel, is a somewhat important operation in the case of many 
 oils intended for lubricating and other purposes, where they are 
 liable to be considerably heated ; with animal and vegetable oils 
 the " flashing points " are generally high, but much lower num- 
 bers are often given by mixtures containing hydrocarbon oils, 
 such as paraffin oil and petroleum distillates, rosin oils, and such 
 
126 
 
 OILS, FATS, AVAXES, ETC. 
 
 like products. For the determination of the flashing point of 
 petroleum distillates and similar substances, several special forms 
 of instrument have been devised by different experimenters ; in 
 some of the earlier forms the vapour emitted from the warmed 
 oil was allowed free access to the air ; this mode of operating was 
 known as the " open test," and was subject to serious irregulari- 
 ties according to the way in which the heating was conducted, 
 and so on. In the later instruments the top of the heating vessel 
 is closed in to prevent the escape of inflammable vapours when 
 first generated ; in consequence a considerably lower tempera- 
 ture is registered by the application of the " close test," whilst 
 the sources of fluctuation in the results are much lessened. 
 
 Fig. 28 represents Abel's 
 flashing point apparatus, 
 used in Britain as the legal- 
 ised appliance for testing 
 petroleum, c., under the 
 Petroleum Act. Similar ar- 
 rangements are in use in 
 other countries with minor 
 modifications, partly as to 
 the construction of the in- 
 strument itself, and partly 
 as to the exact details of 
 manipulation to be observed 
 during use ; for as the tem- 
 perature values deduced are 
 liable to slight fluctuation 
 with variations in the mode 
 of heating, etc., a definite 
 prescribed mode of operating 
 must be strictly adhered to. 
 Abel's apparatus consists of 
 a cylindrical metal cup, A f 
 placed inside another with an 
 Fig. 28. air-space between, the outer 
 
 one being surrounded by a 
 
 water bath, B, heated by a lamp, K, underneath. r lhe oil to be 
 tested is carefully poured in without splashing until just level with 
 the top of the gauge, C, 1 J inches from the bottom of the cup, the 
 water in the jacket being at the temperature 130 F. = 54 0< 4 C., 
 as shown by the thermometer, H. The lid of the cup, D, is then 
 put on, the temperature of the oil being known by means of the 
 thermometer, E. A small lamp, G, is arranged at the top of the 
 cover, swinging on an axis, in such a fashion that when a slide 
 covering an aperture in the lid is drawn aside, the lamp flame is 
 made to pass over the aperture. As the contents of the cup 
 slowly heat up, the slide is withdrawn at regular intervals of 
 
EFFECT OF HEAT ON OILS. 
 
 127 
 
 time, governed by the swinging of a pendulum ; by and by, the 
 inflammable vapours are given off in sufficient quantity to yield 
 a flash of blue flame by their kindling when the slide is with- 
 drawn ; the temperature then indicated by the thermometer, E, 
 is noted as the flashing point. Obviously this form of apparatus 
 is only suitable for substances the flashing point of which is 
 below the temperature of boiling water ; when less volatile sub- 
 stances are to be examined, the water jacket is replaced by a hot 
 bath of some other fluid ; or a hot airbath is used instead. 
 
 Fig. 29. 
 
 Pig. 29 indicates Pensky's modification of Abel's instrument for 
 such purposes, where the source of heat is the lamp flame, C, 
 playing on wire gauze, D, and filling the inverted basin, A, with 
 hot air.* 
 
 * An improved form of Pensky's apparatus has been described by Holde 
 (Journ. Soc. Chem. Ind., 1889, p. 734). 
 
128 
 
 OILS, FATS, WAXES, ETC. 
 
 Lubricating oils containing hydrocarbons sufficiently volatile 
 to flash at 150 C. or below are distinctly unsafe as regards risk 
 of fire. Animal and vegetable fixed oils (unmixed with hydro- 
 carbons), as a rule, do not flash below 200 to 250 C. ; thus 
 A. Kiinkler gives the following values * as the flashing points 
 observed with various lubricating fluids, mostly consisting of 
 petroleum hydrocarbons, and some natural oils, &c. : 
 
 Cylinder oils - Russian, 
 ,, American, 
 
 Machine oils Russian, 
 ,, American, 
 
 Spindle oils Russian, 
 ,, American, 
 
 Rape oil crude, 
 ,, refined, 
 
 Olive oil, . 
 
 Castor oil, 
 
 Linseed oil, 
 
 Tallow, . 
 
 
 Sp. Gr. at 17 'o. 
 
 Degrees C. 
 
 
 9 11 --923 
 
 183-238 
 
 
 886--S99 
 
 280-283 
 
 
 893--920 
 
 138-197 
 
 
 884--920 
 
 187-206 
 
 
 893 --895 
 
 163-167 
 
 
 908 --91 1 
 
 187 200 
 
 
 920, 
 
 265 
 
 
 911 
 
 305 
 
 
 914 
 
 205 
 
 
 963 
 
 275 
 
 
 930 
 
 285 
 
 
 951 
 
 265 
 
 Characteristic Oxidation Products. In certain cases the 
 results furnished by cautious oxidation afford useful indications 
 of the nature of the fatty acids ; this is more especially the case 
 when an approximate separation of liquid and solid fatty acids 
 has been previously effected by conversion into lead salts and 
 treatment with ether, so as to dissolve out oleate and linolate 
 of lead, <tc., leaving undissolved lead stearate, palmitate, &c. 
 Hazura recommends the following method of operating : The 
 fatty acids obtained by decomposing the soluble lead salts are 
 neutralised with a slight excess of caustic potash, diluted with 
 60-70 parts of water, and the liquid treated with about an 
 equal volume of a solution of potassium permanganate added 
 in a thin stream with continuous agitation. After ten minutes 
 sulphurous acid solution is similarly added, sufficient to dissolve 
 all precipitated hydratecl manganese dioxide, and to give an 
 acid reaction. The products of oxidation of oleic and linolic 
 acids (dioxystearic and sativic acids) are only difficultly soluble, 
 and consequently precipitate ; whilst linusic and isolinusic 
 acids (the oxidation products respectively of linolenic and 
 isolinolenic acids) remain in solution. These latter acids are 
 extracted by neutralising with potash, evaporating to a small 
 bulk (one-twelfth to one-fourteenth of the original volume) and 
 decomposing with sulphuric acid ; the precipitate is dried in the 
 air, treated with ether to dissolve out matters readily soluble 
 
 * Journ. Hoc. Chem. Ind., 1890, p. 197; from Dinner's Pol. Journ., 274, 
 p. 276. 
 
SPONTANEOUS OXIDATION OF OILS. 129 
 
 therein, and the residue crystallised from alcohol and from water 
 so as to separate the more soluble isolinusic acid from the less 
 soluble linusic acid. Dioxystearic acid and sativic acid are 
 separated in a similar way from the precipitate thrown down in 
 the earlier stage ; the precipitate is washed with a little ether to 
 remove easily soluble fatty acids (unoxidised) and then treated 
 with large bulks of ether (100 parts ether to 1 of substance). 
 Dioxystearic acid is chiefly dissolved out, obtainable by evapora- 
 tion and recrystallisation of the deposited crystals from alcohol 
 twice in succession ; whilst sativic acid is isolated from the 
 insoluble portion by boiling with water, filtering whilst boiling 
 hot, and crystallisation on cooling. The purified acids thus 
 obtained are further identified by means of their melting points 
 (p. 43). According to Benedikt the acetylation test (Chap, viu.) 
 may also be usefully employed for this purpose. 
 
 In somewhat similar fashion trioxystearic and isotrioxystearic 
 acids are obtainable from the fatty acids of castor oil. It is 
 noteworthy in this connection that the acids obtained by the 
 oxidation of isoleic acid and of elaidic acid (the isomeride of 
 oleic acid produced by the action of nitrous acid, p. 28) are 
 dioxystearic acids, isomeric but not identical with that obtained 
 from ordinary oleic acid (Saytzeff, p. 30). Similarly, the oxida- 
 tion products of erucic acid and its elaido derivative brassic acid, 
 yield two isomeric dioxybenic acids (p. 29). 
 
 Spontaneous Oxidation of Oils, Fats, &c. Oils of the 
 drying class, and to a lesser extent many other oils and fats, 
 possess the property of directly absorbing oxygen from the air at 
 the ordinary temperature, the effect being much more marked 
 when more or less heated ; the drying and hardening of paint 
 prepared from linseed oil is an extreme case of such an action, 
 whilst the thickening and " gumming " of various other oils on 
 keeping exhibits the same kind of phenomenon in a lesser 
 degree. The fixation of oxygen during actions of this kind 
 appears to be principally due to a direct combination of oxygen 
 with acid radicles of " unsaturated " character, precisely analogous 
 to the combination therewith of iodine or bromine (p. 31, 45); as 
 the oxidation proceeds, the "iodine absorbing power" of the 
 substance usually diminishes pari passu. 
 
 In some cases the rapidity with which the absorption of oxygen 
 takes place is greatly enhanced by heating the oil to a tempera- 
 ture insufficient to produce any great degree of decomposition, 
 although high enough to cause incipient breaking-up with evolu- 
 tion of vapours ; this process of " boiling " oil, especially when 
 certain metallic compounds or "driers" are added, appears to 
 consist essentially in the formation of substances that act as 
 " carriers " of oxygen ;* so that " boiled oils " dry more rapidly 
 
 * The rotting of painted canvas sometimes observed appears to be largely 
 due to oxidation of the fibres of the fabric in consequence of this carrier 
 
 9 
 
130 
 
 OILS, FATS, WAXES, ETC. 
 
 than the same oils in a raw or unboiled condition, these carriers 
 absorbing oxygen more rapidly from the air, and parting with it 
 again to the unoxidised portions of the oil. Free exposure to 
 air whilst heating, in some cases accompanied by the injection of 
 a current of air through the heated mass, appears to be essential 
 to the production of the initial degree of oxidation effected in 
 the boiling of drying oils ; the latter process when applied to 
 various non-drying oils (more especially fish oils), causes a con- 
 siderable increase in density and viscidity, so that " blown oils " 
 thus prepared are more suitable for lubricating and other 
 purposes than the original untreated substances. 
 
 Effect of Light on Oils. Exposure to light produces a- 
 remarkable increase in the rate at which spontaneous oxidation 
 of oils, &c., takes place at the ordinary temperature j the result 
 of this oxidation is uniformly to cause an increment in specific 
 gravity and in the amount of heat evolved on mixture with 
 sulphuric acid (infra), together with a decrement in the iodine ab- 
 sorption (Chap, viu.) Thus, the following figures were obtained 
 (along with many others) by H. Ballantyne * with olive, castor,, 
 rape, cotton seed, arachis, and linseed oils ; specimens kept in 
 the dark for six months showed little or no alteration whether 
 in tightly corked or open bottles, and whether undisturbed or 
 agitated daily so as to aerate them ; whereas similar specimens 
 exposed to sunlight during the same period exhibited perceptible 
 amounts of alteration, even when kept undisturbed in corked 
 bottles ; and much larger amounts when kept in uncorked 
 bottles and agitated daily : 
 
 VARIATION IN SPECIFIC GRAVITY. 
 
 
 
 Value after Six Months' Exposure 
 
 
 Original Value, 
 
 to Sunlight. 
 
 
 practically 
 
 
 
 Unchanged in the 
 
 
 
 
 Dark. 
 
 Undisturbed, 
 
 Agitated Daily, 
 
 
 
 Corked. 
 
 Uncorked. 
 
 Olive oil, . 
 
 9168 
 
 9185 
 
 9246 
 
 Castor oil, . 
 
 9679 
 
 
 96S3 
 
 Rape oil, 
 Cotton seed oil, . 
 
 9108 
 9225 
 
 9171 
 9236 
 
 9207 
 9320 
 
 Arachis oil, 
 
 9209 
 
 9216 
 
 9267 
 
 Linseed oil, 
 
 9325 
 
 9327 
 
 9385 
 
 action. The presence of certain kinds of resinous matter (such as are 
 employed in the manufacture of tarpaulins, &c.), seems to diminish the 
 tendency to this destructive action. 
 * Journ. Soc. Chem. Int., 1891, p. 29. 
 
EFFECT OF LIGHT ON OILS. 
 
 VARIATION IN IODINE ABSORPTION. 
 
 131 
 
 
 
 
 Value after Six Months' Exposure 
 
 
 Original Value, 
 
 to Sunlight. 
 
 
 practically 
 Unchanged in the 
 
 
 
 
 
 Dark. 
 
 : Undisturbed, 
 ' Corked. 
 
 Agitated Daily, 
 Uncorked. 
 
 Olive oil, 
 
 83-16 
 
 82-64 
 
 78-24 
 
 Castor oil, . 
 
 83-63 
 
 
 83-27 
 
 Rape oil, 
 
 105-59 
 
 105-27 
 
 102-12 
 
 Cotton seed oil, 
 
 106-84 
 
 106-40 
 
 100-12 
 
 Arachis oil, 
 
 98-67 
 
 97-60 
 
 93-20 
 
 Linseed oil, 
 
 173-46 
 
 172-88 
 
 166-17 
 
 VARIATION IN HEAT EVOLUTION WITH SULPHURIC ACID. 
 
 
 Values after Keeping Six Months 
 
 
 In the Dark. 
 
 In Sunlight. 
 
 
 Undisturbed, 
 Corked. 
 
 Agitated 
 Daily, 
 
 Uncorked. 
 
 Undisturbed, 
 Corked. 
 
 Agitated 
 Daily, 
 Uncorked. 
 
 Olive oil, 
 
 44 
 
 43 -5 
 
 47 
 
 67 
 
 Castor oil, 
 
 73 
 
 73 
 
 74 -5 
 
 78-5 
 
 Rape oil, 
 
 61-5 
 
 60 -5 
 
 63 
 
 72 -5 
 
 Cotton seed oil, 
 
 75 "5 
 
 76 -5 
 
 76 -5 
 
 100 
 
 Arachis oil, . 
 
 73 -5 
 
 73 -5 
 
 77 
 
 90 
 
 Linseed oil, . 
 
 11 3 -5 
 
 112 -5 
 
 120 
 
 131 
 
 Only minute amounts of free acid were developed in six months 
 during the course of these observations, indicating but little 
 hydrolysis of glycerides during the oxidation of the insolated 
 samples ; the maximum amounts formed were in the case of 
 linseed and cotton seed oils, and corresponded with a develop- 
 ment of 0*3 4 and 0*50 per cent, respectively of free acid 
 (expressed as oleic acid) in sunlight, none at all being formed 
 in the dark. Olive oil kept six months in the dark gave a hard 
 solid elaidin ; that exposed to sunlight in corked bottles with- 
 out agitation a somewhat less hard mass ; but that insolated 
 and agitated daily, so as to expose as thoroughly as possible 
 to oxidising influences, did not even thicken when sub- 
 mitted to the elaidin test. Similarly Becchi's silver test for 
 cotton seed oil gave only faint indications with the insolated 
 oxidised oil, although reacting thoroughly with oil kept in the 
 dark. The viscosity of rape oil, as indicated by the efflux 
 
132 OILS, FATS, WAXES, ETC. 
 
 test (p. 95), was notably increased by nine months' exposure 
 to sunlight (in corked bottles without agitation) ; oil kept 
 in the dark giving times of flow 56 at 15 -5 and 25-5 at 50, 
 whilst insolated oil gave 66 at 15 0< 5 and 26-5 at 50. Castor oil, 
 mainly consisting of the glycerides of acids already oxidised, as 
 might a priori be expected, is less changed by oxidation than 
 any of the others. 
 
 Similar, but less systematic, observations have been recorded 
 by various other experimenters, the general result of which is 
 to show that the changes brought about in oils and fats by 
 keeping and atmospheric oxidation are greatly accelerated by 
 the influence of light. According to E. Ritsert rancidity is only 
 produced in oils in presence of oxygen (air), the action being 
 greatly accelerated by simultaneous exposure to light. No 
 effect, however, is produced by the action of light alone, when 
 access of oxygen is entirely excluded. 
 
 Spontaneous Combustion. When a film of readily oxidisable 
 oil is spread over a considerable surface, so that a large area is pre- 
 sented for atmospheric oxidation, if the circumstances are such 
 that the heat generated by the action is not readily lost, the mass 
 heats greatly, in some cases to such an extent as to bring about 
 spontaneous inflammation. Gellatly has shown that greasy 
 cotton rags and similar materials kept in a warm place are, 
 in consequence, liable to ignite spontaneously, and are accord- 
 ingly a source of danger as regards fire. Boiled linseed oil 
 appears to be the most energetic of oils in this respect ; a 
 handful of cotton waste soaked in this fluid and squeezed out, 
 and then kept in a box at 70 to 80", soon rises greatly in 
 temperature to near 200 ; in little more than an hour the mass 
 is so hot that smoke issues, and on opening the box the whole 
 takes fire. Unboiled linseed oil takes a much longer time to 
 produce the same result * (from four to six hours), and rape oil 
 longer still (some ten hours). On the other hand, an admixture 
 of mineral oil greatly retards the action. In general, the ten- 
 dency to spontaneous oxidation is greater the greater the iodine 
 absorption of the oil. 
 
 A testing apparatus has been constructed by Allbright & 
 Clark f for determining the comparative liability of oils to 
 spontaneous combustion, consisting of an outer shell formed by 
 a six inch wrought iron tube which can be closed at each end by 
 discs of wood. Inserted into this tube is an inner four inch 
 sheet iron tube with overlapping metal covers at each end, so 
 that an air space is left of one inch around the inner tube, and of 
 three inches at each end ; three thermometers are inserted into 
 the inner shell through the outer one. A ball of say 50 grammes 
 
 * Renouard, Journ. Soc, Chem. Ind., 1882, p. 184, has repeated and con- 
 firmed this difference between boiled and raw linseed oil. 
 t Journ. Soc. Chem. Industry, 1892, p. 547. 
 
ABSORPTION OF OXYGEN BY OILS. 133 
 
 of waste, over which an equal weight of oil is distributed, is care- 
 fully pushed to one end of the inner tube, and the corresponding 
 thermometer bulb inserted into the middle of the ball. A 
 similar ball of unoiled waste is placed at the other end, with 
 another thermometer bulb inserted as before. The third ther- 
 mometer is placed between the two. On heating the outer tube 
 by means of a Bunsen burner, so that the central thermometer 
 indicates about 125, the temperature of the unoiled waste ball 
 will be about 100. That of the other rises in proportion as the 
 oil oxidises more rapidly. E. H. Richards reports that this 
 arrangement gives most valuable results as regards gauging the 
 degree of safety of lubricating oils, &c. ; for instance, the per- 
 centage of fatty oil which may be safely mixed with mineral oils 
 may be thus determined. Thus neat's foot oil and best lard oil 
 may be added to the extent of 50-60 per cent., whilst not more 
 than 25 per cent, of cotton seed oil is permissible. 
 
 Film-test. If a film of oil be freely exposed to the air, so that 
 heating to any considerable extent is impracticable, the effect of 
 the oxidation is gradually to inspissate the oil, and finally to con- 
 vert it into a varnish-like product; a test of the quality of a given 
 sample of drying oil is based upon this, a glass plate being 
 coated on one side with a film of oil, after the fashion of a photo- 
 grapher's collodion plate, and then kept in a steam bath for 
 some hours, preferably side by side with another plate similarly 
 coated with oil of standard quality ; the relative length of time 
 requisite before the film ceases to be " tacky," being converted 
 into a dry varnish, serves as a measure of its drying quality. 
 Thus, whilst a good sample of linseed oil is completely solidified 
 in some twelve hours, non-drying oils like arachis and olive oils 
 are scarcely thickened at all ; whilst cotton seed oil and similar 
 substances possessing only a certain degree of drying power are 
 intermediate. In this respect the order in which oils are 
 arranged by means of this test is sensibly the same as that in 
 which they are arranged by means of the iodine absorption 
 reaction (Chap, vm.) 
 
 Livache's Test. Livache finds that the rate of absorption of 
 oxygen is much quickened if finely divided metallic lead is 
 mixed with the oil to be examined ; comparative tests are readily 
 made by placing on a watchglass about a gramme of lead * in a 
 thin layer, and then dropping on to it a few decigrammes (not 
 more than 6 or 7) of oil in small drops, scattered over different 
 portions of the lead, so as not to run into one another. The 
 whole is then weighed and allowed to stand at the ordinary 
 temperature. Drying oils begin to increase measurably in 
 weight in less than twenty-four hours, and cease to gain weight 
 
 * Precipitated from lead acetate solution, and rapidly washed with water, 
 alcohol, and ether in succession, and finally dried in vacuo. According to 
 Hiibl, precipitated copper is preferable to lead. 
 
134 
 
 OILS, FATS, WAX MS, ETC. 
 
 after three to six days, whilst oils possessing little or no drying 
 qualities do not increase at all for several days. Similar remarks 
 apply to the fatty acids isolated from the oils. Thus the follow- 
 ing figures were obtained : 
 
 
 Percentage Increment in Weight 
 
 . 
 
 Of Oil after 
 
 Of Fatty Acids 
 
 
 2 Days. 
 
 7 Days. 
 
 8 Days, 
 
 Linseed oil, . 
 
 14-3 
 
 
 11-0 
 
 Nut oil, 
 
 7-9 
 
 .. 
 
 6-0 
 
 Poppy oil, 
 
 0-8 
 
 .. 
 
 3-7 
 
 Cotton seed oil, 
 
 5-9 
 
 
 0-8 
 
 Beech mast oil, 
 
 4-3 
 
 
 2-6 
 
 Colza oil, 
 
 Nil. 
 
 2-9 
 
 2-6 
 
 Arachis oil, . 
 
 Nil. 
 
 1-8 
 
 1-3 
 
 llape oil, 
 
 Nil. 
 
 2-9 
 
 0-9 
 
 Olive oil, 
 
 Nil. 
 
 1-7 0-7 
 
 Sesame' oil, . 
 
 Nil. 
 
 2-4 
 
 2-0 
 
 Bach,* following Freseiiius, tests the oxygen- absorbing power 
 of oils by heating in a closed tube containing oxygen, and noting 
 the bulk of gas absorbed. The presence of excess of oxygen after 
 the experiment must be proved by means of a glowing splinter 
 of wood. This test is more particularly useful in the valuation 
 of certain kinds of lubricating oils. 
 
 CHEMICAL CHANGES OCCURRING DURING 
 DRYING OF OILS. 
 
 The nature of the chemical changes taking place during the 
 complete atmospheric oxidation and consequent drying up of a 
 drying oil has been the subject of various investigations ; but it 
 can hardly be said that the matter is yet settled beyond dispute. 
 The earlier researches on linseed and other drying oils by 
 Mulder and others led to the conclusion that the chief consti- 
 tuent of drying oils, giving them their peculiar properties, was 
 linolin, the glyceride of linolic acid, regarded as C 16 H 28 O 9 , and 
 then termed linoleic acid. During drying this glyceride was 
 supposed to become hydrolysed or otherwise broken up, 
 losing its glyceridic character, and forming oxylinoleic acid, 
 C 16 Ho 6 O 5 . 2H. 2 O, by oxidation ; a neutral polymerised amorphous 
 anhydro derivative, linoxyn, C 32 H S4 O n , being subsequently 
 developed as the leading ingredient of the " skin " formed as the 
 oil dries. Later researches have indicated that what \vas formerly 
 
 * Journ. Soc. Chem. Twd.,-1889, p. 990 ; from Chem. Zeit., 13, p. 905. 
 
CHEMICAL CHANGES OCCURRING DURING DRYING OF OILS. 135 
 
 termed "linoleic acid," C 16 H 28 O 2 , is really a mixture of three 
 acids of notably higher molecular weights viz., true linolic acid, 
 C 18 H 32 O 2 , related to oleic acid as oleic acid is to stearic ; and 
 two isomeric acids still less saturated, related to linolic acid in 
 the same way, linolenic and isolinolenic acids, both represented 
 by C 18 H 30 O 2 . These substances by gentle oxidation yield 
 crystallisable acid products, sativic acid (tetroxystearic acid), 
 melting at 173, being formed from linolic acid, and linusic and 
 isolinusic acids (hexoxystearic acids), melting at 203 to 205 
 and 173 to 175 respectively (vide p. 43), being produced from 
 the other two acids ; but these crystallisable ultimate oxida- 
 tion products are apparently not formed in the " boiling" 
 process at all \ and even if contained in the dried skins are 
 certainly not the constituents giving the peculiar physical 
 properties to these substances. Moreover, the proportions of 
 oxygen and water requisite to be taken up by linolic and 
 linolenic glycerides in order to convert them into free oxy- 
 stearic acids, are greatly in excess of the increment in weight 
 observed to take place during the drying of oils of this class 
 (p. 134) ; whilst the skins are found to be susceptible of some 
 degree of saponification, furnishing glycerol. Hence it would 
 seem probable that the essential constituents of dried skins are 
 a mixture of polymerised glycerides (possibly more or less hydro- 
 lysed) of acids derived from linolic, linolenic, and isolinolenic 
 acids by oxidation processes not carried so far as to produce the 
 various oxystearic acids obtainable by means of alkaline perman- 
 ganate.* That some of these substances are of a feebly acid 
 character, or at any rate are capable of forming salts by the action 
 of metallic oxides, is suggested by the well-known fact that the 
 effect of basic matters like white lead (basic lead carbonate) and 
 zinc white (chiefly zinc oxide) on the paint produced by their 
 admixture with drying oils is different in many respects from 
 that of neutral pigments like lead sulphate and sulphate of 
 barium ; in practice these latter are found to be far less suitable 
 for the production of firm adherent coats that will stand ordinary 
 wear and tear, which is usually considered to be due to the 
 absence of the metallic salts contained . in white lead and zinc 
 white paints, formed by the neutralisation of acids developed by 
 oxidation, or possibly by the saponification of glycerides. 
 
 The drying qualities of an oil appear to be the more marked 
 the greater the proportion of linolenic and isolinolenic acids is 
 
 *Fahrion (Zeitsch. /. angew. Ckem., 1891, p. 540; 1892, p. 171) finds 
 that the acids formed on saponification of boiled linseed oil where partial 
 oxidation has taken place are not wholly soluble in light petroleum spirit, 
 whereas the fatty acids of unoxidised oil are readily soluble therein ; from 
 0'6 to 31 '0 of such insoluble acids were found in different samples of oil. 
 The proportion present appears to be the greater the more marked the 
 decrement in "iodine absorbing power" produced by the oxidation process. 
 These " oxyacids " readily dissolve both in alcohol and in ether. 
 
136 
 
 OILS, FATS, WAXES, ETC. 
 
 present. Hazura and Griissner deduced the following percentages 
 from the relative proportions in which the oxystearic acids were 
 produced on oxidising the liquid fatty acids of linseed, hemp seed, 
 nut, poppy seed, and cotton seed oils, the solid acids being pre- 
 viously separated by conversion into lead salts and treatment 
 with ether (p. 112). 
 
 
 Linolenic 
 Acid. 
 
 Isolinolenic 
 Acid. 
 
 Linolic 
 Acid. 
 
 Oleic Acid. 
 
 Linseed oil, . 
 
 15 
 
 65 
 
 15 
 
 5 
 
 Hemp seed oil, 
 
 15 
 
 70 
 
 15 
 
 Nut oil, 
 
 13 
 
 80 
 
 7 
 
 Poppy seed oil, 
 
 5 
 
 65 
 
 30 
 
 Cotton seed oil, 
 
 
 60 
 
 40 
 
 Bauer and Hazura regard the drying of oils as being mainly 
 due to the linolenic and isolinolenic acids, which, by taking up 
 oxygen, become converted into the " oxylinoleic acid '' of Mulder, 
 which they regard as C 18 H 30 O 7 . For the most part, however, the 
 glyceridic character of the product is not destroyed during the 
 oxidation, so that, instead of free acid, a neutral body results, 
 substantially the "linoxyn" of Mulder, but termed by them 
 hydroxylinolein. Small quantities of free fatty acids are, however, 
 developed by the decomposition of .the glycerides of the solid 
 fatty acids present (myricin, palmitin, ttc.) ; the glycerol of these 
 glycerides being converted into carbon dioxide and other volatile 
 products. 
 
 According to experiments by Cloez,* the effect produced by 
 prolonged exposure to air of a drying oil is not quite so simple 
 as w T ould appear from the above. The following figures were 
 obtained with linseed and poppy seed oils, the final increment in 
 weight being a little more than 7 per cent, in each case after 
 eighteen months : 
 
 LINSEED OIL. 
 
 
 Before Exposure. 
 
 After Oxidation. 
 
 Percentage 
 Composition. 
 
 Calculated per 100 
 Parts of Linseed Oil 
 originally used. 
 
 Carbon, 
 Hydrogen, . 
 Oxygen, . 
 
 77-57 
 11-33 
 11-10 
 
 67-55 
 9-88 
 25-57 
 
 72-30 
 10-57 
 24-16 
 
 100-00 
 
 100-00 
 
 107-03 
 
 Bulletin Soc. Chimique de Paris, 1865, hi., p. 49. 
 
POUTET'S ELAIDIN REACTION NITROUS ACID TEST. 
 POPPY SEED OIL. 
 
 137 
 
 
 Before Exposure. 
 
 After Oxidation. 
 
 Percentage 
 Composition. 
 
 Calculated per 100 
 Parts of Linseed Oil 
 originally used. 
 
 Carbon, . . . 
 
 77-50 
 
 66-68 
 
 71-38 
 
 Hydrogen, . 
 Oxygen, 
 
 11-40 
 11-10 
 
 9-94 
 23 -38 
 
 10-64 
 25-03 
 
 100-00 
 
 100-00 
 
 107-05 
 
 The original oils thus had a composition closely akin to that of a 
 triglyceride of an acid of formula C 18 H 32 O 2 (p. 33), requiring 
 carbon 77"90, hydrogen 11 "16, oxygen 10*94; during oxidation, 
 from T V to T T T of the carbon disappeared and not far from the 
 same proportion of hydrogen. Even if the whole of the glyceridic 
 part of the oil had been oxidised to volatile products, only Jg- of 
 the carbon would have disappeared ; so that, obviously, carbon 
 dioxide, or acetic acid, &c., must have been formed at the 
 expense of the fatty acids present, indicating a more deep-seated 
 oxidation change than the simple absorption of oxygen, con- 
 verting the glycerides of linolenic and isolinolenic acids into 
 hydroxylinolein. 
 
 With castor oil Cloez found the gain in weight after eighteen 
 months was much less marked (2*68 per cent.) ; whilst only a, 
 practically inappreciable amount (0*4 per cent.) of the original 
 carbon had disappeared. Intermediate results were obtained 
 with a semi-drying oil, sesame oil, the gain in weight in eighteen 
 months being 4-83 per cent., and the loss of carbon about ^ of 
 the original amount. 
 
 POUTET'S ELAIDIN REACTION NITROUS 
 ACID TEST. 
 
 Oils containing unsaturated acid glycerides, more especially 
 olein and its homologues, or ricinolein, often undergo a marked 
 change, when treated with nitrous acid, becoming more or 
 less solidified without alteration of composition. Gaseous, 
 nitrous anhydride (fumes from nitric acid heated with starch 
 or arsenious anhydride) will produce the reaction, or agitation 
 with substance containing nitrous acid dissolved e.g., red nitric 
 acid, solution of a nitrite recently acidified, copper or mercury 
 recently dissolved in nitric acid, or even nitric acid warmed 
 until it begins to act on the oil. Of these the liquid originally 
 
138 
 
 OILS, FATS, WAXES, ETC. 
 
 described by Poutet, obtained by dissolving 12 parts by weight 
 of mercury in 15 of cold nitric acid (sp. gr. 1'35), is the most 
 convenient ; * 2 c.c. of the fresh deep green liquid, and 50 of oil 
 are shaken together in a bottle at intervals for about two hours, 
 at the end of which time the action is nearly complete, although 
 the product usually becomes stiffer or harder on standing twenty- 
 four hours. Olive oil of good quality thus treated gives a 
 bright yellow extremely hard "elaidin;" arachis and lard oils 
 yield products little inferior in stiffness ; mustard, rape, sesame, 
 sunflower, cotton seed, and other oils give softer products, vary- 
 ing in consistency from a stiff buttery mass to a mixture of 
 pasty product with still fluid substance ; whilst linseed and 
 other drying oils are comparatively little affected. 
 
 A. H. Allen classifies the more important fixed oils as follows, 
 in accordance with the physical character of the product : 
 
 Solid Hard Mass. 
 
 Buttery Mass. 
 
 Pasty or Buttery Mass 
 separating 
 from a Fluid 'Portion. 
 
 Liquid Products. 
 
 Olive oil. 
 
 Bottlenose oil. 
 
 Rape oil. 
 
 Linseed oil. 
 
 Almond oil. 
 
 Mustard oil. 
 
 Mustard oil. 
 
 Hempseed oil. 
 
 Arachis oil. 
 
 Neat's foot oil \ 
 
 Sesame oil. 
 
 Walnut oil. 
 
 Lard oil. 
 
 Arachis oil [ Some- 
 
 Cotton seed oil. 
 
 
 Sperm oil. 
 
 Sperm oil / times. 
 
 Sunflower seed oil. 
 
 
 Neat's foot oil 
 (sometimes). 
 
 Rape oil J 
 
 Niger seed oil. 
 Cod liver oil. 
 
 
 
 
 Whale oil. 
 
 
 
 
 Porpoise oil. 
 
 
 In certain cases (more especially with olive oil) the nature 
 and consistency of the elaidin formed on treatment with nitrous 
 acid affords a useful means of detecting the presence of adulter- 
 ations with oils of different character. In all such cases, the 
 most satisfactory results are obtained when the oil examined is 
 tested side by side in the same way with samples of oil of 
 standard purity, and of the same mixed with known proportions 
 of other oils.f 
 
 The free fatty acids obtained by saponifying oils and decom- 
 posing the resulting soaps with a mineral acid, are affected by 
 nitrous acid in similar fashion. Attempts have been made to 
 
 * Archbutt (Journ. Soc. Chem. IncL, 1886, p. 303) dissolves 18 grammes 
 of mercury in 15 '6 c.c. of nitric acid, sp. gr. 1'42 (22'2 grammes of acid), 
 and uses 1 part of the resulting green fluid to 12 of oil (by weight). 
 
 t There is often great difficulty experienced in obtaining absolutely pure 
 samples of oil for use as standards. In many cases it is only possible to 
 obtain such standard substances by actual expression of hand-picked seeds, 
 &c., in the laboratory, and subsequently refining the product; but this is 
 not readily practicable, unless a plentiful supply of pure seed is to hand, 
 as well as a good form of small experimental or laboratory press. 
 
NITRIC ACID TEST. 
 
 139 
 
 utilise for candle-making and other purposes the polymerised 
 solid acids of higher melting point thus formed ; but, hitherto, 
 various practical difficulties have stood in the way of utilising 
 the products effectively. 
 
 Legler's Consistency Tester. Legler has constructed a 
 simple form of apparatus by means of which comparative tests 
 can be made of the degree of consistence of the 
 elaiclin. mass produced when any given oil sample 
 is treated with nitrous acid. It consists of piece of 
 glass tubing narrowed at one end (Fig. 30) ; through 
 the tube passes a glass rod supported by means of 
 a spiral spring, and furnished with a horizontal disc 
 on the top, so that by placing weights on the disc 
 the end of the rod is depressed to an extent pro- 
 portionate to the weight added. The outer tube is 
 held vertically by a suitable clamp holder, so 
 adjusted that the bluntly pointed end of the rod 
 just rests on the surface of the elaidin to be tested. 
 The measurement is made by placing a given 
 weight on the disc and noting how far the rod 
 sinks into the elaidin in a given time (e.g., a 
 minute), by reading off the level on a scale the zero 
 point of which is level with the top of the outer 
 tube when the disc is unweighted. The elaidin 
 samples are best prepared by mixing together 
 10 c.c. of oil, 10 c.c. of nitric acid of 25 per cent., 
 and 1 grin, of copper wire or turnings, and allowing 
 to stand twenty-four hours; the mass is fused by 
 dipping the containing vessel in warm water so as 
 to bring about complete separation of elaidin and 
 watery fluid, and the former removed and allowed 
 to solidify. To obtain comparable results, a uni- 
 form method of manipulating should be adopted, 
 the samples tested being examined side by side 
 with others similarly prepared from genuine oils or 
 known mixtures. 
 
 Exposure of olive oil to sunlight greatly diminishes 
 the solidity of the elaidin formed from it ; the nature j?ig. 30. 
 of the change brought about is uncertain ; probably 
 oxidation takes place with formation of oxyolein (or possibly 
 linolin), as the insolated oil develops more heat by the action of 
 sulphuric acid than the original oil kept in darkness (vide p. 131). 
 
 Nitric Acid Test. When fixed oils are brought into contact 
 with nitric acid a complex effect is often produced ; oxidation of 
 a part of the oil by the acid is brought about with the evolution 
 of lower oxides of nitrogen, which convert the olein constituent 
 of the oil into elaidin. In some cases, characteristic colours are 
 produced with oils of pure nature, so that a comparison of the 
 
140 
 
 OILS, FATS, WAXES, ETC. 
 
 substance tested with a pure standard substance, or with a known 
 mixture, enables deductions to be drawn as to the nature of the 
 admixture or adulteration present. This kind of test is more 
 especially useful in the case of olive oil ; thus, when pure 
 olive oil is treated with one-ninth its volume of nitric acid 
 of sp. gr. 1-42, the mixture being gently warmed in a capacious 
 dish until the acid begins to act pretty vigorously, and then 
 stirred briskly (the source of heat being removed) until no 
 further action is visible, a pale yellow solid mass is formed 
 after standing an hour or two ; whereas, if cotton seed oil be 
 present, a much darker tinted product is formed, which does 
 not set so readily j and similarly when various other oils are 
 present. 
 
 A. H. Allen gives the following table,* indicating the different 
 tests developed when several of the commonest oils are tested in 
 the following ways : 
 
 a. Nauchcorne's Test, as extended by Stoddart. Agitate to- 
 
 Oil. 
 
 a. 
 
 b. 
 
 ! 
 
 Olive oil, 
 
 Colourless or tran- 
 
 Colourless, yel- 
 
 Broad bright 
 
 
 sient yellow. 
 
 lowish, or 
 
 bluish green 
 
 
 
 greenish. 
 
 zone. 
 
 Almond oil, . 
 
 Nearly colourless, 
 
 Colourless or 
 
 Narrow bright 
 
 
 changing to solid 
 white mass. 
 
 slightly greenish. 
 
 green zone ; oil \ 
 flocculent or 
 
 
 
 
 opaque. 
 
 Arachis oil, . 
 
 ... 
 
 Reddish. 
 
 ... 
 
 Peach kernel oil, 
 
 ... 
 
 Immediate red 
 
 
 
 
 liniment. 
 
 
 Rape oil, 
 
 Red or orange. 
 
 Reddish or orange. 
 
 
 Sesame oil, 
 
 
 Yellowish or 
 
 
 j 
 
 
 orange. 
 
 
 Cotton seed oil, 
 
 Red or orange. 
 
 Reddish or orange. 
 
 Brown red, 
 
 
 
 
 greenish below. 
 
 Niger seed oil, 
 
 Red or orange. 
 
 Brown or 
 
 ... 
 
 
 
 brownish red. 
 
 
 Linseed oil, 
 
 Red or orange. 
 
 Red or orange. 
 
 Green zone, oil 
 
 
 
 
 red. 
 
 Poppy seed oil, 
 
 ... 
 
 Reddish. 
 
 Dark green zone, 
 
 
 
 
 oil pink. 
 
 Hemp seed oil, 
 
 ... 
 
 Brownish red. 
 
 
 Castor oil, 
 
 Transient yellow. 
 
 Yellowish or 
 
 ... 
 
 
 
 orange. 
 
 
 Lard oil, 
 
 Colourless or tran- 
 
 ... 
 
 ... 
 
 
 sient yellow. 
 
 
 
 Whale oil, . 
 
 Dark red. 
 
 
 ... 
 
 Seal oil, . 
 
 Dark red. 
 
 
 ... 
 
 Cod liver oil, . 
 
 ... 
 
 . 
 
 Brown red. 
 
 Rosin oil, 
 
 Reddish brown. 
 
 . 
 
 ... 
 
 Mineral oil, . 
 
 Dark red. 
 
 
 
 ... 
 
 Commercial Organic Analysis, vol. ii., p. 61. 
 
ZINC CHLORIDE REACTION AND COLOUR TEST. 141 
 
 gether from 3 to 5 measures of the oil with 1 of nitric acid of 
 specific gravity \'3'2. Heat the tube for five minutes in boiling 
 water ; then take it out and allow it to stand. Observe the 
 colour of the oil from time to time for one and a-half hours. 
 
 b. Massies Test. Agitate 3 measures of the oil for two 
 minutes with 1 measure of colourless nitric acid of specific 
 gravity 1-40. Observe the colour of the oil after separation. 
 
 c. Glassner's Test. Pour the oil cautiously into an equal 
 measure of red fuming nitric acid, and observe the colour of the 
 oil and of the zone which forms between the oil and the acid 
 liquid. 
 
 ZINC CHLORIDE REACTION AND COLOUR TEST. 
 
 Some oils, more especially castor oil, when heated in contact 
 with a highly concentrated solution of zinc chloride, become 
 converted into a gristly mass, which, on treatment with water 
 to dissolve out the zinc chloride, more or less breaks up into 
 cartilaginous or fibrous portions, which swell up largely to white 
 masses closely resembling rasped cartilage, the oil being com- 
 pletely solidified by the process. Apparently, the chemical action 
 consists chiefly of polymerisation, somewhat after the fashion of 
 the elaidin reaction, possibly accompanied by dehydration; by 
 long continued boiling of the product with alkalies, partial 
 saponification is effected, glycerol being set free. 
 
 To produce the most gristly product, the following process 
 may be followed:* Zinc chloride solution is boiled down until 
 the boiling temperature rises to about 175 C. or upwards, the 
 composition of the fluid then being close to that indicated by 
 the formula, ZnCl 2 , H 2 O, or slightly less hydrated. Three parts 
 of this fluid by weight, and one of castor oil are then well 
 intermixed together at a temperature of 125 or thereabouts; 
 the oil speedily, becomes more viscid, and then coagulates to a 
 leathery mass resembling bullock's liver, but tougher, mostly 
 separating from the zinc chloride in so doing. This mass is then 
 chopped up, soaked in water till disintegrated to a mass some- 
 what resembling coarsely scraped horseradish, drained from zinc 
 chloride solution and washed, when it is in suitable condition for 
 use in the manufacture of india-rubber substitutes, insulating 
 coatings for electric leads, &c. 
 
 By using weaker zinc chloride, or smaller proportions, or 
 lower temperatures, the action can be controlled and stopped 
 before going quite so far, so as to produce substances of less 
 cartilaginous and more plastic character ; or other oils, less 
 
 * Patent specification, C580, 1886, Hun-head and Alder Wright. 
 
142 
 
 OILS, FATS, WAXES, ETC. 
 
 readily acted upon, may be mixed with the castor oil ; or resin, 
 Kauri gum, and similar substances may be similarly admixed. 
 
 Colour Test. When zinc chloride solution of somewhat 
 lesser strength (of thick syrupy consistence when cold) is mixed 
 with certain oils, colours are developed. Muter gives the 
 following table, founded on the results of Chateau :* 
 
 To 10 drops of the oil in a porcelain capsule, add 5 drops of 
 syrupy zinc chloride, and stir. 
 
 White or scarcely affected. 
 
 Yellow, Red, or Brown. 
 
 Green or Blue Shades. 
 
 Poppy. 
 Nut. 
 Almond (hot pressed). 
 Gingelly. 
 Cokernut. 
 
 Linseed (English), ) 
 Rape, ' yellow. 
 Groundnut, } 
 Castor, rose yellow. 
 Beech, flesh rose. 
 
 Linseed (foreign), 
 bluish green. 
 
 S}~- 
 
 Gold of pleasure 
 
 Neat's foot. 
 Lard. 
 Horse bone. 
 Sperm. 
 Whale (sometimes 
 pale violet tinge). 
 Cod liver (cold). 
 
 Whale, yellow brown. 
 Fish, orange yellow. 
 Seal, red brown. 
 
 green. 
 Almond, milky with 
 green tinge. 
 
 Cod liver (hot), 
 green. 
 
 Action of Zinc Chloride on Oleic Acid. Zinc chloride, 
 when heated with oleic acid, converts it into a solid isomeride 
 closely resembling elaidic acid, but not identical therewith ; thus, 
 when oleic acid, mixed with 10 per cent, of its weight of zinc 
 chloride, is heated to 180 to 185 (but not exceeding 195) for 
 some time, the transformation is so far complete that a sample 
 taken out and treated with hot dilute hydrochloric acid yields a 
 layer of fatty acids, solidifying on cooling. By diluting with 
 water and subjecting to distillation with superheated steam (or 
 under diminished pressure), a buttery mass is obtained which, 
 on pressing (first cold and then hot), finally yields a hard 
 crystallisable material of melting point 41 to 42, suitable for 
 making certain kinds of candles not requiring fatty matter of 
 high fusing point (Schmidt's process). Benedikt obtained the 
 following results on analysis of the products thus formed : f 
 
 A. Crude product obtained by boiling the heated mass with 
 diluted hydrochloric acid. 
 
 B. Product of distillation under diminished pressure. 
 
 C. Solid mass, after pressing until the melting point rises to 
 41 to 42. 
 
 * Spon's Encyclopaedia of Arts and Manufactures, ii., p. 1473. 
 \-Journ. Soc. Chem. 2nd., 1890, p. 658; from Movatsh., 1890, ii., p. 71. 
 
ACTION OF SULPHURIC ACID ON OILS AND FATS. 
 
 143 
 
 
 A. 
 
 B. 
 
 c. 
 
 Liquid anhydride, 
 
 8 
 
 
 
 Stearolactoiie, . 
 
 28 
 
 31-0 
 
 75-8 
 
 Oxystearic acid, 
 
 17 
 
 ... 
 
 
 Oleic and isoleic acids, 
 
 40 
 
 43-3 
 
 15-7* 
 
 Saturated fatty acids, 
 
 7 
 
 12-1 
 
 8-5 
 
 Unsaponifiable matters, . 
 
 
 13-6 
 
 ... 
 
 
 100 
 
 100-0 
 
 100-0 
 
 The " unsaponifiable matters" contained in B were mainly 
 liquid hydrocarbons of the olefine series (carbon = 84*1, hydro- 
 gen = 13-7, oxygen = 2-2). 
 
 It would appear that the general character of the main action 
 is that zinc chloride directly combines with the oleic acid, and 
 that the resulting compound (or, possibly, pair of isomeric com- 
 pounds) is partly decomposed again into oleic and isoleic acids, 
 and partly hydrolysed with formation of oxystearic acids, more 
 especially the 7 acid, which then loses the elements of water, 
 forming stearolactone (vide p. 39) ; the hydrolytic action pro- 
 bably being as follows : 
 
 Oleic Acid. 
 
 C l8 H 34 2 
 
 Compound. 
 C l8 H 34 2 , ZnCl 2 
 
 Zinc Chloride. 
 
 ZnCl 2 
 
 H 2 
 
 Compound of Zinc Chloride 
 aud Oleic Acid. 
 
 C l8 H 34 2 ,ZnCl 2 . 
 
 Oxystearic Acid. 
 ZnCl 2 + C 18 H 36 3 . 
 
 In all probability, similar reactions occur when glycerides 
 containing olein are saponified by means of sulphuric acid, the 
 yield of liquid oleic acid in the products finally obtained by 
 distillation with superheated steam being very small. 
 
 ACTION OF SULPHURIC ACID ON OILS AND FATS, 
 TURKEY RED OILS. 
 
 When sulphuric acid is added to a fixed oil or fat, various 
 kinds of effects are produced in different cases; in many instances 
 distinctive colours are developed, due not so much to the action 
 of the acid on the glycerides themselves as to that upon other 
 bodies accompanying them in small proportion; this is especially 
 marked in the case of certain fish liver oils where biliary con- 
 stituents are present (vide infra). In other cases action occurs 
 between the acid and the glyceride, producing more or less 
 
 * Isoleic acid only. 
 
144 
 
 OILS, FATS, WAXES, ETC. 
 
 marked heat development, sometimes leading to charring and 
 destruction, sometimes to less deep-seated changes of a definite 
 character. Thus, when oils mainly consisting of olein are 
 cautiously mixed with sulphuric acid hydrolysis ensues, the 
 resulting glycerol being more or less converted into glycero- 
 sulpkuric acid, much as ordinary alcohol is into ethylsulphuric 
 acid. 
 
 Sulphuric Acid. 
 
 o n ,JOH 
 S 2 \OH 
 
 Ethylsulphuric Acid. 
 
 = S0 2 
 
 Iphuric Acii 
 
 O . C 2 H 5 
 OH 
 
 Sulphuric Acid. Glycerosulphuric Acid. 
 
 SO, /RS = S0 2 (O.C 3 H i( OH) 2 
 
 Water. 
 
 H 2 
 
 Water. 
 H 2 
 
 Alcohol. 
 
 C 2 H 5 . OH 
 
 Glycerol. 
 
 ( OH 
 
 C 3 H 5 OH 
 ( OH 
 
 Simultaneously the oleic acid is acted upon, direct combination 
 taking place between the two acids * with the formation of 
 oxystearosulpliuric acid. 
 
 * According to M tiller- Jacobs, the product thus formed contains the 
 elements of a molecule of waterless, C l8 H 34 5 S instead of C^HaflOfjS ; and 
 
 ( SO OFT 
 is represented by him as a sort of sulphonic acid, C l7 H 32 j nr/' QTJ breaking 
 
 tip on hydrolysis with the formation of oxystearic acid, C^Ks.-! nn ntr' 
 
 ( C\~\3 L ^-'^'^-'1 
 
 oxyoleic acid, C^HsoJpQ QTT being also formed, probably by a secondary 
 
 action. Geitel considers that a mixed glyceride is formed, part of the three 
 oleic radicles being modified by direct addition of sulphuric acid thereto so 
 as to form a glyceride where the radicle of oxystearosulphuric acid partly 
 replaces the oleic radicle, saponification of the glyceride not taking place, 
 at any rate, at first. 
 
 Liechti and Suida also consider a mixed glyceride to be the first product, 
 
 containin 
 thus 
 
 2C 3 H 5 
 
 simultaneously the radicles of sulphuric and oxystearic acids, 
 
 Triolein. 
 
 O.C 18 H 33 
 O.C 18 H 3 ,0 
 O.C 8 H S3 
 
 Water. Sulphuric Acid. 
 
 vy.^H^ 
 
 4H 2 
 
 S0 2 (OH) 2 = 
 
 Oleic Acid. 
 4C ]8 H 34 2 
 
 Oxystearosulphuric 
 Diglyceride. 
 
 ( O.C 18 H 35 2 
 OH 
 
 }S0 2 
 
 OH 
 O.C 18 H,,0 2 
 
 Simultaneously, they regard an analogous mixed diglyceride as being 
 formed, containing the radicle of oxyoleic acid (C ]8 H 33 2 ) instead of that 
 of oxystearic acid (C l8 H 3 .50 2 ). this substance being produced in virtue of an 
 oxidising action exerted by the sulphuric acid, whereby S0 2 is evolved. 
 
 Inasmuch as practically no glycerol is obtainable from Turkey red oil by 
 saponification (beyond what is due to undecomposed original oil present 
 therein), whilst free oleic acid gives products similar to those prepared from 
 olive oil (the more free acid contained in the oil the better it is suited for 
 the purpose), it is obvious that these mixed glycerides, even if formed 
 under special conditions, are at any rate not the main constituents of the 
 commercial products. 
 
TURKEY RED OILS. 145 
 
 Oleic Acid. Sulphuric Acid. Oxystearosulphuric Acid. Water. 
 
 C 17 H 33 .COOH + S0 2 = S0 2 Cl ' H34 - CO - OH + H 2 
 
 This product, being a saturated compound, does not combine 
 with iodine like the original oleic acid (Benedikt and Ulzer) ; 
 under the influence of hydrolysing agents it breaks up into 
 oxystearic and sulphuric acids, thus * 
 
 Oxystearosulphuric Acid. Water. Sulphuric Acid. Oxystearic Acid. 
 
 Qn f . C 17 H 34 . CO . OH , w n Qn J OH , r J OH 
 S 2 + H 2 = S0 2 + C 17 H 34 
 
 10H 
 
 Products containing more or less Oxystearosulphuric acid and 
 the oxystearic acid thence formed by hydrolysis, together with 
 unchanged olein, and some free oleic acid (also whatever solid 
 fatty glycerides were originally present in the oil employed and 
 the products of the action of sulphuric acid thereon) are manu- 
 factured from olive, cotton seed, and similar oils chiefly consisting 
 of olein, for use in dyeing and calico printing, especially in the 
 production of " Turkey red," whence the name " Turkey red 
 oils " applied to these products ; the free acidity is usually 
 partially or wholly neutralised by cautious addition of ammonia 
 or other alkali to the oil after washing with brine or water. 
 
 Another variety of Turkey red oil, considerably superior for 
 some special applications, is produced when castor oil is 
 employed instead of olein-containing oils. According to the 
 generally received view, the chief action of the sulphuric acid is 
 precisely analogous to that on ordinary alcohol ; the glyceride is 
 hydrolysed into glycerol and ricinoleic acid, the former being 
 more or less converted into glycerosulphuric acid, as above ; the 
 ricinoleic acid reacts on the sulphuric acid in a parallel way, 
 forming ricinoleosulphuric acid, thus 
 
 Riciuoleic Acid. Sulphuric Acid. Water. Ricinoleosulphuric Acid. 
 
 r w f H i. ^n / OFI w n j. r w /O.S0 2 .OH 
 
 CirH^o -^ CQ QH - =>U 2 j QR = L lr H 32 j C0 OH 
 
 the resulting product differing from that formed from oleic acid in 
 that it contains H 9 less, and is, therefore, an "unsaturated" com- 
 pound, capable of taking up iodine or bromine in the same manner 
 as the original ricinoleic acid itself (Benedikt and Ulzer). Accord- 
 ingly, castor Turkey red oil is capable of taking up oxygen, and 
 generally of behaving in ways not observed in the case of olive 
 Turkey red oil ; which circumstance renders it more suitable for 
 certain particular applications in reference to dyestuffs, &c. 
 
 * The effect of sulphxiric acid in decomposing fatty glycerides, together 
 with the hydrolysing action of water on the product, is utilised in the 
 preparation of caudle material ; a larger yield of solid matter is thus 
 obtained than by the ordinary saponification processes, on account of the 
 conversion of liquid oleic acid into solid substances. According to Geitel, 
 y-oxi/fstearic acid (p. 39) is usually produced (inter alia) by the hydrolysis 
 of the compouud of oleic acid with sulphuric acid, which immediately splits 
 up into water and stearolactone. 
 
 10 
 
14 G OILS, FATS, WAXES, ETC. 
 
 A somewhat different view of the action of sulphuric acid on 
 castor oil has been lately put forth by Scheurer Kestner"* as the 
 result of his investigations. After the glyceride has been hydro- 
 lysed, he finds that part of the resulting ricinoleic acid becomes 
 "polymerised" (or more accurately, dehydrated and "con- 
 densed "), so as to form a more complex molecule of diricinoleic 
 acid, which is then acted upon by sulphuric acid so as to form 
 diricinoleosulphuric acid ; the reactions may be written thus 
 
 Ricinoleic Acid (2 molecules). Diriciuoleic Acid. 
 
 TT JOH (OH 
 
 TT 
 
 17 H 
 
 o OH 1732 ^ CO , 
 
 H TT $ / 
 
 32 co . OH C " H * CO .OH 
 
 Diricinoleic Acid. Sulphuric Acid. Diricinoleosulphuric Acid. 
 
 TT JOH r TT JO. SO.,. OH 
 
 17^32 I rv\ \ ^ir n 32 T Cf) } ~ 
 
 = 
 
 22 2 
 
 C 17 H - 
 
 S0 2 (OH) 2 = H 2 
 | co OH 1732 -| co . oil 
 
 Obviously the diricinoleosulphuric acid thus formed is "un- 
 saturated," and is, therefore, capable of taking up two halogen 
 atoms for each C 1S present. More or less of the diricinoleic acid 
 escapes conversion into diricinoleosulphuric acid; so that in 
 addition to unaltered castor oil, &c., the resulting Turkey red 
 oil consists of a mixture of diricinoleic acid, and diricinoleo- 
 sulphuric acid, together with some amount of ricinoleic acid that 
 has escaped condensation to diricinoleic acid, and of ricinoleo- 
 sulphuric acid formed by the direct action of sulphuric acid upon 
 it. The non- sulphurised fatty acids tend to the development of 
 blue shades with alizarin, whilst the ricinoleosulphuric acids tend 
 to produce yellow shades. 
 
 Diricinoleosulphuric acid is hydrolysed by caustic alkali, the 
 soda or potash salts of diricinoleic and sulphuric acids being 
 formed if the action take place at temperatures below 80 C.: but 
 by prolonged boiling with alkali, or treatment therewith under 
 pressure, water is taken up and ordinary ricinoleic acid regenerated 
 by reversal of the two reactions above indicated. In just the 
 same way ricinoleosulphuric acid becomes hydrolysed into sul- 
 phuric and ricinoleic acids, the action taking place extremely 
 readily in presence of hydrochloric acid. In presence of sulphuric 
 acid, Turkey red oil is apt to be yet further decomposed on 
 heating, osnanthic acid, inter alia, being formed: hence, in the 
 preparation of the oil care must be taken that overheating does not 
 take place } and similarly in washing out the excess of sulphuric 
 acid, (tc., with brine (to avoid solution of the soluble compound 
 sulphuric acids formed), otherwise hydrochloric acid is apt to 
 be formed and considerable loss of soluble acids occasioned by 
 
 * Comptes Rendus, 112, pp. 153 and 395; also, Journ. Soc. Chem. 
 Ind., 1891, p. 471. 
 
.ACTION OF SULPHURIC ACID ON OILS AND FATS. 
 
 147 
 
 hydrolysis ; sodium sulphate is accordingly preferable to sodium 
 chloride as diminishing this tendency to loss. 
 According to Juillard* acids still more 
 highly "polymerised" than diricinoleic acid 
 are formed when sulphuric acid acts on 
 castor oil, three, four, and five molecules of 
 riciiioleic acid becoming condensed and dehy- 
 drated, with the formation of triricinoleic, 
 tetraricinoleic, and pentarwinoleic acids re- 
 spectively. He regards the first action as 
 giving rise, by partial hydrolysis and etherify- 
 ing action jointly, to the product, 
 
 . CO . C 17 H,., . . SO. S H 
 OH 
 (0. CO. C, 7 H 32 . OH 
 
 which then loses a molecule of water forming 
 an anhydride, termed by him dicinolein sul- 
 phuric anhydride. 
 
 (0. CO. C 17 H,,. 0. SO., 
 C 3 H S }0 
 
 (0. CO. C 17 H 32 .OH 
 
 This reacts slowly with riciiioleic acid and 
 sulphuric acids forming the various poly- 
 ricinoleic acids above mentioned, and the 
 polyricinoleo sulphuric acids thence derived ; 
 so that commercial castor Turkey red oils are 
 highly complex mixtures. 
 
 Maumene's Sulphuric Acid Thermal 
 Test. A considerable development of heat 
 usually attends the chemical action brought 
 about 011 mixing together a fixed oil and 
 strong sulphuric acid ; by making compara- 
 tive observations in precisely the same way 
 with standard pure oils, or known mixtures, 
 and the substance to be tested, useful infor- 
 mation can often be obtained as to the 
 character, and to some extent the amount, 
 of foreign admixture present. It is, how- pjg 3^ 
 
 ever, impossible to lay down any precise 
 figures universally applicable in such cases, because the rate of 
 action, and consequently the rise in temperature, greatly de- 
 pends on the way in which the intermixture is effected, and 
 especially on the strength of the acid used. Commercial oil of 
 vitriol varies considerably in its strength, sometimes containing 
 
 * Journ. ,S'oc. Chem. Ind., 1892, p. 355; from Bulletin Soc. Chim., Paris, 
 1891, 6, p. 6,38. 
 
148 OILS, FATS, WAXES, ETC. 
 
 96 to 97 per cent, of true sulphuric acid, H S0 4 , sometimes only 
 90 to 91 per cent., or even less. If the liquid be boiled in a 
 retort under ordinary atmospheric pressure until about a quarter 
 has distilled over, the residue when cool enough may be bottled 
 and kept for use, being acid of about 98 per cent, strength.* 
 
 Eig 31 represents a form of apparatus for applying the test ; a 
 graduated cylinder, B, is provided with an india-rubber stopper, 
 through which passes the stem of a thermometer, A, so graduated 
 that the divisions are all above the stopper ; a short piece of 
 quill tubing, 0, also passes through the stopper, serving as a 
 vent. 25 c.c. of oil are run into the cylinder, and then 5 c.c. of 
 sulphuric acid, the latter by means of a pipette applied to the 
 side of the cylinder, so that the acid falls to the bottom without 
 mixing with the oil. The stopper and thermometer being in- 
 serted and the temperature taken, the end of C is closed by the 
 finger, and the whole shaken up for a few seconds ; C is imme- 
 diately unclosed, and the thermometer watched, so as to note 
 the highest point to which it rises, and hence the range through 
 which the chemical action has heated the mass. 
 
 In order to diminish errors due to radiation and convection, 
 a small beaker may be used, jacketted outside with a somewhat 
 larger one, the interspace being filled with cotton wool or fibrous 
 asbestos. 50 grammes of oil and 10 c.c. of sulphuric acid are 
 convenient quantities, the two being at the same temperature to 
 start with ; the acid is run in slowly from a pipette, the mixture 
 being vigorously stirred with a thermometer, and about a 
 minute being allowed for the addition ; the temperature gra- 
 dually rises to a maximum as the stirring is continued, remains 
 nearly constant for a short time, and then falls again, the precise 
 amount of rise depending, to some extent, on the way in which 
 the admixture is made. When drying oils are examined, 
 Maumene recommends dilution with olive oil, so that the 
 temperature should not rise so high as to char the mixture 
 (paraffin hydrocarbons are regarded by other experimenters as 
 preferable) ; further, he recommends that trials should be made 
 with different proportions of oil and acid, e.r/.,f 
 
 50 grammes oil to 18 c.c. acid. 
 50 36 
 
 100 18 
 
 * Pure "monohydrated" sulphuric acid, H 2 S0 4 , cannot be obtained by 
 evaporation; when a strength of 98 to 98 '5 per cent, is attained, the 
 temperature rises to a point where the substance dissociates into water 
 and sulphur trioxide, the latter passing off at the same rate as the water 
 vapour, so that acid of that strength distils unchanged. Pure H 2 S04 may 
 be obtained by adding the calculated amount of SOjj to oil of vitriol, 
 strengthened by evaporation as far as possible ; or by chilling the acid, and 
 draining off the unfrozen mother liquor from the crystals of H 2 S0 4 that 
 form. When heated, S0 3 is evolved, and acid of about 98 per cent, left, 
 which then distils unchanged. 
 
 \ComptesRendus, xxxv., p. 572; also/owr/?. Soc. Chem. Ind., 1SSC, p. 361. 
 
ACTION OF SULPHURIC ACID ON OILS AND FATS. 
 
 149 
 
 The following table exhibits some of Maumene's results, 
 together with those subsequently obtained by others ; numerous 
 other analogous values have been recorded, exhibiting more or 
 less marked differences according to the particular mode of 
 manipulation adopted : 
 
 
 Maumene". 
 
 Allen. 
 
 Baynes. 
 
 Archbutt. 
 
 
 Degrees. 
 
 Degrees. 
 
 Degrees. 
 
 Degrees. 
 
 Menhaden oil, . 
 
 
 126 
 
 
 123 to 128 
 
 Cod liver oil, . 
 
 102 to 103 
 
 113 
 
 lie 
 
 
 Linseed oil, 
 
 103 
 
 104 to 111 
 
 104 to 124 
 
 
 Walnut oil, 
 
 101 
 
 ... 
 
 
 ... 
 
 Hemp seed oil, 
 
 98 
 
 
 
 
 Seal oil, . 
 
 
 92 
 
 
 ... 
 
 Whale oil, northern, 
 
 ... 
 
 91 
 
 
 
 Whale oil, southern, 
 
 
 ... 
 
 
 92 
 
 Poppy seed oil, 
 
 74 
 
 
 ... 
 
 86 to 88 
 
 Cotton seed oil, crude, 
 
 ... 
 
 67 to 69 
 
 ... 
 
 70 
 
 Cotton seed oil, refined, 
 
 ... 
 
 74 to 75 
 
 77 
 
 75 to 76 
 
 Arachis oil, 
 
 67 
 
 
 
 47 to 60 
 
 Beechnut oil, . 
 
 65 
 
 
 
 ... 
 
 Rape and colza oils, 
 
 57 to 58 
 
 51 to 60 
 
 60 to 92 
 
 55 to 64 
 
 Almond oil, 
 
 52 to 54 
 
 ... 
 
 35 
 
 
 Horse foot oil, . 
 
 51 
 
 ... 
 
 ... 
 
 
 Tallow oil, 
 
 41 to 44 
 
 ... 
 
 ... 
 
 
 Lard oil, . 
 
 
 41 
 
 ... 
 
 ... 
 
 Sperm oil, 
 
 ... 
 
 45 to 47 
 
 ... 
 
 51 
 
 Bottlenose oil, . 
 
 ... 
 
 41 to 47 
 
 
 42 
 
 Olive oil, . 
 
 42 
 
 41 to 43 
 
 40 
 
 4i to 45 
 
 Castor oil, 
 
 47 
 
 65 
 
 
 46 
 
 Neat's foot oil, 
 
 ... 
 
 ... 
 
 ... 
 
 43 
 
 Oleic acid, 
 
 ... 
 
 38-5 
 
 
 37-5 
 
 Obviously, an admixture of rape oil with linseed oil, or vice 
 versa, may be characterised with some degree of precision (the 
 former yielding a value of little more than half that given by 
 the latter), when the suspected sample is examined side by side 
 with samples of known purity mixed in known proportions (e.g., 
 2 to 1, equal proportions, or 1 to 2, and so on). Similarly with 
 olive oil admixed with arachis oil, or with cotton seed oil ; or 
 sperm oil mixed with fish oil. According to Archbutt, olive oil 
 exposed to sunlight for some time develops considerably more 
 heat with sulphuric acid than the same oil kept in the dark ; 
 52-o rise of temperature being noted by him instead of 41'5. 
 
 A yet greater difference was observed by Ballantyne in the 
 case of olive oil exposed to light for six months, and agitated 
 daily so as to promote aerial oxidation (67 instead of 44), 
 analogous differences being also observed with several other 
 kinds of oils similarly treated (p. 131). 
 
 Specific Temperature Reaction. In order to render the 
 thermal test practically independent of variations in the strength 
 
150 
 
 OILS, FATS, WAXES, ETC. 
 
 of the sulphuric acid used, Thomson and Ballantyne* make simul- 
 taneously a comparative valuation with water, and calculate the 
 ratio between the heat developed with the oil examined and 
 that with the water ; the resulting ratio they term the specific, 
 temperature reaction. Thus the following figures were obtained 
 with acid of different strengths, showing a considerably closer 
 concordance between the " specific temperature reactions " than 
 between the uncorrected values first obtained with the different 
 strengths of acids ; of course, exact agreement is not to be ex- 
 pected, as the heat development in the case of an oil is not 
 brought about solely by the mere physical admixture, but is also 
 influenced by the chemical changes set up, which necessarily are 
 apt to vary with the strength of the acid : 
 
 
 Sulphuric Acid of 954 
 
 Sulphuric Acid of 96 8 
 
 Sulphuric Acid of 99 
 
 
 per cent. H 2 S0 4 . 
 
 per cent. H 2 S0 4 . 
 
 per cent. H 2 S0 4 . 
 
 Substance Used. 
 
 Rise in 
 Tempera- 
 ture. 
 
 Specific 
 Tempera- 
 ture 
 Reaction. 
 
 ; Rise in 
 Tempera- 
 ture. 
 
 Specific 
 Tempera-, 
 tu re 
 Reaction. 
 
 Rise in 
 Tempera- 
 ture. 
 
 Specific 
 Tempera- 
 ture 
 Reaction. 
 
 
 Degrees C. 
 
 
 Degrees C. 
 
 
 Degrees C. 
 
 
 Water, 
 
 38-6 
 
 100 
 
 41-4 
 
 100 
 
 46-5 
 
 100 
 
 ( 
 
 36-5 
 
 95 
 
 39-4 95 
 
 44-8 96 
 
 Olive oil, < 
 
 34-0 
 
 88 
 
 38-1 
 
 92 44-2 95 
 
 \ 
 
 ... 
 
 
 39-0 
 
 94 
 
 43-8 
 
 94 
 
 Rape oil, . 
 
 49-0 
 
 1'27 
 
 ... 
 
 58-0 
 
 124 
 
 Castor oil, 
 
 34-0 
 
 88 37-0 
 
 89 
 
 Linseed oil, 
 
 104-5 
 
 270 
 
 
 125-2 
 
 269 
 
 The following values for the specific temperature reactions of 
 various kinds of oils were thus determined : 
 
 Nature of Oil. 
 
 Specific Temperature Reaction 
 Water = 100. 
 
 Olive oil (13 kinds examined), 
 Cotton seed oil (crude), .... 
 ,, (refined 2 kinds), . 
 Rape oil (5 kinds), ..... 
 Arachis oil (commercial), 
 (refined), .... 
 Linseed oil (4 kinds), .... 
 Castor oil (2 kinds), .... 
 Southern sperm oil, .... 
 Arctic sperm oil (bottlenose), 
 Whale oil (pale), 
 Seal oil (4 kinds), 
 
 89 to 95 
 163 
 169 to 170 
 125 to 144 
 137 
 105 
 270 to 349 ' 
 89 to 92 
 100 
 93 
 157 
 212 to 225 
 
 Cod oil (3 kinds), 
 Menhaden oil, ..... 
 
 243 to 272 
 306 
 
 * Journ. Soc. Chem. 2nd,, 1891, p. 233. 
 
ACTION OF SULPHURIC ACID ON OILS AND FATS. 
 
 151 
 
 F. Jean uses a special form of apparatus, termed by him a 
 <f Thermeleometer," "* for the determination of the heat evolved 
 in mixing sulphuric acid and oils (Fig. 32). A is a small vessel 
 40 mm. diameter and 60 high, enclosed in a felt-lined case, E ; 
 this holds the oil (15 c.c.) B is a U-shaped 
 tube, holding 5 c.c. of sulphuric acid (at 65 
 B), furnished with a hollow glass stopper, to 
 which is attached a piece of rubber tubing, 
 Jl.V.; by blowing through the tubing the 
 acid is forced out of the reservoir, B, and 
 runs down on to the oil through the turned- 
 over narrow exit pipe. T is a thermometer 
 clamped to B. To use the instrument the 
 acid is introduced into B by removing the 
 stopper, and the oil run into A up to a 
 given mark representing 15 c.c.; the oil is 
 heated up to 40 to 50 C., the acid-holder 
 placed in it, and the whole allowed to cool 
 with occasional stirring to 30 ; A is then 
 placed in the casing, E, and the acid blown 
 over into the oil, B, the attached ther- 
 mometer being used as a stirrer, and the 
 highest temperature attained read off. 
 
 Colour Reactions produced by Sul- Fig. 32. 
 
 phuric Acid. The table on p. 152 is given 
 
 by A. H. Allen, exhibiting the effect of placing a drop or- two 
 of sulphuric acid in the centre of about twenty drops of oil, 
 observing the colour before and after stirring, f 
 
 Some oils char more or less with sulphuric acid ; in such 
 cases, one drop of the oil may be dissolved in twenty of carbon 
 disulphide, and one drop of sulphuric acid added. Whale oil 
 thus treated gives a fine violet coloration, quickly changing to 
 brown, whereas, with sulphuric acid alone, a mere red or reddish 
 brown colour, changing to brown or black, is obtained. 
 
 Miscellaneous Colour Reactions. Various other reagents 
 have been proposed as colour tests for oils e.g., stannic chloride, 
 barium polysulphide, phosphoric acid, mercuric nitrate (alone or 
 with subsequent addition of sulphuric acid), aqua regia, caustic 
 soda, &c. For the most part, these give but little more informa- 
 tion than is afforded by the colour tests above described, except 
 in some few special cases ; thus, linseed oil boiled with caustic 
 soda gives a yellowish emulsion, but if fish oils are present, a 
 
 *Journ. Soc. Chem. Ind., 1890, p. 113; from Pharm. Chem., 1889, xx., 
 p. 337. 
 
 t Various modifications of the colour test proposed in 1861 by Chateau 
 (by mixing oils with sulphuric acid) have been suggested by different 
 observers ; in some cases the test produced is subject to considerable 
 variation, according to the amount of acid used relatively to the oil, and 
 its strength. 
 
152 
 
 OILS, FATS, WAXES, ETC. 
 
 reddish colour results. A solution of silver nitrate in alcohol 
 (2 parts nitrate to 12 of water, 88 parts alcohol added to the 
 liquid), when heated with about five times its volume of oil, is 
 
 OiL 
 
 Before Stirring. 
 
 After Stirring. 
 
 Vegetable Oils. 
 Olive oil, . 
 
 Yellow, green, or pale \ 
 brown. / 
 
 Light brown or olive 
 green. 
 
 Almond oil, 
 
 Colourless or yellow. - 
 
 Dark yellow, olive, or 
 brown. 
 
 Arachis oil, . -| 
 
 Greyish yellow to \ 
 orange. j 
 
 Greenish or reddish 
 brown. 
 
 Rape oil (crude), 
 
 Green with brown ) 
 riiijjs. \ 
 
 Bright green, turning 
 brownish. 
 
 (refined), | 
 
 Yellow with red or j 
 brown rings. \ 
 
 Brown. 
 
 Mustard oil, 
 
 Bark yellow withl 
 orange streaks. / 
 
 Reddish brown. 
 
 Cotton seed oil (crude), 
 , , (refined), 
 
 Very bright red. 
 Reddish brown. 
 
 Dark red, nearly black. 
 Dark reddish brown. 
 
 Xiger seed oil, . -I 
 
 Yellow with brown 1 
 clot. J 
 
 Reddish or greenish 
 brown. 
 
 ( 
 
 Yellow spot with ) 
 
 
 Poppy seed oil, . 
 
 orange streaks or > 
 
 Olive or reddish brown. 
 
 ( 
 
 rings. ) 
 
 
 Linseed oil (raw), 
 
 Hard brown or green- 1 
 ish brown clot. J 
 
 Mottled, dark brown. 
 
 (boiled), . 
 
 Hard brown clot. 
 
 Mottled, dark brown. 
 
 Castor oil, . 
 
 Yellow to pale brown, j 
 
 Nearly colourless or 
 pale brown. 
 
 Animal Oils. 
 
 
 
 I 
 
 Greenish yellow or } 
 
 
 Lard oil, . . < 
 
 brownish with brown > 
 
 Mottled or dirty brown. 
 
 ( 
 
 streaks. \ 
 
 
 Tallow oil, 
 
 Yellow spot with pink \ 
 streaks. J 
 
 Orange red. 
 
 Whale oil, . . j 
 
 Red, turning violet. 
 
 Brownish red, turning 
 brown or black. 
 
 Seal oil, . . j 
 
 Orange spot with pur- \ 
 pie streaks. J 
 
 Bright red, changing 
 to mottled brown. 
 
 Cod liver oil, . j 
 
 Dark red spot with \ 
 purple streaks. / 
 
 Purple, changing to 
 dark brown. 
 
 Sperm oil, . 
 
 Pure brown spot with \ 
 faint yellow ring. j 
 
 Purple, changing to 
 reddish or dark 
 brown. 
 
 Hydrocarbon Oils. 
 
 
 
 Petroleum lubricating ~| 
 oil, J 
 
 Brown. 
 
 Dark brown with blue 
 fluorescence. 
 
 Shale lubricating oil, . 
 
 Dark reddish brown, -j 
 
 Reddish brown with 
 blue fluorescence. 
 
 Rosin oil (brown), 
 
 Bright mahogany ) 
 brown. \ 
 
 Dark brown with pur- 
 ple fluorescence. 
 
 (pale), . 
 
 Mahogany brown. 
 
 Red-brown with purple 
 fluorescence. 
 
nl 
 
 eq cq 
 
 o o 
 
 ^ ^ 
 
 OO 
 
 S ill 
 
 1 
 d'S 
 
 o s ^ 
 
 S >H 
 
 So 
 
 304 
 
 1 
 
 : 
 
 i jliill.i.ii|l1l 
 
 Nitric and Sulp 
 Acids mixe 
 
 ddish. 
 ddish 
 d bro 
 ddish. 
 
 ^S 
 
 -.2 
 
 . 
 
 ^ S 
 
 IM MM 
 
 
 - 
 
 
 
 t i -i 
 
 S^H *-* 
 
 QJ 
 
 1 
 
 
 s 
 
 
 
 
 ft 
 
 s -i-g-S'S ^2^."^i^2 8 235128^ 2.1.1 Sg 
 
 3 j *-i *-* ^ . ^ . -S k . ^** J? 'TT ^^s /^^^ />^\ /~*\ /+^\ T"\ /*r\ A^ r ^ rv* rA Oi /"^ A . hi4 / 
 
 ! 
 
 Reddish brown. 
 Reddish brown. 
 Black brown. 
 
 O O !> 
 
 S S , ,2 
 
 a) o> rt ^ 
 
 fl ^ ^ r > S Si 
 
 C v 
 
 I i 
 
 ^ 
 
 {x PQ 
 
 IIS 
 
154 OILS, FATS, WAXES, ETC. 
 
 more or less reduced in many cases, developing a brownish red, 
 brown, or black colour ; * cotton seed, bitter almond, hemp, 
 linseed, neat's foot, and colza oils show the reaction most 
 markedly, especially the first named. 
 
 The table on p. 153 (by Schadler) exhibits synoptically the 
 results of various reagents on several of the more commonly oc- 
 curring oils, &c. ; the test with hydrochloric acid and sugar is made 
 by mixing equal quantities of the oil to be examined and hydro- 
 chloric acid of specific gravity 1-125 (about 1 c.c. of each), adding 
 a gramme of cane sugar, and shaking vigorously for some time. 
 
 SULPHUR CHLORIDE REACTION. 
 VULCANISED OILS. 
 
 The use of sulphur chloride in " vulcanising " india-rubber " is 
 well known ; a somewhat analogous change takes place w T hen 
 this substance (preferably diluted with light petroleum oil, 
 carbon disulphide, or other suitable solvent) is intermixed with 
 certain oils, more especially linseed oil ; solidification ensues, 
 with the result of forming a more or less leathery mass, which is 
 employed to some considerable extent in the manufacture of 
 insulating coverings for electric mains and leads, and similar 
 purposes. During the action considerable quantities of hydro- 
 chloric acid are evolved, whilst the final product contains 
 sulphur, some of which is in a condition insoluble in carbon 
 disulphide, apparently combined with the oil constituents ; so 
 that the chemical action of sulphur chloride appears to be of a 
 far more deep-seated nature than that of nitrous acid (elaidin 
 reaction), where the solidification appears to be due simply to 
 polymerisation or isomeric re-arrangement of atoms. Although 
 no true oxidation takes place during the .treatment, the term 
 "oxidised oil" is often applied to this product in the trade, 
 probably because the solidification brought about is some- 
 Avhat akin in appearance to that effected when drying oils 
 are oxidised by exposure to air, forming solid products. 
 
 Another kind of "vulcanised oil" is obtained by mixing 
 fiowers of sulphur with the oil to be treated, and then applying 
 heat, much as in the process of vulcanising india-rubber. In 
 some cases the oils are previously partly saponified. By heating 
 linseed oil to about 230 C., cooling to 176 C. (350 F.), and 
 then stirring in sulphur, an india-rubber like mass is finally 
 obtained, useful in the preparation of rubber substitutes. As 
 with sulphur chloride, hydrogen appears to be removed during 
 the process, sulphuretted hydrogen freely escaping; this renders 
 the manufacture an especially foetid one unless great care be 
 taken to destroy the evil-smelling vapours evolved, by causing 
 
 * Cruciferous oils containing sulphur form black silver sulphide by this 
 treatment. 
 
SULPHUR CHLORIDE REACTION. 
 
 155 
 
 them to pass through a furnace before escaping into the factory 
 chimney, or some analogous treatment. 
 
 The effect of chloride of sulphur (diluted with carbon disul- 
 phide) upon oils of various kinds is so far different that in 
 certain cases it may be employed to discriminate one from 
 another, or to test for admixture ; as in all other analogous 
 cases, comparison of the sample tested with genuine oils, treated 
 side by side, is necessary in order to obtain reliable results. 
 Bruce Warren finds * that when 5 grammes of oil are mixed 
 with 2 c.c. of carbon disulphide and 2 of a mixture of equal 
 volumes of carbon disulphide and yellow sulphur chloride (free 
 from dissolved sulphur) and the whole heated on a waterbath 
 till action commences, the products formed (after evaporating off 
 carbon disulphide) differ in weight and character according to the 
 nature of the oil, being partly soluble in carbon disulphide and 
 partly insoluble therein. Thus poppy seed and linseed oils gave 
 the following figures (5 grammes used in each case) : 
 
 
 Poppy Seed. 
 
 Linseed. 
 
 Mixture of .Equal 
 Quantities of the Two. 
 
 ; 
 
 Soluble, . 
 Insoluble, 
 
 1-96 
 4-50 
 
 0-78 
 5-58 
 
 MO 
 
 5-37 
 
 Total, 
 
 6-46 
 
 6-36 
 
 6-47 
 
 C. A. Fawsitt f employs sulphur chloride, S 2 C1 , purified by 
 distillation, in the proportion of 2 c.c. to 30 grammes of oil, 
 operating as in the case of Maumene's sulphuric acid test ; very 
 considerable differences are observed with different oils as 
 regards the amount of heat evolved, the rate of its evolution, 
 and the formation or otherwise of hydrochloric acid gas ; thus, 
 the following figures were obtained, inter alia. 
 
 
 4 c.c. Sulphur Chloride to 30 grins. Oil. 
 
 Name of Oil. 
 
 
 
 
 
 
 Gas Evolution. 
 
 Rise in 
 Temperature. 
 
 Time in Rising. 
 
 Rise per Minute. 
 
 
 Degrees C. 
 
 Minutes. 
 
 
 Sperm, 
 
 Very small. 
 
 71 
 
 8 
 
 8-8 
 
 Seal, . 
 
 None. 
 
 112 
 
 5 
 
 224 
 
 Whale, 
 
 Slight. 
 
 91 
 
 3 
 
 30-2 
 
 Neat's foot, 
 
 j> 
 
 82 
 
 4 
 
 20-5 
 
 Eape, 
 
 None. 
 
 89 
 
 6 
 
 14-8 
 
 Cotton seed , 
 
 Slight. 
 
 93 
 
 6 
 
 15-4 
 
 Linseed, 
 
 Considerable. 
 
 97 
 
 2 
 
 48-7 
 
 Olive, 
 
 Slight. 
 
 94 
 
 4 
 
 23-5 
 
 Cod liver, 
 
 Abundant. 
 
 103 
 
 3 
 
 34-3 
 
 Palmnut, 
 
 Slight. 
 
 9 
 
 7 
 
 1-4 
 
 Oleic acid, 
 
 Considerable. 
 
 99 
 
 G 
 
 165 
 
 Stearic acid, j None. 
 
 8 
 
 5 
 
 1-6 
 
 Chemical News, 1888, 57, p. 113. t Jour a. Sec. Chem. Ind., 1888, p. 552. 
 
156 
 
 OILS, FATS, WAXES, ETC. 
 
 Name of Oil. 
 
 2 c.c. Sulphur Chloride to 30 grms. Oil. 
 
 Gas Evolution. 
 
 Rise in 
 Temperature. 
 
 Time in Rising. 
 
 Rise per Minute. 
 
 
 
 Degrees C. 
 
 Minutes. 
 
 
 Sperm, 
 
 Very small. 
 
 37 
 
 16 
 
 2-3 
 
 Seal, . 
 
 None. 
 
 45 
 
 10 
 
 4-4 
 
 Whale, 
 
 Slight. 
 
 57 
 
 6 
 
 9'4 
 
 Neat's foot, 
 
 
 
 51 
 
 7 
 
 7-3 
 
 Lard, . 
 
 
 
 40 
 
 16 
 
 2-4 
 
 Rape, 
 
 None. 
 
 53 
 
 10 
 
 5-3 ' 
 
 Cotton seed, 
 
 Slight. 
 
 49 
 
 11 
 
 4-4 
 
 Linseed, 
 
 Considerable. 
 
 57 
 
 5 
 
 11-4 
 
 Olive, 
 
 Slight. 
 
 52 
 
 6 
 
 8-7 
 
 Castor, 
 
 Abundant. 
 
 56 
 
 2 
 
 277 
 
 Cod liver, . 
 
 ) 9 
 
 55 
 
 4 
 
 13-7 
 
 Palm, 
 
 
 35 
 
 3 
 
 11 6 
 
 Palmnut, . 
 
 Slight. 
 
 5 
 
 9 
 
 0-5 
 
 Rosin, 
 
 Abundant. 
 
 31 
 
 ' 7 
 
 4-4 
 
 Oleic acid, . 
 
 Considerable. 
 
 53 
 
 6 
 
 10-6 
 
 Stearic acid, 
 
 None. 
 
 5 
 
 7 
 
 07 
 
 It would hence seem that the relative figures obtained with 
 a given pair of oils often vary considerably according as 2 or 4 
 c.c. of sulphur chloride are used ; so that the value of the test as 
 applied to mixtures is somewhat doubtful. 
 
 CHAPTER VIII. 
 QUANTITATIVE REACTIONS OF OILS, &c. 
 
 A VARIETY of quantitative chemical tests are in use with the 
 object of obtaining information on various points connected with 
 the general chemistry of fatty matters, so as to afford evidence 
 in cases of suspected adulteration, <tc. Some of these depend on 
 the occurrence of saponification changes; others on different 
 principles. Amongst them may be reckoned the determination of 
 the amount of unsaponifiable matter present effected, as described 
 on p. 119, and the valuation of the amount of free fatty acids 
 present, not contained as glycerides (vide p. 116) ; in addition to 
 these, the following tests are also more or less frequently em- 
 ployed, named after the various chemists who have proposed 
 them : 
 
 1 Kattstorfer' s Tes\ Determination of the amount of potash 
 
KCETTSTORFER'S TEST. 157 
 
 (KOH, equivalent 56'1) requisite to saponify 1,000 parts of sub- 
 stance i.e., the permillage of potash requisite for saponification. 
 
 2. Heliner's Test. Determination of the percentage of fatty 
 acids formed, insoluble in hot water. 
 
 3. JBeichert's Test. Determination of the proportion of acids 
 formed, volatile with the steam of water when distilled under 
 certain arbitrary conditions. 
 
 4. llubl's Test. Determination of the quantity of iodine 
 capable of direct combination with 100 parts of substance. 
 
 5. Benedikt and Ulzer's Test. Determination of amount of 
 acetic acid formed by acetylating substances containing alcoholi- 
 form hydroxyl, and saponifying the product ; expressed as per- 
 millage of potash, equivalent to the acetic acid thus formed, 
 reckoned per 1,000 parts of acetylated product. 
 
 6. ZeiseUs Test. Determination of amount of silver iodide 
 formed from the alkyl iodide (methyl, ethyl, &c., iodide), evolved 
 on heating with hydriodic acid ; expressed as the weight of 
 methyl (CH 3 = 15), equivalent to the silver iodide thus formed 
 from 1,000 parts of substance. 
 
 KCETTSTOKFER'S TEST TOTAL ACID NUMBER. 
 
 Owing to the different molecular weights of the various fatty 
 acids contained in glycerides and compound ethers, it necessarily 
 results that equal weights of different substances are chemically 
 equivalent to different amounts of alkali i.e., that the quanti- 
 ties of caustic potash, for example, requisite to bring about the 
 saponification reaction 
 
 Glyreride. Caustic Potash. Glycero!. Potash Soap. 
 
 + 3KOH = C5 3 + 3KOX 
 
 vary with the nature of X when equal weights of fatty matter 
 are used throughout. The greater the molecular weight of X, 
 the less potash will be requisite to saponify a given weight. 
 The quantitv of caustic potash requisite for saponification, being 
 a measure of the molecular weight of the fatty glycerides, &c., 
 present, has been shown by Kcettstorfer to afford in many 
 cases a useful means of checking the nature and purity of the 
 oil, &c., examined. The weight of potash (KOH 56'1) thus 
 consumed by 1,000 parts of substance (milligrammes of potash 
 per gramme) is accordingly known as the " Kcettstorfer number," 
 { Verseifungszahl) ; or otherwise as the " total acid potash per- 
 millage " or " total acid number" of the oil, &c., examined. The 
 determination of this value is effected in somewhat the same 
 fashion as that of the "free acid number" above described 
 
158 
 
 OILS, FATS, WAXES, ETC. 
 
 (p. 116), by saponifying the oil with an excess* of alcoholic potash, 
 and back-titrating the unneutralised surplus ; in this way the 
 potash consumed represents not only the free fatty acid present 
 but also that liberated during saponification i.e., the total fatty 
 acids present whence the name. 
 
 Knowing the total acid number (Koettstorfer number), K of 
 a given substance, the mean equivalent weight of the substance 
 is readily calculated by the proportion 
 
 56-1 
 
 1,000 
 
 The value of x thus deduced is generally referred to as the- 
 " saponification equivalent " of the body in question. 
 
 Substance. 
 
 Total Acid Number, or 
 Koettstorfer Number 
 Chief Sources. (Permillage of Potash 
 required for 
 Saponification, &c.). 
 
 Saponification 
 Equivalent. 
 
 Glycerides. 
 
 
 
 Tributydn, 
 
 Butter fat, 
 
 557-3 
 
 100-7 
 
 Trivalerin, 
 
 Porpoise, dolphin, 
 
 
 
 
 and whale oils, 
 
 489-2 
 
 114-7 
 
 Trilaurin, . 
 
 Cokernut and 
 
 
 
 
 palmnut oils, 
 
 263-8 
 
 2127 
 
 Tripalmitin, 
 
 Palm oil, lard, 
 
 208-8 
 
 268-7 
 
 Tristearin, 
 
 Tallow, lard, cacao 
 
 
 
 
 butter, 
 
 189-1 
 
 296-7 
 
 Triolein, . 
 
 Olive and almond 
 
 
 
 
 oils, 
 
 190-4 
 
 294-7 
 
 Trierucin, 
 
 Colza and rape oils. 
 
 160-0 350-7 
 
 Trilinolin, 
 
 Linseed, hemp, and 
 
 
 
 
 walnut oils, 191-7 2927 
 
 Triricinolein, 
 
 Castor oil, 
 
 180-6 310-7 
 
 Compound Ethers. 
 
 
 
 
 Cetyl palmitate, 
 
 Spermaceti, 
 
 116-9 480 
 
 Myricyl palmitate, 
 
 Beeswax, 
 
 83-0 676 
 
 Ceryl cerotate, . 
 
 Chinese wax, 
 
 71-2 788 
 
 Dodecatyl oleate, 
 
 Sperm oil, 
 
 1247 450 
 
 Dodecatyl 
 
 
 
 doeglate, 
 
 Bottlenose oil, 120-9 464 
 
 The foregoing table represents the total acid numbers and 
 saponification equivalents of various triglycerides and compound 
 ethers of frequent occurrence ; in the case of glycerides the 
 molecular weight is three times the saponification equivalent, 
 whilst with compound ethers of monohydric alcohols it is 
 identical therewith. 
 
 Classification of Oils, &c., by Means of their Saponifica- 
 tion Equivalents. The table on p. 159 has been arranged by 
 
 * Unless a more or less considerable excess be used, it is very difficult to 
 ensure complete saponification. 
 
SAPONIFICATION EQUIVALENTS. 
 
 159 
 
 Percentage of KOH re- Saponification 
 quired lor Saponification. Equivalent. 
 
 ; A. OLEINES 
 
 
 Lard oil, 
 
 19-1 to 19 6 |\ 
 
 Olive oil, 
 
 18-93 to 19 6 I 
 
 Sweet almond oil, 
 
 19-47 to 19 61 1 
 
 Arachis oil, 
 
 19 ^lo^ 9 ' 66 } 285to29G 
 
 Tea oil, .... 
 
 
 Sesame" oil, 
 
 19-00 to 19-24 1 
 
 Cotton seed oil, 
 
 19-10 to 19-66 
 
 B. RAPE OIL CLASS 
 
 
 / 
 
 Colza oil, 
 
 17-08 to 17-90 
 
 
 Rape oil, 
 Mustard seed oil, 
 
 17-02 to 17-64 
 17-4 
 
 313 to 330 
 
 Cabbage seed oil, 
 
 17-52 
 
 
 C. VEGETABLE DRYING OILS 
 
 
 
 Linseed oil, 
 Poppy seed oil, . 
 
 18-74 to 19-52 
 19-28 to 19-46 
 
 \ 
 
 Hemp seed oil, . 
 
 19-31 
 
 > 286 to 300 
 
 Walnut oil, . 
 
 19-60 
 
 L 
 
 Niger seed oil, . 
 
 189 to 19-1 
 
 ) 
 
 D. MARINE OLEINES 
 
 
 
 Cod liver oil, . 
 
 18-51 to 21-32 
 
 1* 
 
 Menhaden oil, . 
 
 19-20 
 
 
 Pilchard oil, 
 
 18-6 to 18-75 
 
 
 Seal oil,. 
 
 189 to 19-6 
 
 250 to 303 
 
 Southern whale oil, 
 
 19-31 
 
 
 Northern whale oil, 
 
 18-85 to 22-44 
 
 
 Porpoise oil, 
 
 21-60 to 21-88 J 
 
 E. BUTTER CLASS 
 
 
 Butter fat, 
 
 22-15 to 23-24 241 to 253 
 
 Cokernut oil, . 
 Palmnut oil, 
 
 24-62 to 26-84 
 22-00 to 24-76 
 
 } 209 to 255 
 
 F. STEARINES, &c. 
 
 
 
 Lard, .... 
 
 19-20 to 19-65 
 
 \ 
 
 Tallow, .... 
 
 19-32 to 19-80 
 
 1 
 
 Dripping, 
 
 19-65 to 19-70 
 
 
 Butterine, 
 Goose fat, 
 
 19-35 to 19'65 
 19-26 
 
 V 277 to 294 
 
 Bone fat, 
 
 19 '06 to 19 71 
 
 
 Palm oil, 
 
 19-C3 to 20-25 
 
 1 
 
 Cacao butter, . 
 
 19-98 
 
 / 
 
 G. FLUID WAXES 
 
 
 
 Sperm oil, . . . 
 
 12 34 to 14 74 
 
 380 to 454 
 
 Bottlenose oil, . . . 
 
 12-30 to 13-40 
 
 419 to 456 
 
 H. SOLID WAXES 
 
 
 
 Spermaceti, 
 
 12-73 to 13-04 
 
 432 to 441 
 
 Beeswax, 
 
 9-2 to 9-7 
 
 ... 
 
 Carnauba wax, . 
 
 7-9 to 851 
 
 
 I. UNCLASSED 
 
 
 
 Shark liver oil, . 
 
 14 00 to 19-76 
 
 284 to 400 
 
 Wool fat (suint), 
 
 17-0 
 
 330 
 
 Olive kernel oil, 
 
 18-85 
 
 298 
 
 Castor oil, 
 
 17-6 to 18-15 
 
 309 to 319 
 
 Japanese wood oil, 
 
 211 
 
 266 
 
 Japan wax, 
 
 21-01 to 22-25 
 
 252 to 267 
 
 Myrtle wax, 
 
 20-57 to 21-17 
 
 265 to 273 
 
 Blown rape oil, 
 
 198 to 20 4 
 
 275 to 284 
 
 Colophony, 
 
 170 to 19 3 
 
 290 to 330 
 
160 
 
 OILS, FATS, WAXES, ETC. 
 
 A. H. Allen * representing the percentages of caustic potash 
 required for the saponification of most of the usually occurring 
 oils, &c., deduced by collecting together the published results of 
 a number of observers, some of the values being deduced from 
 upwards of forty different samples. 
 
 Values but little removed from these have been subsequently 
 collected and recorded by Benediktf and Schadler,| including 
 various later valuations of the Koettstofer's values of other oils 
 and fats : 
 
 Name of Oil, &c. 
 
 Schadler. 
 
 Benedikt. 
 
 Apricot kernel, .... 
 
 192-193 
 
 192-9 
 
 
 194-196 
 
 190-1-197 
 
 Almond, sweet, .... 
 
 190-192 
 
 187-9-196-1 
 
 Almond, bitter, .... 
 
 ... 
 
 194-5-196-6 
 
 Butter, 
 
 225-230 
 
 227 
 
 Beeswax (yellow), 
 
 95-100 > 
 
 97-107 
 
 Bone oil, ..... 
 
 190-191 
 
 ... 
 
 Cacao butter, .... 
 
 198-200 
 
 
 Cokernut, ..... 
 
 255-260 
 
 255 
 
 Colza, 
 
 177-178 
 
 175-179 
 
 
 230-231 
 
 230-5 
 
 Charlock, 
 
 176-177 
 
 
 Castor, 
 
 201-203 
 
 176-181-5 
 
 Carnauba wax, .... 
 
 
 79 
 
 Cotton seed, .... 
 
 194-195 
 
 191-210-5 
 
 Cod liver, medicinal, . 
 Cod liver, brown, 
 
 175-185 
 180-200 
 
 j 171-213-2 
 
 Galam butter, .... 
 
 192-193 
 
 ... 
 
 Gundschit (lallemantia), 
 
 184-185 
 
 185-0 
 
 Hemp seed, .... 
 
 192-194 
 
 193-1 
 
 Hedge radish, .... 
 
 176-177 
 
 174-0 
 
 Japanese wax, .... 
 
 222-223 
 
 ... 
 
 Linseed oil, .... 
 
 190-192 
 
 187 -4-1 95 -2 
 
 Lard, 
 
 195-196 
 
 
 Malabar tallow (piney tallow), . 
 
 191-192 
 
 ... 
 
 Menhaden, ..... 
 
 ... 
 
 192 
 
 Maize, ..... 
 
 188-189 
 
 188-1-189-2 
 
 Neat's foot, .... 
 
 191-193 
 
 
 
 189-191 
 
 189-191 
 
 Nut (Walnut), .... 
 
 196-197 
 
 1960 
 
 Olive, salad, .... 
 Olive, inferior, .... 
 
 191-193 
 
 186-188 
 
 | 185-2-196 
 
 Olive kernel, .... 
 
 188-189 
 
 188-5 
 
 
 193-194 
 
 192-8-194-6 
 
 Palm, 
 
 201-202 
 
 
 Palm kernel, .... 
 
 246-248 
 
 257-6 
 
 Pumpkin seed, .... 
 
 189-190 
 
 189-5 
 
 * Commercial Organic Analysis, vol. ii., p. 41, et seq. The "percentage 
 of caustic potash requisite " is obviously one-tenth of the Kcettstorfer number, 
 or permillage of potash necessary for saponitication. 
 
 t Analyse dtr Fette und Wachsarten, pp. 294 and 317. 
 
 Unttrsuchunrjen der Fette Oele und Wachsarten, pp. 134, 135. 
 
SAPONIPICATION EQUIVALENTS. 
 
 161 
 
 Name of Oil, &c. Schadler. 
 
 Benedikt. 
 
 
 143-9 
 
 Pilchard, 
 Shark liver oil, .... 
 Seal oil, . . . . . 180-195 
 
 Fluid portion 263'0 
 186-187-5 
 84-5 
 191-196 
 
 Sesame, 192-193 
 Sunflower, 193-194 
 Spermaceti, .... 108 
 Sperm oil, 134 
 Suet (ox tallow, beef tallow), . 193-195 
 Tallow (sheep), .... 192-195 
 Tacamahac, .... 199-200 
 
 187-6-192-2 
 193 
 108-1 
 132-2 
 
 Unguadia, 190-192 
 Whale, 190-191 
 
 Whale, bottlenose, ... 
 
 Woolgrease, .... 169-170 
 
 1 
 
 190-191 
 197-3 
 Fluid portion 290 '0 
 
 Practical Determination of Saponiflcation Equivalents 
 of Glycerides, &c. A known weight of the substance to be 
 examined (conveniently 2 or 3 grammes) is accurately weighed 
 up in a flask, and 25 c.c. (or other suitable quantity) of standard 
 alcoholic potash added (approximately seminormal); this should 
 be made from alcohol not methylated spirit that has been coho- 
 bated with caustic potash, and distilled so as to remove as far as 
 possible all compound ethers and other impurities that might be 
 resinised by potash, or otherwise partially neutralise alkali ; 
 methylic alcohol of high purity may be similarly used, preferably 
 after the same treatment. The whole is heated on a waterbath 
 with a reflux condenser attached, and gently agitated at intervals 
 until complete solution has taken place ; after a few minutes 
 more heating to ensure that saponification is complete, the un- 
 neutralised alkali is titrated by seminormal standard acid (pre- 
 ferably hydrochloric), using phenolphthalein as indicator. The 
 standardising of the alcoholic potash in terms of the acid is pre- 
 ferably effected by heating 25 c.c. on the waterbath, with an 
 inverted condenser attached, side by side with the oil examined, 
 and subsequently titrating ; the difference between the acid 
 required in the two cases thus directly represents the acid 
 equivalent to that formed by the saponification. If w be the 
 weight in milligrammes of oil taken, and n the number of c.c. of 
 normal acid equivalent to the acid formed by saponification (i.e., if 
 2n c.c. of seminormal acid be used, lOn of deciiiormal, and so on), 
 then the saponification equivalent E is given by the equation * 
 
 *1 c.c. of "normal" acid represents E milligrammes of fat, whence 
 n c.c. of acid are equivalent to 7iE milligrammes. Since this quantity = w, 
 
162 OILS, FATS, WAXES, ETC. 
 
 and the total acid number (Kcettstorfer number = permillage of 
 potash, or tenfold the percentage, requisite for saponification) by 
 the equation 
 
 K = x 56,100. 
 
 w 
 
 The determination of the total acid number is generally com- 
 bined with that of the free acid number ; the weighed quantity 
 of fat, <fcc., mixed with a little warm alcohol, is titrated with 
 alcoholic alkali, using phenolphthalein as indicator, so as to 
 determine the free acid number (see p. 116); excess of alkali is 
 then added and the determination of the total acid number pro- 
 ceeded with. Thus, suppose that 2-501 grammes (2,501 milli- 
 grammes) of Japanese wax contain sufficient free fatty acid to 
 neutralise 2 '5 c.c. of seminormal alkali (equal to 1-25 c.c. of 
 normal solution) ; whilst after adding excess of alkali, saponify- 
 ing, and back-titrating, 19-0 c.c. of seminormal fluid (equal to 
 9-5 c.c. normal) are neutralised in all; then the free acid and 
 
 1-25 
 total acid numbers are respectively-- , x 56,100= 2S'04, and 
 
 9.5 
 9 x 56,100 = 213-1 ; whilst the saponification equivalent is 
 
 2'SOI _ 
 ~W ' 3 ' 
 
 If A be the free acid number, and K the total acid number 
 (Koattstorfer number), the quantity K - A is a measure of the 
 proportion of compound ethers (esters, glycerides, &c.) present 
 in the substance examined, and may be conveniently termed the 
 ester number (Esterzald* JEtherzaliT) } thus in the above instance 
 the ester number is 263-3 - 28-04 - 235-26. In general, if 
 m c.c. of normal alkali are consumed in neutralising the free 
 acid present in iv milligrammes of substance, and n c.c. in 
 neutralising the total acids, the value of the ester number, 
 K - A, is given by the equation 
 
 K - A = m x 56,1CO - x 56,100 
 w w 
 
 = ^L^ X 56,100. 
 
 In the case of triglycerides, the quantity of glycerol theoreti- 
 cally obtainable from a given weight of substance is readily 
 
 it results that E = . On the other hand, 1 c.c. of normal acid represents 
 56*1 milligrammes of KOH, whence n c.c. are equivalent to n x 56 1 milli- 
 grammes. Then w : n x 56 '1 : : 1,000 : K = -- x 56,100. 
 
ESTER NUMBER. 163 
 
 deduced from the ester number : 3 x 56*1 parts of potash 
 neutralised by the acids liberated from the triglycerides, represent 
 92 parts of glycerol set free : hence, if S is the ester number, the 
 
 92 
 
 glycerol produced is Y~^Q^J x S = 0-5466 x S per mille, or 
 Ibo'o 
 
 05466 x S per cent.; thus, a sample of groundnut oil, yielding 
 the total acid number 195-0, and the free acid number 5-0, and 
 consequently the ester number 195*0 5-0 = 190-0, would 
 theoretically yield 190-0 x -05466 * 10-39 per cent, of glycerol. 
 
 Proportion of Patty Acids formed by Saponifieation. 
 Just as the average molecular weight of a mixture of triglycerides 
 or other compound ethers will depend partly on the molecular 
 weights of the fatty acids formed by saponification, and partly on 
 those of the alcoholic or glyceridic constituents, so will the 
 percentage of fatty acids obtainable vary in like manner. In the 
 case of a mixture of glycerides, where some of the fatty acids are 
 of low molecular weight, obviously a smaller percentage of fatty 
 acids will be formed than would be were all the fatty acids 
 of higher molecular weight. Thus, 100 parts of butyrin, 
 C 3 K 5 (O.C 4 H r O-) 3 , would theoretically yield 87 '4 of butyric acid; 
 whilst 100 parts of stearin, C 3 H 5 (O.C 18 H 35 O) 3 , would similarly 
 furnish 95 "7 parts of stearic acid. 
 
 In certain cases, useful information is obtainable by deter- 
 mining the total percentage of fatty acids actually produced, 
 more especially when, in addition to the total percentage, the 
 amounts respectively soluble and insoluble in water are also 
 deduced ; the information being in some cases further supple- 
 mented by determining the amount and nature of alcoholic or 
 glyceridic complementary products. 
 
 The total percentage of fatty acids can be reckoned from the 
 amount of alkali requisite for saponification (the Kcettstorfer 
 number determined as indicated on p-.'161) if the mean equivalent 
 of the fatty acids is known ; more usually, however, the latter is 
 the principal point to be examined, and the percentage of acids 
 requires to be directly determined ; from which value, together 
 with the quantity of alkali used, the mean equivalent weight of 
 the fatty acids is deduced. Thus, if 100 parts by weight of 
 substance yield a weight, w v of fatty acids (i.e., if w l be the 
 percentage of fatty acids found), and w<, parts of potash, KOH, 
 be required to neutralise these acids, the mean equivalent weight 
 of the acids is given by the proportion 
 
 w a : 56-1 ::wi'.x = x 56'1. 
 w a 
 
 If K be the total acid number (permillage of KOH, or ten times 
 the percentage) the mean equivalent weight of the fatty acids 
 will obviously be 
 
 56>1 = x 56L 
 
164 
 
 OILS, FATS, WAXES, ETC. 
 
 The term neutralisation number of the fatty acids (Versei- 
 fungszahl der Fettsauren) is conveniently employed to indicate 
 the quantity of potash (KOH = 56-1) neutralised by 1000 parts 
 ,of the free acids. This value and the mean equivalent weight of 
 the free acids are related to one another in a fashion similar to 
 that exhibited by the total acid number, and the saponification 
 equivalent of the original fat or oil ; if N be the neutralisation 
 number of the free acids, and F their mean equivalent weight 
 (value of x as above), then 
 
 whence 
 and 
 
 S" : 56-1 :: 1000 : F, 
 _ 56,100 
 
 F 
 ^ 56,100 
 
 F = T- 
 
 The following table represents the average neutralisation 
 numbers of the free fatty acids obtained from various kinds of 
 oils, &c. i.e., the quantities of potash (KOH = 56-1) neutralised 
 'by 1,000 parts of mixed free fatty acids (Schadler) : 
 
 Name of Oil, &c. 
 
 Almond, . 
 
 Arachis, 
 
 Cotton seed, 
 
 Castor, 
 
 Cod liver (med cinal), 
 
 Charlock, 
 
 Colza, . 
 
 Linseed, 
 
 Lard, . 
 
 Nut (walnut), 
 
 Olive, . 
 
 Palm, . 
 
 Palm kernel, 
 
 Poppy, 
 
 Suet (ox), , 
 
 Sesame", 
 
 Sunflower, 
 
 Tallow (sheep) 
 
 Neutralisation Number. 
 204-205 
 196-197 
 204-205 
 187-188 
 202-204 
 180-181 
 181-182 
 198-199 
 215-217 
 208-209 
 199-200 
 206-207 
 265-266 
 204-205 
 205-206 
 197-198 
 201-202 
 206-207 
 
 In the case of a triglyceride, the calculated saponification 
 equivalent of the glyceride always exceeds the equivalent weight 
 of fatty acids produced from it by saponification by 12-67; for the 
 general reaction of saponification being equivalent to 
 
 C s H 5 (OrOs + 3H 2 - C 3 H 5 (OH) 3 + 3HOR 
 
 where R is a fatty acid radicle, it results that the molecular 
 weight (three times the equivalent) of the glyceride, G, plus 
 3 x 18 = 54 parts of water, is identical with the molecular 
 
NEUTRALISATION NUMBER OF FATTY ACIDS. 165 
 
 weight of glycerol = 92, plus three times the equivalent weight 
 of the fatty acid formed by saponification, 3F ; whence, 
 
 G = 3F + 92 - 54, 
 
 and ^ - F + 12-67. 
 
 o 
 
 In similar fashion, in the case of a mixture of a triglyceride , 
 and the fatty acid contained therein (e.g., tri stearin and stearic 
 acid), the mean saponification equivalent of the mixture will 
 exceed the equivalent of the fatty acid by a fraction of the 
 number 12 '6 7, expressing the proportion of fatty acid contained 
 as glyceride to the total fatty acid present. If S be the ester 
 
 QJ 
 
 number, and K the total acid number, this fraction is ^ ] whence, 
 
 , -K. 
 
 the mean saponification equivalent of the mixture, M, is given 
 by the equation 
 
 'M = F + - x 12-67. 
 Jv 
 
 Thus, supposing the free acid number to be 5 per cent. (^V) f ' 
 the total acid number, so that the ester number is 95 per cent. 
 (^J) thereof, the relationship between M and F will be 
 
 M = F + II x 12-67, 
 = F + 12-04. , 
 
 Similarly, if the free acid number be 10 per cent. ( T T ff ) of the 
 total acid number, 
 
 M = F + 11-40. 
 
 Hence, as in the case of most oils and fats, the amount of free 
 acid is only a few per cents, of that of the total acids, it may be 
 taken as a general rule that the mean saponification equivalent of 
 a natural oil or fat exceeds the mean equivalent of the fatty acids 
 contained therein by about 12 ; and by a proportionately less 
 amount when the quantity of free fatty acid present increases 
 beyond a few per cents. 
 
 This relationship enables comparisons to be readily instituted 
 between the values deduced by the saponification of a fat or oil, 
 and by titrating of the fatty acids separated therefrom, when 
 expressed as equivalents ; whereas, such comparisons are much 
 less readily made by means of the potash permillages directly 
 obtained, viz., the "total acid number" of the glyceride, and 
 " neutralisation number" of the free acids thence derived (p. 164). 
 
 Since the saponification equivalent of a triglyceride exceeds 
 the equivalent weight of the fatty acid contained therein by 
 
166 OILS, FATS, WAXES, ETC. 
 
 12 '6 7, it results that for fatty glycerides, where the equivalent 
 weight of the fatty acid contained lies between 250 and 330, the 
 percentage of fatty acid yielded by the glyceride lies between 
 950 33Q 
 
 ' between 95 ' 2 
 
 25CTT1W ' 330 + 12-67 ' 
 
 and 96 -3 ; so that, for the great majority of natural oils and fats 
 containing only small quantities of free fatty acids, the rest being 
 glycerides, the yield of fatty acid per 100 parts of fat is close to 
 95 - 75 parts. Fats containing a considerable amount of glycerides 
 of relatively low molecular weight, such as butter fat, cokernut 
 butter, and palm kernel oil, <fec., yield proportionately smaller 
 percentages of fatty acids ; on the other hand, if much free fatty 
 acid is present in the fat or oil examined, the percentage yield of 
 fatty acids from the mixture is proportionately increased. 
 
 REFINER'S TEST. 
 
 This test consists in determining that fraction of the fatty 
 acids formed on saponification and acidulation which remains 
 undissolved in hot water, repeatedly applied until no more acid 
 is dissolved. With most oils and fats this quantity differs but 
 little from the total percentage (about 95-5 to 96 per cent, as a 
 rule, supra] i.e., only minute quantities of soluble fatty acids 
 are present ; but with cow's butter, cokernut butter, and some 
 few other substances the difference is much greater. Thus with 
 butter fat the total percentage is usually from 93 to 94, whilst 
 the percentage of insoluble acids (the Hehner number) is only 
 87 to 88. With the fatty glycerides employed in the manu- 
 facture of oleomargarine, the soluble acids are present in 
 only very small quantity, so that the insoluble acids amount to 
 95-96 per cent. ; hence, any considerable admixture of oleo- 
 margarine with genuine butter is detected by the increment in 
 percentage of insoluble acids found. 
 
 The following table represents the proportion of genuine butter 
 fat and foreign fats (margarine) present in a sample of mixture 
 yielding a higher Hehner number than genuine butter fat, 
 assuming this to give the value 87 '5, and margarine to give 
 95-5. 
 
 The same result is also obtainable by means of the formula 
 
 x = (H - 87-5) x 12-5, 
 
 where H is the observed Hehner number, and x the calculated 
 percentage of margarine." 55 " 
 
 * When cokernut butter (or the stearine thence isolated by chilling and 
 pressing) is substituted for oleomargarine from beef suet, &c., the above 
 table does not hold good. 
 
HEHNER'S TEST. 
 
 167 
 
 Ilehner Xumber Found. 
 
 Percentage Present of 
 
 Genuine Butter Fat. 
 
 Margarine. 
 
 87 '5 
 
 100 
 
 
 
 88 
 
 93-75 
 
 6-25 
 
 88-5 
 
 87'5 
 
 12-5 
 
 89 
 
 81-25 
 
 18-75 
 
 89-5 
 
 75 
 
 25 
 
 90 
 
 68-75 
 
 31-25 
 
 90-5 
 
 62-5 
 
 37-5 
 
 91 
 
 56-25 
 
 43-75 
 
 91-5 
 
 50 
 
 50 
 
 92 
 
 43-75 
 
 56-25 
 
 92-5 
 
 37-5 
 
 62-5 
 
 93 
 
 31-25 
 
 68-75 
 
 93 '5 
 
 25 
 
 75 
 
 94 
 
 18-75 
 
 81-25 
 
 94-5 
 
 12-5 
 
 87-5 
 
 95 
 
 6-25 
 
 93-75 
 
 95-5 
 
 
 
 100 
 
 Other tests depending on principles somewhat similar to those 
 involved in Hehner's test have been proposed by other chemists 
 for use in special cases ; thus the difference in solubility of 
 barium salts has been proposed as a criterion instead of the 
 difference in solubility of free acids for butter analysis, &c. 
 A modification of this principle is utilised as a means of deter- 
 mining the relative proportions of stearic and oleic acids in 
 mixtures of the two based on the different solubilities of their 
 lead salts in ether (vide p. 112). 
 
 PRACTICAL DETERMINATION OF THE AMOUNT OF 
 FATTY ACIDS FORMED ON SAPONIFICATION 
 (SOLUBLE AND INSOLUBLE IN WATER), AND 
 THEIR AVERAGE EQUIVALENT WEIGHTS. 
 
 The neutralised alcoholic solution left after determining the 
 saponifieation equivalent (or the product obtained by saponifying 
 & larger quantity of fat, say 10 grammes, with alkali without 
 titratioii) is evaporated to drive off alcohol, dissolved in hot 
 water, and treated with an excess of acid (standardised or other- 
 wise, according to circumstances vide infra) ; a few minutes 
 boiling decomposes all soap present, so that a clear layer of fused 
 fatty acids swims up to the top on standing. A weighed filter 
 (weighed in a dish after drying in the steam bath) is prepared 
 and wetted with water (otherwise fatty acids may pass through), 
 and the acidified fluid filtered through, the oily fatty acids 
 
168 OILS, FATS, WAXES, ETC. 
 
 remaining on the filter being washed with boiling water until 
 no more acidity is found in the filtrate. The filter is then dried 
 inside the weighed dish, and thus the weight of insoluble acids 
 determined. If w grammes of oil give n grammes of insoluble 
 acids, the "Hehner number," H, or percentage of insoluble acids, 
 is obviously 
 
 H = n - x 100. 
 w 
 
 The fatty acids thus formed are dissolved in pure alcohol and 
 titrated with standard alcoholic alkali precisely as in the deter- 
 mination of the "free acid number" of an oil, &c. (p. 116). The 
 quantity of potash (KOH = 56*1) neutralised by the insoluble 
 fatty acids obtained from 1,000 parts of original substance is 
 conveniently referred to as the " insoluble acid potash per- 
 millage," or "insoluble acid number" of the oil, etc., examined. 
 
 The difference between the quantity of potash neutralised in 
 the determination of the saponification equivalent (total acid 
 number) and that thus found as the insoluble acid number, is 
 obviously the potash equivalent to the acids present that are 
 soluble in water ; this difference is conveniently referred to as 
 the "soluble acid number" of the oil, &c., tested. If the composi- 
 tion of these soluble acids is known or assumed (e.g., regarding 
 them as butyric acid in the case of butter fat), their weight is 
 reckoned from the alkali neutralised as percentage on the original 
 fat examined, and by adding this value to that deduced as above 
 for the insoluble acids, the percentage of total acids formed is 
 obtained. 
 
 For example, suppose 2,500 grammes of butter fat to be 
 saponified with 25 c.c. of seminormal potash, and that on 
 titrating the excess of alkali 4 '9 c.c. are found to be unneutralised 
 by the acids formed on saponification ; then the total acids 
 formed are equivalent to 25 4'9 = 20*1 c.c. of serainormal 
 alkali, or 10 '05 c.c. of normal alkali. Hence the total acid 
 number is 
 
 56,100 = 225-5, 
 
 and the saponification equivalent is 
 2,500 
 
 After separation of the insoluble fatty acids, these are found to 
 weigh 2-187 grms., and to neutralise 16 '6 c.c. of seminormal 
 alkali = 8'3 c.c. of normal alkali \ hence the insoluble acid 
 number is 
 
 2,500 x5f ' 10) = U6 - 5; 
 the percentage of insoluble fatty acids (Hekner number) is 
 
PRACTICAL DETERMINATIONS. 169 
 
 =87 '48; 
 
 and their average equivalent weight is 
 
 i.e., 1 c.c. of normal alkali neutralises 263'5 milligrammes of the 
 mixed acids. Since the total acids neutralise lO'Oo c.c. of normal 
 alkali, and the insoluble acids 8-3 c.c., the difference = 1'75 c.c. 
 represents the soluble acids. This corresponds with the soluble 
 acid number 
 
 If it be supposed that the soluble acids are essentially butyric 
 acid (equivalent = 88), 1 c.c. of normal alkali will neutralise 
 88 milligrammes, and consequently 1'75 c.c. will neutralise 154 
 milligrammes = 6*16 per cent, of the 2,500 grms. of butter fat 
 employed. Hence the total percentage of fatty acids formed on 
 sapomfication is 
 
 Insoluble acids (Hehner number), . . 87 '48 
 Soluble acids (reckoned as butyric acid), . 6'1G 
 
 Total, . . . 93-64 
 The mean equivalent weight of the total acids is deduced thus 
 
 Weight of insoluble acids, . . 2,187 milligrammes. 
 
 ,, soluble ,, . 154 ,, 
 
 2,341 
 
 Since these neutralise 20*1 c.c. of seminormal alkali, equivalent 
 to 10*05 c.c. of normal alkali, the mean equivalent weight is 
 
 O QJ.1 
 
 w '* 1 _ 009-0 
 
 10-05 
 
 The soluble acids may also be directly estimated by employing 
 a known quantity of standard acid to decompose the soap left 
 after determination of the saponifi cation equivalent, and deter- 
 mining the acidity of the watery nitrate, using phenolphthalein 
 as indicator. Thus, in the above case, suppose that 25 c.c. of 
 seminormal acid were used to decompose the soap, and that 8 '4 
 c.c. of seminormal alkali were neutralised by the watery filtrate : 
 since the alkali present in the neutral soap represents 20 -1 c.c., 
 25 - 20-1 == 4'9 c.c. of the acid used would remain unneutralised 
 in the filtrate; whence, 8'4 4*9 = 3-5 c.c. of seminormal acid, 
 equal to 1'75 c.c. normal, would represent the soluble acids as 
 before. In practice, this method is less accurate than the other, 
 as the dilution of the fluid and the unavoidable absorption 
 of carbonic acid from the air (which interferes with phenol- 
 
 ci CP i mo /> 
 
170 OILS, FATS, WAXES, ETC. 
 
 phthalein as an indicator) generally prevent so sharp a valuation 
 being obtained. 
 
 With the exception of butter fat and allied animal fats, and 
 cokernut and palmiiut oils, the amount of soluble acids present 
 in ordinary oils and fatty matters is usually so small as to be 
 negligible, so that the total acid number and the insoluble acid 
 number are sensibly identical i.e., the amount of alkali 
 neutralised during saponification is practically identical with 
 that neutralised subsequently by the liberated fatty acids, 
 insoluble in water. 
 
 Correction for Anhydro derivatives, e.g., Stearolac- 
 tone. Certain distilled oleines, Turkey red oils, &c., contain 
 stearolactone, the "inner" anhydride of 7 oxystearic acid (p. 39); 
 when this is heated with alcoholic potash, it forms potassium 
 oxystearate, which neutralises an equivalent of alkali (C 18 H 36 O 3 
 = 300); but when the resulting soap is decomposed by a mineral 
 acid, stearolactone is reproduced. If the mixed fatty acids, &c., 
 thus formed be titrated without heating, an insoluble acid 
 number, corresponding with only the free fatty acids, will be 
 indicated, the stearolactone not being converted into potassium 
 oxystearate instantaneously in the cold; so that an apparent 
 existence of soluble fatty acids is indicated by the difference 
 between the total acid number obtained at first, and the value 
 obtained during the titration of the free fatty acids i.e., their 
 apparent neutralisation number. The difficiency, however, is 
 made up if the neutralised fatty acids, &c., be heated with excess 
 of alcoholic potash, and then back-titrated, so as to determine the 
 alkali neutralised by the formation of oxystearate ; from the 
 .amount thus neutralised the stearolactone can be calculated, 
 1 c.c. of normal acid representing 282 milligrammes. Or the 
 stearolactone may be dissolved out from the neutralised fatty 
 .acids by means of ether or benzoline, and directly weighed * 
 (p. 119). 
 
 Corrections for Free Fatty Acids and for Unsaponinable 
 Matters. If the substance examined contain free fatty acids or 
 unsaponifiable matters the above methods require certain 
 
 rtH 
 
 corrections ; thus, the value E = found as above for the 
 
 n 
 
 saponification equivalent, does not represent the true equivalent 
 of the glyceride or other compound ether present along with 
 other matters, but only the mean equivalent of all the substances 
 present (infinity in the case of non-saponifiable substances). If, 
 as is usually the case, the unsaponifiable matters present are 
 insoluble in water, the weight of substances obtained on saponi- 
 fying and weighing the liberated fatty acids, is too great by the 
 amount of unsaponifiable substances present ; and also by the 
 
 * Benedikt, Monatshefte fur Chemie, 11, p. 71. 
 
CORRECTIONS. 171 
 
 weight of fatty acids originally present in the free state : these 
 are determined as described on pp. 116, 119. 
 
 Suppose that a weight of substance, W, when saponified with 
 alkali, neutralises n^ c.c. of normal fluid ; and, as the result of a 
 previous titration before saponifying, suppose that n. 2 c.c. represent 
 the normal alkali equivalent to the free fatty acids present in the 
 same weight, W, and that w 1 milligrammes is the weight of 
 these fatty acids. Further, let the weight of unsaponifiable 
 matter contained in W of substance be iv. 2 milligrammes. Then 
 the saponifiable compound ethers, glycerides, &c., present weigh 
 W iv -^ w,-) milligrammes ; and the normal alkali neutralised 
 by them on saponification is n-^ - n. 2 ; hence the corrected 
 saponificatioii equivalent of the saponifiable matters free from 
 impurities is 
 
 w " w ~ w 
 
 and the potash permillage for these saponifiable matters free from 
 impurities is 
 
 K ' = "i-" 2 x 50,100. 
 
 Sometimes it happens that during saponification products are 
 formed that are insoluble in water and consequently swim up to 
 the top when the resulting soaps are decomposed by a mineral 
 acid so as to separate the fatty acids formed by saponification ; 
 e.g., in the case of cetacean oils, waxes, &c., where alcohols of 
 high molecular weight, and not glycerol, are set free; in such 
 cases, in order to obtain a correct valuation of the fatty acids, 
 the quantity of such alcohols, &c., mixed with them must be 
 determined. * This is usually conveniently effected by evaporat- 
 ing to dryness the alcoholic solution obtained when the weighed 
 impure acids have been titrated (p. 164), and dissolving away the 
 alcohols, &c., with ether or benzoliiie, so. as to separate them from 
 the soap ; the filtered solution thus obtained is then evaporated, 
 and the residue weighed and subtracted from the weight of crude 
 fatty acids. 
 
 The equivalent weight of the fatty acids then will be 
 
 where iv is the weight in milligrammes of crude fatty acids, 
 tv that of alcohols, etc., admixed therewith, and n the number of 
 c.c. of normal alkali neutralised. 
 
 * Owing to saponification changes occurring on keeping or during 
 refining, it sometimes happens that considerable quantities of ,cet3 7 lic, 
 dodecylic, &c., alcohols are contained as such in sperm oil, spermaceti, 
 beeswax, and similar substances, in addition to those existing as compound 
 ethers ; as much as 40 to 50 per cent, has been found in extreme cases 
 {Allen and Thomson). 
 
172 OILS, FATS, WAXES,; ETC. 
 
 Mean Equivalent of Fatty Acids Contained in Soap. 
 
 In the examination of soap it is often required to determine the 
 mean equivalent of the fatty acids present therein as potash or 
 soda soap; methods of calculation analogous to the above are 
 then used. In such cases the analytical methods used (Chap, 
 xxi.) usually give the following data : 
 
 Percentage of total alkali present (reckoned say as Xa 2 0), = a 
 ,, alkali not combined with fatty acids (so 
 
 called "free alkali "), . . . . b 
 ,, free fatty acids formed on decomposition of 
 
 the soap by mineral acids (together with 
 unsaponified fat and neutral bodies, &c.), = c 
 ,, unsaponified fat and neutral bodies, &c., . = d 
 
 Then 100 parts of material contain a b per cent, of alkali 
 (reckoned as Na 2 O) combined as soap with fatty acids, which 
 soap again yields, on decomposition by a stronger acid, c - d per 
 cent, of fatty acids free from unsaponified fat and neutral bodies. 
 The mean equivalent E of these fatty acids is then given by the 
 proportion (31 being the equivalent of sodium oxide, Na.,0) 
 
 a - 6 : 31 : : c - d : E, 
 
 whence E = x 31. 
 
 a - o 
 
 The fatty acids yielded by cokernut oil have an average equi- 
 valent weight of not far from 200, whilst those from tallow, 
 palm oil, and olive oil have much higher values, near 275, still 
 higher equivalent weights being possessed by the mixtures of 
 acids yielded by castor oil (near 300) and oil of ben and rape 
 oil (near 330) ; cerotic and melissic acids from beeswax have 
 equivalent weights of 410 and 452 respectively. Hence in 
 many cases the numerical value of the equivalent weight of the 
 fatty acids affords a useful indication as to the nature of the oils, 
 &c., used in manufacturing the soap examined. 
 
 Calculation of Composition of a Mixture of Two Fatty 
 Acids from their Mean Neutralisation Number. In certain 
 cases where a substance is examined known to be a mixture of 
 two different fatty acids, the relative amounts of the two consti- 
 tuents can be at least approximately calculated from their mean 
 neutralisation number. Thus in the case of a mixture of palmitic 
 acid (molecular weight = 256) and stearic acid (284), let the 
 neutralisation number of the mixture be n ; the mean molecular 
 
 weight of the mixture will accordingly be (p. 164). Hence 
 
 the following table gives the relative proportions of the two 
 acids : 
 
REICHERT'S TEST. 
 
 173 
 
 
 Percentage of 
 
 Mean Molecular Weight. 
 
 
 
 
 Palmitic Acid. 
 
 Stearic Acid. 
 
 256 
 
 100 
 
 
 
 258-8 
 
 90 
 
 10 
 
 2S1 -6 
 
 80 
 
 20 
 
 264-4 
 
 70 
 
 30 
 
 267-2 
 
 60 
 
 40 
 
 270-0 
 
 50 
 
 50 
 
 272-8 
 
 40 
 
 60 
 
 275-6 
 
 30 
 
 70 
 
 278-4 
 
 20 
 
 80 
 
 281-2 
 
 10 
 
 90 
 
 284-0 
 
 100 
 
 The following formula gives the same result : Let S be per- 
 centage of stearic acid, and M the mean molecular weight ; then 
 
 S = (M - 256) x 
 
 x& 
 
 = (M - 256) x 3-5716. 
 
 In similar fashion the relative proportions of any other two fatty 
 acids in a mixture thereof can be calculated. 
 
 REICHERT'S TEST. 
 
 Various natural oils and fats yield on saponification the alkali 
 salts of mixtures of acids, some of which are readily volatile with 
 the steam of water at ordinary pressure, and others practically 
 non- volatile. Reichert * has based on this a useful method for 
 the examination of butter as regards adulteration with other 
 kinds of fatty matter (oleomargarine, &c.), these adulterants 
 furnishing much smaller proportions of volatile acids. In prac- 
 tice, it is not convenient to continue the distillation until all the 
 volatile acid present has passed over, so that a particular method 
 of manipulation is employed, in order that an approximately 
 constant fraction of the volatile acids may be distilled off. For 
 this purpose 2-5 grammes of the fat to be examined are heated 
 with 25 c.c. of approximately seminormal alcoholic potash in a 
 flask with reflux condenser, until saponification is complete ; the 
 alcohol is evaporated off (by transferring to an evaporating dish), 
 and the residue dissolved in water, slightly acidulated with 
 dilute sulphuric acid, and made up to 70 c.c., of which 50 are 
 distilled offf The distillate is filtered if solid acids insoluble in 
 
 * Zeits. Anal. Chem., 18, p. 68. 
 
 t To avoid bumping, pumice stone with platinum wire coiled round should 
 be placed in the distilling vessel. 
 
174 
 
 OILS, FATS, WAXES, ETC. 
 
 cold water have passed over, and titrated with decinormal alkali, 
 using phenolphthalein as indicator. Working in this way about 
 -| of the total volatile acids, soluble in water, of genuine butter 
 are obtained in the distillate. 
 
 The following table is given by A. H. Allen,* representing 
 the collected results obtained by himself and other analysts 
 employing this method of manipulating : 
 
 
 C.c. of Decinormal 
 
 Substance of which 2'5 grammes are used. 
 
 Alkali neutralised by Percentage of KOII 
 Distillate (filtered neutralised. 
 
 
 when necessary). 
 
 
 MILK FATS 
 
 
 Cow's butter, .... 
 
 12 -5 to 15 "2 2 -SO to 3 -41 
 
 Ewe's butter, .... 
 
 13-7 
 
 3-07 
 
 Goat's butter, .... 
 
 13-G 
 
 3-05 
 
 Porpoise's butter, 
 
 11-3 
 
 2-51 
 
 ANIMAL & VEGETABLE OILS & FATS 
 
 
 
 Cokerimt oil,t .... 
 
 3-5 to 37 
 
 078 to 0-83 
 
 Palmnut oil, .... 
 
 2-4 
 
 0-54 
 
 Palm oil, 
 
 0-8 
 
 0-18 
 
 Cacao butter, .... 
 
 1-6 0-36 
 
 Butterine and oleomargarine, . 
 
 0-2 to 1-6 
 
 0-04 to 0-36 
 
 Whale oil, .... 
 
 37 to 12-5 
 
 0-83 to 2 -SO 
 
 Porpoise oil, .... 
 
 11 to 12 
 
 2-47 to 2-69 
 
 Sperm oil, .... 
 
 1-3 
 
 0-29 
 
 Bottlenose oil, .... 1*4 
 
 0'31 
 
 Menhaden oil, .... 
 
 1-2 0-27 
 
 Cod liver oil, .... 
 
 1-1 to 21 0-24 to 0-47 
 
 Sesame oil, .... 
 
 2-2 
 
 0-48 
 
 Cotton seed oil, 
 
 0-3 
 
 0-07 
 
 Castor oil, .... 
 
 1-4 
 
 0-31 
 
 Meissl i slightly modifies Eeichert's test by using 5 grammes 
 of fat instead of 2 -5; the evaporated alcoholic soap is dissolved in 
 100 c.c. of water, and acidified with 40 c.c. of 10 per cent, 
 sulphuric acid solution. 110 c.c. are distilled off, of which 100 is 
 filtered through a dry filter and titrated, the decinormal alkali 
 consumed being increased by one tenth, to allow for the 10 c.c. 
 not used. The results are usually somewhere about double those 
 obtained by Reichert's method of manipulation i.e., are much 
 the same per given weight of butter, taking into account the 
 doubled weight of fatty matter used. 
 
 The following table is given by Schadler, representing the 
 number of c.c. of decinormal alkali neutralised by the volatile 
 
 * Commercial Organic Analysis, vol. ii., p. 46. 
 
 t By adding more water and continuing the distillation, a large amount 
 of solid fatty acid, mostly insoluble in water (chiefly lauric acid), can be- 
 distilled over in the case of cokernut oil. 
 
 J Dingier s Poly. Journ., 233, p. 229. 
 
REICHERT'S TEST. 
 
 175 
 
 acids distilled off when the Reichert-Meissl test is employed 
 (5 grammes of material used) : 
 
 Xame of Oil, &c. 
 Arachis, . 
 Almond, 
 Cotton seed, 
 Cokernut, . 
 Cod liver, . 
 Castor, 
 Colza, crude, 
 
 ,, refined, 
 Lard, 
 Linseed, 
 Nut (walnut), 
 Olive, 
 Palm, 
 
 ., kernel, 
 Poppy, 
 Seal oil, 
 Sesame', 
 Sunflower, . 
 Tallow (ox), 
 
 (sheep), 
 
 Several other modifications of Reichert's mode of manipulating 
 have been proposed by different chemists with the object of 
 obtaining greater accuracy ; thus Wollny * employs special 
 precautions to avoid the presence of carbon dioxide in the 
 distillate and eliminate its disturbing effect, and prescribes that 
 the distillation (using 5 grammes of butter fat) should always 
 last the same time, 30 minutes. Similarly, Leffmann and Beam 
 use a solution of caustic soda in glycerol instead of alcohol, to 
 diminish possible formation of volatile acids by the action of the 
 alkali on the alcohol. Methylic alcohol is used by others for 
 the same purpose. Admitting that pure butter fat gives a 
 Reichert-Wollny number = 27, and that the corresponding 
 number for average margarine is 2, then a sample of butter fat 
 mixed with margarine and giving the number R will contain 
 x per cent, of margarine, where 
 
 C.c. 
 
 of Decinormal Alkali. 
 
 
 0-4 
 
 
 0'55 
 
 
 0-95 
 
 
 7-3 
 
 
 0-4 
 
 
 4-0 
 
 
 0-90 
 
 
 0-58 
 
 
 MO 
 
 
 0-95 
 
 
 0-92 
 
 
 1-5 
 
 
 0-5 
 
 
 3-4 
 
 
 0-6 
 
 
 2-6 
 
 
 1-2 
 
 
 0-5 
 
 
 1-0 
 
 
 1-2 
 
 x = 100 x 
 
 = 4 (27 - 
 
 The term "Reich ert number" (Reichert 'sche ZaJtl) is frequently 
 given to the figure expressing the number of c.c. of decinormal 
 alkali neutralised by the distillate obtained when operating in 
 the way prescribed by Reichert, using 2*5 grammes of substance; 
 and similarly the terms "Reichert-Meissl number" and "Reichert- 
 Wollny number "(IteicJwrt-MewsrscfoZahl and JReichert- Wollny' sche 
 ZaliT) to the corresponding figures obtained when Meissl's or 
 "Wollny's modification of Reichert's process is used (employing 
 
 * The Analyst, 1887, p. 203, et sea.; from the Milch Zeitung, 1887, 
 Nos. 32-35. 
 
176 OIL?, FATS, WAXES, ETC. 
 
 o grammes of substance). The two latter numbers are each 
 approximately double the first on account of the larger weight of 
 material. To avoid confusion between these different values, it 
 is convenient to translate them into terms of caustic potash 
 (KOH = 56-1) neutralised by the volatile acid obtained from 
 1,000 parts of substance, to which value the term "volatile acid 
 number" (or volatile acid potash permillage) may be conveniently 
 applied ; this translation is effected by means of the formulae 
 
 Volatile acid number = Reichert number . . x 2 '244 
 ,, ,, = Reichert-Meissl number x 1'122 
 
 ,, ,, = Reicherb-Wollny number x l'J22 
 
 The volatile acids thus indicated are usually considerably below 
 the total amount actually present; according to Allen, the defi- 
 ciency is somewhere about one-fifth in the case of butter fat, and 
 presumably in about the same proportion in other cases. When 
 a nearer approximation is requisite to the total volatile acid 
 present, water must be added to the residue in the retort and 
 distillation recommenced, and so on as long as acid vapours pass 
 over ; or more conveniently, steam may be blown through the 
 liquid from a separate boiling vessel. 
 
 BROMINE AND IODINE ABSORPTION. 
 
 Organic compounds containing a group of the character 
 
 CR = CS - tend to combine with two atoms of a given 
 halogen such as bromine or iodine, forming a group of formula 
 
 - CKBr - CSBr - , or - CRI - CSI - . Accordingly, organic acids 
 thus constituted are capable of uniting directly with halogens to 
 an extent dependent on the number of times that such " doubly 
 linked " carbon groups occur ; thus oleic and ricinoleic acids, 
 which contain one such doubly linked pair of carbon atoms, 
 unite with Br.,. 
 
 Oleic Acid. Dibromostearic Acid. 
 
 C 17 H 33 .CO.OH + Br 2 = C, 7 H 33 Br 2 . CO .OH 
 
 Ricinoleic Acid. Dibromoxystearic Acid. 
 
 P TT fOH TC p TT -R /OH 
 
 Ci 7 H 32 1 CQ OH C 17 H 32 Br 2 j CQ OH 
 
 Similarly, linolic acid combines with Br 4 , as it contains two * such 
 doubly-linked pairs of carbon atoms. 
 
 Linolic Acid. Tetrabromostearic Acid. 
 
 C ]7 H 31 .CO.OH + Br 4 = C 17 H 31 Br 4 . CO. OH 
 Whilst linolenic acid, containing 3 such pairs,! unites with Br 
 
 Linolenic Acid. Hexabromostearic Acid. 
 
 C 17 H 29 .CO.OH + Br 6 = C 17 H 29 Br 6 . CO . OH 
 
 * Or possibly a trebly-linked pair of carbon atoms, forming the group 
 
 CJ C -, which, by uniting with Br 4 , produces a group of formula 
 
 - CBr^- CBr,-. 
 
 t Or possibly one trebly-linked pair, and one doubly-linked pair. 
 
BROMINE ABSORPTION. 177 
 
 In certain cases, the bromine addition products thus formed 
 are crystallisable, and thus afford the means of separating organic 
 acids from one another (pp. 27, 35, 36); in any case, by determining 
 the quantity of halogen fixed by a given acid or mixture of acids, 
 useful information is often obtained as to the nature of the fatty 
 acids present ; for instance, if a mixture of stearic and oleic acids 
 took up, say, 45 per cent, of its weight of iodine, since stearic 
 acid takes up no iodine, and oleic acid 90 per cent, of its weight, 
 it would result that the mixture contained the two acids in 
 approximately equal quantities. Methods for the determination 
 of the amount of oleic acid in mixtures of this kind are of 
 considerable practical utility; in particular, the author has 
 found the method useful in determining the proportion of oleic 
 acid contained in the " stearine " used for candle making. 
 
 Precisely the same remarks also apply to the glycerides of the 
 fatty acids, with the sole difference that their combination with 
 halogens generally takes place more slowly than is the case with 
 the fatty acids contained, or with the parent hydrocarbons of 
 these fatty acids. 
 
 As far back as 1857, attempts to utilise the reaction with 
 bromine for the practical discrimination of fats were made by 
 Cailletet, and subsequently by A. H. Allen, Mills, and others; 
 but although in certain cases useful results are thus obtainable, 
 in practice it is found that the use of iodine is preferable, more 
 especially when applied in the modified form proposed by Hiibl 
 (vide infra), where mercuric chloride and iodine are dissolved in 
 alcohol, and the compound solution allowed to act on the fat. 
 
 in this case, the product formed is not simply an iodine 
 addition product ; the mercuric chloride appears to be ntore or 
 less transformed into mercuric iodide, with formation of chloride 
 of iodine, so that the addition product contains both chlorine and 
 iodine; thus oleic acid, C 18 H 34 O 2 , treated with this reagent 
 becomes mostly converted into chloriodostearic acid, C 18 H 34 C1IO 2 , 
 and similarly in other cases. The chlorine thus added on is in 
 practice never reckoned as such, but as its equivalent in iodine ; 
 so that 282 parts of oleic acid, when treated with Hiibl' s reagent, 
 are regarded as combining with 2 x 127 = 256 parts of iodine, 
 although usually the compound produced is formed by taking up 
 127 parts of iodine + 35-5 parts of chlorine. 
 
 Bromine Process. The bromine absorption process, as im- 
 proved by Mills and Snodgrass,* and Mills and Akitt,f consists 
 in dissolving bromine in carbon disulphide, or preferably carbon 
 tetrachloride, to a solution containing 0'6 to O7 per cent, of 
 bromine, and adding this to a solution of a weighed quantity 
 of oil in the same solvent, until no more combination takes place. 
 In the earlier experiments with carbon disulphide a slight excess 
 of bromine was added, and the colour, after standing 15 minutes, 
 
 * Journ. Soc. Chem. Industry, 1883, p. 435. t Ibid., 1884, p. 366. 
 
 12 
 
178 
 
 OILS, FATS, WAXES, ETC. 
 
 Substance. 
 
 Percentage 
 of Bromine 
 absorbed. 
 
 Specific 
 Gravity at 
 
 ll-12 e . 
 
 Melting 
 Point. 
 
 Remarks. 
 
 Almond oil, 
 
 26-27 
 
 9168 
 
 ... 
 
 Expressed from bitter 
 
 
 
 
 
 almonds. 
 
 . 
 
 53-74 
 
 9154 
 
 ... 
 
 Expressed from sweet 
 
 
 
 
 
 almonds ; yellower. 
 
 Beeswax, 
 
 0-54 
 
 
 63-9 
 
 English, a few months 
 
 
 
 
 
 old ; very yellow. 
 
 > 
 
 
 
 
 632 
 
 Scotch, 8 years old ; pale. 
 
 
 
 
 ... 
 
 62-9 
 
 ,, 2 ,, yellow. 
 
 , , 
 
 
 
 ... 
 
 63-3 
 
 " * ' > 
 
 Ben oil, . 
 
 52-95 
 
 9198 
 
 ... 
 
 Much solid fat. 
 
 . 
 
 50-89 
 
 9161 
 
 ... 
 
 No solid fat. 
 
 Camauba wax, 
 
 33-50 
 
 ... 
 
 84-1 
 
 
 Cod liver oil, . 
 
 83-12 
 
 9269 
 
 
 Scotch, 7 years old ; ran- 
 
 
 
 
 
 cid ; clear portion used; 
 
 
 
 
 
 1 hour's absorption. 
 
 
 
 84-03 
 
 9292 
 
 ... 
 
 Norwegian, refined, 2 
 
 
 
 
 
 years old. 
 
 
 82-94 
 
 9257 
 
 ... 
 
 Japanese, 2 years old. 
 
 . 
 
 81-61 
 
 9277 
 
 
 Scotch, 2 years old. 
 
 < 
 
 86-69 
 
 9281 
 
 ... 
 
 Crude, from liver refuse ; 
 
 
 
 
 
 a few months old. 
 
 . 
 
 83-01 
 
 9318 
 
 ... 
 
 Norwegian, 1 year old. 
 
 . 
 
 82-07 
 
 9278 
 
 
 Scotch ,, 
 
 Croton oil, 
 
 46-66 
 
 D441 
 
 ... 
 
 20 hours' absorption. 
 
 Eucalyptus oil, 
 
 94-09 
 
 8691 
 
 ... 
 
 ... 
 
 Horse fat, 
 
 35-67 
 
 ... 
 
 ... 
 
 Pasty ; well mixed. 
 
 Japan wax, 
 
 2-33 
 
 ... 
 
 50-5 
 
 
 ,, (another sample), 
 
 1-53 
 
 ... 
 
 50-8 
 
 
 Java nut oil, . 
 
 30-24 
 
 ... 
 
 ... 
 
 ... 
 
 Ling liver oil, 
 
 82-44 
 
 9295 
 
 ... 
 
 2 years old ; 1 hour's 
 
 
 
 
 
 absorption. 
 
 Maize germ oil, 
 
 74-42 
 
 9262 
 
 
 4 years old. 
 
 Mustard seed oil, 
 
 46-15 
 
 9152 
 
 
 East Indian. 
 
 Myrtle wax, . 
 
 6-34 
 
 ... 
 
 44-3 
 
 ... 
 
 Neat's foot oil, 
 
 38-33 
 
 9147 
 
 ... 
 
 Thick. 
 
 Niger seed oil, 
 
 35-11 
 
 9244 
 
 ... 
 
 
 Olive oil, 
 
 59-34 
 
 9266 
 
 ... 
 
 Thick brown ; ' ' best 
 
 
 
 
 
 sulphocarbon." 
 
 ?9 * * 
 
 60-61 
 
 9382 
 
 ... 
 
 Thinner greener ; ' ' low 
 
 
 
 
 
 quality sulphocarbon." 
 
 Palm oil, 
 
 35-44 
 
 ... 
 
 ... 
 
 Crude old Calabar. 
 
 5 ) * 
 
 34-96 
 
 ... 
 
 ... 
 
 ,, Lagos. 
 
 Peach kernel oil, 
 
 25'40 
 
 9175 
 
 ... 
 
 ... 
 
 Poppy oil, 
 Besin. (common), 
 Seal oil, . 
 
 56-54 
 112-70 
 57-34 
 
 9244 
 9241 
 
 ... 
 
 Turbid; filtered. 
 Light colour. 
 Pale; 1 hour's absorption. 
 
 J 5 
 
 59-92 
 
 9216 
 
 
 Dark. 
 
 Sesame oil, 
 
 47-35 
 
 9250 
 
 ... 
 
 ... 
 
 Shark liver oil, 
 
 84-36 
 
 9293 
 
 ... 
 
 A few months old ; 
 
 
 
 
 
 1 hour's absorption. 
 
 Sunflower oil, . 
 
 54-32 
 
 9391 
 
 
 Colourless ; about 16 
 
 
 
 
 
 years old. 
 
 Whale oil, 
 
 30-92 
 
 9199 
 
 ... 
 
 Norwegian white whale; 
 
 
 
 
 
 very thick. 
 
 > 
 
 48-69 
 
 8780 
 
 ... 
 
 Bottlenose whale. 
 
HUBL'S IODINE TEST. 179 
 
 compared with that of a known amount of bromine dissolved in 
 carbon disulphide, so as to obtain a colorimetric valuation of the 
 excess ; or the excess of bromine was estimated by adding 
 potassium iodide and titrating with thiosulphate. In the later 
 experiments with carbon tetrachloride, about Ol gramme of 
 oil was dissolved in 50 c.c. of tetrachloride, an excess of bromine 
 solution added, and after 15 minutes the excess back-titrated, 
 either by the coloration method,* by iodide and thiosulphate, 
 or by a standard solution of j3 naphthol in carbon tetrachloride. 
 
 The table on p. 178 gives the results of a number of deter- 
 minations thus made. 
 
 Iodine Process Hiibl's Test. The iodine absorption pro- 
 cess of Baron Hubl is thus worked, f An alcoholic solution of 
 mercuric chloride and iodine in pure 95 per cent, alcohol is pre- 
 pared by dissolving 50 grins, iodine in one litre of spirit, and 
 60 grms. corrosive sublimate in another litre, filtering the latter 
 if necessary, and mixing the two solutions ; preferably they are 
 kept apart and only mixed a day or two before use ; J the com- 
 pound solution rapidly loses strength (as regards free iodine) if 
 fusel oils are present in the alcohol, methylated spirit being wholly 
 inadmissible; in any case the liquid should be allowed to stand at 
 least a day before use, so that any small quantity of iodine- 
 consuming impurities may be eliminated as far as possible ; the 
 actual iodine strength must be determined from time to time to 
 allow for depreciation. From -2 to *3 grm. of drying oils, '3 to '4 
 of non-drying oils, or -8 to 1 -0 grm. of solid fat, is dissolved in 
 10 c.c. of pure chloroform (i.e., containing no iodine-destroying 
 impurity), and to the solution 30 or 40 c.c. of iodine solution 
 added, more being added if on standing awhile the brown colour 
 lightens materially ; enough solution must be added in all to 
 give a large excess of free iodine when the action is complete 
 after several hours standing. The excess of iodine is titrated by 
 adding some aqueous potassium iodide solution (10-15 c.c. of 
 10 per cent, solution, along with 150 c.c. of water), and then 
 standard sodium thiosulphate (about 24 grms. to litre, standard- 
 ised by means of pure sublimed iodine, or by pure potassium 
 dichromate) until the blue colour with starch paste is just 
 decolorised, the starch being only added when nearly all the free 
 
 * When the oil is yellow, as with certain fish oils, the redness due to 
 excess of bromine is best examined by viewing through a solution of 
 potassium chromate. 
 
 t Dingler's PolytecJt. Journal, 1884, pp. 253, 281 ; in abstract, Journ* 
 Soc. Chem. Intl., 1884, p. 641. 
 
 According to Say tzetf, mercuric bromide is preferable to corrosive sub- 
 limate, the solution being more stable. Some chemists only mix the two 
 solutions at the moment they are wanted ; but according to the author's 
 experience, this considerably increases the chances of error. If mercuric 
 chloride be not added at all (e.g., if a solution of iodine in carbon tetra- 
 chloride be used), the quantity of iodine absorbed is in some cases largely 
 diminished as compared with that taken up with Hiibl's fluid. 
 
180 OILS, FATS, WAXES, ETC. 
 
 iodine is destroyed. As the excess of iodine is dissolved partly 
 in the aqueous liquor and partly in the chloroform, the whole 
 must be well agitated. Unless a considerable excess of free 
 iodine is present, and the whole allowed to stand for several 
 hours, defective results are apt to be obtained with glycerides, as 
 the assimilation of iodine with these bodies is not always rapid ; 
 free fatty acids combine with iodine more quickly. A good rule 
 is to use an excess of iodine approximately equal to the amount 
 absorbed, * and to allow the whole to stand until the next day 
 before titration of the uncombined iodine ; one or more blank 
 experiments being simultaneously arranged to allow for possible 
 depreciation in strength of the iodine solution during the period ; 
 this lengthened time is more especially requisite in the case of 
 oils absorbing large amounts of iodine. Thus the following 
 figures illustrate this point (Thomson and Ballantyne) : 
 
 Iodine Number found. 
 
 Time of Absorption. 
 
 -, 
 
 . 
 
 Seal Oil. 
 
 Linseed Oil. 
 
 2 hours. 
 
 136-6 
 
 175-5 
 
 4 
 
 140-8 
 
 1797 
 
 6 
 
 145-1 
 
 184-1 
 
 8 145-8 
 
 1877 
 
 18 145-8 
 
 187-7 
 
 Similar figures have been published by various other observers in 
 the case of glycerides absorbing large proportions of iodine, whereas, 
 with free fatty acids and glycerides absorbing but little iodine, the 
 reaction is ordinarily-found to be practically complete in 2 hours. 
 
 When the iodine absorption of free iatty acids is to be 
 determined," it is unnecessary to dissolve in chloroform ; the 
 alcoholic mercury-iodine solution may be added directly to the 
 weighed fatty acids, previously thinned a little by warming 
 with a small quantity of pure alcohol. The following table 
 represents the amounts of iodine theoretically taken up by 100 
 parts of the several acids and their respective triglycerides : 
 
 
 Iodine Absorption. 
 
 
 
 
 
 Acid. 
 
 Giyceride. 
 
 Hypogieid acid, ' - : . 
 Oleic acid, 
 
 CieH 3 002 100*00 
 Ci 8 H 34 2 9007 
 
 95-25 
 
 86-20 
 
 Erucic acid, . ; - . ,' 
 
 . C22H 42 02 75*15 
 
 72-43 
 
 Ricinoleic acid, 
 
 Cj8H3 4 3 85*24 
 
 81-76 
 
 Linolic acid, . - - C]8H 32 02 
 
 173-57 : 
 
 Linolenic acid, C]gH 30 02 j 274'10 
 
 262-15 
 
 * In the case of oils absorbing large quantities of iodine, a still greater 
 excess is preferable, about twice the quantity absorbed. In all cases the 
 quantity of iodine used for the blank experiment should be approximately 
 equal to the excess employed. 
 
IODINE TEST. 
 
 181 
 
 
 
 T3 "^ 
 
 
 o5 s 
 
 
 1 1 
 
 
 ~s' S l 
 
 c5 
 
 
 
 Oo_o^^ 
 
 B . , .co 
 
 ^ *5^*5 
 
 
 
 li|P 
 
 o 
 
 * i 1 
 
 ft 
 
 hH 33 
 
 : : :SS : 2 R : : 
 
 ! w is 
 
 <* 3" 
 
 
 a? 02 
 
 
 S^ ^ 
 
 
 
 
 "o 2*5 *-* 
 
 CO i i O O lO 
 
 oocoo cs-tor^to 
 
 OS CM O O O CO CM 
 
 -s^tf 5 
 
 -* CO O *-f O 
 CS C5 CS CS CO 
 
 O '^ -^ t>- (M>O 'F-^CO 
 
 cscscsi-- cscscocsco 
 
 : To 01 : o o ; r- CM 
 
 l| 2 - 
 
 
 
 
 u 
 
 o 
 
 
 
 ? 
 
 g co o o o ip 
 
 CO O CO CM O O CM 
 
 p f co i--p pop p co ~f< . 
 
 2 
 
 1 s 
 
 I " 
 
 gJ " S " W "" : 
 
 co rcsdoicoO' ooo : 
 
 CM CO-^CM-^T^kO^COCM 
 
 *> 
 
 
 
 
 
 
 go p pp p 
 
 Ot^i--'-H O O O O 
 
 p . o cp p p co p ip p p 
 
 1 
 
 |5S88a 
 
 CM CN CN CN i p4 C4 
 
 o :cMt-t^xo cMcMco-'j* : 
 
 CO rf<'^CM-<ji--^tO'*COCM 
 
 I 
 
 lO <*< -^ CO CM 
 
 Tj< -^,00 CO 
 
 COCOCOO OCOrJ*O1^-i 
 CS CO CO CO 
 
 CO CS lO F^ CS O CO ^ ~H p-^ CO ^ 
 COlO^O lO^-VCOCOCOCO 
 
 1 
 
 2 
 
 II 
 
 
 
 1 
 
 1 
 
 
 
 
 
 1. 
 
 o ^ co 
 
 1 * 1 1 
 
 
 pp ^ ^ 
 
 O O CM O 
 l^CO.lO CO .. 
 
 8 
 
 CD ' CM ' 
 
 o * co 
 
 c8Sc7'^2^ ' 
 
 pp -* p 
 
 2 
 
 
 CO CO 
 
 CO.O .0 
 
 
 
 
 
 
 
 
 _r 
 
 
 
 
 
 
 s sf 
 
 
 
 *o 
 
 ^ o 
 
 Jl,^" i = - ; 'A 
 
 ^-1 r : i|iilH 
 
 I 
 
 i ./o.S 
 
 'o S'g ^ o-^^^g 
 
 
 I 
 
 1 11 if 
 
 Ijitlli'H 
 
 gS s**g S-I.E 
 
 'o ^ 'o 3 r g o -^ of tj go 
 C "g^ ^pSSS^S^^JS-l, 
 
 
 5 w^jgfS 
 
 g -i e3 &^5 2 ^ ^ 
 
 ccO^W -^-^OOO 
 
 
 
 3 
 
 s $ 
 
 
 
 ll 
 
 II I 
 
 
 
 s p 
 
 ^1 l^ : 
 
 
 
 p 
 
 H-;P ^o 
 
 F-I 
 
 
 1 I rH 
 
 1 i I 1 
 
 
182 
 
 OILS, FATS, WAXES, ETC. 
 
 In actual practice, Hiibl found that pure oleic acid took up 
 8 9 '8-90 '5 per cent, of iodine, and obtained the values quoted 011 
 p. 181 on examining a variety of fats and oils by different pro- 
 cesses simultaneously, the substances being divided into 7 classes, 
 according to the magnitude of the iodine absorption. 
 
 Schadler gives the following values as those most generally 
 found pertaining to various oils and fats, &c. : 
 
 Name of Oil or Fat. 
 
 Iodine Number of 
 
 Oil, &c. Fatty Acids. 
 
 
 82-83 
 100-102 
 94-96 
 28-32 
 66 68 
 34 
 93-94 
 98-97 
 100-101 
 9-9-5 
 106-107 
 127 
 128-130 
 135-140 
 143-144 
 105 
 4-2 
 177-178 
 162 
 59-60 
 119-5 
 142-143 
 82-83 
 82 
 51-5 
 13-5-14 
 134-135 
 121 
 98-100 
 38-40 
 125-130 
 103-105 
 129 
 88 
 108 
 63 
 43-44 
 81-5-82 
 36 
 
 87-90 
 96-97 
 
 56-57 
 
 97-99 
 8-5-9-0 
 112-115 
 
 122-124 
 
 155 
 167 
 
 125 
 
 87-88 
 
 12 
 
 97-99 
 26-30 
 
 110-111 
 133-134 
 
 86-87 
 
 Apricot kernel, 
 Arachis, 
 Butter, 
 Bone, . . 
 Cacao butter, 
 Castor, . . 
 Charlock, . 
 Colza, . . . 
 Cokernut, 
 Cotton seed, 
 Curcas, 
 
 c - dl MSr 1> : : 
 
 Hedge radish, 
 Japanese wax, 
 Linseed, 
 
 Lallemantia (Gundschit), 
 
 
 Nut (walnut), 
 Olive (salad), 
 Olive kernel, 
 Palm, ....." 
 
 Palm kernel, 
 Poppy, .... 
 Pumpkin seed, 
 Rape seed, .... 
 Suet (ox tallow, beef tallow), 
 Seal, . 
 
 Sesam6, .... 
 Sunflower, .... 
 Sperm oil, .... 
 Spermaceti, .... 
 Tacamahac, . . " 
 Tallow (sheep), . 
 Ungnadia, .... 
 Wool grease, 
 
 The following tables represent the collected results published 
 
IODINE TEST. 
 
 183 
 
 by numerous observers,* ' during the last few years, as the 
 amounts of iodine taken up by 100 parts of different oils and 
 fats : 
 
 VEGETABLE OILS. 
 
 Name. 
 
 Minimum. 
 
 Maximum. 
 
 Average. 
 
 Fresh linseed oil, . 
 
 170 
 
 181 
 
 175 
 
 Commercial oil, . 
 
 148 
 
 181 
 
 170 
 
 Lallemantia oil, . . . 
 
 
 
 162 
 
 Hemp seed oil, . . 
 
 142 
 
 158 
 
 150 
 
 Nut oil, .... 
 
 143 
 
 152 
 
 146 
 
 Poppy seed oil, 
 
 134 
 
 142 
 
 138 
 
 Sunflower seed oil, 
 
 122 
 
 133 
 
 128 
 
 Curcas oil, .... 
 
 
 ... 
 
 127 
 
 Pumpkin seed oil, 
 
 
 ... 
 
 121 
 
 Maize oil, .... 
 
 
 ... 
 
 120 
 
 Cotton seed oil, 
 
 102 
 
 Ill 
 
 108 
 
 Sesame oil, .... 
 
 103 
 
 112 
 
 108 
 
 Hedge radish oil, . 
 
 
 ... 
 
 105 
 
 Rape seed oil, 
 
 99 
 
 105 
 
 101 
 
 Apricot kernel oil, 
 
 99 
 
 102 
 
 100 
 
 Almond oil, 
 
 96 
 
 102 
 
 98 
 
 Arachis oil, .... 
 
 87-3 
 
 103 
 
 96 
 
 Mustard oil, 
 
 ... 
 
 ... 
 
 96 
 
 Castor oil, . 
 
 83 
 
 85 
 
 84-5 
 
 Olive oil, . 
 
 81 
 
 84-5 
 
 82-8 
 
 Olive kernel oil, . 
 
 ... 
 
 ... 
 
 81-8 
 
 ANIMAL OILS. 
 
 Name. 
 
 Minimum. 
 
 Maximum. 
 
 Average. 
 
 Cod liver oil, 
 
 126 
 
 153 
 
 140 
 
 Seal oil, .... 
 
 127 
 
 128 
 
 127 
 
 Japanese cod liver oil, 
 
 ... 
 
 ... 
 
 120 
 
 Bottlenose oil, 
 
 ... 
 
 ... 
 
 99-5 
 
 Porpoise oil, 
 
 ... 
 
 
 76'8 
 
 Neat's foot oil, 
 
 
 
 70-3 
 
 Bone oil, .... 
 
 66 
 
 70 
 
 68 
 
 Porpoise oil oleine, 
 
 30-9 
 
 49-6 
 
 40-2 
 
 Bottlenose oleine, . 
 
 ... 
 
 
 32-8 
 
 * Hiibl, Moore, Dieterich, Wilson, Erban, Herz, Spiiller, Horn, Richter, 
 Kremel, Beringer, and Benedikt ; collated by Bsnedikt. Analyse der Fette 
 und Wachsarten, 2nd edition, pp. 298 and 317. 
 
184 
 
 OILS, FATS, WAXES, ETC. 
 SOLID FATS. 
 
 Name. 
 
 Minimum. 
 
 Maximum. 
 
 Average. 
 
 Cotton seed stearine, 
 
 
 
 89-6 
 
 Goose grease, 
 
 ... 
 
 
 71-5 
 
 Hog's lard, .... 
 
 56 
 
 63 
 
 59 
 
 Macassar oil, 
 
 ... 
 
 
 53 
 
 Bone grease, 
 
 46-3 55-5 
 
 52 
 
 Palm butter, 
 
 50-3 53-9 
 
 51 
 
 Oleomargarine. . 
 
 47'5 55-3 50 
 
 Laurel butter, 
 
 
 49 
 
 Ox tallow, .... 
 
 40 
 
 44 42 
 
 Sheep's tallow, 
 
 32-7 46-2 42 
 
 Wool grease, 
 
 36 
 
 Cacao butter, 
 
 34 37-7 36 
 
 Nutmeg butter, . 
 
 31 
 
 Butter fat, . 
 
 19-5 
 
 38-0 
 
 30 
 
 Palm kernel butter, 
 
 10-3 
 
 17-5 
 
 14 
 
 Coker butter, 
 
 7-9 
 
 9-4 
 
 9 
 
 Japanese wax, 
 
 ... 
 
 
 4-2 
 
 Slightly higher values still for some of the drying oils have 
 been recently deduced by Holde in the course of an investigation 
 on the sources of error in the Hiibl test,* the cause being 
 assigned to more complete saturation with iodine through use 
 of a larger excess of solution. Thus 
 
 Linseed oil, 179 to 180 
 
 Hempseed oil, 175 
 
 Poppy seed oil, 139 to 143 
 
 Sesame" oil, 106 to 109 
 
 Cotton seed oil, 110 to 115 
 
 Common rape oil, 100 to 108 
 
 Refined rape oil, 100 to 107 
 
 The following values have also been recorded for the mixed 
 fatty acids from various commercial oils : 
 
 
 Morawski and Demski. 
 
 Williams. 
 
 Linseed oil acids, . . . 
 Hempseed oil acids, 
 Cotton seed oil acids, . 
 Sesame oil acids, . . . 
 Rape seed oil acids, 
 Arachis oil acids, . . . 
 Castor oil acids, . . 
 Olive oil acids, ..... 
 
 155 -2 to 155 -9 
 122-2 to 125 -2 
 110-9 to 111-2 
 108-9 to 111-4 
 96-3 to 99-02 
 95-5 to 96-9 
 86 -6 to 88-3 
 86-1 
 
 178-5 
 115-7 
 105*6 
 
 93-9 
 
 90-2 
 
 
 
 
 Owing to the tendency towards absorption of oxygen exhibited 
 by drying oils and the fatty acids obtained from them, there is 
 
 * Journ. Soc. Chem. Ind., 1891, p. 954; from Mitth. Kcnigl. tech. 
 Vcrsuchs, Berlin, 1891, 9, p. 81. 
 
IODINE TEST. 185 
 
 always a liability to obtain somewhat different results with free 
 fatty acids as compared with the original oils from which they 
 were obtained, owing to partial oxidation during isolation and 
 drying. As a rule, absorption of oxygen seems to diminish the 
 iodine absorption as might, a priori, be expected. 
 
 Neglecting this alteration, the amounts of iodine absorbed by 
 an oil, &c., and by the fatty acids thence obtainable, necessarily 
 stand to one another in the inverse ratio of their respective 
 mean equivalent weights ; for if E be the saponification equiva- 
 lent of an oil, and F the mean equivalent weight of the fatty 
 acids thence obtainable, quantities of oil and free acid in the 
 respective proportion of E to F will combine with the same 
 quantity of iodine ; so that the iodine taken up by 100 parts of 
 
 oil will be ^ times that taken up by 100 parts of fatty acids ; 
 .hi 
 
 i.e., if I be the iodine number of the oil and I' that of the fatty 
 ;icids 
 
 and 
 
 <=!' 
 
 If the oil, &c., consist wholly of triglycerides, E = F + 12 -67 
 (p. 165); whence 
 
 F + 12 67 
 
 ~~ 
 
 Hence for fatty acids of molecular weight between 250 and 330, 
 the iodine number of the fatty acids is between 5'1 and 3-8 per 
 cent, greater than that of the original oil ; so that for the great 
 majority of natural oils and fats, the iodine number of the free 
 fatty acids exceeds that of the oil by an amount sensibly close to 
 4-5 per cent, of the latter value. 
 
 Obviously, in some of the cases above tabulated, a notable 
 difference must have subsisted between the samples used for the 
 determination of the iodine number of a given oil, and of that of 
 the fatty acids derived from the same kind of oil, since the latter 
 values are, in some instances, less than the former ones instead 
 of exceeding them by about 4 '5 per cent, of their value. 
 
 The theoretical amount of iodine corresponding with 100 parts 
 of pure olein is 86-2 parts. From the numbers above tabulated, 
 it is obvious that many of the fluid vegetable oils, usually 
 regarded as non-drying (arachis, almond, apricot kernel, &c.), 
 contain some small amount of glycerides of the linolic or drying 
 class, since their iodine absorptions exceed 86 -2 ; a fortiori, with 
 oils of the intermediate class exhibiting a slight amount of 
 
186 
 
 OILS, FATS, WAXES, ETC. 
 
 drying quality (cotton seed, sesame, sunflower, &c), a larger 
 iodine absorption is observed, corresponding with a still more 
 marked proportion of drying oil constituents. 
 
 ACETYLATION TEST BENEDIKT AND 
 ULZER'S TEST. 
 
 When organic substances containing alcoholiform hydroxyl are 
 heated in contact with acetic anhydride, an action takes place 
 which may be regarded as the converse of saponincation or 
 hydrolysis ; the hydroxylated body, X . OH, acts upon the 
 anhydride in accordance with the equation 
 
 Alcohol. Acetic Anhydride. Compound Acetic Ether. Acetic Acid. 
 
 X - OH + 8$$} = X.O.C.H.O + C2 H 3 o! 
 
 giving rise to a compound ether. Polyhydroxylated bodies 
 behave in the same way, one acetyl group being taken up for 
 each alcoholiform hydroxyl group present ; thus glycerol treated 
 with acetic anhydride becomes transformed into triacetin in 
 accordance with the equation 
 
 Glycerol. Acetic Anhydride. Triacetin. Acetic Acid. 
 
 CH 2 . OH CH, . O . C,H 3 
 
 CH . OH + 3(CoH 3 0)oO = CH. . aH 3 + 3C.,H 4 O, 
 
 CH 2 . OH CH 2 . . CoH 3 
 
 On this reaction is based a method for the analytical examination 
 of commercial glycerol (Chap, xxn.) Benedikt and Ulzer have 
 also attempted to utilise this reaction to distinguish hydroxylated 
 organic acids (like oxystearic and ricinoleic acids) from non- 
 hydroxylated acids, such as stearic and palmitic acids. Their 
 method is based on the assumption that acetic anhydride exerts 
 no action on the hydroxyl of the CO . OH group of an organic 
 acid, but does act, in accordance with the above equation, 
 on any alcoholiform hydroxyl contained therein ; so that if, for 
 example, stearic acid be treated with acetic anhydride, and the 
 product heated wrih water so as to decompose excess of acetic 
 anhydride, simply unchanged stearic acid results;* whereas, if 
 oxystearic acid be similarly treated, acetyl oxystearic acid is 
 produced, thus 
 
 Oxystearic Acid. Acetic Anhydride. Acetyl Oxystearic Acid. Acetic Acid. 
 
 OH C,H 3 ) n \0. CoHsO 
 
 CO . OH C 2 H 3 \ U ^IT U M j co . OH 
 
 The acetylated acids thus formed are stated to be moderately 
 stable, not being appreciably hydrolysed by the action of the hot 
 
 * This assumption is entirely at variance with the results obtained by 
 Lewkowitsch ; vide infra. 
 
ACETYLATION TEST BENEDIKT AND ULZER's TEST. 187 
 
 water requisite to decompose the excess of acetic anhydride pre- 
 sent. Accordingly, if after thus removing excess of acetic anhy- 
 dride, the resulting acetyl acid be titrated with standard alkali, 
 one equivalent of alkali will be directly neutralised ; whilst if it 
 be heated with excess of alcoholic alkali so as to saponify it, 
 reproducing oxystearic acid and acetic acid, thus 
 
 Acetyl Oxystearic Acid. Water. Oxystearic Acid. Acetic Acid. 
 
 + H,0 C 17 H 34 + CoH 4 
 
 two equivalents will be neutralised in all, the second by the 
 acetic acid formed. In the case of a mixture of acids containing 
 hydroxylated and non-hydroxylated constituents, the proportion 
 of the latter can be estimated by determining the extra amount 
 of potash neutralised on saponification, as compared with that 
 neutralised directly. The term " acetyl number " (acetylzahl], 
 is used to indicate the weight of potash (KOH = 56*1) neutral- 
 ised by the acetic acid formed from 1,000 parts of mixed 
 acetylated product.* 
 
 The acetylation process is carried out thus : The free fatty 
 acids formed by saponifying a given sample of oil and decom- 
 posing the soap by a mineral acid, are boiled for two hours with 
 an equal volume of acetic anhydride in a flask with inverted 
 condenser attached ; the mass is then boiled for half an hour 
 with about 20 parts of water ; the acetic acid solution formed is 
 siphoned off, and the treatment with boiling water repeated three 
 times, so that finally the water is free from acidity after boiling 
 for half an hour. The acetylated product is then filtered through 
 a dry filter paper to remove water, and a weighed quantity 
 dissolved in pure alcohol. Standard alcoholic potash is added to 
 neutrality, and the amount neutralised noted; more than as much 
 again is then added, and the whole heated to boiling, whereby 
 the acetyl derivative is saponified ; the unneutralised alkali is 
 then back-titrated. Thus in the case of the fatty acids from a 
 sample of castor oil the following figures were obtained :f 3-379 
 grammes of acetylated product neutralised 17 '2 c.c. of seminormal 
 potash, whence the " acetyl acid number " is 142-8. After 
 
 * Benedikt and Ulzer term the potash directly neutralised by 1,000 parts 
 of mixed acetylated product, the "acetyl acid number " (acetylsaurezahl), 
 and the total neutralised on saponification (sum of acetylzahl and acetyl- 
 fiiiurezahl) "the acetyl saponification number" (acetylverseifunyszahl). 
 Thus the theoretical values tor acetyl oxyoleic (ricinoleic) acid are 
 
 Acetyl number, . . . 165'0 
 
 Acetyl acid number, . . . IGo'O 
 
 Acetyl saponification number, . 330 '0 
 t Benedikt, Analyse der Fette und Wacltsarten, 2nd edition, 1892, p. 114. 
 
188 
 
 OILS, FATS, WAXES, ETC. 
 
 addition of 32 -8 c.c. more potash and boiling, 14*3 c.c. were found 
 to be unneutralised, whence 18 '5 c.c. represent the acetic acid 
 formed on saponification, giving the " acetyl number" 153-6, and 
 the "acetyl saponification number" 142-8 + 153-6 = 269-4. 
 Since the acetyl number exceeded the acetyl acid number, it would 
 hence result that some amount of a dihydroxylated acid was pre- 
 sent, especially as the mixed acids of castor oil contain a small 
 quantity of stearic (non-hydroxylated) acid to begin with (vide 
 infra}. 
 
 Operating in this way, Benedikt and Ulzer found the following 
 values for various oils : * 
 
 Oil Used. 
 
 "Neutralisation 
 Number" of 
 Fatty Acids 
 before 
 Acetylation. 
 
 Acetyl Acid 
 Number. 
 
 Acetyl 
 Number. 
 
 Acetyl 
 Saponification 
 Number. 
 
 Arachis, 
 
 198-8 
 
 193-3 
 
 3-4 
 
 1967 
 
 Cotton seed, . 
 
 199-8 
 
 195-7 
 
 16-6 
 
 212-3 
 
 Croton, . 
 
 201-0 
 
 1957 
 
 8-5 
 
 204-2 
 
 Hemp seed, . 
 
 199-4 
 
 196-8 
 
 7'5 
 
 204-3 
 
 Linseed, 
 
 201-3 
 
 196-6 
 
 8-5 
 
 205-1 
 
 Almond, 
 
 201-6 
 
 196-5 
 
 5-8 
 
 2023 
 
 Poppy seed, . 
 
 200-6 
 
 194-1 
 
 13-1 
 
 207-2 
 
 Nut, . 
 
 204-8 
 
 198-0 
 
 7-6 
 
 205-0 
 
 Olive, . 
 
 197-1 
 
 197-3 
 
 4-7 
 
 202-0 
 
 Peach kernel, 
 
 202-5 
 
 196-0 
 
 6-4 
 
 202-4 
 
 Castor, . 
 
 177-4 
 
 142-8 
 
 153-4 
 
 296-2 
 
 Rape, 
 
 182-5 
 
 178-5 
 
 6-3 
 
 184-8 
 
 Sesame, . 
 
 200-4 
 
 192-0 
 
 11-5 
 
 203-5 
 
 "Soluble castor oil " 
 
 
 184-5 
 
 62-2 
 
 246-7 
 
 J. A. Wilson f found the following average values for castor, 
 olive, and cotton seed oils : 
 
 
 Acetyl Acid 
 Number. 
 
 Acetyl Number. 
 
 Acetyl Saponification 
 Number. 
 
 Castor oil, 
 Olive oil, . 
 Cotton seed oil, 
 
 136-7 
 170-0 
 189-5 
 
 155-0 
 360 
 21-0 
 
 291-7 
 2060 
 210-5 
 
 Obviously these figures do not agree very sharply with the 
 preceding ones. If the results of the acetyl test could be re- 
 garded as perfectly trustworthy, these values would indicate the 
 existence of more or less considerable amounts of hydroxy acids in 
 all the samples examined, amounting, in the case of the cotton seed 
 and sesame oils examined by Benedikt and Ulzer, to 6-8 per cent, 
 of the total acids present, and to much larger amounts in the 
 
 * Monat'hefte f. Chemie, 1S87, S, p. 41. 
 \Journ. Soc. Chem. Intl., 1892, p. 495.- 
 
ACETYLATION TEST. 189 
 
 case of the olive and cotton seed oils examined by Wilson. The 
 figures, however, do not exhibit such concordance as to be 
 unexceptionable ; the effect of acetylating the hydroxylated con- 
 stituents of a mixture of acids containing only a small proportion 
 of hydroxylated acids would be to cause the neutralisation number 
 of the acetylated fatty acids (the acetyl acid number) to be only 
 slightly less than their neutralisation number before acetylation, 
 whereas the observed differences are materially larger. Thus 
 the neutralisation numbers of oleic, oxyoleic, and acetyl oxyoleic 
 acids are respectively 198-9, 188-25, and 165-0; whence a 
 mixture of 90 parts oleic acid and 10 parts oxyoleic acid would 
 have the neutralisation number 197*9 ; and after acetylation 
 would furnish a mixture of oleic and acetyl oxyoleic acids having 
 the neutralisation number (acetyl acid number) 195'5, or only 
 2*4 less than the original mixture. Similarly a mixture of 
 9o parts oleic acid and 5 parts oxyoleic acid would have the 
 neutralisation number 198-4 before acetylation, and 197*2 after, 
 giving the difference 1-2. The actual differences deduced from 
 the above figures obtained by Benedikt and Ulzer with oils other 
 than castor oil, vary between 0*2 (olive oil) and +8-4 (sesame 
 oil), but in most cases amount to from 5 to 6; strongly suggesting 
 that some cause is at work abnormally diminishing the " acetyl 
 acid number " by some units, and in consequence giving an ap- 
 parent " acetyl number " of some units in magnitude, the result 
 of this cause, and not of the existence of hydroxy acids in the fatty 
 asids examined. The same conclusion also results from the figures 
 obtained with castor oil acids, as the supposition that a consider- 
 able percentage of dihydroxylated acids is present is manifestly 
 untenable. 
 
 Lewkowitsch has made some observations that throw light on 
 the probable cause of these discrepancies.* His results indicate 
 that by the action of acetic anhydride in excess the higher acids 
 of the acetic family (such as lauric, palmitic, and stearic acids, 
 &c.) become more or less completely converted into the corre- 
 sponding anhydrides.f When the products freed from the 
 excess of acetic anhydride by the action of water are neutralised 
 by alkali, a diminution in the apparent amount of free acid is 
 noticed proportionate to the amount of fatty anhydrides present 
 not decomposed by the water treatment ; and when the neutral- 
 ised substance is heated with excess of alcoholic alkali, and 
 subsequently back-titrated, a quantity of alkali is neutralised 
 proportionate to the fatty acid formed by the hydration of the 
 
 * Proceeding* of the Chemical Society, 1890, pp. 72 and 91. 
 
 t Anschiitz found [Aimalen d. Chem. Pharm. (1884) 226, p. 6] that when 
 acetic anhydride and benzoic acid were heated together in a sealed tube at 
 220 benzoic anhydride was produced ; whilst the dibasic acids, succinic, 
 camphoric, orthophthalic, and diphenic acids were largely transformed into 
 their respective anhydrides by heating with acetic anhydride at 120 
 to 150. 
 
190 
 
 OILS, FATS, WAXES, ETC. 
 
 fatty acid present; so that an apparent "acetyl number" is 
 obtained even when no alcoholiforin hydroxyl whatever is present 
 in the body examined. Thus he obtained the following figures 
 with samples of capric, lauric, palmitic, oleic, stearic, and cerotic 
 acids in a state of only approximate purity so far as chemical 
 identity is concerned, but any rate free from any notable amount 
 of hydroxy acids : 
 
 
 NeutraHsutio 
 
 n Number. 
 
 
 
 Acetyl 
 
 Fatty Acid Used. 
 
 Theoretical 
 
 
 Acetyl Acid 
 Number. 
 
 Acetyl 
 Number. 
 
 Saponification 
 
 
 for pure 
 
 Found. 
 
 
 
 1 
 
 
 fatty acid. 
 
 
 
 
 
 Capric, 
 
 326-2 
 
 318-05 
 
 176-40 
 
 174-00 
 
 350-40 
 
 Lauric, 
 
 280-5 
 
 273-02 
 
 161-50 
 
 132-49 
 
 293-99 
 
 Palmitic, 
 
 219-1 
 
 213-4 
 
 143-53 
 
 82-60 
 
 222-13 
 
 Oleic, . 
 
 198-0 
 
 183-0 
 
 116-50 
 
 125-55 
 
 242-05 
 
 Stearic, 
 
 197-5 
 
 203-0 
 
 138-89 
 
 82-29 
 
 221-18 
 
 Cerotic, 
 
 13t>-8 
 
 1284 
 
 73-87 
 
 68-23 
 
 142-10 
 
 From these figures it obviously results that but little reliance 
 is to be placed on the result of the acetylation test for alcoholi- 
 form hydroxyl in fatty acids when based simply on the titra- 
 tioii process above described. Better results, however, can 
 be obtained by modifying the test in the way proposed by 
 Lewkowitsch * the acetylated product is saponified with alcoholic- 
 potash, the alcohol boiled off, and the residue distilled with 
 dilute sulphuric acid, much as in Reichert's test (p. 173). Any 
 acetic acid formed by hydrolysis of acetyl derivatives is thus, 
 distilled over, and may be titrated by means of standard alkali 
 and phenolphthalein. In this way dioxystearic acid (from oleic 
 acid by alkaline permanganate) was found to form the anhydride 
 
 O TT /Q p TT r\\ rir\ \ 
 
 of diacetyloxystearic acid, p 17 TT 84 /Q ' p 2 TT 8 O 2 TO I ^' on ^ rea *~ 
 ment with acetic anhydride ; from this acetic acid was obtained 
 on saponificatioii and distillation in quantity but little below 
 the theoretical amount. A revision of the fatty acids obtainable 
 from oils and fats, &c. (as regards the amount of hydroxylated 
 constituents present), based on the acetyl test thus applied 
 would be desirable, but as yet does not appear to have been 
 made. 
 
 On the other hand, the acetylation test gives good results with 
 bodies not of an acid character, containing alcoholiform hydroxyl, 
 more especially in the case of the higher homologues of ethylic 
 alcohol : thus in the examination of waxes and bodies generally 
 that give rise to higher alcohols, the amount of hydroxylated 
 substances present may be measured by conversion into com- 
 
 * Journ. Soc. Chem. Ind, 1890, p. 842. 
 
METHYL IODIDE TEST ZEISEI/S TEST. 191 
 
 pound ethers by means of acetic anhydride, and determining the 
 permillage of potash neutralised on saponifying the product. 
 Thus pure cetylic alcohol, C 16 H 33 . OH, furnishes an acetyl deri- 
 vative, cetyt acetate, C 16 H 33 . O . C 2 H 3 O, of molecular weight 284 
 i.e., 284 milligrammes of cetyl acetate will furnish 60 milligrammes, 
 of acetic acid on saponification, neutralising Ic.c. of normal potash 
 solution containing 56'1 milligrammes of potash (KOH); whence 
 
 the "acetyl number" of cetyl acetate is ^ . x 1000 = 197'5. 
 
 If a given sample of cetyl alcohol (known to be admixed with 
 foreign matter not capable of forming acetyl derivatives) furnish 
 an acetyl derivative of which the acetyl number is found to be 98, 
 obviously about one half of the substance is cetylic alcohol. A 
 more exact value is obtained by determining the quantity of 
 foreign matter present, subtracting that from the weight of 
 acetylated product, and reckoning the acetyl number on the 
 difference as 1000, in a way similar to that adopted in the parallel 
 case of the determination of the Koettstorfer number of a saponi- 
 fiable body after correction for unsaponifiable matters present 
 (p. 171). 
 
 In the case of impure glycerol the acetylation test is employed 
 in a similar way ; 92 parts of pure glycerol would furnish 3 x 60 
 = 180 parts of acetic acid on saponification of the triacetiii 
 formed therefrom, capable of neutralising 3 x 56 '1 =-- 168 -3 parts 
 of potash. If a given sample of impure glycerol were found to 
 neutralise n parts of potash per 92 of substance, the percentage 
 
 M 
 
 of glycerol present would be TgcTTo x 100. Or otherwise, 92 milli- 
 grammes of pure glycerol would furnish acid neutralising 3 c.c. 
 of normal alkali solution ; hence if a weight w milligrammes of 
 impure glycerol furnish acid neutralising x c.c. the percentage 
 
 I x 92 
 of glycerol would be x 100 . x 3066-7. 
 
 IV W 
 
 Iii the examination of the unsaponifiable matters left 011 treat- 
 ing oils and fats, &c., with alkalies (p. 121), the substance may 
 conveniently be converted into acetyl derivative by treatment 
 with acetic anhydride, boiled with water to decompose excess of 
 anhydride, crystallised from alcohol, and examined as to the 
 acetyl number obtained on saponification of the product ; choles- 
 terol acetate (0 06 H 43 . O . C.,H 3 O) and its isomerides thus give the 
 number 135 -5. 
 
 METHYL IODIDE TEST ZEISEL'S TEST. 
 
 Compound ethers of methylic alcohol and its next higher 
 homologues do not appear to have been hitherto recognised as 
 
192 OILS, FATS, WAXES, ETC. 
 
 important constituents of natural fixed oils and fats, although 
 the corresponding compounds of the higher homologues of 
 methylic alcohol, such as cetylic alcohol, are well marked con- 
 stituents of certain cetacean oils, waxes, &c. Many essential 
 oils, however, contain constituents of analogous character 
 e.g., oil of wintergreen, largely consisting of metliyl salicylate, 
 
 ( OTT 
 C 6 H 4 -j Q Q jT . Another class of essential oils containing 
 
 the methoxyl group (O . OH 3 ) also exists, where the hydrogen 
 displaced by methyl is alcoholiform in character, and not con- 
 tained in the organic acid group CO . OH ; thus, anetkol or anise 
 oil camphor is the methylic ether of a phenoloid derived from 
 allyl-benzene, C 3 H 5 . C ( .H 4 . 0. CH.,. When substances containing 
 a methoxyl group are heated in contact with hydriodic acid, a 
 reaction is brought about whereby the methyl group is elimi- 
 nated in the form of methyl iodide, thus 
 
 Methoxyl Compound. Hydriodic Acid. Methyl Iodide. Hydroxyl Compound. 
 
 X . . CH 3 + HI CH 3 I + X . OH 
 
 A test for the presence of methoxyl in certain bodies (e.g., 
 codeine) based on this action was employed by the author as far 
 back as 1871,* the methyl iodide vapours evolved being passed 
 through a red hot combustion tube containing lead chromate, 
 so as to burn the methyl iodide, the resulting carbon dioxide 
 being absorbed by potash bulbs in the usual way. Zeisel t has 
 modified the process by determining the iodine contained in the 
 methyl iodide produced instead of the carbon ; for this purpose 
 the vapours of methyl iodide evolved are carried off by a stream 
 of carbon dioxide and received in bulb tubes containing alcoholic 
 silver nitrate, intercepting vessels, &c., being employed to pre- 
 vent vapours of hydriodic acid or iodine from passing over also. 
 On standing, diluting with water, and adding nitric acid, silver 
 iodide is precipitated, the weight of which is a measure of the 
 amount of methyl iodide formed, and consequently of the pro- 
 portion of methoxyl-containing substances present. 
 
 Fig. 33 represents the arrangement employed by Benedikt 
 and Griissner ; a few decigrammes of substance are heated with 
 10 c.c. of hydriodic acid solution of sp. gr. 1'70 in the flask A, 
 warmed by means of a glycerol bath ; a current of carbon dioxide 
 is led through the flask, the issuing vapours passing through a 
 3-bulb condenser, bulb I. being empty to condense steam, &c. ; 
 bulb II. contains water to absorb hydriodic acid ; and III., 
 red phosphorus and water to retain any traces of free iodine 
 
 * Proceedings of the Royal Society, xx., p. 8 (1871). 
 
 t Journ. Soc. Chem. Ind., 1886, p. 335; from Monatsh. f. Chemie, vi., 
 p. 989. See also Journ. Soc. Chem. Jnd., 1889, pp. 735 and 923 (Benedikt 
 and Griissner). 
 
ZEISEL S TEST. 
 
 193 
 
 evolved by decomposition of hydriodic acid by heat. After 
 passing through the bulbs the carbon dioxide, mixed with methyl 
 iodide vapour, is led into the flask B containing 5 c.c. of a 40 per 
 cent, solution of silver nitrate and 50 c.c. of 95 per cent, alcohol; 
 the safety flask D contains 1 c.c. of the same silver solution with 
 10 c.c. of alcohol, but is usually unnecessary, all methyl iodide 
 being retained in the first flask B. 
 
 Substances containing ethoxyl (O . C 2 H 5 ) and homologues are 
 similarly affected ; as the molecular weight of the alkyl iodide 
 formed increases, slight differences in manipulation become 
 necessary, principally consisting in the employment of a higher 
 temperature to enable the alkyl iodide vapours to pass over \ 
 for which reason the method is only applicable to the lower 
 members of the series and not to compound ethers of the higher 
 alcohols, such as cetylic alcohol. 
 
 Water 
 
 Water 
 
 Fig. 33. 
 
 The term " methyl number " is conveniently employed to 
 indicate the weight of methyl (OH 3 =15) equivalent to the 
 silver iodide thus formed from 1000 parts by weight of sub- 
 stance: if a weight w milligrammes of substance give n milli- 
 
 13 
 
194 OILS, FATS, WAXES, ETC. 
 
 grammes of silver iodide (equivalent to n x - - milligrammes 
 
 liOO 
 
 of CH 3 ) the methyl number, M, is obviously given by the 
 equation 
 
 AT n 15,000 
 M == - x rt -_ 
 w 235 
 
 = - x 63-83 
 
 M; 
 
 Thus, 296'3 milligrammes of oil of cloves gave 373-7 milli- 
 
 *>'""> " 
 
 grammes of silver iodide, whence M = ]r ' x 63-83 = 80-5. 
 
 *2i\J\)'d 
 
 The theoretical methyl number for pure eugenof, C 10 H r ,O , or 
 C.jH 5 . C 6 H 3 <^ Q pjT- is 91 '5 ; whence the sample examined con- 
 
 tained Q - = 87'9 percent, of eugenol. Similarly, a sample of 
 y A "o 
 
 anise oil gave the methyl number 82'8 ; since pure anethol, 
 3 H 5 . 6 H 4 . . CH 3 , corresponds with the methyl number 101-4, 
 
 82-8 
 the sample contained 77-7 = 81*6 per cent, of anethol. 
 
 The results of the various quantitative tests above described 
 may be conveniently tabulated as follows : 
 
 L VALUES RECKONED PER 1,000 PARTS OF OIL, 
 FAT, OR WAX, &c., EXAMINED, OR DEDUCED 
 FROM FIGURES THUS CALCULATED. 
 
 Total acid number = Saponification number Koettstorfer 
 number = Total acid potash permillage ( Verseifungszahl). 
 
 The weight of potash (KOH = 56-1) requisite to saponify 
 completely 1,000 parts by weight of substance, including that 
 neutralised by any free acids present. 
 
 Saponification Equivalent. The number of milligrammes of 
 substance capable of furnishing on saponificatioii fatty acids 
 sufficient to neutralise 1 c.c. of normal alkaline solution (con- 
 taining or equivalent to 56'1 milligrammes of potash, KOH) ; 
 any free fatty acids present being also included. When the 
 total acid number is K, the sponification equivalent, E, is given 
 by the equation 
 
 50,100 
 
 Free acid number = Free acid potash permillage (Saiirezahl). 
 The weight of potash (KOH = 56-1) requisite to neutralise the 
 
RESULTS OF QUANTITATIVE TESTS. 195 
 
 free acids present in 1,000 parts by weight of substance. If K 
 be the total acid number, and A the free acid number, then 
 j^ 
 
 -^ x 100 represents the proportion of free acids present per 100 
 
 of total acids, assuming the mean equivalent to be the same in 
 each case. 
 
 Ester number = Compound ether potash permillage (jEtlierzahl ; 
 EsterzaliT). The difference between the total acid number and 
 the free acid number, or value of K - A ; expressing the weight 
 of potash (KOH = 56'1) requisite to neutralise the acids formed 
 by the saponification of the compound ethers, glycerides, &c., 
 present in 1,000 parts of substance. 
 
 The yield of glycerol, theoretically obtainable from an oil or 
 fat consisting of triglycerides (with more or less free fatty 
 acids), is 0'05466 x S per cent., where S is the ester number 
 = K - A. 
 
 Insoluble acid number = insoluble acid potash permillage. 
 The weight of potash (KOH = 56*1) required to neutralise the 
 fatty acids, insoluble in boiling water, obtained from 1,000 parts 
 of substance. 
 
 This figure must not be confounded with the " Hehner 
 number " (Nekner'sche Zahl) expressing the percentage (not per- 
 millage) of insoluble acids yielded by the substance. 
 
 Soluble acid number = soluble acid potash permillage. The 
 weight of potash (KOH = 56 -1) required to neutralise the fatty 
 acids, soluble in boiling water, obtained from 1,000 parts of 
 substance. 
 
 Obviously the total acid number, K, = the sum of the insoluble 
 acid number and the soluble acid number. In practice, the 
 soluble acid number is usually best determined by subtracting 
 the insoluble acid number from the total acid number (p. 168) 
 i.e., the soluble acid number is K N, where N is the insoluble 
 acid number. 
 
 Volatile acid number volatile acid potash permillage. The 
 weight of potash (KOH = 56'1) requisite to neutralise the vola- 
 tile fatty acids obtained from 1,000 parts of substance. 
 
 The Reichert number (Reiclierf sche Zahl} being the number of 
 c.c. of decinormal alkali required to neutralise the volatile acids 
 obtained from 2*5 grammes of substance by employing the 
 particular mode of operating described by Reichert (p. 173), if n 
 be the Reichert number, the corresponding " volatile acid potash 
 
 permillage" will be n x ^ - = n x 2-244. This value is neces- 
 
 lJ'0 
 
 sarily somewhat below the true " volatile acid number" obtain- 
 able by continuing the distillation until the whole of the 
 volatile acids have passed over. 
 
 If Meissl's modification .of the Reichert test be employed 
 (p. 174), 5 grammes of substance being taken instead of 2*5, if 
 
196 OILS, FATS, WAXES, ETC. 
 
 m be the Reichert-Meissl number (Reichert-MeissVsche Zahl), the 
 corresponding volatile acid potash permillage will be m x 1-122 ; 
 as before this value will be below that corresponding with the 
 total amount of volatile acids present. 
 
 If K be the " total acid number," and V the " volatile acid 
 
 y 
 number," then - x 100 represents the percentage of volatile 
 
 iv 
 
 acids (expressed in terms of some given acid) reckoned per 100 
 of total acids present free and combined as glycerides, &c., 
 (similarly expressed) i.e., the percentage of acids that are vola- 
 tile, reckoned on the sum of the volatile and nonvolatile acids, 
 and assuming these to have the same equivalent weight. 
 
 Methyl N^lmber. The weight of methyl (CH 3 =15) equivalent 
 to the silver iodide formed from the alkyl iodide vapours evolved 
 on heating 1,000 parts by weight of substance with hydriodic 
 acid. 
 
 II. VALUES RECKONED PER 100 PARTS OF OIL, 
 FAT, OR WAX, &c., EXAMINED. 
 
 Iodine number = iodine percentage = Hiibl number (lodzald}. 
 The maximum weight of iodine capable of combining with 100 
 parts of substance ; or the weight of iodine equivalent to the 
 sum of the chlorine and iodine (or bromine and iodine) requisite 
 to saturate 100 parts of substance. 
 
 Hehner number = Ifehner'sche Zald. The weight of fatty acids 
 insoluble in boiling water yielded by 100 parts of substance. 
 
 III. VALUES RECKONED PER 1,000 PARTS OF THE 
 FREE FATTY ACIDS FORMED ON SAPONIFI- 
 CATION, OR DEDUCED FROM FIGURES THUS 
 CALCULATED. 
 
 Fatty acid neutralisation number = potash permillage requisite 
 for neutralisation of mixed free fatty acids, reckoned per 1,000 
 parts of fatty acids ( Verseifungszahl der Fettsailren). The weight 
 of potash (KOH = 56'1) required to neutralise 1,000 parts of 
 the mixed fatty acids obtained by saponification of a, fat or oil, 
 &c., and separation of fatty acids from the resulting soap. 
 
 Mean Equivalent of the Fatty Acids. The number of milli- 
 grammes of mixed fatty acids requisite to neutralise 1 c.c. of 
 normal alkaline solution (containing or equivalent to 56-1 milli- 
 grammes of potash, KOH). If N be the neutralisation number, 
 the mean equivalent F is given by the equation 
 
 _ 56,100 
 
 N ' 
 
RESULTS OF QUANTITATIVE TESTS. 197 
 
 In the case of an oil, &c., consisting wholly of triglycerides 
 (i.e., where the free acid number is so small as to be negligible), 
 the saponificatioii equivalent of the oil, E, and the mean equi- 
 valent of the fatty acids obtainable therefrom, F, are related 
 thus 
 
 E = F + 12-67. 
 
 If, however, the oil contain free acids in measurable quantity the 
 relationship is 
 
 E = F + 1 x 12 ' 67 ' 
 
 where S is the ester number and K the total acid number of 
 the oil. 
 
 The fatty acid neutralisation number, N, and the total acid 
 number of the original oil, K, are related thus 
 
 -* 
 
 IV. VALUES RECKONED PER 100 PARTS OF FREE 
 FATTY ACIDS FORMED ON SAPONIFICATION. 
 
 Iodine Number of Free Fatty Acids (lodzahl der Fettsaureri). 
 The maximum weight of iodine (or iodine equivalent to the 
 sum of chlorine and iodine or bromine and iodine) capable of 
 combining with 100 parts of free fatty acids. 
 
 If I be the iodine number of the original oil, &c., and I' that 
 of the fatty acids thence obtained, then 
 
 In the case of an oil, &c., consisting substantially of tri- 
 glycerides, so that E = F + 12-67, and where the mean equi- 
 valent of the free fatty acids lies between 250 and 330, the 
 
 F 
 
 value of lies between 1*0507 and 1-0384 i.e.. the iodine 
 .b 
 
 number of the fatty acids exceeds that of the original oil by 
 close to 4*5 per cent, of the latter value. 
 
 V. VALUES RECKONED PER 1,000 PARTS OF 
 PRODUCT OF ACETYLATION OF FREE FATTY ACIDS. 
 
 Acetyl Number = Acetyl potash permillage (Acetylzahl}. The 
 weight of potash (KOH = 56 -1) neutralised by the acetic acid 
 formed on saponification of 1,000 parts of the productof the 
 action of acetic anhydride on the 
 
108 OILS, FATS, WAXES, ETC. 
 
 The acetyl number as thus defined includes both the titratioii 
 value obtained by Benedikt and Ulzer, conveniently referred to 
 as the titration acetyl number ; and the result of applying the 
 distillation process so as to separate acetic acid, as proposed by 
 Lewkowitsch, conveniently distinguished as the distillation acetyl 
 number. Like the volatile acid number, this latter value is 
 always apt to be more or less erroneous in defect on account of 
 the difficulty of distilling off and titrating every trace of acetic 
 acid. 
 
 On the other hand, in the case of free fatty acids very little 
 dependence can be placed on the former number, although for 
 alcoholiform substances this objection does not apply. 
 
EARLIER FORMS OF PRESS. 199 
 
 4. Processes Used for Extracting, Rendering, 
 Refining, and Bleaching Oils, Fats, &c. 
 
 CHAPTER IX. 
 
 EXTRACTION OF OILS FROM SEEDS, &e., BY 
 PRESSURE OR SOLVENTS. 
 
 EARLIER FORMS OF PRESS. 
 
 THE use of olives and various kinds of seeds and nuts as sources 
 of oil has been known from at least the commencement of the 
 historic period, the earliest appliances for the expression of the 
 fluid consisting of " mills " somewhat after the fashion of the 
 primeval corn grinding hand mills, where a rounded stone was 
 made to revolve in a basin shaped stone vessel by means of 
 projecting handles, worked usually by two women seated on the 
 ground on opposite sides of the mill ; * the pulp thus produced 
 was then placed in sacking and pressed by means of planks 
 weighted with stones, very much as grape juice was expressed 
 in the earliest forms of wine press ; or a powerful lever was 
 applied, somewhat after the style of an enormous lemon squeezer. 
 Yarious forms of lever press have been in use at different times, 
 some of more complex order than the simple lemon squeezer type 
 of machine, a bent lever working a cam pressing upon the upper 
 board so as to force it downwards ; or the pressure board being 
 arranged vertically, and the sacking being compressed between 
 it and a stout vertical standard, such as the stump of a tree. 
 Double action presses of this kind, working alternately, have also 
 been constructed. A further improvement in oil pressing appli- 
 ances was the introduction of wedges between the pressure 
 boards, actuated by levers and cams or by percussion ; in the 
 latter case, the press consisted of a stout framework of beams, 
 inside of which the pressure boards and seed bags were arranged, 
 so that by hammering in wedges between adjacent pairs of 
 boards, or between the boards and the framework, the seed bags 
 were gradually compressed and finally subjected to considerable 
 
 * " There shall be two women grinding together ; the one shall be taken, 
 and the other shall be left." Luke xvii. 35. 
 
200 OILS, FATS, WAXES, ETC. 
 
 pressure. Even at the present day lever presses and wedge 
 presses of a more or less rude manufacture, but of considerable 
 practical efficiency, are still in use to a considerable extent 
 amongst those nations and in those districts to which improved 
 machinery and engineering appliances have not yet penetrated 
 e.g.] in China and some parts of Japan* whilst improved modifi- 
 cations of the older lever press, constructed with elbow levers 
 actuated by steam or water power, are employed with advantage 
 for various oil and grease expression purposes (p. 202). 
 
 Screw presses have also been extensively used, and are still 
 largely employed in the smaller factories ; but of late years 
 they have been mostly superseded by hydraulic presses in the 
 larger and more modern seed oil mills. In similar fashion 
 various forms of appliances have been successively introduced 
 and used for the crushing of oleiferous material, and otherwise 
 treating it previously to expression, so as to render the flow of 
 oil more easy and complete ; thus pairs of crushing rollers 
 working on parallel axes so as to squeeze the olives, seeds, &c., 
 introduced between them, and " edge runners " (Fig. 48) 
 arranged like a mortarmill, are more recent developments which 
 have, for the most part, superseded the older form of " stamps " 
 where mechanically worked pestles pounded the seed, &c., to be 
 crushed in large basins or mortars. 
 
 Even at the present . day a considerable amount of oil of 
 various kinds is manufactured (on the small scale) by a process 
 probably of greater antiquity still than any mechanical expres- 
 sion method. In most tropical and subtropical countries oleifer- 
 ous seeds and nuts of various kinds abound ; in order to extract 
 the oil these are simply pounded or crushed and then boiled with 
 water, the oil rising to the top and being skimmed off. Experi- 
 ence has generally guided the natives to the use of a previous 
 roasting of the nuts or beans, the effect of the heat being to 
 coagulate and solidify mucilaginous and albuminous matter, 
 rendering the after separation of the oil by means of water 
 much more easy and complete. Castor oil, for example, is thus 
 largely extracted for local use in India ; palm oil and palmnut 
 oil, until comparatively recently, were almost wholly prepared 
 by this method, all the oil shipped from Africa having been 
 extracted by a water-boiling process applied to the pulp and 
 roasted kernels ; of late years, however, it has been more usual 
 to separate the kernels from the pulp and export them untreated, 
 the oil being subsequently extracted by the ordinary expression 
 or solvent processes. 
 
 In the rural olive producing districts a considerable amount 
 of oil is prepared by a sort of combination of the two methods, 
 
 * For a description of a peculiar form of wedge press used in Formosa for 
 the extraction of olive oil, see Report by Consul Warren on the trade of 
 Taiwan, Journal Soc. Chem. Industry, 1S91, p. 556. 
 
HOT WATER PROCESSES. 201 
 
 the appliances being somewhat rude and primeval in the smaller 
 oil factories, but more modern in the larger ones. The crushed 
 pulp is washed by agitation with water, the oil as it separates 
 from the husks and rises to the top running off along with water 
 to separation tanks ; the residual wet oil-containing husks are 
 strained and boiled down to a kind of porridge or soft pulpy 
 dough, and the oil mixed with water then separated by pressure 
 in some sort of rough screwpress. In some cases the resulting 
 marc is ground up again by heavy edgerunners of granite, &c. 
 (worked by water or cattle power), boiled up afresh with water, 
 and subjected to further pressing.* 
 
 A somewhat analogous process is sometimes used in the 
 extraction of the fat or " butter " of the tallow tree (Stillingia, 
 sebifera), and other vegetable semisolid oils or fats ; the crushed 
 seeds, nuts, etc., are placed in wicker or bamboo baskets, weighted 
 with stones under boiling water, so that the melted fat gradually 
 separates and rises to the top ; the remaining oil is then- 
 extracted by pressure applied to the still hot material. This 
 method is more particularly suited to those nuts, ttc., where the 
 kernel is surrounded with a highly oleaginous pericarp, which is. 
 thus melted away by a process closely akin to that whereby 
 animal fats are " rendered " by means of steam or boiling water 
 (vide Chap, x.) Processes closely analogous in general character 
 are in use in various countries for the extraction of oil from fish 
 of various kinds (e.g., sardines), and from fish and shark livers, 
 whilst the mode of preparation of most kinds of wax is very 
 similar ; thus in the case of Chinese wax (Peh-Ia), the insect 
 producing the wax is a species of coccus (possibly several different 
 species), the young brood of which sticks to, and punctures the 
 bark and twigs of the trees (Fraxinus chinensis, Liyustrum 
 lucidum, &c.,) selected as domicile. A waxy material is secreted f 
 covering the bark, in which the insects ultimately imbed them- 
 selves, forming chrysalides. To obtain the wax, the branches 
 are scraped, some of the cocoons being reserved for breeding, the 
 rearing of the insects being a special industry like silk growing ; 
 the scrapings are heated with boiling water so as to melt off the 
 waxy matter, which is separated by skimming from the dirt, dead 
 insects, &c. 
 
 The different kinds of vegetable wax (myrtle wax, Japanese 
 wax, carnauba wax, <tc.), are mostly obtained by similarly treat- 
 ing with boiling water the berries, bark, c., in or on which 
 the material is naturally secreted or deposited, and separating 
 the melted wax as it rises. Bees' combs, &c., are similarly 
 
 * Descriptions of the appliances in use in the Maritime Alps and in 
 Southern Sicily for the preparation of olive oil are given in the Journal 
 Soc. Arts., Nov. 20, 1891, and June 16, 1893. 
 
 t As with beeswax, opinions differ somewhat as to how far the wax is 
 precontained in the sap of the trees serving as food, and how far it is formed 
 or altered by animal life action. 
 
202 
 
 OILS, FATS, WAXES, ETC. 
 
 treated to obtain beeswax, and separate it from adherent 
 honey and solid impurities. 
 
 Elbow Press. Although the older rude forms of lever press 
 and wedge press are rapidly being superseded by more modern 
 devices, more especially by hydraulic pressure, they are still by 
 110 means extinct amongst those peoples where advancing 
 
 Fig. 31. Elbow Press. 
 
 civilisation has not yet entirely improved away the ancient 
 methods and customs, whilst improved machines of these classes 
 are still in active use to some extent even in Europe and 
 America. Fig. 34 represents a form of " elbow press," largely 
 used in the United States for expressing hot melted tallow, &c., 
 from animal adipose tissue. As the screw is worked (by hand 
 
WEDGE PRESS. 
 
 203 
 
 wheel or band and pulley) the two powerful elbows are 
 straightened, and the ram depressed ; owing to the mechanical 
 nature of the action, the pressure is automatically increased 
 towards the end of the operation as the elbows straighten. 
 
 Wedge Press. An improved form of wedge press is repre- 
 sented by Figs. 35 and 36 (from Schtidler) in front and side 
 elevation, Fig. 37 indicating the longitudinal section of the lower 
 portion. Inside each of a pair of troughs, J J, is placed an 
 arranges e:it of wooden wedges and planking, B L S K B, 
 
 Press Front and Side Elevation. 
 
 together with two bags containing the crushed seed, ttc., to be 
 expressed, O O, each enclosed between cast iron frames, T P. The 
 " loose -wedges," L L, are suspended by ropes, and serve to lock 
 the whole arrangement together, the loosening when the pressure 
 is completed being effected by casting off the ropes and allowing 
 the suspended vertical beams, C C, to descend, pile-driver fashion, 
 so as to drive these wedges, L L, down ; A A, B B represent a 
 stout timber frame supporting the driving beams. The pressure 
 is obtained by similarly forcing downwards the "press-wedges," 
 
204 
 
 OILS, FATS, WAXES, ETC. 
 
 K K, by the beam drivers, D D. These drivers are raised by 
 means of stout teeth, G, projecting from a horizontal axle work- 
 ing on studs, E and F, attached to the beams respectively, a 
 system of ropes, b, c, bent lever, a, and studs, d, d, being attached, 
 so that when the ropes are pulled, either of the drivers can at 
 will be raised so as to bring it out of the reach of the teeth, and 
 keep it suspended out of action. The oil bag, being placed in 
 position between the plates, T P, of the iron frames, L, is adjusted 
 at a convenient height by means of the attached rope. The 
 drivers, D, being then set in action, the press wedge, K, is 
 forced down, and the oil bag consequently strongly compressed. 
 When the oil ceases to run and the wedge is driven home, D is 
 thrown out of action and C allowed to hammer on the loose 
 wedge (the rope attached being slackened) ; the loose wedge, L, 
 soon falls, and the bags with exhausted oilcake are then removed 
 and fresh ones substituted. 
 
 Fig. 37. Wedge Press Longitudinal Section of Lower Portion. 
 
 In some of the Marseilles oil factories an arrangement is in 
 use known as the " Estrayer Cylinder,"* the action of which is 
 somewhat akin to that of the wedge press. The apparatus con- 
 sists of two cylinders, one inside the other, of which the outer 
 acts upon the inner by means of a series of inclined planes, the 
 inner cylinder being composed of eight segments which either 
 close up tightly or separate slightly according as pressure is 
 exercised or removed by the position of the outer cylinder. 
 Screens made of esparto grass and horsehair are employed 
 instead of oilbags of the same material ("scourtins ") such as 
 are employed in other forms of press ; these are subject to much 
 less wear and tear than the scourtins, whereby an economy of 
 80 to 90 per cent, in the cost of the scourtins is effected. An 
 
 *Jonm. Soc. Chcm. Ind., 1893, p. 49. 
 
SCREW PRESS. 
 
 205 
 
 interior movement allows of the cylinder being enlarged in 
 diameter, so that the cakes can be readily removed. The appa- 
 ratus will withstand a pressure of 500 kilos per square centimetre 
 (63^ cwts. per square inch) ; half of this is as much as can be 
 safely applied to the ordinary bags without great risk of bursting 
 them. A cylinder holding 80 to 100 kilos of seeds can be dis- 
 charged and refilled in 7 to 8 minutes, the pressing occupying 
 30 to 35 minutes. 
 
 Fig. 38. 
 
 Screw Press. In districts where more modern machinery 
 has not been extensively adopted (e.g. many parts of Spain, 
 China, West Indies, South America, Africa, &c.), rude screw 
 presses are still largely in use in the comparatively small oil 
 mills where oil is expressed in much the same fashion as has 
 been practised for centuries ; these mostly work on the principle 
 
206 
 
 OILS, FATS, WAXES, ETC. 
 
 of an ordinary copying press, the sacking (or wicker or straw 
 basketing, &c.) containing the material to be expressed being 
 placed between the two plates of the press, and the screw (fre- 
 quently of wood) turned by means of a long lever so as to bring 
 the plates nearer together and express the oil, much as a wet 
 
 sponge would be squeezed in 
 handle. 
 
 copying press by turning the 
 
 Fig. 39. 
 
 Fig. 38 represents an English improved form of screw press 
 for expressing oil, tfec., from fish or similar materials where only 
 a moderate pressure is required. Motion is communicated by 
 
HYDRAULIC PRESS. 207 
 
 belts from shafting to a horizontal axle carrying a worm which 
 gears into a toothed wheel, the revolution of which raises or 
 depresses the screw passing concentrically through the wheel, 
 and consequently elevates or lowers the plunger. According as 
 a straight belt is used connected with one pair of fast and loose 
 pulleys on the axle, or a crossed belt connected with the other 
 pair, the plunger moves in one direction or the other. The 
 material to be pressed is placed in bags between loose metal 
 plates, the press itself being enclosed in a wrought iron steam 
 casing (stayed to resist pressure) provided with a steam-heated 
 door of similar construction, so that when requisite the temper- 
 ature inside the press can be elevated up to that of the steam or 
 nearly so. 
 
 Fig. 39 represents a screw press of German make. The mate- 
 rial to be expressed is placed inside the perforated cylinder B, 
 Avhich is then placed inside the cylinder, C, and mounted 011 the 
 platform, A ; the ram, D, attached to the screw, F F, being raised 
 to a convenient height. On turning the horizontal wheel, G, the 
 screw and ram descend and the material is strongly compressed 
 in the inner cylinder. The expressed liquid passes through the 
 perforations in the walls of B and runs out through others at the 
 base of C into a circular groove in the platform, A, and thence 
 by the spout to a vessel placed to receive it. A small hydraulic 
 arrangement is attached at the base, such that by turning the 
 handle, E, a piston is screwed slowly inwards, thus raising a 
 hydraulic ram on to the top of which the platform, A, is fixed, 
 and so obtaining at the end of the operation a more powerful 
 pressure than would be possible by means of the screw, F F, alone. 
 
 Hydraulic Press. The ordinary form of hydraulic press as- 
 adapted for oil expression consists of a ram raised by admission 
 of water into its cylinder, either intermittently by pumps (worked 
 by hand or power) or continuously from an accumulator. The 
 former method is preferred for many purposes, since the pulsating 
 pressure obtained by means of a pump appears to be better 
 adapted for the expression of oil from most kinds of seeds, &c., 
 than the continuous steady pressure of an accumulator. Presses 
 in which the ram works horizontally instead of vertically are 
 sometimes preferred. Fig. 40 represents a German form of 
 hydraulic press, empty before charging, and Fig. 41 the same 
 after the ram has risen. The bags are placed in the cavities of 
 the shelves or press boxes, E E E, and the ram started working. 
 As it rises each bag is strongly compressed between the base of 
 the press box containing it and the projecting lower portion of 
 the box next above it ; the oil runs out into the circular grooves, 
 F F, and thence to delivery spouts, J J, and so through the pipes,, 
 G G, to the vertical oil shoot, H, leading to the oil well or tank^ 
 The headpiece of the press, C, is supported by stout pillars, D D,, 
 to resist the strain. 
 
208 OILS, FATS, WAXES, ETC. 
 
 Fig. 40. Hydraulic Press (German Form). 
 
HYDRAULIC PRESS. 
 
 209 
 
 Fig. 41, 
 
210 
 
 OILS, FATS, WAXES, ETC. 
 
 Fig. 42 represents an English handworked hydraulic press, 
 specially suitable for light work such as that in a small olive oil 
 mill. The press being filled, the larger of two differently sized 
 pumps attached to it is worked by means of the detachable lever 
 handle, until the bulk of the oil is expressed ; to obtain a 
 stronger pressure for the extraction of the remainder, the lever 
 
 Fig. 42. 
 
 handle is then applied to a second smaller pump arranged by 
 the side of the first one, whereby a considerable increment in 
 power is obtained. 
 
 Fig. 43 represents a press arranged for working on the "Anglo- 
 American System " (vide infra). The plates are corrugated, and 
 arranged at such distances apart as just to allow of the moulded 
 cakes of hot ground seed, &c., from the kettle and moulding 
 
HYDRAULIC PRESS. 
 
 211 
 
 machine (p. 221) being introduced, preferably from each opposite 
 side alternately. Usually sixteen cakes are pressed simultaneously 
 in one press, whilst four such presses are worked together in one 
 block, all four being erected inside the same wrought iron oil 
 tank, which serves as a foundation and collects the expressed 
 oil in a most efficient man- 
 ner. The pressure employed 
 usually rises from 700 or 800 
 Ibs. per square inch at first 
 up to 2 tons at the end. 
 Fig. 44 represents the plan 
 and longitudinal section of 
 one of the press plates, Fig. 
 45 indicating the cross-sec- 
 tion. 
 
 The dimensions of the oil- 
 cakes produced vary con- 
 siderably with the size of 
 the oil mill, the system of 
 working, and the nature of 
 the seed, c., used ; the 
 cakes are always made to 
 taper somewhat so as to 
 facilitate withdrawal from 
 the cake boxes. Thus with 
 the smallest mills the cakes 
 may weigh about 3 Ibs., and 
 the dimensions may be 14 
 inches long, and 6i- inches 
 wide at one end and 5| at 
 the other, the press being 
 constructed to take from 4 
 to 6 such cakes at a time ; 
 whilst with somewhat larger 
 mills the cakes may weigh 
 about 4 Ibs., being 20 inches 
 long, and 1\ wide at one end 
 by 5J at the other. Still 
 larger cakes (up to some 30 inches long, and 10 or 11 wide at one 
 end and 7 or 8 at the other) are made in mills of greater magnitude 
 (especially when working linseed), where the scale of manufacture 
 is large enough to enable full-sized presses, <fec., to be employed. 
 Such a linseed cake generally weighs from 6 to 13 Ibs., averaging 
 about 8 or 9 Ibs., varying with the source and richness in oil of 
 the seed used ; the weight of the pressed oilcake obtained from 
 a given quantity of seed is obviously the less the larger the yield 
 of oil. When working on the older system the press usually 
 contains only four cake boxes, three such 
 
 j 
 
 UNIVERSITY 
 
212 
 
 OILS, FATS, WAXES, ETC. 
 
 by one man and a boy, including paring and storing the cakes ; 
 the presses are charged from three to six times an hour, accord- 
 ing to the seed used (cotton seed about four times, linseed five). 
 With some kinds of seed (e.g., rape and gingelly) the crushed 
 seed is worked over twice, two presses being employed for the 
 first^ expression and three for the second the press cake pro- 
 
 n 
 
 Fig. 44. 
 
 duced by the first treatment being reground before the second 
 expression, usually by means of edge runners (p. 219). Seeds 
 less rich in oil than linseed and cotton seed yield proportionately 
 heavier cakes for the same weight of seed ; as a rule, with the 
 less oleaginous seeds, &c., a better yield is obtained by pressing 
 proportionately smaller quantities at a time, so as to form in all 
 cases oilcakes of about the same thickness. 
 
 Fig. 45. 
 
 With certain kinds of seeds furnishing " salad " oils of finest 
 character, the expression is carried out in three stages : First 
 of all cold pressure is applied to a moderate extent, whereby a 
 " cold-drawn " oil is obtained of the purest quality (after refining, 
 i.e., removal of mucilage, &c.). Then the cake is again ground, 
 slightly moistened with water, and pressed a second time, using 
 somewhat higher pressure ; the oil thus obtained is cold-drawn 
 oil of second quality. Finally, the cakes are again ground and 
 
OILCAKE. 213 
 
 heated and pressed hot ; the oil thus obtained is far inferior to 
 either of the former runnings. The oilcake thus left often 
 retains a sufficient quantity of oil to render it worth while to 
 treat by some solvent extraction process (p. 231), whereby a still 
 lower grade of oil is ultimately obtained. This mode of treat- 
 ment in several stages is more especially adopted in the case of 
 higher class edible oils such as those from the arachis nut, and 
 from sunflower seed ; or in the production of the more highly 
 priced oils used for other purposes e.g., almond oil. Coarse oils, 
 such as linseed, are usually expressed but once, the pulp being 
 heated to commence with as described below, partly to render 
 the oil more fluid, and partly to coagulate albuminous matter. 
 Some kinds of seeds, however (e.g., sesame and rape), are gener- 
 ally treated in two stages i.e., pressed twice successively so as to 
 obtain two qualities of oil. When the cakes are removed from 
 the press, the cloths are stripped off and the edges pared off; 
 the parings contain a notable amount of oil, and are therefore 
 ground up and mixed with fresh crushed seed for another 
 batch. 
 
 In some cases mixtures of seeds are intentionally prepared arid 
 crushed and treated together ; in others the seed as harvested is 
 a mixture, two or more kinds of plants being grown together ; so 
 that, excepting when the seeds differ sufficiently in size to be capable 
 of separation by sifting, the oil ultimately obtained is necessarily 
 of a mixed character. Partly from causes of this kind, and partly 
 on account of subsequent adulteration, it is difficult, if not impos- 
 sible, to obtain an absolutely pure oil of any given kind in 
 commerce, the only practicable method of procuring a perfectly 
 pure sample being to hand-pick the seeds and express the oil 
 in a small press kept for such purposes. Accordingly, a small 
 press for the purpose of preparing samples of genuine seed oils 
 from time to time is an indispensable part of the equipment of 
 a laboratory where oil examinations are made by comparison of 
 the substances tested with specimens of oils and mixtures of oils 
 known to be themselves unadulterated. 
 
 Composition of Oilcake. The analyses quoted on p. 214 
 are given by Schadler.as representing the average composition of 
 oilcakes of various kinds. 
 
 According to Yoelcker, linseed cake made by the older system 
 usually contains from below 10 to about 16 per cent, of oil, and 
 cotton seed cake from 6 per cent, (undecorticated) up to 16 per 
 cent, (decorticated). Oilcakes made by the Anglo-American 
 system of working are usually more completely expressed, so as 
 to contain distinctly smaller percentages of residual oily matter 
 than cakes prepared without the aid of a moulding machine. If, 
 however, the expression be carried too far, the value of the cake 
 as cattle fodder is greatly diminished, so that in extreme cases it 
 may be rendered unsaleable. 
 
214 
 
 OILS, FATS, WAXES, ETC. 
 
 Oilcake from 
 
 Water. 
 
 Cellulose 
 
 Fatfcv anc * ^ on ~ 
 ivf tt r- nitrogenous 
 Matter. V egltable 
 ! Matter. 
 
 Ash. 
 
 Proteids. 
 
 Nitrogen. 
 
 Arachis nuts, . 
 
 11-50 
 
 8-80 ! 31-10 
 
 7-25 
 
 41-35 
 
 6-80 
 
 Cotton seed, 
 
 13-00 
 
 7'50/ 51-00 
 
 8-50 
 
 20-00 * 
 
 2-90 
 
 Rape seed, . . 
 
 10-12 
 
 9-23 41-93 
 
 6-84 
 
 31-88 
 
 5-00 
 
 Colza, . . . 
 
 11-35 
 
 9-00 42-82 
 
 6-28 
 
 30-55 
 
 4-50 
 
 Sesame seed, . 
 
 10-35 
 
 10-10 
 
 38-80 
 
 9-80 
 
 31-93 
 
 5-00 
 
 Beechnuts, . . 
 
 11-40 
 
 8-50 
 
 49-80 
 
 5-30 
 
 24-00 
 
 3-20 
 
 Linseed, . . . 
 
 10-5(5 
 
 9-83 
 
 44-01 
 
 6-50 
 
 28-50 
 
 4-25 
 
 Cress seed, . . 
 
 12-23 
 
 7-68 
 
 47-00 
 
 12-50 
 
 20-50 
 
 3-00 
 
 Camelina seed, 
 
 9-60 
 
 9-20 
 
 50-90 
 
 7-00 
 
 23-30 
 
 3-60 
 
 Poppy seed, 
 Sunflower seed, 
 
 9-50 
 10-20 
 
 890 
 8-50 
 
 37-67 
 48-90 
 
 11-43 
 11-40 
 
 32-50 5-00 
 21*00 2-40 
 
 Madia, . . 
 
 11-86 
 
 7-90 
 
 50-00 I 12-24 
 
 18-00 
 
 2-50 
 
 Hemp seed, 
 
 10-00 
 
 8-20 
 
 48-00 12-24 
 
 21-50 
 
 3-30 
 
 Palm kernels, . 
 
 9-50 
 
 8-43 
 
 40-95 
 
 10-62 
 
 30-40 
 
 4-50 
 
 Cokernuts, . 
 
 1000 
 
 9-20/ 
 
 40-50 . 
 
 10-50 
 
 30-00 * 
 
 4-50 
 
 Nordlinger has found (p. 115) from 6 to 15 per cent, of total 
 fatty matters contained in rape, poppy, earthnut, sesame, palmnut, 
 cokernut, linseed, and castor bean cakes ; of which the free acids 
 constituted fractions varying between less than T i^ and above -. 
 
 According to B. Dyer,* linseed cake, as made at the present 
 day, contains, on an average, about 10 per cent, of oil, varying 
 between 7 and 16 per cent.; of this a quantity varying between 
 one-thirteenth and one-fifth, usually consists of free fatty acid, 
 the proportion being less the purer the linseed. With some 
 freshly expressed cakes, free acid is practically absent ; on the 
 other hand, with cakes that have "heated" on keeping, the 
 greater portion of the glycerides originally present is decom- 
 posed, producing free fatty acids. Obviously, the proportion of 
 free acid formed chiefly depends on the extent to which hydrolytic 
 actions have taken place during storage. 
 
 OIL MILL PLANT. 
 
 The plant in use in modern oil mills varies somewhat in 
 details according to the nature of the material to be treated, and 
 according as the substance is intended first to be submitted to a 
 preliminary cold pressing so as to obtain a portion of the oil as a 
 product of finer quality, and then to hot pressings to obtain lower 
 grades; or to be treated hot at one operation only. Further, 
 the climate somewhat modifies the character of the process, 
 inasmuch as many substances can be sufficiently completely 
 ^expressed in a tropical climate, without any extraneous heat 
 
 * Journ. Sec. Ckem. Ind., 1893, p. 8. 
 
OIL MILL PLANT. 215 
 
 being requisite, that would require to be artificially warmed in a 
 colder climate to render the oil sufficiently fluid to exude properly 
 by pressure. Again, the scale on which the operations are to be 
 conducted, and considerations as to relative cost of labour, fuel, 
 animal power (horses or bullocks, &c.), value of oilcake when 
 expressed as far as practicable, or only to a lesser extent, and 
 whether to be subsequently treated by solvent processes or not, 
 and so forth, have also to be taken into account. In general 
 terms, however, the plant may be described as essentially con- 
 sisting of boilers and engines for steam raising for heating pur- 
 poses and power ; crushing machinery (rolls, edge runners, &c.) 
 for breaking up the material so as to rupture the walls of the 
 cellular tissues in which the oily matter is contained ; heating 
 appliances whereby the material (either as delivered from the 
 crushers, or after a preliminary cold pressure, and subsequent 
 disintegration of the partly expressed cake) is subjected to heat 
 for the twofold purpose of rendering the oil more fluid, so as to 
 facilitate expression, and of partially coagulating albuminous 
 matter so as to obtain a purer product ; hydraulic presses 
 whereby the expression is effected; and finally, filter presses, 
 refining tanks, settlers, and analogous appliances, whereby the 
 crude oil is refined and more or less completely separated from 
 watery and organic matters accompanying it when first ex- 
 pressed. What is now generally known as the " Anglo-American 
 system '"' substantially consists in the use of a selection of par- 
 ticular appliances for the above purposes conjoined with a special 
 feature viz., that the crushed material, after damping and 
 heating in a suitable "kettle," is subjected to a preliminary 
 moulding operation so as to shape and compress it into compact 
 thin blocks or " cakes," which are then expressed. 
 
 The chief advantages of this system, as employed in the plant 
 constructed by Messrs. Rose, Downs & Thompson, of Hull, are 
 claimed to be as follows, when contrasted with older systems of 
 arranging and working oil mill plant : 
 
 All the machinery is belt-driven ; whereby not only is greater 
 economy secured in the cost of gearing and greater facility in 
 erection, but also a considerable saving (about 20 per cent.) in 
 driving power. 
 
 The weight of the machinery requisite to work a given 
 quantity of seed is materially reduced, whilst the process is 
 equally applicable to all oil seeds and nuts, slight variations in 
 the nature of the rolls, &c., being made in some cases, according 
 to the nature of the seed, &c., treated. 
 
 The plant is less bulky, a great economy in space being 
 effected ; whilst a large saving (50 per cent. ) of labour in the 
 press room is also brought about. 
 
 The oil is more perfectly extracted; thus linseed cakes made 
 on the old system usually contain about 10|- per cent, of oil, and 
 
Fig. 46 
 
OIL MILL PLANT. 217 
 
 those made by the modern process only about 7 per cent., giving 
 an extra yield of oil to the extent of about 3J per cent, of the 
 weight of the cake. 
 
 The bagging requisite for moulded cakes is subjected to less 
 severe wear and tear than that used in the ordinary process ; 
 whilst the costly hair envelopes are altogether abolished. More- 
 over, the cakes produced have a better surface and fracture, and 
 are better branded when the crushing is effected by rollers than 
 when done by means of edge stones in the ordinary way. 
 
 In what is termed a " unit " mill on this system, the plant is 
 capable of crushing from 160 to 200 cwts. of linseed or rape 
 seed per day, or 155 to 190 cwts. of cotton seed. The seed 
 passes down a shoot to a series of crushing rolls (usually five in 
 number), thence by an elevator to the kettle, where it is heated; 
 a moulding machine forms it into cakes, which are placed in 
 presses (four standing in one oil tank) and expressed. A paring 
 machine cuts off the oil-containing edges of the pressed oilcakes ; 
 these are ground up under small edgestones and returned to 
 the kettle to be worked over again with a fresh batch of 
 crushed seed. One set of four presses requires three men in the 
 pressroom and about 45 actual horse power to work it. For 
 larger mills, this "unit" set of plant is simply doubled, trebled, 
 or quadrupled, and so on, each additional set requiring a further 
 addition of about 35 actual horse power. In. very large 
 installations, where more than two sets (eight presses) are used, 
 a system of accumulators is preferable rather than separate 
 pumps for each set of four presses ; accumulators at a lower 
 pressure being also used for the moulding machines, cake hoists, 
 ike., whereby a considerable saving is effected in gearing and 
 space. Fig. 46 exhibits the ground plan of a 16-press installation 
 containing the following plant : 
 
 1 High pressure accumulator. 
 
 2 Low ,, 
 
 16 Hydraulic presses, each with a hydraulic gauge. 
 
 1 Set of hydraulic pumps. 
 
 4 Sets of accumulator stops. 
 
 4 ,, seedrolls (5 rolls in each). 
 
 4 Seed kettles. 
 
 4 Moulding machines. 
 
 2 Paring ,, 
 4 Sets of elevators. 
 
 2 Sets of edgestones. 
 2 Oil pumps and cisterns. 
 4 Seed screens. 
 
 Oil cisterns to hold 200 tons of oil. 
 Engine to work up to 200 actual horse power. 
 Boilers ,, 250 
 
 together with gearing, elevators, sack lift, pipirg, &c. 
 
 Such an installation requires twelve men in the press room, 
 which should measure 66 ft. by 44 ft., the whole building being 
 
218 
 
 OILS, FATS, WAXES, ETC. 
 
 275 ft. by 44 ft., four floors. From 640 to 800 cwts. of linseed or 
 rape seed, or from 620 to 760 cwts. of cotton seed can then be 
 treated per day of 1 1 hours. 
 
 Crushing Rolls and Edge Runners. Fig. 47 represents a 
 set of four superposed rolls used as above described ; these are 
 42 inches long and 16 inches diameter, and are so arranged that 
 the seed is delivered from the hopper above (by means of a fluted 
 feed roller the same length as the crushing rolls, and a slanting 
 .shoot), between the two uppermost rolls ; having passed between 
 
 Fig. 47. 
 
 these, another curved shoot or guide plate on the other side 
 delivers it between the second and third rolls, which crush it 
 further; in similar fashion it passes by another guide plate 
 between the third and fourth rolls, where it receives the final 
 grinding. The seed is thus crushed three successive times in its 
 passage through the rolls, which are brought into contact by a 
 combination of a screw and india-rubber springs, thus giving a 
 smooth and easily regulated pressure; a much more complete 
 
EDGE RUNNERS. 
 
 219 
 
 and perfect grinding is thus effected than is possible with single 
 pairs of rolls and edgestones of the older construction. When 
 five rolls are employed in the same train, the arrangement is 
 precisely similar, four successive crushings being effected. For 
 small installations the rolls used are similar in character, but of 
 proportionately smaller size ; thus a set of four rolls (crushing 
 the seeds thrice successively), each 15 inches long and 12 inches 
 
 diameter, suffices for a steam driven mill of about half the 
 capacity of a " unit ;' and one of three rolls (giving two suc- 
 cessive crushings), each 8 inches long and 8 inches diameter, 
 for smaller sizes still, driven by bullock power. 
 
 In some oil-crushing establishments heavy edge runners are 
 preferred to rolls for certain kinds of material e.g., Egyptian 
 cotton seed and coprah. Fig. 48 indicates a belt-driven pair of 
 stones, 8 feet diameter and 20 inches thick (the face being 
 
220 
 
 OILS, FATS, WAXES, ETC. 
 
 chamfered to 16 inches); with these, about 6 tons of Egyptian 
 cotton seed may be crushed in eleven hours. The best stones 
 are made of well dressed Derbyshire gritstone, free from all 
 sandholes, cracks, shells, and other imperfections, the bedstone 
 (6 feet 6 inches diameter and 22 inches thick) being of the 
 same material. 
 
 Smaller sized stones suffice for grinding cake parings ; for the 
 4-press "unit" installation above described one set of stones 
 suffices, 4 feet diameter and 12 inches thick (face 9 inches). For 
 this purpose, two carfe plates are used instead of one, as shown 
 
 Fig. 49. 
 
 in Pig. 48, the upper one being perforated, so that the material 
 that is being ground' may pass through 011 to the lower one as 
 soon as it is sufficiently pulverised ; from the lower plate it is 
 gathered together and discharged through a shuttle at any 
 convenient point. The texture of the material thus ground is 
 regulated by the fineness or coarseness of the perforations. In 
 
KETTLE AND MOULDING MACHINE. 
 
 221 
 
 some mills working coprah, slicing or rasping machines are em- 
 ployed to cut up the material before grinding ; but so much 
 damage is done to the knives by stones mixed with the coprah 
 that this previous treatment is now but seldom employed, special 
 disintegrators being used instead (p. 225). 
 
 Kettle. The " kettle " used in the Anglo-American system 
 consists of a steam-jacketted circular castiron vessel, furnished 
 with an agitator (Fig. 49) driven by a belt; a steam damping 
 apparatus with perforated boss is fixed inside, so that the crushed 
 seed delivered into the kettle by an elevator is moistened by the 
 condensation of steam from the damping arrangement, and 
 heated up uniformly as the mass is stirred by the agitator. By 
 means of a slide at the bottom the heated substance is delivered 
 into a box supplying the moulding machine. The kettle body is 
 fitted with a wooden frame, and covered over with felt or slag 
 wool enclosed within iron sheeting to keep in the heat. In order 
 to save space, the crushing rolls are sometimes arranged vertically 
 above the kettle ; but in addition to the inconvenience caused by 
 this elevation as regards inspection and adjustment, the steam 
 from the kettle is apt to condense on the rolls and clog them ; so 
 that this disposition is generally abandoned in the newer mills, 
 the crushed seed being delivered into the kettles by means of 
 elevators (Fig. 55) or screws, and not by gravity. 
 
 In the older system of working where moulding machines 
 are not employed, the kettles used for heating the crushed seed, 
 <kc., are of similar character, but are usually not supplied with a 
 damping arrangement, as the necessity for moistening the 
 material in order to mould it better does not then arise. 
 
 Moulding Machine. The use of this appliance is the most 
 distinctive feature of the Anglo-American system ; the differences 
 between this and the older 
 method of procedure may be 
 thus stated. In the old system 
 from 11 to 16 Ibs. of seed are 
 placed by a boy in a woollen bag ; 
 the press man takes up the bag, 
 doubles it back so as to close the 
 mouth, and then places it on the 
 lower half of a " hair " or other 
 envelope (Figs. 50 and 5.1 *) 
 
 Fig. 51. 
 
 Fig. 0. 
 
 * Envelopes of vulcanised fibre, paper, and other materials are frequently 
 employed instead of the more expensive "hairs." 
 
999 
 
 OILS, FATS, WAXES, ETC. 
 
 that he has previously placed on a table in front of the press. 
 He then smooths the bag with his hand until the seed is distri- 
 buted throughout the interior as equally as possible. The envelope 
 is then closed over the bag, and the whole taken up and placed 
 in the press. This process is continued until the press is filled, 
 each cake, together with its box, occupying a vertical thickness 
 of upwards of 10 inches. When the moulding machine is used, 
 
 Fig. 52. 
 
 each cake with its plate only occupies 3 inches, thereby greatly 
 increasing the capacity of the press ; whilst the cost of labour is 
 considerably lessened. The moulding is thus effected ; the work- 
 man begins by raising a measuring frame and placing underneath 
 it a sliding frame holding a tray with a piece of woollen cloth 
 about double the length of the tray placed thereon centre to 
 centre, the ends of the cloth hanging down ; the measuring frame 
 
PARING MACHINE. 223 
 
 is now brought down on the top of the tray and cloth, and 
 crushed seed introduced from a box (fed automatically from the 
 kettle as required) until the frame is full. The frame is then 
 thrown back, the loose ends of the cloth folded over the seed, 
 and the sliding frame carrying the tray, seed, and cloth pushed 
 forward over the pressing plate. This motion of the frame sets 
 the machine at work, the pressing plate ascending and squeezing 
 the seed into a compact mass about li inch thick, after remain- 
 ing in contact with it about a quarter of a minute. The pressing 
 plate then falls, and the machine stops, enabling the press man 
 to remove the compressed cake to the press, carrying it 011 the 
 tray which is withdrawn as soon as the cake is in position. 
 During the time that the cake is being compressed, the moulder 
 is engaged in forming another one on a tray in front of the 
 machine as before ; so that cakes to the number of 240 may be 
 thus moulded in an hour. 
 
 Fig. 49 represents a moulding machine actuated by steam in 
 position with respect to the kettle ; other forms are sometimes 
 used worked by hydraulic power. 
 
 Paring Machine. The cakes obtained in the hydraulic press 
 are usually oily at the edges where the oil exuded, so that the 
 edges require to be cut off, not only to trim the cakes, but also 
 to save the oil with which they are impregnated, the parings 
 being ground up and returned to the kettle. In mills working 
 on the older systems the press cakes are generally trimmed by 
 hand ; but the simple form of machine indicated in Fig. 52 not 
 only enables the parers to do much more work in a given time,, 
 but also to cut the edges far more regularly and neatly. The 
 cake to be pared is placed with one edge over a central longi- 
 tudinal trough ; a cutter block with attached knife passes along^ 
 and shears off the portion of the cake projecting beyond a given 
 line, being driven by the excentric working a bar jointed to the 
 upper part of the frame. The other side and ends of the cake 
 are trimmed in the same way, two knives being attached to the 
 cutter block, one cutting when the motion is in one direction,, 
 the other when in the opposite direction. A screw works in the 
 trough, so that as the parings fall they are carried onward by the- 
 screw and delivered on to the upper carfe plate of a pair of edge- 
 stones (Fig. 48), whereby they are reduced to meal, which is then 
 taken up and distributed to the kettles by elevators and screws. 
 
 Supplementary Appliances. In. addition to the preceding- 
 principal appliances, various other minor arrangements are re- 
 quisite in a well appointed oil mill. Thus, screens of various 
 sizes of mesh are necessary in order to sift out stones, &c., and 
 to partially separate different kinds of admixed seeds when their 
 respective dimensions renders this practicable. Machines for 
 decorticating seeds are also employed. Fig. 53 represents cotton 
 seed treated by such a machine. A, ordinary Egyptian seed 
 
224 
 
 OILS, PATS, WAXES, ETC. 
 
 coated with "cotton filaments ; the machine cuts through the 
 husk and kernel, B ; a separator then divides the husks, C, from 
 
 Fig. 53. 
 
 the oily kernels, D, the latter being crushed and expressed, and 
 the former used for manure, Arc. Similarly, castor beans are 
 contained in an outer shell (Fig. 54, A) ; a special castor seed 
 
 decorticating machine removes the outer shell, B, leaving the 
 white kernel, C, ready for the press. Analogous machines are 
 employed for decorticating arachis nuts and for splitting coker- 
 nuts, cutting through husk, shell, and kernel at one opera- 
 tion ; and for grinding and disintegrating coprah. Pulverising 
 machines for this purpose, where the action is brought about by 
 a series of blows from rapidly moving flat beaters, answer better 
 than those where the grinding is effected between parallel iron 
 
CHEMICAL DECORTICATION. 
 
 225 
 
 discs by friction. Fig. 55 illustrates the arrangement used when 
 such a disintegrator is mounted directly over the kettle, and fed 
 by an elevator. 
 
 Dudley <fe Perry have patented a process* for chemically 
 decorticating cotton seed. The seeds, after linting, are subjected 
 to the action of gases containing nitrous anhydride and sulphur 
 dioxide, with enough air to " regenerate " the higher oxides of 
 nitrogen as fast as they are reduced. After a few seconds 
 
 Fig. 55. 
 
 exposure the fibre has changed but little in appearance, but its 
 structure is completely destroyed, so that the slightest friction 
 causes it to fall to an impalpable powder, leaving the seeds 
 perfectly smooth, and showing no signs of corrosion. A slight 
 acid reaction is perceptible on the outside, easily removable by 
 washing ; but no acid penetrates into the interior. 
 
 *U. S. Patent 344, 951. 
 
 15 
 
226 
 
 OILS, FATS, WAXES, ETC. 
 
 The crude expressed oil carries with it more or less watery 
 matter, together with mucilaginous and albuminous organic sub- 
 
 Fig. 56. 
 
 . 
 
 Fig. 57. 
 
 Fig. 58. 
 
FILTER PRESS. 
 
 227 
 
228 OILS, FATS, WAXES, ETC. 
 
 stances, requiring processes to be adopted for their removal. 
 Formerly these generally involved long continued standing, so as 
 to enable the solid impurities to form and settle, the process being 
 in some cases hastened by heating to coagulate albuminous matter, 
 or by the use of chemicals (vide Chap, xi.) In many cases, how- 
 ever, it is found that a degree of clarification sufficient to render 
 the oils immediately saleable, can be rapidly effected by simply 
 pumping the oil (either just as it runs from the press into the oil 
 well, or after heating to a temperature somewhat short of 100 C. 
 to coagulate mucilage, &c.) through a filter press ; the matters 
 thus filtered out from the oil are generally returned to the kettle- 
 
 Fig. 60. 
 
 and worked over again with a fresh batch of crushed seed, so 
 that the only products finally obtained are filtered oil and 
 pressed cake, no "foots" of any kind being made. In the case 
 of many kinds of oil this simple treatment suffices to refine the 
 oil sufficiently for most purposes ; in other cases, although subse- 
 quent refining methods are still requisite, yet on account of the 
 previous removal by filtration of a large proportion of the 
 impurities, the rest of the refining process is much facilitated 
 and shortened. Accordingly, in the newest installations suit- 
 able filter presses form an important part of the subsidiary 
 appliances employed. 
 
 Fig. 56 represents a hydraulic filter press with self-contained 
 
SEPARATION OF STEARINES. 229 
 
 engine and pump, made by Messrs. S. IT. Johnson Co., of 
 Stratford ; the plates are " recessed," so that the raised rims of 
 the consecutive plates enclose a space when they come together, 
 which finally becomes filled with the solid matters taken from 
 the material filtered. Figs. 57 and 58 represent the front eleva- 
 tion and sectional elevation of the plates, which are provided 
 with adjustable tension hooks to carry the cloths, and stay boss 
 projections so as to prevent fracture of the plates when work- 
 ing under high pressure, each plate supporting the next adjoin- 
 ing one from end to end of the machine. Figs. 59 and 60 
 
 Fig. 61. 
 
 represent a different type of plate surface (" Pyramid drainage " 
 surface), whereby washing of the cakes produced is more readily 
 effected, and the efficiency of the press largely increased in the 
 case of viscid liquids. Fig. 61 represents a miniature pattern 
 of hand-worked press for small operations and experimental 
 purposes. 
 
 SEPARATION OF SOLID STEARINES FROM OILS, &c. 
 
 Many oils when allowed to stand for some time at a sufficiently 
 low temperature deposit more or less copious amounts of solid 
 matter, sometimes becoming semisolid or buttery in so doing. 
 If the temperature be raised the whole mass melts again to a 
 fluid oil ; but by " bagging " (or straining off the liquid portion 
 through canvas bags forming rough filter-strainers) without apply- 
 ing heat, the solid matter may be collected ; and by applying 
 pressure to the " bagged " mass the remaining liquid may be 
 squeezed out. When the solid matter thus collected is sufficiently 
 granular, the ordinary method of cold pressing may be conve- 
 niently applied, the process being carried out in much the same 
 
230 OILS, FATS, WAXES, ETC. 
 
 way as that above described in the case of crushed seed pulp, 
 excepting that the pressure is applied more gradually and gently ; 
 but in many cases the solid particles are so fine that they are 
 largely forced through the interstices of the press cloth (even 
 when specially made cloths are employed) and thus lost in the 
 liquid runnings. In cases where the solid matter is present in 
 too small quantity for ordinary cold pressing filter presses may 
 often be conveniently employed to collect and consolidate the 
 solidified constituents. Thus olive oil when cooled for some time 
 deposits a considerable fraction of the more solid glycerides con- 
 tained (palmitin, stearin, arachin) ; these when collected by the 
 filter press furnish an "olive stearine," whilst the filtered oil is 
 proportionately less liable to thicken and deposit in cold weather. 
 Similarly cotton seed oil furnishes a considerable amount of 
 " cotton stearine " and a more fluid liquid oil, known in conse- 
 quence as winter oil. Animal oils, such as cod liver oil and whale 
 oil, furnish analogous stearines ; from sperm oil, spermaceti is 
 similarly separated. 
 
 In the manufacture of paraffin wax for candle making, &c., 
 certain fractions of the distillates obtained consist of mixtures of 
 hydrocarbons of different melting points, some fusing at con- 
 siderably above the ordinary temperature. On chilling such 
 " oils," by means of a suitable frigorific machine, the hydro- 
 carbons of higher fusing point mostly separate in the solid 
 form ; so that by straining the magma, or subjecting it to filter 
 pressure, the solid paraffins are separated from those yet liquid. 
 The solid matters thus obtained (paraffin scale), when refined, 
 redistilled, and subjected to further pressings at regulated tem- 
 peratures, ultimately furnish " paraffin wax " of melting point 
 the more elevated the higher the temperature at which the last 
 warm pressing has been effected, this temperature being regu- 
 lated by the nature of the material dealt with, some kinds of 
 distillates furnishing paraffin wax of higher melting point than 
 can be isolated from others. 
 
 Similar operations are gone through in various other manufac- 
 tures connected with the coaltar and mineral oil industry ; thus 
 the separation of carbolic acid from mixtures of that substance 
 and its homologues and other bodies accompanying it, is effected 
 by chilling by means of an ether or ammonia freezing machine, 
 and draining off the unfrozen liquid from the mass of crystals 
 that gradually forms. Similarly " anthracene oils," obtained at 
 a certain stage of coaltar distillation, become more or less pasty 
 and semisolid on cooling and standing ; so that by straining 
 off the liquid portions (by filter pressing or otherwise) and sub- 
 sequently expressing the remaining liquid by more powerful 
 pressure, a solid residue is ultimately obtained, consisting of 
 anthracene intermixed with other solid hydrocarbons, &c. 
 
 In the manufacture of "stearine" for candles (stearic and 
 
EXTRACTION OF OIL BY SOLVENTS. 231 
 
 palmitic acids, &c., p. 110), similar operations are gone through 
 for the purpose of isolating mechanically the solid fatty acids 
 that have crystallised into a honeycombed mass, the interstices 
 of which are filled with the liquid acids (" red oils."). Hydraulic 
 pressure of the spongy solid mass in sacking serves to effect a 
 first separation of matters respectively solid and liquid at the 
 ordinary temperature. Further " hot pressing " at a more 
 elevated temperature brings about a more complete elimina- 
 tion of liquid acids from the crude once-pressed stearine ; whilst 
 by chilling the red oils, a separation of part of the solid acids 
 dissolved in them takes place, so that by filter pressing the 
 mass fluid red oils run through, whilst an additional quantity of 
 impure solid acids is retained on the filter cloths. 
 
 Manufacture of Lard Oil, and Allied Products. At the 
 ordinary temperature of 15 to 25 C., lard constitutes a soft 
 mass consisting of two kinds of matter, one solid and one fluid; 
 it is, in fact, an exaggerated case of the mechanical separation 
 from one another of two constituents of a mixture possessing 
 different solidifying points when the temperature is maintained 
 between the two temperatures of fusion, chiefly differing from 
 the partial solidification of fluid oils on cooling and standing 
 in that the solid constituent has a higher melting point, and is 
 present in larger quantity. By placing the lard in close textured 
 woollen bags supported by wickerwork frames, and subjecting 
 it to long continued cold pressure (about 10 cwts. per square 
 inch, lasting for some 18 hours), the fluid constituent is grad- 
 ually expressed and the solid retained. The former is known as 
 "lard oil," and constitutes about three-fifths of the whole; the 
 latter is "lard stearine," and is a valuable material for the pre- 
 paration of the better kinds of soaps. 
 
 Coker butter (cokernut oil kept at not too high a temperature) 
 and other analogous vegetable semisplid oils or butters, can, in 
 like manner, be separated by pressure into a fluid " coker oleine," 
 and a solid " coker stearine ; " and in similar fashion, the more 
 fusible fats obtained in the first process for the manufacture of 
 butterine, solidify at a suitable temperature to a semisolid mass, 
 which, when carefully pressed, yields a fluid portion becoming 
 of a buttery consistence when cooled a little further, and a solid 
 stearine suitable for candle and soap making. Fats of greater 
 .solidity at ordinary temperatures, such as tallow, when similarly 
 expressed, also separate into two portions e.g., liquid " tallow 
 oil " and solid " tallow stearine." 
 
 EXTRACTION OF OIL FROM SEEDS, OIL CAKE, &c., 
 BY SOLVENTS. 
 
 Most oily matters are extremely freely soluble in benzene, 
 light petroleum distillate, ether, chloroform, carbon disulphide, 
 
232 OILS, FATS, WAXES, ETC. 
 
 and other readily volatile solvents ; so that by bringing such 
 fluids in contact with the material to be treated, the oleaginous 
 matter is dissolved, whilst the other constituents are mainly 
 unaffected. By drawing off the solution and subjecting it to 
 distillation the solvent is volatilised, and with proper condens- 
 ing arrangements can be regained with but little loss for use 
 over again, whilst the oil remains in the still. 
 
 A large number of different arrangements have been proposed, 
 and many are in actual use (more especially on the Continent) 
 for effecting this purpose, differing in various respects according 
 to the nature of the material to be treated and the solvent 
 employed, c. When the material is rich in oil e.g., when 
 palm kernels (ground to meal) are used, and similar substances 
 not already largely deprived of oil by expression, the apparatus 
 employed essentially consists of a cylinder or other closed tank 
 of boiler plate, provided with a manhole for charging and dis- 
 charging the meal, which is supported on a perforated false 
 bottom. Into this carbon disulphide is run by gravitation, or 
 pumped from a well, entering at the bottom and passing upwards 
 through the mass (or vice versa when light petroleum spirit is 
 used) the fluid dissolves out the oil, and runs away at the exit 
 either direct to the distilling apparatus, or to another similar 
 cylinder where it dissolves out more oil, furnishing a stronger 
 solution. With substances less rich in oil, such as oilcakes, 
 several cylinders are usually worked in succession, the fluid 
 percolating through each, and ultimately yielding a largely con- 
 centrated fatty solution, much as in the methodical lixiviation 
 apparatus employed in dissolving crude sodium carbonate from 
 black ash in the Leblanc soda process. The supply of disulphide 
 to the first cylinder is kept up until a sample of the issuing fluid 
 is found to contain little or no oil in solution. The connection 
 with the disulphide supply is cut off, and then by means of a 
 current of compressed air or of steam, the fluid in the first 
 cylinder is forced onwards into the second, which is then 
 coupled to the supply, becoming the first of the series. The 
 disulphide still adherent to the exhausted material in the first 
 cylinder is volatilised by means of steam, let in under the false 
 bottom (or at the top), the vapours being carried to a condensing 
 worm, where a mixture of water and disulphide is condensed. 
 The exhausted material is then discharged, the cylinder refilled, 
 and coupled to the series at the far end, so that the disulphide 
 passing in has already a considerable amount of oil in solution. 
 In this way the nearly exhausted material is fed with fresh 
 disulphide, whilst the newly refilled cylinder is supplied with 
 comparatively strong solution ; the liquid ultimately passing out 
 is led away to a distilling apparatus, where the volatile disulphide 
 is steamed off, and the residual fat finally collected. 
 
 Fig. 62 (Schadler) illustrates a set of four steam-jacketted 
 
EXTRACTION OF OIL BY SOLVENTS. 
 
 233 
 
 cylinders thus used in series. A 1? A 2 , A 3 , A 4 , are the four vessels 
 so connected by pipes D 1? D 2 , D 3 , D 4 , that the liquid passing off 
 at the top of each is supplied to the bottom of the next, A l being 
 reckoned as next to A 4 . These connections are opened and 
 closed as required by means of the cocks E I} E , E 3 , E 4 ; H 15 H 2 , 
 H 3 , H 4 are pieces of glass tubing serving as gauges. B is the 
 carbon disulphide supply pipe ; by means of the two-way cocks, 
 Cj, C 2 , C 3 , C 4 , fresh disulphide can be supplied to any one of the 
 four vessels as required. N is a steam pipe from which steam is 
 blown in to any vessel by means of the cocks O 15 O 2 , O 3 , O 4 , or 
 into the jackets through the cocks Pj, P 2 , P 3 , P 4 . F is the 
 saturated carbon disulphide main, the final solution flowing into 
 it through the cocks Q- v G 2 , G 3 , G 4 . J is a pipe into which the 
 liquid contents of the cylinders can be blown off through the 
 cocks K 1? K 2 , K 3 , K 4 . L is a compressed air main from which 
 air can be supplied to each cylinder by the cocks J\J v M 2 , M 3 , M 4 . 
 
 Fig. 02. 
 
 Suppose all four vessels filled with material to be exhausted; 
 by opening the cock C 15 connection is established between the 
 disulphide main, B, and the cylinder A 2 , through the pipe D,, 
 and cock E 2 ; disulphide then flows into A , percolating through 
 the material until the level of the cock C 2 is reached ; this is 
 set so as to shut off the disulphide main and open the connection 
 with A 3 through D 2 and E , consequently the disulphide passes 
 onwards into A r In similar fashion it passes successively into 
 A 4 through C 3 , D 3 , and E 4 , and into A l through C 4 , D 4 , and E r 
 Finally, it is drawn off through G l into the saturated solution 
 main, F, whence it flows to the still (or an intermediate store 
 tank). The progress of the extraction is judged by the colour 
 visible at the gauge, H 2 ; when the liquor is seen to be devoid of 
 colour, all available oil has been dissolved. The cock Cj is 
 then closed so as to shut off the disulphide supply, E 2 is closed, 
 
234 
 
 OILS, FATS, WAXES, ETC. 
 
 and M 2 and K 2 opened, so that compressed air enters A 9 and 
 forces the liquid contents out through the discharge pipe, j"; the 
 steam cocks O 2 , P 2 are then opened, so that the cylinder and 
 contents are heated, the disulphide vapour thus produced being 
 driven out along with some water vapour through J to a con- 
 densing apparatus. To avoid loss of disulphide vapours not 
 completely condensed but carried away with the escaping air, 
 this is made to pass through an absorbing vessel containing oil 
 which dissolves out the disulphide, forming a liquid from which 
 the disulphide is recovered by distillation when strong enough. 
 
 The cylinder A 2 being exhausted and all disulphide steamed off, 
 the manhole is opened, the exhausted charge withdrawn, and 
 a new one introduced. A 2 is then coupled on in front of A 1 and 
 the whole operation recommenced, the order in which the fresh 
 disulphide passes through the series being now A 3 , A 4 , A 1? A , 
 
 J J 
 
 1C 
 
 Fig. 63. 
 
 instead of A 9 , A 3 , A 4 , A p as at first. In similar fashion, A 3 , A 4 , 
 and A! are in turn exhausted and recharged. 
 
 Fig. 63 represents a Heyl's distillation apparatus for boiling 
 off the carbon disulphide from the fatty solution thus obtained. 
 A is a boiler-plate vessel furnished with a steam jacket, B, at 
 the base. Steam is let in at C, and the condensed water drawn 
 off at D. The disulphide solution is supplied at E, the gauge F 
 enabling the right level to be attained. L is the draw-off pipe 
 
EXTRACTION OF OIL BY SOLVENTS. 
 
 235 
 
 for the oil finally left ; J J exit leading to condenser ; H an 
 agitator worked by a handle, G ; K, a tube through which 
 steam can be led in to a circular pipe at the base inside, per- 
 forated with a number of minute orifices. The solution being 
 run in, steam is turned on when boiling soon commences, the 
 disulphide vapours being led away through J to the condenser. 
 The agitator, H, facilitates the evaporation ; at the end steam 
 is blown in through K, so as to pass through the residual' oil in 
 a multitude of fine streams, and so drive off the last traces of 
 disulphide vapour. Finally, the oil is drawn off through L, and 
 a fresh charge introduced. 
 
 Fig. 64 represents a simpler form of extraction apparatus 
 (Deitz's), consisting of an extraction tank, B, into which disul- 
 phide is pumped at the bottom from the well, A, by the pipe, h, 
 the fatty solution passing off at the top through the pipe,j^ to 
 the still, D ; the vapours here evolved are led away through 
 the pipe, ee, and condensed by the worm, C, the condensed 
 disulphide returning to the well, A. When the extraction is 
 complete, the disulphide supply is shut off and steam injected 
 into B through a coil at the base below the false bottom, d d ; 
 
 Fig. 64. 
 
 the residual fluid in B is thus forced back into A, and as the 
 heat becomes greater, the disulphide still remaining in the ex- 
 hausted mass is volatilised and carried to the worm, C, through 
 the pipe, e e. The heat is supplied to the still, D, by means of a 
 steam coil inside ; finally, steam is blown through the residual 
 oil to remove the last traces of disulphide, and the oil drawn off 
 through the discharge pipe, i. A series of these extractors is 
 generally employed, worked in couples alternately. 
 
 Carbon disulphide being heavier than water is comparatively 
 readily protected from evaporation by a layer of that fluid on 
 its surface ; on the other hand, its vapour is very - readily 
 
236 OILS, FATS, WAXES, ETC. 
 
 inflammable, and when breathed for long periods produces a 
 peculiar form of poisonous action, culminating in a species of 
 insanity. Light petroleum spirit is cheaper, but, owing to its 
 being lighter than water, cannot be so well protected from 
 evaporation and consequent danger of fire and of explosion when 
 a mixture of its vapour and air is ignited ; moreover, its solvent 
 action is less rapid. The former solvent is more generally used 
 in Europe, the latter in America. Grills & Schrceder have 
 patented the use of liquefied sulphur dioxide at 30 to 40 C. 
 under a pressure of some six atmospheres as a solvent for oils 
 for extraction purposes (Patent No. 19,948, Dec. 11, 1889) ; and 
 Lever & Scott have similarly patented the use of carbon tetra- 
 chloride, which is said to yield a purer product than carbon 
 disulphide (Patent No. 18,988, Nov. 26, 1889). 
 
 Extraction of Grease from Engine Waste, &c. The 
 greasy cotton waste, rags, &c., that accumulate where machinery 
 is largely used from the wiping of spindles and cleansing of metal 
 work, &c., and similar materials are sometimes treated with 
 solvents for the purpose of recovering the oily matter, after 
 which the material is more or less cleansed by boiling with 
 alkalies, &c., and washing, so as either to be capable of use over 
 again or to be suitable for paper making. The plant used for this 
 purpose differs little from that above described. An old boiler 
 or some similar vessel is erected, a false bottom, or grating sup- 
 plied at the base, and suitable manholes. The solvent liquid is 
 run in (from the base, if carbon disulphide, because that liquid 
 becomes lighter by dissolving fatty matters ; from the top, if 
 light petroleum spirit, for the opposite reason), so as to percolate 
 through the greasy rags, tfcc., the solution obtained being distilled 
 so as to recover the solvent and separate the grease. Owing to 
 the prevalent use of hydrocarbons in preparing lubricating oils, 
 the grease thus obtained is rarely available for soap making, 
 except when largely admixed with other fatty materials. 
 
 Fig. 65 represents an arrangement used in Lancashire for the 
 purpose of cleansing engine waste, and recovering grease there- 
 from. It consists of a vessel of boiler plate, about 9 feet high 
 and 6 diameter, with a grating, F, forming a false bottom, and a 
 gooseneck leading to a worm condenser, C ; G is a pipe supplying 
 steam, and E a cock for withdrawing grease. The grating, F, is 
 fixed about 2 feet above the bottom, and consists of a disc of 
 i-inch boiler plate pierced with numerous slightly conical holes, 
 1J inch diameter on the upper side, 1 inch diameter on the 
 under side. Some 3 tons of greasy waste are shovelled in 
 through the upper manhole, A. Coaltar benzene, boiling not 
 higher than 100 C., or benzoline (light petroleum distillate) 
 is then pumped in through A, and percolating through the mass 
 dissolves out grease, accumulating under the false bottom. A is 
 then closed and made vapour tight with lime paste. 
 
EXTRACTION OF GREASE FROM ENGINE WASTE. 
 
 237 
 
 Steam is then blown in through the pipe, G ; the vapours 
 evolved at first become condensed in the comparatively cool mass 
 of waste above, and thus serve to wash out the remaining greasy 
 solution adhering thereto ; by and bye the vapours pass over into 
 the condensing worm, C, made of 2 to 3-inch leaden or iron 
 piping, arranged so as to form 10 to 12 turns 6 feet in diameter; 
 a plentiful supply of cold water is admitted at the base of the 
 cistern in which the worm is set, passing off by an overflow pipe 
 at the top. Finally, when all volatile matters are expelled from 
 the still, and nothing but water is condensed in the worm, the 
 steam is shut off, and the waste extracted through the lower 
 manhole, B. To complete the cleansing it is boiled in a kier 
 with soda, washed plentifully with water in a dash- wheel, soaked 
 in dilute hydrochloric acid to dissolve out oxide of iron, again 
 
 Fig. 65. 
 
 washed in the dash- wheel, drained in a centrifugal machine, and 
 hung up to dry. From 50 to 60 per cent, of cleansed waste is 
 usually thus obtained from the greasy raw material. 
 
 The recovered benzene runs along with the condensed water 
 through D to a covered cistern (conveniently an old boiler), 
 where the two separate by gravitation ; the lighter hydrocarbon 
 is pumped up again into the extraction vessel for a new charge, 
 whilst the water is run away from time to time as it accumulates, 
 by means of a cock at the bottom of the cistern. The grease thus 
 recovered is generally too impure to be used directly for anything 
 but cart grease or other coarse lubricating purposes. By distil- 
 lation with superheated steam, it may be partially purified 
 and rendered serviceable for various other purposes. 
 
 Somewhat similar methods are in use for the extraction of 
 " woolfat " from raw wool (vide Chap, xv., lanolin). 
 
 Determination of Fat in Seeds, &c. When it is required 
 to determine analytically the amount of oleaginous matter 
 
238 
 
 OILS, FATS, WAXES, ETC. 
 
 present in a solid substance chiefly containing non-fatty con- 
 stituents (e.y. t crushed seeds or oilcake, the residue left on 
 evaporating milk or cream, and such like materials), the process 
 adopted is substantially an application on the small scale of the 
 general principles involved in the large-scale extraction methods- 
 above described. When the fatty matter predominates, the 
 weighed portion of substance is stirred up with ether, chloroform , 
 light petroleum spirit, carbon disulphide, or other convenient 
 solvent, and the whole poured into a weighed paper filter, the 
 undissolved matters being thoroughly washed out, and examined 
 as found requisite after drying and weighing (p. 123). When, 
 however, the fatty constituents are in the minority, the process 
 is slightly modified : the coarsely powdered material is placed 
 inside a piece of glass tubing, the lower part of which is 
 constricted and blocked with cotton wool, glass wool, or asbestos 
 fibres, &c., so as to form a strainer; the solvent is poured into 
 the tube, percolates slowly through the pulverised material, and 
 passes out at the lower end (filtered clear. by the cotton W T OO!) 
 into a vessel placed to receive it, the dissolved fatty matters 
 being obtained in weighable form by evaporating off the solvent. 
 Solution of fatty matter takes place more rapidly under such 
 circumstances if the solvent be warm; to effect this, as well as 
 to economise labour and solvent, various devices are in use, 
 
 essentially modifications of the 
 arrangement described bySoxhlet, 
 and generally known as "Soxhlet's 
 tube." Fig. 66 represents one of 
 the earliest forms, and Fig. 67 an 
 improved form, less fragile. The 
 substance to be exhausted is placed 
 .in the wider tube, A (Fig. 66), the 
 lower part of which is stopped 
 with a loose plug of cotton wool, 
 &c., or it is wrapped in filter paper 
 so as to form a cylindrical package, 
 fitting loosely into A. No con- 
 nection subsists between the inte- 
 rior of B and A except through 
 the side pipe, C. The lower end 
 of B is made to pass through a 
 perforated cork into a weighed 
 flask ; the upper end of A is 
 similarly connected with a reflux 
 condenser, preferably of Allihns 
 form, Fig. 68. A suitable quan- 
 tity of solvent being placed in the flask, on heating this (by 
 a waterbath, <fcc.) the liquid is vapourised, and passes upwards 
 through B and C to the condenser; the condensed fluid drops 
 
 
 Fig. 66. 
 
 Fig. 67. 
 
LABORATORY FAT EXTRACTION PROCESSES. 
 
 239 
 
 down into A on to the substance to be exhausted ; when the 
 fatty solution accumulates to the level, h, the siphon, D D D, 
 begins to act, and draws off the fluid into the flask. After some 
 20 or 30 siphonings, all trace of fatty matter is dissolved out; 
 by disconnecting the flask, and evaporating off the remaining 
 
 Fig. 68. 
 
 solvent, the dissolved oil is obtained. In this way the solution 
 is effected by means of solvent appreciably warmed by contact 
 with the hot vapour in the upper part of A, whilst the operation 
 goes on automatically. v 
 
 Figs. 69 and 70 represent an improved form of 
 Soxhlet tube, arranged by B. Friihling * the sub- 
 stance to be examined is placed in the vessel A, 
 Fig. 69, provided with an internal siphon ; this, 
 when weighed, is' placed inside the Soxhlet 
 reservoir, Fig. 70, connected at the top with the 
 lower end of the reflex condenser, C, and at the 
 bottom, 6, with the flask for receiving the fatty 
 solution. The weight of substance left after 
 removal of oil can thus be determined by simply 
 reweighing A. 
 
 Many other forms of extraction apparatus have 
 been devised and recommended by various experi- 
 menters for the quantitative determination of but- 
 ter fat in milk residues, and such like purposes. 
 
 Fig. 71 represents a convenient arrangement on the principle 
 of Soxhlet's tube for the laboratory extraction of oleaginous 
 matter from somewhat larger quantities of material. 
 
 Fig. 72 represents a modification useful for extracting unsapo- 
 nifiable matters from liquids e.g., the alcoholic soap solutions- 
 obtained by saponifying oils with alcoholic potash. The liquid 
 is placed in the extraction vessel, A, which contains a number of 
 glass beads ; the condensed solvent (light petroleum spirit) drops 
 into the funnel, B, rises up between the beads, washing out 
 soluble matters from the liquid, and overflows into the distilla- 
 tion flask, E, down the side tube, h.j 
 
 * Zeitsckrift fur anyewanflte Chemie, 1889, p. 242. 
 
 t Hcnig & Spitz, Journ. Soc. Chem. Imt., 1891, p. 1039 ; from Zeitsch. f, 
 angziu. (Jhertue, 1S91, 19, p. 05. 
 
 Fig. 69. 
 
240 
 
 OILS, FATS, WAXES, ETC. 
 
 Some kinds of seeds contain a notable proportion of substances 
 soluble in ether, other than fatty matters e.g., phytosterol 
 (p. 17) and lecithin (or a mixture of lecithins) ; the latter, con- 
 
 Fig. 70. 
 
 Fig. 71. 
 
 Fig. 72. 
 
 taining phosphorus, may be estimated by determining the quan- 
 tity of that element contained in the ether extract (p. 124). 
 
 The following table is abbreviated from a larger one given by 
 Schadler,* representing the usual proportions of total oily or 
 fatty matter yielded by seeds, nuts, etc., of various kinds on 
 extraction by solvents : 
 
 * [7nlerxucJtitngen der Fette Ode und Wachsarfen, 1889, p, 4. 
 
PROPORTION OF FATTY MATTER CONTAINED IN SEEDS, ETC. 241 
 
243 
 
 OILS, FATS, WAXES, ETC. 
 
 fi **&8:S3&S 
 
 .2 
 
 *wuj*SK4 
 
 r|4l4 rw ,g..O' 
 
 111 J| fPJf If IM^-H I? 
 
 >, 'cS ^^.c'^'g ^^." Qj'S'^"^ 2 SJ3 .-^ 
 
 U.a > 
 1 1 all Ill-jl" 51 
 
 
PROPORTION OP FATTY MATTER CONTAINED IN SEEDS, ETC. 243 
 
 Europe. 
 
 i- S O 
 
 J 
 
 o 
 
 ca'C . 
 
 |i 
 3 -^1 I 
 
 .3Jj3 
 
 "" OJ -^ 
 
 QHSa<lQuSsWH^S 
 
 * ^ N 02 J -fJ 55 
 
 S r^ Cfi S-l 4) J3 .! 
 
 O O fe OJ t>. o M - 
 
 M Upqpn^^ <J r 
 
 02 
 I 
 
 H 
 
 _2-* * * 
 
 a S ^= 3 
 3 ^ cr 
 
 M^ 
 
 
 w s 
 
 S g 
 
 a" ?S 
 
 o P< 
 
 o S 
 
 | i 
 
 *^3 r*" 
 
 s a 
 
 
 "" -8 'o i^ 
 
 S-s s 
 
 M ^ r - ^ ^r- 
 
 lilJh-Srfi* 
 
 ^> P W'Tr^.S o^d W 
 
244 
 
 OILS, FATS, WAXES, ETC. 
 
 ' O O >O O O O W <M O 
 
 I^Ttl^TTCOr-HCOCO"* 
 
 'OOOOOOOOO 
 
 '-fJ+J-M-fJ.^.^.^.^*- 
 
 '8i38?l >8gg! 
 
 O 
 
 II 
 
 . 
 .<U^Ta) 
 
 III! 
 
 M 
 
 
 o . 
 
 
 o^ = ^ e olijliiijiiiipir 
 
 H 02 O W W OQ ^5 d3 S ^ &q w ^ H? Q <; w ^ S <C W 
 
 
 -d ^60 g 
 
 ^i ^^ 
 
 g .ll^lfll % g l^-Sg ;5j g S4f I 
 
 '-3 gp2 -f2 | J- I g S * | || s S| 5 &|'8 
 
 S ^ft|3g^s^2S^5^J|i' e 8cr.2 f 5J 
 
 .2-| i * s s*g S^^-g |rf *^^ lisj 1 4? 
 
 , 1.1 1 ' 4 a,1 S 
 
 &0^ g o O 2P a, - 
 
 .oi^t^cg'ScjGa) 
 
 H ^j <: o o fc ^ ^ 
 
ANIMAL FATS. 245 
 
 CHAPTER X. 
 
 ANIMAL FATTY TISSUE : EXTRACTION OF OILS AND 
 FATS THEREFROM. 
 
 THE " adipose tissue " (ordinarily known as " fat ") of the higher 
 animals varies considerably in consistence in different cases, but 
 uniformly consists of a cellular or honeycomb-like structure of 
 nitrogenous non-fatty matter, the interstices of which are more 
 or less filled with the true non-nitrogenous fatty material ; 
 hence mechanical or chemical processes are requisite to separate 
 the two, just as in the case of vegetable oil-containing seeds, &c. 
 In some cases the melting point of the animal fat or oil is so 
 low that processes of expression are applicable at the ordinary 
 temperature, as in the case of certain fish livers (cod liver oil, &c.) ; 
 either the fresh organ being used, or livers that have been stored 
 until partial decomposition has set in, more or less rupturing the 
 oil cells. In other cases, the temperature requires to be raised 
 in order that the fatty matter may become sufficiently fluid to 
 exude, as in the "rendering" of tallow and lard; for this 
 purpose the adipose tissue may either be subjected alone to 
 heat, or may be steamed or boiled with water at the ordinary 
 pressure or in digesters, or may be treated with hot or cold 
 solvents for the fat, or with substances acting chemically on the 
 nitrogenous matter of the cell- walls, and thus tending to liberate 
 the fat. When the nitrogenous matter is required to be saved 
 in a solid form for manure making, the manufacture of dog- 
 biscuit, pig feeding, or other purposes according to its quality, 
 the first method may be employed, care being taken to prevent 
 burning by overheating if free fire is used ; or the fatty tissue 
 may be heated in a closed vessel by means of steam and a 
 minimum of water ; or it may be minced fine and placed on 
 sloping trays in a chamber heated by steam, so that the' fatty 
 matter gradually runs away from the solid nitrogenous cellular 
 tissue. If, on the other hand, the saving of the nitrogenous 
 matter in the solid form is of no consequence, the comminuted 
 fat may be heated for some time with water in a digester under 
 4 or 5 atmospheres pressure ; by this means a considerable pro- 
 portion of the nitrogenous tissue is gelatinised and dissolved as a 
 sort of glue, utilised either as such or for manure making. In 
 extracting fat from bones this process is generally employed; 
 on the other hand, when the carcases of slaughtered horses, &c., 
 are treated, long continued boiling in open pans under ordinary 
 
246 OILS, FATS, WAXES, ETC. 
 
 pressure is more usually adopted, the fat being skimmed off from 
 time to time as it rises. Sometimes a small quantity of soda, or 
 of sulphuric acid, is added to the water with which rough fats 
 are boiled, with the object of attacking the cell walls, and 
 liberating the fatty matter more rapidly. A certain amount of 
 loss by saponification takes place when soda is thus used (unless 
 the impure soap formed is collected and utilised) ; whilst hydro- 
 lysis of glycerides (p. 7) is apt to be brought about by the 
 action of acid, so that the resulting fat contains free fatty 
 acids interfering with its use for certain purposes e.g., the 
 manufacture of some kinds of lubricants. In the Mege-Mouries 
 process for preparing oleomargarine of best quality (vide Chap, 
 xiv.), a sort of artificial digestion of the nitrogenous matter 
 is brought about, chopped suet being warmed with minced 
 sheep's stomachs and a little potassium carbonate, so as to pep- 
 tonise the albuminoids of the tissue and liberate the fatty 
 matter; a much purer product is thus obtained, owing to the 
 comparatively low temperature employed (about 45 C.) than is 
 possible with any boiling process. 
 
 Rendering of Fatty Tissues by Dry Fusion. W 7 hen rough 
 fats from the ox, sheep, pig, &c., are minced fine and gently 
 heated, the melted grease gradually runs away from the solid 
 cellular tissue. In the manufacture of butter substitutes (oleo- 
 margarine) finely chopped beef suet is sometimes thus heated to 
 a temperature only just sufficient to partially fuse the fatty 
 matter, and the runnings subsequently treated so as to separate 
 the mass into a solid stearine, and a buttery mass largely con- 
 sisting of oleine. Owing to the low temperature employed, 
 50 to 55 C., noxious vapours are not evolved at all during the 
 process, especially as none but the freshest fatty matter is used, 
 any admixture of slightly tainted material greatly depreciating 
 the value of the product. 
 
 When higher temperatures (above 100 C.) are used, the rough 
 fats being heated over a free fire with continual stirring, the 
 moisture present is evaporated, and the nitrogenous tissue 
 gradually dries up and shrivels ; the oil cells are thus ruptured, 
 and the melted fat escapes. The heat usually causes a con- 
 siderable amount of decomposition of the tissue, leading to the 
 evolution of most atrocious smells, especially if the fatty tissue is 
 stale, tainted, or partly decomposed. By straining off the melted 
 fat, and pressing the residual " greaves ' ; or " cracklings," in such 
 a press as is indicated by Figs. 34, 38, or 39 (pp. 202, 205, 206), the 
 majority of the fat present is extracted ; if the cracklings are in- 
 tended as food (for dogs or pigs) the presence of a little residual 
 fat therein is an improvement rather than otherwise; if required, 
 a further amount of grease can be extracted by boiling with dilute 
 sulphuric acid, or heating in a pressure vessel, so as partly to 
 gelatinise the solid animal matter and liberate the remaining fat. 
 
RENDERING BY DRY FUSION. 247 
 
 An improved dry heat rendering arrangement has been 
 patented by Merryweather & Sons, in which the materials to 
 be rendered are placed in a steam jacketted pan into the jacket 
 of which superheated steam is passed, so that the danger of 
 " burning " the fat is greatly lessened, whilst the heat can be 
 much more easily regulated ; accidents from fire through the pan 
 contents suddenly foaming over can be minimised, whilst fuel is 
 economised, and the wear and tear of the pan lessened. 
 
 The blubbers of the whale, seal, dugong, porpoise, and other 
 cetacea, and the livers of the shark, cod, dogfish, kulp, and other 
 fish, are generally allowed to remain in baskets or other perfor- 
 ated vessels at the ordinary temperature for some time, so that a 
 first running of purer oil may be obtained spontaneously ; later 
 on heat is applied to facilitate the extraction. Formerly " boil- 
 ing down " whale blubber for train oil was an operation per- 
 formed on the whaling vessel shortly after the capture of the 
 animal ; at the present day the blubber is more frequently 
 brought ashore (either to port or to fishing stations for the pur- 
 pose) for treatment. A certain amount of oil is generally 
 collected by the simple process of placing the cut up mass in 
 racks, from which the oil drips gradually into casks ; later on 
 decomposition commences, and the oil then exuding is inferior in 
 quality. Finally, the remaining mass is "boiled" i.e., sub- 
 jected to dry heat to extract the remaining oil. In some cases 
 wet steam heating (infra) is applied at first, whereby the process 
 is much shortened. 
 
 In order to mitigate the nuisance arising from the emanation 
 of foul smelling vapours during the dry process for rendering 
 fats, (fee., various contrivances have been tried from time to 
 time, such as passing the evolved vapours through layers of 
 charcoal or through scrubbers containing alkaline or acid solu- 
 tions, *&c. ; the only really effective method, however, depends on 
 the destruction by combustion of the malodorous emanations, 
 the fumes and vapours evolved being collected by a hood or pipe 
 and made to traverse the fireplace of one of the works' boilers ; 
 or otherwise similarly consumed. Preferably the vessels are 
 enclosed in a sort of casing, so that the vapours evolved are led 
 away by means of a pipe to the spot where they are consumed, 
 an indraught being maintained by means of a fan or steam jet. 
 
 Rendering of Fatty Tissues by Heating with Water or 
 Steam under ordinary Atmospheric Pressure. The ex- 
 traction of fatty matter from adipose tissue is often greatly 
 facilitated by mincing the tissue fine, or crushing it between 
 rollers, and then placing it in a pan with water, the temperature 
 of which can be raised as required, either by injecting wet steam, 
 employing a dry steam coil or steam jacket, or by means of free 
 fire, &c. For the preparation of oleomargarine a process of this 
 description is often used as the first stage, selected fresh fat of 
 
248 OILS, FATS, WAXES, ETC. 
 
 highest quality being chosen, and the temperature being kept as 
 low as possible, consistent with the melting out of the more 
 fusible constituents which rise to the top and are skimmed off. 
 Latterly, a higher temperature is used, whereby a more solid fat 
 (when cold) is obtained; and, finally, the heat is raised to 100* 
 to extract the last portions of fatty matter. This, however, is 
 rarely completely effected unless either a higher temperature 
 (under pressure) is applied so as largely to gelatinise the nitro- 
 genous tissue, or sulphuric acid is added so as to break up the fat 
 cells by its solvent action on the nitrogenous matter. In the 
 extraction of fat from bones boiling in open pans for some 
 twenty-four hours with simple water is often employed, the 
 bones being broken up into lumps so as to expose the fat cells 
 as much as possible; the fat is skimmed off as it rises, and the 
 liquor utilised for the preparation of size ; a larger yield of fat, 
 however, is obtained when high pressure vessels are employed 
 (vide infra, p. 251). 
 
 Various fish oils are extracted by similar processes ; thus, in 
 the preparation of cod liver oil, the fresh healthy livers are first 
 placed in open barrels, so that a certain proportion of oil 
 spontaneously exudes ; after a while they are transferred to 
 metal pans, heated gluepot fashion in a larger external hot 
 water vessel, or by a steam jacket ; here a further separation of 
 oil ensues, of second quality. Finally, the livers are boiled with 
 water, when a still lower grade separates. According to the 
 temperature employed in the first heating, the quality of the 
 second runnings varies ; when 40 to 50 C. is not exceeded, a 
 much finer oil is obtained than when 75 to 80 is reached, more 
 nearly approximating to the first runnings (" cold drawn" oil), 
 but possessing a more marked brownish yellow tinge. Oil 
 extracted by boiling with water is usually of a more or less deep 
 brown hue. 
 
 According to P. Moller, of Christiania,* the fishy unpleasant 
 flavour of cod liver oil is largely due to the absorption of oxygen 
 during its extraction, and may consequently be to a considerable 
 extent avoided by rendering the livers in vessels from which all 
 atmospheric air is excluded by means of a current of indifferent 
 gas, such as hydrogen or carbon dioxide. 
 
 Several species of fish of the herring and sardine class are 
 employed in different countries as sources of oil, the simplest 
 method of procedure adopted being to slice and mash the fish, 
 and pour boiling water over the mass, which is then stored 
 in barrels, &c., for some time ; decomposition sets in, and the fat 
 tissues become disintegrated, so that the oil floats up and is 
 skimmed off at intervals, A more systematic method, adopted 
 in the case of menhaden oil and other fish oils extracted by 
 means cf modernised appliances, consists in thoroughly boiling 
 * English patent, No. 13,803, 1890. 
 
BOILING PROCESSES. 249 
 
 or steaming the fish (whole and unbroken, or sliced and mashed), 
 and then subjecting to comparatively gentle pressure ; the first 
 runnings thus obtained are considerably superior to the second 
 grade, prepared by boiling or steaming the residue a second time, 
 and pressing again with stronger pressure, and at a higher 
 temperature; the screw press heated by steam, shown in Fig. 38, 
 p. 205, is well adapted for this process. The ultimate residue is 
 utilised for manure : after being squeezed as dry as possible, 
 preferably by hydraulic pressure, the residual solid mass is 
 broken up and allowed to ferment, dried somewhat, ground and 
 .sifted, and finally dried further, so as to form a powder 
 convenient for transport. Large quantities of fish manure are 
 thus prepared from the residues of the extraction of oil from the 
 " menhaden " or " porgie " at numerous places along the North 
 American Atlantic coast. 
 
 D'Arcet's sulphuric acid process for rendering tallow consists in 
 melting the adipose tissue with from one fifth to half its weight 
 of water, and a few per cents, of sulphuric acid, keeping the 
 entire mass boiling until the separation of fat is completed, the 
 heat being applied by means of a free fire, by a steam jacket, or 
 by directly blowing in steam ; in the latter case, somewhat less 
 water is originally added, with a proportionate increase in 
 sulphuric acid strength, to compensate for dilution by condensa- 
 tion of steam. When this method is adopted, the vessel may be 
 simply constructed by lining a cask or tank with sheet lead; 
 whereas, for boiling over free fire, a copper vessel must be 
 employed, iron being too readily attacked by the acid. In 
 Evrard's process the sulphuric acid is replaced by caustic soda ; 
 the evolution of foetid smells is thereby lessened, but loss is apt 
 to be occasioned through the formation of soap by the action of 
 the soda on the fat. 
 
 When rough fats are rendered in a soapery for use therein, a 
 simple method of procedure is to place the tissues to be treated 
 in one of the soap "kettles" or "coppers" (Chap, xix.), and blow 
 wet steam through the mass ; a large proportion of the fatty 
 matter is then melted down, and is removed by skimming. To 
 extract the remainder, weak alkaline leys from other operations 
 are run in, and the whole boiled up with steam so as to convert 
 the fat into a kind of impure soap solution, which is run off and 
 worked up along with other inferior material in the manufacture 
 of lower grades of scouring soaps. 
 
 When partly decomposed tissues, (fee., are boiled to extract fat, 
 much the same kinds of noxious smells are apt to be evolved as in 
 the dry process (p. 247); accordingly, when it is essential to avoid 
 nuisance, it is usual to box in the pans, and lead the evolved 
 vapours to a condensing chamber where the steam is condensed, 
 the remaining air, itc., being drawn off to the main chimney 
 stalk of the works, by which means a continuous indraught is 
 
250 
 
 OILS, FATS, WAXES, ETC. 
 
 set up, and outward leakage of malodorous vapours avoided. In 
 the case of putrid materials, the mere dilution of noxious vapours 
 with the chimney gases thus brought about is not always 
 sufficient, and destruction of smell by fire must be resorted to in 
 order to avoid nuisance in certain situations, such as crowded 
 towns, and the like. 
 
 Hendering under Increased Pressure. Of all processes 
 
 Fig. 73. 
 
 for obtaining fats from their natural animal sources this one is 
 the most extensively used, as the higher temperature attained 
 leads to the more complete gelatinisation of nitrogenous tissue, 
 and consequently to the more thorough separation of fat. Fig. 73 
 represents a digester employed in Wilson's process for rendering 
 
RENDERING UNDER PRESSURE. 251 
 
 tallow and lard ; a series of these is generally worked together, 
 each of 10,000 or 15,000 gallons capacity, or even more. In 
 large American slaughterhouses (e.g., at Chicago, St. Louis, 
 Cincinnati, <tc.), each digester is kept for the production of one 
 kind of fatty matter only, the adipose tissue being usually 
 worked up therein within a few minutes after slaughtering ; 
 hence injury through use of stale or decomposed fatty tissue is 
 avoided, and extremely uniform grades of lard and tallow ob- 
 tained, the various portions of the carcases being separately 
 treated in different vessels according to the part of the body 
 employed. The boiler is provided with a false bottom ; a dis- 
 charging orifice, E, covered when required by a plate, F, raised 
 or lowered as required by the rod, G, passing through a stuffing 
 box ; an internal steam coil at the base fed with steam from an 
 ordinary boiler by the pipe, "V, and steam cock, B ; and a series 
 of draw-off cocks at the side, TJ, p, j), p, p, R. A safety valve, O, 
 is also provided, and a manhole at the top, K. The discharging 
 valve being closed by lowering F, the fat to be rendered is 
 introduced through the manhole, K, until within 2 to 2^- feet of 
 the top ; the manhole being closed steam is admitted through 
 the cock, B, until the desired pressure is obtained (usually 3 to 
 4 atmospheres). Much water condenses during the heating up ; 
 if requisite this is drawn off from time to time by means of the 
 lowest cock, U, the progress of the fusion being tested and 
 regulated by opening the top cock, R, so as to see whether steam 
 only escapes, or melted fat. After ten to fifteen hours the steam 
 supply is shut off and the excess pressure relieved by opening 
 the safety valve ; the whole is then allowed to remain at rest 
 <i while so that the fatty matter and water may separate, when 
 the former is drawn off into coolers through the side cocks, 
 Pi Pi Pi Pi an d the latter through the lowest cock, U. The aque- 
 ous liquor contains much nitrogenous 'matter in solution and is 
 utilised for manurial purposes. The boiler is finally discharged 
 of solid contents by raising the valve, F ; the matters ejected are 
 collected in a tub, T, and if not completely freed from fat are 
 returned to the boiler and worked over again with the next 
 charge. 
 
 Extraction of Fat from Bones. Before bones are treated 
 for the preparation of manure, animal charcoal, &c., the fatty 
 matters contained therein are usually more or less completely 
 extracted by one or other of a variety of processes ; of these the 
 simplest consists in boiling the bones (preferably crushed into 
 coarse fragments) with water heated by a steam jet or otherwise; 
 the fatty matters are thus melted out and obtained by skimming 
 off as they rise to the top of the water. A large fraction of the 
 total fatty matter is thus left behind in the osseous tissue through 
 incomplete removal ; a better yield is obtained when the heating 
 is effected under increased pressure in a digester, the steam then 
 
252 
 
 OILS, FATS, WAXES, ETC. 
 
 penetrating into the minute cavities and more completely dis- 
 placing the melted fat ; moreover, the nitrogenous cell wall con- 
 stituents are usually gelatinised to a greater extent than is 
 effected by open pan boiling, so as to facilitate the escape of fat ; 
 for this same reason, however, the bones thus treated are ren- 
 dered poorer in organic constituents, and, therefore, less suitable 
 as manure or for animal charcoal making ; on the other hand, 
 more soluble organic matter, suitable for glue making or for 
 manure, tfcc., is obtained in the watery liquor. 
 
 Various forms of digester are in use ; a useful variety consists 
 of a vertical wrought iron barrel or cylinder some 6 feet long and 
 
 3 feet 6 inches diameter, slightly 
 tapering at each end, and fitted with 
 flanges to which iron discs can be 
 bolted (Fig. 74). The upper plate, 
 b, serves as lid, so that when re- 
 moved fresh bones can be introduced ; 
 the lower one, .c, is slightly curved ; 
 when removed the boiled bones are 
 discharged. A charge of 2 to 2J tons 
 of crushed bones being introduced the 
 plates are bolted on steamtight, the 
 operation being facilitated by fasten- 
 ing the plates on with hinges so that 
 they are virtually doors. Steam at 
 3J to 4 atmospheres pressure (56 to 
 65 Ibs.) is then introduced for about 
 three-quarters of an hour ; w r hen shut 
 off the pressure is relieved, and the 
 whole allowed to stand for half an hour, when the condensed 
 water and melted fat are drawn off through a tap, /, in the 
 bottom plate or door. This door is then opened and the ex- 
 hausted bones removed, after which a fresh charge is intro- 
 duced and worked off as before. Even when operating in this 
 way a certain amount of fatty matter is still left in the bones ; 
 to avoid this, in some Continental factories solvents are used 
 (carbon disulphide, benzene, light petroleum distillate, &c.), the 
 mode of treatment being very much the same as that adopted 
 for the similar extraction of grease from vegetable marcs, engine 
 waste, &c. (vide p. 236) ; the crushed bones being placed in suit- 
 able vessels into which the solvent is run, preferably traversing 
 several in succession, and the fatty solution being subsequently 
 distilled to recover the solvent and obtain the grease. 
 
 Owing to the peculiar texture of bone as compared with 
 vegetable seeds, even this mode of treatment does not produce 
 a perfect solution and removal of all the fatty matters present ; 
 in order to obtain a larger yield, various modifications of the 
 plant have been introduced, whereby the solvents are made to 
 
 Fig. 74. 
 
EXTRACTION OF FAT FROM BONES. 
 
 253 
 
 act on the crushed bones in the form of vapour. In one form of 
 apparatus, this is effected under increased pressure (after pump- 
 ing out all atmospheric air from the vessel employed), so that the 
 solvent enters thoroughly into the pores of the bone fragments, 
 and being attracted to and condensed by the fatty matters, forms 
 a fluid solution of fat which exudes and runs down to the 
 bottom, and is subsequently distilled (Seltsam's process). In. 
 
 another form the crushed bones are permeated with a mixture 
 of steam and vapour of solvent, which is condensed by a worm 
 so as to drop down again upon the bones and percolate through 
 them to a false bottom, where the solvent is again volatilised 
 by a steam coil, the whole arrangement being not unlike that 
 used for cleansing engine waste (Fig. 65, p. 237). Fig. 75 re- 
 presents Leuner's apparatus arranged on this principle (Schadler). 
 
254: OILS, FATS, WAXES, ETC. 
 
 The crushed bones are placed in A above the perforated false 
 bottom, B. C is a steam pipe, by means of which the bones are 
 steamed as a preliminary, the surplus steam escaping through 
 the exit pipe D. After steaming, water and benzene are run in 
 from the reservoir, F, into the space under the false bottom, and 
 heated up by the steam coil, P. The evolved vapours are con- 
 densed in the worm, K, and at first run back over the bones 
 through the cock, L, the vapour passing upwards to the worm 
 through J, and the condensed liquid being divided into separate 
 streams by the spreading plate, O. After some time the cock, 
 G, is opened, so that the condensed liquid runs into the reser- 
 voir, F, instead of flowing back into A. When all the solvent 
 has been volatilised, nothing but water condenses in the worm, 
 which is known by means of a sampling cock attached to J ; the 
 draw off cock, E, is then opened, and the watery gelatine solu- 
 tion and oily matter run off into a suitable separating receptacle ; 
 A, is then discharged through a manhole and refilled, and the 
 whole operation repeated. 
 
 Another method of operating is to introduce the crushed bones 
 into a sufficiently strong false-bottomed vessel, from which the 
 air is then pumped. Benzene, carbon disulphide, or other con- 
 venient volatile solvent is then run in until the vessel is filled, 
 whereby the solvent fluid is driven thoroughly into the pores of 
 the bone tissues. By drawing off most of the fluid and then again 
 exhausting, the solvent is to a great extent volatilised ; and by 
 readmitting* air the vapour is again condensed by the increased 
 pressure so as to wash out the fat solution from the bone frag- 
 ments. This solution runs down to the base of the vessel, and 
 is ultimately distilled by working the air pump, leaving the fat 
 whilst the vapour of the solvent pumped out is condensed by 
 cooling and used over again.* 
 
 CHAPTER XI. 
 
 REFINING AND BLEACHING ANIMAL AND VEGETABLE 
 OILS AND FATS, WAXES, &c. 
 
 SUSPENDED MATTERS. 
 
 OILS and fats as obtained by many of the processes in ordinary 
 use contain various impurities partly in suspension, partly in 
 solution. Of these the most objectionable are the gummy 
 
 * For further details of bonefat extracting plant vide Schadler, Technologic 
 der Fette und Oete, 2nd Edition, edited by Lohmaun, p. 9_'8, et. seq. Also 
 for Seltsam's process, Journ. Soc. Chem. Ind., 1882, p. 112. 
 
CLARIFICATION. 255 
 
 mucilaginous or albuminous matters which generally accompany 
 expressed oils and rendered fats to a greater or lesser extent, 
 because unless speedily removed they are apt to undergo 
 fermentative or putrefactive changes, which not only induce 
 hydrolysis of the glycerides (p. 10) but also charge the oil with 
 malodorous bye-products of decomposition, rendering the oil 
 "rancid." Substances of this kind are usually chiefly in suspen- 
 sion in the oil ; so that by passing the freshly expressed oil 
 through a filterpress (p. 228), a considerable proportion of the 
 suspended matter is removed, rendering the oil in many cases 
 sufficiently clear and free from visible impurities to be at once 
 saleable. Sometimes, however, the suspended matter is present 
 in a form where filtration alone produces only an insufficient 
 amount of purification, and where even prolonged standing does 
 not efficiently clarify the oil by subsidence ; this happens more 
 especially when the mucilaginous matter is disseminated through- 
 out the oil in a sort of highly diluted jelly-like condition, some- 
 what analogous to colloidal gelatine or thin starch paste, where 
 the constituent particles are mostly too fine to be stopped by 
 means of ordinary porous filtering media, or to gravitate rapidly. 
 In such cases special mechanical or chemical treatment must 
 be resorted to in order to coagulate the mucilaginous matter : 
 sometimes simply heating produces this effect, the albuminous- 
 substances being solidified and coagulated somewhat like white 
 of egg. This is conveniently effected by blowing steam through 
 the oil by means of a fine rose jet ; the condensation of water 
 facilitates the action as the coagulated albuminous matter attracts 
 moisture and becomes increased in bulk and deposits more readily 
 as a flocculent precipitate on standing. The addition of small 
 quantities of various chemicals often produces an analogous effect ; 
 thus a small percentage of sulphuric acid, or of concentrated zinc 
 chloride solution (sp. gr. 1*65), well agitated with the oil causes 
 on standing the gradual deposition of mucilage, along with most 
 of the acid, the rest being subsequently removed by agitation 
 with water. Oils containing resinous matter (e.g., cotton-seed 
 oil) as well as mucilage are preferably refined by similar treat- 
 ment with alkalies, the resin being thereby dissolved out and 
 removed as well as vegetable mucus. 
 
 The purely physical action exerted by particles of suspended 
 matter as regards attracting the colloidal mucilage often serves 
 to remove the latter ; thus clay, fuller's earth, sand, particles of 
 oilcake, powdered charcoal, and similar materials, when well 
 agitated with the oil or melted fat to be treated, tend to unite 
 with the mucilage, in such fashion that by allowing the whole to 
 subside, or by filtering it, the whole of the suspended matter is 
 simultaneously separated.* 
 
 * In many cases a very satisfactory degree of purification is readily 
 effected by b mply adding to the mucilaginous oil, as it runs from the press, 
 
256 OILS, FATS, WAXES, ETC. 
 
 In certain cases the addition of chemicals that combine with 
 the albuminous matter forming precipitates answers the same 
 purpose ; thus oakbark infusion and other forms of tannin solu- 
 tion, when well agitated with the oil to be treated, cause the 
 formation of insoluble tanno-gelatinous matter which precipitates 
 on standing carrying down with it most of the colloidal suspended 
 matter. Various metallic salts (copper sulphate, manganese sul- 
 phate, lead acetate, <fec.) are sometimes used with a similar object. 
 A process of this kind sometimes used for cleansing rancid tallow 
 is to boil up with a small quantity of soda ley ; the melted 
 fat is removed from the soap produced by ladling off, and then 
 boiled up with a weak solution of alum ; after settling, the 
 purified tallow is again run off and heated by itself to 150 C. 
 and upwards, whereby it becomes greatly whitened and har- 
 dened.* 
 
 Dissolved Matters. Other impurities are dissolved in the 
 oil, and the complete separation of these is in many cases imprac- 
 ticable. Resinous matters are the commonest impurities found 
 in solution ; these are generally of a feebly acid character, so that 
 agitation with small proportions of alkaline solution removes the 
 larger part or even the whole of these. For this purpose soda, 
 potash, milk of lime, and calcined magnesia are employed in 
 different instances ; carbonated alkalies and alkaline earths 
 (carbonate of soda, lime, &c.) usually act only imperfectly. 
 When the proportion of resin is at all large the saponaceous 
 compound formed sometimes separates only with difficulty from 
 the clarified oil ; agitation with saline solutions (sulphate of soda, 
 or common salt, <kc.) in such cases generally causes the mass to 
 separate into three layers on standing : the lowest one a watery 
 fluid containing chiefly inorganic salts in solution ; the upper- 
 most, clarified oil ; intermediately, a more or less frothy spumous 
 mass of " foots." Frequently this contains so much unaltered oil 
 mechanically entangled as to be a highly valuable material for 
 soapmaking, the resinous soap also present usually not interfering 
 with this application. 
 
 Bonefat extracted by boiling processes generally retains in 
 solution phosphate of lime and other calcium salts to an extent 
 greatly interfering with the preparation of soap from this mate- 
 rial : boiling with dilute sulphuric or hydrochloric acid converts 
 the lime into calcium sulphate or chloride, and completely 
 removes these inorganic dissolved impurities, the operation 
 being very simply performed by placing the fat in a tank lined 
 
 a small quantity of cake parings ground up by edgestones (p. 219), and then 
 passing the whole through a lilterpress ; the residue left in the filterpress 
 is returned to the kettle and worked up with fresh crushed seed, &c. 
 Still better clarification may often be effected by heating the mixture of 
 oil and parings, so as to coagulate albuminous matter, and then passing 
 through the filterpress. 
 
 *0il Trade Review, Oct. 1884. 
 
DISSOLVED IMPURITIES. 
 
 257 
 
 with sheet lead along with a sufficient quantity of highly diluted 
 acid, and blowing wet steam through the mass so as to agitate it 
 thoroughly. Sulphuric acid has the advantage of cheapness and 
 of acting less on the lead than hydrochloric acid ; on the other 
 hand insoluble calcium sulphate forms and is deposited, whereas 
 calcium chloride, being readily soluble, does not separate in the 
 solid form. 
 
 Certain oils when chilled deposit the less readily fusible con- 
 stituents as " stearines " (p. 110) ; on subjecting these to nitration 
 and pressure, an oleine practically free from suspended albu- 
 minous matters generally results, any such impurities being 
 mostly retained along with the stearine. A partial separation 
 of stearine by allowing to stand at a relatively low temperature, 
 is accordingly sometimes resorted to as a means of clarifying and 
 refining oils, more especially the more expensive edible oils 
 (" salad " oils) ; the thickened mass being filterpressed whilst 
 chilled, or on the small scale being strained through rough filters 
 of moss, cotton wool, charcoal, &c., placed between the perforated 
 bottoms of two boxes, one just fitting inside the other. Oils 
 that have been thus treated are sometimes termed " winter oils " 
 i.e., oils still remaining fluid in winter ; whilst untreated oils 
 that become turbid or partially solidify on chilling and are only 
 clear in warm situations are designated " summer oils." 
 
 Oil or Fat. 
 
 Percentage of 
 Unsaponiflable Matter. 
 
 Allen & Thomson 
 
 Schiidler. 
 
 Cotton seed oil, 
 
 1-64 
 
 1-85 
 
 Coker butter, . 
 
 
 0-80 
 
 Hempseed oil, . 
 
 
 1-00 
 
 Japanese wax, . 
 
 1-14 
 
 1-20 
 
 Cod liver oil (brown), 
 
 1-32 
 
 1-45 
 
 (light), . 
 
 0-46 
 
 0-50 
 
 Linseed oil, 
 
 
 1-10 
 
 Almond oil, 
 
 
 0-45 
 
 Poppyseed oil, . 
 Olive oil (yellow), 
 
 : 75 
 
 1-15 
 
 0-80 
 
 ,, ,, (green), 
 
 
 1-50 
 
 Palm butter, . 
 
 
 1-25 
 
 Rapeseed oil (crude), 
 
 1-00 
 
 1-30 
 
 ,, ,, (refined), 
 
 
 0-15 
 
 Hog's lard, 
 Tallow, . 
 
 0-23 
 
 0-30 
 0'50 
 
 Even after as complete a removal as possible of suspended 
 albuminous and mucilaginous matter and of dissolved resin, most 
 natural oils and fats contain in solution small quantities of non- 
 saponifiable nonresinous matters ; in some cases cholesterol or 
 
 17 
 
258 
 
 OILS, FATS, WAXES, ETC. 
 
 isomerides thereof (isocholesterol, phytosterol, &c.) have been 
 identified as present e.g., in olive oil. The figures quoted on 
 p. 257 are given by Allen and Thomson * and Schadler f as 
 representative ones in various cases. 
 
 The folio wing figures were obtained by Thomson and Ballantine| 
 in the course of an extended examination of numerous samples 
 of oils : 
 
 Xame of Oil. 
 
 Percentage of 
 TJnsaponifiable Matter. 
 
 Olive oil (13 kinds), . 
 
 1-04 to 1-42 
 
 Cotton seed oil (crude), 
 
 1-12 
 
 ,, ,, (refined), 
 
 TO? 
 
 Rape oil (Colza, 5 kinds), 
 
 58 to '70 
 
 Arachis oil, . 
 
 54 to -94 
 
 Linseed oil (4 kinds), . 
 
 1-06 to 1-28 
 
 Castor oil, . 
 
 30 to -37 
 
 Southern sperm oil, 
 
 37-41 
 
 Arctic sperm oil (bottlenose , 
 
 36-32 
 
 Whale oil (pale), . 
 
 1-82 
 
 Seal oil (4 kinds), 
 
 42 to '51 
 
 Cod oil (3 kinds), 
 
 87 to 1-87 
 
 Menhaden, . 
 
 1-60 
 
 In the analysis of soap (Chap, xxi.), as the unsaponifiable sub- 
 stances originally contained in the fatty matters employed for 
 the most part pass into the soap during manufacture, a correction 
 on this score is requisite when it is desired to determine the 
 mean equivalent of the fatty acids present (p. 172). According to 
 the author's experience the amount of matters of unsaponifiable 
 nature thus contained in 100 parts of fatty acids, &c., separable 
 from the soap by means of a mineral acid generally lies between 
 25 and I'O part, averaging near to '5 to '75 i.e., in the case of 
 soaps made from natural oils and fats, to which no additional 
 unsaponifiable matters have been intentionally added. When 
 woolgrease or Yorkshire grease (Chap, xn.) has been used, either 
 purposely as an ingredient, or unwittingly in the form of an 
 adulteration of tallow, &c., the proportion becomes markedly 
 increased ; with oleine soaps made from distilled oleine a, 
 few per cents, of hydrocarbons are often present, formed during 
 the distillation of the fatty acids, smaller quantities being often 
 found in soaps made from oleines prepared in the autoclave 
 without distillation. When paraffin oils have been intermixed 
 with the soap, as in the case of certain kinds of laundry soaps, 
 the percentage of unsaponifiable matters is largely increased. 
 
 * Chemical News, 43, 267. 
 
 t Technologic der Fette und Ode, p. 61. 
 
 $Journ. Soc. Chem. Ind., 1891, p. 233. 
 
OIL REFINING ACID PROCESS. 259 
 
 The fatty matters extracted by solvents from certain legu- 
 minous plant seeds (peas, lupins, &c.) contain relatively consider- 
 able proportions of glycerophosphoric choline derivatives of the 
 nature of lecithin (p. 121) : the existence of small quantities of 
 substances of this class in oils expressed for commercial purposes 
 is extremely probable, but little or no knowledge is extant as to 
 how far this is the case. The husk of the seeds of Lupinus luteus 
 yields to ether a crystallisable substance, lupeol, analogous to 
 cholesterol, but derived from a hydrocarbon poorer in hydrogen 
 (vide p. 17) ; whilst the seed husks of PJiaseolus vulgaris contain 
 a higher homologue of phenol (viz. pliasol, C 15 H 24 O) together 
 with paraphytosterol (p. 16); in all probability several such 
 substances akin to cholesterol and phytosterol are contained in 
 small quantities in seed oils. 
 
 SULPHURIC ACID PROCESS FOR REFINING OILS, &c.. 
 (THENARD PROCESS). 
 
 In employing sulphuric acid as a clarifying agent it is requisite 
 that no large excess should be used otherwise a charring action 
 is apt to be set up on the oil itself, darkening its colour and 
 depreciating its value. In refining linseed oil from one-hundredth 
 to one-fiftieth part (1 to 2 per cent.) of acid* is thoroughly inter- 
 mixed with the oil in an efficient agitator at a temperature not 
 exceeding 40 (about 104 F.), and the whole allowed to rest for 
 24 hours. 60 to 70 per cent, of warm water at about 60 C. 
 (140 F.) is then well intermixed and the whole allowed to stand 
 some days ; a watery acid liquid separates at the bottom with a 
 layer of flocculent " foots," above which is the clarified oil, which 
 is drawn off and again agitated with warm water as before to 
 wash out any residual suspended acid vesicles. Another method 
 of operating (Cogaii's process) is to use 1 per cent, of acid diluted 
 with as much more of water ; this is well intermixed, and after 
 standing some hours is heated up to 100 C. by blowing in steam 
 through a fine rose jet at the bottom of a copper vessel. This 
 temperature is maintained for several hours, after which the 
 whole is allowed to stand at rest so as to separate the watery 
 acid and foots from the clear oil. In order to draw off the oil 
 without disturbing the water and foots, a conical separating 
 vessel is generally employed with taps at various levels so that 
 all clear oil above a given level can be drawn off without disturb- 
 ing that below. 
 
 Rape (colza) and linseed oils and certain fish oils are those most 
 usually refined by the acid process. Oils intended for lubrication 
 
 * Hartley recommends that the acid should be diluted with water before 
 mixing with the oil, so as not to contain more than 30 per cent, of actual 
 
^60 OILS, FATS, WAXES, ETC. 
 
 are as a rule the least suitable for such treatment, inasmuch as 
 the presence of free fatty acids (and a fortiori of possible traces 
 of mineral acids) is a serious objection with most such substances, 
 corrosion of bearings and shafts, &c., being apt to be thereby 
 occasioned. For oils intended for burning in lamps the presence 
 of any considerable amount of free fatty acids is also objectionable 
 as tending to cause charring of the wick. 
 
 R. v. Wagner recommends the use of zinc chloride solution of 
 sp. gr. 1-85 instead of sulphuric acid, using about 1^ parts per 
 100 of oil. Albuminous impurities are equally destroyed or 
 coagulated, whilst there is less danger of injurious action on the 
 oil itself. Hartley finds that a strong solution of manganese 
 sulphate answers well. 
 
 ALKALINE REFINING PROCESSES. 
 
 As already stated, processes where alkalies are used as agents 
 for coagulating and removing mucus, albuminoids, &c., have 
 several advantages over the acid methods, notably that free fatty 
 acids and resins are also removed. The quantity and strength 
 of the alkaline ley employed varies with the nature of the oil to 
 be treated ; any undue excess is apt to lead to more or less 
 considerable loss, not only by producing more saponification but 
 also because the extra amount of saponaceous products gives rise 
 to the formation of more foots containing clarified oil entangled 
 therein. The requisite quantity of ley and the oil are well 
 agitated together by any suitable mechanical mixer (either in 
 the cold or heated to the requisite temperature, as the case may 
 require), and the whole then allowed to settle ; a heavier watery 
 fluid with soapy foots separates ; this is drawn off and the process 
 repeated with a much weaker alkaline solution, and subsequently 
 with plain water. When considerable quantities of resin are 
 present, as in the case of cotton seed oil, the ley may conveniently 
 be of sp. gr. 1-06 up to 1*10 ; in such cases it frequently happens 
 that the watery layer and foots will not separate thoroughly 
 from the oil without the subsequent addition of a little salt 
 or brine. To avoid the formation of emulsions Hageman 
 employs as purifying agent soda crystals heated to about 
 80 so as to fuse in their water of crystallisation ; after inter- 
 mixture by agitation the mass separates on standing into three 
 sharply defined layers of purified oil, soapy matters, and watery 
 fluid respectively, but without any notable production of emul- 
 sion. 
 
 Sometimes oils are required to be treated that have become 
 more or less rancid by keeping, owing to fermentative changes, 
 atmospheric oxidation, or other causes, but where most of the 
 mucilage, &c., originally present has been already removed. In 
 such cases thorough agitation with a weak solution of caustic 
 
ALKALINE PROCESSES FOOTS. 261 
 
 soda, or a somewhat stronger one of sodium carbonate, suffices 
 to remove the free fatty acids of low molecular weight (butyric, 
 caproic acids, &c.) that are present, as well as others, if already 
 formed by hydrolysis ; and to dissolve out most, if not all of the 
 malodorous non-acid products of decomposition, so as to sweeten 
 the oil. Diluted milk of lime and calcined magnesia are some- 
 times used in a similar fashion. As a rule oils that have once 
 become rancid, even if pretty thoroughly 'sweetened by such 
 refining, are more apt to turn rancid again on keeping than 
 fresh ones. In some cases agitation with water alone without 
 alkalies suffices to wash out the objectionable decomposition 
 products to a considerable extent ; thus rank butter is greatly 
 sweetened by simply being thoroughly worked about and washed 
 in water. 
 
 Cokemut oil of inferior quality may be greatly improved by 
 boiling up with about ^ of its weight of soda lye, specific 
 gravity 1 -03, for half an hour, skimming frequently. Some 4 or 
 5 Ibs. of salt per ton of oil are then added, and the boiling con- 
 tinued for another half hour. Another equal quantity of salt is 
 then added, and the whole boiled up : after standing till next 
 day the cleansed oil is run off from the brine and foots that have 
 subsided. 
 
 Crude spermaceti is generally refined by processes partly 
 involving the mechanical expression of fluid oil, somewhat 
 after the fashion of stearine pressing (p. 229), and partly 
 of a chemical nature, more especially boiling up with a small 
 quantity of potash ley ; this dissolves out free fatty acid formed 
 by the hydrolysis of the cetin or otherwise, and saponifies most 
 of the residual fluid oil, this being more readily acted upon by 
 alkalies than cetyl palmitate itself. Simultaneously, however, 
 some of the latter becomes saponified, and in consequence the 
 foots contain more or less considerable amounts of potassium 
 palmitate, etc., whilst the purified spermaceti contains an ad- 
 mixture of cetylic alcohol (p. 171). 
 
 Utilisation of " Foots." The foots obtained from oils con- 
 taining considerable quantities of resinous matter (e.g., cotton 
 seed oil foots) are sometimes directly worked up into soap by 
 admixture with other materials in the soap boiling process. 
 When their colour or nature prevents this being done, they are 
 generally acidified so as to decompose the soaps present; the 
 mixture of fatty and resinous acids and more or less unde- 
 composed glycerides thus obtained is usually distilled by means 
 of superheated steam, whereby the glycerides present are hydro- 
 lysed; the fatty acids distil over, whilst the resinous matters 
 mostly remain behind as a pitchy mass. To some extent, how- 
 ever, the materials are generally broken up by the heat with the 
 formation of high-boiling hydrocarbons and water, the former of 
 which partly distil with the fatty acids ; the result of which is 
 
262 OILS, FATS, WAXES, ETC. 
 
 that "distilled oleines" obtained from products of this kind 
 (p. 110) will not wholly dissolve in alkaline solutions to soaps, 
 the hydrocarbons remaining undissolved. On agitating the 
 liquid with an appropriate volatile solvent (ether, benzoline, <fec.) 
 a quantity of unsaponifiable matter can usually be dissolved out 
 from the soap solution to the amount of several per cents, of the 
 distilled oleine employed. The same remarks apply a fortiori 
 to the analogous products obtained when "Yorkshire grease" 
 (Chap, xii.), woolgrease, and similar materials are distilled by 
 means of superheated steam. 
 
 The appliances used for such distillation with superheated 
 steam essentially consist of a boiler for steam raising ; a super- 
 heater whereby the steam is heated considerably above the 
 temperature of the boiler, generally consisting of a coil of iron 
 tubing heated in a flue or some analogous arrangement; a 
 distilling vessel into which the material to be distilled is run, the 
 steam being then blown through it in numerous fine streams by 
 means of a rose jet at the bottom, or a coil perforated with small 
 holes ; and a condensing apparatus in which the evolved vapours 
 and the steam are condensed. In Chap. xvi. are described the 
 arrangements employed in the candle material manufacture for 
 the distillation of fatty acids and glycerol by means of super- 
 heated steam ; those used for the distillation of foots, recovered 
 greases, &c., do not greatly differ therefrom. 
 
 It often happens that the solidity of a grease, ifec., is greatly 
 increased by the process of distillation with superheated steam, 
 so that a comparatively soft grease after distillation gives a 
 product of much stiffer consistence, and capable of yielding 
 a considerable amount of solid "stearine" by pressure. The 
 cause of this is not absolutely certain ; but it is extremelv 
 probable that it is due to the conversion of oleic acid into 
 isomerides of higher melting point, isoleic acid, or stearolactone, 
 or both (p. 30) ; just as these products are formed by the action 
 of zinc chloride on oleic acid (p. 142), or during the decomposition 
 of glycerides by sulphuric acid and their subsequent distillation 
 with superheated steam in the "Wilson" process for obtaining 
 candle material (Chap, xvi.) 
 
 Precipitation Processes. In some few cases mucilaginous 
 or albuminous matters are contained in oils and fats not readily 
 removable by mechanical means alone, such as subsidence or 
 filtration, but readily coagulable by means of certain metallic 
 compounds or substances containing tannin. Thus in " boiling " 
 linseed oil to improve its drying qualities (Chap, xiv.) sulphate of 
 zinc, acetate of lead, sulphate of manganese, and other metallic 
 salts are sometimes used not only for the purpose of facilitating 
 the incipient oxidation and physical alteration required to 
 make the oil dry to a varnish more rapidly, but also in order 
 to combine with, and remove by subsidence, the last portions of 
 
BLEACHING OILS AND FATS. 263 
 
 vegetable mucilage, &c., not entirely removed by previous refining 
 operations. Some kinds of fish oils are similarly improved by 
 vigorous agitation with oakbark infusion or other liquors con- 
 taining tannin, conveniently effected by blowing a rapid current 
 of steam through the whole : gelatin is thus precipitated and 
 removed by deposition on standing, any excess of tannin taken 
 up by the oil being subsequently removed by agitation with lead 
 solution or other appropriate metallic salt. Copper sulphate 
 solution, alone or mixed with brine, when thoroughly inter- 
 mixed with fish oils, may often be used effectively for removing 
 gelatin, etc., therefrom by precipitating it as an insoluble com- 
 pound. 
 
 H. Nordlinger has recently patented * a process for refining 
 vegetable oils and precipitating mucilaginous matter consisting 
 of the preparation of "purification-oils" by dissolving in from 
 
 10 to 20 parts of oil the zinc, cadmium, iron, manganese, lead or 
 copper salts of the higher fatty aciols (metallic soaps), at a 
 temperature of about 150 C., and allowing to clarify by sub- 
 sidence. From 5 to 10 per cent, of the metallic soap solution 
 thus prepared is then added to the oil to be treated and the 
 whole allowed to stand some time, when precipitates are formed 
 by the interaction on one another of the mucilaginous matter 
 and the metallic compounds ; the clear supernatant purified oil 
 is drawn off when the action is complete. 
 
 Hartley and Blenkinsop have patented (No. 11629, 1890) the 
 use for refining linseed oil of a solution of manganese linoleate in 
 
 011 of turpentine or other suitable solvent : 1 part of manganese 
 salt to 800 of oil suffices. If much mucilage is present the oil 
 is previously treated with sulphuric acid of 30 per cent. By 
 blowing a current of air or oxygen through the mass at a tem- 
 perature of about 190 F. (88 C.), bleaching is readily effected, 
 the manganese salt acting as a carrier of oxygen. 
 
 BLEACHING OILS AND FATS. 
 
 The colours exhibited by certain oils and fats, as obtained from 
 their respective sources, are in general due to the presence of 
 natural organic colouring matters (xanthophyll, erythrophyll, 
 chlorophyll, &c.) in solution in the oil ; in some cases these are 
 mostly mechanically carried down by the mucilaginous matter 
 present during clarification by subsidence, &c., more especially 
 when heat is also applied to promote the coagulation of albu- 
 minous impurities, and particularly when oakbark or other 
 sources of tannin are employed as precipitants of these bodies ; 
 in some instances albumin or gelatin is purposely added along 
 with tannin, to precipitate the colour. Some colouring matters 
 are removable by treatment with animal charcoal and filtration 
 
 * German Patent, No. 58959. 
 
264 OILS, FATS, WAXES, ETC. 
 
 somewhat after the fashion of sugar refining ; exposure to a 
 moderately high temperature destroys others ; whilst in yet 
 other cases chemical bleaching agents are requisite, such as 
 oxidation by the action of air blown through the heated oil, 
 either alone or in presence of oxygen carriers ; or chlorination 
 by means of small quantities of bleaching powder or chlorate 
 along with hydrochloric acid ; or both together by means of 
 potassium dichromate and dilute hydrochloric acid. With high 
 priced substances such as beeswax, bleaching by exposure to air 
 and light in thin cakes or ribbons, and in some cases treatment 
 with nitric acid or peroxide of hydrogen, is applicable, although 
 the cost of labour and chemicals is prohibitive of such methods 
 in the case of the cheaper oils, c. On the other hand, reducing 
 agents, such as ferrous sulphate or sulphurous acid, answer better 
 than oxidising ones with some kinds of oils e.g., linseed oil. 
 
 Hot Air Process. Certain fats, especially tallow and palm 
 butter, can be pretty thoroughly decolorised by heating them 
 and passing a current of air through the dry mass (containing no 
 interspersed water) by means of a large rose with fine orifices, so 
 that many fine streams of air bubbles rise through the hot fat. 
 A temperature somewhat short of that of boiling w r ater generally 
 suffices (80 to 90 C.) In the case of palm oil a somewhat 
 higher temperature, 125 to 130 C.,* also effects the destruction 
 of the colouring matter in the absence of air ; a considerable 
 amount of the glyceride is thereby decomposed with evolution of 
 acrolein, and formation of free palmitic acid. Many fish oils are 
 greatly lightened in colour by blowing air through the mass, 
 heated to near 100 in a steam jacketted vessel ; in these cases 
 the oil itself generally becomes more or less oxidised, increasing 
 in density and viscidity, especially if the air-treatment be 
 carried too far (vide "blown oils," Chap, xiv.) In. Hartley and 
 Blinkinsop's process for refining linseed oil (supra), the oxidising 
 action of the air is intensified by adding a manganese soap 
 which acts as a carrier of oxygen. 
 
 Instead of blowing a stream of air through the oil to be treated, 
 Teal f exposes rapeseed or linseed oil, &c., in a finely divided 
 stream to air at a temperature of about 170 F. (71 C.), in order 
 to " brighten " the oil. 
 
 W. Mills I bleaches and purifies nondrying oils and fats by 
 means of a mixture of hot air and volatilised sulphur trioxide, 
 S0 3 , passed into a " mixer " capable of withstanding a pressure 
 of 2 atmospheres. The sulphur trioxide acts as an oxidising 
 agent, becoming reduced to sulphur dioxide, which also is 
 effective, especially whilst nascent. 
 
 * 240 C. , according to Pohl, who first introduced the process. Dingier 
 Polyt. Journ., cxxxv., 140. 
 
 + Eng. Patent Spec., 18,744, 1892. 
 I Eng. Patent Spec., 18,224, 181)1. 
 
BICHROMATE PROCESS. 265 
 
 Bichromate Processes. Tn the bleaching of raw palm oil 
 by Watts' bichromate process, the oil is rendered quite fluid by 
 heating it to 40 to 50 C., and is intermixed with 1 to 1-25 per 
 cent, of its weight of potassium dichromate dissolved in hot 
 water (22 to 28 Ibs. per ton). Strong hydrochloric acid solution 
 to the extent of 2 to 2 -5 per cent, of the oil is then run in with 
 vigorous agitation, enough being used to ensure that a slight 
 excess of free acid shall finally be present in addition to that 
 neutralised by the chromium and potassium. The reddish orange 
 hue changes rapidly, first to a dark brown, then to a brownish 
 green, and finally to a light green, the operation taking only a 
 few minutes. The whole is then heated up by blowing wet 
 steam through, and allowed to stand at rest for some hours ; the 
 supernatant bleached oil is drawn off and used directly for 
 soapmaking, &c., or is washed by agitation with hot water, and 
 standing to remove traces of chrome liquor. The " green liquor " 
 resulting from the operation is sometimes worked up to recover 
 the chrome by adding milk of lime so as to form a precipitate of 
 chromium hydrate mixed with lime ; this is washed and drained, 
 and then roasted, whereby oxygen is taken up and calcium 
 chromate formed, used for a fresh batch instead of potassium 
 dichromate. When there are difficulties as to running waste 
 chrome liquors away into water courses, c., this method of 
 regeneration is practically imperative ; but unless a proper 
 amount of scientific skill and supervision is exercised (not always 
 available in a soapery), the cost of labour and fuel, ttc., is apt to 
 materially outweigh the value of the potassium dichromate saved, 
 except when the price of this salt is unusually high. 
 
 Instead of hydrochloric acid, a mixture of two parts sulphuric 
 acid and three common salt may be employed, the latter being 
 dissolved along with the dichromate, and the former gradually 
 run in to the mass after having been diluted with about twice 
 its bulk of water. If the temperature be too high, the bleach- 
 ing is not always successful, a brownish " foxy " shade being 
 developed ; about 45 to 50 C. may be taken as a working 
 maximum ; the proportion of dichromate used need not exceed 
 28 Ib. to the ton (J^ part = 1'25 per cent.) in skilled hands. 
 
 A similar mode of treatment is available with many other oils, 
 the use of hydrochloric acid to generate nascent chlorine not 
 being necessary in all cases ; thus with various fish oils a few 
 pounds of dichromate to the ton, with about half as much 
 sulphuric acid, answer best, the oxidation being completed by 
 adding a small proportion of nitric acid largely diluted, and 
 boiling up with steam. In other instances, treatment with 
 dichromate improves the product, not so much by simply bleach- 
 ing as by oxidising and removing the small quantities of malo- 
 dorous substances present that communicate a foetid or rancid 
 odour e.g., kitchen grease, horse grease, &c. 
 
266 OILS, FATS, WAXES, ETC. 
 
 Beeswax is frequently bleached by boiling with a weak solu- 
 tion of potassium dichromate, acidulated with sulphuric acid. 
 The product is apt to retain chromium compounds, giving it a 
 greenish hue ; boiling up with oxalic acid solution appears to be 
 the best mode of dissolving out the chrome and furnishing a 
 white product. Instead of " chromic liquor," dilute nitric acid 
 is sometimes employed, taking care not to use too much or of 
 too great strength, otherwise more or less considerable loss is 
 apt to occur through oxidation of the wax itself. 
 
 Wax thus bleached by oxidising chemicals is generally more 
 crystalline than air bleached wax, and consequently not so 
 well suited for the manufacture of wax candles. According to 
 Leopold Field, * whilst the solubility in alcohol of air bleached 
 \vax differs but little from that of the raw wax, that of 
 -chemically bleached wax is much greater, leading to the idea 
 that free fatty acids are largely formed during the bleaching 
 process, giving greater crystallimty. 
 
 Instead of potassium dichromate, manganese dioxide has been 
 employed for bleaching oils, especially palm oil ; the powdered 
 substance suspended in water is intermixed with the oil by 
 vigorous agitation, and hydrochloric acid added so as to generate 
 chlorine, whilst the whole is heated by blowing in steam. The 
 only advantage of the process seems to be the lessened cost, 
 against which several other inconveniences must be set off, the 
 action being far less regular. The same remark applies to the 
 process formerly used to some extent where manganese dioxide 
 and sulphuric acid were employed. 
 
 Chlorine Processes. Chlorine evolved from substances other 
 than potassium dichromate and hydrochloric acid is sometimes 
 -employed as a bleaching agent ; thus tallow may be bleached by 
 boiling it on a solution of bleaching powder or potassium chlorate 
 to which hydrochloric or sulphuric acid is added; about 2 to 2 '5 
 Ibs. of chlorate per ton usually suffices. In all such processes, 
 when the fat is intended for soapmaking, excess of chlorine is 
 apt to produce a worse result than none at all so far as colour 
 is concerned (leaving deodorising out of the question) ; for if the 
 fatty glycerides themselves are sensibly attacked by the chlorine 
 after the colouring matters have been destroyed, the resulting 
 soap is apt to " work foxy " i.e., either to become brown in the 
 pan during boiling, or to darken in colour subsequently when 
 cut up into bars. On the other hand, the unpleasant odour of 
 rancid tallow and grease from tainted or putrid carcases, tannery 
 refuse, and suchlike materials is apt to be communicated in some 
 degree to the resulting soap unless the grease is previously 
 deodorised by chlorine, etc. In many cases a great improvement 
 in odour may be brought about by simply blowing steam through 
 
 * Journ. Soc. Arts, xxxi., p. 836. 
 
CHLORINE PROCESSES. 267 
 
 the melted grease for some time, the volatile evil-scented matters 
 present being thus largely expelled. 
 
 With rank fish oils larger proportions of bleaching powder are 
 requisite up to 1 per cent, and upwards, with an equivalent 
 quantity of sulphuric acid ; the bleaching powder is made into 
 a milk with water and well intermixed with the oil, which is 
 slightly heated by blowing in a little steam ; the acid diluted 
 w^ith several times its volume of water is then run in with 
 vigorous agitation. Finally, steam is blown through and the 
 whole allowed to rest and subside. 
 
 Chlorine bleaches wax readily, but chlorosubstitution products 
 are apt to be formed, so that if the bleached wax is used for 
 making tapers or candles, hydrochloric acid vapours are evolved 
 when these are burnt, causing considerable annoyance.* 
 
 Cotton seed oil in the raw state contains a peculiar colouring 
 matter capable of being dissolved out along with resinous matters 
 by agitation with aqueous solutions of caustic alkalies (p. 260). 
 Sometimes this purification is only partly carried out, the 
 residual colouring matter being destroyed by boiling with a dilute 
 solution of bleaching powder and treatment with dilute sul- 
 phuric acid. The oils thus more or less completely refined and 
 decolorised by chemicals are, as a rule, only used for soapmaking 
 and similar technical purposes ; whereas those completely refined 
 by soda alone are used as edible oils, being largely used for 
 cooking purposes, and to a great extent intermixed with olive 
 and other high-priced "salad" oils. As a rule each oil refiner- 
 has his own particular special methods of effecting the final 
 clarification and finish of such superior products, which are looked 
 upon as valuable trade secrets. 
 
 Dark coloured soaps are sometimes bleached more or less com- 
 pletely by intermixing with the hot curd freed from ley, a solution 
 of " chloride of soda " (bleaching powder made into a cream and 
 treated with enough carbonate or silicate of soda to remove all 
 lime from solution). This may be effected in the pan itself, but 
 is best done by crutching the liquid into the soap in the frame 
 (A. Watt): the precipitated carbonate or silicate of lime need 
 not be previously removed. If made from coarse rank " goods," 
 the soap will be largely deodorised by the process. 
 
 Peroxide of Hydrogen Process. The bleaching action of 
 peroxide of hydrogen on certain forms of organic colouring 
 matters has long been known and utilised in certain cases where 
 the cost was not prohibitive e.g., in the manufacture of various 
 
 *The important chemical discovery that "electropositive" hydrogen 
 could be replaced in organic compounds by highly "electronegative" chlorine 
 without materially altering the character of the substance affected was first 
 made in consequence of investigations carried out by Gay Lussac in order 
 to elucidate the cause of this occurrence in the reception rooms of the 
 Emperor Napoleon I., where wax candles were largely burnt. 
 
268 OILS, FATS, WAXES, ETC. 
 
 high-priced toilet fluids for converting dark hair into substances 
 of golden hue, or even bleaching completely white. Notwith- 
 standing improvements whereby the cost of manufacture of per- 
 oxide of hydrogen is greatly reduced, this substance is still too 
 expensive for use on the large scale for low-priced oils, &c., 
 although in many cases it is well fitted for the purpose. Drying 
 oils required for artists' varnishes are sometimes bleached by 
 floating them in a thin layer on the surface of hydrogen peroxide 
 dissolved in water, the whole being warmed and if possible 
 exposed to sunlight to facilitate the operation. By shaking up 
 repeatedly in a closed vessel Avith about ^ part of a 10 per cent, 
 solution of peroxide of hydrogen most oils can be rapidly 
 bleached, or at least greatly lightened in colour. 
 
 Wax Bleaching by Exposure to Air. The effect of light 
 and air 011 beeswax in removing the natural yellowish tinge is 
 utilised thus : The wax is first melted and boiled up with water 
 acidulated with a small quantity of sulphuric acid (about 1 part 
 by weight of oil of vitriol per 1000 of wax); impurities are thus 
 washed out, and a clear bright melted wax obtained. This is 
 then run from a sort of cullender pierced with holes on to a 
 drum half immersed in a tank of cold water ; as the streams of 
 fluid wax come in contact with the cool wet surface they solidify 
 into thin ribbons which are scraped off the drum after they have 
 passed down under the water so as to complete their solidification. 
 .Filially, the ribbons are spread out in thin layers on canvas 
 sheeting, and placed in the open air so as to be exposed to the 
 sun and air. After a time, the partially bleached ribbons are 
 remelted and again cast into ribbons, and exposed for a further 
 period, the whole operation lasting several weeks according to the 
 weather and the nature of the wax, some kinds yielding much 
 more rapidly to atmospheric oxidation than others. Usually 
 only the outer portions of the ribbons become bleached, the action 
 not penetrating far into the interior ; so that to expose the whole 
 equally to light and moisture, the mass requires to be turned 
 over from time to time and sprinkled with water ; obviously the 
 thinner the ribbons are, the better. 
 
 In the purification of Japanese wax a very similar process 
 is adopted ; the crude wax as obtained from the dried berries 
 of the Rhus succedanea, is melted and strained, dripping into 
 water kept agitated so that it solidifies in thin flakes ; these 
 are then exposed to sun and air in trays, being now and then 
 sprinkled with water and turned over ; the vegetable colouring 
 matter present in the crude wax is thus readily blanched, an 
 almost white product being obtained. In the case of some 
 varieties of beeswax this result cannot be so readily secured, the 
 colour sometimes not yielding at all readily to atmospheric 
 influences. Addition of a small quantity of fatty matter to 
 beeswax often facilitates the bleaching action of the atmosphere 
 
WAX BLEACHING. 
 
 269 
 
 under the influence of sunlight ; according to some authorities 
 the quality of the wax is not improved thereby, whilst the 
 presence of glycerides is usually regarded as proof of adulter- 
 ation ; on the other hand, A. & P. Buisine (infra] state that 
 the addition of 3 to 5 per cent, of tallow is universal amongst 
 French airbleachers in order to prevent the product becoming 
 brittle, and is not regarded at all as an adulteration. A small 
 percentage of oil of turpentine is sometimes used instead of fatty 
 matter ; the volatile hydrocarbon mostly escapes during the 
 process by exposure to air ; but a small quantity becomes 
 resinised by oxidation and retained by the wax ; probably this 
 oxidation gives rise to peroxide of hydrogen in minute quantity 
 which assists the bleaching action. 
 
 According to A. & P. Buisine * the chemical bleaching of 
 beeswax is always accompanied by an increase in the total 
 acid number, and a diminution in the iodine number, indicating 
 the direct addition of oxygen to the uiisaturated acids present; 
 thus the following figures w r ere obtained in a long series of 
 experiments : 
 
 
 Iodine absorbed 
 by 100 parts of wax. 
 
 Total acid 
 number. 
 
 Pure yellow waxes, .... 
 Pure airbleached waxes, 
 
 10 -87 to 11-23 
 6 to 7 
 
 91 to 95 
 93 to 100 
 
 Airbleached, with addition of 3 to 5 per 
 cent, of tallow, ..... 
 
 6 to 7 
 
 105 to 115 
 
 Airbleached with addition of 5 per cent, 
 spirit of turpentine, .... 
 Bleached by hydrogen dioxide, 
 Decolorised by permanganate, 
 Decolorised by bichromate, . 
 
 6-78 
 6'26 
 2-64 to 5-80 
 1-08 to 7-94 
 
 100-4 
 98-4 
 92-2 to 103-3 
 98 -9 to 107 '7 
 
 On the other hand, decolorisation "by means of animal char- 
 coal caused no marked alteration in either the total acid number 
 or the iodine absorption. 
 
 An indirect method of bleaching by means of air is sometimes 
 practised, especially with linseed oil; the oil to be treated is 
 agitated at intervals with ferrous sulphate solution ; this has a 
 tendency to peroxidise by absorption of oxygen from the air, 
 whilst the resulting ferric compound parts with oxygen to the 
 colouring matter, oxidising the latter and blanching it, whilst 
 becoming itself again reduced to the ferrous state ; and so on 
 continuously. 
 
 * Bulletin Soc. Chim., Paris, 1890, iv., p. 465. 
 
270 OILS, FATS, WAXES, ETC. 
 
 CHAPTER XII. 
 RECOVERY OF GREASE FROM "SUDS," &c. 
 
 IN certain textile industries, more especially the woollen manufac- 
 ture, and to a somewhat lesser extent the silk and cotton 
 industries, the materials are treated at particular stages of the 
 process with soap liquors for the purpose of washing out impuri- 
 ties of various kinds ; whilst in various dyeing operations soaping 
 is also resorted to for the purpose of clearing off superfluous 
 dyestuff, cleansing the undyed portions, and so on. Formerly, 
 the " soap suds " thus produced were thrown away by running 
 into the nearest available stream, &c.; but the great amount of 
 river pollution thus brought about has in many cases rendered 
 it imperative that at least some amount of purification of such 
 liquors should be effected before they are thus run away ; 
 whilst the value of the fatty matters saved by adopting proper 
 processes for such purification, often renders it profitable to 
 employ such methods, even when so doing is not otherwise 
 compulsory. 
 
 The methods adopted necessarily vary to some extent with the 
 nature of the materials to be dealt with ; in cases where coloured 
 waste liquors from dyeworks, (fee., constitute the great bulk of 
 the substance to be treated, the cheapest and most satisfactory 
 methods appear to be modifications of the precipitation processes 
 employed in similarly dealing with sewage ; thus by adding a 
 small proportion of milk of lime to the liquors, and simultane- 
 ously running in a solution of crude aluminium sulphate,* the 
 alumina and ferric oxide precipitated by the lime unite with the 
 colouring matters forming " lakes," which ultimately subside by 
 gravitation in suitable settling tanks, carrying down mechanically 
 with them various other impurities (albuminoid matters, fatty 
 acids, &c.), so as finally to yield a clear almost colourless effluent 
 containing in solution only non-precipitable matters such as 
 alkaline salts, (fee. The " sludge " thus resulting is usually of but 
 little value, even for manure. When, however, soap suds con- 
 stitute a sufficiently large proportion of the waste liquors, it is 
 preferable to collect and treat these separately so as to recover 
 
 * Aluminoferric cake containing somewhat large amounts of iron,, 
 chiefly obtained from the mother liquors of purer aluminium sulphate made 
 by treating bauxite, clay, &c. , with sulphuric acid. 
 
YORKSHIRE GREASE. 271 
 
 the grease, the slightly acid watery liquors left after this opera- 
 tion being either run away directly, or, preferably, admixed 
 with the coloured waste liquors, and the whole treated together 
 as above described ; a little more lime is requisite in this case 
 to neutralise the free acid contained in the grease recovery 
 liquors, which must be done before the alumina can be effectively 
 precipitated from the sulphate. The precise details of the 
 method of working necessarily vary in each instance ; but it is 
 within the author's knowledge that processes substantially of the 
 character described can be so worked as to answer the purpose in 
 most satisfactory fashion, especially when carefully carried out 
 under pressure of an impending injunction. 
 
 Two methods of treating soap suds are thus applicable ; in one 
 the soap is made to react upon a lime compound such as thin milk 
 of lime or solution of calcium chloride so as to form insoluble lime 
 soaps by double decomposition; these are collected by subsidence 
 and nitration (the more or less purified liquor being run away), 
 and subsequently decomposed by sulphuric or hydrochloric acid 
 so as to liberate the fatty acids, thus obtaining a more or less, 
 impure grease ; after hot pressing or filtration the fatty acids 
 are obtained separate from the solid matters admixed with 
 them, and may be utilised in the production of rough soap, cart 
 grease, &c., or submitted to distillation with superheated steam, 
 according to their nature and degree of impurity. This lime 
 process is more especially applicable to comparatively dilute 
 suds, &c., where the object is rather to get rid in some way or 
 other of a dirty waste liquor which, from the circumstances of the 
 case, must be somewhat purified before discharging, than to work 
 a recovery process profitable in itself. When, however, the soap 
 liquors are more concentrated, the other method is preferable, 
 consisting of simple acidulation of the suds with sulphuric * or 
 hydrochloric acid ; the fatty acids thus liberated would naturally 
 float up as a sort of greasy scum, were it not for the presence of 
 other heavier suspended matters which, in most cases, and more 
 especially with wool scouring soap suds, render the total preci- 
 pitate ("magma" or "coagulate") somewhat heavier than the 
 watery fluid, causing it to sink. This process is more especially 
 employed in the recovery of " Wakefield fat" or "Yorkshire 
 grease," which essentially consists not only of free fatty acids 
 derived from soap, but also of wool grease contained in the raw 
 wool, and other oleaginous matters used in the spinning and 
 weaving processes. 
 
 In the English woollen industry, the method of cleansing wool 
 usually adopted essentially consists in scouring with soft soap, or 
 
 * Chamber acid suffices, or acid from the Glover tower, rectified oil of 
 vitriol being too costly, except in cases where the less cost of carriage of the 
 smaller bulk outweighs the increased price through cost of further concen- 
 tration. 
 
272 OILS, FATS, WAXES, ETC. 
 
 other soaps of special character ; during the further processes 
 through which the wool is put before it is finally converted 
 into woven cloth, soap and oil are tolerably freely used in the 
 spinning, fulling, and milling of the fibre, yarn, and cloth. 
 The soap suds and similar waste liquors produced in these 
 various operations are collected in large tanks or reservoirs, 
 holding several thousand gallons, and acidulated with a mineral 
 acid e.g., B.O. V. (brown oil of vitriol) ; after agitation and 
 subsequent standing for some hours, a fatty " magma " or 
 coagulate deposits at the bottom of the tank ; the supernatant 
 watery fluid (which should be slightly acid, otherwise the whole 
 of the soap has not been decomposed) is then run off, and the 
 tank filled up with fresh suds and acidulated as before, excepting 
 that somewhat less acid is now requisite, owing to the smaller 
 quantity of suds treated, the tank having been partly filled with 
 magma and watery fluid (with a tank 6 feet deep, the magma, 
 etc., usually fills up 15 or 18 inches). The process is again 
 repeated, the magma (known locally in Yorkshire as " sake ") 
 being ultimately thrown on filter beds, where most of the 
 remaining watery liquor separates, and then subjected to 
 pressure in bagging ; at first the pressure is very gently applied, 
 so as to squeeze out water only, but subsequently it is increased 
 and heat applied (hot press), so as to filter the fused mass 
 through the bagging, furnishing a dark sticky grease, and a 
 residual " sudcake " available as manure. This grease is what 
 is properly called " Yorkshire grease ;" but similar recovered 
 products ("Fuller's grease") obtained by treating the soap suds 
 produced in other industries where scouring with soap is largely 
 employed, are sometimes included in the term (cotton industry, 
 silk manufacture, dyeing, &c.) Genuine Yorkshire grease from 
 wool scouring essentially consists of the free fatty acids derived 
 from the soap used, the wool grease contained in the wool, 
 and such unsaponified oil and mineral hydrocarbons, &c., as 
 may have been used in the spinning and weaving operations 
 for the purpose of oiling or sizing the yarn, &c. ; whilst 
 analogous greases from other sources are more or less different 
 as regards the nature of the substances present other than free 
 fatty acids. 
 
 According to Lewkowitsch,* Yorkshire grease rarely, if ever, 
 contains unsaponified glycerides, any glyceridic oils used in the 
 spinning process becoming saponified during the after processes 
 of washing, tfcc. ; so that the essential organic constituents are 
 (1) free fatty acids, partly derived from the wool grease, but 
 chiefly from the soaps used in washing ; (2) cholesterol and 
 isocholesterol ethers, and similar derivatives of other high 
 alcohols e.g., cetylic and cerylic alcohols ; (3) free alcohols 
 (cholesterol, &c.), either naturally contained in wool grease, or 
 * Journ. Soc. Chem. Ind., 1892, p. 134. 
 
ANALYSIS OF YORKSHIRE GREASE. 273 
 
 produced during scouring by the partial saponification of their 
 compound ethers ; together with hydrocarbons contained in the 
 oils used for greasing during spinning, &c. 
 
 Analysis of Yorkshire Grease. The free acids are usually 
 determined by titration in the usual way (p. 116), their average 
 molecular weight being assumed to be some constant value e.g., 
 282 = oleic acid ; inasmuch, however, as they usually contain a 
 notable amount of acids of much higher molecular weight, derived 
 from the wool grease, this mode of calculation is apt to give too 
 low a result. In order to obtain a more exact valuation, the 
 alcoholic soap solution thus formed may be diluted with water, 
 and shaken with ether or light petroleum spirit, so as to dissolve 
 out all other constituents (or better, evaporated to dryness and 
 exhausted with ether or, preferably, light petroleum spirit, 
 p. 119, as the ethereal and watery fluids are apt to form frothy 
 emulsions, not readily separating into two liquids) ; the weight of 
 the free fatty acids insoluble in water is then determined by 
 acidulation, etc., as in Hehner's process (p. 166 ); by titrating 
 these with alkali, and subtracting the amount neutralised from 
 that neutralised during the first titration, the alkali equivalent 
 to the soluble acids may be deduced (p. 168); so that these latter 
 may be calculated, assuming an average molecular weight e.g., 
 102 = valeric acid, C 5 H 10 O 2 . 
 
 The sum of the cholesterol ethers, &c., and unsaponifiable 
 matters is obtained by weighing the ether or petroleum spirit 
 extract ; \vhen only an approximately exact result is required, 
 this may be got by difference, subtracting the fatty acids found 
 by titration (together with water, mineral matters, &c.) from 100 
 (vide infra}. The cholesterol ethers saponify only with great 
 difficulty ; the best mode of procedure is to heat under pressure 
 with excess of double-normal alcoholic potash (in a tightly 
 closed vessel heated to 100) : in this way a measure of the 
 amount of compound ethers present is obtained,* so that by 
 again assuming a mean molecular weight (e.g., that of cholesterol 
 stearate, C. >6 H 43 . O . C 18 H 35 O = 638), their amount may be calcu- 
 lated. A preferable method, however, is to separate the soaps 
 thus formed as before by means of ether, &c., dissolving out the 
 alcohols formed by saponification (or pre-existing in the grease) 
 and hydrocarbons, <fcc. ; the fatty acids contained in the soaps 
 are separated and weighed, and the alcohols, &c., obtained by 
 evaporating off the solvent. The acetyl test (p. 186) applied to 
 this residue allows an estimation to be made of the alcoholiform 
 constituents, again assuming a mean molecular weight e.g., that 
 of cholesterol, C., 6 H 44 O = 372, whence the amount of hydrocarbons 
 present is known by difference. 
 
 *If substances analogous to stearolactone (p. 170) are present, or organic 
 anhydrides (possibly present in distilled grease), alkali is also neutralised by 
 them during; this operation. 
 
 18 
 
274 OILS, FATS, WAXES, ETC. 
 
 The figures thus obtained will then come out as follows : 
 FIRST TREATMENT. 
 
 A B 
 
 Free fatty acids insoluble in water (weighed). 
 ,, ,, ,, soluble in water (calculated 
 from difference of titration). 
 
 SECOND TREATMENT OF B. 
 
 Compound ethers, alcohols, 
 and hydrocarbons 
 
 (weighed). 
 
 Fatty acids contained in 
 compound ethers 
 (weighed). 
 
 D 
 
 Alcohols (pre-existing and formed by saponi- 
 fication) and hydrocarbons (weighed). 
 
 The former calculated as CgeH^O from 
 the acetyl test ; the latter by subtracting 
 the quantity thus found from D. 
 
 Since water is taken up during the saponification of the com- 
 pound ethers, the sum of the organic constituents thus reckoned 
 should exceed 100, as in the parallel case of soap when the total 
 alkali and fatty acids present are determined (Chap, xxi.) 
 
 For certain purposes, more especially the preparation of 
 "lanolin" or similar cholesterol products of more or less 
 purity, the proportion of alcohols present regulates the value 
 of the material more than does the amount of fatty acids. 
 The presence of hydrocarbons (whether intentionally added as 
 ingredients in the oiling process during spinning, <fcc., or due to 
 adulteration of the oils thus used with petroleum products or 
 rosin oils, or formed during distillation of grease, the "oleine" 
 thereby obtained, p. 279, being used for wool-oiling) considerably 
 depreciates the value of the material for these purposes: in 
 many cases the presence of such substances in the extract D 
 obtained as above can be indicated, and the amounts roughly 
 judged, by treating this residue with alcohol or glacial acetic 
 acid, in which solvents the hydrocarbons are only sparingly 
 soluble. 
 
 For many purposes a less troublesome method of analysis 
 suffices ; thus Lewkowitsch (loc. cit. supra) recommends the 
 following process for the examination of Yorkshire grease : 
 About 5 grammes are titrated with alcohol and seminormal 
 alkali ; another portion is similarly titrated by boiling with 
 excess of alkali (i.e., the "free acid number" and the "total 
 acid numbers" are determined); the difference between these 
 titrations gives a measure of the compound ethers, glycerides, 
 and other saponifiable matters present. By means of ether 
 (preferably, light petroleum spirit, p. 119) the " unsaponifiable 
 
ANALYSIS OF YORKSHIRE GREASE. 75 
 
 matters" (alcohols, hydrocarbons, c.) are dissolved out and 
 weighed, whilst the " insoluble fatty acids " and " volatile " acids 
 are determined by the Hehner and lleichert-Meissl processes 
 (pp. 166, 174). Thus a sample of Yorkshire grease yielded the 
 following results : 
 
 Unsapotritiable matters (weighed), . . . . 36*47 per cent. 
 
 Free fatty acids ; insoluble (weighed Hehner 
 
 number), 20 '22 ,, 
 
 Free volatile acids (calculated as C S H 10 O 2 ), . . 1'2S 
 
 Combined fatty acids (calculated from difference of 
 titrations, assuming the mean molecular weight 
 = 327-5), 48-47 
 
 106-44 
 
 The excess of 6 '44 per cent, thus found is partly due to the 
 water taken up during hydrolysis of the compound ethers ; pro- 
 bably also the assumed mean molecular weight of the combined 
 fatty acids (327 '5) is somewhat too high. On the other hand the 
 value 282 (oleic acid) would be too low. 
 
 In the determination of the unsaponifiable matters present 
 "W. Mansbridge * recommends in place of ether the use of light 
 petroleum spirit (commercial benzoline redistilled, collecting the 
 part distilling at about 110 F. = 43 C.); the grease is saponified 
 with excess of alcoholic potash (under pressure if requisite), and 
 the product decomposed with mineral acid, whereby a mixture of 
 free fatty acids and unsaponifiable matters is obtained. Of this 
 a portion sufficient to yield about O5 gramme of unsaponifiable 
 matter is dissolved in 50 c.c. of methylated spirit saturated 
 with benzoline distillate, and 50 c.c. of that distillate added; the 
 whole is heated just to boiling, directly neutralised with semi- 
 normal potash, and then transferred to a separating funnel, 
 where the hot benzoline solution of unsaponifiable matter, and 
 the alcoholic soap solution, separate from one another rapidly. 
 The alcoholic soap solution is run off, and 50 c.c. of water at 
 100 F. (37'8C.) added, and the whole agitated to wash out any 
 soap dissolved by the benzoline. After separating by standing, 
 the watery fluid is run off, and replaced by 40 c.c. of warm 70 
 per cent, alcohol : this when agitated with the benzoline removes 
 the last traces of dissolved soap. The alcoholic soap solution 
 first run off is agitated a second time with benzoline, and the 
 benzoline solution purified as before : for some kinds of grease 
 more than two such extractions are requisite, but in general two 
 suffice. 
 
 The percentage of unsaponifiable matters (including choles- 
 terol, &c., produced by decomposition of cholesterol ethers) thus 
 deduced is not far removed from, but is usually somewhat less 
 
 * C.'um'x.tl News, 27th May, 1892. 
 
276 
 
 OILS, FATS, WAXES, ETC. 
 
 than, that calculated by assuming that the fatty acids present (free 
 and combined as cholesterol ethers, *fcc.) have the mean molecular 
 weight 282 (oleic acid), and subtracting their weight (together 
 with water, suspended matters, &c.) from 100. Thus Mansbridge 
 
 gives the following comparisons : 
 
 Pure woolfat, .... 
 
 ,, ,, another sample, 
 
 West of England recovered grease, 
 
 West of England recovered grease, 
 another sample, .... 
 
 Distilled woolfat, .... 
 
 Oleine from distilled woolfat, . 
 
 Oleine from distilled \voolfat, 
 
 another sample, .... 
 
 Black srease recovered from shoddy 
 scourings, ..... 
 
 Unsaponifiable Matters. 
 
 By extraction 
 as above. 
 
 By titration, 
 
 &c. 
 
 { 
 
 29-05 
 29-25 
 
 39-36 
 
 
 41-70 
 41 70 
 
 46-79 
 
 ( 
 
 21 -55 
 
 ( 23-16 
 
 i 
 
 21-05 
 
 j 23-16 
 
 | 
 
 22-81 
 
 23-63 
 
 1 
 
 52-25 
 
 I 48-64 
 
 1 
 
 51-90 
 
 I 48-64 
 
 r 
 
 44-35 
 44-25 
 
 44-31 
 
 { 
 
 50-25 
 50-35 
 
 47-13 
 
 ( 
 
 22-61 
 
 5"55 
 
 1 
 
 22*72 
 
 
 According to A. Hess * the difference between the amounts of 
 unsaponifiable matters deduced in these two ways gives a rough 
 valuation of the cholesteroid bodies present, the proportion of 
 these latter being approximately deducible by multiplying the 
 difference by 10. 
 
 The following analyses of Yorkshire grease (method of analysis 
 not stated) are given by G. H. Hurst f as fairly typical : 
 
 Sp. gr. at 15-5C., . 
 
 J 55 98 ,, 
 
 Water, . 
 Fatty acid, 
 Neutral oil, . 
 Unsaponifiable oil, . 
 Ash, 
 
 
 1 
 
 2 
 
 3 
 
 4 
 
 : 
 
 0-9391 
 0-8900 
 
 0-9417 
 0-8952 
 
 ... 
 
 0-9570 
 0-8720 
 
 . 
 
 0-98 
 18-61 
 68-62 
 11-68 
 O'll 
 
 1-53 
 24-25 
 58-25 
 15-83 
 14 
 
 1-21 
 24-15 
 30-02 
 44-44 
 0-18 
 
 0-94 
 26-43 
 16-86 
 
 55-77 
 trace 
 
 
 100-00 
 
 100-00 
 
 100-00 
 
 100-00 
 
 * Jaurn. Soc. Chnn. Iml., 1892, p. 144. 
 t Journ. Soc. Chem. 2nd., 1889, p. 90. 
 
DISTILLED GREASE. 277 
 
 Thus, the higher the density, the greater the percentage of 
 imsaponifiable oil. Such greases generally melt at near 44 C. ; 
 they can be saponified with alkalies, but only imperfectly ; the 
 flashing point is usually near 220 C. (p. 128). 
 
 Distilled Grease. Yorkshire grease from wool, and analo- 
 gous recovered greases from other sources, are rarely sufficiently 
 free from odour and otherwise of general good character, to 
 enable them to ba directly used for anything but the coarsest 
 purposes e.g., cart grease, and similar rough lubricating 
 materials, such as that required for the hot axles of tin plate 
 rolling machines. When subjected to distillation in cast iron* 
 stills of about 1,000 gallons capacity, holding about 4 tons of 
 grease, a variety of products are obtained, to some extent varying 
 with the quality and nature of the grease. The stills are first 
 heated for 10 to 16 hours with free fire to drive off water, and 
 then for 20 to 24 hours more with superheated steam, during 
 which time a pale yellow product comes over, known as " first 
 distilled grease," sometimes preceded by a lighter " spirit oil/' 
 sometimes not. After the "first distilled grease," "green oil" 
 comes over, sometimes used for coarse lubricating greases, but 
 more often put back into the still and worked over along with 
 the next batch. Finally, the distillate comes over as a thick oil, 
 when the operation is regarded as finished ; the fires are drawn, 
 the superheated steam turned off, and the pitch run out of the 
 still : 100 parts of Yorkshire grease thus treated gave 
 
 Pitch, . . 14-1 parts. 
 
 Green oil, . . . . 15 "5 ,, 
 
 First distilled grease, . . . 45*5 ,, 
 
 Spirit oil, .... 4'1 ,, 
 
 Water and loss, . . . 20'S ,, 
 
 100-0 
 
 The pitch thus obtained forms a useful lubricant for the necks of 
 hot rollers. 
 
 The " first distilled grease " is sometimes allowed to " seed " or 
 crystallise in the usual way (Chap, xvi.), and then pressed in a 
 hydraulic press, so as to obtain a liquid " oleine " and a solid 
 " stearine ' ; in. about the relative proportions, 2 to 1 ; the oleine 
 that exudes spontaneously from the crystallised cake before 
 pressing, is sometimes collected apart and designated "No. 1 oil." 
 Or the grease is distilled a second time, so as to obtain about 
 
 * Cast iron is much less rapidly corroded by the fatty acids than wrought 
 iron ride G. H. Hurst, loc. cit. sttpra. 
 
278 OILS, FATS, WAXES, ETC. 
 
 96 per cent, of " second distilled grease," and 4 per cent, of 
 " soft pitch." 
 
 The " spirit oil," as it first runs from the stills, is pale yellow 
 in colour, but darkens on keeping, probably by oxidation, like the 
 somewhat analogous oils obtained on the redistillation of bone 
 tar and other products of destructive distillation ; it contains a 
 small quantity of free fatty acids, equivalent to 4 or 5 per cent, 
 of oleic acid; on redistillation, it begins to boil at near 150 C., 
 about two-thirds distilling below 240, and seven-eighths below 
 320. It finds a limited use in making black varnish. Of what 
 constituent of the original grease it is a product of decomposition 
 by heat, is not known certainly ; possibly it is derived from 
 cholesterol, ttc., but as hydrocarbons are always formed in small 
 quantity in the redistillation of " red oils " (crude oleic acid) and 
 similar substances containing little or no constituents analogous 
 to cholesterol, it is more probable that it comes from the decom- 
 position of the oleic acid present. 
 
 " Distilled grease " is of pale yellow colour, and of granular 
 texture ; two samples gave the following numbers (Hurst) : 
 
 First Distilled Grease. 
 
 Second Distilled Grease. 
 
 Water, 
 Free acid, .... 
 Uusapornfiable matter, . 
 Neutral oil, .... 
 
 0-98 
 63-12 
 12-88 
 23-02 
 
 1-04 
 66-f>6 
 1324 
 19-16 
 
 
 10000 
 
 100-00 
 
 Lewkowitsch found a considerably larger percentage of hydro- 
 carbons in a sample of distilled grease examined by him, viz. : 
 
 Free fatty acids (molecular weight = 286), . . 54-91 per cent. 
 Combined fatty acids (molecular weight = 327'5),. 7 "02 ,, 
 ,Unsaponifiable matters, . . . . .38*80 ,, 
 
 100-73 
 
 The combined fatty acids would represent about 11-28 per cent, 
 of compound ethers ("neutral fat"), leaving 34-54 per cent, of 
 hydrocarbons. 
 
 The " stearine " obtained from distilled grease by pressure is 
 
 a hard pale yellow greasy solid ; that from the " first distilled 
 
 grease" is darker than that from " second distilled grease," but 
 
 vhas usually a slightly higher melting point. Apparently the 
 
 fatty acids present have a higher molecular weight than stearic 
 
ENGINE WASTE GREASE, FULLERS GREASE. 
 
 279 
 
 acid, inasmuch as the free acid found on analysis, when cal- 
 culated as stearic acid and added to the other constituents, gives 
 a total considerably under 100 ( Hurst). * Thus 
 
 
 Stearin e. 
 
 From First Distilled 
 Grease. 
 
 From Second Distilled 
 Grease. 
 
 Sp. Gr. at 15 -5, .... 
 
 98, .... 
 
 0-9044 
 
 0-9193 
 0-836 
 
 Water, 
 
 Free acid calculated as stearic acid, 
 Unsaponifiable oil, 
 Neutral oil, 
 
 1-48 
 76-3 
 0-4 
 
 7-7 
 
 0-6 
 88-6 
 0-49 
 2-11 
 
 85-88 
 
 91-80 
 
 Melting point, .... 
 Solidifying point, 
 
 57 (134F.) 
 53-5 (128F.) 
 
 48 (118 P.) 
 45(113F.) 
 
 The oleine simultaneously obtained is pale when fresh, but 
 gradually darkens, probably owing to the presence of iron 
 derived from the press or the tanks, in which it is stored. It is 
 generally known in the district of production as " wool oil," 
 because it is chiefly used for oiling woollen yarns, c.; lubricating 
 greases and soap are sometimes prepared from it ; but for the 
 latter purpose it is not at all well suited on account of the large 
 proportion of unsaponifiable matters. It varies much in com- 
 position, even when from the same maker, on account of the 
 varying composition of the Yorkshire grease originally employed, 
 the neutral oil amounting to between and 28 per cent., and the 
 unsaponifiable oil to between 10 and 38, whilst the free acid 
 (calculated as oleic acid) constitutes 53 to 65 per cent. The 
 Hashing point usually lies between 322 F. and 342 F. (Hurst). 
 
 Engine Waste Grease and Fuller's Grease. The grease 
 recovered from greasy engine waste (p. 236) is closely akin to 
 that obtained from soap suds ; but owing to the large use of 
 hydrocarbons as ingredients in lubricating oils at the present 
 day, it is usually much less valuable, the yield of solid "stearine" 
 being but small, and the "oleine" containing large quantities 
 of unsaponifiable hydrocarbons. When the spindles, &c., are 
 lubricated with tolerably pure vegetable oils or with sperm 
 oil, &c., a much better form of grease results ; but this is 
 comparatively rare. 
 
 Grease recovered from silk soap suds and soap baths from 
 cotton dyeing works, &c., mostly consists of free fatty acids with 
 
 "" The presence of stearolactone (p. 170) might possibly explain thfe 
 apparent deficiency in free acids. 
 
280 OILS, FATS, WAXES, ETC. 
 
 but little unsaponifiable matter, and is often clean enough to be 
 used directly for soapmaking. Its commercial valuation for such 
 purposes is generally effected by determining the percentage of 
 water present (p. 122), and of matters insoluble in alcohol (un- 
 saponifiable matters), subtracting the sum from 100, and reckoning 
 the difference as available fatty acids. When too dirty for use 
 in even the coarsest soap, such grease is either directly utilised 
 for lubricating materials of the roughest kind, or is distilled 
 by means of superheated steam, and the distillate pressed for 
 stearine and oleine. 
 
CLASSIFICATION OF OILS, ETC. 281 
 
 5. Classification and Uses of Fixed Oils, Fats, 
 Waxes, &c.; Adulterations. 
 
 CHAPTER XIII. 
 CLASSIFICATION. 
 
 In accordance with their ordinary physical texture, sources 
 (whether animal or vegetable), and essential chemical nature, 
 the fixed oils, fats, butters, and waxes, <fcc., may be conveniently 
 divided into twelve classes, falling into two principal divisions, 
 according as the main components are of glyceridic or non- 
 glyceridic nature. 
 
 DIVISION I. ESSENTIALLY GLYCERIDIC. 
 A . Fluid at Ordinary Temperatures : 
 
 1. Non-drying Oils 
 
 Vegetable 
 
 (1) Olive (almond) class. 
 
 (2) Rape (colza) class. 
 
 (3) Ricinoleic (castor) class. 
 
 Animal 
 
 (4) Lard oil class. 
 
 2. Intermediate : Drying Qualities possessed to a limited 
 
 extent : 
 Vegetable 
 
 (5) Cotton (sesame) class. 
 
 Animal 
 
 (6) Train, fish, and liver class. 
 
 3. Drying Oils : well marked Drying Qualities : 
 
 Vegetable 
 
 (7) Linseed class. 
 
382 OILS, FATS, WAXES, ETC. 
 
 B. Solid or Semisolid at Ordinary Temperatures : 
 
 Vegetable 
 
 (8) Palm butter, and Japanese wax class. 
 
 Animal 
 
 (9) Tallow, lard, and cow's butter class. 
 
 DIVISION II. ESSENTIALLY NON-GLYCERIDIC. 
 
 A. Fluid at Ordinary Temperatures : 
 
 Animal 
 
 (10) Sperm oil class. 
 
 B. Solid or Semisolid at Ordinary Temperatures : 
 
 Vegetable 
 
 (11) Carnauba wax class. 
 
 Animal 
 
 (12) Beeswax and spermaceti class. 
 
 CLASS I. OLIVE (ALMOND) CLASS. 
 
 A large number of oils are known completely fluid at ordinary 
 temperatures and not congealing until greatly chilled, consisting 
 chiefly of olein with smaller quantities of more solid glycerides 
 (myricin, palmitin, stearin, arachin, &c. ), and in some cases small 
 admixtures of glycerides of other kinds ; as a rule, however, 
 glycerides of the "drying oil" division are either absent 
 altogether, or only present in very small quantities, so that oils 
 of this class are practically non-drying. The presence of the 
 other constituents raises the relative density somewhat above 
 that of pure olein (near 0-905 at 15), usually to between -913 
 and '92-1 and at the same time tends to dimmish the iodine 
 number below 86 -2 per cent., the calculated value for pure olein 
 (p. 180), excepting in those cases where a notable admixture 
 of less saturated glycerides is present, when the superior iodine 
 absorbing power of these ingredients slightly raises the value 
 instead of lowering it. The calculated saponification equivalent 
 of pure olein is 294'7 (p. 158) ; that of an oil of this kind 
 generally differs but little therefrom, being a little higher or a 
 little lower, according as the other constituents have mean 
 equivalent weights above or below this value. The proportion 
 of glycerides other than those of oleic and the solid fatty acids 
 is not large enough to interfere with the production of a tolerably 
 hard solid elaidin with nitrous acid (p. 137), nor to cause that 
 heat evolution on mixture with sulphuric acid to be large 
 (p. 147). 
 
 The chief oils of commercial or local importance belonging to 
 
VEGETABLE OLEINES. 283 
 
 this class that have been investigated to any extent are as 
 follows : . 
 
 Name of Oil. Source. 
 
 Almond oil (sweet), . . Amyydalus communis (Prunus amyg- 
 
 dalux), var. dulcis. 
 ,, var. amara. 
 
 (bitter), 
 Arachis oil (grouudimt oil), 
 Beechmast oil, 
 Ben oil, . . . 
 
 Hazelnut oil, . 
 Olive oil, 
 
 Araclii* hypogcea. 
 
 Fagus sylvatica. 
 
 Morinrja pterygosperma ; M. apt era 
 
 (Guilandia moringa). 
 Corylus arellana. 
 Olea Europcea sylvestris : 0. E. satira. 
 
 Plum, peach, cherry, and ) P nu * domestica ; P. persica 
 
 apricot kernel oils, . . , arme ^ aca * P ' 
 
 P. ongandaca ; P. serotina. 
 
 Tea seed oil, 
 
 Camellia theifera C. oleifera : 
 C. drupifera. 
 
 Besides these, however, a large number of oils are in use to 
 varying extents in different countries for edible purposes, burning, 
 .anointing, <fcc., many of which agree in their general physical 
 characters with the above, more especially in being practically 
 non-drying in character and only solidifying at low temperatures, 
 And hence presumably consisting essentially of olein ; the 
 chemical examination of most of these, however, has not yet 
 been undertaken ; and as yet they are but little exported, and 
 consequently have not found their way into general trade in any 
 large quantities (vide pp. 287, 296). 
 
 Vegetable Expression Oleines. Semisolid vegetable tal- 
 lows and butters, when subjected to cold pressure, yield a solid 
 mass of higher fusing point together with a comparatively fluid 
 oil or oleine ; in certain cases, more- especially for the production 
 of the higher fatty acids for candle making, this treatment is 
 resorted to in order to partially separate the more fluid glycerides 
 from the others. Cokernut and palm kernel butters when thus 
 treated yield fluid oleines, solidifying a few degrees above ; 
 these consist partly of oleic glyceride, partly of the glycerides of 
 the acetic series of lower molecular weight contained in the 
 original butters ; and, in consequence of the presence of these 
 latter in considerable quantity, possess a somewhat different 
 composition from ordinary oils of the olive class e.g., the iodine 
 .absorption is much lower (often below 30 to 40) owing to the 
 relatively small amount of oleic glyceride present ; and similarly, 
 the heat development on mixture with sulphuric acid is below 
 that observed with olive oil (cokernut oleine = 26 to 27 ; olive 
 oil = 41 to 43 A. H. Allen). On account of the absence of 
 linolic and similar glycerides, these products are almost com- 
 pletely non-drying. 
 
284 
 
 OILS, FATS, WAXES, ETC. 
 
 CLASS II. RAPE (COLZA) CLASS. 
 
 The characteristic property of this class of oils is that of 
 possessing a much higher saponification equivalent than the oils 
 of Classes I. and III. in virtue of the presence of considerable 
 quantities of a higher homologue of oleic acid viz., erucic acid, 
 (X 2 H 4 . 2 O , crystallisable and melting at 34. In the case of 
 colza oil another acid, rapic acid, C 1S H 0)4 O. } , isomeric with ricin- 
 oleic acid, has been stated to be also present in considerable 
 quantity (p. 41). More precise information, however, is decidedly 
 wanted as regards the constituents not only of the lesser known 
 members of the group, but also of those most commonly 
 occurring. 
 
 The specific gravity is relatively low, mostly below -918 ; the 
 .saponification equivalent usually lies between 315 and 325, 
 whilst the iodine number is between 95 and 105, indicating the 
 presence of a certain amount of glycerides of linolic character,* 
 a result also borne out by the possession of some degree of drying 
 character by the oils themselves, not, however, of a strongly 
 marked kind. 
 
 Oils of this class do not give a particularly solid elaidin re- 
 action with nitrous acid, buttery masses being usually formed 
 which often separate on standing into two portions, one solid and 
 the other liquid. 
 
 The principal oils of this class are those undermentioned, but 
 in all probability many of the lesser known oils are of similar com- 
 position, judging from their general physical characteristics : 
 
 Name of Oil. 
 
 Source 
 
 Colza (rape) oil, 
 
 Hedge mustard oil (hedge \ 
 radish oil), . . . . J 
 Mustard oils (black and white ; } 
 Chinese cabbage oil), . . 1 
 
 Different cultivated varieties of 
 Brasxica campestris. 
 Raphanus raphaniMrum (Raphanis- 
 trum arrense). 
 Sinapis nirjra : S. alba ; and other 
 species of Sinapis. 
 Uaphanns Kotivus. 
 
 
 
 CLASS III. CASTOR OIL CLASS. 
 
 In this class of oils the prevailing glyceride is that of an oxy- 
 acid, such as ricinoleic acid, which gives to oils of this description 
 peculiar chemical characteristics. Comparatively few oils besides 
 castor oil have been sufficiently closely examined to render it 
 certain that they belong to this class ; but it is highly probable 
 that several of the lesser known oils used locally for edible 
 
 * The calculated value for erucin is 72 '4, that for olein, 86 "2. 
 
ANIMAL NON-DRYING OILS. 285 
 
 purposes, or as lamp oils, in different parts of the world, really 
 consist to a greater or lesser extent of oxy-acid glycerides. 
 
 A tolerably high specific gravity, from -950 to -970, is possessed 
 by oils of this class, and a saponification equivalent of 305 to 315 
 (calculated value for ricinoleiii = 310-67). The elaidins are soft 
 and buttery. The following oils appear to contain more or less 
 considerable proportions of oxy-acid glycerides : 
 
 Name of Oil. Source. 
 
 Castor oil, . . . Ricihux communi* (var. minor and major). 
 C ureas oil (purqueiraoil),. Jatropha curcaa (Curcas purgans). 
 Grape seed oil, . . . Vitls vinifera. 
 
 CLASS IV. ANIMAL NON-DRYING OILS- 
 LARD OIL CLASS. 
 
 When comparatively solid animal fats are subjected to a 
 regulated pressure (p. 231), a mechanical separation of the solid 
 and liquid constituents is effected if the temperature be suitably 
 adjusted ; the fluid substances thus expressed are, strictly 
 speaking, the only products to which the term " oleine " is 
 applicable (besides the analogous fluid constituents of vegetable 
 oils); but in commercial practice the fluid free fatty acids 
 separated by similar means from the products of saponification 
 of such fats, are also designated " oleines," as also are the 
 analogous fluid acids obtained from steam-distilled fatty acids 
 from greases of various kinds (p. 110); further, oils treated with 
 sulphuric acid (Turkey red ohs) are often termed "oleine" in 
 the cotton dyeing industry. Accordingly, the glyceridic ex- 
 pression products are more usually spoken of as " oils " (e.g., 
 tallow oil) than as oleines ; although, even then, confusion is 
 not always avoided, since the terms " tallow oil " and " red oil " 
 are sometimes also applied to the expressed crude oleic acid of 
 the candle maker. 
 
 Products of this class closely resemble vegetable oils of Class I., 
 especially when free from any animal or rancid odour betraying 
 their origin. According to the way in which the expression is 
 effected (more especially as regards temperature), they contain 
 varying quantities of the solid constituents (" stearines," chiefly 
 palmitin and actual stearin i.e., stearic glyceride) in solution, 
 but otherwise consist essentially of olein (oleic glyceride). They 
 usually have a specific gravity of about -915 or -916 at 15, and 
 solidify within a few degrees of C. (above or below). With 
 nitrous acid they form firm solid elaidins ; with sulphuric acid 
 (Maumene's test) the heat evolution is small, as compared with 
 most other oils. The chief oils of the class are : 
 
286 
 
 OILS, FATS, WAXES, ETC. 
 
 Name of Oil. 
 
 Source. 
 
 Lard oil, .... 
 Neat's foot oil, horse foot oil, \ 
 sheep's trotter oil, . . / 
 Tallow oil, . 
 
 Hogs' lard subjected to expression. 
 The " feet" (hoofs and hocks) of oxen, 
 
 horses, and sheep. 
 Ox and mutton tallow subjected to 
 
 expression. 
 
 CLASS V. SESAME OR COTTON SEED CLASS- 
 VEGETABLE SEMI-DRYING OILS. 
 
 The distinctions between this class of oils and those of Classes 
 I. and VI. are not always very clearly marked, the differences 
 being rather of degree than of kind, chiefly consisting in the 
 presence of distinctly larger proportions of glycerides of the 
 drying class than are present in non-drying oils of Class I., 
 although these ingredients are not contained in sufficient 
 quantity to give true drying qualities, such as are possessed by 
 oils of Class VI. i.e., the power of absorbing oxygen from the 
 air, and becoming a solid varnish-like mass. Accordingly, the 
 effect of the elaidin test (p. 137) is to form a soft solid mass, far 
 inferior in hardness and consistency to that furnished by typical 
 non-drying oils, such as olive or arachis oil, but considerably 
 more solid in character than the soft nearly fluid products formed 
 by the true drying oils, such as linseed oil. 
 
 In general, the specific gravity at 15 is a little higher than 
 that of oils of Class I., mostly lying between -923 and -'J35 : and 
 the iodine absorption is similarly raised considerably above 86*2, 
 the theoretical value for pure olein. In most cases, solid 
 glycerides (palmitin, stearin, <tc.) are present to a greater or 
 lesser extent, together with small quantities of glycerides of oxy- 
 acids. The following are the best known oils of the class : 
 
 Name of Oil. 
 
 Camelina oil (German oil of 
 sesame or gold of pleasure 
 oil) 
 
 Cotton seed oil, 
 
 Cress oil, .... 
 Madia oil, .... 
 Maize oil, .... 
 Niger oil (ramtil oil), 
 Sesame oil (gingelly oil, til oil, 
 
 benne oil), . 
 Sunflower oil, .... 
 
 Source. 
 
 Camelina saliva. 
 
 Gow/pium herbaccum ; G. hirautum ; 
 
 G. barbadense ; G. arboreum ; G. 
 
 relirjiosum. 
 Lepidium sativum. 
 Madia sativa. 
 Zea mnis. 
 Guizotia oltifera. 
 
 Sesamum orientale. 
 
 Helianthufi annuus ; H. pereniri*. 
 
LESSER KNOWN VEGETABLE OILS. 287 
 
 Lesser Known Vegetable Oils. In addition to the leading 
 vegetable oils above mentioned belonging to Classes I., II., III., 
 and V., a large number of other oils are locally known and used to 
 a considerable extent in various parts of the world. In most 
 instances nothing whatever is known as to the chemical constitu- 
 tion of these substances; judging from their general physical char- 
 acters they are, as a rule, either nondrying oils of the olive class, 
 or semidrying oils of the cotton seed type; some, however, in all 
 probability are more or less akin to rape or to castor oil. Amongst 
 these lesser known imperfectly drying oils may be mentioned 
 that derived from the soja bean (Soja hispida or Glycine soja) of 
 China and Japan, where both the beans themselves and the oil 
 thence expressed are important articles of food. Recently the 
 plant has been introduced into Europe ; the seeds yield about a 
 sixth of their weight of oil by pressure, furnishing an excellent 
 oilcake for cattle feeding. The oil itself thickens on chilling, and 
 when exposed to air oxidises somewhat rapidly. 
 
 The nuts of the candlenut trees (Aleurites moluccana,A. triloba; 
 Jatropha moluccanum, Croton moluccanum\ found in the Eastern 
 Archipelago, Malay, Cochin China and Southern China ; Cali- 
 fornia, Chili and Venezuela ; Bourbon, Mauritius, Jamaica,. 
 Polynesia and North Australia) furnish similar oils, chiefly used 
 for cooking and burning, but sometimes possessing sufficient 
 drying power to be capable of use for painting purposes in hot 
 climates. In different countries the oil is known by different 
 names e.g., Bankulnut oil, Kekune oil, &c. According to Lach 
 a sample of candlenut fat fusing at 24 and solidifying at 21 
 yielded fatty acids melting at 65 -5 and solidifying at 56 : the 
 iodine number was 118, indicating the presence of a considerable 
 proportion of drying oils. 
 
 L. Field describes candlenut oil as limpid and sweet, not soli- 
 difying at 0, and capable of forming a fine waxy looking soap 
 by the cold process. It is stated to be well adapted for cloth 
 dressing and to be largely exported to Europe for soapmaking r 
 but does not appear to be much used in England for those 
 purposes. The nuts are extremely hard, so as to be cracked 
 by ordinary machinery only with difficulty ; when strung on a 
 twig they can be burnt like a tallow candle, whence the ordinary 
 name. 
 
 The seeds of various species of pine (Pinus sylvestris, P. cibies y 
 P. picea furnish by expression or solvents imperfectly drying oils 
 used to some extent for burning and other purposes ; these vary 
 in specific gravity from '925 to '931 at 15, and mostly thicken at 
 about 15, solidifying at about '27. 
 
 Croton oil, from Croton tiglium, is possessed of weak drying 
 characters, but has a composition differing in many respects from 
 most of the oils of the nondrying and semidrying classes. The 
 specific gravity of the fresh oil is '942 at 15, older oil that has 
 
288 OILS, FATS, WAXES, ETC. 
 
 absorbed oxygen from the air being more dense, about .'955 ; 
 solidification occurs at about - 16. The oil is strongly purgative 
 when taken in small doses internally, and vesicatory when applied 
 to the skin ; it does not form any solid elaidin with nitrous acid. 
 It mainly consists of glycerides, and on saponification furnishes 
 stearic, palmitic, myristic, lauric, caproic, valeric, butyric, .acetic, 
 and formic acids of the acetic family, together with tiglic (methyl 
 cro tonic), and crotonic acids of the oleic series. Oleic acid has 
 been stated to be present by some investigators, and to be absent 
 by others, a nonvolatile " crotonoleic acid " yielding a barium 
 salt soluble in alcohol having also been found. The vesicatory 
 agent is believed to be " crotonol," a semisolid body indicated by 
 the formula C 9 H U O 2 ; this is not identical with the purgative 
 principle, the nature of which is uncertain. 
 
 An excellent fatty oil is largely used in Morocco, derived from 
 the Argan tree (Argania sideroxylon, Elwodendron argan, or 
 Sideroxylon spinosum) : the fruit is fleshy and is eaten greedily 
 by sheep and goats, cows and camels, but the kernels or stones 
 are hard and bony, and are consequently rejected by the animals. 
 These stones are collected and cracked, and the inner white 
 kernels carefully roasted, ground, and kneaded with a little 
 warm water, whereby the oil is gradually expelled, more water 
 being added from time to time, and the mass kneaded until no 
 more oil exudes. After settling the oil is a clear light brown 
 iluid, often of somewhat rancid flavour and odour; it is largely 
 used by the Moors as an edible oil, somewhat cheaper than olive 
 oil. Somewhat similar oils are obtained from the kernels of the 
 fruit of titapliylea pinnata (bladdernuts) in Eastern Europe ; the 
 berries of the dogwood (Cornus sanguined) in Italy, Cashmere, 
 and Siberia ; the seeds of the spindel tree (Euonymus europoeus) 
 of Central Europe ; horsechestnuts (^Esculus liippocastanum) ; 
 and the seeds of Sarcostigma Kleinii (known as Adul or Odal oil 
 in Southern India), of several Hibiscus species, and of Penta- 
 clethra macrophylla (Owala oil of the Gaboon, Opochala oil of 
 Fernando Po). 
 
 The Brazil nut or Castanha (BertJiolletia excelsa) of South 
 America yields a clear yellow bland oil closely resembling that 
 of almonds, soon becoming rancid ; the edible seeds of the 
 Telfairia pedata of South-east Africa furnish a similar oil, said 
 to be equal to the finest olive oil. Pumpkin seed oil (Curcurbita 
 pepo) is a clear sweet-tasting oil, yellowish or nearly colourless 
 when obtained by cold pressure, possessed of only faintly marked 
 drying qualities ; its relative density is '923 at 15 ; at - 15 
 it solidifies to a greyish-yellow mass. Similar oils are obtain- 
 able from the seeds of other curcurbitaceous plants e.g., the 
 watermelon (Cucumis citrullus), sweet melon (C. melo), gherkin 
 (C. sativus), colocynth (C. colocynthis}, Arc. The oil of the 
 Boma nut (Pycnocoma macrophylla) is sweet and bland, and is 
 
LESSER KNOWN VEGETABLE OILS. 289 
 
 much used for cooking by the natives of Central Africa ; that of 
 the Cashew or Acajou nut (Anacardium occidentals) is similarly 
 employed in the East and West Indies and the West Coast of 
 Africa; in the Brazils it has been in use for centuries as an 
 edible oil ; it is a light yellow sweet-tasting oil much like that of 
 almonds, of relative density -916. Mango seeds (Mangifera 
 indica) and pistachio nuts (Pistachio, vera) yield similar oils, as 
 also do the fruit kernels of BucJianania latifolia, a forest tree 
 common in Coromandel, Malabar, and Mysore ; the oil from the 
 last is limpid and of a pale straw colour and is sometimes known 
 as Chironji oil. Various species of (Enocarpus bear oleaginous 
 nuts furnishing sweet cooking and eating oils, known in Para as 
 "coumu oil," resembling olive oil but becoming solid much more 
 readily 011 chilling ; hickory nuts (Gary a olivceformis), M'poga 
 nuts (common in the Gaboon), breadnuts (OmpJialea diandra 
 and 0. triandra St. Domingo and Jamaica), and many other 
 lesser known nuts and seeds are also sources of similar pro- 
 ducts. 
 
 According to J. R. Jackson,* a large number of new oil seeds 
 have come into the English market of late years from the 
 West Coast of Africa, but the supplies have mostly been inter- 
 mittent ; some few are particularly well adapted for use were a 
 constant supply forthcoming, more especially the seeds of the 
 Telfairia occidentalis (a cucurbitaceous plant) ; the Myristica 
 angolensis (a scentless nutmeg) ; the Hyptis spicigera (a herbaceous 
 labiate plant); the Poly gala rarifolia ("Maluku" seeds); the 
 Lophira alata (" Meni " or " Laintlaintain " seeds, from one of 
 the Dipterocarpece ; Senegambia and Sierra Leone) ; and the 
 Penteclethra macropJiylla (a leguminous tree, the " Owala " of the 
 Gaboon, and the " Opachala " of the Eboe country. " M'poga," 
 " Mabo," and " Niko " nuts also furnish oils of a character that 
 might render them very useful. 
 
 Similar remarks apply to the oil bearing produce of many 
 other countries ; in many instances the oils thence obtainable are 
 of characters so good for a variety of purposes as to leave little 
 doubt that a considerable amount of trade in such materials will 
 hereafter become developed whenever the conditions are realised 
 necessary for the economical growth of the trees and plants, and 
 the harvesting of their seeds, nuts, or other fruits, &c., or for their 
 treatment on the spot for the extraction of oil ; together with the 
 necessary opening up of the districts for transport purposes, so 
 as to enable regular supplies to be obtained. In all probability 
 the uncertainty as to what quantity of material could be obtained, 
 and its price, has largely militated against the importation into 
 Europe of numerous raw materials of the kind, manufacturers 
 not caring to expend time, skill, and capital in working up sale- 
 able products until assured on these points. 
 
 * Journal Society of Arts, 1891, 40, p. 122. 
 
 19 
 
290 OILS, FATS, WAXES, ETC. 
 
 LASS VI. DRYING OILS LINSEED OIL CLASS. 
 
 The drying oils proper principally differ from the semi-drying 
 oils in containing much larger proportions of the glycerides of 
 the more " unsaturated " acids (linolic, linolenic, and isolinolenic 
 acids), these substances greatly predominating, and only compara- 
 tively small amounts of olein and of the glycerides of the solid 
 fatty acids being present, so that these latter rarely separate in 
 any quantity as solid " stearines" on chilling and standing. 
 
 Owing to the more or less considerable amount present of 
 these unsaturated constituents, both drying and semi-drying oils 
 possess higher iodine absorbing powers than the oils of the first 
 four classes, and develop more heat on mixture with sulphuric 
 acid (Maumene^s test, p. 147). When drying oils are spread 
 out in a thin layer they rapidly absorb oxygen from the air, 
 increasing in weight and " drying up " to a solid varnish, which 
 in time becomes perfectly hard and not in the least sticky or 
 "tacky;" semi-drying oils, similarly treated, increase in weight 
 to a much less extent, and more slowly, and never dry up 
 thoroughly to a hard varnish free from stickiness. With nitrous 
 acid, drying oils give no solid elaidins ; semi-drying oils usually 
 give buttery masses from which fluid matter separates. 
 
 The specific gravity of drying oils is usually distinctly higher 
 than that of oils of Class I., generally lying between '923 and 
 935, and increasing as oxidation goes 011 until finally the dried 
 films or " skins " are heavier than water. According to Bauer 
 and Hazura, the drying qualities are the more pronounced the 
 larger the proportion of linolenic and isolinolenic acids present, 
 linolic acid contributing less markedly to the drying properties ; 
 so that an oil consisting mainly of the glycerides of oleic and 
 linolic acids, even when the latter predominates, does not 
 exhibit drying powers equal to that of another containing a 
 considerable proportion of linolenic and isolinolenic glycerides. 
 They regard non-drying, semi-drying, and drying vegetable oils 
 as distinguishable by the following characters so far as liquid 
 constituents are concerned : 
 
 Non-Drying Oils contain none, or at most only small per- 
 centages, of the glycerides of either linolic, linolenic, or isolin- 
 olenic acids. 
 
 Semi-Drying Oils contain more or less considerable amounts 
 of linolic glyceride, but little or no glycerides of linolenic or iso- 
 linolenic acid; the drying action being also retarded by the 
 presence of more or less olein and other non-drying glycerides. 
 
 True Drying Oils contain considerable amounts of linolenic 
 and isolinolenic glycerides, together with linolin, and but small 
 amounts of olein and non-drying glycerides. 
 
 Obviously the exact lines of demarcation between non-drying 
 
DRYING OILS. 291 
 
 and semi-drying oils, on the one hand, and between semi-drying 
 and truly drying oils, on the other, are but faintly traced j so 
 that it often happens that a given oil is classed by one writer 
 amongst the oils of one class, and by another amongst those of 
 the adjacent class. 
 
 As regards non-drying and semi-drying animal oils, it is 
 noticeable that the fatty acids thence obtainable yield no sativic 
 acid on oxidation by alkaline permanganate (Benedikt and 
 Hazura) ; from which it results that linolic acid is not a consti- 
 tuent of oils of this class ; whereas larger or smaller quantities 
 of sativic acid appear to be obtainable from many, if not all, 
 vegetable oils by this treatment. 
 
 The best known drying oils are the following : 
 
 Name of Oil. 
 
 Source. 
 
 Hemp seed oil, 
 Lallemaiitia oil, 
 Linseed oil, 
 Poppy seed oil, 
 
 Tobacco seed oil, 
 Walnut oil (nut oil), 
 Weldseed oil, . 
 
 Cannabis saliva. 
 Lallemantia iberica. 
 Linum usitatissimum (L. perenne). 
 Papaver somniferum ; P. rheas ; Glau- 
 cium luteum; Argemone mexicana. 
 Nicotiana tabacum. 
 Juylans regia. 
 Reseda luteola. 
 
 Many other oils of pretty strongly marked drying qualities are 
 known and employed locally, without being articles in which any 
 considerable amount of export trade is done ; few of these have 
 been submitted to any detailed examination. Hickory nut oil 
 (Gary a olivcrformis) is sometimes sold under the name of 
 "American walnut oil," but appears to be very inferior in drying 
 qualities. The seeds of Calopliyllum inophyllum, a forest tree 
 widely distributed in the eastern tropics, furnish an oil known 
 by various names (dilo, domba, pinnay, poon seed, or tamanu 
 oil) ; when mixed with pigments, this forms a paint that dries in 
 1 2 hours, without any previous boiling ; owing to the large yield 
 of oil, and the plentifulness of the tree in India, Ceylon, the 
 Malay Archipelago and Java, and the South Pacific Islands, &c., 
 this oil appears likely to be an important article in future. The 
 kernels of the Aleurites cordata (Elceococca vernicia) furnish an oil 
 ("Japanese wood oil," " tung oil") largely used as a varnish in 
 China and Japan on account of its extremely rapid drying 
 qualities. According to Cloez, this oil contains about 25 per 
 cent, of olein, and 75 of a homologue of linolin, furnishing on 
 saponificatioii elceomargaric acid, C ir H 30 Oo/ /r Further investiga- 
 tion is desirable, as the qualities of the oil are such as to render 
 it valuable. 
 
 * Ccmptes rmdw, 83, p. 943. 
 
292 OILS, FATS, WAXES, ETC. 
 
 CLASS vii. TRAIN, LIVER, AND FISH OILS. 
 
 The term " train oil," strictly speaking, applies to any oil 
 extracted from the blubber of cetaceans and allied marine 
 mammalia (such as the seal, porpoise, dolphin, walrus, &c.), and, 
 therefore, in the widest sense includes the sperm oil class, No. X. ; 
 but in the present connection it is intended to apply only to 
 those blubber oils that are essentially of glyceridic character, and 
 not to those that mainly consist of compound ethers of mono- 
 hydric alcohols. It is not quite the equivalent of the German 
 term "thran," which also includes fish oils (sardine oil, menhaden 
 oil, &c.) as well as liver oils (cod liver oil, sunfish liver oil, &c.) 
 
 Oils of this class have been much less thoroughly examined as 
 to their chemical constitution than their importance as trade 
 products warrants. In some cases they consist mainly of the 
 glyceride of physetoleic acid, a lower homologue of oleic acid ; but 
 other glycerides are generally present as well, preventing the 
 formation of solid elaidins ; soft products from which liquid 
 matter separates on standing are generally formed, much as with 
 the oils of Classes II. and VI. ; from which circumstance, toge- 
 ther with the high iodine number generally indicated, and the 
 possession of some degree of drying qualities, it appears probable 
 that drying oil glycerides are also present. Liver oils (cod and 
 shark's livers, &c.) generally contain perceptible amounts of 
 cholesterol and allied biliary products ; like fish oils proper (e.g., 
 menhaden oil), they evolve large amounts of heat on admixture 
 with sulphuric acid, resembling the vegetable drying oils in this 
 respect; whilst train oils (whale oil, seal oil, &c.) give a somewhat 
 lower degree of heat evolution, probably on account of the presence 
 of notable amounts of the glycerides of solid fatty acids (stearin, 
 &c.) When oils of this class are separated from the nitrogenous 
 tissues immediately, so that no decomposition takes place, they 
 are comparatively inodorous and tasteless, and contain no 
 appreciable quantity of free fatty acids ; but if the livers, blubber, 
 fish, &c., are kept for any length of time before the oil is 
 extracted, a more or less strongly marked animal fishy smell is 
 developed, becoming excessively rank in extreme cases ; as in the 
 case of rancid vegetable oils, more or less hydrolysis of glycerides 
 with production of free fatty acids, appears to accompany the 
 development of the strong-smelling bye products thus formed. 
 
 The distinction between oils of this class (mainly glyceridic in 
 character) and those of Class X. (mainly non-glyceridic) is in 
 actual practice not extremely sharply marked ; for sperm oils 
 usually contain small quantities of glycerides, although the chief 
 constituents are non-glyceridic compound ethers ; whilst on the 
 other hand, some of the blubber oils contain notable amounts of 
 solid non-glyceridic compound ethers (spermaceti), deposited on 
 
TRAIN OILS. 
 
 293 
 
 cooling and standing. In fact, it is as difficult or impossible to 
 draw a hard and fast line of demarcation between the glyceridic 
 and non-glyceridic animal oils, as it is between the drying and 
 non-drying vegetable oils ; and for the same reason, viz., that 
 whilst the two extremes are tolerably sharply contrasted in 
 general composition, yet various intermediates exist, partaking 
 of the character of both classes. To some extent, this may 
 possibly arise from the circumstance, that when a ship is engaged 
 in oil-fishery, it is not always practicable to keep apart the 
 blubbers obtained from different species, so that the oil ultimately 
 extracted is often a mixture of the products obtained from 
 different kinds of animal, each of which, if examined separately, 
 would exhibit special characteristics analogous to those dis- 
 tinguishing different seed oils. In general, it appears that 
 whalebone-yielding whales * (Balcenoidea] furnish oils containing 
 little or no monohydric compound ethers like spermaceti ; whilst 
 toothed whales (Delphinoidea) yield oil where these substances 
 are usually present, in some cases as chief constituents ; these 
 latter form the oils of Class X. 
 
 The chief oils of this class ate the following : ' A 
 
 Name of Oil. 
 
 Sources. 
 
 Train Oils- 
 Dolphin and Porpoise oils, 
 
 Seal oils, 
 
 Walrus oil, 
 
 (morse oil, dugong oil, 
 manatee oil). 
 
 Whale oils and Blackfish 
 oils. 
 
 Delphinus phoccena (Phoccena communis), 
 or common porpoise. P. orca, or grampus. 
 Delphinus ddphis, or common dolphin. 
 Delphinus globiceps. D.tursio. Monodon 
 monoce.ros, or narwhal. 
 
 Phoca vttulina; P. groznlandica; P. barbata; 
 P.annelata; P. lagura; P.foetida; P. cas- 
 pica ; P. proboscidea. Otaria jubata. 0. 
 australis. 
 
 Trichechus rosmarus, morse or walrus. 
 lialicore australis and //. indicus, or 
 dugong. Manatus australis and M. 
 >tmt.ricanus, or manatee. 
 
 Baloznus mysticetus or B. grcenlandicus, 
 the "right whale." B. glacialis, or polar 
 whale. B. bb'ops, or humpbacked whale. 
 B. antarctica, or cape whale. B. australis, 
 or southern black whale. Balcenoptera 
 gibbar, or finner whale. Globiocephalus 
 intermedias, or pilot whale. G. macro- 
 rhyncus, or killer. Beluga catodon, or 
 white whale. 
 
 * Huxley classes the existing cetacea (exclusive of extinct genera) as 
 Balcenoidea and Delphinoidea, the latter group including Platinistidce, 
 Delphinidce (dolphins, porpoises, grampus, and narwhal) and P/t.yseteridce ; 
 these last being further subdivided into Physeterina> (cachelots or sperm 
 whales) and Ilhyncoceti (bottlenose whales). 
 
294 
 
 OILS, FATS, WAXES, ETC. 
 
 Name of Oil. 
 
 Sources. 
 
 Liver Oils- 
 Cod oils, . 
 
 Malabar oils, . 
 Ray and Shark oils, 
 
 Fish Oils- 
 Herring oils, . 
 (sardine, sprat, pilchard, 
 anchovy, louar, &c. ) 
 
 Menhaden oil, 
 Oolachan oil, . 
 Tunny oil, 
 
 Gadus morrhua(Asellus major). G. cellarius. 
 
 O. molva (Molva vulgaris). G. (Kglefinus. 
 
 G. carbonarius (Meriangus carbonarius). 
 
 G. merlangus (Merlangus vulgaris). 
 
 G. pollachius (Merlangus pollachius). 
 
 Merluccius communis. 
 Rhyncobatus pectinata. R. Icevis. Galio- 
 
 cerda tigrina. Carcharias melanopterus. 
 Raja clavata. R. batis. Trigon pastinaca. 
 
 Squalus carckarias, or common shark. 
 
 S. maxima, or basking shark. S. glacialis, 
 
 or Greenland shark. S. zygcena (Zygcena 
 
 malleus), or hammerfish. S. acanthius, or 
 
 picked dogfish. S. spinax niger, or kulp. 
 
 Clupcea pontica (Astrakan herring). 
 
 O. sardinus, or sardine ; C. neohouri, C. 
 
 lemuru, and C. palasah, or Indian and 
 
 Malayan louar. C. sprattus, or sprat. 
 
 C. pilchardus, or pilchard. Engraulis 
 
 encrasicholus, or anchovy. 
 Alosa menhaden (Brevoordia menhaden). 
 Thaleichthys paciferus osmerus. 
 Thynnus vulgaris. 
 
 Schadler gives the following table of colour reactions of seal, 
 whale, liver, and fish oils with strong nitric acid (sp. gr. 1*45); 
 sulphuric acid (sp. gr. 1/6 1 '7) ; and the two mixed in equal pro- 
 portions (compare p. 153). 
 
 Nitric Acid. 
 
 Sulphuric Acid. 
 
 Mixed Acids. 
 
 SEAL OIL 
 Red brown, 
 
 WHALE OIL 
 Brownish, becoming 
 full brown, and 
 finally black brown. 
 
 LIVER OILS 
 Blood red, becoming 
 brownish red to 
 brown. 
 
 FISH OILS 
 Brown, . 
 
 Reddish yellow, becoming 
 reddish brown, and ul- 
 timately brownish red, 
 somewhat like blood. 
 
 Brown, becoming black 
 brown. 
 
 Violet to black violet. 
 
 At first greenish, then 
 brown, and finally quite 
 black. 
 
 Reddish, becoming 
 brown. 
 
 Yellow, becoming 
 reddish, and finally 
 dirty brown. 
 
 Yellow red, becoming 
 bright red, finally 
 reddish brown with 
 violet streak. 
 
 Yellow, then greenish, 
 afterwards brown. 
 
VEGETABLE BUTTERS, ETC. 
 
 295 
 
 CLASS VIII. VEGETABLE BUTTERS, FATS AND 
 WAXES, &c. 
 
 When the proportion of glycerides of relatively high melting 
 point to olein is large, the physical texture of a substance that 
 would be an oil in the tropics becomes more like that of butter 
 at 15-20; concurrently with the change in comparative fluidity 
 the iodine absorption is largely reduced as compared with oils 
 of Classes I. and VI., on account of the diminished proportion 
 of olein present. In the case of certain vegetable glyceridic 
 waxes (e.g., Japanese wax), the olein is reduced to insignificant 
 proportions or to nil, with the result of increasing the relative 
 solidity and considerably raising the melting point. Some of the 
 substances of this class contain a notable proportion of glycerides 
 of acids of the acetic family of sufficiently low molecular weight 
 to be readily volatile with steam at ordinary pressure (e.g., coker- 
 nut and laurel butters and palm kernel fat) ; others are practically 
 destitute of such ingredients. When subjected to regulated 
 pressure (p. 283) liquid oleines are squeezed out, and solid 
 stearines left, the former closely resembling oils of Classes I. 
 and VI. when sufficiently freed from the latter. 
 
 The best known substances of this class are the following : 
 
 Name of Butter, &c. 
 
 Bassia fat; HUpe* butter, 
 Mahwa butter, Phulwara 
 fat (Fulwa fat), Shea but- 
 ter (Galam butter), &c. 
 
 Cacao butter, . 
 
 Chinese tallow, 
 Cokernut butter (copra 
 butter or copra fat). 
 Cotton seed stearine, 
 Dika fat, .... 
 
 Japanese wax, . 
 
 Malabar tallow (Piney- 
 
 tallow). 
 Myrtle wax, 
 
 Myristica butters ( Xutrneg 
 butter, Virola tallow, 
 Otaba wax, Deuba or 
 ocuba wax, &c. ) 
 
 Palm butter (palm oil). 
 
 Palmmit butter (palm 
 kernel oil). 
 
 Sources. 
 
 Bassia lalifolia (Roxb. ) B. longifolia(L\aja.. ) 
 B. butyracea. B. Parkii (Butyrosperma 
 Parkii Kotschy). 
 
 Theobroma cacao (Linn. ) T. bicolor (Humb. ) 
 T. aufjustifolium (Sesse). T. leiocarpium 
 and T. pentagonum (Bern. ) T. microcar- 
 pium (Mart.) 
 
 Stillingia sebifera (Croton sebiferum,Lmn.) 
 
 Cocos nucifera; C. butyracea, 
 
 Cotton seed oil by chilling and pressing. 
 Irvingia barteri (Hock.) Mangifera gabo- 
 
 nensis (Aubry Le Comte). 
 Rhus succedanea (Linn.); E. acuminata 
 
 (De C.); 2t. vernidfera (De C.); R.juglan- 
 
 difolia (Don). It. sylvestris (Siebold). 
 Vateria indica (Linn.) ; V- malabarica 
 
 (Blum.); JSlaeocarpus copaliferus (Retz.) 
 Myrica cerifera, and several other species 
 
 of myrtle. 
 Myristica officinalis (Linn.); M. moscliata 
 
 (Thumb.); M. sebifera (Virola sebifera)', 
 
 M. otoba (Humb. and B.); M. ocuba (M. 
 
 ucuba, M. bicuhyba); M. malabarica. 
 
 Elais fjuineensis (Jacq.) ; E. melanococca 
 (Gaert.); Alfonsia oleifera (Humb.) 
 
296 OILS, FATS, WAXES, ETC. 
 
 Similar solid or semisolid vegetable fats are also furnished by the 
 following trees and plants : 
 
 Nephelium lappaceum (Linn.) ; indigenous to Sunda Island, 
 Malacca, and some parts of China. The seeds furnish " Ram- 
 butan tallow," melting at about 65, the solid stearine of which 
 is chiefly the glyceride of arachic acid; a little olein is also 
 present (Oudemanns). 
 
 Carapa guyanensis (C. guineensis) and C. indica (or C. moluc- 
 censis) ; found in Brazil, Guiana, Cruinea, Sierra Leone, India, 
 Ceylon, &c. The seeds of these two species furnish " Carapa fat " 
 (otherwise designated " Andiroba fat," "Coundi oil," " Crabwood 
 oil," " Touloucoona oil," &c.), possessing a composition akin to 
 that of palm oil i.e., consisting chiefly of the glycerides of 
 palmitic and oleic acid. It usually possesses a sickly persistent 
 odour almost impossible to get rid of. The coloured natives use 
 it largely as an unguent and insectifuge for the head, its pro- 
 perties in this respect being apparently due to an admixed bitter 
 principle termed carapin. 
 
 Mafureira oleifera (Bert.) or Trichelia emetica (Vahl.) This 
 tree grows in Mozambique, and about Zambesi and the White 
 Nile ; by crushing the seeds and boiling with water a fat known 
 as " Mafura tallow " is obtained, much resembling cacao butter, 
 melting at 42, and chiefly consisting of palmitin and olein. 
 
 Calophyllum inophyllum (Linn.), indigenous to India and the 
 Malay Archipelago, and C. calaba, found in the Antilles, yield 
 respectively "Poona fat" (" poon seed oil ") or "Tacamahac fat") 
 and " Calabar oil." The former is also known by various other 
 names (vide p. 291). 
 
 Laurus nobilis, found largely in Southern Europe and Asia, 
 yields "laurel butter" ("bayberry fat"), largely consisting of 
 the glyceride of lauric acid, along with a little myristin and 
 other homologues, and some olein. A similar product is obtained 
 from L. persea (Linn.) or Persea gratissima (Gaert.), the Alligator 
 pear tree of Brazil and the West Indies ; known as " Alligator 
 pear oil," " Persea fat," and "Avocado oil." 
 
 In addition to these, a large number of more or less hard 
 vegetable fats and tallows are obtainable from other sources, 
 concerning the chemical constitution of which little or nothing 
 is known thus " Malayan tallow " and " Borneo tallow " are 
 solid fats obtained from the nuts of various species of Hopea in 
 Java, Sumatra, and Borneo. An analogous product, "Sierra 
 Leone butter," is obtained in Sierra Leone from Pentadesma 
 butyracea. " Goa butter" ("Kokum butter" or " Mangosteen 
 oil ") is a similar fat obtained in the East Indies from the seeds 
 of Garcinia indica (Mangosteena indica). The allied species 
 G. pictoria or gamboge tree furnishes "gamboge butter." The 
 seeds of Pongamia glabra, another East Indian shrub, furnish 
 " Korinje (Karanja) butter," " Poondi oil " or " Ponga oil," some- 
 
LESSER KNOWN VEGETABLE FATS. 297 
 
 what more readily fusible than most of the vegetable fats and 
 tallows. " Macaja butter " is derived from the edible fruit of 
 Cocos aculeata (Acromia sclerocarpa, Mart.; Bactris minor, Gaert.), 
 indigenous to Brazil, Guiana, and the W T est Indies. In Java a 
 fat much resembling coker butter, " tangkallak fat," is derived 
 from the Cylicodaphne sebifera. Semisolid fats are obtained 
 from the Canarium commune of the Moluccas and Malabar 
 (" Canary oil," "Java almond oil ") and the butternut tree of the 
 Brazils (Rhizobolus butyrosa; the allied species, R. amygdalifera 
 (Caryocar brasiliensis) and Caryocar tomentosum, respectively 
 furnish " Caryocar oil " and " Sawarri (or Souari) nut butter." 
 The soap tree of Bengal, Southern India, and the West Indies 
 (Sapindus emarginatus, Roxb.; S. trifoliatus, Linn.; S.laurifolia, 
 Vahl.), furnishes a fruit rich in saponin, and also yielding a semi- 
 solid fat. " Maccassar oil " is a semisolid fat obtained from the 
 seeds of Sckleicliera trijuga ;* and "Piquia oil" ("Pekea fat") 
 is a similar product from Pekea butyrosa and P. ternatea, found 
 in Guiana and the Antilles. Melia azedarach (Linn.), the "pater- 
 noster tree " of Syria, Northern India, and the Deccan, <kc. (so- 
 called from the employment of its stones in Italy and elsewhere 
 for making rosaries), also known as Melia indica (Brand.) and 
 Azadirachta indica (Juss.), furnishes a very similar semisolid fat, 
 known as " Zedrach oil," " Margosa oil," " Veppam fat," or 
 " Nimb (or Neem) oil." " Niam fat " is derived from the 
 Lophira alata, found in Eastern and Western Africa. " Chaul- 
 moogra oil" is a soft fat fusing at about 17C., obtained from 
 the seeds of Gynocardia odorata (Cliaulmoogra odorata), much 
 used in India, China, and elsewhere for medicinal application to 
 the skin. "Soudan butter" is a soft fat obtained by boiling 
 with water the seeds of Vitellaria paradoxa, or Soudanese butter 
 plant ; a similar product is obtained in Cochin China and Japan 
 from the seeds of Sebifera glutinosa (Tetrantliera laurifolia, Jacq.) 
 The seeds of (Enocarpus bacaba and CE. patawa, of Central 
 America, yield by similar treatment a soft fat known locally as 
 "Comou butter." "Para butter" or "Assai oil" is similarly 
 obtained from the Assai palm (Euterpe oleracea], common in 
 Brazil and the neighbourhood of Para. "Chequito" is a fatty 
 substance obtained by the Kaffirs of Southeast Africa from the 
 "butter tree," Combretum butyraceum. The seeds of Cocculus 
 indicus contain a solid fat, extracted and used by the natives in 
 India, but apparently not yet known commercially ; similar pro- 
 ducts are obtained from the fruit kernels of Lucuma bonj)landi 
 in Mexico, and the Ochoco (Dryobalanops) of Guinea. 
 
 * Also from the oleaginous fruit of Stadmannia (Cupania) Sideroxylon, 
 growing in Sunda and Timor Islands, and from the seeds of the safflower 
 (Oarthamus tinctorins) ; other varieties of socalled "Macassor" oil are 
 simply more or less fluid oils in which odorous flowers, &c., have been 
 digested so as to scent them. 
 
 CFTHE 
 
298 OILS, FATS, WAXES, ETC. 
 
 In addition to the above, a large number of other sources of 
 vegetable fats exist in different parts of the world, the knowledge 
 of which is as yet chiefly confined to the natives ; there can, 
 however, be little doubt that in due time, as civilisation advances 
 and opportunities for export and manufacture become more 
 frequent, many of these little-known products will be found to 
 be of considerable value as sources of oleaginous material. 
 
 CLASS IX. ANIMAL FATS TALLOW, LAUD, AND 
 BUTTER CLASS. 
 
 Almost every known animal is capable of yielding more or less 
 considerable amounts of fatty matter by appropriate treatment ; 
 but in practice, comparatively few are actually employed as 
 sources of fat, apart from their consumption as food. The solid 
 fat of oxen and sheep (known as tallow or suet when derived from 
 the adipose tissues of the body), the grease extracted from their 
 hoofs (neat's foot oil, sheep's trotter oil), and that obtained by 
 boiling the bones (bone grease) are closely akin in general 
 composition, except that the latter are softer in character, chiefly 
 because containing a larger proportion of olein, and a smaller 
 amount of solid glycerides. The fatty matters (butters) contained 
 in the milk of cows and ewes, on the other hand, have a composi- 
 tion materially different from that of the fats present in the 
 adipose tissues of the body ; and the same remark applies to the 
 milk fats of all other mammalia, so far as they have been 
 examined. In general, the milk fats of various animals do not 
 differ very greatly in character ; thus, the butters derived from 
 the cow, ass, ewe, goat, elephant, hippopotamus, sow, mare, and 
 woman, appear to be as closely akin as are the more or less solid 
 tallows, greases, and suets obtainable from the body tissues of 
 these various animals ; but whilst the latter fats are all essentially 
 mixtures of the liquid glyceride of oleic acid, and the solid 
 glycerides of stearic and palmitic acids (the liquid constituents 
 being present in larger quantity in the softer fats, like lard), the 
 former fats contain a considerable amount of the glycerides of 
 acids, also of the stearic series, but of much lower molecular 
 weight than palmitic acid. Similarly, the milk fat of the whale 
 is not widely different from that of the cow, although the oil of 
 whales' blubber differs much from suet in composition. 
 
 The fats obtained from the carcases of birds (goose grease, 
 turkey fat, pheasant grease, &c.) appear to be substantially 
 similar to the softer body fats of mammalia in general composi- 
 tion, essentially consisting of olein, with enough stearin and 
 palmitin to render them semisolid at the ordinary temperature ; 
 the oleaginous matter contained in eggs (e.g., hen's eggs) is softer 
 
ANIMAL FATS AND OILS. 
 
 299 
 
 still, and consists of olein and palmitin, together with other 
 substances foreign to the oil proper (vide p. 121). 
 
 Various reptiles (turtles, crocodiles, &c.) are utilised in different 
 parts of the world as sources of oleaginous matters, apparently, 
 for the most part, closely akin to the fats of the mammalian 
 vertebrates ; on the other hand, the oily matters derived from 
 fish are differently constituted (supra, p. 292). 
 
 The following list includes the more important solid or semi- 
 solid animal fats, apart from those derived from fishes and 
 cetacea : 
 
 Name of Fat. 
 
 Sources. 
 
 Bone fat, .... 
 
 Butter (cow's milk fat), 
 Butter substitutes (butterine, 
 margarine, oleomargarine), 
 
 Crocodile fat (alligator fat), . 
 
 Egg oil, 
 Goose grease, 
 Horse grease (mare's grease) 
 Lard, .... 
 Tallow, 
 
 Tannery grease, kitchen grease, 
 wool grease, 
 
 Bones of oxen and horses, &c., extracted 
 
 by boiling or by solvents. 
 Domestic cow. 
 The softer portions of the fat of oxen 
 
 and sheep, &c., separated by special 
 
 processes. 
 Indian crocodile and common alligator 
 
 (Alligator Iticius). 
 
 Yolks of hen's eggs (Gallus domesticus). 
 Common goose. 
 
 Horse carcases (Equus caballus}. 
 Common hog. 
 Ox, sheep, goat, &c. 
 Animal greases from various kinds of 
 
 trade refuse. 
 
 In addition to these, the fat of the alpaca is used to a con- 
 siderable extent in some parts of South America; that of the 
 dog in continental Europe, that of the hippopotamus in Africa, and 
 that of the turtle in the islands "of the South Pacific, Brazil, and 
 along the South American coast. The last is sufficiently fluid in 
 a tropical or subtropical climate to be used as a burning oil. 
 Bear's grease was at one time highly esteemed as a pomade, but 
 is now mostly superseded by other forms of clarified fat. Many 
 other animal fats are also used locally in different countries to a 
 greater or lesser extent, but as yet are not articles of regular 
 trade. When the solid or semisolid fats of this class are 
 subjected to expression, the liquid animal oleines of Class IV. 
 result e.g., lard oil, tallow oil, &c. 
 
 CLASS X. ANIMAL OILS SPERM OIL CLASS. 
 
 The blubber oils included in Class VII. (whale, seal, porpoise, 
 <fec.) differ from those belonging to this class essentially in that they 
 consist chiefly of fatty glycerides ; whereas the oils now under 
 consideration, whilst not invariably free from glyceridic con- 
 
300 OILS, FATS, WAXES, ETC. 
 
 stituents, have, as regards their leading constituents, an entirely 
 different composition, these substances being compound ethers 
 formed from monohydric alcohols and fatty acids, analogous to 
 ethyl acetate and similar substances. In general, two kinds of 
 such compound ethers appear to be present simultaneously one 
 liquid at ordinary temperatures, corresponding with the olein of 
 ordinary vegetable oils, and consisting of ethers of acids of the 
 oleic family ; the other solid, corresponding with stearin or 
 palmitin. and consisting of ethers of acids of the acetic family. 
 Just as a vegetable oil on chilling deposits solid matter of the 
 stearin character, readily separable by filtration or straining, so 
 does a blubber oil of the sperm class similarly deposit solid 
 crystallisable matter, generally the substance known as spermaceti 
 (mainly consisting of cetyl palmitate); the liquid portions 
 separated from this deposit appear to be mixtures not only of 
 compound ethers of different homologous acids, but also of 
 different homologous alcohols, some of which belong to the ethylic 
 series, whilst others are apparently homologues of acrylic alcohol, 
 capable of combining with iodine, like the unsaturated acids. In 
 consequence, when saponified, these liquid oils yield large 
 percentages of products insoluble in water, but soluble in ether, 
 fec., consisting of mixtures of the alcohols formed during saponi- 
 fication ; a circumstance sharply distinguishing them from the 
 glyceridic oils of Class VII., which yield only comparatively 
 small quantities of unsaponifiable matters insoluble in water, 
 chiefly consisting of cholesterol and similar substances. 
 
 On account of the presence of compound ethers of the oleic 
 family, oils of the sperm class become more or less solidified by 
 nitrous acid in virtue of the elaidin reaction ; with Maumene's 
 test (p. 147) they develop but little more heat than olive oil, 
 being thus sharply distinguished from most fish oils of Class VII., 
 which give a much greater heat evolution (pp. 149, 150). Their 
 peculiar compound ether composition largely raises the saponifi- 
 cation equivalent. 
 
 The physical characters of this class of oils also are peculiar in 
 virtue of their unusual constitution ; thus their efflux viscosity 
 (p. 101) is much less influenced by variation of temperature than 
 is the case with most other oils, whence their value as lubricants 
 for special purposes. Their specific gravity is low, usually con- 
 siderably below -900, near -880. 
 
 The principal oils of this class are as follows : 
 
 Name of Oil. 
 
 Sources. 
 
 Sperm oil, . 
 
 Doegling oil (Arctic sperm 
 oil or true bottlenose oil), 
 
 Physeter macrocephalus, L. (Cachelot 
 
 whale). 
 Hypeioodon rostratus (Balcena rostrata), 
 
 or true bottlenose whale, H. Bid ens. 
 
WAXES. 301 
 
 Various other toothed cetaceans also furnish oils containing 
 spermaceti in sufficient quantity to separate out in the solid 
 state on chilling and standing, more especially the oil from the 
 bottlenose dolphin, Delphinus globiceps, which appears to be 
 essentially intermediate in character between the almost wholly 
 glyceridic and largely valerin-containing oil from the common 
 porpoise, and the mainly compound ethereal sperm oil of the 
 cachelot in which only small amounts of valerin are present. 
 
 CLASS XI. VEGETABLE NONGLYCERIDIC WAXES. 
 
 Several species of plants are known, the berries, leaves, stalks, 
 <fec., of which are naturally covered with a waxy exudation closely 
 akin in its origin to certain of the more solid vegetable fats, but 
 differing therefrom in being essentially nonglyceridic in character. 
 Of these substances the principal are as follows : 
 
 Name of Wax. 
 
 Source. 
 
 Carnauba wax, 
 Cowtree wax, 
 
 Corypha cerifera (Linn.); Copernicia 
 cerifera (Mart.) 
 Galactodendron americaum (Linn.); 
 (G. utile, Kunth ; Brosimum galacto- 
 dendron, Don.) 
 
 In addition very similar products are obtained from several 
 other sources e.g., Petha wax, from the bloom on the Indian 
 white gourd (Benincasa cerifera) ; Fig wax (Getah wax), pre- 
 pared in Java and Sumatra from Ficus umbellata and F. cerifera 
 (Blume) ; Palm ivax (Ceroxylin), largely used in Brazil, from the 
 common wax palm, Ceroxylon andicola (Humb.), and the Klop- 
 stock palm, Klopstockia cerifera (Karsten) ; and Cordillera wax 
 from the Cordillera waxtree (Elceagia utilis. 
 
 These products, however, do not seem to have been submitted 
 as yet to full chemical investigation, so that it is not certain 
 whether they are true vegetable waxes of nonglyceridic character, 
 or simply vegetable fats of waxy texture analogous to socalled 
 Japanese wax. Comparatively little of these various kinds 
 of vegetable waxes is as yet exported to Europe, most being 
 used for candlemaking, &c., in the countries where they are 
 indigenous. 
 
 CLASS XII. BEESWAX AND SPERMACETI CLASS. 
 
 The nonglyceridic waxlike compound ethers of animal origin 
 used to any extent industrially are but few in number, the prin- 
 cipal being as follows : 
 
302 
 
 OILS, FATS, WAXES, ETC. 
 
 Name of Wax. 
 
 Beeswax (ordinary beeswax. 
 Andaquia wax, Antilles wax, 
 African beeswax, Abyssinian 
 beeswax, &c.), 
 
 Chinese wax (Peh-la or Pela), 
 Indian wax (Arjun wax), 
 Niin fat, .... 
 Spermaceti, .... 
 Woolgrease, 
 
 Source. 
 
 Apis meUifera, or common bee. Numer- 
 ous allied species exist, many of which 
 are also wax producers e.g., Apis 
 fasciata (Melipona fasciata), or South 
 American bee ; Apis unicolor, or Mada- 
 gascan bee ; Apis dorsata, of the Eastern 
 Archipelago. The common wasp and 
 other allied genera are also wax pro- 
 ducers to a limited extent. 
 j Coccus sinensis (Coccus pe-la, C.chinensis} 
 
 Ceroplastes ceriferus. 
 
 Coccus adipofera. 
 
 Physeter macrocephalus. 
 
 Natural grease (inspissated perspiration) 
 of the common sheep. 
 
 CHAPTER XIY. 
 PRINCIPAL USES OF OILS AND FATS, &c. 
 
 THE classification described in the previous chapter is mainly 
 based on the physical and chemical characters of the natural fixed 
 oils and allied substances ; from the point of view of their leadiDg 
 practical uses they may be conveniently considered under one or 
 other of the following six heads : 
 
 1. Substances used for edible purposes, including cooking and 
 preservation of food (e.g., sardines). 
 
 2. Fluid oils employed for burning in lamps or otherwise. 
 
 3. Substances furnishing solid materials for candlernaking. 
 
 4. Substances used in the manufacture of soap. 
 
 5. Drying oils employed for paint manufacture and in the pre-. 
 paration of varnishes, linoleum, and such like products. 
 
 6. Substances used for miscellaneous purposes ; more especially 
 as lubricants or ingredients in lubricating mixtures ; for currying 
 leather, dressing cloth and textile fabrics, and similar purposes ; 
 as oil baths for tempering metals ; as solvents for odorous matters 
 in the process of enfleurage in perfumery manufacture ; for the 
 preparation of unguents, pomades, cosmetics, &c. ; in the manu- 
 facture of sealing wax and analogous compositions ; and for, 
 numerous minor uses in the arts generally. 
 
 Of these six groups, Nos. 3 and 4 are separately considered in 
 6 and 7 (candle and soapmaking, including glycerol extrac- 
 tion) ; with respect to the other uses, some few points are of 
 special interest from the technological point of view, in connection 
 with which the question of purity and freedom from adulteration 
 with inferior materials is frequently of prime importance. 
 
EDIBLE OILS AND FATS. 303 
 
 EDIBLE AND CULINARY USES OF OILS, 
 FATS, fec. 
 
 Fatty matters of various kinds are ingredients in most kinds 
 of food stuffs in common use to a greater or lesser extent ; thus 
 apart from suet and the adipose tissues interleaved with the 
 " lean " of most kinds of animal meat, most vegetable seeds, nuts, 
 and other edible produce contain more or less considerable 
 quantities of oleaginous matter ; sometimes to an extent suffi- 
 ciently large to admit of oil being extracted by pressure fy.g. t 
 olives, walnuts, hazelnuts, &c.), sometimes only in smaller quan- 
 tity, so that a solvent (ether, Ac.) is requisite before the presence 
 of oil can be demonstrated. When thus treated, however, even 
 such substances as wheaten flour and cereal produce generally, 
 rice, and dried vegetables can be shown to contain small quan- 
 tities of oleaginous ingredients. 
 
 Apart from the consumption of oily matter for food in forms 
 such as these, large quantities of separately extracted fatty sub- 
 stances are habitually used as edibles by both civilised and 
 uncivilised races e.g., " salad " oils employed for " dressing " raw 
 vegetables and otherwise as food materials ; more or less purified 
 and rendered animal fats, especially dripping and lard ; and the 
 fatty matter of cow's milk (butter). In cold climates seal and 
 whale oil are eagerly partaken of by the natives as heat-generating 
 foods, whilst a lump of tallow is a delicacy ; elsewhere fish pre- 
 served in oil (e.g., sardines), or cooked in hot oil, pastry containing 
 butter, suet puddings, and numberless other viands into the com- 
 position of which more or less oleaginous matter enters, are- 
 everyday articles of diet. 
 
 With the exception of actively medicinal oils (such as croton and 
 castor oils), the great bulk of natural glycerides are suitable as 
 food material for cattle, especially when used without separation 
 from the other vegetable matters naturally accompanying them. 
 Linseed cake (crushed linseed subjected to pressure so as to 
 express most of the oil), and similar substances from other kinds of 
 seeds, &c., are well known cattle foods, the value of which largely 
 depends on the amount of residual oily matter left in the mass. 
 
 Waxes, on the other hand, are but little adapted for nutritive 
 purposes ; thus beeswax (even when eaten along with honey) 
 mostly passes unchanged through the alimentary canal, and is not 
 assimilated at all, either by human beings or other mammalia. 
 
 In the preparation for table and culinary use of oils and fats r 
 &c., but little treatment of a technical nature is usually requisite, 
 the chief points requiring attention being good quality of the 
 raw material, and cleanliness in the treatment to which it is 
 subjected ; thus the excellence of the butter prepared in a given 
 dairy chiefly depends on the quality of the milk from which it is. 
 separated, and the care and cleanliness employed throughout the 
 
304 OILS, FATS, WAXES, ETC. 
 
 process. Very similar remarks apply to the preparation of the 
 finer qualities of refined lard intended for food, and the ordin- 
 ary kitchen operations of clarifying dripping, &c., and to the 
 extraction of vegetable oils generally. As already described, 
 "virgin" oils, and "first runnings" are generally prepared from 
 choice oil sources (olives, arachis nuts, &c.) by gentle pressure 
 without heat, somewhat coarser grades being subsequently ex- 
 pressed by stronger pressure and heat combined; refining by 
 agitation with water, subsidence, and straining, being usually 
 preferred to processes involving chemical treatment. In some 
 parts of Russia and Eastern Europe much coarser oils are con- 
 sumed by the peasantry than are usually similarly employed 
 amongst either Western Nations or Asiatics ; hempseed, poppy 
 seed, and linseed oils, often somewhat crudely extracted, being 
 largely used as cooking oils. | Of late years, however, sunflower 
 seed oil has to a great extent superseded these coarser oils ; whilst 
 in Western Europe, America, and many other parts of the world, 
 cotton seed oil, expressed by the hydraulic process described 
 in Chap, ix., and subsequently refined by boiling with alkalies, 
 ifec., is now very largely employed for many purposes for which 
 formerly only olive oil was used, or the better grades of arachis 
 oil, sesame oil, and similar high-class substances ; the result of 
 properly refining a fair quality of raw cotton seed oil being to 
 produce a light coloured pleasantly tasting wholesome product 
 eminently well adapted for frying fish and such like cooking 
 operations. In connection with this the following table by 
 Grimshaw is of interest, showing the way in which a ton of seeds 
 is practically utilised : 
 
 Cotton seeds = 2000 pounds. 
 
 i 
 
 About 1089 Ibs. of " Meats " About 20 Ibs. About 891 Ibs. of "Hulls" 
 or decorticated seeds ready of Lint. ultimately separated into 
 
 for crushing 
 
 Fibre used for high class 
 
 papermaking. 
 About 800 Ibs. About 289 Ibs. of , ., , , ,. , 
 
 Oilcake used Crude oil. Fu ^ the ashes f ^ 
 
 for cattle feeding. After refining this J an excellent fer ' 
 
 yields tlllser ' 
 
 I 
 
 Summer yellow (refined). Foots, 
 
 After chilling and filterpressing, &c., used for soapmaking, &c. 
 this yields 
 
 Winter yellow. Cotton seed stearine. 
 
VEGETABLE LARD. 305 
 
 Cotton Seed Stearine (Vegetable Margarine). When 
 cotton seed oil is chilled, a portion solidifies as solid glycerides ; 
 when these are separated by " bagging " or the use of a filterpress 
 (p. 229), and subsequently subjected to hydraulic pressure, a com- 
 pletely solid fat results. The more solid substances thus obtained 
 are largely used as ingredients in artificial butter ; the physical 
 characters, and especially the melting point, vary somewhat with 
 the extent to which the expression has been carried ; usually 
 cotton seed stearine is pressed so as to melt at a little above 30. 
 
 Amongst the Hindoos and others whose religious beliefs 
 preclude the use of animal fats for edible and cooking purposes, 
 a large sale now exists for purely vegetable fats of buttery con- 
 sistence (vegetable lard) ; the process of semisolid stearine 
 extraction from vegetable oils (such as cotton seed, cokernut, 
 and many other native oils) is consequently somewhat largely 
 adopted for the purpose of meeting this demand ; quite 
 irrespective of the illegitimate use of these products for purely 
 adulterative purposes in reference to more highly priced animal 
 fats, especially butter and lard. 
 
 Another substance, improperly called cotton seed stearine, is 
 obtained by distilling with superheated steam the mixture of 
 organic acids formed when a mineral acid is made to decompose 
 the " foots " obtained during the process of refining cotton seed 
 oil by alkalies (p. 261), and pressing out the "oleine" from the 
 distillate after cooling and solidification. Products of this kind 
 appear to contain a large amount of un saturated solid fatty 
 acids, possibly isoleic acid (p. 29). A. H. Allen found that a 
 " stearine " of this kind had the specific gravity 0-868 at 99, 
 and melted at 40, whilst the iodine number was 89 '9 ; the theo- 
 retical value for pure isoleic (oleic) acid being 90'1. 
 
 Recent Cultivation of Sunflower Seeds in Russia. Of 
 late years the oil obtained in Russia from sunflower seeds has 
 very largely displaced the other cooking and table oils (chiefly 
 poppy and hemp) in popular estimation, and the cultivation of 
 the plant has increased enormously; with due care in the drying 
 and cleaning of the seeds, the oil first expressed is equal to the 
 best French table oils in colour, flavour, and taste. The shells 
 form a considerable article of trade for heating purposes, whilst 
 the stalks, dried in piles, are preferred even to pine wood for 
 producing a quick and hot- flame fire ; each acre yields about 
 2,000 Ibs. of such firewood and some 1,350 Ibs. of oil. The ashes 
 contain much potash ; 1,000 Ibs. of dried stalks yield 5 7 '2 of 
 ash, from which about 35 per cent, of the best potashes are 
 obtainable. The oilcakes are looked upon as the best in Russia ; 
 superior to either hemp or rape seed cake ; upwards of 2,000,000 
 Ibs. are exported by the Government of Saratov alone. The 
 seed cups are used as food for sheep. In the larger mills the 
 process of extraction is much the same as that used in England 
 
 20 
 
306 OILS, FATS, WAXES, ETC. 
 
 for linseed and rape seed (Chap. XL), the shelled seeds being 
 dusted and crushed to a paste in a steam heated vessel ; the 
 warm paste is wrapped in camel's hair webbing, and pressed. 
 Out of 104 oil mills in Russia, 85 are employed solely in 
 obtaining sunflower oil, steam being used in 24, and manual 
 labour only in the others (Journ. Soc. of Arts, March 18, 1892). 
 
 Manufacture of Lard. The fatty tissues of the hog when 
 properly rendered furnish a white semisolid grease considerably 
 softer than the corresponding fat (tallow) from oxen and sheep, 
 chiefly differing therefrom in containing more olein and less 
 solid glycerides. In most of the larger American hog slaughter- 
 ing factories the fats from different parts of the body are kept 
 separate from one another, each being treated in a steam render- 
 ing pan reserved for that kind only ; s@ that different grades are 
 obtained of considerable constancy of character. The fat from 
 the vicinity of the kidneys, and the "leaf" fat from underneath 
 the skin furnish a superior and harder lard; whilst the fats from 
 tainted carcases and diseased hogs, being generally melted down 
 all together, produce the lowest grade. The finest qualities are 
 usually put up in bladders, and the other sorts in kegs, whence 
 the terms "bladder lard" and "keg lard" are respectively applied. 
 Bladder lard, when pure, fuses at 42 to 45 ; keg lard at 28 to 
 38, according to its quality (Allen). The particular texture 
 exhibited by any given example depends largely on the way in 
 which the cooling and solidification of the fused fat was effected, 
 the texture being rendered firmer "by stirring during solidifica- 
 tion, or subsequent chilling in a refrigerating chamber. Some- 
 times water, salt, and a variety of other weigh tgiviDg adul- 
 terants (such as Iceland moss and starch) are stirred in for the 
 purpose of increasing the solidity of the mass. Sodium carbonate 
 solution thus admixed whitens the fat, and enables it to hold a 
 larger proportion of water. The chief sophistication of American 
 lard consists in subjecting the pure lard to pressure so as to 
 express "lard oil" (p. 231), and then working up the residue 
 with cotton seed or other cheap oil so as ultimately to obtain a 
 mass of the proper consistency and texture ; beef suet, mutton 
 tallow, and other fatty matters being often also introduced. 
 A test at one time much relied on for the detection of cotton 
 seed oil in such mixtures was Becchi's silver nitrate test 
 (variously modified by different chemists*), depending on the 
 reduction by some constituent of cotton seed oil of silver from 
 silver nitrate, with the formation of a brown mass in a way 
 not observed with other fats, &c. ; but latterly it has been 
 found that by thoroughly refining or otherwise treating the 
 cotton seed oil this constituent is mostly either removed or 
 altered, so that the presence of that oil is no longer indicated 
 . with certainty by silver nitrate. Sesame oil, cokernut butter, 
 
 *Vide Analyst, 1887, 170 ; 1SSS, 95, 161, et seq. 
 ti 
 
LARD. 
 
 307 
 
 and similar materials are also used as admixtures, generally 
 along with more or less harder fat, especially " beef stearine." 
 
 According to A. H. Allen the presence of any considerable 
 quantity of cotton seed stearine or coker butter may be detected 
 by the effect produced on the relative density, melting point, 
 saponification equivalent, and iodine number, as indicated by the 
 following table : 
 
 
 Lard. 
 
 Cokernut Butter. 
 
 Cotton Seed 
 Stearine. 
 
 Specific gravity at ' ~ * 
 lo *o 
 
 860--861 
 
 SG8--874 
 
 ... 
 
 Specific gravity at 37 '8 \ 
 (=100F.),t . . J 
 
 903--907 
 
 910- -916 
 
 911- -912 
 
 Melting point, 
 Saponification equivalent, 
 
 33-45 
 286-292 
 
 20-28 
 
 209-228 
 
 32 
 
 285- 294 
 
 Iodine number, 
 
 59-62 
 
 9 
 
 
 The percentage of water present is determined as described on 
 p. 122; substances insoluble in ether (starch, limesoap, <fec.) as 
 indicated on p. 123. Mineral nonvolatile matters (lime, salt, 
 alum, <kc.) may be found by incineration: soluble substances 
 (salt, alum, &c.) by agitating thoroughly with hot water and 
 separating the aqueous solution for further examination. 
 
 Pure unadulterated lard has, according to various authorities, 
 the total acid number 192-197, corresponding with the saponi- 
 fication equivalent 285-292, averaging about 289, whence the 
 mean equivalent of the fatty acids is about 277 (p. 1G5); the 
 average value directly found is near 278. The iodine number 
 has been found to lie between 50 and 64, indicating about two- 
 thirds olein and one-third palmitin and stearin as the essential 
 composition. Traces of unsaponifiable matters (0*2 0'3 percent.) 
 are also generally present. When perfectly fresh, lard contains 
 only minute quantities of free fatty acids, less than 1 per cent, j 
 larger amounts are usually found in stale or partly rancid lard. 
 
 When chilled to and pressed, lard furnished a solid stearine 
 (sometimes known as solar stearine) and lard oil (p. 231) : the 
 examination of the fluid oil thus obtained is often better adapted 
 than that of the original lard for the purpose of detecting adul- 
 teration ; thus admixture of cotton seed oil largely increases its 
 iodine number, and interferes with the formation of a solid elaidin 
 (p. 137), and similarly in other cases. Still better results are ob- 
 tained on separating the solid and liquid fatty acids by Muter 
 and Koningh's process and examining the latter apart (Chap, xv.) 
 
 Artificial Lard. This name is sometimes applied to various 
 mixtures of " beef stearine " (vide infra) and cotton seed oil, or 
 similar hard fats and vegetable oils, in such proportions as to 
 
 Water at 15 '5 = 1. 
 
 t Water also at 37' 8 = 1. 
 
308 OILS, FATS, WAXES, ETC. 
 
 give a product possessing the consistency of genuine lard. 
 These substances are less frequently sold under names clearly 
 indicating their nature than used for admixture in larger or 
 smaller proportions with genuine lard for purposes of sophisti- 
 cation. According to some writers adulterations of this kind 
 are becoming much less common than they were a few years 
 ago ; but it is doubtful if any great improvement has really 
 taken place in the trade, as a whole. 
 
 Manufacture of Artificial Butter. Several processes are 
 in use whereby the more fusible portions of fresh animal fatty 
 matters are separated from the more solid constituents, so as to 
 yield a mass of buttery consistence which, when treated with 
 annatto or other harmless vegetable colouring matter, and 
 churned up with milk or otherwise treated so as to acquire a 
 weak buttery flavour, furnishes a cheap palatable foodstuff. The 
 better kinds of product thus obtained are undeniably valuable 
 additions to the general food supply ; but the practice of mixing 
 them with genuine cow's butter and selling the mixture (or the 
 substitute alone) at considerably above its proper value under 
 the name of "butter," is obviously not a desirable one.* More- 
 over, the inferior kinds of oleomargarine are not invariably of 
 harmless character, as the earlier forms of tapeworm (cysticerci) 
 and other entozoa are sometimes present. 
 
 The earliest processes are said to date commercially from the 
 Franco-German war, when the scarcity of butter in Paris during 
 the siege led to the utilisation of various other forms of fat (more 
 especially that of horses) and their treatment so as to obtain a 
 softer and more palatable substance. The original Mege Mouries 
 process consists in treating chopped-up adipose tissue with a 
 weak alkaline solution (potassium carbonate) and minced sheep's 
 or hog's stomach at about 45 C., when partial digestion of the 
 albuminous fatty envelopes and cellular tissue is brought about 
 so that the fat separates, being "rendered" completely at the 
 comparatively low temperature used. On cooling and standing 
 the solid glycerides more or less completely separate in a crystalline 
 form, so that by applying pressure in cloths in an ordinary 
 hydraulic press (p. 231) the still liquid portion is squeezed out, 
 whilst a tolerably hard mixture of glycerides is left, valuable for 
 candlemaking. Instead of alkaline potash solution dilute hydro- 
 chloric acid is preferred by some, more especially with an addition 
 of calcium phosphate, so as to form phosphoric acid or an acid 
 phosphate of calcium : the digestive action is thus promoted and 
 hastened. 
 
 Much of the "bosch," "Dutch butter," "butterine," "mar- 
 garine,"! and "oleomargarine" of the present day is prepared 
 
 * In certain of the United States the Legislature requires that oleomar- 
 garine must be coloured pink in order to prevent its being sold as butter, 
 f The term "margarine" is an unfortunate survival of a misnomer 
 
ARTIFICIAL BUTTER. 309 
 
 by processes analogous to that of Mege Mouries, excepting that 
 the digestive operation is omitted. The sorted adipose tissue 
 (carefully handpicked, and sometimes washed to separate traces 
 of blood and suchlike animal matters, and then finely minced) is 
 subjected to gentle heat ; in some cases alone, so that the more 
 fusible constituents liquate away from the rest, the mass being 
 supported in trays on sloping racks in a room kept at a temper- 
 ature not much exceeding 50 C. ; in other cases in tubs in contact 
 with water at about 45 48, when the more fluid matters gradu- 
 ally float up and are withdrawn from time to time. Beef suet 
 is the preferable material, but sheep's fat is also employed ; much 
 of the margarine made in America is derived from hog's fat, 
 being in fact a variety of lard from which much of the solid 
 matter has been removed. The partially exhausted tissues left 
 are rendered in the usual way (p. 245), either alone or mixed 
 with other fatty matters, so as to produce a superior quality of 
 tallow : the oleaginous fluid matters that result from the first 
 processes are cooled and kept at about 25 for some time to allow 
 the solid glycerides to crystallise, and the mass is then pressed. 
 The solid pressed residue is generally known as " beef stearine," 
 and is largely used in the manufacture of factitious lard by 
 incorporation with cotton seed or other fluid vegetable oil so 
 as to form a mass of the required physical consistency. 
 
 The resulting expressed oil acquires a buttery consistence at 
 the ordinary temperature, but is usually somewhat softer than 
 cow's butter ; by thoroughly churning it up with fresh (or, as 
 preferred by some, sour) milk, and a little minced cow's udder, 
 it acquires a slightly firmer consistence and a buttery flavour. 
 If the temperature during pressing has been too high, or if the 
 solid glycerides have not sufficiently thoroughly separated whilst 
 standing, the expressed substance may be too solid, in which 
 case it is admixed with fluid vegetable oil (cotton seed, arachis, 
 sesame, tire.) The temperature at which the churning is effected 
 
 applied to certain fat constituents in earlier days before the chemistry of 
 these substances was well elucidated. By saponifying tallow, lard, and 
 other animal fats, and separating the fatty acids thence ultimately obtained 
 as far as practicable, various substances" were got of somewhat different 
 characters in different cases, but mostly consisting of a liquid fatty acid 
 (oleic acid) ; a solid constituent melting at about 75, known originally as 
 maryarous acid (Chevreul), subsequently as stearic acid; and another solid 
 product termed maryaric acid, crystallising in pearly scales (whence the 
 name, from /mupyapov, or ^npyupiT^ pearl), and melting at a lower 
 temperature, near 60. This last was long regarded as a single substance 
 indicated by the formula C^H^C^; the glyceride containing it in the 
 original fat was accordingly known as margarine. Subsequently, how- 
 ever, it was shown by Heintz that this pearly-scale crystalline substance 
 was a mixture of homologous substances, consisting chiefly of stearic and 
 palmitic acids; and that whilst true margaric acid, C]7Hg40 2 , could be 
 produced artificially (p. 21), it was not a product of the saponification of 
 natural fats, and its supposed glyceride, margarine, was not contained 
 therein. 
 
310 OILS, FATS, WAXES, ETC. 
 
 has a good deal of influence on the physical character of the 
 product; preferably the factitious "butter" is withdrawn and 
 quickly chilled, either by running into ice cold water or on to 
 slabs of solid ice, and then made up into " pats " for the market. 
 Annatto, turmeric, saffron, and various other colouring matters 
 (preferably vegetable, but sometimes of coaltar origin) are used 
 to communicate a yellow tint ; sometimes a minute quantity of 
 butyric ether or other special flavouring and odour-giving sub- 
 stance is added. Inferior kinds of socalled margarine are some- 
 times made by the simple process of working up comparatively 
 hard fats (such as moderately scentless tallow) with fluid vegetable 
 oils, coker butter, lard oil, and similar softer materials ; when such 
 mixtures are further incorporated with more or less stale genuine 
 butter and churned up with milk, &c., products are obtained very 
 closely simulating genuine butter of second or third rate quality ; 
 they may be made to correspond with actual butter so closely as 
 to pass most of the tests applicable thereto, excepting that a more 
 or less marked increment is observable in the " Hehner number ;5 
 (p. 166), and a decrement in the Reichert number (p. 173) ; with 
 in many cases a slight depreciation of the specific gravity. 
 
 Margarine and oleomargarine prepared from solid animal fats, 
 without admixture with cokernut oil, possess a higher total acid 
 number than genuine butter viz., 192 to 199 corresponding 
 with the saporiification equivalent 282 to 293 (tripalmitin 
 = 268-7, trioleine = 294-7, tristearin - 296-7) ; the iodine 
 number is also higher, being usually between 45 and 55; but since 
 methods have been discovered * for removing the characteristic 
 odour of cokernut oil, the deodorised substance can be admixed 
 with animal margarine in such fashion as to bring down both the 
 saponification equivalent and iodine number to close to the 
 figures observed with genuine butter. Moreover, since cokernut 
 and palmnut oils furnish much smaller percentages of insoluble 
 fatty acids, and larger ones of volatile acids than ordinary soft 
 animal fats, their admixture in the mass tends to lower the 
 Hehner number, and raise the Eeichert number, thus rendering 
 detection by these tests more difficult. 
 
 The following table, based on one given by Schadler,f repre- 
 sents the w r ay in which the fatty matter from an ox is utilised : 
 
 * Schlink's method for removing the volatile and odorous fatty acids, &c. , 
 from cokernut oil, consists in treatment with alcohol and animal charcoal, 
 whereby a perfectly white mass is obtained, of the consistency of butter, 
 and of sweet neutral agreeable flavour. A very considerable sale for the 
 product exists, nominally as a " vegetable lard " for cooking purposes 
 (supra) ; practically, however, the material is largely if not mainly em- 
 ployed in sophisticating cow's butter. For a description of tests emploj^ed 
 in the examination of butter supposed to be thus adulterated, vide F. Jean, 
 Moniteur Stientifique, 1890, 36, p. 1116; in abstract, Journ. Soc. Chem. Ind., 
 1891, p. 275. 
 
 t From results obtained in Sarg's factory, Vienna. 
 
UTILISATION OF OX FAT. 
 
 311 
 
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 ibout 83 kilogrammes 
 
 1 
 
 A 
 
 cilos. of so-called kidn 
 fusing and pressing t] 
 
 3S. of socalled Abou 
 :. After wash- m< 
 i-, and working 
 fee. , this yields 
 . of "artificial 
 About 50 kilos. 
 
 water (dilute glycerol 
 ultimately extracted ' 
 , distillation, &c., a 
 mercial "glycerine." 
 
 stearicacid. About 
 acid 
 batcl 
 
 ^ 
 
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 = about 24 kilos, ste 
 
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312 OILS, FATS, WAXES, ETC. 
 
 FINAL PRODUCTS. 
 
 " Artificial butter," about 18 kilos, representing of 
 
 oleomargarine, .... about 16'5 kilos. 
 
 Pure commercial " glycerine," 
 
 " Stearine " (stearic and palmitic acids), 
 
 " Oleine " (impure oleic acid), 
 
 " Scraps " used for manure, 
 
 2-5 
 24-0 
 23-5 
 16-5 
 
 83-0 
 
 It would hence seem that a very considerable loss of glycerol 
 accompanies the various processes gone through in the course of 
 the isolation of the pure redistilled commercial article; for 
 24 kilos, of stearic acid, together with 23-5 of oleic acid, theo- 
 retically correspond with about 5 -3 kilos, of glycerol instead of 
 2-5, indicating a total loss of more than 50 per cent, of the 
 glycerol formed during saponification. 
 
 LAMP OILS. 
 
 From the earliest ages the use of lamps has been general, 
 essentially consisting of a vessel for holding the oily matter, 
 provided with some kind of porous wick up which the oil rises, 
 by capillary action, to supply the place of that burnt in the 
 flame. Probably this arrangement was actually a development 
 of the still earlier torch or flambeau, consisting in its simplest 
 form of a splinter of pine containing natural resin, and in a more 
 elaborate shape of strands of vegetable fibre dipped in resin, 
 asphalt, and similar materials (obviously the prototype of the 
 more modern wicked candle). The wicks used in some of the 
 early forms of lamp appear to have been of rush-pith, apparently 
 closely akin to the rush-candle or rush-light ; saving that in the 
 latter the vegetable wick was dipped in a comparatively solid 
 fat melted by heat, and then taken out and allowed to 
 harden, whilst in the former the wick was held in position by 
 some simple device, and a thinner fat or oil used, fluid enough 
 to moisten the wick without extraneous heat. In the modern 
 " nightlight " both forms are substantially combined, the arrange- 
 ment being virtually a candle on first lighting, and practically an 
 oil lamp after burning sufficiently long to melt the remainder of 
 the fatty matter by the heat developed. 
 
 Amongst the Eastern nations, crude natural naphtha or 
 petroleum has been largely used as a burning oil from time 
 immemorial ; but the methods now in use for purifying it and 
 separating it into different fractions (some of which are far better 
 adapted for burning in lamps than the raw material, whilst others 
 are quite unfit for that purpose) are of quite modern origin. 
 Amongst the Greeks and Romans, olive oil appears to have been 
 
LAMP OILS. 313 
 
 largely used for the purpose ; whilst rough candles of tallow, 
 and superior ones of wax, were also in use. In all the early 
 forms of household lamp no chimney was employed, so that the 
 flame was invariably more or less smoky, a circumstance which 
 considerably limited the number of vegetable oils available ; in 
 1784, Argand introduced the form of lamp still bearing his name 
 (although greatly altered and improved by subsequent inventors), 
 essentially consisting of a circular wick with an air supply in the 
 centre, a chimney of iron (later of glass) being also applied, so as to 
 increase the draught and so facilitate combustion, thus diminish- 
 ing smoke and increasing the light emitted.* This invention 
 greatly stimulated the use of oil lamps, and colza oil and sperm 
 oil soon became extensively used for consumption therein, together 
 with many other varieties, notably the oils from rape seed, ground 
 nuts, and cotton seed. At the present day, however, the use of 
 these oils in this way, though by no means inconsiderable, is 
 small as compared with that of the hydrocarbon oils from 
 petroleum and paraffin shale, &c. (at any rate in those countries 
 where the latter are readily obtainable), on account of the greater 
 cost ; but in many semicivilised lands the cost of vegetable oils 
 indigenous to the district is often below that of imported 
 petroleum burning oils, so that the mineral oils have in such 
 cases not yet largely supplanted the vegetable ones. 
 
 When rape (colza) oil is burnt, a tendency to charring of the 
 wick appears to exist if the oil contain much free fatty acids 
 (formed by decomposition of the original glycerides during ex- 
 traction and refining, <fcc.) ; this is also marked in the case of 
 olive oil. According to Arch butt, 5 per cent, of free fatty acids 
 is the maximum permissible, otherwise a defective light results, 
 arid the wick soon chars. 
 
 DRYING OILS USED FOR PAINT MANUFACTURE 
 
 AND IN THE PREPARATION OF VARNISHES, 
 
 LINOLEUM, AND SUCH LIKE PRODUCTS. 
 
 Drying oils, such as linseed oil, in their natural state as 
 obtained by expression and refining (raw oils), absorb oxygen 
 from the air and inspissate at much lower rates than are observed 
 after subjecting them to a form of treatment usually spoken of as 
 " boiling/' although the term is not strictly correct, inasmuch as 
 the oils do not become converted into vapour capable of recon- 
 
 * Flues or chimneys applied to lamps were not wholly unknown to the 
 ancients ; thus the lamp (of pure gold), designed by Callimachus about 
 400 B.C. for the Erechtheum of the Athens Acropolis, was provided with a 
 chimney in the form of an inverted palm tree of bronze. Argand's use of a 
 chimney was also previously suggested by Quinquet (Leopold Field, Cantor 
 Lectures, Soc. of Arts Journ., 1883, pp. 826 and 848). 
 
314 OILS, FATS, WAXES, ETC. 
 
 densation to the original substance as water or alcohol does when 
 boiled, but only become partially decomposed so as to evolve 
 vapours in consequence of incipient destructive distillation 
 (p. 125) or other decomposition, more especially of the glyceridic 
 portion of the molecule, whereby acrolein is formed. 
 
 In the older processes for preparing "boiled" oils, this effect 
 was brought about by heat alone ; subsequently various sub- 
 stances known as "driers" were added to the oil in small 
 quantity for the purpose of promoting the particular changes in 
 view. In the more modern methods somewhat lower tempera- 
 tures are mostly employed, whilst the action is accelerated by 
 injecting air into the hot mass, whereby a greater degree of 
 incipient oxidation is effected, the result of which is to render 
 the oil much more prone to oxidise spontaneously by subsequent 
 exposure to air, and hence to " dry " more rapidly. 
 
 The nature of the driers used, and the exact methods of mani- 
 pulation are often supposed to be valuable trade secrets ; but the 
 practical result of working secret " rule of thumb " methods of 
 the kind has not always proved commercially successful. Some 
 of the substances used under the name of " driers " (e.g., dried 
 alum, and zinc sulphate) contribute but little, if anything at all, 
 to the drying effect, their action being simply to coagulate re- 
 maining mucilage, and aid its subsequent removal by subsidence. 
 Numerous metallic salts and oxides, <kc., are, or have been, 
 employed for the purpose ; according to the experiments of 
 Livache, the most marked effect in the way of increasing the 
 rate of drying is produced by manganese and lead salts, copper, 
 cobalt, and zinc compounds being much less active, and salts of 
 iron, chromium, and nickel still less so. In actual practice, com- 
 pounds of lead are those most frequently used, especially litharge, 
 red lead, and lead acetate ; the result of which is that the boiled 
 oil finally obtained contains lead in solution as some kind of lead 
 soap (to the formation of which, in the first instance, the action 
 of improving drying qualities is probably due, the lead soap acting 
 as carrier of oxygen) ; hence, more or less discoloration of paint 
 made with such oil is apt to occur, especially in towns, inde- 
 pendently of that brought about by the white lead added to most 
 kinds of paint. This result is avoided by substituting manganese 
 salts, &c., for lead compounds ; accordingly, manganese hydroxide, 
 dioxide, borate, oleate, oxalate, and other organic salts are now 
 .somewhat largely employed.* 
 
 When the drier is added in fine powder, a considerable fraction 
 of it can be recovered, as it settles to the bottom when the oil is 
 allowed to cool and stand ; but a portion is taken into solution 
 as metallic soap and permanently retained in the oil. Apparently 
 
 * According to K Clarke (Journ. Soc. Art*, Feb. 10, 1893, p. 289), boiled 
 oil prepared with manganese is unsuitable for varnish making, as it produces 
 a bloom on any varnish made with it. 
 
DRYING OILS. 315 
 
 this soap absorbs oxygen from the air, and then in some way 
 parts with it again to the glycerides present ; but the precise way 
 in which the carrying action is effected is not thoroughly under- 
 stood. In some cases, if too large a proportion of metallic soap 
 is formed, the boiled oil produced is deteriorated, probably because 
 the oxidising action then gets carried too far. By the use of the 
 drier in the form of a solution of known strength, any required 
 proportion can be readily introduced; manganese oleate or 
 linolate, or other fatty acid manganese soap, dissolved in oil of 
 turpentine or similar solvent, is accordingly coming into use for 
 the purpose,* more especially for oils intended to mix with zinc 
 white or other pigments of light tint where darkening is desired 
 to be avoided, such as is liable to be produced in lead-containing 
 oil by the action of sulphur compounds in the air. Moreover, 
 oils " boiled " with manganese driers are generally of a lighter 
 colour than when lead is used. Occasionally, to meet trade pre- 
 judices as regards colour, a mixture of lead and manganese com- 
 pounds is used, so that the darker red tint produced by the lead 
 may be developed to an extent proportionate to the quantity of 
 lead employed. 
 
 The proportion of driers employed is usually but small, not 
 exceeding 0-25 to O75 per cent, of the weight of the oil (a few 
 Ibs. per ton) ; when used in the solid form it is important that 
 they should be in the finest possible state of division, for which 
 purpose they are usually subjected to a process of levigation after 
 continued grinding ; finally, they are ground with oil, much 
 as paint is ground, so as to form a mixture that can be readily 
 disseminated through the mass of oil treated by means of 
 agitators. 
 
 In the older method of " boiling," the oil is simply heated 
 along with the driers for some hours to a temperature varying 
 from 200 to 250 C., free fire being, used as the heating agent. 
 Fig. 76 represents the kind of arrangement employed ; a lid, e, 
 is arranged, capable of being lowered on to the pan, a, and 
 closing it up airtight by means of the flanged rim, b b, so that in 
 the event of the evolved vapours taking fire they can be almost 
 instantaneously extinguished. To avoid frothing over, the part 
 is originally filled not more than half full with oil. 
 
 Fig. 77 represents a pair of steam heated kettles, the jackets 
 being strong enough to resist several atmospheres pressure : 
 usually 4 to 5 atmospheres are employed, the oil being heated to 
 1 30 0. or a little upwards. When air is blown through the hot 
 
 * Hartley & Blenkinsop's process (Patent No. 11,629, 1890) combines the 
 drying action of manganese soap added in this form with the bleaching 
 action produced by blowing a current of air through the mass at a tempera- 
 ture a little short of 100 C. ; by using only a small proportion of manganese 
 linolate solution, the oxidising action can be almost wholly confined to the 
 colouring matter, so as to bleach the oil without producing any notable 
 degree of other oxidation (Journ. Soc. Arts, loc. ctt. supra). 
 
316 
 
 OILS, FATS, WAXES, ETC. 
 
 oil a dome-shaped cover is fitted on to keep in splashes, provided 
 with an exit pipe for the vapours evolved. 
 
 An improved vessel for boiling oil and suitable for many other 
 kindred purposes has been recently described by T. Frederking.* 
 
 Fig. 76. 
 
 A coil of stout piping is arranged in a casting mould so that the 
 molten metal forming the pan is cast round the coil ; much as is 
 done in the case of the water-tuyeres of a blast furnace. Steam 
 at any required pressure being passed through the coil, the pan 
 
 * Chemical News, Jan. 27, 1893 : German Patent No. 63,315. 
 
BOILED OILS. 317 
 
 is heated up proportionately without any danger, the pressure 
 bearing solely on the piping and not on the metal pan itself, 
 whilst the well-conducting metal walls allow the heat to pass 
 readily. Temperatures up to 350 and 400 C. can be thus 
 obtained. 
 
 According to C. W. Vincent * the use of air alone without 
 driers does nothing towards making oil " drying." Linseed oil 
 heated for three days consecutively at a high temperature in 
 presence of the air but without driers required the same time to 
 dry as the raw oil from which it was prepared, but the " body " 
 was much increased. Heating alone for the same time with only 
 surface exposure to air produced no such increase of body ; the oil 
 became more greasy, less penetrative, and less drying. 
 
 The exact nature of the changes taking place during the boiling 
 of drying oils is not clearly understood ; beyond the fact than an 
 incipient alteration is produced (either by decomposition by 
 
 Fig. 77. 
 
 heat, or by oxidation, or both together, largely assisted by the 
 carrier action of the driers), which tends in the direction of the 
 further changes effected by the absorption of oxygen whilst 
 drying, little is known with certainty. No considerable destruc- 
 tion of glycerides appears to occur until the action is pushed 
 very far, ordinary "boiled" linseed oil furnishing nearly the 
 same amount of glycerol on saponification as raw unboiled oil ; on 
 the other hand, a more or less distinguishable small diminution 
 in iodine absorbing power is generally brought about indicating 
 oxidation. For the further changes effected during actual 
 "drying," see pp. 129, 134. 
 
 In the manufacture of printing ink, the action is pushed 
 considerably further. In the older direct-firing process (still 
 preferred by many) the oil is heated until the escaping vapours 
 
 * Muspratt's Dictionary of Chemistry, edited by C. W. Vincent, p. 475, 
 vol. ii. 
 
318 OILS, FATS, WAXES, ETC. 
 
 will fire freely; the mass thickens considerably as the action 
 progresses ; when a sample taken out and dropped on a cold 
 porcelain surface can be drawn into strings half an inch long, 
 a cover is put on to extinguish the flame ; amber or rosin is 
 then dissolved in the hot oil, and slices of soap (essential in 
 order to enable the ink to adhere to damp paper) ; and finally 
 the pigment (lamp black, ivory black, <fcc., mixed with prussian 
 blue or other coloured pigments to tone the black as required). 
 Obviously in this case the heat causes a partial decomposition of 
 the oil, and the thickening is probably due largely to an action 
 of polymerisation taking place in the nascent acids or anhydrides, 
 thus formed, somewhat analogous to that which occurs during 
 the "vulcanising" of oils by the action of sulphur chloride, &c. 
 (p. 154). 
 
 The varnishlike film of oxidised oil produced when boiled 
 linseed oil is made to form a thin coating on a suitable large 
 surface 'freely exposed to the air can be increased to an almost 
 indefinite extent by painting a second film over the first when 
 approaching dryness, and so on in succession. The product thus 
 formed is largely employed in the manufacture of linoleum and 
 floorcloth, thin sheets of canvas or cotton scrim being suspended 
 vertically in a room freely supplied with air, and " flooded " with 
 oil from an overhead reservoir or tank running on wheels like a 
 travelling crane ; the sheets thus moistened with a film of oil 
 are kept suspended with free access of air, and when the coating 
 is nearly dry, alternate floodings and exposure to air are 
 repeated for some weeks until the "skin" formed is sufficiently 
 thick, the chamber being supplied with warmed air if necessary, 
 so as to keep its temperature up to at least 70 F. = 21 C., and 
 freely ventilated, much acrid vapour (acrolein, c.) being evolved 
 during the oxidation by the destruction of the glyceridic portion 
 of the oil. The oxidised oil thus formed is heavier than water 
 (raw linseed oil has the specific gravity -935 or thereabouts), and 
 forms a yellow translucent mass, insoluble in alcohol, ether, 
 chloroform, and carbon disulphide ; boiling naphtha (under 
 pressure) softens it so that it can be worked into a paste. For 
 the manufacture of linoleum the skins are ground between rollers, 
 and heated with rosin and kaurie gum in a mixing pan, and the 
 resulting paste or "cement" then intermixed with rasped cork 
 and ultimately spread upon a canvas backing. 
 
 Notwithstanding the loss of weight due to the evolution of 
 acrolein and other volatile products during this process, a gain 
 in weight averaging about 11 per cent, is experienced, so that 
 the fixation of oxygen is considerable. In order to shorten 
 the time requisite for the oxidation of drying oils for linoleum 
 manufacture, F. Walton* forces air at a pressure of 5 to 10 
 atmospheres through the oil warmed to about 100 F. = 37 C., 
 * Patent Specification No. 12,000, July 31, 1890. 
 
BLOWN OILS. 319 
 
 the air current being divided by means of perforated plates ; 
 an agitator is provided, by means of which the product when 
 approaching solidification is more or less granulated, whilst fused 
 gums, &c., can be incorporated. 
 
 Blown Oils. Of late years the manufacture of oils oxidised 
 by the direct action of air upon them, has acquired a considerable 
 magnitude, the effect produced usually being a considerable 
 increment in density and viscosity, rendering nondrying or 
 semidrying oils (rape, cotton seed, fish oils, &c.) more suitable 
 for use as lubricants, either directly or as ingredients in lubri- 
 cating mixtures : and in the case of drying oils (more especially 
 linseed oil), bringing about more rapidly and certainly those 
 incipient oxidation changes requisite to produce more rapid 
 spontaneous absorption of oxygen from the air by the oil, when 
 spread out in thin layers i.e., the changes effected in socalled 
 " boiled " oil, rendering it better applicable for the production of 
 paint and varnish, <fcc., owing to its more rapidly "drying" up 
 to a comparatively hard varnish-like coating when thus applied. 
 
 The plant employed for the process is of simple construction, 
 consisting of a pan or tank fitted with a steam jacket (or an 
 internal dry steam coil) for heating up the oil, and with a false 
 bottom perforated with numerous small holes, cullender-fashion ; 
 air being pumped in under the false bottom rises up through the 
 hot oil in numerous minute streams of bubbles. Instead of a 
 false bottom, a horizontal serpentine with numerous pin holes is 
 sometimes employed. When the action is intended to be carried 
 to the limit, as in oxidising drying oils for linoleum making, an 
 agitating arrangement is also added for the purpose of breaking 
 up clots, and keeping the mass well stirred up (supra). 
 
 The nature of the chemical changes taking place during the 
 action of air on hot lard oil, cotton seed oil, rape oil, &c., has 
 not been thoroughly elucidated ; a considerable amount of heat 
 is developed during the process, so that, when once started, no 
 further extraneous heating is requisite, but in some cases rather 
 the converse, otherwise the temperature may rise so high as to- 
 injure the product by incipient decomposition. In all probability 
 the olein present (or other homologous glyceride) becomes largely 
 converted into the glyceride of an oxyoleic or oxystearic acid, 
 either analogous to the ricinoleic acid of castor oil (i.e., an 
 unsaturated hydroxylated acid), or more* probably constituted 
 like anhydrodioxystearic acid (pp. 42, 46), where the oxygen is 
 directly added on in the same way that iodine or bromine is 
 added, so as to convert an unsaturated acid into a saturated 
 derivative ; for in proportion as the oxidation proceeds, the 
 iodine absorption lessens. Other subsidiary actions, however, 
 also take place ; thus, the proportion of insoluble acids (Hehner 
 number) lessens as the oxidation goes on, whilst increasing 
 amounts of soluble acids are formed; the mean saponification 
 
320 
 
 OILS, FATS, WAXES, ETC. 
 
 equivalent of the blown oil is usually less than that of the 
 original oil (i.e., the "total acid number" increases), although 
 but little increment is brought about in the "free acid number." 
 Blown oils develop much more heat on mixing with sulphuric 
 acid than the original untreated oils. 
 
 The following figures were obtained by Thomson and Bal- 
 lantyne* in the course of a series of experiments on the oxidation 
 of rape and sperm oils by blowing hot air through them : 
 
 RAPE OIL. 
 
 
 Original 
 
 Partly 
 blown after 
 5 hours. 
 
 More fully 
 blown after 
 20 hours. 
 
 Commercial 
 Blown Rape 
 Oil. 
 
 Specific gravity at 15 "5, 
 
 0-9141 
 
 0-9275 
 
 0-9615 
 
 0-9672 
 
 Percentage of free acid (calcu- | 
 lated as oleic acid), . . \ 
 
 5-10 
 
 5-01 
 
 7-09 
 
 4-93 
 
 Percentage of unsaponifiable ^ rt . Rri 
 
 
 0'76 
 
 2-80 
 
 matter, . . . . / 
 
 
 
 
 
 Total acid number, 
 
 173-9 
 
 183-0 
 
 194-9 
 
 197-7 
 
 Iodine number, 
 
 100-5 
 
 88-4 
 
 63-2 
 
 63-6 
 
 Specific temperature reaction ) 
 
 135 
 
 
 
 253 
 
 (p. 149), . . . ! 
 
 
 
 
 Percentage of insoluble acids ) 04. "(j 
 (Hehner number), . . ^ 
 
 ... 
 
 85-94 
 
 82-40 
 
 Molecular weight of insoluble ) 
 acids, . . . . ( j 
 
 ... 
 
 327 
 
 317 
 
 Percentage of soluble non- \ , 
 volatile acids, . . . f Q' r 2 < 
 
 ... 
 
 9-20 
 
 11-16 
 
 Percentage of soluble volatile ( ) 
 acids, . . . . ) 
 
 0-82 
 
 1-90 
 
 Iodine number of soluble \ 
 
 66-5 70-2 
 
 acids, . . . . \ ; 
 
 
 I 
 
 1 
 
 SPERM OIL. 
 
 
 Before blowing. 
 
 After blowing for 
 25 hours. 
 
 Specific gravity at 15 '5, 
 Free acid (calculated as oleic) 
 
 0-8799 
 1-97 
 
 0-8989 
 3-27 
 
 Unsaponifiable matter, . 
 Total acid number, 
 
 36-32 
 130-4 
 
 34-65 
 142-3 
 
 Iodine number, 
 
 82-1 
 
 67-1 
 
 Commercial blown oils usually present nearly the same density 
 and viscosity as castor oil, but differ therefrom in not dissolving 
 freely in alcohol, whilst they are readily soluble in petroleum 
 spirit, and mix readily with the heavier petroleum hydrocarbons, 
 thus enabling homogeneous .lubricating mixtures to be produced. 
 
 * Journ. Soc. Chem. Ind. t 1892, p. 500. 
 
LUBRICANTS. 321 
 
 Castor oil itself when similarly blown, undergoes analogous 
 changes, becoming still more viscid, and acquiring the property 
 of being miscible with hydrocarbons (ordinary castor oil is 
 almost insoluble in petroleum hydrocarbons, &c.) ; accordingly, 
 blown castor oil is often spoken of as " soluble castor oil." The 
 same term, however, is sometimes applied to the oil treated with 
 sulphuric acid (Turkey red oil). 
 
 Oxygen Process. A process has been brought out under 
 the auspices of "Brin's Oxygen Co." whereby commercially 
 pure oxygen (containing 90-93 per cent, of actual oxygen) is 
 used instead of air for the purpose of "boiling" linseed oil for 
 varnish oil and linoleum, and similarly blowing other oxidisable 
 oils, either in presence of a small quantity of driers, or without 
 them.* In carrying out this process it is found unnecessary to 
 blow the gas through the oil ; a steam jacketted pan is provided 
 capable of being closed by a cover, and containing an agitator 
 consisting of vertical rods or vanes moving round horizontally. 
 When the oil to be treated has become heated nearly to 100 C., 
 the agitator is set in motion, and oxygen led in to the space 
 above the oil ; the splashing oil drops present a large absorbent 
 surface, so that the oxygen is absorbed, at first comparatively 
 slowly but later on with great vigour, so that although a rapid 
 stream of gas is delivered into the pan it is absorbed more 
 rapidly than it is supplied, producing a partial vacuum. As the 
 action goes on the oil heats greatly, so that ultimately it becomes 
 necessary to cool the jacket by admitting water into it. It is 
 claimed that the oxidising action is under better control by this 
 treatment, and that a superior result can be effected in a much 
 shorter time, so that the extra cost of the oxygen gas is amply 
 recouped. 
 
 A somewhat similar process has been subsequently patented 
 by E. Opderbeck f for making ' ; consistent fish fat, train, and 
 other oils," by heating them to 90-100 C., and then intimately 
 commingling them with compressed oxygen. 
 
 MISCELLANEOUS USES OF OILS, FATS, &c. 
 MANUFACTURE OF LUBRICANTS. 
 
 The substances employed to diminish the friction between sur- 
 faces in motion relatively to one another are of very various kinds 
 according to the nature of the mechanism, c., to be lubricated ; 
 thus for watches and chronometers on the one hand, and railway 
 axles on the other, widely different substances are respectively 
 
 * English Patent Specs., 12,652, 1886; 18,628, 1889. 
 t English Patent Spec., 24,153, 1892. 
 
 _ 21 
 
322 OILS, FATS, WAXES, ETC. 
 
 best suitable ; whilst the spindles of cotton spinning jennies, 
 the piston boxes of steam engines, and the bearings of shafting 
 generally, represent other different classes of moving objects for 
 each of which special kinds of lubricants are requisite. Formerly 
 animal and vegetable oils and fats were almost exclusively used 
 for lubricating purposes, the finer qualities being employed for 
 the more delicate machinery and the coarser varieties and dirtier 
 greases for the greasing of cartwheels and similar rough purposes ; 
 the introduction of railway travelling and the extended use of 
 machinery of all kinds led to the modification of some of these 
 materials by partial saponification with lime or alkalies so as to 
 produce an imperfect soap containing much unsaponified fat, and 
 to the admixture with them of more or less viscous hydro- 
 carbons, more especially the "rosin oils" prepared by the 
 distillation of rosin, and certain higher boiling fractions obtained 
 in the treatment of petroleum shale oils, coal and other tars, 
 and similar substances. At the present day " mineral oils JJ of 
 this latter kind are most extensively used, either alone or in 
 combination with saponifiable oils, although for certain special 
 purposes the latter are still preferable. Obviously only those 
 kinds of mineral oil are available that do not readily give off 
 inflammable vapours on account of risk of fire, and the drying 
 up of the lubricant by evaporation ; moreover, lighter oils of this 
 kind have not sufficient " body," especially for heavy machinery. 
 Of the animal oils, sperm oil stands pre-eminent, neat's foot oil, 
 tallow, and lard oil being also valuable ingredients largely used, 
 and to a lesser extent whale oil and various fish oils ; whilst olive 
 oil, palm oil, and rape oil, and to a lesser extent cotton seed, 
 sesame, and groundnut oils, &c., are also extensively employed. 
 In all such cases it is imperative that no free mineral acid should 
 be present, as otherwise bearings, (fee., are apt to be rapidly 
 corroded : hence oils refined by acid processes (p. 259) are usually 
 regarded as inadmissible as ingredients in first-class lubricating 
 oils, unless the small quantities of admixed mineral acid have 
 been thoroughly removed by a subsequent washing with an 
 alkaline fluid. There appears also to be good reason for regarding 
 the presence of any considerable percentage of free organic acids 
 as objectionable for similar reasons, more especially in the case 
 of bearings made of gun metal and other copper alloys, inasmuch 
 as in presence of such acids the copper is apt to become oxidised, 
 producing corrosion and pitting hence oils refined by alkaline 
 treatment are preferable. Cotton seed oil thus refined (for 
 the purpose of removing resin, p. 260) owes much of its value 
 to the circumstance that it is practically destitute of free acids, 
 which to a great extent counterbalances the objection to its use 
 that, as a considerable proportion of drying glycerides is present, 
 it possesses a rather marked tendency to absorb oxygen and 
 thicken or " gum " in use. 
 
LUBRICANTS. 
 
 323 
 
 Animal and vegetable oils liable to contain free mineral acids, 
 may be conveniently examined as to the presence of such 
 constituents by the process described on p. 123; or the oil 
 may be well shaken up with distilled water, and the aqueous 
 liquor separated and examined, whilst the amount of free organic 
 acids may be determined by the titration method described on 
 p. 116. A practical test as to the relative tendency to gumming 
 is to place equal quantities (drops) of the oils to be examined on 
 an inclined plane, noting the distance run down by each sample 
 in a given time, and the time required before the oil ceases to 
 run, owing to the increased viscidity through oxidation ; thus, 
 the following figures are quoted from Appleton's Dictionary of 
 Mechanics, representing the run of each oil in inches : 
 
 
 Sperm Oil. 
 
 
 i 
 
 
 
 
 
 Gallipoli 
 (OJive) Oil. 
 
 Lard Oil. 
 
 Rape Oil. 
 
 Linseed 
 Oil. 
 
 
 
 
 Best. 
 
 Common. 
 
 
 
 
 
 1st clay, 
 
 32 
 
 19 
 
 10 
 
 10-25 
 
 14 
 
 17-5 
 
 2nd 
 
 50 
 
 45 
 
 14 
 
 10-5 
 
 18 
 
 18 
 
 3rd 
 
 53-5 
 
 55 
 
 18 
 
 10-75 
 
 19 
 
 18 
 
 4th 
 
 54 
 
 59 
 
 18-5 
 
 10-75 
 
 19 
 
 18-25 
 
 5th 
 
 54 
 
 62 
 
 19-5 
 
 11-75 
 
 19-25 
 
 18-5 
 
 6th 
 
 54 
 
 64 
 
 20-5 
 
 Still 
 
 19-25 
 
 Still. 
 
 7th 
 
 54 
 
 67 
 
 21 
 
 ... 
 
 19-75 
 
 ... 
 
 8th 
 
 54 
 
 67-5 
 
 21-25 
 
 
 Still. 
 
 ... 
 
 9th 
 
 
 68 
 
 21-5 
 
 ... 
 
 .... 
 
 ... 
 
 Only comparatively small amounts of unmixed animal and 
 vegetable fats and oils are used alone at the present day as 
 lubricants ; a large proportion of the lubricating agents employed 
 consist of hydrocarbons only, and the remainder are much more 
 frequently mixtures of hydrocarbons with saponifiable oils, than 
 substances free from petroleum and rosin oils, and such like 
 hydrocarbons. 
 
 One advantage gained in the case of such mixtures (apart from 
 cheapness) is, that greasy rags, engine waste, &c., impregnated 
 with oil, are much less likely to heat spontaneously through 
 oxidation on storage (p. 132), when a large fraction of the oil is 
 nonspontaneously oxidisable hydrocarbon, than would be the 
 case were the oil wholly composed of glycerides and such like 
 saponifiable bodies. 
 
 W. Brink finds * that the solution of a small quantity of 
 caoutchouc in a lubricating oil consisting of mineral hydrocarbons 
 increases its viscosity and tends to prevent gumming, without 
 introducing any corresponding disadvantages. Yarious metallic 
 
 * English Patent Spec., 17,163, 1889. 
 
324 OILS, FATS, WAXES, ETC. 
 
 soaps, more especially aluminium oleate, are often added to 
 lubricating oils for the purpose of increasing their " viscosity ;" 
 it is open to much question, however, whether such an addition 
 really adds to the true lubricating power of the composition, and 
 whether it should not be looked upon simply as an adulteration 
 or falsification giving a fictitious appearance of consistency to 
 the oil. 
 
 Lubricating materials other than pure fats and oils, may be 
 conveniently classified in the following divisions : 
 
 1. Solid, semisolid, or more or less viscid liquid compositions 
 of animal and vegetable oils and fats, with hydrocarbons from 
 petroleum or destructive distillation (shale and paraffin oils), or 
 resin oils containing little or no inorganic matters intermixed. 
 
 2. Solid or semisolid greases containing a considerable propor- 
 tion of saponaceous matters (alkali or lime soaps of fatty or 
 resinous acids), together with more or less additional mineral or 
 organic " antifriction " substances (ground mica, steatite, plum- 
 bago, seaweed jelly, &c.) 
 
 3. Excessively coarse and generally dark coloured greases, 
 consisting of byeproducts of various industries, the refining of 
 which is too costly to permit of the materials being purified 
 sufficiently to enable them to be utilised in other ways e.g., 
 " Yorkshire grease," and grease from engine waste (p. 236), 
 containing too much hydrocarbons, &c., to be worth distilling for 
 socalled ' k stearine" and "oleine " (p. 277) ; "dead oils" obtained 
 in coaltar distillation ; certain kinds of " foots " obtained in 
 refining ; pitchy and tarry matters of various kinds not available 
 for other purposes, and so on. 
 
 Lubricants of the first class include " engine oils," " engine 
 tallow," and similar compositions ; "cylinder oils" for lubricating 
 the piston rods, &c., of steam engines ; " machinery oils " for 
 shafting, bearings, crank axles, and the like ; " spindle oils " for 
 quick moving light machinery, like the spindles of cotton 
 spinning jennies ; watchmakers', clock, and " turret " oils, 
 specially adapted for delicate machinery like chronometers, and 
 not liable to thicken by cold and a large variety of subordinate 
 kinds. Those of the second class are chiefly compositions used 
 for the axle boxes of locomotive stock (railway trucks and 
 carriages, &c.) Coarse greases of the third class are used for 
 cartwheels and rough machinery, such as the pumping engines 
 employed in mining, where, through the circumstances of the 
 case, high class lubricants are unnecessary. 
 
 Lubricants of the First Class Lubricating Oils. The 
 examination as to the practical lubricating value of materials 
 and compositions of this class is rather a mechanical than a 
 chemical problem. A laboratory test greatly relied on as an 
 indication of their suitability for the particular purposes in view, 
 is the determination of their relative efflux rates at given tern- 
 
LUBRICATING OILS. 325 
 
 peratures. The socalled "viscosity" values thus obtained by 
 means of one or other of the various forms of efflux viscosimeter 
 described in Chapter v. (or better still, the figures obtained by 
 means of appropriate large scale testing machines, &c., whereby 
 the conditions obtaining during actual use can be nearly imitated) 
 are generally of more practical value to the consumer than 
 chemical analyses of the substances; especially when coupled 
 with valuations of the flashing point (p. 125) and the degree of 
 volatility i.e., the rate of loss by volatilisation on heating to 
 known temperatures. On the Continent considerable stress is 
 often laid on the determination of the " congealing point " (vide 
 p. 67). For an outline of the standard methods and appliances 
 in use for the purpose, vide Journ. Soc. CJiem. Ind., 1890, p. 772. 
 Lant Carpenter summarises the general experience gained as 
 to the character and behaviour of the various oils used for 
 lubricating as follows : 
 
 1. A mineral oil flashing below 300 F. (149 C.) is unsafe on 
 account of causing fire. 
 
 2. A mineral oil evaporating more than 5 per cent, in ten 
 hours at 140 F. (60 C.) is inadmissible, as the evaporation 
 creates a viscous residue, or leaves the bearing dry. 
 
 3. The most fluid oil that will remain in its plabe, fulfilling 
 all other conditions, is the best for all light bearings at high 
 speeds. 
 
 4. The best oil is that which has the greatest adhesion to 
 metallic surfaces, and the least cohesion in its own particles ; in 
 this respect fine mineral oils are 1st, sperm oil 2nd, neat's foot 
 oil 3rd, and lard oil 4th. 
 
 5. Consequently, the finest mineral oils are best for light 
 bearings and high velocities. 
 
 6. The best animal oil to give " body " to fine mineral oils is 
 sperm oil. 
 
 7. Lard and neat's foot oil may replace sperm oil when greater 
 tenacity is required. 
 
 8. The best mineral oil for cylinders is one having specific 
 gravity 0-893 at 60 F. (15 -5 C.), evaporating point 550 F. 
 (288 C.), and flashing point 680 F. (360 C.) 
 
 9. The best mineral oil for heavy machinery has specific 
 gravity 0-880 at 60 F. (15 -5 C.), evaporating point 443 F. 
 (229 C.), and flashing point 518 F. (269 C.) 
 
 10. The best mineral oil for light bearings and high velocities 
 has specific gravity 0-871 at 60 F. (15 -50.), evaporating point 
 424 F. (218 C.), and flashing point 505 F. (262 C.) 
 
 11. Mineral oils alone are not suited for the heaviest 
 machinery on account of want of "body" and higher degree 
 of inflammability. 
 
 12. Well purified animal oils are applicable to very heavy 
 machinery. 
 
326 OILS, FATS, WAXES, ETC. 
 
 13. Olive oil is foremost amongst vegetable oils, as it can be 
 purified without the aid of mineral acids. 
 
 14. The other vegetable oils admissible, but far inferior, stated 
 in their order of merit, are gingelly, groundnut, colza, and 
 cotton seed oils. 
 
 15. No oil is admissible which has been purified by means of 
 mineral acids. 
 
 A. H. Allen regards the following characters as those which 
 should be taken into consideration in forming an opinion as to 
 the suitability of a lubricating oil for a given class of work : 
 
 1. The viscosity or "body" of the oil at the temperature at 
 which it is to be used. 
 
 2. The temperature at which the oil thickens or actually 
 solidifies. 
 
 3. The flashing point or temperature at which the oil gives 
 off inflammable vapours in notable quantity. 
 
 4. The volatility or loss in weight which the oil suffers on 
 exposure in a thin film to an elevated temperature. 
 
 5. The " gumming " character or tendency of the oil to become 
 oxidised. 
 
 6. The relative proportions in which the fatty and hydrocarbon 
 oils of a mixture are present. 
 
 7. The proportion and nature of the free acid, if any, in the 
 oil. 
 
 8. The tendency of the oil to act on metals. 
 
 9. The presence of mineral matters, such as the metallic bases 
 of soaps, &c. 
 
 As regards the degree of volatility of a lubricating oil, J. Carter 
 Bell considers that it would be well for insurance companies to 
 lay down a hard and fast rule that no lubricating oil should be 
 used in any mill that has a flashing point lower than 350 F. 
 (177 C.), and that loses more than 5 per cent, in twelve hours at 
 140 F. (60 C.) 
 
 Lubricants of the Second Class Carriage and Waggon 
 Greases. For the axle boxes of railway rolling stock a peculiar 
 kind of imperfect soap is found to answer well, usually made by 
 melting tallow and palm oil together, and then thoroughly inter- 
 mixing a solution of sodium carbonate in water, for which purpose 
 Morfit's steam twirl (Chap, xix.) answers well ; or a boiled palm 
 oil soap is dissolved in hot water and thoroughly intermixed with 
 melted tallow, the emulsified mass being then cooled so as to 
 solidify. 
 
 Richardson <fe Watts * give the following receipts as furnishing 
 compositions of this kind that have been used with excellent 
 results, that marked "summer" running for 1,200 miles : 
 
 * Chemistry applied to the Arts and Manufactures, vol. i., part iii. 
 p. 744. 
 
LUBRICATING GREASES. 
 
 327 
 
 
 w 
 
 nter. 
 
 
 
 Summer. 
 
 
 Cwts. 
 
 qrs. 
 
 Ibs. 
 
 Lbs. 
 
 Cwts. 
 
 qrs. 
 
 Ibs. 
 
 Lbs. 
 
 Tallow, . 
 
 3 
 
 3 
 
 
 
 = 420 4 
 
 2 
 
 
 
 = 504 
 
 Palm oil, 
 
 o 
 
 2 
 
 
 
 = 280 i 2 
 
 2 
 
 
 
 = 280 
 
 Sperm oil, 
 
 
 
 1 
 
 7 
 
 35 
 
 
 
 27 
 
 = 27 
 
 Soda crystals, 
 Water, . 
 
 1 
 12 
 
 
 3 
 
 14 
 
 12 
 
 = 126 
 = 1,440 
 
 1 
 
 12 
 
 
 
 
 8 
 
 2G 
 
 120 
 = 1,370 
 
 
 20 
 
 2 
 
 5 
 
 2,301 
 
 20 
 
 2 
 
 5 
 
 2,301 
 
 These quantities are reckoned to give 1 ton = 2,240 Ibs. of 
 grease, allowing about 2J- per cent, for loss. 
 
 A. H. Allen gives the following composition of a similar 
 German waggon grease : 
 
 Tallow, . 
 Palm oil, 
 Rape oil, 
 Caustic soda, 
 Water, . 
 
 24-6 
 9-8 
 1-1 
 5-2 
 
 59-3 
 
 100-0 
 
 The following composition, containing a smaller proportion of 
 saponaceous matter, has been patented by Hervieux and Bedard * 
 as a superior form of axle grease : 
 
 Codfish oil, 
 Beef tallow, 
 Rosin, 
 Soft soap, . 
 
 24 parts. 
 16 
 
 1 
 
 2 , 
 
 A somewhat analogous imperfect lime resin soap is used for 
 railway trucks unprovided with axle boxes, carts, and waggons, 
 and similar vehicles ; this is made .by elutriating slaked lime 
 (by stirring up with water and running the " milk of lime " 
 through a succession of settling tanks), and thoroughly inter- 
 mixing the limemud with rosin oil in the cold ; the resulting 
 mass is often intermixed with coarse greases and other sub- 
 stances of the third class, and sometimes with mineral substances 
 possessed of antifrictional qualities j thus the following com- 
 position has been patented by A. Purvis f as an improved 
 lubricant capable of resisting unusually high temperatures : 
 
 Japanese tallow, 
 Russian tallow, 
 Olive soft soap, 
 Lard oil, 
 Castor oil, 
 Carbonate of lime, 
 Carbonate of soda, 
 
 * English Patent Spec., 4190, 1889. 
 t English Patent Spec., 13,936, I860 
 
 2 cwt. 
 
 3 
 
 2 
 
 108 Ibs. 
 108 
 
 10 
 
 10 
 
328 OILS, FATS, WAXES, ETC. 
 
 The mass is heated and well intermixed, with the addition of 
 J cwt. of finely pulverised mica, or of china clay, or of the two 
 together. After standing twenty-four hours it is again heated, 
 and 20 Ibs. of zinc oxide added ; after thoroughly commingling 
 the mass is then subjected to hydraulic pressure so as to squeeze 
 out any water present. 
 
 Numerous analogous mixtures, consisting essentially of tallow 
 or oil, soap of some kind, and solid powdery matter (such as 
 graphite, steatite, or sulphur) are in use as antifriction com- 
 positions. 
 
 Greases of the Third Class. These are the most dangerous 
 lubricating materials in use from the point of view of liability 
 to inflammation ; refuse coaltar dead oils, anthracene oils, creosote 
 oils, &c., have frequently a relatively very low flashing point, and 
 when once set on fire are not easily extinguished. Such com- 
 pounds should not be used at all in a mill or similar building 
 where great damage by fire might be occasioned. 
 
 Analysis of Lubricating Oils and .Greases. Oils, &c., 
 consisting wholly of organic matters will obviously leave no 
 ash on careful incineration, whereas if any soapy material or 
 other inorganic " antifriction " constituent be present, more or 
 less residue will be left when a known weight of substance is 
 cautiously heated (e.g., in a platinum dish) and the residual 
 carbon burnt off. An examination of this residue may be made 
 as regards the quantity of alkali contained, the amount of lime, 
 alumina, steatite, &c., present, and so on. 
 
 Organic suspended matters, such as Irish moss or seaweed 
 jelly, lime or other soaps insoluble in ether or petroleum spirit, 
 <fec., may be conveniently sought for by thinning the material 
 with the solvent, and passing through a weighed filter, finally 
 washing out all soluble matters ; the residue may be weighed, a 
 portion incinerated to obtain the proportion of inorganic matters 
 present, and the remainder further examined as may seem 
 requisite. When metallic soaps (alumina, iron, &c.) are present, 
 the metallic basis can be conveniently removed by thining the 
 grease with ether, &c., and agitating with water strongly acidu- 
 lated with hydrochloric acid. 
 
 When saponaceous matters are present (e.g., when the "foots" 
 from oil refining by alkaline processes (p. 260) are used as in- 
 gredients, or when lime and rosin spirit, or soda and palm oil, 
 <fec., are used, as with certain kinds of waggon grease), the 
 methods employed in soap analysis are available with suitable 
 modifications ; thus the total alkali present may be conveniently 
 found by shaking with ether and a slight excess of standard 
 acid (hydrochloric or nitric), separating the watery part and 
 back-titrating the excess of acid not neutralised. By adding 
 phenolphthalein to an alcoholic solution of the oil or grease, 
 and cautiously dropping in standard acid, and shaking after each 
 
LUBRICATING OILS AND GREASES. 329 
 
 addition, the amount of alkali or alkaline earth present other- 
 wise than as soap may be at least approximately determined ; 
 and by further diluting with water, adding ether, petroleum 
 spirit, carbon disulphide, or other convenient solvent, and excess 
 of standard acid, the total alkali, tfcc., may be determined as 
 above ; whilst after separating the solution of oil in ether, &c., 
 the fatty and resinous acids set free may be titrated therein in 
 the usual way (p. 116). 
 
 Glycerides (animal and vegetable oils and fats) and liquid 
 waxes (sperm oil, &c.) are determined as with ordinary oils 
 (p. 162) ; after neutralisation of free fatty acids (or alkalies) 
 excess of standard alkali is added with alcohol, and the whole 
 boiled some time with an inverted condenser and the alkali not 
 neutralised determined ; the product diluted with water and 
 shaken with petroleum spirit gives a watery solution of the soap 
 formed by saponification of the glyceride, from which the con- 
 tained fatty acid may be separated and subjected to examination; 
 whilst the petroleum spirit contains in solution the hydrocarbons 
 present in the original grease, together with non-fatty acid oxi- 
 dised matters, such as cholesterol from woolgrease, <fcc., the 
 higher alcohols formed by saponification of sperm oil, and the like. 
 When requisite these may be further examined by the acetyla- 
 tion process (p. 186). 
 
 As a general rule, the chemical analysis of a given lubricant 
 affords very little information as to its suitability for any parti- 
 cular purpose ; but certain laboratory determinations are often of 
 considerable value, more especially the determinations of rate of 
 loss of weight on heating to given temperatures for specified times ; 
 of the efflux " viscosity " at specified temperatures ; and to a lesser 
 extent of the specific gravity. The "flashing point" and the 
 somwhat higher temperature of firing ("ignition point") are also 
 important, especially with mineral oiis. The principal chemical 
 tests of practical value are those for free mineral and organic 
 acids, more especially the former. The chief utility of analysis 
 in the case of lubricating oils is to decide whether they are of 
 the composition stipulated for in a contract e.g., as to containing 
 a given percentage of sperm oil intermixed with hydrocarbons, 
 and so on ; or to see whether otherwise genuine e.g., in the case 
 of rape or castor oil, as to whether adulterated with other sub- 
 stances, such as cheaper oils or hydrocarbons ; or in the case of 
 blown oils whether artificially thickened by addition of soft 
 soap, aluminium oleate, rosin, and so on. 
 
 Occasionally it is required to find out whether rosin oils have 
 been admixed with mineral oil lubricants ; for this purpose the 
 glacial acetic test described on p. 57 may be conveniently used, 
 rosin oils being readily soluble in that solvent whilst mineral 
 oils are practically insoluble therein. 
 
 Rate of Absorption of Oxygen. According to O. Bach 
 
330 
 
 OILS, FATS, WAXES, KTC. 
 
 the facility with which a lubricating oil absorbs free oxygen is 
 a useful measure of its "gumming" tendency. By sealing up in 
 a glass tube containing 100-125 c.c. quantities of oil of from 3 to 
 5 c.c., after displacing all air by oxygen, and heating for ten 
 hours to 110C., a more or less considerable absorption of gas 
 takes place, readily determined by opening the sealed-up end of 
 the tube under water, and noting the amount of inrush. Thus 
 various kinds of oils gave the following numbers : 
 
 1 gramme of Valve oil (mineral) 
 Valveoline 
 Lubricating oil 
 Oleonaphtha 
 
 socalled "Cod oil:" sp. gr. 963 
 Olive oil 
 Rape seed oil 
 Cotton seed oil 
 Rosin oil 
 
 absorbed O'l c.c. of oxygen. 
 0-45 
 07 
 8-6 
 76-3 
 144-0 
 166-0 
 111-0 
 181-0 
 
 Little or no acidity is shown by the water sucked in with 
 mineral oils, but with others with which the absorption of 
 oxygen is large, a strong acid reaction is manifest, especially 
 in the case of rosin oil. 
 
 TURKEY RED OILS. 
 
 The chemical differences between the two kinds of oils treated 
 with sulphuric acid known under the name of " Turkey red oils " 
 have been already described (p. 143, et seq.)* In the practical 
 
 * Since that description was written a paper by P. Juillard has appeared 
 on the action of sulphuric acid on olive oil, and the nature of olive Turkey 
 red oil (Journ. Soc. Chem. Ind., 1893, p. 528, from Bulletin Soc. Ind., 
 Mulhouse, 1892, p. 413). The first action at to 5 is described as the 
 direct combination of one and of two molecules of sulphuric acid with olein 
 forming mixed glycerides, containing simultaneously the radicals of oleic 
 and oxystearosulphuric acids, and respectively indicated by the formulae 
 
 O.CO.C 17 H 34 .0. S0 3 H 
 C 3 H 5 <|O.CO.C 17 H 33 
 O.CO.C 17 H 33 
 
 and CH, 
 
 O.CO.C 17 H 34 . O.S0 3 H 
 O.CO.C 17 H 34 .O.S0 3 H 
 O.CO.C 17 H 33 
 
 By the further action of sulphuric acid, these give rise to other more 
 complex mixed glycerides containing simultaneously the radicals of sul- 
 phuric and oleic or oxystearosulphuric acids, and also that of a " poly- 
 merised " oleo-oxystearic acid, viz. : 
 
 (O.CO.C 17 H 34 .O.CO.C 17 H 33 
 C 3 HJO.CO.C 17 H 33 
 ( . S0 3 H 
 
 ( . CO . C 17 H 34 . . CO . C 17 H 33 
 and C 3 H 5 \ . CO . C 17 H 34 . . S0 3 H 
 ( . S0 3 H 
 
 Commercial olive Turkey red oil chiefly consists of the sodium salts of these 
 acids and of their derivatives and products of decomposition (oleic, oxy- 
 
TURKEY RED OILS. 331 
 
 manufacture of the castor oil products it is generally considered 
 indispensable to prevent the temperature from rising materially 
 above 35 or at most 40 C., otherwise secondary reactions take 
 place, leading to evolution of sulphurous acid, and production of 
 inferior products. The oil is run into a wooden tank, preferably 
 lined with sheet lead, and provided with cocks at different 
 heights to facilitate the running off of wash liquors, &c. ; the 
 sulphuric acid is then gradually run in with continual agitation, 
 either by hand- worked paddles or by a mechanical agitator. 
 Considerable differences in the practice of various makers occur 
 in this stage of the process, the precise details of working being 
 usually regarded as trade secrets ; in some cases the acid is run in 
 at one operation, more especially when the proportion employed 
 is smaller; in others part added at one time, and the rest at 
 intervals ; sometimes half being added one dav, and the other 
 half the next day. The proportion of acid used also varies 
 considerably/' 5 " from 15 to 40 per cent, of the weight of oil used. 
 After standing 1424 hours, a solution of common salt is run in 
 and the whole well agitated with the object of removing excess 
 of free sulphuric acid not converted into compound acids, glycerol, 
 glycerosulphuric acid, and such like substances soluble in water, 
 without removing the soluble compound sulphuric acids formed, 
 these being much less soluble in brine than in plain water. If 
 during this washing the liquor become much heated, considerable 
 loss is brought about because dilute hydrochloric acid is formed 
 which rapidly hydrolyses the compound acids present ; plain 
 water is, therefore, sometimes used for a first washing, and brine 
 or, better still, sulphate of soda solution for subsequent ones. A 
 certain amount of soda or ammonia is then run in to the washed 
 oil and well admixed, so as to neutralise part (but usually not all) 
 of the free acidity ; finally enough water is added to bring down 
 the percentage of oleaginous matter -present to the requisite 
 extent, 50 or even less in some cases. The ultimate product is 
 consequently a sort of emulsion of undecomposed fatty matter 
 and free acids disseminated through a watery solution of the 
 soaps formed by the action of the alkali added on the free fatty 
 acids and compound sulphuric acids formed ; if properly prepared 
 so as to contain the latter in sufficient quantity, castor Turkey 
 red oil can be diluted with water without allowing oily drops to 
 separate until after standing some considerable time ; and may 
 be dissolved in ammonia and diluted with water without becoming 
 seriously turbid through separation of oil, &c. If much precipi- 
 tation is visible solid fatty glycerides are present, due to adulter- 
 
 stearic, oleostearic, oleo-oxystearic acids, &c. ) formed during the process 
 of washing out the uncombined sulphuric acid. 
 
 For a summary of the bibliography of the chemistry of Turkey red oils 
 vide Journ. Soc. Chem. Ind., loc. cit. 
 
 * J. A. Wilson, Journ. Soc. Chem. Ind., 1891, p. 26; 1892, p. 495. 
 
332 OILS, FATS, WAXES, ETC. 
 
 ation of the original castor oil with rape or cotton seed oil, 
 &c. 
 
 According to P. Loch tin * the risk of spoiling the product 
 prepared from castor oil and sulphuric acid by overheating is 
 much less than is commonly supposed, firstly because no decom- 
 position involving the formation of sulphuric acid is produced at 
 temperatures not exceeding 70, excepting that due to albuminoid 
 impurities ; and secondly, because in his view only the free fatty 
 acid is of use in the dyeing process, some of the best preparations 
 only containing 2 to 5 per cent, of sulphuric anhydride (SO 3 ) per 
 100 of fatty acids (ricinoleosulphuric acid theoretically corre- 
 sponds with a ratio of 80 parts S0 3 to 298 of ricinoleic acid, or 
 27 per 100). Moreover, the product of saponification by alkali 
 (necessarily containing no compound sulphuric acid) gives very 
 fine shades in practical dyeing, although the tendency to frothing 
 causes the colour to be a little uneven. The alkali added, he 
 considers, should be ammonia and not soda or potash, because in 
 printing steam colours the alkali is volatilised and the free fatty 
 acid left on the cloth. In winter 20 to 30 parts, and in summer 
 15 to 20, of concentrated sulphuric acid are used (in Russia) per 
 100 of castor oil ; about one half of the acid is stirred gradually 
 into the oil during nine hours of a working day \ the mixture is 
 allowed to stand all night, and the next day the rest of the acid 
 is stirred in and the mixture allowed to stand until a sample 
 taken out exhibits a clear solution, when a few drops are shaken 
 with distilled water in a test tube : if allowed to stand too long 
 a cloudy fluid is obtained, just as when the action has not been 
 sufficiently prolonged. At the proper time, an equal bulk of 
 cold water is added to the fluid, when the oil separates and floats 
 on the diluted acid solution ; if a larger proportion of free fatty 
 acid (hydrolysed sulphuric compounds) is desired, hot water is 
 used instead of cold. 
 
 Formerly this hydrolytic decomposition was usually regarded 
 as the chief thing to be feared and avoided in manufacturing 
 Turkey red oils ; but recently such oils have been placed on the 
 market under the name of "oxyoleates" by Messrs. Schmitz <fc 
 Tcenges, of Heerdt (Dlisseldorf), in the preparation of which the 
 salted out fatty acid is purposely heated to 105 to 120 C., 
 whereby practically all sulphur is eliminated in the form of 
 sulphurous and sulphuric acids. f According to P. Werner,! 
 these products are, for certain applications, superior to the usual 
 Turkey red oils containing sulphurised acids. 
 
 Analysis of Turkey Red Oils. In order to hydrolyse the 
 compound sulphuric acids present, a weighed quantity is agitated 
 with about twice its volume of saturated brine, and about one- 
 
 * Journ. Soc. Chem. Ind., 1890, p. 498. 
 
 t English Patent, 14,430, 1891. 
 
 I Journ. Soc. Chem. Ind., 1893, p. 40. 
 
ANALYSIS OF TURKEY RED OILS. 333 
 
 tenth its volume of strong hydrochloric acid, whereby hydrolysis 
 is speedily brought about ; the product is then shaken up with 
 ether, the ethereal solution evaporated to dryness, and the residue 
 purified by solution in alcohol and nitration to remove saline 
 matters, and evaporation till all alcohol is driven off (J. A. 
 Wilson). The residue is examined so as to determine the 
 amount of unaltered glycerides present along with the free acid 
 by the ordinary methods described on pp. 116, 157. The pro- 
 portion of ricinoleosulphuric acid originally present is ascer- 
 tained by determining the total amount of barium sulphate 
 obtained from the acid brine, and subtracting therefrom the 
 amount present as ordinary sulphate obtained by agitating 
 the oil with brine and ether in the same way, but without the 
 addition of hydrochloric acid. Obviously the weight of com- 
 pound sulphuric acid deduced from the corrected weight of 
 barium sulphate thus obtained will be very different according 
 as it is reckoned as ricinoleosulphuric acid or diricinoleosulphuric 
 acid (p. 146), 233 parts of barium sulphate corresponding with 
 378 parts of the first and with 658 of the second, and con- 
 sequently with 518 parts of a mixture of the two in equivalent 
 proportions.* 
 
 Another mode of determining the relative proportions of 
 sulphurised and non-sulphurised acids present is to titrate with 
 standard alkali twice, using litmus as indicator in one case, and 
 phenolphthalein in the other ; the sulphurised acids are given 
 by the first titration, and the others by the difference between 
 the two. Scheurer Kestner recommends ammonia as the alkali, 
 notwithstanding the uncertainty of the indications of phenol- 
 phthalein therewith. 
 
 Juillard f condemns this method of examination as giving 
 inaccurate results, in the light of his own more recent re- 
 searches (supra; vide also p. 147), more especially when 
 diricinolein sulphuric anhydride is present, as is usually the 
 case. He considers that the essential determinations are those 
 of the fatty acids in the usual way, and of sulphuric acid and 
 glycerol after hydrolysis of the oil by boiling with dilute 
 hydrochloric acid. In view of the different shades yielded in 
 dyeing and printing by the various components of the oil, a 
 determination is desirable of the molecular weights of the 
 fatty acids present in the soluble and insoluble states. This 
 may be accomplished by Raoult's method, care being taken to 
 use enough water to bring into solution the whole of the 
 
 * 402 was found by Scheurer Kestner as the equivalent weight of mixed 
 compound sulphuric acids formed in one case, 480 being the corresponding 
 value of the non-sulphurised acids simultaneously produced (riciuoleic 
 acid = 298 ; diricinoleic acid = 578). 
 
 -\Journ. Soc. Chem. hid., 1892, p. 357; from Bulletin Soc. Chim., Paris, 
 1891, 6, p. 638. 
 
334 OILS, FATS, WAXES, ETC. 
 
 soluble acids. As usually prepared, Turkey red oils contain 
 some 45 or 50 per cent, of oil capable of being separated 
 by means of hydrochloric acid and brine, the balance being 
 water and small quantities of saline matter, &c. Of the 
 separated oil generally about one-fourth consists of unaltered 
 glycerides. The alkali added is usually insufficient to neutralise 
 all the free acid, as a rule only about one-third being neutralised. 
 On addition of water and ammonia to the product a clear 
 emulsion or solution is formed if solid glycerides are absent ; 
 but a more or less turbid fluid on account of precipitation if 
 these are present through use of adulterated oil, ttc. 
 
 In order to examine Turkey red oil (from castor oil) for 
 adulteration with cotton seed oil and other glycerides, J. A. 
 Wilson recommends (loc. cit. supra) that a weighed quantity of 
 oil (100 grammes) should be saponified by boiling with methy- 
 lated spirit (250 c.c.) and pure caustic potash (20 grammes) for 
 an hour, with inverted condenser attached ; after evaporating off 
 the alcohol, the residue is dissolved in half a litre of water, and 
 the soap decomposed with a slight excess of sulphuric acid, boil- 
 ing the whole for an hour. To avoid bumping, a piece of pumice 
 stone coiled round with platinum wire should be placed in the 
 flask. After standing, the fatty acids are collected by siphoning 
 off the acid liquid through a filter, and washed several times with 
 hot water, and then dried at 100, and examined further. The 
 specific gravity at 98, as taken with a Westphal balance, varies 
 considerably according as the fatty acids are derived from castor, 
 olive, or cotton seed oil ; thus 
 
 Castor oil acids, . . . "892 at 98 C. 
 
 Olive oil acids, . . . 0'851 ,, 
 
 Cotton seed oil acids, . . . 0'872 ,, 
 
 The fatty acids derived from pure castor Turkey red oil, not 
 sophisticated with any other oil, do not deposit more than traces 
 of solid matter at 15 -5, whilst much more is obtained with olive 
 oil, and still larger amounts with cotton seed oil. The melting 
 points of the latter two acids, when tested by the capillary tube 
 pressure method after solidification, are 
 
 Cotton seed oil acids, . . . 44 C. 
 
 Olive oil acids, .... 40 C. 
 
 The neutralisation numbers of the fatty acids do not differ 
 much 
 
 Castor oil acids, . . . 180 to 184 
 
 Olive oil acids, ... 173 to 170 
 
 Cotton seed oil acids, . . . 171 to 175 
 
 The iodine number of the castor oil acids is very variable, being 
 dependent on the age of the castor oil, and the method of pre- 
 paring the Turkey red oil, especially the amount of sulphuric 
 
ANALYSIS OF TURKEY RED OILS. 
 
 335 
 
 acid used ; so that no indications of any value as regards adul- 
 teration can be derived by its means. 
 
 The acetyl test, on the other hand, gives indications that are 
 of service in this direction : the fatty acids are boiled for an hour 
 and a half with four-fifths their weight of acetic anhydride with a 
 reflux condenser, and the acetylised product washed with hot 
 water till the washings are neutral to delicate litmus paper. A 
 weighed quantity of the acetyl product is then exactly neutralised 
 with alcoholic potash in the cold (whereby the " acetyl acid 
 number" is obtained, p. 187); excess of potash is then added 
 (about 1| times the first amount), and the whole boiled half an 
 hour to saponify acetyl derivatives, the unneutralised potash 
 being finally titrated. The amount of potash neutralised during 
 this second part of the titration (acetyl number) varies consider- 
 ably, according as pure castor oil has been employed, or castor 
 oil admixed with olive or cotton seed oils ; so that whether the 
 observed " acetyl number " is wholly due to the saponification of 
 acetyl derivatives, or (as seems more probable, p. 189) is partly 
 due to the hydration of anhydrides formed by the action of acetic 
 anhydride on fatty acids, in any case it affords a means of 
 detecting adulterations ; thus Wilson gives the following aver- 
 ages: 
 
 1 
 
 1 
 
 Acetyl Acid 
 Number. 
 
 Acetyl Number. 
 
 Sum (socalled 
 "Acetyl Saponifi- 
 cation Number"). 
 
 Castor oil maximum, . 
 ,, minimum, . 
 I Olive oil, . 
 | Cotton seed oil, . 
 
 144-0 
 149-2 
 1587 
 179-0 
 
 143-4 
 138-7 
 106-3 
 53-0 
 
 287 '4 
 287-9 
 265-0 
 232-0 
 
 These acetyl numbers are considerably higher than those yielded 
 by the fatty acids obtained on saponifying olive and cotton seed 
 oils not treated with sulphuric acid, quoted on p. 188, suggesting 
 that either a considerable amount of oxystearic acid, or some 
 analogous substance, is formed by the action of sulphuric acid on 
 olein and saponification of the product ; or else that the forma- 
 tion of anhydrides under the influence of acetic anhydride takes 
 place more readily with the fatty acids obtained after treatment 
 with sulphuric acid, than with those formed by the saponification 
 of the original oils.* 
 
 Hydrocarbons (petroleum, rosin oils, Arc.) are easily detected 
 
 * In all probability, the modification of the acetyl test proposed by 
 Lewkowitsch (determination of "distillation acetyl number" instead of 
 "titration acid number," pp. 190, 198) would give better results than 
 those obtained by Benedikt and TJlzer's method, errors due to formation, 
 of anhydrides being thus eliminated. 
 
336 OILS, FATS, WAXES, ETC. 
 
 in Turkey red oil by the process ordinarily used for the purpose 
 described on pp. 119, 124. 
 
 CURRIERS' GREASE, SOD OILS, AND DEGRAS. 
 
 During certain operations for tanning and currying skins, 
 various forms of oil and grease are worked into the skin 
 mechanically, and the excess subsequently removed, partly by 
 pressure, partly by the emulsifying and saponifying action of 
 alkaline solutions. When these fluids are decomposed by an 
 inorganic acid an oily mass results, partly consisting of free fatty 
 acids and partly of undecomposed glycerides. When tallow has 
 formed part of the original grease or "dubbin" employed, the 
 resulting recovered grease is of thicker consistency than that 
 obtained when only liquid oils have been employed, such as olive 
 oil, whale or cod oil, or menhaden oil. The greases thus obtained, 
 or regained by pressure only, are sometimes known as " sod oils " 
 or "degras"; when cod oil and similar substances are absorbed 
 in skins and exposed to the air, a certain amount of oxidation is 
 brought about rendering the regained oil even better for use than 
 the original unoxidised material ; accordingly it is sometimes the 
 practice (more especially in France) to prepare sod oil (Moellon) 
 for currying by absorption in skins used solely for the purpose, 
 and subsequently wrung out again after sufficient exposure to 
 air. Part of the good effect produced by sod oil and grease that 
 has been already used previously is supposed by some to be due 
 to the presence of tanning matters therein dissolved out from the 
 leather and contained in a condition peculiarly adapted to the 
 finishing of the tanning process in another skin ; others believe 
 that the beneficial effect is at least partly due to the solution in 
 the grease of nitrogenous matters not affected by tanning and 
 their subsequent removal by squeezing out the greasy solution, 
 especially if the operation is done hot. The recovered degras at 
 any rate contains more or less nitrogenous matter, which is left 
 undissolved as a resinoid mass when the material is treated with 
 light petroleum spirit ; further, a considerable amount of oxyoleic 
 acid (or some similar oxy acid, such as dioxypalmitic acid) is 
 usually present, and in the case of degras made from train oils, 
 more or less cetylic alcohol and similar bodies produced by the 
 hydrolysis or saponification of their compound ethers, together 
 with cholesterol ; the presence of these substances enables fatty 
 matters to become emulsified with water and thus to penetrate 
 the tissues more readily, just as in the case of lanolin applied to 
 a living skin (infra). * 
 
 Artificial degras and curriers' greases and dubbin are prepared 
 
 * For analyses of various kinds of de"gras, and a discussion of their general 
 nature, vide Journ. Soc, Chem. Ind., 1891, p. 557 ; 1892, p. 639. 
 
LANOLIN. 337 
 
 by intermixing tallow and cod oil or similar materials, red oil 
 (crude oleic acid from the candle factory, Chap, xvi.) and wool- 
 grease sometimes entering into the composition, together with 
 neutral soap, or imperfectly made soap prepared by heating 
 together oil with an amount of alkali insufficient to saponify it 
 completely. These products, however, are generally regarded 
 as greatly inferior to that prepared by the oxidation of cod or 
 other fish oils in contact with skins, so that for the finer kinds 
 of French leather only the latter are employed. 
 
 Sod oils obtained by simple pressure from skins treated with 
 olive, cod, or menhaden oil are valuable when properly refined 
 for the lubrication of delicate machinery (clocks and watches, &c.), 
 not being liable to clog and thicken. 
 
 MANUFACTURE OF LANOLIN. 
 
 Wool, as cut from the sheep's back, is largely impregnated 
 with a greasy material, suint, the inspissated perspiration of the 
 animal this partly consists of various natural potash salts and 
 soaps soluble in water, partly of cholesterol and isocholesterol 
 and their stearic and other compound ethers, and to a small 
 extent of cerylic cerotate, and other waxy organic matters. 
 When solvent processes are employed for dissolving out the 
 grease (e.g., by means of ether or carbon disulphide) the sub- 
 stance obtained by distilling off the solvent is a tarry brown 
 mass of unpleasant odour, of specific gravity at 15 about 0-973, 
 melting at near 40, sparingly soluble in alcohol, and only very 
 difficultly saponifiable, as the cholesterol ethers are compara- 
 tively very stable ; the " woolgrease " thus obtained is usually 
 distilled by means of superheated steam, whereby a mixture is 
 produced mainly consisting of free fatty acids and cholesterol, 
 from which " wool stearine " is obtained by expression. Methods 
 for cleansing wool by means of grease solvents have not come 
 largely into use in Britain, it being usually considered that the 
 heating requisite to remove the residual solvent from the wool 
 does more injury than the action of soap in the ordinary wet 
 process of wool scouring. Opinions on this point, however, are 
 by no means unanimous. 
 
 On the Continent wool cleansing by means of solvents has 
 made much more progress, and a variety of different forms of 
 apparatus have been patented in which the use of ether, fusel oil, 
 carbon disulphide, light petroleum spirit, benzene, &c., has been 
 claimed.* 
 
 By treatment with water, fleeces yield a solution of potash 
 
 * For a description of Singer & Judell's arrangements in which carbon 
 disulphide is the solvent, ride a paper by Watson Smith, Journ. Soc. Chem. 
 Ind., 1889, p. 24. 
 
 22 
 
338 OILS, FATS, WAXES, ETC. 
 
 soaps in which the cholesterol and other compound ethers, <tc., 
 are emulsified; the extraction from the watery product thus 
 formed of a purified emulsion for medicinal purposes was de- 
 scribed by Dioscorides in the first century A. P., under the name 
 of 'OIOVKOS; a more refined preparation of the kind has of late 
 years been somewhat largely employed under the name of 
 lanolin. To prepare this material, Braun & Liebreich * subject 
 the suds in which fleeces have been washed (or a mixture of 
 woolfat and soap water forming an analogous emulsion) to centri- 
 fugal action, whereby a separation is effected somewhat analogous 
 to that produced in a cream separator ; watery soap solution 
 flows away, whilst a soft grease along with solid dirty particles is 
 retained. The former is subjected to treatment with acids, etc., 
 for the recovery of the fatty acids contained in the soap 
 (Chap, xii.) ; the latter is purified by kneading with water, 
 melting, and filtration, or solution in appropriate solvents, 
 followed by further kneading with water until all soluble im- 
 purities are washed away. The purified greasy matter thus 
 obtained possesses a remarkable power of forming a soft lard-like 
 mass by the intimate commingling of water and grease so as to 
 form a stiff semisolid emulsion. On account of the peculiar 
 utility of this product as a vehicle for enabling drugs, etc., to be 
 passed into the body by rubbing on the skin lanolin impreg- 
 nated with the desired active material, and its use as an 
 emollient unguent, either alone or in combination with other 
 materials, it has of late years come somewhat prominently before 
 the public ; as also have various other substances differing there- 
 from in 110 essential particulars except the trade name, and in 
 possessing varying degrees of purity. 
 
 Several modifications of Braun & Liebreich's centrifugal 
 separation process have been subsequently introduced. In one 
 of these, calcium chloride, or other similar salt, is added to the 
 water so as to form insoluble lime salts or other metallic soaps ; 
 the separation of the grease is thus facilitated, whilst by means 
 of hot acetone the cholesterol ethers, waxes, etc., present are 
 subsequently dissolved out from the soaps ; after distillation 
 of the solvent the residual purified woolgrease is treated with 
 oxidising agents to remove animal odour and lighten the colour, 
 and is then kneaded with water till the requisite consistency 
 is attained. Other processes of a fractional solvent character 
 are also employed to separate from the crude " anhydrous 
 lanolin " i* some of the waxy ingredients, and thus obtain a 
 product consisting principally of cholesterol, isocholesterol, and 
 their ethers, and in consequence better adapted to form a semi- 
 solid emulsion with water, suitable as an unguent, &c. 
 
 Some of the products sent into the market and sold as 
 
 * English Patent Spec., 4,992, 1882. 
 
 t Vide Levinstein, Journ. Soc. Chem. Ind., 18S6, p. 579. 
 
LANOLIN. 339 
 
 "purified woolgrease," or under various fancy names, are of 
 much less desirable character than others. Levinstein gives the 
 following tests as those by which the purity of commercial lanolin 
 may be ascertained : 
 
 1. If 2 to 3 grammes of lanolin be heated with 10 c.c. of a 
 30 per cent, caustic soda solution, no ammonia must be dis- 
 engaged. 
 
 2. 10 parts lanolin heated with 50 of distilled water must 
 yield a clear oil. Impure lanolin becomes frothy and turbid. 
 
 3. If oily, the lanolin thus separated must be free from 
 glycerol. 
 
 4. If rubbed with water with an iron spatula on a ground 
 glass plate, the oil must be capable of taking up at least its own 
 weight of water, forming a sticky and paste-like mass ; if impure, 
 the mass will have a soap-like smoothness, and will not adhere 
 to the spatula. 
 
 Langbeck * describes the following process for preparing a 
 purified lanolin : The wool is washed twice in water at a 
 temperature not exceeding 110 F., and dried by pressure 
 or centrifugal action, whereby soluble potash salts are mostly 
 removed ; the residual wool is then scoured with a mix- 
 ture of potash ley and olive oil, whereby all the "woolfat'' 
 is removed and the wool thoroughly cleansed. The watery 
 emulsion is evaporated and treated with alcohol of 40 to 60 per 
 cent., which dissolves out potash soaps, .leaving behind crude 
 "woolfat," purified by solution in benzene or carbon disulphide, 
 filtration, and distillation of the solvent. The product, after 
 further purification and decolorisation with animal charcoal 
 (preferably " prussiate waste "), and subsequently with peroxide 
 of hydrogen, produces an excellent white basis for pomades, 
 ointments, &c., containing 20 to 30 per cent, of mechanically 
 intermixed water. The unpurified. woolfat forms a valuable- 
 lubricant and leather grease. 
 
 A. Seibel has recently introduced a sulphurised lanolin f for 
 medicinal and other purposes prepared by heating lanolin to 
 120 C., with about 20 per cent, of flowers of sulphur, whereby 
 most of the sulphur is dissolved ; after allowing to subside, the 
 supernatant sulphur-containing liquid is poured off and heated 
 to 230, whereby much sulphuretted hydrogen is formed, together 
 with the sulphurised lanolin ; like ordinary lanolin, this mixes 
 freely with water without separation, forming a soft semisolid 
 emulsion. 
 
 * Journ. Soc. Chem. Intl., 1S90, p. 356. 
 t German Patent, No. 56,49]. 
 
340 OILS, FATS, WAXES, ETC. 
 
 CHAPTER XV. 
 ADULTERATION OF OILS AND FATS, &c. 
 
 THE adulterations mostly practised in the case of oils and fats, 
 &c., may be broadly divided into two classes viz., (1) those 
 where some weight-giving ingredient is added of wholly foreign 
 nature, as where an undue proportion of water is mechanically 
 admixed with soft fats, such as butter and lard, or where starchy 
 matters are added to the latter substance ; and (2) those where 
 the adulterant is a lower priced substance of tolerably similar 
 nature, as where cotton seed oil is admixed with olive oil, hemp 
 seed oil with linseed oil, or oleomargarine with cow's butter. In 
 some cases mineral hydrocarbons (petroleum distillates) or 
 destructive distillation oils (paraffin oils, rosin oil, &c.) are 
 admixed with animal and vegetable oils; or substances largely 
 consisting of unsaponifiable matters derived from woolgrease, 
 &c., with tallow and similar saponifiable solid fats ; here the 
 nature of the adulteration is rather of the first class than of the 
 second, inasmuch as by appropriate processes the adulterating 
 impurity may (to a greater or lesser extent) be analytically 
 separated from the material examined, and directly determined 
 quantitatively ; whereas when two closely similar natural oils, 
 <fec., are admixed, in most cases it is difficult, if not impossible, to 
 effect any quantitative separation of constituents whereby the 
 -extent of the admixture can be directly determined, although in 
 many cases the fact of the admixture, and some rough idea of 
 its extent, can be arrived at by indirect means e.g., by the 
 alteration in the melting point of the mixed fatty acids obtain- 
 able on saponification, or the increase (or decrease) in the iodine 
 number or the saponification equivalent ; or by the production 
 of some particular colour change with a given chemical reagent, 
 not shown by the natural unadulterated oil, &c. 
 
 In most cases of the kind, moderate certainty can only be 
 ensured by making comparison tests side by side with the 
 substances examined, and with known mixtures of pure oils, &c. ; 
 and here a great difficulty is at once encountered in obtaining 
 standard samples of pure materials. In many instances this can 
 only be done satisfactorily by preparation of the standards in the 
 laboratory itself e.g., by expressing hand-picked samples of 
 seeds, &c., so as to ensure that the seeds themselves shall not be 
 mixtures of various kinds, and the oils extracted shall be free 
 from all other sophistications. Even with all possible care in 
 preparing pure substances for comparison, there still remains a 
 certain amount of possibility of error, owing to the natural 
 
ADULTERATION OF OILS, FATS, ETC. 341 
 
 fluctuations brought about by differences in the soil and climate, 
 the degree of cultivation, and similar causes. Accordingly, the 
 analytical detection of adulteration in oils and fats, <fec., not only 
 depends for the most part on very different principles from those 
 involved in mineral analysis, e.g., for metals, but also is a matter 
 permitting of much less quantitative certainty. 
 
 The methods adopted in testing commercial samples of oils, 
 fats, &c., necessarily vary with each substance examined, but in 
 general consist of a suitable selection from the various methods 
 above described, based on the physical and chemical properties 
 of the oils, c. ($ 2 and 3) ; more especially 
 
 The physical texture, colour, taste, and odour of the sub- 
 stance examined. 
 
 The effect on polarised light, and the refractive index. 
 The specific gravity of the substance, or of the fatty acids 
 
 thence obtainable. 
 
 The fusing and solidifying points of these fatty acids. 
 The solubility in various solvents. 
 The efflux velocity at various temperatures. 
 The value of the " free acid number." 
 The percentage of unsaponifiable matters present (including 
 
 water, suspended substances, and inorganic matters). 
 The nature of the elaidin formed, and its degree of con- 
 sistency. 
 In the case of drying oils, the result of tests of rate of 
 
 inspissation through oxygen absorption. 
 
 The effect of qualitative reagents in producing colour 
 
 reactions (nitric acid, sulphuric acid, zinc chloride, &c.) 
 
 The degree of heat evolution on mixture with sulphuric 
 
 acid. 
 The nature and consistency of the product formed with 
 
 sulphur chloride. 
 The quantitative result of Kcettstorfer's test (sapoiiification 
 
 equivalent). 
 Hehner's test (insoluble acid 
 
 number). 
 Reichert's test ( volatile acid 
 
 number). 
 
 Hiibl's test (iodine number). 
 
 Benedikt and Ulzer's test (acetyl 
 
 number). 
 
 The results of various special tests applicable in certain 
 particular cases. 
 
 The following particulars respecting the normal properties of a 
 few typical oils and fats, &c., and the effect thereon of various 
 adulterations, will serve as illustrations of the methods usually 
 
342 OILS, FATS, WAXES, ETC. 
 
 adopted in practice ; for more full details, and for particulars 
 respecting other substances, analytical treatises specially dealing 
 with the subject must be consulted.* The methods of analysis 
 applicable in the case of grease recovered from suds have been 
 already discussed in Chap, xn., and those employed in the case 
 of certain manufactured oils, &c. (Turkey red oils, butter sub- 
 stitutes, lubricants, &c.), in Chap. xiv. ; soap analysis generally 
 is dealt with in Chap. xxi. 
 
 As regards the general principles of detection of adulteration, 
 it 'is to be borne in mind that the object of sophistication is 
 essentially to sell a cheaper article at the price of a more costly 
 one, by admixing the former with the latter ; hence the relative 
 price of different kinds of oils and fats, &c., at any given time, 
 largely affects the question as to whether certain kinds of 
 adulteration are likely to be practised or not. Although con- 
 siderable variations in prices necessarily occur in the market 
 from time to time, still it is possible to draw up a rough 
 classification of oils, tfec., according to their relative values when 
 genuine. The following list is given by A. H. Allen (on the 
 authority of Mr. T. Duggan), indicating the usual order of price, 
 subject to market fluctuations : 
 
 1. Olive oil. t/11. Colza and rape oil. 
 
 2. Sperm oil. 12. Seal oil. 
 
 3. Neat's foot oil (genuine). 13. Niger seed oil 
 ( Bottlenose oil. 14. Linseed oil. 
 
 4 to 6. j Lard oil. 15. Whale oil. 
 
 ( Castor oil. 16. Cotton seed oil. 
 
 7. Cod oil. 17. Menhaden oil. 
 
 >- ( Arachis oil. 18. Japan fish oil. 
 
 8 to 10. j Sesam5 oil. ^ ] 9. Mineral oils. 
 
 .( Poppy seed oil. 20. Rosin oil. 
 
 Olive Oil. The natural variations in the quality of genuine 
 oil of olives are much less marked than might a priori be 
 expected, considering the wide range of country over which the 
 olive is grown for the purpose of oil production, and the number 
 of varieties that have been induced by centuries of cultivation 
 in different climates and on different soils of the different species 
 of Olea. Thus 0. europcea (var. sylvestris) was alluded to by 
 Dioscorides as a thorny tree growing wild ('EXa/a aypta] ; but 
 losing its thorns by cultivation (like the sloe bush, the parent of 
 the garden plums), giving the variety 0. europoea (var. sativa) 
 or 'EA/a r^Mtpa; which again has been the parent of numerous 
 distinct kinds of olive trees producing fruit of very different 
 sizes; thus the socalled "French" olive of the present day is 
 much smaller than the "Spanish" olive. Apart, however, from 
 these subspecies of 0. europcea grown in Greece, Phoenicia, 
 
 * E.g., Allen's Commercial Organic Analysis; Benedikt's Analyse der 
 Fette und Wachsarten ; the Analyst, passim, &c. 
 
OLIVE OIL. 343 
 
 Palestine, and the south of Europe since the commencement of 
 the historic period, and thence introduced and acclimatised into 
 such parts of America, Australia, and elsewhere as possess suit- 
 able soils and climates, other oil-bearing species are utilised in 
 other countries e.g., 0. ferruginea (0. cuspidata) in Afghanistan 
 and other Himalaya regions, and 0. capensis at the Cape of Good 
 Hope. 
 
 Even with the best known southern European varieties, notable 
 differences in the quality of the oil extracted are found to exist 
 according to circumstances, more especially according as the fruit 
 has thoroughly ripened on the trees, or has been plucked before 
 quite ripe and stored; and according as the oil has been extracted 
 by gentle pressure in the cold, or by hot pressure, especially when 
 accompanied by grinding processes whereby the stones are also 
 broken up and expressed : indeed the differences in quality due 
 to these causes appear to be quite as strongly marked as those 
 due to soil, climate, and degree of cultivation. The finest 
 qualities of all are obtained by handpicking olives from the trees, 
 selecting those not over ripe, but ripe enough to allow oil to 
 exude slightly on gentle pressure between the finger and thumb, 
 and pressing very gently by hand in cloths : the " virgin oil " 
 thus produced is subsequently agitated with water, and allowed 
 to stand so as to remove mucilaginous matter, the purified oil 
 being skimmed off. A slightly inferior, but still fine, grade of 
 oil is obtained by crushing ripe olives (preferably with edge- 
 stones, but without breaking up the olive kernels), and then 
 pressing cold with comparatively little pressure. The residual 
 marc (known in Italy as Sanza or Nocciulo) is broken up, stirred 
 with boiling water, and then pressed again with somewhat 
 stronger pressure ; the second marc (Buccia) is then ground 
 again with heavier millstones so as to crush the olive stones 
 (if this were not done at the first. crushing), and is then again 
 stirred up with boiling water and subjected to the heaviest 
 pressure attainable with the appliances used : in small mills 
 these are usually rough screw presses (p. 200, et seq.), but in larger 
 ones hydraulic presses are employed (p. 207, et seq.) Finally, 
 the residual oil (several per cents.) is extracted from the marc 
 by means of carbon disulphide or other solvents (p. 231). The 
 details of the processes used for extracting olive oil vary widely 
 in different districts and countries ; thus in some establish- 
 ments the stones are separated from the pericarp and the two 
 treated separately ; a superior oil is thus obtained from the 
 pulp, whilst " olive kernel oil " is extracted from the stones by 
 grinding them to a coarse meal and then pressing or treating 
 with carbon disulphide, tfec. Excepting in being darker coloured 
 and more unpleasantly smelling, the oil thus obtained is said not 
 to differ materially from the lower grade oils obtained from the 
 fruit pulp ; it often contains a large percentage of free fatty acids 
 
344 OILS, FATS, WAXES, ETC. 
 
 rendering it more readily soluble in alcohol than ordinary olive 
 oil, thus resembling the " huiles tournantes " derived from the 
 pulp (infra). 
 
 In this kind of fashion several qualities of olive oil are ulti- 
 mately obtained, more especially "virgin" and "salad" oils of 
 finest flavour, generally greenish through presence of chlorophyll, 
 and of specific gravity near to '916 at 15 ; "huiles d'enfer," * or 
 somewhat lower grades of inferior flavour (sometimes with more 
 or less marked acrid aftertaste and disagreeable odour) ; "pyrene" 
 and " sulphocarbon " oils (the former obtained by hot pressing 
 and the latter extracted by carbon disulphide or other solvent) 
 generally unfit for edible purposes, brownish yellow, and of specific 
 gravity -920 to -925 at 15; and "huiles tournantes" obtained 
 from more or less fermented stored fruit, and in consequence 
 considerably rancid, and containing large amounts (25 to 30 per 
 cent.) of free fatty acids. The denser varieties deposit solid 
 matters (mostly palmitin) on chilling somewhat sooner than the 
 lighter ones. 
 
 The total acid number of various grades of olive oil has been 
 found by different authorities to lie between 185 and 206, 
 corresponding with the saponification equivalent 272 to 303 ; the 
 better grades, however, generally furnish a total acid number 
 near to 191 (saponification equivalent 294), and an iodine number 
 near to 83. f Any considerable addition of rape oil would raise 
 the saponification equivalent materially, whilst admixture with 
 poppy seed oil, and to a lesser extent with sesame, cotton seed, 
 and rape oils, distinctly increases the iodine number. Maumene's 
 test (p. 147) indicates a smaller degree of heat evolution on 
 mixing with sulphuric acid in the case of olive oil than with 
 most other oils ; so that by making comparative experiments 
 with pure olive oil and the substance examined side by side, 
 indications of want of purity are obtainable ; lard oil, however, 
 gives about the same heat evolution as olive oil. Sophistication 
 with arachis oil is moderately easily detected thus,]: although 
 many other tests fail to show its presence. 
 
 * Socalled because the oil (mixed with water to separate mucilage by 
 standing) is stored in large underground tanks or reservoirs so as to avoid 
 exposure to air as much as possible. 
 
 t Olive oil usually consists of one-fourth glycerides of solid saturated 
 acids (palmitic, &c. ), and three-fourths liquid glycerides, mostly oleiii. 
 This composition would correspond with an iodine absorption of about 67 ; 
 the somewhat higher values usually found consequently suggest the presence 
 of a small quantity of linolic acid. In confirmation of this, Hazura and 
 \GriIssner have obtained small quantities of sativic acid (p. 128) from the 
 products of oxidation of the fatty acids of olive oil. 
 
 + Renard's test for groundnut oil is said by A. H. Allen to be sufficiently 
 delicate to indicate clearly an admixture of 10 per cent, of that substance 
 with olive oil, although failing with only 4 per cent. The small quantity 
 of arachin naturally contained in olive oil does not materially interfere. 
 The oil to be examined is saponified and the fatty acids separated and 
 
ADULTERATION OF OLIVE OIL. 
 
 345 
 
 Admixture with heavier oils, such as cotton seed oil, tends to 
 raise the specific gravity; whilst, conversely, addition of rape oil 
 tends to lower it ; thus Souchere gives the following table in- 
 dicating the effect of such admixtures on the relative density at 
 15 of pure olive oil : 
 
 
 
 
 
 Specific Gravity 
 
 Percentage Added. 
 
 Oil. 
 
 at 15 s of Pure 
 Oil. 
 
 10 
 
 20 
 
 so 
 
 40 
 
 50 
 
 Olive, . . 
 
 9153 
 
 
 
 
 
 
 Colza, . . 
 
 9142 
 
 91519 
 
 91508 
 
 91497 
 
 91486 
 
 91475 
 
 Sesame, 
 
 9225 
 
 91602 
 
 91674 
 
 91741 
 
 91818 
 
 91890 
 
 Cotton seed, 
 
 923 
 
 91607 
 
 91684 
 
 'J1761 
 
 91838 
 
 91915 
 
 Arachis, . 
 
 917 
 
 91547 
 
 91564 
 
 91581 
 
 91598 
 
 91615 
 
 The elaidin test (p. 137) serves to distinguish adulteration 
 with many oils giving soft elaidins ; a distinct softening of the 
 product as compared with that obtained with pure oil treated 
 side by side is noticeable when only a few per cents, of poppy 
 seed or linseed oil are present, and with somewhat larger 
 proportions of cotton seed, rape seed, or sesame oils ; moreover, 
 the elaidin formed with pure olive oil is nearly colourless or pale 
 yellow, whereas much darker tints are generally produced with 
 adulterated oils ; based on which property are numerous modifi- 
 cations of the nitric acid test proposed by various observers for 
 the purpose of examining olive oil. 
 
 Examination of the cohesion figure (p. 48), formed when oil 
 is placed on water, has been recommended by Tomlinson as a- 
 useful test of the purity of olive oil. A drop of oil is allowed to 
 fall gently on the surface of pure water contained in a chemically 
 clean basin of sufficiently large size, at a temperature not below 
 15C.; with pure olive oil the drop slowly spreads out into the- 
 shape of a large disc with slightly recurved edges ; little spaces 
 shortly appear round the edge, the film commencing to retract 
 again, so that the edge resembles a string of beads. The spaces 
 between the beads soon open out more, and the edge becomes 
 toothed ; portions become detached, reuniting themselves in some 
 
 dissolved in five parts of rectified spirit, and precipitated with alcoholic 
 lead acetate ; or the oil is directly saponified with litharge by boiling with 
 that substance and water. The resulting lead soaps are agitated several 
 times with ether to dissolve out lead oleate (hypogaeate, &c. ).; the residual 
 lead stearate, palmitate, and arachate are decomposed by hot dilute hydro- 
 chloric acid, and the fatty acid cake formed on cooling and standing, dis- 
 solved in five parts of hot rectified spirit per one of original oil. On cooling, 
 crystals of arachic acid arc deposited if earthnut oil were originally pre- 
 sent ; from the weight of these, corrected for solubility in the mother 
 liquors, an approximate notion of the proportion of earthnut oil present can 
 be deduced, on the assumption that 100 parts of this oil correspond with 
 five of arachic acid. 
 
346 OILS, FATS, WAXES, ETC. 
 
 places to the main oil film enclosing polygonal spaces bounded 
 by fine beads, and covered by a dew of oil so fine as to be visible 
 only with difficulty. About 35 seconds are requisite for the 
 entire succession of changes. With sesame oil the film first 
 formed soon begins to contract again, ultimately forming a figure 
 consisting of a central spot with distinctly marked rays, between 
 which other smaller rayed spots appear, the whole resembling a 
 spider's web loaded with dew ; about 60 seconds are required to 
 complete these changes. Mixtures of olive and sesame oils give 
 figures of intermediate character, the features of the one or the 
 other figure predominating according as the first or the second 
 oil forms the majority of the mixture ; and analogous differences 
 in the olive oil figure are produced by admixture with other 
 oils. 
 
 Baudouin's test for the presence of sesame oil is to shake up 
 
 10 c.c. of the sample for some minutes with 5 c.c. of hydro- 
 chloric acid, specific gravity 1'17, in which 0*1 gramme of sugar 
 has been dissolved. On separation of the oil from the watery 
 liquid, the latter is found to be tinted rose colour, more or less 
 marked according to the proportion of sesame oil present. As 
 little as 1 per cent, may be thus detected if the agitation be 
 prolonged for at least ten minutes (A. H. .Allen). Or a lump of 
 sugar on which fuming hydrochloric acid has been dropped may 
 be shaken up with the oil. On the other hand, according to 
 Villavecchia and Fabris,* olive oil of undoubted purity from 
 various localities in Italy gives the same red coloration to the 
 aqueous layer as other oil to which some 5 per cent, of sesame 
 
 011 has been added ; but if the agitation be only kept up for one 
 minute, in the case of such pure olive oils, the watery layer 
 immediately separates and remains colourless for at least two 
 minutes ; whilst the milky oily layer remains greenish or 
 yellowish. If only a minute quantity of sesame oil be present, 
 however, this oily layer turns red; the coloration of the oil, 
 rather than of the watery fluid, is the distinctive part of the 
 test (vide also p. 153). 
 
 Becchi's test (p. 306) for cotton seed oil gives useful indica- 
 tions of the presence of that adulterant, provided that the 
 refining of the cotton seed oil has not been carried so far as to 
 bring about the entire withdrawal of the constituent that acts 
 on the silver nitrate. 
 
 In many cases evidence of adulteration is obtainable by saponi- 
 fying the oil, separating the fatty acids, and determining their 
 fusing and solidifying points (p. 69) side by side with the corre- 
 sponding acids obtained from genuine oil, or mixtures of knoivn 
 composition, as the precise numbers obtained vary according to 
 the particular mode of manipulation adopted. Values varying 
 from 22 to 29 C. for the fusing point, and from 21 to 25 as 
 * Journ. Soc. Chem. Ind. t 1893, p. 67. 
 
ADULTERATION OF OLIVE OIL. 
 
 347 
 
 the solidifying point, have been recorded by different observers. 
 Dieterich gives the following comparative values in different 
 cases, using the same process throughout : 
 
 
 Melting Point. Solidification Point. 
 
 Olive oil (average of 
 
 19 samples), . 
 
 26 to 28 -5 23 -5 to 24 -6 
 
 3 
 
 parts olive oil to 1 
 
 of arachis oil, 
 cotton seed oil, 
 
 29 
 
 30 
 
 26 
 27'3 
 
 
 
 sunflower seed oil, 
 
 25 
 
 20-5 
 
 
 
 sesame" oil, 
 
 28 
 
 25 
 
 
 
 linseed oil, . 24 '5 
 
 19-5 
 
 
 ' 
 
 colza oil, . 23 
 
 19 
 
 The figures thus deduced, however, are rarely sufficiently deci- 
 sive of themselves to warrant any accurate deduction being 
 drawn as to the nature and extent of the adulteration. 
 
 Much the same remark applies to tests' based on the amount 
 of solubility in various menstrua e.g., mixtures of alcohol, water, 
 and glacial acetic acid (Valenta's test, p. 55), although in certain 
 cases this method gives useful corroborative indications, especially 
 when carried out side by side with genuine oil and mixtures of 
 known characters. 
 
 Admixtures of hydrocarbons may be detected by completely 
 saponifying the oil with alcoholic soda or potash, evaporating off 
 most of the spirit and adding water, shaking up with ether, 
 separating the ethereal liquid and evaporating off' the solvent ; 
 with pure oil only infinitesimal amounts of unsaponified matter 
 (phytosterol, &c.) will be left, whereas hydrocarbon oils, if 
 present, will be obtained in much larger quantity after evapora- 
 tion of the ether. This test may be made a quantitative one by 
 using a weighed amount of oil and evaporating a known fraction 
 of the ethereal solution in a weighed vessel (vide p. 119). 
 
 Occasionally metallic compounds are found in solution in olive 
 oil or substances purporting to be such ; thus copper (added to 
 communicate a chlorophyll-like green shade) is occasionally 
 present. Lead compounds are said to be occasionally added for 
 the purpose of communicating a sweeter taste to the oil. Metallic 
 impurities of this kind may be detected as described on p. 122. 
 
 Several special instruments have been invented for the purpose 
 of examining olive oil, in order to detect adulterations, based on 
 different physical properties e.g., the thermal araeometer (p. 82); 
 the oleorefractometer (p. 51); and the diagometer (p. 53). The 
 polariscope may also be utilised, olive oil being slightly dextro- 
 gyrate, and most other oils Isevogyrate. 
 
 Very similar processes suffice (mutatis mutandis) for the 
 examination of other oils of the olive class e.g., almond oil, oil. 
 of ben (or behen), and groundnut (arachis) oil and to some 
 extent of oils of the semidrying class, such as cotton seed oil and 
 
348 OILS, FATS, WAXES, ETC. 
 
 sesame oil. With the cheaper oils of this kind, hydrocarbons and 
 deodorised fish oils are the most likely kinds of adulterants ; 
 the former are detected and determined as described on p. 119; 
 the latter largely increase the heat evolution with sulphuric acid, 
 and in some instances give special colour reactions with that acid 
 and other reagents. 
 
 Rape Seed, and Colza Oils. Several species of Brassica 
 exist, and several varieties of the rape plant have been developed 
 by successive cultivations ; the oils from these are generally 
 termed indiscriminately "rape" or "colza" oils in Britain. On 
 the Continent, however, the different kinds are still frequently 
 distinguished by separate names. Thus Schadler divides these 
 oils into three classes, viz. : 
 
 Colza oil (Colzaol or Kohlsaatol) from the original plaiih, " kohlsaat " 
 
 (Brassica campesfris). 
 L'ape seed oil (Rapsol or Rapsamenol) from a developed variety, 
 
 "raps" (Brassica campevtris var. nap us, or Brassica no pus 
 
 oleifera. 
 Riibsen oil (Rubol or Riibsenol) from a different variety, " rubsen " 
 
 (Brassica campestris var. rapa, or Brassica rapa oleifera. 
 
 Each class is further subdivided according as the plant is an 
 annual or a biennial, the former yielding " summer oils," and the 
 latter " winter oils." Thus 
 
 Winter rape seed oil from winter raps (Brassica napus oleifera biennis). 
 Summer ,, ,, summer raps ,, ,, annua). 
 
 Winter rubsen oil from winter riibsen (B. rapa oleijera biennis}. 
 Summer ,, ,, summer riibsen ,, ,, annua). 
 
 Brassica nigra and Brassica alba are now more usually desig- 
 nated Sinapis nigra and Sinapis alba respectively (black and 
 white mustard), being plants different in many respects from the 
 cole or kohl, the seeds of which (kohlsaat) furnish the term 
 " colza " by corruption. Similarly, the allied Brassica juncea is 
 now generally known as Sinapis juncea, and Brassica cJiinensis 
 (Chinese cabbage) as Sinapis chinensis. 
 
 Cole or rape seed is largely cultivated in various parts of 
 Europe, especially France, Belgium, Germany, and Hungary ; 
 also in Roumania, Russia, India, and China. Much is shipped 
 from the Black Sea and Baltic ports, the expression being usually 
 carried out in large mills after the fashion described in Chap, ix., 
 the seeds being crushed between rollers, steamed to coagulate 
 mucilage and increase fluidity, and subjected by hydraulic 
 pressure before cooling. 
 
 The yield is usually from 30 to 45 per cent, according to the 
 variety employed. Schadler gives the following averages : 
 
 Summer rubsen and summer raps, . . .30 to 35 per cent. 
 Winter ,, winter ,, . . . 35 to 40 ,, 
 
 Winter colza, . . . . . . . 35 to 45 ,, 
 
LINSEED OIL. 349 
 
 Much mucilage accompanies the crude oil ; this is generally 
 eliminated by the sulphuric acid refining process (p. 259), in 
 some cases supplemented by an alkaline treatment to get rid of 
 free acid, injurious for lubricant purposes. 
 
 Rape seed oil usually exhibits a total acid number of 175 to 
 179, corresponding with the saponification equivalent, 320 to 325, 
 the iodine number being 98 -5 to 105.* The fatty acids isolated 
 on saponification melt at 18 to 22, whilst the specific gravity of 
 the oil at 15 ordinarily lies between -911 and -9175. Accord- 
 ingly, the usual result of adulteration with other fixed oils is a 
 rise in specific gravity, and a fall in saponification equivalent. 
 Linseed and other drying oils raise the iodine number ; fish and 
 drying oils increase the heat evolution on mixture with sulphuric 
 acid. Thus Thomson and Ballantyne found the "specific tempera- 
 ture reaction" (water = 100) for rape oil to be between 125 and 
 144, whereas that for linseed oil was 270 to 349, cod liver oil 
 giving 243 to 273, and menhaden oil 306 (p. 149). Pure rape 
 seed oil is practically immiscible with glacial acetic acid at the 
 ordinary temperature, and has a lower efflux velocity (higher 
 viscosity), than most oils likely to be used as adulterants. 
 
 Hydrocarbon oils are detected in the usual way (p. 119). 
 
 Linseed Oil. The oil expressed from the seeds of the flax 
 plant (Linum usitatissimum) is generally known as linseed oil ; 
 usually it is extracted on the large scale in crushing mills by the 
 process described in Chap. ix. ; but small quantities are prepared 
 for home consumption in different parts of the world, more 
 especially Russia, on a much smaller scale. The seeds as found 
 in commerce are rarely all of one kind, more or less considerable 
 admixtures of the seeds of other plants being often present, the 
 result of which occasionally is to seriously impair the quality of 
 the oil ; this sometimes arises from intentional admixture, more 
 especially in the case of hemp seed, which is stated to be inva- 
 riably added to the extent of 5 per cent, and upwards to all 
 linseed shipped from the Black Sea ports ; but quite as frequently 
 it is accidental, on account of other plants being grown along 
 with flax e.g., mustard and rape ; this is more especially the 
 case with the red variety of Indian seed. The presence of 
 mustard seed in any considerable quantity is liable to render 
 the oilcake acrid and unsuitable as a cattle food. 
 
 Linseed is chiefly imported from the Baltic ports, Russia 
 (Black Sea), and India ; but it is also grown in considerable 
 quantity in various parts of Europe, especially Poland, in Egypt, 
 and the Brazils. Seed grown in hotter climates is reputed to 
 yield oil comparatively defective in drying power and of lighter 
 colour than that produced in colder regions ; possibly, however, 
 
 * Hence, some considerable amount of linolin or other drying glyceride 
 must be present, since the iodine number of erucin is 72 "4, and that of 
 rapin (isomeride of ricinolein) 81 ? 
 
350 OILS, FATS, WAXKS, ETC. 
 
 this is chiefly due to admixture of other seed oils and not to 
 actual differences in the oil contained in the flax seed. When 
 subjected to pressure, some 20 to 22 per cent, of superior " cold 
 drawn " oil can be extracted ; in Poland, Russia, and other 
 countries this is used as an article of food, being not unpleasantly 
 tasting. Later runnings prepared by hot pressure are darker in 
 colour and have a disagreeable acrid flavour, rendering them only 
 suitable for technical purposes. If the seeds are expressed com- 
 paratively "green," much more watery mucilage accompanies the 
 oil ; after keeping some months they dry somewhat and a better 
 yield of oil with a lessened admixture of vegetable extractive 
 matter results. Schadler describes the average yield as being 
 
 Cold pressed oil, . . . . 20 to 21 per cent. 
 Hot pressed oil, . . . 27 to 28 ,, 
 
 Obtained by solvents, . . , 32 to 33 ,, 
 
 The proportion of oil obtained, however, varies somewhat wdth 
 the source of the seed ; thus Italian linseed yields somewhat 
 more than Russian, and white Indian some 2 per cent, more 
 than red Indian. Again, the yield varies according as the seed 
 has been allowed to ripen fully, or as the plant has been harvested 
 earlier for the flax crop, in which case a smaller yield of oil is 
 usually obtained. 
 
 In practice, pure linseed oil is never met with commercially, 
 and can only be obtained by carefully handpicking the seed 
 before expression. When freshly expressed, after refining by 
 sulphuric acid (p. 259), it has a specific gravity at 15 of 
 932 to '937, averaging close to '935 (Allen) : if any considerable 
 admixture of rape or other lighter oil is present, the specific 
 gravity falls to -930 and lower. If, on the other hand, the oil is 
 old and has absorbed oxygen, the specific gravity is more or less 
 considerably raised. 
 
 Linseed oil contains some 10 or 15 per cent, of glycerides of 
 solid fatty acids (palmitin, myristin, &c.) The remaining liquid 
 glycerides consist of those of oleic, linolic, linolenic, and isolino- 
 lenic acids, in the relative proportions 5, 15, 15, and 65 per cent, 
 of the sum of the four (Hazura and Griissner). The total acid 
 number is variously stated by different observers at 189 to 195-2, 
 corresponding with a saponification equivalent of 287 to 297, 
 representing a mean molecular weight of fatty acids of 274 to 285. 
 By directly titrating the acids prepared as carefully as possible 
 to avoid oxidation, molecular weights varying between 282 and 
 295 have been observed in many cases ; but perceptibly higher 
 values up to 307 have been noticed in some instances, leading to 
 the belief that a higher homologue of linolic acid, C 00 H. 1(3 O , was 
 present (p. 34). 
 
 The iodine number of linseed oil has been very variously stated 
 by different observers. Dieterich found different samples to give 
 
ADULTERATION OF LINSEED OIL. 351 
 
 values between 161 '9 and 180-9 ; Benedikt found 170 to 181 ; 
 Holde 179 to 180 ; Thomson and Ballantyne 175-5 to 187*7 accord- 
 ing to the time allowed (vide p. 180). Lower values down to 149 
 have been recorded by other observers ; but in view of the results 
 of later researches on the difficulty of completely saturating 
 glycerides with iodine unless a considerable time is allowed and 
 a large excess of iodine employed, it would seem very doubtful 
 whether these lower values are correct : probably 180 to 185 is 
 nearer the true ultimate value for pure linseed oil.* 
 
 The fatty acids separable from linseed oil have been found by 
 various observers to melt at temperatures lying between 17 and 
 24, solidifying at 13 to 17-5 ; as linseed oil occurs in commerce, 
 a small proportion of these acids is usually present in the free 
 state, free acid numbers being obtained varying from 0*7 to 8-0, 
 corresponding with amounts of free acid from 0-4 to upwards of 
 4 per cent, of the total acids present. 
 
 Linseed oil is especially characterised by the high heat evolu- 
 tion brought about by admixture with sulphuric acid (Maumene's. 
 test, p. 147) ; in the absence of fish oils, any considerable admix- 
 ture of rape or other oil giving less heat evolution can be readily 
 detected in this way. Livache's test (p. 133) also affords an 
 indication as to whether semidrying oils or drying oils of inferior 
 quality have been admixed, inasmuch as the increment of weight 
 after a few days, when no further increase is noticeable, is from 
 14 to 15 per cent, in the case of fresh genuine linseed oil, but 
 considerably less if any large admixture of other oils be present. 
 A simpler test based on the shorter time required by genuine lin- 
 seed oil to dry thoroughly, as compared with adulterated samples 
 and other drying oils, is the "film test" described on p. 133 ; the 
 character of the dried film formed is also taken into account, 
 whether resinoid and brittle when cold, or hard and varnish-like 
 but tough, or inclined to be readily broken up and crumbly; 
 such a practical test, although not quantitative in character, is 
 
 * Assuming linseed oil to contain only SO per cent, of unsaturated 
 glycerides in the relative proportions given by Ha/ura and Griissner 
 (siipra), the calculated iodine number would be 1S2 05. 
 
 Proportional Amount Iodine Number of 
 
 Present. Glyceride. 
 
 Olein, 0-8 x -05 x 86 -20 = 3 "45 
 
 Linolin, 0'8 x -15 x 173'57 20'S3 
 
 Linolenin, O'S x -15 x 262*15 - 31 "46 
 
 Isolinolenin, 0'8 x "63 x 262*15 = 136 "31 
 
 192-05 
 
 whence it would seem probable that the proportions of linolenin and iso- 
 linolenin deduced by Hazura and Griissner are a little overstated, at least 
 so far as these values are applicable to average qualities of oil. 
 
352 OILS, FATS, WAXES, ETC. 
 
 often of great value.* Moreover, an old sample of oil that has 
 already taken up some amount of oxygen, although by no means 
 deteriorated for many ordinary applications thereby, would be 
 indicated as of inferior quality by Livache's test if alone relied 
 on ; but would not be shown to be deficient in drying power by 
 the " film test." Such an oil, however, would possess a lower 
 iodine number than fresh oil, even if otherwise genuine, inasmuch 
 as the oxygen taken up appears to be largely added on to the 
 unsaturated carbon groups just as iodine is. 
 
 Fish oils (cod, menhaden, &c.) possess high thermal values by 
 Maumene's test, and high iodine numbers, so that adulteration 
 therewith is not indicated by either reaction. Boiling with 
 caustic soda develops a peculiar reddish colour when these oils 
 are present ; chlorine gas blown through the oil causes a great 
 darkening in tint not observed with pure linseed oil. The 
 sulphuric acid test (p. 151) gives simply a dark brown clot with 
 genuine linseed oil, but a reddish brown spot if fish oils are 
 present. 
 
 Hydrocarbons are not unfrequently added as adulterants ; of 
 these, mineral oils lower the specific gravity, and rosin oils raise 
 it, so that a suitable mixture of the two has little or no effect. 
 The test described on p. 119 enables this admixture to be readily 
 detected and the quantity determined ; if any considerable 
 amount is present the film test indicates the fact, as the film 
 remains a long time sticky with only small quantities, and never 
 properly hardens and dries w T ith larger proportions.! 
 
 Rosin (colophony) is another adulterant often added along 
 with other substances ; to detect and determine this admixture 
 the oil is dissolved in a little pure alcohol, and the free fatty 
 acids and resin acids titrated by standard alkali; water is added 
 to the neutral mass, and the glyceridic oils separated by gravi- 
 tation or petroleum spirit (p. 118) ; the aqueous fluid is acidu- 
 lated, the mixed fatty and resinous acids separated and weighed, 
 and the resin determined therein, as in the case of rosin soaps 
 (yellow soaps, Chap, xxi.) 
 
 Hemp seed oil is a frequent constituent of linseed oil, owing 
 to the admixture of hemp seed with linseed before reaching the 
 crushing mills ; to detect such an admixture the oil is stirred 
 with concentrated hydrochloric acid, when a more or less marked 
 
 * The h'lm test is often modified by mixing the oil to be tested with three 
 times its weight of white lead, so as to form a paint which is then applied 
 by a brush to a clean surface ; a precisely similar trial is made side by side 
 with a standard sample of oil, and the rates of drying compared. If 
 nondrying oils be present, even in only small quantity, the rate of drying 
 is markedly slackened. 
 
 t Eosin oils, being strongly dextrogyrate, can be detected by the polari- 
 scope (p. 50), pure linseed oil being faintly laevorotatory. Sesame oil is 
 also dextrorotatory; the sugar test (p. 346) serves to detect it if present. 
 
SPERM OIL. 353 
 
 green coloration is developed if hemp seed oil be present, pure 
 linseed oil giving a yellow colour. 
 
 Sperm Oil. Two varieties of sperm oil proper are obtained 
 from the Cachelot whale (Pliyseter macroceplialus) ; one from the 
 blubber by the ordinary processes of rendering, the other from 
 the "head matter" or contents of the cranial cavities. This 
 latter usually contains a larger* proportion of solid constituents, 
 so that on standing it soon becomes more or less pasty or semi- 
 solid from the separation of spermaceti. This solid constituent 
 also deposits from the blubber oil on standing and chilling, but 
 to a somewhat lesser extent. 
 
 Sperm oil thus freed from spermaceti is pale yellow and nearly 
 odourless when prepared at comparatively low temperatures from 
 fresh blubber, c. ; although, like all other fish and blubber oils, 
 possessed of a marked unpleasant smell and darker colour when 
 extracted by greater heat from partly decomposed blubber. Its 
 specific gravity at 15 usually lies between -875 and -884 : it has 
 but little tendency to become rancid, or to " gum " and thicken 
 by exposure to air, whilst its viscosity is but little affected by 
 change of temperature, so that it forms a valuable lubricating oil. 
 Its total acid number lies between 123 and 147, averaging near 
 132, corresponding with the saponification equivalent 426 ;* its 
 iodine number is near 84. The fatty acids obtained on saponi- 
 fication melt at near 13, and possess an iodine number near 88, 
 and the average molecular weight 281-294 (Allen oleic acid = 
 282, physetoleic acid = 254). Their specific gravity at 15 is 
 near -899 ; nitrous acid solidifies them readily. 
 
 On saponification sperm oil yields 60-63 per cent, of insoluble 
 fatty acids, separated from the monohydric alcohol simultaneously 
 formed which constitutes 39-41-5 per cent, (theoretical values for 
 cetyl physetoleate, cetylic alcohol = 50 - 6 per cent., physetoleic 
 acid 53-1 per cent. ; for dodecatyl physetoleate, dodecatylic 
 alcohol, 44-1 per cent., physetoleic acid, 60'2 per cent.) 
 
 Sperm oil is often adulterated with cheaper vegetable and 
 animal oils, the presence of which is usually detected by the 
 lowering of the percentage of alcoholiform constituents produced 
 on saponification, and by the circumstance that the viscosity of 
 genuine sperm oil is affected less by temperature variations than 
 that of most other oils, so that if other oils be present the differ- 
 ences between the efflux viscosity rates (p. 94) at different 
 temperatures (e.g., 15C., 50C., and 100C.) will be considerably 
 increased. Further, such admixture tends to lower the saponi- 
 fication equivalent. Hydrocarbon oils increase the saponification 
 equivalent and the amount of ether residue obtained by the process 
 described on p. 119 ; but this residue, consisting largely of fluid 
 hydrocarbons, is readily distinguishable from the alcoholiform 
 residue obtained with pure sperm oil, more particularly by the 
 * Cetyl physetoleate = 478. Dodecatyl physetoleate = 422. 
 
 23 
 
354 OILS, FATS, WAXES, ETC. 
 
 acetyl test (p. 186). Vegetable and animal glyceridic oils lead 
 to the presence of more or less considerable amounts of glycerol 
 in the products of saponification ; genuine sperm oil gives but 
 little. Fish and sharkliver oils give special colorations with 
 sulphuric acid on account of the biliary constituents present. 
 
 Tallow. The terms " tallow " and " suet," especially the 
 former, are often used indiscriminately to denote both the solid 
 adipose tissues of various quadrupeds (more particularly the ox 
 and sheep), and the fatty matters thence rendered by suitable 
 treatment so as to separate them from the nitrogenous cellular 
 tissue ; preferably, however, the term " suet " should only be ap- 
 plied to the untreated animal fatty tissues, whilst the word "tallow" 
 should only imply the fatty matters thence extracted and freed 
 from cell walls, &c. In this sense " tallow " includes the rendered 
 fats obtained from the ox, sheep, goat, stag, and other quadrupeds, 
 excluding the horse and hog, the fats from which are generally 
 known as " horsegrease " (maresgrease) and "lard" respectively. 
 According to the breed, age, and sex of the cattle or sheep 
 from which the tallow is obtained, the hardness of the substance 
 varies ; the mode of feeding and climate also produce variations ; 
 whilst, as in the case of hog's lard, the consistency of the product 
 differs considerably with the part of the carcase furnishing the 
 fatty tissue. These variations, however, so far as is known, do 
 not affect the general character of the fat as regards its consti- 
 tution; whether harder or softer it essentially consists of the 
 glycerides of oleic, stearic, and palmitic acids, the former being 
 present in the larger proportion the softer the fat. In general, 
 veal tallow (from calves) is softer than that similarly obtained 
 from oxen ; whilst cow tallow and bull tallow are harder still : 
 these are all generally included in the term " beef tallow." 
 " Mutton tallow " from sheep (ewes and rams) is usually harder 
 than beef tallow, but not invariably : " goat's tallow " (often 
 included in mutton tallow) much resembles that substance. In 
 the trade a variety of grades exist, in many cases known by 
 special names either denoting the country from which the 
 material is shipped ("River Plate tallow," " Australian tallow," 
 " Eussian tallow," &c.) or given for some other reason e.g., 
 P. Y. C. tallow = Petersburg yellow candle (or prime yellow 
 candle), a particular quality irrespective of source ; " Prime 
 Butchers' Association tallow," or " North American," mostly 
 shipped from New York ; " Western," imported from New 
 Orleans: "tripe tallow" and "town tallow," grades usually 
 softer and somewhat inferior because of admixture with waste 
 dripping, kitchen grease, and other similar materials. In many 
 cases large admixtures of other foreign substances are added 
 e.g., cotton seed stearine ;* woolgrease and Yorkshire grease, and 
 
 * According to R. Williams cotton seed oil is often used as an adulterant 
 in the case of softer tallows (vide Journ. Soc. Chem. Ind., 1888, p. 186). 
 
TALLOW. 355 
 
 the stearines thence obtained by distillation and pressure ; bone 
 grease ; together with solid non-fatty matters such as China clay, 
 whiting, starch, &c., the presence of which is easily recognised 
 by applying a solvent and filtering (p. 123). 
 
 The specific gravity at 15 of tallow lies between 0-925 and 
 0-940, values between 0-925 and 0-929 being obtained with beef 
 tallow, and somewhat higher ones, between 0-937 and 0-940, with 
 mutton tallow (Hager). Dieterich found slightly higher values 
 up to 0-952. The melting point and solidifying point vary 
 considerably, 41 to 51 being recorded by different observers for 
 the former, and a few degrees lower for the latter. The fatty 
 acids obtained on saponification also vary similarly with the 
 hardness i.e., the proportion of olein, the melting point being 
 usually near 47 with tallow of good quality. The solidifying 
 point as determined by Dalican's process (p. 74), sometimes 
 termed the " titre " of the tallow, affords the best criterion of 
 quality, so far as such physical tests go: 44 represents a mixture 
 of equal quantities of stearic and oleic acids, lower values being- 
 obtained when oleic acid preponderates, and higher ones when 
 stearic acid is in excess. On the Continent, it is often stipulated 
 that the solidification point shall not fall below 44 when the 
 tallow is intended for candlemaking ; whereby not only are the 
 softer genuine (or comparatively so) tallows excluded, but also 
 those largely adulterated with such substances as cotton seed 
 oil, cotton seed stearine, Yorkshire grease, stearine from dis- 
 tilled grease, c., as the presence of these materials tends to 
 lower the melting point of the mixed fatty acids obtained. 
 Woolgrease and Yorkshire grease products are especially ob- 
 jectionable in this connection, because they contain more or less 
 considerable quantities of cholesterol hydrocarbons and other 
 unsaponifiable substances, which not only directly diminish the 
 amount of stearic acid present, but also further diminish the 
 quantity of solid fatty acids obtainable by pressing, as they 
 interfere with the proper "seeding" or crystallisation of the 
 press cake (vide p. 367). The determination of these unsaponi- 
 fiable matters in tallow adulterated therewith, is carried out as 
 described on p. 119. 
 
 Fresh tallow contains very little free fatty acid ; but tallow 
 that has become more or less rancid often contains considerable 
 amounts, up to 12 per cent, (calculated as oleic acid); 25 per 
 cent, was found by Deering in a sample six years old. When 
 tallow is not particularly rancid, and yet contains a considerable 
 amount of free acid, it is very probable that it has been 
 adulterated with distilled " stearine " (largely consisting of free 
 fatty acids). The total acid number usually lies between 193 
 and 198, representing the saponification equivalent 283 to 293, 
 averaging near 288, and corresponding with a mean molecular 
 weight of fatty acids of near 276 (palmitic acid = 256, oleic 
 
356 OILS, FATS, WAXES, ETC. 
 
 acid = 282, stearic acid 284). The iodine number has been 
 found by different observers to lie between 35 and 45, with an 
 average of about 40 ; since pure olein has the iodine number 
 86 "2, this indicates an average amount of olein. of somewhat less 
 than 50 per cent, (about 46), and a proportion of solid glycerides 
 of somewhat above 50 per cent, (about 54). According to the 
 author's experience, in the absence of adulterations the deter- 
 mination of the iodine value can be made into a useful test of 
 quality for candlemaking purposes, the proportion of solid fatty 
 acids obtainable being greater the less the iodine absorption ; 
 but when pressed coker butter or palm kernel oil has been 
 added, the iodine number is reduced without a corresponding 
 increase in amount of solid fatty acids of high melting point 
 obtainable ; and the same remark applies to w T oolgrease, wool 
 stearine, and similar substances. When circumstances permit, the 
 best indications as to adulterations of this kind are obtained by 
 saponifying, separating the fatty acids, allowing them to crystal- 
 lise, and expressing them in a small experimental laboratory 
 press, determining the quantity and melting point of the press 
 cake, and subjecting the expressed oleic acid to examination as 
 regards its iodine absorption, elaidin reaction, colour reactions 
 with sulphuric and nitric acids, tfec., heat evolution with sulphuric 
 acid (Maumene's test. p. 147), amount of unsaponifiable matters 
 present, and so on ; samples of genuine tallow of different 
 qualities being examined side by side in the same way. 
 
 Muter and Koningh* recommend a process based on somewhat 
 similar principles, where the solid and liquid fatty acids are 
 separated by conversion into lead salts and solution of lead oleate, 
 &c., by ether, wherein lead stearate and palmitate are but 
 sparingly soluble. By carrying out the saponification and subse- 
 quent processes in a uniform prescribed way, the quantity and 
 characters of the liquid fatty acids ultimately separated from the 
 soluble lead salt, afford useful indications respecting adultera- 
 tion. Thus, they found that the iodine number of the liquid 
 acid obtainable from pure tallow, is uniformly close to 90, 
 substantially identical with that theoretically requisite for pure 
 oleic acid. Lard, on the other hand, gives a liquid acid possessing 
 a distinctly higher iodine number, close to 93; whilst the liquid 
 acids from cotton seed oil give a considerably higher iodine 
 value, near to 135. 
 
 Tallow that has become rancid by keeping generally whitens 
 during the process ; owing to the large amount of decomposition 
 with formation of free fatty acids that occurs (supra), such tallow 
 is unsuitable for lubricating purposes ; the byeproducts of the 
 decomposition, moreover, cause soap made from such tallow to 
 " work foxy," or become discoloured of a brownish red, so that 
 for milled or other toilet soaps intended to be white or tinted 
 * Analyst, 1889, p. 61 ; 1890. 
 
BEESWAX. 357 
 
 delicate shades, such tallow should be avoided in the manufacture 
 of the " stock soap " used. 
 
 Beeswax. A good deal of dispute has taken place at various 
 times as to whether the wax of the bee, wasp, and similar insects 
 is a distinct product of secretion due to their own special life 
 action, or is simply precontained in the pollen and nectar of 
 flowers, &c., serving as their food, and isolated therefrom by 
 digesting away or otherwise removing the other constituents. 
 This latter view appears probable, inasmuch as when bees are 
 fed upon sugar only, they appear to be incapable of developing 
 wax to any notable extent. On the other hand, although the 
 character of bee food necessarily varies much in different parts 
 of the world, yet the chemical constitution of beeswax does not 
 differ anything like so widely. Samples of beeswax from numerous 
 localities in Europe, Asia, South America, and Australia, all pos- 
 sessed very similar compositions (Hehner*) viz., they essentially 
 consisted of a mixture of about 1 part of free cerotic acid to 6 of 
 myricin (vide infra) ; a result hardly compatible with the notion 
 that the wax pre-existed as such in the pollen and nectar of the 
 very wide variety of flowers, &c., furnishing food to the bees 
 in these different quarters of the globe. Andaquia wax (wax 
 of Apis fasciata, largely used for candlemaking in South 
 America) appears to be substantially identical with the ordinary 
 beeswax of Apis mellifera ; and the same remark applies to 
 Antilles wax (Apis fasciata ?), and to Madagascar wax (Apis uni- 
 color), although frequently beeswax of tropical and subtropical 
 origin is darker coloured and less readily bleached than that 
 produced in more temperate climates. f The wax of the Eastern 
 Archipelago, again, differs but little from that obtained from 
 other sources, although mainly produced by a different species 
 (Apis dorsata). 
 
 In order to obtain beeswax the ^ombs are simply drained of 
 honey and then melted in hot water and stirred about ; the wax 
 collects on the top as an oily layer, which is removed after cooling 
 and hardening ; after remelting by heat alone (without water) 
 and casting into blocks, the "virgin" wax is ready for the 
 market. A large proportion is used for numerous purposes 
 without further preparation ; for certain purposes bleaching is 
 requisite, effected either by means of exposure to air and sunlight 
 in thin shavings (p. 268), or by means of chemicals, preferably 
 dilute sulphuric acid and potassium dichromate (p. 266). 
 
 Beeswax is readily soluble in carbon disulphide and fusel oil ; 
 it dissolves in about 10 parts of boiling ether, less completely in 
 cold ether, benzene, or petroleum ; in cold alcohol it is nearly 
 
 * Vide Analyst, 1883, vol. viii., p. 16. 
 
 t Wax from the vicinity of Bordeaux appears to be the variety most 
 difficult to bleach; whether from some local peculiarity in 'the flowers 
 frequented by the bees ; or for some other reason, is unknown. 
 
358 OILS, FATS, WAXES, ETC. 
 
 insoluble, but dissolves in about 300 parts of boiling spirit. In 
 the case of most solvents, some parts of the wax dissolve much 
 more freely than other portions ; thus in the case of hot alcohol 
 a small quantity of " cerolein " is left undissolved, consisting of 
 fatty matter, principally palmitin and olein ; the proportion of 
 this constituent varies in waxes of different origin, but is never 
 large, so that the presence of fatty glycerides in any quantity is 
 only due to adulteration. Natural wax contains a considerable 
 amount of free acid (from 12 to 16 per cent., calculated as cerotic 
 acid Hehner) ; that bleached by means of dichromate usually 
 contains somewhat more (17 to 18 per cent.) ; but airbleaching 
 appears to produce no measurable increase in the free acidity. 
 The free acid in raw wax appears to be chiefly cerotic acid, 
 C 2 -H 54 O 2 , together with a little melissic acid, C 30 H" 60 2 , ; by 
 treating the wax with limited quantities of hot alcohol these are 
 dissolved out, myricin (the palmitic ether of myricylic alcohol, 
 i C 30 H 61 . O . C 16 H 0jl O) constituting the great majority of the un- 
 dissolved part. 
 
 Beeswax has at 15 C. the specific gravity nearly -96 (numbers 
 varying between '956 and '975 being recorded by different 
 observers). At 98 to 99 the specific gravity is '818 to '827 
 (Allen). Airbleaching seems to produce little or no alteration 
 in the density, but chemically bleached wax is usually rendered 
 a little more dense by the process. The melting point is always 
 close to 63, values varying between 61 and 65 being recorded 
 by numerous observers ; the melted substance re-solidifies at one 
 or two degrees lower than the temperature of complete fusion. 
 The free acid number has been found by Hehner, Hiibl, Buisine, 
 and other observers to be subject to comparatively little varia- 
 tion, almost invariably lying between 17 and 21 in the case of 
 unbleached wax, corresponding with 12*5 to 15*5 per cent, of 
 cerotic acid) ; whilst the ester number (p. 162) lies between 72 
 and 76 (corresponding with 87 to 92 per cent, of myricin) ; the 
 sum of the cerotic acid arid myricin thus calculated is generally 
 a little above 100, showing that some amount of other consti- 
 tuents of lower molecular weight is also present. In confirma- 
 tion of this the iodine number has been found to be appreciable, 
 though low, averaging about 10 (8*3 to ll'O, Buisine), indicating 
 the presence of a perceptible amount of unsaturated compounds 
 (possibly hydrocarbons). On saponification with continued boil- 
 ing (for at least an hour) with excess of alcoholic potash, genuine 
 beeswax furnishes 53 to 54 per cent, of crude myricylic alcohol 
 (Benedikt), corresponding with 81 '8 to 83'4 of myricin (myricylic 
 palmitate).* 
 
 * Wax bleached by the air process is often admixed with a few per cents, 
 of fatty matter which seems to facilitate the bleaching action in some way 
 not thoroughly understood. A small quantity of oil of turpentine is some- 
 times added for the same reason ; in this case the bleaching is probably 
 
SPERMACETI. 359 
 
 Beeswax is often largely adulterated, more especially with 
 paraffin wax and allied hydrocarbons (cerasin and similar high- 
 melting mineral waxes) ; stearic acid ; colophony, burgundy 
 pitch, and other similar resinous matters ; and solid weighting 
 materials, such as china clay, barium sulphate, yellow ochre, 
 starch, and sulphur. Vegetable waxes (carnauba wax, &c.) are 
 often added ; and in some cases several per cents, of water are 
 artfully worked into the mass. This last admixture is readily 
 detected by the methods described in Chap, vi., p. 122. Mineral 
 adulterations are readily detected by incinerating the wax and 
 burning off carbonaceous matters so as to obtain the clay, &c., as 
 residue. By dissolving in ether, warm oil of turpentine, chloro- 
 form, benzene, or other suitable solvent, these substances, as 
 well as starchy matters, and other analogous adulterants, are left 
 undissolved, and may be obtained by filtration and washing.* 
 Stearic acid, if added in any quantity, is detected by the increased 
 free acid number, and by the melting point and general characters 
 of the acids ultimately obtained from the soap formed on shaking 
 the wax with hot alcohol, and titrating with standard alkali and 
 phenolphthalein (p. 118). Glycerides, similarly, may be detected 
 and, to some extent, estimated by the formation of glycerol on 
 saponification ; whilst adulteration with carnauba wax may be 
 detected by the examination of the fatty acids formed by saponi- 
 fying the impure myricin left insoluble on agitation with alcohol 
 and alkali, palmitic acid (m.p. 62, and equivalent 256) being 
 the chief constituent formed from genuine wax, whilst carnauba 
 wax mostly produces cerotic acid (m.p. 79, and equivalent 410). 
 The presence of hydrocarbons is indicated by the decreased ester 
 number ; or the wax may be carbonised by heating 5 grammes 
 with 50 c.c. of concentrated sulphuric acid to 130 0. in a 
 capacious flask for ten minutes ; much sulphurous acid, &c., is 
 evolved, and the mass chars, finally becoming nearly solid ; the 
 acid is washed out with water, adherent water removed by 
 alcohol, and the residue treated with ether, preferably in a Soxhlet 
 tube (p. 238), whereby the hydrocarbon is dissolved out, along 
 with a little wax that has escaped the action of the acid. By 
 repeating the acid treatment this is removed, and the cerasin, &c., 
 finally obtained in a weighable fcjrm.f 
 
 Spermaceti. The true origin of spermaceti (formerly regarded 
 as whale-spawn, Sperma ceti) appears to have been unknown, 
 
 quickened by the formation of peroxide of hydrogen during the oxidation 
 of the turpentine by the oxygen of the air in contact with water (ride p. 269). 
 
 * Traces of flour are often normally present in pressed or rolled wax 
 owing to the use of flour for dusting over the rollers or press to prevent the 
 wax from sticking (Allen). 
 
 t Respecting the detection of adulterations of beeswax, vide Journ. Soc. 
 Ohem. Ind., 1890, p. 771 ; 1891, pp. 728, 729, 860, 1014. For the 
 bibliography of beeswax and the waxes used for its adulteration, vide ibid., 
 1892, pp. 756, 757. 
 
360 OILS, FATS, WAXES, ETC. 
 
 long after it had come into some amount of use for the prepara- 
 tion of unguents ; its employment for candlemaking, like that of 
 whale oils for burning in lamps, seems practically to date from 
 somewhat upwards of a century ago when the whale fishery 
 began to be extensively pursued for commercial purposes. Even 
 at the present day, however, considerable misapprehension 
 appears to exist both as to the species of cetacea yielding it 
 and the part of the body from which it is derived. Whilst the 
 best known source is the "head matter" of the Pltyseter macro- 
 cephalus (p. 300), which largely consists of solid crystallised 
 spermaceti when taken from the dead carcase, it is also the fact 
 that considerable quantities are obtainable from the blubber oil 
 of the same cetacean ; during winter this oil sets so far solid by 
 deposition of spermaceti that it requires to be steamed to enable 
 it to be removed from the casks. Moreover, analogous if not 
 identical solid deposits form on similarly chilling for lengthened 
 periods the blubber oils of various other species (vide p. 301). 
 
 The semisolid oils containing scales of spermaceti will not bear 
 any great degree of pressure during filtration to separate the 
 solid matter, as this very readily passes through even the most 
 impervious filter cloths : accordingly the first operation consists 
 of " bagging " i.e., the material is placed inside long bags of hair 
 or canvas where gravitation only effects a separation between 
 the solid and liquid constituents. The "bagged sperm" is then 
 transferred to square bags, forming a soft flaky mass : a pile of 
 bags and boards is formed in successive alternate layers, and by 
 placing weights on the top of the pile, at first small but subse- 
 quently greater, most of the remaining fluid oil is gradually 
 squeezed out until the mass is sufficiently firm to bear hydraulic 
 cold pressure carried out in presses closely akin to those used 
 for stearine After cold pressing, the sperm cake is remelted, 
 granulated, and pressed several times over at gradually increasing 
 pressures and temperatures so as to remove the last portions of 
 fluid oil, a refining treatment with potash (p. 261) being inter- 
 polated between the last pressings so as to remove not only the 
 last traces of colouring matter, but also free fatty acids formed 
 by hydrolysis. Finally, a glistening white mass is obtained, 
 mainly consisting of cetylic palmitate (0 16 H 31 . O . C 16 H 33 O), 
 melting at near 45 C.,* and of specific gravity near '810 at 99. 
 
 The pressings from these various operations are methodically 
 worked up, in such fashion as ultimately to obtain a second 
 quality of spermaceti of somewhat lower melting point : the 
 potash foots obtained during refining yield on acidulation with a 
 mineral acid a mixture of impure spermaceti and palmitic acid ; 
 
 * According to L. Field (Journ. Soc. Arts, vol. xxxi., p. 840), the 
 spermaceti extracted from the blubber oils of the true bottlenose whale 
 (Balcena rosirata) has a slightly higher melting point than that from the 
 sperm whale or cachelot (Physeter macrocephalus). 
 
SPERMACETI. 3G1 
 
 when this is worked up with the other runnings a considerable 
 amount of free fatty acids is contained in the ultimate product. 
 30 per cent, and upwards of such free acids (essentially palmitic 
 acid) are sometimes present in spermaceti of this lower grade. 
 
 Spermaceti is sometimes adulterated with free stearic and 
 palmitic acids (not derived from the foots, as above described), 
 hard pressed glycerides (pressed tallow), and animal waxes and 
 paraffin wax. These latter additions raise the saponification 
 equivalent, whilst free fatty acids and glycerides lower it. The 
 detection of these adulterants is effected in ways substantially 
 the same as those above mentioned with respect to beeswax. 
 
362 OILS, FATS, WAXES, ETC. 
 
 6. The Candle Industry. 
 
 CHAPTER XVI. 
 MATERIALS USED IN CANDLEMAKING. 
 
 ORIGIN OF CANDLES. 
 
 IN all probability the earliest forms of illuminating agents of the 
 nature of candles (i.e., containing something serving the purpose 
 of wick surrounded by more or less solid combustible matter 
 adherent thereto) were simple links or flambeaux consisting of 
 fibrous vegetable stalks, &c., soaked in natural bitumen or 
 asphalt, vegetable resin, or animal fatty matter ; these being- 
 obvious developments of the yet simpler primeval torches con- 
 sisting of splinters of pine and similar woods, either naturally 
 full of resinous matter, or externally smeared therewith. 
 
 Lamps, or reservoirs of fluid oil furnished w r ith a wick for 
 burning, seem to have been invented at a very early period of 
 the world's history, and to have speedily superseded the primeval 
 resinous wooden torch for general household purposes amongst 
 the earlier civilised nations, although for outdoor illuminations, 
 and especially amongst the Scandinavians and other northern 
 tribes, pine splinter torches and similar rude contrivances of the 
 flambeau character were still chiefly used. 
 
 Rushlights, where the pith of rushes served as wick and where 
 the combustible matter was tallow or other animal fat applied 
 by dipping the pith in melted grease, and superior forms where 
 wax was used instead of tallow, moulded by hand round the rush 
 whilst rendered plastic by means of warmth, * appear to have 
 been in considerable use amongst the Romans, hempen or flaxen 
 unspun wicks taking the place of rush pith in the better kinds of 
 wax lights ; thus in Herculaneum the remains of a chandler's 
 establishment have been unearthed, whilst numerous passages in 
 various Latin authors indicate that the torch (tceda), the lamp 
 {lucerna), the tallow candle or rushlight (sebaceus), and the wax 
 
 * Such a candle, believed to date from the 1st century, is in the British 
 Museum. 
 
CANDLE MATERIALS. 363 
 
 light (cereus) were all in use in the early centuries of the Christian 
 era;* the oil lamp being still the most extensively used illuminant 
 amongst the well to do classes, wax lights ranking next. 
 
 With the exception that wax tapers were largely used for 
 ecclesiastical purposes, as well as private illumination, during 
 the middle ages, and that some improvements were consequently 
 introduced as regards their general size and finish, little advance 
 in the art of candlemaking seems to have been brought about 
 until the fifteenth century, when the process of "moulding" was 
 introduced by the Sieur de Brez ; but the manufacture of rush- 
 lights and of " dip " tallow candles, as well as of waxen tapers, 
 had by that time become a trade of itself, having to a consider- 
 able extent passed out of the region of ordinary household 
 operations carried on by each family for the supply of its own 
 wants, and into the hands of special candlemakers (candelarii, or 
 chandlers), who made tallow and other candles for sale to the 
 general public, at any rate in the larger towns. In country 
 districts, however, rushlights and tallow candles, of more or less 
 rough home-made manufacture, still continued to be the only 
 available means of artificial illumination other than oil lamps, 
 for the great majority of the population; a state of matters, 
 indeed, not entirely obsolete even at the present day in some 
 highly rural localities. In some savage countries highly olei- 
 ferous nuts, strung together on a fibrous twig, are burnt like 
 candles ; as one is consumed the next one becomes lighted and 
 burns till exhausted. 
 
 Combustible Materials. At the present time the com- 
 bustible matters (in addition to the wicks) used for candle- 
 making may be divided into four classes viz., (1) those natural 
 glycerides which are sufficiently solid at ordinary temperatures 
 to admit of being used for the purpose, or which yield sufficiently 
 solid glycerides by pressure; more especially tallow and similar 
 animal fats, together with vegetable products of corresponding 
 consistency, such as coker stearine, piney tallow, and the solid 
 fats of the Stillingia, Bassia, and other genera. (2) Substances of 
 waxy character, such as beeswax and the vegetable waxes, essen- 
 tially consisting of nonglyceridic compound ethers ; also including 
 spermaceti. (3) Free fatty acids of sufficiently high melting point, 
 obtained from natural oils and fats by saponification processes, 
 and mechanical separation of more fluid ingredients. (4) Paraffin 
 wax and analogous hydrocarbons of mineral origin, or formed by 
 destructive distillation. Of these the substances of the latter 
 two classes are those most largely used, more especially the last, 
 in this country, although "stearine" candles are somewhat pre- 
 ferred on the Continent. The trade in wax and spermaceti 
 candles is comparatively small, although by no means insigni- 
 
 * Vide Leopold Field, "Cantor Lectures, " Journ. Soc. Arts, vol. xxxii., 
 p. 821, et seq. 
 
364: OILS, FATS, WAXES, ETC. 
 
 ficant in actual amount ; whilst the use of unsaponified glycerides, 
 whether as tallow " dip " candles, consisting of such glycerides 
 only, or as " composite '' mixtures of glycerides and free fatty 
 acids, is steadily diminishing in favour of the other kinds of 
 illuminants, although far from being extinct, especially in the 
 case of iiightlights, which are largely made of coker stearine. 
 
 In the manufacture of tallow dip candles no special preparation 
 of the tallow for use is requisite further than the rendering and 
 purifying processes already described (Chaps, x. and xi.) ; the 
 harder varieties are usually preferred, although if too hard there 
 is more risk of cracking. In the case of beeswax, air and light- 
 bleached wax (p. 268) is employed in preference to that bleached 
 by chemical processes, especially such as involve the use of chlor- 
 ine ; for, irrespective of a greater tendency to become yellowish 
 on keeping, such chemically bleached waxes are apt to possess a 
 crystalline grain which spoils the appearance of the candle, and 
 when bleached by chlorine, to give off fumes of hydrochloric acid 
 when burnt, owing to the formation of chloro-substitutioii com- 
 pounds during the bleaching process. Paraffin wax and the 
 analogous waxy hydrocarbons obtained from ozokerite, &c., 
 require no further treatment for caiidlemaking other than the 
 pressing and purifying processes gone through during their 
 manufacture for the purpose of raising the melting point to the 
 requisite extent (compare p. 230). The isolation of solid free 
 fatty acids from natural glycerides, however, is a somewhat 
 complex operation capable of being carried out in several ways. 
 
 MANUFACTURE OF "STEARINE." 
 
 The numerous processes proposed, and more or less actually 
 used on a manufacturing scale for the isolation of solid fatty 
 acids from appropriate glycerides, may be classified under the 
 following heads : 
 
 1. Processes where the glycerides are saponified by alkalies, 
 alkaline earths (such as lime), or other suitable basic materials, 
 by boiling under ordinary pressure ; to effect which operation a 
 more or less considerable excess of base is usually found necessary 
 in order to complete the saponification. 
 
 2. Processes analogous to the preceding, except that the opera- 
 tion is carried out at a somewhat higher temperature obtained 
 under increased pressure ; excess of base is in this case unneces- 
 sary, for, in general, practically complete saponification and 
 hydrolysis can be thus easily brought about even when consider- 
 ably less base is present than is chemically equivalent to the 
 fatty acids formed, and although the temperature does not rise 
 sufficiently high to decompose any considerable fraction of the 
 glycerol set free. 
 
MANUFACTURE OF STEARINE. 365 
 
 3. Processes where hydrolysis is effected under the influence 
 of acids, especially sulphuric acid ; in this case the liberated 
 acids are usually distilled over by the aid of superheated steam, 
 so as to separate them from nonvolatile pitchy matters formed 
 as bye products ; in Bock's process (infra} this distillation is 
 unnecessary. More or less glycerol is usually destroyed by the 
 action of the acid. 
 
 4. Processes where hydrolysis is brought about under the 
 influence of water alone (under great pressure, or as highly 
 superheated steam). In these processes the glycerol is often 
 largely destroyed by the heat (sometimes completely so), a much 
 higher temperature being requisite than in the case of methods 
 of the second class. 
 
 The Chevreul-Milly Process Alkaline Saponiflcation 
 Process in Open Pans under Ordinary Pressure. The first 
 attempts to utilise solid free fatty acids for candle material, were 
 made about 1825 by Chevreul and Gay Lussac, employing 
 alkalies (potash and soda) to effect the saponification of tallow ; 
 for a variety of reasons, this process proved to be commercially a 
 failure ; but a few years later, by substituting lime for alkalies 
 and otherwise employing more suitable arrangements, M. de 
 Milly succeeded in making the manufacture of " stearine " 
 candles from tallow a sufficiently remunerative undertaking to 
 render it a practical industry. As carried out at the present 
 day, the process differs little in essential points from what it was 
 more than half a century ago, the chief differences lying in the 
 scale on which the operations are effected, and the frequent use 
 of mixtures of vegetable and other substances with tallow (e.g., a 
 mixture of palm oil and tallow or other suitable fatty matters) 
 instead of tallow only,* a better quality of mixed fatty acids 
 being thereby usually obtained i.e., a mixture which allows the 
 solid acids to crystallise and "granulate" more readily, so as to 
 be more easily pressed for the separation of liquid acids. 
 
 The fatty matters being generally purchased in casks, by means 
 of a steam jet applied at the bunghole, the fats are melted out 
 into a tank, whence they are pumped or run by gravitation into 
 the decomposing pan, usually constructed of wooden staves 
 (preferably of oak) strongly bound together, and forming a large 
 tub or tun, sometimes lined with sheet lead. This is provided 
 with a stirring arrangement, consisting of a central vertical shaft 
 with arms carrying paddles and rakes, so as to intermix the 
 contents thoroughly (Fig. 78). Quicklime, in the proportion of 
 12 to 15 pounds per 100 of fat, is mixed with water to a cream 
 and run into the tun,f and the whole heated up by steam blown 
 
 * In France the use of palm oil is much less frequent than in Britain, thus 
 leading to some slight differences between many kinds of French "stearine," 
 as compared with British. 
 
 t Assuming the mixture of fatty matters to have a mean saponification 
 
3G6 
 
 OILS, FATS, WAXES, ETC. 
 
 in through a perforated horizontal coil at the bottom of the tub, 
 or a series of jets distributed over the bottom, and the whole 
 kept agitated for some hours, [a cover being placed over the 
 
 tub to keep in splashes, 
 and steam being blown 
 through gently so as to 
 keep the whole boiling. 
 Glycerol is thus set free, 
 and a mixture of lime- 
 salts formed (mostly 
 stearate, palmitate, and 
 oleate), practically in- 
 soluble in water, and 
 solidifying on cooling to 
 a hard mass known as 
 "rock;" the aqueous 
 glycerol solution or 
 "sweet water" is run 
 off and utilised for 
 glycerol extraction. 
 
 To isolate the fatty 
 acids, the rock is boiled 
 
 Fig. 78. 
 
 up in a lead-lined vat with steam, diluted sulphuric acid bein^ 
 added in slight excess of the quantity requisite to saturate 
 all the lime present.* Sulphate of calcium separates out, 
 whilst the free fatty acids swim up to the top ; after standing 
 and cooling somewhat, these are skimmed off and boiled up, 
 firstly with highly dilute sulphuric acid to decompose the 
 last traces of lime soap, and then with water, using wet steam, 
 so as thoroughly to wash out all sulphuric acid and admixed 
 mineral matters. Finally, the fluid fatty acids are transferred 
 to shallow cooling pans, such as the series indicated in Figs. 
 79 and 80. Here the melted fatty acids are run from a 
 trough, F, through nozzles, D D D, into the uppermost of the 
 pans, C C C, supported by a wooden framework, A A, and iron 
 crossbars, B B B. When the pans are filled, the stream of melted 
 
 equivalent of 280, the quantity of liine (CaO) theoretically equivalent to the 
 fatty acids formed would be 28 parts per 280, or 10 per cent. ; with fatty 
 matters of higher saponification equivalent, proportionately less lime would 
 be required, and vice versa. Some excess of lime, however, is requisite in 
 order to ensure tolerably complete action ; moreover, in practice, quicklime 
 is not pure CaO, a little moisture, calcium carbonate, and more or less 
 siliceous and clayey matter being present, all of which are inert so far as 
 effecting saponification is concerned. A first class quicklime, made from a 
 pure limestone, may contain (when freshly burnt) some 95 per cent, of CaO 
 (exclusive of calcium carbonate) ; but 85 to 90 per cent, is more nearly the 
 usual average, and less with very poor limes. 
 
 * For every 56 parts of actual lime, CaO, used, 98 parts of actual 
 sulphuric acid, HJ30 4 , are required ; roughly, 2 parts of B.O. V. (brown oil 
 of vitriol) to 1 of quicklime. 
 
STEARINE ; CRYSTALLISATION. 
 
 367 
 
 matter is shut off by means of the spigot, E. In these cooling 
 pans they solidify to a semicrystalline mass on cooling and stand- 
 ing ; for the purpose of pressing out the fluid acids, this solidifi- 
 cation is best allowed to take place in metal dishes, so that the 
 solid cakes formed are obtained in the form of slabs about an 
 inch or three-fourths inch thick, and of such size as to fit into the 
 cake boxes of the hydraulic press used ; the temperature during 
 
 M U 4! 
 
 Fig. 79. 
 
 Fig. 80. 
 
 this period should lie between 21 and 32 C. (70 to 90 R), so 
 that whilst the "seeding" or crystallisation of the solid acids 
 (mostly stearic and palmitic) may take place completely, as little 
 oleic acid as possible may be retained in the body of the crystals 
 formed. The slabs of " separation cake " finally consist of a 
 spongy mass of granular or crystallised solid acids, with liquid 
 oleic acid (containing solid acids and colouring matters in solu- 
 tion) disseminated through the interstices. By enveloping them 
 in press cloths, and placing them in the cake boxes of a hydraulic 
 press, the brownish liquid acids are gradually squeezed out, and 
 the comparatively colourless solid crystals retained. Instead of 
 directly pressing the granulated cakes, it is often preferable to 
 rasp them into shreds by a machine, and to press the raspings ; 
 a more complete expression of liquid acids is thus brought about. 
 The press cake left, however, still retains a certain amount of 
 
368 
 
 OILS, FATS. WAXES, ETC. 
 
 liquid acids, rendering its fusing point too low ; to remove these 
 the press cakes are melted by steam, cast afresh into slabs in 
 shallow trays, allowed to stand to granulate at a temperature of 
 about 30 C., rasped to coarse powder, and again pressed in a 
 different machine where the cake boxes are heated by the regu- 
 lated admission of steam into the plates, in the body of which 
 channels are hollowed out for the purpose. Fig. 81 represents 
 n form of horizontal hot press thus arranged, steam being ad- 
 mitted to the plates by the pipes, E E. A A A represent the 
 packets of raspings undergoing pressure ; B the piston of the 
 hydraulic ram working in the cylinder, C ; D the framework ; 
 P a chain whereby the plates are drawn asunder for the removal 
 of the cakes when the operation is finished ; G water supply 
 pipe to ram cylinder from accumulator. The temperature of the 
 hot press varies somewhat with the kind of material employed, 
 but is generally not far from 50 (122 F.) for stearine of high 
 
 JIM. 
 
 Fig. 81. 
 
 melting point ; for inferior stearine melting more easily, the 
 temperature is proportionately lower. 
 
 The hot press cake finally obtained is melted by means of steam 
 along with a little water acidulated with sulphuric acid, and then 
 vigorously agitated with the acid fluid for some time for the 
 purpose of removing traces of lime salts still retained ; finally 
 the acid liquor is run off, and several successive boilings-up 
 carried out with plain water. The purified mixture of stearic 
 and palmitic acids is then cast into blocks for use in the candle 
 factory ; small quantities of vegetable wax, beeswax, c., are 
 sometimes added to "break the grain" i.e., to prevent the 
 formation of visibly large crystals during solidification. 
 
 Even when the fatty matters employed are highly rancid and 
 impure, an almost perfectly white " stearine " can be thus manu- 
 factured by the lime process. The yield of pure solid hot pressed 
 acids, however, is materially influenced by the presence and 
 
OPEN PAN PROCESS. 
 
 369 
 
 nature of abnormally large proportions of oleine (existing in 
 softer fats, &c.) or other substances (e.g., woolgrease), not only 
 on account of the diminution in amount of solid fat acids present, 
 but also because of the increased amount of these acids removed 
 in the "red oils" (vide infra). 
 
 Fig. 82 represents a general view of the disposition of the 
 apparatus used in the 
 saponification of fatty 
 matters by the open pan 
 process.* A, tub from 
 which lime is emitted. 
 B, leadlined vats with 
 steam pipes for boiling 
 lime and fats. C, similar 
 decomposing vats where 
 the rock is boiled with 
 sulphuric acid. D D, rack 
 holding pans for caking 
 mixed acids. E, cold 
 press. F, hydraulic 
 pumps. G, pan for re- 
 melting press cake. H, 
 hot press. I, vat for 
 melting hot pressed 
 stearine for final wash- 
 ing with water and cast- 
 ing into blocks. 
 
 Moinier and Boutigny 
 modify the Chevreul- 
 Milly process by sub- 
 mitting the melted tal- 
 low, &c., to a preliminary 
 treatment with hot water 
 and a current of impure 
 sulphur dioxide (pro- 
 duced by the action of 
 hot sulphuric acid on 
 sawdust, charcoal, &c.) ; 
 after an hour the lime- 
 cream is added and the 
 whole well agitated, 
 whereby the mass in- 
 creases in consistence 
 with considerable froth- 
 ing, by and bye becoming pasty. The sulphur dioxide is then 
 shut off and the rock finished by boiling up with steam, ifcc., as 
 usual. The yield of fatty acids is stated to be thus increased 
 * L. Field, Journ. Soc. Arts, vol. xxxi., p. 859. 
 
 24 
 
370 OILS, FATS, WAXES, ETC. 
 
 by some 4 per cent. The hot press cake is finally refined by 
 boiling up first with water acidulated with sulphuric acid, then 
 with water alone, white of egg (1 egg per 100 Ibs.) being intro- 
 duced whilst boiling so as to coagulate and remove impurities 
 as in clarifying coffee, &c. 
 
 On p. 375 are given some analyses of original fatty acid mixture, 
 cold press cake, and hot press cake, c., illustrating the eifect of 
 the process in separating oleic acid from the solid fatty acids, 
 and the increment inf melting point thus effected. The hot press 
 grease usually contains enough solid fatty acids to raise its fusing 
 point to at least that of the original mixture of fatty acids before 
 cold pressing ; it is generally worked up along with fresh fatty 
 acids by fusing therewith and granulating the mixture in trays for 
 the cold press. The outer edges of the hot press cake retain some 
 amount of more fusible grease, and are therefore usually pared 
 off and worked up along with the rest of the hot press grease. 
 
 The "red oil" or "oleine" running from the cold press contains 
 a considerable quantity of palmitic and stearic acids in solution, 
 the precise amount depending on the temperature at which the 
 pressing is conducted ; on chilling somewhat, more or less solid 
 fatty acids separate, usually in a finely divided form. When it 
 is desired to obtain red oils containing as large a proportion of 
 oleic acid and as little solid acids as possible, the oil is chilled 
 and the resulting somewhat pasty mass passed through a filter 
 press, such as shown in Figs. 56, 59, the greasy solid fatty 
 acids thus obtained being worked up with fresh batches of the 
 original mixture of acids ; for the manufacture of oleine soap 
 this treatment is not indispensable, but inasmuch as the solid 
 fatty acids are considerably more valuable than the fluid ones, 
 it is obviously desirable to obtain as large a proportion of the 
 former as possible. For the same reason it is essential that the 
 saponification of the fats used should be as nearly complete as 
 possible, not only because all the stearic and palmitic glycerides 
 that escape saponification are lost so far as solid fatty acids are 
 concerned (being expressed fluid during the pressing operations), 
 but also because their presence tends to prevent the proper 
 crystallisation of the solid acids, and thus to increase the pro- 
 portion of these contained in the red oils. In actual practice, it 
 is impossible to carry the decomposition in open pans to absolute 
 completeness without seriously prolonging the operation, which 
 entails extra cost ; so that a few per cents, (and sometimes much 
 more, up to 10 or 12 per cent.) of the glycerides used are gener- 
 ally left undecomposed in the rock, ultimately finding their way 
 into the red oils. 
 
 When the tallow used has been adulterated by mixing in 
 woolgrease or similar material containing unsaponifiable matters, 
 these substances are generally also ultimately contained in the 
 red oils, thereby diminishing the proportion of " stearine '* 
 
COMPOSITION OF "ROCK." 371 
 
 obtainable, partly because of the smaller proportion of solid 
 glycerides present in the adulterated tallow, and partly because 
 the presence of woolgrease, like that of unsaponified fat, tends to 
 interfere with the crystallisation of the acids, and hence causes 
 the red oils to retain more solid acids. Moreover, when the red 
 oils are made into soap, a deteriorating effect (for certain pur- 
 poses) is brought about in the resulting soap j on solution in 
 water and standing, soap containing such unsaponifiable matter 
 is apt to throw up an oily film, rendering the solution liable to spot 
 and grease goods rinsed through the soap solution. Accordingly, 
 it is preferable to buy tallow by analysis, the price varying accord- 
 ing to the proportion of solid fatty acids present (estimated by 
 Dalican's process, p. 74, or otherwise) and deductions being 
 made for unsaponifiable constituents. As yet, however, this sys- 
 tem does not seem to have been widely adopted in this country. 
 Composition of "Rock." The following analyses represent 
 the general composition of open pan "rock" as obtained on the 
 manufacturing scale ; A being normal rock made from genuine 
 tallow mixed with about one-fourth its weight of palm oil ; and 
 B rock from tallow adulterated with woolgrease containing a 
 considerable amount of cholesterol and other unsaponifiable 
 
 matters : 
 
 A B 
 
 Lime present as lime soap (CaO), 
 
 Lime used in excess (CaO), 
 
 Fatty anhydrides* present as lime soap, 
 
 Unsapoiiined glycerides, . 
 
 Unsaponifiable organic matter, 
 
 Water and carbonic acid (C0 2 ), combined with 
 
 the excess of lime; sand and grit, &e 
 
 uncombined water (moisture), 
 
 7-50 6-27 
 
 1-95 241 
 
 73-30 61-20 
 
 5-55 8-40 
 
 2-75 12-00 
 
 8-95 9-72 
 
 100-00 100-00 
 
 Since 100 parts of triglycerides of mean molecular weight near 
 285, represent about 92 parts fatty anhydrides, the fatty anhy- 
 drides present in these two samples represent respectively about 
 80 and 66 parts of original glycerides per 100 of rock j hence 
 the proportion of glycerides originally used which remain 
 
 5*55 
 
 unsaponified are (A) -7- - x 100 = G'5 per cent, and 
 
 v ' 80 + 5-55 
 
 (B) - x 100 = 11 '3 per cent. i.e., in the first case 
 
 6t> + O"4:0 
 
 about Jg-, and in the second about l, of the original glycerides 
 escaped sapoiiification. 
 
 * "Fatty anhydrides "= fatty acids, less an equivalent of water 
 p.g., in the case of stearic anhydride ^ j 85 Q J- ; so that the sum of the 
 
 fatty anhydrides and the lime combined with them as lime soap, represents 
 the actual amount of lime soap present. In the above two instances the 
 amounts of lime soap are (A) 73'30 + 7'50 = 80 35 ; (B) 61'20 + 6'27 = 67 '47. 
 
372 OILS, FATS, WAXES, ETC. 
 
 Analysis of Hock. This is conveniently effected by taking 
 a known weight of an average sample and boiling it with water 
 to which an excess of standard acid (preferably hydrochloric) has 
 been added, until completely decomposed ; on standing, the 
 liberated fatty acids, c., form a cake on the top, which is care- 
 fully removed, dried, and weighed ;* the free fatty acids therein 
 are then titrated in alcoholic solution with standard alkali, and 
 the examination for admixed glycerides and unsaponifiable 
 matters proceeded with, as in the case of separation cake (vide 
 infra, p. 378). The excess of acid in the watery fluid is back 
 titrated, so as to obtain the acid neutralised by the total lime 
 present, which is thence calculable ; whilst the lime present 
 as lime soap (combined with fatty acids) is similarly calculated 
 from the amount of alkali neutralised by the fatty acids. For 
 example, 10 grammes of a given sample of rock were boiled with 
 water and 50 c.c. of normal acid ; on back titration 16 '7 c.c. were 
 found to be unneutralised ; hence 33*3 c.c. were neutralised, 
 equivalent to 0-932 CaO = 9*32 per cent, of total lime. The 
 separated fatty acids, &c., weighed 8-215 grammes, and neutralised 
 25'9 c.c. of normal alkali, equivalent to 0*725 gramme, or 7 "25 
 per cent, of CaO ; whence 0-932 - 0-725 = 0*207 gramme of 
 excess of lime was present, or 2*07 per cent. On further ex- 
 amination (p. 378) the separated fatty acids were found to con- 
 tain 0*535 gramme of unsaponified glycerides and 0*235 grammes 
 of unsaponifiable matters. Hence the actual fatty acids pre- 
 sent in the 8*215 grammes of cake obtained amount to 
 8*215 - (0*535 + 0*235) = 7-445 grammes. In order to reckon 
 the fatty anhydrides equivalent to this amount of fatty acids, 
 18 parts of water must be subtracted for 56 of CaO combined 
 
 1 R 
 with them as lime soap i.e., ^ x 0-725 = 0-233 gramme of 
 
 water must be subtracted, leaving 7-445 - 0-233 = 7'212 grammes 
 of fatty anhydrides present as lime soap. 
 Hence the whole analysis is 
 
 Lime present as lime soap (CaO), . 0'725 grammes = 7'25 per cent. 
 
 ,, in excess, .... 0'207 ,, = 2D7 
 
 Fatty anhydrides present as lime 
 
 soap 7-212 ,, = 72-12 ,, 
 
 Unsaponitied glycerides, . . 0'535 ,, = 5*35 ,, 
 
 Unsaponifiable matter, . . .0 235 ,, = 2 '35 ,, 
 
 Combined water, CC>2, sand, mois- 
 ture, &c. (by diflerence), . . 1'086 = 10'SG 
 
 10-000 100-00 
 
 Total lime soap present, 7 "25 + 72*12 = 79*37 per cent. 
 
 Total lime present, . 7 '25 + 2 "07 = 9 -32 
 
 * If the quantity is too small for accurate determination in this way the 
 liberated fatty acids, &c. , may be dissolved by ether, and the ethereal 
 solution separated and evaporated, &c., as in the parallel case of soap 
 analysis (Chap, xxi.) 
 
AUTOCLAVE PROCESS. 373 
 
 Milly Autoclave Process Saponiflcation with Alkalies 
 (Lime) under Increased Pressure. As practically carried 
 out, this process is virtually a combination of the previous 
 process, and that subsequently described due to Tilghmanns, 
 where fats are hydrolysed by the action of water under high 
 pressure. The tallow and palm oil or other fatty mixture is 
 pumped into a stout copper pressure vessel or autoclave, and lime 
 made into a thin cream with water added in much smaller pro- 
 portion than in the open pan process, usually 2 to 3 parts of 
 lime per 100 of fat, or somewhere about one-quarter of the 
 theoretical amount instead of an excess. High pressure steam is 
 then gradually blown in from a boiler until the pressure amounts 
 to at least 7 or 8 atmospheres, and preferably 12 to 15, especially 
 when tallow only is used, as in many Continental factories. 
 After some hours continuance of digestion under pressure the 
 fat is practically completely saponified and hydrolysed, partly by 
 the lime, partly by the action of water only, the presence of the 
 lime soap formed by the saponification greatly facilitating the 
 hydrolysis ; the mixed " sweet water," fatty acids, and lime soap 
 are blown off into a tank, where the latter separate from the 
 watery glycerol solution, and are then treated with sulphuric 
 acid precisely as in the open pan process, saving that as much 
 less lime is used, a proportionately smaller quantity of acid is 
 requisite. The further operations of separating solid fatty acids 
 by pressure, etc., are identical in the two processes. 
 
 The remarks above made respecting the objectionable results 
 brought about when any considerable amount of glycerides escapes 
 saponification, and when the tallow is adulterated with wool- 
 grease or other unsaponifiable matters, obviously apply equally 
 in the present case. As regards the former point, the following 
 figures were obtained by the author in a set of experiments on a 
 manufacturing scale made with the. object of tracing out the 
 effect of increased time in diminishing the amount of unsaponified 
 grease. A series of charges was worked off in the same auto- 
 clave, the mixture of fats (tallow and palm oil), and the proportion 
 of lime used, and the pressure being as nearly as possible the 
 same throughout, but the times being different. The fatty acids 
 obtained (after separation from lime by sulphuric acid) were 
 analysed so as to obtain the data for determining the proportion 
 of grease unsaponified during the digestion. The figures ulti- 
 mately obtained on averaging a number of trials were 
 
 Time in Hours. 
 
 Unsaponified Grease Reckoned per 100 
 parts Originally Employed. 
 
 4* 
 5| 
 
 74 
 
 9-4 
 5-8 
 3-1 
 
374 
 
 OILS, FATS, WAXES, ETC. 
 
 During the first hour or two the rate of decomposition of the 
 fats employed was rapid, from f to ^ being converted at the end 
 of 2 hours ; subsequently the action was much slower, becoming 
 practically complete at the end of 6 to 6J hours, not more than 
 about -Jg- then remaining unconverted. 
 
 The following analyses indicate the composition of the " rock " 
 obtained by the autoclave process ; they principally differ from 
 those above cited for open pan rock, in that whereas in the open 
 pan process excess of lime is used, so that the rock contains all 
 the fatty acids as lime soap ; in the autoclave lime process a 
 deficiency of lime is employed, so that the fatty acids are obtained 
 partly as lime soap and partly as free acids : 
 
 1 L 
 
 II. 
 
 in. 
 
 Lime present as lime soap (CaO), 
 
 3-20 
 
 2-38 
 
 2-52 
 
 Fatty anhydrides combined therewith, 
 Free fatty acids, .... 
 
 31-90 
 57*75 
 
 22-62 
 58-50 
 
 23-94 
 66-30 
 
 Unsaponified glycerides, . 
 
 5-90 
 
 G-60 
 
 3-20 
 
 Unsaponifiable organic matter, 
 
 0-70 
 
 1-33 
 
 1-85 
 
 Grit and mineral matters ; water, . 
 
 0-55 
 
 8-57 
 
 2-19 
 
 
 100-00 
 
 100-00 
 
 100-00 
 
 100 parts of the fatty glycerides used originally represent 
 about 95 of free fatty acids and 92 of fatty anhydrides, whence 
 100 parts of rock represent in these three cases respectively about 
 95, 86, and 96 parts of fatty glycerides that have been saponified 
 and hydrolysed ; whence the proportions of glycerides not acted 
 upon are 
 
 I. 
 
 II. 
 
 III. 
 
 5-90 
 
 95 + 5-90 
 
 6-60 
 86 + C'60 
 
 3-20 
 
 96 + 32 
 
 100 = 5-8 per cent. 
 
 x 100 = 7-1 
 
 x 100 = 3-2 
 
 In general, with unadulterated tallow, the autoclave process, 
 properly worked, saponifies and hydrolyses about 95 per cent. 
 
 of the glycerides used, leaving some 5 per cent 
 
 unacted 
 
 on ; if, however, too low a pressure be applied, the proportion of 
 undecomposed glycerides may amount to considerably more than 
 this unless a proportionately longer time be allowed, involving 
 greater cost for fuel, labour, &c. 
 
 The " separation cake " or mixture of fatty acids obtained by 
 decomposing with sulphuric acid the "rock" formed in the 
 
IODINE TEST APPLIED TO SEPARATION CAKE, ETC. 
 
 375 
 
 autoclave or open pan process consists of the solid fatty acids 
 produced (chiefly stearic and palmitic) ; the liquid acids (mainly 
 oleic) ; and whatever undecomposed glycerides and unsaponifiable 
 organic matters may be present ; the latter two ingredients 
 obviously vary with the degree of perfection or imperfection 
 attained in saponification, and with the purity of the materials. 
 The ratio between solid and liquid fatty acids also varies some- 
 what with the character of the tallow and other fatty matters 
 used; in general, it is not far from 2 to 1. In examining such 
 materials, the author has found the '"'iodine test" (pp. 177, 179, 
 et seq.) particularly useful, especially in the case of press cake in 
 different stages of pressing. The further the pressing (hot after 
 cold) is carried, the smaller the quantity of oleic acid left in the 
 "stearine;" but no amount of hot pressing will completely 
 eliminate " unsaturated " acids,* from 1 to 2 per cent, being 
 retained even when the pressing has been carried to the utmost 
 possible extent permissible for commercial purposes in the pre- 
 paration of articles of exceptionally high melting points, and 
 larger proportions up to 4 or even 5 per cent, in products less 
 thoroughly hot pressed. Even crystallisation several times from 
 alcohol of a mixture of palmitic and stearic acid does not succeed 
 in removing all the oleic or other iodine-absorbing acid present. 
 Thus the following typical figures may be cited, obtained by the 
 author with the fatty acids manufactured from a mixture of 
 tallow and palm oil : f 
 
 
 Percentage of Oleic 
 Acid by Iodine Test. 
 
 Melting Point in 
 Capillary Tube. 
 
 Separation cake (mixture of fatty acids 
 before pressing), .... 
 
 32-0 
 
 
 Cold-pressed cake, .... 
 
 11 -5 
 
 52 -8 C. 
 
 Once hot pressed, . . . . . 
 
 5-6 
 
 54 -2 
 
 Twice ,, . 
 
 2-5 
 
 56 -1 
 
 Three times hot pressed, 
 
 1-3 
 
 56 '2 
 
 ,, twice recrystallised from 
 
 
 
 alcohol, .... 
 
 0-8 
 
 56 -25 
 
 Red oils (oleine) from cold pressing, 
 
 71-5 
 
 
 Grease from hot pressing, 
 
 14-9 
 
 51 -6 
 
 The percentage of solid fatty acids contained in red oils can be 
 deduced approximately from the determination of the oleic acid, 
 reckoning 111 -02 parts of acid per 100 of iodine consumed, as 
 indicated by the equation 
 
 * Possibly isoleic acid (m.p. 45), and not oleic acid, remains. 
 
 t When a pressed stearine is examined, presumably only containing a 
 small percentage of oleic acid, 5 grammes may be conveniently taken for 
 analysis ; on the other hand, with a substance containing a high percentage 
 of oleic acid, proportionally less should be weighed up, usually from 0'2 
 to O4 gramme. 
 
376 OILS, FATS, WAXES, ETC. 
 
 Oleic Acid. Saturated Iodine Addition 
 
 Product. 
 
 Ci 8 H 3 40 2 + I 2 C ]8 H 34 T 2 2 . 
 
 If the percentage of unsaponified grease and unsaponifiable 
 organic matters present be known = a, and that of oleic acid 
 thus determined = 6, the percentage of solid fatty acids is 
 approximately 100 - (a + b). 
 
 Muter' s process for the determination of the proportion of 
 oleic acid present in a mixture of that substance with solid fatty 
 acids (stearic and palmitic) is based on the solubility of lead 
 oleate in ether. In the case of a glyceride, a quantity of sub- 
 stance not exceeding 1*5 grammes is saponified with excess of 
 alcoholic potash ; with free fatty acids it is dissolved in the same 
 solvent ; water is added and the alcohol boiled off; dilute acetic- 
 acid is then added to neutralise excess of alkali, until a decided 
 permanent turbidity is produced, and then dilute caustic potash 
 with continuous agitation until the liquid just clears again. The 
 clear solution is then precipitated by lead acetate in slight 
 excess, and stirred until the lead soap settles thoroughly ; the 
 supernatant liquor is poured off, and the precipitate washed by 
 boiling with a large bulk of distilled water and decanting. 
 Perfectly neutral lead stearate + palmitate + oleate is thus 
 obtained; the precipitate is transferred to a flask of about 100 c.c. 
 capacity and digested for some hours (with frequent agitation) 
 with absolute ether ; the ethereal solution of lead oleate is 
 filtered into a stoppered graduated tube holding 250 c.c., and the 
 filtrate and washings decomposed by agitation with about 20 c.c. of 
 a mixture of 1 volume strong hydrochloric acid and 2 volumes 
 water. Finally, a known fraction of the ethereal fluid is drawn 
 off and evaporated to dryness ; whence the weight of oleic acid 
 is deduced. The ethereal solution is conveniently drawn off by 
 means of a side tap fixed to the graduated tube about one-fifth of 
 the way up from the bottom, so as to be above the level of the 
 acid watery fluid ("Muter's oleine tube"); or it may be blown 
 off by the washbottle device (p. 120). 
 
 De Schepper and Geitel have constructed the table quoted on 
 p. 377, exhibiting the relative proportions of commercial "oleine" 
 (impure oleic acid) of solidifying point 5 -4, and commercial 
 " stearine " (stearic and palmitic acids) of solidifying point 48 
 present in a sample of separation cake of given solidifying point 
 (compare pp. 75, 76). 
 
 The " filter cake " obtained from the red oils when these are 
 chilled and passed through a filter press varies considerably in 
 composition ; besides particles of fibre (derived from filter press 
 coverings, &c.) and dust, &c., filtered out, portions of unsaponified 
 grease separate in the solid state from the cooled red oils, and 
 smaller quantities of unsaponifiable matters (cholesterol, &c.) con- 
 tained in the grease originally used. 
 
RED OIL FILTER PRESS CAKE. 
 
 377 
 
 Solidifying Point of 
 Separation Cake. 
 
 Percentage of Commercial 
 
 Stearic Acid. 
 
 Oleic Acid. 
 
 Degrees C. 
 
 
 
 5-4 
 
 
 
 100 
 
 10 
 
 2-5 
 
 97-5 
 
 15 
 
 6-6 
 
 93-4 
 
 20 
 
 12-1 
 
 87-9 
 
 25 
 
 18-5 
 
 81-5 
 
 30 
 
 27-2 
 
 72-8 
 
 32 
 
 31-5 68-5 
 
 34 
 
 36-6 63-4 
 
 36 
 
 43-0 57-0 
 
 37 
 
 46-9 53-1 
 
 38 
 
 50-5 49-5 
 
 39 
 
 54-5 45-5 
 
 40 
 
 589 41-1 
 
 41 
 
 63-3 
 
 367 
 
 42 
 
 68-5 
 
 31-5 
 
 43 
 
 73-5 
 
 26-5 
 
 44 
 
 78-9 
 
 21-1 
 
 45 
 
 83-5 16-5 
 
 46 
 
 89-0 ll'O 
 
 47 
 
 94-1 
 
 5-9 
 
 48 
 
 100-0 
 
 
 
 The following analyses represent its usual composition : 
 
 Free fatty acids, solid, . 
 
 ,, ,, liquid (oleic acid), 
 
 Unsaponified glycerides, 
 Unsaponifiable organic matters, 
 Fibres, dust, &c., .... 
 
 54-2 
 
 25-0 
 
 11-2 
 
 4-3 
 
 5-3 
 
 100-0 
 
 51-4 
 
 21-5 
 
 12-3 
 
 4-9 
 
 9'3 
 
 100-0 
 
 Since the great majority of the unsaponified glycerides con- 
 tained in the rock find their way into the red oils, whilst these 
 latter constitute the smaller half of the fatty acids obtained (the 
 " stearine " amounting to upwards of 50 per cent, of the total 
 acids) it results that the percentage of unsaponified glycerides 
 present in the red oils is usually more than double that in the 
 separation cake. The same remark applies to the unsaponifiable 
 organic matters. If the red oils be distilled by means of super- 
 heated steam the unsaponified glycerides present mostly become 
 hydrolysed during the operation, so that "distilled oleine" is 
 practically free from glycerides. On the other hand, a small 
 proportion of the oleic acid becomes decomposed during the 
 process, forming hydrocarbons (compare p. 278), so that the 
 unsaponifiable organic matters usually become notably increased 
 in amount. The following analyses indicate the composition of 
 
378 
 
 OILS, FATS, WAXES, ETC. 
 
 different samples of red oils and "distilled oleines," and illustrate 
 these points : 
 
 
 Red Oils. 
 
 
 
 
 Distilled Oleines 
 
 
 Tallow and 
 
 Tallow- 
 
 
 
 Palm Oil. 
 
 only. 
 
 
 Free fatty acids, 
 
 86-5 
 
 87-85 
 
 90-0 
 
 89-65 
 
 Unsaponified glycerides, . 
 Unsaponifiable organic matters, \ 
 hydrocarbons, &c., . . / 
 
 11-7 
 
 1-8 
 
 11-30 
 0-85 
 
 1-6 
 
 8-4 
 
 2-95 
 7-40 
 
 
 100-0 
 
 100-00 
 
 100-0 100-00 
 
 Analysis of Red Oils, Separation Cake, and Similar 
 Products. This is carried out substantially in the way indi- 
 cated on p. 162. The "free acid number," A, being determined, 
 and also the " total acid number," K, the data are obtained for 
 calculating the percentage of free fatty acids and unsaponified 
 glycerides present if the mean molecular weight of the fatty acids 
 is known or assumed. The unsaponifiable organic matters being 
 determined (by the methods described on p. 119) and the per- 
 centage of these constituents subtracted from 100 (as also that 
 of any water or other foreign substance accidentally present), a 
 sufficiently close approximation to the truth is obtained by 
 
 multiplying the difference, D, by 
 
 A. -r \&- ~~ A j X 
 / TZ" A \ 
 
 centage of free fatty acids, and by -. 
 
 - for the per- 
 l-Oo 
 
 x 1-05 
 
 -7T- for that 
 
 (K-A)x 1-05 
 
 of the undecomposed glycerides ; for if E be the mean equivalent 
 of the fatty acids, E + 12-67 is that of the glycerides (p. 165); 
 and as E usually lies between 255 and 285, the ratio of E to 
 E + 12-67 will lie between 1 to 1-050 and 1 to 1-045, and may 
 safely be taken as 1 to 1 -05 ; so that the weights of free fatty 
 acids and glycerides will be substantially in the ratio of A to 
 (K-A) x 1-05, whence the percentages will be 
 
 Free fatty acids 
 Glycerides 
 
 A + (K - A) x 1-05 ' 
 
 (K - A) x 1-05 
 A + (K - A) x 1^05 ' 
 
 Thus supposing that a given substance contains 5 per cent, of 
 unsaponifiable matter, &c., and consequently that D = 95 ; if 
 the free acid number, A, be found = 175-0 and the total acid 
 number, K, = 195-0, so that K - A = 20, the composition will 
 be 
 
ANALYSIS OF RED OILS, ETC. 379 
 
 Free fatty acids 1?5 + 20 x = = 89*28 
 
 20 x 1-05 21 
 
 175 + 20 x 05 196 
 
 Unsaponifiable matters, &c., . . . . = 5 '00 
 
 100-00 
 
 From these figures it results that the value of E is close to 
 286; for 1,000 parts of substance contain 892 '8 of free fatty acids 
 neutralising 175-0 of KOH ; whence 
 
 175-0 : 56-1 : : 892'8 : x = 2S6'2 
 
 Similarly the mean equivalent of the glycerides is close to 
 286-2 + 12-67, or nearly 299. 
 
 Several attempts have been made to substitute metallic oxides 
 for lime in the autoclave lime process, more especially magnesia 
 and zinc oxide. At ordinary pressure these bodies usually act 
 upon fatty glycerides (such as tallow) appreciably more slowly 
 than lime, probably on account of their greater insolubility in 
 water; but it is claimed that under pressure this difference is 
 not observed, but rather the contrary, so that a much smaller 
 proportion of zinc oxide, will effect the saponification and hydro- 
 lysis of fatty matter than is necessary in the case of lime : thus 
 in the British patent specification of Poullain, E. F. Michaud, 
 and E. K Michaud (No. 5,112, 1882) from 2 to 5 parts of zinc 
 oxide are directed to be used per 1,000 of fatty matter (0'2 to 0'5 
 per cent.), heat being continued for 3 to 4 hours under a pressure 
 of 100 to 130 Ibs. (7 to 9 atmospheres). It is claimed that the 
 smaller proportion of base employed renders it necessary to use 
 much less acid to obtain pure free fatty acids than would other- 
 wise be required ; whilst for certain purposes e.g., manufacture 
 of scouring soaps it is not necessary to dissolve out the zinc 
 at all. As regards magnesia, comparative experiments with 
 lime and magnesia show that the action of the latter is always 
 inferior to that of the former (vide Journ. Soc. Chem. Industry, 
 1893, p. 163). 
 
 A somewhat analogous process has been proposed, where 
 ammonia is used as saponifying agent, fatty matters and aqueous 
 ammonia being heated together under pressure. Ammonia soaps, 
 if formed, are so far wanting in permanency that by blowing 
 steam through them they are decomposed, ammonia passing off 
 (collected for use over again), whilst free fatty acids and glycerol 
 solution remain. It does not appear that this system has as yet 
 been adopted so largely as to rank as an established practical 
 manufacture; but if sufficiently complete decomposition is obtain- 
 able in a moderate time, a priori the method would seem to be 
 of a workable character. 
 
380 OILS, FATS, WAXES, ETC. 
 
 Stein, Berge, and de Roubaix have patented * the use of 
 solution of sulphurous acid or alkaline bisulphite as hydrolytic 
 agent ; from 2 J to 3 per cent, of solution is added to the fat in a 
 pressure vessel, and the temperature raised to 170 to 180, 
 whereby a pressure of some 18 atmospheres is attained ; the 
 reaction is said to be complete in about 9 hours. The tempera- 
 ture should not exceed 200 C. 
 
 Hydrolysis of Fats by means of Sulphuric Acid. It has 
 long been known that free fatty acids are obtainable from 
 glycerides by acting upon them with sulphuric acid, the glycerol 
 being largely converted into glycerosulphuric acid (p. 144), 
 subsequently more or less decomposed by the heat, and the fatty 
 acids being to some extent similarly acted upon, especially in the 
 case of oleic acid. The " Wilson " process (sometimes called the 
 "Dubrunfaut" process), the outcome of various methods originally 
 patented in England by Gwynne, Jones, and Wilson (Price & Co.) 
 in 1840 to 1843, substantially depends on these reactions, with 
 the further addition of purification of the fatty acids by distilla- 
 tion with superheated steam ; the melted fats (more especially 
 palm oil) are heated in a stout copper vessel (the " acidifier ") to 
 about 300 to 350 F = 149 to 177 C., by means of superheated 
 steam ; sulphuric acid is then run in to the extent of 3 to 5 per 
 cent., the whole intermixed, and allowed to stand some hours ; 
 during this period the glycerides are broken up, and foreign 
 organic matters present mostly carbonised. In general, the less 
 the quantity of sulphuric acid used, the higher is the temperature 
 employed. The acid mixture is then run off and boiled up with 
 water by means of wet steam, so as to wash out sulphuric acid 
 and other products soluble in water; after standing for some 
 hours to settle, the crude fatty acids are separated and heated to 
 about 240 F. (116 0.) to complete the removal of water; finally 
 superheated steam at a higher temperature is passed through, 
 the precise temperature varying with the nature of the fatty 
 matter used, but being usually near 560 F. (294 C.) 
 
 Under these conditions the fatty acids are volatilised, and are 
 condensed along with most of the steam in a series of copper 
 serpentine refrigerating pipes exposed to the air, the escaping 
 vapours being deodorised as far as possible by a water shower 
 to absorb acrolein, &c., and subsequently burned, much as in the 
 somewhat analogous case of rendering animal fats (p. 247). The 
 fatty acids thus obtained contain a much larger proportion of 
 solid acids, and less fluid oleic acid than those obtained by the 
 lime saponification process from the same material, whether by 
 the open pan or autoclave method ; it would seem very probable 
 that this is due to the transformation by the action of sulphuric 
 acid of oleic acid into isoleic acid (melting at near 45 C.), as in 
 the case of the action of zinc chloride on oleic acid (p. 142) ; or, 
 * German patent, No. 61,329. 
 
SULPHURIC ACID PROCESSES. 
 
 381 
 
 possibly, stearolactone or oxystearic acid is formed. According* 
 to Lant Carpenter,* tallow which will only yield about 50 per 
 cent, of its weight of 
 candle material when 
 treated by the lime 
 process, gives by the 
 sulphuric acid process 
 at least 75 per cent, of 
 such material of but 
 slightly inferior quality. 
 Of this, about three- 
 fourths is ready for 
 candlemaking without 
 further treatment ; the 
 other fourth, when 
 pressed and redistilled, 
 yields some 75 per 
 cent, of its weight of 
 stearic acid, and 25 
 of oleic acid ; ulti- 
 mately, only about 5 
 parts of oleic acid per 
 100 of fat are obtained. 
 A considerable pro- 
 portion of black pitch 
 (often amounting to 
 15 per cent, and up- 
 wards) is obtained as 
 bye product, whilst the 
 glycerol obtainable 
 from the acid liquors, 
 &c., is much less in 
 quantity and more 
 costly to isolate than 
 that from the lime 
 process ; accordingly, 
 whilst the larger yield 
 of solid fatty acids 
 renders the acid method 
 more economical from 
 one point of view, it 
 must be taken into 
 consideration, per con- 
 tra, that pitch instead 
 of oleine is obtained as part of the product,! and that glycerol 
 
 * Spon's Encyclopaedia, p. 581, et seq. 
 
 t By distillation at a higher temperature the pitch left on the first 
 distillation affords a certain proportion of fatty acids of inferior quality. 
 
382 
 
 OILS, FATS, WAXES, ETC. 
 
 is lost, thus materially diminishing the apparent advant- 
 ages. 
 
 Fig. 83 illustrates the general character of the plant 'used in 
 the process.* A is the tank into which the tallow, &c., is melted 
 by means of a steam jet directed upwards into the bunghole of 
 the cask. B, one of a series of leadlined tanks, in which the grease 
 is heated before treatment with sulphuric acid, so as to boil off 
 water. C, pump with suitable taps and connections enabling it to 
 pump up the hot grease into the " acidifier," D; or into the tank, 
 H, supplying the still, I, after the sulphuric acid has been washed 
 out with water. E, acid tank supplying acidifier. F F, super- 
 heaters. G G G G, washing vats, where the acidified grease is 
 boiled up with water and steam to wash out sulphuric acid, &c. 
 H, grease tank supplying still, I, through which superheated 
 steam is blown, the vapours being condensed by the refrigerator, 
 K, and copper cooling coils contained in the tanks, k. L, scrubber 
 to condense acrolein, &c. M, pipe leading uncondensed vapours, 
 fec., away to combustion flue for destruction. 
 
 Fig. 84 represents Knab's apparatus for continuous distillation 
 
 Fig. 84. 
 
 by superheated steam. A is the distillation vessel, into which 
 the fatty acids to be distilled are run through the supply funnel, 
 C, at intervals regulated by the rising and falling of the float 
 valve, D. Superheated steam enters by the pipe, F (furnished 
 with regulating valve and safety valve, E), and passes in small 
 streams through the molten fatty acids from the horizontal coil 
 
 * L. Field, "Cantor Lectures, 1 ' 18S3 (Journ. Soc. Arts, vol. xxxi., p. 861), 
 
DISTILLATION OF FATTY ACIDS. 383 
 
 at the base. The vapours pass off through the neck, G, to the 
 condenser ; the most easily condensed fatty acids are collected in 
 H, and drawn off from time to time through the cocks, J J, 
 whilst the other vapours pass on. K K is a blow off pipe for 
 removing residual pitch at intervals, the supply of fatty acids 
 through C being temporarily shut off. Heat is applied by means 
 of a bath of molten lead or other suitable metal contained in the 
 outer pan, B. 
 
 According to Schadler, the quantities of steam requisite for 
 distillation of a given quantity of fatty acids at different tem- 
 peratures are as follows : 
 
 Temperature. Weight of Steam for 1 part of Fatty Acids. 
 
 200 to 230 C 
 230 to 260 C 
 
 290 
 325 to 356 C 
 
 7 parts. 
 
 3 to 4 parts. 
 
 2 parts. 
 
 1 part. 
 
 When the distillation temperature does not exceed 240, the 
 distilled fatty acids are almost white ; at 260 a little coloration 
 is manifest ; at 290 this is more marked, whilst at temperatures 
 above 300 the distillate is yellow or brown. 
 
 Numerous other forms of apparatus for effecting distillation by 
 means of superheated steam have been constructed for particular 
 purposes e.g., the purification of grease from cotton seed foots 
 (p. 261), of Yorkshire grease (p. 277), and similar substances ; 
 for the most part these differ from the above arrangements more in 
 details of construction than in general principles. 
 
 In Marix' arrangement for the distillation of free fatty acids 
 produced by hydrolysis or otherwise an air pump is applied, so 
 that a temperature of 250-255 suffices for the distillation under 
 diminished pressure. A similar process has been patented by 
 Lewkowitsch (English patent, 5,985, 1888), the pressure being 
 reduced by 10 to 13 Ibs., so that a temperature of about 460 F. 
 (238 C.) suffices, instead of about 600 F. (316 C.) 
 
 It is noticeable that when the products of distillation of a 
 charge of given material are collected in separate fractions, it is 
 found that in some cases the portions first passing over are the 
 most fusible, those coming over later possessing successively 
 higher and higher melting points ; whilst with other fatty matters 
 the reverse is the case. Thus, with palm oil the first distillate is 
 sufficiently solid to be used for candlemaking without any further 
 treatment, whilst the later portions are softer, and must be 
 pressed before they can be thus employed. With bone fat, on 
 the other hand, the successive fractions show a regular increment 
 in consistency. The following illustrative figures are given by 
 
384 
 
 OILS, FATS, WAXES, ETC. 
 
 Payne as the melting points of the fatty acids collected in seven 
 different fractions : 
 
 Fraction. 
 
 Bone Fat. 
 
 Palm Oil. 
 
 
 Degrees C. 
 
 Degrees C. 
 
 1 
 
 40 
 
 54-5 
 
 2 
 
 41 
 
 52 
 
 3 
 
 41 
 
 48 
 
 4 
 
 42 
 
 46 
 
 5 
 
 45 
 
 44 
 
 6 
 
 45 
 
 41 
 
 7 
 
 47 
 
 39-5 
 
 In almost all cases, however, the average melting point of the 
 distilled fatty acids exceeds that of the crude acids before 
 distillation. 
 
 Bock's Process. In Wilson's process the hydrolysis of the 
 glycerides is mainly effected under the influence of comparatively 
 concentrated sulphuric acid at a tolerably high temperature (150 
 to 180 C.), and subsequently completed partly by adding water 
 and boiling up with wet steam, and partly by distillation with 
 superheated steam ; Bock's process differs therefrom in that the 
 hydrolysis is mainly effected by comparatively dilute sulphuric 
 acid, the action of which is facilitated by the removal of the 
 nitrogeneous films or envelopes coating the fatty globules by 
 means of concentrated sulphuric acid acting at a much lower 
 temperature than in Wilson's process. Tallow, &c., is heated to 
 115 in an open vat * and well agitated with from 4 to 6 per cent, 
 of sulphuric acid, whereby the albuminous envelopes are charred 
 and broken up, but little or no hydrolysis effected. Water is 
 then added, and the blackened but still neutral fat boiled up 
 with the resulting dilute sulphuric acid for some hours until the 
 decomposition of the glycerides is complete, the degree being 
 judged by the mode of crystallisation of the fatty acids on cooling 
 a sample. When complete, the acid fluid is run off and neutral- 
 ised with lime, and the resulting aqueous crude glycerine solution 
 concentrated for sale. The blackened fatty acids are then sub- 
 jected to oxidation by means of bichromate or permanganate of 
 potash and sulphuric or hydrochloric acid, or of nitric acid, bleach- 
 ing powder, ifec., whereby the albuminous charred matters are 
 largely increased in density so that they subside, leaving the 
 fatty acids of a pale brown tint ; these are then washed and 
 crystallised, and subjected to cold and hot pressure in the usual 
 way, whereby a brown oil and a white stearirie are obtained. 
 The solid acids obtained are said to be whiter, of higher melting 
 point, and larger in quantity than those obtained from the same 
 
 * Lant Carpenter, British Association Reports, 1872, p. 72; vide also 
 Dinyler's Po'ylech. Jovrn., May, 1873. 
 
HYDROLYSIS OF GLYCERIDES. 385 
 
 material by lime sapoiiification, probably through formation of 
 isoleic acid, stearolactone, or oxystearic acid, &c. (pp. 29, 39) ; 
 whilst 6 to 7 per cent, of glycerine solution at 38 T. (specific 
 gravity 1*19, containing about 70 per cent, of actual glycerol) is 
 obtainable. The plant is simple, all the operations being carried 
 out in one vessel ; and as only open steam is used there is no 
 danger of explosion as with autoclave processes. If desired, the 
 brown oleic acid can be distilled by means of superheated steam ; 
 or it can ba converted into palmitic acid by Radisson's process 
 (infra), for which purpose it is well fitted. 100 parts tallow 
 yield 95 of crude fatty acids, reduced to 93 by oxidation and 
 washing, of which 55 to 60 parts are obtainable as candle stearine, 
 melting at 58 to 60 C. (136 to 140 F.) 
 
 Hydrolysis of Glycerides by Water Only. In 1854 a 
 patent was taken out by Tilghmann for the decomposition of 
 glycerides by means of water under great pressure, and corre- 
 spondingly high temperature ; in one form of apparatus a mixture 
 of fat and water was forced through a coil heated to about 
 420 C. (upwards of 800 F. ), the pressure approximating to a ton 
 per square inch (some 140 atmospheres). Various improvements 
 were subsequently made ; but the practical difficulties attending 
 the working of manufacturing operations of the kind prevented 
 the method being largely adopted. A modification of the process, 
 patented shortly after wards by Wilson & Payne (No. 1,624, 1854), 
 effects the same result in a much simpler way. The fatty 
 matter being heated in a still to about 300 C., steam from a 
 superheater is blown through it by means of a rose jet or false 
 bottom perforated with a large number of small holes, so that 
 numerous jets of steam rise through the mass. Hydrolysis takes 
 place, and the fatty acids and glycerol formed are volatilised and 
 carried over with the excess of steam to the condensers, where 
 the free fatty acids and glycerol in aqueous solution are obtained ; 
 the former condense first, so that by using a series of condensing 
 chambers, little but fatty acids are obtained in the earlier ones, 
 whilst chiefly watery glycerol condenses in the later ones, yielding 
 a very pure commercial glycerine by simple concentration after 
 separating the small quantity of accompanying fatty acids. 
 Fig. 85 represents the general character of this plant. Steam is 
 superheated in the superheater A, and passes into the retort, C, 
 covered in with a lid, E ; the vapours pass off to the condensers, 
 G, for fatty acids, and F for glycerol water. If the temperature 
 is too high (above 315), much loss of glycerol occurs through the 
 formation of acrolein. 
 
 In France, the saponification of fatty matters by means of 
 water alone (without lime, <fcc.) is much more largely carried 
 out than in Britain, on account of the more frequent use of pure 
 " stearine " candles, instead of those made largely or wholly of 
 paraffin wax. Several different forms of apparatus are in use : for 
 
 25 
 
386 
 
 OILS, FATS, WAXES, ETC. 
 
 a description of some of these exhibited at the Paris Exhibition, 
 vide B. Lach, Chem. Zeit., 13, pp. 1157, 1218, 1335, 1374; in 
 abstract Journal tioc. Ckem. Ind., 1890, p. 82. 
 
 Utilisation of Red Oils. In the manufacture of candle 
 material from glycerides a more or less considerable propor- 
 tion of "red oils'" is obtained, the amount varying with the 
 
 Fig. 85. 
 
 method of saponificatioii or hydrolysis adopted, the nature of 
 the fatty matters used, and the temperature at which the cold 
 pressing is effected. Commercially, the " oleine " thus produced 
 is considerably less valuable than the solid "stearine;" whence, 
 cceteris paribus, it is desirable so to conduct the operations as to 
 obtain the maximum yield of solid products and the minimum of 
 liquid ones. In general: the red oils thus produced are utilised 
 by conversion into socalled " oil soap/'? by direct saturation with 
 soda ley of appropriate strength (vide Chap, xx.) ; but various 
 attempts to employ them as a source of other more valuable 
 products have been made. One such process, due to v. Schmidt, 
 consists in heating the red oils with about 10 per cent, of zinc- 
 chloride to a temperature of about 185, whereby conversion into 
 more solid substances is brought about, chiefly by formation of 
 isoleic acid and stearolactone (vide p. 142). Another process 
 (Radisson's, vide infra) depends on the conversion of oleic into 
 palmitic acid by fusion with alkalies; whilst Ziirer has attempted* 
 to convert oleic into stearic acid by first subjecting to the action 
 of chlorine, and then treating the dichloride of oleic acid formed 
 
 * German Patent, No. 62,407. 
 
KADISSON'S ARTIFICIAL PALMITIC ACID. 387 
 
 with nascent hydrogen evolved from zinc dust (or finely divided 
 iron or magnesium) and water heated under pressure.* 
 
 Radisson's Artificial Palmitic Acid. It has long been 
 known that acids of the oleic family when fused with caustic 
 potash undergo a peculiar decomposition evolving hydrogen, and 
 breaking up so as to form two acids of the stearic family, of 
 which acetic acid is generally, if not invariably, one (p. 24) ; 
 e.g., oleic acid when thus treated breaks up, forming palmitic 
 acid in accordance with the equation 
 
 Oleic Acid. Caustic Potash. 
 
 C 18 H 34 2 + 2KOH - C ]6 H 31 K0 2 + C 2 H 3 K0 2 + H 2 . 
 
 M. St. Cyr Radisson. has succeeded in carrying out this reaction 
 on a manufacturing scale, converting some 3 tons oleic acid 
 into palmitic acid per diem. The fusion is effected in a covered 
 iron cylindrical pan or " cartouche " with dished base, provided 
 with a mechanical agitator, and set in brickwork some distance 
 (nearly 6 feet) above the firebars of a grate, so that a large 
 hot air chamber is formed underneath, enabling the tempera- 
 ture to be more easily regulated. 1,650 Ibs. of oleic acid 
 and 2,750 of caustic potash ley, specific gravity 1-4, are run in; 
 when steam ceases to be evolved, a manhole in the cover is 
 closed, and the evolved hydrogen passes off by a pipe to a purifier 
 and gasholder for other use. The temperature requires to be 
 very nicely adjusted, 300 to 310 being the proper value, whilst 
 at 320 destructive distillation commences ; to avoid overheating 
 a Gifford steam injector is provided whereby the temperature of 
 the interior can be reduced when requisite. Some 36 to 40 hours 
 are required for completely working off a charge, including filling 
 the pan and emptying; the progress of the operation is judged 
 by sampling and testing the solidifying point of the acids 
 liberated from the mass by a mineral acid, preferably by 
 Dalican's method (p. 74). When complete, the contents of the 
 pan are run off through an outlet pipe into a tank containing a 
 small quantity of water, and the whole heated up by a steam jet. 
 The excess of potash present then dissolves, forming a strong ley 
 (specific gravity about 1'14) in which the potassium palmitate 
 is insoluble, floating up as a soap ; this is transferred to a decom- 
 posing vessel where the palmitic acid is set free by means of 
 sulphuric acid ; the acid is then distilled in the usual apparatus, 
 leaving some 3 per cent, of pitch, and furnishing a perfectly white 
 acid, melting at 50 to 53 C., burning with a clear smokeless 
 flame. About 87 per cent, of white palmitic acid is obtainable 
 
 * De Wilde and Eeychler had previously shown that by heating oleic 
 acid with a small quantity of iodine or bromine under pressure, some 70 
 per cent, becomes converted into stearic acid (Bulletin &oc. Chem., Paris, 
 1889, 1, p. 295). 
 
388 
 
 OILS, FATS, WAXES, ETC. 
 
 in practice, the theoretical yield being 91 per cent, of the oleic 
 acid used. According to Lant Carpenter, the oleic acid produced 
 by Bock's process (supra) is better adapted to the purpose than 
 ordinary red oils prepared by alkaline saponification, a higher 
 yield of palmitic acid being thereby obtained. For further 
 details, vide Spon's Encyclopaedia of Arts and Manufactures, 
 p. 584. 
 
 CHAPTER XVII. 
 
 MANUFACTURE OF CANDLES, TAPERS, AND 
 NIGHTLIGHTS. 
 
 SEVERAL different kinds of process are or have been employed in 
 the manufacture of candles for the purpose of surrounding the 
 wick with a more or less uniform coating of solid combustible 
 matter. In the early and middle ages, when wax was the 
 material used by the more wealthy classes as illuminant, a 
 simple mechanical process of hand manufacture was usually 
 
 adopted, a lump of 
 wax being softened 
 by heat and kneaded 
 until sufficiently plas- 
 tic, then applied 
 round the wick, and 
 rolled into shape. A 
 similar process is still 
 employed, with the 
 difference that the 
 wax is applied by 
 " pouring " the just 
 melted material over 
 the wick so as to iii- 
 crust it with a layer 
 of wax ; after cooling, 
 another layer is simi- 
 larly poured over, and 
 so on, the candle 
 
 Fig> 8C being reversed in 
 
 position from time to 
 
 iime until the requisite thickness is attained; the still somewhat 
 plastic wax candles are then rolled into shape, some half dozen 
 at a time, on a smooth marble table with a board on which the 
 workman presses heavily; the finished candle consequently 
 exhibits concentric layers of wax, something like the rings of a 
 
DRAWING WAX TAPERS. 
 
 389 
 
 tree. The process requires considerable skill to produce a per- 
 fectly even surface with truly central wick, especially in the case 
 of large sized candles ; to facilitate the " pouring" or " basting" 
 operation, the wicks are usually hung on a horizontal wheel 
 (Fig. 86) fixed over the projecting lip of a large basin holding 
 the melted wax, so that each is "basted" in turn. Large conical 
 altar candles (cierges) are still generally made substantially by 
 the older process, the plastic wax being rolled into a long thin 
 strip or ribbon, which is then coiled round the wick (previously 
 soaked in melted wax) and rolled into shape on the marble slab, 
 instead of being basted on. 
 
 In practice it is difficult to "mould" wax candles satisfactorily 
 oil account of sticking to the mould and shrinkage during solidi- 
 fication, and consequent tendency to crack ; but thin candles can 
 
 Fig. 87. 
 
 be "drawn" somewhat after the fashion of wire by running the 
 wick through a pan of melted wax, and subsequently making it 
 pass through a drawplate so as to reduce the layer of wax to 
 uniform thickness (Fig. 87). The wick is usually wound from 
 one drum on to another ; after one coating is applied it is wound 
 back again, this time passing through a somewhat wider draw- 
 hole, so as to give an increased thickness of wax ; as a rule, 
 however, neat tapers of more than about half an inch diameter 
 cannot be conveniently made thus, as the tendency to crack 
 becomes too great when the diameter increases beyond this 
 point. In whatever way the wick is coated, whether by " rolling," 
 " pouring," or " drawing," the candles are ultimately finished by 
 cutting off the butt ends clean with a sharp knife (Fig. 88), and 
 trimming the other ends to conical tips. When tinted wax 
 candles are requisite usually only the last batches basted on are 
 
390 
 
 OILS, FATS, WAXES, ETC. 
 
 coloured, as the tinting- materials are generally apt to clog the 
 wick, especially if solid ; for white candles airbleached wax 
 (p. 268) is employed, w T ax blanched by chemicals (especially 
 chlorine) being- unsuitable (p. 267). 
 
 Fig. 88. 
 
 Dip Candles. In the preparation of rough candles for house- 
 hold use in mediaeval times and even still more recently,* the 
 wicks used were generally rushes (Juncus conglomeratus) skilfully 
 
 Fig. 89. 
 
 peeled so as to leave the pith supported by one thin rib of green 
 rind, whence the familiar term "rushlight." These were soaked 
 (after drying) in melted tallow or kitchen grease, held up to 
 
 * Gilbert White, "Natural History of Selborne" 1789. 
 
EDINBURGH WHEEL. 
 
 391 
 
 cool, and then dipped again carefully into the just melted grease 
 and quickly withdrawn, so that the film of adherent tallow 
 solidified before it had time to run down ; for which purpose 
 it was imperative that the grease should not be overheated. 
 The dipping was then repeated at intervals until the coating of 
 tallow was sufficiently thick. By and bye when tallow candle- 
 making became a trade of itself this method of manipulation was. 
 adopted on a larger scale with appropriate modifications ; linen 
 or cotton wicks supplanted rush pith, whilst the dipping was 
 effected by fixing a number of wicks (previously soaked in tallow) 
 on hooks driven side by side a little way apart into the bottom 
 of a piece of board or wooden lattice frame, so that by lifting the 
 board by means of a knob or handle on the upper side, all the 
 wicks attached could be simultaneously dipped and withdrawn. 
 To facilitate the dipping, the board with dependent candles was 
 attached to a rope passing over a pulley (Fig. 89) ; each frame of 
 candles when dipped being unhooked from the rope and suspended 
 from the periphery of a horizontal wheel so as to hang up and 
 harden ; by dipping in regular succession each one of a number 
 of frames thus suspended, each batch of candles became suffi- 
 ciently cooled and " set " to be ready for another dip by the time 
 its turn came ; the wheel thus slowly revolved, making one 
 revolution for each dipping of the whole series of frames suspended 
 therefrom. By attaching suitable weights to the end of the cord 
 as counterpoise the time is easily ascertained when the candles 
 have been dipped sufficiently often to be of the right weight. 
 
 To avoid the trouble of unhooking each frame and hanging it 
 up from the wheel a series 
 of separate radiating bars 
 have been substituted for 
 the complete wheel, each 
 bar being capable of oscil- 
 lating in a vertical plane 
 working 011 a pin in a 
 slot in the vertical axis. 
 Fig. 90 represents a form 
 of "Edinburgh wheel" 
 of this description ; each 
 bar, B B, carries two 
 dipping frames, one at 
 each end, the second 
 serving as counterpoise 
 to the first ; each frame 
 is successively pulled 
 down and dipped in the 
 tallow cauldron and then 
 
 Fig. 90. 
 
 raised again, the wheel being made to revolve partially so as to 
 bring the next succeeding frame over the cauldron. Various 
 
392 
 
 OILS, FATS, WAXES, ETC. 
 
 subsidiary arrangements are sometimes applied for the purpose 
 of ensuring horizontality of the radiating bars when raised after 
 dipping even though the newly dipped end may be a little 
 heavier than its counterpoise. 
 
 The wicks may be suspended from the hooks by means of a 
 loop of cotton thread tied to them ; but a more convenient plan 
 is to double the wick, stringing the series over a rod as indicated 
 in Fig. 91. The rod with the dependent wicks is then dipped 
 by hand into a trough of melted tallow and hung up on a rack 
 or otherwise supported until the tallow is sufficiently set to 
 permit of another dipping ; or a series of rods are attached side by 
 side to a frame supported by cords and attached to an hdinburgh 
 wheel, ifcc. In order to impregnate the wicks with tallow in the 
 first instance and to get them all of the right length, the wick is 
 
 = $F$F$ = ^^ 
 
 Fig. 91. 
 
 unwound from a bobbin, and wound round a square frame of 
 suitable size so as to form a sort of loose covering ; this is then 
 dipped bodily in hot tallow to within an inch or so of the top 
 of the frame, so as to fill up all the pores in the immersed 
 portion of the wicking : the entire row of strands at the bottom 
 of the frame is then cut through w y ith a knife, and the different 
 doubled wicks separated, and strung on the rods as indicated. 
 
 Another mode of proceeding, formerly much used in the larger 
 dipping establishments, is to have the cauldron of melted tallow 
 movable, so as to pass in succession beneath each one of a series 
 of frames. Fig. 92 represents the section of an arrangement of 
 the kind : the two frames, D D, are connected by a cord passing 
 over pulleys supported by a beam arid posts, so that one counter- 
 poises the other ; by pulling the cords, E E, the one or the other 
 can be made to descend. A number of these pairs of frames are 
 arranged side by side (Fig. 93) the cauldron of tallow (kept fluid 
 by means of a brazier) running on a railway down one side of the 
 row and up the other, so that each one of the frames is dipped in 
 regular rotation. A sort of mechanical wiper is conveniently 
 connected with the cauldron, so that by moving a lever after the 
 candles have emerged from the molten tallow the drops of melted 
 grease that run down to the bottoms are removed. When well- 
 shaped candles are required, the irregularities may be smoothed 
 down by pulling each candle in succession by hand through a 
 series of holes in a drawplate (graded in diameter, the smallest 
 
DIP CANDLES. 
 
 393 
 
 being the size ultimately required) so as to strip off a portion of 
 the outer coating, leaving the remainder fairly cylindrical. 
 
 A peculiar modification of the dipping process is sometimes 
 practised : the wicks are dipped in hot melted tallow as usual to 
 fill up pores; instead of applying the outer coatings by successive 
 dippings of the treated wicks, thin steel rods are dipped in the 
 tallow ; when the candles are of the requisite thickness they are 
 cooled completely, and the steel cores extracted ; the wicks are 
 then passed through instead, and fastened in position by a few 
 
 L_J 
 
 Fig. 92. 
 
 Fig. 93. 
 
 drops of melted tallow. A similar device is also employed in the 
 manufacture of certain kinds of night lights (infra), except that 
 the wickless hollow candles are made by casting instead of 
 dipping. 
 
 At the present day, although the manufacture of dip candles 
 made of unsaponified tallow is by no means extinct (there being 
 still some considerable demand, especially in country districts), 
 the quantity manufactured is much less than that of " moulded" 
 candles, mostly prepared from solid fatty acids ( socalled 
 "stearine") and paraffin wax, but sometimes from unsaponified 
 
394 OILS, FATS, WAXES, ETC. 
 
 tallow or mixtures containing both free fatty acids and solid 
 unsaponified glycerides (composites). Tallow candles, when 
 blown out, generally emit an acrid vapour, due to the decomposi- 
 tion of the glyceride by the heat of the smouldering wick, with 
 formation of acroleiii ; this circumstance, together with their 
 comparative softness inducing "guttering," the necessity for 
 " snuffing," and the tendency to emit smoke and give a less 
 clear brilliant light than stearine and paraffin candles, has caused 
 them gradually to fall comparatively into disuse, especially 
 amongst dwellers in towns. 
 
 Wicks. The nature of the wick employed in a candle very 
 greatly affects the way in which it burns, and consequently the 
 light emitted. In the old fashioned tallow dip candle, thick 
 twisted cotton wicks are still used ; these do not thoroughly 
 consume away, and consequently " snuffers " are requisite in 
 order to remove the charred smouldering cotton, otherwise much 
 less light is given out, and a smoky flame produced. By various 
 mechanical devices, attempts have been made to give to such 
 twisted wicks a tendency to bend outwards in the flame, so as to 
 come in contact with the air and consume spontaneously ; others 
 have sought to attain the same end by incorporating a thin wire 
 with the cotton strands. Palmer's " metallic wick " was an 
 analogous device, where a thread impregnated with powdered 
 bismuth was bound up with a number of others of ordinary 
 fibres by winding one round the bunch ; when burnt, the 
 bismuth formed a minute globule at the end of the wick, the 
 weight of which tended to draw the wick outwards ; so that the 
 carbonised cotton was burnt away, and the bismuth volatilised, 
 or was otherwise dissipated by combustion. De Milly attempted 
 to gain the same result by impregnating the wicks with boracic 
 and phosphoric acids, &c., so as to form a globule of fused 
 mineral matter. All such devices, however, have been super- 
 seded for the better classes of candle by the use of flat plaited or 
 " braided " wicks (first introduced by Cambaceres), where the 
 mode of construction imparts a natural tendency to bend 
 outwards. The precise mode of plaiting adopted considerably 
 modifies the way in which the wick burns, one kind of braiding 
 being better suited than another for certain kinds of combustible 
 matter ; thus, paraffin candles require a wick more tightly 
 braided than is requisite for stearine candles, whilst looser 
 wicks are used for wax and sperm candles. As a rule, the 
 plaiting of the wicks is not carried out in the candle factory, but 
 by spinners making a speciality of this particular line, and 
 delivering the braids in hanks of convenient size ; the machines 
 used much resemble those employed in the manufacture of 
 ordinary braids. 
 
 Wick Pickling. Before conversion into candles, the wicks 
 are soaked or "pickled" in a suitable saline solution for some 
 
MOULDED CANDLES. 395 
 
 hours ; they are then drained and finally wrung out by means of a 
 rapidly rotating centrifugal machine so as expel almost the whole 
 of the fluid without twisting the threads in any way, and finally 
 hung up to dry in a room heated by steam pipes. The object of 
 the pickling is, on the one hand, to counteract the accumulation 
 of mineral matter or "ash" in the wick as it burns, and on the 
 other, to prevent the too rapid burning away of the wick fibres 
 before the due quantity of melted fatty matter has passed along 
 them and been consumed in the flame. The choice of the parti- 
 cular solutions employed and their strengths is usually regarded 
 as a trade secret, each manufacturer having his own views on the 
 subject to which experience has guided him ; solutions varying 
 from 1 to 5 per cent, of saline matter in strength have been 
 recommended, such as borax (alone, or acidulated 'with a minute 
 quantity of sulphuric acid), salammoniac, saltpetre, phosphate of 
 ammonium, or mixtures of such salts ; although only very minute 
 quantities of saline matters ultimately remain in the dried wicks, 
 yet the effect thereby produced on the way in which the candle 
 burns is often very marked. 
 
 MOULDED CANDLES. 
 
 The art of moulding candles, instead of dipping them, is due 
 to the Sieur de Brez in the fifteenth century; but excepting for 
 the employment of this method in the manufacture of spermaceti 
 candles in the latter part of the last century, but little advance 
 was made in this direction until the introduction of " stearine " 
 (solid free fatty acids) as candle material instead of tallow, and 
 the subsequent employment of paraffin wax for the same purposes 
 a little after the middle of the present century. The earlier 
 moulding machines were socalled " hand frames " (still in use for 
 small operations and special sizes for which only a small demand 
 exists) containing a series of pewter moulds with removable- 
 mouthpieces, Fig. 94, depending downwards from a shallow 
 trough, Fig. 95, the top end being lowest and the butt end 
 uppermost. By means of a wire with a hook at the end the 
 wick was hooked through a narrow orifice at the conical lowest 
 end of the mould and brought upwards, and finally fixed to a 
 wire hook, n, by means of a knot on the wick, or preferably a 
 little loop of cotton thread tied to the wick ; so that by gently 
 pulling the wick downwards at the bottom and fixing it with 
 a peg, it was stretched in the axis of the cylindrical mould 
 (Fig. 96) ; or instead of a removable mouthpiece carrying a hook 
 like n, a short piece of wire was passed through the loop and 
 allowed to rest in a couple of shallow notches opposite to one 
 another in the upper rim of the mould, so that the wick depended 
 axial ly therefrom. Figs. 97 arid 98 represent an improved 
 modification of this arrangement, where, instead of having a 
 
,396 
 
 OILS, FATS, WAXES, ETC. 
 
 VJ 
 Fig. 94. 
 
 
 Y 
 
 Fig. 96. 
 
 Fig. 93. 
 
 Fig. 97. 
 
 Fig. 98. 
 
HAND MOULDING FRAMES. 
 
 397 
 
 separate wire for each candle, a whole row of wicks is simul- 
 taneously supported by a single rod, D D, which is with- 
 drawn when the candles are extricated from the moulds after 
 cooling. The use of this rod generally leaves a corresponding 
 mark or groove at the base of the finished candle, whereby a 
 hand made article can be 
 readily recognised. The 
 moulds being somewhat 
 warmed so as not to chill 
 the candle material too 
 quickly, the molten sub- 
 stance is poured into the 
 trough so as to fill all the 
 moulds, and also part of 
 the trough to allow for 
 shrinkage ; the whole is 
 then set by to cool, and 
 when the candles are suf- 
 ficiently set, the contents 
 of the trough are scooped 
 out with a trowel. Pre- 
 ferably, the frame carry- 
 ing the series of moulds is 
 immersed in a water tank 
 so as to facilitate the chill- 
 ing, the temperature of the 
 water varying with the 
 nature of the material 
 used and the dimensions 
 of the candles moulded ; it 
 being usually necessary 
 that the solidification 
 should go on at a par- 
 ticular rate, otherwise a 
 crystalline structure may 
 be developed by too slow 
 cooling, injuring the ap- 
 pearance of the candle, or 
 cracking may occur with 
 too rapid chilling. When 
 the candles are completely 
 set, the frame is removed 
 from the water, and the Fig. 99. 
 
 candles extricated by re- 
 moving the pegs and inverting the frame, when they mostly 
 fall out of themselves owing to the moulds being slightly conical; 
 if sticking occur, gently tapping the mould generally suffices to 
 dislodge the candle. Including "threading" i.e., setting the wicks 
 
.398 
 
 OILS, FATS, WAXES, ETC. 
 
 in position by hand (by passing it through the lower orifice and 
 pulling it upwards by means of a wire) filling, and emptying, 
 hand frames can only be worked off about once in an hour, or 
 somewhat less frequently. In the later " continuous " candle 
 moulding machines, three times this speed is attained, much time 
 being saved by a device whereby the wick is passed continuously 
 at stated intervals through the mould, a candle being cast at each 
 period, and when set, lifted upwards so as to draw the wick into 
 position for the next moulding, so that a string of candles, one 
 after the other, is cast around each wick. 
 
 Fig. 99 represents Royan's form of continuous wick moulding 
 machine as used in Germany (Schadler) ; as each batch of candles 
 is cast and becomes sufficiently hard, they are lifted upwards out 
 
 
 Fig. 100. 
 
 of the moulds by means of a rack and pinion which elevates a 
 platform to the under side of which the wicks are fastened by a 
 series of clips ; in this way the wicks are always kept gently 
 stretched along the axes of the moulds ; several successive tiers 
 of candles are thus moulded without altering the attachments. 
 When the platform reaches its highest elevation the wicks are 
 severed below the lowest tier, and the strings of candles removed 
 from the clips that support them ; the platform is then lowered 
 and the wick ends affixed to the clips, and the operations com- 
 menced afresh. 
 
 Fig. 100 represents " Camp's moulding wheel," a combination of 
 the principle of the " Edinburgh wheel '' used for dipping candles 
 with this "continuous" moulding action; this arrangement has been 
 .somewhat extensively used in America (Christian!). A revolving 
 
CONTINUOUS MOULDING MACHINES. 
 
 399 
 
 horizontal wheel, B, is supported by iron rods, O O O, and turns 
 on a pivot, C, attached to the roof. A series of moulding frames, 
 A A A, are supported by the wheel, regularly arranged radiating 
 from the centre; the troughs, b b, b b, surrounding these can be 
 filled with water heated to any required temperature by means 
 of steam pipes, or if need be cooled with ice. Just below the 
 tips of the moulds are the rows of bobbins of wick, the ends of 
 which, to begin with, are drawn upwards by hand and adjusted 
 in the axes of the moulds. When all the moulds are ready the 
 discharge valve, P, of a tank of melted candle material, M, is 
 opened so as to fill one of the mould frames in position under- 
 neath ; the wheel is then pushed round until the next mould 
 frame is in position under the spout, when this is similarly filled ; 
 and so on with all in turn. By the time the last frame is filled 
 the first will have cooled sufficiently to enable the candles to be 
 cautiously withdrawn and laid over in grooves cut for their 
 support in the ledges of the frame ; as this is done the w r icks 
 are drawn upwards, so that the moulds are threaded ready for 
 the next filling. The mould frame thus emptied is refilled with 
 melted candle material ; and similarly with the next, so that the 
 wheel is revolved a second time, each mould frame being filled 
 in succession as before ; when all the frames are filled the candles- 
 lying over in the grooves (by this time perfectly 
 hard and solid) are cut off and removed, and these 
 now filling the moulds are pulled upwards and 
 made to take their place. 
 
 The moulding machines in use at the present 
 day in the larger factories are mostly constructed 
 on the "piston" principle, whereby the candles 
 when sufficiently set are mechanically expelled 
 from the moulds by means of a series of pistons 
 rising up therein and lifting the candles out. Fig. 
 101 represents the general mode of action, identical 
 in principle with that of an ordinary " lifting 
 pump " without the valve, excepting that the 
 piston-rod is below instead of above ; the piston is 
 hollowed conically so as to form the mould of the 
 candle tip ; the wick passes upwards through the 
 tubular piston-rod. A series of moulds is arranged 
 in a convenient frame or trough into which water 
 can be run heated by means of steam, or artificially 
 cooled as may be requisite according to the tem- 
 perature at which the moulds are to be kept, which Fig. 101. 
 varies with the nature of the candle material. 
 
 Fig. 102 represents a moulding machine containing two such 
 troughs arranged parallel, each containing a double row of 
 moulds set in a suitable frame with the piston-rods all depressed; 
 this is effected by connecting them all to a horizontal shelf 
 
400 
 
 OILS, FATS, WAXES, ETC. 
 
 (driving plate) capable of being raised or lowered at will by 
 means of a handle working a pinion gearing into a rack ; as the 
 shelf is raised the four rows of candles are simultaneously lifted 
 upward by the ascent of the pistons. As they rise they pass 
 through four series of grooved jaws or ' : nippers" slightly open ; 
 at the summit of the elevation these jaws close, gently grasping 
 iind supporting the candles, the grooves being lined with felt or 
 preferably india rubber. The handle is then turned the reverse 
 way so as to depress the pistons to the lower ends of the moulds ; 
 the wicks attached at the upper ends to the rows of candles 
 supported by the nippers are consequently stretched in the axes 
 of the moulds, having been unwound from the bobbins beneath 
 during the ascent of the candles. 
 
 Fig. 102. 
 
 To commence operations, each wick is hooked up by means of 
 a wire through the hollow piston-rod and fixed in the axis of the 
 mould, as in the hand frame ; melted candle material is then 
 poured into the moulds, and when set the candles are lifted out 
 (by raising the pistons) and held by the nippers, the wicks being 
 thus pulled upwards into position for the next casting ; the 
 
MOULDED CANDLES. 401 
 
 pistons are then depressed, sliding over the wicks as they 
 descend ; the temperature of the water trough is adjusted if 
 requisite, and a new batch of candles cast by pouring in more 
 melted candle material. When this has set sufficiently to keep 
 the wick in its central position without extraneous aid, the upper 
 rows of candles held by the nippers are detached by cutting 
 through the wicks ; the nippers holding the candles are then 
 opened and the candles extracted, or, preferably, are lifted off 
 (being detachable) and emptied on to a table, &c. The nippers 
 are then replaced and the process repeated until the wick bobbins 
 are exhausted. 
 
 The lengths of the candles thus moulded in a given set of 
 cylinders can be regulated at will by simply raising the driving 
 plate by means of set screws, so as to shorten the distance 
 between each piston and the top of the corresponding mould, and 
 thus form a shorter candle ; or vice versd. When the butt ends 
 of the candles are required to be conical (so as to fit into any 
 sized stick), a special kind of cutting machine is employed to 
 shave down the ends. If the cone is to be of greater diameter at 
 its base than the rest of the candle, a special modification of the 
 mould is employed (infra}. 
 
 The chief skill required in working the candle moulding 
 machine lies in properly regulating the temperature, the modus 
 operandi varying in this respect with the material. With pure 
 stearine (i.e., solid fatty acids with just enough paraffin wax, 
 beeswax, or vegetable wax, or other similar material to u break 
 the grain," and prevent or diminish crystallinity), the moulds 
 are kept at a temperature slightly below the setting point of the 
 candle material, which is poured in on the point of congealing, 
 well stirred so as to form a gruel-like mass. The workman 
 generally judges the temperature by simply putting his hand into 
 the water trough surrounding the moulds, cooling it by running 
 in a little cold water if requisite, or vice versd. With paraffin 
 wax, on the other hand, the moulds must be heated by hot water 
 or steam well above the melting point of the wax (usually up to 
 80 to 85, or about 170 F.), whilst the wax also should be hotter 
 than its fusing point; when the moulds are filled, the surrounding 
 hot water is run off and cold water run in instead, whereby the 
 material is quickly chilled, and the peculiar translucency and 
 lustre desired is attained. In certain cases this effect is 
 heightened by alternately admitting hot and cold water into 
 the water box, the precise mode of operating varying somewhat 
 according as paraffin scale of relatively low melting point is used, 
 or harder paraffin (cerasin, ozokerite, &c.) of higher melting point, 
 witli or without the addition of a few per cents, of stearic acid, 
 either for the purpose of serving as vehicle for colour (p. 405), or 
 to prevent the tendency to soften and bend often shown by pure 
 paraffin candles, even at temperatures considerably below the 
 
 26 
 
402 
 
 OILS, FATS, WAXES, ETC. 
 
 fusing point. In some cases, where mixed materials are used 
 with stearine in larger quantity, intermediate temperatures are 
 employed for the water box. In Britain, paraffin candles have 
 largely driven fatty acid candles out of the market on account of 
 their greater cheapness, but this is not so much the case on the 
 Continent. 
 
 Moulded tallow candles were formerly somewhat largely 
 employed, but latterly have mostly gone out of use along with 
 dips on account of the objections to glycerides as combustible 
 matter (p. 394). The same remark also largely applies to 
 " composites," or mixtures of free fatty acids and glycerides, 
 except for night lights (p. 406). 
 
 Spermaceti candles are usually moulded in much the same 
 way as paraffin wax candles, the material being heated above its 
 melting point and run into hot moulds, which are then rapidly 
 chilled by means of cold water. During the latter part of the 
 last century and the earlier portion of the present one they were 
 in some considerable amount of use by the wealthier classes ; 
 but like wax candles, their use is but small nowadays as com- 
 pared with candles of "stearine" and paraffin wax. With 
 properly adjusted wicks they burn with considerable regularity 
 and brightness, and are accordingly selected as the practical 
 standard for photometric observations ; a " standard candle ; ' 
 being one burning 120 grains of spermaceti per hour. 
 
 For certain special forms of candle particular modifications of 
 the moulding machine are requisite ; thus stearine 
 candles, especially on the Continent, are often cast 
 with longitudinal internal spaces or tubes, which 
 tend to prevent " guttering " whilst burning. 
 Spiral exteriors are also much in favour; formerly 
 these were made by lathing cylindrical candles 
 cast in the ordinary moulds ; but in the more 
 recent machines the pistons are made to ascend 
 by a screw motion, the moulds themselves being 
 correspondingly grooved, so that the candles are 
 screwed out of the moulds. For " self-fitting " 
 butt ends (Fig. 103), where the thickest portion 
 of the conical part is of greater diameter than the 
 rest of the candle, the frame above described 
 requires modification. Fig. 104 represents a 
 machine for moulding self-fitting butt end candles, 
 constructed by E. Cowles, of Hounslow, where the 
 butts are shaped by a separate series of moulds 
 fitting on the top of the cylindrical moulds, and ultimately lifted 
 off from the conical candle ends by means of the chain, the candles 
 being then raised by the piston and held in removable nipping 
 frames in the usual way. This arrangement does not permit of the 
 wick being run continuously ; after each batch of candles is cast 
 
 Fi<r. 103. 
 
SELF-PITTING BUTT ENDS. 
 
 403 
 
404 
 
 OILS, FATS, WAXES, ETC. 
 
 the wicks must bo severed, and after removal of the nipping 
 frames and candles the butt mould lowered into position ; each 
 wick is then hooked up through its appropriate butt mould and 
 clamped centrally in the axis of the mould so as to be ready for 
 the next casting. This involves much trouble and delay, besides 
 causing the waste of a short length of wick at each candle end. 
 
 These objections are obviated by making the butt end moulds 
 in two halves, separable from one another at will, so as to permit 
 of the candles rising upwards when the half-moulds are apart, but 
 tightly closing together and fitting accurately on the tops of the 
 piston moulds when required ; the opening and shutting is simply 
 effected by the motion to or fro of a separate handle. When the 
 moulds are closed, the melted candle material is poured in ; after 
 
TINTED CANDLES. 
 
 405 
 
 setting, this handle is moved back so as to open the butt moulds ; 
 the main handle actuating the pistons is then moved so as to 
 raise the candles into the nipping frame ; the pistons are then 
 lowered, the butt moulds closed, and a new casting proceeded 
 with. 
 
 Fig. 105 represents a "turnover" machine, swinging on trun- 
 nions, so that when a hard candle material has been run into 
 the moulds and has partly solidified round the sides, the machine 
 can be tipped over so as to allow the still liquid portion of the 
 material in the centre of the moulds to run out, thus leaving 
 hollow candles which are then filled in with softer material; 
 candles of comparatively easily fusible substance can thus be 
 prepared with an outer casing of less fusible material which pre- 
 vents the guttering that would otherwise occur. 
 
 Stearine candles are comparatively seldom tinted, being gener- 
 
 Fig. 106.' 
 
 ally burnt uncoloured ; sometimes, however, they are tinted 
 yellowish with gamboge, &c. For tinted paraffin candles, how- 
 ever, a considerable demand exists. Formerly the candle 
 material was coloured by incorporating a small quantity of very 
 finely ground pigment ; but this is now never done if it can be 
 avoided, as the wick almost invariably becomes clogged after 
 burning a short time, so that a smoky less luminous flame 
 results. Coaltar dyestutf's are generally preferred, as far as pos- 
 sible free from fixed mineral constituents ; in many cases these 
 will not dissolve in pure paraffin wax; but by dissolving them 
 in fused stearic acid, and incorporating a little of the solution 
 with the melted paraffin, the latter can usually be readily tinted 
 any required depth of shade. 
 
 In the case of stearine and wax candles, and sometimes with 
 other varieties also, an extra degree of gloss and polish is some- 
 
406 OILS, FATS, WAXES, ETC. 
 
 times given to the surface by rubbing and rolling them by hand 
 or between cloth-covered rollers, &c. ; several machines have 
 been constructed for this purpose. Fig. 106 indicates a simple 
 arrangement where the candles are gradually passed out of the 
 tray, A (by means of the grooved roller, B) on to the endless 
 cloth, E D E D, and rolled between the cloth-covered rollers, 
 G G G, and the cloth ; the latter moves in such a direction as to 
 carry the candles forward towards the tray, H, whilst the rollers, 
 G G G, revolve in a contrary direction so as to rub and polish 
 the surfaces of the candles. A small circular saw, G, trims the 
 bases of the candles as they emerge from the tray, A. Paraffin 
 candles as a rule are sufficiently smooth and glossy when properly 
 moulded without any additional polishing. 
 
 Nigh.tligh.ts. The use of " mortars," or mortuary candles, for 
 burning in death chambers, etc., is very ancient, w T ax tapers being 
 the form usually employed until comparatively recently, when 
 the use of short stumpy candles of peculiar composition and 
 construction became general for burning at night under such 
 circumstances that whilst only a feeble illumination is requisite, 
 the flame is required to burn steadily and constantly for a number 
 < >f hours together. 
 
 Two different forms of " iiightlights " are now chiefly employed, 
 one set in a case of paper, wood-shaving, or similar material, 
 sufficiently fluid-tight to prevent the melted combustible material 
 from running out ; the other cast into shape without any such 
 covering. The wick in each case is generally supported at the 
 base by a " sustainer," consisting either of a little metal disc with 
 ;i small central perforation through which the wick passes, or a 
 similar small plaster of Paris plate, &c., the object being to 
 prevent the wick from falling over when the light has nearly 
 burnt out so that little or no solid grease is left to support the 
 wick. The nature of the materials burnt varies considerably ; 
 for encased nightlights substances are generally chosen the fusing 
 points of which are not extremely high, so that the cost is less ; 
 while for nightlights of the "pyramid" kind without cases, 
 substances of comparatively high melting points are preferable. 
 
 Different manufacturers vary considerably in the way in which 
 their nightlights are prepared. Tn some instances the pasteboard 
 or wooden case is simply filled up with melted candle material 
 from a can after the bit of wick and "sustainer" are fixed in 
 position by means of a drop of melted grease applied after the 
 wick has been passed upwards through a minute hole in the 
 bottom of the box : such nightlights are generally placed in a 
 saucer of water when burnt. Others are moulded round the 
 wicks in much the same fashion as ordinary longer candles ; whilst 
 others are cast as solid cylinders of fatty matter, through the 
 centre of which a hole is perforated; the wick previously threaded 
 on a little bit of tinfoil, is passed upwards through the perforation, 
 
N1GHTLIGHTS. 407 
 
 and fixed in position sufficiently securely by a blow carefully given 
 with a peculiar kind of hammer : these are generally burnt in 
 glass dishes without water. Palmitic acid from palm oil, highly 
 pressed coker stearine, and pressed tallow are the materials most 
 frequently employed as combustible matter ; wicks of rush pith 
 peeled so that two small strips of peel are left adherent on oppo- 
 site sides are used for some, the effect of the strips being to turn 
 outwards in burning, giving a well-shaped flame. 
 
 Spills for lighting candles, &c., are generally drawn by much 
 the same process as that above described for thin wax tapers 
 (p. 389), the wicks being wound on a drum after passing through 
 the melted composition and a suitable sized drawplate. After 
 cutting to length the ends are "feathered'"' by dipping into hot 
 water so as to melt half an inch or so of composition and giving 
 n vigorous shake or jerk which dislodges most of the melted 
 materials, slightly separating the strands in so doing. 
 
 Medicated Candles. For the purpose of impregnating the 
 air of sickrooms, &c., with disinfecting vapours, certain substances 
 are sometimes intermixed with the candle material e.g., iodine 
 and eucalyptus oil. In the latter case the effect is produced by 
 the volatilisation of eucalyptol from the hot cup of melted grease 
 at the base of the wick, that portion which is burnt in the flame 
 being ineffective ; with iodine, the free element is evolved from 
 the flame itself, hydriodic acid, if formed, being largely decom- 
 posed again by the heat. Sulphur * has been used in similar 
 fashion, sulphur dioxide being formed on combustion. 
 
 " :: A spirit lamp charged with a mixture of alcohol and carbon disulphide 
 affords a convenient means of producing sulphur dioxide for disinfecting 
 chambers, &c. 
 
408 OILS, FATS, WAXES, ETC. 
 
 7. The Soap Industry. 
 
 CHAPTER XVIII. 
 MATERIALS USED IN THE MANUFACTURE OF SOAP. 
 
 FATTY MATTERS AND ALKALIES. 
 
 THE raw fatty materials employed in any large quantities for 
 the manufacture of ordinary household soaps and those used for 
 technical purposes, such as wool - scouring, &c., are far less 
 numerous than the different varieties of oleaginous matters 
 used for culinary, edible, and miscellaneous purposes through- 
 out the world in different countries ; but almost every day 
 new sources of oily and fatty matters from abroad are brought 
 to light, many of which only require suitable development to 
 furnish excellent material for soapmaking as well as for more 
 superfine uses. 
 
 The leading substances of animal origin in largest use for soap- 
 making are the fats of the sheep and ox (tallow), horse grease, 
 damaged hog's lard, kitchen grease, and similar materials derived 
 from trade refuse of different kinds (such as tannery, bone- 
 boiling and gluemaking greases), together with seal and whale 
 oils, cod and shark liver oils, fish oils of various kinds, and 
 such like materials, including sewage grease, egg yolks, and 
 greases recovered from soapsuds, wool washing, engine waste 
 cleansing, &c. Amongst the more prominent materials of vege- 
 table origin may be mentioned the oils and butters derived from 
 olives ; cotton, sesame, sunflower, rape, and linseeds ; arachis 
 and cokernuts ; palm fruits and kernels ; niger and poppy seeds ; 
 castor beans and almonds ; and in lesser degree a large variety of 
 analogous substances, mostly either the " foots ; ' formed during 
 refining (p. 261), or the interior qualities obtained as the last 
 hot pressings, or by treatment with carbon di sulphide and similar 
 solvents, of the partially exhausted mass from which oils of finer 
 quality, suitable for superior applications, have been previously 
 expressed or otherwise obtained ; it being a sort of general 
 
ALKALIES. 409 
 
 axiom that any kind of greasy or oleaginous matter can be made 
 into soap of a more or less useful and valuable character, even 
 when fit for no other applications, the coarsest kind of cart grease 
 and such like rough lubricants alone excepted. 
 
 A certain amount of higher priced soaps (toilet and special 
 varieties) is also prepared from less coarse fatty matters, in some 
 instances from materials of the finest qualities ; but the quantity 
 of these superior grades made bears only a small proportion to 
 the total amount of ordinary coarser soaps manufactured for 
 scouring and laundry purposes (vide Chap, xx.) 
 
 Alkalies. The term alkali is usually traced to the Arabic 
 Al kali, a name applied to a particular plant (a kind of " glass- 
 wort "), the ashes of which abound in potash, and have conse- 
 quently been used from the earliest ages, not only for the manu- 
 facture of glass (whence the English trivial name), but also for 
 laundry and detergent purposes generally. The term " potash," 
 indeed, connotes much the same idea, being originally applied to 
 the soluble part of woodashes dissolved out by water and re- 
 covered by boiling down the solution in a pot ; pearlash being 
 the same material subjected to further purification so as to 
 whiten it. Even at the present d^y crude ashes from vegetable 
 combustibles are often used as a detergent without purification, 
 the earthy and calcareous insoluble matters present serving 
 rather to aid scouring purposes ] thus, cigar ash furnishes a 
 very effective dentifrice.* 
 
 The difference in character (from the soap boiler's point of 
 view) between the alkali contained in the ashes of inland vege- 
 tation (potash) and that present in marine plant ash (soda), 
 appears to have been known to a considerable extent to the 
 alchemists of the earlier and middle ages of the Christian era ; 
 although the essential chemical differences between the two, and 
 the practical identity of the latter with the mineral product 
 natron, were probably not so clearly understood. The effect of 
 treatment with quicklime so as to render " mild alkali " (car- 
 bonate) "quick" or "caustic," and the superior action of the 
 quickened product on oleaginous matters, so as to form soap, 
 were also more or less imperfectly known to them. At the pre- 
 sent day the alkalies used in soapmaking are generally (though 
 not invariably) used in the caustic condition because of this more 
 rapid action ; but saponification can be effected by carbonated 
 alkalies if sufficient time be allowed, or if the action be acceler- 
 ated by increased heat and pressure. In all probability the 
 action of an alkaline carbonate essentially consists in the forma- 
 
 * A few years ago an ancient tomb was duo; up in Rome ; a quantity of 
 what appeared to be ashes were found therein, which were appropriated 
 by one of the workmen for his wife to use in washing. It subsequently 
 transpired that the ashes were the remains of the Emperor Galba, who was 
 cremated some eighteen centuries ago (Time*). 
 
410 OILS, FATS, WAXES, ETC. 
 
 tion of soap and bicarbonate ; thus with stearin and sodium 
 carbonate 
 
 Stearin. Sodium Carbonate. Water. Glycerol. 
 
 C 3 H 5 (C 18 H 35 2 )3 + 3Na a C0 3 + 3H,0 C 3 H 5 (OH) 3 
 
 Sodium Stearate. Sodium Bicarbonate. 
 
 + 3Na(C ]8 H 35 O 2 ) + 3NaHCO 3 . 
 
 Under the influence of heat the bicarbonate breaks up into 
 carbon dioxide, water, and neutral carbonate, which last then 
 reacts as before 
 
 Sodium Bicarbonate. Sodium Carbonate. Carbon Dioxide. Water. 
 
 2NaHC0 3 Na 2 C0 3 + C0 2 + H 2 0. 
 
 Ammonia usually exerts a considerably less; energetic saponi- 
 fying action on most kinds of fatty matters than the fixed 
 .alkalies ; whilst lime, magnesia, zinc oxide, lead oxide, and 
 .similar materials, although useful in the preparation of earth}' 
 and metallic soaps for other purposes (candlemaking, preparation 
 of lead plasters, tfec.), are not used in the direct manufacture 
 of ordinary soaps ; excepting in so far as small quantities of lime, 
 iron, and other metallic soaps are often present therein as im- 
 purities derived from the water or the materials and utensils 
 used, &c. 
 
 Formerly the manufacture of alkali, especially soda, was very 
 frequently conjoined with that of soap ; but of late years it has 
 become more usual to dissever the two trades, the soapboiler 
 purchasing either caustic or carbonated alkali from the alkali 
 manufacturer instead of preparing it himself. At one time the 
 chief source of potash was the ashes of terrestrial vegetation 
 /whence the term " vegetable alkali ") ; but mineral potassium 
 chloride (chiefly from the Stassfurth deposits) is now largely 
 employed as raw material, being converted into potassium 
 carbonate by the Leblanc process.* Similarly, in the earliest 
 ages, soda (natron) was derived from saline efflorescences on the 
 soil, whence the term " mineral alkali ;" subsequently, the ashes 
 of seaweeds and marine plants furnished a cheaper source known 
 as "barilla;" whilst latterly, soda produced by the method of 
 Leblanc, or by the more recent "ammonia process" for converting 
 rocksalt into sodium carbonate, has mostly superseded all other 
 kinds. By either of these processes, "soda ash" (more or less 
 impure anhydrous sodium carbonate) and "caustic soda" (sodium 
 hydroxide) are prepared in the solid state, the latter being 
 usually put up in airtight iron drums for transport and preserva- 
 tion ; when caustic liquors of a given strength are requisite, they 
 
 * Conversion into sulphate by treatment with sulphuric acid, and subse- 
 quent heating of the sulphate with small coal and calcium carbonate, so as 
 to form alkaline carbonate and calcium sulphide (as "black ash"), separated 
 by dissolving out the former by means of water. 
 
CAUSTICI8IN6 PROCESS. 411 
 
 are readily prepared by simply dissolving a known weight of the 
 solid caustic soda in a given volume of water, and are then ready 
 for use. When, however, sodium carbonate or potassium 
 carbonate is bought, before caustic leys suitable for soap boiling 
 can be obtained, the operation of " causticising " must be gone 
 through, consisting in dissolving the carbonated alkali in water, 
 adding lime, and boiling up with agitation so that the calcium 
 hydroxide and alkaline carbonate may react on one another in 
 accordance with the equations 
 
 Sodium Carbonate. Slaked Lime. Caustic Soda. Calcium Carbonate. 
 
 + CaHA = . 2NaOH + CaC0 
 
 Potassium Carbonate. Calcium Hydroxide. Potassium Hydroxide. Calcium Carbonate. 
 
 K._,CO, + CaFLO, 2KOH + CaC0 3 
 
 Causticising Process. Tii the earlier days of soapmaking 
 the causticising of the alkalies employed was generally effected 
 in the cold ; a purer ley being thus obtained from crude " ashes " 
 (rough potashes and "black ash") than when the whole was 
 boiled up together, and then allowed to settle. At the present 
 <lay this method of treatment is but seldom employed in this 
 country, although still in use on the Continent. In order to 
 carry it out to the best advantage the bottom of the vat is 
 covered with lumps of quicklime, over which water is thrown to 
 slake it ; 5 parts of soda ash * for every 6 of quicklime originally 
 used are then shovelled in on the top as uniformly as possible. 
 Another layer of lime is then added, and a second of soda ash, 
 equal in weight to the lime ; then a third layer of lime, and a 
 third of soda ash, equal to the second layers. Water, or weak 
 runnings from a previous batch, is then gradually run on, and 
 the whole allowed to stand till next day, when the caustic soda 
 ley formed is run off through a cock at the base of the vat into 
 <i settling tank. More water is then added and allowed to stand 
 as before, and finally run off, giving a much weaker liquor either 
 mixed with the first, or used for lixiviating another batch. The 
 lime mud is then stirred up with more water, and the final weak 
 liquor thus obtained used to work a new batch. Conveniently 
 three (or even four) vats are worked in series, exactly like black 
 ash lixiviating tanks; the second liquor from No. 2 is passed 
 through No. 1, coming out of full strength, being itself obtained 
 as the third liquor from No. 3, which is then exhausted. No. 3, 
 being refilled, then becomes No. 1 of a new series ; the former 
 No. 1 becomes the second; and so on, methodically. Crude 
 Leblanc soda liquors are much less frequently used now than 
 
 * Theoretically, 106 parts of Na 2 C0 3 are equivalent to 56 parts of CaO ; 
 a considerable excess of lime, however, is requisite to ensure causticising 
 in the cold. For steam boiling in practice 200 parts of soda ash are used 
 per 100 of quicklime. 
 
412 
 
 OILS, FATS, WAXES, ETC. 
 
 was the case before the ammonia soda process had made much 
 headway ; when carbonated alkali, free from sulphide, is treated 
 (as when ammonia soda ash is employed, or Leblanc soda ash 
 prepared from the " salts " that separate on evaporating the crude 
 liquors obtained on lixiviating black ash), the plant used consists 
 simply of some form of steam vessel, such as an old boiler, pro- 
 vided with an efficient agitator ; lumps of quicklime are added 
 (preferably placed on a grating or enclosed in a sort of cage to 
 keep back hard lumps and stones when the lime disintegrates by 
 slaking), and the whole boiled up for one or more hours until 
 the operation is complete, either under pressure in a closed vessel 
 (whereby a considerable saving of fuel and labour is effected), 
 or by means of wet steam in an open pan. If, on the other 
 hand, crude black ash liquors be used (impure sodium carbonate, 
 tfec., dissolved out from black ash by water, containing sulphide 
 owing to the reaction of sodium carbonate" solution on calcium 
 sulphide), or the " red liquors " obtained as mother liquors when 
 the crude black ash liquor is evaporated until " salts " (mostly 
 sodium carbonate) crystallise out during evaporation, the causti- 
 cising action of lime is conveniently conjoined with the oxidising 
 action of a current of air blown into the fluid for the purpose of 
 destroying sulphide by conversion into thiosulphate, sulphite, 
 and sulphate ; for which purpose a vessel is employed provided 
 at the base with a large rose jet or spiral tube pierced with 
 holes, or a perforated false bottom, through which the air and 
 steam are blown in together so as to keep the whole in agita- 
 tion and effect the causticising and oxidation simultaneously. 
 Finally, the whole is allowed to stand at rest awhile, so that 
 the " lime mud " (calcium carbonate, c.) may settle, and the 
 clear caustic alkali solution run off or pumped into tanks for 
 storage. These are generally made of boiler plate rivetted 
 together (Fig. 107). When intended to hold ley for toilet soap, 
 
 Dussauce recommends that they 
 should be lined with sheet lead to 
 prevent possible discoloration of 
 soap through contact of the ley 
 with iron. 
 
 In order to causticise the car- 
 bonate thoroughly an excess of 
 lime is desirable ; the remaining 
 caustic lime in the lime mud, if 
 of sufficient quantity to be worth 
 saving, may be utilised by boiling 
 up again with a fresh batch of 
 carbonated liquors ; after allowing 
 
 Fig. 107. 
 
 to settle, the clear liquor is pumped off to another pan, 
 where the causticising is finished with another batch of fresh 
 lime, the mud from which operation is again boiled up with 
 
CAUSTICISING PROCESS. 413 
 
 fresh carbonated liquor, and so on continuously alternately. The 
 lime mud resulting from the second treatment with carbonated 
 liquors usually contains too little caustic lime to be worth using 
 a third time ; but by boiling up with water the adhering soda 
 solution is mostly washed out, and a weak ley obtained, utilised 
 either to dissolve more carbonated alkali, or for other purposes 
 in the factory.* 
 
 To ciusticise sodium carbonate solution thoroughly, the liquor 
 must not be too strong, otherwise a considerable portion of the 
 alkaline carbonate escapes the causticising action of the lime ; on 
 the other hand, when the leys are made too weak, the quantity of 
 salt subsequently requisite for " salting out " the soap (Chap, xx.) 
 is increased. When the open pan system is adopted, a sufficiently 
 complete degree of causticising is generally effected by using 
 liquors of such strengths that the ley finally obtained has a 
 specific gravity not exceeding about 1-075 to I'lO (15 to 20 Tw.), 
 although slightly higher strengths, up to specific gravity I'll or 
 1'125 (22 to 25 Tw.), are sometimes made; by causticising 
 under pressure, considerably stronger leys may be effectively 
 prepared, provided that the subsidence of the lime mud and the 
 running off of the clear ley is still effected under the same 
 pressure ; thus, with a pressure of 50 Ibs. per square inch, caustic 
 leys up to specific gravity 1-16 to 1'20 (32 to 40 Tw.) may be 
 readily prepared, provided this precaution is adopted ; otherwise 
 the reverse action goes on, caustic soda reacting on calcium 
 carbonate so as to reproduce sodium carbonate (Parnell). When 
 more concentrated leys are required, they are obtained by 
 quickly boiling down with as little access of air as possible ; 
 weaker leys are got by diluting stronger ones with water, or 
 with the very weak liquors obtained by " washing " the lime 
 mud left after running off the caustic liquor i.e., by adding 
 water to the mud, boiling up, allowing to settle, running off 
 the weak ley thus obtained, and repeating the operation so as to 
 obtain another batch of still weaker washings. The storage 
 tanks in which the caustic leys are kept should be well closed to 
 prevent absorption of carbonic acid from the air ; this is some- 
 times done by pouring a layer of paraffin oil or melted paraffin 
 wax on the ley, of course taking the requisite precautions to 
 avoid any hydrocarbon being drawn off with the ley used for 
 making soap ; when properly prepared, no visible disengagement 
 of bubbles of gas should be noticeable on adding sufficient hydro- 
 
 * The lime mud finally obtained from soda leys usually retains a notable 
 proportion of sodiiim carbonate in a form insoluble in water, chiefly as a 
 double carbonate of calcium and sodium. This may be regained in Leblanc 
 alkali works by drying and using the impure calcium carbonate obtained 
 over again in the black ash operation ; but in an ordinary soap work, 
 where the residual lime mud is little better than a waste product, the soda 
 thus retained in the lime mud is usually lost. 
 
414 OILS, FATS, WAXES, ETC. 
 
 chloric or other mineral acid to supersaturate the alkali ; this 
 serves as a test of completion during the causticising process. 
 In order to know what quantity of alkali is used for a given 
 operation, the tanks are fitted with gauges ; so that if the level 
 is reduced by a given number of inches, for instance, it is known 
 that so many gallons of fluid have been run off ; the alkaline 
 strength of the fluid being known, the total weight of alkali 
 present in the fluid run off is then known. In general it is 
 more convenient to arrange the ley tanks at an elevation (in 
 the upper part of the factory) so as to run off the leys by 
 gravitation, than to have them in the basenient and pump 
 up the leys to the coppers, although this latter arrangement 
 economises space. 
 
 Valuation of Alkalinity of Leys. In order to determine 
 the alkaline strength of soap leys with absolute accuracy, a 
 volumetric assay with a standard acid solution must be employed ; 
 but for general soapmaking purposes, the specific gravity of the 
 solution is a sufficiently near indication. It should be borne in 
 mind, however, that the specific gravity is only to be trusted as 
 an indication of alkalinity in cases where the character of the 
 liquor is always sensibly the same i.e., where the proportion of 
 saline matters other than caustic alkali (sodium or potassium 
 chloride, sulphate, &c.) does not vary much. This is usually the 
 case when soda ash, <fec., of a tolerably uniform quality is always 
 employed ; but when different grades are used at different times, 
 leys may easily be obtained of considerably different alkaline 
 strengths although of the same specific gravity. Thus, if soda 
 ash be used, made by the ammonia process and containing say 
 56 per cent, of " anhydrous soda " (Na O = 62), equivalent to- 
 about 96 per cent, of anhydrous sodium carbonate, Na 2 CO 3 , a ley 
 having a given specific gravity (say 1-075) at the ordinary 
 temperature will be notably stronger in alkali, bulk for bulk, 
 than a similar ley prepared from Leblanc soda of say 52 per cent., 
 equivalent to about 89 per cent, of anhydrous carbonate, because 
 the latter contains a larger proportion of sodium salts (chloride, 
 sulphate, &c.), which increase the relative density of the liquor 
 without adding to its alkaline strength. A fortiori, if a "48 per 
 cent, soda ash " (i.e., an ash containing alkali equivalent to 
 only 48 per cent, of Na.,O, equivalent to about 82 per cent, of 
 Na 2 CO 3 ) be used, the alkaline strength of the ley will be lower 
 still for the same specific gravity, since, in order to reduce the 
 alkalinity of the ash to "48 degrees" (48 per cent. Ka 2 O), an 
 extra amount of some diluting agent (usually salt) must be 
 added. Similar remarks obviously apply to potash leys made 
 from potash of different grades, and to caustic soda leys made 
 by directly dissolving solid caustic soda in water; the ley 
 from a " 70 per cent, caustic " (containing 70 per cent. 
 = about 90 per cent. NaOH) will usually be stronger, 
 
ALKALINITY OP LEYS. 
 
 415 
 
 bulk for bulk, at a given specific gravity than that from a 
 " 60 per cent, caustic " (containing 60 per cent. Na 2 O = about 
 77 per cent. NaOH), except in so far as the difference in 
 strength between the two kinds of caustic is due simply to water, 
 and not to saline matters, such as sulphate and chloride. 
 
 The following tables exhibit the relationships between the 
 alkaline strengths of pure solutions of sodium and potassium 
 hydroxides and carbonates, and their respective specific gravities, 
 at the ordinary temperature (15 C.), or at more elevated tem- 
 peratures : 
 
 * 
 SPECIFIC GRAVITV OF CAUSTIC SODA SOLUTION AT 15 (Tunnermanri). 
 
 Specific Gravity. 
 
 Per Cent, of Na 2 O 
 
 Specific Gravity. 
 
 Per Cent, of Na 2 0. 
 
 1-42S5 
 
 30-22 
 
 1 -2392 
 
 15-11 
 
 1-4193 
 
 29-62 
 
 2280 
 
 14-50 
 
 1-4101 
 
 29-01 
 
 2178 
 
 13-90 
 
 1-4011 
 
 28-41 
 
 2058 
 
 13-30 
 
 1-3923 
 
 27-80 
 
 1948 
 
 12-69 
 
 1-383G 
 
 27-20 
 
 1841 
 
 12-09 
 
 1-3751 
 
 26-59 
 
 1734 
 
 11-48 
 
 1-3668 
 
 25-99 
 
 1-1630 
 
 10-88 
 
 1 -3580 
 
 25-39 
 
 1-1528 
 
 10-28 - 
 
 1 -3505 
 
 24-78 
 
 1-1428 
 
 9-67 
 
 1-3426 
 
 24-18 
 
 1-1330 
 
 9-07 
 
 1-3349 
 
 23-57 
 
 1-1233 
 
 8-46 
 
 1-3273 
 
 22-97 
 
 1-1137 
 
 7-86 
 
 1-3198 
 
 22-36 
 
 -1-1042 
 
 7-25 
 
 1 -3143 
 
 21-89 
 
 1-0948 
 
 6-65 
 
 1-3125 
 
 21-76 
 
 1-0855 
 
 6-04 
 
 1-3053 
 
 21-15 
 
 10764 
 
 5-44 
 
 1 -2982 
 
 20-55 
 
 1-0675 
 
 4-84 
 
 1 -2912 
 
 19-95 
 
 1-0587 
 
 4-23 
 
 1 -2843 
 
 19-34 
 
 1-0500 
 
 3-63 
 
 1 -2775 
 
 18-73 
 
 1-0414 
 
 3-02 
 
 1-2708 
 
 18-13 
 
 1 -0330 
 
 2-42 
 
 1-2642 
 
 17-53 
 
 1-0246 
 
 1-81 
 
 1-2578 
 
 16-92 
 
 1-0163 
 
 1-21 
 
 1-2515 
 
 16-38 
 
 1 -0081 
 
 1-60 
 
 1-2453 
 
 15-71 
 
 1 -0040 
 
 1 30 
 
416 
 
 OILS, FATS, WAXES, ETC. 
 
 SPECIFIC GRAVITY OF CAUSTIC SODA SOLUTION AT 15 
 (Lunge and Hurter). 
 
 Specific Gravity. 
 
 Grammes of Na 2 
 per Litre. 
 
 Specific Gravity. 
 
 Grammes of Na 2 
 per Litre. 
 
 1-005 
 
 3-7 
 
 1-260 
 
 228-9 
 
 1-010 
 
 7'5 
 
 1 270 
 
 240-0 
 
 1-020 
 
 15 1 
 
 1-280 
 
 251-0 
 
 1 -030 
 
 22-6 
 
 1 -290 
 
 252-1 
 
 1-040 
 
 30-2 
 
 300 
 
 273-2 
 
 1 -050 
 
 377 
 
 310 
 
 285-4 
 
 1-060 
 
 45-5 
 
 320 
 
 297-7 
 
 1-070 
 
 53-2 
 
 330 
 
 309-9 
 
 1-080 
 
 61-0 
 
 340 
 
 322-2 
 
 1-090 
 
 68-8 
 
 350 
 
 334-4 
 
 1-100 
 
 76-5 
 
 360 
 
 347-2 
 
 1-110 
 
 84-3 
 
 370 
 
 360-1 
 
 1-120 
 
 92 -1 
 
 380 . 
 
 372-9 
 
 1-130 
 
 100-5 
 
 390 
 
 385-7 
 
 1-140 
 
 109-6 
 
 400 
 
 398-5 
 
 1-150 
 
 118-6 
 
 410 
 
 411-8 
 
 1-1(50 
 
 1277 
 
 420 
 
 4250 
 
 1-170 
 
 136-8 
 
 430 
 
 438-2 
 
 1-180 
 
 145-8 
 
 440 
 
 451-4 
 
 1-190 
 
 154-9 
 
 450 
 
 464-6 
 
 1-200 
 
 l'J4-0 
 
 460 
 
 479-9 
 
 1-210 
 
 174-7 
 
 470 
 
 495-3 
 
 1-220 
 
 185-5 
 
 480 
 
 510-6 
 
 1 -230 
 
 196-3 
 
 490 
 
 525-9 
 
 1-240 
 
 207-0 
 
 500 
 
 541-2 
 
 1-250 
 
 217-8 
 
 
 
 INFLUENCE OF TEMPERATURE ox THE SPECIFIC GRAVITY OF 
 CAUSTIC SODA SOLUTION. 
 
 Temperature. 
 
 Specific Gravity. 
 
 Degrees C. 
 
 
 
 
 
 
 
 
 1-015 
 
 1-030 
 
 1-060! 1-100 
 
 150 
 
 1-200 
 
 1-250 
 
 1 -320 
 
 370 
 
 10 
 
 1-012 
 
 1-027 
 
 1-057 1 1-097 
 
 146 
 
 1-195 
 
 1-245 
 
 1315 
 
 365 
 
 20 
 
 1-009 
 
 1-024 
 
 1 054' 1-093 
 
 142 
 
 1-190 
 
 1-240 
 
 1 -310 
 
 360 
 
 30 
 
 1 -007 
 
 1-022 
 
 1-052 1-091 -138 
 
 1-186 
 
 1-235 
 
 1 -305 
 
 355 
 
 40 
 
 1 003 
 
 1-018 
 
 1-048 1-087 -136 
 
 1-181 
 
 1 -231 
 
 1-299 
 
 350 
 
 50 
 
 0-999 
 
 1-014 
 
 1-044 1-082 -129 
 
 1-177 
 
 1-226 
 
 1-294 
 
 345 
 
 60 
 
 994 
 
 1-009 
 
 1-039 1-077 '124 
 
 1-173 
 
 1-221 
 
 1-288 
 
 339 
 
 70 
 
 988 ! 1 -003 
 
 1-033 1-071 
 
 118 
 
 1-168 
 
 1-216 
 
 1 '283 1 1 -334 
 
 80 
 
 982 
 
 997 
 
 1-027 1-065 
 
 1-112 
 
 1-162 
 
 1-211 
 
 1-277 
 
 1-329 
 
 90 
 
 977 
 
 992 
 
 1-022 [ 1-059 
 
 1-107 
 
 1-156 
 
 1-206 
 
 1-271 
 
 1-324 
 
 100 
 
 971 
 
 986 
 
 1-016 1-053 
 
 1 101 
 
 1-151 
 
 1-200 
 
 1-265 
 
 1-319 
 
ALKALINITY OF LEYS. 
 
 417 
 
 SPECIFIC GRAVITY OF CAUSTIC POTASH SOLUTION AT 15 (Tunnermann). 
 
 
 Percentage of 
 
 
 Percentage of 
 
 Specific 
 
 
 SpeciSc 
 
 
 Gravity. 
 
 KHO. 
 
 K 3 0. 
 
 Gravity. 
 
 KHO. 
 
 K 2 0. 
 
 1-3300 
 
 33-69 
 
 28-29 
 
 1-1437 
 
 16-85 
 
 14-15 
 
 1 -3131 
 
 32-35 
 
 27-16 
 
 1-1308 
 
 15-50 
 
 13-01 
 
 1-2966 
 
 31-00 
 
 26-03 
 
 1-1182 
 
 14-15 
 
 11-88 
 
 T2805 
 
 29-65 
 
 2490 
 
 1-1059 
 
 12-80 
 
 10-75 
 
 1-2648 
 
 28-30 
 
 2376 
 
 1-0938 
 
 11-46 
 
 9-62 
 
 1-2493 
 
 26-95 
 
 22-63 
 
 1-0819 
 
 10-11 
 
 8-49 
 
 1-2342 
 
 25-61 
 
 21-50 
 
 1-0703 
 
 8-76 
 
 7-36 
 
 1-2268 
 
 24-93 
 
 20-94 
 
 1-0589 
 
 7-41 
 
 6-22 
 
 1-2122 
 
 23-59 
 
 19-80 
 
 1 -0478 
 
 5-96 
 
 5-00 
 
 1-1979 
 
 22-24 
 
 18-67 
 
 1 -0369 
 
 4-72 
 
 3-96 
 
 1-1839 
 
 20-89 
 
 17-54 
 
 1 -0260 
 
 3-67 
 
 2-83 
 
 1-1702 
 
 19-54 
 
 16-41 
 
 1-0153 
 
 2-02 
 
 1-70 
 
 1-1568 
 
 18-20 
 
 15-28 
 
 1 -0050 
 
 0-674 
 
 0-566 
 
 SPECIFIC GRAVITY OF CAUSTIC POTASH SOLUTION AT 15. 
 (Lunge and Hurter). 
 
 
 Grammes per Litre. 
 
 
 Grammes per Litre. 
 
 Specific 
 Gravity. 
 
 
 Specific 
 Gravity. 
 
 
 K 2 0. 
 
 KOH. 
 
 K 2 0. 
 
 KOH. 
 
 1-007 
 
 7 
 
 9 
 
 1-252 
 
 284 
 
 338 
 
 1-014 
 
 14 
 
 17 
 
 1 263 
 
 297 
 
 353 
 
 1-022 
 
 22 
 
 26 
 
 1-274 
 
 308 
 
 368 
 
 1-029 
 
 30 
 
 36 
 
 1-285 
 
 321 
 
 385 
 
 1-037 
 
 39 
 
 46 
 
 1-297 
 
 335 
 
 398 
 
 1-045 
 
 49 
 
 58 
 
 1-308 
 
 349 
 
 416 
 
 1-052 
 
 57 
 
 67 
 
 1-320 
 
 363 
 
 432 
 
 1-060 
 
 66 
 
 78 
 
 1-332 
 
 377 
 
 449 
 
 1-067 
 
 74 
 
 88 
 
 345 
 
 394 
 
 469 
 
 1-075 
 
 83 
 
 99 
 
 357 
 
 410 
 
 487 
 
 1-083 
 
 92 
 
 109 
 
 370 
 
 425 
 
 506 
 
 091 
 
 100 
 
 119 
 
 383 
 
 440 
 
 522 
 
 100 
 
 111 
 
 132 
 
 397 
 
 457 
 
 543 
 
 108 
 
 119 
 
 143 
 
 410 
 
 472 
 
 563 
 
 116 
 
 129 
 
 153 
 
 424 
 
 490 
 
 582 
 
 125 
 
 140 
 
 167 
 
 438 
 
 509 
 
 605 
 
 134 
 
 150 
 
 178 
 
 453 
 
 530 
 
 631 
 
 142 
 
 159 
 
 188 
 
 468 
 
 549 
 
 655 
 
 152 
 
 170 
 
 203 
 
 483 
 
 571 
 
 679 
 
 1-162 
 
 181 
 
 216 
 
 498 
 
 593 
 
 706 
 
 1-171 
 
 192 
 
 228 
 
 514 
 
 615 
 
 731 
 
 1-180 
 
 203 
 
 242 
 
 530 
 
 635 
 
 756 
 
 1-190 
 
 214 
 
 255 
 
 546 
 
 655 
 
 779 
 
 1-200 
 
 226 
 
 269 
 
 563 
 
 681 
 
 811 
 
 1-210 
 
 237 
 
 282 
 
 580 
 
 706 
 
 840 
 
 1-220 
 
 248 
 
 295 
 
 1-597 
 
 731 
 
 870 
 
 1-231 
 
 260 
 
 309 
 
 1-615 
 
 759 
 
 902 
 
 1-241 
 
 272 
 
 324 
 
 1-634 
 
 789 
 
 940 
 
418 
 
 OILS, FATS, WAXES, ETC. 
 
 SPECIFIC GRAVITY AT 15 C. or SODIUM CARBONATE SOLUTION 
 (Lunge and Hurter). 
 
 Specific 
 Gravity. 
 
 Percentage of 
 
 Specific 
 Gravity. 
 
 Percentage of 
 
 Na c O. 
 
 Na 2 C0 3 . 
 
 Na 2 0. 
 
 Na 2 C0 3 . 
 
 1-005 
 
 0-28 
 
 0-47 
 
 1-080 
 
 4-42 
 
 7-57 
 
 1-010 
 
 0-56 
 
 0-95 
 
 T085 
 
 4-70 
 
 8-04 
 
 1-015 
 
 0-84 
 
 1-42 
 
 1-090 
 
 4-97 
 
 8-51 
 
 1-020 
 
 1-11 
 
 1-90 
 
 1-095 
 
 5'24 
 
 8-97 
 
 1-025 
 
 1-39 
 
 2-38 
 
 1-100 
 
 5-52 
 
 9-43 
 
 i 
 
 
 
 
 
 1-030 1-67 
 
 2-85 
 
 1-105 
 
 5-79 
 
 9-90 
 
 1-035 
 
 1-95 
 
 3-33 
 
 1-110 
 
 6-06 
 
 10-37 
 
 1-040 
 
 2'22 
 
 3-80 
 
 1-115 
 
 6-33 
 
 10-83 
 
 1-045 
 
 2-50 
 
 4-28 
 
 1-120 
 
 6-61 
 
 11-30 
 
 
 
 
 
 
 
 1-050 
 
 2-78 
 
 4-76 
 
 1-125 
 
 6-88 
 
 11-76 
 
 1 -055 
 
 3-06 
 
 5-23 
 
 1-130 
 
 7-15 
 
 12-23 
 
 1-060 
 
 3-34 
 
 5-71 
 
 1-135 
 
 7-42 
 
 12-70 
 
 1-065 
 
 3-61 
 
 6-17 
 
 1-140 
 
 770 
 
 13-16 
 
 1-070 
 
 3-88 
 
 6-64 
 
 1-145 
 
 7-97 
 
 13-63 
 
 1-075 
 
 4-16 
 
 7-10 
 
 1-150 
 
 8-24 
 
 14-09 
 
 SPECIFIC GRAVITY AT 30 C. OF CONCENTRATED SODIUM CARBONATE 
 SOLUTION (Lunge and Hurter). 
 
 Specific 
 Gravity. 
 
 Percentage of 
 
 'Specific 
 Gravity. 
 
 Percentage of 
 
 Na 2 0. 
 
 Na 2 C0 3 . 
 
 Na 2 0. 
 
 Na 2 C0 3 . 
 
 1-140 
 
 7-97 
 
 13-62 
 
 1-230 12-48 
 
 21-33 
 
 1-150 
 
 8-46 
 
 14-47 
 
 1-240 
 
 12-98 
 
 22-20 
 
 1-160 
 
 8-96 
 
 15-32 
 
 1-250 
 
 13-49 
 
 23-07 
 
 1-170 
 
 9-46 
 
 16-18 
 
 1-260 
 
 14-00 
 
 23-93 
 
 1-180 
 
 9-96 
 
 17-04 
 
 1-270 
 
 14'49 
 
 24-77 
 
 1-190 
 
 10-46 
 
 17-89 
 
 1-280 
 
 14-98 
 
 25-61 
 
 1-200 
 
 10-97 
 
 18-75 
 
 1-290 
 
 15-47 
 
 26-45 
 
 1-210 
 
 11-47 
 
 19-61 
 
 1-300 
 
 15-96 
 
 27-29 
 
 1-220 
 
 11-97 
 
 20-47 
 
 1-310 
 
 16-45 
 
 28-13 
 
CORRECTION FOR IMPURITIES. 
 
 419 
 
 POTASSIUM CARBONATE (Gerlach). 
 
 Percentage 
 of K 2 C0 3 . 
 
 Specific 
 Gravity at 15. 
 
 Percentage 
 of K 2 C0 3 . 
 
 Specific 
 Gravity at 15. 
 
 Percentage 
 of K 2 C0 3 . 
 
 Specific 
 Gravity at 15. 
 
 1 
 
 1-0091 
 
 19 
 
 1-1827 
 
 37 
 
 1-3828 
 
 2 
 
 1-0183 
 
 20 
 
 1-1929 
 
 38 
 
 1-3948 
 
 I 
 
 1-0274 
 
 21 
 
 1-2034 
 
 39 
 
 1-4067 
 
 4 
 
 1-0366 
 
 22 
 
 1-2140 
 
 40 
 
 1-4187 
 
 5 
 
 1-0457 
 
 23 
 
 1-2246 
 
 41 
 
 1-4310 
 
 6 
 
 1-0551 
 
 24 
 
 1-2352 
 
 42 
 
 1-4434 
 
 7 
 
 1-0645 
 
 25 
 
 1-2458 
 
 43 
 
 1-4557 
 
 8 
 
 1 -0740 
 
 26 
 
 1-2568 
 
 44 
 
 1-4681 
 
 9 
 
 1 -0834 
 
 27 
 
 1-2679 
 
 45 
 
 1 -4804 
 
 10 
 
 1-0928 
 
 28 
 
 1-2789 
 
 46 
 
 1-4931 
 
 11 
 
 1-1026 
 
 29 
 
 1-2900 
 
 47 
 
 1-5059 
 
 12 
 
 1-1124 
 
 30 
 
 3011 
 
 48 
 
 1-5186 
 
 13 
 
 1-1222 
 
 31 
 
 3126 
 
 49 
 
 1-5314 
 
 14 
 
 1-1320 
 
 32 
 
 3242 
 
 50 
 
 1-5441 
 
 15 
 
 1-1418 
 
 33 
 
 3357 
 
 51 
 
 1-5573 
 
 16 
 
 1-1520 
 
 34 
 
 3473 
 
 52 
 
 1-5705 
 
 17 
 
 1-1622 
 
 35 
 
 3589 
 
 52-024 
 
 1-57079 
 
 18 
 
 1-1724 
 
 36 
 
 1-3708 
 
 
 
 The above tables only apply to pure solutions of alkaline car- 
 bonates and hydroxides ; with commercial substances containing 
 other neutral saline matters (chloride, sulphate, &c.) a correction 
 is necessary to allow for the increment in specific gravity brought 
 about by the presence of these impurities without any corre- 
 sponding increase in alkaline strength : the amount of this cor- 
 rection necessarily varies with the proportion and nature of the 
 saline matter present, and consequently no very accurate allow- 
 ance on this score is practicable in most cases ; but an approxi- 
 mation sufficiently near for most practical purposes is obtained 
 by assuming that the effect of a given quantity of neutral saline 
 matter in increasing the specific gravity is the same as that of 
 the same quantity of actual alkali ; so that if it is known that a 
 given sample contains n per cent, of neutral saline matters, 
 together with 100 - n per cent, of actual alkali (reckoned on the 
 sum of alkali and salts as 100), the correction is obtained by 
 subtracting from the tabular number corresponding with the 
 particular specific gravity n per cent, of its value. Thus, for 
 example, if a solution of sodium carbonate be made from a soda 
 ash, &c., where the saline impurities (sulphate, chloride, &c.) 
 jointly represent 5 per cent, of the total solids dissolved (the 
 sodium carbonate consequently representing 95 per cent.), the 
 amount of sodium carbonate given in the table for a given 
 specific gravity is to be reduced by 5 per cent, of its value. 
 Similarly if the actual caustic soda, NaOH, in a sample of 
 commercial caustic be 90 per cent., and the saline impurities 
 
420 OILS, FATS, WAXES, ETC. 
 
 10 per cent., of the total soluble solid matters present (exclusive 
 of moisture), the tabular number must be decreased by 10 per 
 cent, of its value. Where more exact valuations are requisite, 
 as is sometimes necessary in order to avoid using excess or 
 deficiency of alkali, specific gravity indications must be dis- 
 carded, and the results of alkalimetrical assays substituted 
 for them ; for this purpose a normal or seminormal solution of 
 hydrochloric or sulphuric acid is convenient, using an indicator 
 not affected by carbon dioxide (litmus employed in hot solution, 
 cochineal, methyl orange, &c.) * 
 
 English, French, and German Degrees. A peculiar trade 
 custom obtains in Britain whereby the alkaline strength of 
 soda ash and caustic soda is represented as higher than the 
 truth to the extent of about 1'32 per cent, or 1 part in 76. 
 This is brought about by the incorrect assumption that the atomic 
 weight of sodium is 24 instead of 23 ; whence the percentage 
 of Na 2 O in pure sodium carbonate, Na 2 CO ;] , is reckoned as 
 
 ^4 x 100 = 59-26, instead of ^ x 100 - 58 : 49. Hence 58-49 
 108 lOb 
 
 parts of soda are reckoned as 5 9 -2 6, thus giving an error in 
 excess of 0'77 in 58-49 = 1-32 in 100. A still more erroneous 
 mode of calculation was recently current in some districts, based 
 on the same assumption that Na = 24 ; only in this case the 
 molecular weight of Na 2 O was reckoned as 64 instead of 62, 
 thus giving an error in excess of 2 parts in 64 --= 3-23 parts in 
 100, more than twice the former error. 
 
 In Germany the alkaline strength is usually expressed in 
 "degrees" representing the percentage of pure Na 2 CO 3 equi- 
 valent to the alkali present i.e., pure sodium carbonate would 
 be a soda ash of 100. In France " Descroizilles degrees " are in 
 use, representing the quantity of pure sulphuric acid, H 2 SO 4 , 
 neutralised by 100 parts of soda ash i.e., pure sodium car- 
 bonate, Na.,CO. ? , would represent a product of strength equal to 
 
 98 
 
 _ x 100 = 92 -45 Descroizilles. The. relationships between 
 
 Descroizilles and German degrees and the true percentage of 
 anhydrous soda (Na 9 O = 31, not affected by the above named 
 errors in excess due to English trade customs) are consequently 
 given by the formula 
 
 * When it is required to determine the amount of alkali present in the 
 caustic and in the carbonated state, two assays are requisite ; in one case 
 the total alkali is determined contained in a given volume of fluid ; in the 
 other the same volume of solution is boiled with barium chloride or nitrate, 
 and after cooling, made up to double the original bulk with water ; after 
 subsidence or filtration the caustic alkali in half the total fluid is determined, 
 and the amount found doubled and subtracted from that found in the first 
 assay. The difference represents the carbonated alkali present with more 
 or less accuracy according as access of carbonic acid from the air has been 
 avoided during the operations. 
 
ENGLISH, FRENCH, AND GERMAN DEGREES. 
 
 421 
 
 I) 
 
 40 
 
 G 
 53 
 
 where S is the alkaline strength expressed as percentage of Na 2 O 
 (equivalent 31 sometimes spoken of as the strength in "Gay 
 Lussac degrees ") ; D the same in Descroizilles degrees (equivalent 
 of H. 2 SO 4 = 49) ; and G the same expressed in German degrees 
 (equivalent of Na,CO 3 = 53). 
 
 From this formula result the equations 
 
 S 
 
 D - 
 
 49 " 
 
 31 
 53 
 
 49 
 31 S 
 
 G 
 
 G = . 
 
 = 0-6327 D 
 
 = 0-5849 G 
 
 = 1-5806S 
 
 = 0-3245 G 
 
 - 1-7097 S 
 
 = D = 1-0316D 
 
 The following table represents the same relationships 
 
 S. 
 
 D. 
 
 G. 
 
 S. 
 
 D. 
 
 G. 
 
 2 
 
 3-16 
 
 342 
 
 42 
 
 66-39 
 
 71-81 
 
 4 
 
 6-32 
 
 9-84 
 
 44 
 
 69-55 
 
 75-23 
 
 6 
 
 9-48 
 
 10-26 
 
 46 
 
 72-71 
 
 78-66 
 
 8 12-64 
 
 13-68 
 
 48 
 
 76-87 
 
 82-07 
 
 10 15-81 
 
 17-10 
 
 50 
 
 79-03 
 
 85-48 
 
 12 18-97 
 
 20-52 
 
 >52 
 
 82-19 
 
 88-90 
 
 14 22-13 
 
 23-94 
 
 54 
 
 85-35 
 
 92-32 
 
 16 25-29 
 
 27-36 
 
 56 
 
 88-52 
 
 95-74 
 
 18 28-45 
 
 30-78 
 
 58 
 
 91-68 
 
 99-16 
 
 20 
 
 31-61 
 
 34-20 
 
 60 
 
 94-84 
 
 102-58 
 
 22 
 
 34-77 
 
 37-62 
 
 62 
 
 98-00 
 
 106-01 
 
 24 37-93 41-04 
 
 64 
 
 101-16 
 
 109-43 
 
 2<i 
 
 41-09 44-46 
 
 66 
 
 104-32 
 
 112-85 
 
 28 44-25 47-88 
 
 68 
 
 107-48 
 
 116-27 
 
 30 
 
 47-42 
 
 51-29 
 
 70 
 
 110-64 
 
 119-69 
 
 32 
 
 50-88 
 
 54-71 
 
 72 
 
 113-81 
 
 123-10 
 
 34 
 
 53-74 58-13 
 
 74 
 
 116-97 
 
 126-52 
 
 36 
 
 56-90 61-55 
 
 76 
 
 120-13 
 
 129-94 
 
 38 
 
 60-06 64-97 
 
 77 '5 
 
 122-50 
 
 132-50 
 
 40 
 
 63-22 
 
 68-39 
 
 
 
 
 Calculation of Quantity of Alkaline Ley requisite for 
 Saponiflcation. When an alkaline solution of known strength 
 (either determined by titration, or inferred from the specific 
 
422 OILS, FATS, WAXES, ETC. 
 
 gravity after correction of the tabular value for saline impurities) 
 is to be used for converting into soap a given kind of fatty matter 
 or mixture of fats, &c., the quantity requisite for exactly saponi- 
 fying a given weight of fat depends not only on the alkalinity 
 of the ley but also on the mean saponification equivalent of 
 the fatty matters (p. 158) ; the lower the value of this latter 
 quantity the more alkali will be required, the relationship being 
 indicated thus Let E be the mean saponification equivalent of 
 the fats, etc., used ; then E units of weight of fat will be equivalent 
 to 31 units of Na 2 O (or to 40 of NaOH, 47-1 of K,O, or 56-1 
 of KOH). Let 1~000 parts by weight of alkaline ley be equi- 
 valent to 0J parts of Na 2 O (or to a. 2 of NaOH, a 3 of K 2 0, or 4 of 
 KOH) i.e., let a 1 (, a s , or a 4 ) be the permillage of alkali in 
 the ley. Then E units of weight of fat will obviously be equi- 
 valent to 31 x units of weight of ley (or to 40 x , 
 
 a l \ #2 
 
 1 000 1 000\ 
 
 47-1 x -' , or 56 -1 x - ) ; whence one part of fat is equi- 
 
 1,000 I 4 31,000 / 40,000 
 
 valent to 31 x - - x = = - ^ parts of ley or to - ^, 
 
 a 1 E 1 x L A \ a. 2 x Jjj 
 
 , or - ., parts). Thus one part by weight of cokernut 
 
 3 x E 4 x E r / 
 
 oil of mean saponification equivalent 215 w r ill be exactly saponified 
 
 by , r = 0'846 parts of caustic soda ley containing 220 per 
 
 mille of NaOH ; whilst one part of linseed oil of mean saponifi- 
 cation equivalent 291 '5 will correspond with =- ? -= = 1*077 
 
 150 x 291-5 
 
 parts of a potash ley containing total active alkali (caustic + 
 carbonated) equivalent to 150 per mille of K 2 O ; and so 
 on. 
 
 When the alkalinity of the leys is expressed as parts ~by weight 
 per unit of volume (grammes per litre, pounds per gallon,* &c.) 
 the above calculation still applies in slightly modified form. 
 Let the alkaline ley contain b l grammes of Na^O per litre (b> 2 
 grammes of NaOH, b 3 of K O, b of KOH), then E grammes of 
 
 . . 31 ... . , / 40 47-1 56-1 
 
 fat are equivalent to - - litres of ley f or to -, -y , or =- 
 
 litres J ; whence 1 gramme of fat represents -. ^ -^ for 7-^-^5 
 
 * A solution of anything containing n grammes per litre (n milligrammes 
 per c.c. or n kilogrammes per cubic metre), contains n pounds per hecto- 
 gallon (100 gallons), since 1 gallon of water weighs 10 Ibs. Hence when 
 laboratory estimations are made, as usual, on the metrical system, the 
 results can, if required, be referred to pounds and gallons for practical 
 British works' use in a "Very simple way. 
 
QUANTITY OF LEY REQUISITE FOR SAPONIFICATION. 
 
 , or T -- res o 
 
 56,100\ 
 
 423 
 
 y =, v/x , ) litres of ley ; or 1 kilogramme represents 
 
 31,000 /40,000 47,100 56,100\ 
 
 or j-l ) litres. Thus, one kilo. 
 
 b t x E \b 2 x E' b s x E' 
 
 of cokernut oil (E = 215) would be exactly saponified by 
 
 r.TTTT^ JTT^- = 0-930 litres of caustic soda solution of such 
 200 x 21o 
 
 strength that 1 litre = 200 grammes NaOH; or 1 kilo, of lin- 
 seed oil (E = 291-5) would correspond with -^---7^- OQ , = 1'029 
 
 10/ "U X ZiV I'D 
 
 litres of potash ley of which 1 litre = 157'0 grammes K 2 O. 
 
 f n ' * w ' f 40 ' 000 l 56 ' 100 f 
 
 Ihe following table gives the values of ^ and ^ for 
 
 Talues of E between 190 and 400 ; by its means the number of 
 litres, x, of caustic soda (or potash) solution can be readily 
 calculated, requisite for the saponification of a kilogramme of any 
 fatty mixture the mean saponification equivalent of which is E, 
 by the simple formula 
 
 n 
 
 X = TVf' 
 
 where n is the tabular number corresponding with E, and N the 
 number of grammes of NaOH (or of KOH) contained in a litre of 
 the ley used : 
 
 E. 
 
 40,000. 
 
 Difference. 
 
 56,100. 
 E 
 
 Difference. 
 
 E 
 
 190 
 
 210-5 
 
 
 295-2 
 
 
 200 
 
 200-0 
 
 10 -5 
 
 280-5 
 
 14 7 
 
 210 
 
 190-5 
 
 9-5 - 
 
 267-2 
 
 13-3 
 
 220 
 
 181-8 
 
 8-7 
 
 255-0 
 
 12-2 
 
 230 
 
 173-9 
 
 7-9 
 
 243-9 
 
 11-1 
 
 240 
 
 166-7 
 
 7-2 
 
 233-7 
 
 10-2 
 
 250 
 
 160-0 
 
 6-7 
 
 224-4 
 
 9-3 
 
 260 
 
 153-8 
 
 6-2 
 
 215-8 
 
 8-6 
 
 270 
 
 148-1 
 
 5-7 
 
 207-8 
 
 8-0 
 
 280 
 
 142-8 
 
 5-3 
 
 200-4 
 
 7-4 
 
 290 
 
 137-9 
 
 4-9 
 
 193-5 
 
 6-9 
 
 300 
 
 133-3 
 
 4'6 
 
 187-0 
 
 6-5 
 
 310 
 
 129-0 
 
 4-3 
 
 181-0 
 
 6-0 
 
 320 
 
 125-0 
 
 4-0 
 
 175-3 
 
 5-7 
 
 330 
 
 121-2 
 
 3-8 
 
 170-0 
 
 5'3 
 
 340 
 
 117-6 
 
 3-6 
 
 165-0 
 
 5-0 
 
 350 
 
 114-3 
 
 3-3 
 
 160-3 
 
 4-7 
 
 360 
 
 111-1 
 
 3-2 
 
 155-8 
 
 4-5 
 
 370 
 
 108-1 
 
 3-0 
 
 151-6 
 
 4-2 
 
 380 
 
 105-3 
 
 2-8 
 
 147-6 
 
 4-0 
 
 390 
 
 102-6 
 
 2-7 
 
 143-8 
 
 3-8 
 
 400 
 
 100-0 
 
 2-6 
 
 140-25 
 
 3-55 
 
424 OILS, FATS, WAXES, ETC. 
 
 Thus, suppose a mixture of tallow, palm oil, and cokernut oil to 
 have the mean saponification equivalent 250 ; then n = 160 r 
 and the number of litres of caustic soda solution requisite to 
 
 saponify a kilogramme is -^--> where N is the number of 
 
 grammes of NaOH contained in a litre of the ley; if N = 1GO 
 the quotient is, obviously, 1,000 i.e., 1 litre exactly is re- 
 quired ; whilst for stronger and weaker solutions, where N is 
 respectively 320 and 80, the corresponding quotient values are 
 0-500 and 2 '000 i.e., exactly 0*5 litre of the stronger fluid is 
 required, and 2*0 litres of the weaker one. 
 
 If the saponification equivalent is not exactly indicated by 
 the table, the value is readily obtained by interpolation by 
 means of the difference columns without introducing any material 
 error; thus a commercial "oleine" (impure oleic acid) of which 
 the saponification equivalent is 282*5 corresponds with a value 
 
 A-0 000 
 f or ^ of 142-8 - 0-25 x 4'9 = 141-6; hence, if a soda ley 
 
 containing 293-6 grammes of NaOH per litre be used (N = 293*6), 
 
 -1 A~\ ./? . -'. 
 
 = 0-482 litre of ley will contain alkali exactly corre- 
 
 ' ' * *O 
 
 spending with 1 kilo, of fatty matter. 
 
 Obviously, the above formula x= -- 7 will also enable the 
 
 number of parts by weight of ley to be calculated, requisite to 
 saponify one part by weight of fatty matter of mean equivalent 
 E, if N denote the permillage of NaOH (or of KOH) in the 
 ley. Thus in one of the examples above quoted, one part of 
 
 cokernut oil of equivalent 215 represents a value for ' , - of 
 190'5 - 0-5 x 8-7= 186-1 ; whence the quantity of soda ley at 
 220 per mille of NaOH, equivalent thereto is = 0-846 part, 
 
 as before. 
 
 When it is required to use fatty matters and alkaline leys in 
 as nearly as possible equivalent quantities so as to avoid excess 
 of either constituent, calculations such as the foregoing afford 
 the simplest method of arriving at the relative quantities 
 requisite. In practice, when the same kind of operation is 
 to be repeated over and over again as a matter of routine, 
 the fatty matter employed being sensibly of the same quality 
 throughout, it usually suffices to gauge the tanks and vessels 
 employed once for all by means of calculations founded on 
 these principles, and preferably checked by careful analyses 
 of the resulting products ; the weight of fatty matters taken and 
 their mean saponification equivalent being practically constant 
 for each operation, the volume of alkaline ley used is slightly 
 
QUANTITY OF LEY REQUISITE FOR SAPONIFICATIOX. 425 
 
 increased or diminished below that corresponding with the 
 original gaugings according as the alkalimetrical test of the 
 liquor (or the value deduced from its specific gravity) shows 
 that it is a little below or above its normal strength i.e., that 
 pertaining to the original gaugings. 
 
 When it is required to calculate the amount of sodium or 
 potassium hydroxide or carbonate equivalent to a given amount 
 of anhydrous oxide, or vice versd, the following formulae may be 
 employed, based on the molecular weights 
 
 Na = 23 
 
 Na 2 = 6'2 
 
 NaOH = 40 
 
 Na 2 C0 3 = 106 
 
 K 39-1 
 
 KoO = 94 -2 
 
 KOH = 56' I 
 
 K 2 C0 3 = 138'2 
 
 Let a given weight A of .Na.,O be equivalent to B of 
 and C of Na.,CO 3 ; and let a given weight D of K 2 O be equivalent 
 to E of KOH: and F of K 2 CO 3 : then 
 
 To reduce Formula. 
 
 NaOH to Na 2 A ^^^ T > = '"" 50 B 
 
 Na 2 C0 3 to Na 2 A = ^ C = 0-5849 C 
 
 9 v 10 
 
 Na 2 to NaOH B = ^ A = 1-2903 A 
 
 Na 2 C0 3 to NaOH B = '^T C = 0'7547 C 
 
 Na 2 to Na 2 C0 3 C ^ A T7097 A 
 
 106 
 NaOH to Na 2 C0 3 C = ^ ^ B = 1-3250 B 
 
 04-9 
 KOH to K 2 D = g^P^l E = ' 8396 E 
 
 94 '2 
 K 2 C0 3 to K a O D = -j^ F = 0-6816 F 
 
 K 2 to KOH E - 2 -^4^ D = 1 1911 D 
 
 9 v ^fi-1 
 
 K 2 C0 3 to KOH E - -Tooo F = ' 8119 F 
 
 lOo t 
 
 1 ^8 *2 
 
 K 2 to K 2 C0 3 F = j~ D = 1-4671 D 
 
 1 qq .o 
 
 KOH to K 2 C0 3 F - o-^^Y E = 1-2317 E 
 
 Thus a solution of sodium hydroxide of specific gravity 1-206 
 containing 13-3 per cent, of NaOH will contain 13-3 x 0-775 = 
 10-3 per cent, of Na 2 O ; one containing 21'5 per cent, of K 2 CO 3 
 is equivalent to another containing 21*5 x 0*8119 17*46 per 
 cent, of KOH * and so on. 
 
426 OILS, FATS, WAXES, ETC. 
 
 The following analogous formulae may be used to calculate the 
 quantity of soda equivalent to a given weight of potash or vice 
 versd. Let H be a given quantity of sodium carbonate and I 
 the potassium carbonate equivalent thereto ; similarly let J be 
 a given amount of sodium hydroxide and K the potassium 
 hydroxide corresponding therewith ; and let L be a given quantity 
 of Na^O, and M the K 2 O equivalent thereto. Then 
 
 1^ l = ' 767 I 
 Carbonates, . . 
 
 H - 1-3038 H 
 
 J = -Jf.- K = 0-7130 J 
 
 GO 1 
 
 Hydroxides, . . . 
 
 ' K ^ J 1-4025 K 
 
 L -^r M 0-6582 L 
 
 Anhydrous oxides, 
 
 M *^i L = 1-5194 M 
 
 Thus 10 per cent, of K 2 O in a given soap is equivalent to 
 10 x 0-6582 = 6-582 per cent, of Na 2 O. A liquor containing 
 8 per cent, of NaOH is of the same alkaline strength as one 
 containing 8 x 1-4025 = 11-22 per cent, of KOH ; and so on. 
 
 CHAPTER XIX. 
 SOAPMAKING PLANT. 
 
 HEATING APPLIANCES. 
 
 THE plant and appliances requisite for the manufacture of soap 
 vary somewhat according to the nature of the process used and 
 the scale on which it is conducted. Formerly the vessels (usually 
 known as " pans," " coppers," or " kettles ") in which the boiling 
 operations were conducted were uniformly mounted over free 
 fires, so that the flame produced by the combustion of fuel in a 
 fireplace placed beneath the pan was made to play over the rest 
 of the bottom and part of the sides of the pan by means of a 
 suitably arranged circular flue provided with a damper for the 
 purpose of regulating the draught. Several coppers were usually 
 mounted side by side, so that the products of combustion of their 
 respective fires passed into the same common tunnel or flue lead- 
 
FREE-FIRED SOAP PANS. 
 
 427 
 
 ing to the main chimney of the works. At the present day this 
 system of free firing is comparatively seldom applied in the 
 larger soap factories, the coppers being more frequently heated 
 by steam supplied from a special boiler, and in some cases super- 
 heated before use. Fig. 108 gives a general idea of the disposi- 
 
 Fig. 108. 
 
 tion of the arrangements adopted for a free-fired pan. The 
 pan, J, is mounted in masonry over the fireplace, B, placed 
 centrally beneath it, a nearly circular flue, E, carrying the flame 
 round the lower part of the pan to the chimney, F ; C is the 
 grate or range of firebars supporting the fuel, and D the ashpit. 
 The leys, &c., are drawn off 
 as required by the tube and 
 draw-off cock, K ; the level 
 of the flooring or staging 
 round the pan, A, A, is raised 
 so that the top of the pan 
 projects upwards some 3 feet. 
 Fig. 109 represents a cast 
 iron pan of slightly different 
 type, A, also mounted so as 
 to be heated by free firing ; 
 in this case the fireplace, B, 
 is not placed centrally be- 
 neath the pan, but somewhat Fig. 109. 
 in front of it, the heating 
 
 being chiefly effected by the hot air chamber, E, in which 
 the products of combustion circulate round and under the 
 
428 
 
 OILS, FATS, WAXES, ETC. 
 
 base of the pan before passing away to the flue. C, firebars ; 
 D, ashpit. 
 
 In the case of modern steam heated pans, the steam is applied 
 in various ways. Heating by " wet " steam consists in blowing 
 steam at a sufficient pressure direct into the mass to be heated, 
 so that the water produced by the condensation of the steam 
 dilutes the whole until the temperature rises so high that the 
 steam simply blows through without becoming materially con- 
 densed ; for most general boiling purposes a wet steam coil is 
 thus used, consisting of an iron pipe descending to near the 
 bottom of the copper arid terminating in a ring perforated with 
 holes through which the steam issues, bubbling up through the 
 mass and producing a very effective agitation and intermixture 
 of the contents when the heat is sufficient to cause the steam to 
 blow through. In some districts this wet steam coil is accord- 
 ingly spoken of as the "blowpipe;" superheated steam is some- 
 
 Fig. 11U. 
 
 times employed instead of steam supplied direct from the boiler, 
 so as to diminish the amount of water condensation. 
 
 Heating by " dry " steam consists in causing steam (either 
 direct from a high pressure boiler, or preferably for many pur- 
 poses, superheated) to circulate through a sort of spiral tube or 
 coil arranged in the lower part of the copper ; the water con- 
 densed in the coil accordingly does not pass into the heated 
 mass, thereby diluting the leys, &c., but is blown off along with 
 the exit steam. Dry steam is also sometimes employed to heat 
 an external jacket usually only surrounding the lower part of 
 the pan; Fig. 110 indicates the kind of arrangement C, steam 
 supply pipe ; D, pipe and cock for drawing off condensed water ; 
 A, copper; B, steam jacket at base of copper ; E, draw off pipe 
 from copper. A mechanical stirring arrangement to keep the 
 mass agitated is conveniently added. 
 
 In order to facilitate intermixture of materials in the pan 
 whilst heating up by dry steam an appliance known as " Morfit's 
 steam twirl " is much used. Fig. Ill represents one form of 
 arrangement applied to a comparatively shallow copper sup- 
 
MORFIT'S STEAM TWIRL. 
 
 429 
 
 ported by a wooden frame work, A A, B B. The steam from the 
 steam pipe, G, passes into a hollow spindle, D D E, the central 
 part of which is 
 blocked, so that the 
 steam is obliged to 
 pass through the con- 
 voluted tubes, K K, 
 KK, braced together 
 by cross pieces, 
 HHH, which also 
 serve as stirring 
 vanes. By means 
 of the bevel wheels, 
 L L, worked from 
 the shaft and pulley, 
 M N, the twirl is set 
 in motion, so that 
 the contents of the 
 pan are thoroughly 
 agitated whilst being 
 heated up. The con- 
 densed water blows 
 off at E with the 
 surplus steam, whilst 
 C is the discharge 
 cock of the pan. 
 The same appliance 
 can also be used with 
 wet steam, the con- 
 voluted tubes being 
 pierced with holes 
 so as to allow part of the steam to escape directly into the mass 
 of material. 
 
 Soap Coppers. Formerly the vessels in which soap and leys 
 were boiled together were made of various kinds of materials ; 
 sometimes of masonry, iron bottoms being provided for heating 
 by free fire ; sometimes of cast iron, like the pan represented in 
 Fig. 109, or of wrought iron plates ri vetted together subse- 
 quently, or of wooden staves strongly bound together like 
 enormous tubs, wet steam being the source of heat. 
 
 These forms, however, were mostly adapted only for use with 
 quantities of material small in comparison with those in use at 
 the present day, when charges of 30 to 40 tons and upwards of 
 fatty matters are not uncommon ; a more recent form of soap 
 kettle is a cylindrical or conical cauldron with somewhat rounded 
 apex, placed base upwards, constructed of boiler plates well 
 rivetted together, as indicated in Fig. 112; the degree of slope 
 of the sides (regulating the ratio between the top and bottom 
 
430 
 
 OILS, FATS, WAXES, ETC. 
 
 diameters) and the relation between the depth and maximum 
 diameters vary somewhat in different countries e.g., soap kettles 
 
 Fist. 113. 
 
SOAP COPPERS. 
 
 431 
 
 of this pattern in America are generally from two to three times 
 as deep as they are wide, sometimes filling a building of two or 
 three stories; whilst in Britain the depth rarely exceeds once 
 and half times the diameter, still shallower pans being often used. 
 A copper 15 feet diameter and 15 feet deep will turn out 20 to 
 
 Fig. 114. 
 
 30 tons of soap, a usual rule being to allow 6 cubic feet capacity 
 (about 37-5 gallons) for each 100 Ibs. weight of fatty matters 
 treated, or about 135 cubic feet (nearly 850 gallons) per ton; so that 
 a copper holding some 2,500 cubic feet (upwards of 15,000 gallons) 
 will suffice for about 18 tons of fatty matters yielding 25 to 30 
 
432 
 
 OILS, PATS, WAXES, ETC. 
 
 tons of soap according to the amount of water contained therein. 
 Fig. 113 represents " Morfit's Steam Series," a set of three coppers 
 supplied with both sets of steam coils (wet and dry). B B is the 
 steam main supplied from the boiler, A ; K is the wet steam 
 pipe ; and D F G the dry steam coil. The lowest part of the 
 
 Fig. 115. 
 
 copper is usually provided with a narrower basin or hat-shaped 
 downward prolongation for the more easy collection and separa- 
 tion of watery leys, &c. ; in the figure it is represented as con- 
 nected with a draw off tube, H, provided with a cock, J. F F F 
 represent " Curbs " (infra) of different shapes to prevent boiling 
 over. 
 
CURB AND FAN. 433 
 
 Figs. 114 and 115 represent a modern form of pan for heat- 
 ing with either dry or wet steam as required, constructed by 
 Messrs. W. Neill & Son, of St. Helens, Lancashire. This is a 
 square tank made of steel plates rivetted together, with rounded 
 corners and dished bottom, the square form being preferably 
 employed as taking up less room than the circular shape requisite 
 in the case of free-fired coppers provided with flues running 
 round the lower part of the pan (Fig. 108). The pan is fitted 
 with wet and dry steam coils, and a cock at the bottom for run- 
 ning off spent leys. A "skimmer pipe" is provided, working 
 on a swivel joint, and capable of being adjusted at any required 
 height by a supporting chain ; as represented in the figure, the 
 fluid soap is run off by gravity through a down pipe; but if 
 required a pump can be connected at the elbow instead, a cock 
 being affixed to shut off connection when the pump is not at 
 work. 
 
 An airblast has been employed by Dunn for the purpose of 
 intermixing the ley and fatty matters during the preliminary 
 stage of " killing the goods," and the subsequent operations when 
 free-fired pans are employed, whereby tumultuous boiling is 
 largely avoided ; the air was introduced by a " blowpipe " 
 arranged in much the same way as the more modern wet 
 t steam coil. The process was said to answer well ; but has 
 nowadays fallen into disuse through the substitution of steam- 
 heate'oHpans for free-fired kettles. 
 
 Cui*9 and Fan. With certain kinds of materials, and parti- 
 1/cularly at certain stages of the operation, tumultuous boiling up 
 or "bumping," and vigorous frothing are apt to occur, more 
 especially when oleine soap is made by the direct addition of hot 
 carbonated leys to free oleic acid (red oils, vide Chap, xx.), and 
 during the -"'graining " or "cutting" of boiled soaps i.e., the 
 throwing them out of watery solutions by addition of salt (vide 
 Chap, xx.) Two appliances are of considerable utility in diminish- 
 ing the chance of loss by boiling over under such conditions. One, 
 known as the " curb," is simply a temporary expansion of the 
 upper part of the pan, consisting of a conical, circular, or barrel- 
 shaped addition bolted on so as virtually to amplify considerably 
 the dimensions of the copper at the top. Fig. 113 represents 
 a cone, F, of wooden staves, hooped together with iron, applied 
 to one kettle, and a barrel -shaped analogous curb applied to 
 another. 
 
 The other arrangement is termed a "fan," Fig. 116, and 
 consists of a sort of pair of paddle-wheels suspended in the pan 
 at such a depth below the surface as may be requisite, so that as 
 the paddles revolve the froth is broken by them and prevented 
 from rising up and boiling over. Motion is communicated to the 
 paddles by means of a vertical shaft with bevel wheels at top 
 and bottom, the shaft being telescopic so as to admit of being 
 
 28 
 
434 
 
 OILS, FATS, WAXES, ETC. 
 
 drawn up and down to adjust the level of the paddles as re- 
 quired j it rotates within a tube carrying a Y-shaped frame at 
 
 each end, the whole 
 being suspended from 
 the upper horizontal 
 shaft, by means of 
 w r hich motion is com- 
 municated to the ver- 
 tical shaft through the 
 bevel wheels, whilst 
 the lower Y serves as 
 bearings for the axle of 
 the paddles. 
 
 Soap Fra-mes. 
 When the operation of 
 soapmaking is finished, 
 and the spent leys 
 (when such are present) 
 removed by subsidence, 
 etc., the resulting soap 
 usually forms a hot 
 semifluid or pasty mass 
 which, on cooling, more 
 or less thoroughly 
 solidifies to a soft solid 
 substance. In order 
 to facilitate the opera- 
 tion of cutting up the 
 mass into bars and 
 tablets for sale without 
 waste, the hot soap is 
 run by gravitation, or 
 ladled, or pumped out 
 of the copper in which 
 it is made into "frames," in which it is allowed to solidify. The 
 pumps used for this purpose are generally of somewhat different 
 construction from the ordinary suction pump used for wells, &c. 
 Fig. 117 represents a rotary soap pump as constructed by Hersee 
 Brothers of Boston. Instead of pumping out the soap, it may 
 more conveniently be run off by gravity by means of the adjust- 
 able "skimmer pipe" shown in Fig. 114, the frames being 
 arranged so that their tops are at a level below the elbow joint 
 of the pipe. 
 
 A method sometimes used for emptying kettles and raising 
 their contents to a higher elevation was introduced by Gossage, 
 consisting of the application of a cover fitting airtight, and then 
 forcing in compressed air, so as to press the semifluid soap up a 
 pipe the lower end of which dips into the kettle to the required 
 
 Fig. 116. 
 
SOAP FRAMES. 
 
 435 
 
 depth; the whole arrangement working on the principle of the 
 " acid egg " used in vitriol factories for elevating the acid without 
 employing ordinary pumps. 
 
 Fig. 119. 
 
 The size of the frames employed and the material of which 
 they are composed vary, wood being preferable when slow cooling 
 
436 
 
 OILS, FAT?, WAXES, ETC. 
 
 I 
 
 Fig. 120. 
 
SLABBING AND BARBING. 
 
 437 
 
 is essential, but iron being considerably more convenient in other 
 cases. For toilet soaps, frames holding 1 cwt. or less are often 
 
 Fig. 121. 
 
 employed ; for scouring soaps much larger ones, furnishing ulti- 
 mately a block of cooled soap weighing 8, 10, 15, or more cwts.* 
 Fig. 118 indicates the way in which a wooden frame may be 
 built up of a set of squares pegged together 
 and superposed on a bottom board. Fig. 119 
 represents a frame constructed of galvanised 
 iron plates where the ends fit into grooves 
 formed by turning round the corners of the 
 side plates, or fitting pieces of angle iron 
 thereto; the side and end plates are similarly 
 fitted to the iron bottom, and the whole kept 
 together by two transverse rods at the top 
 fitted with screws and nuts. Fig. 120 repre- 
 sents an improved form of steel soap frame, 
 mounted on four wheels, and held together 
 by cap fastenings. 
 
 When the block of soap has .completely 
 cooled down and set solid, the frame is taken 
 to pieces and the block cut into slabs, which 
 are then transversely cut up into bars. 
 When this is done by hand the block is cut 
 in a very simple fashion by simply pulling a 
 looped wire (Figs. 121 and 122) through it 
 horizontally so as to cut through the mass 
 along a series of parallel lines previously 
 
 Fig. 122. 
 
 marked 011 the outside by means of a scribe (Fig. 123). Slabbing 
 and barring machines of various patterns are frequently employed 
 for this purpose (Fig. 124). When it is requisite that the soap 
 
 * Formerly, the size of the soap frames was fixed by excise laws and regula 
 tions, and required to be 45 inches long by 15 wide, inside measurement, 
 and not less than 45 inches deep (usually made 50 to 60 inches deep) ; so as to 
 hold some 15 to 20 cubic feet, or about 9 to 11 cwts. of soap, Although no 
 longer compulsory, this size is still largely employed. 
 
438 OILS, FATS, WAXES, ETC. 
 
 should cool very slowly in the frame (e.g., in. order to promote 
 saponification in making cold process soap p. 457 ; or to 
 facilitate mottling Chap, xx.) the sides of the frame 
 are sometimes padded to keep in the heat (Fig. 125). 
 The bars of soap into which a block is cut gener- 
 ally weigh about 3 Ibs. ; they are usually stacked in 
 a hollow pile to dry the outside slightly so as to case- 
 harden them, as it were, or else are stored on lattice 
 work shelves in an open rack allowing free access of 
 Fig ^123. a ^ r - With very moist soaps, this drying action is apt 
 to go too far, warping the bar out of shape, besides 
 causing it to lose weight largely ; accordingly such bars are 
 often "pickled" by immersion in brine, which slightly indurates 
 the outside. Of late years a considerable demand has sprung 
 up for 1 Ib. blocks instead of 3 Ib. bars ; such blocks are gener- 
 ally cut to size and shape and then stamped like toilet cakes in 
 similar machines but of larger size (p. 444). Often the block is 
 grooved in the centre, so that it can be readily broken into two ; 
 or three grooves are stamped at equidistant intervals enabling 
 four 4 oz. blocks to be obtained. 
 
 Crutching Machines. Formerly, when it was requisite to 
 stir up soap containing excess of w r ater in the cooling frames to 
 prevent its separating into two liquids, a peculiar hand worked 
 agitator termed a " crutch " was largely used, consisting of a 
 square piece of board with a handle attached to the centre of 
 the square perpendicular to its plane (Fig. 126) ; by plunging this 
 into the pasty mass, and working it up and down, a sufficiently 
 efficient mixing was brought about. Such implements are still 
 in use, especially for small-scale operations, but have been largely 
 superseded by mixing machines, the operation of agitation by 
 their means being still spoken of as " crutching." For inter- 
 mixing silicate or resinate of soda solution with boiled soaps in 
 large quantities at a time, or for otherwise working in saline 
 solutions to dilute and harden the soap or improve its detergent 
 qualities, or " filling " of various kinds, as well as for preventing 
 separation of watery fluid from the mass, such machines are 
 largely employed. Various forms are employed Fig 127 repre- 
 sents a horizontal cylindrical form, with a rotating internal axle 
 provided with projecting vanes for stirring up the contents ; when 
 required for rapid cooling or heating an outer jacket is applied 
 into which water or steam can be admitted as required 
 (Fig. 128). 
 
 Figs. 129 and 130 represent a series of three crutching pans 
 arranged so as to be worked from the same shaft. By means 
 of the clutches indicated, any one of the three can be set in 
 motion or stopped as required : the stirring vanes are here 
 horizontal, projecting from a vertical axle, similar fixed vanes 
 being arranged internally so as to prevent the liquid mass from 
 
CRUTCHING MACHINES. 
 
 439 
 
 simply swinging round and round without being broken up and 
 intermixed. 
 
 In another form of mixing machine two sets of vanes are 
 
 provided, moved in opposite directions by means of bevel 
 wheels, one axle being hollow and the other working inside it 
 like the axles carrying the two hands of a watch. The vanes 
 slope at an angle of 45, so that the material is continually 
 
440 
 
 OILS, FATS, WAXES, ETC. 
 
 lifted and the different layers intermixed, the general action 
 resembling that of an ordinary eggwhisk. Large steam driven 
 
 Fig. 127. 
 
 sizes are very effective ; but if worked too rapidly the mass is 
 apt to become frothy. For very stiff soap, an archimedean 
 screw, working inside a wider cylinder, answers very well. 
 
TOILET SOAP MACHINERY. 
 
 441 
 
 Toilet Soap Machinery. In the manufacture of various 
 kinds of toilet soaps, several special kinds of appliances are used 
 varying in their nature with the process adopted. When 
 " stock " soaps prepared on the large scale are " remelted," 
 for the purpose of blending together different kinds, with the 
 addition of colouring or scenting materials, fcc., a steam jacketted 
 pan is generally preferred, somewhat after the fashion of Fig. 110 ; 
 as the soap (previously cut up into small lumps) melts, it is 
 mixed together either by hand crutching (supra) or by means 
 
 Fig. 128. 
 
 of some form of agitator; too rapid a movement must not 
 be communicated to this, otherwise air bubbles are stirred 
 in and the soap becomes more or less frothy, forming a spongy 
 mass when solid.* Figs. 131 and 132 represent a very effec- 
 tive form of remelter constructed by W. Neill & Son, where 
 the heating action of the outer steam jacket is greatly amplified 
 by means of the internal cross steam pipes ; the pieces of 
 soap are continually brought in contact with these by the 
 motion of the agitating arms, and as a large heating surface 
 is thus brought into play the remelting proceeds rapidly. 
 When finished, after intermixture of the various ingredients 
 
 "Floating" soaps are purposely prepared in this way, enough air 
 bubbles bein^ worked in to enable the tablet to float in water, even after 
 compression in the stamping press. 
 
442 
 
 OILS, FATS, WAXES, ETC. 
 
REMELTINC PANS. 
 
 443 
 
 Fig. 132. 
 
444 
 
 OILS, FATS, WAXES, ETC. 
 
 intended to render the soap emollient, to scent it, or otherwise 
 to improve its qualities, the fluid mass is cast in small frames so 
 as to form blocks of J cwt. or upwards, according to circum- 
 stances ; usually these are made of iron plates bolted together, as 
 indicated in Fig. 119, so as to cool quickly and avoid as far as 
 possible loss of volatile scenting materials, and the injurious 
 effect of heat thereon. The blocks when cold are then slabbed 
 and barred by hand or machine, and the bars cut into short 
 lengths, each of which is then stamped into tablet form by some 
 form of press acting on the principle of a coining press, where 
 
 Fig. 133. 
 
 both sides of the coin or medal are embossed at once, a ring or 
 collar being adjusted round the medal so as to prevent its swell- 
 ing out sideways under the pressure. A large variety of tablet 
 stamping machines are in use ; some are worked by hand, the 
 upper die and collar being attached to a rod or plunger worked 
 by a lever provided with a balance weight, so that by forcibly 
 pulling down the lever the die descends and stamps the tablet. 
 Fig. 133 represents a machine of this description, and Figs. 134 
 and 135 a steam stamping machine, where the impact of the die 
 is given by letting steam into the cylinder by means of the valve 
 
STAMPING MACHINES. 
 
 445 
 
 handle, so that the piston suddenly rises, and consequently 
 depresses the plunger to which the die is attached on the 
 opposite side of the axis of motion. In another form of machine 
 
 Fig. 134. 
 
 Fig. 135. 
 
 the requisite impact is given by raising the upper die to which 
 a considerable weight is attached, and then letting it fall, pile- 
 driver fashion. 
 
 In the case of transparent toilet soaps made by the spirit 
 process (Chap. xx.\ the pan in which the solution of the soap in 
 
446 OILS, FATS, WAXES, ETC. 
 
 spirit is effected is connected with a still head and worm, so that 
 the alcoholic vapours evolved are condensed and regained. With 
 soaps of this class, the liquid soap left when most of the spirit is 
 distilled off is run into frames, so as to gelatinise and solidify, 
 and is then cut up into tablet blanks, which are exposed to the 
 air for a considerable length of time (several weeks or even 
 months) in a warm room, so as to consolidate them by gradual 
 evaporation of remaining alcohol, etc., otherwise they would be 
 too soft to keep their shape properly. Moreover, when freshly 
 
 Fig. 136. 
 
 prepared the mass is often "muddy;" but on keeping, it gradually 
 becomes transparent and clear. 
 
 Milled Soaps. Much more elaborate machinery is requisite 
 for the manufacture of " milled " soaps. The bars of stock soap 
 are first " stripped " i.e., cut into slices or chips by a slicing 
 machine, actuated like a rotary plane or vegetable cutter. 
 Fig. 136 represents Rutschmann's stripping machine. The chips 
 are dried in a warm air chamber until only a few per cents, 
 of moisture are retained, and are then ground between successive 
 
MILLED SOAPS. 
 
 447 
 
 pairs of heavy horizontal rollers, so arranged that the soap first 
 passes between No. 1 and No. 2 rollers, then between No. 2 and 
 No. 3, and so on, somewhat as in the case of seed crushing for 
 oil extraction (p. 218). Each roller is made to revolve somewhat 
 faster than the previous one, so that the soap slices are not 
 merely crushed in passing through, but are also rubbed ; the 
 soap always adheres to the more quickly moving roller, so that it 
 passes onwards automatically. By means of " doctors " or 
 scrapers, it is detached from the last roller in strips or ribbons, 
 which are returned to the front of the machine and passed 
 
 Fig. 137. 
 
 through again and again. Fig. 137 represents a form of mill for 
 the purpose. 
 
 In order to facilitate the preliminary drying of the stock soap r 
 A. & E. des Cressonnieres* use a series of rollers arranged 
 vertically one above another in an enclosed space heated by 
 steam or hot air, &c. Soap in a just fluid state from the remelter, 
 &c., passes in a flat stream from a hopper on to the top roller, the 
 contact with which partly solidifies it; the resulting semisolid 
 sheet passes alternately from right to left, and vice versd, between 
 each successive pair of rollers, as in the mill itself, finally 
 emerging at the bottom in the form of a solid sheet, which is 
 separated by an automatic cutter into strips. The temperature 
 
 * English patent, No. 2,446, 1890. 
 
448 
 
 OILS, FATS, WAXES, ETC. 
 
 
 of the chamber and the rate of soap supply are so adjusted that 
 the strips are sufficiently dried by the time they emerge. 
 
 When the various stock soaps used, colouring matters, 
 perfumes, unguents (lanolin, vaseline, spermaceti, tfec., as re- 
 quired in special cases), or medicinal agents, are thoroughly 
 incorporated together in the mill, the whole mass (if not over- 
 dried) becomes compara- 
 tively soft and plastic, 
 much as partially dried 
 putty is softened by roll- 
 ing and working it in the 
 hand. When thoroughly 
 intermixed, the ribbons 
 stripped off the last roller 
 are strongly compressed 
 together ; in one class of 
 machine by filling them 
 into a barrel or cylinder 
 provided with a conical 
 end terminating in a 
 nozzle, and forcing the 
 mass outwards by means 
 of a piston worked by a 
 screw or by hydraulic 
 power : the plastic rib- 
 bons are thus " squirted " 
 outwards through the 
 nozzle as a continuous bar, which is then cut into short lengths and 
 stamped into tablets. In another class of "plotting machine,"* 
 the ribbons are made to fall from a hopper into the grooves of a 
 large conical archimedean screw working in a funnel shaped 
 barrel, terminating in a nozzle of appropriate size ; as the screw 
 revolves the soap is gradually propelled onwards towards the 
 nozzle, and on account of the diminishing diameter of the worm, 
 becomes strongly compressed together, so as finally to issue from 
 the nozzle as a firm solid bar, which is then cut up and 
 stamped as before. Fig. 138 represents Beyer's plotting machine 
 working on this principle. 
 
 Cylindrical and spherical soap tablets and wash balls are some- 
 times prepared; these are usually stamped into approximately the 
 required shape by means of suitable presses, or by hand, and when 
 sufficiently dry, finished by turning and polishing in a kind of lathe. 
 In order to give a polished surface to soap tablets, a method 
 frequently employed is to expose them to wet steam for a few 
 seconds, which glazes the exterior. More expensive varieties 
 are sometimes polished by hand, using a cloth dipped in 
 alcohol, &c. 
 
 * From the French term, " pelotage," applied to this squirting process. 
 
SOAPMAKING PROCESSES. 449 
 
 CHAPTER XX. 
 MANUFACTURE OF SOAP. 
 
 As compared with metallurgical and textile industries the art of 
 soapmaking is not possessed of any claims to great antiquity ; 
 the ancients were acquainted with the detergent power of wood 
 ashes (vegetable alkali) and probably also with that of mineral 
 soda or natron* but do not appear to have known anything of 
 the products of the action of these substances on oleaginous 
 materials, no mention of any such compounds being to be found 
 in Homer or other early Grecian authors ; whilst the Hebrew 
 term borith f used by the prophets Jeremiah and Malachi, 
 although translated " soap," appears to have simply meant ivood- 
 ash alkali. 
 
 Pliny the elder, however, in the first century A.D. described 
 a sort of imperfect soft soap made from goat's tallow and the 
 alkali from beech wood ash ; and also a harder variety (possibly 
 got by the action of salt on the former, producing soda soap) ; 
 and another writer in the second century in a work entitled 
 De Simplicitus Medicaminibus refers to a softer " German " 
 variety of soap (probably chiefly made from the ashes of land 
 plants) and a harder " Gallic " form (probably derived from sea- 
 weed ash). Later still, soapmaking appears to have been some- 
 what more extensively practised, as the remains of a soap factory 
 have been found at Pompeii. 
 
 Soapmaking Processes. The variations in the different 
 methods by which soaps are prepared on the manufacturing 
 scale are somewhat numerous, but all may be conveniently 
 classified under one or other of the three following heads, so far 
 as the essential parts of the soap producing processes are concerned. 
 In many cases, however, various subsequent operations are gone 
 through before the goods are finally ready for the market, con- 
 sisting either of mechanical cutting and shaping operations, such 
 as casting into blocks, cutting these up into slabs, bars, and 
 tablets, and stamping the latter into shape in appropriate presses ; 
 or of the addition of other substances to the soap before cooling 
 
 * Proverbs xxv. 20. "As vinegar upon nitre [or soda, marginal note, 
 Revised Version], so is he that singeth songs to an heavy heart." The 
 frothy uon-perinanent effervescence due to the action of the acid on natron 
 is doubtless what is here alluded to ; acetic acid and nitre (potassium 
 nitrate) having no mutual action whatever. 
 
 t Jeremiah ii. 22. "Wash thee with lye, and take thee much soap." 
 Malachi iii. 2. "Like a refiner's fire and like fuller's soap." 
 
 29 
 
450 OILS, FATS, WAXES, ETC. 
 
 or solidifying, so as to increase its detergent properties ; or to 
 give it special qualities (e.g., disinfecting action); or to harden it, 
 so as to enable more water or other weight-giving "filling" to 
 be added without rendering it too soft for ordinary scouring 
 purposes, c. 
 
 I. Direct Neutralisation Processes. Where free fatty 
 acids and alkalies are brought together and converted into soaps 
 by directly neutralising one another, with or without evolution 
 of carbonic acid gas according as carbonated or caustic alkalies 
 are employed. Obviously no glycerol is produced in the formation 
 of soaps of this kind. 
 
 The free fatty acids thus employed are practically almost con- 
 fined to the "red oils'" of the candlemaker (p. 386) i.e., the 
 liquid fatty acids expressed from the mixed products of saponi- 
 fication leaving behind the solid acids (commercial " stearine "). 
 Certain distilled and recovered greases (such as Yorkshire grease 
 from the suds of wool scouring, &c., Chap. XH.) are of similar 
 character, and are sometimes intermixed with red oils for the 
 purpose of soapmaking in this way ; but, as a rule, they are not 
 suitable alone for the preparation of soap of good quality. 
 Resinate of soda (rosin dissolved in soda ley) used in the manu- 
 facture of rosin soaps (infra) is a product of precisely similar 
 nature, excepting that the rosin acids do not belong to the 
 ordinary fatty acid families described in Chap. in. 
 
 II. Soapmaking Processes where Glycerol is set free 
 taut not separated from the resulting Soap. In these pro- 
 cesses natural glycerides are employed, being acted upon by 
 alkalies (usually caustic) used in regulated quantity so as to 
 suffice to saponify the total fatty matters without introducing 
 any large excess of alkali ; the strength of the ley being made 
 such that the product becomes more or less solid after cooling 
 and standing, the glycerol consequently being contained in the 
 product. 
 
 To this class belong more particularly soft soaps made by 
 boiling together appropriate oils, &c., and potash ; marine soaps 
 and hydrated soaps prepared in similar fashion, mostly with 
 soda and largely from cokernut or palmnut oil ; socalled cold 
 process soaps of various kinds, more especially certain forms of 
 transparent soaps, perfumer's soaps, and analogous products ; and 
 certain kinds of soap prepared under pressure. 
 
 III. Soapmaking Processes where the Glycerol set free 
 and the resulting Soap are separated from one another. 
 In these processes the essential feature is that glycerides are 
 more or less completely saponified by boiling up with compara- 
 tively weak alkaline leys, and the soap formed " salted out ; ' by 
 addition of brine or solid salt so as to separate it as a pasty mass 
 from the watery fluid in which the glycerol remains dissolved. 
 The half made soap thus obtained is then finished by one or 
 
DIRECT NEUTRALISATION PROCESSES. 451 
 
 other of various processes, leading to the production of some 
 variety of "curd," "mottled," or "fitted soap;" whilst the 
 watery liquors are either thrown away or utilised by boiling 
 down so as to recover more or less of the dissolved salt for use 
 over again, and ultimately obtain the glycerol in an impure form 
 (vide Chap, xxn.) As regards the magnitude of the scale on which 
 they are made, and the total quantity manufactured, boiled soaps 
 of this class are the most important of all. Additional materials 
 are frequently added to the soap thus prepared for special pur- 
 poses e.g., silicate of soda, borax, and aluminate of soda, to 
 increase the detergent action of household and laundry scouring 
 soaps ; sulphate and carbonate of soda, to stiffen and harden the 
 soap, and prevent it from wasting too rapidly in use ; resinate of 
 soda, in the manufacture of yellow soaps ; carbolic acid, creosote 
 oils, and similar substances, in the manufacture of disinfecting 
 soaps ; and so on. When potassium carbonate is thus added to 
 molten soda soap in not too large a quantity double decomposi- 
 tion takes place between the sodium salts of the fatty acids and 
 the potassium carbonate ; thus in the case of stearate 
 
 Sodium Potassium Potassium Sodium 
 
 Stearate. Carbonate. Stearate. Carbonate. 
 
 2Na.C 18 H 35 2 + K 2 C0 3 - 2K.C 18 H 3 502 + Na 2 CO 3 
 
 The result of this is accordingly the formation of a certain pro- 
 portion of comparatively soft potash soap instead of the harder 
 soda soap, which alters the texture of the mass ; this operation 
 of " pearlashing " is consequently employed in the preparation of 
 certain kinds of toilet soaps (infra). On the other hand, if fatty 
 matters be saponified with boiling potash ley, and the resulting 
 soap salted out with ordinary salt, the opposite kind of change 
 takes place, soda soap and potassium chloride being formed 
 e.g., in the case of palmitate 
 
 Potassium Sodium Potassium Sodium 
 
 Pulmitate. Chloride. Chloride. Palinitate. 
 
 K.C 16 H 31 2 + NaCl - KC1 + Na.C 16 H 3l 2 
 
 In the earlier days of soapmaokingfwhen woodash was the most 
 available form of alkali, this reaction was of some technical 
 importance as enabling a hard soda soap to be obtained in lieu of 
 a soft greasy product ; but although the effect appears to have 
 been known and the operation practised to some considerable 
 extent, it is doubtful if the chemical nature of the change was 
 understood until recently (vide Chap, xxi.) 
 
 DIRECT NEUTRALISATION PROCESSES. 
 
 The preparation of soap by the direct combination of free fatty 
 acids and alkalies is an extremely simple operation, more especi- 
 ally when the alkali is caustic ; all that is required is a suitable 
 mixing pan provided with an agitator so that the fluid ingredients 
 
452 
 
 OILS, FATS, WAXES, ETC. 
 
 can be intimately intermixed. Fig. 139 represents a steam 
 jacketted pan with steam pipes, ppp, projecting upwards into 
 the pan, whilst an agitator, <?, worked by bevel wheels, carries 
 a series of vertical vanes projecting downwards, so that clots are 
 broken up by the interlacing of the pipes and vanes. Another 
 form of agitator consists of two sets of rods or vanes made to 
 revolve in opposite directions by means of bevel wheels. The 
 red oils, &c., are run into the pan (steam jacketted for large 
 operations) and heated up ; the alkaline ley is gradually run in 
 
 Fig. 139. 
 
 with agitation, and finally the hot pasty mass transferred to a 
 "frame" in which it solidifies to a block of soap. 
 
 A slight surplus of alkali is practically imperative in order to 
 ensure complete conversion of the fatty acid into soap ; this 
 surplus mostly remains disseminated through the mass as it 
 solidifies, although a small quantity generally exudes as a watery 
 fluid ; by carefully regulating the quantities used the excess 
 may when requisite be diminished considerably below that indi- 
 cated in the example given below, where 5 parts of free alkali 
 are reckoned for 40 combined, representing a ratio of 1 to 8 
 
RESINATE OF SODA. 453 
 
 or 12-5 to 100. On the other hand, for soaps intended to be 
 highly detergent a larger excess of alkali is intentionally used. 
 
 Carbonated alkali is sometimes used, instead of caustic, in the 
 preparation of " oleine soap " (Morfit's process) ; of late years, 
 however, the facilities for obtaining solid caustic soda as a com- 
 mercial product have increased so largely that the slight saving 
 in cost effected by the use of the former is generally considered 
 to be more than outweighed by the increased amount of trouble 
 involved in the process. When employed, the mixing pan is 
 fitted with a large movable " curb " (a funnel or barrel shaped 
 top Fig. 113) in which the froth rises, due to the liberation of 
 carbonic acid, and the operation is carried out somewhat more 
 slowly to avoid frothing over. 
 
 With inferior soaps, largely made from recovered greases and 
 such like materials, silicate of soda is sometimes mixed or 
 " crutched " into the mass when the combination is complete, 
 just before running into the frames. For this purpose crutching 
 machines, such as those represented by Figs. 127 to 130, are con- 
 veniently used. Resinate of soda is also employed as an ingredient 
 to increase the detergent action. On the other hand, with soaps 
 required to contain as little free alkali as possible, not only is 
 great care taken to reduce the proportion of free alkali present 
 to the minimum consistent with proper combination of the fatty 
 acids, but in special cases e.g., for wool-scouring soaps and 
 soaps used in the silk industries, further means are adopted to 
 render the small excess innocuous. One method, found in 
 practice to be very effective (patented by the author), consists 
 of the addition of a regulated quantity of an ammoniacal salt 
 (usually dissolved in a minimum of water) to the pasty mass, 
 and well incorporating by a crutching machine or otherwise 
 before running into the frame. Any free alkali is thus neutralised 
 by the acid contained in the ammoniacal salt, with the formation 
 of an equivalent amount of free ammonia. This latter mostly 
 escapes when the soap is cut into bars and stored, but the little 
 that remains is beneficial rather than injurious to wool and silk, 
 unlike the original free fixed alkali. 
 
 Resinate of soda is often prepared for intermixture with soaps 
 of various kinds by boiling up rosin with rather less than twice 
 its weight of soda ley of about 16 T. (specific gravity 1'08), con- 
 taining about 7 per cent, of NaOH * until completely dissolved. 
 The liquid sets to a sort of thin jelly when cold, containing the 
 soda salts of the rosin acids and more or less excess of alkali, 
 according to the quantity used. Any kind of pan will answer if 
 furnished with a wet steam coil, or with an agitator and some 
 other suitable means of heating. Morfit's steam twirl (Fig. Ill, 
 p. 429) answers well. 
 
 * The saponiti cation equivalent of rosin usually lies between 330 and 370, 
 so that 10U parts of rosin correspond with between 10'8 and 12*1 parts of 
 NaOH. 
 
454 OILS, FATS, WAXES, ETC. 
 
 Calculation of Quantity and Strength of Ley required, 
 and of Composition of resulting Soap. The quantity of ley 
 of a given strength employed depends partly on the mean equi- 
 valent of the oleine, c., used, and partly on the amount of excess 
 of alkali intended to be added to ensure complete neutralisation 
 and communicate extra detergent properties to the soap ; whilst 
 the exact strength employed depends on the proportion of water 
 the finished soap is intended to contain. Assuming the oleine 
 to be pure oleic acid, its saponificatioii equivalent would be 
 282 i.e., 282 parts of oleine would neutralise 40 of NaOH in 
 accordance with the reaction. 
 
 Gleic Acid. Caustic Soda. Sodium Oleite. Water. 
 
 C] S H 34 Oo + NaOH NaC 18 H 33 O 2 + H 2 
 
 Supposing the ley to be a pure solution of sodium hydroxide, if 
 such a quantity were used as would contain 45 parts of NaOH, 
 5 would consequently remain unneutralised, or the " free alkali '' 
 would bear to the " combined alkali " the ratio 5 to 40 = 1 to 8 
 = 12*5 per cent.; if, then, 140 parts of ley were used, containing 
 45 of NaOH (32-1 per cent), neglecting mechanical losses and 
 evaporation, the resulting mass would consist of 282 + 140 = 422 
 parts, made up thus 
 
 Sodium oleate, . . 304 parts 72 '04 per cent. 
 
 Excess of caustic soda, . 5 ,, = 1'18 ,, 
 Water, . . . . 113 ,, = 26'78 
 
 422 100-00 
 
 The 113 parts of water are made up of 140 45 = 95 parts con- 
 tained in the ley used, arid 18 parts formed by the above 
 reaction. 
 
 If a proportionately larger amount of weaker ley were used 
 containing 45 parts of NaOH in 160 (28-1 per cent, of NaOH) 
 the resulting mass would consist of 282 + 160 = 442 parts, 
 made up thus 
 
 Sodium oleate, . . . 304 parts = 68 '78 per cent. 
 Excess of caustic soda, . . 5 ,, 1'13 ,, 
 
 Water, 133 = 30'09 
 
 442 100-00 
 
 On the other hand, if a proportionately less amount of stronger 
 ley were used containing 45 parts of NaOH in 120 (37 '5 per 
 cent, of NaOH) the composition of the resulting 282 + 120 
 = 402 parts would be 
 
 Sodium oleate, . . . 304 parts = 75 "62 per cent. 
 Excess of alkali, . . . 5 = 1'24 
 
 Water, 93 = 23'14 
 
 402 100-00 
 
CALCULATIONS. 455 
 
 In similar fashion the strength and quantity of ley requisite for 
 any other given mixtures of free fatty acids can be calculated ; 
 thus suppose the mean equivalent of the fatty acids to be E, and 
 that the surplus free alkali is to be n per cent, of that combined 
 as soap ; then for E parts of fatty acid a quantity of ley must be 
 
 used containing 40 x ^ = CH x (100 + n) parts of NaOH 
 
 altogether. With a ley containing saline matters (chloride, 
 sulphate, &c.) representing m parts per 100 of NaOH, the 
 
 quantity of saline matter will be -^-= x 0*4 x (100 + n) = 
 0-004 x m x (100 + n); so that a weight, W, of ley will contain 
 
 NaOH, 0'4 x (100 + n) 
 
 Saline matters, .... m x 0'004 x (100 + n) 
 Water, . . . . W - O'OOl x (100 + m) (100 + n) 
 
 Hence the total water present will be 
 
 18 + W - 0-004 x (100 + m) (100 + ), 
 and the resulting soap will consist of 
 
 Sodium oleate, E + 40 - 18 . . . . * ; ; = E + 22 
 Excess of NaOH, - x 40 =0'4xn. 
 
 Saline matters, -_ x 0'4 x (100 + n) . = 0'004 x m x (100 + n) 
 LOO 
 
 Water, W + 18 - 0-004 (100 + m) (100 + n) 
 
 Total, E + W. 
 
 Suppose that w parts of resinate of soda solution be added to 
 the soap, consisting of 
 
 Resinate of soda, . . ..- . . a parts. 
 
 Excess of NaOH, b ,, 
 
 Water, w - (a + b) 
 
 then the total mass, neglecting mechanical loss and evaporation, 
 will consist of 
 
 Soap (sodium oleate + resinate), . . . E + a + 22 
 
 Excess of NaOH, 0'4 x n + b 
 
 Saline matters, .... 0'004 x m x (100 + ) 
 Water, W + w + 18 - {0'004 (100 + m) (100 + n) + a + b} 
 
 Total, E + W + w. 
 
 If, on the other hand, w parts of silicate of soda be added, 
 containing 
 
 Silicate of soda and other saline matters, . . c parts. 
 
 Excess of NaOH, d ,, 
 
 Water, w' - (c + d) ,, 
 
456 OILS, FATS, WAXES, ETC. 
 
 then the total mass will contain 
 
 Sodium oleate, . . . . . . . . . E + 22 
 
 Excess of NaOH, 0'4 x n -f d 
 
 Sodium silicate and other saline matters, . 0'004 x m (100 + n) + c 
 Water, . W + w' + 18 - {0'OP4 (100 - m) (100 - n) + c + d] 
 
 Total, . E + W + ;'. 
 
 These various quantities are readily calculated into per- 
 centages when the values of E, m, n, a, b, c, c/, W, w, w' are 
 given for any particular case e.g., suppose E = 280, n = 10, 
 m = 12, and W = 150 in the case of a soap not treated with 
 resinate or silicate, &c., then the composition is 
 
 Sodium oleate, . . . 2SO + 22 = 302 "0 = 70 '23 per cent. 
 
 Excess of NaUH, . . . 0'4 x 10 = 4/0 = 0'93 
 
 Saline matters, . , 0'004 x 12 x 110 = 5'2S = 1-23 ,, 
 
 Water, . 150+ 18 - 0'004 x 112 x 110 = 11872 = 27 61 
 
 Total, 280 + 150 = 430 00 = 100 '00 
 
 and similarly in other cases. 
 
 SOAPMAKING PROCESSES WHERE THE GLYCEROL 
 IS SET FREE BUT NOT SEPARATED. 
 
 The methods of this character may be divided into three 
 classes according to the temperature and pressure employed. In 
 socalled "cold process" soaps the materials to be saponified and 
 the alkaline ley are intimately intermixed in open vessels at 
 temperatures usually considerably below the boiling point, and 
 allowed to stand until the action is complete, the leys used 
 being of sufficient strength to yield a product not too moist. 
 " Hydrated " soaps (including " marine " soap) and " soft " soaps 
 are prepared by boiling together the materials under the ordinary 
 pressure ; whilst soaps prepared under increased pressure are 
 treated in closed vessels so as to obtain a still higher temperature 
 for the purpose of shortening the operations and rendering them 
 more complete. In all cases the amount of alkali employed must 
 be carefully proportioned to the quantity of fatty matters used 
 and their mean saponification equivalent, otherwise either an 
 imperfect soap will result containing more or less unaltered 
 grease owing to the use of a deficiency of alkali, or a strongly 
 alkaline one through the use of too great an excess. Sometimes 
 these two faults occur simultaneously through the action not 
 having been completely carried through ; this is not unfrequently 
 the case with soaps made on the small scale with highly scented 
 materials (perfumer's soap), where avoidance of much rise of 
 temperature is indispensable, since otherwise the delicacy of the 
 odour would be deteriorated, so that the product is apt to contain 
 
COLD PROCESS SOAPS. 
 
 457 
 
 simultaneously unaltered fatty glycerides and uncombined caustic 
 alkali. Soaps of this kind, however, have now been largely driven 
 out of the market by " milled " toilet soaps where the evil effect 
 of heat on delicate perfumes is avoided, and at the same time a 
 perfectly made soap ensured, by mixing a good kind of stock 
 soap with the scenting materials, &c., by machinery, grinding 
 them together in the cold (vide infra, also p. 446). 
 
 Cold Process Soaps. For the preparation of cold process 
 soaps on the large scale a " Hawes' boiler " is convenient. The 
 fatty matters (tallow, either alone or mixed with palm oil or 
 lard, and preferably a small quantity of cokernut oil, the presence 
 of which facilitates the saponification; or other similar mixtures) 
 are introduced into a pan such as that indicated in Fig. 140, or into 
 a horizontal cylinder, Fig. 141 (5 to 6 feet diameter), provided 
 
 D 
 
 Fig. 140. 
 
 Fig. 141. 
 
 with a mechanical agitator and heated till sufficiently fluid, usually 
 to about 45 C. (about 113 F.) Strong soda ley of about specific 
 gravity 1-33 (66 Twaddell, containing about 24 per cent, of 
 NaOH) is then run in in sufficient quantity (approximately two 
 parts of fat to one of ley, the exact- proportion varying with the 
 mean saponification equivalent of the fatty matters), with con- 
 tinuous agitation until the whole becomes pasty and thoroughly 
 intermixed ; the paste is then run out into a wooden frame and 
 well covered up to keep in the heat ; as warmth is produced by 
 the saponification change, the mass doe^sjjiofr cool until the action 
 is completed ; at first the change takes place only languidly, but 
 after a while it becomes more rapid and the mass sensibly heats ; 
 by and bye as the action approaches completion the temperature 
 begins to fall again. If the materials are too highly heated at 
 first the paste is apt to be too fluid, so that unsaponified grease 
 and watery ley tend to separate partially during the period of 
 standing, thus yielding an imperfect product. Instead of soda 
 alone a mixture of soda and potash (the former largely predomi- 
 nating) is often employed with the object of obtaining a product 
 of superior texture. 
 
458 OILS, FATS, WAXES, ETC. 
 
 Certain kinds of transparent soaps (often termed "glycerine 
 soaps") are frequently prepared by means of a modification of 
 the cold process ; the warm fatty materials employed (of which 
 castor oil is generally a considerable ingredient on account of 
 its ready saponifiability and its tendency to form translucent 
 soaps) are intimately intermixed with soda ley (and in certain 
 cases a small proportion of alcohol) ; soluble colouring matters 
 <and essential oils and other scents are then stirred in and 
 the whole allowed to stand until saponification is complete : 
 with suitably chosen ingredients and proportions the resulting 
 block of soap is more or less transparent, the presence of 
 the glycerol formed on saponification tending to cause the 
 soap to assume a "colloid" or gum-like structure instead of 
 the semicrystalliiie opaque condition usually developed in 
 ordinary hard soaps. When alcohol is not used as an ingre- 
 dient in the mass, the transparency is usually only imperfect, 
 but by incorporating extra glycerol instead a highly transparent 
 mass can be readily obtained. Cane sugar effects the same result, 
 and is generally employed instead of either alcohol or glycerol 
 on account of its cheapness ; but the effect on the nature of the 
 resulting product is by no means the same, inasmuch as saccharine 
 substances are apt to produce a very unpleasant irritating effect 
 when applied to highly sensitive skins (ladies', babies', invalids', 
 and so forth). This, moreover, is apt to be greatly aggravated 
 by the presence of a more or less considerable excess of alkali in 
 the soap mass, necessarily added to effect complete saponification,* 
 inasmuch as muddiness is apt to be produced if any of the fatty 
 glycerides remain unchanged, which is likely to be the case, 
 unless some excess of caustic alkali is present. It accordingly 
 results that many kinds of transparent socalled " glycerine soaps " 
 are of the worst possible quality from the point of view of liability 
 to excoriate and irritate extremely tender skins ; although their 
 appearance, when attractively tinted and agreeably scented, render 
 them apparently very elegant articles. 
 
 The cheaper kinds of transparent soap of this description are 
 often extensively " filled in " with liquid paraffin and petroleum 
 hydrocarbons which possess the property of blending with the 
 sugary soap mass without seriously interfering with either its 
 consistency or transparency ; taking into account some 20 to 
 25 per cent, of "loading" thus introduced, together with some 
 12 to 18 per cent, of sugar, and 20 to 25 per cent, at least of 
 water, it often results that the actual soap present does not 
 exceed 33 to 40 per cent, of the mass. On the other hand, a 
 well made soap where the minimum possible excess of alkali 
 only has been used, where the rate of saponification and ten- 
 transparent soaps made by the "spirit process" (infra) are generally 
 free f roui this defect, although as usually sent into the market they contain 
 considerable amounts of cane sugar. . 
 
SOFT SOAPS. 459 
 
 dency to colloidal structure of the product have been intensified 
 by the use of an admixture of spirit in the original materials, 
 together with a little glycerol instead of sugar, and where no 
 loading has been added, not only contains a far larger proportion 
 of useful ingredients of much better quality, but also for that very 
 reason resists the wasting and solvent action of water (especially 
 when hot) much more completely, and is consequently much more 
 economical in use, as well as comparatively free from corrosive* 
 action, on delicate skins. 
 
 Soft Soaps. Potash soaps appear to possess, on the whole, a 
 greater tendency to assume the colloid form than soda soaps, in 
 consequence of which, when prepared from suitable fatty matters, 
 they are more inclined to be jelly-like and transparent or trans- 
 lucent, than to form comparatively hard opaque semicrystalline 
 masses like ordinary soda soaps; moreover, they are generally 
 deliquescent, so that they do not readily dry up. The precise 
 texture of a given mass, however, largely depends on the tempera- 
 ture, as in cold weather crystalline grains often form, more especi- 
 ally when the fatty matters used contain palmitic or stearic acid : 
 soap exhibiting this peculiarity (known as " figging ") is gener- 
 ally supposed to be of superior quality for that reason, although 
 on what grounds it is difficult to say ; the granular appearance 
 is sometimes imitated by mixing in starch, clay, steatite, &c. 
 Linseed and other drying oils (poppy seed, hempseed, &c.) ; non- 
 drying and semidrying vegetable oils (such as rape, camelina, 
 and cotton seed) and similar animal oils (train, liver, arid fish 
 oils); together with the "red oils" of the candlemaker (crude 
 oleic acid), are those most largely employed in the manufacture 
 of soft soaps, a little tallow being added to furnish stearate for 
 "figging," and in many cases indigo in small quantity so as to 
 give a greenish shade (by conjunction with the yellow tinge of 
 the untinted soap) ; this tint being natural to hemp seed oil, and, 
 therefore, artificially imitated in other cases. When whale and fish 
 oils are employed an unpleasant smell is apt to be communicated 
 to linen, &c., washed with such soap. Considerable practice and 
 skill is requisite in boiling soft soap, although the actual opera- 
 tions are of the simplest character ; the " copper " or pan (usually 
 made of iron plates rivetted together boiler- fashion Fig. 112) 
 in which the boiling takes place was formerly mounted over a 
 free fire, but is now generally heated by means of two steam 
 coils, one for " dry steam " (i.e., simply a coil through which 
 superheated steam circulates so as to heat up the contents of 
 the pan), the other for " wet steam " (i.e., a coil perforated with 
 holes, so that when steam is let in from the boiler it escapes into 
 the mass through the holes, heating it up and becoming itself 
 condensed, until the temperature is so high that the steam simply 
 blows through). Figs. 1 14, 1 ] 5 illustrate a pan fitted with the two 
 kinds of steam coils. The mixed fatty matters are run into the 
 
460 OILS, FATS, WAXES, ETC. 
 
 copper so as to fill it to about one-fifth or one-fourth of its capacity ; 
 the whole is then heated up (by free fire when that is used, by 
 means of the dry steam coil if no free fire is employed), and whilst 
 heating potash ley (usually of specific gravity 1 -07 to 1 -08) is 
 slowly run in. This ley is found by experience to act better if 
 not completely causticised, a portion (some 15 to 25 per cent.) of 
 the alkali being still carbonated ;* the heat should be so applied, 
 and the rate of supply o c ley so adjusted, that by the time that a 
 volumn of liquor about equal to that of the oil has been run in, 
 the whole mass is beginning to boil ; to prevent frothing over a 
 "fan" (Fig. 116) is conveniently arranged over the pan. The 
 boiling is continued with wet or dry steam, usually the former, 
 with further additions of ley from time to time, until the proper 
 consistency and appearance are arrived at as judged by taking 
 out samples and quickly chilling them ; as long as an insufficient 
 quantity of ley has been used a visible appearance of unsaponified 
 fat is manifest, giving a peculiar border to the sample ; whilst if 
 excess has been added the sample more or less tends to separate 
 into two different portions, one of soap, the other of watery liquor; 
 in this case more oil (agitated and emulsified with a little weak 
 liquor to enable it to mix better with the boiling mass) is added, 
 and so on until the sample sets to a clear translucent mass. 
 Finally the wet steam is shut off and the mass boiled either by 
 dry steam or free fire until sufficiently concentrated by evapora- 
 tion, when the finished soap is barrelled or put up in canisters 
 or drums for sale. 
 
 Some makers prefer to use stronger leys in the first instance 
 (specific gravity 1-120 to 1-150 = 24 to 30 Tw.), whereby less 
 boiling down is requisite in the final stage. In some cases a 
 mixture of potash and soda leys is employed, the former, how- 
 ever, always constituting more than half of the total alkali (60 to 
 75 per cent.) Soft soap containing soda is apt to become muddy 
 in cold weather, and hence is preferably made only in summer. 
 
 The exact nature of the mixture of fatty matters employed is 
 generally regarded as a valuable trade secret ; the relative 
 proportions of the constituents are often varied somewhat 
 according to the season ; in winter the consistency of the product 
 is usually much greater than in summer, so that in the former 
 case, such a mixture is employed as would (for the same atmo- 
 spheric temperature) give a softer jelly, and vice versa. For 
 household soft soaps, silicate of soda (or potash) is sometimes 
 mixed in with the finished soap, whilst rosin is often added to 
 the fatty mixture employed as basis ; when the soap is intended 
 for silk and wool scouring, however, such admixtures are highly 
 
 * When the soft soap is required to be as nearly neutral as possible, car- 
 bonated alkali is undesirable as tending to give a product containing a 
 larger amount of "free alkali" than that obtainable by the judicious use 
 of caustic alkali free from carbonate. 
 
MARINE SOAP. 401 
 
 injurious, partly because of the presence of silicated alkali in the 
 soap, which has a very bad effect on the fibre ; partly because 
 soaps thus treated usually contain a larger proportion of 
 uncornbined potash or soda, or both, than genuine well made soft 
 soap. It is generally supposed that because ordinary woolgrease 
 (suint) naturally contains much potash and but little soda, there- 
 fore soda has a more injurious action on wool fibre than potash. 
 Apart from the somewhat illogical character of this reasoning, 
 however, there does not seem to be any experimental evidence 
 extant to show that this is really the case ; on the contrary, 
 experience seems rather to indicate that, provided a soap is 
 sensibly neutral (i.e., devoid of alkali uncombined with fatty 
 acids), it is but of little consequence whether it be a potash soap 
 or a soda soap as regards injury to the fibre of wool during use 
 in scouring ; on the other hand, a highly alkaline potash soap, 
 otherwise pure, exerts more deleterious action than a compara- 
 tively neutral soda soap ; although, without doubt an alkaline 
 soda soap, especially if silicated, is extremely objectionable. 
 Probably the prejudice respecting the superiority of potash over 
 soda soaps for wool scouring is largely due to the inferiority of 
 the soda (silicated) soaps now manufactured in great quantity for 
 household scouring purposes, when compared with potash soft 
 soaps of good quality as regards the amount and nature of the 
 alkaline constituents present other than true soaps i.e., com- 
 pounds with fatty acids ; for a well made soda (oleine) soap devoid 
 of silicate or other forms of " free alkali," such as the dealkalised 
 soap described on p. 453, appears to be in practice quite as well 
 suited for wool scouring purposes as the best potash soft soap 
 obtainable. 
 
 Hydrated Soaps. The term " hydrated soap " is often 
 applied to soap manufactured in much the same way as soft soap, 
 but made with soda as alkali, and with fatty matters of such 
 nature as to furnish a comparatively hard opaque product rather 
 than a soft jellylike mass.* Cokernut or palm kernel oil is 
 generally an ingredient in the mixture of fatty matters used, its 
 presence facilitating the saponification of other fats less readily 
 attacked by alkalies ; when this substance constitutes the great 
 majority or the whole of the mass, the product is known as 
 marine soap, as the solubility in brine of the soda salts formed 
 from cokernut oil is sufficient to enable it to form a lather with 
 seawater. 
 
 Marine Soap. This is readily prepared by boiling up together 
 with wet steam cokernut or palm kernel oil, and strong soda ley 
 of specific gravity about 1-15 to M75 (30 to 50 Tw.), the latter 
 
 * In Germany, soap of similar character is often designated eschweyer 
 seife; in America, the term "Swiss soap" is similarly applied. Soaps of 
 this kind are often intermixed with boiled soaps containing no glycerol, so 
 as to form products of mixed character. 
 
4G2 OILS, FATS, WAXES, ETC. 
 
 being run in slowly. Saponification proceeds very rapidly when 
 once commenced, the mass frothing up largely, and requiring a 
 largo pan and curb to avoid loss by boiling over. A boiling 
 temperature, in fact, is not absolutely necessary, nor even 
 desirable to begin with, as the heat liberated by the action rapidly 
 raises the temperature, whence the copious frothing. Owing to 
 the low saponification equivalent of cokernut oil (about 210 to 
 215), a much larger quantity of alkali is requisite to bring about 
 complete saponification than is the case with most other kinds of 
 fatty matter ; 100 parts of cokernut oil correspond with about 
 19 of NaOH, whereas 100 parts of tallow represent only about 
 14 parts of NaOH (vide infra). A considerable quantity of 
 silicate of soda is generally run into the finished mass and well 
 " crutched in" (i.e., intermixed by agitation); the effect of this is 
 greatly to intensify the natural tendency of cokernut oil soap to 
 form a tolerably solid mass, even when incorporated with a con- 
 siderable amount of water ; so that silicated marine soap often 
 contains less than 20 per cent, of actual soap (sodium salts of 
 fatty acids), and upwards of 70 per cent, of water. Such a soap, 
 when heated alone, generally separates into two distinct sub- 
 stances, viz., a watery solution of silicate, etc., and a pasty mass 
 of actual soap. On account of this tendency to separation, the 
 crutching of the original mass must be prolonged until solidifica- 
 tion is tolerably far advanced, in order to ensure a uniform pro- 
 duct. Asa general rule, the price at which such highly watered 
 soap is sold is not reduced to anything like the extent that would 
 correspond with the amount of water added. 
 
 Hydrated soaps made from mixtures containing palm oil, 
 tallow, bone fat, horse grease, &c., are sometimes silicated, but 
 are more frequently hardened by crutching in a strong solution 
 of sodium carbonate (sometimes together with sodium sulphate), 
 whereby not only extra detergent quality is communicated, but 
 also a greater degree of firmness, enabling a larger proportion of 
 water to be present without rendering the soap too soft for 
 sale; the term "hydrated" (or "watered"), indeed, is originally 
 derived from the circumstance that the method of manufacture 
 enables a product to be obtained containing a much larger pro- 
 portion of water, and a correspondingly less quantity of actual 
 soap, than was formerly practicable with " boiled soaps " of the 
 third class. Even with these, however, it has been found 
 possible to produce an analogous result by somewhat similar 
 devices, more especially by cautiously crutching in saline solutions 
 (sodium silicate, carbonate, &c.) whilst cooling and solidifying 
 (vide infra}. 
 
 Hydrated Soaps prepared under Pressure. A large 
 number of patents have been taken out from time to time for 
 various processes and modifications of plant, intended to shorten 
 and simplify the manufacture of hydrated soaps by causing the 
 
HYDRATED SOAPS PREPARED UNDER PRESSURE. 
 
 463 
 
 reaction to occur at a more elevated temperature under increased 
 pressure. Thus Tilghmann proposed the use for soapmaking of 
 the same plant as used by him for hydrolysing glycerides by 
 water alone (p. 385). The apparatus that has been generally 
 found to answer best is some kind of autoclave where the 
 mutually adjusted quantities of fatty matter and lye are either 
 run in through a manhole or pumped in through a pipe, and 
 then heated up either by means of a free fire or by blowing in 
 high-pressure steam, much as in the manufacture of " steariiie }> 
 for candlemaking (p. 
 373). Fig. 142 illus- 
 trates Dunn's plant, 
 consisting of a ver- 
 tical boiler, B, with 
 manhole and safety 
 valve ; the fat and 
 ley are pumped in 
 through the safety 
 pipe, A, and the 
 finished mass ejected 
 through the empty- 
 ing tube and cock, C. 
 Heat is communi- 
 cated by means of 
 free firing, the tem- 
 perature attained be- 
 ing determined by 
 means of a long- 
 stemmed thermo- 
 
 Fig. 142. 
 
 meter, inserted in a tube filled with mercury or paraffin wax,. 
 projecting inwards into the boiler.* 
 
 In Bennett and Gibb's process a. horizontal boiler furnished 
 with an agitator is employed, somewhat similar to that used by 
 Hawe's (p. 457) ; into this are continuously pumped at one end 
 the fatty matters to be saponified and soda leys not causticised 
 (sodium carbonate solution), containing the appropriate quantity 
 of alkali (30 to 33 parts of soda ash at 48 per cent. Na 2 O 
 dissolved in 100 of water to 100 of fatty matter). At the other 
 end the finished soap mass emerges through a weighted exit 
 valve, the pressure 'being maintained at 220 to 280 Ibs. per 
 square inch (about 15 to 20 atmospheres, corresponding with a 
 
 * This boiler also serves for the preparation of silicate of soda (or potash) 
 solution. The boiler is charged with broken up flints or quartz pebbles and 
 soda ley of specific gravity 1*15 to 1*175 (30 to 35 Tw.), and is gradually 
 heated up until a pressure of 4 to 5 atmospheres is attained (corresponding- 
 with a temperature of about 150 C.), which is maintained for some hours. 
 At the end of this time the soda has dissolved silica to approximate satura- 
 tion ; the liquor is then blown off into a settling tank, and the clear portion 
 used for intermixture with soap. 
 
464 OILS, FATS, WAXES, ETC. 
 
 temperature of 190 to 215 C.) At this higher temperature the 
 carbonated alkali is stated by the inventor to act as efficiently as 
 caustic alkali at lower pressures. 
 
 Calculation of Quantity and Strength of Ley required 
 and of Composition of resulting Soap. Much the same 
 general principles apply in the case of the soaps at present 
 under discussion as in the case of those prepared by direct 
 neutralisation of fatty acids (p. 454), the chief difference being 
 that in the present instance no water is formed, whilst the 
 glycerol produced instead must be taken into account. If E 
 be the sapoiiification equivalent of a mixture of triglycerides, 
 E parts by weight of the mixture will require 40 parts of NaOH, 
 or 57 '1 parts of KOII, for sapoiiification, and will produce by 
 
 92 
 
 acting thereon ' ' parts of glycerol, in accordance with the 
 o 
 
 equation. 
 
 Trk'lyceride. Caustic Soda. G'ycerol. Soda Soup. 
 
 CH 2 . OX CH 2 . OH 
 
 i I 
 
 CH .OX + SNa.OH = CH . OH + 3Na . OX 
 
 CH 2 . OX CH 2 . OH 
 
 Suppose that a soda ley is used, containing m parts of neutral 
 saline matters (chloride, sulphate, c.) per 100 of NaOH ; 
 and that the proportion of ley employed is such that for 100 
 parts of NaOH converted into soap n parts are employed in 
 excess. The total NaOH employed will, consequently, be 
 
 40 x 1" n = 0-4 (100 + n) parts for E parts of fatty matter 
 
 as before; whilst a given weight of ley, W, will contain, as 
 before 
 
 NaOH, 0-4 x (100 + ) 
 
 Saline matters, . . . -^ x 0'4 x (100 + n) = m x 0'004 x (100 + w) 
 
 Water, W - 0'4 (100 + n) - 0'004 x m (100 + n) = W - 0'004 (100 -H m) (100 + n) 
 
 Total, W 
 
 Hence the resulting soap mass (neglecting mechanical losses 
 and|evaporation) will contain 
 
 Soda soap, E + 40 - -* - . . . . E + 9'33 
 
 Glycerol, ~ ..... - 30'67 
 
 o 
 
 Excess of NaOH, T " 7r x 40 . . . . = 0'4 x n 
 
 100 
 
 Saline matters, 0'004 x m (100 + n) 
 
 Water, W - 0'004 (100 + m) (100 + n) 
 
 Total, E + W 
 
CALCULATIONS. 465 
 
 In the case of a potash soap, if m parts of neutral saline 
 matters be present per 100 of KOH, and if n parts of KOH in 
 excess be used per 100 converted into soap, the total KOH used 
 
 will be 57-1 x 1Q * n = 0-571 x (100 + n) per E parts of tri- 
 glyceride mixture; whilst a given weight of ley, W, will contain 
 
 KOH, 0-571 x (100 + n) 
 
 Saline matters, -^ x 0'571 x (100 + n) = 0'0057l x m x (ICO + n) 
 Water, j ^ ' 0-57,1(100^) - 0B71 1 = w _ ^ (10D + m) (100 + n) 
 
 Total, W 
 
 Whence the entire soap mass produced will consist of 
 
 no 
 
 Potash soap, E + 57'1 - .... E x 26'43 
 
 o 
 
 99 
 Glycerol, -^- = 30 "67 
 
 Excess of KOH, ^ x 57 '1 .... = 000571 x n 
 
 Saline matters, '00571 x m x (100 + n) 
 
 Water, W-0'00571 (100 + m) (100 + n) 
 
 Total, E + W 
 
 Suppose that an admixture of silicate of soda, resinate of soda, 
 syrup, or loading of any kind be made to the extent of w parts 
 by weight, the composition of the total mass will be similarly 
 arrived at ; thus suppose a mixture of fatty matters of mean 
 saponification equivalent 290 (E = 290) be saponified with excess 
 of soda ley such that W = 160, n = 15, and m = 10, and that 150 
 parts of syrup be added per 290 of fatty matters, consisting of 
 
 Sugar, . . 50 parts. 
 Water, . .100 ,, 
 
 150 
 
 i.e., let w = 150 ; then the composition of the resulting mass will 
 be 
 
 Soap, . . . .290 + 9-33 = 299 '33 = 49 -89 percent. 
 
 Glycerol, ... - 30'67 - 5'11 
 
 Excess of NaOH, . 0'4 x 15 = 6'00 = I'OO 
 
 Saline matters, . 0'004 x 10 x 115 = 4'60 = 0'77 
 
 Sugar, 50-00 = 8 '33 
 
 Water, . 160 + 100 - 0'004 x 110 x 115 = 209'40 = 34-90 
 
 Total, 290 + 160 + 150 = (300 '00 = 100 '00 
 
 30 
 
466 OILS, FATS, WAXES, ETC. 
 
 In the preparation of soft soap, the quantity of ley and fatty 
 matter used are usually not adjusted to one another beforehand 
 in the way requisite for cold process soaps \ the ley is run in 
 gradually during the operation until the requisite consistency is 
 attained, more fatty matter being added in case of an excess of 
 alkali having been used, practical experience in carrying out the 
 manipulations being the guide to the quantities employed rather 
 than accurate weighing or measuring. Similar remarks apply to 
 most hydrated soaps prepared by boiling in open pans ; on the 
 other hand, for soaps made under pressure in autoclaves, tfec., 
 the relative quantities of materials must be carefully adjusted at 
 the commencement of the operation, as the nature of the process 
 does not conveniently admit of more material being added after 
 the operation has been once commenced and the increased pressure 
 attained. 
 
 SOAPMAKING PROCESSES WHERE THE GLYCEROL 
 
 AND SOAP FORMED ARE SEPARATED 
 
 FROM ONE ANOTHER. 
 
 Methods of this class substantially depend upon the general 
 principle that whereas most alkali soaps are pretty freely soluble 
 in pure water, especially when hot, the presence of various kinds 
 of neutral saline matter e.y., common salt and even of a large 
 excess of caustic or carbonated alkali, renders them insoluble ; 
 so that the addition of salt or strong ley to an aqueous soap 
 solution causes the soap to separate or precipitate in more or less 
 solid flakes, the physical structure of which is more akin to that 
 of crystalloid substances than to the colloid gum-like form in 
 which transparent soap is obtained. The process of manufacture 
 may accordingly be broadly described as consisting o^f boiling up 
 the fatty matter to be saponified with comparatively weak alkaline 
 fluids not used in excess, but employed in such quantity that 
 when the alkali has been practically all neutralised by combina- 
 tion with the fatty acids the great majority of the fatty matter 
 is decomposed, the remaining portion being distributed through 
 the soap solution formed as a sort of emulsion. At this stage, 
 on adding solid salt or strong brine, the dissolved soap is thrown 
 out of solution and separates as a more or less granular curd, 
 carrying with it the unaltered fat ; the watery fluid containing 
 the liberated glycerol being run off, the pasty imperfect soap is 
 further treated with successive small quantities of stronger ley, 
 being boiled up therewith until the saponification is complete. 
 Finally, the soap is "finished" by one or other of various kinds of 
 operation, according to the nature of the intended product. For 
 "mottled" soaps, the curd resulting after complete saponification 
 is boiled down (by dry steam, or in the older w^ay of working, by 
 
CURD SOAP. 467 
 
 free fire), together with excess of strong ley, until it acquires a 
 sufficient consistency i.e., until it is so thick that on running 
 into the frames the coloured impurities present (iron soap, &c., 
 formed during the process, or produced by adding green vitriol, 
 &c., to the curd) are unable to sink to the bottom by gravitation; 
 in which case, as the mass cools and solidifies, these coloured 
 matters segregate into veins producing " mottling " of the old 
 fashioned type.* 
 
 For "fitted" soaps, the curd produced after complete saponifi- 
 cation is effected is allowed to stand awhile so as to separate 
 from the leys ; these are run off, and the curd boiled up with 
 wet steam and weak leys or water until it is sufficiently thinned 
 in texture to permit of the coloured heavier metallic soaps falling 
 to the bottom by gravitation on standing ; with rosin soaps more 
 particularly, peculiar textures ("coarse fit," "fine fit") are thus 
 arrived at, respectively suitable for different purposes. 
 
 Curd Soap. For "cleansed" curd soaps, the diluted curd 
 thus freed from coloured impurities is pumped off into another 
 copper, and theie boiled up with dry steam and a small quantity 
 of strong ley until again concentrated to the required extent 
 (i.e., until the curd, freed from ley by subsidence, has the desired 
 proportion of water associated with it) ; the water retained by 
 the curd being less the longer the boiling is continued, and the 
 stronger the ley (pp. 470, 4b6). 
 
 In boiling for curd soap,f the first saponification operation is 
 usually carried out by running into the copper caustic leys of 
 strength not exceeding specific gravity 1'05 to 1'075 (10 to 
 15T.),J together with' the melted fatty matters, and boiling 
 them up together. The way in which this is done varies much 
 in different cases and in different districts ; sometimes *tKe wfrole 
 batch of " goods " (fatty matters) is. run in, and then, a fraction 
 of the ley, and the whole boiled up^more ley bfeing added from 
 
 * Totally distinct from the modern" mottled soaps of highly watered and 
 silicated character vide p. 472. 
 
 t British curd soaps are almost invariably made from tallow as chief 
 basis, the hard difficultly lathering character of pure tallow soap being 
 modified by the addition of other oils and fats (small quantities of cokernut 
 oil, more or less cotton seed or groundnut oil, lard, and so on), according 
 to the object in view. On the Continent, and especially in France, vegeta- 
 ble oils are used in much larger proportion ; thus Marseilles (Castile) soap 
 is supposed to be made almost wholly from olive oil, and, in point of fact, 
 is chiefly prepared from the highly sophisticated mixtures sold under that 
 name ; and even in those cases where tallow is used, a pretty large propor- 
 tion of mixed vegetable oil is generally also added, rape oil being generally 
 one of the constituents added to give lathering qualities. 
 
 % Leys containing more than some 5 per cent, of JSa 2 act much less 
 slowly on tallow and most other oils and fats than weaker solutions, at 
 any rate in the first instance. When, however, the action is once fairly 
 started, somewhat stronger leys may be run in (in small quantities at a 
 time). 
 
468 OILS, FATS, WAXES, ETC. 
 
 time to time. Sometimes the majority of the ley is run in first, 
 and the goods added in successive portions, with continuous 
 boiling. More frequently the ley and goods are run in alter- 
 nately until the full complement of the latter is in the kettle, 
 with somewhat less than the corresponding quantity of ley, the 
 rest of which is subsequently added. When wet steam is used 
 to heat up the copper the leys initially employed may be a little 
 stronger than if dry steam be used on account of the dilution 
 with condensed water ; the later leys may also be stronger than 
 the first ones, as they become greatly diluted with the water 
 already present from the former leys. The effect of the action of 
 the hot ley on the melted fatty matter is to "kill the goods " 
 i.e., to emulsify the whole, so that no distinct layer of melted fat 
 swims up on taking a sample. 
 
 When the saponification has gone on to such an extent that a 
 large fraction of the glycerides is acted upon and but little alkali 
 remains dissolved in the ley, the whole mass forms a homo- 
 geneous pasty mass, consisting of the half made soap with 
 portions of emulsified fatty matter not yet saponified distributed 
 throughout it.* In this state it is known as "close" soap (in 
 some districts, as being in a "hitch" or "glue"). If too much 
 ley has been added this peculiar texture is not attained, a sample 
 taken out on a trowel exhibiting more or less marked tendency 
 to separate into two fluids, one more watery than the other ; 
 whilst, if the boiling has not been continued long enough, or if 
 the ley be too concentrated, a large surplus of undecomposed fat 
 is visible, giving a greasy texture to the imperfectly made soap 
 that thus separates from the watery ley. With proper care, 
 
 * It is extremely probable that the saponifying action of the alkali is 
 exerted in three stages, forming successively one, two, and three molecules 
 of soda soap ; thus (in the case of stearin) 
 
 Tristearin. Caustic Soda. Distearin. Sodium Stearate. 
 
 (O.C 18 H 3 ;0 (O.C 18 H 8 fiO 
 
 C 3 H 5 O.C 18 H 35 + NaOH = C 3 H 5 \ 0. C 18 H 33 + Na. 0. C 18 H 35 0. 
 (O.C 13 H 35 (OH 
 
 Distearin. Monostearin. 
 
 I O.C 18 H 35 <O.C J8 H 35 
 
 C 8 H 5 {O.C 18 H 35 + NaOH - C 3 H 5 \ OR + Na. 0. C 18 H 35 0. 
 
 /OH (OH 
 
 Monostearin. Glycerol. 
 
 (O.C 18 H 35 (OH 
 
 C 3 H 5 I OH + NaOH - C 3 H 5 \ OH + Na. 0. C 18 H, 5 0. 
 
 (OH (OH 
 
 On this view "half made soap ; ' consists of a mixture of sodium stearate 
 with emulsified tristearin, distearin, and monostearin, uniformly dissemi- 
 nated through the water as a sort of jelly. A circumstance favouring 
 this view is that the quantity of glycerol obtainable from the first spent leys 
 is considerably less than the amount corresponding with the goods killed, 
 not much above one half as a rule. 
 
GRAINING. 469 
 
 guided by indications only obtainable by practical experience, 
 the requisite physical condition is attained, representing a state 
 of matters where most but not quite all of the fatty matter is 
 saponified, whilst practically all the caustic soda in the leys has 
 been used up, furnishing an aqueous soap solution, or thin jelly, 
 with a little emulsified fat disseminated throughout. 
 
 Graining. The next stage consists in "graining" or "cutting" 
 the soap by the addition of sufficient saline matter to render the 
 dissolved soap insoluble in the resulting weak brine. For this 
 purpose common salt is used, either solid fresh salt or that 
 regained from previous batches of liquor during boiling down to 
 recover glycerol (p. 514); or a strong brine is run in. The 
 quantity added depends on the proportion of water already 
 present in the copper relatively to the soap, which in turn 
 depends on the strength of the leys used and the quantity of 
 water condensed from " wet " steam ; moreover, soaps containing 
 much coker or palmnut oil require more salt than others, cceteris 
 paribus. When sufficient salt is present in the watery liquor, 
 a sample of the contents of the copper taken out on a trowel 
 shows a mass of grains of semisolid soap, whilst a clear watery 
 fluid runs away, which should not be markedly alkaline to the 
 taste, and should throw up no scum of fatty acids on acidulation ; 
 showing that practically all the soda used has been converted 
 into soap, and all the soap formed thrown out of solution by the 
 addition of sufficient salt. Explosive evolution of steam (violent 
 " bumping ;; ) is very apt to occur during the graining process, 
 whence the use of a fan and curb (p. 433) in moderating the 
 frothing, whilst the kettle or copper used is only partly filled 
 with materials. 
 
 After standing for a few hours (steam being shut off) the 
 contents of the copper separate into watery " spent ley " which 
 is run off and utilised (for glycerol extraction, &c.), and pasty 
 " grain soap " consisting of about 3 parts actual soap to 2 of 
 adherent water : this is either finished at once (usually 
 pumped off into a smaller copper, or mixed with another batch 
 from another copper, there being less liability of violent frothing 
 over during the subsequent stages) ; or else more goods are 
 added with weak ley and the boiling recommenced as before 
 until the new batch of fatty matters is properly " killed," when 
 the whole mass is again salted out. 
 
 The grained soap, freed from spent ley, is then boiled up with 
 wet steam and an additional quantity of somewhat stronger ley 
 containing some 9 per cent, of NaOH (specific gravity about 
 1*09 to I'll) gradually run in so as to complete the saponification ; 
 the quantity finally added being sufficient to cause the mass to 
 separate into two (aqueous ley, and soap paste), the excess of 
 caustic soda throwing the soap out of solution just as salt does. 
 In some cases this operation is carried out in two stages, the 
 
470 OILS, FATS, WAXES, ETC. 
 
 alkaline " half spent " ley run off in the first stage being utilised 
 for killing fresh goods ; this ley washes out entangled brine and 
 contains most of the remaining glycerol developed by the com- 
 pletion of the saponification. ] 11 the second stage sufficient water 
 is added (including that condensed from wet steam) to cause 
 the paste to again assume the " close " state by dilution of the 
 leys admixed with it, and the boiling continued long enough to 
 ensure the saponification of the last portions of glycerides, when 
 the soap is again grained or "made" by running in sufficient 
 stronger ley to throw it out of solution in grains. Finally the 
 half spent leys are partly, but not wholly, run off, and the soap 
 paste and remaining ley boiled up by means of the dry steam 
 coils, so that water is evaporated, whereby the residual ley 
 becomes more concentrated, and the soap paste less watery 
 (p. 467) : when the paste sets on cooling to the required con- 
 sistency and degree of hardness, the boiling is stopped and the 
 mass allowed to stand some hours so that the leys and curd may 
 thoroughly separate from one another : the. curd is then trans- 
 ferred to the cooling frames. Unless purposely watered or 
 boiled down to a less extent, curd soaps generally contain only 
 20 to 25 per cent, of water. When required to be as white as 
 possible, the curd is allowed to stand for some time before the 
 final boiling operation, so that coloured impurities may subside ; 
 the " cleansed ; ' curd is then ladled or pumped off into another 
 copper in which the boiling down with close steam is effected. 
 
 The time occupied during these various operations varies with 
 the scale of operations and the skill of the workman : with batches 
 of 40 to 50 tons of goods (tallow and rosin for yellow soap) the 
 " killing " may be effected by an experienced hand in one day, 
 and the further process up to " making " the soap carried out on 
 the next day, the whole being furnished on the third day (Lant 
 Carpenter). 
 
 British curd soaps are usually made with tallow as chief in- 
 gredient with comparatively small admixtures of other oils and 
 fats ; they do not lather very freely, and " waste " in hot water 
 less rapidly than many other kinds of soap. The term " curd " 
 soap, however, does not necessarily denote a tallow soap, but 
 rather a soap boiled in a particular way. 
 
 Fitted Soaps. In the manufacture of curd soaps more or less 
 of the alkaline ley on which the soap is finally boiled, is neces- 
 sarily left entangled in the interstices of the soap, incompletely 
 removed by gravitation whilst standing ; so that on analysis a 
 curd soap thus prepared always shows a considerable proportion 
 of " free alkali." In order to eliminate this an operation termed 
 " fitting " is carried out, more especially in the case of rosin 
 (yellow) soaps, whereby a peculiar texture is attained as the 
 result. The " made "" soap is allowed to stand some twelve 
 hours or more so as to bring about as complete separation of 
 
FITTED AND MOTTLED SOAPS. 471 
 
 ley and curd as possible, and the half spent ley completely 
 pumped away. Wet steam is then turned on, the -condensation 
 of which dilutes the ley still entangled in the interstices of the 
 soap grains. With a particular stage of dilution (attained if 
 need be by adding water to dilute further, or a little stronger 
 ley if the dilution have gone too far) the mass of soap acquires 
 the property of allowing a watery soap solution to separate at 
 the bottom of the mass on standing (for some days with large 
 batches, for twenty-four hours with smaller ones), whilst the 
 rest of the soap forms a mass of jelly-like flakes, which solidify 
 on cooling to a yellow somewhat waxy and translucent solid, 
 usually containing a little under 30 per cent, of water. Before 
 this cools, it remains sufficiently soft to allow all dirt and solid 
 impurities, such as coloured metallic soaps (containing iron, &c.), 
 to subside by gravity, so that the lowest watery stratum is very 
 dirty and much discoloured, and in consequence is known as the 
 " negur " (sometimes spelt negre, nigre, nigger, &c.) The upper- 
 most layer of the " neat soap " resting on the negur generally 
 solidifies whilst standing to a solid frothy crust known as the 
 " fob." * 
 
 The character of the "fit" attained, whether "fine" or 
 "coarse," is judged by the indications observed on sampling 
 the mass from time to time with a trowel when the physical 
 indications known by experience to denote the desired constitu- 
 tion of the mass are observed, the boiling is stopped, and the 
 copper covered over to keep in the heat, the whole being allowed 
 to stand at rest for from two to six days according to the size of 
 the batch. Finally the cover is removed, the fob carefully cut 
 away, and the still soft and semifluid neat soap pumped into the 
 frames. After cooling, fitted soaps generally contain notably 
 more water than curd soaps : from 28 to 33 per cent, is usually 
 present in nonsilicated genuine fitted soaps. The fob is gener- 
 ally worked up with the next batch"; the negur is either worked 
 up with coarse fats and darker rosin and made into a brown 
 rosin soap, or is utilised for making mottled soap. 
 
 Mottled Soaps. In the earlier half and middle of the pre- 
 sent century the majority of soap manufactured was of the 
 curd class, and being made from leys directly prepared from 
 black ash without purification, generally contained more or less 
 sulphide of iron, or metallic soaps disseminated through it, 
 derived from the impure liquors, or in some cases purposely 
 added (in the form of raw or calcined green vitriol = ferrous 
 sulphate, &c.) The curd was boiled down until the proportion 
 of water therein was reduced to a quantity not exceeding about 
 
 * Society has been compared with a pot of porter, "dregs at foot, scum at 
 top, and good liquor in the middle ;" a copper of fitted soap with "negur " 
 and " fob " as the extremes and clean " neat soap " in the midst, would be 
 quite as apt a comparison. 
 
472 OILS, FATS, WAXES, ETC. 
 
 20 to 23 per cent., and more frequently lying between 17 and 20 
 per cent. ; after standing and running off the leys, the whole was 
 well intermixed, and the greyish or otherwise coloured mass 
 run into the frames. During cooling and solidification the 
 colouring matters (chiefly iron soap) segregated from the rest of 
 the mass into veins ; so that when the solid soap was cut across a 
 peculiar characteristic marbling or mottling was evident. By 
 exposure to air the iron soap changed its colour from bluish grey 
 to red in consequence of oxidation, forming what was known in 
 the Marseilles district as the Manteau Isabelle. As this effect 
 could not be produced in the case of a curd soap insufficiently 
 boiled down (on account of the thinner texture permitting the 
 heavier metallic soaps, &c., to sink completely to the bottom, 
 like the negur of a fitted soap), the existence of a mottled appear- 
 ance came to be regarded as a criterion of good quality so far as 
 absence of an undue excess of water (say not above 20 per cent.) 
 was concerned. "Castile," "Marseilles," "Olive" and other 
 mottled soaps of this class, although still manufactured to some 
 considerable extent, are, however, but little made at the present 
 day for household use as compared with other varieties of 
 mottled soaps in which the one especial good point characterising 
 the old mottled soaps is wholly absent viz., that only a limited 
 amount of water is present. A considerable degree of skill is 
 requisite in adjusting the proportions of materials used so that a 
 maximum of water can be incorporated without unduly inter- 
 fering with the veining of the mass. Usually silicate of soda 
 solution is used as stiffening agent, the fatty matters being 
 selected according to the judgment of the maker, and generally 
 containing a considerable proportion of palm kernel oil or coker- 
 nut oil, on account of the property of these oils to form soda 
 soaps possessing considerable stiffness even when largely watered 
 (p. 462). After admixture of the silicate the pigments intended 
 to give the mottle are added, and the mass thoroughly crutched 
 until sufficiently stiffened to run into the frames ; these are usually 
 made of wood so as to allow the mass to cool as slowly as possible 
 and cause the mottle to " strike " properly into veins. Soaps thus 
 made and " filled " with water and silicate often contain 50 per 
 cent, and upwards of water and not more than 40 to 45 per cent, 
 of actual soap. 
 
 Absolutely no good purpose whatever is fulfilled in com- 
 municating a mottle of this kind to household scouring soaps : 
 the only effect is that the public is induced to buy a greatly 
 inferior article on the strength of the reputation for quality 
 gained years ago by mottled soaps of the old style. Whatever 
 advantages may be gained by the addition of silicate as a cheap 
 detergent, these are wholly independent of the mottling. 
 
 A method of preparing hard soda soaps without employing 
 caustic soda (sometimes referred to as the "old German process'') 
 
ROSIN SOAPS. 473 
 
 was formerly of considerable importance, although at the present 
 day the relative prices of potash and soda are such as to render 
 the process inapplicable, except in backwoods districts where 
 potashes are more readily obtainable than soda ash or caustic 
 soda. The tallow, or other mixture of fats and oils to be 
 saponified, is boiled up with potash ley (made by causticising 
 potashes with lime) much as in the process of soft soap making, 
 until a syrupy " close " soap is obtained ; this is then salted out 
 by the addition of common salt or brine, whereby a curd is 
 obtained mainly consisting of soda soap, the potash soap and 
 sodium chloride reacting on one another by double decomposition 
 (pp. 451, 489). The curd thus obtained is finished by repeating 
 the operations of boiling up with potash ley to complete saponifi- 
 cation, and salting out so as to transform the majority of the 
 potash soap still present into soda soap ; the curd ultimately 
 obtained after a sufficient number of such treatments being 
 finally boiled up with ley until any entangled salt is washed out, 
 whilst the ley becomes sufficiently concentrated for the curd to 
 separate properly. 
 
 In all probability, hard soda soaps were first prepared on a 
 comparatively large scale by this kind of process, rather than by 
 saponitication with caustic soda direct ; although the use of 
 " maritime alkali " (barilla) appears to have been practised in the 
 Marseilles district as long as the soap manufacture has existed 
 there. In inland districts, however, where seaweed ash was 
 practically unattainable, or at any rate costly as compared with 
 vegetable potashes, this "old German" process was the one 
 chiefly employed for making hard soaps until the discovery by 
 Leblanc of the method of preparing soda from common salt that 
 bears his name. 
 
 SPECIAL VARIETIES OF SOAP. 
 
 Rosin Soaps (Yellow Soaps). In the manufacture of soaps 
 of this description ordinary rosin (colophony) is used as an 
 ingredient, the mixture of alkaline salts of rosin acids and of 
 fatty acids being peculiarly well adapted for certain purposes. 
 In one method of procedure (Meinecke's) crude turpentine is 
 added to the soap pan, which is fitted with a still-head, so that 
 the spirit of turpentine volatilised along with the steam is con- 
 densed and utilised. A much more frequently used process, 
 however, is to separate the spirit and rosin by the ordinary dis- 
 tillation process, and to mix the latter with the fats, &c., to be 
 saponified, so that a mixture of the alkali salts of fatty and resinous 
 acids results ; whilst a further improvement (sometimes termed 
 the " French process " for rosin soap) consists in dissolving the 
 rosin in hot alkaline ley separately (p. 453), adding the resulting 
 
474 OILS, FATS, WAXES, ETC. 
 
 resinate of soda solution to the finished soap, well crutching the 
 two together ; or adding it to the soap in the pan and inter- 
 mixing by boiling up for a few minutes. 
 
 Rosin soaps of the better quality are generally " fitted " 
 (p. 470). When made from sound fatty matters and light 
 coloured rosin (" windowglass rosin") they possess a peculiar 
 odour not disagreeable, and are known in the south of England 
 as " Primrose " soap ;* such soaps usually contain about 30 to 
 33 per cent, of water and 66 to 69 per cent, of actual soap 
 (including resinate of soda). Coarser rosin soaps made from 
 dark brown rosin, damaged fats, horsegrease, and the like, have 
 generally a more or less marked unpleasant animal odour, partly 
 disguised by the rosin, or by the addition of nitrobenzene (arti- 
 ficial oil of almonds, or essence de mirbane) or other cheap scents. 
 Rosin soaps are generally preferred as stock soaps for trans- 
 parent soapmaking by the spirit process, as the presence of 
 alkaline resiiiates facilitates the acquisition and retention of the 
 colloid structure requisite for transparency ; moreover, a well 
 fitted rosin soap will dissolve practically completely in spirit, 
 not leaving behind any sodium carbonate or other insoluble 
 matters requiring separation by subsidence or filtration. A 
 similar product is also obtainable by dissolving in spirit an 
 ordinary curd soap (cut into shavings and dried) simultaneously 
 with rosin, whereby the free alkali contained in the stock soap 
 is neutralised, and an alcoholic solution of mixed fatty and 
 resinous soaps directly obtained. 
 
 The determination of the relative amount of resinous acids and 
 fatty acids present in a given sample of soap is in many such 
 cases a somewhat important matter ; this may be effected by the 
 methods described on p. 501, et seq. 
 
 Silicated Soaps. Household soaps, properly socallecl, consist 
 of the alkaline (potash or soda) salts of certain organic acids, 
 either belonging to the various fatty acid series, being derived 
 from natural oils and fats, or to other series of more feebly, 
 marked acids derived from resins, more especially colophony. 
 The older soaps (of the first half of the present century) were 
 essentially of this character ; but a considerable proportion of 
 those now manufactured are cheapened by the admixture of 
 various ingredients possessing more or less marked detergent 
 power, the addition of which enables a given weight of socallecl 
 soap to be manufactured from a greatly decreased quantity of 
 fatty matters. Of these detergent substances, obviously the 
 most natural constituents are the alkalies themselves, either in 
 the form of hydroxides (caustic alkalies) or as carbonates ; in the 
 
 * In some districts in the north of England the term "primrose'' is 
 applied to greatly inferior articles, usually largely watered and treated 
 with silicate of soda to stiffen them, so that the actual soap present consti- 
 tutes notably less than one half the mass, like the inferior mottled soaps 
 described on p. 472. 
 
SILICATED AND SULPHATED SOAPS. 475 
 
 manufacture of "oil" soaps (oleic acid soaps, p. 452) these con- 
 stituents are introduced by the simple process of using a larger 
 quantity of alkaline ley than is equivalent to the fatty acids ; in 
 other cases, the alkalies are dissolved in water and crutched into 
 the soap before framing. The introduction of silicate of soda 
 solution has various advantages as compared with that of caustic 
 alkalies, proper incorporation being more easy ; whilst for such 
 purposes as scouring floors, &c., the increased detergence thereby 
 gained is distinctly advantageous. For laundry soaps, on the 
 other hand, the utility of silicates is far less manifest ; so much 
 so, that various much advertised laundry soaps of the present day 
 are purposely prepared without that ingredient (sodium carbonate 
 being in some cases used instead) ; to which circumstances they 
 largely owe what superiority they may possess over other silicated 
 soaps. 
 
 One notable advantage gained by the admixture of silicate of 
 soda with soaps made from cheap soft fats, &c., is that the texture 
 of the bar of soap is considerably stiffened and hardened, so that 
 the soap does not waste so rapidly in hot water or when rubbed 
 against the clothing, tfec., to be washed, as it otherwise would 
 necessarily do. 
 
 Normandy Soaps (Sulphated Soaps). In order to harden 
 and stiffen a comparatively soft soap mass various neutral salts 
 may also be employed, more especially sodium sulphate or thio- 
 sulphate. The use of these stiffening agents was originally 
 introduced by Dr. Normandy, not for purposes of adulteration 
 or "filling," but in order to enable useful household scouring 
 soaps to be made from materials that otherwise would give a 
 product too soft for economical use in scrubbing, especially with 
 hot water. When sodium sulphate (Glauber's salt) was used, 
 the crystallised salt (not salt cake) was heated so as to fuse in 
 its own water of crystallisation,* the liquid being immediately 
 crutched into the hot soap ; from one-fifth to one-third of the 
 weight of the soap being thus added. The soaps thus made 
 rapidly become unsightly through efflorescence ; so that their 
 use at the present day is not large, other stiffening agents (more 
 especially alkaline carbonates and sodium silicate) being pre- 
 ferred. 
 
 Aluminated Soaps. Aluminate of soda has been proposed, 
 and to some extent used, as a substitute for silicate of soda in 
 the preparation of scouring soaps, for which purpose it does not 
 seem to have any special advantages or marked disadvantages. 
 
 Borax Soaps. The addition of borax to laundry soaps is 
 sometimes made, that salt possessing considerable detergent 
 power without injurious action on textile fibres j it is usually 
 
 * If salt cake is used, it must be dissolved in the right quantity of water 
 and treated with a little soda ash, so as to neutralise the free acid present 
 and precipitate the ferric oxide contained as sulphate. 
 
476 OILS, FATS, WAXES, ETC. 
 
 supposed, moreover, to have a special blanching action on linen. 
 Some socalled " borax soaps," however, are in the market that 
 contain only extremely minute amounts of borax, or none at all. 
 
 Phosphated Soaps. In order to diminish the waste of soap 
 with hard water through double decomposition by the lime and 
 magnesia salts present, H. Grimshaw* adds an alkaline phosphate 
 to the soap, with the object of forming calcium and magnesium 
 phosphates instead of lime and magnesia soaps insoluble in water. 
 
 Paraffin Oil and Petroleum Soaps. Hydrocarbons of the 
 paraffin series possess the physical property of forming jellies 
 when admixed with soap solutions under suitable circum- 
 stances ; a small quantity of soap will thus solidify a large 
 quantity of hydrocarbon, a circumstance taken advantage of in 
 manufacturing " solidified petroleum " for fuel. On the other 
 hand, 10 or 20 per cent, of such oil can be crutched into a hot 
 soap paste without materially interfering with its setting on 
 cooling, so that a large amount of "loading" may be thus effected. 
 With certain kinds of transparent soap (made by the cold process, 
 pp. 458, 482) this addition is frequently made. 
 
 For laundry purposes the diluting effect of the hydrocarbon 
 oils is more or less compensated by an increased detergent action : 
 greasy linen, &c., soaped with "paraffin soap" can often be cleansed 
 with less rubbing and friction than would otherwise be necessary 
 because the hydrocarbon tends to dissolve the grease and so to 
 facilitate the detergent action of the soap so far as other dirt is 
 concerned. 
 
 Sand, Puller's Earth, Pipeclay, Kaolin, and Brickdust 
 Soaps. When soap is required for household or other cleansing 
 purposes to be used in conjunction with fuller's earth, powdered 
 brickdust or pumicestone, sand, emery, or such like materials so 
 as to brighten metallic surfaces, cleanse greasy paint (insides of 
 baths, &c.), and so on, it is often found convenient to prepare 
 blocks of mixed mineral powder and soap for sale ; these are 
 made by crutching the pulverised pumicestone, &c., into the 
 hot melted soap in as large a proportion as is consistent with its 
 sticking together in blocks when cold, and are then sold under 
 various proprietary names, chosen according to the fancy of the 
 maker. For general cleansing purposes such mixtures are often 
 very handy; but the price charged, although moderate enough as 
 regards the weight of the block as a whole, is generally high 
 with respect to the quantity of soap actually present therein. 
 Superior kinds of such soaps are sometimes sold as "tooth soaps," 
 prepared by incorporating with a good kind of remelted toilet soap 
 some 10 to 20 per cent, of finely powdered marble or pumice- 
 stone, cuttlefish bone, prepared chalk, &c., &c. 
 
 Disinfectant Soaps. A large variety of soaps are in the 
 market consisting of ordinary soaps of more or less good quality 
 * English Patent, No. 983, 1890. 
 
COLDWATKR SOAPS. 477 
 
 into which have been crutched, before finally cooling and 
 solidifying, fluid or other disinfecting materials, more espe- 
 cially those derived from coaltar products e.g., carbolic and 
 cresylic acids, naphthol, naphthalene and creosote oils, &c. ; or 
 the artificial camphoraceous products got by the oxidation of oil 
 of turpentine (Sanitas oil) ; or hydrocarbons, such as terebene ; 
 or various inorganic germicide materials. Of these different 
 products, a considerable number are highly valuable for the 
 particular purposes for which they are intended ; but the value 
 of others is, at the best, only small as antiseptic and disinfectant 
 agents. 
 
 To this category also belong a variety of " medicinal " soaps, 
 usually put up in tablet form like "toilet" soaps (p. 478); in 
 these a stock soap of more or less good quality forms the basis, 
 sulphur, iodine, ichthyol, mercurial preparations, or other medi- 
 caments, supposed to exert beneficial action in certain cases when 
 thus applied to the skin, being mixed in either by remelting or 
 milling, or in some cases being added to the mass formed by the 
 cold process before it finally solidities. 
 
 Coldwater Soaps. Various soaps are sold under this name, 
 the alleged advantage of which is usually stated to be that they 
 will lather freely with cold water and therefore do not require 
 clothes, etc., to be boiled. In many cases a more accurate 
 description w r ould be that they dissolve so freely in hot water as 
 to be highly wasteful when used therewith. They generally 
 consist of more or less watered soaps * containing cokernut or 
 palm kernel oil to give consistency, with a liberal intermixture of 
 potassium or sodium carbonate (less frequently of silicate) to 
 harden and give increased detergent action ; in practice they are 
 equivalent to a mixture of 'true soap and soda crystals, and like 
 sand and brickdust soaps they are accordingly very handy in 
 use ; but in general the price is high .as compared with the actual 
 amount of soap present. 
 
 Soap Powders. The above remark applies a fortiori to these 
 substances which in general consist of ground-up soda crystals 
 (sometimes of ordinary soda ash) with more or less pulverised 
 dry soap intermixed ; they are usually highly efficacious as deter- 
 gents, but somewhat dear as compared with the value of the 
 alkali present and the soap, taken separately from the water of 
 crystallisation and other inert constituents. 
 
 Starch Soaps, Oatmeal Soap, &c. More than one patent 
 has been taken out for the preparation of products where potato 
 jiour, starch, and similar materials are intermixed with ordinary 
 
 * Some few "cold water 1 ' soaps do not contain more than 20 to 25 per 
 cent, of water, and are made with only comparatively small additions of 
 potassium or sodium carbonate, the former being preferably used to soften 
 the texture, a result also partly brought about by the use of semidrying oils 
 as ingredients e.g., cotton seed oil. 
 
478 OILS, FATS, WAXES, ETC. 
 
 soaps. The advantages of such mixtures are difficult to under- 
 stand. Oatmeal, however, well intermixed with some reasonably 
 good quality of stock soap, enjoys some degree of popularity as a 
 "skinsoap." Bran and gluten have been used for the same 
 purpose ; as also dextrine, Iceland moss and other lichen jellies, 
 sawdust, cornflour, and various analogous substances. 
 
 TOILET AND FANCY SOAPS. 
 
 The term " toilet soap " is generally supposed to denote a 
 superfine variety of soap specially prepared with the object not 
 only of effecting cleansing during ablution, but of doing this 
 in the most delicate way with regard to injurious action on the 
 skin, thus serving as a sort of cosmetic. Some of the socalled 
 toilet soaps in the market well fulfil this description ; but, 
 unfortunately, many others are largely advertised and sold which 
 are of a far less satisfactory character, either through imperfections 
 of manufacture (more especially presence of excess of alkali), or 
 because of their having an objectionable action on tender skins, 
 through admixture of other ingredients (particularly cane sugar). 
 
 Some varieties of socalled toilet soaps are simply household 
 soaps of the finer class, more especially curd and yellow soaps 
 made from first class materials, cut up into tablets, and stamped 
 into shape by one or other of the various kinds of stamping 
 press referred to on p. 444. As a rule these are scentless, but 
 sometimes a small proportion of cheap essential oil or other 
 perfume (such as citronella, mirbane, &c.) is crutched in before 
 framing. 
 
 More frequently stock soaps of good quality are prepared on 
 the large scale from choice, or at least sound, materials, and 
 are then cut up, intermixed or blended, remelted, and again 
 framed, working on a smaller scale : usually scenting materials 
 are introduced just before transferring to the frames, and in 
 some cases emollient ingredients or unguents e.g., lanolin, vase- 
 line, beeswax, spermaceti, or various undecomposed glycerides, 
 such as the finest beef marrow, lard, the socalled " beef stearine " 
 separated from the more fusible fats in the manufacture of mar- 
 garine (p. 309), kc. Of late years "superfatted" soaps of this 
 description (in some cases made by remelting, in others by 
 milling vide infra) have been somewhat largely "boomed," 
 the special advantage derived from their use being supposed to 
 be that an extremely thin greasy film adheres to the skin after 
 use, which more or less prevents the drying and chapping 
 action otherwise produced by ordinary soaps on tender skins. 
 Opinions differ widely as to how far this alleged advantage is 
 really gained or not, some regarding the presence of a few 
 per cents, of glycerides in the soap as actually furnishing a 
 
TOILET AND FANCY SOAPS. 479 
 
 protective film of the kind, rendering the outer layer of the 
 skin soft and supple ; whilst others consider that inasmuch as 
 the action of water on perfectly neutral soap always liberates 
 more or less free alkali, which emulsifies grease and enables it 
 to be washed off, whilst any excess of alkali naturally contained 
 in the soap accelerates the action, the notion .of an adherent 
 protective grease film is a priori improbable ; the advantage of 
 such soaps lying rather in their freedom from excess of alkali 
 arid other objectionable skin roughening substances such as. 
 sugar. On the whole, the preponderance of opinion rather 
 seems to be in the direction of regarding nonglyceridic un- 
 guents (lanolin, spermaceti, etc.) as being more " emollient ;> 
 when thus admixed with soap than glyceridic materials such 
 as usually found in "superfatted" soaps i.e., when all other 
 things are equal, especially absence of free alkali ; moreover, 
 the presence of unsaponified fatty matters seems sometimes to- 
 facilitate discoloration on keeping through the development of a, 
 kind of rancidity. 
 
 In some cases "pearlashing" (pp. 451, 489) is adopted to improve 
 the texture and lathering power ; when this is done the pearlash 
 liquor (solution of potassium carbonate) is simply crutched in 
 with the other ingredients before framing. Since an equivalent 
 of sodium carbonate is formed for one of potassium carbonate 
 introduced, obviously, a pearlashed soap is apt to be strongly 
 alkaline and objectionable for persons suffering from tender 
 skins, or a tendency to acne or eczema. 
 
 Milled Soaps. "Perfumers' soaps," sometimes known as. 
 " little-pan soaps," were formerly largely made by perfumers by 
 means of the cold process. The fatty matters thus employed 
 were generally of excellent quality, being mainly the oils and 
 fatty cakes used to absorb flower perfume (odorous essential 
 oils) by packing the fat cakes and flower petals together, or by 
 passing air over the flowers and bringing it in contact with oil, 
 etc., to absorb the volatile odorous matter; after the oil or fat 
 was fully charged by numerous repetitions of the process it was 
 treated with alcohol, whereby a flower essence was obtained by 
 dissolving out the essential oils, leaving behind a delicately 
 scented fat, capable of furnishing a deliciously perfumed soap. 
 Owing, however, to the necessity for avoiding heat as much 
 as possible in the preparation of the soap, it often happened 
 that these soaps contained simultaneously much undecomposed 
 fat and a large amount of free alkali. Accordingly, of late years 
 they have been largely supplanted by "milled" soaps, where 
 stock soaps of good quality are " stripped " or reduced to chips 
 and dried until only a few per cents, of moisture are retained, 
 and then ground (together ^ with perfumes, colouring matters, 
 glycerine, or other emollient ingredients, etc., as required) be- 
 tween rollers until reduced to a stiff putty-like mass, which is 
 
480 OILS, FATS, WAXES, ETC. 
 
 then squirted or screwed into bars and so formed into tablets 
 (p. 448). The advantages of this method are, firstly, that inas- 
 much as no artificial heat is applied, delicate flower perfumes, &c., 
 can be readily incorporated with the soap mass, which it would 
 be impossible to use with a remelted soap because the heat 
 would dissipate or destroy the odorous matter; and secondly, 
 that as the resulting tablets usually contain only a small quantity 
 of water, a given weight of soap tablet generally contains a much 
 larger quantity of actual soap than another tablet of the same 
 weight prepared by remelting or by the cold process, whilst, 
 being harder and stiffer, it lasts longer, wasting less rapidly 
 during use. By suitably choosing the stock soaps used, em- 
 ploying only such as have been prepared from first class oils and 
 fats, etc., and refined or otherwise treated to remove " free " 
 alkaline matters, "fancy" and "toilet" soaps of the finest possible 
 qualities are thus readily obtainable. Frequently the stock soaps 
 are partly made with potash and partly with soda, so as to arrive 
 at a suitable texture through the softer nature of the potash soap, 
 as well as to produce a better lather. 
 
 In this connection it is worth noticing that there is some 
 reason for supposing that soap with which an extremely large 
 proportion of flower essences and essential oils is incorporated, 
 may thereby become less suitable for use by persons suffering 
 from tender skins than would be the case with a lessened amount 
 of odorous matter, inasmuch as many essential oils of the kind 
 possess more or less marked rubefacient (skin-reddening) action, 
 analogous in character to the stimulating and blistering action of 
 mustard, oil of turpentine, and similar substances. It is within 
 the author's own personal observation that when the same high- 
 class soap mass is used for preparing two differently priced fancy 
 soaps, only differing in that the more expensive one is impregnated 
 with a much larger proportion of scent than the other, persons 
 possessing exceptionally sensitive skins can sometimes use tablets 
 made from the less highly scented portion with impunity, whilst 
 the employment of tablets made from the more strongly per- 
 fumed portion speedily sets up a disagreeable amount of skin 
 irritation. 
 
 From the point of view of irritating skin action, however, the 
 presence of sugar appears to be much more objectionable than 
 that of most scenting materials, even in large quantity. Opaque 
 fancy soaps are rarely, if ever, admixed with this adulterant ; 
 but very little transparent soap is in the market that does not 
 contain more or less. 
 
 Brown Windsor Soap. The term " Brown Windsor " has 
 long been applied to a peculiar brown soap highly esteemed for 
 toilet purposes. Originally this substance deserved its reputation ; 
 but as in the case of "mottled" soap, the perverted ingenuity of the 
 modern adulterator has completely altered the character of the 
 
TRANSPARENT SOAPS. 481 
 
 great majority of toilet tablets sold under that name. The " Old 
 Brown. Windsor " of a generation or two back was simply a form 
 of soap (usually mostly curd) that had been kept in stock for a 
 great length of time, and occasionally remelted ; with the 
 result of acquiring a pretty deep brown tint through oxidation 
 of fatty acids, &c., and of becoming practically wholly devoid 
 of free alkali, any excess of alkali originally present being 
 neutralised by the weakly acid oxidation products formed 
 during keeping or " ageing," or whilst being remelted. Such a 
 soap, pleasantly scented at the last remelting before making into 
 tablets, and originally made from suitable materials, lathered 
 sufficiently freely to be conveniently used, and had as little 
 deleterious action on sensitive skins as is compatible with the 
 hydrolytic properties of soaps generally. The modern substitutes, 
 however, are frequently nothing but coarse soaps made from dis- 
 coloured fats, and further browned by coaltar dyes or admixture 
 of brown ochre : all sorts of scraps (including floor scrapings) 
 incapable of utilisation in any other way are worked into the 
 mass, which frequently is alkaline to a highly objectionable 
 extent. In short, advantage is taken of the reputation deservedly 
 gained in former years by an excellent article to sell under the 
 same name an eminently inferior product. Similarly, socalled 
 " White Windsor " soaps are sometimes to be met with, largely 
 made from cokernut oil, highly alkaline, and wholly different in 
 character from the genuine old fashioned brown article. 
 
 Transparent Soaps. As already stated, soap can in many 
 cases assume two distinct physical conditions, one a more or less 
 distinctly crystalline form in which the "grains" retain associated 
 by a sort of physical attraction a considerable quantity of water, 
 the amount of which varies with circumstances e.g., a curd soap, 
 when granulated from a dilute liquor with a minimum of salt or 
 alkali, will contain as much as 35 to 40 per cent, of such associated 
 water, which becomes gradually lessened down to 20 to 25 per 
 cent, or less by boiling down with dry steam or free fire so as to 
 concentrate the leys. The other is a structureless colloidal state, 
 constituting a mass which under suitable conditions is clear and 
 transparent like a strong jelly. Soft soaps (potash soaps) appear 
 to have a stronger tendency to retain this colloidal state than 
 hard (soda) soaps, so that it is only with comparative difficulty 
 that they become granular ; soda soaps, on the other hand, 
 although granular when separated from watery solutions by 
 means of salt, readily become colloidal when dissolved in alcohol, 
 so as to form transparent masses when the solvent evaporates. 
 This physical condition is facilitated in many cases by the presence 
 of various other substances, of which glycerol is one of the best 
 known ; so that fats saponified by the cold process, even in the 
 absence of alcohol, often yield transparent products owing to 
 the production of glycerol during the process. Castor oil, in 
 
 31 
 
482 OILS, FATS, WAXES, ETC. 
 
 particular, readily yields a transparent product in this way. 
 Cane sugar possesses the same property ; and being cheaper and 
 easier to work with in some respects, is largely substituted for 
 glycerol, to the great disadvantage of the consumer, excepting in 
 one respect, viz., that whilst transparent soaps containing large 
 percentages of glycerol are apt to " sweat," by attracting moisture 
 from the air, sugared soaps do not deliquesce so markedly. 
 Resinates mixed with ordinary fatty acid soaps generally form 
 colloidal masses more readily than the latter alone ; accordingly, 
 rosin soaps are preferred as " stock " when granular soaps are to 
 be rendered transparent. This tendency to transparency is often 
 strongly marked even with water-made rosin soaps of good quality 
 ("fitted" soaps), which generally become translucent and some- 
 times tolerably clear when spontaneously dried in not too thick 
 masses. 
 
 Accordingly, two principal methods are in use for the prepar- 
 ation of transparent soaps. In the "spirit" process the stock 
 soap is dissolved in spirit and treated as described (p. 445), rosin 
 being sometimes added to the mass for the double purpose of 
 aiding transparency and combining with free alkali so as to 
 neutralise it.* The mass left when the bulk of the spirit is 
 distilled off is usually turbid ; but on slow drying in a warm 
 storage room (temperature near 35 C. = 95 F.) it becomes clear, 
 especially when a liberal addition of sugar has been made to the 
 mass before finally casting in the frames. Usually the blocks 
 are cut up into tablets which are shaped by stamping in blank 
 dies, and then slowly dried, the final impression being given by 
 a later stamping. When glycerol is added instead of sugar, the 
 resulting transparent soap is as innocuous, even to the most 
 sensitive skin, as any kind of soap can possibly be ; but the same 
 can by no means be said of sugared soaps (which constitute the 
 large majority of those in the market), persons of unusually 
 tender skins being generally unable to use such compositions 
 long without suffering more or less severely in consequence. 
 
 Similar remarks apply to the transparent soaps made by the 
 other process (cold process, p. 458) ; when sound fatty and oily 
 matters are used, together with alkali not in excess, no sugar 
 being employed, an article results of superior kind ; but the 
 great bulk of socalled " glycerine " soap made in this way is 
 alkaline to an extent highly prejudicial to tender skins, besides 
 being largely admixed with sugar, f whilst in many cases the oils 
 used (chiefly castor oil, together with cokernut oil, &c.) are of 
 such quality as to leave an unpleasant odour on the skin, easily 
 
 * Some transparent soaps thus prepared when dissolved in water and 
 agitated with petroleum spirit, or when dried and percolated therewith in 
 a Soxhlet tube, will yield several per cents, of uncombined colophony to the 
 solvent. 
 
 t For a typical analysis of a soap of this kind (not loaded with hydro- 
 carbons) vide p. 511. 
 
NEUTRALISED SOAPS. 483 
 
 perceptible when the scenting material has evaporated and in 
 addition, large percentages of valueless " loading " (petroleum 
 hydrocarbons, c.) are added to increase the weight. In short, 
 transparent toilet soaps, like artificially mottled scouring soaps, 
 are articles in the purchase of which caution is pre-eminently 
 desirable. For further details concerning transparent and other 
 toilet soaps and their manufacture, vide the author's " Cantor 
 Lectures on the Manufacture of Toilet Soaps " (Journal Society of 
 Arts, 1885). 
 
 Soap Leaves. A very convenient form of soap for travellers 
 is obtained by melting a good quality of stock soap with a little 
 water, perfuming to taste, and passing sheets of tissue paper 
 through the fluid; the paper thus filmed with soap is dried and 
 cut up into leaves, one of which generally suffices for ordinary 
 washing of the hands, &c., thus avoiding the necessity of having 
 to carry about a wet cake of soap. 
 
 Marbled Soaps and Harlequin Soaps. A peculiar marbled 
 appearance is sometimes given to soap balls, tablets, &c., by 
 remelting a more or less white stock soap, and running 'it into a 
 small frame ; a comb with wide teeth is then dipped into a 
 colouring composition (melted soap with pigments or dissolved 
 colouring matters), withdrawn, and passed through the semifluid 
 soap in the frame, so as to streak it according to fancy. The 
 same method is applicable to cold process compositions, before 
 they have completely solidified. By cutting up pieces of variously 
 tinted soaps into fragments, and scattering them through a cold 
 process transparent soap mass on the point of solidifying, a 
 mixture of transparent soap with variously tinted lumps inter- 
 spersed is ultimately obtained ; when cut up and stamped into 
 tablets, these are sometimes sold as " harlequin soaps." Tablets 
 are sometimes ornamented by stamping a device somewhat 
 deeply, and then filling the grooves with melted coloured trans- 
 parent soap, &c. 
 
 Shaving Creams. Cold process soaps made from refined lard 
 or other superfine fatty matters and caustic potash, not used in 
 excess, are usually the basis of these preparations ; to facilitate 
 lathering, a small quantity of the finest cokernut oil is often 
 added. The resulting mass is ultimately ground in a marble 
 mortar, <fcc., with scenting materials (oil of bitter almonds for 
 almond cream, and so on), glycerol or other emollient ingredients 
 being added to taste, and sometimes tinting materials e.g., a few 
 grains of vermilion per Ib. to give a faint flesh colour, &c. A 
 perfumed concentrated alcoholic solution of soap forms a variety 
 sometimes known as " liquid soap." 
 
 Neutralised Soaps. For certain special purposes it is highly 
 important that the soapr employed should be as devoid of free 
 alkali as possible. In order to effect this object a variety of 
 methods have been proposed and more or less largely employed, 
 
484 OILS, FATS, WAXES, ETC. 
 
 according to circumstances. In the generality of cases soaps 
 that have been put through the operation of "fitting" (p. 470) 
 are almost absolutely neutral, any entangled alkaline ley present 
 in the curd before fitting having been washed out during the 
 process ; if, however, after " cleansing " in this way so as to 
 separate coloured impurities, the soap be again boiled down on a 
 fresh portion of ley, the resulting curd soap is always consider- 
 ably alkaline through entangled ley. A method used with some 
 degree of success consists in remelting (p. 441) the soap to be 
 treated with a small proportion of fatty matter which becomes 
 more or less saponified by the treatment ; inasmuch, however, as 
 the alkali present is generally carbonated, this method rarely 
 gets rid of all the free alkali, excepting in cases where the addi- 
 tional fatty matters used consist largely of free fatty acids like 
 some kinds of largely hydrolysed palm oil.* In the manufacture of 
 transparent toilet soaps by the spirit process, any carbonated 
 alkali present is left undissolved and is, consequently, separated 
 by subsidence or straining ; whilst if rosin be directly added, the 
 free alkali present is more or less converted into resinate and so 
 eliminated. When, however, resinous or fatty materials are 
 added to a soap mass in the milling process, no action ensues 
 between them and the free alkali ; so that " superfatted " soaps 
 thus prepared (without long continued fusion of the glycerides 
 with the soap by remelting) often contain simultaneously excess of 
 alkali and unsaponified glycerides, like imperfectly made cold pro- 
 cess soap (p. 457). The author's ammonium salt process, referred 
 to on p. 453, on the other hand, acts equally well in the way of 
 removing "free " alkali, whether applied to soap shavings during 
 the milling process, or to fused soap during remelting, or to soap 
 curd, &c., in the crutching pan; any alkaline carbonate or 
 hydroxide being converted into a neutral salt with simultaneous 
 evolution of ammonia which mostly escapes. 
 
 CHAPTER XXL 
 GENERAL CHEMISTRY OF SOAP SOAP ANALYSIS. 
 
 IN addition to various points previously discussed in connection 
 with the general chemical and physical properties of oils, &c., a 
 variety of other matters are of some interest relating to the 
 properties of soaps of various kinds. 
 
 * According to A. Watts, the superiority of the madder purples for which 
 the firm of lloyle & Sons were long famous, was due to their practice of 
 remelting the best soaps procurable with an additional quantity of palm 
 oil. 
 
CHEMISTRY OP SOAPS. 485 
 
 As already explained, what is ordinarily meant by the term 
 "soap" is simply the various substances obtainable consisting 
 of the alkaline (potash and soda) salts of the various fatty acids 
 contained as glycerides in oils and fats, and of the rosin acids 
 contained in colophony and allied resinous matters. Numerous 
 corresponding salts of the alkaline earths and heavy metals, 
 however, exist, all of which, strictly speaking, are also soaps 
 e.g., the lime "rock" obtained in the manufacture of candle 
 stearine (pp. 365, 373), and the "lead plaster" obtained by mixing 
 together olive oil (or other analogous oil) and litharge. As a 
 general rule these earthy and metallic soaps are insoluble in 
 water, at any rate as compared with alkali soaps ; so that on 
 adding a metallic salt solution to an aqueous solution of alkali 
 soap, double decomposition occurs, and a precipitate is formed of 
 the metallic soap. Thus, for example, the applicability of Clark's 
 soap test for lime and magnesia in water depends on such 
 actions e.g., in the case of stearates 
 
 Sodium Stearate. Calcium Sulphate. Calcium Stearate. Sodium Sulphate. 
 
 2Na . . C 18 H 85 + CaS0 4 = 
 
 Similarly Gladding's test (p. 501) for rosin acids in soap depends 
 on the precipitation of silver stearate, oleate, &c., insoluble in 
 ether containing a little alcohol when silver nitrate acts on an 
 alcoholic solution of mixed alkali salts ; whereas silver resinate 
 is soluble in that medium. 
 
 Alkali soaps often possess in a high degree the peculiar 
 property of gelatin and other colloid bodies viz., that whilst on 
 heating with hot water they apparently dissolve to an ordinary 
 solution, on cooling this does not allow crystals of material to 
 form through diminished solubility on account of lowered tem- 
 perature, but instead sets to a more or less firm jelly. This 
 property of "jellifying" is often used as a practical test of the 
 value of soap for certain purposes ; a known weight of soap is 
 dissolved in water (conveniently 1J ounce to a pint = 20 fluid 
 ounces, or 62 -5 grammes per litre) and the solution allowed to 
 cool ; the rate at which the fluid gelatinises, and the texture of 
 the resulting jelly are noted. Preferably the soap is dissolved 
 in about half the total quantity of water, boiling, and when all 
 is in solution the rest of the water is added cold. 
 
 Although alkali soaps are usually freely soluble in water, 
 especially when hot, yet the presence of certain other substances 
 in solution prevents their dissolving, whilst the addition of these 
 substances to aqueous soap solution causes the precipitation of 
 more or less of the dissolved soap ; thus the process of " salting 
 out" half made soap in the open pan boiling process (p. 469) 
 depends on the less degree of solubility of soap in brine than 
 in pure water. Similarly, when curd soap is boiled down on 
 
486 OILS, FATS, WAXES, ETC. 
 
 an alkaline ley, the soap is rendered less and less soluble in 
 the watery liquor as the concentration proceeds, and at the end 
 of the operation is wholly insoluble therein, even if partially 
 soluble at first when the ley was weaker. 
 
 The proportion of salt relatively to water required to render 
 a given soap insoluble, obviously varies with the nature of the 
 fatty acids present ; thus whilst sodium stearate and palmitate 
 are precipitated from solution by comparatively small amounts 
 of salt, cokernut and palmnut oil soaps are sufficiently soluble 
 to remain dissolved in seawater, which usually contains 3 to 
 4 per cent, of dissolved solid matters, mostly sodium chloride. 
 In hot brine the solubility of soap is usually greater than in 
 cold : thus in the course of a variety of experiments on the 
 solubility of soaps in saline solutions Whitelaw found * that 
 tallow soap was completely soluble to a clear fluid in a boiling 
 solution containing not more than 3'0 per cent, of NaCl, the 
 whole setting to a firm jelly on cooling ; whilst palmnut oil 
 soap dissolved clear in a boiling solution containing not more 
 than 13*0 of NaCl, a large portion of the soap being thrown out 
 of solution on cooling. 
 
 The curd thrown out of solution by salting retains an amount of 
 associated water incapable of expression mechanically by moderate 
 pressure in a dry cloth, and hence not in quite the same condition 
 as ordinary mechanically entangled fluid ; the amount of this 
 water varies inversely with the concentration of the saline solu- 
 tion ; thus the longer a curd soap is boiled down on the ley so 
 as to concentrate this, the less is the proportion of moisture 
 retained by the soap after separation from the ley and framing 
 so as to solidify. In similar fashion, Whitelaw found that an 
 olive oil soap retained the following amounts of water after half 
 an hour's boiling with different brine solutions : 
 
 Salt in Brine. Water in Curd. 
 
 8 per cent. 31 '6 per cent. 
 
 17 25-7 
 
 27 (saturated). | 19'1 
 
 Hydrolysis of Soap Solutions. When soaps are dissolved 
 in absolute alcohol, or in spirit containing but little admixture 
 of water, no visible decomposition ensues ; a neutral soap 
 gives a solution which has no action on suitable indicators 
 e.g., phenolphthalein. If, however, water be substituted for 
 spirit, the soap is more or less broken up into caustic soda and 
 an acid soap e.g., in the case of stearate 
 
 Sodium Stearate. Water. Caustic Soda, Sodium Acid Stearate. 
 
 2Na . . C 18 H 35 + H 2 NaOH + { H* ! O ! C^O 
 
 A pretty way of illustrating this action is to boil a piece of dried 
 * Journ. Soc. Chem. Ind., 1886, p. GO. 
 
HYDROLYSIS OF SOAP SOLUTIONS. 
 
 487 
 
 soap with alcohol to which a little phenolphthalein has been 
 added, and filter the solution into a tall jar or large test tube ; 
 the solution should be strong enough to set to a firm jelly on 
 standing. When set, a little distilled water is poured on the 
 top of the jelly ; this hydrolyses the soap in the top layer so as 
 to turn it pink by the reaction on the phenolphthalein of the 
 liberated alkali. On standing, the water gradually dialyses 
 downward through the colloid soap mass, and the pink colour 
 descends with it. 
 
 By adding salt to an aqueous solution of soap so as to salt out 
 the curd completely, filtering off, and examining the filtrate 
 alkalimetrically, the amount of alkali set free under given condi- 
 tions can be determined ; or the same result can be got at (with 
 more trouble) by collecting the salted out curd, washing with 
 brine over the vacuum filter, dissolving the curd in absolute 
 alcohol, and titrating the acidity with phenolphthalein as indi- 
 cator. A long series of observations thus made led to the 
 following results : * 
 
 
 
 Hydrolysis brought about by x Molecules 
 
 
 Mean 
 
 of Water. 
 
 Fatty Acids. 
 
 Molecular 
 
 
 
 Weight. 
 
 
 
 
 
 
 
 
 a; =150 
 
 33 = 250 
 
 x = 500 
 
 03 = 1000 
 
 x = 2000 
 
 Pure stearic acid, 
 
 284 
 
 07 
 
 i-o 
 
 1-7 
 
 2-6 
 
 3-55 
 
 Nearly pure palmitic acid, 
 
 250 
 
 1-45 
 
 1-9 
 
 2-6 
 
 3-15 
 
 3-75 
 
 Crude lauric acid (cokernut 
 
 
 
 
 
 
 
 oil), .... 
 
 195 
 
 3-75 
 
 4-5 
 
 5-4 
 
 6-45 
 
 7-1 
 
 Pure oleic acid, 
 
 2S2 
 
 1-85 
 
 2-6 
 
 3-8 
 
 5-2 
 
 6-65 
 
 Crude ricinoleic acid, 
 
 294 
 
 1-55 
 
 2-2 
 
 3-0 
 
 3-8 
 
 4-5 
 
 Chiefly stearic, palmitic, 
 
 
 
 
 
 
 
 and oleic acids (palm oil 
 
 
 
 
 
 
 
 tallow soap), 
 
 271 
 
 1-1 
 
 1-55 
 
 2-6 
 
 4-1 
 
 5-3 
 
 Chiefly tallow and rosin 
 
 
 * 
 
 
 
 
 
 (primrose), 
 
 280 
 
 1-5 
 
 2-2 
 
 3-1 
 
 4-2 
 
 5-3 
 
 Cotton seed, 
 
 250 
 
 2-25 
 
 3-0 
 
 5-0 
 
 7-5 
 
 9-5 
 
 Fig. 143 represents these results in the form of curves, from 
 which it would seem to result inter alia that amongst homologous 
 soaps (stearic acid, palmitic acid, cokernut oil acids) the higher 
 the molecular weight the less rapid the hydrolysis. 
 
 If extra alkali be added to the soap solution, the hydrolytic 
 effect is proportionately weakened, as suggested by the character 
 of these curves, concave downwards ; thus the following figures 
 were obtained with some of these same soaps : 
 
 * Alder Wright and Thompson, Journ. Soc. Chem. Ind., 1885, p. 625; 
 Alder Wright, "Cantor Lectures," Society of Arts (Journal Soc. Arts, 
 xxxiii., 1885, p. 1124). 
 
488 
 
 OILS, FATS, WAXKS, ETC. 
 
 Nature of Fatty Acids Used. 
 
 Extra Na 2 O 
 added to 
 Solution, per 100 
 
 Soap. 
 
 Hydrolysis brought about by 
 x Molecules of Water. 
 
 x= 50 
 
 a= 250 
 
 x = 2000 
 
 Crude lauric acid (cokernut), 
 Cotton seed oil soap, 
 Stearic and oleic (tallow), 
 Tallow rosin (primrose), . 
 
 11-0 
 15-0 
 20-0 
 150 
 
 1-1 
 
 nil. 
 nil. 
 
 nil. 
 
 1-6 
 nil. 
 nil. 
 
 o-i 
 
 2-0 
 6-5 
 nil. 
 1-3 
 
 The property of becoming hydrolysed by water has a great 
 deal to do with the cleansing and detergent action of soap ; the 
 
 Values of X. 
 Fig. 143. 
 
 minute amount of alkali set free helps to emulsify greasy matters, 
 and thus greatly facilitates their removal by washing out under 
 friction. 
 
 Heaction of Soap Solution or of Fused Soap on In- 
 organic and other Salts. When a solution of sodium chloride 
 is added to one of a soda soap, or one of potassium carbonate to 
 a potash soap, there being but one base present, obviously, no 
 tendency can exist towards double decomposition and exchange 
 of bases ; but it is otherwise if sodium chloride be added to a 
 potash soap, or potassium chloride to a soda soap ; or if potassium 
 carbonate be added to a soda soap or sodium carbonate to a 
 potash soap. In certain of these cases it is well known that 
 double decomposition ensues ; thus, if a potash soap be made by 
 
PEARLASHING. 489 
 
 boiling fatty matter and wood ash ley together, and sodium 
 chloride be then used to salt it out of solution, the resulting curd 
 is largely composed of soda soap formed by the reaction (in the 
 case of stearate). 
 
 Sodium Chloride. Potassium Stearate. Sodium Stearate. Potassium .Chloride. 
 
 NaCl + K.O.C 18 H 35 = Na . . Ci 8 H 35 + KC1 
 
 In former days this reaction was utilised to prepare hard soaps in 
 places where wood ashes only were obtainable as alkali (p. 473). 
 Similarly, it has long been a practice to improve the softness 
 and texture of soda soaps intended for toilet soapmaking by 
 remelting and " pearlashing " i.e., adding to the melted soap 
 potassium carbonate dissolved in a little water ; the rationale of 
 which has been shown to be * that double decomposition takes 
 place with formation of potash soap and sodium carbonate, 
 thus 
 
 Sodium Stearate. Potassium Carbonate. Potassium Stearate. Sodium Carbonate. 
 2Na.O.C 18 H 35 + K 2 C0 3 2K.O.C 18 H 35 O + Na 2 C0 3 
 
 The presence of the potash soap makes the resulting mass less 
 liable to crack during stamping, and also gives it better lathering 
 qualities. 
 
 In these and all similar cases the general principle involved 
 seems to be this. Potassium and sodium are so related that when 
 both alkalies are simultaneously in presence of two acids, one 
 weaker than the other, the potash tends to unite with the 
 stronger acid and the soda with the other. Thus when stearic 
 and hydrochloric acids are in question, the prevailing tendency is 
 to form potassium chloride and sodium stearate, because hydro- 
 chloric acid is the stronger acid of the two; whilst when stearic 
 and carbonic acids are the two acids, the chief tendency is to 
 form potassium stearate and sodium carbonate, because stearic 
 acid is a stronger acid than carbonic acid. As in most analogous 
 cases, however, the question of relative masses is also concerned 
 in the result ; if these be suitably chosen the actions may to 
 some extent be reversed e.g., if a large mass of potassium 
 chloride act on a relatively small quantity of sodium stearate, a. 
 notable amount of soft potassium stearate is formed with a 
 corresponding quantity of sodium chloride, in opposition to the 
 above described actions occurring when the masses of potassium 
 and sodium salts are not widely different. Similarly, if a 
 relatively large amount of sodium carbonate acts on a small 
 quantity of fused potash soap, a measurable amount of soda 
 soap and a corresponding quantity of potassium carbonate are 
 produced, notwithstanding the usual tendency to the opposite 
 
 * Alder Wright and Thompson, Journ. Soc. Chem. Ind., 1885, p. 625. 
 
490 
 
 OILS, FATS, WAXES, ETC. 
 
 change. Thus the following figures were obtained by Alder 
 Wright and Thompson (loc. cit. supra) : 
 
 
 (<j) Soda Soaps fused with 
 KoCO 3 . Percentage of total 
 Fatty Acids present 
 
 (b) Potash Soaps fused with 
 Na 2 CO 3 . Percentage of 
 totat Fatty Acids present 
 
 Fatty Acids Employed. 
 
 Equivalent to 
 the K 2 C0 3 
 
 Actually con- 
 verted into 
 
 Equivalent to 
 the Na 2 (J0 3 
 
 Actually con- 
 verted into 
 
 
 added. 
 
 Potash Soup. 
 
 added. 
 
 Soda Soap. 
 
 Stearic and oleic (tallow), 
 
 10-4 
 
 8-0 
 
 
 
 53 
 
 45-7 
 
 34-4 ! 
 
 ... 
 
 33 55 
 
 100-0 
 
 97-95 
 
 100-0 
 
 4-3 
 
 
 104-2 
 
 99-0 
 
 1000-0 
 
 15-0 
 
 Stearic, palmitic, and 
 
 
 
 
 
 oleic (palm oil and tal- 
 
 57-2 
 
 52-1 
 
 
 
 low), .... 
 
 
 
 
 
 5 5 3 
 
 108-0 
 
 90-8 
 
 177-0 
 
 9-5 
 
 Crude Jauric acid (coker- \ 
 nut oil), . . . J 
 
 52-8 
 
 464 
 
 
 
 55 55 
 
 114-8 
 
 87-9 
 
 197-0 
 
 6-2 
 
 Crude ricinoleic acid (cas- 
 
 50-0 
 
 48-4 
 
 
 
 tor oil), 
 
 
 
 
 
 53 33 
 
 100-0 
 
 93-8 
 
 2050 
 
 8-2 
 
 
 
 
 
 Obviously the proportion of potassium carbonate converted 
 into potash soap in the series (a) is uniformly much larger than 
 the fraction of sodium carbonate converted into sodium soap in 
 series (b) i.e., not far from the maximum possible in the first case, 
 and only a few per cents, in the second ; showing the much 
 stronger tendency towards the first change than towards its 
 converse. 
 
 In similar fashion the following figures were obtained on 
 salting out potash soaps with sodium chloride, and soda soaps 
 with potassium chloride ; in series (a) m molecules of water were 
 used to dissolve 1 of potash soap, and n molecules of sodium 
 chloride added ; in series (b) m molecules of water were added for 
 1 of soda soap, and n molecules of potassium chloride added : 
 
 Fatty Acid Used. 
 
 m. 
 
 n. 
 
 (a) Potash Soaps salted 
 out with NaCl. Per- 
 centage of Fatty Acid 
 in Curd. 
 
 (b) Soda Soaps salted 
 out with KC1. Per- 
 centage of Fatty Acid 
 in Curd. 
 
 As Potash 
 Soap. 
 
 As Soda 
 Soap. 
 
 As Potash 
 Soap. 
 
 As Soda 
 Soap. 
 
 Stearic and oleic acids 
 (tallow), 
 Stearic and oleic acids 
 (tallow), 
 Stearic, palmitic, and oleic 
 acids (palm oil & tallow) , 
 Crude lauric acid (coker- 
 nut oil), 
 
 100 
 200 
 200 
 200 
 
 5 
 20 
 20 
 20 
 
 10-5 
 5-1 
 
 3-8 
 5-4 
 
 89-5 
 94-9 
 96-2 
 94-6 
 
 79-1 
 
 82-1 
 95-8 
 74-8 
 
 20-9 
 17-9 
 4-2 
 25-2 
 
SALTING OUT. 
 
 491 
 
 Here the disproportion between the results in the (a] series and 
 those in the (b) series is much less than in the case of carbonates, 
 although it is still obvious that on the whole there is a greater 
 tendency for sodium chloride to form a soda soap by acting on a 
 potash soap, than for the converse reaction to occur. 
 
 The same result follows if a mixture of equivalent quantities 
 of potash and soda soaps (obtained by halving the fatty acid, and 
 neutralising one half with one alkali, and the other with the 
 other) be dissolved in water and salted out with a mixture of 
 equivalent quantities of potassium and sodium chlorides ; a much 
 larger proportion of soda soap is thus separated than is equiva- 
 lent to the potash soap simultaneously thrown out of solution, 
 the precise proportion varying with the nature of the fatty acids. 
 Thus the following figures were obtained, indicating from 1'6 to 
 5 '7 molecules of soda soap to 1 of potash soap: 
 
 - 
 
 Percentage of Fatty Acid contained. 
 
 Molecular Ratio of 
 
 
 
 
 Soda Soap to 
 
 
 As Potash Soap. 
 
 As Soda Soap. 
 
 Potash soap. 
 
 Pure oleic acid, . 
 
 38-0 
 
 62-0 
 
 1-63 to 1 
 
 Crude ricinoleic acid (from 
 
 
 
 
 castor oil), 
 
 17-8 
 
 82-2 
 
 4-6 to 1 
 
 Stearic, oleic, and rosin acids 
 
 
 
 
 mixed (primrose soap), . 
 
 17-2 
 
 82-8 
 
 4-8 to 1 
 
 Crude lauric acid ( from 
 
 
 
 
 cokernut oil soap), . 
 
 15-1 
 
 85-9 
 
 5-7 to 1 
 
 It is remarkable that when only one acid is present, or a 
 mixture of organic acids not greatly differing in strength, the 
 proportion of soda and potash soaps formed by acting on a mixture 
 of the two bases is sensibly the same as the proportion of the 
 bases ; thus with equal molecular quantities of potash and soda, 
 and amounts of acid exactly equivalent to either of the alkalies 
 separately, or to one-half of the two jointly, the following figures 
 were obtained : 
 
 Fatty Acids Employed. 
 
 Percentage of Total Fatty Acid 
 converted into 
 
 Soda Soap. 
 
 Potash Soap. 
 
 
 51-2 
 50-8 
 51-5 
 
 48-2 
 49-7 
 
 48-8 
 49-2 
 48-5 
 
 51-8 
 50-3 
 
 ,, oleic acid, ..... 
 Crude stearic and oleic acids (tallow), . 
 ,, stearic, palmitic, and oleic acids ) 
 (palm oil and tallow), . . f 
 ,, lauric acid (cokernut oil), . 
 
 Mean, 
 
 50-3 
 
 49-7 
 
492 OILS, FATS, WAXES, ETC. 
 
 In similar fashion, if a soda soap be melted and well inter- 
 mixed with just as much caustic potash as is chemically 
 equivalent to the soda present, or if a potash soap be similarly 
 treated with the equivalent amount of caustic soda, the result in 
 either case is the formation of a mixture of potash and soda soaps 
 in practically equivalent quantities. 
 
 ANALYSIS OF SOAPS. 
 
 The general composition and character of soaps of different 
 kinds being subject to considerable variation, the analytical 
 determinations most useful in certain cases are not always those 
 most valuable in other instances. Thus in the case of a fulling or 
 woolscouring soap, freedom from excess of alkali or from alkaline 
 salts (silicate, c.) that might act injuriously on the wool fibre is 
 the most important point, together with the proper nature of the 
 fatty matters employed ; whilst in the case of a laundry soap, 
 freedom from excess of alkali is not at all an important condition, 
 the presence of certain kinds of alkaline material (more especially 
 alkaline carbonates) being generally beneficial rather than other- 
 wise, cceteris paribus. In all cases, however, a highly important 
 consideration is the proportion of actual soap present i.e., the 
 proportion of the alkaline salts of fatty and resinous acids, apart 
 from other saline matters, uncombined alkalies, unsaponified 
 glycerides, water, glycerol, and substances added to give weight, 
 or to increase the stiffness, or the detergent action, or for other 
 reasons. An examination of the fatty acids set free on decom- 
 position with a mineral acid is often useful, as giving information 
 as to the nature and quality of the fatty matters originally 
 employed ; the first results being corrected, when necessary, by 
 determining the amount of unsaponified fat present, and also the 
 amount and general nature of unsaponifiable constituents, such 
 as cholesterol, hydrocarbons, &c. Moreover, with certain kinds 
 of medicated and disinfectant soaps the amount of active 
 ingredient incorporated therein requires determination. 
 
 When the amount of total alkaline matter present (soda, 
 or potash, or both) is known, expressed as anhydrous oxide 
 (Na.,O, or K 2 O) and also that portion which is " free " i.e., not 
 combined with fatty and resinous acids, the difference obviously 
 represents the combined alkali contained as actual soap : i.e., if 
 the percentage of "total alkali" (expressed as Na 2 0) be a, and 
 that of "free alkali = b, a - b is the percentage of "combined 
 alkali." Similarly if c be the percentage of crude fatty acids, &c., 
 obtained on decomposition with a mineral acid, whilst d is the 
 percentage of unsaponified grease and unsaponifiable matters 
 present therein admixed with the pure fatty acids, c - d is the 
 percentage of fatty acids contained combined as soap. The 
 
ANALYSIS OF SOAPS. 493 
 
 weight of actual soap present then is a - b + (c - d) - n per cent., 
 where n is the amount to be subtracted in order to calculate 
 fatty acids into fatty anhydrides (the soap being viewed for 
 present purposes as made up of compounds of metallic oxides 
 and the anhydrides of acids, such as Na 2 0, (C ]8 H 35 O). 2 O for 
 sodium stearate, and so on). Obviously, if the alkali be expressed 
 
 9 
 
 as Na.,O, n = ^ (a - b) ; whilst if it be expressed as K O, 
 ol 
 
 Q 
 
 n = (a-b); so that in the first case the percentage of actual 
 
 soap is 
 
 - + (c-d)- -Ji(a-b) = ~(o-6) + (c-d) 
 
 and in the second case 
 
 Q 38 ! 
 
 a-b + (c-d)-~(a-b) = ^-(a-b) + (c-d) 
 
 For instance, suppose that a soda soap gave the following 
 results on analysis 
 
 Crude mixture of fatty acids, &c., = c = 67 '05 per cent. 
 Unsaponifiable matters, &c., . = rf - 1*80 
 
 Fatty acids present in soap, . = c-d 65 '24 
 
 Total alkali (expressed as Na 2 0), = a = 8' 55 
 Free alkali ,, = b = 0'85 ,, 
 
 Combined alkali present in soap, = a-b = 7 '70 ,, 
 
 Hence n = ~ - x 7 "70 = 2 -23 
 
 ol 
 
 Whence the fatty anhydrides are 65'25 - 2'23 = 03 -02 
 And the actual soap present = 63 '02 + 7 '70 = 70 '72 
 
 The analysis would then be stated thus 
 
 Fatty anhydrides, . . 63 '02 per cent. "I Jointly = 7072 per cent, of 
 
 Combined alkali (Na 2 0), . 7'70 ,, J actual soap. 
 
 Unsaponifiable matters, &c., 1*80 ,, 
 
 Water, free alkali, saline ) /Containing free alkali equi- 
 
 matters, &c. (by differ- > 27 '48 ,, I valent to ' 85 P er cent - 
 ence )' ) ) Na 2 0, or ~| = about ? of 
 
 \ 
 
 100-00 V the combined alkali. 
 
 In order, therefore, to determine the percentage of actual soap 
 present, the four quantities a, b, c, and d must be determined ; 
 during the course of which analysis, the separate percentages of 
 potash and soda may conveniently be also determined (when the 
 two alkalies are simultaneously present) ; moreover, whilst c and d 
 
494 OILS, FATS, WAXES, ETC. 
 
 are being separated from one another, the respective amounts of 
 unsaponified glycerides and of unsaponifiable matters present in d 
 may be conveniently determined, and further examinations made 
 as to the characters of the separated and purified fatty acids, c d, 
 and of the unsaponifiable matters ; in particular the proportion of 
 rosin acids in the former may be determined, as also the melting 
 point, &c., so as to obtain information as to the probable nature of 
 the fatty matters used. This last point, however, is one where 
 analytical data, as such, often fail to give satisfactory results i.e., 
 the inspection of the mixed fatty acids and the valuation of their 
 fusing points, &c., often leads to nothing definite ; in some cases, 
 however, the application of other tests (qualitative or quantita- 
 tive) leads to useful results e.g., the elaidin test, &c. 
 
 The average molecular weight, E, of the fatty acids contained 
 in the soap is frequently a datum of considerable value ; this is 
 readily deduced when a, b, c, and d are known, as shown on 
 p. 172, being given by the equation 
 
 E = x 31, when the alkali is expressed as Na<>0 
 
 a- 6 
 
 B=~-|-x47'l K 2 
 
 Thus, in the above example, the value of E is 
 
 ^^> x 31 =263. 
 
 7'7u 
 
 "When required, the proportion of water present in the soap may 
 be directly determined, as also any other constituents present, 
 such, for example, as admixed weighting substances of mineral 
 or organic nature (china clay, steatite, starch, sand, bran, <fec.); 
 saline matters (sodium chloride, sulphate, <fec.) ; silica (from 
 sodium silicate) ; glycerol sugar ; and so on. 
 
 In order to carry out a complete detailed analysis the follow- 
 ing methods of procedure have been found convenient by the 
 author,* the exact selection to be made varying with circum- 
 stances. 
 
 Water. A convenient weight of an average sample of the 
 soap cut up into thin shavings is dried, first at a temperature 
 somewhat below 100 so as to avoid fusion, finally at 110-120. 
 The loss of weight may be taken as water, especially when other 
 volatile substances (carbolic acid, essential oils, <kc.) are absent 
 
 * Various more or less similar methods and processes have been pre- 
 viously put forward by other chemists e.g., C. Hope, Chemical News, 
 xliii. (1881), p. 219; Filsinger, Chemiker Zeituny, April, 1884; Allen, Com- 
 mercial Organic Analysis, Second Edition, vol. ii., p. 251; Leeds, Chemical 
 News, xlviii. (1885), p. 166; Alder Wright & Thompson, Analyst (1886), 
 p. 44 ; &c. 
 
WATER, UNSAPONIFIED FAT, ETC. 495 
 
 or only present in small quantities. For many purposes this 
 direct determination is one of the most important valuations, 
 especially in conjunction with an estimation of free alkali (e.g., 
 in the case of soft soap). In other cases the direct determination 
 is quite unnecessary, more particularly when the amount of 
 actual soap present is determined, w T ater and saline matters being 
 conveniently taken by difference. Instead of reducing the soap 
 to thin slices and drying without fusion, the amount of water may 
 be arrived at by heating 5 or 10 grammes in a large porcelain 
 crucible set in a sand bath, and stirring with a bit of glass rod 
 (weighed with the crucible) until no more dew is deposited on 
 a piece of glass placed over the crucible (the lamp being removed). 
 "When this stage is reached the water is practically all expelled, 
 and a nearly constant weight attained. Care must be taken not 
 to overheat and burn the soap ; the glass rod should have a 
 rough jagged end to facilitate the breaking up of clots.* 
 
 J. A. Wilson recommends t weighing out about 2 -5 grammes 
 of soap in a dish and dissolving in about 5 c.c. of absolute alcohol 
 by means of heat ; about 10 grammes of ignited sand are then 
 added and the whole evaporated to dryness ; the residue is again 
 treated with 5 c.c. of absolute alcohol and evaporated and finally 
 dried at 100 to 105 in an airbath. The addition of the sand 
 facilitates the expulsion of water along with the alcohol, and 
 renders it more easy to treat the dried soap in a Soxhlet 
 apparatus for dissolving out unsaponified fat, &c. 
 
 Un saponified. Fat, Hydrocarbons, Spermaceti, Wax, &c. 
 5 (or preferably 10) grammes of soap are dried, first at 100 or 
 below r , and finally at 120 ; or in a crucible, or with alcohol and 
 sand as above : the residue is exhausted in a Soxhlet tube (p. 238) 
 with light petroleum spirit ; or a little spirit is poured on, allowed 
 to digest, poured off (if necessary through a filter), and so on until 
 all fat, &c., is dissolved out. Ether may also be used, but is more 
 apt to dissolve out soap. The residue left on evaporation of the 
 solvent may be examined as to its physical properties, and the 
 saponifiable portion thereof determined by heating with excess, 
 of standard alcoholic potash, precisely as in determining the "total 
 acid number" of an oil or fat (p. 157, et seq.) When saponifica- 
 tion is complete (which may in some cases require an hour's 
 boiling with a reflex condenser, or more) the unneutralised 
 alkali is back-titrated : the exactly neutral fluid is then evapor- 
 ated and the residue again treated with light petroleum spirit 
 so as to dissolve out hydrocarbons, cholesterol or other alco- 
 holiform saponification products, &c., obtained by evaporating 
 the extract ; whilst the undissolved portion on acidulation and 
 shaking with ether enables the fatty acids, &c., produced by the 
 saponification to be isolated for examination. In cases where 
 
 * Watson Smith, Journ. Soc. Dyers and Colour ist*, vol. i., p. 31. 
 t Chemical News, October 21, 1892, p. 200. 
 
496 OILS, FATS, WAXES, ETC. 
 
 a full examination of the unsaponified fat, &c., is requisite it is 
 preferable to employ a larger quantity (50 grammes or even 
 100) of soap, and not to combine this determination with that of 
 water, &c., lost by drying. As a rule little but unsaponified 
 glycerides are thus extracted; but " oleine " soaps often contain 
 a small percentage of hydrocarbons contained in the oleine 
 (distilled, p. 278), whilst if woolgrease have been used to adul- 
 terate tallow, notable amounts of cholesterol, ttc., may be present. 
 Spermaceti, vaseline, &c.,* may be present in special kinds of 
 toilet soap ; whilst certain laundry soaps are purposely inter- 
 mixed with paraffin oil and similar hydrocarbons. 
 
 The unsaponified fat, ttc., may also be isolated by dissolving 
 the soap (which need not be dried) in hot alcohol and somewhat 
 diluting with water ; before complete cooling a little ether is 
 dropped in (care being taken that no light is near to inflame 
 ether vapour), which will generally prevent the mass gelatin- 
 ising. More ether is added and the whole well agitated, and 
 if separation does not occur, more water is added, the ethereal 
 solution being finally drawn off by means of a separating funnel 
 or Chatta way's tube (p. 120). The ethereal extract thus obtained 
 usually contains soap, so that it should be evaporated and the 
 residue dissolved in petroleum spirit and filtered. Some little 
 .amount of "dodging" is sometimes requisite to get the alcohol, 
 ether, and water in the right proportions to bring about a proper 
 separation into two fluids, one a watery alcoholic soap solution, 
 the other an ethereal solution of fat, &c. 
 
 Fatty Anhydrides and Total Alkali. The residue de- 
 prived of fat, &c., by petroleum spirit left in the Soxhlet tube 
 as above, is dissolved in water f and decomposed by boiling with a 
 slight excess of standard acid. On standing and cooling the fatty 
 acids separate as a cake, which is washed, dried, and weighed, J 
 
 * When wax is present, toluene dissolves it out in the Soxhlet tube 
 better than petroleum spirit (Schuaible). 
 
 tlf mineral matters, &c., insoluble in alcohol are present, the soap 
 may be treated (conveniently still in the Soxhlet tube) with alcohol, so as 
 to dissolve out the soap, and leave the insoluble substances. In this case 
 drying without addition of sand, &c. , is preferable. The alcoholic extract 
 may be evaporated to dryness and the residue weighed, so as directly to 
 determine the "actual soap " present ; or it may be diluted with hot water 
 and treated with excess of standard acid, &c. 
 
 0r the hot fluids may be washed into a separating funnel, the watery 
 part run off, and the fluid fatty acids washed out on to a wet filter as in 
 determining the Hehner number of an oil, &c. (p. 166). If particles of 
 fatty acid adhere to the vessels either in this mode of operating or with 
 the solid cake, they should be washed off with a little ether, &c., into a 
 small beaker or basin, and the solvent evaporated, the rest of the fatty 
 acids being subsequently added, and the whole weighed together after 
 drying. When the soap contains any considerable amount of soluble fatty 
 acids (e.g., when made from mixtures containing cokernut or palm kernel 
 oil) these partly remain in the aqueous liquor from which they may be 
 mostly extracted by shaking with ether. 
 
FATTY ANHYDRIDES AND TOTAL ALKALI. 497 
 
 and then subjected to such further tests as may be deemed 
 necessary (melting point, elaidin test, &c.), more especially rosin 
 acid determination (infra). If the fatty acids are very soft, or 
 are derived from coker or palm kernel oil, a known weight (5 or 
 10 grammes) of beeswax or paraffin wax may be advantageously 
 added before cooling so as to form a more solid cake, and to 
 assist in dissolving out from the water the more soluble acids, 
 due correction being made for the weight of added substance : 
 this, however, obviously prevents any physical or other examina- 
 tion of the fatty acids after their being separated from the soap. 
 If such an examination is not requisite it often saves time to 
 weigh up a separate amount of average soap (10 grammes*) and 
 without drying or treating with petroleum spirit to dissolve this 
 in water, decompose with acid, and weigh the resulting mixture 
 of fatty acids, unsaponified fat, &c., correcting the result by 
 means of a separate determination of the latter quantity. The 
 corrected percentage of fatty acids is calculated to fatty anhy- 
 drides as above described (p. 493). 
 
 "When nitric acid is used as the standard acid, and the alkali 
 employed for back-titration f is free from chloride and sulphate, 
 the neutralised fluid may be divided into two halves for the 
 determination of sulphate and chloride respectively ; or, if 
 requisite, a portion may be reserved for glycerol determination 
 (infra). 
 
 From the amount of standard acid used, less that titrated in 
 the liquid after removal of fatty acids, the total quantity of 
 alkali present is known, including that present as soap, that 
 contained as hydroxide or carbonate, and that present as other 
 inorganic salts of alkaline reaction e.g., silicate. 
 
 * Instead of using 10 grammes of soap, a smaller quantity, say 2 grammes, 
 may be dissolved in water, acidulated, shaken with ether in a well closed 
 vessel, and the ethereal solution separated and evaporated ; this method is 
 preferable with soaps made from cokeriiut and palm kernel oils on account 
 of the partial solubility of the fatty acids thence derived in water. In 
 order to avoid loss of volatile acids during drying, the ethereal solution 
 may be exactly neutralised with alcoholic solution of pure soda, evaporated 
 to complete dryness, and weighed. By subtracting the Na 2 contained 
 in the alcoholic soda from the weight of the pure soap (together with 
 unsaponified grease and unsaponinable matters) thus obtained, the weight 
 of fatty anhydrides + unsaponified grease and imsaponifiable matters is 
 known. The soda thus neutralised is the "combined alkali" (vide infra, 
 " fatty acid titration test " for free alkali). 
 
 t Cochineal is a convenient indicator for the purpose. If any soluble 
 organic acids are present in the watery fluid, they may be approximately 
 estimated by first titrating with methyl orange as indicator, the colour 
 change occurring when all the mineral acid present is neutralised ; and 
 then g"ing on with addition of phenolphthalein, which is not reddened till 
 the organic acids are neutralised. The additional alkali thus consumed 
 may be calculated as valeric acid, C 5 H 10 2 , in the case of soaps containing 
 whale oils ; or as heptoic acid, C7H 14 2 , or octoic acid, CsHje^^, in the case 
 of cokernut oil soaps. 
 
 32 
 
498 OILS, FATS, WAXES, ETC. 
 
 Free Alkali. The term "free alkali" is generally understood 
 as including the alkalinity of all substances present in soap pos- 
 sessing an alkaline reaction i.e., the sum of the alkalinity due 
 to hydroxide (caustic alkali), carbonate, and other salts such as 
 silicate ; so that the difference between the " total alkali " and 
 the "free alkali " exactly represents the alkali combined with 
 fatty and resinous acids as actual soap. 
 
 Excepting with freshly made soap, especially when preserved 
 in large sized blocks, but little caustic alkali is ever found in 
 commercial soap, because the absorption of carbon dioxide from 
 the air is tolerably rapid ; but the passage of that gas into the 
 interior of a large mass, and to a lesser extent into the centre of 
 an ordinary bar, is by no means instantaneous, so that the 
 interior portion of a comparatively freshly made curd or hydrated 
 soap (pp. 461, 470) often contains a notable amount of hydroxide. 
 In order to distinguish the free alkali present as hydroxide from 
 that contained in other forms, C. PI ope * dissolves a known 
 weight of an average sample in strong alcohol and filters ; car- 
 bonate, silicate, &c., are left on the filter ; 'whilst caustic alkali 
 (whether potash or soda) passes through, dissolved in the alcohol 
 along with the neutral soap. The operation may be conveniently 
 carried out thus, constituting the "alcohol test" for free alkali. 
 5 grammes of undried average sample of soap are dissolved in 
 hot alcohol (free from all acidity or alkalinity, and as strong as 
 possible) and the solution filtered through a hot water funnel : 
 after completely washing out with alcohol, the undissolved 
 residue is treated with water and the alkalinity determined. 
 As a general rule, the alcoholic filtrate is neutral, but sometimes 
 it is faintly acid to phenolphthalein ; apparently with a slightly 
 moist soap mass, absorption of carbonic acid from the air tends 
 to develop a trace of "acid soap" (pp. 23, 486) with a correspond- 
 ing quantity of alkaline carbonate; as this latter is undissolved 
 by the alcohol it does not react on the acid soap during solu- 
 tion so as to neutralise it again, f In such a case the acidity 
 (" negative alkalinity ") of the alcoholic solution is determined, 
 and the amount subtracted from the positive alkalinity of the 
 residue. Thus 5 grammes of soap gave an alcoholic solution 
 where the acidity represented 0'25 c.c. of seminormal alkali; 
 whilst the residue neutralised 0'6 c.c. of seminormal acid : hence 
 the "free alkali" is reckoned as O6 - O25 = 0-35 c.c. of semi- 
 normal acid corresponding with 0-0054 gramme of soda (Na 2 O) 
 or 0-108 per cent. 
 
 Sometimes, on the other hand, the alcoholic filtrate is more or 
 
 * Chemical News, xliii. (1881), p. 219. 
 
 t With some kinds of soap, if a stream of pure carbon dioxide be passed 
 through a hot clear filtered alcoholic solution of the soap, a slight visible 
 precipitation of alkaline carbonate results, together with the formation of an 
 equivalent amount of "acid soap." 
 
FREE ALKALI. ,499 
 
 less alkaline (through the presence of hydroxide in the soap) ; 
 in which case the amount of alkali present in the nitrate is 
 determined (using phenolphthalein as indicator) and added to 
 that found in the residue, this method of operating being 
 " Hope's test " in its original form. It has been pointed out by 
 J. A. Wilson * that when caustic alkali is present in a soap 
 which also contains unsaponified glycerides, the alcoholic alkaline 
 solution is apt to act on these glycerides, diminishing the alka- 
 linity by saponifying them, and so causing the amount of free 
 alkali to be understated. The author has found that this 
 source of error is readily avoided by cutting the soap to be 
 examined into very thin slices or shavings, and exposing these 
 loosely piled together in a small dish or beaker to the action of 
 carbon dioxide, conveniently by placing the dish in a wide 
 mouthed bottle filled with the gas, loosely corking it, and leaving 
 the whole till next day. By that time all caustic alkali is car- 
 bonated, so that the alcohol test can be applied without any 
 error due to saponification of glycerides, due correction being 
 made, if requisite, for the " negative alkalinity " of the alcoholic 
 nitrate caused by the action of the carbon dioxide forming small 
 quantities of acid soap and alkaline carbonate. This mode of 
 operating, however, obviously does not enable the relative amount 
 of alkali to be distinguished present as hydroxide and carbonate, 
 &c., respectively. 
 
 In the case of strongly alkaline soaps where a slight 
 amount of error in determining the total amount of free alkali 
 is not material, two other tests are applicable, respectively desig- 
 nated the " fatty acid titration test " and the " salting out test/'f 
 The first of these consists in determining the total alkali as 
 above, separating the fatty acids, and titrating them, reckoning 
 the difference as free alkali. In practice the unavoidable experi- 
 mental error of this differential method is sometimes found to be 
 sufficiently great to render the determination of minute quantities 
 of free alkali decidedly uncertain, so that for nearly neutral soaps 
 the method is useless. Moreover, the fatty acids separated by 
 the action of dilute aqueous acid on soap are sometimes partly 
 soluble in water, so that although the insoluble acids largely 
 dissolve the soluble ones and bring them out of solution in water 
 into the supernatant layer of fused fatty acids (as ether would 
 dissolve out similar matters from watery solution), still a small 
 proportion of the soluble acids are apt to be retained by the 
 water and lost, thus tending to increase unduly the value of the 
 free alkali determination ; this is especially noticeable when 
 cokernut or palm kernel oil has been employed in making the 
 soap. When, however, the free alkali is large, so that a small 
 
 * Chemical News, lix. (1889), p. 280. 
 
 t Alder Wright and Thompson, Journ. Soc. Chem. Ind., 1885, p. 625. 
 
500 
 
 OILS, FATS, WAXES, ETC. 
 
 degree of possible error in its determination is not of great 
 importance, this method is very convenient. 
 
 The " salting out test " is worked by dissolving a weighed 
 quantity of soap in hot water, adding salt so as to throw the curd 
 out of solution, filtering off, and titrating the alkali in the filtrate. 
 This may be conveniently done in two fractions, one titrated 
 directly so as to obtain the total alkali present (caustic -f- car- 
 bonated) ; the other treated with barium chloride in excess, and 
 the caustic alkali determined present in the filtrate from the 
 barium carbonate, &c., thus precipitated (vide p. 420, footnote). 
 Apart from error in deficiency of the caustic alkali value 
 thus deduced due to unavoidable absorption of carbon dioxide 
 from the air during the operations, a source of error in excess is 
 that hydrolysis of the soap examined necessarily takes place to 
 an extent variable with the temperature, the quantity of water 
 present relatively to the soap, the nature of the fatty acids 
 present, and the amount of free alkali. When, however, a 
 uniform mode of manipulating is adhered to, the results got 
 with a given kind of soap are comparable .amongst themselves, 
 so that the figures obtained are often of considerable practical 
 use, especially when corrected (by means of carefully made tests 
 using the alcohol process) so as to get an approximate valuation 
 of the excess of alkali due to the hydrolytic action. For instance, 
 the following figures represent the difference in amount of free 
 alkali found with a variety of soaps according as the alcohol 
 test (A.T.) or salting out test (S.O.T.) was used : the numbers 
 are reckoned per 100 parts of alkali combined with fatty acids as 
 soap i.e., if the combined alkali = lO'O and the free alkali = 
 0-52 per 100 of soap, this would correspond with 5-2 parts of 
 free alkali per 100 of combined alkali : 
 
 Nature of Soap Used. 
 
 A.T. 
 
 S.O.T. 
 
 Excess of S.O.T. 
 over A.T. 
 
 Pure cokernut oil soap, not strongly \ 
 alkaline, . . . . . / 
 
 5-0 
 
 9-1 
 
 4-1 
 
 Another sample of ditto, . 
 
 2-8 
 
 58 
 
 3-0 
 
 A British toilet soap, largely made 1 
 from cokernut oil, . . . . / 
 
 1-3 
 
 5-8 
 
 4-5 
 
 A foreign toilet soap, largely madel 
 from cokernut oil (neutral), . . / 
 
 
 
 3-5 
 
 3 '5 
 
 A high-class American toilet soap, 
 
 1-8 
 
 54 
 
 3-6 
 
 A toilet soap largely made from lard \ 
 (neutral), . . . . . / 
 
 
 
 3-2 
 
 3-2 
 
 A second-class ditto, chiefly made from ) 
 
 i -q 
 
 4*8 
 
 0-0 
 
 tallow, i 
 
 J. *J 
 
 Tt O 
 
 *7 
 
 A cotton seed oil soap, 
 
 7'2 
 
 9-8 
 
 2-6 
 
 A tallow rosin (primrose), . 
 
 1-1 
 
 3-0 
 
 19 
 
 A neutral castor oil soap, . 
 
 
 
 1-7 
 
 1-7 
 
 A bleached palm oil soap, . 
 
 50 
 
 6-4 
 
 1-4 
 
 A tolerably alkaline curd soap, . j 
 Pure stearic acid soda soap (neutral), 
 
 18-3 
 
 
 18-3 
 07 
 
 
 0-7 
 
ROSIN ACIDS. 501 
 
 When the watery soap solution is tolerably concentrated (about 
 1 part by weight of actual anhydrous soap to 10 of water), and 
 the soap itself contains a good deal of free alkali, the error due 
 to hydrolysis becomes small enough to be quite negligible ; but 
 with a nearly neutral soap the hydrolytic error becomes several 
 times as large as the free alkali actually present. 
 
 Potash and Soda. When both alkalies are present, and it 
 is required to determine their relative amount, several methods 
 of operating are available. One of the simplest is to decompose 
 a known quantity of soap with dilute hydrochloric acid, evaporate 
 down the watery nitrate, convert potassium chloride into platino- 
 ehloride, and weigh this. In the absence of more than minute 
 quantities of sulphate, silicate, &c., the mixed alkaline chloride 
 solution may be evaporated down and weighed, the chlorine 
 contained determined (volumetrically or otherwise), and the ratio 
 of potassium to sodium calculated from the indirect results. 
 The soap may also conveniently be charred and the alkalies 
 dissolved out from the ash for treatment. When much sulphate 
 is present the alkalies should be weighed as sulphates and the 
 indirect determination made by determining the barium sulphate 
 yielded by the mixture. 
 
 Rosin Acids. It is often of considerable importance to deter- 
 mine with some degree of approximate accuracy the proportion 
 between the rosin acids and the ordinary fatty acids present in a 
 given sample of soap. Several older methods have been pro- 
 posed, none of which yield very accurate results j but more 
 recently two processes have been introduced of a somewhat more 
 satisfactory nature, although still leaving a good deal to be 
 desired. The earlier of these is that of Gladding * based upon 
 much the same principle as the ordinary separation of oleic and 
 stearic acids, viz., conversion into metallic salts, one soluble in 
 ether, the other insoluble. The soap- to be tested is freed from 
 unsaponified fat, &c., by treatment with petroleum spirit ; or if 
 glycerides only are present by heating with strong alcohol and a 
 few drops of alcoholic potash in excess of the neutralising amount 
 to effect complete saponification. The alcoholic soap solution is 
 then agitated with powdered neutral silver nitrate and ether in 
 a closed vessel for some time (0'5 grm. fatty acid, 1 grm. silver 
 nitrate, and 100 c.c. of ethereal fluid altogether, answer well) : 
 after some minutes shaking flocculent silver stearate, &c., sub- 
 sides, whilst silver resinate remains dissolved. A known fraction 
 of the ether is siphoned off or removed by a " Chattaway tube " 
 (p. 120) and agitated with dilute hydrochloric acid, whereby the 
 silver is removed and an ethereal solution of rosin acids produced, 
 by evaporating which the rosin acids are obtained in weighable 
 form. Finally, a correction is made for the solubility of silver 
 
 * Chemical Fews, xlv. (1882), p. 159. 
 
502 
 
 OILS, FATS, WAXES, ETC. 
 
 oleate, &c., amounting to a subtraction from the weight of rosin 
 acids obtained of 23'5 milligrammes per 100 c.c. of ether. 
 
 A notable source of error in this method lies in the uncertainty 
 of this correction, inasmuch as somewhat widely different values 
 are found with different acids e.g.* 
 
 Nature of Fatty Matters in Soap 
 Examined. 
 
 Fatty Matters Dissolved (as Silver Salt) in 
 100 c.c. of Alcoholic Ether. 
 
 Maximum. 
 
 Minimum. 
 
 General Average. 
 
 
 Milligrammes. 
 
 Milligrammes. 
 
 Milligrammes. 
 
 Pure stearic acid, 
 
 16-0 
 
 8-0 
 
 11-6 
 
 ,, oleic ,, . 15'0 
 
 9-0 
 
 12-0 
 
 Nearly pure palmitic acid, 30 '0 
 
 2SO 
 
 29-1 
 
 Cotton seed oil, . . 34'0 
 
 20-0 
 
 26-9 
 
 Castor oil, ... 62 "0 
 
 49-0 
 
 53-9 
 
 Cokernut oil (fatty acids dried 
 
 
 
 on water bath), . . 17*5 
 
 12-0 
 
 14-8 
 
 Cokernut oil (fatty acids dried ' 
 
 
 
 over H 2 S0 4 ), ... 23 '0 
 
 19-0 
 
 21-1 
 
 Stearic and oleic acids, in 
 
 
 
 nearly equal proportions, 22 '0 
 Stearic acid and cotton seed oil, 
 
 IS'O J9-1 
 
 in nearly equal proportions, 
 
 ... 
 
 ... 
 
 25-5 
 
 Oleic acid and cottonseed oil, 
 
 
 
 
 in nearly equal proportions, 
 
 
 ... 
 
 24-5 
 
 Stearic acid and cokernut oil 
 
 
 
 
 (water bath), in nearly equal 
 
 
 
 
 proportions, 
 
 
 ... 
 
 23-4 
 
 Oleic acid aud cokernut oil 
 
 
 
 
 (water bath), in nearly 
 
 
 
 
 equal proportions, . 
 
 ... 
 
 ... 
 
 25-6 
 
 According to the nature of the fatty acids, the correction may 
 thus vary between 8 and 62 milligrammes in the most extreme 
 cases, and between 11 '6 and 53*9 for average values, these 
 quantities representing on 500 milligrammes of fatty acids 
 respectively 2-3 and 10 -8 per cent. ; so that whilst 2 3 -5 milli- 
 grammes ( - 4*7 per cent.) is not far from a mean value, it is by 
 no means equally applicable in all cases, f 
 
 * Alder Wright and Thompson, Proceedings of the Chemical Society, 1886, 
 p. 175 ; also Chemical News, vol. liii. (1886), p. 165. 
 
 t Lewkowitsch has subsequently found still wider discrepancies between 
 the corrections necessary in the case of stearic and oleic acids e.g., 
 
 Correction per TOO c.c. of Alcoholic Ether. 
 
 Oleic acid, . . . 109*0 to 109 '4 milligrammes. 
 Stearic acid, . . . 5 "4 to 5 '8 ,, 
 
 (Journ. Soc. Chem. Ind., 1893, p. 503.) 
 
 Hubl and Stadler modify Gladding's process by precipitating the mixed 
 silver salts from the largely diluted soap solution by means of aqueous 
 silver nitrate, drying, and dissolving out silver resinate with ether in a 
 Soxhlet tube (p. 238). Grittner and Szilazi add alcoholic calcium nitrate 
 solution to the alcoholic soap solution to be tested, so as to remove most of 
 
TWITCHELL'S METHOD. 503 
 
 E. Twitchell's method * depends on the property of ordinary 
 fatty acids to form compound ethers when dissolved in alcohol 
 and treated with hydrochloric acid gas ; if the alcohol be absolute 
 and the solution saturated with the gas, the conversion is stated 
 to be complete with fatty acids, whereas rosin acids are not acted 
 upon at all ; with alcohol of only 90 per cent., however, the 
 action is not complete, several per cents, of the fatty acids 
 escaping conversion. 2 or 3 grammes of mixed acids are dissolved 
 in 10 volumes of absolute alcohol, and dry hydrochloric acid 
 gas passed through for 45 minutes, the vessel being cooled 
 by immersion in water ; by and bye the fatty ethers separate, 
 floating on the surface. After standing half an hour the mixture 
 is diluted with five times its volume of water and boiled till clear, 
 the ethers and rosin acids floating on the top; the whole is shaken 
 with about 50 c.c. of light petroleum spirit; after separation, the 
 hydrocarbon solution is washed by shaking with water, and 
 finally shaken with 5 c.c. alcohol and 50 of water containing 0-5 
 gramme of caustic potash. The alkali dissolves out the rosin 
 acids from the hydrocarbon, leaving the fatty ether still dissolved 
 therein ; on separation of the aqueous solution of resinate, and 
 agitation with ether or petroleum spirit after acidulation, the 
 rosin acids are obtained in solution, and may either be weighed 
 (after evaporation to dryness) or titrated, assuming some par- 
 ticular value for their mean equivalent.! If glycerides are 
 
 the stearate, palmitate, and oleate present by precipitation ; the filtrate is 
 then treated with silver nitrate and ether as in Cladding's process. 
 According to Lewkowitsch (loc, cit. supra] neither modification gives satis- 
 factory results, the quantity of rosin found being generally below that 
 actually present when soap made from known mixtures of fatty matters 
 and rosin are examined as test samples. On the other hand, the figures 
 obtained by means of Gladding's original process are generally several per 
 cents, too high, even when the correction to be used has been separately 
 determined for the particular fatty acids, &c., used for the test samples 
 employed. 
 
 * Analyst, 1891, p. 169; also Journ. Soc. Chem. Industry, 1891, p. 804, 
 from Journ. Anal, and Applied CTiem., vol. v., p. 379. 
 
 t Test experiments made by E. Twitchell showed that when the value 
 346, found as the mean equivalent weight of a sample of colophony, was 
 used to calculate the result of titration of the rosin acids isolated from 
 known mixtures of that colophony and fatty acids, the titration values 
 always came out higher than those got by weighing ; thus 
 
 Volumetric. Gravimetric. 
 
 21-40 
 20-36 
 19-91 
 
 Average 20 "56 18 '93 
 
 Hence apparently one or two per cents, of constituents were present, 
 not of acid nature, and, consequently, not dissolved by the caustic potash 
 and, therefore, not ultimately weighed along with the true rosin acids. 
 Such constituents would be weighed along with the rosin acids isolated 
 
504 OILS, FATS, WAXES, ETC. 
 
 present in the fatty acid mixture, this does not in any way 
 invalidate the rosin determination, as the glycerides are not 
 dissolved out by the alkaline liquor along with the rosin acids. 
 
 Silicate of Soda. The substance left undissolved by alcohol in 
 the determination of free alkali by the "alcohol test" (supra), after 
 treatment of water and nitration, may be titrated for alkalinity 
 and then evaporated to dryness with a slight excess of hydro- 
 chloric acid ; the silicon dioxide formed in the event of silicate 
 being present in the soap, is then left undissolved on treatment 
 of the residue with water. Or a known weight of soap may be 
 charred, and the ashes supersaturated with hydrochloric acid and 
 thoroughly dried, so that silica and carbon are left undissolved 
 by water, the latter being ultimately burnt off. 
 
 Starch, China Clay, Steatite, Pigments, &c. Substances 
 of this description other than colouring matters are not often 
 found in soaps, but are occasionally added, especially to certain 
 varieties of fancy soap e.g., "oatmeal" soap, certain socalled 
 "milk" soaps, and the like. The residue from the previous 
 examination for silicate and carbonate, &c., left undissolved by 
 water on treating the matters insoluble in alcohol therewith 
 consists of these substances. Ultramarine, chrome green, ver- 
 milion and similar pigments are sought after by the appropriate 
 tests suggested by the colour; starchy matters by means of 
 iodine ; mineral constituents generally by incineration ; and so on. 
 The presence of such substances as oatmeal, farina, &c., sometimes 
 renders it necessary to modify slightly the method for deter- 
 mining fatty acids above described, where the cake of fatty acids 
 obtained is weighed, as it may contain some of these matters 
 mechanically intermixed ; to separate them the cake is dissolved 
 in ether, benzene, &c., and filtered; the residue is well washed 
 and the nitrate evaporated to dryness. 
 
 Glycerol and Sugar. When glycerol is contained (as in 
 the case of soft soaps, cold process soaps, hydrated soaps, &c.) it 
 may be determined, with a fair degree of accuracy, in a variety 
 
 by Gladding's process. Lewkowitsch finds (Journ. Soc. Chem. Ind., 1893, 
 p. 505) that the mean equivalent* of different samples of commercial rosin 
 varies within somewhat wide limits ; thus, with six samples of American 
 rosin values were found varying between 340 '8 and 364, with an average of 
 348 "3. Hence, the percentage of rosin found by titration can only be 
 regarded as a somewhat rough approximation. On the other hand, 
 Twitchell's process, applied to pure stearic acid and other fatty acids and 
 mixtures free from rosin, indicated from 1'07 to 3'67 per cent, of that 
 substance, the products obtained being weighed ; whence it would seem that 
 the quantity of rosin apparently found in a given sample of soap by Twitchell's 
 process would be too high, and that a correction should be made to allow 
 for this source of error (probably incomplete conversion of fatty acids- 
 into compound ethers, or subsequent decomposition of compound ethers) 
 In practice, however, the quantity of rosin actually found is generally 
 somewhat beloiv that known to be present when test samples of known 
 composition are examined. 
 
GLYCEROL AND SUGAR. 505 
 
 of ways in the absence of sugar ; but in presence of sugar its 
 accurate determination is not easy. If sugar be not present, one 
 of the simplest methods of procedure is to decompose the soap 
 with a slight excess of sulphuric acid, and after separating the 
 fatty acids to render neutral or slightly alkaline with sodium 
 carbonate, evaporate to dryness, and dissolve out the glycerol 
 from the sodium sulphate, &c., by absolute alcohol : the residue 
 left on evaporating off the alcohol may be weighed, and any 
 inorganic matters present determined by incineration and sub- 
 tracted. The crude glycerol may, preferably, be purified as 
 described on p. 523; or it may be converted into acetin by 
 acetic anhydride (pp. 186, 516); or if sufficiently free from other 
 organic substances it may be determined by the dichromate 
 process (p. 522), or oxidised to oxalate (p. 519). A little gly- 
 cerol is volatilised during the latter part of the evaporation ; 
 hence when either of these two latter methods is employed, 
 instead of evaporating the aqueous solution to complete dryness, 
 it may preferably be only partially concentrated. Muter's method 
 consists in treating with copper sulphate and caustic soda, the 
 copper kept in solution being determined colorimetrically or by 
 potassium cyanide (p. 523), parallel observations being made 
 with liquids treated in just the same way after addition of known 
 quantities of glycerol solution from a burette, so as to afford the 
 means of calculating the glycerol present from the amount of 
 copper kept in solution. In general the glycerol may be thus 
 estimated conveniently in the watery fluid left after determining 
 total alkali and fatty acids (supra). When sugar is present this 
 is inverted by heating with dilute hydrochloric or sulphuric 
 acid ; the liquid is then rendered alkaline and copper sulphate 
 added in excess, and the sugar deduced from the amount of pre- 
 cipitated cuprous oxide ; the alkaline liquid containing glycerol 
 and the products of the oxidation of the sugar may be tested for 
 glycerol by determining the amount of dissolved copper as before, 
 checking the results by means of similar tests with liquids con- 
 taining known quantities of sugar + glycerol; the results, 
 however, are apt to be only approximate even with the greatest 
 care. Instead of determining sugar by the copper reduction pro- 
 cess the polariscope may be employed. Knowing the amount of 
 sugar present and the specific gravity, the proportion of glycerol 
 present may be approximately calculated in the case of a liquid 
 containing no other substances in solution. 
 
 Volatile Substances other than Water. Sometimes a 
 transparent soap contains alcohol, the proportion of which is 
 desired to be known ; other volatile constituents are sometimes 
 present in other kinds of soap e.g., carbolic acid, thymol, 
 camphor, &c. In such cases special methods must usually be 
 resorted to to determine the volatile substance, dependent on its 
 nature. Alcohol, if in quantities above inconsiderable traces, may 
 
506 OILS, FATS, WAXES, ETC. 
 
 be determined by dissolving in water a sufficient quantity of 
 soap, adding salt, filtering off say one half of the total fluid, and 
 distilling until about half has passed over; this distillate is simi- 
 larly redistilled, and ultimately the quantity of alcohol inferred 
 either from the specific gravity of the final distillate, or by 
 oxidising with chromic acid, ifec. The following method of 
 determining phenoloids is recommended by A. H. Allen * : 
 5 grammes of soap are dissolved in hot water, 20 to 30 c.c. of a 
 10 per cent, solution of caustic soda added, and the whole cooled 
 and agitated with ether to dissolve hydrocarbons. The alkaline 
 liquor is separated and treated with excess of strong brine ; 
 fatty acid soaps are precipitated, but sodium phenolate and 
 cresylate, etc., remain in solution ; the liquid is filtered and 
 the precipitate washed with brine, and the nitrate and washings 
 diluted to a litre. 100 c.c. of the solution (representing 0'5 
 gramme of soap) are acidulated with sulphuric acid, and the 
 solution (clear if fatty acids have been thoroughly removed) 
 titrated with bromine water standardised by means of carbolic 
 iicid (or cresylic, &c. ), operating in the same way ; when enough 
 bromine has been added to cause all the phenoloids to become 
 converted into tribromo derivatives, the yellow tint due to excess 
 of bromine becomes visible. By treating the other 900 c.c. of 
 solution with sulphuric acid and excess of bromine, and agitating 
 with successive small quantities of carbon disulphide, the tri- 
 bromo derivatives may be dissolved out and examined after 
 evaporation of the solvent. Pure phenol (crystallised " carbolic 
 acid") gives nearly colourless long needles of tribromophenol, 
 whereas cresylic acids give deep yellow, orange, or red difficultly 
 crystallisable or non-crystalline products ; so that the character of 
 the phenoloids present may be ascertained, as well as the amount. 
 
 The following general scheme represents a selection from the 
 -above processes applicable in most cases : 
 
 Dry 10 grammes of average sample, finally at 120, and reckon 
 the loss of weight as water. 
 
 Exhaust the residue with light petroleum spirit, and examine 
 the extract for unsaponified glycerides, hydrocarbons, spermaceti, 
 wax, cholesterol, &c. 
 
 Treat the exhausted residue with water and excess of standard 
 ^nitric) acid ; separate and weigh the fatty acids, and subject 
 them to such further examination as may be required, more 
 especially as regards the presence of rosin acids. Back-titrate 
 the aqueous liquor so as to determine the total alkali, using 
 alkaline solution free from sulphate and chloride. Determine 
 sulphate and chloride in the neutralised liquid ; also glycerol and 
 sugar if present ; and potassium if required. 
 
 Treat 5 grammes of average sample with hot strong alcohol, and 
 titrate acidity or alkalinity of filtered solution : dissolve the 
 * Commercial Organic Analysis, 2nd edition, vol. ii., p. 255. 
 
CAILLETET'S METHOD. 507 
 
 undissolved part in water and titrate for carbonated alkali, &c., 
 so as ultimately to deduce the free alkali. Examine the sub- 
 stances not dissolved by alcohol for silica, clay, starch, pigments, 
 and similar substances.* If unsaponified glycerides and caustic 
 alkali be simultaneously present, the latter should be carbonated 
 before dissolving the soap in alcohol, otherwise a deficiency in 
 the total " free alkali " will result (supra, p. 499). 
 
 An objection to this mode of operation is that if any caustic 
 alkali be contained in the soap, it becomes more or less carbonated 
 during the drying, so that an incorrect valuation of caustic alkali 
 results. When much caustic alkali is present, it may be deter- 
 mined by the salting out test (supra), adding barium chloride 
 to convert alkaline carbonate into chloride, and filtering before 
 titrating (compare p. 500). 
 
 Instead of decomposing the soap dissolved with alcohol with 
 excess of standard acid, and back-titrating after separation of 
 fatty acids, the alcoholic solution may be rendered neutral to 
 phenolphthalein, and then directly titrated with a standard 
 mineral acid solution, using methyl orange as an indicator, 
 organic fatty acids having no reaction on this substance: per- 
 fectly sharp results are thus obtainable (Allen). 
 
 Cailletet's method of Analysis. t For determinations where 
 speed is indispensable but minute accuracy unnecessary, a con- 
 venient process has been proposed by Cailletet for the determin- 
 ation of fatty acids and alkali. A tube holding 50 c.c. and 
 divided into 100 parts is provided, into which are introduced 10 c.c. 
 of diluted sulphuric acid of known strength (about four times 
 normal), 20 c.c. of oil of turpentine, and 10 grammes of the soap 
 in shavings. The tube is closed with a stopper or cork and well 
 shaken up ; when all the soap is decomposed it is allowed to 
 stand, and the volume of the turpentine solution of fatty acids 
 read off. Subtracting the 20 c.c. of turpentine used, the differ- 
 ence gives the volume of the fatty acids : thus, if the turpentine 
 solution occupied 50 divisions = 25 c.c., the fatty acids would 
 represent 25 20 = 5 c.c. per 10 grammes of soap. Assuming 
 the specific gravity of the fatty acids to be n, their weight would 
 be 5 x n grammes = 50 x n per cent, by weight. The alkali 
 is obtainable by back-titrating the excess of acid. 
 
 Cailletet gives the following values for n in the case of soaps 
 of different kinds, experimentally determined by noting the 
 
 * Instead of weighing up two portions of soap, one portion (preferably of 
 10 grammes) may be employed for all the determinations, being first dried, 
 then exhausted with petroleum ether to extract fat, and then treated 
 (still in the Soxhlet tube) with alcohol to dissolve out soap, glycerol, &c. 
 The alcoholic extract thus obtained is titrated for acidity or alkalinity, 
 then largely diluted with hot water and decomposed with standard acid so 
 as to obtain fatty acids and total alkali ; whilst the residue undissolved by 
 alcohol is tested for alkali, silicate, sulphate, chloride, starch, pigments, &c. 
 
 f Bulletin Soc. Ind., Mulhouse, xxix., p. 8. 
 
508 
 
 OILS, FATS, WAXES, ETC. 
 
 increment in volume of turpentine oil as above indicated, and 
 directly determining the percentage by weight of fatty acids in 
 another portion of the same soap : 
 
 Specific Gravity of Fatty Acids. 
 
 Olive oil (Marseilles) soap 0'9188 
 
 Cokernut oil soap, ....... 0'9400 
 
 Palm oil soap, 0'9220 
 
 Tallow soap 0'9714 
 
 Oleic acid soap, 0'9003 
 
 In the case of rosin soaps, the rosin acids do not readily dis- 
 solve in the turpentine, 20 c.c. only increasing 0-15 c.c. in volume 
 by virtue of the rosin acids dissolved, whilst a bulky layer of 
 undissolved rosin collects below the turpentine. 
 
 Calcium Salt Test. A rough method of arriving at the value 
 of a given soap is to dissolve in dilute alcohol and determine the 
 quantity of the solution requisite to be added to a known volume 
 of a solution of calcium chloride, sulphate, &c., so as to produce 
 a permanent lather, as in Clark's test for the hardness of water ; 
 a parallel determination being made with a standard sample of 
 similar soap of known composition, the ratio between the volumes 
 of the two soap solutions used gives approximately their relative 
 detergent value. The soap solutions may be conveniently made 
 of the strength of 10 grammes per litre ; the lime salt solution 
 maybe made by dissolving 0'2 gramme of pure calcium carbonate 
 in dilute hydrochloric acid, evaporating to dry ness on the water 
 bath to expel excess of acid, dissolving the residue in distilled 
 water and diluting to a litre ; the solution consequently repre- 
 sents 20 milligrammes of CaCO 3 per 100 c.c. or 14 grains per 
 gallon (14 of hardness on Clark's scale). 
 
 The folio wing analyses represent the composition of a consider- 
 
 
 Best Tal- 
 low Curd, 
 London 
 make. 
 
 Bleached 
 Palm Oil, 
 London 
 make. 
 
 Marine 
 Soap, non- 
 siiicated. 
 
 Marine 
 Soap, 
 silicated. 
 
 Imitation 
 Castile 
 Soap, 
 English. 
 
 Fatty anhydrides, . 
 Combined alkali (Na 2 0), 
 
 66-60 
 7-51 
 
 66-20 
 7-83 
 
 32-00 
 5-20 
 
 13-50 
 2-27 
 
 61-45 
 8-46 
 
 Freealkali(includingthat } 
 present as silicate), . J 
 
 50 
 
 40 
 
 2-25 
 
 8'36 
 
 1-16 
 
 Silica (Si0 2 ), . 
 
 
 
 ... 
 
 10-50 
 
 
 Sodium chloride, . 
 
 1-35 
 
 2-05 
 
 765 
 
 5-05 
 
 1-17 
 
 Sodium sulphate, . 
 
 20 
 
 traces 
 
 1-45 
 
 35 
 
 1-23 
 
 Water, carbonic acid, and j 
 
 
 
 
 
 
 insoluble matters, pig- > 
 
 23-84 
 
 23-52 
 
 51-45 
 
 59-97 
 
 26-53* 
 
 ments, &c., . . . ) 
 
 
 
 
 
 
 
 100-00 
 
 100-00 
 
 100-00 
 
 100-00 
 
 100-00 
 
 Percentage of true soap, 
 
 74-11 
 
 74-03 
 
 37-20 
 
 15-77 
 
 69-91 
 
 Mean molecular weight! 
 of fatty acids, . . / 
 
 284 
 
 271 
 
 200 
 
 197 
 
 234 
 
 Including '74 per cent, of insoluble pigments. 
 
MANUFACTURERS', HOUSEHOLD, AND LAUNDRY SOAPS. 509 
 
 able variety of British and colonial manufacturers' and other 
 scouring and laundry soaps. Where no analyst's name is men- 
 tioned, the analyses were made by the author. 
 
 
 "Prim- 
 
 
 "Cold 
 
 "Cold 
 
 Oleic Acid 
 
 
 London 
 make. 
 
 "Ivory," 
 Canadian.* 
 
 Water," 
 English. 
 
 Water," 
 Canadian.* 
 
 Soap, 
 London 
 make. 
 
 Fatty anhydrides, . 
 Resinous anhydrides, 
 
 | 46-88 
 \ 15 -40 
 
 43-33 
 25-00 
 
 43-70 
 22-00 
 
 45-85 
 24-00 
 
 62-71 
 
 Combined alkali (Na 2 0), 
 
 7-12 
 
 7-72 
 
 9-28 
 
 8-00 
 
 7-36 
 
 Sodium carbonate, . 
 
 14 
 
 2-64 
 
 58 
 
 2-22 
 
 68 
 
 ,, chloride. . 
 
 14 
 
 
 
 
 
 ,, sulphate, . 
 Water with minute quan- 
 
 07 
 
 21-31 
 
 24-44 
 
 1993 
 
 29-25 
 
 tities of insoluble mat- 
 
 on n- 
 
 
 
 
 
 ters, lime, ferric oxide, 
 
 &r> 
 
 
 
 
 
 
 
 100-00 
 
 100-00 
 
 100-00 
 
 100-00 
 
 100-00 
 
 Percentage of true soap, 
 
 69-40 
 
 76-05 
 
 7498 
 
 72-07 
 
 70-07 
 
 Free alkali (N T a 2 0), 
 
 08 
 
 1-54 
 
 34 
 
 1-30 
 
 40 
 
 Mean molecular weight \ 
 of fatty acids, &c. , . / 
 
 280 
 
 283 
 
 230 
 
 280 
 
 273 
 
 MANUFACTURERS' SOAPS (C. Hope). 
 
 
 
 
 ;_r~ 
 
 ;_. 
 
 | 
 
 *..s 
 
 , i 
 
 
 ti &Tii 
 
 c'O 
 
 o" 
 
 d -to 
 
 ^ 3 ^'-- > 0! 
 
 so 
 
 
 jjsjOd 
 
 
 fr 
 
 ^o 
 
 2 S 
 
 S 
 
 
 ^^"c 
 
 ^0 
 
 O 
 
 e 2 
 
 s ^ofe 
 
 f^ 2 
 
 
 e -ei'S 
 
 *s s* 
 
 
 -^ Cl^* 
 
 2^ fifc^^ 
 
 3 . 
 
 
 3 C? fl 02 
 
 ^d 
 
 Q 
 
 
 pq ^ 
 
 
 
 ?"3 
 
 g 
 
 ? 
 
 Si5 
 
 ^l d 
 
 ?! 
 
 Fatty anhydrides and rosin, 
 
 71-30 
 
 62-66 
 
 59-28 
 
 38-89 
 
 19-42 
 
 60-90 
 
 Soda (Na 2 0), combined as soap, 
 Free alkali (Na 2 O), including 
 
 7-98 
 
 7-27 
 
 6-65 
 
 5-76 
 
 3-11 
 
 7-22 i 
 
 carbonate and silicate, 
 
 1-23 
 
 80 
 
 40 
 
 2-91 
 
 698 
 
 10 
 
 Sodium chloride, . 
 
 36 
 
 76 
 
 47 
 
 1-78 
 
 513 
 
 46 
 
 Sodium sulphate, 
 
 30 
 
 30 
 
 13 
 
 72 
 
 35 
 
 12 
 
 Silica, ..... 
 
 1-07 
 
 06 
 
 42 
 
 640 
 
 900 
 
 04 
 
 Lime, oxide of iron, &c. , 
 
 16 
 
 16 
 
 16 
 
 03 
 
 16 
 
 02 
 
 Water, .... 
 
 17-44 
 
 28-20 
 
 32-35 
 
 38-70 
 
 5332 
 
 3122 
 
 
 
 
 
 
 
 
 Total, 
 
 99-84 
 
 100-21 
 
 99-86 
 
 95-1 9t 
 
 97-47t 
 
 100 08 
 
 Actual soap present, 
 
 79-28 
 
 69-93 
 
 65-93 
 
 4465 
 
 22-53 
 
 68-12 
 
 * Exhibited in the "Colonial and Indian Exhibition," London, 1886. 
 For analyses of various of the Colonial soaps, made by the author, vide 
 "Colonial and Indian Exhibition Reports Oils and Fats" (Leopold Field). 
 
 fOlycerol present, but not determined. 
 
510 
 
 OILS, FATS, WAXES, ETC. 
 
 MANUFACTURERS' SOAPS (Lant Carpenter}. 
 
 "Primrose" Soap. 
 
 
 
 
 
 "Cold 
 Water" 
 Soap. 
 
 " Neutral 
 Curd." 
 
 "Oil" 
 Soap, 
 "Oleic 
 Acid." 
 
 Genuine 
 Rosin Soap 
 (South of 
 
 Watered 
 & Silicated 
 (North of 
 
 England). 
 
 England). 
 
 
 
 
 Fatty acids,* . . . 62 -3 
 
 42-66 
 
 70-2 
 
 67-9 
 
 68-6 
 
 Combined soda (Na,0), 6 '7 
 
 5-4] 
 
 7-3 
 
 7-0 
 
 7-88 
 
 " Free alkali " (Na 2 0), 
 
 1-21 
 
 1-8 
 
 nil. 
 
 1-0 
 
 Silica, .... 
 
 94 
 
 1-6 
 
 ... 
 
 ... 
 
 Neutral salts, . . '2 
 
 55 
 
 4 
 
 2 
 
 i-o 
 
 Water, . . . . 32 '8 
 
 50-40 
 
 22-0 
 
 28-0 
 
 21-0 
 
 Total, . . . 102-0 
 
 101-17 
 
 103-3 
 
 103-1 
 
 99-48 
 
 PHARMACEUTICAL SOAPS (M. Dechan). 
 
 
 Sapo 
 
 S. Castil. 
 
 
 8. Ani- 
 
 
 
 durus, 
 
 albus, 
 
 Mottled 
 
 malis, 
 
 S. Mollis, 
 
 
 Hard 
 
 White 
 
 Castile. 
 
 Tallow 
 
 Soft Soap. 
 
 
 Soap. 
 
 Castile. 
 
 
 Soap. 
 
 
 Fatty acids,*. 
 
 81-50 
 
 76-70 
 
 68-10 
 
 78-30 
 
 48-50 
 
 Combined alkali, . 
 
 9-92 
 
 9 14 
 
 8-90 
 
 9-57 
 
 12-60 
 
 Free alkali, 
 
 08 
 
 09 
 
 19 
 
 28 
 
 30 
 
 Silica, .... 
 
 
 
 15 
 
 
 17 
 
 Sulphates and chlorides, 
 Matters insoluble in alcohol, 
 
 28 
 50 
 
 36 
 60 
 
 63 
 1-30 
 
 47 
 1-10 
 
 93 
 1-60 
 
 Other insoluble matter, . 
 
 20 
 
 90 
 
 80 
 
 40 
 
 1-00 
 
 Water, .... 
 
 10-65 
 
 13-25 
 
 21-70 
 
 12-50 
 
 39-50 
 
 
 103-13 
 
 101-04 
 
 101-77 
 
 102-62 
 
 104-68 
 
 SOFT SOAPS (Ure). 
 
 
 London 
 Soft 
 Soap. 
 
 Belgian 
 Green 
 Soap. 
 
 Scotch. 
 
 Rape Oil 
 
 Soft 
 Soap. 
 
 Olive Oil 
 Soft 
 Soap. 
 
 Fatty acids, . 
 Dry potash (K 2 0), 
 Water, salts, glycerol, &c., 
 
 45-0 
 8-5 
 46-5 
 
 36-0 
 
 7-0 
 57 
 
 47-0 
 8-0 
 450 
 
 51-7 
 
 10-0 
 
 38-3 
 
 480 
 
 10-0 
 
 42-0 
 
 
 100-0 
 
 100-0 
 
 100-0 
 
 100-0 
 
 100-0 
 
 In general, similar partial analyses of soft soaps meet the 
 objects in view, inasmuch as such soaps are generally purchased 
 in quantity under contract either to contain a given percentage 
 (40, 50, &c.) of fatty acids producible on decomposition by a 
 mineral acid, or to lose not more than a given percentage in 
 weight (water) on drying completely ; the degree of alkalinity is 
 usually judged by the u touch " or taste of the sample, the tongue 
 being regarded as a sufficiently delicate indicator for such pur- 
 poses. When more definite information is required the methods 
 * Not calculated to fatty anhydrides. 
 
ANALYSES OF TOILET SOAPS. 
 
 511 
 
 above described are applicable ; thus the water is directly deter- 
 mined by drying in a sand bath (p. 494) ; the total fatty acids, 
 free alkali, combined alkali, unsaponitied oil, and matters insol- 
 uble in water (such as starch added to simulate "figging," &c.) 
 by the respective processes above detailed ; the rosin acids by 
 Gladding's process (p. 501) or Twitchell's method (p. 503); silicate 
 by incineration and analysis of the mineral constituents of the 
 ash ; and so on. 
 
 In the case of household and laundry soaps it is to be noticed 
 that the physical consistence of the substance is in many cases 
 of as much importance as its chemical constitution. From the 
 consumer's point of view what is required in the case of a hard 
 soda soap is an article from which, during use, no more is dis- 
 solved or abraded than is just requisite for the object in view. 
 If the soap be of too soft a consistency (either through over 
 watering, or bad selection of materials), a much larger amount 
 is rubbed on the clothes, <fcc., to be washed or scoured than is 
 absolutely necessary, leading to much waste. On the other 
 hand, pure tallow curd soaps largely boiled down are so hard as 
 only to rub off and lather with difficulty. With manufacturers' 
 soaps intended to be dissolved in water before use (e.g., soft soap 
 for wool scouring, &c.), the rate of solution must be sufficient 
 for the purpose ; whilst hydrocarbons and other insoluble 
 impurities which might spot and stain goods must be absent 
 from soaps intended for treatment during dyeing and subsequent 
 operations. 
 
 TOILET SOAPS. 
 
 
 High-class 
 Milled 
 Soap of 
 Conti- 
 nental 
 make. 
 
 High-class 
 Opaque 
 Soap, 
 English. 
 
 Inferior 
 Ouaque 
 Soap, 
 English. 
 
 Transparent Soaps. 
 
 Made by 
 Cold 
 Process. 
 
 Made hy Spirit 
 Process. 
 
 Sugared. 
 
 Genuine, 
 not 
 Sugared. 
 
 Fatty anhydrides, . 
 Uncombined rosin and 
 unsaponified fats, 
 Combined alkali, . 
 Sodium carbonate, 
 Sugar, . 
 Glycerol, 
 Water and minute 
 quantities of salts, 
 
 Percentage of true 
 soap, . 
 Free alkali (Na 2 0), 
 Mean molecular 
 \veight of fatty acids, 
 
 83-60 
 
 1-00 
 9-80 
 24 
 
 5-36 
 
 GO -20 
 
 G-9S 
 17 
 
 3-00 
 29-65 
 
 6500 
 
 8-91 
 1-73 
 
 6-00 
 18-36 
 
 38-90 
 
 40 
 5-57 
 3-80 
 28-00 
 3-00 
 
 20-33 
 
 65-60 
 
 3'00 
 7-73 
 
 nil. 
 14-00 
 
 9-67 
 
 68-10 
 
 3-20 
 
 7-62 
 20 
 nil. 
 7-00 
 
 13-88 
 
 100-00 
 
 100-00 
 
 100-00 
 
 100-00 
 
 100-00 100-00 
 
 93-40 
 14 
 
 274 
 
 67'18 
 10 
 
 276 
 
 73-91 
 1-01 
 
 228 
 
 44-47 
 2-22 
 
 225 
 
 73-33 
 
 nil. 
 
 272 
 
 75-72 
 nil. 
 
 286 
 
512 OILS, FATS, WAXES, ETC. 
 
 In the case of " toilet " soaps, the most important quality is 
 that of furnishing a sufficient lather without at the same time 
 causing the application of too alkaline a substance to the skin ; 
 the small amount of free alkali developed by hydrolysis when a 
 tablet of soap is rubbed on the skin or between the hands is 
 practically insensible, excepting to extremely sensitively skinned 
 persons who, in consequence, are rarely able to use soap in any 
 form without suffering more or less irritating effects. Such 
 individuals are comparatively rare; but a much larger portion 
 of the population, especially ladies and young children, are prone 
 to suffer inconvenience (particularly in windy and wintry weather) 
 through the use of soap containing more than traces of free 
 alkali ; to some extent this inconvenience may be mitigated by 
 introducing into the soap such substances as vaseline, spermaceti, 
 or even purified lard, &c., whereby a film of greasy or unguent- 
 like substance is left adherent to the skin, or at least pressed 
 into its pores (vide p. 478) ; but a far safer plan is so to prepare 
 or refine the soap as to ensure that it shall not contain any 
 material amount of free alkali. The author has proposed* to 
 classify toilet soaps into three grades from this point of view, 
 viz. : 
 
 First grade. Soaps containing a total amount of " free alkali " 
 not exceeding JQ- (2*5 per 100) of the alkali present combined with 
 fatty anhydrides as soap ; so that if the soap contained 8*0 per 
 cent, of combined alkali, the free alkali would not exceed 0*2 per 
 cent. 
 
 Second grade. Soaps where the "free alkali" ranges between 
 Jg- and -Q (2-5 to 7 '5 per 100) of that present as actual soap 
 i.e., for a soap containing S'O per cent, of combined alkali the 
 free alkali would be between 0'2 and 0*6 per cent. 
 
 Third grade. Soaps where the "free alkali" exceeds - (7*5 
 per 100) of that present as actual soap. 
 
 It is to be borne in mind, however, that other possible ingre- 
 dients besides alkali are apt to be detrimental to sensitive skins: 
 of these sugar (almost invariably present in transparent soaps) is 
 the one most certainly known to be noxious (pp. 478, 480, 482); 
 but there is also reason for supposing that some extremely 
 highly perfumed soaps may exert a more or less marked irri- 
 tating action of the same kind in virtue of the comparatively high 
 proportion of essential oils, etc., present (p. 480), even though 
 entirely destitute of free alkali, and containing no sugar. 
 
 When a soap (toilet, household, or manufacturer's) contains 
 an amount of glycerol approximately corresponding with that 
 equivalent to the fatty acids found (92 parts glycerol for 3 x n 
 parts of fatty acids of mean molecular weight n), the probability 
 
 *" Cantor Lectures," Society of Arts, Jo-urn. Sor. Arts, vol. xxxiii., 
 p. 112i (18S5), where also various other analyses of toilet soaps are given. 
 
MANUFACTURE OF GLYCERINE. 513 
 
 is that the soap has been prepared by a cold process : such a soap, 
 for instance, might yield fatty acids of mean molecular weight 
 270, in which case 100 parts of fatty acids would correspond with 
 
 ~Q o7n = 11*3 parts of glycerol, if triglycerides were employed, 
 o x 2i i U 
 
 Larger proportions of glycerol can only be contained in cases 
 where extra glycerol has been added. On the other hand, as 
 soaps prepared by boiling and salting out contain no glycerol at 
 all, the presence of smaller proportions of glycerol suggests 
 either that the soap mass is a mixture of hydrated soaps or cold 
 process soaps (Chap, xx.) and boiled soaps, or that free oleic acid, 
 &c., has been employed along with glycerides in its manufacture. 
 
 CHAPTER XXII. 
 
 GLYCEROL EXTRACTION MANUFACTURE OF 
 GLYCERINE. 
 
 IN the manufacture of soaps and " stearine" for candlemaking, 
 large quantities of glycerol * are produced as product comple- 
 mentary to the fatty acids formed by saponification of the oils 
 and fats employed. Until comparatively recently, much of the 
 glycerol thus formed was wasted, being run away along with 
 other watery fluids into the drains, <fcc. ; but since the introduc- 
 tion of various applications for which glycerol is suited, more 
 especially the manufacture of dynamite and other explosives, 
 much of the substance formerly thrown away as worthless, is 
 now extracted and utilised by processes which substantially 
 consist of evaporation so as to remove saline matters by 
 crystallisation, and distillation with superheated steam of the 
 final mother liquors. 
 
 The " sweet water " obtained in the saponification of glycerides 
 by lime in the autoclave or open pan processes (pp. 365, 373), is 
 one of the most eligible sources of commercial glycerine when re- 
 quired of high purity ; the distillation of fatty matters by means of 
 superheated steam, so as to hydrolyse them and form fatty acids 
 and glycerol (p. 385), furnishes a still purer raw product ; if the 
 temperature of distillation be too high (above 310 to 320 C.), 
 more or less decomposition of glycerol into water and acrolein 
 (acrylic aldehyde) results. 
 
 The watery glycerol solutions thus obtained are concentrated 
 
 * As already stated (p. 110) the word "glycerol" is employed in the 
 present work to denote the chemical substance C 3 H 5 (OH) 3 , and the term 
 " glycerine " to indicate commercial products more or less largely consisting 
 of glycerol in varying states of purity. 
 
 33 
 
514 OILS, FATS, WAXES, ETC. 
 
 by evaporation, preferably not in ordinary pans, but by special 
 devices analogous to those used in the sugar industry, where a 
 series of convoluted tubes or hollow plates heated by the 
 internal admission of steam, are made to revolve, so that the 
 tubes or plates partly dip into the fluid to be evaporated and 
 carry upwards an adherent film thereof as they revolve, which 
 film rapidly loses water by evaporation whilst the part of the 
 tube or plate to which it adheres is exposed to the air after 
 emerging from the liquid, especially if the whole arrangement is 
 placed inside an exhausted vessel or " vacuum pan." 
 
 When the glycerol solution is sufficiently concentrated, it 
 is decolorised by treatment with animal charcoal, and again 
 distilled by means of superheated steam,* the processes being 
 repeated several times for products of high purity, such as the 
 glycerine required for the manufacture of nitroglycerine for 
 dynamite arid similar explosives. Glycerines of the highest 
 degree of purity are best obtained by crystallising, draining 
 off the unsolidified portion by a centrifugal machine, and melt- 
 ing the residual crystals. 
 
 The extraction and purification of glycerol from soap leys is a 
 much more troublesome matter, not so much because of the dis- 
 solved salt, &c., which requires to be fished out as the evapora- 
 tion proceeds, as because various organic impurities derived 
 from the fats, &c., are also present. C. T. Kingzett f found the 
 following compositions in the case of the salts deposited on 
 evaporation, and of the evaporated mother liquor of specific 
 gravity 1-236: 
 
 SALTS. 
 
 Sodium chloride, . . . . 78 '12 
 
 Sodium sulphate, . . . . 8 '61 
 
 Sodium carbonate, . . . . . 2 - 61 
 
 Insoluble organic matter, . . . . 0'22 
 
 Glycerol and other organic soluble matters, . 3 '55 
 
 Water, ...... 7'50 
 
 100-61 
 CRUDE GLYCERINE. 
 
 Water, . . . 7 '53 pounds per gallon. 
 
 Glycerol, . . .2-04 
 
 Salts, . .2-78 
 
 12-35 
 
 The removal of the inorganic salts and the saponaceous, 
 resinous, and albuminous organic matters contained in the crude 
 leys may be more or less completely effected in a variety of 
 ways the subject of a number of patents. Thus, by acidulating 
 the liquor any soap is decomposed, and fatty and resinous acids 
 
 * An improved form of glycerine rectifying apparatus has been patented 
 by R. O. Unglaub (Eng. Pat., 8,196, 1889). 
 t Journ. Soc. Chem. Ind., 1882, p. 77. 
 
COMMERCIAL GLYCERINES. 515 
 
 set Jfree, separable by filtration. By treating with carbon dioxide 
 any caustic alkali is carbonated, and its removal by salting out 
 on evaporation rendered more easy (Versmann). By adding 
 tannin in some form or other, albuminous matters may be 
 coagulated and precipitated (Payne). The substitution of 
 sodium sulphate for common salt in the salting out process is 
 said to facilitate the separation of saline matters on evaporation, 
 and the remaining sodium sulphate finally remaining to interfere 
 less with the purification by distillation, ultimately necessary to 
 render the glycerol suitable for most of the purposes for which it 
 is employed (Benno, Jappe, & Co.) Spent leys produced when 
 black ash liquors are directly used for soapmaking, contain a 
 variety of impurities not present when purer caustic soda is used, 
 especially that made by the ammonia process ; such liquors may 
 be considerably purified by the addition of soluble copper salts, 
 whereby sulphocyanides and organic matters, <fec., are precipi- 
 tated (Allen, and Nickels). 
 
 A few years ago the Michaud-Freres process for saponifying 
 glycerides with zinc oxide (p. 379) instead of lime, attracted 
 considerable attention, it being expected that fatty acids and 
 glycerol would be so readily obtained that the older soap boiling 
 processes would be superseded, and direct neutralisation processes 
 (p. 451) substituted for them, whilst almost pure glycerol would 
 result, as in the candlemaking lime autoclave process. As yet, 
 however, this result has not been brought about to such an 
 extent as seriously to interfere with the older soapmaking 
 processes. A similar remark applies to methods based on 
 sapouification with ammonia solution under pressure (p. 379). 
 
 Commercial glycerines often contain impurities of various 
 descriptions best estimated by direct determination. Lime, lead, 
 magnesia, saline matters, and similar nonvolatile substances are 
 left behind on evaporation and incineration, and may be examined 
 in the ordinary ways ; distilled glycerines only contain minute 
 amounts of inorganic matter, rarely exceeding 0*1 to 0'2 per cent. 
 Silver nitrate forms no precipitate or darkening in colour after 
 standing 24 hours when added to glycerines free from acrolein, 
 formic acid, or other substances capable of reducing silver salts, 
 but blackens considerably in their presence.* Traces of chlorides 
 will not precipitate silver nitrate, silver chloride being slightly 
 soluble in glycerol ; glycerines from soap leys, however, give 
 copious precipitates, as they usually contain several per cents, of 
 sodium chloride. Such leys often contain resinous matters, albu- 
 minoids, fatty acids, and other substances precipitable by basic 
 lead acetate. Cane sugar and glucose are sometimes added as 
 adulterations, easily detected by the cuprous oxide (Fehling's) 
 
 * According to Ritsert, pure glycerol gives neither deposit of metallic 
 silver, nor formation of yellow colour, when mixed with its own volume of 
 ammonia solution, heated to boiling, and treated with silver nitrate. 
 
516 OILS, FATS, WAXES, ETC. 
 
 test. Glycerol intended for dynamite manufacture should be 
 wholly free from organic impurities, because the action of nitric 
 acid thereon during nitration might seriously endanger the suc- 
 cess of the process and the stability of the product. Chlorides, 
 except in the merest traces, should similarly be absent ; whilst 
 other inorganic matters (lime, &c.) should only be present in traces. 
 
 Estimation of Glycerol in Watery Solutions. For the 
 qualitative detection of glycerol in aqueous solution a variety of 
 tests have been proposed, one of which (Reichl's) is described 011 
 p. 8. Kohn * recommends the following method : The liquid 
 to be examined is evaporated with acid potassium sulphate and 
 the residue heated in a retort ; if glycerol is present, acrolein is 
 formed, so that the distillate gives a red coloration on treatment 
 with a solution of rosaniline that has been just decolorised by 
 sulphurous acid. 
 
 Several processes have also been proposed for the quantitative 
 determination of glycerol, some of which are only suitable under 
 particular conditions: thus in the case of distilled glycerines of 
 considerable or tolerable purity where organic matters are absent 
 and inorganic constituents and water are the only impurities (no 
 adulteration with glucose or other sugar, &c., being present), the 
 amount of glycerol may be conveniently ascertained by oxidation 
 with potassium dichromate and sulphuric acid, either collecting 
 the carbon dioxide formed, or determining the dichromate reduced 
 by using a known quantity and back-titrating with a standard 
 iron solution.! Another method applicable under such condi- 
 tions is the "acetin process" of Benedikt (p. 186), where the 
 substance is heated with excess of acetic anhydride and anhy- 
 drous sodium acetate, and the weight of potash (KOH = 56'1) 
 determined, neutralised by the acetic acid formed on saponiti- 
 cation of the triacetin produced (after destroying the excess 
 of acetic anhydride by boiling with water). J 92 parts of glycerol 
 correspond with 3 x 56*1 = 168'3 parts of KOH thus neutralised. 
 Weak glycerol solutions must be evaporated down until at least 
 50 per cent, of glycerol is present in the fluid. 
 
 Two physical methods are applicable in the case of glycerol 
 solutions where no appreciable amount of interfering impurity 
 is present, so that practically only glycerol and water are con- 
 tained ; these are based respectively on the determination of 
 the specific gravity at 15, and of the refractive index at the 
 same temperature. 
 
 Skalweit gives the following table for the purpose of exam- 
 ining glycerol solutions in these ways : older tables have also 
 
 * Journ. Soc. Chem. Ind., 1890, p. 148. 
 
 tFor comparative results of various modes of testing commercial gly- 
 cerines, vide 0. Hehner, Journ. Soc. Clvm. Ind., 1889, p. 4. 
 
 J According to Hehner (loc. cit. ) the liquid must vot be boiled, as the tri- 
 acetin rapidly hydrolyses. Repert. Analyt. Chemie, v., 18. 
 
SPECIFIC GRAVITY OF GLYCEROL SOLUTIONS. 
 
 517 
 
 been given by Strohmer* and Lenz, f reproduced by Benedikt. J 
 Hehner (loc. cit. supra} considers Lsnz's table accurate, and 
 Richmond has recalculated it to 15-50. 
 
 SPECIFIC GRAVITY AT 15"5 (Lenz, recalculated by Richmond'). 
 
 Percentage of 
 Glycerul. 
 
 Specific Gravity at 
 15 -5. ' 
 
 Percentage of 
 Glycerol. 
 
 Specific Gravity at 
 15-5. 
 
 100 
 
 1-2674 
 
 87 
 
 1-2327 
 
 99 
 
 1-2647 
 
 86 
 
 1 -2301 
 
 98 
 
 1-2620 
 
 85 
 
 1-2274 
 
 97 
 
 1-2594 
 
 84 
 
 1-2248 
 
 98 
 
 1-2567 
 
 83 
 
 1-2222 
 
 95 
 
 1-2540] 
 
 82 
 
 1-2196 
 
 94 
 
 1-2513 
 
 81 
 
 1-2169 
 
 93 
 
 1-2486 
 
 80 
 
 1-2143 
 
 92 
 
 1 -2460 
 
 79 
 
 1-2117 
 
 91 
 
 1 -2433 ] 
 
 78 
 
 1-2090 
 
 90 
 
 1-2406 
 
 77 
 
 1-2064 
 
 89 
 
 1-2380 
 
 76 
 
 1-2037 
 
 88 
 
 1-2353 
 
 75 
 
 1-2011 
 
 SPECIFIC GRAVITY AND REFRACTIVE INDEX OF GLYCEROL 
 SOLUTIONS (Skalweit). 
 
 Percentage 
 of 
 Glycerol. 
 
 Specific 
 Gravity at 
 15 0. 
 
 Refractive 
 Index for D at 
 16 0. 
 
 Percentage 
 of 
 Glycerol 
 
 Specific 
 Gravity at 
 15 0. 
 
 Refractive 
 Index for D at 
 15 0. 
 
 100 
 
 1 -2650 
 
 1-4742 
 
 50 
 
 1290 
 
 3996 
 
 98 
 
 1 -2600 
 
 1-4712 
 
 48 
 
 1236 
 
 3966 
 
 96 
 
 1 -2550 
 
 1-4684 
 
 46 
 
 1182 
 
 3938 
 
 94 
 
 1 -2499 
 
 1 -4655 
 
 44 
 
 1128 
 
 3910 
 
 92 
 
 2447 
 
 1 -4625 
 
 42 
 
 1074 
 
 3882 
 
 90 
 
 2395 
 
 1 -4595 
 
 40 
 
 1020 
 
 3854 
 
 88 
 
 -2341 
 
 1-4565 
 
 38 
 
 0966 
 
 3827 
 
 86 
 
 2287 
 
 1 -4535 
 
 36 
 
 1-0912 
 
 3799 
 
 84 
 
 2233 
 
 1 -4505 
 
 34 
 
 1-0858 
 
 3771 
 
 82 
 
 2179 
 
 1-4475 
 
 32 
 
 1-0804 
 
 3743 
 
 80 
 
 2125 
 
 1-4444 
 
 30 
 
 1-0750 
 
 3715 
 
 78 
 
 2071 
 
 1-4414 
 
 28 
 
 1-0698 
 
 3687 
 
 76 
 
 2017 
 
 1-4384 
 
 26 
 
 1-0646 
 
 3660 
 
 74 
 
 1963 
 
 1-4354 
 
 24 
 
 1-0594 
 
 3633 
 
 72 
 
 1909 
 
 1-4324 
 
 22 
 
 1-0542 
 
 3607 
 
 70 
 
 1855 
 
 1 -4295 
 
 20 
 
 1 -0490 
 
 3581 
 
 68 
 
 1-1799 
 
 1-4265 
 
 18 
 
 1 -0440 
 
 3555 
 
 66 
 
 1-1743 
 
 1-4235 
 
 16 
 
 1-0390 
 
 3529 
 
 64 
 
 M686 
 
 1-4205 
 
 14 
 
 1 -0340 
 
 3503 
 
 62 
 
 1-1628 
 
 1-4175 
 
 12 
 
 1-0290 
 
 3477 
 
 60 
 
 1-1570 
 
 1-4144 
 
 10 
 
 1-0240 
 
 3452 
 
 58 
 
 1-1514 
 
 1-4104 
 
 8 
 
 1-0192 
 
 3426 
 
 56 
 
 1-1458 
 
 1-4084 
 
 6 
 
 1-0144 
 
 3402 
 
 54 
 
 1-1402 
 
 1 -4054 
 
 4 
 
 1-0096 
 
 3378 
 
 52 
 
 1-1346 
 
 1-4024 
 
 2 
 
 1-0048 
 
 3354 
 
 * Monatsh. ,/iir Chemie, v., 61. t Zeitsch. f. Analyt. Chemie, xix., 302 
 J Analyse der Fette, 2nd edition, p. 256, et seq. 
 
518 
 
 OILS, FATS, WAXES, ETC. 
 
 Another physical process is also available for such fluids as 
 the comparatively pure solutions of glycerol obtained k in the 
 
 Fig. 144. 
 
 course of preparing candle materials (autoclave " sweet waters "), 
 or for distilled glycerines retaining only small quantities of 
 
519 
 
 impurities ; this is based on the differences in the tension of 
 the vapour emitted by glycerol solutions of various degrees of 
 concentration. Gerlach's vaporimeter for this purpose is repre- 
 sented by Fig. 144. A B is a hollow metal cylinder with dished 
 bottom for heating ; G a glass cylinder fitting therein and made 
 watertight by the indiarubber ring, H. To use the instrument, 
 G is disconnected and the whole turned upside-down ; the reser- 
 voir, F, filled with mercury and a little of the fluid to be examined, 
 is then connected by a bit of rubber tubing to the end of the 
 pressure tube, D D, passing inwards through the tubulus, C. The 
 instrument is then erected, and filled with hot water after fixing 
 G in position, the temperature being then raised to boiling by 
 heating B. The expansion of the mercury on heating and the 
 further expulsion thereof by the vapour emitted from the glycerol 
 solution fill the pressure tube, D D, with mercury up to a given 
 level : the length in millimetres of the level-difference between 
 the mercury in the reservoir and that in the open limb of the 
 pressure tube (known by means of the attached scales) repre- 
 sents the difference between the tension of aqueous vapour 
 emitted from pure water (equal to the existing barometric 
 pressure) and that of the vapour emitted by the glycerol solution: 
 from this the percentage of glycerol is reckoned by means of the 
 table on next page. 
 
 When organic substances are absent capable of forming oxalic 
 acid under the influence of alkaline permanganate, moderately 
 sharp valuations may be obtained by converting the glycerol 
 into oxalate (Wanklyn and Fox ; Benedikt and Zsigmondy ; 
 A. H. Allen). The liquid is rendered strongly alkaline and 
 boiled with excess of permanganate ; this is destroyed by sodium 
 sulphite or sulphur dioxide and the liquid filtered and precipi- 
 tated as calcium oxalate. 
 
 When this process is applied to the determination of the 
 amount of glycerol furnished on saponification by a given oil or 
 fat, the preliminary saponification should be effected by means 
 of caustic potash and pure methylic alcohol ; the solution 
 obtained by treating 2 to 3 grammes of oil is evaporated and 
 the residue treated with hot water and dilute hydrochloric acid : 
 a little solid paraffin wax may conveniently be added to help the 
 solidification of liquid fatty acids on cooling. The whole is 
 filtered and washed, neutralised with potash and about 10 
 grammes more potash added ; enough 5 per cent, potassium 
 permanganate solution (or the powdered salt) is then added to 
 render the fluid no longer green, but blue or blackish : the whole 
 is then heated to boiling whereby hydrated manganese dioxide 
 separates, the liquid becoming red ; aqueous sulphurous acid is 
 then added till decolorisation is produced, and the whole filtered : 
 the filtrate is acidulated with acetic acid (whereby any turbidity 
 due to passage of manganese dioxide through the filter is removed 
 
520 
 
 OILS, FATS, WAXES, ETC. 
 
 by the action of the sulphurous acid set free) and the oxalic acid 
 present precipitated by calcium chloride or acetate ; the calcium 
 oxalate is ignited, dissolved in excess of seminormal acid and 
 back-titrated with seminormal alkali, using methyl orange as 
 indicator. 1 c.c. of normal acid (2 c.c. of seminormal) corresponds 
 with 46 milligrammes of glycerine. 
 
 Percentage o 
 Glycerol. 
 
 Specific Gravity of Solution. 
 
 Boiling Poin 
 of Solution. 
 
 Tension of 
 Vapour 
 emitted 
 at 100. 
 
 Diminution in 
 Tensiou 
 Compared wit 
 Water giving 
 760 Millimetres. 
 
 At 15. 
 Water at 
 15 = 1. 
 
 At 20. 
 Water at 
 20 = 1. 
 
 
 
 
 Degrees C. 
 
 
 
 100 
 
 1-2653 
 
 1-2620 
 
 290 
 
 64 
 
 696 
 
 99 
 
 1 -2628 
 
 1-2594 
 
 239 
 
 87 
 
 673 
 
 98 
 
 1 -2602 
 
 1 -2568 
 
 208 
 
 107 
 
 653 
 
 97 
 
 1-2577 
 
 1 -2542 
 
 188 
 
 126 
 
 634 
 
 96 
 
 1 -2552 
 
 1 -2516 
 
 175 
 
 144 
 
 616 
 
 95 
 
 1 -2526 
 
 1-2490 
 
 164 
 
 162 
 
 698 
 
 94 
 
 1-2501 
 
 1-2464 
 
 156 
 
 180 
 
 580 
 
 93 
 
 1 -2476 
 
 1-2438 
 
 150 
 
 198 
 
 562 
 
 92 
 
 1 -2451 
 
 1-2412 
 
 145 
 
 215 
 
 545 
 
 91 
 
 1 -2425 
 
 1-2386 
 
 141 
 
 231 
 
 529 
 
 90 
 
 1 -2400 
 
 1 -2360 
 
 138 
 
 247 
 
 513 
 
 89 
 
 1 -2373 
 
 1 -2333 
 
 135 
 
 263 
 
 497 
 
 88 
 
 1 -2346 
 
 1-2306 
 
 132-5 
 
 279 
 
 481 
 
 87 
 
 1-2319 
 
 1-2279 
 
 130-5 
 
 295 
 
 465 
 
 86 
 
 1-2292 
 
 1 2252 
 
 129 
 
 311 
 
 449 
 
 85 
 
 1-2265 
 
 1-2225 
 
 127-5 
 
 326 
 
 434 
 
 84 
 
 1-2238 
 
 1-2198 
 
 126 
 
 340 
 
 420 
 
 83 
 
 1-2211 
 
 1-2171 
 
 124-5 
 
 355 
 
 405 
 
 82 
 
 1-2184 
 
 1-2144 
 
 123 
 
 370 
 
 390 
 
 81 
 
 1-2157 
 
 1-2117 
 
 122 
 
 384 
 
 376 
 
 80 
 
 1 2130 
 
 1-2090 
 
 121 
 
 396 
 
 364 
 
 79 
 
 1-2102 
 
 1 -2063 
 
 120 
 
 408 
 
 352 
 
 78 
 
 1 -2074 
 
 1-2036 
 
 119-0 
 
 419 
 
 341 
 
 77 
 
 1 -2046 
 
 1-2009 
 
 118-2 
 
 430 
 
 330 
 
 76 
 
 1-2018 
 
 1-1982 
 
 117-4 
 
 440 
 
 320 
 
 75 
 
 1-1990 
 
 1-1955 
 
 116-7 
 
 450 
 
 310 
 
 74 
 
 1-1962 
 
 1-1928 
 
 116 
 
 460 
 
 300 
 
 73 
 
 1-1934 
 
 1-1901 
 
 1154 
 
 470 
 
 290 
 
 72 
 
 M906 
 
 T1874 
 
 114-8 
 
 480 
 
 280 
 
 71 
 
 1-1878 
 
 1-1847 
 
 114-2 
 
 489 
 
 271 
 
 70 
 
 1-1850 
 
 1-1820 
 
 113-6 
 
 496 
 
 264 
 
 65 
 
 1-1710 
 
 1-1685 
 
 111-3 
 
 533 
 
 227 
 
 60 
 
 1-1570 
 
 1-1550 
 
 109 
 
 565 
 
 195 
 
 55 
 
 1-1430 
 
 1-1415 
 
 107-5 
 
 593 
 
 167 
 
 50 
 
 1-1290 
 
 1-1280 
 
 106 
 
 618 
 
 142 
 
 45 
 
 1-1155 
 
 1-1145 
 
 105 
 
 639 
 
 121 
 
 40 
 
 1-1020 
 
 1-1010 
 
 104 
 
 657 
 
 103 
 
 35 
 
 1 -0885 
 
 1 -0875 
 
 103-4 
 
 675 
 
 85 
 
 30 
 
 1 -0750 
 
 1-0740 
 
 102-8 
 
 690 
 
 70 
 
 25 
 
 1-0620 
 
 1-0610 
 
 1023 
 
 704 
 
 56 
 
 20 
 
 1 -0490 
 
 1-0480 
 
 101-8 
 
 717 
 
 43 
 
 10 
 
 1 -0245 
 
 1-0235 
 
 100-9 
 
 740 
 
 20 
 
 
 
 1-0000 
 
 1-0000 
 
 100-0 
 
 760 
 
 
 
OXALATE PROCESS FOR VALUATION OF GLYCERINES. 
 
 521 
 
 The quantity of glycerol thus found is close to, but generally 
 a little below, that deduced from the saponification equivalent 
 of the substance on the assumption that only triglycerides are 
 present.* In the case of oxidised drying oils, however, a notable 
 excess is observed, doubtless on account of the formation of other 
 products yielding oxalic acid by oxidation. Thus Benedikt and 
 Zsigmondy obtained the following values : 
 
 Name of Oil, &c. 
 
 Glycerol ca^ulated from 
 the Saponification 
 Equivalent. 
 
 Glycerol found by Oxalic 
 Acid Process. 
 
 Olive oil, .... 
 
 10-49 to 11-10 
 
 10-15 to 10-38 
 
 Coker butter, . 
 Tallow 
 Cows' butter fat, 
 Linseed oil, 
 Skins from boiled linseed oil, 
 
 14-76 to 14-83 
 10-72 
 12-51 
 10-24 to 10-66 
 
 13-3 to 14-5 
 9-94 to 10 21 
 11-59 
 9-45 to 9-97 
 15-5 (Allen) 
 
 The following table exhibits the amounts of glycerol theo- 
 retically obtainable from 100 parts of the triglycerides of the 
 respective acids named ; the last column indicates the amount 
 of fatty acid simultaneously produced : 
 
 Glyceride of 
 
 Formula of Acid. 
 
 Percentage of 
 Glycerol. 
 
 Percentage of 
 Fatty Acid. 
 
 Butyric acid, 
 
 ^14^8^2 
 
 30-5 
 
 87-41 
 
 Laurie 
 
 CifHgjOa 
 
 14-4 
 
 94-04 
 
 Myristic 
 
 Ci4H 28 O 2 
 
 127 
 
 94-47 
 
 Palmitic 
 
 Ci 6 H 32 2 
 
 11-42 
 
 95-28 
 
 Steario 
 
 Ci8H 36 2 
 
 10-34 
 
 95-73 
 
 Oleic 
 
 V\$H S 40 2 
 
 10-41 
 
 95-70 
 
 Ricinoleic 
 
 CisHsjOs 
 
 9-98 
 
 95-92 
 
 Lmolic 
 
 Ci8H 32 O 2 
 
 10-48 
 
 95-67 
 
 In the case of the higher acids the sum of the glycerol and 
 fatty acids is approximately constant viz., 106 to 107 per 100 of 
 glyceride used. 
 
 C. Mangold f modifies the oxalic acid process by dissolving 
 0'4 gramme of the glycerine to be tested in 300 c.c. of water 
 containing 10 grammes caustic potash, and adding 55 c.c. of a 
 5 per cent, solution of potassium permanganate. After standing 
 half an hour hydrogen peroxide solution is added until all 
 manganese is precipitated. A known fraction of the total fluid 
 
 * If E is the mean saponification equivalent of a mixture of triglycerides, 
 3E milligrammes of the mixture theoretically yield 92 of glycerol = 
 
 x 100, or 
 
 per cent. 
 
 t Zeits. angew. Chem., 1891, p. 400. 
 
522 OILS, FATS, WAXES, ETC. 
 
 is filtered off, boiled for half an hour to destroy excess of 
 hydrogen peroxide, acidulated with sulphuric acid after cooling, 
 and titrated with permanganate so as to determine the oxalic 
 .acid produced. 
 
 David recommends the following process for determining the 
 amount of glycerol formed on saponifi cation. 100 grammes of 
 fat are heated with 65 of crystallised barium hydrate, and 80 c.c. 
 of 95 per cent, alcohol added with agitation. The nearly solid 
 mass is boiled with 500 c.c. of water and allowed to settle ; the 
 residue left on pouring off the supernatant fluid is washed twice 
 by decantatioii, and the total fluid evaporated to half its bulk 
 with sulphuric acid, the surplus being removed by barium car- 
 bonate. Finally the filtered fluid is evaporated to 50 c.c. and 
 examined either as to its refractive power or as to its specific 
 gravity, the amount of glycerol being deducible by means of the 
 table given on p. 517. 
 
 According to Hehner (loc. cit. supra) the bichromate process 
 (p. 516) gives sufficiently accurate results for practical purposes 
 with fats and soaps when thus carried out ; the fat is saponified 
 with alcoholic potash (about 3 grammes being used) and diluted 
 to about 200 c.c. ; the fatty acids are separated by means of 
 dilute sulphuric acid and filtered oft'; the filtrate is boiled down 
 to half its bulk and treated with sulphuric acid and dichromate; 
 Obviously if any traces of alcohol are left in the fluid, or if 
 soluble acids or other organic matters capable of reducing di- 
 chromate are present, the results will come out too high. Oper- 
 ating in this way Hehner obtained the following percentages of 
 glycerol : 
 
 Olive oil, .... 10-20 per cent. 
 Cod liver oil, . . . 9'87 ,, 
 
 Linseed oil, . . . 10 '24 ,, 
 
 Margarine, . . . 10 '01 ,, 
 
 Butter fat, . . 11 -96 to 12 -4 
 
 When chlorides or aldehydic matters are present (e.g., acrolein 
 in distilled glycerines) the glycerol solution is first treated with 
 silver oxide, being slightly diluted and warmed therewith in a 
 flask ; basic lead acetate is then added in slight excess, the fluid 
 made up to a known bulk, and an aliquot part filtered off through 
 a dry filter and treated with dichromate. 
 
 Glycerol in Soap Leys. On account of the organic im- 
 purities present in soap leys along with large amounts of in- 
 organic salts, the above methods, as a rule, are not directly 
 available for the estimation of glycerol in such liquors. By 
 evaporation these may be concentrated without material loss 
 of glycerol at first, although subsequently a perceptible amount 
 is carried away with the escaping water vapour as the liquors 
 become highly concentrated. When the evaporation is carried 
 
GLYCEROL IN SOAP LEYS. 523 
 
 nearly to dryness a residue is obtained from which nearly 
 absolute alcohol dissolves out glycerol along with more or less 
 inorganic matter ; a rough estimate of the glycerol present is 
 obtainable by evaporating the alcoholic solution to dryness 
 and weighing, and then gently incinerating so as to burn off 
 organic matter, the weight of ash left being deducted from that 
 of the total residue. If, however, other organic matters soluble 
 in alcohol be present, obviously they would thus be reckoned 
 as glycerol ; in some cases a partial purification of the glycerol 
 may be brought about by again evaporating the alcoholic extract, 
 treating the residue with a small quantity of absolute alcohol, 
 and then adding one and a-half times the volume of ether ; 
 glycerol is kept in solution, but some of the other organic matters 
 are usually precipitated, so that a partial purification is brought 
 about. In other cases the crude glycerol may be purified by 
 treatment with neutral or basic lead acetate to precipitate 
 colouring matters, &c. When rosin is present in the liquors 
 they may be conveniently purified by evaporating down after 
 neutralising with dilute sulphuric and adding a little milk of 
 lime (whereby most of the rosin is converted into insoluble 
 lime salt) and filtering ; the residue is treated with a mixture of 
 three volumes absolute alcohol and one of pure ether, the dis- 
 solved matter weighed (after expulsion of the solvent) and 
 corrected for ash left on incineration (Fleming"). 
 
 Another process (Muter's)* consists in heating the crude 
 glycerol liquors with basic lead acetate to remove certain kinds 
 of organic matters that would interfere with the subsequent 
 part of the test, filtering and removing the lead by sulphuretted 
 hydrogen, and then treating with caustic soda or potash, and 
 dropping in copper sulphate solution with continuous agitation 
 until copper hydroxide remains permanently undissolved ; the 
 quantity of copper contained in the blue solution is about pro- 
 portionate to the amount of glycerol present (under certain con- 
 ditions vide infra), so that by determining the dissolved copper 
 the glycerol is known. For this purpose Muter employs a 
 standard solution of potassium cyanide, for which the author 
 has substituted a colorimetric process based 011 comparison of 
 the hue of the tinted fluid (filtered) with that of a known relative 
 thickness of copper solution containing a known amount of 
 copper also dissolved in glycerol solution under the same con- 
 ditions.! 
 
 Unless the proportion of caustic alkali present is uniform, a 
 measurable difference in the solvent power of glycerol for copper 
 hydroxide is noticeable, as the amount of alkali varies (Puls) ; 
 so that when a cyanide solution is used it should be standardised 
 
 * Analyst, 1881, p. 41. 
 
 t Alder Wright, "Cantor Lectures," Society of Arts Journal, 1885, 
 xxxiii., p. 1123. 
 
524 OILS, FATS, WAXES, ETC. 
 
 by means of a known glycerol copper solution prepared side by 
 side with the substance examined in exactly the same way. 
 
 Crude glycerol solution, purified by basic lead acetate, usually 
 retains but little of any organic matters of an alcoholiform or 
 liydroxylated character, so that the acetin method (supra] can 
 generally be applied without serious error to the residue left on 
 evaporation and extraction with alcohol. This, however, is not 
 so certainly the case as regards the oxalate method, there being 
 a possibility of obtaining oxalate by the oxidation of organic 
 matters other than glycerol ; whilst the dichromate process is 
 usually inapplicable, organic impurities being generally still left 
 which readily reduce dichromate. 
 
 A method sometimes employed is to heat a quantity of crude 
 glycerine, representing about 2 grammes of glycerol, with 40 
 grammes of litharge to about 130, taking care that no carbonic 
 acid gets access to the mass ; when the weight becomes constant 
 the whole is similarly heated to 160, at which temperature the 
 glycerol is volatilised excepting that a molecule of water remains 
 behind combined with the lead oxide, so that the loss of weight 
 
 74 
 is times the glycerol present; hence the loss of weight at 
 
 92 
 160 multiplied by = 1*243 represents the glycerol present. 
 
 "With glycerol containing resinous matter it is impracticable to 
 expel all the glycerol at 160; whilst if chlorides or sulphates of 
 alkali metals are present these react on the lead oxide forming 
 hydroxides which readily absorb carbonic acid (Hehner). 
 
525 
 
 INDEX. 
 
 ABB, refractive index, 51. 
 
 Abel, flashing point apparatus, 
 
 126. 
 Absolute measure, determination of 
 
 viscosity in, 107. 
 Absorption of oxygen by fatty acids, 
 
 by oils, 42, 125, 129- 
 
 137, 318, 341. 
 
 ,, ,, during cod liver oil 
 
 extraction, preven- 
 tion of, 248. 
 
 ,, quickened by boil- 
 ing, 129, 313. 
 
 ,, ,, test for lubricating 
 
 oils, 134, 330. 
 See also Oils 
 (blown), Oils (dry- 
 ing), Gumming. 
 ,, spectrum, 50. 
 
 Acajou see Oil (cashewnut). 
 Accumulators see Hydraulic presses. 
 Acetic anhydride, action on acids 
 from Turkey red oils, 
 335. 
 ,, action on alcohols, glycerol, 
 
 &c., 8, 13, 186, 191. 
 ,, action on cholesterol and 
 
 allied bodies, 17, 191. 
 ,, action on hydroxylated 
 acids, 35, 37, 41, 186-191. 
 action on non- hydroxy- 
 lated acids, 189-191. 
 ,, action on cenanthol, 25. 
 Acetyl acid number (acetyl saponiti- 
 
 cation number), 187. 
 Acetyl number, titration ; acetyl 
 
 number, distillation, 198. 
 Acetylation test (acetyl test, acetyl 
 number), 17, 43, 
 121, 129, 157, 341. 
 ,, ,, process of working, 
 
 186-191. 
 
 ,, ,, process of working, 
 
 Lewkowitsch's dis- 
 tillation modifica- 
 tion, 190, 198. 
 
 Acetylation test, use of, in analysis of 
 glycerine, 8, 186, 
 516. 
 
 ,, ,, in analysis of 
 
 lubricants, 329. 
 
 ,, in analysis of 
 
 Turkey red oils, 
 335. 
 
 ,, in analysis of 
 
 Yor ks hire 
 grease, 273. 
 Acid, acetic, 20, 288. 
 
 ,, as solvent (Valenta's 
 
 test), 55-57, 347, 349. 
 formed from oleic acid 
 
 24, 28, 30, 387. 
 acetyl oxyoleic, 189. 
 
 ,, oxystearic, 186. 
 acrylic, 25, 27. 
 aldepalmitic, 24, 25. 
 angelic, 25. 
 anhydrodioxystearic, 42, 46. 
 
 ,, possibly formed in 
 blown oils, 319. 
 ,, arachic (arachidic, butic), 21. 
 ,, ,, separation from other 
 
 fatty acids, 112. 
 ,, azelaic, 34, 35, 36. 
 ,, benic (behenic, benistearic),21. 
 ,, benolic (behenolic), 31, 32, 45. 
 ,, benomargaric, 21, 22. 
 ,, benoxylic, 45. 
 ,, benzole, 19, 32. 
 ,, bcnzoleic, 32. 
 ,, benzoyl oxymyristic, 37. 
 brassic (brassaidic), 28, 29, 44, 
 
 129. 
 
 ,, bromohypogseic, 42. 
 ,, bromoleic, 28, 41. 
 ,, bromomyristic, 38. 
 ,, bromostearic, 30. 
 ,, butic see Acid (arachic). 
 ,, butyric, 20, 288. 
 ,, camphic, 32. 
 ,, campholenic, 32. 
 ,, caproic see Acid (hexoic). 
 capric see Acid (decoic). 
 ,, caprylic see Acid (octoic). 
 carbolic see Phenol. 
 
526 
 
 INDEX. 
 
 Acid, carnaubic, 21. 
 
 ,, cerotic, 21, 190, 358. 
 ,, formation, test of adulter- 
 
 ation of beeswax, 359. 
 
 ,, cetic, 21, 22. 
 
 ,, chloriodostearic, 177. 
 
 ,, chlorocrotonic, 31, 32. 
 
 ,, chloropropiolic, 32. 
 
 ,, cimioic, 25. 
 
 ,, cimiamic, 19. 
 
 cocinic, 20, 22. 
 
 ,, crotonic, 25, 288. 
 
 ,, crotonoleic, 288. 
 
 ,, damaluric, 24, 25. 
 
 ,, daturic, 21. 
 
 ,, decenoic, 25. 
 
 ,, decoic (capric), 20, 190. 
 
 ,, diacetyloxysteario, 190. 
 
 ,, diallyl acetic, 32. 
 
 ,, dibromopropionic, 27. 
 
 ,, dibromostearic, 31, 41, 176. 
 
 ,, dibromoxystearic, 176. 
 
 ,, dichloracylic, 32. 
 
 ,, diiodostearic, 26. 
 
 ,, dioxybenic, 28, 29, 44, 129. 
 
 ,, dioxybenolic, 45. 
 
 ,, dioxyheiidecoic, 44. 
 
 ,, dioxypalmitic, 42, 44, 336. 
 
 dioxystearic, 28, 30, 41-45, 
 
 128, 190. 
 
 ,, diricinoleic, 146. 
 
 ,, diricinoleosulphuric, 146, 333. 
 
 ,, dodecenoic, 25. 
 
 ,, dodecoic see Acid (lauric). 
 
 ,, doeglic, 25. 
 
 ,, ,, existence doubted. 24. 
 
 ,, elceomargaric, 32. 
 
 ,, eloeostearic, 32. 
 
 elaidic, 28, 29, 43, 44. 
 
 ,, enneadecoic, 21. 
 
 ,, ennenoic, 25. 
 
 ,, eiinoic, 20, 36. 
 
 erucic, 25, 28, 29, 32, 44, 129, 
 
 180. 
 ,, ,, characteristic of rape 
 
 class, 284. 
 ,, ,, oxidation products of, 
 
 28, 29, 44, 129. 
 
 ,, formic, 20, 288. 
 
 ,, geoceric, 21, 22. 
 
 ,, geranic, 15. 
 
 ,, glycerosulphuric, 144. 
 
 , , hendecenoic, 20, 25, 32, 40, 44. 
 
 ,, hendecinoic (hendecolic, unde- 
 
 colic), 31, 32. 
 
 ,, hen decoic, 20. 
 
 ,, hendecolic, 31, 32. 
 
 ,, heptadecenoic, 25. 
 
 ,, heptoic (cenanthic),20,40,41,146 
 
 Acid, hexabromostearic, 176. 
 ,, hexacetyllinusic, 37. 
 , , hexoic (caproic), 20, 288. 
 ,, hexoxacetylstearic, 37. 
 ,, hexoxystearic, 19, 37, 43, 44, 
 
 128, 135. 
 
 ,, hyaenic, 21, 22. 
 ,, hydrobeiizoic, 32. 
 ,, hydrochloric-see Hydrochloric 
 
 acid. 
 
 hypogseic, 25, 44, 180. 
 ,, ,, doubt as to existence 
 
 of, 24, 111. 
 
 ,, iodopropionic, 27. 
 ,, iodostearic, 30, 38. 
 ,, isobutyric, 20. 
 ,, isodioxybenic, 29. 
 , , isodioxy stearic .see Isomerides 
 
 (dioxystearic acid). 
 ,, isohexoic, 20. 
 ,, isohexoxystearic see Acid 
 
 (isolinusic). 
 
 , , isoleic, 25, 29, 38, 43, 44. 
 ,, ,, contained in distilled cot- 
 
 ton seed stearine, 305. 
 ,, ,, in candle stearine, 262, 
 
 375, 380. 
 
 ,, ,, formed from zinc chlo- 
 
 ride and oleic acid, 
 143, 262, 380. 
 
 ,, ,, formed during distilla- 
 
 tion, 262, 380. 
 
 isolinolenic. 37, 43, 128, 135. 
 ,, isolinusic, 37, 43, 128, 135. 
 ,, isoricinoleic, 41. 
 ,, isotrioxystearic, 40, 43, 44. 
 ,, isovaleric, 20. 
 ,, isoxy stearic see Isomerides 
 
 (oxystearic acid). 
 ,, lauric, 20, 71-74, 190, 288. 
 ,, lignoceric, 21. 
 ,, linoleic, 33, 134. 
 ,, linolenic, 35, 36, 43, 44, 128, 
 
 135, 176, 180. 
 
 ,, linolic, 30-33, 90, 176, 180. 
 ,, ,, not contained in animal 
 
 oils, 291. 
 
 ,, ,, oxidationproductsof,19, 
 
 34, 35, 43-45, 128-137. 
 linusic, 19, 37, 43, 44, 128, 135. 
 margaric, 21, 22, 309. 
 artificial, 21, 309. 
 
 medullic, 21, 22. 
 melissic, 13, 21, 358. 
 ,, methyl crotonic see Acid 
 
 (tiglic). 
 
 ,, moringic, 24, 25. 
 ,, myristic, 20, 31,32, 71-73, 113, 
 
 288. 
 
INDEX. 
 
 527 
 
 Acid, myristolic, 31, 32. 
 ,, nitrous, test with see Elaidin 
 
 reaction. 
 
 , , nitric, test with -sec Nitric acid 
 ,, octenoic, 25. 
 ,, octoic, 20. 
 
 ,, oenanthic see Acid (heptoic). 
 oleic, 25, 38, 68, 75, 90-92, 113. 
 ,, ,, action of acetic anhy- 
 dride on, 190. 
 ,, ,, ,, of bromine and iodine 
 
 on, 27, 176, 180. 
 ,, ,, ,, of fused potash on, 
 
 24, 28, 30, 387. 
 
 ,, ,, of nitrous acid on 
 
 (elaidin reaction), 28. 
 
 ,, ,, ,, of sulphuric acid on, 
 
 27, 145, 149. 
 ,, ,, ,, of sulphur chloride 
 
 on, 155, 156. 
 ,, ,, ,, of zinc chloride on, 
 
 39, 142. 
 ,, ,, amount in candle stear- 
 
 ine, 375-377. 
 ,, ,, conversion into stearic 
 
 acid, 26, 386, 387. 
 ,, ,, determination of ( Muter 's 
 
 process), 376. 
 ,, ,, oxidation products of, 
 
 10, 28, 43-45, 128. 
 ,, ,, separation from other 
 
 acids, 112, 376. 
 
 ,, soap see, Soapmaking. 
 ,, ,, yield from ox fat, 311. 
 
 See also Red oils. 
 ,, oleo-oxystearic, 330, 331. 
 oleo-stearic, 331. 
 orthopropionic, 12. 
 ,, oxybenzoic see Acid (sali- 
 cylic). 
 
 ,, oxyhypogaeic, 41, 43. 
 oxylinoleic, 125, 134. 
 ,, oxymyristic, 37, 38. 
 ,, oxy oleic, 41, 42, 43, 332. 
 , , , , contained in de"gras, 336. 
 
 ,, formed in blowing oils, 
 
 319. 
 
 ,, oxypalmitic, 38. 
 oxystearic, 25, 27, 38, 39, 43, 
 
 143-145, 330, 384. 
 oxystearosulphuric, 27, 29, 38, 
 
 144, 330. 
 
 ,, palmitic, 21, 44, 72, 74, 91. 
 ., , , , action of acetic anhy- 
 
 dride on, 190. 
 .,, ,, artificial, manufac- 
 
 ture of, 387. 
 .,, ,, formation from cety- 
 
 lic alcohol, 13. 
 
 Acid, palmitic, formation from oleic, 
 isoleic, and elaidic 
 acids, 30 see also 
 Acid, oleic, action of 
 potash on. 
 ,, ,, mixed with stearic see 
 
 Candle stearine. 
 , , , , occurrence in arachis oil 
 
 denied, 111. 
 ,, ,, present in spermaceti of 
 
 low grade, 361. 
 ,, ,, separation from other 
 
 acids, 112, 113,376. 
 ,, used for night lights, 407. 
 palmitolic, 31, 32, 45. 
 palmitoxylic, 45. 
 paraffmic, 21. 
 parasorbic, 32. 
 
 pelargonic see Acid (ennoic). 
 pentadecoic, 20, 21. 
 pentaricinoleic, 147. 
 pentoic, 20. 
 pentolic, 32. 
 petroleumic, 25. 
 phoronic, 25. 
 
 phosphoric, colour test, 151. 
 physetoleic, 4, 25. 
 
 ,, characteristic of train 
 
 oils, 292. 
 propiolic, 32. 
 propionic. 20. 
 pyroterebic, 25. 
 rapic, 41, 43, 284. 
 ricilinolic, 32, 36. 
 ricinelaidic, 40, 43, 44. 
 ricinic, 41. 
 
 ricinoleic, 39, 40, 90, 176, 180. 
 , , action of fused potash on, 
 
 40. 
 ,, oxidation products of, 19, 
 
 40, 43, 44, 129. 
 , , polymerised, 1 46, 1 47, 333. 
 ricinoleos ul ph uric, 1 45 , 332, 333. 
 salicylic, 5, 19. 
 sativic, 19, 34, 35, 43-45, 135. 
 ,, as characteristic oxidation 
 
 product, 128, 344. 
 ,, formed from olive oil, 344. 
 ,, not formed from animal 
 
 oils, 291. 
 sebacic, 40. 
 sorbic, 32. 
 stearic, 21, 72, 73, 88-92, 155, 
 
 156, 190, 309. 
 ,, adulterant of beeswax and 
 
 spermaceti, 359, 361. 
 ,, formed fromlinolic acid, 34. 
 ,, ,, from oleic acid, 26, 
 386, 387. 
 
528 
 
 INDEX. 
 
 Acid, stearic, formed from ricinoleic 
 
 acid, 40. 
 
 ,, ,, formed from sativic acid, 35. 
 ,, ,, separation from other 
 
 acids, 112, 113,376. 
 ,, ,, yield from ox fat, 311. 
 
 See also Candle stearine. 
 ,, stearidic, 25, 30. 
 stearolic, 31-33, 35, 45. 
 ,, stearoxylic, 33, 36, 45. 
 ,, stillistearic, 21, 22. 
 ,, suberic, 36. 
 
 ,, sulphuric see Sulphuric acid. 
 ,, sulphurous see Sulphurous 
 
 acid. 
 
 ,, tariric, 32, 36. 
 ,, terebic, 25. 
 
 ,, tetrabromostearic, 31, 176. 
 ,, tetracetyl sativic, 35. 
 ,, tetradecenoic, 25. 
 ,, tetraricinoleic, 147. 
 ,, tetrolic, 31, 32. 
 ,, tetroxy stearic see Acid (sati- 
 vic). 
 
 ,, tetroxacetyl stearic, 35. 
 theobromic, 21, 22. 
 tiglic (methylcrotonic), 25, 288. 
 ,, toluic, 19. 
 tridecenoic, 25. 
 ,, tridecoic, 20, 22. 
 trioxy stearic, 19,40,43,44,129. 
 ,, trioxacetyl stearic, 41. 
 ,, triricinoleic, 147. 
 ,, tritylic, 20. 
 umbellulic, 20. 
 ,, undecolic see Acid (hende- 
 
 colic). 
 undecylic see Acid (hende- 
 
 coic). 
 ,, undecylenic see Acid (hende- 
 
 cenoic). 
 
 valeric, 20, 275, 288. 
 Acid number, free see Acids (free 
 
 fatty). 
 ,, ,, total see Total acid 
 
 number. 
 
 ,, process (oil refining), 259. 
 ,, salts, 23. 
 Acidity of soaps, 24, 498. 
 Acids, dibasic, 18. 
 
 , , distilled (manuf acturingplant), 
 
 382-384. 
 
 ,, ,, melting points, 384. 
 
 ,, fatty; formed by hydrolysis and 
 saponitication, 7, 10, 
 12, 114. 
 
 during systematic 
 examination of oils, 
 &c., 124. 
 
 Acids, fatty; formed from alcohols by 
 
 action of fused potash, 13. 
 
 ,, from glycerides, yield of, 
 
 163. 
 
 ,, ,, from soap, 172. 
 ,, ,, from tallow, palm oil, &c. ; 
 valuation by melting 
 point, 75, 76. 
 ,, ,, from various oils, &c. ; 
 
 melting points, 69-76. 
 ,, ,, insoluble in water see 
 Hehner number; Insol- 
 uble acid number. 
 ,, ,, insoluble in petroleum 
 ether, from boiled oils, 
 135. 
 ,, ,, iodine number of see 
 
 Iodine number. 
 ,, ,, mean equivalent, 116, 164- 
 
 173, 196. 
 
 ,, ,, mean equivalent is less 
 than saponitication equi- 
 valent of glycerides by 
 12-67, 165, 197. 
 ,, ,, melting points of see 
 
 Melting points. 
 ,, ,, mixtures of; calculation 
 
 of composition, 172. 
 ,, ,, neutralisation numbers 
 of see Neutralisation 
 number. 
 ,, ,, oxidation during drying, 
 
 113. 
 ,, ,, oxidation of, from drying 
 
 oils, 136. 
 ,, ,, polymerised, from castor 
 
 oil, 146. 
 
 ,, ,, separation of, as lead 
 salts, &c., 112, 128, 136, 
 356, 376. 
 
 ,, ,, solid from tallow and 
 palm oil, 74-76 see 
 Candle stearine. 
 ,, ,, soluble in alcohol, 23. 
 ,, ,, soluble in water, 23, 163, 
 
 167-170, 195. 
 ,, ,, soluble in soap analysis, 
 
 497. 
 ,, ,, soluble acid number see 
 
 Soluble acid number. 
 volatile, 22, 113 see also 
 
 Boiling points. 
 
 ,, ,, acid number see 
 Volatile acid number. 
 ,, ,, ,, contained in York- 
 shire grease, 275. 
 
 ,, ,, ,, with superheated 
 steam see Distil- 
 lation. 
 
INDEX. 
 
 529 
 
 Acids, fatty, volatile, with wet steam, 
 22, 112 see also Reich ert 
 number ; Volatile acid 
 number. 
 
 ,, ,, unsaturated, in pressed 
 candle stearine, 375. 
 
 ,, free fatty, amount present in 
 oilcakes, 115,214. 
 
 ,, ,, as candle material 
 
 see Candles, 
 stearine. 
 
 ,, ,, determination of 
 
 free acid number, 
 24, 115-119, 194, 
 341. 
 
 ,, ,, determination of, 
 
 by Burstyn's 
 method, 118. 
 
 ,, ,, detrimental effects 
 
 of, 115,260,313, 
 322, 356. 
 
 ,, ,, examination of, for 
 
 detecting adul- 
 teration, 356. 
 
 ,, ,, formed by hydro- 
 
 lysis see Hydro- 
 lysis. 
 
 ,, ,, from Turkey red 
 
 oils, 334, 335. 
 
 ,, ,, iodine number, 180, 
 
 184, 197, 356. 
 
 ,, ,, iodine number ex- 
 
 ceeds that of gly- 
 cerides by about 
 4'5 per cent., 
 
 185, 197. 
 
 ,, ,, occurrence in natu- 
 
 ral oils, &c., 114- 
 119, 292, 355. 
 
 ,, ,. production of, in 
 
 orease recovery, 
 271, 272. 
 ,, ,, proportion usually 
 
 present, 115. 
 
 ,, mineral, detection of, 123, 323. 
 ,, ,, inadmissible in puri- 
 
 fying lubricants, 325. 
 ,, ,, injurious eti'ects of, 
 
 115, 260, 322, 325. 
 ,, monobasic, 18. 
 ,, polyhydroxylated stearic, 43- 
 
 46, 128-137. 
 ,, series of, acetic (stearic), 18, 
 
 19. 
 
 acrylic (oleic), 18, 24. 
 benzoic, 19. 
 bromoleic, 28. 
 cinnamic, 19. 
 dichloroacetic, 31. 
 
 Acids, series of, dibromoacetic, 26,31. 
 ,, ,, diiodoacetic, 26. 
 
 ,, ,, dioxystearic see 
 
 Glyceric series. 
 ,, ,, erythroglucic (trioxy- 
 
 stearic), 19, 43. 
 
 ,, glyceric (dioxy- 
 
 stearic), 19, 27,43. 
 ,, ,, gly collie see Oxy- 
 
 acetic series. 
 
 ,, ,, hexoxystearic, 19, 43. 
 
 linolenic, 18, 36. 
 
 ,, ,, linolic see Propiolic 
 
 series. 
 ,, ,, oleic see Acrylic 
 
 series. 
 
 ,, ,, oxyacetic (oxy- 
 
 stearic, glycollic), 
 19, 27, 37. 
 ,, oxyacrylic(ricinoleic). 
 
 19, 39. 
 
 ,, ,, oxy benzoic, 19. 
 
 ,, ,, oxy oleic see Oxy- 
 
 acrylic series. 
 
 ,, ,, oxystearic see Oxy- 
 
 acetic series. 
 ,, ,, propiolic ( linolic), 18, 
 
 28, 30. 
 ,, ,, ricinoleic see Oxy- 
 
 acrylic series. 
 ,, ,, salicylic, 19. 
 
 ,, ,, stearic see Acetic 
 
 series. 
 
 ,, stearolic, 30, 31, 45. 
 
 ,, ,, stearoxylic, 33, 45. 
 
 tetroxystearic, 19, 43. 
 
 ,, ,, trioxystearic see 
 
 Erythroglucic series. 
 Acrojein (acrylic aldehyde), 15, 25. 
 ,, in glycerine, 515. 
 ,, produced by action of heat 
 
 on oils, 125. 
 
 ,, ,, dehydration of 
 
 glycerol,8,513. 
 
 ,, ,, oxidation of lin- 
 
 seed oil (lino- 
 leum), 318. 
 Actual density, incorrect use of term, 
 
 89. 
 
 Adipose tissues, Mege Mouries pro- 
 cess, 308. 
 
 ,, rendering of, 245-251. 
 
 ,, use of, as food, 303. 
 
 Adulteration, general methods of de- 
 tecting, 340-342 see also 
 each oil, &c., separately. 
 ,, with solid suspended mat- 
 ters, determination, 123. 
 JSsculin, 50. 
 
 34 
 
530 
 
 INDEX. 
 
 ^Etherzahl see Ester number. 
 
 Air, bleaching oils by means of hot, 
 
 264. 
 ,, used in preparing blown oils 
 
 see Oils, blown. 
 
 ,, ,, ,, boiled oils see Oils, 
 
 drying, boiling of. 
 
 ,, wax bleaching by exposure to, 
 
 and light, -268. 
 
 Air bath, Pensky's,flashingpoint, 1 27. 
 ,, Pohl's, melting point, 63. 
 ,, specific gravity, 80. 
 Air blast, Dunn's (soapboiling),- 433. 
 Albuminous matters, determination, 
 
 119-123. 
 
 , , , , removal from crude 
 
 glycerine, 5 14,515. 
 ,, ,, removal from oils, 
 
 &c. see Oils 
 (clarification). 
 Alcohol, allylic, 15, 44. 
 ,, amylic, 14. 
 ,, benzylic, 16. 
 ,, butylic, 14. 
 ,, cerylic, 14. 
 ,, ,, present in Yorkshire 
 
 grease, 272. 
 
 ,, cetylic, 4, 6, 7, 14. 
 ,, ,, action of acetic anhy- 
 
 dride on, 15, 191. 
 ,, ,, action of fused potash 
 
 on, 13. 
 ,, ,, contained in cetacean 
 
 oils, 114, 116, 121. 
 ,, ,, contained in degras, 336. 
 
 ,, ,, contained in spermaceti 
 
 see Spermaceti. 
 ,, ,, contained in Yorkshire 
 
 grease, 272. 
 
 ,, palmitic acid from, 13. 
 cinnamic, 16. 
 decylic (decatylic), 14, 40. 
 dodecylic (dodecatylic), 14, 
 
 114. 
 
 ethylic, 4, 14. 
 hendecylic, 14. 
 heptadecylic, 14. 
 heptylic, 14. 
 hexadecylic, 14. 
 hexylic, 14. 
 isobutylic, 14, 20. 
 isocerylic, 14. 
 isomyricylic, 14. 
 isopropylic, 14. 
 methylic, 5, 14. 
 myricylic, 4, 14, 21, 358. 
 ,, action of fused 
 
 potash on, 13. 
 nonylic, 14. 
 
 Alcohol, octodecylic, 14. 
 ,, octylic, 5, 14. 
 ,, pentadecylic, 14. 
 ,, propylic, 14, 20. 
 ,, sycocerylic, 16. 
 ,, tetradecylic, 14. 
 ,, tridecylic, 14. 
 
 xylylic, 16. 
 
 Alcohol, solubility in see Solubilitjr. 
 Alcoholiform products of saponifica- 
 
 tion, 4-18, 121. 
 
 Alcohols, acetyl numbers of, 17. 
 ,, dihydric see Glycols. 
 ,, fermentation see Oils 
 
 (fusel). 
 
 ,, free in oils, due to hydro- 
 lysis, 7, 114, 116, 171. 
 ,, hexhydric, 5. 
 ,, higher, contained in York- 
 shire grease, 272. 
 ,, monohydric, 4, 13. 
 ,, pentahydric, 5. 
 series of, acrylic (allylic), 
 
 13, 15, 44, 114. 
 benzylic, 15, 16. 
 cholesteric, 16. 
 cinnamic, 13, 16. 
 ethylic, 13, 14, 
 
 114, 116. 
 geranic, 15. 
 phenolic, 13, 15. 
 ,, tetrahydric see Erythrol. 
 ,, trihydric see Glycerols. 
 Aldehydes, 3, 6, 15. 
 
 ,, hydrogenation of, 14. 
 
 ,, oxidation of, 20, 25. 
 
 Alkali, calculated quantity requisite 
 for saponification see Cal- 
 culations. 
 ,, free, in soaps, injurious effects 
 
 of see Soaps, alkaline. 
 Alkalies, action on brominated and 
 chlorinated acids, 28-32, 38. 
 ,, effect of fusion with see Hy- 
 drogen. 
 
 ,, effect of fusion with, on oleic 
 acid and isomerides 
 see Acid (oleic, 
 palmitic). 
 
 ,, ,, on ricinoleic acid, 40. 
 
 ,, manufacture of, 410. 
 ,, mild and caustic, 409 see Po- 
 tash (caustic), Soda (caustic). 
 ,, quantities mutually equivalent 
 
 to one another, 425. 
 , , use of, in refining oils, &c. , 260. 
 ,, use of, in soapmaking, 409. 
 ,, vegetableand mineral, 410 see 
 Potash, Soda. 
 
INDEX. 
 
 531 
 
 Alkalimetrical assay, 420. 
 
 Alkaline carbonates as saponifying 
 
 agents, 409, 410. 
 ,, ,, causticising of see 
 
 Causticising. 
 
 ,, ,, direct use in soap- 
 
 making, 409, 433, 
 453, 460, 463. 
 
 ,, earths, use in refining, 256. 
 ,, refining processes-see Refining. 
 ,, soap, injurious effects see 
 
 Soap, alkaline. 
 
 ,, solutions, strength of, 418, 419. 
 Alkalinity, degrees of see Degrees, 
 negative, 498, 499. 
 of leys, 414-419. 
 
 ,, ,, corrections for impur- 
 
 ities, 419. 
 ,, ,, effect of temperature 
 
 on density, 416. 
 
 ,, of soda, British trade cus- 
 tom, 420. 
 
 Allbright & Clark, spontaneous in- 
 ""flammation, 132. 
 Allen, A. H., beeswax, 358, 359. 
 ,, bromine reaction, 177. 
 
 ,, distilled cotton seed 
 
 stearine, 305. 
 
 ,, glycerine valuation, 519. 
 
 ,, linolic acid, 34. 
 
 ,, Maumene's test, 149. 
 
 ,, melting points, 71. 
 
 ,, nitric acid test, 140. 
 
 Reichert's test, 174. 
 
 relative density, 89, 93. 
 , , saponification equiva- 
 
 lents, 160. 
 
 ,, soap analysis, 494, 507. 
 
 , , sugar test for sesame", 346. 
 
 ,, sulphur in oils, 123. 
 
 ,, sulphuric acid colour re- 
 
 actions, 151. 
 
 ,, test for arachis oil, 344. 
 
 ,, Valenta's test, 56. 
 
 viscosimetry, 99, 101, 104. 
 
 ,, waggon grease, 327. 
 
 Allen and Nickels, glycerine extrac- 
 tion, 515 
 Allen and Thomson, free alcohols in 
 
 sperm oil, &c., 171. 
 ,, unsaponifiable matters in 
 various oils, &c., 257. 
 Alligator fat, 299. 
 Allihn's condenser, 239. 
 Allyl cyanide, 25. 
 
 ,, ethers, 15, 25. 
 Almonds, sweet and bitter see Oil 
 
 (almonds). 
 Alpaca fat, 299. 
 
 Alum in lard, 307. 
 
 ,, use in cleansing rancid tallow, 
 
 256. 
 
 Aluminium oleate used in thickening 
 oils, 121-124, 324, 329. 
 ,, soaps, 121-124, 324, 328, 329. 
 Aluminoferric cake, aluminium sul- 
 phate, use in recovering grease, 
 270. 
 Amagat and Jean, oleorefractometer, 
 
 51. 
 
 Ambreol (ambergris), 3, 17. 
 Ambiihl, specific gravity vapour bath, 
 
 80. 
 
 American mineral oils, viscosity, 105. 
 Ammonia process for alkali manufac- 
 ture, 410. 
 ,, saponification process, 379, 
 
 410, 515. 
 
 ,, salt, dealkalising process 
 ( Alder Wright's ) see 
 Wright, Alder. 
 Angelica, 25. 
 
 Anglo-American system of oil pres- 
 sing, 210, 215-218. 
 Anhydrides, fatty, in analysis, 371. 
 ,, of dioxystearic acids, 42, 46. 
 , , of nonhy droxy lated acids, 189. 
 ,, of oxystearic acids, 30, 39. 
 Animal charcoal, use of, in decoloris- 
 ing oils, &c. , 263, 269. 
 ,, ,, use of, in deodorising 
 cokernut oil, 310. 
 ,, ,, ,, in purifying gly- 
 cerine, 514. 
 
 ,, ,, ,, in purifying lan- 
 olin, 339. 
 
 ,, fats, acids from, 21, 25. 
 ,, ,, rendering of, 245-251. 
 Anise camphor (anethol), 192, 194. 
 Anschtitz, action of acetic anhydride 
 
 on benzoic acid, &c., 189. 
 Anthracene, extraction from anthra- 
 cene oils, 230. 
 
 ,, oils (coarse lubricants), 328. 
 Antifriction ingredients, 324-328. 
 Aqua regia, colour test, 151. 
 Arachin (arachicglyceride), chief con- 
 stituent of Rambutan tallow, 296. 
 Arachis nuts, decortication of, 224. 
 Araeometer, 77. 
 
 ,, (Burstyn's method), 118. 
 
 ,, Lefebre's, 79. 
 
 thermal, 82, 347. 
 
 Archimedean screw (mixing soap), 
 
 440. 
 Archbutt, elaidin test, 138. 
 
 ,, free fatty acids in burning 
 oils, 313. 
 
532 
 
 INDEX. 
 
 Archbutt, Maumene's test, 149. 
 Argand lamp, 313. 
 Arnaud, tariric acid, 36. 
 Ashes as detergents, 409. 
 Artificial butter see Margarine. 
 
 ,, lard see Lard. 
 Autoclave for soapmaking see Soap- 
 making (hydrated soaps). 
 ,, rock, 374. 
 ,, stearine process, 373 see 
 
 Candle stearine. 
 Axle grease see Lubricants. 
 
 B 
 
 BACH, absorption of oxygen, 134, 329. 
 
 ,, melting points, 71. 
 Bagging for presscakes, 217. 
 
 ,, of semisolid oils to separate 
 " stearines," spermaceti, 
 &c., 229, 305, 360. 
 
 Ballantyne, effect of light on oils, 
 130-132, 149 see also Thomson and 
 Ballantyne. 
 Balsam of Peru, 16. 
 Tolu, 19. 
 Barilla, 410, 473. 
 
 Barium polysulphide (colour test), 151. 
 ,, sulphate, adulterant of wax, 359. 
 Barring (soap), 437, 438, 444. 
 Baths see Air bath, Hot baths, 
 Chilling baths, Vapour baths, 
 Water baths, &c. 
 
 Bauerand Hazura, dry ing oils 136,290. 
 Baynes, Maumene's test, 149. 
 Beans, fatty matter contained in 
 
 various kinds of, 241-244. 
 Bears' grease, 299. 
 Beaume, rational scale, 86. 
 Becchi's test for cotton seed oil, 131, 
 
 306, 346. 
 
 Beech wood tar, 21. 
 Beef fat, beef tallow see Tallow. 
 Beef stearine see Stearine (beef). 
 Beeswax see, Wax (bees). 
 Beet fusel oils, 14. 
 
 Bell, J. Carter, lubricating oils, 325. 
 Bender, viscosity, 106. 
 Benedikt, beeswax, 358. 
 
 ,, density of glycerol solu- 
 tion, 517. 
 
 hydrometer scales, 85. 
 iodine numbers, 183. 
 iodine number of linseed 
 
 oil, 351. 
 
 phosphorus in oils, 124. 
 total acid numbers, 160. 
 use of acetylation test, 129, 
 516. 
 
 Benedikt, zinc chloride and oleic acid 
 
 39, 142. 
 
 Benedikt and Griissner, methyl num- 
 ber, 192. 
 
 Benedikt and Hazura, nonformation 
 
 of sativic acid from animal oils, 291. 
 
 Benedikt and Ulzer, acetylation test 
 
 see Acetylation test. 
 
 ,, ,, oxy oleic acid, 42. 
 
 ,, ,, oxystearosulphuric 
 
 acid, 145. 
 Benedikt and Zsigmondy, glycerine 
 
 valuation, 519, 521. 
 Bennett and Oibbs (soapmaking under 
 
 pressure), 463. 
 
 Benno Jappe & Co., glycerine extrac- 
 tion, 515. 
 Bensemann, melting points, 71- 
 
 tubes, 62. 
 Benzene, 3. 
 
 as solvent, 55, 23 1 , 236, 252, 
 
 254, 337, 339, 359. 
 Benzoic aldehyde, 3. 
 
 ethers, 17. 
 
 Benzoline see Petroleum ether. 
 Beyer, plotting machine, 448. 
 Bicarbonate formed during saponifi- 
 
 cation, 410. 
 
 Bichromate process, glycerol estima- 
 tion see Glycerine, 
 manufacture of 
 (valuation). 
 
 ,, (oil bleaching), 264-266. 
 ,, ,, (wax bleaching), 266, 
 
 269. 
 Biliary constitu tents in liver oils, 
 
 292, 354. 
 
 Bishop, polarised light, 50. 
 Bladder lard, 306. 
 Bleaching oils, &c., 50, 263-269, 358, 
 
 364 
 
 , , powder, use of in decoloris- 
 ing oils, 264, 266, 267. 
 Blown oils see Oils (blown). 
 Blowpipe, 428, 433. 
 Blubber, extraction of oil from, 247. 
 Bock's process, 384. 
 Boiling down blubber, &c., 247. 
 
 , , oils, changes occur ring during, 
 
 125, 129. 
 
 points, acetic acid series, 20. 
 ,, acrylic, 25, 28, 29. 
 ,, alcohols, 14. 
 ,, pure triglycerides, 11. 
 processes, 313-318. 
 Bone fat (bone grease, bone oil), 67, 
 88-91,160,181-184,298,299. 
 ,, adulteration of tallow fat 
 with, 355. 
 
INDEX. 
 
 533 
 
 Bone fat, extraction of, from bones, 
 
 251-254. 
 ,, removal of calcium phosphate, 
 
 &c., contained in, 256. 
 Bone tar (bone oil, Dippel's oil), 2, 5. 
 Borneol, 15. 
 Borith, 449. 
 Bosch see Margarine. 
 Bottlenose whale see Oil (Doegling). 
 Bran from cotton seeds, 304. 
 Brandy fusel oils, 14. 
 Brassica (rape, colza), various species 
 
 of, 348. 
 
 Braun and Liebreich, lanolin, 338. 
 Brez, de, moulded caudles invented 
 
 by, 363, 395. 
 Brine see Salting out. 
 Brink, caoutchouc in lubricating oils, 
 
 323. 
 Brin's Oxygen Co. , oil boiling process, 
 
 321. 
 
 Bromine absorption, 26, 176-179. 
 ,, reaction, forming propiolic 
 
 acids, 31, 32, 45. 
 Bromo substitution derivatives see 
 
 Substitution. 
 Bruijn, de, and von Leent, oleore- 
 
 fractometer, 51-53. 
 Buccia (olive marc), 343. 
 Buisine, beeswax, 269, 358. 
 Bursty n's method, 118. 
 Butter, animal, 174, 298. 
 
 ,, (ewes', goats', por- 
 
 poises'), Reichert 
 number of, 174. 
 ,, cow's, adulteration of, 310. 
 
 fat of, 3, 9, 299. 
 ,, ,, ,, acids obtainable 
 
 from, 20, 25, 70. 
 ,, ,, ,, Hehner number, 
 
 166, 310. 
 ,, ,, ,, iodine number, 
 
 181-134, 310. 
 ,, ,, ,, melting point, 67- 
 
 70. 
 ,, ,, ,, refractive power, 
 
 51-53. 
 ,, ,, ,, Reichert number, 
 
 174, 310. 
 
 ,, ,, saponification 
 
 equivalent, 160, 
 310. 
 
 ,, ,, ,, solubility, 54-56. 
 
 ,, ,, ,, specific gravity, 
 
 88-92. 
 
 ,, ,, quality of, 303. 
 
 ,, ,, salt contained in, 123. 
 
 ,, ,, sweetening rancid, by 
 
 washing with water, 261. 
 
 Butter, cow's, water contained in, 122. 
 ,, general nature of, 1. 
 ,, mineral (antimony, tin), 1. 
 , , vegetable (vegetable fat, veget- 
 able tallow), 2, 6, 47. 
 ,, class, 282, 295. 
 
 Butters, vegetable, expression oleines 
 
 from see Oleines. 
 ? ,, lesser known, 295-298. 
 
 Butters, vegetable 
 
 Andiroba fat see Oil (carapa). 
 Bassia fat (Illipe butter, Mahwa 
 butter), 21, 56, 67, 87, 241, 243, 
 295, 363. 
 Bay berry fat see infra Laurel 
 
 butter. 
 Borneo tallow (Malayan tallow, 
 
 Fever nut butter), 242, 296. 
 Butter nut fat, 297. 
 Cacao butter, 21, 241, 295. 
 
 ,, chemical properties, 
 
 160, 174, 181-184. 
 
 ,, physical properties, 
 
 55, 56, 67-70, 87, 
 
 88, 91. 
 
 ,, theobromic acid in, 
 
 21, 22. 
 
 Carapa fat see Oil (carapa). 
 Chinese (Stillingia) tallow, 21, 70, 
 
 295, 363. 
 
 ,, ,, extraction by hot 
 
 water process, 
 201. 
 
 ,, yield of, 242. 
 Chequito butter, 297. 
 Cocculus indicus fat, 297. 
 Coker butter see Oil (cokernut). 
 Copra butter ,, ,, 
 
 Caumou butter xee Oil (comnu). 
 Dika fat, 2, 20, 242, 295. 
 Fever nut butter see supra Borneo 
 
 tallow. 
 Fulwah butter (Indian butter), 242, 
 
 295. 
 Gal am butter see infra (Shea 
 
 butter). 
 Goa butter (Kokum fat, Mangosteen 
 
 oil), 68, 242, 296. 
 
 Illipe butter see supra Bassia fat. 
 Indian (Fulwa) butter see supra 
 
 Fulwah butter. 
 
 Karanja butter, Korinje butter 
 (Ponga butter, Ponga oil, Poondi 
 oil), 242, 296. 
 
 Kokum fat see supra Goa butter. 
 Laurel butter (Laurel oil, Bayberry 
 fat), 20, 56, 68, 181-184, 243, 296. 
 Macaja butter, 243, 297. 
 Mafura tallow, 243, 296. 
 
534: 
 
 INDEX. 
 
 Butters, vegetable 
 
 Mahwa butter see supra Bassia 
 
 fat. 
 Malayan tallow see supra Borneo 
 
 tallow. 
 Malabar (Piney) tallow, 70, 160, 
 
 244, 295, 363. 
 Myristica butters, 295. 
 Nutmeg butter see Oil (nutmeg). 
 Ochoco fat, 297. 
 Ocuba fat, 295. 
 
 Otoba fat (Otoba wax), 243, 295. 
 Palm butter see Oil (palm). 
 Palm kernel (Palm nut) butter see 
 
 Oil (palm kernel). 
 Para butter (Assai oil), 297. 
 Pekea butter (Piquia fat) see Oil 
 
 (piquia). 
 
 Persea fat see Oil (alligator pear). 
 Phulwara fat see Fulwah butter. 
 Pichurim bean fat, 20. 
 Piney tallow see supra Malabar 
 
 tallow. 
 Ponga butter see supra Karanja 
 
 butter. 
 
 Poona fat see Oil (calabar bean). 
 Rambutan tallow, 296. 
 Sawarri (Souari) nut butter, 297. 
 Shea (Galam) butter, 2, 21, 70, 71, 
 
 160, 242, 295. 
 
 Sierra Leone butter, 244, 296. 
 Soapberry butter (Soap tree fat), 
 
 244, 297. 
 
 Soudan butter, 297. 
 Stillingia tallow see supra Chinese 
 
 tallow. 
 Tacamahac fat see Oil (calabar 
 
 bean). 
 
 Tangkallak fat, 244, 297. 
 Ucubafat (Ucuba wax, 295. 
 Virola fat, 68, 295. 
 Veppam fat see Oil (zedrach). 
 Butterine (butter substitutes ; arti- 
 ficial butter) see Margarine. 
 Butyrin (butyric triglyceride), 9, 
 
 ,, not contained in butter, 9. 
 
 CABBAGE palm oil see Oil(arecanut). 
 Cacao butter see Butters, vegetable 
 
 (Cacao butter). 
 
 Cadmium salts, use in refining oils, 263. 
 Cailletet, bromine reaction, 177. 
 ,, soap analysis, 507, 508. 
 Cake, cold press see Cold press cake. 
 
 ,, filter see Filter cake. 
 
 ,, hot press see Hot press cake. 
 
 Cake, separation-see Separation cake. 
 Cakes, linseed, &c. see Oilcakes. 
 
 ,, moulded, 221-223. 
 Calcium chloride, use of, in grease 
 
 recovery, 271. 
 
 ,, sulphate, formed in decom- 
 position of rock, 366. 
 Calculations, composition of mixtures.. 
 
 172. 
 
 ,, of rock, 372. 
 
 ,, ,, of separation 
 
 cake, &c., 378. 
 
 ,, respecting alkaline leys 
 
 and composition of 
 soaps, 421-426, 454- 
 456, 464-466. 
 
 Cambaceres, bi-aided wicks, 394. 
 Camphor, acids from, 25, 32. 
 ,, analogues, 3, 6. 
 ,, Borneo, 15. 
 ,, sodium, oxidation of, 25. 
 Camp, moulding wheel, 398. 
 Candle polishing, 405. 
 Candle stearine, 110, 230, 393. 
 
 ,, ,, breaking grain of, 368 r 
 
 397,401. 
 ,, ,, crystallising see 
 
 Separation cake. 
 
 ,, manufacture, 364-388. 
 
 ,, ,, ,, autoclave lime 
 
 process, 364, 
 373-376. 
 
 ,, ,, ,, conversion of red 
 
 oils into stear- 
 ine, 142,386-388. 
 ,, ,, ,, cold pressing 
 
 see Cold press. 
 ,, ,, hot pressing 
 
 see Hot press. 
 
 ,, ,, hydrolysis by 
 
 water under in- 
 creased pres- 
 sure, 365, 385, 
 386. 
 
 ,, ,, ,, open pan lime 
 
 process, 364-370. 
 
 ,, ,, ,, rock (lime soaps) 
 
 366, 371-374. 
 
 ,, ,, ,, sulphuric acid 
 
 processes, 365, 
 380-385. 
 
 ,, ,, ,, unsaponified fat, 
 
 &c. see Un- 
 saponified. 
 yield, 368, 370- 
 
 374. 
 
 ,, ,, mixed fatty acids see 
 
 Acids, fatty, mixtures 
 of; Melting points. 
 
INDEX. 
 
 535 
 
 Candle wicks see Wicks. 
 Candlemaking materials, 302, 363. 
 
 ,, processes, basting wax 
 
 tapers, &c.,389. 
 ,, dipping by hand, 
 
 :i90, 391. 
 ,, ,, dipping by machine, 
 
 391-394. 
 
 ,, ,, drawing wax tapers, 
 
 spills,&c., 389,407. 
 ,, ,, manipulation re- 
 
 quired in moulding 
 with various ma- 
 terials, 401. 
 ,, ,, moulding by hand, 
 
 395-398. 
 
 ,, ,, moulding by ma- 
 
 chine, 398-406. 
 ,, pouring, 388, 389. 
 
 ,, ,, threading wicks, 
 
 397, 399, 400, 406. 
 ,, ,, trimming, 389. 
 
 ,, ,, turnover machine, 
 
 405. 
 
 Candles, ceresin, ozokerite, and par- 
 affin, 363, 364, 401, 402. 
 ,, composite, 364, 402. 
 , , early forms of, 312, 313, 362, 
 
 390, 391. 
 
 ,, hollow, 402, 405. 
 ,, medicated, 407. 
 ,, self-fitting butt end, 402. 
 ,, spermaceti (sperm), 360, 
 
 363, 402. 
 ,, spiral, 402. 
 ,, standard (photometric), 
 
 402. 
 
 ,, stearine, 395, 401. 
 tallow, 363, 402. 
 tinted, 390, 401, 405. 
 
 wax, 301, 362-364, 389. 
 Caoutchouc, use in lubricating oils, 
 
 323. 
 
 Capillary tubes (m elting points) ,60-63. 
 ,, (friction coefficient), 
 
 107, 109. 
 
 Capric aldehyde, 14. 
 Carapin, 296. 
 Carbolic acid see Phenol. 
 
 soaps, 6, 477, 505, 506. 
 
 ,, soaps, valuation of 
 
 phenoloids in, 506. 
 Carbon dioxide, atmosphere of, for 
 
 cod liver oil extraction, 248. 
 Carbon disulphide as solvent, 55, 123, 
 124,231-236,252, 
 254, 337, 339, 343. 
 ,, diluent for sulphur 
 chloride, 155. 
 
 Carbon disulphide lamp for disinfect- 
 ing, 407. 
 
 ,, ,, " sulphocarbon 
 
 oils " extracted 
 by, 344, 408. 
 
 Carbon tetrachloride as solvent, 55, 236 
 Carbonates, alkaline, direct saponifi- 
 cation by see Alkaline carbonates, 
 Sodium carbonate. 
 Carnauba wax see Wax (Carnauba). 
 Carriage grease see Lubricants. 
 Carriers of oxygen (driers), 129, 264. 
 Cart grease see Lubricants. 
 Casein in butter, 123. 
 Cast iron less corroded than wrought 
 
 by fatty acids, 277. 
 Castor beans, decortication of, 224. 
 Castorol (castoreum), 17. 
 Cattle food, 303 see also Oilcake. 
 Caustic soda see Soda, caustic. 
 Causticising alkaline leys, 409-414. 
 ,, boiling process, 412. 
 
 ,, cold process, 411. 
 
 ,, under pressure, 413, 
 
 Centigrade scale, 57-60. 
 Ceresin (cerasin), 2, 88. 
 
 ,, ,, detection of, in 
 
 beeswax, 359. 
 Cerolein, 358. 
 Ceroxylin, 301. 
 Cetaceans, oil from blubber of see 
 
 Oils (cetacean). 
 
 Cetyl cyanide, margaric acid from, 21. 
 Cetylic ethers, 4, 7. 
 Chandlery (candlemaking trade), 363. 
 Charcoal, use of, in clarifying and 
 decolorising oils, &c., 255, 263, 
 269 see also Animal charcoal. 
 Charring of wicks see Wicks. 
 Chateau, colour reactions, 142, 151. 
 Chattaway's tube, 120. 
 Chemical changes during boiling, 317. 
 ,, ,, during drying of oils 
 
 see Oils (drying of). 
 Chevreul, researches on fats, 309. 
 Chevreul and Gay Lussac, candle 
 
 material, 365. 
 
 Chevreul-Milly process, 365. 
 Chequito, 297. 
 Chilling baths, 66, 67. 
 
 ,, effect on viscosity, 106. 
 
 Chimneys (lamp), 313. 
 China clay as adulterant, 123, 355, 359. 
 
 ,, (antifriction), 328. 
 
 Chinese wax see Wax (Chinese). 
 Chlorate, potassium, use of, in bleach- 
 ing oils, &c., 264, 266. 
 Chloride of soda for soap bleaching, 
 267. 
 
536 
 
 INDEX. 
 
 Chlorine, action 011 ethylene, 26. 
 
 ,, bleaching by means of, 264- 
 
 267, 364. 
 ,, gas, test for fish oils in 
 
 linseed oil, 352. 
 
 Chloroform as solvent, 17, 55, 231, 359. 
 Chlorophyll, 49, 50. 
 Chloro substitution derivatives see 
 
 Substitution. 
 
 Cholesterol, allied bodies, and their 
 ethers, 3, 6, 16, 17,259. 
 ,, and its ethers in York- 
 
 shire grease, 272-276. 
 ,, determination of, in 
 
 lubricants, 329. 
 ,, ethers, 17. 
 
 ,, extraction from oils, 
 
 119-121. 
 
 lanolin, 337-339. 
 ,, occurs in de"gras, 336. 
 
 ,, ., liver and cetacean 
 
 oils, 17, 292. 
 
 ,, ,, suint, 337. 
 
 Choline derivatives -see Lecithin. 
 Chromate, processes for bleaching 
 oils, wax, &c. -see Bi- 
 chromate. 
 
 ,, reaction with glycerol 
 
 ste Glycerol extraction 
 (valuation by bichro- 
 mate process). 
 Chrome recovery, 265. 
 Chromium compounds as driers, 314. 
 Cierges (altar candles), 389. 
 Cinchol, 22. 
 
 Claritication nee Oils (clarification). 
 Clarke, oils boiled with manganese 
 
 driers, 314. 
 Clark's soap test for hard water, 485, 
 
 508. 
 
 Classification of oils, &c., according 
 to chemical com- 
 position, 5. 
 
 ,, ,, according to com- 
 
 position, sources, 
 and texture, 281 
 302. 
 
 ,, ,, according to rela 
 
 tive density, 89 
 92. 
 
 ,, ,, according to sapo 
 
 nification equiva 
 lents, 158. 
 ,, ,, according to uses 
 
 302-339. 
 ,, of soaps according t< 
 
 alkalinity, 512. 
 "Clay, China see China clay. 
 
 , , use of, in refining oils, &c. , 255 
 
 Cleansing engine waste, 237. 
 >loez, elseococca oil, 291. 
 )lose soap, 468, 473. 
 
 ,, test (flashing point), 126. 
 )loth dressing, use of oils for, 302 
 Coagulate (grease recovery), 271, 272. 
 Coagulation of mucilage and albu- 
 minous matters see Oils, clarifica- 
 tion of. 
 
 Joaltar oils Sfc Oils (coaltar). 
 )obalt compounds as driers, 314. 
 Cochineal as indicator, 420, 497. 
 Jod livers, extraction of oil from, 247. 
 Joefficient of expansion of glass, 77. 
 oils, 79, 92-94. 
 
 ,, friction in capillary tubes, 107. 
 ,, ,, Traube's apparatus, 109. 
 ogan's process (oil refining), 259. 
 ohesion figures, 48, 345. 
 Coils, steam - see Steam (wetand dry). 
 ?'0kernut, machine for splitting, 224. 
 ,, oleine see Oleine (cokernut). 
 ,, spelling .of word, 3. 
 ,, stearine see Stearine (coker- 
 nut). 
 ^old drawn oils see Oils (cold 
 
 drawn). 
 
 ,, press cake, 375. 
 ,, ,, (candle stearine), 231, 
 
 355, 368. 
 
 , , process soaps see Soap- 
 making. 
 Colloidal mucilage, 255. 
 
 , , state of soap, 458, 466, 481, 485. 
 
 ,, ,, facilitated by presence 
 
 of alcohol, 
 
 sugar, glycerol, 
 
 458, 481. 
 
 ,, ,, ,, by use of castor 
 
 oil, 481. 
 
 ,, ,, ,, by use of potash 
 
 instead of soda, 
 
 459, 481. 
 Colorimeter, 50. 
 
 Colour of boiled oils, 315. 
 
 oils, 49, 263, 341. 
 Colour reactions with nitric acid, 139. 
 
 153. 
 ,, ,, sulphuric acid, 
 
 151-153. 
 ,, ,, zinc, chloride, &c., 
 
 141, 151-154. 
 
 , , of seal, whale, liver, 
 
 arid fish oils, 294. 
 
 Colouring matters contained in oils, 
 
 49, 263. 
 
 ,, ,, for candles, 405. 
 
 Colza (rape, coleseed), various species 
 of, 348. 
 
INDEX. 
 
 537 
 
 Combustion, destruction of noxious 
 
 smells by, 247, 250. 
 Composite candles see Candles. 
 Composition of mixtures, calculation 
 
 of, 172. 
 
 ,, soaps by analysis see 
 
 Soaps, commercial. 
 ,, soaps, calculated see 
 
 Calculations. 
 Compound ethers, 3, 4, 15. 
 
 ,, ,, saponification equi- 
 
 valent of, 158. 
 
 ,, ,, synthesis of, 13, 17- 
 
 Condensed ricinoleic acids see Poly- 
 merised. 
 
 Congealing temperatures see Melt- 
 ing points. 
 
 Consistency of elaidin formed see 
 Elaidin ; also Classification 
 according to chemical na- 
 ture, &c., pp. 281-300. 
 ,, of oils, &c., 47. 
 ,, tester, Legler's, 139. 
 Cooling pans (candle stearine), 366. 
 Copper and nitric acid test, 137, 139. 
 ,, compounds as driers, 314. 
 ,, contained in glycerine, 515. 
 
 ,, in oils, 121-124. 
 , , soaps, use of, in refining, 263. 
 ,, sulphate, use of, in refining, 
 
 256, 263. 
 
 , , test for drying oils (Hiibl), 133. 
 ,, test for sugar in soaps, 505. 
 Coppers for soap boiling see Kettles. 
 Coprah (copra), crushing and grind- 
 ing appliances, 219-221, 224. 
 Correction for anhydro derivatives, 
 
 170. 
 
 ,, ,, errors of hydrostatic 
 
 balance and hydro- 
 meter, 82-84. 
 ,, ,, free fatty acids, &c., 
 
 170. 
 
 ,, ,, impurities (alkalin- 
 
 ity), 419. 
 ,, ,, temperature (specific 
 
 gravity), 79. 
 
 Corrosion of bearings, &c. see Acids, 
 free fatty (detrimental 
 effects of), and Acids 
 (mineral). 
 
 ,, ,, iron by fatty acids, 277. 
 Cosmetics, oils used in preparation 
 
 of, 302. 
 
 Cottonseed, decortication of, 224. 
 , , stearine see Stearine (cotton- 
 
 ,, utilisation of a ton of, 304. 
 Cowles, candle moulding machines, 1 04 
 
 Cracklings, 246. 
 
 Crampton, expansion of oils, 93. 
 Creosote oils, 2, 451. 
 Jresol, 6, 16. 
 "ressonnieres', A. and E. des, drying 
 
 soap, 447. 
 Crocodile fat, 299. 
 
 Cross and Bevan, melting point de- 
 termination, 64. 
 ZJrotonol, 288. 
 Cruciferous plants, sulphurised oils 
 
 from, 123, 154. 
 Crushing rolls, 215, 218-220. 
 Crutching (soap), 438-440 
 rystallisation, fractional, separation 
 
 by, 112. 
 
 ,, from solvents, 23. 
 ,, of separation cake see 
 
 Separation cake, 
 rystallising pans (stearine), 367. 
 Culinary uses of oils and fats see 
 
 Oils (cooking). 
 Cupreol, 16. 
 
 Curbs, 432, 433, 453, 469. 
 Curd soap see Soapmaking. 
 Curriers' grease, 326. 
 
 DALICAX'S process (tallow, &c.), 74. 
 D'Arcet's sulphuric acid process, 249. 
 Dechan, pharmaceutical soaps, 510. 
 Decolorising of oils see Oils, bleach- 
 ing of. 
 
 Decomposing pan, stearine, 365. 
 Decortication of seeds, &c., 223-225. 
 ,, ,, Dudley and Perry's 
 
 chemical process, 
 225. 
 Deering, free acids in rancid tallow, 
 
 355. 
 
 Degras, 336. 
 Degrees (alkalies), English, French, 
 
 and German, 420, 421. 
 ,, Burstyn's, 119. 
 ,, Centigrade, Reaumur, Fah- 
 renheit, 58. 
 Dehydration, formation of isoleic acid 
 
 by, 29. 
 ,, of oxystearic acids, 29, 
 
 39, 42, 46. 
 
 ,, of ricinoleic acid, 36. 
 
 Deitz, extraction apparatus, 235. 
 Delphinum phocasna, 20. 
 Density see Specific gravity. 
 Deodorising cokernut oil, 261, 310. 
 ,, soaps, &c., 267 see Ran- 
 cid ; Noxious vapours. 
 Descroizilles, degrees (alkali), 420. 
 
538 
 
 INDEX. 
 
 Destruction of noxious vapours by 
 
 combustion, 247, 250. 
 Destructive distillation see Distilla- 
 tion. 
 Determination of fat in seeds, &c. 
 
 see Yield. 
 Detrimental effects of free fatty acids 
 
 see Acids (free fatty). 
 Detrimental effects of free mineral 
 
 acids see Acids (mineral). 
 Diagometer, 53, 347. 
 Diallyl, oxidised to an erythrol, 44. 
 Dibromcamphor, 32. 
 Dibromides of acids, &c., 27, 29-31, 
 
 41, 43, 44, 176. 
 
 Dibromo substitution derivatives- 
 see Substitution. 
 
 Dichlorides of acids, &c., 26, 29, 31. 
 Dichloro substitution derivatives 
 
 see Substitution. 
 Dichromate, bleaching with see 
 
 Bichromate. 
 Dieff and Reformatsky, ricinoleic 
 
 acid, 40. 
 Dierucin, 11. 
 Dieterich, iodine number of linseed 
 
 oil, 350. 
 
 , , specific gravity of fats, 88, 355. 
 Digester, for extracting bone fat, 252. 
 ,, Wilson's, for rendering tal- 
 low, &c., 250. 
 Diglycerides, 10, 468. 
 
 ,, formed by action of sul- 
 phuric acid, 144-147. 
 ,, synthesis of, 11. 
 Diglycerol, 8. 
 
 Diiodides of acids, &c., 26, 179-186. 
 Diiodo substitution derivatives see 
 
 Substitution. 
 
 Dikafat see Butters (vegetable). 
 Diminution in density with rising 
 
 temperature, 92-94. 
 Dippel's oil, 2. 
 Diricinolein sulphuric anhydride, 
 
 147. 
 
 Disintegrating machines, 224. 
 Dissolved impurities, 256. 
 Distearates, 23. 
 Distearin, 468. 
 
 Distillation acetyl number, 198. 
 destructive, 2, 3, 5. 
 Heyl's apparatus, 234. 
 of carbon disulphide solutions, 
 
 234-239, 254, 339. 
 of castor oil, 20, 25, 40. 
 of dioxystearic acid, 42, 46. 
 of glycerine, 513-516. 
 of oxystearic acid, 25. 
 of ricinoleic acid, 36, 40. 
 
 Distillation of spirit (transparent 
 
 soap), 446. 
 ,, of turpentine spirit (Mein- 
 
 ecke's rosin soap), 473. 
 ,, under diminished pressure, 
 14, 20, 21, 25, 28, 29, 34, 
 36, 40, 41, 113. 
 ,, under diminished pressure; 
 
 technical processes, 383. 
 ,, with superheated steam, 110, 
 113, 262, 271, 277, 278, 337, 
 513, 514. 
 ,, with superheated steam, plant 
 
 used for, 382-386. 
 ,, with wetsteam, 22, 112,173-176 
 
 see also Reichert's test. 
 Distilled grease (Yorkshire), 277. 
 
 ,, oleines see Oleines (distilled). 
 Dog fat, 299. 
 
 DogH sh liver, extraction of oil f rom,247. 
 Dragon's blood, 19. 
 Driers, 129, 262, 314-317. 
 Dripping, 91, 303. 
 
 , , tallow adulterated with, 354. 
 Dry fusion, rendering animal fats by, 
 
 246. 
 
 ,, steam see Steam. 
 Drying soap, 438, 447. 
 Dubbin, 326. 
 Dubrunfaut, sulphuric acid process, 
 
 380. 
 Dudley and Perry, chemical decorti- 
 
 cation, 225. 
 Dugong blubber, extraction of oil 
 
 from, 247. 
 
 Dunn, air blast in soap boiling, 433. 
 
 , , boiler (hydrated soaps, &c. ), 463. 
 
 Dussauce, ley tanks lined with lead, 
 
 412. 
 
 Dutch liquid, 26. 
 Dyer, linseed cake, 214. 
 Dyestuffs for candles, 405. 
 
 EARTHNUT see Oil (arachis). 
 Earthwax see Wax (mineral). 
 Edgerunners, 215, 218-221. 
 Edible uses of oils and fats, 302-312. 
 Edinburgh wheel, 391. 
 Effect, detrimental, of free fatty 
 acids see Acids (free fatty). 
 
 ,, of light on physical properties 
 
 of oils see Light (effect of). 
 Efflux viscosity see Viscosity. 
 Egg, white of, used in clarifying 
 
 candle stearine, 370. 
 Elseococca vernicia see Oil (Elseo- 
 
INDEX. 
 
 539 
 
 Elaidin reaction, 28, 40, 341. 
 
 ,, ,, methods of working, 
 
 137-139. 
 ,, ,, solubility diminished 
 
 by, 55. 
 
 Elbow press, 202. 
 Electrical conductivity, 53. 
 
 ,, method (melting points), 65. 
 Elevators, 221-225. 
 Ellinger, Danish butter, 53. 
 Ellwood, Valenta's test, 57. 
 Enfleurage, 302. 
 Engine waste, grease from see 
 
 Grease. 
 
 Engler, viscosimeter, 101. 
 EnglerandKunkler, viscosimeter,101. 
 English degrees (alkali), 420. 
 Entozoa present in inferior margarine, 
 
 308. 
 
 Envelopes (oil pressing), 217, 221. 
 Equivalent quantities of soda and 
 
 potash, 425, 426. 
 Error due to neglect of expansion, 77, 
 
 78. 
 
 Errors, tables of, construction, 82-84. 
 Equivalent, mean, of fatty acids see 
 
 Acids (fatty). 
 
 , , saponification see Sa- 
 
 ponification equivalent. 
 Erucin (erucic triglyceride), 11. 
 Erythrol, 4. 
 Erythrols from diallyl hydrocarbons 
 
 by oxidation, 44. 
 Eschwege seife, 461. 
 Essential oils -see Oils (essential). 
 Ester number (Esterzahl), 162, 195. 
 Estrayer cylinder (oil press), 204. 
 Ether as solvent for lead salts, 112, 
 128, 136, 356, 
 376, 501. 
 
 ,, oils, &c., 55, 119- 
 
 124, 231, 262, 
 
 273, 328, 359, 
 
 495-497, 501-503. 
 
 Ether, petroleum see Petroleum 
 
 ether. 
 Ethers, compound see Compound 
 
 ethers. 
 Ethyl acetate, 4. 
 
 ,, linolate, 34. 
 Ethylene, action of chlorine on, 26. 
 
 ,, diacetate, 4. 
 Eugenol, 194. 
 Evaporating point (lubricating oils), 
 
 325. 
 Evrard, alkaline tallow rendering 
 
 process, 249. 
 
 Examination of oils, &c., general 
 scheme for, 124. 
 
 Expansion of glass, 77. 
 
 ,, ,, correction for, 77, 78. 
 
 ,, oils, &c., Allen's results, 
 
 92. 
 
 ,, ,, Crampton's re- 
 
 sults, 93. 
 
 ,, ,, Lohmann's re- 
 
 sults, 94. 
 
 ,, ,, Wenzell's re- 
 
 sults, 93. 
 
 Experimental laboratory press, 213. 
 Expression in stages, 212. 
 Extraction of oils by solvents, ap- 
 pliances for, 232-240. 
 Extractive matters, fermentation, 
 causes hydrolysis, 10. 
 
 FAHRENHEIT scale, 57-59. 
 Fahrion, boiled oil, 135. 
 Fan (soapboiliug), 433, 434, 460, 469. 
 Farina as adulterant of fats, 123 see 
 
 Starch. 
 
 Fat, animal, class, 282, 298. 
 ,, nature of, 1. 
 ,, uiisaponilied, determination of, 
 
 119. 
 Fats, animal, expression of oleines 
 
 from, 299. 
 
 ,, ,, from birds, 298. 
 
 ,, ,, from milk (animal but- 
 
 ters), 174, 298-see 
 also Butter (cow's). 
 ,, ,, from reptiles, 299. 
 
 ,, ,, refining and bleaching, 
 
 254-268. 
 
 ,, ,, rendering of, 245-251. 
 
 ,, ,, tallow, lard, butter 
 
 class, 282, 298. 
 
 ,, vegetable see Butters, vege- 
 table. 
 Fatty acids see Acids, fatty. 
 
 ,, matters in seeds, nuts, &c., 
 
 115, 237-244. 
 Fawsitt, sulphur chloride and oils, 
 
 155. 
 
 Ferrous sulphate as decolorising 
 agent, 264, 269. 
 
 ,, ,, used in soap mot- 
 
 tling, 471. 
 
 Fibre from cotton seeds, 304. 
 Ficus gummiflua, 14. 
 ,, rubiginosa, 16. 
 Field, Leopold, candle nut oil, 287. 
 ,, candles, c., in the Ro- 
 man period, 363. 
 ,, lamp chimneys, 31 3. 
 ,, soaps, 509. 
 
540 
 
 INDEX. 
 
 Field, Leopold, spermaceti, 360. 
 
 ,, steariiie plant, 369, 382. 
 ,, wax bleaching, 266. 
 Figging of soft soap, 459. 
 Filling (soap) see Soapmaking. 
 Film test, 133, 351, 352. 
 Filsinger, soap analysis, 494. 
 Filter cake (red oils), 376, 377. 
 Filtration of oils without extra pres- 
 sure, 257, 264. 
 Filter presses, 226-229. 
 
 ,, use in clarifying ex- 
 
 pressed oils, 228, 
 
 254-257. 
 ,, ,, in purifying red 
 
 oils, 231, 376. 
 
 Fiukener on Dalican's method, 75. 
 Firing point (ignition point), 329. 
 First runnings, 304. 
 Fish livers, extraction of oil from, 247. 
 ,, manure from residues of fish oil 
 
 extraction, 249. 
 
 Fit (coarse or fine) of soap, 471. 
 Fitted soap see Soapmaking. 
 Fixed oils see Oils (fixed). 
 Flambeau, 312, 362. 
 Flashing point, 125-128. 
 
 ,, of coaltar oils, &c., 328. 
 ,, of lubricating oils, 325- 
 
 qoq 
 
 o^y. 
 
 ,, ,, insurance, 325. 
 
 ,, of oleine from Yorkshire 
 
 grease, 279. 
 
 Flavour of oils, &c. , 49. 
 Flax plant, 349. 
 Flaxen wicks, 362. 
 Fleeces see Wool. 
 Fletcher, thermhydrometer, 80. 
 Floating soaps, 441. 
 Flour as adulterant of fats, 123 see 
 
 Starch. 
 
 ,, in beeswax, 359. 
 Fluorescence, 50. 
 Fob (fitted soap), 471. 
 Foots, 115, 256, 259, 324. 
 
 ,, avoidance of formation of, 228. 
 distillation of, 261, 383. 
 spermaceti, 261, 360. 
 utilisation of, 261, 324, 408. 
 Formula, alkaline degrees, 421. 
 
 ,, equivalent quantities of 
 
 soda and potash, 426. 
 ,, thermometer degrees, 58. 
 Foxy colour developed, 265, 266, 356. 
 Fractional crystallisation, 112. 
 distillation, 113. 
 ,, precipitation, 112. 
 
 saturation, 112, 113. 
 Frames (soapmaking), 434-437, 444. 
 
 Frederking, oil boiling pan, 316. 
 Free fatty acids see Acids, free fatty. 
 Free fire process of boiling oils, 315. 
 
 ,, soap pans, 427. 
 Freezing points see Melting points. 
 French degrees (alkali), 420. 
 Fresenius, absorption of oxygen, 134. 
 Friction coefficient, Mills, 107. 
 
 ,, Poiseuille, 107. 
 
 Traube, 109. 
 Fuel from cotton and sunflower 
 
 seeds, 304, 305. 
 
 Fullers' earth, use in refining oils, 
 &c., 255. 
 
 ,, grease, 272, 279. 
 
 ,, ,, valuation of, 280. 
 
 Fusel oil, use in woolscouring, 337. 
 Fusel oils (fermentation oils) see 
 
 Oils (fusel). 
 
 Fusing points see Melting points. 
 Fusion with alkalies see Hydrogen. 
 
 GALIPOT resin, 88. 
 Gay Lussac, candle material, 365. 
 degrees (alkali), 421. 
 Geitel, stearolactone, 38, 145. 
 
 ,, sulphuric acid and oils, 144. 
 
 ,, see Schepper and Geitel. 
 
 Gelatin, removal of, from fish oils, &c., 
 
 256, 263. 
 ,, use of, to remove colouring 
 
 matters, &c., 263. 
 Gellatley, spontaneous combustion, 
 
 132. 
 
 Geraiiic aldehyde, 15. 
 Geraniol, 15. 
 Gerlach, specific gravity of potassium 
 
 carbonate solutions, 419. 
 ,, vaporimeter (glycerine 
 
 valuation, 519. 
 German degrees (alkali), 420. 
 
 ,, sesame see Oil, Camelina. 
 ,, soap process, 449, 472. 
 Girard, solubility in alcohol, 54. 
 Glacial acetic acid test see Acid 
 
 (acetic). 
 Gladding's process, rosin in soap, 
 
 485, 501, 502. 
 
 Glass, expansion of see Expansion. 
 Glassner, nitric acid test, 141. 
 Glycerides, 3, 9. 
 
 ,, determination of, in lub- 
 ricants, 329. 
 ,, hydrolysis of, in three 
 
 stages, 10. 
 
 ,, iodine absorbed by pure, 
 180. 
 
INDEX. 
 
 541 
 
 Glycerides, mixed see Mixed gly- 
 
 cerides. 
 ,, saponification equivalents 
 
 of pure, 158. 
 ,, of, in three stages, 
 
 468. 
 
 ., synthesis of, 11. 
 
 Glycerine, manufacture of (glycerol 
 
 extraction), 513-516. 
 ,, analysis and detection of 
 
 impurities, 515. 
 
 ,, extraction from soap leys, 
 451, 468, 469, 
 541. 
 
 ,, ,, from soap leys, com- 
 
 position, 514. 
 ,, ,, from sweet waters, 
 
 513, 514. 
 
 ,, loss in sulphuric acid hy- 
 drolysis processes, 381. 
 ,, production in candlemak- 
 ing processes, 311, 366, 
 373, 385, 513. 
 
 , , production in soapmaking 
 processes, 450, 45 1 , 
 466-470. 
 ,, valuation, acetyl process, 
 
 8, 191, 516. 
 ,, ,, bichromate process, 
 
 8, 516. 
 
 ,, ,, David's process, 522. 
 
 ,, litharge 524. 
 
 ,, Muter's ,, 523. 
 
 ,, ., oxalic acid process, 
 
 8, 519. 
 ,, ,, by specific gravity, 
 
 516, 517. 
 
 ,, by tension of vap- 
 
 our, 518, 519. 
 
 , , yield from ox fat, 311,312. 
 ,, ,, practical, from 
 
 various glycerides, 
 521. 
 
 ,, theoretical, 162, 195. 
 
 Glycerine soaps see Soaps (special 
 
 kinds). 
 Glycerines (commercial products), 8, 
 
 110, 513. 
 
 Glycerol, 4, 7, 110, 513. [144. 
 
 ,, action of sulphuric acid on, 
 ,, ,, heaton see Acrolein. 
 ,, as standard in viscosi- 
 
 metry, 101. 
 ,, calculated yield from tri- 
 
 glycerides, 521. 
 ,, crystallised, 7. 514. 
 ,, formation during examina- 
 tion of oils, 124. 
 ,, ,, from allylic alcohol, 44. 
 
 Glycerol, formation on saponifying 
 adulterated beeswax, 
 359. 
 
 ,, ,,011 saponifying adulter- 
 
 ated sperm oil, 354. 
 ,, ,, on saponifying Tur- 
 
 key red oils, as a test 
 33-1 
 
 ,, physical properties of, 7. 
 ,, qualitative tests for, 8, 516. 
 ,, quantitative .see Glycerine, 
 manufacture of (valua- 
 tion). 
 
 ,, retained in cold process 
 soaps, &c. , 450, 
 456-466. 
 
 ,, ,, calculations respect- 
 
 ing, 464-466. 
 Glycol, 4. 
 
 ,, from Carnauba wax, 5, 18. 
 ,, ,, defines by oxidation, 44. 
 Goat's tallow see Tallow. 
 Goods, "killing" of, in soapmaking, 
 
 433, 468. 
 ,, rancid, deodorising soap made 
 
 from, 267. 
 
 Goose grease, 68, 184, 298, 299. 
 Gossage, method of emptying soap 
 
 pans, 434. 
 
 Graf, theobromic acid, 22. 
 Grain spirit fusel oils, 14. 
 Graining soap see Soapmaking. 
 Granulating presscake see Separa- 
 tion cake. 
 
 Grape fusel oils, 20. 
 Grease, birds, 298. 
 
 ,, bone see Bone grease. 
 
 ,, curriers', 336. 
 
 ,, distilled, 111 -see Distillation. 
 
 engine waste, 236, 279, 324. 
 
 ,, from hot pressing see Hot 
 
 press. 
 
 ,, from silk soap suds, 279. 
 ,, fullers', 279, 2hO. 
 ,, horse,rnare's .see Oils (horse). 
 ,, lubricating see Lubricants. 
 ,, recovered, 262, 270-280. 
 
 , , used in soapmaking, 
 
 450, 453. 
 
 ,, recovery by Yorkshire pro- 
 cess, 272 see 
 Yorkshire grease. 
 ,, ,, by lime process, 271. 
 
 ,, trade refuse (tannery grease. 
 
 &c.), 299. 
 
 ,, ,, used in soap- 
 
 making, 409. 
 
 ,, Yorkshire see Yorkshire 
 grease. 
 
542 
 
 INDEX. 
 
 Greasy rags, spontaneous combustion 
 of, 132, 133. 
 
 Greaves, 246. 
 
 Green liquor see Chrome liquor re- 
 covery. 
 
 Green oil (Yorkshire grease distilla- 
 tion), 277. 
 
 Grills and Schroeder, liquid sulphur 
 dioxide as solvent, 236. 
 
 Grimshaw, phosphated soaps, 476. 
 , , utilisation of cotton seeds, 304. 
 
 Grittner and Szilazi, rosin in soap, 502. 
 
 Grb'ger, dioxy palmitic acid, 44. 
 
 Ground mica (antifriction), 324. 
 
 Groundnut see Arachis nuts and 
 Oil (arachis). 
 
 Ground plan of 16-press installation, 
 216. 
 
 Gum arabic, Eideal, 108. 
 ,, benzoin, 19. 
 
 Gumming of oils, 129, 322, 325. 
 
 ,, ,, practical test of, 323. 
 
 Gwynne, Jones, andWilson, sulphuric 
 acid process, 380. 
 
 H 
 
 HAUEMAN, soda crystals in oil refin- 
 ing, 2GO. 
 
 Hagenbach, viscosity, 107. 
 Hager, specific gravity of fats, 88, 355. 
 Hairs, hair envelopes, 217, 221. 
 Handpicking seeds, necessary to ob- 
 tain standards, 213, 340, 350. 
 Hartley, acid refining process, 259. 
 ,, manganese sulphate in re- 
 fining, 260. 
 
 Hartley and Blenkinsop, patent re- 
 fining process, 263, 264, 315. 
 Hauchcorne, nitric acid test, 140. 
 Haussknecht, benoxylic acid, 45. 
 ,, brassa'idic acid, 28. 
 
 Hawes' boiler (cold process soap), 
 
 457, 463. 
 
 Hazura, characteristic oxidation pro- 
 ducts, 128. 
 
 ,, oxidation of stearolic acid, 
 
 36 see "Benedikt and 
 
 Hazura ; Bauer and Hazura. 
 
 Hazura and Grlissner, glycerides in 
 
 linseed oil, 350, 
 
 351. 
 
 ,, ,, liuolic acid, 35. 
 
 ,, ,, linolic acid in olive 
 
 oil, 344. 
 
 ,, ,, oxidation of drying 
 
 oil acids, 136. 
 
 ,, ,, ,, of ricinoleic 
 
 acid, 40. 
 
 Hazura and Griissner, oxidation of 
 stearolic acid, 45. 
 ,, ,, rule concerning oxi- 
 
 dation, 44. 
 
 Head matter (whales), 360. 
 Heat, coagulation of albuminous 
 
 matter by, 255, 263. 
 ,, effect of, on oils see Oils 
 
 (effect of heat on). 
 ,, evolution with sulphuric acid 
 
 see Oils (heat evolution). 
 Hehner, beeswax, 357, 358. 
 
 , , glycerine valuation, 516, 522. 
 number, 113, 157, 166-170, 
 
 195, 196, 341. 
 Heintz, melting point tables, 71-74. 
 Hell, hydrogen method, 13, 121. 
 Hempen wicks, 362. 
 Hersee, soap pump, 434. 
 Hervieux and Bedard, waggon grease, 
 
 327. 
 
 Hess, Yorkshire grease analysis, 276. 
 Hexacetyl derivatives, 37. 
 Hexbromides of fatty acids, 34-37, 
 
 176. 
 
 Heyl, distillation apparatus, 234. 
 Hippopotamus grease, 299. 
 
 milk, 298. 
 
 Hoffmeister, chilling baths, 67. 
 Holde, improved flashing point ap- 
 paratus, 127. 
 ,, iodine absorption of drying 
 
 oils, 184, 351. 
 ,, oleorefractometer, 52. 
 Holt, brassic acid, 29. 
 Homologous acids, separation of, 112, 
 
 113. 
 Homologues of linolic acid (supposed), 
 
 32, 34. 
 
 Honig and Spitz, extraction appara- 
 tus, 120, 239. 
 
 Hope, soap analysis, 494, 498, 499, 509. 
 Horse grease, horse fat see Oil 
 
 (horse). 
 ,, power requisite in oil mill, 215- 
 
 217. 
 
 Hot baths, 61-65, 80, 95-101. 
 Hot air bleaching processes see Air. 
 Hot press, 231, 368. 
 
 cake, 368, 370, 375. 
 Hubl, beeswax, 358. 
 
 ,, iodine test see Iodine number. 
 
 ,, melting points, 71. 
 
 ,, modification of Livache's test, 
 
 133. 
 
 Hubl and Stadler, rosin in soap, 502. 
 Huiles d'enfer, 344. 
 
 tournantes, 116, 344. 
 Hulls from cotton seed, 304. 
 
INDEX. 
 
 543 
 
 Hurst, efflux viscosity values, 105. 
 ,, \ r alenta's test, 56, 57. 
 ,, viscosimeter, 101. 
 ,, Yorkshire grease, 276-279. 
 Hyaena fat, 21. 
 
 Hydrated soaps see Soapmaking. 
 Hydration of anhydrides, &c., 41-43, 
 
 45. 
 
 ,, of isoleic acid, 38. 
 Hydraulic filter press see Filter 
 
 press. 
 
 presses, 207-212, 215-218. 
 Hydriodic acid, action on isoleic 
 
 acid, 30. 
 ,, ,, action on linolic acid, 
 
 34. 
 Hydrocarbons, 2, 3, 5, 54, 90. 
 
 , , detection in linseed oil, 352. 
 ,, ,, in olive oil, 347. 
 
 5 , in rape oil, 349. 
 
 ,, ,, in Turkey red oils, 
 
 335. 
 
 ,, ,, in wax and sper- 
 
 maceti, 359, 361. 
 ,, determination in lubri- 
 cants, 329. 
 ,, insoluble in glacial acetic 
 
 acid, 57. 
 , , mineral, solid see Cerasin, 
 
 Ozokerite. 
 ,, miscible with blown oils, 
 
 320, 321. 
 
 ,, presence of, in distilled 
 
 oleines, &c., 120, 258, 
 
 261,274-278,377,378. 
 
 ,, ,, in engine waste 
 
 grease, 279. 
 ,, saturated and unsaturated, 
 
 3, 26. 
 ,, separation of, from oils, 
 
 119-124. 
 ,, use of, in manufacture of 
 
 lubricants, 322-329. 
 ,, used as adulterants, 120, 
 
 121, 335, 347-349, 352. 
 Hydrocarotin, 18. 
 
 Hydrochloric acid, evolved from 
 burning wax tap- 
 ers, 267, 365. 
 ,, ,, formed in Turkey red 
 
 oil making. 331. 
 ,, ,, removal of lime salts 
 
 from bone fat by, 256. 
 ,, ,, used in grease re- 
 
 covery, 271. 
 ,, ,, ,, in Mege Mouries 
 
 process, 308. 
 
 ,, ,, ,, in oleic acid 
 
 valuation, 376. 
 
 Hy drochloricacid used with bleaching 
 powder, &c., in decolorising oils, 
 &c., 264-266. 
 Hydrogen, atmosphere of, in cod liver 
 
 oil extraction, 248. 
 ,, evolved by fusion with 
 alkalies, from 
 acrylic acids, 24. 
 ,, ,, from alcohols, 13, 121. 
 
 ,, ,, from glycols, 18. 
 
 ,, ,, from gly collie acids, 
 
 37. 
 ,, nascent, as dechlorinising 
 
 agent, 31, 35. 
 ,, peroxide as bleaching 
 
 agent, 264, 339, 359. 
 Hydrogenation of acids, 20, 26, 32, 
 
 34, 40. 
 
 aldehydes, 14, 15. 
 Hydrolysis accompanies rancidity, 
 
 10, 12, 114, 292. 
 ,, but little effected by light, 
 
 131. 
 ,, by superheated steam, 10, 
 
 110, 125, 261. 
 
 ,, in autoclaves, &c., 373 
 
 see also Distillation. 
 
 ,, of condensed ricinoleic 
 
 acids, 146, 333. 
 
 ofoils,&c.,7, 10, 12, 114, 116. 
 ,, of soap solutions, 12, 23, 
 
 486-488. 
 
 ,, of soap solutions, rate 
 diminished by presence 
 of alkali, 487. 
 
 ,, of sulphuric acid com- 
 pounds, 27, 29, 331, 333. 
 of Turkey red oils, 331-333. 
 ,, water taken up during, 10, 
 
 275. 
 Hydrometer, 77. 
 
 ,, scales, 84-86. 
 
 ,, table of errors, con- 
 
 struction of, 83. 
 Hydrostatic balance, 77-79, 81. 
 
 ,, table of errors, construc- 
 
 tion of, 83. 
 Hydroxylinolein, 136, 137. 
 
 ICELAND moss in lard, 306. 
 Ignition point, 329. 
 Illipti fat see Butters, vegetable. 
 Impurities, systematic examination 
 
 for, 124. 
 Incipient melting and solidifying 
 
 points see Melting point. 
 
544 
 
 INDEX. 
 
 Increment in weight during drying of 
 
 fatty acids, 113. 
 Increment in weight during drying of 
 
 oils, 133. 
 
 Indicators in titration, 420 see 
 Phenolphthalein, Titration, Cochi- 
 neal, Litmus, Methyl orange. 
 Indigo, used to tint soft soap, 459. 
 Inner anhydrides, 30, 39. 
 Insolation, effect of see Light, effect 
 
 of. 
 
 Insoluble acid number, 168, 195, 341. 
 ,, f atty acids >ee Acids, fatty, 
 
 insoluble. 
 
 Installation (16-press), plan of, 217. 
 Insurance companies and lubricating 
 
 oils, 325. 
 Iodine candles, 407- 
 
 ,, number (iodine absorption),. 
 
 26,34,157,176-186,341. 
 
 ,, ,, as test of drying 
 
 power, 133. 
 
 ,, ,, effect of light on, 131. 
 
 ,, ,, lessens as oxysen taken 
 
 up, 42, 129,^135, 185. 
 ,, ,, of free acids, 180, 184, 
 
 197, 356. 
 
 ,, ,, of glyceride falls short 
 
 of that of free fatty 
 
 acid by about 4 - 5 per 
 
 cent., 185, 197. 
 
 ,, ,, of oils, determinations 
 
 of, 181-184, 196. 
 lodo substitution derivatives see 
 
 Substitution. 
 
 Irish moss (antifriction), 328. 
 Iron, cast, less corroded by fatty 
 acids than wrought iron, 277. 
 ,, salts, use in refining, 263. 
 ,, soaps see Metallic soaps. 
 Isocholesterol, 16, 17. 
 
 , , and ether s in Yorkshire 
 
 grease, 272-276. 
 Isoglyceride theory, 12. 
 Isomerides of dioxybenic acid, 28, 29, 
 
 44, 129. 
 ,, dioxystearic acid, 28, 30, 
 
 41, 43, 129. 
 linolic acid, 32, 35. 
 ofoleicacid, 28, 29, 129. 
 oxystearic acid, 29,38,39. 
 oxystearosulphuric acid, 
 
 27, 30, 38. 
 
 ricinoleic acid, 40, 41. 
 trioxystearic acid, 40, 
 
 43, 44, 129. 
 Isomerism of brassic and erucic acids, 
 
 28, 29. 
 ,, stereochemical, 29. 
 
 JACKSON, African oils, 289. 
 Japanese wax see Wax (Japanese). 
 Jean, adulteration of butter, 310. 
 
 ,, oleorefractometerreadings, 51-53. 
 
 ,, thermeleometer, 151. 
 Jellifying of soap solutions, 485. 
 Johnson & Co., filter presses, 229. 
 Juillard, Turkey red oils, 147, 330, 
 333. 
 
 KAOLIN as adulterant, 123. 
 
 Kauri gum admixed with thickened 
 
 oils, &c., 142, 318. 
 Keg lard, 306. 
 Kerosene, 2, 5. 
 Ketones, 3, 6. 
 Kettles for boiling drying oil, 315, 316. 
 
 ,, for boiling soap, free fired, 426- 
 428. 
 
 ,, for heating crushed seed, &c., 
 215, 221. 
 
 ,, heated by dry steam, 247, 428. 
 
 ,, ,, by wet steam, 428. 
 
 ,, skimmer pipe for, 433. 
 
 ,, square, 433. 
 
 ,, various older forms of, 429-432. 
 Kitchen grease, 299, 408. 
 
 ,, ,, deodorising, 265. 
 
 ,, tallow adulterated 
 
 with, 354. 
 
 Kcettstorfer's test (Kcettstorfer num- 
 ber) see Total acid number. 
 Kidney fat (ox), 311. 
 " Killing the goods," 433, 468. 
 Knab's superheated steam distilla- 
 tion plant, 382. 
 Kohn, qualitative test for glycerol, 
 
 516. 
 Krafft, ricilinolic acid, 36. 
 
 ,, ricinic acid, 41. 
 Krafft and Noerdlinger, brassic and 
 
 elaidic acids, 28. 
 
 Kingzett, glycerine extraction, 514. 
 Kulp livers, extraction of oil from, 
 
 247. 
 
 LABOUR requisite in oil mill, 215-218. 
 
 Lach, candlenut oil, 287. 
 
 ,, French candle stearine plant, 386. 
 
 Lactucerol, 16. 
 
 Lamp for carbon disulphide (disin- 
 fecting), 407. 
 
INDEX. 
 
 545 
 
 Lamps, 312, 313, 362. 
 Langbeck, lanolin 339. 
 Langlet, thermal areometer, 82. 
 Lanolin, 274, 336, 337-339. 
 ,, in soaps, 448. 
 ,, manufacture of, 337. 
 ,, sulphurised, 339. 
 
 tests of quality of, 339. 
 Lant Carpenter, lubricating oils, 325. 
 ,, soap analysis, 510. 
 
 ,, soap boiling, 470. 
 
 ,, sulphuric acid pro- 
 
 cess, 381 , 388. 
 Lard, 21, 164, 299, 303-308. 
 ,, adulteration of, 306, 307. 
 artificial, 307. 
 ,, damaged, used for soapmaking, 
 
 408. 
 free fatty acids in, small when 
 
 fresh, 307. 
 , , iodine number of, 181-184, 307, 
 
 356. 
 
 ,, manufacture of, 306. 
 ,, melting point of. 68, 306, 307. 
 ,, oil see Oil (lard). 
 ,, Reichert number of, 175. 
 ,, saponification equivalent of, 
 
 160, 307. 
 
 ,, solid suspended matters in, 123. 
 ,, solubility of, 56. 
 specific gravity of, 88-93, 307. 
 ,, stearine (solar stearine) see 
 
 Stearine (lard). 
 ,, unsaponifiable constituents in, 
 
 &c., 257, 307. 
 ,, vegetable, 305, 310. 
 ,, water contained in, 122, 307. 
 Laurent, polarimeter, 50. 
 Laurie aldehyde, 14. 
 Laurin, lauric triglyceride, 11. 
 Lead acetate, use in boiling oils, 262, 
 
 314. 
 
 contained in oils, 121-124, 314. 
 , , oxide as saponifying agent, 410. 
 ,, oxides as driers, 314. 
 ,, plasters, 410, 485. 
 , , salts soluble in ether see Ether 
 
 as solvent. 
 
 , , salts, use of, in refining, 256, 263. 
 ,, test (Livache's), 133. 
 Leather currying, leather grease, 302, 
 
 336, 339. 
 
 Leblanc process of alkali manufac- 
 ture, 410. 
 Lecithin, 121, 240, 259. 
 
 ,, determination of phospho- 
 rus in, 124, 240. 
 Leeds, soap analysis, 494. 
 Lefebre, oleometer, 79. 
 
 Leffmann and Beam, Reichert number, 
 
 175. 
 
 Legler, consistency tester, 139. 
 Lenz, density of glycerol solution, 517. 
 Lepenau, leptometer, 106. 
 Leuner, bonefat extraction apparatus, 
 
 253. 
 
 Lever presses, 199. 
 Lever and Scott, carbon tetrachloride 
 
 as solvent, 236. 
 Levinstein, lanolin, 339. 
 Lewkowitsch, acetylation test and 
 modification thereof, 
 189-191, 198. 
 
 , , distillation under dim- 
 
 inished pressure, 383. 
 ,, rosin in soap, 502-504. 
 
 , , Yorkshire grease, 272. 
 
 analysis 
 of, 274. 
 
 Leys, alkalinity of see Alkalinity. 
 , , calculations respectingquantity 
 and strength of see Calcula- 
 tions. 
 
 , , causticising see Causticising. 
 ,, spent see Soapmaking, Glycer- 
 ine manufacture. 
 ,, use of, in soapmaking see 
 
 Soapmaking. 
 Liechti and Suida, sulphuric acid and 
 
 oils, 144. 
 Liebig, distillation of acids, fractional 
 
 saturation, 112. 
 Light coaltar oils, 2. 
 
 , , petroleum distillate see Petro- 
 leum ether. 
 Light, effect of, on oils see Oils, effect 
 
 of light on. 
 , , facilitates air bleaching of wax, 
 
 268, 269. 
 ,, polarised (polariscope), 17, 50, 
 
 347, 352. 
 ,, ,, sugar valuation in 
 
 soap, 505. 
 
 Limburg cheese, 20. 
 Lime, use of, in causticising alkalies 
 see Causticising. 
 ,, ,, making railway 
 
 grease, 327. 
 
 ,, ,, recovering grease, 270. 
 
 ,, ,, refining oils, 256, 261. 
 
 ,, steariue manufacture, 
 
 365, 369. 
 
 Lime rosin soap (railway grease), 327. 
 Lime soap (grease recovery), 271. 
 ,, in candlemaking see 
 
 Candle stearine. 
 ,, in lard, 307. 
 
 in lubricants, 324,327,328. 
 35 
 
546 
 
 INDEX. 
 
 Limpach, stearolic acid, 36. 
 
 Linoleum, 302, 318, 319. 
 
 Linolic anhydride, 125. 
 
 Linolin (linolic triglyceride), 134, 139. 
 
 Linoxyn, 134, 136. 
 
 Linseed cake see Oilcake 
 
 Linseed, sources of, 349. 
 
 ,, usually mixed with hemp- 
 seed, 349. 
 Lint, 304. 
 
 Litmus as indicator, 420. 
 Liquid waxes see Waxes. 
 Litharge as drier see Driers. 
 Livache, comparative action of 
 
 driers, 314. 
 
 Livache's test, 133, 351, 352. 
 Livers, fish and shark, &c., extrac- 
 tion of oil from, 247. 
 Loading (soap) see Soapmaking. 
 Lcewe, melting points, 65. 
 Lohmann, expansion, 93. 
 Lubricants, analysis of, 328-330. 
 
 , , coarse, 27 1 , 280, 324, 326-328. 
 ,, corrosion by free acids in, 
 
 115, 260, 322. 
 ,, for hot rollers (pitch from 
 
 Yorkshire grease), 277. 
 ,, greases (cart, carriage, wag- 
 gon, railway grease, anti- 
 friction grease, &c.), 325- 
 329, 409. 
 ., materials used for, 302, 321- 
 
 328, 339. 
 
 ,, use of blown oils for, 320. 
 viscosity of see Viscosity. 
 Lubrication, 5, 48. 
 Lunge and Hurter, Beaume" scale, 86. 
 ,, ,, specific gravity of al- 
 
 kalineleys, 416-418. 
 Lupeol, 17, 259. 
 
 M 
 
 M 'NAUGHT, pendulum machine, 94. 
 Magma (grease recovery), 271, 272. 
 Magnesia as saponifying agent, 379, 
 
 410. 
 ,, calcined, use of, in refining, 
 
 256, 261. 
 
 Magnesium soaps, 121. 
 Manganese compounds, use of, as 
 
 driers, 314, 315. 
 
 , , dioxide, use of, in bleach- 
 
 ing, 268. 
 ,, salts, use of, in refining, 
 
 256, 260-264. 
 
 Mangold, glycerine valuation, 521. 
 Mannitol, 5. 
 
 Mansbridge, analysis of Yorkshire 
 
 grease, 275, 276. 
 
 Manteau Isabelle (mottled soap), 472. 
 Manure from fish oil extraction resi- 
 dues, 249. 
 
 ,, scraps from ox fat, 311, 312. 
 ,, sludge from suds and sud- 
 
 cake, 271, 2/2. 
 
 Mare's grease -see Oil (horse). 
 Margarin, glyceride of artificial mar- 
 
 garic acid, 21, 22, 110, 309. 
 Margarine (Oleomargarine, Butterine, 
 Artificial butter, Dutch 
 butter, Bosch, Butter sub- 
 stitutes), 22, 114, 299, 305, 
 308-312. 
 ,, cokernut and palmnut oils 
 
 in, 310. 
 
 ,, Hehner number, 166, 310. 
 ,, iodine number, 181, 184, 310. 
 ,, manufacture, 246, 247, 308- 
 
 312. 
 ,, manufacture byMegeMouries 
 
 process, ;,08. 
 ,, origin of name, 308. 
 ,, Reichertnumber,173,174,310. 
 ,, specific gravity, 88, 91. 
 , , total acid number and saponi- 
 
 fication equivalent, 159. 
 ,, use of oleorefractometer in 
 
 detecting, 53. 
 ,, vegetable, 305. 
 Marine soap - see Soapmaking. 
 Maritime alkali see Barilla. 
 Marix, distillation under diminished 
 
 pressure, 383. 
 Marrow, 21. 
 
 Massie, nitric acid test, 141. 
 Maumene's test see Oils (heat evolu- 
 tion). 
 
 Meal as adulterant, 123. 
 Mean equivalent see Acids, fatty, 
 
 (mean equivalent). 
 Meats from cotton seed, 304. 
 Mechanical viscosity testers, 94. 
 Mege M curies process, 308. 
 Meinecke's process (rosin soap), 473. 
 Meissl, Beichert number, 53, 174. 
 Melting points (Congealing, Solidifica- 
 tion, Fusing, Freezing 
 points), acetic acid 
 series, 20. 
 
 ,, acrylic acid series, 25. 
 ,, alcohols, 14. 
 ,, candle stearine, 370,375. 377. 
 ,, cholesterol and allied 
 
 bodies, 17. 
 
 ,, congealing of lubricants, 
 67, 325. 
 
INDEX. 
 
 547 
 
 Melting points, determination of, 
 
 60-67. 
 
 distilled fatty acids, 384. 
 ,, erucic and brassic acid 
 
 derivatives, 29. 
 
 ,, mixed fatty acids,69-76,341. 
 ,, oils and fats, &c., 67-69. 
 ,, polyhydroxylated stearic 
 
 acids, 43. 
 
 ,, propiolic acids, 32. 
 ,, synthetic triglycerides, 11. 
 Mercuric bromide, use of, in Hiibl's 
 
 test, 179. 
 
 ,, nitrate, colour test, 151. 
 Mercury and nitric acid test, 138. 
 Merryweather & Sons, improved dry 
 
 heat rendering arrangement, 247. 
 Metallic salts, used in refining oils, 
 
 262, 263. 
 
 soaps, detection in olive oil, 347. 
 formed in paint, 135. 
 in lubricants, 324, 328. 
 in oils, &c., 121-124, 315, 
 
 324, 485. 
 
 in ordinary soaps, 410. 
 iron soap in mottling, 472. 
 isolation of metallic con- 
 stituent (analysis), 328. 
 Methyl esters (brassic and erucic), 29. 
 ,, number (methyl iodide test), 
 
 157, 191-194, 196. 
 ,, orange as indicator, 420, 497, 
 
 507. 
 
 Methylic ethers, 5. 
 Mica (antifriction), 324, 328. 
 Michaud Freres, glycerine manufac- 
 ture, 515. 
 Milk fats, composition unlike that of 
 
 body fats, 298. 
 ,, Reichert number, 174. 
 Milling machinery (toilet soaps), 446- 
 
 448. 
 Mills, viscosity, 107, 108. 
 
 ,, W., oil bleaching, 264. 
 Mills and Akett, Mills and Snodgrass, 
 
 bromine absorption, 177. 
 Milly, de, candle material, 365. 
 
 ,, wicks, 394. 
 Mineral acids, injurious effect of see 
 
 Acids, mineral. 
 Moellon, 336. 
 
 M oiler, improved cod liver oil extrac- 
 tion process, 248. 
 Moinier and Bontigny, candle stear- 
 
 ine, 369. 
 Monoglycerides, 10. 
 
 ,, synthesis of, 11. 
 
 Morawski and Demski, iodine absorp- 
 tion, 184. 
 
 Morfit, oleine soap process, 453. 
 ,, steam series of soap pans, 432. 
 ,, steam twirl, 428, 429. 
 ,, ,, use in making lub- 
 
 ricating grease, 325. 
 ,, ,, use in making resin- 
 
 ate of soda, 453. 
 
 Mortars (mortuary candles), 406. 
 Mottled soaps see Soapmaking. 
 Moulding, Moulding machine (oil 
 
 pressing), 215, 221-223. 
 Mountain ash berries, 32. 
 Mucilage (vegetable mucus), deter- 
 mination of, 
 118-123. 
 
 ,, ,, removal from 
 
 oils see Oils 
 
 (clarification). 
 
 Miiller- Jacobs, sulphuric acid and 
 
 oils, 144. 
 
 Muirhead and Alder Wright, zinc 
 i chloride and oils, 141. 
 Mulder, drying oils, 134, 136. 
 Muntz, thermal arceometer, 82. 
 Muter, colour reactions, 142. 
 
 ,, determination of oleic acid, 
 
 376. 
 
 ,, olein tube, 376. 
 ,, specific gravities, 88. 
 Muter and Koningh, separation of 
 
 fatty acids, 307, 356. 
 Mutton tallow see Tallow. 
 Myricin (myricylicpalnritate), 4, 358, 
 
 359. 
 
 Myristic aldehyde, 14. 
 Myristin (myristic triglyceride), 11. 
 
 N 
 
 NATRON, 409, 449. 
 
 Natural naphtha .see Oils (mineral). 
 Negative alkalinity, 498, 499. 
 Negur (negre, nigre, nigger) of fitted 
 
 soaps, 471. 
 Neill & Sons, modern soap coppers, 
 
 433. 
 
 ,, rem citing pans, 441. 
 
 Neutral oil (Yorkshire grease), 276- 
 
 279. 
 Neutralisation number of fatty acids, 
 
 164, 169. 
 
 ,, ,, mixed acids, calcu- 
 
 lation of composi- 
 tion from, 172. 
 Nightlights, 312, 402. 
 
 ,, manufacture of, 406. 
 
 Niin fat, Niin wax, 302. 
 Nitric acid test, 139, 153, 294, 341. 
 
548 
 
 INDEX. 
 
 Nitric acid as standard acid in soap 
 
 analysis, 497. 
 ,, use of in wax bleaching 
 
 264, 265. 
 
 Nitrous acid test see Elaidin reac- 
 tion. 
 
 Nocciulo (olive marc), 343. 
 Noerdlinger, oilcakes, 114, 214. 
 refining oil, 263. 
 
 ,, see Krafft and Noerd- 
 
 linger. 
 Norton and Richardson, linolic acid, 
 
 34. 
 Noxious smells evolved in rendering 
 
 animal fats, 247, 249. 
 Number, acetyl see Acetylation test. 
 , , ester see Ester number. 
 , , free acid see Acids, free fatty. 
 ,, Hehner see Hehiier number. 
 ,, Hiibl see Iodine number. 
 ,, iodine see Iodine number. 
 ,, insoluble acid see Insoluble 
 
 acid number. 
 ,, Koettstorfer see Total acid 
 
 number. 
 
 , , methyl see Methyl number. 
 ,, neutralisation see Neutrali- 
 sation number. 
 
 ,, Reichert see Reichert num- 
 ber. 
 ,, saponificatioii see Total acid 
 
 number. 
 ,, soluble acid see Soluble acid 
 
 number. 
 
 , , total acid see Total acid num- 
 ber. 
 , , volatile acid see Volatile acid 
 
 number. 
 Nuisance in rendering fats see 
 
 Noxious smells. 
 
 Nutmeg butter see Oil (nutmeg). 
 Nuts strung together used as candles, 
 
 363. 
 
 ,, yield of fat from various kinds 
 of, 241-244. 
 
 OAKBARK infusion, use of, in refining, 
 
 256, 263. 
 
 Octylic ethers, 5, 20. 
 Odour of oils, &c., 49, 341. 
 
 ,, rancid, removal of see Ran- 
 cid, R,ancidity. 
 
 CEnanthol (oenanthic aldehyde), ac- 
 tion of acetic anhydride on, 25. 
 , , formed by heating castor oil, 40. 
 ,, hydrogenised to heptylic alco- 
 hol, 14. 
 
 CEnanthol, oxidised to heptoic acid, 20. 
 
 Oil. For the specific gravity and other 
 
 physical properties of each oil 
 
 severally, vide Chaps, iv., v. 
 
 (pp. 47-109). 
 
 ,, For the chemical properties and 
 reactions, vide Chaps, vi., vii., 
 viii. (pp. 110-198). 
 ,, acajou see Oil (cashew). 
 ,, adul, 288. 
 ,, alligator pear (avocado oil, 
 
 persea fat), 296. 
 ,, almond, 3, 19, 241, 257, 283. 
 
 class, 281, 282. 
 
 ,, ,, detection of adultera- 
 tions, 347t 
 ,, anchovy, 294. 
 ,, angelica, 37. 
 ,, anise, 192, 194. 
 ,, apricot kernel, 283. 
 ,, American walnut see Oil (hic- 
 kory nut). 
 
 ,, arachis (earthnut, groundnut, 
 peanut), 21, 25, 241, 
 258, 283. 
 
 ,, ,, adulteration of, 347. 
 ,, ,, detection of, in olive oil, 
 
 344. 
 
 ,, ,, doubt as to existence of 
 hypogseic acid in, 24, 111. 
 ,, ,, natural variations in com- 
 position of, 111. 
 ,, ,, relative price of, 342. 
 ,, ,, tests for, in olive oil, 344. 
 ,, ,, use of, in soapmaking 
 
 see Soapmaking. 
 ,, ,, used as lubricant, 322. 
 ,, arctic sperm see Oil (doegling). 
 ,, areca nut, 241. 
 ,, argan, 288. 
 ,, assai see Butters, vegetable 
 
 (Para butter). 
 ,, avocado, 296. 
 
 ,, bankulnut see Oil (candle nut). 
 ,, beechnut (beechmast) 241, 283. 
 ,, belladonna seeds, 241. 
 ,, ben (behen), 21, 25, 241, 283. 
 detection of adulterations, 347. 
 benne see Oil (sesame^, 
 bitter apple see Oil (colocynth). 
 blackfish, 293. 
 bladdernut, 288. 
 boma nut, 288. 
 bone see Bone fat. 
 bottlenose whale see Oil (doeg- 
 ling). 
 brazil nut (castanha nut), 241, 
 
 242, 288. 
 breadnut, 289. 
 
INDEX. 
 
 549 
 
 Oil, cabbage, 115. 
 ,, calabar bean (poon seed, dilo, 
 domba, pinnay, tamanu oil ; 
 poona fat, tacamahac fat), 241, 
 291, 296. 
 
 ,, camelina (German sesame", gold 
 of pleasure), 241, 
 286. 
 ,, ,, ,, tests for sulphur in, 
 
 123. 
 
 ,, ,, ,, use in soapmaking 
 see Soapmaking. 
 ,, canary see Oil (Java nut). 
 ,, candle nut (bankulnut, kekune), 
 
 241, 287. 
 
 ,, carapa nut (crab wood nut oil, 
 touloucoona oil, coundi oil, 
 andiroba fat), 242, 296. 
 caryocar, 297. 
 cashe\v (acajou), 241, 289. 
 cassia, 19. 
 
 castanha see Oil (brazil nut), 
 castor, 14, 20, 25, 43, 241, 285. 
 ,, action of sulphuric acid 
 see Oils (Turkey red). 
 ,, zinc chloride on, 141. 
 blown, 321. 
 class, 281, 284. 
 effect of exposure to air, 136. 
 
 ,, heat on, 40. 
 extraction by hot water 
 
 process, 200. 
 relative price of, 342. 
 soap see Soapmaking. 
 soluble, 188, 321 see Oils 
 
 (Turkey red). 
 ,, use in soapmaking, 408. 
 centaury, 242. 
 chamomile, 14, 25. 
 charlock, 241. 
 chaulmoogra, 20, 242, 297. 
 cherry kernel, 283. 
 Chinese cabbage, 284, 348. 
 chironji, 242, 289. 
 cinnamon, 19. 
 cloves, 194. 
 cod (lubricating), 330. 
 cod fish and cod liver, 257, 258, 294. 
 , , , , extraction of, 247, 
 
 248. 
 
 ,, ,, extraction of, ex- 
 
 clusion of air dur- 
 ing, 248. 
 
 ,, ,, relative price of, 
 
 342 see Oils 
 (liver, fish liver). 
 ,, ,, used for soapmak- 
 
 ing see Soapmaking. 
 cokenmt, 20, 241, 257, 258, 295. 
 
 Oil, cokernut, deodorisingrancid,261, 
 
 310. 
 
 ,, ,, separation of coker 
 
 stearine from, 231, 
 305 see Stearine 
 (cokernut). 
 
 ,, spelling of, 3. 
 
 ,, ,, use in soapmaking see 
 
 Soapmaking. 
 
 ,, colocynth (bitter apple, 241, 288. 
 ,, colza (cole, cole seed, kohlsaat), 
 
 348 see Oil (rape). 
 ,, combo nut, 242. 
 ,, copra (coprah)-see Oil (cokernut). 
 ,, corn poppy, 242. 
 ,, cotton seed, 241, 257, 258, 286. 
 ,, ,, absorption of oxygen 
 
 by, 330. 
 
 ,, ,, action of sulphuric 
 
 acid on see Oils 
 (Turkey red). 
 
 ,, ,, adulteration of, 347. 
 
 ,, ,, adulteration of lard 
 
 with, 306-308. 
 
 ,, ,, as lubricant, 322,325. 
 
 ,, ,, Becchi's test for 
 
 see Becchi's test. 
 ,, ,, blown, 319. 
 
 ,, ,, clarifying and refin- 
 
 ing, 255-263. 
 class, 281, 286. 
 
 ,, ,, refined, use as edible 
 
 and cooking oil, and 
 as adulterant of sa- 
 lad oils, 267, 304. 
 
 ,, ,, relative price of, 342. 
 
 ,, ,, use in soapmaking 
 
 s<>e Soapmaking. 
 ,, ,, utilisation of a ton of 
 
 cotton seeds, 304. 
 ,, coumu nut (coumu butter), 289, 
 
 297. 
 
 cow parsnep (heracleum), 5, 14, 20. 
 , , crab wood nut-see Oil (carapa nut). 
 ,, cress seed, 241, 286. 
 ,, croton, 20, 25, 287. 
 ,, curcas (purqueira, purgir, jatro- 
 
 pha), 20, 285. 
 ,, datura (strammonium seed), 21, 
 
 244. 
 
 ,, dilo, 291 see Oil (calabar bean). 
 
 ,, doegling (bottlenose whale, arctic 
 
 sperm), 3, 25,258,300,360. 
 
 ,, ,, doubt as to existence of 
 
 doeglic acid in, 24. 
 ,, ,, relative price of, 342. 
 ,, ,, yields spermaceti of higher 
 melting point thancachelot 
 spermaceti, 360. 
 
550 
 
 INDEX. 
 
 Oil, dogfish liver, 247, 294. 
 
 ,, dogwood berry, 288. 
 
 ,, dolphin, 293, 301. 
 
 ,, ,, bottlenose, yields sper- 
 maceti, 301. 
 
 ,, domba, 291 see Oil (calabar 
 bean). 
 
 ,, dugoiig, 247, 293. 
 
 ,, earth nut see Oil (arachis). 
 
 ,, egg see Oil (lien's egg). 
 
 ,, eleeococca (Japanese wood, tung, 
 wood oil), 32, 291. 
 
 ,, ,, extremely rapid dry ing 
 
 qualities, 291. 
 
 ,, eucalyptus, 6, 178. 
 
 ,, ,, medicated candles, 407. 
 
 ,, euonymus see Oil (spindlenut). 
 
 , , fever nut see Butters, vegetable 
 (Borneo tallow). 
 
 ,, fish, class, 281, 292. 
 
 .,, gamboge (gamboge butter), 242, 
 296. 
 
 ,, garlic, 15. 
 
 ,, gaultheria-see Oil (winter-green). 
 
 ,, geranium, 3, 15. 
 
 ,, German sesame" see Oil (came- 
 lina). 
 
 .,, gherkin seed, 288. 
 
 3, gingelly see Oil (sesame"). 
 
 ,, gold of pleasure see Oil (came- 
 lina). 
 
 ,, gourd seed see Oil (pumpkin 
 seed). 
 
 ,, grape seed, 25, 242, 285. 
 
 ,, green (Yorkshire grease distilla- 
 tion), 277. 
 
 ,, groundnut -see Oil (arachis). 
 
 ,, gundschit see Oil (lallemeiitia). 
 
 ,, hammerfish, 294. 
 
 ,, hazelnut, 242, 283. 
 
 ,, hedge radish (hedge mustard), 
 284. 
 
 ,, hempseed, 33, 35, 242, 257, 291. 
 
 ,, ,, detection of , in linseed 
 
 oil, 352, 353. 
 
 ,, ,, use as cooking oil, 304. 
 
 ,, ,, ,, in soft soapmaking 
 
 see Soapmaking. 
 
 ,, ,, usually mixed with lin- 
 
 seed oil, 349, 352. 
 
 ,, henbane seed, 242. 
 
 ,, hen's egg, 121, 298, 299, 408. 
 
 ,, heracleum see Oil(cowparsnep). 
 
 ,, herring, 294. 
 
 ,, hickory nut (American walnut 
 oil), 242, 289, 291. 
 
 ,, holly seed, 242. 
 
 ,, horned poppy see Oil (yellow- 
 horn poppy). 
 
 Oil, horse (horse grease, horse fat, 
 
 mare's grease), 286, 299. 
 ,, ,, deodorising,465- see Rancid. 
 ,, ,, use in soapmaking, 408. 
 ,, horsefoot, 286. 
 ,, horsechestnut, 242, 288. 
 ,, Indian cress, 242. 
 ,, Japanese wood see Oil (elseo- 
 
 cocca). 
 
 ,, Japan fish, 342. 
 ,, jatropha see Oil (curcas). 
 ,, Java nut, Java almond (canary 
 
 oil), 242, 296. 
 
 ,, kekune see Oil (candle nut). 
 ,, kulp liver, 247, 294. 
 ,, laintlaintain seed, 289. 
 ,, lallemantia (gundschit), 242, 291. 
 ,, lard, 231, 286, 307. 
 ,, ,, class, 2S1, 285. 
 ,, ,, relative tendency to gum- 
 ming, 323. 
 
 ,, ,, used as lubricant, 322, 325. 
 ,, laurel berry see Butters, veget- 
 able (laurel). 
 ,, lettuce seed, 243. 
 ,, linden seed, 243. 
 ,, ling liver, 178. 
 
 linseed, 32-34, 243, 257, 258, 291. 
 ,, ,, acid process for refining, 
 
 259. 
 
 ,, adulterations of, 351, 352. 
 ,, boiled, 262, 313-318. 
 
 class, 281, 290. 
 ,, ,, film test, Livache's test, 
 
 133, 351. 
 ,, ,, iodine number, 351 (see 
 
 Iodine number). 
 , , ,, pure, only obtainable by 
 
 handpickiiig, 350. 
 ,, ,, relative price of, 342. 
 ,, ,, tendency to gum- 
 
 ming, 323. 
 
 ,, ,, use as cooking oil, 304. 
 ,, ,, ,, in soft soapmaking 
 see Soapmaking. 
 ,, ,, various glycerides con- 
 tained in, 350, 351. 
 ,, liver class, 281, 292, 294. 
 ,, louar, 294. 
 ,, mabo nuts, 289. 
 ,, maccassar, 184, 297. 
 madia, 243, 286. 
 ,, maize, 243, 286. 
 ,, malabar, 294. 
 ,, malaka, 289. 
 ,, manatee, 293. 
 ,, mango seeds, 289. 
 ,, mang;osteen see Butters, veget- 
 able (goa butter). 
 
INDEX. 
 
 551 
 
 Oil, margosa see Oil (zedrach). 
 ,, menhaden (porgie), 249, 258, 294. 
 ,, ,, relative price of, 342. 
 
 ,, meni seed, 289. 
 ,, morse, 293. 
 ,, m'poga nut, 289. 
 mustard, 15, 21, 25, 243, 234, 348. 
 ,, ,, tests for sulphur in, 123. 
 neat's foot, 286, 298. 
 ,, ,, as lubricant, 322, 325. 
 
 ,, ,, relative price of, 342. 
 
 , , nettle seed, 243. 
 ,, neutral (Yorkshire grease), 276- 
 
 279. 
 
 ,, niger seed (ramtil), 243, 286,408. 
 , , , , relative price of, 342. 
 
 night shade seed, 243. 
 niko nut, 289. 
 
 nimb (neem) tee Oil (zedrach). 
 nut (walnut), 243, 291. 
 nutmeg, 20, 243, 295. 
 odal, 288. 
 
 olive, 243, 257, 258, 283, 322. 
 ,, absorption of oxygen by, 330. 
 ,, action of sulphuric acid on 
 
 see Oils (Turkey red). 
 , , adulterations of, 344-347. 
 ,, as lubricant, 326. 
 ,, class, 281, 282. 
 ,, extraction by hot water 
 
 process, 200. 
 ,, relative price of, 342. 
 ,, relative tendency to gum- 
 ming, 323. 
 ,, sources and production of, 
 
 342-344. 
 ,, taste improved by presence 
 
 of free acids, 116. 
 ,, used for soapmaking see 
 
 Soapmaking. 
 olive kernel, 243, 343. 
 
 ,, ,, extraction of, 343. 
 oolachan, 294. 
 opochala, 288, 289. 
 owala, 288, 289. 
 palm (palm butter), 21, 243, 257, 
 
 295, 322. 
 
 ,, bleaching processes, 264, 265. 
 ,, as candle material see 
 
 Candle stearine. 
 ,, extraction of, by hot water 
 
 process, 200. 
 , , use in soapmakiug see 
 
 Soapmaking. 
 
 palmkernel(palmnut),20,243,295. 
 ,, extraction by sol- 
 
 vents, 200. 
 
 , , use in soapmaking 
 
 see Soapmaking. 
 
 Oil, pea, 121, 259. 
 
 peach kernel, 243, 283. 
 peanut see Oil (arachis). 
 pelargonium, 20. 
 pilchard, 161, 294. 
 pine see Oil (red pine), 
 pinnay, 291 see Oil (calabar 
 
 bean). 
 
 piquia (pekea), 297. 
 pistachio nut, 244, 289. 
 plum kernel, 283. 
 poppy seed, 33, 243, 257, 291. 
 , , relative price of, 342. 
 , , use as cooking oil, 304. 
 ,, ,, in soft soapmaking 
 see Soapmaking. 
 porpoise (Delphinus phocsenaoil), 
 
 247, 293. 
 
 ,, contains valerin, 301. 
 ponga see Butters, vegetable 
 
 (karanja butter), 
 poon seed see Oil (calabar bean), 
 poondi see Butters, vegetable 
 
 (karanja butter), 
 porgie see Oil (menhaden), 
 pumpkin seed (gourd seed), 243, 
 
 288. 
 purgir nut (purqueira, jatropha, 
 
 curcas) see Oil (curcas). 
 radish seed, 244. 
 ramtil .see Oil (niger seed), 
 ray liver, 294. 
 rape (colza), 21, 25, 49, 257-259, 
 
 284, 313, 322. 
 
 ,, absorptionof oxygen by, 330. 
 ,, adulteration of, 349. 
 ,, as standard of viscosity, 
 
 101, 349. 
 
 ,, blown, 319, 320. 
 ,, class, 281, 284. 
 ,, fatty acids and glycerides 
 
 contained in, 11, 41. 
 ,, injurious effects of free 
 
 acids on, 115, 313. 
 ,, insoluble in acetic acid, 55, 
 
 349. 
 
 ,, refining of see Oils, refining. 
 ,, relative price of, 342. 
 ,, ,, tendency to gumming, 
 
 323. 
 
 ,, tests for sulphur in, 123. 
 ,, used for soapmaking, 408. 
 ,, yield of, 241, 348. 
 raps (rapsamen), 348. 
 red pine seed (pine oil, pinaster 
 
 oil), 244, 287. 
 rosemary, 15. 
 rosin see Rosin oils, 
 riibsen, 348. 
 
552 
 
 INDEX. 
 
 Oil, rue, 3, 14, 20. 
 safflower seed, 244. 
 sanitas, 6, 477. 
 sapucaja nuts, 244. 
 ,, sardine, 294. 
 ,, Scotch fir seeds, 244. 
 seal, 247, 258, 293, 303. 
 ,, ,, relative price of, 342. 
 ,, ,, used for soapmaking see 
 
 Soapmaking. 
 ,, sesame* (gingelly, benne", til oil), 
 
 244, 286. 
 ,, ,, Baudoin's sugar test for 
 
 see Sugar test. 
 class, 281, 286. 
 ,, ,, detection of adultera- 
 tions in, 347. 
 
 ,, ,, relative price of, 342. 
 used for soapmaking,408. 
 shark, shark's liver, 247, 294, 408. 
 sheep's trotter, 52, 286, 298. 
 ,, soap berry see Butters, vege- 
 table (soap berry). 
 soja bean, 287. 
 ,, sperm, 3, 14, 258, 313. 
 
 adulteration of, 353. 
 
 as lubricant, 322-325. 
 
 blown, 320. 
 
 class, 282, 299. 
 
 deposits spermaceti, 300, 353. 
 
 relative tendency to gum- 
 ming, 323. 
 ,, ,, sources, 300, 353. 
 ,, spindlenut (euonymus), 244, 288. 
 ,, spirit (Yorkshire grease distilla- 
 tion), 277, 278. 
 sprat, 294. 
 spring poppy seed, 244. 
 ,, spruce fir seed, 244. 
 spurge, 244. 
 ,, strammonium seeds see Oil 
 
 (datura). 
 
 ,, sunflower, 244, 286, 304, 408. 
 , , , , production in Russia, 305. 
 ,, tacamahac (tacamahac fat) see 
 
 Oil (calabar bean). 
 tallow, 231, 285, 286. 
 ,, tamanu, 291 see Oil (calabar 
 
 bean). 
 ,, tansy, 3. 
 tea seed, 244, 283. 
 ,, thistle seed, 244. 
 til see Oil (sesam). 
 tobacco seed, 244, 291. 
 ,, touloucoona see Oil(carapanut). 
 train see Oil (whale). 
 ,, tung, 291 see Oil (elaeococca). 
 tunny, 294. 
 ,, turpentine, 6, 25. 
 
 Oil, turpentine, distilled off in Mei- 
 
 necke's process, 473. 
 ,, ,, facilitates air bleaching 
 
 of wax, 269, 359. 
 ,, ,, oxidation of, 477. 
 
 ,, ,, solvent for manganese 
 
 salts as driers, 315. 
 ,, ungnadia, 244. 
 ,, valerian, 15. 
 valve (valveoline), 330. 
 ,, walnut see Oil (nut). 
 walrus, 293. 
 watermelon seed, 244, 288. 
 ,, weld seed, 244, 291. 
 whale (train), 247, 258, 293, 303, 
 
 322. 
 
 class, 281, 292, 293. 
 ,, ,, communicates unpleasant 
 smell to soft soap, 459. 
 ,, ,, relative price of, 342. 
 ,, ,, used for soapmaking see 
 
 Soapmaking. 
 ,, wild radish seed, 244. 
 ,, wintergreen (gaultheria), 3, 5, 
 
 14, 19, 192. 
 ,, wood (elaeococca, Japanese wood), 
 
 see Oil (elaeococca). 
 ,, wool (from Yorkshire grease dis- 
 tillation), 279. 
 ,, yellow horn poppy, 242. 
 ,, zedrach (margosa, nimb, neem 
 
 oil, veppam fat), 297. 
 Oil baths for tempering metals, 302, 
 Oilcake parings, use in clarifying 
 
 oils, 255, 256. 
 Oilcakes, 114, 211-214, 303-305. 
 
 acrid, from mustard seed, 349. 
 composition of, 213-214. 
 cotton seed, 212, 214, 304. 
 dimensions and weight of, 21 1. 
 fatty matters contained in, 
 
 115, 213-217. 
 free fatty acids contained in, 
 
 115, 214. 
 sunflower, superior to hemp 
 
 and rape, 305. 
 Oil lamps see Lamps. 
 Oil mill plant, 214-229. 
 
 ,, used in olive oil pro- 
 
 duction, 200, 343. 
 Dils, absorption of oxygen by see 
 
 Absorption. 
 , , acety lation test for see Acety- 
 
 lation test. 
 
 adulteration of, 340-361. 
 animal, 281, 282, 285, 292, 298, 
 
 299, 325. 
 
 ,, ,, do not yield sativic 
 acid, 291. 
 

 INDEX. 
 
 Oils, anthracene sec Anthracene. 
 ,, Benedikt and Ulzer's test see 
 
 Acetylation test. 
 ,, blacktish, 293. 
 ,, bleaching of, 263-268. 
 ,, partly effected by pre- 
 
 cipitation of mucilage, 
 &c., 263 
 
 ,, blown, 4-2, 90, 125, 130. 
 ,, ,, chemical changes during 
 manufacture of, 319-321. 
 ,, ,, manufacture of, 264, 319. 
 ,, blubber see Oils (cetacean). 
 ,, body of see Viscosity. 
 , , boiled see Oils, drying (boiling 
 
 of). 
 
 ,, bone see Bone fat, 
 ,, bromine absorption of, 176-179. 
 ,, burning (lamp oils), 2, 5, 302, 
 
 312. 
 
 ,, injurious effect of free 
 
 acid on, 116,260,313. 
 
 ,, cetacean (blubber oils, train 
 
 oils), 6, 113, 116, 
 
 292, 293, 299, 360. 
 ,, ,, extraction of, 247. 
 
 ,, from toothed whales 
 
 yield spermaceti, 
 
 293, 300, 301. 
 
 ,, ,, separation of alco- 
 
 holiform constitu- 
 ents from, 121. 
 
 ,, ,, separation of sper- 
 
 maceti from, 300, 
 301, 360. 
 
 characteristic oxidation pro- 
 ducts of, 123. 
 ,, chemical changes during drying 
 
 of, 134-137. 
 
 ,, clarification of, by chemica] 
 
 processes, 254-263, 349. 
 
 ,, by filter presses and ordin 
 
 ary filters, 228, 255, 257 
 
 ,, ,, by standing in contact 
 
 with water, 344. 
 ,, classification of see Classifica 
 
 tion. 
 
 ,, cleansing of see Oils (refining) 
 ,, coaltar, 2, 5, 50, 328. 
 ,, cod, 294 see Oil (codfish, cod 
 
 liver). 
 ,, cohesion figures of see Cohe 
 
 sion figures. 
 
 cold drawn, 114, 212. 
 ,, colour of see Colour. 
 }} ,, reactions of see Coloui 
 
 reactions. 
 ,, congealing point of see Melt 
 ing points. 
 
 Oils, 
 
 553 
 
 cooking, 302-304. 
 creosote, 2, 328. 
 cylinder, 105, 128, 324. 
 dead, 324, 328. 
 decolorising of see Oils, 
 
 bleaching of. 
 
 dissolved impurities, 256. 
 dolphin, 293. 
 drying, 32, 33, 55. 
 boiling of, by air blowing 
 
 process, 314-316. 
 ,, ,, by free fire process, 
 
 314, 315. 
 
 ,, by oxygen process,321. 
 class, 281, 290. 
 decolorising high class, 268. 
 film test, Livache'stest, 133. 
 present in nonxlrying oils 
 in small quantity, 185, 
 282, 344. 
 
 ,, relative proportions of dif- 
 ferent glycerides in, 136, 
 290. 
 ,, used in paint manufacture, 
 
 &c., 313. 
 ,, ,, soft soapmaking 
 
 see Soapmaking. 
 drying of, chemical changes dur- 
 ing, 129, 134-137. 
 edible, 302-312. 
 elaidin test see Elaidin test, 
 effect of heat on, 125-128, 314. 
 light on, 130-132, 139, 
 
 149. 
 ,, polarised light see 
 
 Light (polarised), 
 electrical conductivity of, 53. 
 engine, 324. 
 essential, artificial, 6. 
 
 ,, natural, 2, 5, 20, 53. 
 ester numbers of see Ester 
 
 number, 
 examination of, general scheme 
 
 for, 124. 
 
 expression of, 303 see Presses, 
 extraction of, by solvents, 231- 
 
 244, 303. 
 ,, fish and liver, by 
 
 hot water, 248. 
 , , vegetable, fats, &c. , 
 by hot water, 200. 
 fish, 248, 259, 263, 294, 299. 
 ,, bleached by hot air, 264. 
 J} ,, bichromate, 265. 
 
 , , colour reactions of, 294. 
 ,, detection in linseed oil, 
 
 352. 
 
 ,, give unpleasant smell to 
 soft soap, 459. 
 
554 
 
 INDEX. 
 
 Oils, fish, used as adulterants, 348. 
 ,, ,, used for soapmaking, 408 
 
 see Soapmaking. 
 ,, fish liver, 247, 294, 408 see 
 
 also Oil (cod liver). 
 ,, fixed, 2. 
 ,, flashing points of see Flashing 
 
 point. 
 ,, free acid, number of see Acids 
 
 (free fatty). 
 
 fusel, C, 14, 20, 53. 
 ,, fusing points of see Melting 
 
 points. 
 
 ,, general nature of, 1. 
 ,, glyceridic, 3, 93, 281. 
 ,, ,, detected in sperm oil by 
 
 saponificatiou, 354. 
 ,, gumming of see Gumming. 
 ,, heat evolution with sulphuric 
 acid, 147-151, 341. 
 ,, ,, with sulphuric acid, 
 
 effect of light on, 
 131, 139. 
 ,, Hehner's test for see Hehner 
 
 number. 
 
 ,, herring, 294. 
 
 , , Hiibl's test see Iodine number, 
 ,, hydrocarbon, 2, 5, 54, 90 see 
 also Oils (mineral, paraffin, 
 coaltar). 
 
 ,, hydrolysis of see Hydrolysis. 
 ,, insoluble acid, number of see 
 
 Insoluble acid number. 
 ,, iodine number of (iodine absorp- 
 tion of) see Iodine number. 
 ,, kerosene, 2, 5. 
 ,, Koettstorfer's test see Total 
 
 acid number. 
 
 ,, lamp see Oils (burning). 
 ,', lesser known, 287-289. 
 ,, ,, some probably 
 
 valuable, 289. 
 ,, liver, 294see; Oils (fish liver, 
 
 shark liver). 
 
 ,, ,, colour reactions of, 294. 
 
 ,, ,, contain cholesterol and 
 
 biliary constituents, 292. 
 lubricating, 2, 5, 67, 321-330. 
 ,, ,, absorption of oxygen 
 
 by, 134, 329, 330. 
 ,, ,, analysis of, 328. 
 
 ,, ,, characters and be- 
 
 haviour of, 325, 326. 
 ,, ,, congelation of, 67,325. 
 
 ,, flashing points of 
 
 see Flashing point. 
 ,, ,, free mineral acids in, 
 
 260, 322 see also 
 Lubricants. 
 
 Oils, lubricating, manufacture of, 321- 
 
 328. 
 
 ,, ,, metallic soaps con- 
 
 tained in, 121, 324, 
 ,, ,, of fine quality from 
 
 degras, 337. 
 
 ,, ,, specific gravity of, 325. 
 
 ,, ,, spontaneous combus- 
 
 tion of, 133. 
 
 ,, ,, viscosity of see Vis- 
 
 cosity. 
 
 ,, ,, volatility of, 325. 
 
 ,, machinery, 128, 324. 
 ,, medicinal, 303. 
 ,, malabar, 294. 
 ,, melting points of see Melting 
 
 points. 
 ,, methyl iodide, test for see 
 
 Methyl number. 
 ,, mineral (petroleum, natural 
 
 naphtha), 2, 5, 25. 
 ,, ,, absorption of oxygen 
 
 by, 330. 
 
 flashingpointof,126-128. 
 lubricants containing, 
 
 322-330. 
 
 refraction of, 52. 
 relative price of, 342. 
 specific gravity of, 90,91. 
 use of, in early ages for 
 
 burning, 312. 
 ,, viscosity of, 105. 
 nitric acid on, action of see 
 
 Nitric acid test. 
 nitrous acid on, action of see 
 
 Elaidin reaction, 
 nondrying, 281. 
 
 ,, usually contain small 
 quantities of drying oils, 185, 
 282, 284, 344. 
 nonglyceridic, 3, 93, 282. 
 odour of see Odour, 
 order of price of, 342. 
 oxidation of sf e Absorption of 
 oxygen, Oils (blown), Oils 
 (drying), Gumming, 
 oxidised see Oxidised oils, 
 paraffin, 2, 5, 91, 313. 
 
 ,, in soap, 258 see Soap, 
 
 special kinds of. 
 petroleum see Oils (mineral), 
 phosphorised, from leguminous 
 
 plants, 123, 259. 
 polarised light, action of, 50. 
 porpoise, 293. 
 proximate constituents of, 110- 
 
 124. 
 
 purification (Noerdlinger's), 
 263. 
 
INDEX. 
 
 555 
 
 Oils, pyrene, 344. 
 
 ,, rancidity in see Rancid, Ran- 
 cidity. 
 
 ,, ray, 294. 
 
 ,, red see Red oils. 
 
 ,, refining of, 254-263. 
 
 , , refractive index of see Refrac- 
 tive index. 
 
 , , Reichert's test for seeReichert 
 number. 
 
 , , rosin see Rosin oils. 
 
 salad, 212, 257, 303, 344. 
 
 ,, ,, refined cotton seed oil 
 intermixed with, 267. 
 
 ,, saponaceous matters contained 
 in, 121. 
 
 ., saponifiable, 3, 6, 323. 
 
 ,, saponification number of see 
 Total acid number. 
 
 ,, saponitication equivalents of 
 see Saponitication equivalents. 
 
 seal, 293. 
 
 ,, ,, colour reactions of, 294. 
 
 semidrying, 286, 290. 
 
 ., ,, proportions between 
 
 different glycerides 
 in, 290, 291. 
 
 ,, separation of stearines from 
 see Stearines. 
 
 shale, 2, 5, 90, 91, 313, 322. 
 
 ,, shark liver, 247, 294, 403. 
 
 sod, 336. 
 
 ,, solidifying points of see Melt- 
 ing points. 
 
 , , soluble acid numbers of see 
 Soluble acid number. 
 
 ,, solubility in solvents of see 
 Solubility. 
 
 ,, specific gravity of, 76-94, 341. 
 ,,' e fleet of light on, 130. 
 
 ,, spindle, 128, 324. 
 
 , , spontaneous combustion of, 132. 
 
 ,, ,, oxidation of see 
 
 Spontaneous oxidation. 
 
 ,, standard, preparation of see 
 Standard. 
 
 ,, sulphur chloride on, action of 
 see Sulphur chloride. 
 
 ,, sulphocarbon, 344, 408. 
 
 ,, sulphuric acid on, action of 
 see Sulphuric acid. 
 
 ,, sulphurised, tests for, 123, 154. 
 
 ,, summer, 257, 304, 348. 
 
 ,, table see Oils (edible, salad, 
 virgin). 
 
 ,, taste of see Taste. 
 
 ,, tournantes see Huiles. 
 
 ,, total acid numbers of see 
 Total acid number, 
 
 Oils, train see Oils (cetacean). 
 class, 281, 292, 293. 
 Turkey red, 27, 42. 
 ,, ,, adulterations of, 334- 
 
 336. 
 
 ,, ,, analysis of, 332-336. 
 
 ,, ,, bibliography of, 331. 
 
 ,, ,, constitution of, 143- 
 
 147, 330, 331. 
 ,, ,, manufacture of, 330- 
 
 332. 
 
 ,, turret, 324. 
 ,, uses of, 302. 
 
 ,, unsaponifiable matters con- 
 tained in see Unsaponifi- 
 able matters. 
 vegetable, 281-285, 286-291, 
 
 295-298. 
 
 ,, ,, lesser known, 287. 
 
 ,, virgin, 304,344 see also Oils 
 
 (salad). 
 
 ,, viscosity of see Viscosity. 
 volatile, 2. 
 
 ,, ,, acids from see Vola- 
 
 tile acids. 
 
 ,, ,, number of see Vola- 
 
 tile acid number. 
 ,, vulcanised, 154. 
 ,, water contained in see Water. 
 ,, whale, 293 see Oils (cetacean). 
 ,, ,, colour reactions of, 294. 
 winter, 230, 257, 348. 
 ,, yield of, from seeds, &c. see 
 
 Yield. 
 
 , , , , fatty acids from, 76, 1 63. 
 
 ,, Zeisel's test for see Methyl 
 
 number. 
 , ,<- zinc chloride on, action of see 
 
 Zinc chloride. 
 Olberg, water bath, 61. 
 Olefjant gas, 26. 
 
 Olefines form glycols by oxidation, 44. 
 Olein (oleic triglyceride), 7, 11, 28, 
 
 110, 285. 
 ,, action of nitrous acid on see 
 
 Elaidin reaction. 
 ,, ,, sulphuric acid on see 
 
 Oils (Turkey red). 
 Oleine, candle see Red oils. 
 
 cokermit, 90, 92, 231, 283. 
 ,, palm kernel, 283. 
 Oleines (commercial products), 90, 
 
 92, 110, 285. 
 animal, 285, 299. 
 distilled, 110, 262, 277, 285, 
 
 324, 377. 
 
 ,, ,, hydrocarbons pre- 
 
 sent in see Hy- 
 drocarbons. 
 
556 
 
 INDEX. 
 
 Oleines, from wool grease, 276-279. 
 ,, Turkey red oils, 285. 
 ,, vegetable expressed, 110, 
 
 229, 257, 283. 
 
 Oleine soaps see Soapmaking. 
 Oleomargarine see Margarine. 
 Oleometer, Lefebre's, 79. 
 Oleonaphtha, 330. 
 Oleorefractorneter, 51-53, 347. 
 Oleostearine, 93. 
 Olive stearine, 230. 
 Olive trees, different species and 
 
 varieties of, 342. 
 Opderbeck, oxygen process, 321. 
 Open test (flashing point), 126. 
 Oudemauns, Kambutan tallow, 296. 
 
 ,, stearidic acid, 30. 
 
 Overbeck, oxidation of stearolic acid, 
 
 36, 45. 
 
 ,, oxyoleic acid, 41. 
 Ox tallow -see Tallow. 
 Ox, utilisation of fat of an, 311. 
 Oxalic acid from glycerol, 8, 519-522. 
 ,, acids from glycols by fusion 
 
 with potash, 18. 
 Oxidation during boiling, 125. 
 of aldehydes, 20, 25. 
 ,, of fatty acids during dry- 
 ing, 113. 
 of oils by light, 130-132, 
 
 139, 149. 
 
 ,, of oils during drying, 42, 
 129-137 see Absorption 
 of oxygen, Gumming. 
 ,, products of fatty acids, 19, 
 33/36, 40, 43. 
 ,, ,, characteristic, 
 
 128, 129. 
 
 ,, spontaneous see Spon- 
 taneous oxidation. 
 
 Oxidised oils (oils naturally contain- 
 ing oxygen), 3. 
 ,, (commercial; really are 
 
 sulphurised), 154. 
 ,, (linseed "skins" for 
 
 linoleum), 318. 
 
 , , (oils treated with oxidis- 
 
 ing materials), 42 
 see al*o Oils (blown, 
 and refining of). 
 
 Oxy acids formed during drying, 135. 
 Oxygen, absorption of see Absorp- 
 tion. 
 ,, addition to " unsaturated " 
 
 acids, 33, 36, 45. 
 Oxyoleates, 42, 332. 
 Oxyoleic acid, 41. 
 
 ,, mixed glyceride, 144. 
 Oxyolein, 139. 
 
 Oxystearic mixed glyceride, 144. 
 
 Ozokerite (solid mineral hydrocar- 
 bons, earthwax), 2, 5, 6, 88, 
 91, 364 see also Cerasin. 
 ,, used as beeswax adulterant, 
 359. 
 
 Paint, 135, 302. 
 Palmer, metallic wick, 394. 
 Palmieri, electrical conductivity, 53. 
 Palmitin (palmitic triglyceride), 11, 
 
 285. 
 ,, chief solid constituent of 
 
 olive oil, 344. 
 Palmitine (commercial product), 387, 
 
 407 see also Candle stearine. 
 Pans for boiling oil, soap, &c. see 
 Kettles, Decomposing pan, 
 Cooling pan, lie-melting pan, 
 Crystallising pan, &c. 
 ,, crutching soap, 438-442. 
 Paracholesterol, 18. 
 Paraffin wax see Wax (paraffin). 
 Paraphytosterol, 16, 17. 
 Paring machine (oilcake), 223. 
 Parings, edge runners for grinding, 
 
 220, 223. 
 
 Paris Municipal Laboratory, 65, 82. 
 Parnell, causticising under pressure, 
 
 413. 
 
 Paterson, spectrum colorimeter, 50. 
 Payne, glycerine manufacture, 515. 
 ,, melting points of distilled 
 
 fatty acids, 384. 
 Pea nut see Oil, arachis. 
 Pearlash, 409. 
 Pearlashing, 451, 479, 489. 
 Peh-la see Wax, Chinese. 
 Pelargonium, 20. 
 
 Pendulum machine, M'Xaught's, 94. 
 Pensky, flashing point apparatus, 127. 
 Perfumes, injurious effects of excess 
 
 of, in toilet soap, 480. 
 ,, oils used in extraction of, 
 
 302, 479. 
 
 ,, used for soap see Soap- 
 making (perfuming). 
 Permanganate, oxidation by, charac- 
 teristic pro- 
 ducts of, 128, 
 129. 
 ,, ,, of acrylic acids, 
 
 28, 30, 41-44. 
 
 ,, ,, of animal oils does 
 
 notformsativic 
 acid, 291. 
 
 ,, of linolenic acid, 
 37, 43, 128. 
 
INDEX. 
 
 557 
 
 Permanganate, oxidation of linolic acid 
 
 34, 35, 43, 128. 
 
 ,, ,, of ricinoleic acid, 
 
 40, 43, 129. 
 ,, ,, of stearolic acids, 
 
 33, 36, 45. 
 ,, ,, rule respecting, 
 
 44. 
 ,, wax bleached by 
 
 means of, 269. 
 Peroxide of hydrogen as bleaching 
 
 agent see Hydrogen peroxide. 
 Peters, linolic acid, 34. 
 
 ,, polarised light, 51. 
 Petroleum see Oil (mineral). 
 
 ,, ether (light petroleum spirit, 
 
 benzoline), 2, 5. 
 
 ,, ,, as solvent, 55, 115, 118- 
 124, 231, 236, 252, 
 262, 273, 275, 328, 
 329, 336, 337 see also 
 Soap analysis. 
 ,, ,, fatty acids insoluble in, 
 
 from boiled oil, 135. 
 ,, ,, preferable to ordinary 
 
 ether as solvent, 118, 
 120, 273, 275. 
 Phasol, 16, 259. 
 Pheasant grease, 298. 
 Phenol (carbolic acid) and homologues, 
 
 3, 6, 15, 16, 53. 
 
 ,, determination of, in soap, 506. 
 ,, extraction from coaltar, 230. 
 ,, use of, in disinfectant soaps 
 see Soaps, special kinds of 
 (carbolic, disinfectant). 
 Phenolphthalein as indicator, 23, 115- 
 
 117, 124, 328, 333, 359, 497. 
 Phlorol, 16. 
 
 Phosphorised constituents, 121. 
 Phosphorus, determination of, 124. 
 Physical properties of glycerol, 7. 
 
 ,, oils, &c., 47-109. 
 
 Phytosterol, 6, 16, 17, 240, 259. 
 
 , , determination of inoils, &c.,121. 
 Pichurim bean fat, 20. 
 Pickling soap bars, 438. 
 
 ,, wicks, 394, 395. 
 Pigments (mottled soap), 472. 
 Piston candlemoulding machines, 399, 
 Pitch, Burgundy, adulterant of bees- 
 wax, 359. 
 
 Pitch formed in Wilson's process, 381, 
 ,, from distillation of foots by 
 superheated steam 
 261. 
 
 ,, ,, of Yorkshire grease 
 
 by superheated 
 steam, 277. 
 
 'itchused as coarse lubricant,277,324. 
 :*liny, early soapmaking processes, 
 
 449. 
 
 'lotting (milled soap), 448. 
 ^lumbago (antifriction), 324. 
 3 ohl, melting points, 64. 
 oiseuille, viscosity, 107. 
 5 olariscope, polarised light see 
 
 Light, polarised. 
 D olishing candles, 406. 
 
 ,. soap tablets, 448. 
 ^olyglycerols, 8. 
 Polymerised fatty acids formed by 
 
 elaidin reaction, 139. 
 , , glycerides formed during 
 
 boiling and drying, 
 135, 318. 
 
 ,, oleo-oxystearic acid, 330. 
 
 ,, ricinoleic acids see 
 
 Acid, ricinoleic. 
 Pomades, lanolin used in making, 339. 
 
 ,, oils used in making, 302. 
 Porpoise blubber, extraction of oil 
 
 from, 247. 
 Potassium carbonate, causticising see 
 
 Causticising. 
 ,, ,, leys, alkalinity 
 
 of, 419. 
 
 ,, ,, used in Mege 
 
 Mouries pro- 
 cess, 308. 
 
 ,, ., used in pearl- 
 
 ashing see 
 Pear-lashing. 
 
 ,, ,, used in soap- 
 
 making see 
 Soapmaking. 
 
 ,, chloride, action on soda 
 
 soaps, 490, 491. 
 
 ,, ,, source of potash, 
 
 410. 
 Potash, action on brominated acids, 
 
 28. 
 
 ,, caustic (potassium hydroxide), 
 effect of fusion with see 
 Hydrogen. 
 
 ,, from sunflower seeds, 305. 
 leys, alkalinity of, 417, 419, 
 
 420. 
 
 ,, leys, preparation of, 411-414. 
 
 ,, neutralised see Free acid 
 
 number, Total acid number, 
 
 &c. 
 
 ,, quantity equivalent to soda, 
 
 425. 
 
 to fats see 
 Calculations. 
 
 ,, soaps, action of soda salts on, 
 451, 472, 473. 
 
558 
 
 INDEX. 
 
 Potash, use of, in refining oils,256,261. 
 
 ,, vegetable alkali, 409. 
 Potato fusel oils, 14. 
 Poullain and Michaud, zinc oxide 
 
 process, 379, 515. 
 
 Poutet, elaidin reaction seeElaidin. 
 Power requisite in oil mill, 215-217. 
 Precipitation processes (removing 
 
 mucilage, &c.), 255, 262, 263. 
 Press cake see Cold press cake, Hot 
 
 press cake, Separation cake. 
 Presses, cold see Cold press, 
 earlier forms of, 199. 
 elbow, 2U2. 
 hot see Hot press, 
 hydraulic, 207, 343. 
 pressure requisite in, 211. 
 screw, 205, 343. 
 wedge, 203. 
 Pressure, distillation under dimin- 
 ished see Distillation. 
 in autoclaves, 373. 
 ,, in oil presses, 211. 
 ,, rendering tallow under in- 
 creased, 250. 
 
 ,, soapmaking under in- 
 creased, 462-464. 
 Prices of oils, &c., 342. 
 Primrose soaps, 474, 509, 510. 
 Printing ink, 125, 317, 318. 
 Proximate constituents, 110-124. 
 
 ,, ,, information wanted 
 
 concerning, 113. 
 ,, ,, separation of, 111- 
 
 113. 
 
 ,, ,, variation with soil, 
 
 climate, &c., 111. 
 Pumps, soap, 434. 
 Pulfrich, refractometer, 51. 
 Purvis, waggon grease, 327. 
 Pyknometer, 77. 
 
 Pyramid drainage surface (filter- 
 press), 229. 
 night lights, 406. 
 
 Q 
 
 QUANTITATIVE reactions of oils, &c., 
 
 156-198. 
 tests for oils, tabulated, 
 
 194-198. 
 Quantity of alkali requisite for 
 
 saponification see Calculations. 
 Quebrachol, 16. 
 Quicklime -see Lime. 
 Quinquet, use of lamp chimneys, 313. 
 
 EADISSON, palmitic acid process, 387. 
 
 Railway grease see Lubricants. 
 Rancid tallow, &c., cleansing of, 
 
 256, 260, 261, 265, 310. 
 Rancidity, 10, 49, 69, 255. 
 
 ,, due to oxidation, 132. 
 ,, light promotes, 132. 
 ,, produces much free fatty 
 acid, 10, 114, 255, 355. 
 Rape seed (colza, cole seed), various 
 
 species of, 348. 
 Raphigaster, 25. 
 Rational Beaume scale, 86. 
 Raw oils, 313 see Oils (drying). 
 Reaction, specific temperature, 149. 
 Reactions of oils, &c., quantitative, 
 
 156-198. 
 
 Reaumur scale, 57, 58. 
 Recovered greases .see Grease. 
 Red oils (crude oleic acid, candle 
 
 oleine), 110, 231, 285. 
 analysis of, 375, 378. 
 expression of, 231, 370. 
 filter cake see Filter cake, 
 palmitic acid from, 387. 
 soap from see Soapmaking 
 unsaponified grease in see 
 
 Unsaponified fat. 
 ,, utilisation of, 386-388. 
 ,, yield from ox fat, 311, 312. 
 Redwood, viscosimeter, 98. 
 
 ,, ,, results obtained 
 
 by, 101-105. 
 Refining oils, &c., 254-263. 
 
 ,, acid processes, 259, 349. 
 
 alkaline 260, 349. 
 
 ,, ,, process removes free 
 
 acids, 12, 115, 260, 322. 
 , , by treatment with water, 344 
 ,, Hartley and Blenkinsop's- 
 
 process, 263. 
 
 ,, Noerdlinger's process, 263 
 , , precipitation processes, 262. 
 ,, virgin oils, 304. 
 Reformatsky, linolic acid, 34, 35. 
 Refractive index, refractometer, 51 ,. 
 
 341. 
 Reichert's test (Reichert number), 23, 
 
 53, 157, 195, 341. 
 ,, mode of working, 173-176. 
 Reichert-Meissl test, 174, 195. 
 Reichert- Wollny 175. 
 Reichl, test for glycerol, 8, 516. 
 Reimer and Will, dierucin, 11. 
 
 ,, rapic acid, 41. 
 
 Relative density see Specific gravity. 
 
 ,, viscosity see Viscosity. 
 Remelting pans, 441-443. 
 Renard, test for arachis oil, 344. 
 Rendering animal fats, 245.-251. 
 
INDEX. 
 
 559 
 
 4tf S 
 
 Resin (pine) see Rosin. 
 
 ,, used for early torches, 312. 
 Resinate of soda, 450, 453. 
 
 , , calculations respect- 
 
 ing, 455, 465. 
 
 ,, useofjinsoapmaking 
 
 see Soapmaking ; 
 Soap, special kinds 
 (yellow soap). 
 Resinous constituents of oils, 118. 
 
 ,, ,, removal of, from 
 
 oils, 255, 256, 
 260, 262, 322. 
 Resins and resinoid bodies, 3, 25. 
 
 ,, ,, used as beeswax 
 
 adulterants, 359. 
 
 Richards, testing liability to spon- 
 taneous inflammability, 133. 
 Richardson and Watts, railway 
 
 grease, 327. 
 
 Richmond, density of glycerol solu- 
 tion, 517. 
 
 Ricinelaidin, 40, 137. 
 Ricinolein (ricinoleic triglyceride), 
 ,, action of nitrous acid on, 137. 
 ,, distillation of, 40. 
 Rideal, viscosity of gum solutions, 
 
 108. 
 Ritsert, causes of rancidity, 132. 
 
 ,, glycerine testing, 515. 
 Rock see Candle stearine. 
 Rolls see Crushing rolls. 
 Rose, Down and Thompson, oil press 
 
 machinery, 215. 
 
 Rosin, (colophony), 88, 92, 118, 178. 
 ,, action of sulphur chloride on, 
 
 156. 
 ., admixed with thickened oils, 
 
 &c., 142. 
 ,, adulteration of linseed oil 
 
 with, 352. 
 
 ,, ,, of beeswax with, 359. 
 ,, manufacture of resinate of 
 
 soda, 453. 
 ,, use in making lubricating 
 
 greases, 327-329. 
 
 ,, soapmaking see Soap- 
 making. 
 
 ,, window glass, 474. 
 Rosin oils, 2, 92. 
 
 ,, ,, absorption of oxygen by, 
 
 330. 
 ,, ,, action of, on polarised 
 
 light, 50. 
 ,, ,, adulteration of linseed 
 
 oil with, 352. 
 ,, ,, detection of, in Turkey 
 
 red oils, 335. 
 ,, fluorescence of, 50. 
 
 Rosin oils, refractive index of, 52. 
 
 ,, ,, relative price of, 342. 
 
 ,, ,, solubility in glacial acetic 
 acid, 55, 57, 329. 
 
 , , , , use of, in preparing lubri- 
 cants, 322-324, 327-329. 
 
 ,, ,, viscosity of, 105. 
 Rotation of polarised light see Light 
 
 (polarised). 
 Roy an, candle moulding machine, 
 
 398. 
 
 Riidorff, melting points, 69. 
 Rule followed in oxidation, 44. 
 Rush lights, rush pith wicks, 312, 362 r 
 
 390. 
 
 Russian mineral oils (viscosity), 105. 
 Rutschmann, stripping machine, 446. 
 
 SAKE, grease recovery, 272. 
 Salad oils see Oils (salad), 
 alt as source of alkali (soda), 410. 
 ,, in butter, &c., 123, 307. 
 Salting out, 23, 33, 54. 
 
 ,, in refining oils, &c., 256. 
 
 ,, in soapboiling see Soap- 
 
 making. 
 
 ,, in Turkey red oil mak- 
 
 ing, 331. 
 
 Sand, use of, in clarifying oils, 255. 
 Sanza (olive marc), 343. 
 Saponaceous matters in oils, &c., 121- 
 
 124, 135, 315, 324, 328, 347. 
 Saponitication by alkaline carbonates,. 
 
 409, 410. 
 Saponification equivalents, 33, 158, 
 
 194, 341. 
 ,, ,, determination of r 
 
 161-170. 
 
 ,, ,, of glycerides ex- 
 
 ceed mean equi- 
 valents of acids 
 by 12-67, 165. 
 
 ,, in three stages, 468. 
 
 , , number see Total acid: 
 
 number. 
 
 ,, quantity of ley requisite- 
 
 for see Calculations. 
 
 Saponification, typical reactions of,. 
 
 3-5. 
 
 Saponin, 297. 
 
 Sarg, utilisation of fat of an ox, 311. 
 Saturated hydrocarbons see Hydro- 
 carbons. 
 
 Saturation, fractional, 112, 113. 
 Saytzeff, dioxystearic acids, 28, 30, 
 41, 42, 46, 129. 
 
560 
 
 INDEX. 
 
 Saytzeff, oxystearic acids, 38, 39. 
 , , use of mercuric bromide in 
 
 Hiibl's test, 179. 
 Scales, hydrometer, 84-86. 
 ,, thermometer, 57-60. 
 Schadler, amounts of fatty matter in 
 
 seeds, &c, 241-244. 
 ,, cohesion figures, 49. 
 ,, colour reactions, 154, 294. 
 ,, distillation with superheated 
 
 steam, 383. 
 
 ,, hydrometer scales, 85. 
 ,, iodine numbers, 182. 
 ,, melting points, 67-70. 
 ,, nonexistence of doeglic acid, 
 
 24. 
 
 ,, polarised light, 50. 
 , , Reichert-Meissl numbers, 1 74 
 ,, Roy an's candle moulding 
 
 machine, 398. 
 ,, solubilities, 54, 55. 
 ,, specific gravities, 87. 
 ,, total acid numbers, 160. 
 ,, unsaponifiable matters, 257. 
 ,, yield of linseed oil, 351. 
 ,, ,, rape seed oils, 348. 
 
 Schepperand Geitel, melting points. 76 
 ,, separation cake, 376. 
 Scheme for examination of oils, 124. 
 
 , , , , soaps, 506. 
 
 Scheurer Kestner, Turkey red oils, 
 
 146, 333. 
 
 Schlink, deodorising cokernut oil,310. 
 Schmid, viscosimeter, 95. 
 Schmidt's process (zinc chloride and 
 
 oleic acid), 142, 386. 
 Schmitz and Toenges, oxyoleates, 332, 
 Schnaible, toluene as solvent for wax 
 
 in soap, 496. 
 
 Schfin, hypogseic acid, 24. 
 Schroder, oxyhypogseic acid, 41. 
 ,, palmitoxylic acid, 45. 
 ,, see Grills and Schroder. 
 Schiibler, viscosimeter, 95. 
 
 results with, 102. 
 Schuler, linoleic acid, 33. 
 Scotch mineral oils, viscosity of, 105. 
 Scourtins (oil extraction), 204. 
 Scraps from ox fat, 311. 
 Screens for sifting seeds, &c., 223. 
 Screw presses, 205-207. 
 Scribe for marking soap blocks, 437. 
 Seal blubber, extraction of oil f rom,247 
 Sealing wax, 302. 
 
 Sea weed jelly (antifriction), 324, 328. 
 Seed crushing see Oil mill plant, anc 
 
 Crushing rolls. 
 
 Seeding (of press cake) see Separa 
 tion cake. 
 
 seeds, determination of fat in, 237. 
 , , yield of fatty matter from, 241- 
 
 244. 
 
 eibel, sulphurised lanolin, 339. 
 teltsam, bone fat extraction process, 
 
 253, 254. 
 
 Separation of fatty acids, 112, 113. 
 ,, proximate constituents, 
 
 111. 
 
 Separation cake, (press cake), 311. 
 ,, analysis of , 375, 378. 
 
 ,, seeding (granula- 
 
 tion, crystallisa- 
 tion) of, 355, 367- 
 'Shale oils see Oils (shale). 
 Shark livers, extraction of oils from, 
 
 247. 
 
 Shaving cream. 483. 
 Shea butter see Butters, vegetable 
 
 (Shea). 
 Q heep's tallow see Tallow. 
 
 hoddy scourings, grease from, 276. 
 Silver, bromostearate, action of water 
 
 on, 25, 30. 
 ,, hydroxide, action on bromin- 
 
 ated acids, &c., 27, 30, 41, 43. 
 ,, nitrate test, 152-154. 
 ,, test(Becchi's) seeBecchi's test. 
 Skalweit, density of glycerine solu- 
 tion, 516, 517. 
 
 Singer and Judell, wool scouring, 337. 
 Skimmer pipe (soap kettle), 433, 434. 
 Skins from drying oils, 135, 381. 
 , , tanning and currying, 302, 336. 
 , tender, injurious effects of 
 alkaline, highly perfumed, 
 and sugared soaps on see 
 Soap, alkaline ; Soap, special 
 kinds of (transparent; highly 
 scented). 
 Slabbing soap, 437, 438, 444. 
 Smith, Watson, wool scouring, 337. 
 Soap, alkaline, calculations respecting 
 excess of alkali in, 454, 464. 
 ,, ,, degree of alkalinity judged 
 
 by tongue, 510. 
 
 ,, ,, injurious effects of, on ten- 
 der skins, 458, 479. 
 ,, ,, ,, on wool, silk, &c.,. 
 
 453, 461. 
 Soap analysis 
 
 Cailletet's method, 507, 508. 
 Calcium salt test, 508. 
 Classification of toilet soaps, 512. 
 Determination of actual soap, 492, 
 
 493. 
 
 ,, ,, calcula- 
 
 tion respecting, 493. 
 of alcohol, 505, 506. 
 
INDEX. 
 
 561 
 
 Soap analysis 
 
 Determination of average molecular 
 weight of fatty acids, 
 172, 494. 
 ,, crude fatty acids, 492, 
 
 493, 496, 506. 
 fatty anhydrides, 493,496, 
 
 497, 50(5. 
 ,, free alkali, 492, 497-501, 
 
 507, 512. 
 ,, ,, as caustic, 498-500, 
 
 507. 
 
 ,, ,, ascarbonate,500,507. 
 ,, ,, by alcohol test, 498. 
 ,, ,, by fatty acid titra- 
 
 tion test, 499. 
 .,, ,, by salting out test, 
 
 500. 
 
 ,, , by salting out test, 
 excess found by, 
 500. 
 
 ,, glycerol 494, 504-506, 512. 
 ,, hydrocarbons (paraffin, 
 &c.), 258, 495, 496,506. 
 ,, mineral weighting ad- 
 mixtures (China clay, 
 steatite, &c.), 494, 504, 
 507. 
 
 .,, organic weigh ting admix- 
 tures (starch, oatmeal, 
 sawdust, &c.), 494, 
 504, 507. 
 ,, phenol and phenoloids, 
 
 506. 
 
 ,, pigments, 504. 
 potash, 501, 506. 
 , , rosin acids, 474, 497, 506, 
 
 508. 
 
 .,, ,, by Gladding's pro- 
 
 cess, 485, 501, 
 502, 511. 
 
 ,, ,, ,, sources of er- 
 ror in, 502. 
 
 ,, ,, by modified Glad- 
 ding's process, 502. 
 .,, ,, bv Twitchell's pro- 
 cess, 503, 504, 511. 
 .,, salts (sulphates,chlorides, 
 &c.), 494, 497, 499, 506, 
 507. 
 
 , , silicate, 494, 497, 504, 507- 
 soluble acids, 496, 497, 
 
 499 
 
 sugar, 494, 504-506. 
 , , total alkali, 492, 493, 496, 
 
 497, 506. 
 
 ,, unsaponifiable matters 
 119, 258, 492-495, 497, 
 506. 
 
 Soap analysis 
 Determination of unsaponified fat, 
 
 492, 495-497, 506. 
 ,, volatile matters, 505. 
 water, 494, 495, 506. 
 ,, waxy matters (beeswax, 
 spermaceti, cholesterol, 
 &c.), 495, 496,506. 
 General schemes, 494, 506, 507. 
 Typical results ( manufacturers', 
 pharmaceutical, toilet, soft soaps, 
 &c.), 508,511. 
 Soap, bleaching dark coloured, 267. 
 
 chemistry of, 484-492. 
 Soap factory plant, 426-448. 
 Crutchincr pans, 438-441. 
 Curbs, 432, 433. 
 Cutting appliances, 437, 438. 
 Fan, 433, 434, 460. 
 Frames, 434-437, 444. 
 Kettles (coppers, pans) see Ket- 
 tles. 
 
 Milling machinery, 446. 
 Plotting machinery, 448. 
 Pumps, 434. 
 
 Remelting pans, 441-443. 
 Slabbing and barring machines, 
 
 437, 438. 
 
 Stamping machines, 444, 445. 
 Steam twirl, 428 see also Morfit. 
 Stripping machine, 446. 
 Soap, fused, reaction of salts, &c. , on, 
 
 451, 473, 488-492. 
 ,, ,, alkaline carbonates 
 
 on, 451, 489, 490 
 see also Pearlashing. 
 historical references to, 449. 
 hydrolysis of, 486-488. 
 
 ,, Wright and Thompson's 
 
 experiments, 487. 
 leaves, 483. 
 powders, 477. 
 saline matters in, calculations 
 
 respecting, 455, 465. 
 Soap, special kinds of 
 Aluminated, 451, 475. 
 Bleached palm oil, 508. 
 Borax, 451, 475. 
 Castile, 467, 472, 508. 
 Carbolic, 451, 477. 
 Carbonated, 451, 462, 475, 477 
 
 see also Pearlashing. 
 Cold water, 477, 509, 510. 
 Curd see Soapmaking. 
 ,, amount of water present in, 
 
 470. 
 
 ,, analysis of, 508, 510. 
 Dealkalised (neutralised), 453, 461, 
 480, 481, 483, 484. 
 
 36 
 
562 
 
 INDEX. 
 
 Soap, special kinds of 
 
 Disinfectant ( carbolic, cresylic, 
 naphthol, sanitas, terebene, &c.), 
 451, 476, 477. 
 
 Emollient (containing lanolin, sper- 
 maceti, vaseline, wax, &c. ), 448, 
 478, 479. 
 
 Fancy see infra (Toilet). 
 
 Filled see Soapmaking (tilling). 
 
 Fitted see Soapmaking (fitting). 
 ,, amount of waterpresentin, 470. 
 
 Floating, 441. 
 
 Glycerine, 458. 
 
 ,, containing additional 
 glycerol, 458, 479, 482, 512, 513. 
 
 Harlequin, 483. 
 
 Highly scented, injurious action of, 
 480, 512. 
 
 Ivory, 509. 
 
 Little pan, 479. 
 
 Marbled, 483. 
 
 Marine see Soapmaking. 
 ,, analysis of, 508, 509. 
 
 Marseilles, 407, 472, 508, 509. 
 
 Medicinal (creosote, cresylic, ich- 
 thyol, iodine, mercurial, naph- 
 thol, sanitas, sulphur, terebene, 
 &c.), 477. 
 
 Metallic see Metallic soaps. 
 
 Milled, 446-448, 457, 479, 480, 511. 
 
 Mottled see Soapmaking. 
 
 ,, amount of water present 
 in, 472. 
 
 Neutralised see supra (Dealka- 
 lised). 
 
 Normandy, 475. 
 
 Oil (red oil, oleine) see Soap- 
 making. 
 
 Old brown Windsor, 480. 
 
 ,, ,, modern inferior 
 
 kinds of, 481. 
 
 Oleine see Soapmaking. 
 ,, analysis of, 509, 510. 
 ,, contains hydrocarbons, 258, 
 279, 496. 
 
 Olive, 467, 472, 508. 
 
 Paraffin and petroleum, 458, 476. 
 
 Perfumers', 450, 456, 479. 
 
 Pharmaceutical, 510. 
 
 Phpsphated, 476. 
 
 Primrose see infra Rosin soap. 
 
 Remelted and blended toilet, 441, 
 478. 
 
 Rosin (yellow), 450, 451, 453, 473, 
 
 474, 509. 
 ,, calculations respecting, 455, 
 
 465. 
 
 French process, 473. 
 primrose, 474, 509, 510. 
 
 Soap, special kinds of 
 
 Rosin, primrose, analyses of, 509, 
 
 510. 
 
 Sand (brickdust, emery, fullers' 
 earth, kaolin, pipeclay, pumice- 
 stone, &c.), 476. 
 Shaving cream, 483. 
 Silicated, 451, 453, 462, 472, 474, 
 
 475. 
 ,, calculations respecting, 
 
 455, 4(55. 
 
 ,, objectionable for wool 
 scouring and laundry 
 purposes, 461, 475. 
 ,, wastes less rapidly, 475. 
 Soft see Soapmaking. 
 Starch (oatmeal, bran, cornflour, 
 dextrine, gluten, Iceland moss, 
 sawdust, &c. ), 477. 
 Sugared see infra Transparent. 
 Sulphated, 451, 475. 
 Superfatted, 478, 479. 
 Toilet (fancy), 409, 441, 478-480. 
 ,, analyses of, 511. 
 
 ,, classification of, 512. 
 
 Tooth, 476. 
 Transparent, cold process, 450, 458, 
 
 476, 482. 
 
 ,, - ,, analysis of, 511. 
 
 ,, ,, calculations re- 
 
 specting, 465. 
 
 ,, ,, injurious effects 
 
 on tender skins, 
 
 458, 459, 480, 
 
 482, 512. 
 
 ,, ,, sugared, 458, 480, 
 
 482, 511, 512. 
 
 ,, ,, transparency in- 
 
 creased by alco- 
 hol, glycerol, 
 sugar, 458, 481. 
 ,, spirit process, 445, 446, 
 
 458, 474, 482. 
 
 ,, ,, analyses of, 511. 
 
 ,, ,, distillation of 
 
 spirit, 446, 482. 
 White Windsor, 481. 
 Wool scouring, 458. 
 Soap, water in, calculations, respect- 
 ing, 454, 464. 
 
 ,, determination of see 
 
 Soap analysis (water). 
 Soapmaking, classification of pro- 
 cesses direct neutralisa- 
 tion, 450-456. 
 ,, glycerides used and glycerol 
 
 retained, 450, 456-466. 
 ,, glycerides used and glycerol 
 eliminated, 451, 466-473. 
 
INDEX. 
 
 563 
 
 Soapmaking, factory operations 
 Cleansing curd, 467. 
 Crutching, 438-440, 441. 
 Cutting, slabbing, and barring, 437, 
 
 438, 444, 449. 
 Dealkalising see Soap, special 
 
 kinds of (dealkalised). 
 Drying, 438, 447. 
 Filling (loading), 438,450, 458, 462, 
 
 465, 472, 476, 483, 511. 
 Fitting, 451, 467, 470, 471. 
 Framing, 434-437, 444, 449. 
 Graining (cutting the soap ; salting 
 out), 54, 413, 433, 450, 469, 
 485. 
 Killing see infra Manufacture of 
 
 curd. 
 
 Loading see supra Filling. 
 Manufacture by cold process, 450, 
 457, 513 
 
 ,, ,, calculations 
 
 respecting, 464-466. 
 
 ,, by old German process, 
 
 449, 451, 472, 473. 
 ,, of curd soap, boiling for 
 curd, 451, 467-470. 
 ,, ,, analysis of curd 
 
 soap, 508, 510. 
 ,, of fitted soaps see supra 
 
 Fitting. 
 ,, of hydrated soap, 450, 
 
 456, 461. 
 ,, ,, (Swiss soap, Esch- 
 
 wegeSeife),461. 
 ,, ,, under pressure, 450, 
 
 456, 461. 
 ,, of marine soap, 450, 456, 
 
 461, 508, 509. 
 ,, of milled soap see infra 
 
 Milling. 
 ,, of mottled soap, 451, 466, 
 
 471, 472, 509. 
 
 ,, ,, modern inferior 
 
 kinds, 467, 472. 
 
 ,, of oleine soap (oil soap), 
 
 258,451-453. 
 
 ,, analyses of, 509, 510. 
 ,, ,, calculations respect- 
 ing, 454-456. 
 
 ,, of resinate of soda, 453. 
 ,, of soft soap, 450, 456, 
 
 459, 466. 
 
 ,, ,, analyses of, 510. 
 
 ,, of transparent soap see 
 Soap, special kinds of 
 (transparent). 
 
 ,, of yellow soap (rosin soap) 
 see Soap, special 
 kinds of (rosin). 
 
 Soapmaking, factory operations 
 Milling, 446, 457, 479, 480. 
 Pearlashing, 451, 479, 489. 
 Perfuming (scenting), 441,444,448, 
 
 457, 478-480, 483, 512. 
 Pickling bars, 438. 
 Plotting, 448. 
 
 Preparation of leys, 411-426 see 
 also Alkali, Alkalinity, Caus- 
 
 ticising, Potash, Soda. 
 ,, calculation of quantity re- 
 quisite for saponification, 
 421-426. 
 
 Kernel ting, 441-443, 478. 
 Running off spent leys, 428, 432, 
 
 433, 469. 
 
 Salting out see supra Graining. 
 Slabbing and barring, 437, 444, 449. 
 Stamping tablets, 444, 445, 449. 
 Stripping, 446. 
 Tinting, 441, 479. 
 Soapmaking, raw materials for, 302, 
 
 408-411. 
 Soaps, colonial, 509. 
 
 ,, commercial (manufacturer's, 
 
 laundry, &c.), composition 
 
 of, by analysis, 508-510. 
 
 , , discoloration of, 266, 356, 479. 
 
 ,, discoloured, bleaching of, 267. 
 
 ,, ingredients in lubricating 
 
 ' mixtures, 324-329. 
 ,, jellifying of, 485. 
 ,, manufacturers see Soaps, 
 
 commercial. 
 
 ,, metallic see Metallic soaps. 
 , , mixed, formed from mixture of 
 acids and excess of alkali, 491. 
 ,, salting out from solution 
 (Whitelaw) see Soapmak- 
 ing (graining), 486. 
 ,, solubility in water, &c., 485. 
 ,, toilet, classification of, accord- 
 ing to free alkali, 512. 
 ,, ,, composition of, by 
 
 analysis, 511. 
 Soapsuds, recovery of grease from 
 
 see Grease. 
 Soap test, Clark's (water hardness), 
 
 485, 508. 
 Soda ash, 410. 
 ,, causticising see Causti- 
 
 cising. 
 
 ,, caustic (sodium hydroxide),410. 
 
 colour test, 151, 153,352. 
 
 ,, ,, effect of fusion with 
 
 (soda lime) see 
 
 Hydrogen. 
 
 ,, ,, leys, alkalinity of, 414- 
 
 416, 419, 420. 
 
564 
 
 INDEX. 
 
 Soda, caustic leys, employment in 
 soap boiling see 
 Soapmaking. 
 ,, ,, ,, preparation of, 411- 
 
 414. 
 
 ,, ,, ,, quantity equiva- 
 
 lent to fats see 
 Calculations. 
 
 ,, ,, ,, storage of, 412. 
 
 ,, ,, ,, variation of density 
 
 of, with tempera- 
 ture, 416. 
 
 ,, ,, manufacture of, 410. 
 
 ,, ,, use in making waggon 
 
 grease, 327. 
 
 ,, ,, refining oils, 260, 261. 
 
 ,, crystals, fused, use in oil re- 
 fining, 260. 
 
 ,, degrees see Degrees. 
 ,, quantity equivalent to potash, 
 
 425. 
 ,, trade, British custom as to 
 
 alkalinity, 420. 
 Sodium carbonate, action on potash 
 
 soaps, 488-490. 
 ,, as lard adulterant, 306. 
 , , direct use in soapmaking, 
 
 409, 433, 453, 463. 
 leys, alkalinity of, 418 
 see also Caustic soda. 
 ,, use in making waggon 
 
 grease, 327. 
 ,, use in refining oils, 256, 
 
 261. 
 Sodium chloride, action on potash 
 
 soaps, 451, 473, 490. 
 ,, silicate, manufacture of, 463. 
 ,, sulphate, Leblanc process, 410. 
 ,, ,, used in refining oils, 256. 
 Soft soap see Soapmaking. 
 Softening point, 61. 
 Solar stearine see Stearine (lard). 
 Solutions for chilling baths, 67. 
 Solid adulterants of fats, &c., 123. 
 Solidification points see Melting 
 
 points. 
 
 Soluble acid number, 168, 195. 
 Solubility of blown oils, 320. 
 
 of fatty acids in alcohol, '23. 
 , , in water, 23. 
 of lead salts in ether see 
 
 Ether. 
 
 of oils, &c., in alcohol, 54. 
 ,, in glacial acetic acid, 
 55-57, 329, 347, 349. 
 , , in water, 53, 54. 
 Solubility of oils in various solvents, 
 
 55, 341. 
 ,, of wax in various sol vents, 359. 
 
 Solvents, extraction of oils by means 
 
 of, 114, 231-244, 303. 
 , , for oils, &c. see Solubility. 
 ,, oils used as, for odorous 
 
 matters, 302. 
 
 ,, treatment of wool with, 337. 
 Souche're, adulteration of olive oil, 345. 
 Soxhlet's tube, 119, 238. 
 
 ,, modifications of, 239. 
 
 Specific gravity of alkaline leys, 415- 
 
 419. 
 
 ,, caustic soda, effect of 
 temperature on, 416. 
 ,, lubricating oils, 325. 
 ,, oils, &c., 76-94, 341. 
 ,, ,, effect of light on, 130. 
 ,, ,, ,, temperature 
 on, 79, 92-94. 
 
 Specific temperature reaction, 149. 
 Spectroscope, absorption, 50. 
 Spermaceti, 4, 14, 21, 292, 302, 353, 
 
 359-361. 
 
 ,, added to soaps, 448. 
 
 ,, adulterations of, 360. 
 
 ,, candles see Candles 
 
 (sperm). 
 
 ,, chiefly obtained from oils 
 
 of toothed whales, 293, 
 300, 301. 
 class, 282, 301. 
 ,, foots, 261, 360. 
 
 ,, free cetylic alcohol in, 
 
 116, 171, 361. 
 
 ,, iodine absorption of, 182. 
 
 refining, 261, 360. 
 
 ,, saponification equivalent 
 
 of, 161. 
 
 ,, various physical proper- 
 
 ties of, 68-70, 88, 91-93, 360. 
 Spills, manufacture of, 407. 
 Spirit oil (Yorkshire grease dis- 
 tillation), 277, 278. 
 Spirit soap (transparent) see Soap- 
 making ; Soap (special kinds). 
 Spontaneous combustion, 132. 
 
 , , oxidation, 42, 1 1 3, 1 29 1 37, 323. 
 ,, ,, more rapid under influence 
 
 of light, 130-132. 
 Square soap kettles, 433. 
 Squirting soap, 448. 
 Stamping machines, 444, 445. 
 Standard candles (sperm), 402. 
 
 ,, oils, preparation of , 213, 340. 
 ,, water as, specific temperature 
 
 reaction, 149. 
 
 Standards of comparison, oils and 
 mixtures, &c. , 340, 346. 
 ,, efflux viscosity, 101. 
 specific gravity, 78, 89. 
 
INDEX. 
 
 565 
 
 Stannic chloride, colour test, 151. 
 Starch as adulterant of beeswax, 359. 
 ,, fats, 123, 307, 355. 
 
 Starch in soft soap, 459. 
 Steam, distillation with see Distilla- 
 tion. 
 
 ,, dry, 428-433, 459. 
 ,, kettles heated by, 428, 432, 
 
 433, 441, 452, 459. 
 ,, twirl (Morfit's) see Morfit. 
 ,, wet, 428-433, 459. 
 Stearic aldehyde, 1 4. 
 Stearin (stearic triglyceride), 4, 11, 
 
 110, 285. 
 Stearine, beef, 307, 309. 
 
 . , candle ste Candle stearine. 
 
 ,, candles see Candles. 
 
 ,, cokernut, 91, 92, 231, 283, 
 
 305, 3G3. 
 
 ,, ,, use for nigh tlights, 
 
 candles, &c.,~363, 
 364, 407. 
 
 cotton seed, 91, 184, 230, 
 295, 304, 305, 
 307, 354. 
 
 ,, ,, socalled, from distilla- 
 
 tion of foots, 262, 305. 
 ,, French, 365. 
 ,, lard (solar stearine), 93, 
 
 231, 307. 
 olive, 230. 
 ,, tallow (pressed tallow), 231, 
 
 361, 407. 
 
 ,, yield from ox fat. 311, 312. 
 Stearines (commercial products), 88, 
 
 91-93, 230, 285. 
 distilled, 110, 262, 277, 305, 
 
 324. 
 
 ,, ,, adulteration of 
 
 tallow with, 355. 
 
 ,, ,, from cotton seed 
 
 foots, 262, 305. 
 
 ,, ,, from Yorkshire 
 
 grease, 277, 355. 
 
 ,, ,, useinsoapmaking, 
 
 450. 
 
 , , expressed from natural oils, 
 &c., 11 0,229, 257, 
 305, 309, 407. 
 
 ,, ,, used as lard adul- 
 
 terants, 307. 
 
 ,, ,, . ,, as tallow 
 
 adulterants, 354. 
 
 ,, from animal oils and fats, 
 
 230,231, 307, 311. 
 
 Stearolactone, 30, 39, 143,262,273,384. 
 , , correction for presence 
 
 of, 170, 273. 
 Stearyl cyanide, 21. 
 
 Steatite added to soft soap, 459. 
 
 ,, (antifriction), 324. 
 Stein, Berge", and de lloubaix, sul- 
 phurous acid process, 380. 
 Stereochemical isomerism, 29. 
 Stills see Distillation. 
 Stoddart, nitric acid test, 140. 
 Storax, 16, 19. 
 Stripping (soap), 446. 
 Strohmer, density of glycerol solu- 
 tion, 517. 
 
 ,, refractive index, 51. 
 Stiircke, Carnauba wax derivatives, 
 
 18, 37. 
 
 Substitution derivatives, bromo, 26- 
 28, 30, 31, 34, 38, 
 41, 42, 45, 176. 
 ,, ,, chloriodo, 177. 
 
 ,, chloro, 30-32,267,364 
 ,, iodo, 26, 27, 30, 31, 
 
 38, 177 see also 
 Iodine number. 
 Sudcake, 272. 
 Suds, grease recovered from see 
 
 Grease. 
 
 Sugar in toilet soaps see Soap, 
 
 special kinds (transparent). 
 
 ,, test for sesame oil, &c., 153, 
 
 346 352. 
 
 Suet, 55, 70,' 91/161, 164, 181, 298. 
 Suint, 337. 
 
 Sulphur, adulterant of beeswax, 359. 
 ,, candles, 407. 
 
 , , chloride reaction, 154-156,341 . 
 dioxide (liquefied) as solvent, 
 
 236. 
 ,, ,, use in candle stearine 
 
 making, 369, 370. 
 ,, trioxide, use of, in bleaching 
 
 oils, 264. 
 
 Sulphuric acid, action on glycerol, 144. 
 ,, ,, isoleic acid, 38. 
 
 ,, ,, oleic acid, 27, 29. 
 
 ,, ,, olein and ricin- 
 
 olein see Oils 
 (Turkey red). 
 
 ,, colour reactions with oils, 
 
 151-153, 294, 341,352,354. 
 
 ,, decomposing rock by, 366. 
 
 ,, heat evolved by see Oils 
 
 (heat evolution). 
 ,, preparation of, of constant 
 
 strength, 148. 
 
 ,, presence of, in oils, &c., 123. 
 ,, reaction with cholesterol 
 
 and allied bodies, 17. 
 ,, refining with, 123, 255, 259. 
 ,, removal of lime salts from 
 bone fat by, 256. 
 
566 
 
 INDEX. 
 
 Sulphuric acid, saponificatioii by, 143, 
 
 145, 380-382. 
 ,, test for hydrocarbons in 
 
 beeswax, 359. 
 ,, use of, in finishing hot 
 
 press cake, 368. 
 ,, ,, in rendering tallow, 249. 
 ,, ,, in Yorkshire grease 
 
 process, 271. 
 Sulphurised constituents of oils, 123, 
 
 154. 
 Sulphurous acid as bleaching agent, 
 
 264. 
 
 ,, ,, saponifying agent,3SO. 
 
 Sumbul root, 25. 
 Summer oils see Oils, summer. 
 
 railway grease, 327. 
 Superheated steam see Distillation 
 
 (with superheated steam). 
 Suspended matters, action of. in re- 
 moving mucilage, 255. 
 ,, in solid fats, &c., 123, 341. 
 ,, removal of, from oils, &c., 
 
 228, 254-256. 
 
 Sustainer for night lights, 406. 
 Sweet water (crude glycerol solution) 
 
 see Glycerine manufacture. 
 Sycocerylic alcohol, 16. 
 .Synthesis of glycerides, 11. 
 
 TABLES of errors, hydrometer, 82, 83. 
 
 ,, hydrostatic balance, 83, 84. 
 
 Tablets (soap), cutting and stamping, 
 
 444. 
 
 Tallow (ox tallow, mutton tallow ; 
 
 ox, sheep, &c. , fat ; beef 
 
 fat), 3, 21, 55, 56, 29 3, 299, 
 
 303, 311, 322, 354. 
 
 , , adulteration of, 1 23, 258, 354- 
 
 356, 370. 
 
 bleaching of, 264-266. 
 candles see Candles (tallow), 
 different varieties of, 354. 
 engine, 324. 
 flashing point, 128. 
 free fatty acids present in, 
 
 355, 356. 
 
 iodine number, 181-184, 356. 
 ,, useful as test of 
 
 quality, 356. 
 melting point, 68, 69, 355. 
 
 ,, of fatty acids 
 
 from, 69-71, 
 74-76. 
 
 neutralisation number of 
 fatty acids from, 164. 
 
 Tallow oil see Oil (tallow). 
 
 ,, rancid, cleansing of see 
 
 Rancid. 
 
 ,, Reichert number, 175. 
 ,, relative viscosity, 102-105. 
 ,, rendering, 246-251. 
 ,, saponification equivalent and 
 total acid number, 159, 
 161, 355. 
 
 ,, specific gravity, 88-93, 355. 
 ,, stearine see Stearine 
 
 (tallow). 
 ,, unsaponifiable matters 
 
 present in, 257. 
 
 ,, use of, in lubricating mix- 
 tures, &c. , 322-328, 356. 
 ,, ,, in soapmaking, 356, 408 
 
 see Soapmaking. 
 ,, valuation of, by Dalican's 
 
 method, 74, 355. 
 
 ,, de Schepper and 
 
 Geitel's tables, 76. 
 
 Tallows, vegetable see Butters, vege- 
 table. 
 
 Tannery grease, 299. 
 Tannin, use of, in refining, 256, 263. 
 Tapers, 389. 
 
 Tar as lubricant see Lubricants. 
 Tariri, 36. 
 Taste of oils, &c., 49, 341. 
 
 ,, improved by presence of 
 
 free acid, 116. 
 Teal, oil bleaching, 264. 
 Temperature of complete fusion, 61. 
 ,, of incipient fusion, 62. 
 ,, of turbidity (Valenta's test), 
 
 55-57. 
 
 ,, reaction, specific, 149. 
 ,, variation of specific gravity 
 
 with, 92-94, 416. 
 ,, ,, viscosity with, 102-106. 
 Tempering metals in oil baths, 302. 
 Testing machines, viscosity, 94. 
 Tetrabromides, 31, 34, 36, 176. 
 Tetracetyl derivative, 35. 
 Tetrachloride of carbon see Carbon. 
 Tetraiodides, 31. 
 
 Textile fabrics, oil used in prepara- 
 tion of, 270, 272, 279, 302. 
 Texture, physical, of oils, &c., 47, 341. 
 Thenard process (oil refining), 259. 
 Thermal araeometer, Langlet's,82,347. 
 Thermeleometer, Jean's, 151. 
 Thermohydrometer, Fletcher's, 80. 
 Thermometric scales, 57. 
 Thiocyanic ethers, 15, 123. 
 Thomson and Ballantyne, blown oils, 
 
 320. 
 ,, ,, iodine numbers, 180. 
 
INDEX. 
 
 567 
 
 Thomson and Ballantyne, iodine num- 
 bers of linseed oil, 
 180, 351. 
 
 ,, ,, specific temperature 
 
 reaction, 149,349. 
 ,, ,, unsaponifiable mat- 
 
 ters, 259. 
 
 ,, ., Valenta's test, 57. 
 
 Thousandfold scale of specific gravity, 
 
 83, 84. 
 
 Thum, fractional saturation, 13. 
 ,, free acids formed by hydro- 
 lysis, 12. 
 Thymol, 
 
 Tilghmann, hydrolysis under pres- 
 sure, 385. 
 
 ,, soapmaking under pres- 
 
 sure, 463. 
 
 Time of efflux see Viscosity. 
 Titration, 23, 116, 161, 168, 173, 323, 
 328, 352, 359, 420 see 
 also Soap analysis. 
 ,, acetyl number, 198. 
 ,, of alkaline leys preferable 
 to density valuation, 420. 
 ,, test, fatty acid see Soap 
 analysis (determination 
 of free alkali). 
 
 Toluene (solvent for wax in soap), 496. 
 Tomlinson, cohesion figures, 345. 
 Torches, 312, 362. 
 
 Total acid number (saponification 
 number, Kcettstorfer number), 33, 
 157, 168, 194, 341. 
 
 Transparent soap see Soapmaking, 
 Soap (special kinds), Colloidal 
 state of soap. 
 
 Traube, friction in tubes, 109. 
 Triacetin, 8, 186. 
 Triglycerides, 9. 
 
 ,, synthesis of, 11. 
 
 Triglycerol, 8. 
 
 Tiinnermann, specific gravity of alka- 
 line leys, 415, 417. 
 Turkey fat, 298. 
 
 ,, red oils see Oils (Turkey red). 
 Turpentine see Oil (turpentine). 
 Turpentine, crude (Meinecke's rosin 
 
 soap), 473. 
 Turtle fat, 299. 
 
 Twaddell, hydrometer scale, 84, 86. 
 Twitchell, rosin in soap, 503, 504. 
 
 u 
 
 UNIT mill (Anglo-American system), 
 
 217. 
 
 Unsaponifiable matters contained in 
 oils, &c., 116,257,258,341,355. 
 
 Unsaponifiable matters in candle 
 
 stearine products, 371-374. 
 ,, in Yorkshire grease, 273-279. 
 ,, determination of , 119-124. 
 ,, proportions usually present in 
 oils, 257, 258. 
 
 ,, ,, in soaps, 258. 
 
 Unsapoiiified fat, amount less with 
 longer time, 373. 
 ,, in red oils, 370, 
 
 377-379. 
 
 in rock, 371-374. 
 ,, in separation 
 
 cakes and press 
 cakes, 376-379. 
 ,, in soap, 119, 371. 
 
 , , interferes with 
 
 crystallisation,370. 
 Unsaturated compounds, acids, 24. 
 ,, alcohols, 15. 
 
 ,, hvdrocarbons, 3, 
 
 "24, 26. 
 
 , , oxidation of, 44. 
 
 Unguents in toilet soaps, 448. 
 
 , , lanolin preparations as, 338. 
 ,, oils used for, 302. 
 Ure, soft soap analyses, 510. 
 Urine, damaluric acid from, 25. 
 Utilisation of fat of an ox, 311. 
 
 red oils see Red oils. 
 
 VALENTA'S test see Acid (acetic). 
 Valerin (valeric triglyceride), 20, 301. 
 Vapour bath, AmbuhFs, 80. 
 Varnish making, 302. 
 Variation of constituents of oils with 
 soil, climate, &c., 111. 
 ,, density with tempera- 
 
 ture see Expansion. 
 Vaseline, 91. 
 
 ,, in soaps, 448. 
 Vegetable alkali, 410. 
 
 ,, fats, butters, and tallows 
 see Butters (vegetable). 
 ,, lard see Lard. 
 Versmann, glycerine manufacture, 
 
 515. 
 
 Villavecchia and Fabris, test for 
 sesame oil, 346. 
 ,, ,, viscosity, 106. 
 
 Vincent, boiling oils, 317. 
 Viscidity of oils increased by blowing, 
 
 164 see Oils (blown). 
 Viscosimetry, 94-109. 
 Viscosity (body), 47, 94, 101. 
 ,, degree, 102. 
 
568 
 
 INDEX. 
 
 Viscosity, determination in absolute 
 
 measure, 107. 
 effect of lighten, 131. 
 efflux, 48,94-106, 324-326,341. 
 ,, of oils increased by addition 
 of caoutchouc, 323. 
 by blowing, 320. 
 
 ,, ,, by metallic soaps, 
 
 121, 324. 
 
 ,, standards of, 101. 
 Voelcker, amount of oil in linseed 
 
 cake, 213. 
 
 Volatile acid number, 176, 195, 341. 
 acids, 22, 113. 
 ,, ,, determination of see 
 
 Reichert test. 
 
 Volatility of lubricating oils, 325. 
 Vulcanising, 154, 318. 
 
 W 
 
 WAGGON grease see Lubricants. 
 Wagner, refining with, zinc chloride, 
 
 260. 
 
 ,, rule concerning oxidation, 44. 
 Wakefield fat see Yorkshire grease. 
 Walton, linoleum manufacture, 318. 
 Wanklyn, aldepalmitic acid, 24. 
 
 ,, and Fox, glycerine valua- 
 tion, 519. 
 
 Warren, sulphur chloride and oils, 155. 
 Washballs (soap), 448. 
 Waste cleansing see Engine waste. 
 Water, action of, on silver bromo- 
 
 stearate, 25, 30. 
 ,, agitation with, as purifying 
 
 agent, 261. 
 
 ,, as standard for efflux velo- 
 city, 101. 
 
 ,, ,, for specific tem- 
 
 perature reaction, 149, 150. 
 ,, contained in beeswax, 359. 
 
 oils, 122-124,341. 
 
 ,, hot, extraction of vegetable 
 
 oils, &c. , by means of, 
 
 200-202. 
 
 ,, ,, rendering animal fats, 
 
 &c., with, 247. 
 
 ,, solubility in see Solubility, 
 
 Water bath for melting points, 60-64. 
 
 ,, ,, specific gravity, 80. 
 
 ,, ,, viscosimetry, 95-101. 
 
 Watt, bichromate bleaching process, 
 
 265. 
 
 ,, chloride of soda bleaching pro- 
 cess for soaps, 267. 
 Watts see Richardson and Watts. 
 Wax candles see Candles. 
 
 Waxes, animal and vegetable 
 Abyssinian, African, Andaquia, 
 
 Antilles, 302. 
 Beeswax, 4, 14, 21, 357-359. 
 
 ,, addition of fatty matter or 
 
 oil of turpentine facilitates 
 
 air bleaching, 268, 269, 358. 
 
 ,, adulterations of, 359. 
 
 air bleaching, 264, 268, 357, 
 
 358. 
 ,, ,, produces little change 
 
 in density, 358. 
 ,, bibliography of, 359. 
 ,, bleached by chlorine apt to 
 contain chloro substitution 
 products, 267, 364, 390. 
 ,, bleaching by chemical pro- 
 cesses, 264-267, 357. 
 ,, ,, increases total acid 
 number, and renders 
 more crystalline, 
 266, 269, 364 
 
 ,, bromine absorption, 178. 
 ,, class, 282, 301, 302.. 
 ,, ester number, 358. 
 ,, free acid number, 358. 
 ,, fusing point, 68, 69, 358. 
 ,, iodine number, 269, 358. 
 ,, iodine number diminished 
 by chemical bleaching, 269. 
 ,, preparation of 201, 357. 
 ,, saponification equivalent 
 and total acid number, 
 160, 269. 
 
 ,, solubility in solvents, 357. 
 ,, specific gravity, 88, 91-93, 
 
 358. 
 
 ,, virgin, 357. 
 Carnauba wax, 14, 21, 301. 
 
 ,, an oxyacetic acid from, 
 
 37. 
 
 bromine absorption, 178. 
 class, 282, 301. 
 glycol from, 5, 18. 
 saponification equiva- 
 lent, 160. 
 
 specific gravity, 91. 
 used as beeswax adul- 
 terant, 359. 
 
 Chinese wax (Peh-la), 14, 21,91, 302. 
 ,, extraction by hot 
 
 water process, 201. 
 Cordillera wax, 301. 
 Cowtree wax, 301.. 
 Ficus wax, (fig wax, Getah wax), 
 
 14, 301. 
 
 Indian wax (Arjun wax), 302. 
 Japanese wax, 5, 21, 295. 
 
 ,, bromine absorption, 178. 
 
INDEX. 
 
 569 
 
 Waxes, animal and vegetable 
 Japanese wax contains practically 
 
 no olein, 295. 
 ,, fusing point, 68-71. 
 ,, iodine number, 181-184. 
 , , purification and bleach- 
 ing, 268. 
 
 ,, saponiti cation equiva- 
 lent and total acid 
 number, 160. 
 
 ,, solubility in alcohol, 55. 
 ,, specific gravity, 88, 91- 
 
 93. 
 ,, unsaponifiable matter 
 
 contained in, 257. 
 yield of, 242. 
 Myrtle wax, 71, 91, 178, 295. 
 Niin wax (niin fat), 302. 
 Ocuba wax, 243, 295. 
 Otaba wax, 295. 
 Palm wax, 301. 
 Paraffin wax, 2, 5, 21, 91-93. 
 
 ,, adulterant of bees wax and 
 
 spermaceti, 359, 361. 
 ,, as candle material see 
 
 Candles. 
 
 manufacture of, 230, 364. 
 Pe-la (Peh-la, Pe-lah) wax see 
 
 supra, Chinese wax. 
 Petha wax, 301. 
 
 Spermaceti wax see Spermaceti. 
 Ucuba wax, 295. 
 
 Waxes, free alcohols in, 114, 116. 
 ,, general nature of, 1. 
 , , glyceridic and non-glyceridic, 
 
 3-5, 282, 301, 302. 
 ,, liquid, 6. 
 
 ,, mineral (earthwax) see Ozo- 
 kerite. 
 
 ,, mostly indigestible, 303. 
 ,, used as spermaceti adulter- 
 ants, 361. 
 ,, vegetable, hot water process 
 
 of preparation, 201. 
 Waxy matters, separation from oils, 
 
 119. 
 Wedge presses, 1 99, 203. 
 
 Chinese, 200. 
 Wenzell, expansion, 93. 
 Werner, oxyoleates, 332. 
 Westphal, hydrostatic balance, 79, 80. 
 Wet steam see Steam. 
 Whale blubber, extraction of oil 
 
 from, 247. 
 
 Whales, toothed, yield most sper- 
 maceti, 293, 300, 301. 
 Whitelaw, salting out soap, 486. 
 Whitelead in paint, 135. 
 Whiting, adulterant of tallow, 355. 
 
 Wicks, 312, 362, 363, 394. 
 
 ,, charring of, 116, 260, 313. 
 ,, Palmer's metallic, 394. 
 ,, pickling, 394. 
 Wilde, de, and Eeichler, conversion 
 
 of oleic into stearic acid, 387. 
 Wilson, acetyl number, 188, 335. 
 ,, analysis of Turkey red oils, 
 
 333-335. 
 
 ,, soap analysis, 495, 499. 
 ,, viscosity, 102. 
 ,, water in soap, 495. 
 Wilson and Payne, hydrolysis by 
 
 superheated water, 385. 
 Wilson's process (preparing candle 
 material), 262, 380, 334. 
 ,, (tallow rendering), 250. 
 
 Wimmell, melting points, 68. 
 Winter oils see Oils (winter). 
 
 ,, railway grease, 327. 
 Wire (soap cutting), 437. 
 Wollny, Keichert number, 53, 175. 
 Wool cleansing, wool scouring, 271, 
 
 337, 338. 
 
 ,, ,, injurious effect of 
 
 alkaline and 
 silicated soaps 
 see Soap, 
 alkaline ; Soap 
 (special kinds), 
 silicated. 
 
 Wool fat, analysis of, 276. 
 Woolgrease, 3, 70, 161, 182, 184, 299, 
 302, 337, 461 -.see York- 
 shire grease; Lanolin. 
 ,, effect on soap, 258. 
 ,, tallow adulterated with, 
 
 258, 354, 369. 
 
 Wool oil (from Yorkshire grease dis- 
 tillation), 279. 
 
 Wright, Alder (author), analyses of 
 manufacturers' and toilet 
 soaps, 508-512. 
 
 ,, analysis of rock, steariiie 
 cakes, red oils, &c., 
 371-375. 
 , , analysis of soap (free alkali). 
 
 500. 
 
 ,, autoclave experiments, 373. 
 ,, Cantor lectures, 487, 512, 
 
 523. 
 
 ,, classification of soaps ac- 
 cording to alkalinity, 512. 
 ,, dealkalising process, 453, 
 
 461, 484. 
 
 ,, glycerine valuation, 523. 
 , , hydrolysis of soap solutions, 
 
 487. 
 ,, methoxyl test, 192. 
 
570 
 
 INDEX. 
 
 Wright, Alder, use of iodine number 
 
 in tallow valuation, 356, 375. 
 Wright (Alder) and Muirhead, zinc 
 
 chloride and oils, 141. 
 Wright (Alder) and Thompson, chem- 
 istry of soap, 
 490-492. 
 
 ,, ,, Cladding's pro- 
 
 cess, 502. 
 ,, ,, hydrolysis of 
 
 soap, 487. 
 
 ,, ,, systematic soap 
 
 analysis, 494. 
 
 XYLENOL, 16. 
 
 YELLOW ochre, beeswax adulterant, 
 
 359. 
 Yield of fatty acids from oils, &c., 
 
 74, 163. 
 
 ,, fatty matter from seeds, nuts, 
 beans, &c., 241-244, 348, 351. 
 ,, glycerol from oils, &c. , 75, 162. 
 ,, solid stearine, 368. 
 Yorkshire grease, 110, 271-279, 324. 
 ,, adulteration of tallow with, 
 
 258, 354. 
 
 ,, amount of unsaponifiable 
 matters increases with 
 the density, 277. 
 
 Yorkshire grease, analysis of, 273. 
 ,, distillation of, 277, 383. 
 ,, hydrocarbons in distilled, 
 
 262. 
 ,, injurious effect on soap, 258. 
 
 ZEISEL'S test see Methyl number. 
 Zinc and hydrochloric acid, as de- 
 
 chlorinising agents, 35. 36. 
 ,, chloride, action on oils, 141, 142, 
 
 153. 
 ,, ,, action on oleic acid, 39, 
 
 142, 262, 386. 
 
 ,, ,, colour test, 153. 341. 
 ,, ,, refining by means of, 
 
 255, 260. 
 ,, dust, as dechlorinising agent, 
 
 27, 31. 
 
 ,, isoleate, 30. 
 ,, oxide (antifriction) , 328. 
 ,, ,, as saponifying agent, 379, 
 
 410, 515. 
 ,, salts, separation of rapic and 
 
 erucic acids by, 41. 
 ,, used in refining, 262, 263. 
 ,, sulphate (boiled oils), 262. 
 ,, soap, added to oils, &c., 121. 
 ,, white, in paint, 135. 
 Ziirer, conversion of oleic into stearic 
 acid, 386. 
 
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