INDUSTRIAL ORGANIC CHEMISTRY ADAPTED FOR THE USE OF MANUFACTURERS, CHEMISTS, AND ALL INTERESTED IN THE UTILIZATION OF ORGANIC MATERIALS IN THE INDUSTRIAL ARTS. BY SAMUEL P. SADTLER, PH.D., LL.D. CONSULTING CHEMIST; PROFESSOR OF CHEMISTRY IN THE PHILADELPHIA COLLEGE OF PHARMACY AND FORMER PROFESSOR OF ORGANIC AND INDUSTRIAL CHEMISTRY IN THE UNIVERSITY OF PENN- SYLVANIA ; PAST PRESIDENT OF THE AMERICAN INSTITUTE OF CHEMICAL ENGINEERS. FOURTH EDITION (REVISED, ENLARGED, AND RESET) PHILADELPHIA : J. B. LIPPINCOTT COMPANY. LONDON : 5 HENRIETTA STREET, COVENT GARDEN. 1912. Copyright, 1891, by SAMUEL P. SADTLER. Copyright, 1895, by SAMUEL P. SADTLER. Copyright, 1900, by SAMUEL P. SADTLER. Copyright, 1912, by SAMUEL P. SADTLER. All rights reserved. ELECTROTVPEO AND PRINTED BY ). B. LIPPINCOTT COMPANY, PHILADELPHIA, U.S.A. PREFACE TO THE FOURTH EDITION. THAT over eleven years have passed since the previous (third) edi- tion of this work was issued has been due to the fact that the author could not free himself at an earlier date from other literary and pro- fessional engagements sufficiently to take up the careful review of the field of industrial organic work required for a proper revision of this book. Organic chemical industries have grown and developed greatly in the meantime, so that, although the same division of the subject-matter has been retained as one approved by experience, much new matter has been introduced in every chapter and many new technical products described and classified. In some cases practically new industries have developed or are de- veloping as new possibilities have been found for organic materials, as is seen in the artificial silk industry, the by-product coke-oven, the dis- placement of natural indigo by the synthetic indigo, and similar examples. The author has endeavored to present full and accurate statements of these new lines of manufacture. While, as in previous revisions, the bibliography and statistics have been rewritten and brought down to date, it has been sought, in this revision, to make the sections on analytical methods fuller for some of the industries and to choose only such methods as are in present use and have been approved by the consensus of those directly interested as specialists in the several industries. At the same time we must recall the fact that the limitations of space have from the beginning precluded the thought of giving more than the most necessary methods, and these the author has given in concise form. There are numerous excellent analytical manuals or reference works on analysis, both of a general kind, like Allen's Commercial Organic Analysis, and special ones on almost every separate industry. The titles of these latter will be found very generally in the several bibliographical lists under the appropriate chapter headings. Several new tabular statements have been incor- porated and some new tables for reference have been inserted in the Appendix. As in the preface of the first edition, the acknowledgments of the author are due to his friend, Mr. Louis J. Matos, for corrections and additions to Chapters XII, XIII, and XIV. The author hopes that both chemical students preparing for entrance on practical work and manufacturers engaged in the development of our industrial resources will find assistance and benefit from the use of the book in its revised form. PHILADELPHIA, April, 1912. Ul 295803 PREFACE TO THE FIRST EDITION. THE literature of Applied Chemistry is reasonably voluminous. We have dictionaries and encyclopaedic works upon the subject, a series of small hand-books for individual industries, and a mass of technical journals of both general and special application. Works, however, in which the effort is made to give within the bounds of a single volume a general view of the various industries based upon the applications of chemistry to the arts are much rarer, and especially is this true of works printed in the Eng- lish language. In German we have Wagner's " Chemische Technologic," brought down to date by its present editor, Ferd. Fischer Post's " Chem- ische Technologic," Bolley's " Technische-Chemische Untersuchungen," Heinzerling's " Technische Chemie," Ost's " Chemische Technologic," and others ; in French, Payen's " Chimie Industrielle" and Girardin's " Chimie applique" aux Arts Industrials," etc. ; while in English we have only the now antiquated translations of Wagner and Payen. In speaking thus, the writer wishes to be understood as referring only to general works on chemical technology of moderate size. The excellent " Dictionary of Applied Chem- istry," in three volumes, now being published by Longmans & Co., does not therefore come into the consideration, for the twofold reason of its size and of its encyclopaedic and disconnected method of treatment. Similarly, works which cover only a single side of the subject, like Allen's " Commercial Organic Analysis," are not referred to in the above statement. The author has endeavored within the compass of a moderate-sized octavo to take up a number of the more important chemical industries or groups of related industries, and to show in language capable of being under- stood even by those not specially trained in chemistry the existing conditions of those industries. The present volume, it will be noticed, is limited to "Industrial Organic Chemistry." This field, while covering many very important lines of manufacture, does not seem at present to be so well pro- vided for as the inorganic part of the subject. A companion volume, covering this other side of industrial chemistry, is in contemplation. In taking up the several industries for survey, it has been thought de- sirable first to enumerate and describe the raw materials which serve as the basis of the industrial treatment ; second, the processes of manufacture are given in outline and explained ; third, the products, both intermediate and final, are characterized and their composition illustrated in many cases by tables of analyses ; fourth, the most important analytical tests and methods vi PREFACE. are given, which seem to be of value either in the control of the processes of manufacture or in determining the purity of the product ; and, fifth, the bibliography and statistics of each industry are given, so that an idea of the present development and relative importance of the industry may be had. The author has endeavored in a number of cases to give a clearer picture of the lines of treatment for an industry by the introduction of schematic views of the several processes through which the raw material is carried until it is brought out as the finished product. A number of these dia- grams have been taken from German and English sources, and several have been constructed by the author specially for this work. A list of these diagrams will be found appended. A large number of the illustrations have been drawn specially for this work, and others have been procured from the best German and American sources. Frequent foot references are made to authorities and sources of informa- tion, although this may not have been done in all cases. The author has in the analytical section made frequent use of Allen's " Commercial Organic Analysis," and hereby desires to acknowledge his special indebtedness to that most valuable work. He has also made frequent use of Wagner's "Chemische Technologic," thirteenth edition, and Stohmann and KerPs " Angewandte Chemie." Besides these works of a general character he has also consulted a large number of special works, the titles of which will be found in the bibliographical lists appended to each chapter. The author desires here to acknowledge his indebtedness to the many friends who have aided him by information and helped him especially in the collating of the statistics of the several industries. His special indebtedness is due to his friend and former pupil, Mr. Louis J. Matos, M.E., who aided him in the completion of Chapters XI. and XII., and to whom Chapter XIV. in its entirety belongs. To his colleague, Professor Henry Trimble, of the Philadelphia College of Pharmacy, he is also indebted for information upon the subject of Tannin and Dye-woods, as treated in Chapter XIII. The original drawings made for this work and the index are also due to o o Mr. L. J. Matos. The author hopes that this work may prove of some value to those en- gaged in the several lines of manufacturing industry touched upon by show- ing the chemical nature of the materials which are handled by them, and of the change which these materials undergo in the course of treatment and preparation as marketable commodities ; that it may be suggestive to those engaged in research or invention in connection with chemistry ; and, lastly, that it may be found to possess some interest for the general reader or the student of scientific or economic topics. PHILADELPHIA, August 3, 1891. TABLE OF CONTENTS. CHAPTER I. PETROLEUM AND MINERAL OIL INDUSTRY. PAGES I. Raw Materials 13-18 1. Natural Gas, 13. 2. Crude Petroleum, 14-16. 3. Crude Paraffin, 16, 17. 4. Bitumen and Asphalt, 17, 18. II.' Processes of Treatment 18-30 1. Of Natural Gas, 18, 19. 2. Of Crude Petroleum, 19-27. 3. Of Ozokerite and Natural Paraffin, 27. 4. Of Natural Bitumens and Asphalts and of Bituminous Shales, 28-30. III. Products 30-36 1 From Natural Gas (a, Fuel Gas; 6, Illuminating Gas; c, Lamp- black; and, d, Electric-light Carbons), 30-31. 2. From Petroleum, 31-33. 3. From Ozokerite and Natural Paraffin, 35. 4. From Bitumens, Asphalts, and Bituminous Shales, 35-36. IV. Analytical Tests and Methods 36-48 1. For Natural Gas, 36. 2. For Petroleum, 36-47. 3. For Ozokerite, 47. 4. For Asphalts, 47-48. V. Bibliography and Statistics 48-52 CHAPTER II. INDUSTRY OF THE FATS AND FATTY OILS. I. Raw Materials 53-64 1. Occurrence of the Materials (a, Vegetable Oils, Fats, and Waxes; b, Animal Oils, Fats, and Waxes), 53-58. 2. Physical and Chemical Characters of the Different Oils and Fats, 58i, 59. 3. Extraction of the Raw Materials and Purification of the same, 59-64. II. Processes of Treatment 64-79 1. Saponification of Fats, 64-66. 2. Practical Soap-making, 66-73. 3. Stearic Acid and Candle Manufacture, 74-77. 4. Oleo- margarine or Artificial Butter Manufacture, 77. 5. Glycerine Manufacture (5a, Nitro-glycerine and Dynamite), 77-79. III. Products 79-85 1. Purified Oils, Fats, and Waxes, and Products from the same, 79-81. 2. Soaps, 81-83. 3. Candles, 85. 4. Oleomargarine or Butterine, 83. 5. Glycerine and Nitro-glycerine, 83-85. viii TABLE OF CONTENTS. PAGES IV. Analytical Tests and Methods 85-95 1. For Oils and Fats, 85-91. 2. For Soaps, 91-93. 3. Glycerine, 94-95. V. Bibliography and Statistics 95-102 CHAPTER III. INDUSTBY OF THE ESSENTIAL OILS AND RESINS. I. Raw Materials 103-111 1. Essential Oils, 103-106. 2. Resins, 106-108. 3. Caoutchouc, 108-110. 4. Gutta-percha and Similar Products, 110-111. 5. Natural Varnishes, 111. II. Processes of Treatment III-IIQ 1. Manufacture of Perfumes and Similar Products, 111, 112. 2. Manufacture of Varnishes, 112-115. 3. Manufacture of Printer's Ink, 115, 116. 4. Manufacture of Oil-cloth, Linoleum, etc., 116, 117. 5. Processes of Treatment of Caoutchouc and Gutta-percha, 117-119. III. Products 119-124 1. Perfumes, 119. 2. Varnishes, 119-121. 3. Printing Inks, 121. 4. Miscellaneous Products from Resins and Essential Oils, 121, 122. 5. India-rubber and Gutta-percha Products, 122-124. IV. Analytical Tests and Methods 124-129 1. For Essential Oils, 124-126. 2. For Resins, 127-128. 3. For Varnishes, 128. 4. For Caoutchouc and Gutta-percha, 128, 129. V. Bibliography and Statistics 129-133 CHAPTER IV. THE CANE- SUGAR INDUSTRY. I. Raw Materials I33~i37 1. The Sugar-cane, 133. 2. Sugar-beet, 134-135. 3. Sorghum Plant, 134-136. 4. The Sugar-maple, 136. II. Processes of Treatment 137-167 1. Production of Sugar from the Sugar-cane, 137-150. 2. Produc- tion of Sugar from the Sugar-beet, 150-159. 3. The Working up of the Molasses, 159-164. 4. Revivifying of the Bone- black, 164-167. III. Products of Manufacture 167-171 1. Raw Sugars, 167, 168. 2. Refined Sugars, 168. 3. Molasses and Cane-sugar Syrups, 168-170. 4. Miscellaneous Side-products, 170, 171. TABLE OF CONTENTS. IX PAGES IV. Analytical Tests and Methods 172-182 1. Determination of Sucrose, 172-174. 2. Determination of Glucose, or Invert Sugar, 174, 175. 3. Analysis of Com- mercial Raw Sugars, 170-177. 4. Analyses of Molasses and Syrups, 177, 178. 5. Analyses of Sugar-canes and Sugar- beets and Raw Juices therefrom, 179. 6. Analyses of Side- products, 179-182. V. Bibliography and Statistics 182-184 CHAPTER V. THE INDUSTRIES OF STARCH AND ITS ALTERATION PRODUCTS. I. Raw Materials 185-187 II. Processes of Manufacture 187-195 1. Extraction and Purifying of the Starch, 187-190. 2. Manu- facture of Glucose, or Grape-sugar, 190-192. 3. Manufacture of Levulose, 192. 4. Manufacture of Maltose, 192, 193. 5. Soluble Starch, 193. 6. Manufacture of Dextrine, 194. 7. Manu- facture of Sugar-coloring, 194, 195. III. Products 195-197 1. Starch, 195. 2. Glucose and Grape-sugar, 195. 3. Maltose, 196. 4. Dextrine, 196. 5. Unfermentable Carbohydrates, 197. IV. Analytical Tests and Methods 197-201 1. For Starch, 197-199. 2. For Glucose, or Dextrose, 199. 3. For Maltose, 199. 4. Dextrine, 200. 5. Commercial Glucose and Similar Mixtures derived from Starch, 200, 201. V. Bibliography and Statistics 201, 202 CHAPTER VI. FERMENTATION INDUSTRIES. A. Nature and Varieties of Fermentation, 203-208. B. Malt Liquors and the Industries connected therewith. I. Raw Materials 208-210 1. Malt, 208, 209. 2. Hops, 209, 210. 3. Water, 210. II. Processes of Manufacture 210-218 1. Malting of the Grain, 210-212. 2. Preparation of the Wort, 212-215. 3. Boiling and Cooling, 215, 216. 4. Fermentation of the Wort, 216, 217. 5. Preservation of the Beer, 218. III. Products 218, 219 IV. Analytical Tests and Methods 219-223 1. For Malt, 219, 220. 2. For Beer-worts, 220, 221. 3. For Beer, 221-223. X TABLE OF CONTENTS. C. The Manufacture of Wine. PAGES I. Raw Materials 223-225 1. The Grape, 223, 224. 2. The Must, 224, 225. II. Processes of Manufacture 225-231 1. Fermentation, 225, 226. 2. Diseases of Wines and Methods of Treating and Improving them, 226-229. 3. Manufacture of Effervescing Wines, 229. 4. Manufacture of Fortified, Mixed, and Imitation Wines, 229-231. III. Products . 231-235 IV. Analytical Tests and Methods 235-239 D. Manufacture of Distilled Liquors, or Ardent Spirits. I. Raw Materials 239-241 1. Alcoholic Liquids, 239, 240. 2. Sugar-containing Raw Ma- terials, 240. 3. Starch-containing Eaw Materials, 240, 241. II. Processes of Manufacture 241-251 1. Preparation of the Wort, 241, 242. 2. Fermentation of the Wort, or Saccharine Liquid, 242-244. 3. Distillation of the Fermented Mash, or Alcoholic Liquid, 244-249. 4. Rectifying and Purifying of the Distilled Spirit, 249, 250. 5. Manu- facture of Alcoholic Beverages from Rectified Spirit, 250, 251. III. Products 251-255 1. Rectified and Proof Spirit, 251. 2. Alcoholic Beverages made by Direct Distillation of the Fermentation Products, 251-253. 3. Alcoholic Beverages made from Grain Spirit by Distillation under Special Conditions, 253. 4. Liqueurs and Cordials, 253, 254. 5. Side products, 255. IV. Analytical Tests and Methods 255, 256 E. Bread-making. I. Raw Materials 257-260 1. Flour, 257, 258. 2. Yeast, or Ferment, 259, 260. 3. Baking- powders, 260. II. Processes of Manufacture 260, 261 1. The Mixing of the Dough and its Fermentation, 260. 2. Baking, 261. 3. The Use of Chemicals Foreign to the Bread, 261. III. Products 261-263 1. Bread, 261, 262. 2. Crackers and Hard Biscuit, 263. IV. Analytical Tests and Methods 263-265 1. For the Flour, 263-265. 2. For Bread, 265. TABLE OF CONTENTS. xi F. The Manufacture of Vinegar. PAGES I. Raw Materials 266, 267 II. Processes of Manufacture 267-270 1. The Orleans Process, 267, 268. 2. The Quick-vinegar Process, 268, 269. 3. The Manufacture of Malt Vinegar, 269, 270. 4. The Manufacture of Cider Vinegar, 270. 5. Pasteur's Process for Vinegar-making, 270. III. Products 270, 271 IV. Analytical Tests and Methods 271, 272 V. Bibliography and Statistics for Fermentation Industries 272-277 CHAPTEE VII. MILK INDUSTRIES. I. Raw Materials 278-281 II. Processes of Manufacture 281-288 1. Manufacture of Condensed and Preserved Milk, 281. 2. Of Butter, 281-284. 3. Of Artificial Butter (Oleomargarine), 284-286. 4. Cheese-making, 286-288. III. Products 288-293 1. Condensed and Preserved Milk, 288, 289. 2. Butter and Butter Substitutes, 289, 290. 3. Cheese, 290, 291. 4. Milk-sugar, 291. 5. Koumiss, 291. 6. Kephir, 292. 7. Casein Prepara- tions, 292, 293. 8. Whey, 293. IV. Analytical Tests and Methods 293-299 1. For Milk, 293-296. 2. For Butter, 296-299. 3. For Cheese, 299. V. Bibliography and Statistics 300, 301 CHAPTER VIII. VEGETABLE TEXTILE FIBRES. I. General Characters 302-311 1. Cotton Fibre, 303, 304. 2. Flax, 305, 306. 3. Hemp, 306, 307. 4. Jute, 307, 308. 5. Miscellaneous Vegetable Fibres, 308, 309. 6. Classification of the Vegetable Fibres, 310, 311. INDUSTRIES BASED UPON THE UTILIZATION OF VEGETABLE FIBRES. A. Paper-making, L Raw Materials 3 II ~3 I 4 1. Rags, 311. 2. Wood-fibre, 312, 313. 3. Esparto, 313. 4. Straw, 313, 314. 5. Jute, 314. 6. Manila Hemp, 314. 7. Paper-mul- berry, 314. xii TABLE OF CONTENTS. PAGES II. Processes of Treatment 314-322 1. Mechanical Preparation of the Paper-making Material, 314, 315. 2. Boiling, 315, 316. 3. Washing, 316, 317. 4. Bleaching, 317- 320. 5. Beating, 320, 321. 6. Loading, Sizing, Coloring, etc., 321. 7. Manufacture of Paper from the Pulp, 321, 322. III. Products ( Different Varieties of Paper ) 322-325 IV. Analytical Tests and Methods 325-327 1. Determination of the Nature of the Fibre, 325-327. 2. De- termination of the Nature of the Loading Materials, 327. 3. Determination as to Nature of the Sizing Materials, 327. 4. Determination of the Nature of the Coloring Material, 327. B. Gun-cotton, Pyroxyline, Collodion, and Celluloid. I. Raw Materials 327, 328 II. Processes of Manufacture 328-331 1. Gun-cotton, 328, 329. 2. Pyroxyline and Collodion, 329, 330. 3. Celluloid, 330, 331. Ill- Products 331, 332 1. Gun-cotton, 331. 2. Pyroxyline, 331. 3. Collodion, 332. 4. Pyroxyline Varnishes, 332. 5. Celluloid, 332. IV. Analytical Tests and Methods 332, 333 C. Artificial Silk. I. Raw Materials 334, 335 1. Nitro-cellulose or Chardonnet Process, 334. The Cupram- monium Process, 334. 3. The Viscose Process, 334, 335. II. Processes of Manufacture 335, 336 1. Spinning of the Artificial Silk Filament. 2. The Collodion or Chardonnet Process, 335. 3. The Cuprammonium Process, 335. 4. The Viscose Process, 336. III. Products 336 IV. Analytical Tests and Methods 337 V. Bibliography and Statistics of Vegetable Fibres and their Industries 337~34o CHAPTER IX. TEXTILE FIBRES OF ANIMAL ORIGIN. I. Raw Materials 341-346 A. Wool and Animal Hairs, 341-344. B. Silk, 344-346. II. Processes of Manufacture and Treatment 346-350 A. Wool. 1. Wool-scouring, 346, 347. 2. Bleaching of Wool, 347, 348. B. Silk. 1. Reeling of Silk, 348. 2. Silk-conditioning, 348, 349. 3. Silk-scouring, 349, 350. TABLE OF CONTENTS. xiii PAGES III. Products 350, 351 A. Woollen Products, 350, 351. B. Silken Products, 351. IV. Analytical Tests and Methods 351-353 V. Bibliography and Statistics 353~355 CHAPTER X. ANIMAL TISSUES AND THEIR PRODUCTS. A. Leather Industry. I. Raw Materials 356-360 1. Animal Hides and Skins, 356, 357. 2. Tannin-containing Ma- terials, 357-360. II. Processes of Manufacture 361-370 A. Manufacture of Sole-Leather, 361-365. B. Upper and Harness Leathers, 365, 366. (7. Morocco Leather, 366. D. Mineral Tanning or " Tawing," 366-369. E. Chamois and Oil -tanned Leather, 369, 370. III. Products 370-372 1. Sole-leather, 370. 2. Upper and Harness Leathers, 370. 3. Morocco Leather, 370, 371. 4. Enamelled or Patent Leathers, " 371. 5. Russia Leather, 371. 6. Chamois Leather, 371. 7. White-tanned or "Tawed" Leather, 371. 8. Crown Leather, 371, 372. 9. Parchment and Vellum, 372. 10. Degras, 372. IV. Analytical Tests and Methods 372-376 1. Qualitative Tests for the Several Tanning Materials, 373. 2. Analysis of Liquid and Solid Tanning Extracts, 374. 3. Quantitative Estimation of Tannin, 374, 375. 4. De- termination of Acidity of Tan-liquors, 375, 376. B. Glue and Gelatine Manufacture. I. Raw Materials 376, 377 1. Hides and Leather, 376, 377. 2. Bones, 377. 3. Fish-bladders, 377. 4. Vegetable Glue, 377. II. Processes of Manufacture 377-380 1. Manufacture of Glue from Hides, 377-379. 2. Manufacture of Glue from Leather-waste, 379. 3. Manufacture of Glue or Gelatine from Bones, 379, 380. 4. Manufacture of Fish Gelatine, 380. III. Products 380, 381 1. Hide Glue, 380. 2. Bone Glue (or Bone Gelatine), 380, 381. 3. Isinglass (or Fish Gelatine), 381. 4. Liquid Glue, 381. IV. Analytical Tests and Methods 381, 382 1. Absorption of Water, 381. 2. Inorganic Impurities, 382. 3. Adulteration of Isinglass with Glue, 382. V. Bibliography and Statistics of Leather and Glue and Gelatine. . 382-384 xiv TABLE OF CONTENTS. CHAPTER XL INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. A. Destructive Distillation of Wood. PAGES I. Raw Materials 385-387 1. Composition of Wood, 385, 386. 2. Effect of Heat upon Wood, 386, 387. II. Processes of Manufacture 387-393 1. Distillation of the Wood, 387-389. 2. Treatment and Purifica- tion of the Crude Wood-vinegar, 389-392. 3. Purification of the Crude Wood-spirit, 392. 4. Treatment of the Wood- tar, 392, 393. III. Products 393-395 1. Pyroligneous Acid and Products therefrom, 393. 2. Methyl Alcohol and Wood-spirit, 393, 394. 3. Acetone, 394. 4. Creosote, 394. 5. Paraffin, 394. 6. Charcoal, 394, 395. IV. Analytical Tests and Methods 395~397 1. Assay of Pyroligneous Acid and Crude Acetates, 395. 2. De- termination of Methyl Alcohol in Commercial Wood-spirit, 395, 396. 3. Determination of the Acetone in Commercial Wood-spirit, 396. 4. Qualitative Tests for Wood-tar Creosote, 396, 397. B. Destructive Distillation of Coal. I. Raw Materials 397-401 1. Varieties of Coal, 397-399. 2. Effects of Temperature in the Distillation of Coal, 399-401. II. Processes of Treatment 401-415 I. Gas-retort Distillations of Coal, 401-405. 2. Coke-oven Dis- tillation of Coal, 405-408. 3. Fractional Separation of Crude Coal-tar, 408-411. 4. Treatment of Ammoniacal Liquor, 411- 415. III. Products 415-423 1. First Light Oil, 415-417. 2. Middle Oil, 417-419. 3. Creosote Oil (or Heavy Oil), 419-421. 4. Anthracene Oil, 421, 422. 5. Pitch, 423. IV. Analytical Tests and Methods 423-430 1. Valuation of Tar Samples, 423, 424. 2. Special Tests for Tar Constituents, 424-428. 3. Valuation of Ammonia-liquor, 428, 429. 4. Analysis of Illuminating Gas, 429, 430. V. Bibliography and Statistics of Destructive Distillation Industries 430-432 TABLE OF CONTENTS. xv CHAPTER XII. THE ARTIFICIAL COLORING MATTERS. PAGES I. Raw Materials 433-448 1. Hydrocarbons, 433-436. 2. Halogen Derivatives, 437, 438. 3. Nitro-Derivatives, 438-440. 4. Amine Derivatives, 440-443. 5. Phenol Derivatives, 443, 444. 6. Sulpho- Acids, 444, 445. 7. Pyridine and Quinoline Bases, 445, 446. 8. Diazo- Com- pounds, 446, 447. 9. Aromatic Acids and Aldehydes, 447, 448. 10. Ketones and Derivatives (Anthraquinone), 448. II. Processes of Manufacture 449~455 1. Of Nitrobenzene and Aniline, 449-451. 2. Of Phenols, Naph- thols, etc., 451, 452. 3. Of Aromatic Acids and Phthalems, 452, 453. 4. Of Anthraquinone and Alizarin, 453, 454. 5. Of Quinoline and Acridine, 454. 6. Sulphonating, 454. 7. Diazo- tizing, 455. III. Products 455-468 1. Aniline or Amine Dye-colors, 457-459. 2. Phenol Dye-colors, 459, 460. 3. Nitroso and Oxyazine Colors, 460, 461. 4. Azo Dye-colors, 461-465. 5. Quinoline and Acridine Dyes, 465. 6. Artificial Indigo, 465, 466. 7. Oxyketone Colors, 466-468. 8. The Sulphur or Sulphide Colors, 468. IV. Analytical Tests and Methods 468-484 1. Fastness of Colors to Light and Soap, 469. 2. Comparative Dye-trials, 469-471. 3. Identification of Coal-tar Dyes, 471- 473. 4. Chemical Analysis of Commercial Dyes, 474. 5. Ex- amination of Dyed Fibres, 474-484. V. Bibliography and Statistics 485-487 CHAPTER XIII. NATURAL DYE-COLORS. I. Raw Materials 488-497 A. Red Dyes, 488-492. B. Yellow Dyes, 492, 493. C. Blue Dyes, 493-496. D. Green Dyes, 496, 497. E. Brown Dyes, 497. II. Processes of Treatment 497-504 1. Cutting of Dye-woods, 497. 2. Fermentation or Curing of Dye-woods, 498-500. 3. Manufacture of Dye-wood Extracts, 500-502. 4. Miscellaneous Processes, 502-504. III. Products 505-511 1. From Red Dyestuffs, 505-508. 2. From Yellow Dyestuffs, 508. 3. From Blue Dyestuffs, 508-511. 4. From Brown Dyes, 511. xvi TABLE OF CONTENTS. PAGES IV. Analytical Tests and Methods 511-519 1. For Dye-woods, 511-512. 2. For Dye-wood and other Extracts, 512-515. 3. For Cochineal, 515. 4. For Indigo and its Preparations, 515-519. V. Bibliography and Statistics 519-521 CHAPTER XIV. BLEACHING, DYEING, AND TEXTILE PRINTING. I. Preliminary Treatment 522 II. Bleaching 523-529 1. For Cotton, 523-527. 2. For Linen, 527, 528. 3. For Jute, 528. 4. For Wool, 528, 529. 5. For Silk, 529. III. Bleaching Agents and Assistants 529, 530 IV. Mordants Employed in Dyeing and Printing 530-534 1. Mordants of Mineral Origin, 531-533. 2. Mordants of Organic Origin, 533, 534. V.-Dyeing 534 - 545 1. Cotton-dyeing, 535-541. 2. Linen-dyeing, 541. 3. Jute-dyeing, 541. 4. Wood-dyeing, 541-544. 5. Silk-dyeing, 544-545. VI. Printing Textile Fabrics 545~557 VII Bibliography 557~559 APPENDIX I. The Metric System 561, 562 II. Tables for Determination of Temperature 562-565 Relations between Thermometers, 562. Thermometric Equivalents, 563-565. III. Specific Gravity Tables 566-578 1. Baumg's Scale for Liquids Lighter than Water, 566. 2. Com- parison of Various BaumS Hydrometers for Liquids Heavier than Water, 567. 3. Twaddle's Scale for Liquids Heavier than Water, 568. 4. Comparison of the Twaddle Scale with the Rational Baume' Scale, 569. 5. Comparison between Specific Gravity Figures, Degree Baum6 and Degree Brix, 570-576. 6. Table of Weight and Volume Relations, 577, 578. IV. Alcohol Tables 579-584 V. Physical and Chemical Constants of Fixed Oils and Fats 585, 586 LIST OF ILLUSTRATIONS. FIGURE 1. 2. PAGE Lateral Section of Cylindrical Oil-still 21 Vertical Section of Cylindrical Oil-still 21 3. Oil-still with Superheated Steam 23 4. Still for Continuous Distilla- tion, 1 24 5. Still for Continuous Distilla- tion, II 24 6. Commercial Analysis of Crude Petroleum 37 7. Tagliabue's Open-cup Oil-tester 40 8. Saybolt's Open-cup Oil-tester. . 40 9. Abel Oil-testing Apparatus.... 41 10. Heumann Oil-test Apparatus. . 41 11. Stoddard Flash-test Apparatus 43 12. Tagliabue Cold-test Apparatus. 43 13. Fischer's Viscosimeter 44 14. Engler's Viscosimeter 44 15. Thurston's Lubricating i 1 - tester 45 16. Wilson's Chromometer, 1 47 17. Wilson's Chromometer, II 47 18. Rendering of Tallow by Steam. 61 19. Anglo-American Seed Press.... 62 20. Distillation of Free Fatty Acids 66 21. Wilson and Gwynne Apparatus for Decomposing Fats 66 22. Soap-coppers 69 23. W T ooden Soap-frames 72' 24. Iron Soap-frames 72 25. Soap-cutting Machine 73 26. Crystallization of Solid Fatty Acids 74 27. Stearic-acid Press 74 28. Candle-moulding Frame 76 29. Soxhlet Extractor 86 30. Westphal Specific Gravity Bal- ance 87 31. Boiling Linseed Oil over Free Fire 112 32. Boiling Linseed Oil with Steam 113 33. Distillation of Copal and Am- ber Resins 115 34. Vessel for Vulcanizing Caout- chouc '. 118 35. Three-roll Sugar-mill 138 36. Vacuum-pan 142 37. Quadruple Effect Evaporator.. 143 b8. Yaryan Evaporator (sectional view ) 144 39. Centrifugal for Sugars 146 40. Wetzel-pan 147 FIGURE 41, PAGE Sectional View of Sugar Refin- ery ( full page ) 149 42. Centrifugal for Sugar-cones.... 151 43. Diffusion Battery Elevation . . 152 44. Diffusion Battery Plan 153 45. Circular Diffusion Battery (full page ) 155 46. Filter-press for Sugar-scums . . 156 47. Osmogene 160 48. Steffen Process for Molasses . . . 163 49. Char-kiln for Sugar Refineries. 165 50. Klusemann Washer (full page) 166 51. Polariscope Scheibler Form . . 172 52. Payen's Rendement Method.... 178 53. Scheibler's Apparatus for Anal- ysis of Char 181 54. Hoffmann's Converter for Glu- cose Manufacture 190 55. Maubre's Converter for Glu- cose Manufacture 191 56. Linter's Pressure-flask 198 57. Varieties of Yeast, after Han- sen (full page) 2X)6 58. Effect of Temperature upon Fer- mentation 207 59. " Thick-mash " Process for Beer (full page) 214 60. Pasteurizing Wine in Casks. . . . 228 61. Apparatus for Determining Al- coholic Strength 236 62. Coffey Still (full page) 245 63. Derosne Still 247 64. Savalle Still 248 65. Element in Column Still, I 248 66. Element in Column Still, II... 248 67. Savalle Rectifying Column 250 68. Aleurometer of Boland 264 69. Quick-vinegar Process 269 70. Malt Vinegar Cask 269 71. Laval Cream Separator, 1 282 72. Laval Cream Separator, II 282 73. Fat-cutting Machine for Oleo- margarine 284 74. Churning-machine for Oleomar- garine 285 75. Cotton Fibre Magnified Thirty Times 304 76. Cotton Fibre Magnified Two Hundred Times 304 77. Sectional View of Stems and Bast Fibres 305 78. Flax Fibre under the Micro- scope 306 79. Hemp Fibre under the Micro- scope 306 xvii XV111 LIST OF DIAGRAMS. FIGURE PAGE 80. Jute Fibre under the Micro- scope 307 81. Manila Hemp under the Micro- scope . . . 307 82. China-grass under the Micro- scope 309 83. Vomiting Boiler for Paper- makers 315 84. Hollander, 1 310 85. Hollander, II. (full page) ... 318 86. Fourdrinier Machine (full page ) 323 87. Nitration of Cellulose in Cel- luloid Manufacture 330 88. Wool Fibre under the Micro- scope 343 89. Alpaca Hair under the Micro- scope 343 90. Silk Fibre under the Micro- scope 345 91. Spinning of the Silk Cocoon.. 345 92. Silk-conditioning 349 93. Magnified Section of Ox-hide. 356 94. Lime-pits and Liming Process (full page) 362 95. Unhairing Machines and Wash- ing Drums (full page) 367 96. Revolving Tumblers for Mo- rocco-tanning 368 97. Vacuum Pan for Glue Liquor Evaporation 378 98. Distillation of Sawdust from Retorts 389 FIGURE 99. PAGE Tar-condensera of Gas-works, I 403 100. Tar-condensers of Gas-works, II 403 101. Lime-purifiers of Gas-works. . 404 102. Simon-Carvers Coke-oven (full page ) 406 103. Tar-still 409 104. Griineberg and Blum Am- monia-still 414 105. Benzene Rectification Column. 416 106. Naphthalene Subliming-cham- ber 419 107. Anthracene-press . . . . ; 421 108. Sublimation of Anthracene... 422 109. Manufacture of Nitrobenzene. 450 110. Horizontal Aniline-still 451 111. Autoclave for Alizarin Manu- facture 454 112. Madder, Indigo, and Archil... 489 113. Cutting of Dye-woods 498 1 14. Extractor for Dye-woods .... 499 115. Cell of Dye-wood Extraction- battery 501 116. Vacuum-pan for Dye-wood Ex- tracts 502 117. Indigo Grinding-mill 505 118. Madder Bleach 523 119. Injector-kier 525 120. Steaming-chest for Turkey-red Yarn 540 121. Calico Printing machine 546 122. Steaming Indigo Prints 553 LIST OF DIAGRAMS. PAGE General View of the Refining of Crude Petroleum 22 View of the Practical Utilization of a Fat 67 Utilization of Cotton-seed and Products 80 Outline for the Analysis of Fatty Oils 92 Leed's Scheme for Soap Analysis 93 General View of the Composition of the Sugar-beet 135 Outline showing the Production of Sugar from the Sugar-cane 139 Outline showing the Production of Sugar from the Sugar-beet 157 View of Products Obtained from Sweet Milk 281 Outline of Tanning Process for Sole-leather 364 Qualitative Tests for Tanning Materials 373 General View of the Treatment of Wood-tar 390 General View of the Products of the Distillation of Coal 400 Scheme for the Distillation of Coal-tar 412 Development of Production Values from Coal by Distillation 455 Tables for the Identification of Coal-tar Dyes 471-473 Tables for the Detection of Coloring Matters upon the Fibre 476-484 Reactions of the Most Important Natural Dyestuffs 518 Table of Artificial Dye-colors which have Replaced or Compete with Natural Dyestuffs 556, 557 INDUSTRIAL ORGANIC CHEMISTRY. CHAPTER I. PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. I. Raw Materials. THE raw materials of this industry are hydrocarbons and products derived from them by alteration, which occur associated together in nature. They may be gaseous, liquid, or solid, and very frequently all three of these physical modifications are found admixed in the same crude material. As, on the other hand, they occur at times separate and distinct, they will be separately noted. 1. NATURAL GAS. Under this name is generally known now the mixture of inflammable gases that is found issuing from the earth in various localities. While it is chiefly in connection with the boring of wells for oil or salt, or as a constantly-forming product of decomposi- tion in coal-mines, that it has been obtained, we find that it often occurs entirely independently of these. ' ' Burning springs, ' ' as they have been termed, have been known from the earliest historical times. Those of Baku, on the Caspian Sea, are supposed to have been burning as early as the sixth century before Christ, and to have been a sacred shrine of the Persian fire-worshippers. The Chinese have employed natural gas for centuries in their salt-mines as a source of illumination. In the United States it was employed already in 1821, at Fredonia, New York, as a source of illumination, and for sixty years past has served as the fuel for the evaporation of brine at the salt-wells of the Kanawha Valley, West Virginia. The gas exists in the porous rock reservoirs under great pressure, 900 Ibs. per sq. inch closed pressure and 38 to 45 Ibs. open pressure having been measured. Yields of 15,000,000 cubic feet and in extreme cases 32,000,000 cubic feet daily have been attained in Ohio gas wells. John F. Carll estimated in 1889 that the Murrayville gas field in Western Pennsylvania has produced in four years 438,000,000,000 cubic feet, 13 14 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. which compressed under 900 Ibs. (60 atmospheres) pressure would occupy a storage space of 7,300,000,000 cubic feet. In chemical composition, natural gas is relatively uniform. It con- sists essentially of methane (marsh-gas), the first member of the paraffin series of hydrocarbons, which may be accompanied by ethane, propane, and the members of the paraffin series next following methane. Small quantities of hydrogen, carbon monoxide, and dioxide have been found to be present at times, while nitrogen is apparently an invariable impurity. The following table gives the results of analyses of natural gases, made in 1886, by Prof. F. C. Phillips for the Second Geological Survey of Pennsylvania. The localities chosen are all in Western Pennsylvania, with the exception of Fredonia, New York, which is intro- duced because of its historical interest: J oi =3 ft fi i 3 fi .*iS i- ti M 6 6 6 2 c"S ^ o S5 CONSTITUENTS. .a. c 55 a a o> a**? wl gg >- C -S S3* ^ u Be 11 "c 3 si ^ C 3 c r 02 | S tS " so OO l4 w i 5 Paraffin hydrocarbons 90.05 90.64 90.38 90.01 95.42 97.70 90.09 87.27 84.26 Olefine hydrocarbons Carbon dioxide . . . 0.41 0.30 0.21 0.20 0.05 0.20 Trace. 0.41 0.44 0.02 Oxveren . Trace. Trace. Trace. Trace. Trace. Trace. Trace. Trace. Trace. Nitrogen 9.54 9.06 9.41 9.79 4.51 2.02 9.91 12.32 15.30 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 With these may be compared the natural gas from two important petroleum-yielding localities in Europe, viz., Pechelbronn, in Alsace, and Baku, on the Caspian. Pechelbronn Pechelbronn Pechelbronn Baku Baku I. II. III. I. II. (Engler.) (Bugler.) (Engler.) (Schmidt.) (Schmidt.) Methane . . . 73.6 68.2 77.3 92.49 93.09 Olefines . . . 4.0 3.4 4.8 4.11 3.26 Carbon dioxide 2.2 2.9 3.6 0.93 2.18 Carbon monoxide 3.0 3.7 3.4 Hydrogen . . . . . 0.34 6.98 Oxygen . . . Nitrogen . . . 17.2 4.3 16.9 2.0 9.0 2.13 0.49 100.00 99.6 100.10 100.00 100.00 2. CRUDE PETROLEUM (syn. Erdoel, Naphtha, etc.). Under this heading is included the liquid product which is obtained so abundantly in various parts of the earth, either issuing from the ground naturally RAW MATERIALS. 15 or gotten by the boring of wells through the overlying rocks to the oil- bearing strata. The oldest and until recently the most important petro- leum district of the world is the Appalachian field of Western Penn- sylvania, extending from Allegany County, New York, through Penn- sylvania, southwesterly into West Virginia and Eastern Ohio. While the oils found in this district may differ considerably in gravity, color, and undoubtedly in chemical composition, the differences are not funda- mental, and with certain special exceptions the crude oils from various localities are all brought together by the pipe-lines and become mixed before going to the refineries. None of these Pennsylvania or West Virginia oils contain any appreciable amount of sulphur or other impurity which would require a modification of the general refining methods. The heavy oils of Franklin and Smith's Ferry, Pennsylva- nia, and some few other localities are so valuable for the manufacture of lubricating oils that they are collected and worked separately. . The Pennsylvania crude oil has in general a dark greenish-black color, appear- ing claret-red by transmitted light, and varies ordinarily in specific gravity from 0.782 to 0.850, or, as it is frequently expressed, from 49 B. to 34 B. In chemical composition it is essentially composed of hydrocarbons of the paraffin series C n H 2n+2 , the gaseous and the solid members of the series being alike held dissolved in the liquid ones, and smaller amounts of the hydrocarbons of the benzene series C n H 2n - G . According to Markownikoff, confirmed by Mabery, Pennsylvania petro- leum also contains hydrocarbons of a series C n H 2n , which he termed " naphthenes," but which are now generally known as methylenes. Within recent years another important field has developed, viz., Ohio, which includes the two distinct districts, the Lima oil district and the Macksburg district. The former is by far the more important, but the product is peculiar in that it contains sulphur, and has an offensive odor similar to Canadian crude oil. Careful analyses made in the author's laboratory have shown that it contains on an average 0.42 per cent, of sulphur, combined in relatively stable forms not decomposed by simple distillation.* Reference will be made to it in speaking of refining methods. Within recent years the extension of the Lima (or Trenton Limestone) oil-field westerly into Indiana has added to the production of this grade of oil. The most important localities in the United States, outside of the Pennsylvania and Ohio oil-fields, are Texas and California, in which latter State a blackish petroleum of rather heavier consistency than Pennsylvania petroleum is found quite abundantly. This California petroleum is peculiar in containing nitrog- enous bases of the pyridine and quinoline groups, and in leaving, instead Of paraffin, an asphaltic base or residuum. The Texas oil differs radically from Pennsylvania oil in being com- * Mabery identified in Ohio petroleum methyl, ethyl, normal propyl, iso- and normal butyl, pentyl, ethyl-pentyl, and hexyl sulphides and later other compounds of the formula C n H 2 nS to which he has given the name of "thiophanes." 16 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. posed chiefly of methylene hydrocarbons. It does not yield much burn- ing oil distillate and contains as much as 2 per cent, of sulphur, part of which exists as free sulphur in solution. The residue is asphaltic. Still more recent than the Texas oil development is that of the Mid- continent field, including specially Kansas and Oklahoma. The oil from this field varies greatly, and sometimes contains both an asphalt and a paraffin base. Closely related to the Pennsylvania and New York oil-fields is the oil district of Canada. This is in the neighborhood of Enniskillen, in the western section of the province of Ontario. The Canadian petro- leum, however, is distinctly different from that of Pennsylvania. It is darker in color, heavier in gravity, and is of a very offensive odor on account of sulphur impurity, and is therefore more difficult and expen- sive to refine. As before stated, it finds- a counterpart in the oil of Lima, Ohio. Second in importance to the Pennsylvania oil-fields, and even more prolific in the yield of individual wells, is the Russian petroleum district of Baku, on the Caspian. For detailed accounts of the extraordinary production of these wells, the reader is referred to Boverton Redwood's " Petroleum and its Products," 2nd ed., vol. i, p. 7, or to Engler's articles in Dingier 's Polytechnisches Journal, Bd. cclx and cclxi. The Russian petroleum has a higher gravity than the American, averaging 0.873, or 31 B., and has been found to be entirely different in its chemical composition, consisting for the most part of hydrocarbons of the series C n H 2H , isomeric with the olefine series, and called " naph- thenes. " As will be seen later, this difference in chemical composition involves a difference in the refining results. The most important of the other European petroleum-fields are those of Galicia, which produce a variety of oils, both light and heavy, either accompanying or independent of the ozokerite of the region, those of Hanover, which yield thick oils, varying in specific gravity from .862 to .910, and those of Alsace, which also yield oils predominantly heavy, and used chiefly for lubricants. The Asiatic petroleum-fields are those of Burmah, which have long been known to be very rich, and which, under British control, will now be developed, and those of Rangoon, in India, the oils from which are thick and heavy, yielding much lubricating oil and paraffin, and those of Japan. 3. CRUDE PARAFFIN. Under this head may be understood the more or less compact solid material which often accompanies crude petroleum, is deposited from it on standing, and in some cases is found in extensive deposits independently of it. Thus, a deposit of buttery consistency separates from some crude oils, such as Bradford oil, and adheres to the pumping machinery and derrick, forming a crust which has to be scraped off from time to time. The same oils deposit crude paraffin in the pipe-lines, necessitating a periodical scraping of the interior of the pipe-lines. Much of the deposit which accumulates in the storage-tanks of crude oil is of the same material. RAW MATERIALS. 17 More important, however, is the occurrence of solid native paraffin, under the name of " ozokerite," or earth- wax. The best-known locality for this native paraffin is Boryslaw, in Eastern Galicia, although it is found also in the Caucasian oil district, and in Persia under the name of " neftgil, " and some years ago was found in Southern Utah, in the United States. In color it varies from dark green to black, and possesses a lamellar or conchoidal fracture, according to the variety. It fuses between 56 and 74 C., or even higher. In chemical composition it does not differ much from the separated paraffin of petroleum oils. 4. BITUMEN AND ASPHALT. We may have liquid bitumens, usually called malthas, and solid bitumens, called asphalts. Both may be con- sidered as alteration products of petroleum hydrocarbons resulting from evaporation and oxidation. Maltha (or mineral tar) was first found at Bechelbronn, in Alsace, and was studied by Boussingault, who described it as a viscid, tarry liquid of bituminous odor and a specific gravity of .966. It contains besides hydrocarbons both sulphur and nitrogen. In the United States malthas are found in California in Kern, Ven- tura, and Santa Barbara Counties, as well as in Utah, Kentucky, Ten- nessee, and Texas. Those from California, which have been chemically examined, invariably contain some nitrogen present in the form of basic hydrocarbons. They also contain some water and dissolved gases. The purest of the solid bitumens are known sometimes as " glance pitch " or " gum asphaltum." Prominent among them is gilsonite, which is found in the Uintah Indian reservation in Wasatch and Uintah Counties, Utah. The purity of this product (generally ninety-eight per cent, soluble in carbon disulphide) is such that it finds large applica- tion in the manufacture of varnishes and insulating compounds, the production being some three thousand tons annually. Of solid asphalts, those of greatest commercial importance are the Trinidad Lake asphalt from the Island of Trinidad in the West Indies and the Bermudez asphalt from Venezuela, South America. The first of these contains in the crude state 39.83 per cent, of bitumen, 33.99 per cent, of earthy matter, 9.31 per cent, of vegetable non-bituminous matter, and 16.87 per cent, of water. After refining the water is elim- inated and the bitumen is raised to about sixty per cent. The Bermudez asphalt contains but 2.63 per cent, of mineral matter and over ninety per cent, of bitumen. The solid asphalts of California contain from sixty to ninety per cent, of bitumen, while the mineral matter in most cases is a very pure silica, or in some cases infusorial earth. Other solid asphalts, but less valuable, are those of Cuba and Syria, containing some seventy-five per cent, of a hard, brittle bitumen. Very important also are the bituminous limestones or ' ' rock asphalts ' ' of Europe. Among these may be mentioned those of Seyssel, France, Val de Travers in the canton of Neufchatel, Switzerland, Ragusa in Sicily, and Limmer and Vorwohle in Germany. These contain from five and three-tenths to fourteen per cent, of bitumen, and about eighty- 2 18 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. six to ninety per cent, of carbonate of lime, and as they are largely used both in this country and in Europe in the manufacture of asphaltic mix- tures or mastics, a table showing their exact composition is given : Seyssel, France. Valde Travers, Switzerland. Ragusa, Sicily. Limmer, Germany. Vorwohle, Germany. Bitumen 8.15 10.15 8.92 14 30 5.37 Calcium carbonate . . Magnesium carbonate . Clay and oxide of iron . Sand 91.30 .10 .15 88.40 .30 .25 88.21 .96 .91 .60 67.00 1?'. 52 90.80 .35 .59 2 55 .10 .45 .20 .45 .40 1.18 .34 100.00 100.00 100.00 100.00 100.00 In the United States the most important occurrence of bituminous limestone is that of Uvalde County, Texas, from which is obtained the product known as ' ' litho-carbon, " used in varnish-making and for insu- lating purposes. Related to the natural asphalts are also such minerals as Albertite, from the Albert mines in New Brunswick, and the Ritchie mineral from Ritchie County, West Virginia. The Torbane mineral, from Bathgate, Scotland, and Boghead coal, together with bituminous shales, also should be noted here. They form the crude material for the Scotch paraffin distillation. II. Processes of Treatment. 1. OF NATURAL GAS. If we refer to the composition of natural gas, as already stated, it will be seen that it is largely made up of methane and its homologues, with some nitrogen as impurity. The defines, or "illuminating hydrocarbons" of ordinary coal-gas, are practically absent in most cases. This at once indicates quite clearly the value of natural gas as a fuel and its lack of value in the natural state for illu- minating purposes. But that it can be readily converted into an excel- lent illuminating gas has been shown, and in Western Pennsylvania, where natural gas is abundant, it is being used for illumination as well as for fuel. To illustrate the treatment that is necessary for the pur- pose we may describe the McKay and Critchlow process, which has proven quite successful in practice. The apparatus consists essentially like the water-gas generators of a combustion-chamber filled with coal brought to a white heat by an air-blast and a fixing-ch amber above filled with fire-brick, where the gaseous products of the first reaction combine with oil vapors to form a permanent illuminating gas. The procedure is as follows: The fuel having been rendered thoroughly incandescent, and the fire-brick structure having been heated to a light orange tint, the air-blast is shut off, the lid of the cupola closed, and the gas outlet opened. Natural gas is then introduced into the ash-pit PROCESSES OF TREATMENT. 19 and forced up and through the incandescent fuel-bed, depositing its carbon on the surfaces of the fuel as decomposition is effected, and hydrogen gas is thus liberated, which, passing up through the open chamber, meets the vapors of the hydrocarbon, which are projected into the chambers by means of a steam- or gas-injector. All of these products of decomposition passing together into the upper or fixing chamber, a part of the hydrogen unites with the heavy hydrocarbons, producing the lighter hydrocarbons, while an intimate mixture of all the gases is effected, forming a completely permanent illuminating gas, which passes off through the water-seal, condensers, scrubbers, and purifiers to the holder in the ordinary w r ay. Natural gas is used quite largely now with Welsbach gas-mantles, and an excellent illumination is thus obtained. The most recent industry based upon natural gas is the compression of the gas by the aid of powerful compressors so as to liquefy the least volatile portions and thus obtain a gasolene yield, as the great demand for gasolene for automobile, motor-boat and manufacturing purposes has caused a great demand for such a light fraction. What is called "casing-head gas," that obtained in pumping crude oil, is best adapted. The gas from the deep wells of the California oil field are said to yield three gallons of gasolene per 1000 cubic feet of gas. Natural gas is also burned for the production of a very pure grade of lamp-black. This manufacture, first carried out at Gambier, Ohio, is now introduced at various places in the oil regions of Pennsylvania. The gas is burned from rows of burners placed in such position that the flame impinges upon slate or metallic slabs or revolving cylinders, and there deposits its carbon. In one building at Gambier, eighteen hundred burners have been used, consuming two hundred and seventy- five thousand cubic feet of gas per twenty-four hours. \ 2. OF CRUDE PETROLEUM. As petroleum has been shown to be a mixture of hydrocarbons of different volatility, the first operation would naturally be to effect a partial separation of these hydrocarbons by a process of fractional distillation. But, in fact, simpler lines of treatment were first tried. It was found that crude oils spread out over warm water in tanks and exposed to the sun were much improved in gravity and consistency. This process was chiefly employed for the production of lubricating oils, and the products were called " sunned oils." This was followed by the application of methods of partial evaporation or concentration in stills, either by direct application of heat or by the use of steam coils, carefully avoiding overheating. The products are called "reduced oils," and form the best material for the manufacture of high- grade lubricating oils. They will be referred to again. The process to which the great bulk o crude petroleum is submitted, however, is that of fractional distillation continued to the eventual coking of the resi- due. As the most valuable of the several distillates is that which is to be used as illuminating oil, the percentage of that distillate obtainable is an important item in an oil refinery. A normally-conducted frac- tional distillation of Pennsylvania petroleum will give from thirty-five to fifty-five per cent, of oil suitable for illuminating purposes, and from 20 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. twenty to thirty per cent, of lubricating oils. About 1865, however, it was found that if during the distillation the heavy vapors were made to drop back upon the hot oil in the still they became superheated and were decomposed. This process of destructive distillation or ''crack- ing" allowed of a notable increase of the illuminating oil fraction at the expense of the lubricating oil. So at present some seventy-five to eighty per cent, of burning oil is obtained, while the residuum from which the lubricating oil is gotten is reduced to six per cent. A general outline of the petroleum refining process as at present con- ducted is presented in tabular form on the accompanying diagram. The Results of a Normal Distillation of One Hundred Cubic Centimetres of Crude Oils are thus given by Engler : CRUDE OIL FROM Sp. gr. at V s C. Began to boil. Came over under 150 C. Between 150 C. and 300 C. Over 300 C. Pennsylvania (I.) Pennsylvania (II.) Galicia (Sloboda) . Baku (Bibieybat) . Baku (Balakhani) Alsace (Pechelbronn) Hanover (Oelheim) 0.8175 0.8010 0.8235 0.8590 0.8710 0.9075 0.8990 82 C. 74 C. 90 C. 91 C. 105 C. 135 C. 170 C. 21 per cent. 31.5 per cent. 26.5 per cent. 23 per cent. 8.5 per cent. 3 per cent. 38.25 per cent. 35 per cent. 47 per cent. 38 per cent. 39.5 per cent. 50 per cent. 32 per cent. 40.75 per cent. 33.6 per cent. 26.5 per cent. 39 per cent. 52 per cent. 47 per cent. 68 per cent. The Commercial Results usually obtained, on the other hand, are thus stated by the same authority: CRUDE OIL FROM Benzine and volatile oils. Burning oil, first quality. Burning oil, second quality. Residuum. 10 to 20 3 to 6 60 t 55 t 35 t cot 40 27 to 33 o75 65 345 o70 13.5 5 to 6 5 to 10 30 to 40 55 to 60 25 to 35 36 50 to 60 4 10.5 6 to 6 The process is generally divided into two quite distinct parts. The benzine and burning oil distillates are run from the same still, when the fluid residuum is transferred to what are usually called "tar-stills," in which the rest of the distilling operation is conducted. The crude-oil stills are of two forms, the cylindrical still, as illus- trated in section in Figs. 1 and 2, and the "cheese-box " still, although the latter is little used now. The former consists of a cylinder of boiler-plate, the lower half being generally of steel, thirty feet in length by twelve feet six inches in diameter. This still is set horizontally, as shown in the sectional view, in a furnace of brick-work, usually so con- structed that the upper part of the still is exposed to the air. The "cheese-box " still has a body and dome-shaped top of boiler-plate and a double-curved bottom of steel plate. It is thirty feet in diameter and nine feet in height, and is set on a series of brick arches. The working charge of the cylindrical stills is about seven hundred barrels of crude PROCESSES OF TREATMENT. 21 8.B 3 2.S. W *- B 3 a w * M " Oo "^ A *% P'B'P i&o" ?Scr 2. ai*% "!l M I 2 ^ O ^ 2. * ^CTQ 3 hH |"'^|^ | Q O G Ullfi il t) W 8*SS I a M 1 22 ? |ji jf mi II O {^' P ^* hP (to P *- 3 *- LLATE. PETF STILLE ifii* I r> g g-O-g r 55 . ^ B M * 3 C! p S S. n 3 (- 1 S ttB.5 c B s 5 W fH B OQ ' * ifjf ^ W O I ir^s ^*sr sT SP*S^ C *"^r1 of WS S3 S DC (t i i IE? "1 A- s :|"l5I 3 i3 w a B^O s -a s,2s J sr^ 1 o 2 P>g 2. c! H L. eL ff& S ~- Bs P-K H'5'^. S. m B 1 pjB'O ? 838 ' i III 22 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. oil, although more recently stills of one thousand barrels capacity have been used. The still is usually provided with coils of steam-pipes, both closed and perforated. The steam, issuing in jets from the perforated pipe, has been found to facilitate distillation by carrying over mechan- ically the oil vapors. FIG. 1. Lateral vertical section of cylindrical still. The condensing apparatus varies somewhat in the details of its con- struction, but consists essentially of long coils of pipe immersed in tanks, through which water is kept flowing. The terminal portions of the con- densing pipes all converge and enter the receiving house within a few FIG. 2. Transverse vertical section of cylindrical still. inches of each other. Near the extremity of each a trap in the pipe is made for the purpose of carrying away the uncondensable vapor. This may be allowed to escape, or is burned underneath the boilers or stills, effecting thereby a large saving in fuel. The condensing pipes generally deliver into box-like receptacles, with plate-glass sides, through which the running of the distillate can be observed, and from which test por- tions can be taken from time to time for the proper control of the process. PROCESSES OF TREATMENT. 23 The tar-stills are usually of steel, cylindrical in shape, holding about two hundred and sixty barrels, and are set in groups of two or more, sur- rounded by brick-work. They are either upright or horizontally placed, usage inclining now to the latter position. Vacuum-stills have been and are still used to some extent, especially in the preparation of reduced oils for the manufacture of lubricants and products like vaseline. Of course, the evaporation in these stills takes place rapidly, and at the lowest tem- perature possible, insuring a fractional distillation and not a decom- position. If superheated steam be used, moreover, instead of direct firing, it is possible to reduce oils to 26 B. without any production of pyrogenic products. A still arranged with superheated steam is shown FIG. 3. in Fig. 3. Continuous distillation has not proved commercially success- ful in the United States. In Russia, on the other hand, continuous dis- tillation has been eminently successful, being especially suited to Baku petroleum, as the quantity of burning oil separated being comparatively small, the residuum is not very much less fluid than the crude oil. The stills, each of the capacity of four thousand four hundred gallons, are arranged in groups or series of not more than twenty-five, as shown in Figs. 4 and 5, one of which is a front view, and the other a section, and a stream of oil is kept continuously flowing through the entire number. The crude oil, entering the first still, parts with its most volatile con- stituents; passing into the next still, has rather less volatile hydro- carbons distilled from it ; and, finally, flows from the last still in the con- dition of residuum, which in Russia is termed astatki, or masut. The several stills are maintained at temperatures corresponding with the boiling-points of the products to be volatilized. Superheated steam is used for all the stills, the steam being delivered partly under the oil and 24 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. partly above the level of the oil, that is, in the vapor space above. The fuel used under all the stills in Baku is petroleum residuum, or astatki. To recur, now, to the products of the first rough distillation of crude oil, the first fraction, known as the "benzine distillate," and amounting usually to twelve per cent, of the crude oil, is redistilled by steam heat in cylindrical stills, holding five hundred barrels, and is sometimes separated FIG. 4. into the following products: cymogene, 100 to 110 B. gravity; rhigo- lene, 90 to 100 B. gravity; gasolene, 80 to 90 B. gravity; naphtha, 70 to 76 B. gravity; benzine, 62 to 70 B. gravity. The time occupied in working the charge is about forty-eight hours. The percentage of these products varies, but, as a rule, amounts to about twenty-five per cent, of the first three collectively, rather more than FIG. 5. twenty-five per cent, of the naphtha, and about forty per cent, of the benzine. The deodorization of the benzine which is to be used for solvent purposes in pharmacy or the arts is effected somewhat after the manner to be described under burning oils by the action of sulphuric acid. Only the proportion of acid used is much smaller and the agitation is effected by revolving paddles instead of by an air-blast. One-half of one per cent, is sufficient in this case. Other processes have been proposed for the deodorization, such as the use of dilute sulphuric acid and potassium PROCESSES OF TREATMENT. 25 permanganate, followed by sodium hydroxide, which oxidize the impuri- ties and sweeten the product. The treatment of the illuminating oil fraction is a more important process. It must be freed from the empyreumatic products resulting from the distillation, which give it both color and disagreeable odor. To effect this it is subjected to a treatment with sulphuric acid, washing with water and a solution of caustic soda. This operation is conducted in tall cylindrical tanks of wrought iron, lined with sheet-lead, which are called "agitators." The bottom is funnel-shaped, terminating in a pipe furnished with a stopcock for drawing off the refuse acid and soda wash- ings. The distillate to be treated must be cooled to at least 60 F., and before the main body of acid is added for the treatment, any water present must be carefully withdrawn. This is done by starting the agitation of the oil by the air-pump and introducing a small quantity of acid. This is allowed to settle, and withdrawn. The oil is now agitated, and about one-half of the charge of acid is introduced gradually from above. The agitation is now to be continued as long as action is indicated by rise of temperature, when the dark "sludge acid " is allowed to settle, and withdrawn. The remaining portion of acid is added, and a second thorough agitation takes place. The whole charge of acid needed for an average distillate is about one and one-half to two per cent., or about six pounds of acid to the barrel of oil. The acid, as drawn off, is dark-blue or reddish-brown in color, and is charged with sulpho-compounds of the hydrocarbons other than paraffins and poly- merized products, while free sulphur dioxide gas is present in abun- dance. The oil, after treatment, consists of the paraffin hydrocarbons almost freed from impurities. In color it has been changed to a very light straw shade. The oil is now washed with water introduced through a perforated pipe running around the upper circumference of the tank. This water percolates through the body of the oil, removes the acid, and is allowed to escape in a constant stream from the bottom. When the wash-water shows no appreciable acid taste or reaction, the washing is stopped, and about one per cent, of a caustic soda solution of 12 B. is in- troduced, and the oil is again agitated. When this is drawn off, the oil is ready for the settling tanks. A washing with water after the soda treatment is sometimes followed, but it is not general. A washing with dilute ammonia is also sometimes used to remove the dissolved sulpho- compounds. The settling tanks are shallow tanks, exposed to air and light on the sides, and here any water contained in the oil settles out, and the oil becomes clear and brilliant. They are provided with steam- coils for gently warming the oil in cold weather to facilitate this separa- tion. A spraying of the finished oil to raise the fire-test by volatilizing a small quantity of the lighter hydrocarbon present was formerly prac- tised at this stage, but this result is now obtained by "steam-stilling " and collecting the volatile vapors. The Lima oil and Canadian oil, which, as before stated, contain sul- phur impurity, cannot be refined and good illuminating oils obtained by this simple treatment with acid and alkali. Various methods of 26 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. treatment have been proposed and patented for these oils, such 'as the alternate treatment with litharge and caustic soda, distillation over finely-divided copper and iron, but the method finally adopted and now in successful use is to distil over a mixture of oxides of copper and lead, which take up the sulphur. The oil is also sold for fuel purposes. This latter utilization has been one of great importance, and it is employed in all classes of manufacturing establishments with great success and economy as a substitute for solid fuel. "With the aid of injector burners, it has been found possible to use it in smelting and annealing furnaces, in all kinds of forges, in burning brick, tiles, and lime, and for raising steam with all forms of boilers. It is used in these burners in connec- tion with either steam or compressed air. The residuum of the original crude-oil distillation is, as was said, distilled from the " tar-stills." The "first runnings, constituting from twenty to twenty-five per cent., will have a gravity of 38 B., and are returned to the crude-oil tank for redistillation, or are treated and purified as burning oil. The paraffin oil which now runs over may be caught in separate lots as it deepens in color and increases in density, or it may be all received together to be treated in the paraffin agitator with acid and purified for the separation of paraffin wax. The agitator in this case must be provided with steam-pipes, so that its contents can be kept perfectly liquid, and the charge of acid is larger, amounting to three, four, or even five per cent. The treatment includes the usual washing with water and soda, all at the proper temperature.* After settling, the paraffin oil goes to the chill-rooms, where, by the aid of the ammonia refrigerating machines and the circulation of cooled brine, the whole mass is brought to a semi-solid condition. This is pressed between bagging by hydraulic pressure, is filter-pressed, or more gen- erally at present is "sweated," and the refined heavy oil which drains off; is collected as lubricating oil. Its gravity should be about 32 B., fire-test, 325 F., and cold test, 30 F. The press-cake may be broken up, melted, and recrystallized, and then submitted to still greater pressure at a higher temperature (70 F.) than before, when it is gotten as " refined wax." To convert it into block paraffin, it must be washed with benzine, pressed, melted, and filtered through bone-black or other filtering medium, when it is gotten perfectly colorless and solidifying to a hard, translucent block. The characters of paraffin will be referred to farther on. The distillation of residuum is continued until the bottom of the still becomes red-hot, when yellow vapors issue from the tail-pipe, and a dense resinous product, of a light-yellow color, and nearly solid consistency, distils over. This "yellow wax " contains anthracene, chrysene, picene, and other higher pyrogenic hydrocarbons. Its use at present is to add * With the lubricating oils from certain crude petroleums, it is found advan- tageous not to wash after the acid treatment, but to treat immediately with a strong caustic lye (of 33 B.), and then to wash as a final step. This is said to prevent the emulsifying of the oil and water which sometimes takes place and greatly re- tards the separating out of the oil. PROCESSES OF TREATMENT. 27 it to paraffin oils to increase density and lower cold test. Its chemical character will be referred to again. The coke remaining in the tar-still at the end of the process amounts to about twelve per cent., and is largely used in the manufacture of elec- tric-light carbons. Reduced oils gotten by careful driving off of the light fractions of the crude petroleum, without cracking, as stated above, are of great value as lubricants. They are generally made by vacuum dis- tillation and the use of superheated steam instead of direct firing. They are either brought into the market at once, without further treatment, or after a bone-black or clay filtration. This production of filtered oils is usually combined with the manufacture of vaseline, or petrolatum, as it is now known in the United States Pharmacopoeia. Taking a vacuum residuum as the raw material, this is melted and run on to filters of fine granular w r ell-dried bone-black. The filters are either steam-jacketed or are placed in rooms heated by steam-coils to 120 F. or higher. The first runnings are colorless, and all up to a certain grade of color go to the manufacture of vaseline. Beyond that the filtrate is known as " filtered cylinder stock," and is used as a lubricant exclusively. 3. OF OZOKERITE AND NATURAL PARAFFIN. The Galician ozokerite is in the main a natural paraffin, but contains some oil in mechanical admixture. Until within ten to twelve years ago it was worked exclu- sively for the production of paraffin, but now not more than one-third of the annual production is so worked. The most of it is distilled, yielding five per cent, of benzine, fifteen to twenty per cent, of illu- minating oil, fifteen per cent, of "blue oil," and about fifty per cent, of paraffin. The " blue oil " is a buttery-like mixture of heavy oils with paraffin crystals, and corresponds to a paraffin oil as distilled from petroleum. It is run into filter-presses and pressed, first cold, and then the press-cake broken up and pressed warm to remove the adhering oils. If the paraffin scale so obtained is to be worked up into block paraffin, it is repeatedly treated with benzine of not over .785 specific gravity, and pressed, then melted and filtered through bone-black, as before described under petroleum paraffin. If the ozokerite is to be worked up as a whole into the wax-like product known as Ceresine, the operation may be conducted in one of two ways. The older method was, after a preliminary melting of the ozokerite, to free it from earthy impurities, and continuing the heating until all water was driven out of the melted mass, to treat it with ten per cent, of sulphuric acid as long as sulphurous oxide was evolved. This was followed by treatment with water and soda solution. To more thoroughly separate out the black carbonaceous matter produced by the action of the sulphuric acid, one-half to one per cent, of stearic acid is added, and this then saponified with caustic soda. The soap so formed carries down all carbonaceous matter with it, and allows the ceresine to be filtered clear by using filter-paper. The product is the Yellow Ceresine, much resembling beeswax. The White Ceresine, resembling bleached beeswax, is gotten by melting the yellow ceresine by the aid of 28 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. steam, digesting it with bone-black, with frequent stirring, and filtering through paper. The newer method, more frequently followed now, is to extract the ozokerite with benzine and ligroine. The forms of appa- ratus devised for this purpose allow of a complete exhaustion of the ozokerite mass and a subsequent recovery of the solvent used in the extraction. The natural paraffin that separates spontaneously from crude petro- leum, and accumulates at times, as before mentioned, in pipe-lines, etc., is chiefly used as a basis for the manufacture of vaseline and similar products, being melted and filtered through bone-black, as already described. 4. OF NATURAL BITUMENS AND ASPHALTS AND OF BITUMINOUS SHALES. The asphalt or solid bitumen from the Island of Trinidad is exported largely to the United States, where it is used in the manu- facture of roofing materials and of asphalt pavements. It yields from one and three-fourths to two and a half per cent, of paraffin on dis- tillation, and contains sulphur as an invariable constituent. Efforts made to manufacture illuminating and other oils from the asphalt have failed of practical results. Within recent years artificial asphalts have been made by a variety of methods. As already mentioned, the California petroleums all seem to have an asphaltic instead of a paraffin base. Hence the residuum from the refining of California crude oils is manufactured into artificial asphalts. As much as eleven per cent, of artificial asphalt has been obtained in practice from Ventura County petroleum. Again, artificial asphalts have been made by treating Lima and Oklahoma oil residuums with a current of heated air whereby a solid tenacious mass is obtained by polymerization and oxidation. Byerlite and Sarco asphalts are thus obtained. Still another process consists of melting oil residuums with sulphur and heating until a product is obtained which becomes solid on cooling, while hydrogen sulphide is set free. An interesting production of arti- ficial asphalt was that of Dr. W. C. Day, who distilled a mixture of fish and pine wood and then submitted the oil obtained to a second destruc- tive distillation. The residuum left when the distillation was carried to about 425 C. solidified to a black, shining mass, which in physical properties and chemical composition strikingly resembles Utah gilsonite. Very much more important are the industries based upon the dis- tillation of bituminous shales. As these shales do not contain either liquid or solid hydrocarbons as such, but much more complex com- pounds called bitumens, the distillation is exclusively a destructive one, and the character of the distillation products becomes dependent upon the conditions of the operation, temperature being the most important consideration. The theory of destructive distillation will be entered upon at length later (see p. 385), and we will here only say that for paraffin and illuminating oil production the distillation is essentially a low-temperature one. The material originally used in Scotland was Boghead coal, or the PROCESSES OF TREATMENT. 29 Torbane Hill mineral from Bathgate, near Glasgow., which was exhausted in 1872. This yielded thirty-three per cent, of tar or oily distillate and one to one and one-half per cent, of crude paraffin. At present shales are used which furnish about thirteen per cent, of tar. The material for the German paraffin production is an earthy brown coal, which, when dry, is of a light-brownish or yellowish color and crumbling char- acter; it yields on an average 8.1 per cent, of tar and .G per cent, of paraffin. The shales are usually distilled with some steam, which increases the amount of the tar, as well as the ammonia from the shale. The distillation may be intermittent, but in Scotland is now carried on in a continuous process by the two methods devised by Hen- derson and by Young & Beilby respectively, the exhausted shale being dropped from the bottom of the upright retort into a combustion-chamber beneath. As the spent shale sometimes contains as much as from twelve to fourteen per cent, of carbon, this, with the uncondensed gas of the distillation, suffices for fuel. The several products of the distillation are (1) gas, which is freed from gasolene vapors by passing through a coke tower, down which heavy oil is trickling; (2) watery or ammo- niacal liquor, which is obtained to the amount of from sixty to eighty gallons per ton of shale, and yields from fourteen to eighteen pounds of sulphate of ammonia per ton worked; (3) oily liquor, or tar proper, of dark greenish color, and ranging from .865 to .880 in specific gravity, varying in amount from thirty to thirty-three gallons per ton of shale used. This is distilled in cast-iron stills holding from two hundred to two thousand gallons, for the purpose of purifying it, until only coke amounting to from five to ten per cent, of the tar is left. The mixed distillates (the paraffin magma being added to the others), according to the usage of the German paraffin-works, are stirred with two per cent, by volume of caustic soda solution in order to take up phenols and ' ' creosote, ' ' together with other acid products ; the soda washings drawn off below, and the supernatant liquid, after washing with water, is agitated with five per cent, of sulphuric acid. The refined oil is now fractionally distilled. The first fraction (specific gravity .60 to .68) is a gasolene used for carburetting illuminating gas; the second (specific gravity .68 to .76) is naphtha, used as a solvent; the third (specific gravity .81 to .82) is illuminating oil; the fourth lubricating oil (specific gravity .865 to .900). The next distillate solidifies on cooling, yielding brown crystals of hard paraffin, whose mother-liquor, removed by a filter-press, is "blue oil," whence more but soft crystals can be obtained by artificial refrigeration. The mother-liquid of these is again treated with vitriol and soda and distilled ; the earlier fractions constitute heavy illuminating oil, the later lubricating oil. The percentage of solid paraffin gotten from the crude shale oil is from eleven to twelve and a half per cent. The shale oil does not yield any product corresponding to vaseline. B. Hiibner, a German paraffin manufacturer, believing that the distillations of the process just described act injuriously upon the quantity and hardness of the paraffin obtained, has modified the process as follows. He treats the crude shale oil with sulphuric acid, 30 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. and, after the separation of this, distils the oil over several per cent, of slaked lime. After the crystallization of the paraffin from the dis- tillate, it is purified by washing with shale oils and pressing. He thus avoids one distillation and obtains a larger yield of paraffin, distinctly harder in character than the usual product. In the Scotch shale-works the distilled oil is treated first with sul- phuric acid and then with caustic soda, as in the purifying of petroleum oils, and then fractionally distilled. These fractions are again treated with acid and alkali before being considered pure enough for the market. In some works (as those at Broxburn) continuous distillation is prac- tised, so that a set of three boiler stills and two residue- or coking-stills, used together, can put through thirty-five thousand gallons of crude oil per day. The solid paraffin, by careful processes of extraction, can be brought up to twelve and a half per 'cent. HI. Products. 1. FROM NATURAL GAS. (a) Fuel Gas. The great value of natural gas as fuel for manufacturing and industrial purposes has only been realized in recent years, and it was rapidly introduced as a substitute for coal and coke. In Western Pennsylvania and Ohio, particularly in Pittsburg and its vicinity, for manufacturing purposes, it had for a time almost entirely displaced coal and coke, but its production has reached a maximum, and is now rapidly falling off despite the opening of new wells. That natural gas, largely made up of methane and similar hydro- carbons, is one of the best of gaseous fuels is seen from the accompany- ing table, prepared by a committee of the American Society of Mechan- ical Engineers: Table showing Comparative Effects of Different Gas Fuels. Number of cubic feet needed Heat units yielded by to evaporate 100 pounds one cubic foot. of water at 212 F. Hydrogen 183.1 293 Water gas (from coke) 153.1 351 Blast-furnace gas 51.8 1038 Carbonic oxide 178.3 313 Marsh gas 571.0 93.8 The comparison of its work with that accomplished with solid fuel, as carried out at the works of Carnegie Bros. & Co., in Pittsburg, is also given by the same committee. Using the best selected coal, and charging the furnace in such manner as to obtain the best results, the maximum with coal was nine pounds of water evaporated to the pound of coal con- sumed. "In making the calculations, the standard seventy-six-pound bushel of the Pittsburg district was used; six hundred and eighty-four pounds of water were evaporated per bushel, which was 60.90 per cent, of the theoretical value of the coal. When gas was burned under the same boiler, but with a different furnace, and taking a pound of gas to be equal to 23.5 cubic feet, the amount of water evaporated was found to be PRODUCTS. 31 20.31 pounds, or 83.40 per cent, of the theoretical heat-units were utilized. ' ' (6) Gasolene. The production of a light gasolene from "casing-head gas " has already been alluded to. It is now produced in Pennsylvania, West Virginia, Ohio, and especially in California, where the gas from deep wells is specially adapted to yield a considerable fraction. The product is a very light gasolene (of 85 to 95 B.), and is usually blended with a heavier naphtha to yield a commercial product. (c) Lamp-Uack. The burning of natural gas so as to cause separation of carbon, which is then collected as lamp-black, has been referred to. The lamp-black so manufactured has been shown to be of great purity. It is miseible with water, does not color ether, and is free from oily matter. A sample of it analyzed by Professor J. W. Mallet, of the Uni- versity of Virginia, gave the following results: Specific gravity at 17 C., after complete exhaustion of air, 1.729. The percentage of composition was as follows: Carbon 95.057 Hydrogen 0.665 Nitrogen 0.776 Carbon monoxide 1.378 Carbon dioxide 1.386 Water 0.622 Ash (Fe 2 O, and CuO) 0.056 99.940 (dy Electric-light Carbons. Still another use for carbon from natural gas is the manufacture of carbons for electric arc-lights, the purity of the material making a very pure and uniform carbon pencil possible. 2. FROM PETROLEUM. The names of commercial products obtained from petroleum have, of course, been almost infinitely varied, as each manufacturer has his trade names for his special products. We shall only designate the generally-accepted classes of products. Beginning with the lightest, we have : Cymogene, gaseous at ordinary temperatures, but liquefiable by cold or pressure. Boiling-point, C. (32 F.). Specific gravity, 110 B. Used in the manufacture of artificial ice. Rhigolene, condensable by the use of ice and salt. Boiling-point, 18.3 C. (65 F.). Specific gravity, 0.60 or 100 B. Used as an anaes- thetic for medical purposes. Petroleum Ether (Sherwood oil). Boiling-point, 40 to 70 C. Specific gravity, .650 to .660, or 85 to 80 B. Used as a solvent for caoutchouc and fatty oils, and for carburetting air in gas-machines. Gasolene (canadol). Boiling-point, 70 to 80 C. Specific gravity, .660 to .690, or 80 to 75 B. Used in the extraction of oil from oil- seeds, of grease from raw wool, and in carburetting coal-gas. Naphtha (Danforth's oil). Boiling-point, 80 to 100 C. Specific gravity, .690 to .700, or 76 to 70 B. Used for burning in vapor-stoves 32 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. and street-lamps, as a solvent for resins in making varnishes and in the manufacture of oil-cloths. Ligroine. Boiling-point, 80 to 120 C. Specific gravity, .710 to .730, or 67 to 62 B. For solvent purposes in pharmacy, for burning in sponge-lamps, and in extracting fat from bones. Benzine (deodorized). Boiling-point, 120 to 150 C. Specific gravity, .730 to .750, or 62 to 57 B. Used as a substitute for turpen- tine, for cleaning printers' type, and for dyers', scourers', and painters' use. The three grades last mentioned are sometimes mixed and under the commercial names of " gasolene " or " naphtha " used for the small motors in naphtha launches and motor boats and in automobiles. The official "benzinum " of the U. S. Pharmacopoeia has a specific gravity of 0.638 to 0.660 at 25 C., and boils between 45 and 60 C. Burning Oil, or Kerosene. The different burning oils are known often by special names, of which the number is legion, but they are graded by the American petroleum exporters chiefly according to the standards of color and fire-test. The colors range from pale-yellow (standard white) to straw (prime-white) and colorless (water- white). The fire-tests (see p. 40), to which the commercial oils are mostly brought, are 110 F., 120 F., and 150 F. ; that of 110 going mainly to the continent of Europe and to China and Japan, and that of 120 to England. An oil of 150 P., fire-test, and water-white in color, is known in the trade as " headlight oil." An oil of 300 F., fire-test, and specific gravity .829, is known as "mineral sperm," or "mineral colza oil." "Pyronaphtha " is a product from Russian petroleum, somewhat similar to mineral sperm oil. It has a specific gravity of .865, and fire-test of 265 F. Lubricating oils from petroleum have assumed an importance which is increasing every year. Some crude petroleums, like those of Franklin and Smith's Ferry, Pa.; Mecca, Ohio; Volcano, W. Va., and other local- ities, are natural lubricating oils, requiring little or no treatment to fit them for use. The other petroleum lubricating oils are gotten in one of two ways. Either by driving off the light hydrocarbons from the crude oil, yielding what is called a " reduced oil " (see p. 27), or they are the oils gotten by distilling the petroleum residuums in tar-stills. The lightest of the lubricating oils, varying in gravity from 32 B. to 38 B., are frequently called "neutral oils." They are largely used for the purpose of mixing with animal or vegetable oils, and it is there- fore necessary that they should be thoroughly deodorized, decolorized, and deprived of the blue fluorescence or "bloom " characteristic of petroleum distillates that contain paraffin. The first two results are accomplished by bone-black or clay filtration, the last in various ways, such as treatment with nitric acid, addition of small quantities of nitro- naphthalenes, etc. Heavier lubricating oils are called "spindle " and "cylinder " oils. The most important characters to be possessed by these oils are high fire- test, low cold-test, and a high viscosity. (See analytical tests, p. 36.) PRODUCTS. 33 In the matter of lubricating oils the Russian products are, it is now admitted, distinctly superior in most respects to the American. This is because of the entire difference in the chemical composition of the two, the hydrocarbons characteristic of the Russian oil being heavier and showing less tendency to solidify at low temperatures than those of the American oils. The following statement from Boverton Redwood will illustrate this: Viscosity Viscosity Loss in viscosity, at 70 F. at 120 F. per cent. Russian oil (sp. gr. .913) 1400 166 88 American oil (sp. gr. .914) 231 66 71 Russian oil (sp. gr. .907 ) 649 135 79 American oil (sp. gr. .907) 171 58 66 Russian oil (sp. gr. .898) 173 56 67 American oil (sp. gr. .891 ) 81 40 50 Refined rape oil (for comparison) 321 112 65 It is true that the disproportion is chiefly at lower temperatures, the Russian oil losing its body relatively faster than the less viscous Ameri- can oil. Gas Oils. Since the development in recent years of the Texas oil production on a large scale, as the yield of burning oil fraction is small, much of a product known as "gas oil " (because of its use for the produc- tion of a rich oil gas by destructive distillation) has been made. This is a fraction intermediate between the burning oils and lubricating oil, relatively thin and boiling between 200 C. and 300 C. Paraffin differs somewhat in its hardness and melting point according to the source from which it is derived. The petroleum paraffin is manu- factured generally in three qualities, fusing at 125 F. (51.6 C.), 128 F. (53.3 C.), and 135 F. (57.3 C.), respectively; paraffin from shales melts at 56 C., while that from Rangoon tar melts at 61 C. and that from ozokerite at 62 C. The harder varieties are bluish-white, translu- cent, and glassy on the surface, while the softer varieties are alabaster- white, dull in lustre and only translucent when heated. The harder varieties are resonant. Paraffin is readily soluble in ether, benzine, and all light hydrocarbons, ethereal and fatty oils and carbon disulphide, not entirely in absolute alcohol; while ordinary alcohol only takes up 3.5 per cent, of it. It mixes with stearine, spermaceti, and wax in all proportions. Exposed for some time under a slight pressure to a tem- perature below its melting point, paraffin wax undergoes a molecular change and becomes transparent: but upon a change of temperature, or upon being struck, the original translucent appearance returns. The official "paraffinum " of the U. S. Pharmacopoeia is stated to have a specific gravity of 0.890 to 0.905 at 25 C., and melts at from 51.6 C. (125 F.) to 57.2 C. (135 F.). The harder variety of paraffin is used chiefly in candle-making, for which purpose, however, a small proportion (five per cent.) of stearic acid must be added to it to prevent the softening and bending of the candle. It is also used for finishing calicoes and woven goods, to the 3 34 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. surface of which, it imparts lustre. The softer varieties are used for mixing with wax and stearic acid in candle-making, for the preparation of translucent and water-proof paper of all grades, for impregnating Swedish matches, for the adulteration of ''chewing gums," and, in recent years, for "enfleurage " or extracting delicate perfumes from flowers. Vaseline. This product (petrolatum of the United States Phar- macopoeia and unguentum paraffini of the German Pharmacopoeia) may be obtained from several of the raw materials already mentioned. In the United States, as the name petrolatum indicates, it is a petroleum product and may be called " natural vaseline," as it is merely a purified preparation of naturally existing petroleum constituents; in Germany, and elsewhere in Europe, it is either extracted from other sources (pomade ozokerine), or, as the name unguentum paraffini indicates, it is an "artificial vaseline " made by the solution of paraffin in paraffin oil. American vaseline, as made by the Chesebrough Company and others, is gotten by taking a vacuum residuum (see p. 27) and, without any treatment with sulphuric acid or other chemicals, simply filtering it through heated bone-black. In this way the amorphous character of the hydrocarbons is not changed and no crystalline paraffin is produced, as would be the case if it were a distillation product, and, moreover, no traces of sulphonic acids can remain from the acid treatment to inter- fere with its use as a basis of medicinal ointments. The petrolatum of the United States Pharmacopoeia is an unctuous mass varying in color from yellowish to light amber. It is transparent in thin layers and is completely amorphous. It has a specific gravity at 60 C. (140 F.) of from 0.820 to 0.850. It melts at from 45 to 48 C. (113 to 118.4 F.). Petrolatum liquidum of the U. S. Pharmacopoeia is a colorless yel- lowish oily liquid of specific gravity 0.870 to 0.940 at 25 C. The German vaseline, or unguentum paraffini, is made by taking one part of ceresine (paraffinum solidum) and dissolving it in three parts of a paraffin shale oil, known as "vaseline oil " (paraffinum liquidum). This artificial vaselin'e, as Engler and Bohm have shown,* easily becomes granular on chilling, and shows its composite nature moreover by readily separating on distillation into ceresine and oil. The natural vaseline has greater homogeneity and is more viscous, although at high temperatures it seems to absorb more oxygen than the artificial preparation. At temperatures not exceeding 30 C. the oxygen absorption seems to be practically nothing in either case. Vaseline is largely used in pharmacy and medical practice as a basis of ointments and pomades. Crude Fuel Oil. Much of the California and Texas oil which is of inferior value for refining is burned as fuel with suitable forms of burners. The calorific value of such crude petroleums is quite high. Poole (Calorific Powers of Fuels, 2nd edition, pp. 251 and 252) gives the following values: Pennsylvania crude 20736 B. T. U., Lima, Ohio, crude 21600 B. T. U., Petrolia, Canada, crude 20530 B. T. U., Baku, * Dingier, Polytech. Journal, 262, p. 468. PRODUCTS. 35 Russia, 20160 B. T. U., Residuum, Balacheny 21060 B. T. TL, Galician oil 18416 B. T. U. 3. FROM OZOKERITE AND NATURAL PARAFFIN. The character of several of the products now obtained from Galician ozokerite, viz., illu- minating and lubricating oils and paraffin, has been sufficiently described under other heads. The peculiar product known as Ceresine, gotten from ozokerite without distillation, remains to be described. It resembles beeswax very greatly in appearance, but is of lower specific gravity, ranging from .915 to .925, while wax is from .963 to .969. The fusing point of ceresine varies from 68 C. to 80 C. Ceresine, with a fusing point of over 75 C., shows a fracture and structure like that of wax. Its behavior to water, alcohol, ether, chloroform, fatty and ethereal oils is exactly like that of paraffin. Ceresine is extensively used as a substi- tute for wax as well as for most of the uses before given for paraffin. It is commended especially for the formation of matrices for galvano- plastic work, proving in this respect superior to gutta-percha. It is also being used instead of gutta-percha for hydrofluoric acid bottles. 4. FROM BITUMENS, ASPHALTS, AND BITUMINOUS SHALES. The asphaltic limestones of Europe (see p. 18) furnished the earliest known technical products, and they are still worked extensively in the manu- facture of a variety of useful substances. Asphaltic limestones con- taining from eight to twelve per cent, of bitumen when pulverized and heated furnish a powder which by compression is made to agglutinate and forms a very satisfactory surfacing for roads, etc. Asphalt mastic is made in Europe by incorporating with the natural asphaltic limestone purified and softened bitumens like that of Trinidad in such proportion that the resulting composition, containing from fifteen to twenty per cent, of bitumen, is available for asphalt coating purposes. Asphalt Paving Composition. In this country, the solid asphalts like the imported Trinidad are first softened by the incorporating with them of petroleum residuums or liquid asphalts, and then mixed with quartz sand and finely powdered rock, in such proportion that the voids between the grains of sand are properly filled. This constitutes the asphalt paving surface and is spread with the aid of a binder course of coarser material upon a cement substratum. From the crude shale oil, already described, the following products are obtained: Shale Oil Benzine. Specific gravity .665 to .720, boiling-point 80 to 90 C., is colorless, of ethereal odor, and slightly peppermint-like taste. It is used somewhat as a cleansing benzine, but mainly in the purifying of the shale paraffin. Photogene (shale naphtha). Specific gravity .720 to .810, boiling- point 145 to 150 C., has a slight ethereal odor and peppery taste. It dissolves sulphur, phosphorus, iodine, fats, resins, caoutchouc, etc. It is used somewhat for illuminating purposes and for dissolving the fat from bones and bleaching them in the preparation of artificial ivory. Solar oil comes into the market, according to Grotowski, in two grades, 36 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. known as prima and secunda oils, one with specific gravity .825 to .830 and a boiling-point 175 to 180 C., and the other with specific gravity .830 to .835 and a boiling-point 195 to 200 C. The oils are of slight, yellowish color, and on exposure to air and light lose their free burning qualities, somewhat through the resinifying of the trace of creosote which may remain in them. The fire-test of the solar oil is generally above 100 C., and they are in general both cheap and excellent burning oils. Paraffin Oil. The paraffin itself has been described under a previous heading. The expressed paraffin oil is used considerably as a lubricating oil, but is of greatest importance for gas-making. The gas from this paraffin oil is especially rich in illuminating hydrocarbons and is free from the ordinary impurities of coal-gas. It is extensively manufactured in Germany, in the Hirzel and Pintsch forms of apparatus, and in Eng- land by the Pintsch, Keith, and Alexander & Patterson processes, and compressed for use in railway carriages, etc. Its characters will be referred to more especially under the heading of illuminating gases. IV. Analytical Tests and Methods. 1. FOR NATURAL GAS. These are the methods employed for the analysis of all varieties of illuminating gas, and will be referred to under that heading. (See p. 429.) 2. FOR CRUDE PETROLEUM. According to the rule of the New York Produce Exchange, "crude petroleum shall be understood to be pure natural oil, neither steamed nor treated, free from water, sediment, or any adulteration, of the gravity of 43 to 48 B." (0.809 to 0.786 sp. gr.). In order to determine whether the petroleum is a ' ' pure natural oil " a sample is subjected to fractional distillation, each fraction being one- tenth of the crude oil by volume, and the density of the several distillates is determined. The regular gradation of the densities of the fractions so obtained is taken as a satisfactory indication that the oil is a natural product. To judge of the commercial value of a crude petroleum a fractional distillation is also desirable. For this purpose Engler's system of dis- tillation is to be recommended. He uses a distillation flask, the shape and dimensions of which in cubic centimetres are to be seen hi Fig. 6. One hundred cubic centimetres of the oil are introduced into the flask by the aid of a pipette, and heat is applied. At first wire gauze is inter- posed between the burner and the flask, but afterwards the naked flame is employed, the heat being so regulated that from two to two and a half cubic centimetres of distillate pass over per minute. In this way fractions differing from each other in boiling-point by 50, 25, or 20 C. can be obtained. As soon as the requisite temperature (150 C. for the first fraction) is attained, the lamp is withdrawn until the temperature has fallen at least 20 C., when the oil is reheated to the boiling-point and again cooled, this process being repeated until no more distillate is obtained. The oil is then heated to the next boiling-point, and the cooling and reheating process repeated, and so on. In this way results can be ANALYTICAL TESTS AND METHODS. 37 obtained with not more than a variation of one per cent, even in the hands of different observers. In practice the fractions up to 150 C. are added together for the light naphtha or benzine, those between 150 C. and 300 C. for the burning oil, and those above 300 C. for lubricating oils and residuum. FIG. 6. The following method by Holde is now used : Determination of Paraffin in Crude Petroleums. Taking 100 grams of crude petroleum, in a tubulated glass retort, quickly distill off all up to 300 C. (ther- mometer in vapor). Then, changing the receptacle, collect the remaining distillate in a weighed flask, using no con- denser, and continue without thermometer the distillation until coking of the residue. By again weighing the re- ceptacle, the total weight of the heavy oil which is distilled over is determined, from which the percentage of paraffin found can be reckoned back to the original crude oil taken. Five to ten grams of this heavy oil distillate is then to be dissolved at room temperature, in a mixture of one part ether and one part alcohol, until clear solution is obtained. Then cooling down with the aid of an ice mix- ture until a temperature of 20 C. is obtained, add so much additional of the mixture of alcohol and ether, until all the oily portions remain dissolved at 20, and only paraffin flakes are visible. These latter are then to be filtered on a small filter, sur- rounded by a cooling mixture of ice and salt kept at a temperature of 20, the liquid being drawn off by connecting with a suction pump, the separated paraffin on the filter being washed with previously cooled alcohol-ether mixture, until no oily portion shows in the washings. The precipitate is then taken from the ice mixture, washed off of the filter into a tared glass dish, with the aid of warm benzine, the benzine being then carefully evaporated over the water-bath. If, on cooling the dish, it is found that the paraffin is of hard variety, it is dried for fifteen minutes at 105, and, after cooling in the desiccator, weighed. If, on the other hand, the residue is soft paraffin, melting under 45, this is best dried by keeping it in a vacuum desiccator at a temperature of 50, 38 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. and then weighing. To the weighed amounts of paraffin so obtained, is to be added, because of the slight solubility of paraffin in the alcohol- ether mixture, .2 of one per cent, when the distillate is perfectly liquid, .4 per cent, in the case of distillates which show a separation of solid material at 15, and one per cent, in the case of solid distillate masses. With these corrections, the determination is regarded as accurately representing paraffin in crude oils and in lubricating oils. For such petroleums as contain both paraffin and asphalt base, the modification made by Clifford Richardson (Jour. Soc. Chem. Ind., May 31, 1902) is to be used. 3. FOR PETROLEUM PRODUCTS. For commercial petroleum products, which are, of course, mixtures of hydrocarbons, the boiling-point becomes of only secondary importance, while, with reference to their uses as illu- minants, the element of safety comes "into consideration, so that what is called "flash point " and "burning point," together*mcluded in what is known as "fire-test," becomes important. For lubricating oils, the con- sistency or body determined in the viscosity-test and the "cold-test," or point to which they can be chilled without separating paraffin, is im- portant. For paraffin and solid products the melting-point and amount of oil enclosed are important. And for all classes the color is a not unimportant gauge of purity. So that the general applicable analytical tests for petroleum products may be summed up under the following heads : Specific gravity. Fire-test, including flash-point and burning point. Cold-test. Viscosity. Melting point. Compression-test. Colorimetric tests. (a) Specific Gravity Determinations. While, of course, the methods of the specific gravity bottle and the specific gravity balance are avail- able, the determinations are, in the case of the liquid petroleum products, almost universally made with hydrometers, and these may be of two kinds, either graduated so that specific gravities are read off direct in decimal fractions less than one, or graduated in the arbitrary scales of Beaume, Brix, Gay-Lussac, or Twaddle, the relations of which to simple fractional specific gravity numbers are known. In America and Russia the Beaume scale is universally adopted; in Germany, the Brix spindle is used officially by customs officers ; in France, the Gay-Lussac ; and in England, the Beaume scale for liquids lighter than water, and the Twaddle for liquids heavier than water. For the formulas for conver- sion of readings of these scales into specific gravity figures and for a complete table of Beaume degrees in comparison with the corresponding specific gravity figures, see Appendix. The use of v direct specific gravity hydrometers is gradually extending, especially in Germany, as they do away with the necessity of all reduction tables. The specific gravity tables for liquids lighter than water are calculated for a temperature of ANALYTICAL TESTS AND METHODS. 39 60 F., and in practice it is customary to add to or subtract from the observed specific gravities .004 for every 10 F. above or below 60 F., and this is found to afford a sufficiently close approximation to the truth for all commercial purposes in the case of all the ordinary petroleum products. (b) Fire-test. Just as crude petroleum is dangerous because of the dissolved gases, although its specific gravity may be relatively high, so illuminating oils may give off, at temperatures far below their boiling- point, small amounts of inflammable vapors, which might make these oils dangerous for use in lamps where the oil reservoir gradually becomes warm. A distillate may have vapors of higher and lower boiling-point carried over with it. Two points may be determined with a petroleum oil, the flashing point, or the temperature at which the oil gives off vapors which, mixing with air, cause an explosion or flash of flame, dying out, however, at once, and the burning point, or the temperature at which a spark or lighted jet will ignite the liquid itself, which then continues to burn. The latter point is usually 6 to 20 C. higher than the former, but there is no fixed relation between them. The danger, of course, begins when an oil will flash, so the flash-point is generally taken as the basis of legal prescription ; Austria and the New York Prod- uce Exchange alone recognize formally the burning-test instead of the flash-test. Most European countries and most of the States in the United States prescribe a flash-test. The United States have no national regulation on the subject. The different forms of apparatus in use to determine the safety of oils are based upon either one of two principles, the direct determination of flash or burning point, or the determination of the increased tension of vapor which the oil shows as the temperature rises. The second class is represented by a single form of apparatus, that of Salleron-Urbain, used to some extent in France ; the first class is represented by a dozen or more different forms, chiefly of American, English, and German inven- tion. The earliest form, that of the Tagliabue open-cup tester, is shown in Fig. 7, in which the glass cup Z>, holding the oil to be tested, is heated by the water-bath A. When the thermometer, the mercury of which is just immersed, indicates 90 F. (32 C.), the spirit lamp is withdrawn and the temperature allowed to rise more slowly to 95 F. (35 C.), when a lighted splinter of wood is passed to and fro over the surface of the oil. If the gas rising from the oil does not ignite, the water-bath is heated again and tests are made when the thermometer indicates 100 F. (38 C.), 104 F. (40 C.), and 108 F. (42 C.). A flash at 108 F. is considered as marking the oil at 110 F. This form was the first one officially adopted in the United States, and is still used somewhat in Germany and Austria. The New York Produce Exchange and the -American petroleum inspectors have now adopted an open-cup tester, known as the Saybolt tester, in which the electric induction-spark is made to pass over the top of the open oil-cup. It is shown in Fig. 8. F is a water-bath, the temperature of which is noted by an independent thermometer. Although this was a decided improvement on the first 40 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. Tagliabue apparatus, it was found that, like the other open-cup appa- ratus, it gave readings which were variable and higher than if the top of the cup were covered. This led to the study of the whole subject by Sir Frederick Abel, at the request of the English government, and the adoption by the English government as their official standard of the FIG. 7. Abel tester. This has since been adopted by the German government as well, and is considered by many to be the most exact now in use. It is shown in Fig. 9. The following is a description of the details of the apparatus: "The oil-cup consists of a cylindrical vessel, two inches in diameter, two and two-tenths inches high (internal), with outward projecting rim five-tenths inch wide, three-eighths inch from the top, and one and seven-eighths inches from the bottom of the cup. It is made of gun-metal or brass (17 B. "W. G.), tinned inside. A bracket, ANALYTICAL TESTS AND METHODS. 41 consisting of a short, stout piece of wire, bent upward, and terminating in a point, is fixed to the inside of the cup to serve as a gauge. The dis- tance of the point from the bottom of the cup is one and a half inches. The cup is provided with a close-fitting, overlapping cover, made of brass (22 B. W. G.), which carries the thermometer and test-lamp. The latter is suspended from two supports from the side by means of trun- nions, upon which it may be made to oscillate; it is provided with a FIG. 9. Fia. 10. spout, the mouth of which is one-sixteenth of an inch in diameter. The socket which is to hold the thermometer is fixed at such angle, and its length is so adjusted, that the bulb of the thermometer, when inserted to full depth, shall be one and a half inches below the centre of the lid. The cover is provided with three square holes, one in the centre, five- tenths inch by four-tenths inch, and two smaller ones, three-tenths inch by two-tenths inch, close to the sides and opposite each other. These three holes may be closed and uncovered by means of a slide moving in grooves and having perforations corresponding to those on the lid. In moving the slide so as to uncover the holes, the oscillating lamp is caught by a pin fixed in the slide and tilted in such a way as to bring the end 42 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. of the spout just below the surface of the lid. Upon the slide being pushed back so as to cover the holes, the lamp returns to its original position." Not only are all the dimensions of parts in the Abel appa- ratus prescribed most minutely, but the method of carrying out the test must be followed in minute particulars in order to get accurate results. The opening and closing of the slide must be regulated either by a seconds pendulum or, as in the official German apparatus, by exact clock- work. It gives a flash-test which, on the average, is 27 F. lower than that of the open-cup apparatus, so that 73 P. Abel test is taken as the equivalent of 100 F. open-cup test. A German apparatus, which seems to be fully as^exact, and simpler in its construction and operation, is Heumann's tester, shown in Fig. 10. In it the results are to a considerable degree independent of the dimen- sions of the oil-cup, size of flame, temperature of water, etc. This appa- ratus shows to what temperature a specimen of petroleum must bo heated through and through in order that the vapor given off may suffice to make an explosive mixture with a volume of air exactly equal to the volume of oil. The glass oil-vessel, g, is set direct in the metallic water- bath, &, and is exactly half-filled with oil with the aid of a measure accompanying the instrument. The agitating paddles, c, agitate the oil and the air-and-vapor mixture independently. The little flame or lamp for igniting the explosive mixture is attached to a button at d, and here is a small hole through which the gas-and-air mixture escapes, and, when ignited, yields a flame about five millimetres high. In making the test, after agitation of the mixture, the button, k, is pressed down until the little flame is pushed below the surface, when, if the temperature of flashing has been reached, it ignites the explosive mixture of air and vapor, and is blown out in turn by the slight puff of the explosion. The apparatus is said to give results agreeing perfectly with those gotten with the more complicated but official Abel tester. Other forms of appa- ratus are those of Engler (a closed test apparatus with the Saybolt electric spark attachment), of Parrish, used in Ilolland, and of Bernstein. Victor Meyer first adopted the principle that the true flash-point of a petroleum is that temperature at which air, shaken with petroleum, can be ignited by a small flame, and proposed the thorough agitation of the warmed oil to be tested with air before applying the flame. The simplest form of apparatus in which this principle is applied is the flash-tester of Stoddard, shown in Fig. 11. The air-current escapes from a fine-drawn opening in the glass tube, and must raise a foam several millimetres in height on the surface of the oil. The cylinder containing the oil may be a small Argand lamp-chimney, and the whole apparatus is lowered into a water-bath. The little jet of flame is passed to and fro over the opening at the top of the chimney, while the thermometer, immersed in the oil, is read. For lubricating oils where the flash-point is to be determined with accuracy, the Pensky-Martens testing apparatus, which is a modifica- tion of the Abel tester, is used. Mechanical agitation is provided, and the oil-cup is surrounded with an air-bath. In the United States the ANALYTICAL TESTS AND METHODS. 43 flash, test of lubricating oils is generally taken in a shallow open cup heated directly, the temperature being raised at the rate of 8 F. per minute. (c) Cold Test. This is applied chiefly to lubricating oils. The exe- cution of it with Tagliabue's standard oil-freezer is shown in Fig. 12. The glass oil-cup, four inches in depth and three inches in diameter, is adjusted to a rocking shaft, seen at the side of the cup, so as to show by its motion whether the oil is congealing or not. Surrounding the oil- cooling chamber is the ice-chamber, and outside of this is a non-con- FIG. 12. ducting jacket filled with mineral wool. Three thermometers are used: one in the oil-cup and the other two in the ice-chamber to either side. Two stopcocks below, communicating with the cooling-chamber, allow of the forcing in of warm atmospheric air to raise the temperature within when necessary. A glass door in the side opposite the oil-cup allows of the reading of the thermometer without opening the cooling- chamber. The cold-test is also frequently applied by simply taking the oil in a sample bottle, the diameter of which is about one and a half inches, chilling it in a freezing mixture, and noting the temperature at which, on inclining the tube, the oil no longer flows, or that at which the separation of paraffin commences. (d) Viscosity Test. As before stated, the "viscosity " or body of a lubricating oil is one of its most important characters. Its determina- tion is, therefore, to be made with great care. The earlier forms of apparatus consisted simply of glass tubes, of pipette form, which, being 44 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. filled with oil to a certain mark, were allowed to empty while the time was accurately noted. The pipette was set in a hot-water funnel or similar vessel, and the water in this outer vessel brought to 60 F., so that the observation on the oil might be at a standard temperature. Other forms are those of Coleman, Mason, and Redwood, in England, and F. Fischer and C. Engler, in Germany. The Redwood viscosimeter, a very accurate instrument, will be found described and illustrated fully in "Allen's Commercial Organic Analysis" (2d ed., vol. ii. p. 198). The Fischer viseosimeter is shown in Fig. 13. The outer vessel, B, FIG. 14. FIG. 13. having been filled with warm water, the oil-vessel, A, has placed in it about sixty-five cubic centimetres of the oil sample, filling it to a mark on the inside. "When the thermometer, immersed in the oil, shows the proper temperature, fifty cubic centimetres are allowed to run into a graduated flask placed below and the time required for its flow noted. The exit-tube, a, consists of a platinum tube 1.2 millimetres wide and 5 millimetres long, which is surrounded by a wider copper tube. This exit-tube is enlarged conically at either end, above to allow of the closing by the conical plug, &, and below to allow of the better flow of the escaping oil. In the Engler instrument, illustrated in Fig. 14, still greater care is taken to insure accurate measurement of the volume of oil operated upon, and that it shall flow under exactly similar conditions in comparative tests. Two hundred and forty cubic centimetres of water fill the inner vessel just to the mark c, and when the temperature ANALYTICAL TESTS AND METHODS. Fia. 15. of 20 C. (68 F.) is reached, two hundred cubic centimetres are run out into the vessel below. The oil to be tested is similarly filled in to the mark, and when the temperature 20 C. is reached, after keeping the oil at this for some three minutes, the plug, &, is withdrawn, and two hundred cubic centimetres are run into the vessel below, while the time required is accurately noted. This time in seconds, divided by the time in seconds required for the running of the same volume of water, gives the specific viscosity or viscosity-grade, as Engler terms it. The lubricating value of oils can be determined best by actual use upon the surfaces where friction is felt, and instruments to determine such value are, therefore, based upon experimental trials of the diminu- tion of friction on moving surfaces, when covered by the oils to be com- pared. Such an instrument is the well- known Thurston lubricating oil-tester, shown in Fig. 15, in which both the re- sistance in the speed of revolution of a rotating axis due to friction and the heat- ing of the axis and the bearing in which it rotates are measured. Mineral lubricating oils are frequently adulterated with seed oils like "blown rape oil " or blown cottonseed, both being added to give increased viscosity. Arti- ficial viscosity is also given to less viscous mineral lubricating oils by the addition of aluminum oleate or palmitate. These fixed oils may be detected by saponifying with alcoholic potash (see p. 88). For the detection of rosin oil adulteration Allen recommends the addition to a few drops of the sample dissolved in about one cubic centimetre of carbon disulphide of a solution of stannic bromide with excess of bromine in carbon disul- phide. (The stannic bromide is prepared by allowing bromine to fall drop by drop upon granulated - tin contained in a flask immersed in cold water.) The production of a fine violet color indicates the presence of rosin oil. Gumming tests for lubricating oils are now considered important, as oils containing much dissolved pitchy or asphaltic matter resinify rapidly at 50 C. to 100 C., while pure hydrocarbon lubricating oil slowly evaporates without resinification. Determination of Asphaltic Residue in Lubricating Oils. Holde gives the following method. Five grams of the oil are dissolved at 15 C. in 25 volumes of ether; to this solution is added from a burette drop by drop with constant shaking of the mixture 12.5 volumes of alcohol of ninety-six per cent, strength. After allowing the mixture to stand for five hours at 15, it is filtered through a folded filter, washed with a mixture of alcohol-ether (1:2) until no further oily substances but traces only of pitchy constituents go through into the filtrate. The washed asphaltic residue, which can also contain paraffin, is dissolved in benzol, 46 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. the solution evaporated to dryness, and the residue extracted by thirty cubic centimetres of ninety-six per cent, alcohol at boiling temperature, repeated again until the extraction liquor on cooling shows no further precipitation of paraffin. The residue is then dried for a quarter of an hour at 105 C. and weighed when cold. (e) Melting Point. The "melting point " of paraffin should rather be called the congealing point, as what is taken usually is the tempera- ture at which the sample, after having been melted, and while in the process of cooling, begins to solidify. The American test is con- ducted by melting sufficient of the samples to three-fourths fill a hemi- spherical dish three and three-fourths inches in diameter. A thermom- eter with a round bulb is suspended in the fluid so that the bulb is only three-fourths immersed, and the material being allowed to cool slowly, the temperature is noted at which the first indication of filming, extend- ing from the sides of the vessel to the thermometer bulb, occurs. The English test is made by melting the sample in a test-tube about three- quarters of an inch in diameter, and stirring it with a thermometer as it cools, until a temperature is reached at which the crystallization of the material produces enough heat to arrest the cooling, and the mercury remains stationary for a short time. The results afforded by this test are usually from 2y 2 to 3 P. lower than those furnished by the Ameri- can test. The melting point is also sometimes determined by observing the temperature at which a minute quantity of the sample previously fused into a capillary tube, and allowed to set, becomes transparent when the tube is slowly warmed in a beaker of w r ater. (/) Compression Test. Paraffin scale usually contains oil and some- times water. The percentage of oil is determined by subjecting a weighed quantity of the material to a given pressure for a specified time and noting the loss in weight. The test is made at 60 F., the quantity of material employed five hundred grains, the pressure is nine tons over the whole surface of the circular press-cake, five and five-eighths inches in diameter, and this pressure is maintained for five minutes, the oil expressed being absorbed by blotting-paper. (g) Colorimetric Test. The color of petroleum oil is determined in the United States (as regards oil for export), in England, and in Russia (in the case of oil for export) mainly by the use of the Wilson chro- mometer. In Germany they use both a modification under the name of the Wilson-Ludolph chromometer and Stammer's colorimeter. The Wilson instrument, shown in Fig. 16 and Fig. 17, is fitted with two parallel tubes, furnished with glass caps, and at the lower end of the tubes is a small mirror by means of which light can be reflected upward through the tubes with an eye-piece. One of these tubes is completely filled with the oil to be tested, and beneath the other tube, which remains empty, is placed a disk of stained glass of standard color. On adjusting the mirror and looking into the eye-piece the circular field is seen to be divided down the centre, each half being colored to an extent correspond- ing with the tint of the oil and of the glass standard respectively. An accurate comparison of the two colors can thus be made. The glass ANALYTICAL TESTS AND METHODS. 47 disks, which for the English trade are of five shades of color, termed good merchantable, standard white, prime white, superfine white, and water white, are issued by the Petroleum Association of London. In Germany, the Bremen Exchange recognizes seven shades of color, straw, light straw, prime light straw to standard white, prime light straw to white, standard white, prime white, and water white. In addition to these special tests there may be mentioned a general method recently devised by A. Riche and G. Halphen (Journ. Pliarm. Chem., 1894, xxx. 289) for determining whether a petroleum distillate has been obtained from American or Russian crude petroleum, and for distinguishing crude petroleum from mixtures of petroleum distillate and residuum. The process consists in the gradual addition by means FIG. 16. FIG. 17. of a burette of a mixture of equal volumes of anhydrous chloroform and ninety-three per cent, alcohol to four grammes of the sample of the oil until solution is effected and the liquid becomes clear. It was fd u that samples of crude petroleum required much more of the solvent to produce a clear liquid than fractions of the same density obtained by distillation, and that the higher boiling fractions of American petro- leum required a larger quantity of the solvent than sufficed for the Russian product of corresponding specific gravity. 4. FOR OZOKERITE. The physical tests are the same as those for paraffin scale. 5. FOR ASPHALTS. When asphalts and bitumens are to be used for varnish-making, the determination of the total bitumen soluble in carbon disulphide or oil of turpentine suffices. When, on the other hand, the asphalt is to be considered with reference to its value for asphalt paving purposes, it is necessary to examine into the quality of the bitumen. For this purpose the total bitumen (amount soluble in carbon disul- phide), organic non-bitumen, and ash are first determined. Then the amount of bitumen soluble in petroleum-naphtha (so called petrolene) 48 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. is ascertained. The difference between this and the total bitumen is called asphaltene. The former of these portions is in general tough and elastic, while the latter is hard and brittle. For paving purposes the asphalt should contain an excess of petrolene over asphaltene. Clifford Richardson considers it desirable to extract 'with naphthas of 62 B. and 88 B. separately, in order to get a correct estimate of the quality of the "petrolene." Chloroform is also used at times in place of carbon disulphide. The liquid asphalts or malthas sometimes contain so much material volatile at temperatures below 300 F. that the simple determination of bitumen soluble in petroleum-naphtha would be misleading and valueless unless they were previously heated to drive off these light oils, as these volatile portions are not comparable in value with the petrolene of solid asphalts. Therefore a test is commonly made of the percentage of loss in such asphalts when heated to 300 F. or 400 F. for ten hours, and this is then taken in connection with the extraction tests. V. Bibliography and Statistics. BIBLIOGRAPHY. The following list of titles i3 not meant to be complete, but only gives the more important published works of recent years. It does not cover periodical literature, which is very voluminous: 1876-86. Reports of the Second Geological Survey of Pennsylvania on Oil Regions, Harrisburg, Pa. 1877. Geological Survey of the Oil Lands of Japan, B. S. Lyman, Tokio. 1879. Untersuchungen tiber naturliche Asphalte, R. Kayser, Nuremberg. 1884. Petroleum Distillation, A. N. Leet, New York. Naphtha and Naphtha Industrie, V. Ragosine, St. Petersburg. The Region of Eternal Fire, Chas. Marvin, London. Photogen und Schmierol aus Baku'scher Naphta, F. RossmJissler, Halle. 1885. Lecons sur le P&trole et ses D6riv6s, Chas. Augenot, Antwerp. Census Report of 1880 on Petroleum and its Products, S. F. Peckham, Wash- ington. Destructive Distillation, Ed. J. Mills, third edition, London. 1886. Verarbeitung des Naphta oder des Erdols, F. Rossmassler, Halle. 1886-88. Mineral Resources of the United States for 1886-88 (Petroleum, by J. D. Weeks ) , Washington. 1887. Das Erdol von Baku, C. Engler, Stuttgart. Cantor Lectures on Petroleum and its Products, B. Redwood, London. Practical Treatise on Petroleum, B. Crew, Philadelphia. Ueber das Deutsche Rohpetroleum, Kramer und Bottcher, Berlin. Das Deutsche Erdol, C. Engler, Berlin. Preliminary Report on Petroleum and Inflammable Gas, E. Orton, Columbus, Ohio. Fette und Oele der Fossilien (Mineral Oele), G. Schaedler, Leipzig. Die Deutsche Erdole, C. Engler, Stuttgart. Schmierol Untersuchungen, A. Martens, Berlin. L'Asphalte, son origine, sa preparation, etc., Leon Malo, Paris. 1889. L'Industrie du Petrole, Ph. Delahaye, Paris. 1890. Aux Pays du Pfitrole Histoire, Origines, etc., F. riue, Paris. 1892. Das Erdol und seine Verarbeitung, A. Veith, Braunschweig. Production, Industrie et Commerce des Huiles Min6rales aux Etats-Unis, Riche, Paris. BIBLIOGRAPHY AND STATISTICS. 49 1893. Die Petroleum und Schmierolfabrikation, F. A. Rossmassler, Leipzig. Vegetabilische und Mineral-Maschinenole, L. Andes, Wien. Twenty Years' Experience of Natural Asphalt, W. H. Delano, London. 1894. Die Schmiermittel, J. Grossman, Wiesbaden. Technologic der Landwirthschaftlichen Gewerbe und Abhandlung iiber Mineral Oele, Dr. B. von Posauner, 4te Auf., Wien. Gas- and Petroleum-yielding Formations of California, W. L. Watts, Sacra- mento, California. 1895. Petroleum and Natural Gas, Wm. T. Brannt, Philadelphia. Groves and Thorp's Chemical Technology, vol. ii., The Petroleum Industry and Lamps, Boverton Redwood, Philadelphia. Die Fabrikation der Mineral Oele, W. Schiethauer, Braunschweig. 1896. Le Petrole, Riche et Halphen, Paris. Lubricating Oils, Fats, and Greases, Geo. H. Hurst, London. 1897. Oil- and Gas-yielding Formations of Los Angeles, Ventura, and Santa Barbara Counties, Sacramento, California. Mineral Oils and their By-products, I. I. Redwood, London. 1898. Ueber Hannoverisch Erdoelvorkomnisse, Dr. Otto Lang, Hannover. On the Nature and Origin of Asphalt, Clifford Richardson, New York. A Short Hand-Book of Oil Analysis, A. H. Gill, Philadelphia. 1899. Der Asphalt und seine Anwendung, W. Jeep, Leipzig. 1904. Die Chemie und Technologic der Natiirlichen und Kunstlichen Asphalte, von Hippolyt Kohler, Braunschweig. 1906. Die Untersuchung des Erdoels und seine Producte, von M. A. Rakusin, Braunschweig. Des Erdoel und seine Verwandten, Hans Hb'fer, 2nd Auf., Braunschweig. Petroleum and its Products, by Sir B. Redwood, 2nd Edition, 2 vols. London. Die Asphalt Industrie, von Felix Lindenberg-Hartleben, Wien. 1907. Lubrication and Lubricants, A Treatise on Theory and Practice, etc., L. Arch- butt and R. M. Deeley, London. 1908. Modern Asphalt Pavement, Clifford Richardson, 2nd Edition, New York. Das Erdoel, seine vevarbeitung, etc., R. Kissling, Halle. Exploitation du Petrole, Historique, etc., L. C. Tassart, Paris. Erdwachs, Paraffin, und Montanwachs, R. Gregorius, Wien. 1909. Das Erdoel, von C. Engler und H. Hoefer, 3 Bande, Leipzig. Untersuchung der Mineraloele und Fette, Dr. D. Holde, 3te Auf., Julius Springer, Berlin. Solid Bitumens, Physical and Chemical Properties, S. F. Peckham, Myron C. Clark Pub. Co., New York. 1910. Allen's Commercial Organic Analysis, 4th Edition, vol. iii, Philadelphia. 1911. Oil Analysis, Augustus H. Gill, 6th Ed., Philadelphia. STATISTICS. 1. FOR NATURAL GAS. The production of natural gas is not officially reported in quantities, but in value based on the coal displaced as fuel. Approximate Value of Natural Gas produced in the United States, 1904-09. LOCALITIES. 1904. 1907. 1908. 1909. Pennsylvania . $18,139 914 $18 55*< 245 $19 104 944 $20 475 207 Ohio 5,315,564 7,145 809 8 244 835 9 ggg 938 Indiana 4 342 409 1 750 715 1 312 507 1 616 903 West Virginia 8,114/249 13 735 343 14 837 130 17 538 565 Kansas 1,517,643 4,010,986 7 691 587 8 293 846 Other States 1,066,981 1,672,834 3,616,303 5,485,482 Total $38 496,760 $46 873 932 $54 807 306 $63 376 941 614. Canada, also, in 1910 produced natural gas to the value of $1,312,- 50 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. 2. FOR PETROLEUM. The most important petroleum-producing coun- tries for the years 1907-1910 furnished the following amounts of petro- leum, expressed in metric tons and percentage proportion : 1907. 1908. 1909. 1910. United States . . . . Russia Per cent. 22,149,86263.1-2 8,247,79523.50 Per cent. 24,401,72862.97 7,654 60019.75 Per cent. 24,433,52862.33 8,037 30020.50 Per cent. 29.585,97364.68 8.952 79319.57 Dutch Indies .... Galicia 1,178,797 3.36 1,175,974 3 36 2,348,000 6.06 1 754 002 4 53 1,497,275 3.82 2 150 000 5 49 2.024,000 4.42 1 491 600 3 26 Roumania 1,129 097 3 22 1 147 727 2 96 1 263 946 3.22 1 352 300 2 95 British Indies .... Other countries . . . 579,316 1.65 633,245 0.79 568,000 1.46 880,000 2.27 905,336 2.31 910,000 2.33 1,017,000 2.22 1,328,880 2.90 35,094,086 100.00 38,754,057 100.00 39,197,385 100.00 45,752,546 100.00 The production of the United States for the years 1906 to 1910 was distributed as follows (in barrels of 42 gallons) : 1906. 1907. 1908. 1909. 1910. California 30,538 000 39 748 375 44,854,737 54,433,010 77,707,546 Colorado > .... 400000 331 851 ,-, lf (Texas 13,000,000 ) Qulf { Louisiana . . . . . . . . . . . 7,000,000 j 17,322,917 17,318,330 11,912,058 i f Indiana . 1 Lima {onio .....:::::} 25,680,000 17,335,485 10,032,305 6,600,000 Illinois 24,281,973 33,685,106 30,898,339 33,000,000 Mid-Continental {ggg^ '.'.*', Kentucky and Tennessee 21,924,905 1,200,000 45,933,649 820,844 48,323,810 (Pennsylvania . . . . ) Appalachians New York . . . > 27,345,600 20,356,902 24,945,517 26,535,844 26,550,000 ( West Virginia . . . . j Wyoming 8,000 9339 Other States 3,000 4,000 412,6-4 338,658 350,000 127,099,505 166,095,335 179,572,479 182,134,274 213,531,117 (The Mineral Industry for 1910 and U. S. Geol. Survey, 1907.) The exportation of crude oil and the various products therefrom for the years 1903-1907 is shown in the annexed table : Year ending June 30th. Mineral crude ( all gravi- ties). Naphthas, benzine, gasolene, etc. Illuminating oils. Gallons. Dollars. Gallons. Dollars. Gallons. Dollars. 1903 . . 1904 . . 1905 . . 1906 . . 1907 . . 134,892,170 114,576,920 123,059,010 139,688,615 128,175,737 6,329,899 6,572,923 6,359,435 7,016,131 6,626,896 13,139,228 16,910,121 30,816,655 32,756,694 26,357,054 1,225,661 1,802,207 2,575,851 2,613,677 2,735,598 699,807,201 741,567,086 882,881,953 864,361,210 894,529,432 47,078,971 57,902,503 56,169,606 54,181,617 56,249,991 Year ending June 30th. Lubricating and heavy paraffin oils, etc. Residuum and tar, pitch, etc. Total. Gallons. Dollars. Gallons. Dollars. Gallons. Dollars. 1903 . . 1904 . . 1905 . . 1906 . . 1907 . . 93,318,257 88,810,130 97,357,196 146,110,702 136,140,226 12,052,927 12,048,842 13,142,860 17,974,721 17,179,562 22,801,506 22,560,510 48,949,362 75,031,824 65,228,009 566,115 733,994 1,545,470 2,255,181 2,063,668 963,958,362 984,424,767 1,123,064,176 1,257,949,042 1,250,430,458 67,253,573 79,060,469 79,793,222 84,041,327 84,855,715 (Commerce and Navigation of U. S., 1907.) BIBLIOGRAPHY AND STATISTICS. 51 The exportations of paraffin and paraffin wax for the same years, 1903-1907, according to the same authority, were as follows: For 1903 201,325,210 pounds, valued at $9,411,294 " 1904 . 188,651,119 " " 8,859,964 " 1905 161,894,918 " " 7,789,160 " 1906 178,385,368 " " 8,808,245 " 1907 185,511,773 " " 9,030,992 Next in importance to the production of the United States is that of Russia. This has declined in recent years because of disturbing causes, but is slowly increasing again. The figures for 1903-1907 as quoted from the U. S. Geological Survey Reports are : Baku. Grozny. Total. 1903 in barrels 71,618,386 3,972,870 75,591,256 1904 " " 73,723,290 4,813,365 78,536,655 1905 " " 49,791,356 5,168,914 54,960,270 1906 " " 53,723,889 4,606,675 58,897,311 1907 " " 57,143,097 4,707,637 61,850,734 The petroleum consumption of different countries in kilos, for the year 1904, reckoned on a per capita basis, has been stated as follows : Population. United States of America 80,000,000 Germany 58,000,000 England 44,000,000 France 38,000,000 Russia 140,000,000 Japan 45,000,000 Roumania 6,000,000 Austria-Hungary 50,000,000 India 300,000,000 China 300,000,000 Per capita Consumption in 1904. consumption 20,166,803 metric centners 25.21 kilos. 7,990,601 " 13.78 M 5,209,330 11.84 M 3,122,097 " 8.22 M 10,507,887 " 7.51 M 2,993,700 " " 6.65 " 270,247 " 4.50 " 2,155,464 " " 4.32 " 5,089,290 " 1.70 " 2,544,645 " 0.85 M 3. FOR ASPHALT AND SHALE OIL INDUSTRY. The production of asphalt and bituminous rock in the United States in recent years has been, according to "Mineral Resources of the United States for 1909 ": Short tons. 1906 96,532 1907 154,906 1908 122,156 Value. $1,019,102 2,103,698 1,572,616 The importations of asphaltum of various kinds, according to eral Resources of the United States for 1909," have been: : Min- Short tons. 1908 147,685 1909 148,744 Value. $587,698 646,655 52 PETROLEUM, MINERAL OIL, AND ASPHALT INDUSTRY. The estimated quantity of bituminous shale distilled in recent years in Scotland, according to Boverton Redwood ("Petroleum and its Prod- ucts," 2d ed., vol. i, p. 419), was: 1890 2,180,483 tons. 1891 2,337,932 " 1892 2,077,076 " 1900 2,282,221 tons. 1901 2,354,356 " 1902 2,107,534 " The following are the figures for the German mineral-oil trade for 1892-93. Forty-eight shale-oil works were operated with 1297 ovens and 1067 workmen; 20,521,453 hectolitres of coal were distilled, and 1,195,892 centners of tar and 5,651,566 centners of coke were obtained. The tar was valued at 4,345,422 marks and the coke at 1,643,748 marks. On working up the tar there were obtained 159,250 centners of hard and soft paraffin, 102,306 centners of solar oil, and 623,691 centners of different paraffin oils. The value of the combined products was 11,098,496 marks. RAW MATERIALS. 53 CHAPTER II. INDUSTRY OF THE FATS AND FATTY OILS. I, Raw Materials. 1. OCCURRENCE OF THE MATERIALS. The fats and fatty oils are of both vegetable and animal origin. They occur not only widely spread through these two kingdoms of nature, but constitute often the larger proportion by weight of the material in which they are found. No part of the plant seems to be entirely wanting in fat, although that found in the leaves is more of a wax-like character than the oil obtained from the seeds and fruit; in the animal, fats are present in all tissues and organs and in all fluids with the exception of the normal urine. In plants the percentage of fat seems to be in inverse ratio to the percentage of starch and sugar, and ranges from sixty-seven per cent, in the Brazil nut to one per cent, in barley. While the oil-bearing plants are far too numerous to allow of a complete enumeration here, it will be desirable to state first the occurrence of those technically most important, and afterwards to examine those physical and chemical differences which lie at the basis of their different uses. Similarly the most important animal oils and fats will first be enumerated. (a) VEGETABLE OILS, FATS, AND WAXES. Castor oil (oleum ricini, ricinus-oel) is extracted by pressure or heat from the seeds of the Ricinus communis, originally from the East. It is a thick oil, of specific gravity .9669 at 15 C., colorless or yellowish, transparent, of mild taste, but becoming rancid on long exposure to air, miscible with alcohol and ether, and easily saponifiable. The shelled seeds yield from forty to fifty per cent, of the oil. Cotton-seed oil (oleum gossypii seminum, baumwollen-samen-oel) is obtained by pressure from the hulled seeds of the several species of Gossypium, or cotton-plant. The raw oil is brownish-red in color, some- what viscid, of specific' gravity .920 to .930 at 15 C., and separates some palmitin at from 6 C. to 12 C. The refined oil has a straw- yellow color, or is colorless, of pleasant nutty flavor; specific gravity, .9264 at 15 C. ; boils at about 600 F., and congeals at about 50 F. for summer- and 32 F. for winter-pressed. Even at the ordinary tempera- ture, cotton-seed oil deposits "stearine " on standing. The finer brands of cotton-seed oil intended for edible and culinary purposes are freed from this "stearine " by chilling or simply by allowing the oil to stand for some time in large storage tanks. It possesses slight drying proper- ties, and is saponifiable, but is chiefly used as a substitute or adulterant of lard and olive oils. The hulled seeds yield from eighteen to twenty per cent, of the crude oil. Hemp-seed oil (oleum cannabis, hanf-oel) is obtained from the seeds of the Cannabis sativa, or common hemp. It has a mild odor but a mawkish taste, and greenish-yellow color, turning brown with age. Its 54 INDUSTRY OF THE FATS AND FATTY OILS. specific gravity at 15 C. is .9276. It is freely soluble in boiling alco- hol. Has weaker drying properties than linseed oil, but is used in paint and varnish manufacture and in making soft soaps. The seeds contain some thirty per cent, of the oil. Linseed oil (oleum lini, lein-oel) is pressed from the seeds of the Linum usitatissimum, or flax-plant. The oil differs in quality according to the method of its production. By cold pressure is obtained twenty to twenty-one per cent, of a pale, tasteless oil, which is used in cooking as a substitute for lard or butter in Russia and Poland. By warm pressure is obtained twenty-seven to twenty-eight per cent, of an amber-colored or dark-yellow oil. It is, when fresh, somewhat viscid, but as a drying oil it gradually absorbs oxygen and becomes thick and eventually dry and hard. The specific gravity of the fresh oil is .935 at 15 C. It is used almost exclusively in the preparation of paints, varnishes, printers' ink, and "oil-cloth." (See p. 113.) Poppy-seed oil (oleum papaveris, mohn-oel) is obtained from the seeds of the opium poppy by pressure, is of pale-yellow color, and slightly sweetish taste. Specific gravity, .925 at 15 C. The cold-drawn , oil, the oil of the first pressing, is almost colorless, or very pale golden yellow; this is the "white poppy-seed oil " of commerce. The second quality, expressed at a higher temperature, is much inferior, and con- stitutes the "red poppy-seed oil " of commerce. It is used for salads, paints, soaps, and to adulterate olive and almond oils. The seeds yield from forty-seven to fifty per cent, of oil. Walnut oil (huile de noix, wallnuss-oel) is obtained from the seeds of the common walnut-tree, Juglans regia. The fruit to be pressed should be fully ripe and kept for several months before being pressed, as the fresh seeds yield a turbid oil. The cold-drawn oil is very fluid, almost colorless, or of a pale yellow-greenish tint, and has a pleasant smell and agreeable nutty taste ; the hot-pressed oil, on the other hand, has a greenish tint and an acrid taste and smell. Walnut oil is a very good drying oil, and at least equal if not superior in that respect to lin- seed oil. It is chiefly used by artists for paints, as it dries to a varnish film less liable to crack than the film of linseed-oil varnish. Moreover, the better brands of walnut oil being almost colorless, it is preferred to any other oil for white paints. Sunflower oil (huile de soleil, sonnenblumen-oel) is obtained from the seeds of the sunflower (Helianthus annuus), and is a limpid pale-yellow oil of mild taste and pleasant smell. Specific gravity, .925 at 15 C. It belongs to the class of drying oils, but dries more slowly than linseed oil. The cold-drawn oil is also used in Russia for culinary purposes, while that expressed at a higher temperature is employed in soap-making and for the manufacture of varnishes. Almond oil (oleum amygdalae, mandel-oel) is the fixed oil obtained from both the sweet and the bitter almond. The former contains the more oil, but the latter is cheaper, and the residual cake can be utilized for the preparation of the essential oil of bitter almonds. The oil is odorless, agreeable to the taste, and of yellow color. Specific gravity, .919 at 15 C. It is used in pharmacy and medicine and in soap-making. RAW MATERIALS. 55 Corn oil (maize oil, mais-oel) is obtained from the seeds of the maize or Indian corn, either by expressing the seed before it is employed for the manufacture of starch, or, where the corn has been fermented for the production of alcohol, by recovering it from the residue of the fermen- tation vats. Prepared by the former process, it is of a pale-yellow or golden-yellow color, whereas the oil obtained by the latter process is reddish brown. Specific gravity, .921 to .924 at 15 C. The oil has slight drying properties only. It is used for soap-making, in the manu- facture of artificial rubber, for varnishes, and, when refined, as salad oil. Sesame oil (gingili oil, teel oil, sesam-oel) is obtained from the seeds of the Sesamum orientale and Sesamum indicum. The oil possesses a yellow color, is free from odor, and has a pleasant taste. The cold- drawn oil is therefore considered equal to olive oil for table use. It has very slight drying properties. Specific gravity, .923 at 15 C. In addi- tion to its use as an edible oil, the inferior grades are used in soap- making and as burning oil. Ben oil (oleum balatinum, behen-oel) is obtained by expression from the seeds of the several species of Moringia. Colorless, odorless oil, not readily turning rancid. It is used by perfumers for extracting odors and for lubricating clocks and light machinery. Cacao butter (oleum theobromatis) is obtained from seeds or nibs of Theobroma cacao. Nearly white fat, with pleasant odor and taste. Fuses at 86 F. (30 C.). Specific gravity, .945 to .952. It is used for cosmetics and for pharmaceutical preparations. Cocoa-nut oil (oleum cocois, kokos-oel) is obtained from the dried pulp (copra) of the cocoa-nut by expression. An oil of the consistency of butter, fusing at 73 to 80 F. (22.7 to 26.6 C.). When fresh, is white in color and of sweet taste and agreeable odor, but easily becomes rancid. It is easily saponified, even in the cold. It is used in the manu- facture of candles and padded soaps. (See p. 70.) Colza and rape oils (oleum brassicae, riiboel) are practically identical. They are extracted from the several varieties of Brassica campestris. The seeds are called cole-seed or rape-seed. The term "colza oil " is generally applied to refined rape oil. The crude oils are used as lubri- cating oils, and are of dark, yellow-brown color. Kefined and freed from albumen and mucilage, they become bright-yellow. The specific gravity of the refined oil is .9132 at 15 C. Rape oil is used for lamps, for lubricating machinery, and for adulterating both almond and olive oils. Olive oil (oleum olivarum, oliven-oel) is expressed from the fruit of Olea Europcea. It differs greatly in quality according to the method by which it is obtained. The purest is nearly inodorous, pale-yellow, with pure oily taste. Specific gravity, .918 at 15 C. Does not decom- pose or become rancid easily, and congeals at 32 F. to a granular solid mass. The percentage of oil amounts to thirty-two per cent., of which twenty-one per cent, is furnished by the pericarp, and the remainder, which is inferior, by the seed and woody matter of the fruit. It is used extensively as an article of food or condiment, in pharmacy, as an illu- minant and lubricant, and in soap-making. The lowest grade, ' ' tournant 56 INDUSTRY OF THE FATS AND FATTY OILS. oil," has a high per cent, of free fatty acids and readily emulsifies with sodium carbonate solution. Arachis oil (peanut oil, erdnuss-oel). This oil is obtained from earth-nuts, the seeds of Arachis hypogwa. The cold-drawn oil of the first expression is nearly colorless, and has a pleasant taste resembling the flavor of kidney beans. Specific gravity, .917 at 15 C. The best qual- ities of the oil are used for table oil and the inferior grades for soap- making. Palm oil (oleum palmse, palm-oel) is obtained from the fruit of several species of palm. The fresh palm oil has an orange-yellow tint, a sweetish taste, and an odor resembling violets. Its specific gravity is about .945. Its consistency is that of butter or lard. It ordinarily be- comes rancid rapidly, and hence usually contains free acid. It is used in candle- and soap-making, and also to color and scent ointments, pomades, soap powders, etc. Carnauba wax is obtained from the leaves of the carnauba palm, Copernicia cerifera of Brazil. Its specific gravity is .999 and its melting point 185 F. (84 C.). It is brittle and of yellowish color. It is exten- sively used in the manufacture of candles. Japan wax is obtained by boiling the berries of several trees of the genus Rhus, from incisions in the stems of which flows the famous Japan lacquer varnish. It is properly a fat, as it consists almost entirely of glyceryl palmitate. Its specific gravity is .999 and melting point 120 F. (49 C.). When freshly broken, the fractured surface is almost white or slightly yellowish-green and the odor tallow-like. It is used for mixing with beeswax in the manufacture of candles and in the manufacture of wax-matches. Myrtle wax, a solid fat obtained by pressure from the berries of myrica cerifera. Specific gravity 1.005 at 15 C. ; fusing point 45 to 46 C. It is used as a substitute for beeswax and particularly in candle- making. (6) ANIMAL OILS, FATS, AND WAXES. Neat's- foot oil. Prepared from the feet of oxen collected from the slaughter-houses. It is a clear, yellowish oil of specific gravity .916 at 15 C. It does not congeal until below 32 F., and is not liable to become rancid. Of great value as a lubricant, and used for softening leather and grinding of metals. Butter fat is the oily portion of the milk of mammalia, but in prac- tice the term is restricted to that obtained from cows' milk. The pure fat constitutes from eighty-five to ninety-four per cent, of the finished butter. The pure fat has a specific gravity of .910 to .914, and its melt- ing point varies from 85 to 92 F. For fuller account of manufac- tured butter, see under milk (p. 281.) Lard and lard oil (adeps, schweine-schmalz) is the fat of the pig melted by gentle heat and strained. The crude lard is white, granular, and of the consistency of a salve, of faint odor and sweet, fatty taste. Its specific gravity is .938 to .940 at 15 C. Exposed to the air it becomes yellowish and rancid. When pressed at 32 F., it yields sixty-two parts of colorless lard oil and thirty-eight parts of compact lard. The lard is RAW MATERIALS. 57 used in cooking, the lard oil for greasing wool, as a lubricant and an illuminant. Tallow and tallow oil (sevum, talg). Tallow is the name given to the fat extracted from ' ' suet, ' ' the solid fat of oxen, sheep, and other rumi- nants. The quality of the tallow varies according to the food of the cattle and other circumstances, dry fodder inducing the formation of a hard tallow. Its melting point varies from 115 to 121 F. The best qualities are whitish, but it has in general a yellowish tint. Beef tallow contains about sixty-six per cent, of solid fat and thirty-four per cent, of olein or tallow oil ; mutton tallow contains about seventy per cent, of solid fat and thirty per cent, of tallow oil. The oil is used chiefly in the manufacture of soaps and the harder tallow for candle-making. Bone fat is a whitish-yellow fat obtained by boiling bones or extrac- tion of the same with benzin, and is used in soap-making. Cod-liver oil (oleum jecoris ceselli, leberthran) is an oil ranging in color according to the method of its preparation from pale-straw to dark- brown, and of specific gravity .923 to .924 or even .930 at 15 C. The finer qualities are used for medicinal purposes, the darker for tanners' and curriers' use. Menhaden oil is obtained from the Alosa menhaden, a kind of her- ring. Is used for soap-making and tanning, and, when pure, as a sub- stitute for cod-liver oil. Shark oil is prepared from the livers of various species of shark. It is the lightest of the fixed oils, the specific gravity ranging from .865 to .876. It is used in the adulteration of cod-liver oil and for tanning. Whale oil (train oil) is extracted from the blubber of the common or Greenland whale. Is yellow or brownish in color and of disagreeable odor. Specific gravity .920 to .931. It is used for illumination and for soap-making. Sperm oil is procured from the deposits in the head of the sperm whale. In the living animal, the solid spermaceti is held in solution in the liquid sperm oil; when the liquid becomes cold the spermaceti sepa- rates out. The oil is very limpid, relatively free from odor, and burns well in lamps. Specific gravity, .875. It is used as a lubricant on account of its low cold test and its viscosity, and as an illuminant. Spermaceti (cetaceum, walrath) is the solid wax separated out from the accompanying oil. It is yellowish at first, but when purified is white, brittle, and scaly. Its specific gravity is .943 at 15 C. ; melting point, 43 to 49 C. It is only slightly soluble in alcohol, benzene, and petro- leum-ether, but easily soluble in ether, chloroform, and carbon disul- phide. It is used in the manufacture of candles and in pharmaceutical preparations. Wool grease (woll-fett, lanolin, or adeps lance). Sheep's wool con- tains a large amount of fatty matter of a peculiar character. It contains free fatty acids, esters of cholesterol and isocholesterol, and the free alcohols just named. When purified from fatty acids it yields lanolin, which has the property of taking up large quantities of water in an emulsion and is used extensively in medicine. The esters are true waxes and not glycerides. 58 INDUSTRY OF THE FATS AND FATTY OILS. Beeswax (cera flava, bienenwachs) is the substance of which, the cells of the honey-bee are constructed. The crude melted wax is a tough, compact mass of yellow or brownish color, granular structure, faint taste, and honey-like odor. When bleached it becomes white. . Specific gravity .959 to .969; melting point 62 to 64 C. It is used in making candles, ointments, and pomades. Chinese wax (insect wax) is deposited by an insect, Coccus cerifera, upon the Chinese ash-tree. It is a white, very crystalline, and brittle wax, resembling spermaceti in appearance. Specific gravity .973 at 15 C. ; fuses at 82 to 83 C. It is slightly soluble in alcohol and ether, very soluble in benzene. It is used in candle-making. 2. PHYSICAL AND CHEMICAL CHARACTERS OF THE DIFFERENT OILS AND PATS. (a) Physical Properties. Most of the vegetable fats are liquid at ordinary temperatures, because of the relatively high percentage of olein they contain. Cocoa-nut oil, palm oil, cacao butter, and a few others have a buttery consistence on account of the palmitin present. The fats of animals feeding on straw and hay are solid, because of the stearin present ; the fats of carnivorous animals are all softer ; the fat of fishes is liquid at ordinary temperatures, and somewhat differently con- stituted chemically. The solid waxes, both vegetable and animal, are in general differently constituted from the softer fats. The fats and oils are almost insoluble in water (if the water contains albumen, gum, or alkaline carbonates in solution they readily form an emulsion with it on shaking); alcohol only dissolves them sparingly; ether, carbon disulphide, chloroform, benzene, turpentine oil, fusel oil, and acetone dissolve them readily. On exposure to the air, the fats, and particularly the fatty oils, absorb oxygen. The heat developed by this oxidation at times suffices to inflame wool and cotton tissues soaked with the oil. The oils which absorb oxy- gen in this way become thick, and finally dry to translucent resinous masses. Such oils are called "drying oils," and are used in painting and varnish-making. (See p. 112.) The specific gravity of all the fats and oils is less than unity, although the vegetable waxes are only very slightly less. The boiling-points of the oils and fats cannot in general be taken as distinctive, as many of them begin to decompose when distilled under ordinary pressure. Their fusing and congealing points are more im- portant ; particularly in the case of oils used as lubricants does the latter denote the different value of the oil for use at low temperatures. (&) Chemical Composition of the Oils, Fats, and Waxes. The fatty oils, as distinguished from the mineral oils (see p. 13) and the volatile oils (see p. 103), belong to the class of compound ethers. They are salt- like bodies, composed of characteristic acids (oleic, palmitic, and stearic), known as fatty acids, in combination with an alcohol or base. In most cases the base is the triatomic alcohol glycerine, so that the oils are said to be glycerides of the several fatty acids. Some few, known as waxes, do not contain glycerine, but a monatomic alcohol in combina- tion with the fatty acid. Most of the animal and vegetable fats contain the three proximate constituents, olein, palmitin, and stearin, the com- RAW MATERIALS. 59 binations of oleic, palmitic, and stearic acids respectively with gly- cerine. In the more liquid oils the olein predominates, in the more solid palmitin or stearin. The so-called ' ' drying oils ' ' contain a different acid linoleic acid in combination with glycerine. The fish oils contain a variety of the lower fatty acids and some solid unsaponifiable alcohols like cholesterin. The most satisfactory classification of the oils and fats is that of A. H. Allen,* which is here given in abstract. I. Olive Oil Group. Vegetable oleins. Vegetable non-drying oils. Lighter than Groups III, IV and V. Yield solid elaidins with nitrous acid. Includes olive, almond, earth-nut and ben oils. II. Rape Oil Group, Xon-drying oils from the cruciferce. Yield pasty elaidins and have higher saponification equivalents than Group I. Includes rape seed, colza, and mustard oils. III. Cotton-seed Oil Group. Intermediate between drying and non-drying oils. Undergo more or less drying on exposure. Yield little or no elaidin. Includes cotton-seed, sesame, sunflower, maize, soja-bean, hazel-nut, and beech-nut oils. IV. Linseed Oil Group. Vegetable drying oils. Yield no elaidin. Of less viscosity than the non-drying oils. Includes linseed, hemp-seed, poppy-seed, niger- seed, and walnut oils. V. Castor Oil Group. Medicinal oils. Very viscous and of high density. Includes castor and croton oils. VI. Cacao Butter Group. Solid vegetable fats. Do not contain notable quan- tities of glycerides of lower fatty acids. Includes palm oil, cacao butter, nutmeg butter, and shea butter. VII. Cocoa-nut Oil Group. Solid vegetable fats, in part wax-like. Several contain notable proportions of the glycerides of lower fatty acids. Includes cocoa- nut oil, palm-nut oil, laurel oil, Japan wax, and myrtle wax. VIII. Lard Oil Group. Animal oleins. Do not dry notably on exposure, and give solid elaidins with nitrous acid. Includes neat's-foot oil, bone oil, lard oil, and tallow oil. IX. Tallow Group. Solid animal fats. Predominantly glycerides of palmitic and stearic acid, although butter contains lower glycerides. Includes tallow, lard, bone fat, wool fat, butter fat, oleomargarine, and manufactured stearin. X. Whale Oil Group. Marine animal oils. Characterized by offensive odor and reddish-brown color when treated with caustic soda. Includes whale, porpoise, seal, menhaden, cod-liver, and shark-liver oils. XL Sperm Oil Group. Liquid waxes. These are not glycerides but ethers of monatomic alcohols. Yield solid elaidins. Includes sperm oil, bottle-nose oil, and dolphin oil. XII. Beesicax Group. Waxes proper. Are esters of higher monatomic alco- hols, with higher fatty acids in free state. Includes spermaceti, beeswax, Chinese wax, and carnauba wax. 3. EXTRACTION OF THE EAW MATERIALS AND PURIFICATION OF THE SAME. The method of extraction of the oils and fats is, of course, deter- mined to a considerable degree by their physical condition. Solid fats, like tallow and lard, are obtained free from the enclosing membranes by melting the finely-chopped material and drawing off the fat in the melted state; animal oils are extracted mainly by boiling out with water; oil fruits and seeds are ground fine, and then the oil obtained by submitting the meal to pressure, either cold or with the aid of heat, or the oil is extracted by solvents like carbon disulphide and petroleum ether. * Commercial Organic Analysis, 4th ed., vol. ii, p. 64. 60 INDUSTRY OF THE FATS AND FATTY OILS. In the extraction of fats by the process of melting, three forms of procedure are followed: (1), the so-called "cracklings " process, a melt- ing over direct fire, known, too, as the "dry melting "; (2), the melting over direct fire with the addition of dilute sulphuric acid, known as the "moist melting;" and (3), the melting by the aid of steam. In the first process, a little water is added and the tallow or other chopped fat is heated in open vessels. The mixture of fat globules and water at first gives it a milky appearance, but, as soon as the water is driven off, the cell membranes shrivel more and more together, forming the cracklings, and the fat appears as a clear, fused liquid. A constant stirring is re- quired in order to prevent the fragments of membrane from sticking to the sides or bottom of the vessel and burning. The melted fat is drained from the cracklings by passing through metallic sieves, and cracklings afterwards pressed in suitable presses to recover the adhering fat, which forms a second quality tallow. A raw tallow yields on the average eighty to eighty-two per cent, of drained oil and ten to fifteen per cent, of cracklings; a very pure kidney fat will yield, however, ninety per cent, and over of drained fat. In the second process, now generally followed, to one hundred kilos, of tallow, twenty kilos, of water mixed with one-half to one and one- half kilos, of concentrated sulphuric acid is added. The sulphuric acid attacks and destroys the cell-membranes rapidly when heated, and so allows of the liberation of the fat. In this process, as in the last, pro- vision must be made for preventing the escape into the air of the un- healthy and offensive odors coming from the melting of the impure tallow. The escaping vapors are in part condensed and part burned under the kettles. In the third process, that of melting by steam, the steam may be directly introduced into the fat mass or indirectly used by the aid of coils of pipes. The tallow rendering by steam is illustrated in the apparatus of Wil- son, shown in Fig. 18. The steam enters through the perforated pipe G, under the perforated false bottom. The plate F having been shut down tight upon the opening E, the vessel is two-thirds filled with the tallow and steam applied. The pressure is allowed to rise to three and a half atmospheres (fifty-two and a half pounds per square inch) and kept at this for some ten hours. The condensed water collects under the false bottom and can be drawn off when necessary. The melted tallow is then run off from the stopcocks, PP, and the cracklings finally discharged through the opening E. Some acid may be added to the fat or in the Evrard process, instead of acid, caustic soda, which has the advantage of combining with the noxious volatile acids evolved. The extraction of lard takes place by similar methods to those employed for tallow, but at lower temperatures and more readily. For the extraction of animal oils, like fish oils, the method of boiling out with water is generally employed, elevation of temperature and pro- longed heating being avoided as much as possible in the case of the finer medicinal oils. RAW MATERIALS. 61 For oil-bearing fruits and seeds, the methods of obtaining oil, as already mentioned, are expression, either cold or by the aid of heat, and that of extraction by solvents. For the expression of oils, the carefully cleaned seeds are first crushed to break the shells or kernels and then ground to fine meal. The crush- ing is done very generally in oil-seed mills of the the type known as "edge-runners," where the two stones or metal wheels are made to revolve on a stone foundation on which the oil seeds are placed, and FIG. 18. from which any excess of oil may flow. A much more perfect crushing is possible in this mill than in those in which stamps are used. They are then slightly heated for the double purpose of coagulating any plant albumen and making the oil more liquid. In the case of the best medicinal or table oils all heat is avoided and cold-pressed oils only taken. The meal is then repeatedly pressed. The result of the first pressing is often called "virgin oil," and is of better color and taste than the later lots. The pressing is done with hydraulic presses under pressures rising to 300 atmospheres (equalling about two tons to the square inch). The crushed oil seed is placed in woolen or cotton cloths, usually covered in by bags of horse-hair, and then placed between the press-plates. Following the cold pressing, or at once in the case of oil- 62 INDUSTRY OF THE FATS AND FATTY OILS. bearing seeds of lesser value, the crushed seed is warmed in a steam- jacketed kettle, which is provided with mixing appliances, and then delivered through a mixing box into bags or cloths for the hot pressing. The so-called Anglo-American open press, in which this expression is effected, is shown in Fig. 19. The other process, that of extraction of the oil by solvents, is capable of yielding a much larger amount of oil than is obtained by pressure, but has been more or less opposed on several grounds. The solvents employed are carbon disulphide and petroleum- ether. The former is the better solvent, is used at a lower temperature, FIG. 19. and is easily recovered from the solution afterwards without leaving any appreciable odor adhering to the oil. It, however, dissolves coloring matter and resin from the seed as well as oil, and so introduces impurity, and when not perfectly pure, it leaves sulphur impurities also in the oil. The other solvent does not dissolve so much coloring matter or resin, communicates no odor, and leaves no sulphur or other residues in the oil, and so can be used for fine table oils, if necessary. It requires a higher temperature, however, and, condensing on the surface of water instead of under it, like carbon disulphide, requires more complicated distillation and condensing apparatus. At the present time the carbon disulphide is more generally used. A solvent ^superior to either is carbon tetrachloride, which is coming into increasing use. Like carbon disulphide, it is heavier than water arid insoluble in the same, but its RAW MATERIALS. 63 chief merit is its entire uninflammability. It is still rather too expen- sive for general use, and, like chloroform, its vapors have a certain nar- cotic effect. Moreover, in the presence of moisture, it attacks iron and copper, and hence has to be used in lead-lined extraction vessels. The objection first urged against the extraction of oil by solvents, that they left the oil-cake valueless for cattle food because of the too complete extraction of the oil, is now met by the oil men, who leave eight to ten per cent, of fat or oil in palm-nut or other oil-cake. The expressed or extracted oils are in many cases in quite a crude condition, containing both suspended and dissolved impurities of various kinds. To purify them for use, even in soap-making, some treatment is generally necessary. Often simple but prolonged subsidence suffices if the impurities are only suspended. Instead of subsidence, it may be necessary at times to use filtration through cotton wadding, animal char- coal or fuller's earth. If both subsidence and filtration fail to clear the oils, it is necessary to adopt chemical treatment, as the impurities in time ferment and develop a permanent rancidity or deterioration of the oil. The first process to note is that of Thenard, to add gradually one to two per cent, of sulphuric acid to oil previously heated to about 100 F. and mix by thorough agitation, followed by settling and drawing off from the acid sludge. The sulphuric acid both takes up the water that holds the impurities in solution and chars the impurities themselves. The treatment with acid is to be followed by a thorough washing with warm water 'and final filtration. Cogan 's process follows the addition of sulphuric acid by that of steam. Instead of sulphuric acid, caustic alkalies are sometimes used as in the Evrard process (see p. 60), which is chiefly applied to colza and rape oils. In this case, the caustic soda saponifies a small quantity of the oil, and the soap carries down, mechan- ically, all impurities, leaving the oil perfectly clear. Too prolonged agitation may, however, make an emulsion of soap and oil, which sepa- rates with difficulty. R. von Wagner proposed the use of zinc chloride instead of sulphuric acid, as this chars the impurities without attacking the oil. The zinc chloride is used in concentrated solution of 1.85 specific gravity, about one and one-half per cent, being taken and thor- oughly agitated with the oil. After the zinc chloride solution is with- drawn, the oil is well washed with water and filtered. Tannin is also used to clear some oils, which it effects by coagulating the albumen. Cotton-seed oil is always colored by some resin, which is removed by treatment with alkali, which saponifies the resin and the free acids of the crude oil, converting them into a mucilaginous soap which separates in dark-colored flakes when the oil is heated. This produces a light yellow oil, which may be further purified by being heated to from 150 to 200 F. in kettles with fuller's earth, after which it is filter-pressed. Still more energetic methods for purifying oils are the oxidation methods, using "chloride of lime " or bichromate of potash, and sul- phuric or hydrochloric acids as applied to palm oil. The use of hydrogen peroxide solution has recently been tried for the bleaching of oils, with the best of results. Four or five per cent, of 64 INDUSTRY OF THE FATS AND FATTY OILS. a ten per cent, solution will generally suffice if repeatedly shaken up with the oil to be treated. Sodium and calcium peroxides operate in the same way. Ozone-carriers, like ferrous sulphate solution, will also bleach in the presence of sunlight. This method is often applied with linseed oil. IE. Processes of Treatment. 1. SAPONIFICATION OF PATS. The composition of the proximate prin- ciples, olein, palmitin, and stearin, which make up the bulk of the fats proper, was first established by the researches of Chevreul in 1823. Their decomposition can be effected in a number of ways, by the action of bases like the alkalies and some metallic oxides, by the action of sul- phuric acid liberating the fatty acids; and by the action of water alone, when aided by heat and pressure. Chevreul at first used alkalies, patenting that process in 1825, in conjunction with Gay-Lussac, but this procedure was given up already in 1831, when Ad. de Milly replaced the alkalies by lime. This was used exclusively for a number of years, but was followed in 1854 by the independent discovery of Tilghman and Berthelot of the method of decomposing by the use of hot water superheated by high pressure. Melsens also proposed the same process substantially a little later. In consequence of the danger connected with the high temperature and pressure, this process is not carried out any longer in its original shape, but is now replaced by the "autoclave " process, mentioned later. In 1841 Dubrunfaut found that if neutral fats were treated first with sul- phuric acid, and then boiled with water, the fatty acids might be dis- tilled in an atmosphere of superheated steam without decomposition. This constituted the distillation process. It was extensively used in Eng- land. Wilson and Gwynne found it possible, with proper application of the superheated steam and regulation of the temperature (290 to 315 C.), to dispense with the sulphuric acid, and to decompose the fats and then distil them without any decomposition. This process is now used on a large scale by the Price Candle Company in England. Still later, Bock, of Copenhagen, found that if the membranous cellu- lar tissue that enclosed the fat be decomposed by a preliminary treat- ment with sulphuric acid and the charred tissue, which by oxidation becomes heavier than the fat and sinks through it, be removed, the pure fat could be decomposed by boiling with water in open tanks. The sepa- rated fatty acids are so pure in color that washing suffices, and no dis- tillation is necessary. These several processes have been in time modified and amalgamated until now only three or four processes are practically followed on a large scale : (1) The saponification by alkalies used exclusively in soap-making and yielding a soda or potash salt of the fatty acid. (See SOAPS, p. 68.) (2) A combination of the lime and hot-water processes, known as Milly 's "autoclave process," in which two to four per cent, of lime is PROCESSES OF TREATMENT. 65 made to do the work of saponification, for which 8.7 per cent, is the- oretically needed, and for which fourteen to seventeen per cent, was at first used. The saponification is carried out in the presence of water in strong, closed, metallic vessels, at a temperature of 172 C. One form of such vessel for the saponification by lime under pressure that has been much used is an egg-shaped cylinder. At present the form of the vessel in use is more generally that of a sphere, which stands the eight to ten atmospheres internal pressure better. The lime soap, technically called 11 rock," after its separation is decomposed by sulphuric acid, four parts of acid to each three parts of lime used being taken. After the complete subsidence of the calcium sulphate the free fat acids are thor- oughly washed with water and steam. (3) The sulphuric acid saponification, followed by distillation. This process is almost exclusively followed in England. The amount of sul- phuric acid used has gradually been diminished, as it is found that a relatively smaller percentage will suffice. For offal fats some twelve per cent, is now used, for tallow nine per cent., and for palm oil six per cent. The decomposition generally requires some hours at a tem- perature varying from 120 to 170 C. Milly modified this process by using a smaller quantity of sulphuric acid .(two to three and a half per cent.), which he allows to act at a temperature of 150 C. for two to three minutes only, and then boils with water. In this way the larger portion of the fat acids are white enough to be used for candle-making without previous distillation, while some twenty per cent, only of them needs to be distilled. The form of apparatus for the distillation of the free fatty acids produced in the sulphuric acid saponification is shown in Fig. 20. T is the superheater, from which steam at 300 C. is passed into the retort D, which is previously filled to three-fourths of its capacity with melted tallow through the supply-pipes V V. The fatty acids distil out of the tube U, are condensed by the worm 8, and col- lected by the receiver K. (4) The superheated-steam process of Wilson and Gwynne, before alluded to. This is at present carried out in both England and Ger- many. The apparatus devised by Mr. G. F. Wilson, of the Price Candle Company, of London, is shown in Fig. 21. The fat, previously heated in the flat vessel, A, by the waste-heat from the superheater below, flows into the retort C. This retort must be kept at from 290 to 315 C., and to this end is covered entirely above; the superheated steam at 315 C. comes into the retort by the tube to the side, and some twenty-four to thirty-six hours is necessary to decompose and distil off a charge of fat. If the temperature falls below 310 C., the decomposition is extremely slow, while much above 315 C., acrolein forms from the decomposition of the glycerine. The decomposition of fats by enzymes has also been made a working method quite recently. The enzyme contained in the castor-oil bean has been found best adapted for this. An emulsion of fat, water, ten per cent, of ground castor-oil bean, and a small amount of free acid are used, when the decomposition proceeds rapidly. Before proceeding with the special processes of soap-making, stearine- 5 66 INDUSTRY OF THE FATS AND FATTY OILS. candle manufacture, oleomargarine and glycerine production, it will be well to present in schematic way the complete treatment of a fat such as tallow. The accompanying scheme is taken from Post's "Chemische FIG. 20. Technologic," and shows the processes applicable and the products re- sulting from the technical utilization of tallow. 2. PRACTICAL SOAP-MAKING. In the application of the first method of saponification of fats, that of the use of alkalies, we have, of course, FIG. 21. always a potash or a soda salt of the fatty acid formed, which, singly or admixed, constitute the products known as soaps'. A very great variety of soaps are known, the appearance and properties of which vary accord- ing to the method of manufacture. We may classify the several methods of manufacture as follows: PROCESSES OF TREATMENT. 67 > ^j lisil ^ p 2 CO """^ (-) W *Z Q 3 3 g ^ 3 BS-Sf * A p|i^ ^1 f - P "erg "*SB &(? IT*- 3 * ?rn S-'' 1 5*0 r* H _, O ^" H 0*3 w * O 00^ OH s ^ *r* *_i & E > CO & pi ] tljM jjj >Ij ^ cc g 02 c/3 > rt> C M O Qj f/1 to I C u to O 00 ^5^^*^ 3 - dfi.S 2 x O- B CO S S"*^* *? o ^ < C CK5 H H p "1 w P X" s *^ h> fD T3 1^ ^ i_i 3 i. Ml |g>g>f | O "f jf* T?*- o w -^ o "" 3 il Hi o w co 12 O g g k s (about 32.5 ssed warm. i **J tt > t-t(T> " g -> r-oog |^ES M 2. (about 28 k: ressed. o 1 TJ 5 && ra *" 'p'^: 5" *d Q S S e ff > -,^2S "^^ 0*2! & J3 M >rt (^ S < tr ''? CO en 3. " i * c & 3.| |l H (about 47.5 ki sed cold. .bout 50 kilos by water an eres, and wa F CRAP (about 1 Added to L_ Careful sepa: TICAL r (approxin s o ^-^ o* -* K ' JS E | w SB ^ - CD S O o' 10 < S 3 ?00 '2 g. ~ ro r P o H*. - P and P' LEIC ACID (about 23.5 kilos.) brought into commerce as: leic Acid, lein Soaps (Soda Soaps). >ft Soaps (Potash Soaps). SOLID FAT ACIDS (about 4 kilos.). (a Ided to H. ;ually about :ilos. Oleic Acid. P' I L, LIQUID FATTY ACIDS (aboi Filtered and crystal] ing point, 46.5 C. inder a pressure of h sulphuric acid. > H O, l 0, ^r; n> a f QJ ! O f? 5 '^ f 2-g fD "O o" the fleshy and impure porti LIZATION OF >ld of one Ox), Sulphurli o"*- 1 5' "" ~& 2.^S- W o o C ^ (D M 1-1 e^ t * i* f ^ . *^ "\ c?i to 2. o 'g pr 2L ^ OP pj Tq So & ^ os 1 o Pi P > i3 f e ' o S . H p w , cl^ils^w 3 MO f 3 r f iK V o Paffi^^f? 3 u "i Eg t^ "5"^ * ' ' w Cd M n J O j S" "-^ 2 B.S.B f? 'S' O w PI; gPO(t>pO^*a5 D'wj' 7 '^ PiOW M- 1 ? P o o* ? ag-" 3.5-- 3 a g:o 5 ^Sg- 1 P - ro p;^. B ^5 1 w| 5 a M*? ^ 2iW ^ ( . p P o o o S d a ffS ^ * cj CO t> i S < P cr CJ-^T .^ ff 68 INDUSTRY OF THE FATS AND FATTY OILS. (1) Boiling the fats in open vessels (coppers) with indefinite quan- tities of alkaline lyes until products of definite character are gotten. These are (a), soft soaps, in which the glycerine is retained, potash being the base; (6), the so-called "hydrated soaps," with soda for a base, in which the glycerine is retained, and of which "marine " soap may be taken as the type; (c), hard soaps, with soda for a base, in which the glycerine is eliminated, comprising three kinds, curd, mottled, and yellow soaps. (2) Acting upon the fats with the precise quantity of alkali neces- sary for saponification without the separation of any waste liquor, the glycerine being retained in the soap. This includes (a) soaps made by the "cold process," and (6) soap made under pressure. (3) Direct union of the fatty acids, as in "red oil " and caustic alkali, or alkaline carbonate. The general outlines of these methods may be indicated: In the manufacture of soft soaps the drying oils are preferably used. In England whale, seal, and linseed oil are chiefly used, in Continental Europe hemp-seed, linseed, rape-seed, poppy, and train oils, and in the United States cotton-seed oil and oleic acid. A potash lye containing some carbonate is used, and frequently a portion of the potash is re- placed by soda. The soft soaps, after being boiled to the necessary degree, are not salted, so that the glycerine and any excess of alkali remains in the soap. For use in wool-scouring this excess of alkali is, however, unsuited, so that neutral soft soaps are specially sought to be obtained. The method of making ' ' hydrated " or ' ' filled ' ' soaps is very similar to that of soft soaps. Fatty matter and soda are run into the copper, and the whole is boiled together, care being taken to avoid an excess of alkali at first; when saponification has taken place, lye is cau- tiously added until the soap tastes very faintly of alkali, when the soap is ready to be transferred to the frames, without any salting or sepa- rating of the mixture. Marine soap, for use with sea-water, is made in this way, and is entirely cocoa-nut oil soap. The well-known Eschweger soap is also made by this general method from a mixture of cocoa-nut oil and other fats, saponified either separately or together, and con- taining the glycerine and water in the soap mass. The manufacture of true hard soaps, which still constitute the great bulk of those made in England and the United States, requires more time and care than the varieties just mentioned. Melted fat and a quantity of soda lye of about 11 B., equal to one-fourth that needed for complete saponification, are simultaneously run into the copper and steam turned on. The "soap-copper," as shown in Fig. 22, is an iron kettle, or series of kettles, set in masonry, and equipped with pipes for both open and closed steam, and provided with an outlet for the discharge of the waste lyes when required. They may be used in series, or extra large single ones used. Strong lye should not be used at this first stage, or saponification will not take place. When the mixture becomes homogeneous, lye of 20 to 25 B., in amount equal to that taken before, may be cautiously added. It is now boiled until a sample taken PROCESSES OF TREATMENT. 69 out has a firm consistence between the fingers. Common salt or a brine of 24 B. is now run in. A small sample removed on a spatula or trowel should now allow clear liquor to run from it. The boiling is then stopped, and the copper should be allowed to stand at least two or three hours. The contents now divide themselves into two portions, the upper consisting of soap-paste, containing water, and the lower con- sisting of "spent lye," holding in solution common salt and all the impurities of the liquors, together with glycerine. It should contain no caustic soda and no soap. After removing the spent lye from below, the rest of the caustic soda lye is run in and the soap boiled up again. At this stage the rosin is usually added for rosin or yellow soaps. The boiling is now continued until the frothing mixture boils quietly and FIG. 22. becomes clear, the process being known as "clear boiling." The copper is then boiled with open steam and a small quantity of lye of 12 B. allowed to run in until the soap separates in flakes and feels hard when cold, technically called "making the soap." Boiling is still continued for several hours to insure complete saponification, and it is then allowed to separate and harden. This procedure yields a curd soap if no rosin has been added. If, after a soap is "made," the lye in which it is sus- pended is concentrated to a point short of that necessary to produce hard curd soap, and it is then transferred to the cooling frames with a certain quantity of lye entangled in it, these insoluble particles will, during the solidification of the soap, collect together and produce the appearance known as "mottling;" and the effect is heightened by the partial crystallization of the soap. The lye remaining in the cavities between the curds makes mottled soaps, the most suitable and really economical for washing clothes, etc., in hard waters, although not for toilet purposes. Mottling is sometimes added, as the peculiar greenish mottle, which becomes red on exposure, characteristic of Marseilles and Castile soaps, is produced by adding some solution of ferrous sulphate 70 INDUSTRY OF THE FATS AND FATTY OILS. to the copper when the soap is nearly finished (about four ounces of the salt to one hundred pounds of the fat) ; the precipitated iron protoxide suspended in the soap is greenish, but it becomes peroxide in contact with air, to which the change to a red color on exposure is due. Yellow soaps are made from tallow and rosin, the proportion of rosin varying from one-sixth of the total to an equal weight, or even more, according to the quality of the soap desired. In the presence of the sodium oleate from the tallow, the rosin acids saponify readily and coalesce to form a very uniform soap. In smooth or "cut " soaps water or thin lye is added to the contents of the copper before the soap separates finally to form the curd, and is taken up in considerable amount, giving a smooth yet firm surface to the soap, instead of the hard, granular surface of the curd soap. The so-called "cold process " requires the use of exact weights of well-refined fats and of caustic soda of a given specific gravity, the quantities being such that only just enough soda is present to completely saponify the fat. The materials are allowed to stand together for a short time and then thoroughly mixed in a copper provided with steam, agi- tating paddles, and kept at a temperature of not over 120 F. The reaction proceeds rapidly, and after some fifteen minutes the materials have so far united that they will not separate on standing, although the complete saponification of the materials may require days. They are then run out into the cooling-frames. It is obvious that soaps made in this way retain all the glycerine originally combined with the fatty acids disseminated through the particles of soap, and belong to the class known as "filled" or "padded" soaps, mentioned before. (See p. 68.) When cocoa-nut oil alone is used, the temperature of working in this cold process need not be higher than 75 F. for summer and 90 F. in winter; if one-half tallow, 104 to 108 F.; and if two-thirds tallow, 113 to 120 F. is necessary. Mixtures of cocoa-nut oil and other fats are frequently saponified in this way, the free acid of the cocoa-nut oil readily starting the process of saponification. A well-refined tallow can, however, be saponified in this way too, and mixtures of tallow and rosin worked up also into yellow filled soaps. This combination of cocoa-nut oil with tallow and rosin can also take up on its saponification large quantities of water-glass and similar "filling " material, so that a very large yield of smooth filled soap is obtained. Thus a mixture of one hundred kilos, of cocoa-nut oil, seventy-five to eighty kilos, of rosin, three hundred kilos, of water- glass, one hundred to one hundred and fifty kilos, of tallow, and two hundred and forty kilos, soda lye of 33 B., will make eight hundred kilos, of a finished soap. Saponification under pressure has also been frequently tried, the object being to shorten the time required for open boiling. In this case the quantity of alkali used must be accurately adjusted to the fat to be saponified, the glycerine is retained in the ultimate product. The process is carried out in an autoclave or pressure-boiler, the tempera- PROCESSES OF TREATMENT. 71 ture is allowed to rise to about 310 F. (154.4 C.), equivalent to a steam-pressure of sixty-three pounds to the square inch, and kept at this for an hour, when the contents are discharged into a cooling-frame. There remains to be noted the process of soap-making in which we start not with a fat, but with the free fatty acids, as in the "red oil " or crude oleic acid obtained in stearine candle manufacture. (See p. 74.) These oleic soaps, as they are called, are made preferably from the oleine acid resulting from the saponification of tallow or palm oil by the lime process. That obtained in the distillation process is not so well adapted for use here. The oleic acid may be saponified either with car- bonate or with caustic alkali. The former process has the disadvantage that the escaping carbonic-acid gas causes a strong frothing which easily leads to boiling over. One hundred kilos, of the oleic acid obtained in the lime-saponification yield one hundred and fifty to one hundred and sixty kilos, of soap. The acid obtained by distillation always yields somewhat less. Frequently the oleic acid before saponifying is changed by nitrous acid into the isomeric elaidic acid, which is as hard as tallow, and from which a very fine soap can then be made resembling tallow soap, and capable of being worked at will into a curd soap or a cut soap. If it be made with carbonate of. soda, the copper is filled to one- third its capacity with the oleic acid and the calculated amount of half- crystallized and half-calcined soda added, little by little, while the heating and thorough agitation of the liquid is kept up. When the soap becomes thick and all foaming has ceased, the soap is filled at once into the forms to cool. The portion of crystallized soda used supplies all the water needed for the saponification. In saponification with caustic alkali, a strong lye (25 B.) is taken. No emulsion forms, but a lumpy, mortar-like mass, which, however, as the alkali is more fully taken up and the lye becomes weaker, gradually goes over into ordinary soap-paste. The soap is separated by the addi- tion of a strong lye instead of salting it. After the finishing of the soap in the copper, it may either be put direct into the cooling frame, or it may be transferred to mixing tanks, known as " crutchers, " where various solutions or substances are incor- porated with it prior to its being allowed to solidify. Soap-frames are of two kinds, according as it is desired to cool the soap slowly or quickly. "When slow cooling is required, as is always the case with mottled soap, wooden frames, usually of pine, are em- ployed. These are built up in horizontal sections, nine to twelve inches deep, each section lined with thin sheet-iron, as shown in Fig. 23. Most curd and all yellow soaps are cooled rapidly in cast-iron frames of any desired shape and size. Such an iron soap-frame is illustrated in Fig. 24. The sides and ends of the frame are easily removed after the thor- ough solidification of the soap, and the block is then left upon the truck, which served as the bottom of the frame. It is now ready for the cut- ting into slabs and bars. This is now almost universally done by ma- chinery, and the truck containing the hardened block is run at once into the large frame containing the cutting wires. Such a frame, al- 72 INDUSTRY OF THE FATS AND FATTY OILS. FIG. 23. though of smaller size, and used for slabs of soaps only, is shown in Fig. 25. The best piano-forte wire is necessary for these "Cutting frames, as the tension is very great when the soap is pressed through the wires. While the soaps thus far spoken of are adapted for general or laundry purposes there is a distinct class of soaps known as toilet soaps. As these are to be applied to the skin they must answer other requirements, the most important of which is that they shall not con- tain any free alkali. Some dermatologists even demand that there shall always be some unsaponified fat. We may distinguish transparent soaps, re- melted soaps, and milled soaps. Transparent soaps may be made either by the spirit process, in which case the stock soap is dissolved in alcohol, the solvent almost all distilled off, and the mixture then run into frames to gelatinize and solidify by gradual evaporation of the remaining alcohol, or the cold glycerine process. In this case the warm fatty materials employed (of which castor oil is generally a large ingredient on account of the readiness with which it saponifies) are intimately mixed with soda ley; soluble coloring matters and essential oils or other scenting material are then stirred in and the whole allowed to stand. The glycerine which forms on saponification tends to cause the soap to take a trans- lucent appearance. Perfect transparency can be obtained by the addition of more gly- cerine, or what accomplishes the same result, and is cheaper, cane-sugar. This latter ingredient, however, makes the soap irritating to sensitive skins. In the remelting of soaps, followed chiefly in England, several stock soaps may be mixed together, coloring and scenting materials added, and the mass heated in a steam- jacketed pan. If ,the mixture is rapidly agitated, enough air-bubbles may be worked in to enable the. cake of soap to float in water, even after compression in the stamping press, producing a toilet soap which " floats " on water. The addition of some FIG. 24. PROCESSES OF TREATMENT. 73 pearlash (potassium carbonate) is also made at times to improve the lathering power of the soap, but such soaps are alkaline and injurious to delicate skins. The finest toilet soaps, however, are made by "mill- ing," a process first carried out in France. The bars of stock soap are first "stripped," or cut into slices by a slicing machine. The chips are dried in a warm air-chamber until only a few per cent, of water remains, and then ground between heavy horizontal rollers of the milling ma- chine. At this stage the various coloring and perfuming ingredients are added, or unguents like lanolin and vaseline. The thoroughly mixed material is then put into a cylindrical barrel, in which it is compressed by a piston and comes out as a continuous bar, which is cut into lengths FIG. 25. and stamped into cakes. The advantages of this method are, first, that inasmuch as no artificial heat is applied, delicate flower perfumes, etc., can be readily incorporated with the soap mass which it would be impos- sible to use with a remelted soap, because the heat would dissipate or destroy the odoriferous matter; and, secondly, that as the resulting tablets usually contain only a small quantity of water, a given weight of soap-cake or tablet generally contains a much larger quantity of actual soap than another cake 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. Spherical cakes and wash-balls are finished by turning and polishing in a kind of lathe. Sometimes the polishing is finished by the use of a cloth dipped in alcohol. Shaving creams are made by the cold process from refined lard and caustic potash, adding cocoa-nut oil in small amount to facilitate the making of lather. 74 INDUSTRY OF THE FATS AND FATTY OILS. 3. STEARIO ACID AND CANDLE MANUFACTURE. For the extraction of stearic acid, the washed fatty acids (p. 65) are heated to the melting point and run into dishes or troughs made of tin, as shown in Fig. 26. These are placed in a room, the temperature of which is kept at 68 to 86 F. (20 to 30 C.), and left for two to three days, or until the con- tents have granulated, as the palmitic and stearic acids crystallize, when the dishes are emptied into canvas or woollen bags, which are carefully deposited between the plates of an upright hydraulic press, as shown in Fig. 27. Pressure is now exerted, increasing in degree until the flow FIG. 27 FIG. 26. of the liquid oleic acid ceases. The hard, thin cakes of crude stearic acid so obtained are then melted down again with steam, and after set- tling, the melted acid run into the tin dishes and placed aside to cool. The temperature of the cooling-room in this case should be higher than before, or about 86 F. (30 C.). The blocks of stearic acid gotten are ground to meal, filled in bags of hair or wool, and then submitted to a second pressure, in a horizontal hydraulic press, the plates of which can be heated. In this press, a pressure of six tons per square inch, at tem- peratures of from 104 to 120 F. (40 to 49 C.), is reached. The cakes so obtained are melted by steam, a little wax being sometimes added to destroy the crystalline structure of the stearic acid, which somewhat unfits it for candle-making. PROCESSES OF TREATMENT. 75 The yield of stearic acid obtained varies according to the fat used and the process of saponification employed. F. A. Sarg's Sons (Vienna) use three per cent, of lime under a pressure of ten atmospheres, and get ninety-five per cent, of crude fat acids and thirty per cent, of glycerine water (5 to 6 B.), and a final yield of forty-five per cent, stearic acid, fifty per cent, of oleic acid, and five to six per cent, of glycerine. In England, with the sulphuric acid and distillation process, they get sixty to seventy or even seventy-five per cent, of fat acids suitable for candle- making, although inferior to that obtained in the lime process. Palm oil is now used in enormous quantities for the production of palmitic acid at Price's Candle Company's works, as well as by almost every candle manufacturer in Great Britain, about twenty-five thousand tons being annually consumed. In many continental countries a prohib- itive duty prevents its employment. From this palmitic acid the finest composite candles are made by hot-pressing the distilled palmitic acid. Palmitic acid for candle-making is also made commercially, according to a process of St. Cyr-Radisson, by fusing oleic acid with a great excess of caustic potash, the products of the reaction being potassium palmi- tate, potassium acetate, and hydrogen. As carried out in Marseilles, the oleic acid and potash lye of 41 B. are put into an autoclave provided with a mechanical agitator, and heated until steam ceases to be given off, when the open manhole is closed, and the heat continued until 554 F. (290 C.) is reached. Decomposition now commences, and much hydrogen is given off through an escape-tube set in the lid of the boiler. At 608 F. (320 C.) the odor of the evolved gas suddenly changes, and destructive distillation begins. This is arrested by blowing in steam at once, and the contents are run out. The potassium palmitate is then washed, decomposed with sulphuric acid, the free acid washed and distilled. The product of the distillation is white, and burns excellently when made into candles. In the manufacture of candles, the first operation is the preparation of the wick. For dip-candles the wick is twisted, for others it is plaited, and the kind of plaiting must also vary according to the material used. Stearine candles require a moderately tightly-braided wick, paraffin candles an extra tight braid, and for spermaceti and wax, on the other hand, the braids are measurably loose. After being twisted, or plaited, the wicks are dried and then dipped into a pickling liquor, which is to retard combustion and help in the destruction of the ash. The pickle usually consists of a solution of boracic acid, ammonium phosphate, or ammonium chloride. Three plans of candle-making are at present in use, dipping, moulding, and pouring. The first is employed for com- mon tallow candles, which are accordingly called "dips." Under a frame holding the suspended wicks are placed troughs containing melted tallow, into which the wicks are repeatedly dipped. After each dipping the adherent fat is allowed to cool sufficiently to retain a fresh coating on immersion. When the candles have thus grown to the proper thickness they are left to cool and harden. These cheap "dips " are, however, now being replaced by small, moulded "composite " candles, 76 INDUSTRY OF THE FATS AND FATTY OILS. as well as candles made from the softer, paraffin scale. Pouring is used only with wax candles, which cannot be moulded because of the adher- ing or cracking of the wax in removing it from the moulds. A well- made wax candle should show rings like a tree, where the different layers have been superposed. By far the greater number of candles are moulded, by which process they acquire a much more finished appear- ance. A form of frame in common use is represented in Fig. 28. The materials in general use for candle-making are tallow, palmitic and stearic acids, paraffin, ozokerite or ceresine, spermaceti, and beeswax. FIG. 28. Very generally, several of these materials are admixed. Stearic candles have a small quantity of paraffin added to obviate the crystalline struc- ture of the stearic acid; paraffin candles always have five to ten per cent, of stearic acid in them, to prevent the softening and bending of the paraffin when warmed. Spermaceti and beeswax are more expensive than the other materials, and are only used now for special purposes, as for church-candles and carriage-lights. Ozokerite gives the paraffin candle of highest fusing point, being some six degrees higher than any other variety of paraffin. Colored paraffin candles are made by dis- solving the coloring matter (vegetable or aniline dyes, not mineral colors) in stearic acid, and then mixing this with the paraffin, which itself does not take up the color. Paraffin and other transparent candles must be filled in the mould very hot, and after all air-bubbles have escaped, the moulds must be rapidly cooled by a large flush of cold water PROCESSES OF TREATMENT. 77 to prevent the paraffin, etc., from crystallizing and thus causing opacity. Of interest in this connection is the table of illuminating equivalents, or quantities of different illuminating materials necessary to produce the same amount of light, prepared by Frankland. Young's paraffin oil 1.00 gallon. American petroleum, No. 1 . 1.26 gallons. American petroleum, No. 2. 1.30 gallons. Paraffin candles 18.60 pounds. Sperm candles 22.90 pounds. Wax candles 26.40 pounds. Composite ( stearine ) 29.50 pounds. Tallow 36.00 pounds. 4. OLEOMARGARINE, OR ARTIFICIAL BUTTER MANUFACTURE. The man- ufacture of a butter-substitute from the solution of palmitin in olein, which is known as oleomargarine, is a fat industry, but, because of its close relations to natural butter made from cows' milk, it will be con- sidered as supplementary to the description of butter under milk indus- tries. (See p. 284.) 5. GLYCERINE MANUFACTURE. For many years after the develop- ment of the soap and candle industries, no attempt was made to recover the glycerine which was liberated in the saponification. Its applica- tions in medicine and for technical purposes have made it important to extract and purify it, however, and it has now assumed almost equal importance with the other fat constituents. The two methods of saponi- fication, by which glycerine has been obtained on a large scale, are the process of Wilson & Payne, of decomposing the fats by superheated steam and after distillation (see p. 65), and the lime autoclave process of Milly. (See p. 64.) In the distillation process, however, by suitable arrangement for fractional condensation, it is found possible to con- centrate the aqueous glycerine in the process of distillation. Care must be taken that the temperature of 600 F. (315 C.) is not exceeded, and that plenty of steam is present, otherwise some glycerine is decom- posed and acrolein is formed. In the Milly process, after the decom- position of the fat is completed in the autoclave, the contents are blown out into a tank and the "sweet water " (glycerine) is run off. The concentrating may be done in contact with air or preferably it may be w r orked in some form of vacuum evaporator. Evaporation is continued to 26 B. (1.220 specific gravity), when the glycerine is of a brownish color, and is known as "raw," in which state it is sold for many pur- poses, and contains about ninety per cent, of glycerine and traces only of mineral impurities. At Price's Candle Company's works the further purification is conducted as follows. The raw glycerine, specific gravity 1.240 to 1.245, is heated in a jacketed pan with that kind of animal charcoal known as ivory-black, and is then distilled ; this alternate treat- ment is repeated as often as is necessary. The distillation is performed with superheated steam in a copper still provided with copper fractional condensers, the still being also heated externally; the operation is per- formed at as low a temperature as is consistent with distillation, usually about 440 F. (227 C.). It is obvious that in soap-making, as enormous quantities of the fats are decomposed, corresponding quantities of glycerine go into the spent 78 INDUSTRY OF THE FATS AND FATTY OILS. lyes. It is only very recently that it has been attempted to recover this glycerine. The two processes at present in use are those of Jobbins and Van Ruymbeke and of Garrigues. Another suggestion of more recent date is to deglycerinize all fats before saponifying them. The process of Michaud Freres, of Paris, as carried out by the Continental Gly- cerine Company, of New York, realizes this idea very successfully. According to their patent ''the fatty matter is subjected in a close vessel to the action of the steam, at a pressure of one hundred to one hundred and thirty pounds per square inch, and at corresponding tem- perature in presence of one-fourth to one-third part of its weight of water and one-fifth to three-fifths per cent, of its weight of the oxide of zinc, known commercially as zinc white, or a like proportion of zinc powder or zinc gray, which is a residue in the treatment of zinc, being a mixture of zinc with its oxide. . . The very small proportion of mineral sub- stance used is sufficient for dispensing with the acid treatment applied for decomposing lime soap, and the product obtained, consisting almost exclusively of acid fat, can be converted by the acids usually employed into soap or candles. In soap-making, the dissolving powers of the caustic alkalies remove all objections to the presence of the zinc if it should be used in excess. The reducing power of the zinc powder pre- vents discoloration of the acid fats such as results from the ordinary treatment." The glycerine thus produced finds a ready sale, as it runs from the evaporators, and from it, as "crude," ninety-six per cent, of pure glycerine can be obtained. 5a. NITRO-GLYCERINE AND DYNAMITE. In 1847 Sobrero discovered a very interesting derivative of glycerine, and in 1862 A. Nobel gave it to the world as a technical product of the greatest importance. When strong glycerine is gradually added to a well-cooled mixture of very strong nitric and sulphuric acids, it is converted into glyceryl nitrate, or nitro-glycerine. For the manufacture of nitro-glycerine on a large scale, Nobel recommends that one part of good glycerine be allowed to flow in a thin stream into a well-cooled mixture of four parts of concen- trated sulphuric acid and one part of the very strongest nitric acid (1.52 specific gravity), the mixture being contained in a wooden vessel lined with lead. - Means should be provided by which the mixture can at once be run into a large quantity of water should the action threaten to become too violent. On standing, the nitro-glycerine separates as a layer on the surface of the acid, and is skimmed off and washed with water and solution of sodium carbonate to get rid of every trace of free acid. Or, according to the same authority, a mixture is made of one part nitre with 3.5 parts of sulphuric acid (1.83 specific gravity), the mix- ture cooled to 32 F. (0 C.), and the liquid poured off from the acid potassium sulphate, which separates out; into this liquid the glycerine is slowly dropped, the mixture poured into water, and the separated nitre-glycerine washed thoroughly and dried. The yield is two hundred and twenty-three per cent, of the glycerine used. It has been suggested to mix the glycerine beforehand with the sul- phuric acid, and then run this mixture into the nitric acid, and it is PRODUCTS. 79 claimed that the elevation of temperature is less than when the ordi- nary method is followed ; but the process does not seem to have been satisfactory in practice when tried in England. When absorbed by infusorial earth, " kieselguhr, " sawdust, mica powder, or other inert porous material, nitro-glycerine forms the dif- ferent varieties of dynamite, and, when combined with gun-cotton, it constitutes the explosive known as "blasting gelatine." m. Products. 1. PURIFIED OILS, FATS, AND WAXES, AND PRODUCTS FROM THE SAME. Most of the important oils, fats, and waxes have already been described as raw materials, and the methods of purifying them have been noted. The purified oils are in some cases the final products sought, and, in some cases, only improved raw materials for the main industries, like soap-making, candle-making, and glycerine extraction. These purified oils having, therefore, been referred to as raw materials, will not be further noted. A number of side-products, obtained with or produced from these oils, remain to be mentioned. One of these minor products of great value is the oil-cake, or com- pacted mass of crushed seeds or nuts, from which the oil has been expressed or extracted. This contains all of the woody fibre and mineral matter of the seed or nut, the residue of oil or fatty matter not ex- tracted, and, what gives it special value, the proteids or nitrogenous constituents. The oil-cake thus becomes a most valuable cattle food and a basis for artificial fertilizers. The following table gives the compo- sition of a number of the most important oil-cakes: Water. Fat. Non-rutrogen- ous materials. Woody fibre. Ash. .Protein material. Nitrogen. per cent. Earth-nut cake 11.50 8.80 31.10 7.25 41.35 6.80 Cotton-seed cake 13.00 7.50 51.00 850 2000 2.90 Kape-oil cake . 10.12 9.23 41.93 6.48 31.88 6.00 Colza-oil cake . 11.35 9.00 42.82 6.28 30.55 4.50 Sesame-oil cake 10.35 10.10 38.80 9.80 31.93 5.00 Beech-nut cake 11.40 8.50 49.80 5.30 24.00 3.20 Linseed cake . 10.56 9.83 44.61 6.50 28.50 4.25 Camelina cake . 9.60 9.20 50.90 7.00 23.30 3.60 Poppy-oil cake 9.50 890 37.67 11.43 32.50 6.00 Sunflower-oil cake 10.20 8.50 48.90 11.40 21.00 2.40 Hempseed cake 10.00 8.26 48.00 12.24 21.60 3.30 Palm-nut cake . 9.50 8.43 40.95 10.62 30.40 4.50 Cocoa-nut cake 10.00 9.20 40.50 10.50 30.00 4.50 It will be seen in this table that they vary in proteids or flesh-forming constituents quite widely. All of these cakes, however, are too rich in these proteids and in fats to be used unmixed as fodder. They are, in practice, mixed with cereals, hay, and straw, and then constitute a valu- able food. The ash is, moreover, very rich in phosphoric acid and in potash, and this explains its value for fertilizer manufacture. 80 INDUSTRY OF THE FATS AND FATTY OILS. Thus it is stated that, as a fertilizer, one ton of cotton-seed-hull ashes has as much value as four and one-half of average hard-wood ashes, or fifteen of leached hard-wood ashes. The amount of oil-cake obtained from the expression of the different vegetable oils is enormous. Thus it is stated that one short ton of cotton- seed (constituting forty per cent, of the raw cotton) will yield eight hundred pounds of cotton-seed cake and forty-five gallons of crude cotton-seed oil. The amount of crude cotton-seed annually obtained in the United States is estimated at four thousand million pounds, half of which only is required for sowing. The accompanying table, prepared by Grimshaw, will show how thoroughly the cotton-seed is now utilized: Cotton-seed, 2000 pounds. Cattle food. Meats , 1089 pounds. Lint, 20 pounds. Hulls, i 891 pounds. Cake, 800 pounds. Meal. Crude oil, 289 pounds. i Fibre. High-grade paper. Bran. i Fuel. Ashes. Fertilizer. Summer Soap stock, yellow. i do 1 nil ml Soap. Summer white T nrrl Winter Cotton-seed yellow. stearine. An important manufactured oil is what is known as "Turkey-red oil," used in the process of alizarin dyeing. (See p. 539.) There are, in fact, two entirely distinct oils known under this name. One is simply an inferior grade of olive oil, that known as ' ' Gallipoli oil, ' ' and for this particular use is prepared from somewhat unripe olives, which are steeped for some time in boiling water before being pressed. This treatment causes the oil to contain a large proportion of extractive matter, and hence it soon becomes rancid. This preparation has long been used in the old process of Turkey-red dyeing, under the name huile tournante. The other, used for producing alizarin reds by the quick process, is the ammonium salt of sulpho-ricinoleic acid (C 18 H 33 (HS0 3 )0 3 ), a body which is obtained mixed with unaltered glycerides and with products of its decomposition by the action of sulphuric acid upon castor oil. From linseed oil, as the most important of the class of drying oils, is prepared a product of great value for paint and varnish manufacture. (See p. 112.) What is called "boiled oil" is linseed oil, which has been heated to a high temperature (130 C. and upward), while a current of air is passed through or over the oil, and the temperature increased until the oil begins to effervesce from evolution of products of decom- position. By adding litharge, red-lead, ferric c^xide, or manganese di- oxide, or hydrate, during the process of boiling, the oxidation and con- sequent drying of the product are still further facilitated. The nature, proportion, and mode of adding these substances are usually kept PRODUCTS. 81 jealously secret. Lead acetate and manganous borate are among the most approved. The action of some, at least, of these "dryers " (e. g., compounds of manganese) seems to be that of carriers of oxygen, while litharge dissolves in the oil and acts partly as a carrier of oxygen and partly as the base of certain salts which oxidize very rapidly. Many of the fatty oils and notably some of the non-drying oils are capable of being thickened and increased, especially in specific gravity and viscosity, by having a stream of air blown through them. The prod- ucts of this treatment are known as blown oils or oxidized oils. They are not resinified as when the drying oils are boiled with driers, but become thick and viscid like castor oil. This property is taken advan- tage of, therefore, in the production of heavy viscid products, which are used in admixture with mineral oils for the purpose of preparing lubricants for heavy machinery. While cotton-seed, rape, olive, earth- nut, lard, and linseed oils have all been utilized in this way, the two most commonly employed are rape and cotton-seed oils. In carrying out the blowing operation, the oil is usually heated to 70 C. (138 F.) or slightly more, and air is then blown in through a vertical pipe which passes down nearly to the bottom of the kettle, the air being itself heated to the same temperature. In a short time the oil begins to oxidize and the temperature to rise. The steam is then shut off from the heating coils, and care must now be taken that the temperature does not rise above 80 C. (176 F.). The process usually lasts from twelve to forty-eight hours, according to the nature of the oil being treated and the character of the product desired. By continuing the operation, products may be obtained of specific gravity as high as from .985 to .999 even. Blown oils vary in color from a clear yellow to a dark reddish yellow, and have a peculiar and somewhat disagreeable odor. They are very viscous, as dense or denser than castor oil, from which they differ in not being readily soluble in alcohol but in being soluble in petroleum spirit. Their perfect miscibility with heavy mineral oils is, however, their chief advantage. The percentage of free fatty acids is usually increased by the blowing operation and the percentage of insoluble fatty acids decreased, owing to the formation of soluble oxyacids. The following table from Lewkowitsch ("Oils, Fats, and Waxes," 2d ed., p. 734) will show the change undergone by rape oil in conse- quence of the blowing operation: Specific gravity at 15.5 C. Free acid as oleic. Saponifi- cation value. Iodine value. Insoluble acids. Soluble acids. Rape oil 0.9141 6.10 173.9 100.5 94.76 0.52 Same, 5 hours' blowing . 0.9275 5.01 183 88.4 Same, 20 hours' blowing 0.9615 7.09 194.9 63.2 85.94 10.02 2. SOAPS. In noting the processes for practical soap-making, the following classes of soaps were indicated: (1) compact soaps, including (a) curd soaps; (6) mottled soaps, and (c) yellow soaps; (2) smooth 6 82 INDUSTRY OF THE FATS AND FATTY OILS. or cut soaps; (3) filled or padded soaps; and (4) soft or potash soaps. The most important difference between the compact, cut, and filled soaps is the amount of water present in the soap. In the compact soap it may vary from ten to twenty-five per cent., in the cut soap from twenty-five to forty-five per cent., and in the filled soap from forty-five to seventy-five per cent. In addition, the filled soap contains the gly- cerine, spent lye, and other impurities of the soap copper. The following table of analysis, by Mr. C. Hope, as quoted by Allen,* will illustrate the composition of a variety of soaps belonging to these several classes: NAME OP SOAP. MATERIALS. Fatty and resin an- hydrides. y to '3 o> d cj oj S 1 cw 1 B i 03 g CO Sodium carbonate and hydrate. Neutral salts, lime, and iron oxide. ij I 3 * "3 g White No 1 Tallow Tallow and cocoa-nut oil . . Tallow and cocoa-nut oil . . Tallow and cocoa-nut oil . . Tallow, rosin, and cotton- seed oil 69.06 60.50 55.71 44.27 71.30 49.95 71.20 62.66 59.28 38.89 59.92 42.41 60.69 48.20 39.92 63.06 10.90 19.42 8.98 6.82 6.90 6.23 7.98 7.00 7.58 7.27 6.65 5.76 6.76 4.14 7.22 5.00 4.70 7.25 1.36 3.11 .01 .06 .03 7.02 1.07 2.34 .06 .06 .42 6.40 .02 5.64 .04 .42 .62 .02 .03 9.00 2.36 .48 1.01 .03 .03 .01 1.29 l'.59 '.18 .25 3.98 .27 .06 .92 .75 .75 .33 .22 .77 .39 1.62 .92 2.76 .10 .15 .20 .10 Trace 3.00 .72 .39 .26 1.00 .82 1.01 1.03 1.22 .76 2.53 1.70 .51 .60 .90 1.81 1.90 3.27 5.64 21.14 32.20 36.54 38.14 17.44 38.18 19.70 28.20 32.35 38.70 31.30 42.88 31.22 45.00 52.40 27.47 84.00 53.32 100.18 100.03 100.36 99.77 99.84 99.82 99.82 100.21 99.86 95.19 99.75 99.93 100.00 99.80 99.90 100.00 99.56 97.47 White No 2 White No 3 White No 4 Cold water No. 1 Tallow, rosin, and cotton- seed oil . Olive oil, No. 1 Marseilles No 1 Olive oil Chiefly olive oil Palm oil Palm oil, No. 1 Mottled Palm-nut oil Satinet Tallow and rosin Tallow and rosin Tallow and rosin Tallow and rosin Tallow and rosin Not mentioned . Not mentioned . Palm-nut oil . . Glasgow almond Pale rosin, No. 2 Pale rosin, No. 3 Milling Yellow (for foreign markets) Marine (for emigrants) . . Two of these samples, those designated as "mottled " and "marine," were prepared by the "cold process " (see p. 70), which accounts for the totals being appreciably less than 100.00, as the glycerine was retained in the soap. The chief soaps of pharmacy, as analyzed by M. Dechan,f are com- posed as follows: "3 m 03 t. 03 - e _, I i ft ifldf . be '3 G > pj Sm _, a G c; ~ cp '*"'_- g 2 9 A q I o 1 e "Jo CG C eg oj 0? S = a 3 s B 03 0) SS S 1 1 * H -C g .g S O s .2 P s a A i g < "c " 1.1 1 i1-siS| and ether, or recently-distilled carbon disulphide. T itment was found to remove anything. acid and separate.* Wash residual oil repeatedly by r or carbon disulphide. Distil off the solvent and h iolution of phenol-phthalein. Then add standard so [tion, until a pink color is obtained, which remains i d, as the quantity used is a measure of the free fatty i ing further into their nature. Separate any undissolvei ol at a gentle heat, and agitate with petroleum spirit il to the main portion. . Saponify with alcoholic potash. Boil off alcohol, di id agitate cooled solution with ether. Separate and ag and third time with ether. M a, -5 "O os S "S 5 < g | H "S O > OJ-" '2^200 ri -A ?>>>; S M CO s g s -3 P. 'S '? E a 8 3 5 -S bo ^r Q Q a 5 J 'So * 03 C o* S S 1 -e 1 J S -2 J 03 O C* C H Q. *> "3 M oj . ^ g .e M Z . $ - ~ I! |lf iill{f &1 P. "* ^ * r s tJ f i -g -g 4,' "g a 8| pS^cS.^'^^^'oig^ ^ b g^'^^'ca'^'jS'ObOt,*" Bs^Jfi^-?-! ^s o> w l^ii^^k-^l' 05 ,: M >.'C^ tlC >.5 C.Sfcsc'^ ANALYTICAL TESTS AND METHODS. 93 EXTRACT is uncomMned fat. Dry at 110 and weigh. t^ Q ^5> 3 o O o 1 a "5 O< co P g. a S & o H s ~ PI CD T3 3* n a o ;s m 9 go ~ " 2 3. CD ^ B * o 7 n -2 a o {? s > 1-1 p B f 3 2 S v 3 S S 3 = 5 f. S? ~. i ' s & & M 2 o OT O 2 = 7 o JT %> B > ^ 3^ I r g P o ^ 3 o- u p P CD p CD o, & CD cT P ^ 5 " CO f!H. P Uil 5. r 2 iff 3 p 1 a 1 oa "? a O 7 O ft S * $ 11 o jj H ^ W t> 3 5 jF 2 M j * M e* | o x P """l 3^' D O P Q * r w *^3 t>- P Cl -i~* CD 2 S 1 3 S ' 3 c? CD 2 M tS- 3" so O * & 1 7S " ff ft * 1 2 & I II f ft ' 0) t- 1 ! CD p3--g.3|p,; g s 3 g. CD S' W 2-3 f ~ R O. P 3 CD .~ t ?S^ 2 & ^ P 1 W 2. a x 5- 00 3 w : - M 3* & J ft M B p- P" t* 2. i L 3 ^ ^ i a o * o* B" 3 s^** ) 3 gQ W g JT. 3 S g i g^ sr >- 1 2. ^ S o ; f p Q^ W S- ^ - So' en S" 5" 2 "E- 8s 3 - * 1 o" ^ H fk t a, 1 2, -* .? CD 5 3 3 ! g &2. g 5 o TO Q S 1 CD l| p g ^| S> S*'F jl CD p p 3 P '. 5 g S^-S^ P o" _, 01 a 3' ^ S- $. S o P ff O tf O_ 3" p |2 i& p *< * * o p 3 ft B 5* i^ CD S- S. ct> F O q Illllllps!^ ll*j*!i ^g o 0-g.s g: >* . H- s 2 . p e CB O O 5 II f g CD I O B ? W CD | If B i*!t&Mli? 5 s 3 8 . 1 H>o r| P. s & e t? 2 f& ff (6 S B p o j ? ^r "^ S ^ i-s bd sgf *;. |l * i|| s- J 5 & sr s W AT ? ^ 3. | o B f. 1. 5 P 4 & F w CD 3 F A tr CD i Q5.^^,22o^' *. P CD IT. (D & ft a i'|*| R i| s jI g 1 o , 3 M :|Sg^^ * o ^ ^ ^ fl o CD g O > Treat w irrespon 3 M- <-! i i O i P i M) i ' i ' 2 S P< w . o* ^ S2. tf S- Sodium Carbonate. Titrate with normal sulphuric acid, and calculate as NaaCOs. i* O S' g ^ 1 JB P S- ^ 1 0, | Sodium Chloride. Titrate with silver nitrate or 2 W i weigh as silver chloride. Calculate as NaCl. -5' o* > ^s^ 2. CD 1 W i- - s Sodium Sulphate. Weigh as barium sulphate. ||I li Calculate as NagSO 4 . CD 3- PJ ta 5' v ^ B < B Sodium Silicate Decompose with HC1 and deter- g P 28 mine the soda combined in silicate and the silica. &g.? * " l&l elf 3' ^ CJi 2* i 3 H-. p l| p|| o TO' ^ g, W |t.li " 1 I*.}) ,e||J ** w 3 rt M p ? B 1 9 O a 3 O pi 3. g 1 5' | 1 3 o 1 5' " o' p g* 1 p' & " 1 1 1 p B P. 9 3 O CO o z w w G Q > ? CO w B -J Solid substance of the juice. RAW MATERIALS. 137 sucrose in the sorghum juice, analyzed by the chemists of the depart- ment, was 8.65, in 1884 the mean was 14.70 per cent., in 1885 it was 9.23, and in 1886 it was 8.60 per cent. The sorghum plant grows easily over a very wide range of climate, and if its cultivation can be estab- lished definitely upon correct principles, it may prove to be a most valu- able addition to the world's sugar-producing materials. 4. THE SUGAR-MAPLE. The sap of Acer saccharinum and other species of the genus Acer is a source of sugar and syrup more esteemed for confectionery and table use than because of its commercial import- ance. The sugar is never refined, and only comes into use as a raw, small-grained sugar of peculiar and characteristic flavor; the syrup is a thin, sweet syrup of the same characteristic maple flavor, differing considerably, too, in its composition from both cane- and beet-sugar syrups. The freshly-collected sap contains from two to four per cent, of sucrose, with traces of glucose. "We may now compare the chemical composition of the freshly-ex- pressed juice from the three sources of sugar manufacture above de- scribed, and note those differences which are of importance in deter- mining the successful extraction and crystallization of the cane-sugar. The composition of the fresh juice of the sugar-cane is illustrated in the following table. The first four analyses are by the United States Bureau of Agriculture and were made in connection with its experi- mental work, and the last six from experimental cultivation of certain varieties of cane in Cuba on the Soledad estate of Mr. E. Atkins. LOUISIANA. CUBA. 1884. 1885. 1886. 1887. Crystalline cane. Red ribbon cane. Black Java cane. Specific gravity . Total solids . . . Sucrose 1.068 16.54 13.05 0.67 0.19 78.97 islso 12.11 1.02 0.16 76.64 1.066 16.20 13.50 0.61 0.167 83.33 1.066 16.37 13.69 0.77 83.48 11.6 B. 20.9 19.2 0.66 Non- sugar. 1.04 91.8 12.5 B. 22.6 20.5 0.20 Non- sugar. 1.90 90.7 11 2 B. 20.2 18.5 0.14 Non- sugar. 91.5 12.1 B. 21.9 20.0 0.31 Non- sugar. 1.69 91.3 12.2 B. 22.0 21.3 Trace. Non- sugar. 0.70 96.8 11.8 B. 21.4 20.6 0.08 Non- sugar. 0.71 96.3 Glucose Albuminoids . . Coefficient of It will be seen that under favorable conditions the sucrose percentage in cane-juice may rise to over 20 per cent. The average composition of the fresh beet juice is shown in the fol- lowing analyses, the method of obtaining the juice being also indicated. The first four are from "Stammer's Lehrbuch, " and represent each of the average of a German beet-sugar factory for the season; the fifth is from beets cultivated at Washington, D. C., by the Bureau of Agri- culture; the sixth the average of a week's work at Alvarado, California, in 1888, and the last from a beet grown at Grand Island, Nebraska, and analyzed at the State Agricultural Experiment Station. 138 THE CANE-SUGAR INDUSTRY. German. By press- ure. German. By diffu- sion. German. By cen- trifugat- ing. German. By ma- ceration. Washing- ton. By press- ure. Alvarado, Cal. By diffu- sion. Grand Island, Neb.* H.H.Nichol- son. Total solids (degree Brix.) 16.27 17.20 14.99 18.77 11.78 17.20 23.70 Sucrose . .... 1302 14.63 11.98 14.64 7.61 14.80 21.41 0.39 0.138 Non-sugar .... Coefficient of purity 3.25 80.02 2.57 85.14 3.01 79.92 4.13 77.99 3.78 64.60 2.4 85.5 2.152 90.3 In 1907, at one factory in California (Los Alamitos) the average for the entire campaign was : sugar, 19.3 per cent., with an average co- efficient of purity of 84.8. The composition of the sorghum juice of different seasons, as culti- vated by the United States Department of Agriculture, is shown in the following table: 1883. 1884. 1885. 1886 18 87. Fort Scott. Rio Grande. Total solids 13.59 19.75 1507 17 08 16 14 1402 8.65 14.70 9.23 9.59 9.54 898 Glucose .... 4.08 1.27 3 04 4.25 3 40 3 24 0.86 3.78 2.80 3.24 3 20 1.80 Coefficient of purity 63.65 74.43 61.25 56.15 59 11 64.05 Analyses of fresh maple-sap made at Lunenburg, Vermont, by one of the chemists of the Department of Agriculture, in the spring of 1885, show that it contains an average of 3.50 per cent, of sucrose, traces only of glucose, about .01 per cent, of albuminoids, and has a mean coefficient of purity of 95. n. Processes of Treatment. 1. PRODUCTION OF SUGAR PROM THE SUGAR-CANE. As the cultiva- tion of the sugar-cane is chiefly carried on in the tropical countries, parts of which are dependent upon totally unskilled labor, there is very great diversity in the development which the industry has reached. In some countries the work is still done by hand or with the simplest kind of machinery, with corresponding small yield of inferior products, while, in others, as in Louisiana, Demerara, Cuba and other West Indian islands, there are many sugar plantations equipped with the very latest and best of sugar-making machinery, and producing direct from the juice raw sugars that are almost equal to the refined product. In gen- eral, however, the sugars produced on the plantation are not in a suffi- ciently pure condition for consumption and are termed "raw sugars," having therefore to undergo a process of refining, by which the impuri- ties are eliminated and the sucrose obtained in a r pure, well-crystallized state. "We shall note first the method of producing raw sugar, and afterwards the methods of refining the same at present in use. * Individual beets grown in Nebraska have shown a percentage of 22.08 sucrose, and a coefficient of purity of ninety-three per cent. PROCESSES OF TREATMENT. 139 The canes must be cut when they have arrived at maturity, and must be promptly used to prevent the fermentation of the albuminoid constituents and other non-sugar of the cane, which in turn rapidly changes sucrose into invert sugar and lessens the possible yield of crys- tallizable sugar. At least this immediate use of the cut cane is necessary in Cuba, Demerara, and distinctly tropical countries, where the juices must be expressed within forty-eight hours after the cutting to prevent an excessive inversion taking place. In Louisiana, the experiments of the Department of Agriculture have shown* that sound canes can be kept stored under cover for two or three months without appreciable diminution in the sucrose per cent, or loss in the coefficient of purity. The expression of the juice has been, and in most cases still con- tinues to be, effected by the process of crushing the canes between heavy rolls, which may vary from the crude stone or iron rolls, driven by water or horse-power, to the perfected sugar-mills now in use, in which enor- FIQ. 35. mous, hollow, steam-heated rolls, driven by steam, are used to do the same work. Large, slow-moving rolls have been found in practice to yield better results than smaller, rapid-moving rolls. While four, five, and even nine-roll mills have been constructed, the mill in general use is a three-roll mill, an example of which is shown in Fig. 35. The canes pass by the carrier, down the slide, through the rolls, and the " bagasse " (exhausted canes) emerging below is carried away for fuel purposes, while the juice as expressed collects in a receptacle and is run to the evaporators. While the analyses of sugar-canes, given on a previous page, show that the cane contains ninety per cent, of juice, the percentage of ex- traction of juice by this roller-crushing process on the best-managed Cuban estates does not exceed seventy or seventy-one, and generally ranges from sixty to sixty-five, per cent. This imperfect liberation of * Bulletin No. 5, p. 57. 140 THE CANE-SUGAR INDUSTRY. >l ^ "< ~ G (^ c a f ^-- s || T! *"* O ^ ! s| 3 j; B P. " M 5 ff P.5T t/j I E 23- " 9 g o ^* O -s O w ^ hj* Pu M d p g S J? "2 gZ b>> S * : f S o- 1 pi CO >1 -58 P-PI S ^ PI 03 * p. H CO 9 i 3 ^ ^* o ~. '{ ~o3~l (~> fdO Q 3 ^.o p.O| r a> s -^ S 2.S _. t- > K^ E r* ^ SP > 1 s ?s . in? BL 1 XH^Q ta3r > ~i5a~ Er> - ( " J -1 CRUDE JUICE. If from crushing process is strai Run into clarifier and temper-lime to neutral- or Milk of li: ed. and exc tlOTl" Wi Macerated and crushed, AR-CANES cut and transported to th Si! SB* a | y i 5* wo ""H- 01 2 ? =' i 1 Bo c ! . o s s. c x!*; SJ^Bogo M CO 58 B lli|J ! J p EL. t7 c 5 K o Isii t P|" 3 . |si g 1 >. J9 Q on 2 3 c-i O pg c o<4 ' 2 9 P. |gP 5| | g. A "-j 02* 2. TO S" D'tS' _, J ^"^O- ?2,| 1* 1 II "I f| ll^l 1 111 *3 O 1^3 OS HI 7 ' o 2 n o' d | P 3 pi ^; Sa D 0_ ?i| ?& N" . M " W W g B * * S' 2? B"-i o- P o g o "0 W ' 2 * 25 o r^ sr s 1 ^ w o 2 SM & o P P tfl * JO Sm 1 rirs" 2,3 *S 3 a !*i s| -i c3' ^? 1 2. 3 p 1 PXS & o p- i & I (D * _? & *"J K' o G t-j > H Cn and Jui (The juice, if from pulp, i whatever source, is heated Defecated with li Saturated with c rifugated, or macerated. i i n PURIFIE i ABULAR VIEW ed, and tops cut off. B n ** <-\ >* ^ B0 i 2 w B C m - W g- B PE? -d| 3 a F f '2 fei S 1 S5 i? & 2 3 5" S TI Kn ^ "o ^ 5 gis-fi ^ Li Sff -5 s ^--p I N CO " 35 M *_ ~\ D Si >-<^H '> -T^ 1 ^ ^ E iL i *? i R *""* td O ^ PC 3 1 o L S W lliff D w O M j V * 1 , p Bo | I If o H 3 ! . .IsC * ffe r ?* l ? 2 1 s 1 B-l DC M /T? & ^ W a~ W "" S& M-O o ** CD r*- ?0 B fl, o g ^G FIQ. 47. to allow of a very perfect separation, so that to avoid loss of sugar the operation must be stopped before the elimination of salts is complete. A little more than half of the sugar can be recovered from the molasses in this way. The apparatus in which this treatment of the molasses is carried out is known as an osmogene, and is illustrated in Fig. 47. It consists of a number of very narrow but high and deep cells adjoining each other, the sides ef which are of parchment paper. Through alter- nate cells in this system goes the heated molasses, and through the inter- vening cells the water at the same temperature, each connecting with lateral canals for the supply and withdrawal of the respective liquids. The ordinary osmose apparatus of the German sugar-houses is capable of working 1000 kilos, or upwards of molasses per day, and at a cost of 1.60 marks (38.4 cents) per 100 kilos, of molasses. The osmose sugar is somewhat darker in color than ordinary second or third sugar, but is of pleasanter and sweeter taste. The yield of the osmose process varies 11 162 THE CANE-SUGAR INDUSTRY. with the grade of the molasses taken; a molasses with a purity coeffi- cient of fifty-eight to sixty will yield ten to twelve per cent, of the molasses taken, and one of a coefficient of sixty to sixty-five will yield seventeen, or sometimes as high' as twenty, per cent. By repeating the osmose process thrice the yield can be raised to thirty per cent, out of the possible fifty per cent, of sucrose contained in the molasses. Of the methods depending upon the formation of a lime or strontia sucrate, the most important are the Scheibler-Seyferth elution process, the Steffen substitution and separation processes, and the strontium proc- esses. In the first of these processes, finely powdered quicklime is added to the molasses, which has been previously concentrated in vacuo to 84 to 85 Brix, in the proportion of about twenty-five parts of the former to one hundred parts of the latter. The lime slakes at the expense of the water of the molasses, and leaves the tribasic calcium sucrate in the form of a dry porous mass. This is then broken up and put into the ' ' elutors, ' ' vessels which are somewhat similar in design to the cells of a diffusion- battery. The impure sucrate is here systematically washed with thirty- five per cent, alcohol, which dissolves away from it most of the adhering impurities. The washed sucrate is then brought to the condition of a fine paste with water, and either decomposed with carbon dioxide or used instead of lime in treating fresh beet juice. This process takes out eighty-five to ninety per cent, of the sugar contained in the molasses, but the cost is somewhat greater than in the case of the osmose process. The alcohol is recovered from the washings by distillation. Steffen 's substitution process depends upon the difference in solubility of the tri- calcium sucrate at high and low temperatures. The molasses is first diluted so that it shall contain about eighty per cent, of sugar, and then caustic lime added until some two to three per cent, has been used. The whole mass is then heated to 115 C., when the tricalcium sucrate is pre- cipitated and separated by the use of a filter-press. The sucrate is ground up, again filter-pressed, and then can be used in defecating sugar juice. The washings from the filter-press are used to dilute a fresh quantity of molasses to the degree mentioned before, which, treated with lime in the proper proportion and heated up, separates the sucrate, which is treated as before. After about the twentieth operation, the cooled mother- liquors and wash-waters are treated with lime alone, and the residual liquors after this treatment are then rejected. In the Steffen separation process, on the other hand, the molasses solution is kept cold, the tem- perature not being allowed to rise over 30 C. (86 P.). The molasses is diluted until the density shows 12 Brix, the percentage of sugar being then from seven to eight. This solution is cooled down to 15 C. (59 F.), and finely-powdered quicklime is added in small portions at inter- vals of about a minute, the temperature rising a little each time and being again cooled down. The mixing of the molasses and the lime, in the proportion of fifty to one hundred of powdered lime, according to quality, to one hundred of dry sugar, in the solution takes place in a closed mixing-vessel of iron provided with tubes through which cold PROCESSES OF TREATMENT. 163 water is kept circulating, and with a mechanical agitator to mix the contents uniformly. The insoluble sucrate separates out rapidly in the cold, and the contents of the mixer A (see Fig. 48) are pumped to the filter-press E, where the sucrate is washed, the mother-liquor, containing all the impurities of the molasses, being put aside for fertilizing pur- poses, the wash-water, however, being collected in F for use in diluting new quantities of molasses. The washed sucrate drops from the filter- press into the sucrate-mill G, where it is mixed to a thin paste with water, and then pumped, by means of the monte-jus H, to the receptacle J". From here it can be sent into the first saturation-vessel K, and to the filter-press M, and to the second saturation-vessel 8, and the filter- press 0. The process which at the present time is most favorably regarded and which recovers the highest percentage of sugar is the strontium process. In this the sugar is precipitated either as monostrontium sucrate, which FIG. 48. W/////ff/////////M^^^^ I is quite difficultly soluble in the cold, or as bistrontium sucrate separating from hot solution. According to Scheibler's monosucrate procedure, the molasses is well mixed with hot saturated strontium hydroxide solution, and the mixture passed over cooling apparatus into crystallizing tanks, where a few crystals of the monosucrate are added to start the crystalli- zation. After some hours the whole mass is changed into a crystalline magma, which is broken up and put through a filter-press. The white cakes of strontium sucrate go, as in the case of calcium sucrate, to the treatment of crude beet juice, while the mother-liquor is treated with more caustic strontia and boiled, when bistrontium sucrate is precipi- tated. This is dense enough to be washed by decantation, and then can be used instead of strontia solution with fresh molasses for the formation of monostrontium sucrate. The excess of strontia is recovered from all the mother-liquors and worked over into caustic strontia. By the other strontium process the molasses is added to a twenty-five per cent, stron- tium hydroxide solution, both taken hot, in such amount that for one part 164 THE CANE-SUGAR INDUSTRY. of sugar about two and one-half parts of strontium hydroxide are present. The precipitated bistrontium sucrate separates rapidly, and the mother- liquor can be decanted from it. The sucrate is washed with hot water or with a ten per cent, hot strontium solution. In order to decompose the sucrate, it is brought in a refrigerating chamber and cooled to 10 to 12 C., when, after twenty-four to seventy-two hours' standing, accord- ing to temperature, etc., it decomposes into crystallized strontium hy- droxide and sugar solution, containing something less than half of the strontia. After filtering off the crystallized strontium hydroxide, the sugar-liquor is decomposed with carbon dioxide in the usual way. In Germany in 1891-92, 48 sugar-houses extracted by the osmose process, 28 by the elution and precipitation process, 3 substitution, 20 separation, and 1 strontium process. In 1906, out of a total amount of 222,670 tons of molasses worked for sugar extraction, 210,560 tons were worked by the strontium process and most of the rest by the lime ' ' sepa- ration" process. 4. REVIVIFYING OF THE BONE-BLACK. The bone-black, or "char," after use in the filters, becomes charged with impurities and loses for the time its decolorizing power. It can, however, be restored to activity, or "revivified," by suitable treatment so as to be used again for filtra- tion, and this process can be repeated many times before, by the gradual loss of its porous character and change of composition, it becomes unfit for use. In working sugars from the cane this revivification is a much simpler process than in the case of beet-sugars. In the former case, water as hot as possible is run in at the top of the filter, which displaces the sugar solution remaining in the pores of the char and forms a dilute solution of sugar and the soluble impurities taken up from the liquor. This dilute solution is known as " sweet- water, " and is usually boiled down in triple effects and run in with the lower-grade products. After running additional hot water through, the filters are drained, and the moist char, after a partial drying, is put into the top of the vertical retorts, in which it is to be heated out of access of air for the decom- position of the organic matter still remaining in the pores and the restor- ation of its absorbent power. Various forms of char-kilns are in use in different refineries. That shown in Fig. 49 represents one of the simpler forms of char-kilns. The moist spent black from the filters in which it was washed goes on to the floor H, where it is dried by the waste heat passing through O and F, and then goes into the openings at J, which are kept always heaped up. The black descends in the retort-pipes A from the upper cooler portions into the middle hottest part, and then, as portions are withdrawn below, into a cooler section again. The black drawn off below is protected from the air by being received into closed receptacles or at once filled into the bone-black-filters. In other forms of kilns, the retorts are rotated slowly by mechanism so as to heat all parts equally. In beet-sugar refineries the revivifying of the "char, as before stated, is a more tedious process. This is in part because the juices and syrups have been limed in such excess in the preliminary stages of treatment, PROCESSES OF TREATMENT. 165 and in part because the beet juice contains much more albuminoid and organic non-sugar, which is absorbed in the pores of the char and can- not be gotten rid of by simple washing. The first step in the revivifying, then, in this case, is a treatment with a calculated amount of hydro- chloric acid to remove the excess of carbonate of lime ; after this a thor- FIG. 49. ough washing of the black in special washing-machines, such as the Kluse- mann washer, shown in Fig. 50; then a fermentation to decompose into simpler and soluble constituents the absorbed albuminoids and other organic matter. The fermentation may be either what is termed the dry fermentation, in the presence of a very small quantity of water, or the moist fermentation in the presence of a larger amount. The first takes from twelve to twenty hours, while the latter requires from six to seven hours only. The black, after the fermentation, is treated with 166 THE CANE-SUGAR INDUSTRY. PRODUCTS OF MANUFACTURE. 167 boiling alkaline solutions, washed, and then burned in char-kilns as already described. The char seems to improve in filtering power at first, as a consequence of revivifying, but soon loses again and runs down steadily in value. This is in large part due to the separation out in the pores of carbonized residue from the burning. This carbon has no de- colorizing power like the nitrogenized carbon of the original bone-black, but simply clogs the pores of the char and mechanically obstructs its action. A new process of Soxhlet whereby a mixture of fine ground wood fibre and infusorial earth is added to the solutions before filter-pressing has produced such clear filtrates that the use of bone-black is largely dis- pensed with even in refining the raw beet-sugar. HE. Products of Manufacture. 1. RAW SUGARS. The composition of the juice from both the sugar- cane and the sugar-beet has been stated, and the processes for preparing the raw sugar from each of these sources. We may now examine more closely the character of the products obtained. The raw cane-sugar, made as it is chiefly in the tropics under a variety of conditions of work- ing, from the most primitive to the most highly improved, has come into commerce under a great variety of names as well as of varying grades of purity. The raw beet-sugar is usually known as first, second, or third product sugar. (See p. 158.) Muscovado is a brown sugar produced in the West Indies, generally by open-pan boiling, which has been drained in hogsheads or perforated casks, and so freed in large part from the accompanying molasses. Concrete, or concreted sugar, is the product of the Fryer concretor (see p. 148) or similar form of apparatus, and is a compact, boiled-down mass, containing both the crystallizable sugar and impurities which ordi- narily go into the molasses. It shows little or no distinct grain. Clayed sugars have been freed from the dark molasses by covering them in moulds by moist clay, which allows of a gradual washing and displacement of the adhering syrup. Bastards is the name given to an impure sugar gotten by concen- trating molasses and allowing to crystallize slowly in moulds. Jaggery is the name given to a very impure East Indian palm-sugar, sometimes refined in England, but chiefly consumed in the country of its production. Demerara crystals are the product of the best vacuum-pan boiling and have been well purged in the centrifugals. They have the light yellow bloom due to treatment with sulphuric acid. (See p. 146.) These Demerara crystals have also been brought to the United States with very dark brown color. This, however, was only superficial, and was capable of removal by centrifugating with a lighter-colored syrup. The dark color was imparted like the yellow bloom by the action of sul- phuric acid added in the vacuum-pan before discharging the contents of the same. 168 THE CANE-SUGAR INDUSTRY. The composition of a variety of raw cane- and beet-sugars is given in the accompanying table : DESCRIPTION OF SUGAR. Sucrose. Glucose. Organic non- sugar. Ash. Water. Authority. Cane, Cuba (centrif.) . . . 91.90 2.98 2.70 0.72 1.70 Wigner and Harland. Cuba (muscovado) . 92.35 3.38 0.66 0.77 2.84 Wallace. 9040 3.47 1.55 0.36 4.22 Wigner and Harland. Trinidad 88.00 5.14 1.67 0.96 4.23 Wigner and Harland. Porto Rico 87.50 4.84 2.60 0.81 4.25 Wigner and Harland. St. Vincent 92.50 3.61 2.45 0.63 0.81 Wigner and Harland. 9080 4.11 0.77 1.12 3.20 Wallace. 94.50 2.63 0.39 1.50 0.98 Wigner and Harland. Unclayed Manila . . 82.00 6.79 3.24 2.00 5.97 Wigner and Harland. Concrete 84.20 8.45 1.70 1.10 4.55 Wallace. Melada 67.00 11.36 1.93 0.91 18.80 Wallace. Bastards 68.30 15.00 1.20 1.50 14.00 Wallace. Palm East Indian 86.00 2.19 2.89 2.88 6.04 Wiener and Harland. Beet, First product .... 94.17 2.14 1.48 2.21 Bodenbender. " Second product . . . 91.68 2.49 2.92 2.91 Bodenbender. 2. REFINED SUGARS. The commercial designations of refined sugar are very varied. We may distinguish in general between hard sugars and soft sugars, the former of which are more thoroughly and carefully dried by the aid of artificial heat, while the latter are merely centrifu- gated, and so retain from three to four per cent, of water in the traces of syrup adhering to the sugar. To the former class belongs sugar ' ' crys- tals," or sugar in well-formed individual transparent crystals, which are as pure as rock-candy, as well as loaf-sugar in the forms of pulver- ized, crushed, granulated, and cube sugars. To the latter belong what are called grocery sugars, of which the finest grades are called A sugars, the next B sugars, and so on. In Germany the finest white beet-sugars are known as "raffinade," inferior grades as "melis " (or Brodzucker), as "pile," and as "farm," the last of which is of inferior grain and color. The hard sugars in general all show a sucrose percentage of ninety- nine or over, while the soft cane-sugars and the second grade beet-sugars show from ninety-six to ninety-eight per cent. 3. MOLASSES AND CANE-SUGAR SYRUPS. The molasses may be termed the mother-liquor of the crystallized product, the sugar. It is never found possible in practice, however, to crystallize all the sugar out or to get a molasses which shall not contain sucrose. The potash salts, and in a lesser degree the calcium salts, which are present in the crude juice are "melassigenic," that is, prevent the crystallization of a certain amount of the sucrose ; the invert sugar, or glucose, operates in the same way, and the long-continued heating of the sugar solutions also has the effect of increasing the molasses. In France, for instance, the rende- ment, or amount of crystallized sugar obtainable in refining of raw sugars, is calculated by deducting from the total sucrose twice the glu- cose, and from three to five times the ash. In the' case of cane-sugars the ash is not so melassigenic, not being so largely composed of potassium compounds as with the beet, and a deduction of one and a half times the glucose is considered sufficient to allow for the impurity. PRODUCTS OF MANUFACTURE. 169 The experience during some years with sorghum-sugar, as manu- factured by the United States Bureau of Agriculture and several sorghum-sugar factories in Kansas, has shown that this rule does not apply to sorghum. Professor Swenson, the chemist of the Parkinson Company at Fort Scott, Kansas, found that in the case of sorghum juice the glucose and other solids, known as "non-sugar," prevent only two- fifths of their weight of cane-sugar from crystallizing, so that in the season of 1887, instead of there being only 61.6 pounds available sugar per ton of cane worked as the analyses indicated according to the old rule, as a matter of fact, 130.5 pounds were obtained. But with the sugar-cane and the sugar-beet the percentage of sucrose, in both the raw molasses produced in the extraction of the sugar from the juice and "refined molasses," the syrup produced in the process of refining, is quite large. The composition of the first, second, and third molasses of the Louisiana cane-sugar plantation has already been given (see p. 160), as well as the average composition of beet-root molasses. The following analysis of a variety of molasses will further illustrate the differences in the several grades: Sucrose. Glucose. Ash. Organic non- sugar. Water. Authority. From sugar-cane : Green syrup 62.7 80 1.0 0.6 27.7 Wallace. Golden syrup 39.6 33.0 2.5 2.8 22.7 Wallace. Treacle 32.5 37.2 35 3.5 23.4 Wallace. West Indian molasses . Dark molasses 47.0 35.0 20.4 10.0 2.6 5.0 2.7 10.0 27.3 20.0 Wallace. J. H. Tucker. From beets : Beet-sugar molasses . . Beet-sugar molasses . . Beet-sugar molasses . . 46.7 50.0 55.0 0.6 Trace. 13.2 10.0 12.0 15.8 20.0 13.0 23.7 20.0 20.0 Wallace. Wigner and Harland. J. H. Tucker. It will be seen from these analyses that the percentage of sucrose is usually much higher in the beet-root molasses, which is explained by the large percentage of ash and organic non-sugar. On the other hand, the glucose, or invert sugar, is large in the cane-sugar molasses, but almost entirely wanting in the beet-sugar molasses. The latter, however, always contains raffinose, another variety of sugar always present in the beet juice, betaine, a nitrogenous base, and proteids. The proportion of salts contained in beet-root molasses is usually ten to fourteen per cent., whereas refiner's molasses from cane-sugar rarely contains half that proportion. The term green syrup, used above, is given to the syrup centrifugated from the second products in the refining process. Golden syrup is produced from a refiner's molasses by diluting, filter- ing through bone-black, and then concentrating. Treacle is the name formerly given to the drainings from the dark molasses sugars called bastards. (See p. 167.) Cane-sugar molasses, when refined and brought to the condition of light-colored syrups, forms a common article of domestic consumption 170 THE CANE-SUGAR INDUSTRY. under the general name of table syrup. The table syrups of the present day, however, cannot, as a rule, claim to be simple products of the refin- ing process, as they are almost always largely admixed with the cheaper glucose syrup, and the cane-sugar product in them is often entirely replaced by this latter. A glucose product, known as "mixing syrup," is quite openly sold for this purpose. Beet-sugar molasses is not adapted for use as table syrup on account of the unpleasant taste and odor, due to the nitrogenous principles present. It is, as before described, worked for the extraction of the sugar, or it is fermented for alcohol. 4. MISCELLANEOUS SIDE-PRODUCTS. (1) Exhausted Residue from the Sugar-cane or Sugar-beet. The character of this residue differs very greatly according to the method of juice extraction which has been fol- lowed. The common sugar-cane residue from the roll-mills, known as "bagasse," consists of the fibre and cellular material of the cane still enclosing some six per cent, of sucrose, or about one-third of the total eighteen per cent, which the fresh-cut cane contains. It is very largely used as fuel on the sugar plantations, and the ash serves to some extent as fertilizing material for the soil. The cane-fibre, when freed more fully from the sugar by the diffusion process, has been proposed as a source of paper-stock. (See p. 140.) Both the pressed pulp and the exhausted diffusion-chips from the sugar-beet are recognized as valuable cattle food. Marcker found in the dried press-cake 1.227 per cent, of nitrogen. The exhausted chips of the diffusion-cells are still richer in nitrogen, as the diffusion process does not extract as much nitrogenous matter as the method of crushing. (2) Scums and Saturation Press-cakes. In describing the production of raw cane-sugar mention was made of the scums, which had at one time been thrown away, but which when filter-pressed yielded a very considerable additional amount of sugar. The press-cake obtained in this treatment has also a value. It contains on an average as taken from the press 45.17 per cent, of water, 15.67 per cent, of ash, 3.49 per cent, of phosphoric anhydride, and 1.14 per cent, of nitrogen, or, reckoned on the dry material, 28.56 per cent, of ash, 6.33 per cent, of phosphoric anhydride, and 2.10 per cent, of nitrogen. Its value, as taken from the press, at the ruling rates for fertilizing materials, would be $10.64 per ton.* Where the carbonatation process is used, and the excess of lime removed by carbon dioxide, the scums and carbonate of lime are found together in the press-cake gotten by filtering. In the experimental tests of the carbonatation process as applied to cane-sugar made by the United States Department of Agriculture at Fort Scott, Kansas, in 1886, f the press-cake obtained after saturation and filtering when dried was found to contain 9.585 per cent, of albuminoids and 17.45 per cent, of other organic matter. The saturation press-cake of the beet-sugar process does not contain so high a percentage of albuminoids, but a much * Bulletin of Department of Agriculture, No. 11, p. 16. t Ibid., No. 14, p. 54. PRODUCTS OF MANUFACTURE. 171 larger amount of nitrogenous compounds remains in the clarified juice, giving rise to the escape of ammonia on concentration in the vacuum-pan and showing itself in the molasses. (3) Exhausted Bone-Hack. The bone-black after repeated revivify- ing (see p. 164) becomes at last valueless for filtration purposes and passes out of the sugar-refinery, going to the manufacturer of fertilizers, for whom it is a very valuable material. The more calcium phosphate and the less calcium carbonate it contains, the more valuable it is for superphosphate manufacture, as, on the addition of sulphuric acid, the liberated phosphoric acid remains, adding to the value of the product, while the carbonic acid is driven off. The exhausted bone-black contains on an average thirteen per cent, of calcium carbonate, sixty to seventy- four per cent, of calcium phosphate, four per cent, of carbon, and four- tenths to six-tenths per cent, of nitrogen. (4) Vinasse, or Molasses Residues. When the beet molasses is fer- mented for the production of alcohol, the residual liquor, which contains all the potash salts of the molasses, is known in French as ' ' vinasse, ' ' or in German as "schlempe." It is of about 41 B. and acid in reaction. It is neutralized with calcium carbonate and then evaporated down to dryness and calcined. The black porous residue so obtained contains thirty to thirty-five per cent, of potassium carbonate, eighteen to twenty per cent, of sodium carbonate, eighteen to twenty-two per cent, of potas- sium chloride, six to eight per cent, of potassium sulphate, and fifteen to twenty-eight per cent, of insoluble matter. It is exhausted with hot water, and the extract evaporated down, when potassium sulphate and afterwards sodium carbonate separate out. On cooling, potassium chlo- ride and potassium sulphate crystallize out, and the mother-liquor con- tains potassium carbonate admixed with some sodium carbonate. It is possible by this gradual evaporation and fractional crystallization to bring the crude potashes to a purity of ninety per cent. In this produc- tion of the solid potashes from the molasses residue all the nitrogen of the molasses is lost. To prevent this, C. Vincent, a French chemist, has proposed to submit the evaporated vinasse to a dry distillation instead of calcination in the air. The residue of this distillation is an open and very porous coke containing all the mineral salts of the molasses, which can then be extracted as before. The products of distillation are an illuminating and heating gas, ammonia water, and a small amount of tar. The ammonia water is the most interesting product. It contains besides carbonate, sulphide and cyanide of ammonium, methyl alcohol, and notable quantities of trimethylamine. This latter can be decomposed at 320 C. by dry hydrochloric acid gas into methyl chloride and ammonia, and on passing the products through aqueous hydrochloric acid, the methyl chloride goes through unabsorbed, while the ammonia is taken up. The methyl chloride is of great value for ice machines and for the manufacture of methylated aniline colors. (See p. 457.) The process was quite largely introduced, but as in recent years the molasses is worked over for sugar in increasing amounts, less molasses is fer- mented, and hence less vinasse is obtained. 172 THE CANE-SUGAR INDUSTRY. IV. Analytical Tests and Methods. 1. DETERMINATION OF SUCROSE. (A) Optical Methods. Among the most important physical properties of many of the varieities of sugars is the power possessed by their solutions of rotating the plane of polariza- tion to the right or the left. The}' are accordingly classified as dextro- rotatory, Igevo-rotatory, or optically inactive in case no power of circular polarization is manifested. This property as possessed by solutions of cane-sugar, of deviating the polarized ray in a fixed and definite degree, has been made the basis of the method of analysis by means of polari- scopes. The fundamental idea involved in these instruments is to com- pensate for and so determine the optical rotatory power of sugar solu- FIG. 51, tions of unknown strength by the corresponding circular polarizing action of quartz plates of known thickness, and hence of known power. The earliest of polariscopes was the Mitscherlich instrument, but those now in use for sugar analysis are either the Soleil-Ventzke-Scheibler, the Soleil-Dubosq, the Laurent shadow instrument, or the Schmidt and Haensch, which last claims to combine the best features of the Soleil and the Laurent instruments. A general view and a longitudinal section of this instrument is given in Fig. 51. The glass tube containing the sugar solution is shown lying in the axis of the telescope and the polarizing prisms. To the right below is shown the polarizing prism (the so-called Jellet-Cornu prism), to the left is the analyzing prism, a quartz plate, quartz wedges of opposite rotatory power, and the lenses of the telescope, with a plate of bichromate of potash to correct for any color in the field. ANALYTICAL TESTS AND METHODS. 173 In this instrument, which uses white light, the field of view is a circle, which, with the instrument at and nothing intercepting the light, is of a uniform gray tint. When a sugar solution is interposed, one-half of the circle becomes darker than the other, and the quartz wedges, con- trolled by the screw shown underneath, must be moved to compensate for the rotation due to the sugar solution and to restore the uniformity of tint. The instrument is so graduated that one degree of displacement on the scale corresponds to .26048 gramme of cane-sugar dissolved in 100 cubic centimetres of water and viewed through a 200-millimetre tube. Therefore 26.048 grammes of the sugar to be analyzed are weighed out. If chemically pure and anhydrous, the solution of the strength stated should read one hundred degrees of displacement, or one hundred per cent, of sugar, and if impure, correspondingly less. In the application of polariscope analysis to cane-sugars two cases may arise: first, when no other optically active substance is present, and, second, when glucose or invert sugar is also present. (a) Absence of other Optically Active Substances. The weighed sample is dissolved in about fifty cubic centimetres of water in a flask marked for one hundred cubic centimetres. As soon as the sugar is all dissolved, a few cubic centimetres of a solution of basic acetate of lead are added, and two or three cubic centimetres of cream of hydrated alumina. The liquid is well agitated, and then the flask is filled nearly to the mark on the neck with water and the froth allowed to rise to the surface, when it is flattened by the addition of a drop of ether. Water is now added exactly to the mark, the contents of the flask thoroughly agitated, and the liquid filtered through a dry filter. In the case of very dark sugars, purified and perfectly dry bone-black has been added for clarifying purposes. However, it is generally acknowledged to intro- duce error by its absorption of small amounts of sugar, so that it is now dispensed with, or if used on the dry filter, the first third of the filtrate is rejected and the later portions only used. Allen* recommends instead the use of a ten per cent, solution of sodium sulphite. The tube of the polariscope is now rinsed with the clear sugar solution and then filled with the same, the open end closed with a smooth glass plate held in place by a brass cap, which is screwed on. The tube containing the sugar solution is then placed in the instrument, and the lower thumb- screw turned until the uniformity of shade in the two halves of the field is restored, when the number of degrees (or percentage of cane-sugar in the sample) is read off on the scale. (6) Presence of Glucose, Invert Sugar, or other Optically Active Substance. The action of acids upon cane-sugar has already been stated to cause inversion, i.e., change of the sucrose into dextrose and levu- lose. Both these varieties of sugars differ from sucrose in their optical power. If, then, these alteration products accompany the sucrose in a cane-sugar sample, the results of the polariscope reading may be viti- ated. Some writers have held that the invert sugar present in raw * Commercial Organic Analysis, 3d ed., vol. i. p. 257. 174 THE CANE-SUGAR INDUSTRY. cane-sugars and syrups is optically inactive, but the statement seems to have been disproved by Meissl. Besides, in raw beet-sugars and syrups, raffinose, a very strong dextro-rotatory sugar, is found vitiating the readings for cane-sugar. The correction of the original polarization in such cases is most generally made by the method of inversion pro- posed by Clerget. The direct polarization is taken in the usual way, and a part of the solution remaining from the one hundred cubic centimetres prepared for this test is put into a 50-cubic-centimetre flask, which has also a 55-cubic-centimetre mark on the neck. Fifty cubic centimetres having been taken, five cubic centimetres of concentrated hydrochloric acid is added, and the whole heated on a water-bath to 70 C. for some ten minutes. This suffices to completely invert the cane-sugar present, while the original invert sugar is unacted on. The flask is then cooled, and part of the liquid is filled into -a 220-millimetre tube, closed by glass plates at both ends and provided with a tubulure in the side so that a thermometer may hang suspended in the liquid when the observation is made. The reading will generally be much reduced from the original dextro-rotatory reading, and may even be some degrees to the left. If, then, 8 represent the sum or difference of polariscope readings before and after inversion (difference if both are to the right, sum if the second reading is to the left), T the temperature of the inverted solution when 200 8 polarized, and R the correct percentage sought, E= . Clerget has also prepared an elaborate set of tables which make the use of the formula unnecessary. (See also under molasses, p. 178.) (B) Chemical Methods. The only chemical method for the deter- mination of cane-sugar ever resorted to is the inversion of the cane- sugar, neutralizing with sodium carbonate, and determination of the reducing sugar so obtained by the method to be described under the next head. The inversion takes place in definite proportions, so that nineteen parts of sucrose produce twenty parts of the invert sugar. When in- vert sugar is also present in the solution of which the cane-sugar is to be determined by inversion, the former is first estimated as a separate opera- tion, and then a portion of the original solution is inverted, and the total invert sugar, including that formed from the cane-sugar, is determined. 2. DETERMINATION OP GLUCOSE, OB INVERT SUGAR. The oldest method is that based on Trommer's reaction as applied to sugar analysis by Barreswill and Fehling. This depends upon the fact that an alkaline solution of copper oxide containing a fixed organic acid, as tartaric, is reduced with the separation out of insoluble cuprous oxide by dextrose, or invert sugar, "while cane-sugar has no effect. The composition of a standard Fehling 's solution, as it is called, is thus given,* 34,639 grammes crystallized copper sulphate are dissolved in water and brought to 500 cubic centimetres; 173 grammes Rochelle salt and 50 grammes sodium hydroxide are also dissolved In water and brought to * Bulletin No. 107, Bureau of Chemistry, U. S. Dept. of Agriculture, ANALYTICAL TESTS AND METHODS. 175 500 cubic centimetres. Equal volumes of these solutions are mixed when required for use and constitute the correct Fehling's solution. The ready-prepared Fehling's solution changes in the course of some days in effective power even when kept in a cool place and in the dark. Ten cubic centimetres of the Fehling's solution given above correspond to .05 gramme dextrose, or invert sugar, or .0475 gramme cane-sugar made active by inversion. For technical determinations merely the work with the solution can be volumetric ; for more exact scientific purposes it must be gravimetric, weighing the copper as metal or as cupric oxide. In carrying out the volumetric test, the sugar solution in which glucose is to be determined is placed in a burette. If dark, it may be previously cleared with a small quantity of bone-black, or if it be some of the solu- tion prepared for polarization, it is prepared without lead solution, an aliquot portion taken out for this glucose determination, and the re- mainder treated with a measured quantity of the lead solution, for which allowance is made. Any lead in this glucose solution must be eliminated thoroughly. This is best done with sulphurous acid, the change ,of strength in the liquid being noted. Ten cubic centimetres of the mixed Fehling's solution are now measured into a porcelain dish, diluted with twenty or thirty cubic centimetres of water and brought quickly to boil- ing, when the sugar solution is run in two cubic centimetres at a time, boiling between each addition. When the blue color has nearly disap- peared the sugar solution should be added, in small amount but still rapidly. The end of the reaction is reached when a few drops of the supernatant liquid filtered into a mixture of acetic acid and dilute potas- sium ferrocyanide give no brown color. In carrying out the gravimetric method the Fehling's solution re- mains in excess, while the precipitated cuprous oxide is carefully filtered off and further treated. The procedure is as follows : Sixty cubic centi- metres of the mixed Fehling's solution and thirty cubic centimetres of water are boiled up in a beaker glass, twenty-five cubic centimetres of the dextrose solution of approximately one per cent, strength added, and the mixture again boiled. It is then filtered with the aid of a fiTterv^^ upon a Soxhlet filter (asbestos layer in a tared funnel of narrow cylinder shape), quickly washed with hot water, and then with alcohol and ether, and dried. The asbestos filter, with the cuprous oxide, is now heated with a small flame, while a current of hydrogen is passed into the funnel, so that the precipitate is reduced to metallic copper. It is allowed to cool in the current of hydrogen, placed for a few minutes over sulphuric acid, and then weighed. A table has been constructed by Allihn which gives in milligrammes the dextrose corresponding to the weight of copper found. Other methods for the determination of dextrose are those of Defren, who determines the copper as cupric oxide (Leach, Food Inspection, 2d ed., p. 593) ; of Munson and Walker, who weigh the copper as cuprous oxide (Ibid., p. 598) ; and of Soldaini, who uses a solution of basic car- bon'ate of copper dissolved in potassium bicarbonate. This last reagent has been recently strongly commended as better than Fehling's solution, 176 THE CANE-SUGAR INDUSTRY. in that it is more sensitive to glucose and is much less affected by cane- sugar even after prolonged boiling.* 3. ANALYSIS OF COMMERCIAL RAW SUGARS. Raw sugars contain, be- sides the cane-sugar, invert sugar, moisture, mineral salts, organic non- sugar, and insoluble matter. Raw beet-sugars contain, in addition to the sucrose and glucose just mentioned, small quantities of raffinose, a variety of sugar found in the beet juice and present in all the products from it. The cane-sugar present is partly crystallized and partly uncrystal- lizable. Both are, of course, counted together in the polarization figures, but only the first is capable of extraction in the refining process. The method of estimating the crystallized cane-sugar for itself will be described later on. The polarization methods have already been de- scribed. In raw sugars containing- much invert sugar, such as those from the cane, the double polarization (before and after inversion) is alone to be relied upon. The methods for glucose have also been described. The determination of moisture is made by taking five grammes of the sample and drying it spread out on a weighed watch-crystal in an air- bath not over 100 C. until it ceases to lose weight. As sugars containing much glucose cannot stand the heat without some alteration, in their case a lower temperature (about 70 C.) is used. For very syrupy sugars and melados it becomes necessary to dry with the addition of a weighed amount of clean sand. Drying in a vacuum is also practised in many cases, as the operation is shortened and less risk of alteration exists. The mineral salts are determined as ash. The following analyses give the average composition of raw cane- and beet-sugar ash according to Monier: Cane-sugar. Beet-sugar. Potassium (and sodium) carbonate 16.5 82.2 Calcium carbonate 49.0 6.7 Potassium (and sodium) sulphate 16.0 Sodium chloride 9.0 11.1 Silica and alumina 9.5 None. 100.0 100.0 Owing to this decided difference it is much easier to get the ash of cane-sugars completely burned and in weighable condition than that of beet-sugars, which contain so much of the deliquescent and alkaline car- bonates. To obviate this difficulty, Scheibler proposes to treat the sugar with sulphuric acid before igniting it, by which means the ash obtained contains the bases as non-volatile, difficultly fusible and non-deliquescent sulphates instead of as carbonates. A deduction of one-tenth of the weight of the sulphated ash must be made in this case for the increase due to the sulphuric acid. -The soluble and insoluble ash are often dis- tinguished in addition to total ash. In ordinary commercial analyses of * Bodenbender und Scheller, Zeitschrift fiir Rlibenzucker, 1887, p. 138. ANALYTICAL TESTS AND METHODS. 177 sugars, the sum of the cane-sugar, glucose, ash, and water is subtracted from one hundred, and the difference called organic or undetermined matters. This would include both the soluble organic impurities and the insoluble impurities, such as fibre and particles of cane. Two processes have been proposed for determining the soluble organic impurities sepa- rately: Walkoff's method of precipitation with tannin, and the basic acetate of lead method. Neither method is in very general use. As before stated, the full analysis of a raw sugar will not give any exact measure of its refining value, that is, of the amount of crystal- lized cane-sugar that can be extracted from it. The so-called method of coefficients adopted in France, whereby five times the ash, plus once or twice the glucose percentage subtracted from the cane-sugar percentage, is taken to represent the crystallized cane-sugar obtainable, is not much to be depended upon. The true refining value, or rendement, of a raw sugar can, however, be determined by a special procedure first proposed by Payen and afterwards improved by Scheibler. The process depends upon the fact that if raw sugars be treated with a saturated alcoholic solution of cane-sugar acidified with acetic acid, the coloring matter and other impurities, together with the syrup and other uncrystallizable con- stituents, are removed, while the crystallized sugar remains unchanged. The sugary alcoholic liquids are then displaced by absolute alcohol. Fig. 52 shows the arrangement of vessels. The bottle I contains eighty-five per cent, alcohol, to which fifty cubic centimetres of acetic acid is added per litre, and the mixture allowed to stand in contact with an excess of powdered white sugar for a day, being shaken at intervals; bottle II, alcohol of ninety-two per cent, saturated as the other, but without acetic acid ; bottle III, alcohol of ninety-six per cent., also saturated with sugar ; and bottle IV, a mixture of two-thirds absolute alcohol and one-third ether. Of the sugars to be examined, weights are taken corresponding to the polariscope used, placed in the upright tubes, washed with the succes- sive solutions, and dried by the aid of a filter-pump ready for use in the polariscope test. In carrying out the process, the alcohol and ether mix- ture is first run in that it may take up any moisture and throw out the sugar that such moisture may have dissolved, then successively down to No. I, which is the effective washing solution. This is then displaced by Nos. II, III, and IV in succession. The method is thoroughly reliable, but great care must be taken to keep the alcoholic solutions just satu- rated with sugar through all changes of temperature. 4. ANALYSES OF MOLASSES AND SYRUPS. The composition of both the cane-sugar and the beet-sugar molasses have already been given (see p. 169), and it was seen that they differed notably. Both still contain considerable quantities of sucrose, but for different reasons. With the cane-sugar molasses because of the invert sugar, with the beet-sugar molasses because of the melassigenic salts. In either case the polari- scope reading for sucrose must be corrected by inversion. The glucose is determined as described under raw sugars. The water is determined by weighing out a sample, thinning it with water, putting it into a weighed dish with clean sand, and drying it at a temperature of 60 C. 12 178 THE CANE-SUGAR INDUSTRY. until constant. Drying in a partial vacuum also facilitates the drying off of the moisture. The ash is determined as with raw sugars, sulphuric acid being added, and the bases weighed as sulphates instead of as car- bonates, the proper correction being made. The organic non-sugar is simply taken by difference as with raw sugars. The determination of raffinose in raw beet-sugars, and particularly in beet-molasses, has at- tracted much attention in recent years. Creydt* has suggested a way for FIG. 52. determining it in the presence of cane-sugar in connection w r ith the method of inversion. He finds that while cane-sugar polarizing 100 to the right before inversion polarizes 32 to the left after inversion, a change of 132, raffinose changes from 100 to 50.7 only, a change of 49.3. He proposes two formulas: A = z -f 1.57 R, and c = 1.322 -f 1.57 E X -493, in which A is the direct polarization, c the polarization after inversion, z the percentage of cane-sugar, and R that of raffinose. * Zeitschrift fiir Riibenzucker, vol. xxxvii, p. 163. ANALYTICAL TESTS AND METHODS. 179 From these formulas, A and c being known, z and R can be found. The reading after inversion must be taken uniformly at 20 C. 5. ANALYSES OF SUGAR-CANES AND SUGAR-BEETS AND RAW JUICES THEREFROM. The very different physical characters of the sugar-cane and the sugar-beet, the one a bamboo-like shell enclosing a woody pith, and the other a soft root easily brought into pulpy consistency, make the work upon them quite different. In the case of the cane, the samples to be analyzed are weighed and then pressed between rolls, moistened with hot water and again pressed, and this repeated several times. The ex- hausted stalk, or "bagasse," is usually not further examined, but in the juice the sucrose, glucose, ash, and organic non-sugar are determined as before described. In all analyses of raw cane juices the percentage of total solids is determined by the Brix saccharometer or "spindle." The form of hydrometer in most general use is known as the Balling or Brix, and its readings indicate directly the percentage of impure sugar or solid matter dissolved. Sets of tables also allow of the conversion of the Brix scale into direct specific gravity figures. (See Appendix, p. 570.) With the aid of the specific gravity determination it is possible to make a rapid analysis of raw juice without weighing. The method adopted by Cramp- ton,* one of the chemists of the United States Bureau of Agriculture, for this analysis is to measure out a certain volume of the juice, add lead solution, make up to another definite volume, polarize, and apply the correction for specific gravity to the reading obtained. A set of tables for this correction and the factor needed in the glucose deter- mination are given by Crampton. In the examination of sugar-beets, the system of pressing and mois- tening with hot water can be followed for the extraction of the juice, but the method proposed by Scheibler of extracting the sugar from a weighed quantity of the pulp by the aid of alcohol is much better. This is accomplished by the aid of a Soxhlet or other extractor (see p. 86) connected with an upright condenser. After complete extraction and cooling the necessary amount of lead solution is added, and the liquid brought up to the mark with absolute alcohol and then polarized. Degener has described a still simpler form of extraction, originally sug- gested by Rapp, in which the pulp remains in the alcoholic solution until after it is cleared with the lead solution and brought to the mark, when it is filtered and polarized. A correction must in this case be applied to the reading on account of the volume occupied by the pulp in the measured liquid. The amount of dry residue, or "marc," of the beet can be deter- mined in the Scheibler extraction method at the same time by taking the exhausted residue, drying it in a current of air, and weighing it. The moisture and ash of the beet are determined as with raw sugars. The organic non-sugar is gotten by difference or by one of the methods mentioned under raw sugars. 6. ANALYSES OF SIDE-PRODUCTS. (a) Of Bone-Black. Careful anal- * United States Bureau of Agriculture, Bulletin No. 15, pp. 31-35. 180 THE CANE-SUGAR INDUSTRY. yses of both fresh char and that which is in use are needed to allow of the proper control in filtration. The most important determinations are those of water, carbonate of lime, carbon, and specific gravity, as upon the changes in these depend in the main its efficiency. The water is determined by drying for several hours at 140 C. The sample should not be powdered. The carbon is determined by treating a weighed quan- tity of the char with pure- hydrochloric acid, with the aid of heat, on a water-bath until the soluble portions have been dissolved, diluting and filtering upon a weighed quantitative filter. After thorough washing with hot water, the filter and contents are dried at 100, placed between watch-glasses and weighed, again heated and weighed as long any loss of weight is shown. The filter and carbon are then transferred to a weighed crucible and ignited. The insoluble residue, taken from the previous weight, minus the weight of -the filter, gives the amount of car- bon. The estimation of carbonate of lime in case the char is used with cane-sugar or juices is of much less importance than when the char is used with beet-sugars or juices. In the former case, the percentage decreases at first, and then remains nearly stationary, in the repeated use of the char, while in the latter case it would increase steadily, because of the more thorough liming and carbonatation to which the beet juices are subjected, were it not for the treatment with hydrochloric acid in the revivifying of the char. (See p. 165.) To allow of the proper judg- ment in this use of hydrochloric acid, it becomes necessary in beet-sugar working to determine carefully the amount of carbonate of lime taken up by the char in using before starting the revivification. It is almost universally done at present by the aid of the Scheibler apparatus, shown in Fig. 53. The normal quantity of pulverized char (1.702 grammes) is placed in A, and the tube S filled with acid to the mark is carefully placed in the bottle. E is then filled with water, and the operator, by means of the compression-bulb, forces the liquid into D and C, which connect at the base, until it reaches a little above the zero-point in C, when it is allowed to flow out by opening the pinchcock at p until the level in C is at zero. The stopper now being placed in A, a connection with B is made by the tube r. If the level of the liquid in D and C be then unequal, the equality may be restored by opening the cock q for a few seconds, and which for the rest of the operation remains closed. The vessel A is now held, as shown in the cut, so that the acid may come in contact with the char, and the bottle gently shaken to cause the acid to mix thoroughly with the assay. The pressure of the gas evolved dis- tends the rubber bag in B and depresses the column of water in C. The stopcock p is now opened to allow the water in D to flow out sufficiently rapidly to keep the level in C and D as near the same as possible during the progress of the determination. When all the gas has been given off and the level of the liquid in C becomes stationary, p is closed, after bringing the water in D to the same level as that^ in C, and the volume and temperature read off. A set of tables accompanying the instrument gives the percentage of carbonate of lime from the volume and tempera- ture readings. Assuming seven per cent, to be the normal amount of car- ANALYTICAL TESTS AND METHODS. 181 bonate of lime in the char, any excess, as shown in this determination, can have its equivalent in hydrochloric acid of known strength calcu- lated, and thus the acid treatment in the revivifying process can be made accurate. FIG. 53. In determining specific gravity, both apparent and real specific gravity (the .latter after boiling the char with distilled water to displace air) are to be taken. 182 THE CANE-SUGAR INDUSTRY. (&) Of Scums, Press-cakes, and Sucrates. In the case of the scums and press-cakes obtained in the manufacture of raw sugars, their chief value is in the lime salts they contain, which, notably in the case of beet-sugars, adapt them for use as fertilizing materials. They, however, contain such amounts of sugar, either mechanically held, or, where the carbonatation process has been used, as sucrates, as make it necessary to determine regularly the sucrose in them. In the case of the thin scums from cane-sugar working, the determination can be made exactly as with an impure juice before described. In the case of the heavier press-cake from beet-sugar working, resulting from carbonatation, the procedure is different. Here the sucrate of lime is to be decomposed if possible with- out decomposing the large amount of accompanying carbonate of lime. This is done by careful addition of acetic acid, controlling the reaction with phenol-phthale'in. For details of this process, first proposed by Sidersky, see Friihling and Schultz, "Anleitung ziir Zucker Untersuch- ungen," 3d ed., p. 171. Sucrates, resulting from the working of molasses for sugar by either of the lime or strontium processes (see p. 162), are analyzed by a some- what similar procedure, using strong acetic acid to set the sugar free from its combination with the lime or strontia and phenol-phthalein as an indicator. The excess of acid is afterwards neutralized, lead solution added, the solution brought to strength, and polarized. (Ibid., p. 155.) V. Bibliography and Statistics. BIBLIOGRAPHY. 1877. Tropical Agriculture, P. L. Simmons, London. 1881-90. Bulletins of the United States Department of Agriculture on Sugar Ex- periments, Washington. 1882. Report on Sorghum-Sugar by the National Academy of Sciences, Washington. Foods, Composition and Analysis, A. W. Blyth, London. Traite de la Fabrication du Sucre, Horsin-D6on, Paris. 1884. Guide pour 1'Analyse brute Melasse, etc., Commerson et Langier, Paris. Sorghum, its Culture and Manufacture, P. Collier, Cincinnati. 1887. Lehrbuch der Zuckerfabrikation, C. Stammer, 2te Auf., Braunschweig. 1888. Handbuch der Kohlenhydrate, B. Tollens, Breslau. Die Chemie der Menschlichen Nahrungs und Genussmittel, J. Konig, 3te Auf., Berlin and New York. Sugar: A Hand-Book for Planters and Refiners, Lock and Newlands, London. Manuel pratique du Fabricant de Sucre, P. Boulin, Paris. 1890. Sugar Analysis for Refineries, Sugar-Houses, etc., F. G. Wiechmann, New York. Geschichte des Zuckers, E. O. von Lippmann, Leipzig. A Guide to the Literature of Sugar, H. L. Roth, London. 1891. Anleitung zur Untersuchungen der Zuckerindustrie, Fruhling und Schultz, 4te Auf., Braunschweig. 1892. Leitfaden fiir Zuckerfabriken-Chemiker, E. Preuss, Berlin. 1893. Handbuch der Zuckerfabrikation, F. Stohmann, <5te Auf., Berlin. Manual for Sugar-Growers, Fr. Watts, London. 1894. Die Zuckerfabrikation, Dr. B. von Posanner, Wien. La Sucre et 1'Industrie sucrifcre, Horsin-Deon, Paris. Manual of Sugar Analysis, J. H. Tucker, 4th ed., New York. BIBLIOGRAPHY AND STATISTICS. 183 1895. Die Zuckerarten und ihre Derivate, E. von Lippmann, 2te Auf., Braunsch- weig. Handbuch der Kohlenhydrate, B. Tollens, 2te Bd., Breslau. 1897. Hand-Book for Sugar Manufacturers, etc., G. L. Spencer, 3d ed., New York. Hand-Book for Chemists of Beet-Sugar Houses, G. L. Spencer, New York. Beet-Sugar Analysis, E. S. Peffer, Chino, California. 1898. Sugar-Beet Seed for Farmers, etc., L. S. Ware, New York. Das Optische Drehungsvermogen Organischer Substanzen, H. Landolt, 2te Auf., Braunschweig. 1906. Beet Sugar Manufacture, H. Classen, translated from 2nd German Edition by W. T. Hall and G. W. Rolfe, New York. 1907. Beet Sugar Manufacture and Refining, L. S. Ware, 2 vols., New York. 1909. Sugar: A Handbook for Planters and Refiners, J. A. R. and B. E. R. New- lands, 2nd Edition, E. & F. N. Spon, London. Cane Sugar and Its Manufacture, H. C. Prinsen-Gurligs, Norman Rodger, Manchester, England. Beet Sugar-making and Its Chemical Control, Y. Niceido, Easton, Pa. 1911. Cane Sugar: A Text-book on the Agriculture of the Sugar Cane and the Manufacture of Cane Sugar, Noel Drew, Sugar Technologist, Hawaii; Man- chester, England. STATISTICS. 1. SUGAK PRODUCTION OF THE UNITED STATES. The U. S. Census of 1910 gives the production as well as importations of sugar for 1909 as compared with the figures for the three previous decades : A. SUGAE FROM CANE IN 1909. Louisiana 325,500 short tons. Texas 8,600 short tons. 334,100 short tons. B. SUGAR FROM BEETS IN 1909. California Granulated sugar (tons). 126,600 Raw sugar (tons). 200 Molasses (gallons) . 2,13-5,800 Colorado 147,000 1,600 7,669,200 Michigan 103,900 600 5,016,700 \Visconsin 13,000 832,400 All other States 106,300 2,500 5,158,700 Total 496,800 4,900 20,812,800 C. COMPARISON OF PRODUCTION AND IMPORTS. Imports (in tons). Production (in tons). Cane. 1909 334,100 1899 161,300 1889 150,600 1879 89,400 Beet. 501,700 81,700 2,500 1,400 Total. 835,800 243,000 153,100 90,800 Non- contiguous U.S. Other countries. Total. 927,800 1,959,300 2,887,100 313,400 1,695,600 2,009,000 280,600 1,186,400 1,467,000 139,200 775,400 914,610 184 THE CANE-SUGAR INDUSTRY. 2. PRODUCTION, IMPORTATION, AND CONSUMPTION FOR THE UNITED STATES IN 1910. The Bureau of Statistics reports for the year ending June 30, 1910, as follows: 1910 (tons). 1909 (tons). Production of sugar from cane (in tons) 362,500 414,500 Production of sugar from beet (in tons) 512,500 483,500 Total production in United States 887,500 898,500 Hawaii 555,500 511,500 Porto Rico 284,500 244,000 Philippines 88,000 42,000 Total from U. S. dependencies 928,000 797,500 Total from U. S. and dependencies 1,815,500 1,695,500 Importation from Cuba 1,755,000 Importation from Dutch Indies 157,500 Total imports 1,959,000 2,053,800 Consumption for 1910, 7550 million pounds = 82 pounds per capita. 3. SUGAR-BEETS WORKED AND BEET-SUGAR PRODUCED IN EUROPE. Sugar-beets worked (tons). Beet-sugar produced (tons). 1910-11. 1909-10. 1910-11. 1909-10. Germany 15,275,380 12,904,795 2,424,840 2,027,272 Austria-Hungary 9,981,400 8,166,100 1,529,800 1,245,608 France 5,383,000 6,246,850 703,330 803,006 Belgium 1,932,000 1,777,600 271,800 248,403 Holland 1,523,000 1,330,000 221,400 194,822 Russia 13,080,400 6,837,498 2,085,200 1,123,594 Sweden 1,088,300 897,000 167,160 127,000 Denmark 750,000 500,000 105,000 65,000 Italy 1,500,000 970,000 170,000 118,900 Spain 490,000 667,000 60,000 83,000 Rumania 275,000 208,000 35,000 30,775 Servia 75,000 66,000 10,000 8,630 Bulgaria 35,000 20,000 4,200 2,435 Switzerland 25,000 25,000 3,500 3,500 51,413,480 40,415,843 7,791,330 6,081,945 RAW MATERIALS. 185 CHAPTER V. THE INDUSTRIES OF STARCH AND ITS ALTERATION PRODUCTS. I. Raw Materials. STARCH is one of the most important, as well as most widely occur- ring, productions of the vegetable kingdom. It constitutes, either when extracted from vegetable raw materials, or more generally in admixture with the other plant constituents, the staple article of food for the great bulk of the human race. It is only necessary to call attention to the fact that the principal cereal grains used throughout the world for food con- tain starch as their chief ingredient, and that the tubers of many plants and the stems and roots of some trees also yield starch in great abundance. The most complete enumeration and classification of starches is that of Muter as amplified by Allen* and Blyth,f by which they are divided into five groups on the basis of their physical and microscopical differ- ences, as follows: I. The potato group includes such oval or ovate starches as give a play of colors when examined by polarized light and a selenite plate and having the hilum and concentric rings clearly visible. It includes tout les mois, or canna arrow-root, potato starch, maranta, or St. Vincent arrow-root, Natal arrow-root, and curcuma arrow-root. II. The leguminous starches comprise such round or oval starches as give little or no color with polarized light, have concentric rings all but invisible, though becoming apparent in many cases on treating the starch with chromic acid, while the hilum is well marked and cracked, or stel- late. It includes the starches of the bean, pea, and lentil. III. The wheat group comprises those round or oval starches having both hilum and concentric rings invisible in the majority of granules. It includes the starches of wheat, barley, rye, chestnut, and acorn, and a variety of starches from medicinal plants, such as jalap, rhubarb, senega, etc. IV. The sago group comprises those starches of which all the gran- ules are truncated at one end. It includes sago, tapioca, and arum, together with the starch from belladonna, colchicum, scammony, podo- phyllum, canella, aconite, cassia, and cinnamon. V. The rice group. In this group all the starches are angular or polygonal in form. It includes oats, rice, buckwheat, maize, dari, pepper, as well as ipecacuanha. In addition to the differences in form and marking mentioned above, * Com. Org. Anal., 2d ed., vol. i, p. 335. t Blyth, Foods, Compos, and Anal., p. 139. 186 STARCH AND ITS ALTERATION PRODUCTS. the starch-granules differ in size according to their different sources, so that under the microscope they can be distinguished by the measure- ment of the average diameter of the granule. This ranges, according to Karmarsch, from .01 to .815 millimetre, or from .0004 to .0079 inch. For practical purposes we may now speak of two classes only of these starch-containing materials, vix., the cereals and the plants in which the starch is extracted from tubers, roots, or stems, such as potatoes on the one hand, and the West Indian starch preparations, like arrow-root, sago, and tapioca, on the other. As before stated, starch is the chief ingredient in the cereals, but not at all the only one. The composition of the more important cereals is thus given by Bell :* CONSTITUENTS. Wheat. Winter sown. Wheat. Spring sown. Long- eared barley. English oats. Maize. .Rye. Carolina rice (without husk). Fat 1.48 1.56 1.03 5.14 3.58 1.43 0.19 Starch 63.71 65.86 63.51 49.78 64.66 61.87 77.66 Sugar (as sucrose) 2.57 2.24 1.34 2.36 1.94 4.30 0.38 Albumen (insoluble in alcohol) 1070 7.19 8.18 10.62 9.67 9.78 7.94 Nitrogenous matter (soluble in alcohol) . Cellulose 4.83 303 4.40 293 3.28 7.28 4.05 13.53 4.60 1.86 5.09 3.23 1.40 Traces. Mineral matter 160 1.74 2.32 2.66 1.35 1.85 0.28 Moisture 12.08 14.08 13.06 11.86 12.34 12.45 12.15 Total 10000 100.00 100.00 100.00 100.00 100.00 100.00 The chemical formula of starch is (C 6 H 10 5 ) n . According to Tollens, confirmed by Mylius, it is C 24 H 40 O 20 ; according to Brown soluble starch is C 120 H 200 O 100 , while for the ordinary variety he proposes C 180 H 300 O 15a . Nageli stated that by subjecting the starch-granules to the slow action of saliva, salt solutions, and dilute acids two substances could be shown to be present, granulose, which dissolved, and cellulose (or, as it has been called, farinose}, which remained. Arthur Meyer considers that there is only a single substance originally present, and that the cellulose, or farinose, which remains is a decomposition product of the starch. Air-dried starch always retains from eighteen to twenty per cent, of water. It is soluble in cold water, alcohol, ether, ethereal and fatty oils. When it is heated with twelve to fifteen times its bulk of water to 55 C., it begins to show signs of change, swelling up, and at a temperature of from 70 to 80 C. (or even below 70 C. with some pure starches) the granules burst and it becomes a uniform translucent mass, known as ' ' starch-paste, ' ' which is not, however, a solution, as the water can be frozen out of it. Boiled with water for a long time it goes into solution, one part dissolving in fifty parts of water. The action of heat upon starch is to change it gradually into dextrine, which is soluble in cold water. One of the best known of the reactions of starch is the formation of a blue color with iodine. This has been carefully studied by L. W. An- drews (Jour. Amer. Chem. Society, 1902, p. 865), who considers it * Bell, The Analysis and Adulteration of Foods, Part ii, p. 86. PROCESSES OF MANUFACTURE. 187 to be a dissociable addition compound of iodine with starch molecules. He finds that clear starch solutions made at a temperature of about 150 take up in the cold an amount of iodine corresponding to the formula (C 6 H 10 3 ) 12 I, while starch heated with excess of iodine to 100 for a short time takes up an, amount of iodine corresponding to the formula (C G H 10 O 5 ) 12 I 2 . The blue coloration is constantly availed of to note the presence or gradual disappearance or alteration of starch in many tech- nical processes. The action of dilute acids upon starch brings about the change known as "hydrolysis," and there is produced dextrine, C 12 H 20 10 , and dex- trose, C 6 H 12 O G , the latter eventually as sole product. Many ferments, like saliva, the pancreatic ferment, and especially the diastase of malt, produce in starch a somewhat similar change and yield maltose, C 12 H., 2 O 11 , and a number of intermediate products between this and starch. A great deal of investigation has been devoted to these intermediate products, and as yet no absolute agreement has been reached on the subject. The following is the series of products obtained in this hydrolysis of starch as stated by Tollens:* Starch gives a blue iodine reaction. Soluble starch (amylodextrine) gives a blue iodine reaction. (erythrodextrine gives a violet and red iodine reaction, achroodextrine gives no iodine reaction, maltodextrine gives no iodine reaction. Maltrose reduces Fehling's solution, but not Barfoed's reagent. Dextrose reduces Fehling's solution, and also Barfoed's reagent. Other chemists notably increase the list of these intermediate prod- ucts. The existence of erythrodextrine as a distinct compound is doubted by some investigators, who consider it to be merely a mixture of achroo- or maltodextrine with a little soluble starch, such a mixture giving a violet reaction with iodine. By over-treatment with acids unferment- able carbohydrates, of a character differing from any of the products named, appear to form. The name gallisin has been given to a com- pound of this kind, and the formula C 12 H 24 10 ascribed to it. For a description of the conditions of its formation see later (p. 197). Strong nitric acid in the cold acts upon starch, producing nitro deriv- atives, such as mono-, di-, and tetra-nitro starch, analogous to the nitro- celluloses. Alkalies and alkaline earths form combinations with starch, the barium and calcium compounds being insoluble, of which advantage is taken in the Asboth method for determination of starch. (See p. 199.) n. Processes of Manufacture. 1. EXTRACTION AND PURIFYING OP THE STARCH. Of the various starch-containing materials before enumerated, only a limited number are actually utilized for the extraction of the starch in a pure condition, * Tollens, Kohlenhydrate, Breslau, 1888, p. 177. 188 STARCH AND ITS ALTERATION PRODUCTS. viz., maize, wheat, rice, potatoes, and arrow-root. In the United States by far the greater amount is obtained from maize, or Indian corn, a limited amount only being extracted from wheat. In Europe, on the Continent, potatoes serve as the chief starch-producing material, some also being extracted from wheat and some from rice, while in the West Indies arrow-root starch is manufactured at St. Vincent and elsewhere. In the manufacture of corn starch, after winnowing or cleansing the corn by powerful fans, it is placed in large wooden steeping-vats, holding several thousand bushels of corn, and is covered with warm water at about 140 F., to which is frequently added sulphur dioxide, making a solution of 1 B. sulphurous acid. After twelve hours this water is run off and the germ is separated after a crushing of the softened corn. While the germ is afterwards worked for the corn oil contained, the starchy portion is ground again and 'passes on to the separator tables, where it is continuously washed. These separator tables are inclined sieves of silk bolting-cloth, which are kept in constant motion and are sprayed with jets of water. The starch passes through the bolting-cloth with water as a milky fluid, while the coarser cellular tissue, or husk, of the corn is left behind. This residue is pressed to remove water, and sold as cattle food. The water from the shakers holding the starch in suspension is run into wooden vats, where the starch settles, and the water is drawn off and discarded. The starch is next thoroughly agitated with fresh water, to which a caustic soda solution of 7 to 8 Baume has been added, until the milky liquid has changed to a greenish-yellow color. The object in adding the alkali is to dissolve and remove the gluten and other albuminoids, oil, etc. After sufficient agitation and treatment with alkali, the separated starch and glutinous matter is allowed to deposit, the supernatant solution of gluten, oil, etc., is allowed to run to waste, and the impure starch washed and agitated with water. It is allowed to stand at rest for fifteen to twenty minutes to permit in- soluble gluten to subside, when the top one of a series of plugs arranged in the side of the vat is withdrawn, and the starch suspended in water allowed to flow by means of a gutter into subsiding- vats placed below; then the next lower plug is drawn, and so on until the last plug has been drawn. The plugs are replaced and the vats again filled with water, and the operation repeated as before. This operation, called the siphoning process, is generally repeated three times, and the three runnings of starch are collected in three separate vats, forming the three grades of starch of the factory. These three grades of factory starch are again agitated with water, sieved through bolting-cloth, and run finally as purified starch into wooden "settlers." After it has been compacted sufficiently, which is effected in boxes with perforated bottoms, it is cut into blocks and dried upon an absorbent support of plaster of Paris while heated in a current of warm air. In drying out thoroughly, any remaining impurities come to the surface with the escaping moisture and form a yellowish crust. When this is removed, the interior is found to PROCESSES OF MANUFACTURE. 189 be perfectly white. The results on a bushel of fifty-six pounds of corn are thus stated by Archbold:* Starch recovered 28.000 pounds. Dry refuse for cattle food 13.700 " Bran (in cleansing process) 0.728 " Moisture of the corn 5.626 " Loss (albuminoids, oil, etc.) 7.946 " 56.000 Besides this very complete treatment known as the "alkali process," much of the cheaper grade of starch is purified by the use of sulphurous acid alone without the use of any alkali, and this product is known as "acid process " starch. In either case the removal of the germ as a preliminary step is now practised, as from this is obtained the valuable maize oil together with oil cake and ground husk for cattle food. The starch is moreover ob- tained in a higher state of purity and the process considerably shortened, lessening the danger of fermentation or souring while being treated. In manufacturing starch from wheat two quite different processes are followed, according as the gluten is to be obtained as a side-product or not. In the process generally known as the ' ' sour, ' ' or fermentation, process, the gluten is wasted. In this process the wheat is steeped in tanks until thoroughly softened, then crushed in roller-mills, and placed for fermentation in large oaken cisterns. The temperature is here main- tained at about 20 C., and the operation lasts some fourteen days, the mass being well stirred during its continuance. The sugar of the wheat and a part of the starch are converted into glucose, which undergoes alcoholic fermentation, and passes by oxidation into the acetous fermen- tation also, acetic, propionic, and lactic acids being formed. These rapidly attack and dissolve the gluten, liberating the starch-granules. The impure liquor is drawn off from the starch mass, and the latter is washed, either in hempen sacks while being trodden under foot or in drums with perforated sides. After repeated washings and settlings and renewed sieving through fine hair sieves the starch is sufficiently purified. Wheat starch is also obtained from wheat flour without fermen- tation by what is known as Martin's process, in which a stiff dough is made of the flour. This is then washed in a fine sieve under a jet of water till all the starch has escaped as a milky fluid. This leaves the gluten, of which about twenty-five per cent, of the weight of the flour is gotten suitable for use in the manufacture of macaroni, or to be used instead of albumen or casein in calico-printing. In the manufacture of potato starch, the potatoes are washed and then pulped by a grating or rasping machine. The grated mass, made into a paste with water, then goes at once into the sieving machine, where it is rubbed by revolving brushes against the wire or hair sides of the * Journ. Soc. Chem. Ind., 1887, p. 82. 190 STARCH AND ITS ALTERATION PRODUCTS. rotating cylinder, while a current of water is continuously washing out the fine starch from the pulp. The sifted and washed starch deposits in large tanks, where it is repeatedly Washed by agitation and settling with fresh waters. It is then spread out on absorbent slabs to dry, or dried in drying chambers or kilns heated by steam coils. 2. MANUFACTURE OF GLUCOSE, OR GRAPE-SUGAR. As stated on a pre- ceding page, the action of dilute acids converts starch into dextrine, maltose, and dextrose, the last of which becomes by continued action the sole product. As it is also the most important product of this action of acids, we shall take it up first. The purified starch obtained as described in the preceding section, while yet moist, is taken for the treatment with FIG. 54. acids. The "conversion " can be accomplished in either open or closed converters, although the former have been practically entirely super- seded by the pressure or closed converters. These converters are large, upright vessels of iron or copper lined with sheet lead to prevent the ac- tion of the dilute acids. Sulphuric acid is generally employed in the con- version if a solid grape-sugar is to be made, or hydrochloric acid prefer- ably when glucose syrup is the product to be manufactured. Both oxalic acid and hydrofluoric acid have been used in France as the agents for the conversion. The quantity of the acid employed varies with the object of the manufacturer. For the production of ' ' glucose, ' ' a liquid product which contains much dextrine, a smaller quantity is used than when solid "grape-sugar " is to be produced, in which the conversion into dextrose PROCESSES OF MANUFACTURE. 191 is much more complete. The proportion varies from one-half pound oil of vitriol to one and a quarter pounds per hundred pounds of starch. When the open converter is used, a few inches of water is introduced and the acid added, or half the acid may be added to the starch mixture. The acid water is brought to a boil, and the starch, previously mixed with water to a gravity of from 18 to- 21 Baume, is slowly pumped in, keeping the liquid constantly boiling. When all the starch has been introduced, the whole is boiled until the iodine test ceases to give a blue color and shows a dark cherry color. The boiling is usually continued for about four hours. The closed converters may be made from strong wooden vats or may be of copper; they are provided with safety-valves, and are made of sufficient strength to stand a pressure of six atmos- pheres. Fig. 54 shows the form first introduced in this country by T. A. Hoffmann, while Fig. 55 shows the form proposed by Maubre in London. In this case the starch is mixed with water to a gravity of from 11 to FIG. 55. 16 Baume. This with the acid is introduced into the converter, and the whole is heated under a pressure of from forty-five to seventy-five pounds per square inch. The time required for the conversion is much shorter than in the open converters. The use of open and closed con- verters successively is often resorted to. The starch and water of a gravity of 15 or 16 Baume is first boiled in the open converter for from one to two hours, then transferred to the closed converter and boiled under a pressure of from forty-five to seventy-five pounds per square inch. The time of this boiling varies from ten minutes to half an hour. When the starch has been sufficiently converted, according to the product desired, the liquor is run into the neutralizing-vats. Here a sufficient quantity of marble-dust is added to completely neutralize the sulphuric acid (or when hydrochloric acid has been used, a solution of caustic soda). A little fine bone-black is generally added at the same time. The liquor having a gravity of 12 to 18 Baume, and known as "light liquor," is next filtered through bag filters of cotton cloth or filter-presses. In many establishments the liquor is now treated with sul- phurous acid gas to prevent fermentation, and probably to some extent 192 STARCH AND ITS ALTERATION PRODUCTS. to act as a bleaching agent. It is then filtered through bone-black, by which it is decolorized and at the same time freed from various soluble impurities. Concentration is then effected in the vacuum-pan at a tem- perature of about 140 F. until it has a gravity of from 28 to 30 Baume, when it is called "heavy liquor." A second bag or filter-press filtration is now resorted to in many factories to remove the sulphate of lime, which separates out at this degree of concentration. It is then filtered a second time through bone-black to secure complete decoloriza- tion and purification. The final concentration is effected by boiling the liquor in the vacuum-pan until it reaches 40 to 42 Baume. That product in which the conversion has been least complete remains liquid, and is called "glucose " in the trade; that which is ready to solidify is known as "grape-sugar." Dr. Arno Behr has patented a process for obtaining the solid grape-sugar in pure crystals. While it is still liquid there is added to it a small quantity of crystallized anhydrous dextrose. The mixture is filled into moulds, and in about three days it is found to be a solid mass of crystals of anhydrous dextrose. The blocks are then placed in a centrifugal machine to throw out the still liquid syrup, and the anhydrous dextrose remains as a crystalline mass. 3. MANUFACTURE OF LEVULOSE. From invert sugar (mixture of equal molecules of dextrose and levulose) levulose is now obtained as a commercial product by taking advantage of the insolubility of its cal- cium compound. According to Schering's patent inverted molasses is used, which has been inverted with the aid of hydrochloric acid. After the inversion is completed the solution is diluted to one-sixth strength with water, cooled to C., and the levulose precipitated as the insoluble calcium levulosate. The precipitate is separated, washed with ice water, drained or centrifugated thoroughly and decomposed at a temperature not exceeding 50 with carbon dioxide under pressure. By centrifu- gating the lime precipitate, a syrup of thirty per cent, levulose strength is obtained. This is then acidified with a weak acid and further con- centrated. This manufactured levulose is used extensively in the manufacture of confectionery, as it prevents the crystallizing of the cane-sugar used and so prevents the gradual change of clear transparent sugar products to the opaque condition. It is also used in the manufacture of marma- lades, jellies, and sugared fruits, for the treatment of wines, particularly sweet wines and champagnes. It is also used in medicine in the case of diabetes, where ordinary sugar is forbidden to be used in sweetening foods, and as the basis of infant foods. 4. MANUFACTURE OF MALTOSE. By the action of the diastase of malt upon starch is formed mainly maltose. Dilute sulphuric acid will con- vert this by prolonged boiling into dextrose, but diastase alone will not so convert it. The manufacture of maltose on a large scale as a prepara- tion for use in beer-brewing to simplify the preparation of a suitable wort has been attempted by several. Dubrunfaut'and Cuisinier patented a process in 1883 for preparing maltose, either as syrup or crystallized, by the following procedure: One part of green or partially dried malt PROCESSES OF MANUFACTURE. 193 is warmed with two to three parts of water, digested for several hours at 30 C., and afterwards filter-pressed to obtain an "infusion " of malt. One part of starch-flour is then suspended in two to twelve parts of water, and five to ten per cent, of infusion added, the whole gradually warmed to 80 C., then heated under a pressure of one and a half atmospheres for thirty minutes, quickly cooled to 48 C., and treated with five to twenty per cent, of infusion and hydrochloric acid (from six to twenty- five cubic centimetres of acid per one hundred litres). After one hour the mass is filtered through filter-paper fastened upon linen cloth. The solution is allowed to stand at 48 C. for twelve to fifteen hours, then concentrated to 28 B., filtered, again concentrated to 38 B., fil- tered through animal charcoal, and allowed to crystallize. A sample of the syrup made from corn-starch by the Brussels Maltose Company working under this patent was analyzed by Marcker,* and found to con- tain 19.8 per cent, water, 78.7 per cent, maltose, 1.5 per cent, non-sugar, and no dextrine. The process is, however, said to have failed as yet of commercial success. Saare,f who has recently investigated it, shows that the complete conversion into maltose only takes place with weak mashes, and he concludes from his results that the process is not suitable for German distilleries under the present conditions. 'Sullivan and Val- entinj have also patented a process for producing from starch, or starch- yielding substances, preferably from rice, a compound solid body, which the inventors term "dextrine-maltose," consisting of the same propor- tional quantities of dextrine and maltose as are ordinarily obtained from malt by a properly-conducted mashing process, and which it is intended should replace a portion of the malt used in brewing. For details, see original article. Perfectly pure maltose can be obtained by Herzf eld's process of repeatedly extracting with alcohol from the syrupy product of the action of malt upon starch. The alcohol precipitates the dextrine, but dissolves the maltose, which can then be obtained in crystalline con- dition. 5. SOLUBLE STARCH. In recent years considerable attention has been given to preparing products that will either gelatinize in the cold and yield solutions with cementitious value or dissolve completely in hot water. The starch under the influence of acids, alkalies or of different oxidizing agents will be changed in substance without the starch granules losing their outward appearance. Soluble starch is widely utilized as a substitute for dextrin, casein, gelatin, gums and glue, and specially as a basis of sizing preparations. One of the earlier methods was to heat starch dried at 80-90 with glacial acetic acid. The product of this treatment can be washed with cold water without loss and is soluble in boiling water without gela- tinizing. Volatile organic acids, like formic and acetic acids, are advantage- ously used, as they can be distilled off after the reaction and no neu- * Jahresber. der Chem. Tech., 1886, p. 613. t Dingier, Polytech. Journ., 266, p. 418. t Journ. Soc. Chem. Ind., 1888, p. 446. 13 194 STARCH AND ITS ALTERATION PRODUCTS. tralization of the acid is required. One per cent, of such acid acting for five to six hours at 115 C. suffices to effect the change. Starch so prepared with acid is uniformly soluble in hot water, while soluble starch prepared with alkalies gelatinizes with cold water. To avoid the production of the alkali salts remaining in the product, am- monia has been used. The starch is treated with water containing two per cent, of ammonia and the product is dried in thin layers to volatilize the ammonia. The soluble starch so obtained forms a voluminous powder gelatinizing with cold water. Chlorine, persulphates, and perborates have also been used. 6. MANUFACTURE OF DEXTRINE. This may be effected by acting upon starch with heat alone, by the action of dilute acids and heat, or by the action of diastase. The first and second of these methods are followed in preparing the solid product. In the manufacture by heat alone the limits of temperature are 212 to 250 0., although Pay en says that 200 u to 210 C. produces the most perfectly soluble dextrine. The starch is heated in revolving drums, which are frequently double- jacketed, and contain oil in the outer space in order to insure uniform heating. After the moisture is given off, the loss of weight in roasting is small, two hundred and twenty pounds of starch giving one hundred and seventy- six pounds of finished dextrine. In the manufacture by the aid of acids the starch is mixed with dilute nitric or hydrochloric acid so as to form a damp powder. This is exposed to a temperature of 100 to 120 C. until the transformation is complete, which can be determined by applying the iodine test from time to time. The process must be arrested promptly when the starch is all changed, or the dextrine will pass rapidly into glucose. Oxalic acid is also some- times employed in the manufacture of dextrine. 7. MANUFACTURE OF SUGAR-COLORING (Caramel, or Zucker-couleur). Very considerable quantities of an artificial coloring material for use in coloring beer, rum, cognac, and high wines are made on the Continent of Europe from starch. For the manufacture of rum and cognac coloring, starch is treated with dilute sulphuric acid, as before described for the manufacture of dextrose and dextrine mixtures, but the heating is con- tinued until all the dextrine has been changed into dextrose, as deter- mined by taking a sample from time to time and testing it with an excess of ninety-six per cent, alcohol. When no longer any turbidity from separated dextrine shows, the reaction is considered as finished. The sulphuric acid is then neutralized with carbonate of lime, and after sufficient standing the clear liquor is run off from the precipitated sul- phate of lime. It is now concentrated to 36 B. and filtered. The hot filtrate is then run into a vessel provided with mechanical agitation and heated to boiling, when crystallized soda salt (three kilos, of soda to one hundred kilos, of sugar solution) is added in small portions at a time. The contents of the kettle froth and must be continuously stirred. White and inflammable vapors are grven off and the color rapidly deepens. The heat is now gradually lessened to prevent car- bonizing of the contents of the vessel, and the color is tested. A drop chilled by being dropped into water should harden and be brittle and PRODUCTS. 195 should taste bitter. The contents of the kettle are then cooled some- what by adding hot water. When the production of the color is com- pleted, the contents of the kettle are extracted with water, filtered to remove carbonized particles, and then tested as to quality. The coloring is made in several grades or depths of color, which are also differently soluble, the one in seventy-five per cent, alcohol and the other in eighty per cent, alcohol. For beer- or wine-coloring it is not necessary to be so careful to use a glucose freed perfectly from dextrine, and, instead of soda, ammonium carbonate is taken. The product is soluble in water, but not so readily in alcohol. m. Products. 1. STARCH. The properties and action of reagents upon starch have already been noted in speaking of it as a raw material. It is only neces- sary to subjoin a few analyses of commercial starches in order to show the character of that usually obtainable. Those of potato and wheat starch are by J. Wolff, as quoted in "Wagner's Chemical Technology," and those of corn starch are by Dr. Archbold, as given by him in the "Journal of the Society of Chemical Industry," 1887, p. 188. PERCENTAGE COMPOSI- TION. Potato starch. (Wolff.) Wheat starch, I. (Wolff.) Wheat starch, II. (Wolff.) Corn starch, I. (Archbold.) Corn starch, II. (Archbold.) Corn starch. III. (Archbold.) Starch 83.59 83.91 79.63 98.50 92.88 90.33 Gluten 0.10 1.84 Cellulose Ash 0.50 053 1.44 003 3.77 065 030 | 2.38 0.60 | 4.25 0.65 "Water 15.38 14.52 14.20 1.20 4.14 4.77 Total 100.00 100.00 100.00 100.00 100.00 100.00 2. GLUCOSE AND GRAPE-SUGAR. Starch-sugar appears in commerce in a great variety of grades and under a similar variety of names. As already said, in the United States the name glucose is in general applied to the liquid products, while that of grape-sugar is given to the solid products. In France, w-here large quantities of similar products are manufactured, the liquid product is known as "sirop cristal " and the solid product "glucose masse." The following analyses show the com- position of the commercial products as now manufactured by the Corn Products Co.* Corn syrup. 70 sugar. 80 sugar. Anhydrous sugar. Water per cent. 190 per cent. 197 per cent. 11 2 per cent. 4.0 Dextrose ... 385 702 799 94.6 Dextrine 420 93 80 0.7 Ash 05 08 0.9 0.7 Journ. Soc. Chem. Ind., 1909, p. 347. 196 STARCH AND ITS ALTERATION PRODUCTS. 3. MALTOSE. Maltose forms fine white crystalline needles aggregating in warty groups, which have a faint sweetish taste. It is soluble in water and methyl and ethyl alcohol, but more difficultly in the last than dex- trose. Its formula is C 12 H 22 11 , and it crystallizes with one molecule of water, which it loses slowly at 100 C. in a vacuum. Its specific rotatory power is, according to Meissl, (S) d = 140.375 -- .01837 P -- .095 T, where P equals the percentage strength of the solution and T the tem- perature. A ten per cent, solution at 20 C. would then be 138.3. 'Sullivan takes it as 139.2 for a ten per cent, solution. Its reducing power with Fehling's solution is frequently stated to be two-thirds that of dextrose, but Brown and Heron as well as 'Sullivan make it more exactly sixty-two per cent, of that sKown by dextrose. It has no action, however, upon Barfoed's reagent (see p. 200), which is reduced by dex- trose. Maltose is said to be directly and completely fermentable without previous change into dextrose, but more slowly than this latter, so that if a mixture of maltose and dextrose be fermented with yeast, the whole of the dextrose disappears before the former sugar is acted upon. 4. DEXTRINE. Pure dextrine is a white amorphous solid. It is taste- less, odorless, and non-volatile. It is completely soluble in cold water, but the commercial varieties usually leave from twelve to twenty per cent, or even more of starch and other insoluble residue when dissolved. Heated with dilute acids it yields maltose and ultimately dextrose. It is unf ermentable if free from sugar. It has no reducing power on Fehling 's solution. Probably what is called dextrine is a mixture of products obtained in the breaking down of the complex starch-molecules. Some investigators claim to have obtained sixteen distinct modifications or varieties of dextrine in this way. We have before (see p. 187) alluded to amylodextrine, erythrodextrine, achroodextrine, and maltodextrine. Commercial dextrine, or "British gum," gives a brown coloration with iodine, and probably consists largely of erythrodextrine. The fol- lowing analyses by R. Forster give an idea of the composition of the dex- trines usually obtainable : PERCENTAGE COMPOSITION. First quality dextrose. Dark- burned starch. Brown dextrine. Gommel- ine. Old dextrine. Lightr burned starch. 72.45 70.43 63.60 59.71 49.78 5.34 Su"ar 8.77 1.92 7.67 5.76 1.42 0.24 Insoluble 13.14 19 97 14.51 20.64 30.80 86-47 "Water 5.64 7 68 14 22 13.89 18.00 7.95 100.00 100.00 100.00 100.00 100.00 100.00 Dextrine is used as a substitute for natural gums, especially for gum arabic. It is thus used in calico-printing and in the mordanting and printing of colors upon most other classes of textile goods, for mucilage, for glazing cards and paper, as warp-dressing, arid in the manufacture of beer. It forms the crust on bread by the change of the starch of the flour in baking, and is present in most products from starch or starch- sugar. ANALYTICAL TESTS AND METHODS. 197 5. UNFERMENTABLE CARBOHYDRATES (Gallisin}. The presence of an unfermentable carbohydrate in starch-sugar was long since pointed out by 'Sullivan. The compound which has been specially studied is known as gallisin, and is prepared by fermenting a twenty per cent, solution of starch-sugar with yeast at 18 or 20 C. for five or six days. The resultant liquid was filtered, evaporated to a syrup at 100 C., and shaken with a large excess of absolute alcohol. The treatment with alcohol was repeated several times until the unaltered sugar and other impurities were removed, the syrup being converted into a yellowish crumbling mess, which, by pounding in a mortar with a mixture of equal parts of alcohol and ether, was obtained as a gray powder. After purifying with animal charcoal and drying over sulphuric acid, the gallisin was obtained as a white amorphous extremely hygroscopic powder. Its taste is at first sweet, but afterwards becomes insipid. It is easily decomposable by heat, even at 100 C. It is readily soluble in water, nearly insoluble in abso- lute alcohol, and but slighly more soluble in methy alcohol, in which respect it differs from dextrose. Gallisin is stated to have the composi- tion C 12 H 24 10 . Its concentrated aqueous solution is distinctly acid to litmus and a sparingly soluble barium compound may be obtained there- from by adding alcoholic baryta. It reduces nitrate of silver on heating, especially on addition of ammonia, reduces bichromate and perman- ganate, and precipitates hot Fehling's solution. Its cupric oxide reduc- ing power (dextrose 100) is stated to be 45.6. Gallisin is dextro- rotatory, the value for Sd being stated to be 80.1 in twenty-seven per cent., 82.3 in ten per cent., and 84.9 in 1.6 per cent, solutions. By heating with dilute sulphuric acid for some hours gallisin yields a large proportion of dextrose, but its complete conversion has not so far been effected. It is doubtful whether "gallisin " as hitherto obtained is really a definite compound, but the possibility of isolating a reducing or optically active body from the liquid left after fermenting solutions of many speci- mens of sugar-starch cannot be ignored in considering the composition of commercial glucose. IV. Analytical Tests and Methods. 1. FOR STARCH. The usual method for the determination of starch is to invert by the action of dilute acid, and then determine the dextrose produced by the aid of Fehling's solution. In this case one hundred parts of dextrose are taken as indicating ninety of starch. It has been found, however, that the change to dextrose by the aid of dilute sulphuric acid is not complete, that other non-reducing bodies are formed, and that but ninety-five per cent, of the starch is converted into dextrose. The hydrolysis is more completely effected by the aid of hydrochloric acid, as carried out in Sachsse's method. 2.5 to 3 grammes of dry starch (or so much of the starch-containing substance as would correspond to this amount of starch) are placed in a flask with two hundred cubic centimetres of water and twenty cubic centimetres of hydrochloric acid 198 STARCH AND ITS ALTERATION PRODUCTS. FIG. 56. and heated on the water-bath with inverted condenser for three hours. (Marcker states that heating for three hours with this amount of hydro- chloric acid does not give more than ninety-six to ninety-seven per cent, of the starch as sugar, as some of the latter is destroyed. He recom- mends using fifteen cubic centimetres of acid and heating for two hours.) The contents of the flask are then nearly neutralized with sodium hy- droxide, filled to the mark, and the dextrose determined by Fehling's solution. If other carbohydrates or cellulose are present, which would be also converted into dextrose by hydrochloric acid, the starch must be previously brought into the soluble form, which may be done by heating with water to 130 C. in a pressure- flask like that of Lintner, shown in Fig. 56. Or the starch may be hy- drolyzed in part by infusion of malt or diastase at 62.5 C., filtered from cellulose, etc., and then treated with hydrochloric acid for complete hy- drolysis as above. In this latter case, the process of Reinke* is the simplest. Three grammes of the sample as finely powdered as pos- sible are heated to boiling with fifty cubic centimetres of water, cooled at 62.5 C., and hydrolyzed for an hour at this temperature with .05 gramme of diastase. This is pre- pared according to Lintner's pro- cedure, by making an alcoholic twenty per cent, extract (1:3) of raw malt, adding to the filtrate two volumes of ninety-six per cent, alco- hol, separation of the precipitated diastase, washing with alcohol and ether, and drying in a desiccator. The mixture is then cooled, diluted with water to two hundred and fifty cubic centimetres, and filtered. Of the filtrate, two hundred cubic centimetres are taken and hydrolyzed, as before described, with fifteen cubic centi- metres of hydrochloric acid of 1.125 specific gravity for two and a half hours, when the solution is neutralized and the dextrose determined. A more elaborate course of treatment, following in the main the same lines as the procedure of Reinke just described, but stopping with the action of the diastase, has been published by O 'Sullivan, and is given at length by Allen, f In this case the filtered liquid, assumed to contain nothing but maltose and dextrine, is made up to one hundred cubic centimetres, and the density determined. It is then tested with Fehling's solution for the maltose, and the dextrine deduced from the rotatory power of the solution. The maltose found, divided by 1.055, gives the Jahresber. Chem. Technol., 1887, p. 863. t Commercial Organic Analysis, 3d ed., vol. i, p. 415. ANALYTICAL TESTS AND METHODS. 199 corresponding weight of starch, which, added to the dextrine found, gives the total number of grammes of starch represented by one hundred cubic centimetres of the solution. The method for the determination of starch in cereals most generally used in Germany at present is that of Marcker.* Three grammes of sub- stance are placed in a small beaker (preferably of metal), which is placed as one of several in a Soxhlet pressure-boiler, or the test is carried out in the Lintner pressure-flask, figured on the preceding page, and heated to the temperature of boiling water. It is then cooled to 60 to 65 C., five cubic centimetres of thin malt infusion are added, and it is digested at this temperature for some twenty minutes. It is then made faintly acid (one cubic centimetre of tartaric acid suffices) and heated under a pressure of three to four atmospheres. It is then cooled down and an additional five cubic centimetres of malt infusion added, with which it is digested an half-hour. The solution is then brought up to one hundred cubic centimetres, filtered, and determined with Fehling's solution, either by titration or by weighing the reduced copper. Of other methods proposed for starch determinations it is only neces- sary to notice the Asboth method, proposed in 1887. It depends on the fact that starch forms a compound with baryta-water, C 24 H 40 20 BaO, containing 19.1 per cent, of BaO, which is insoluble in forty-five per cent, alcohol. The baryta-water is used in excess, and the free alkaline earth determined by titration with decinormal hydrochloric acid. Nu- merous experimenters have taken exception to the method that the results were variable, and that starch combined with varying amounts of barium oxide. To these objections the author made a reply later, f and claims that the presence of fat in the cereals interferes with the accuracy of the determination, and that if the fat be previously extracted by ether, the determinations in the fat-free residue are accurate and concordant. J. Napier Spence, in the "Journal of the Society of Chemical Industry," for 1888, p. 77, has also come to the defence of the Asboth method and shown the conditions under which it yields accurate results. 2. GLUCOSE, OR DEXTROSE. For the determination of dextrose alone the Fehling's solution affords the most accurate means. For its use, see analysis of raw sugars, p. 174. In the absence of any other optically active body its examination with the polariscope will also suffice. For mixtures like commercial glucose, which contains dextrose, maltose, and dextrine, see later. 3. MALTOSE. This variety of sugar, as before stated, has optical activity and reducing power on Fehling's solution. It can, however, be distinguished from dextrose by its failure to reduce Barfoed's solution, which is reduced by dextrose and invert sugar. This reagent is made by dissolving one part of neutral copper acetate in fifteen parts of water, to two hundred cubic centimetres of which five cubic centimetres of thirty- eight per cent, acetic acid is added. Boiled for several minutes with maltose solution it shows no reduction. *Jahresber. Chem. Technol., 1885, p. 863. f Chemiker Zeitung, 1889, pp. 591 and 611. 200 STARCH AND ITS ALTERATION PRODUCTS. 4. DEXTRINE. Pure dextrine differs from dextrose and maltose in showing no reducing power with either Fehling's solution or with Knapp 's mercuric cyanide solution. It can, indeed, be freed from admix- ture with dextrose and maltose by heating with an excess of an alkaline solution of mercuric cyanide, which oxidizes these two varieties of sugar, leaving the dextrine unaffected. (See Wiley's method below.) 5. COMMERCIAL GLUCOSE AND SIMILAR MIXTURES DERIVED FROM STARCH. As commercial glucose is likely to be a mixture of the three compounds, dextrose, maltose, and dextrine, its analysis and the deter- mination of the several constituents becomes a frequently-recurring problem. Three methods have been proposed. The first, by Allen,* requires the determination of moisture and ash in the sample, which, subtracted from 100, leaves the total organic solids, 0. The apparent specific rotatory power, 8, and the cupric oxide reducing power (in terms of dextrose reduction = 100), K, are now determined. Then, if m be the maltose, g the dextrose-glucose, and d the dextrine, Allen deter- mines the respective percentages by the use of the formulas m The author states that the presence of gallisin or other unfermentable sugar may vitiate the values of K and 8, as observed, and so make the results inaccurate. The second method is that of Wiley, f which is based upon the theory that boiling with an alkaline solution of mercuric cyanide will destroy the optical activity of maltose and dextrose, leaving that of dextrine unchanged. The cupric oxide reducing power of the sample is ascer- tained in the usual way by Fehling's solution. The specific rotatory power is determined by polarizing a ten per cent, solution (previously heated to boiling) in the ordinary manner. Ten cubic centimetres of this solution used for polarizing are then treated with an excess of an alkaline solution of mercuric cyanide, and the mixture boiled for two to three minutes. It is then cooled and slightly acidulated with hydro- chloric acid, which destroys the reddish-brown color possessed by the alkaline liquid. The solution is then diluted to fifty cubic centimetres, and the rotation observed in a tube four decimetres in length. The angular rotation observed will be due simply to the dextrine, the percentage of which may then be calculated by the formula rotation X 1000 X cubic centimetres of solution polarized - __ _ _ _ Der- 198 X length of tube in centimetres X weight of the sample taken centage of dextrine. The percentages of dextrose and maltose may be deduced from the reducing power of the sample, or from the difference in specific rotatory power before (8) and after (s) the treatment with alka- line mercuric cyanide. Thus, K = 1.00 g + .62m,S = .527 g -+- 139.2 m -f- 1.98 d and s = 1.98 d, whence m =- , - . g can now be 1.UOUAU found from the first of the three equations, and then d in the second. * Commercial Organic Analysis, 3d ed., vol. i, p. 365. f Chemical News, xlvi, p. 175. BIBLIOGRAPHY AND STATISTICS. 201 Wiley's process was employed by the Committee of the National Academy of Science in their investigation of commercial glucose from corn starch. It is, however, based upon several assumptions that have not been specifically proven, and especially in the presence of any con- siderable quantity of "maltose are its results open to doubt. (See Allen, ''Commercial Organic Analysis," 3d ed., vol. i, p. 369, foot-note.) The third method of estimating the constituents in commercial glu- cose is due to C. Graham, and is probably more exact than either of those before mentioned. Dissolve five grammes of the sample in a small quantity of hot water and add the solution drop by drop to one litre of nearly absolute alcohol. Dextrine is precipitated, and on standing becomes attached to the sides of the beaker, while maltose, gallisin, and dextrose are soluble in the large quantity of alcohol employed. If the solution be then decanted from the precipitate, the dextrine in the latter can be ascertained by drying and weighing, or by dissolving it in a definite quantity of water and observing the solution, density, and rota- tion. The alcohol is distilled off from the solution of the sugars and the residual liquid divided into aliquot portions, in one of which the gallisin may be determined after fermentation with yeast, while others are employed for the observation of the specific rotation and reducing power, which data give the means of calculating the proportions of mal- tose and dextrose in the sample. V. Bibliography and Statistics. BIBLIOGRAPHY. 1879. Die Starkefabrikation, F. Stohmann, Berlin. 1881. Starch, Glucose, and Dextrine, Frankel and Hutter, Philadelphia. 1882. Die Starke- und die Mahlproducte, F. von Hohnel, Berlin. 1884. Report on Glucose by the National Academy of Sciences, Washington. 1886. Die Starkefabrikation, Dextrin und Traubenzucker, L. von Wagner, 2te Auf., Braunschweig. Fabrication de PAmidon, E. Guillaume, Paris. 1887. Die Fabrikation der Stlirke, K. Birnbaum, Braunschweig. 1888. Handbuch der Kohlenhydrate, B. Tollens, Breslau. 1890. Manual of Sugar Analysis, J. H. Tucker, 2d ed., New York. Traite" d' Analyse des Mati&res sucres, D. Siderski, Paris. 1891. Die Untersuchung Landwirthschaftlich wichtiger Stoffe, J. Kb'nig, Berlin. 1892. The Principal Starches used as Food, W. Griffith, Cirencester, England. 1893. Introductory Manual for Sugar-Growers, F. Watts, London. 1894. Die Starkefabrikation, Dr. B. von Posanner, Wien. 1895. Handbuch der Kohlenhydrate, B. Tollens, 2te Band, Breslau. 1896. Die Industrie der Stiirke in der Vereinigten Staaten, O. Saare, Berlin. 1897. Die Fabrikation der Kartoffelstiirke, 0. Saare, Berlin. 1900. Die Rohstoffe des Pflanzenreiches, J. Wiesner, 2te Auf., Leipzig. 1901. Die Fabrikation von Stiirkezucker, Dextrine, etc., Joseph Borsch, Wien. 1903. Foods, their Composition and Analysis, A. W. Blyth, 5th ed., London. 1908. Lehrbuch der Stlirkefabrieation, Parow, Berlin. 1909. Die Starkefabrikation, J. Schmidt, Hannover. 1911. Die Starkefabrikation, F. Rehwald, 4te Auf., A. Hartleben, Wien. 202 STARCH AND ITS ALTERATION PRODUCTS. STATISTICS. 1. PRODUCTION OF STARCH IN THE UNITED STATES AND GERMANY. O. Saare in 1896 gave the following summary of the production in these chief producing countries : United States. Germany. Hundred kilos. Hundred kilos. Potato starch 120,000 180,000 2,000,000 3,000,000 Corn starch 2,000,000 3,000,000 25,000 50,000 Wheat starch 150,000 200,000 50,000 100,000 Rice starch 200,000 250,000 2,270,000 3,380,000 2,275,000 3,400,000 2. PRODUCTION OF GRAPE-SUGAR (STARCH-SUGAR), GLUCOSE, DEX- TRINE, ETC. The same authority gives the following figures for the products from starch : United States. Germany. Hundred kilos. Hundred kilos. Grape-sugar and glucose syrup . . 2,500,000 3,000,000 350,000 400,000 Sugar-color ( caramel ) 30,000 40,000 Dextrine 20,000 50,000 150,000 180,000 2,520,000 3,050,000 530,000 620,000 3. PRODUCTION OF STARCH IN THE UNITED STATES (Census of 1905) : 1900. 1905. Corn starch produced (Ibs.) 247,051,744 150,520,009 Value $6,133,001 $4,702,309 Potato starch produced (Ibs.) .. 33,941,826 27,709,400 Value $1,129,129 $924,476 Cassava and wheat starch (Ibs.) 16,809,569 17,845,121 Value $775,835 $1,124,612 Total starch (Ibs.) 297,803,139 196,074,530 Value $8,037,965 $6,751,397 4. CORN PRODUCTS. The corn crop "of the United States in 1908 is said to have been 2,643,000,000 bushels, valued at $1,615,000,000. Of this, ninety per cent, is used as food and ten per cent, is used in the industries and" for export. Two per cent., or 50,000,000 bushels, is used in the starch and glucose industry. Four per cent., or 100,000,000 bushels, is used in the fermentation and milling industry. Four per cent., or 100,000,000 bushels, is exported. (T. B. Wagner, Jour. Soc. Chem. Ind., 1909, p. 343.) 5. EXPORTATIONS OF STARCH, GLUCOSE, AND GRAPE-SUGAR FROM THE UNITED STATES. 1908. 1909. 1910. Starch (Ibs.) 48,125,851 33,228,278 51,535,570 Value $1,042,054 $780,155 $1,274,773 Glucose (Ibs.) 98,608,192 92,652,409 112,730,639 Value $1,898,652 $1,138,405 $2,623,131 Grape-sugar (Ibs.) 31,078,642 19,572,095 37,098,449 Value ' $641,988 $407,683 $792,089 (Commerce and Navigation of the United States, 1910.) NATURE AND VARIETIES OF FERMENTATION. 203 CHAPTER VI. FERMENTATION INDUSTRIES. A. NATURE AND VARIETIES OF FERMENTATION. UNDER the term fermentation are included certain methods of decom- position of organic compounds which presuppose the presence of definite substances called " ferments," which do not, however, apparently take part in the chemical reactions but act after the manner of the inorganic catalytic agents. Their presence in relatively small amount and the existence of conditions of temperature, etc., favorable to them, suffice to bring about the decomposition of large quantities of the fermentable material. The ferments which seem to determine the decomposition may be either soluble unorganized ferments or insoluble organized ferments, which are minute vegetable growths. The decompositions which are brought about by organized ferments differ quite notably in their results from those which can be induced by mere chemical reagents. Thus, the decomposition of sugar into alcohol and carbon dioxide, as it is brought about by the activity of the yeast-cell, cannot be brought about by purely chemical treatment. On the other hand, the action of the unorganized ferments is much more analogous to that induced by chemical reagents. Thus, the hydrolytic action of diastase on starch can also be per- fectly imitated by treating with dilute acids. Buchner has, however, recently shown that the liquid expressed from fresh yeast cells after triturating them can produce all the changes attributed to the cells themselves, and that it owes its activity to an enzyme called zymase, which is produced by the cells. With regard to the chemical nature of the enzymes, or soluble fer- ments, we only know that they belong to the class of proteids. A recent analysis of diastase by Lintner may be taken as typical of the class: carbon, 46.66 per cent.; hydrogen, 7.35 per cent.; nitrogen, 10.42 per cent. ; sulphur, 1.12 per cent. ; and oxygen, 34.45 per cent. While soluble in water and glycerol they are insoluble in alcohol, and are precipitated from aqueous solutions on addition of lead acetate. Their activity is destroyed by heating, that of diastase at 75 C., and all by boiling with water. Their activity is not destroyed by the presence of antiseptics, which arrest the action of the organized ferments. Thus, chloroform, thymol, and salicylic acid will all arrest the activity of the organized growth but not interfere with that of the soluble ferments. Sodium fluoride in one per cent, solution is said to check entirely the growth of the organized ferments, but is without action on those which are soluble. 204 FERMENTATION INDUSTRIES. Foremost among the soluble ferments is diastase. This is the ferment formed from the albuminoids of the cereals during the process of ger- mination. It is especially developed in the malting process as applied to barley. Its chief function is the saccharification of the starch of the grain, changing it into dextrine, maltose, and dextrose. The amount of starch that a given quantity of diastase can convert cannot be stated with absolute certainty, as it varies with the conditions of its preparation, the strength of the infusion, and other points. Its progress vCan, of course, be controlled by the iodine reaction, as stated under starch. Commercial extracts of malt are infusions of malted barley, which contains the products of the inversion of the starch. The solid extracts obtained by evaporation of these infusions in vacuo at low temperatures should be readily soluble, and should show that they still contain active diastatic ferment by being able to convert their own weight of starch within a short time. Invertase. Invertase is capable of converting cane sugar or sucrose into invert sugar. This rather resistant enzyme may be readily ex- tracted from the yeast by various means. From yeast cells which have been killed with chloroform it may be extracted with water, and is pre- cipitated from a water solution by the addition of alcohol. This white precipitate is readily dissolved in water and possesses the property of inverting cane sugar or sucrose quantitatively. Invertase is an impor- tant enzyme in the fermentation of molasses or any other substance con- taining sucrose. Invertase acts only in a slightly acid solution. The best temperature for its action is about 55 C. ; it is slowly destroyed at about 65 C., and immediately at 95 C. Zymase. This enzyme in reality forms a class by itself, in that it possesses the property of converting monosaccharid sugars into alcohol and carbon dioxide. The presence in solution of the enzyme which Buchner named zymase, and which is the cause of alcoholic fermenta- tion, overthrows to a great extent the older theories which regarded the actual cause of the transformation of sugar into alcohol and carbon dioxide as a vital process dependent upon the actual life activities of the yeast cell itself. The organized ferments or vegetable growths may be divided into three classes: first, mould-growths; second, yeast-plants, or the different species and varieties of Saccharomyces ; and, third, bacteria, belonging to the two genera Schizomycetes and Schizophycetes. Tlie most im- portant fermentations from an industrial point of view are the alcoholic, which is brought about mainly* by the presence of ferments of the second class, and the acetic and lactic, which are brought about by fer- ments of the third class. Upon the alcoholic fermentation depend three important groups of industries, viz., the manufacture of malt liquors, the manufacture of wines, and the manufacture of ardent spirits, or distilled liquors. Upon the acetic fermentation depends the manufac- ^ * Buchner (1897) has shown clearly that there is present in the yeast-cells, even when dead, a soluble ferment or enzyme capable of developing the alcoholic fermenta- tion. NATURE AND VARIETIES OF FERMENTATION. 205 ture of different varieties of vinegar, and upon the lactic fermentation the manufacture of cheese and other milk products. The alcoholic fermentation is always meant when we use the word fermentation in the narrower sense, as with reference to the change which starch and saccharine bodies most generally undergo. In this fer- mentation, the action of the yeast-plant seems to differ according to the variety of sugar presented to it. Dextrose is most immediately acted upon, the main reaction being CoH^O,, = 2C 2 H G O -f 2CO,, although, as Pasteur first showed, side-products like glycerine and succinic acid are also formed, and in practice only about ninety-five per cent, of the dex- trose is decomposed by the main reaction. Cane-sugar is not immediately fermentable. If it has been previously exposed to the action of dilute acids, it is changed into invert sugar, which then acts like dextrose. The yeast-plant can effect the same change itself. Invertin (or invertase, as it is also termed) is a soluble ferment existent in yeast. It has the prop- erty of rapidly and completely effecting the transformation of cane- sugar into invert sugar, but is without sensible action on dextrose, levu- lose, maltose, or milk-sugar. Towards dextrine its action is not so certainly negative. The conditions of the activity of the yeast-plant have been studied by many chemists, but notably by Pasteur. It has been found that if an abundance of air is supplied the plant grows and multiplies but fer- mentation proceeds very slowly, when the supply of air is limited, the fermentation proceeds more rapidly while the growth of the cells is largely arrested, and that in the absence of air the fermentation proceeds with greatest rapidity, although the plant-cells do not grow any longer, but gradually disintegrate and die. Pasteur's dictum, that "fermenta- tion is the consequence of life without air, ' ' is no longer taken as strictly accurate, as with the cessation of the growth and extension of the yeast-plant (which is dependent upon air like the life of any other plant), although its fermentation activity then becomes greatest, it begins at the same time a decay which leaves it after a time dead and inactive. The genus Saccharomyces has already been alluded to as the active agent in the alcoholic fermentation. The species Saccharomyces cerevisice is generally known as the special beer ferment and the Saccharomyces ellipsoideus as the wine ferment. Moreover, of the Saccharomyces cere- visice, two well-marked varieties have been recognized. The one is the most active at the ordinary temperature (16 to 20 C.), and carries through its fermentative work in from three to four days; the other works at a lower temperature (6 to 8 C.) and the fermentation is much slower. The first, placed in a saccharine liquid, is carried by the carbon dioxide which it liberates to the surface of the liquid, where it continues its activity ; it is therefore known as a surface or top yeast. The second, on the contrary, is not carried up, and rests during its entire activity on the bottom of the fermenting vessel, and is hence called a bottom yeast. Two quite distinct methods of beer-brewing are practised (see p. 212), depending upon the use of the one or the other of these varieties of yeast. It has been found, however, in practice that, even when a top 206 FERMENTATION INDUSTRIES. FIG. 57. Saccharomyces cerevisise. (After Hansen.) Saccharomyces cerevisise. Ascospores. (After Hansen.) Saccharomyces ellipsoideus. (After Hansen.) Saccharomyces ellipsoideus. Ascospores. (After Hansen.) Saccharomyces Pastorianus. (After Hansen.) Saccharomyces Pastorianus. Ascospores. (After Hansen.) NATURE AND VARIETIES OF FERMENTATION. 207 yeast is used exclusively or a bottom yeast exclusively, the results are not always uniform. These anomalies are now made clear through the re- searches of E. Ch. Hansen, of Copenhagen, who has applied the methods of pure cultivation introduced by bacteriologists to the study of the yeast-plant. He has found that if a single yeast-cell of one of the better varieties of Saccharomyces be cultivated with the precautions needed to exclude what is called "wild yeast " (germs present in the air, notably in the summer months), absolutely uniform results can be gotten in brewing. Beginning in 1883, he has developed the study, and it has FIG. 58. "3 MASH. POTATO MASH EN6LISH BEER. LA6CK BEE* now been accepted by most of the leading authorities on fermentation. He first decribed six species : Saccharomyces cerevisice I., Saccharomyces Pastorianus I., II., and III., Saccharomyces ellipsoideus I. and II., of which the second, fourth, and sixth cause bitterness and turbidity (so- called "diseases " in beer). He has since* increased the list of varie- ties of ferments studied to forty, including both top and bottom yeasts, ferments similar to yeast but not belonging to the genus Saccharomyces, and forms of mould-growh. He divides the representatives of each genus into two groups according as they secrete invertin or not. Fresh yeast resembles a dirty yellowish-gray sediment of unpleasant odor and acid reaction, made up of an immense number of vegetable cells. Three of the pure culture varieties of yeast-plant as obtained by Hansen are shown in the illustration Fig. 57, together wrth the special appearance of the ascospores of the same. Of these, the Saccharomyces * Journ. Soc. Chem. Tnd., 1889, p. 471. 208 FERMENTATION INDUSTRIES. cerevisice and Saccliaromyces Pastorianus are beer ferments, while the Saccharomyces ellipsoidcus is the wine ferment. For many purposes (bread-baking, use in distilleries, etc.), the ferment is prepared as com- pressed yeast in cakes, generally with the addition of potato starch. The special conditions of the alcoholic fermentation are: first, an aqueous solution of sugar of the strength of one part sugar to four to ten parts water; second, the presence of a yeast ferment. If this is not added already developed and active, or if the fermentation is to be spontaneous, that is, brought about by spores from the air, the condi- tions for the development of these spores must also be present. There must be protein compounds and phosphates of the alkalies and alkali earths. Thirdly, the temperature must remain within the limits 5 to 30 C., or, more generally, from 9 to 25 C. Above 30 C. the alcoholic fermentation readily passes into the "butyric and other decomposition. The effect of temperature upon the several different ferments is shown in the graphic illustration of Fig. 58, which represents also the influence of temperature upon the decomposition of starch by diastase. On the right side of the figure, the regularly-dotted line represents the yeast curve. A slight fermentation is already induced at a temperature very little over the melting point of ice. As the temperature rises its activity increases until the maximum is reached, at about 33 C. (92 F.), when it diminishes down to nothing again, and at 50 C. (122 F.) or thereabouts it is killed. The activity of the acetic ferment is repre- sented at the same time by the irregularly-dotted line, and that of the lactic ferment by the uniform black line. B. MALT LIQUORS AND THE INDUSTRIES CONNECTED THEREWITH. I. Raw Materials. 1. MALT. Malt is prepared by steeping barley or other grain in water, and allowing it to germinate in order to change the character of the albuminoids and develop the ferment diastase, which then begins to act upon the starch, the germination and change being stopped at a certain stage by heating in a kiln. The composition of the unmalted barley was given among other cereals on p. 186. The changes which it undergoes in composition by the process of malting will be seen by com- paring this with the two analyses of pale malt following, which are by 'Sullivan : No. I. No. II. Starch 44.15 45.13 Other carbohydrates (of which sixty to seventy per cent, consist of fermentable sugar), inulin and similar bodies soluble in cold water 21.23 19.39 Cellular matter 11.57 10.09 Fat 1.65 1.96 Albuminoids soluble in water 6.71 5.31 Albuminoids insoluble in water 6.38 8.49 Ash 2.60 1.92 Water 5.83 7.47 100.00 100.00 MALT LIQUORS. 209 'Sullivan states that malt contains no ready-formed dextrine, but that it does contain from sixteen to twenty per cent, of fermentable sugars, of which about one-half is probably maltose, and due to the transformation of starch in the malting process, while the remainder exists ready formed in the barley, and is not identical with the sugar produced in the malting. Besides the diastase, a second soluble ferment is formed during the malting process, the so-called peptase, which in the mash process changes the proteids of the malt into peptones and parapeptones, which give nutritive value to the beer. A high percentage of starch in the barley to be used for brewing is desirable in order that when malted it may yield a large amount of "extractive matter." According to Lintner and Aubry,* a good malt should yield at least seventy-one per cent, of extract reckoned on the weight of dry substance. This determination of the value of a sample of malt is one of the most necessary of analytical tests for the malster or brewer. (See p. 219.) Well-malted barley is always yellow or amber-colored, shading to brown. On breaking the grain, the interior should be of a pure white color and floury appearance, except when the drying has been inten- tionally carried so far as to partially caramelize the sugar. Malted wheat, corn, and rice are at times used as partial substitutes for the barley malt, as well as potato starch and starch-sugar. The use of patented maltose and maltose-dextrine preparations has already been referred to. (See p. 193.) 2. HOPS. Hops are the female unfructified blossoms (catkins) of the hop-plant (Humulus lupulus). Under the thin membranous scales of the strobile or catkin is an abundance of a yellowish resinous powder, consisting of minute sessile grains, to which the name lupulin has been given. The active principles of the hops, contained mainly, but not exclusively, in the lupulin, are: First, the ethereal oil, which is present to the amount of .3 per cent, in the air-dried hops. This is yellowish, of strong odor and of burning taste. It consists of a hydrocarbon, C 5 H 8 , and an oxygenized oil, C 10 H 18 O 2 , which by atmospheric oxidation becomes valerianic acid, C 5 H 10 2 , to which old hops owe their odor. Second, the lupulin also contains a resinous bitter principle, which is easily soluble in alcohol, but difficultly soluble in water, and extremely bitter. This is supposed to be an oxidation product of lupulinic acid, which can be gotten in white crystals, speedily becoming resinous. Both the acid and its oxidation products seem to be held dissolved in the ethereal oil. Hops also contain tannic acid of a variety allied to mori- tannic acid and turning iron salts green. Analyses of two well-known Bohemian varieties of hops are given. t The blossoms are produced in August, and the strobiles are fit for gathering from the beginning of September to the middle of October, according to the weather. The prompt drying of the fresh-picked hops * Jahresber. Chem. Tech., 1882, pp. 840 and 851. fKonig, Nahrungs- und Genussmittel, vol. ii, p. 409. 14 210 FERMENTATION INDUSTRIES. is necessary in order that they may be safely baled. This drying takes place by the aid of hot air in a so-called hop-kiln at a temperature of about 40 C., the hops being repeatedly turned with a light wooden shovel as they lie spread out upon a false or perforated floor. When 4 d Residue from Si a < alcohol solu- 03 g ~a ; OS 03 ble in water. a E 2 so '0-3 11 a ig 2 1 '3 d o frt.-. c s s5 ja o 3 3 M 0> Q h jS. 03 a 3 o H O .q M << co tao 3 B Put Milwaukee lager, bottled .... 1.10 1.57 0.51 0.057 0.196 0.065 4.18 4.28 1.0100 Milwaukee export beer, bottled . 1.06 2.63 0.40 0.057 0.309 0.056 5.40 4.42 1.0140 Milwaukee "Bohemian" beer . . 1.82 3.04 0.406 0.071 0.224 0.057 5.88 4.16 1.0183 Milwaukee " Bavarian" beer . . 1.75 2.87 0.556 0.074 0.346 0.077 6.26 5.06 1.0187 St. Louis export beer 214 2.54 0463 0067 0312 0.074 615 440 10178 St. Louis pale lager, bottled . . . 2.17 2.75 0.463 0.067 0.312 0.064 4.64 4.28 1.0178 St. Louis " Erlanger" beer, bottled 2.51 2.58 0.675 .0.046 0.183 0.093 6.82 4.68 1.0203 Philadelphia lager, bottled . . 1.46 2.30 0.538 0.086 0.241 0.078 5.22 4.29 1.0147 Philadelphia " Budweiss," bottled 2.14 2.57 0.531 0.046 0.265 0.095 5.94 4.52 1.0181 Philadelphia ale, bottled .... O.f.9 0.90 0.531 0.232 0.401 0.085 3.46 6.24 1.0059 Reading ale, bottled 0.93 1.99 0.731 0.382 0.472 0.077 5.55 6.92 1 0125 Reading porter, bottled 2.67 2.88 0.763 0.166 0.412 0.100 8.19 4.89 1.0269 IV. Analytical Tests and Methods. 1. FOR MALT. The brewing value of a sample of malt is dependent upon three factors, namely, the proportion of soluble or extractive matter it will yield to water; the character of this extractive matter; and the diastatic activity. The extractive matter in malt is usually determined by a miniature mashing process. This is carried out, according to the accepted method of the Institute of Brewing in England, as follows :f The malt is first crushed uniformly fine ; fifty grammes are then weighed out as rapidly as possible (on account of its hygroscopic character), and placed in a weighed beaker with 360 cubic centimetres of distilled water previously heated to 154 to 155 F. The beaker is covered with a watch-crystal and placed in a water-bath so that its contents are kept at a temperature of 150 F. for fifty- five minutes. The mash is stirred at in- tervals of ten minutes during this time. The temperature is then raised to 150 F. in five minutes, and the whole mash washed into a flask grad- uated to four hundred and fifteen cubic centimetres, cooled to 60 F., made up to the mark at the same temperature, well shaken, and filtered through a large ribbed paper. The specific gravity of the filtrate is then determined at once at 60 F. compared with water at that temperature. For most purposes, it is sufficiently accurate to make up the unfiltered wort to four hundred and fifteen cubic centimetres, filter a portion through a dry filter and take the density. The draff is here assumed to measure fifteen cubic centimetres,, and the tedious washing is dispensed with. The excess of density over that of water (taken at 1000) multiplied by 2.078 will give the percentage of dry extract yielded by the malt. This method is based on the fact that each gramme of malt extract per hun- dred cubic centimetres of infusion has been shown by experiment to raise the density of the liquor by 3.85 degrees (water = 1000). The * United States Department of Agriculture, Bulletin No. 13, Part iii, p. 282. t Allen, 4th ed., vol. i, p. 134. 220 FERMENTATION INDUSTRIES. figure 2.078 is then the fraction -^-^- Instead of ascertaining the o.oO gravity of the infusion, the proportion of solid matter may be deter- mined by evaporating a known measure of the wort to dryness in a flat- bottomed dish so that the residue may form a thin film. This is dried at 105 C. and weighed. Other methods are those of Metz,* with the use of Schultze 's tables, and of Metz as improved by Weiss. The determination of diastatic power in a sample of malt is also of importance in valuing it, even if the full diastatic power is not likely to be called out in the brewing process, where it is usually in excess of the need for the production of a beer-wort. The process of Lintner adopted by the Institute of Brewing-j- determines by the aid of Fehling's solution the amount of maltose produced by the action of a cold infusion of the malt upon a measured starch solution. This supposes that the action of diastase upon starch in the cold is always uniform and produces the same relative amount of maltose, which is now regarded as a matter of some uncertainty. The method proposed by Dunstan (Allen, 2d ed., vol. ii, p. 278) simply notes the end of the transformation of the starch by the absence of color with iodine solution. For it five grammes of very finely-powdered malt are digested and agitated for one hour with fifty cubic centimetres of cold water. The liquid is then strained off and the residue again digested for an hour with fifty cubic centimetres of water, and the liquids are then mixed and made up to one hundred cubic centimetres. Five-tenths gramme of starch (dried at 100 C. before weighing) is gelatinized by boiling with water, and the cold liquid diluted to one hundred cubic centimetres. The solution of malt extract is then added to twenty cubic centimetres of this mucilage by instalments of one cubic centimetre, at intervals of half an hour, until it ceases to give any color, when a small quantity is tested with a dilute solution of iodine. If less than one cubic centimetre of the solution produces this effect, more of the mucilage should be added and the operation continued. To determine the soluble proteids of malt assumed to represent the diastase C. Graham proposes to use the Wanklyn albuminoid-ammonia process. 2. FOR BEER-WORTS. The determination of the specific gravity of the wort is of importance, as from this may be calculated the total solid matter in the wort. If from the specific gravity of the wort we take 1000, and divide the difference by 4,| we get the number of grammes of solid extract contained in one hundred cubic centimetres of the wort. For the purpose of the brewer special forms of hydrometers have been constructed, the readings of which are immediately available. Thus, Bates 's saccharometer gives readings of pounds per barrel (of thirty- six gallons), that is, excess of weight in pounds of a barrel of wort over the same bulk of water. These readings can then be converted into real * Stohmann und Kerl, Technische Chemie, 4th ed., pp. 1345-1351. j- Allen, Com. Org. Analysis, 4th ed., i, p. 136. J See Allen, Com. Org. Anal., 4th ed., vol. i, p. 140. MALT LIQUORS. 221 specific gravity figures by a simple proportion, using the weight of a barrel of pure water, of this wort with the excess of weight shown by the saccharometer reading and the specific gravity of pure water as terms. The Bates saccharometer readings can be converted into those of Balling 260 Bates or Brix by the following formula: Balling OPA , _. ^ . The ob(J -\- JhJates method of ascertaining the original gravity of beer-worts which have undergone fermentation is described later. (See following page.) In brewing, the relative proportion of maltose and dextrine in the wort is of great importance and is liable to considerable variation, being dependent on the temperature at which the mashing was conducted, the length of time occupied in the process, and the diastatic activity of the malt employed. The composition of the wort largely influences the sub- sequent fermentation, as a wort containing little dextrine will produce a beer of low density which will clarify readily, but be "thin" and apparently much weaker than beer of the same original gravity but higher final attenuation. C. Graham estimates the maltose and dextrine in beer-worts from the cupric oxide reducing power of the solution before and after inversion. (For details of his procedure, see Allen, vol. ii, p. 274.) West Knight (Analyst, vii, p. 211) has described a very simple and rapid method of approximately determining the dex- trine in beer-worts. Ten cubic centimetres of the wort is treated in a small weighed beaker with fifty cubic centimetres of methylated spirit of .830 specific gravity. This causes the precipitation of the greater part of the dextrine, which after a few hours collects on the bottom of the beaker as a gummy mass, from which the alcoholic liquid can be poured off. The deposit is rinsed with a little more spirit, and the beaker dried in the water-oven and weighed. To the weight obtained an addition of .045 gramme is made as a correction for the dextrine retained in solu- tion by the spirituous liquid. 3. FOR BEER. The specific gravity of the beer is a determination that is necessary as a basis of calculation for the other determinations as to its composition. It should be made after freeing the beer from carbon dioxide as fully as possible. It can be made with a specific gravity flask, but is most readily and accurately carried out with a Westphal specific gravity balance (see Fig. 30), which for this purpose is provided with a fourth rider giving the fourth place of decimals. The amount of extract is frequently determined by taking a definite volume of beer of which the specific gravity has been determined, evap- orating it to one-third its bulk, and then adding water sufficient to restore it to original bulk. The specific gravity of this liquid is then determined as just described. The percentage of extract can now be found by a reference to Schultze's tables for determining the amount of extract by specific gravity, or more simply by O 'Sullivan's method, in which the excess of this specific gravity over 1000 divided by 4 gives the number of grammes of dry extract per one hundred cubic centimetres of the beer. C. Graham considers it decidedly more accurate to evaporate five 222 FERMENTATION INDUSTRIES. cubic centimetres of the beer on a flat watch-crystal in an air-bath at a temperature of from 70 to 75 C. The complete drying of the film requires about twenty-six hours. The percentage of alcohol is best determined by distillation. For this purpose one hundred cubic centimetres of the beer are taken, a few drops of caustic soda added to neutralize the free acid, and the liquid brought up to about one hundred and fifty cubic centimetres. It is then distilled with the aid of a Liebig condenser into a graduated flask until nearly one hundred cubic centimetres have come over. The distillate is now thoroughly mixed, cooled to 15 C., and then brought exactly to the 100-cubic-centimetre mark and again mixed. Its specific gravity is now taken, and from a set of alcohol tables (see Hehner's tables, Appen- dix, p. 579) the percentage of alcohol by weight of the distillate found. Then as the specific gravity of the original sample is to the specific gravity of the distillate so is the weight per cent, in the distillate to the weight per cent, in the original sample. Indirectly the alcohol percentage can be determined, although not with the same accuracy, by the aid of the data gotten in the determination of extract already narrated. For if the specific gravity of the original sample be divided by the specific gravity of the de-alcoholized solution we get the specific gravity of the alcohol driven off, from which figure the percentage by weight of alcohol can be gotten in the tables. When both the alcohol and the extract percentage of a beer are known, by Balling's method the percentage of extract in the original wort can be calculated, and then with the aid of this and the percentage of extract in the beer the "attenuation " or diminution in the gravity of the original wort due to fermentation and alcohol production can be determined. As the weight of alcohol produced is approximately fifty per cent, of the saccharine matter destroyed by the fermentation, we have the formula 2a -(- c = w, in which a is the alcohol percentage, e the extract percentage of the beer, and w the per- centage strength of the original wort. Then using this figure just obtained w : 100 : : 2a : x, in which x will represent the degree of attenua- tion. More accurately, the actual degree of fermentation (Wirklicher Vergdhrungsgrad) is gotten by the proportion p:p n::WO:v', in which p is the extract in the original wort, n the extract in the beer, and v' the actual fermentation degree; (p n) is termed the "real atten- uation." It is obvious from the two proportions given that in practice 2a is often taken as equivalent to (p n). This is not strictly correct. It is found in the fermentation of beer-worts that 100 parts of extract yield 48.391 parts of alcohol, so that what is termed an "alcohol factor " is necessary to convert one into the other. In England a different pro- cedure is followed. A definite volume of beer is taken and one-half dis- tilled off. This distillate is brought up with water at 60 F. to the original volume and its specific gravity taken. The difference between 1000 and the observed gravity is called the "spirit indication " of the beer. With this can be found, in a table prepared for the Inland Reve- nue Office, the ' ' degrees of gravity lost ' ' by the attenuation of the wort. THE MANUFACTURE OF WINE. 223 Then the liquid left in the retort after the distillation is diluted with water and brought up to the original volume, when its specific gravity is carefully taken. This is called the "extract gravity," and this added to the degrees of gravity lost gives the ' ' original gravity of the wort. ' ' The acidity of beer is partly due to lactic and succinic acids, which are fixed acids, and partly to acetic acid, which is volatiie. The fixed acids are usually determined jointly in terms of lactic acid by dissolving the dry extract of the beer in water and titrating the solution with deci- normal alkali solution. Baryta-water is preferred by many chemists, as the sulphate of baryta which forms carries down much of the coloring and allows the end reaction to be better seen. The volatile acid of beer is chiefly acetic acid, which is usually determined by subtracting the measure of alkali required to neutralize the extract from that required by the original beer (after getting rid of the carbonic acid by shaking thoroughly). The chief adulterations of beer are from the use of salicylic acid as a preservative and the addition of various bitter principles as substitutes for hop-bitters. The salicylic acid may be searched for by concentrating the beer to one-half at a gentle heat and shaking the cooled liquid with ether, or a mixture of ethylic ether and petroleum-ether. The ethereal layer is then separated, evaporated to dryness, and the residue dissolved in warm water. On adding ferric chloride, a violet coloration is pro- duced if salicylic acid be present. Other chemists recommend dialyzing, when the salicylic acid will readily dialyze into the pure water and can then be tested. For the detection of the bitter principles used as substi- tutes for hops elaborate schemes have been proposed by Enders (given in Allen, 4th ed., vol. i, p. 162) and Dragendorff (Gerichtliche-Chemische Ausmittelung der Gifte). C. THE MANUFACTURE OF WINE. I. Raw Materials. 1. THE GRAPE. While the name wine is often used to include the products of the spontaneous alcoholic fermentation of any sweet fruit or berry, it is usually limited to the product of the fermentation of the grape, which alone is cultivated on an extensive scale throughout the civilized world purely for the manufacture of wine. The cultivation of the grape-vine and the production of wine there- from dates back to the earliest historic times. Beginning in the East and the Mediterranean lands, it extended northward and westward until at present France is the chief wine-producing country, while Germany, Austria, Spain, and Portugal have all established flourishing wine in- dustries indigenous to their soil. In this country, the wine industry is mainly established in the States of Ohio, New York, Virginia, and Cali- fornia. The varieties of the vine (estimated to number almost two thousand) hitherto cultivated in Europe are all said to be derived from the single 224 FERMENTATION INDUSTRIES. species, Vitis vinifera. In this country four or five wild species have yielded varieties which when cultivated have proven adapted to wine production. Thus Vitis riparia, or " frost-grape, " has yielded as culti- vated varieties the Taylor and the Clinton grapes ; the Vitis cestivalis, or "summer-grape," has yielded as varieties Norton's Virginia, Cythiana, and Herbemont; the Vitis Labrusca, or "Northern fox-grape," has yielded as varieties the Catawba, Isabella, Concord, and Delaware grapes ; the Vitis vulpina or rotundifolia, or "Southern muscadine," has yielded as varieties the black, red, and white Scuppernong. Numerous varieties of the European vine, the Vitis vinifera, have also been cultivated suc- cessfully in California, among which may be mentioned the Mission, Riesling, Trammer, Rulander, Gutedel, and Zinfandel. The grapes owe their wine-producing value in the first place to the grape (or invert) sugar which they 'contain, and in the second place to the free acids, which in the later ripening of the wine are to develop the fragrant ethers, and to the albuminoids, which exert a great influence on the fermentation. The composition of the grape varies of course in different localities and even from year to year in the same locality, but its mean composition is thus stated by Konig: Grape-sugar, 14.36 per cent.; free acid (tartaric), .79 per cent.; nitrogenous material, .59 per cent. ; non-nitrogenous extract, 1.96 per cent. ; skins and kernel, 3.60 per cent. ; ash, .50 per cent. ; and water, 78.17 per cent. The grapes are taken for wine-making only when they are fully ripe, and in many localities it is even customary to wait until the grape shows a slight appearance of over-ripeness or evidence of wilting, so that the maximum of sweetness may be attained. In some cases the grapes are plucked from the stems, either by hand or by the aid of three-pronged forks, while in other cases the stems are left when they are crushed in order that the tannin so obtained may aid in the clearing of the ferment- ing juice. This juice is known as "must," and the pressed pulp and skins as the "marc." 2. THE MUST. This may properly be considered as still a raw mate- rial, as its expression from the grapes is purely a mechanical process. This is now generally effected by. power-presses of various forms, although at one time largely effected by trampling the grapes under feet. (This method is still followed in the Oporto and the Maderia wine districts.) The first portion of must that runs from the presses is often collected separately, as it is the juice of the ripest and sweetest grapes; that which comes later is richer in acid and in tannin, as it comes partly from unripe grapes and partly from the stems and skins. The amount of must that is obtained usually ranges from sixty to seventy parts in the one hundred of grapes. The composition of this must is of the greatest importance, as upon it depends the character of the wine that will be produced, whether it shall ferment normally throughout and develop ^he perfect flavor and aroma desired, or whether it shall be thin and sour and show tendencies towards alteration or "disease." The proportions of its constituents, especially the grape-sugar, may vary within quite wide limits from year THE MANUFACTURE OF WINE. 225 to year, and in grapes grown in the same year under different conditions of soil, exposure, etc. Thus, two different musts of 1868 are given and two musts of the same variety of grape in two succeeding years, the first of which was a favorable year and the second an unfavorable year. The analyses are all by Neubauer. Sugar. Free acid. Albumi- noids. Ash. Non-nitro- genous extract. Water. Neroberger Kiesling, 1868 Steinbergcr Auslese, 1868 18.06 24.24 0.42 0.43 0.22 18 0.47 0.45 4.11 3.92 76.72 70.78 Hattenheimer, 1868, (good year) . . . Hattenheimer, 1869, (bad year) . . . 23.56 16.67 0.46 0.79 0.19 0.33 0.44 0.24 5.43 5.17 69.92 76.80 The percentage of grape-sugar in the must sinks at times to twelve per cent., and may rise as high as twenty-six to thirty per cent. The ratio between acid and sugar, according to Fresenius, ranges from 1 : 29 for good varieties of grapes in good years to 1 : 16 for inferior varieties in medium years. If the ratio falls as low as 1 : 10, the grapes are un- ripe and taste acid. This ratio of acid to sugar is now generally taken as the criterion for the quality of the must in any year or special locality. In bad seasons the free acid is more generally malic than tartaric, which is the normal constituent. n. Processes of Manufacture. 1. FERMENTATION. The fermentation of the must is a spontaneous one following exposure to the air, and due to the spores which drop upon the surface of the must as exposed in the fermenting-tubs. It may be a surface fermentation, taking place at temperatures of 15 to 20 C., as is the practice in Italy, Spain, and the south of France, or a bottom fermentation, taking place in cooler cellars at 5 to 12 C., as is the practice in Germany and with the finer French wines. The first method produces a fiery wine rich in alcohol, but without bouquet or aroma ; the second method, lighter wines with delicate bouquet, due to the formation of wine esters. In either case the fermentation can be divided, as was the case with malt liquors, into three stages : the first, or main fermenta- tion, which, according as the surface or the bottom fermentation method is followed, lasts from three to eight days, or from two to four weeks; the second, or still fermentation, which lasts until the following spring; and the third, the storage fermentation, which lasts for several years, until by the gradual development of its bouquet it becomes perfectly ripe. In the case of red wines, the main fermentation is allowed to take place with the marc added to the must, so that as the alcohol is developed it may dissolve out the coloring matter (oenocyanin) of the skins as well as some of the tannin, which latter is of benefit in effecting a more rapid separation of the protein materials. To prevent this pulpy mass from rising to the surface and starting a souring of the wine, perforated 15 226 FERMENTATION INDUSTRIES. covers are often used in this case to hold it down. In the main fermen- tation, the casks are usually freely exposed to the air. Many wine ex- perts recommend in addition the aeration of the fermenting must or a whipping of the liquid, so as to induce a fuller and more vigorous fer- mentation. On the other hand, other authorities consider that this exces- sive exposure to air injures the quality and aroma of the wine, and recommend only a partial exposure to the air after the main fermenta- tion has begun. As the main fermentation comes to an end, the yeast (with more or less tartar, gummy matter, and albuminoids) settles to the bottom, the liquid clears and is ready to be racked off into casks, under the name of young wine (Jungwein), to undergo the after- or still- fermentation. If the racking off does not take place promptly with the ending of the more energetic main fermentation, the young wine, of which a considerable surface is exposed to the air, is very apt to start into the acetic fermentation. The casks into which it is now put are kept quite full in order to prevent this undesirable change, slight addi- tions being made every few days if necessary, and the bungs are set loosely in place. During this after-fermentation there deposits upon the inner walls of the cask argols, or impure acid potassium tartrate (Weinstein), with some yeast and albuminoid matter. This fermenta- tion lasts from three to six months, and then the wine is racked off again into smaller casks to undergo the final ripening, in which the bouquet of the wine is especially developed by the formation of esters, while it clears more thoroughly from the remaining particles of yeast, etc. The duration of this ripening may be two, four, or with rich wines even eight years or more, when it is considered "bottle-ripe." During this ripening fungous vegetation is very apt to start, and must be arrested in order to prevent the spoiling of the wine. 2. DISEASES OF WINES AND METHODS OF TREATING AND IMPROVING THEM. The souring of wine, due to the beginning of the acetic fermen- tation, is one of the commonest of these so-called diseases, especially with light wines, poor in alcohol and tannic acid, and hence commoner with white than w r ith red wines. It arises from too free an exposure to the air and too high a temperature during fermentation. If just begun it can be cured by the addition of a small quantity of potashes, which form potassium acetate, or by starting the alcoholic fermentation afresh by adding a new quantity of sugar. If the souring is very pronounced it cannot be cured, and the wine is made into wine-vinegar. The gumminess or ropiness of wine frequently arises from a prema- ture filling into bottles, and is due to the beginning of the mucous fer- mentation of sugar. It takes place in wines poor in tannic acid, and hence more readily with white than with red wines. It can be cured by addition of tannic acid, treatment with sulphurous oxide, or starting a new fermentation by addition of grape-sugar. The development of a stale or flat taste in tne wine is due, according to Pasteur, to the growth of a thread-like ferment. The wine becomes cloudy, diminishes in alcohol and increases in acid percentage, it darkens in color, and often has a disagreeable odor. The wine is racked off and THE MANUFACTURE OF WINE. 227 put into a cask which has been filled with sulphurous oxide fumes, which destroy the ferment. The turning bitter of red wines is due also, according to Pasteur, to a plant-growth, according to others to the formation of a bitter aldehyde resin. Neubauer has found that the tannic acid and the coloring matter both decrease in percentage in this disease. It can be cured completely by heating the wine to 60 to 64 C., or by starting the fermentation anew by adding fresh quantities of grape-sugar. The mouldiness of wine is due to the development of a fungoid growth in the form of a white film on the surface of wines poor in alco- hol, and always precedes the souring of the wine. It is to be obviated by treatment with sulphur dioxide or more effectual protection of the young wine from the air. Of the general lines of treatment adopted to prevent the development of these various diseases, we notice first the clarifying with isinglass (finings) or other form of gelatine. This is particularly applied to the sweet and heavy white wines, which often remain turbid and have to be cleared by the coagulating of the albuminoid which is added. With red wines which contain tannie acid, casein or blood albumen is used instead of gelatine. Fine clays are also used, especially in Spain, for this clarifying. The most important process, however, which is applied for the pres- ervation and protection of wine against diseases is that known as "Pas- teurizing." It consists in heating the wine either in casks or in bottles to a temperature of 60 C., and then preserving it without exposure to the air. This temperature is found to be sufficient to kill most of the germs which bring about the diseases before mentioned. A form of cask much used for this "Pasteurizing " process is shown in Fig. 60. The use of salicylic acid for preserving wines has been extensively tried, but its use here is open to the same objection as before stated in speaking of beer, and it is now forbidden in most countries. Of the methods of "improving " wines, as it is termed, that known as "plastering " is probably most largely practised, its use for red wines extending to Spain, Portugal, Italy, and the South of France. It consists in adding plaster of Paris (burnt gypsum) either to the un- pressed grapes or to the must. The plaster takes up water and so in- creases the alcoholic strength of the fermenting must, which in turn allows of a greater extraction of the coloring matter from the skin. At the same time the wine is given better keeping qualities as well as deeper color. However, the sulphate of lime changes the soluble potash salts of the wine into insoluble tartrate of lime and soluble acid sulphate of potash, which latter remains dissolved along with some of the gypsum, and undoubtedly has an injurious effect upon the consumers of the wine. The process has hence had to be controlled by law, and in France the sale of wine containing over .2 per cent, of potassium sulphate is pro- hibited. The ash of pure wine does not exceed .3 per cent., but in the samples of sherry usually met with it reaches .5 per cent., and is almost entirely composed of sulphates. 228 FERMENTATION INDUSTRIES. Hugonneng recommends adding diealcium phosphate instead of gyp- sum. This process, called ' ' phosphotage, " is said to have all the good effects obtainable from plastering without increasing, as the latter does, the percentage of sulphuric acid and decreasing that of phosphoric acid. Chaptalization consists in neutralizing the excess of acidity in the must by the addition of marble-dust, and increasing the saccharine con- tent by the addition of a certain quantity of cane-sugar, which the vint- ners sometimes replace by starch-sugar. In this process the quantity of the wine is not increased, but it becomes richer in alcohol, poorer in acid, and the bouquet is not injured. It is much used in Burgundy. Gallization, as proposed by Dr. Gall, has for its object the bringing of the must of a bad year up to the standard found to belong to a good FIG. 60. must (he takes as standard 24 per cent, of sugar, .6 per cent, of acid, and 75.4 per cent, of water) by correcting the ratio of acid to sugar. This he does by adding sugar and water in sufficient quantity, and tables have been prepared to indicate the quantity needed according to the acid ratio shown by analysis. In both these processes, starch-sugar ought never to be used as a cheaper substitute for cane-sugar, as com- mercial starch-sugar will always introduce dextrine, an entirely foreign constituent, into the must. Petiotization is a process which takes its name from Petiot, a pro- prietor in Burgundy, and is carried out as follows: The marc from \vhich the juice has been separated as usual by pressure is mixed with a solution of sugar and water and the mixture again fermented, the second steeping containing, like the first, notable quantities of bitartrate of pot- ash, tannie acid, etc., which are far from being exhausted by one extrac- tion. The process may be repeated several times, the different infusions THE MANUFACTURE OF WINE. 229 being mixed. This process is very largely used in France, and is said to produce wines rich in alcohol, of as good bouquet as the original wine, and of good keeping qualities. It is not allowed to be sold there, how- ever, as natural wine. Scheelization consists in the addition of glycerine to the finished wine so as to improve the sweet taste without injuring its keeping qualities. The limits of the addition of glycerine lie between one and three litres to the hectolitre of wine. If the wine has not fully fermented, however, and if yeast-cells are present, the glycerine may yield propionic acid by decomposition. 3. MANUFACTURE OF EFFERVESCING WINES (Champagnes}. For the manufacture of champagne the blue sweet grapes are preferred. They must be pressed promptly after picking in order that the least possible amount of color be taken up by the must. The first pressing only is used for the champagne, and a second pressing of the marc yields a reddish wine, which is differently utilized. The must is first put into vats that impurities may settle and then filled into casks for the main fer- mentation, which is retarded as much as possible by being carried out in cool cellars. Cognac is also added to the amount of about one per cent., so as to increase the alcohol percentage and thus moderate the fermen- tation. After the main fermentation is finished the wine is racked off into other casks and left stopped until winter (end of December). It is then fined (or cleared) with isinglass and transferred to other casks, and this operation is repeated in a month's time. Towards the begin- ning of April it is ready to be transferred to bottles. The wines of different growths are now mixed and the amount of sugar in the wine determined, when a calculated additional quantity is added in the form of "liqueur" (a mixture of alcohol and pure cane-sugar). The bottles which are to receive the champagne must be specially chosen and be sufficiently strong to stand the pressure, which rises later to four to five atmospheres. They must also have sloping sides, so that the sediment may not adhere to ;the sides in the after-process. The wine after being corked is thoroughly secured by an iron fastening called an agrafe, and the bottles are arranged in piles in a horizontal position in the large champagne-vaults, where they remain throughout the summer months. Previous to the wine being prepared for shipment, the bottles are placed in a slanting position, neck downward, in frames, and the incline is gradually increased day by day until the bottle is almost perpendicular. With the sediment thus on the cork it goes into the hands of a workman called a "disgorger," who, holding the bottle still neck downward, pro- ceeds to liberate the cork by slipping off the agrafe, and when the cork is three-fourth parts out he quickly inverts the bottle. The cork is thus forcibly ejected with a loud report by the froth, which carries with it the greater part of the yeast and other solid matters, what remains of these being got rid of by the workman working his finger round the neck of the bottle, whereby they are detached and forced out by the still rising froth. The wine is now dosed again with liqueur, the bottles filled up, wired, and the neck wrapped with foil ready for shipment. 4. MANUFACTURE OF FORTIFIED, MIXED, AND IMITATION WINES. All 230 FERMENTATION INDUSTRIES. the sweet heavy wines, like sherry, malaga, and port, are characterized by a high alcohol percentage, ranging from sixteen to twenty or twenty- two. This they cannot acquire through fermentation alone, as twelve or thirteen per cent, seems to be the limit of alcohol developed in a wine by direct fermentation. They have the additional alcohol added to them directly in order to give them keeping qualities. With some sweet wines the alcohol is added to the must before the fermentation in order that the fermentation shall be arrested, while a certain amount of sugar remains in the wine unchanged. The quality of wines is often improved by blending. Light wines with too little alcohol are mixed with stronger wines with the formation of an excellent product with better keeping qualities, which can then be transported to long distances without in- jury. These mixtures can best be made when the wines are new, in order that after mixing they may undergo an insensible fermentation and take a character distinctive of the new product. The practice of adding flavoring substances totally foreign to the constituents of the must to new and inferior wines in order that they may take the flavor and appearance of older and more valuable wine has also become very wide-spread. Such practices are of course illegal in all countries where laws against adulteration are enforced. Thus, elder flowers, orris-root, iris, cloves, oil of bitter almonds, and numerous perfumes, such as oil of orange flowers, of neroli, of petit-grain, and of violet, are used, as well as coloring infusions like raspberries and walnuts. The heavy wines are the ones most generally imitated. Port is fre- quently flavored with a mixture of elderberry juice, grape juice, brown sugar, and crude brandy. Sherry often consists of the cheaper Cape wine mixed with honey, bitter almonds, and brandy. In Spain and Southern France a wine prepared from the vine known as the Teinturier and possessing an intense bluish-red color is extensively used for coloring of other wines. In recent years, because of the deficiency in the wine crop of France due to the ravages of the Phylloxera, the production of wine from dried raisins or prunes has enormously increased. This product, known as ' ' vin de raisin sec, ' ' is said to be a very close imitation of natural French wines. Spon * gives the following as the components of such a raisin wine: White sugar 5 kilos. Raisins 5 kilos. Common salt 125 grammes. Tartaric acid 200 grammes. Common brandy 12 litres. River water 95 litres. Gall-nuts (bruised) 20 grammes. Brewer's yeast (in paste) .200 grammes. To make this wine of a red color it is necessary only to add to the above ingredients two hundred and fifty to three hundred grammes of dry picked hollyhocks, taking care to keep them at the bottom of the cask. N The reports of the United States consular agents show that the man- ufacture of this raisin wine has become an industry of large propor- tions in France at the present time. A significant additional indication * Spon's Encyclopedia of Industrial Arts, vol. ii, p. 444. THE MANUFACTURE OF WINE. 231 of the development of this artificial wine industry and of the similar one of petiotizing in France is found in the statement of the amounts of cane-sugar used by French wine manufacturers in recent years. In 1885 there was used in France for the manufacture of grape wines 7,933,887 kilos, of cane-sugar; in 1886, 27,856,592 kilos.; for the man- ufacture of fruit wines in 1885, 24,142 kilos, of sugar; in 1886, for the same purpose, 145,555 kilos. Most of this fruit wine forms the basis of factitious champagne, m. Products. The normal constituents of a natural wine agree of course with those contained in the must, except in so far as new compounds have been developed by the fermentation process and previously existing ones have been decomposed or made to separate out. We may divide the constituents of wine into two classes, volatile and fixed. The volatile matters are as follows : Water (eighty to ninety per cent.) ; alcohol (five to fifteen per cent.) ; glycerine (two to eight per cent.) ; volatile acids, acetic, cenanthic, etc., constituting one-fourth to one-third of the total acidity; aldehyde, compound ethers, together with other fragrant indefinite constituents, which give the wine its flavor and bouquet. The fixed matters are glucose, or grape-sugar, in small quan- tities in most wines ; bitartrate of potash, tartaric, malic, and phosphoric acid, partly free and partly combined with various bases, of which com- pounds phosphate of lime is the most abundant, constituting from twenty to sixty per cent, of the weight of the ash, the remainder being chiefly carbonate of potash, resulting from the calcination of the bitar- trate, with a little sulphate and traces of chlorides; coloring matters, pectin and analogous gummy matters; tannin, one to two per cent, in red wines and traces only existing in white wines. No very simple scheme of classification is possible, as the methods and products of most countries are not fixed by rule, but vary widely according to the season and market. Still, we may distinguish between the red and white, and the sweet and the dry, wines; between the light and delicately-flavored German and French wines and the more fiery but coarser Italian and Swiss wines; between natural wines and those fortified by addition of alcohol, as port, sherry, and madeira; between still wines and effervescing or champagne wines. Most of these terms have already found their explanation in the description of the processes of manufacture. We may add that a sweet wine is one in which a notable portion of the original grape-sugar of the must has escaped fermentation, or to which an addition of sugar has been made subsequent to the main fermentation. A dry wine, on the contrary, is one in which the sugar, whether originally present or sub- sequently added, has almost all undergone change in the processes of fer- mentation. Champagnes are wines in which a supplementary fermen- tation is purposely developed subsequent to the bottling, whereby quantities of carbon dioxide gas are developed and held dissolved under pressure. On opening the bottles and thus relieving the pressure a brisk effervescence follows, due to the escape of the absorbed gas. Champagne- 232 FERMENTATION INDUSTRIES. makers distinguish three grades of effervescence. In mousseux the pressure in the bottles amounts to from four to four and a half atmos- pheres; in grand mousseux it reaches five atmospheres; and less than four atmospheres' pressure constitutes cremant (from la creme, "cream "), a wine which throws up a froth, but does not give off car- bonic acid violently. Some manufacturers also distinguish a grade demi-mousseux. Of natural and unfortified foreign wines the following analyses from Eisner * refer to German wines exclusively : o . o .H > bii^. f fit If If 3 * * o "5 ti O s s t-> a . li P >"3 v o> 5 02 c CH A * A Rhine wines, Rudesheimer . . . 0.9960 9.30 1.97 0.50 0.20 0.020 " Rauenthaler .... 0.9960 9.25 210 0.54 0.19 0.023 " " Johannisberger . . 0.9958 8.60 2.20 0.52 0.19 0.023 " " Hochheimer .... 0.9935 8.00 1.50 0.72 0.16 " " Niersteiner .... 0.9956 7.54 1.75 0.62 0.18 6.012 Moselle wines, Brauneberger . . . 2.60 0.18 0.041 " " Pisporter 2.40 0.15 0.038 " " Zeltinger 2.40 0.16 0.039 Hessian wines> Bodenheimer . . . 0.9930 7.54 1.25 6.63 " " Laubenheimer . . 0.9934 6.83 1.00 0.60 O.W " " Liebfrauenmilch . 0.9940 8.00 1.96 0.62 0.20 '. '. '. Palatinate wines, Deidesheimer . 0.9968 9.60 2.12 0.50 0.18 . " " Oppenheimer . 0.9935 8.87 1.50 0.60 0.16 " " Wachenheimer . 0.9954 8.65 1.72 0.65 0.17 Franconian wines, white .... 0.9943 6.65 1.20 0.60 0.015 " " red 0.9932 8.00 1.50 0.47 6.20 The following analyses of French wines are from the official report of the Laboratoire Municipal at Paris for 1883 : f GRAMMES PER LITRE. * a a fcc""" 1 1 2 || 1? g| ij m '3 oj o 'So .s a M _o t<3 H > ^ | "SSU 3 'oW * H H ^ H M 02 ^ Bordeaux wines, St Estephe 1878 11.1 10.3 22.4 19.0 28.3 23.7 2.20 2.05 1.31 1.42 1.50 0.9 0.49 0.76 2.96 3.% " Medoc, 1880 " Latour, 1878 . . .... 95 170 228 2.14 207 1 1 050 4.06 " Chateau Margaux, 1878 10.2 23.6 1.5 0.48 " Larose, 1877 11.2 23.0 30.1 2.34 2.44 1.3 0.63 (white,) Sauterne, 1880 10.4 16.0 3.6 0.53 Burgundy wines, Chambertin, 1882 11.5 23.3 29.5 1.77 3.57 1.4 0.55 . . (white,) Chablis, 1878 11.0 16.7 . . 0.6 0.38 . . Lower Burgundy, average of 7 analyses Upper Burgundy, average of 25 analyses 7.8 9.1 20.2 20.7 ' 1.2 1.1 0.37 0.48 'Praxis des Nahrungsmittels Chemiker, 1880, p. 103. fDeuxiine Rapport du Laboratoire Municipal, Paris, 1884. THE MANUFACTURE OF WINE. 233 Of sweet and fortified or treated wines the following analyses are given by Konig : * OS '3g g& CO Alcohol by weight. Extract. a CO Tartaric acid. Glycerine. Albuminoids. JS < Phosphoric acid. Sulphuric acid. Tokay, 1868 1.0879 9.80 26.36 22.11 0.509 0.212 0.427 0.343 0.050 0.061 Tokay, Ausbruch, 1866 10588 10.29 18.34 14.99 0.517 0.234 0.389 0.300 0.074 0.022 Ruster Ausbruch 1872 10849 896 23.64 21.74 0.512 0.162 0.231 0.409 0.057 0.035 Malaga, 1872 10691 1323 21.23 16.57 0.416 0.248 0.217 0.239 0.042 0.026 Muscat wine, 1872 1.0574 10.02 16.91 15.52 0.555 0.298 0.151 0312 0.036 0.073 Port wine (white), 1860 1.0126 16.28 8.83 4.88 0.538 0.168 0.094 0.208 0.035 0.039 Port wine (red) 1865 1 0125 17.93 8.83 6.42 0.451 0145 0.200 0.236 0.032 0.019 Marsala (Ingham) 09966 16.73 4.94 3.48 0.396 0.298 0.150 0.270 0.024 0087 Marsala (Woodhouse) ....... 10111 1552 545 378 0470 0457 0.231 0.418 0.024 0.155 Madeira, 1868 1.0018 15.34 5.33 3.39 0.489 0.291 0.144 0.376 0.082 0.081 Sherry, 1870 0.9952 18.66 3.78 1.88 0.438 0.506 0.200 0.483 0.032 0.184 Sherry, Amontillado, 1870 0.9924 16.34 2.68 0.52 0.490 0.560 0.200 0.650 0.038 0.268 Samos wine. 1872 1.0519 10.97 14.46 11.82 0.502 0.237 0.563 0.058 0.044 Two analyses of champagne and effervescing wine are also given by Konig : f 2 '3 S _ X! oS o o^ 3 ft H c _g o x: . Si3 03 |M t? 1 1 o XI 4 * S 3* CO "" H CO O ** PL, CO Champagne, Carte Blanche .... 1.0433 9.51 13.96 11.53 0.581 0.084 0.219 0.134 0.027 0.017 Effervescing Rhine wine 1.0374 9.80 10.88 849 0566 062 294 171 0034 0026 Of American wines a large number have been investigated by the United States Bureau of Agriculture. A selection from those analyzed by H. B. Parsons J in 1880 is given : 9 1 S t>, !>, IS S i o '43 sa ^j aj 'a'c g < o '5 g js-SP 2 g 8 || '"* $ WJ rH ^ r2 ^ "S "S I "o K 3 "3 S CO ^ ^ w q o EH N Dry red wines : Concord, Virginia, 1879 0.9953 8.83 11.08 210 0.174 Trace. 0.709 0.452 0.206 Clinton, Virginia, 1879 0.9950 9.82 12.31 2.36 0^238 None. 0.784 0.513 (K217 Norton's Virginia, 1879 09937 1021 1277 288 0298 Trace. 0772 0377 o!si6 Ives's Seedling, Virginia, 1879 .... 0.9944 8.68 10.82 2.18 0.'247 Trace. 0^723 0.512 o!l69 Sonoma Red Mission, California, 1879 0.9968 7.99 10.03 2.42 0.428 None. 0.722 0.301 0.337 Sonoma Red Zinfandel, California, 1879 09962 780 978 243 255 Trace 0693 0391 242 Concord Bouquet, New Jersey .... 0.9928 9.84 12.31 2.18 0.141 0.71 ' 0>41 0'.272 Oi375 Nahrungs- und Genussmittel, vol. ii, p. 463. t Ibid., p. 464. United States Bureau of Agriculture, Bulletin No. 13, pp. 334-338. 234 FERMENTATION INDUSTRIES. t*. O;" S> g &M 02 Alcohol by weight. Alcohol by volume. Extract. 4 1228 888 1025 15.30 11.08 1277 2.09 1.67 1 63 0.121 0.129 113 Trace. Trace 0.542 0.772 728 0.470 0.387 424 0.068 0.308 243 Ruliinder, Virginia, 1880 09914 1046 1305 190 199 545 30 9 194 Delaware, Virginia, 1880 09932 935 11 70 1 88 0255 562 332 184 Taylor, Virginia 1880 9921 1037 1296 1 99 185 Trace 073'> 317 332 Herbemont, Virginia, 1880 09928 7 78 9 80 1 60 146 562 302 208 Dry Muscat, California White Zinfandel, California 0.9928 9911 9.14 952 11.44 11 26 1.8 > 147 0.150 139 Trace. Trace 0.619 0590 0.248 0227 0.289 290 Riesling, California 09918 964 1205 1 72 9 21 0696 210 389 Gutedel, California 09920 936 11 70 1 58 196 Trace 726 0212 411 Sonoma Mission, California, 1879 . . . Sweet wines: Brocton Port, New York . . . 0.9935 1 0508 8.30 1000 10.38 1324 1.67 1704 0.193 139 Trace. 11 80 0.619 0828 0.317 600 0.242 182 Speer's Port, New Jersey 1 0213 1367 1759 1069 0309 744 0705 347 286 Port, Los Angeles, California .... 1 0339 1268 1652 14 18 345 11 39 0508 0348 128 New York Sherry 1 0074 1387 1759 683 166 484 0689 6.209 323 Speer's Sherry, New Jersey 09949 1762 2209 4.89 0219 333 0476 0271 164 California Sherry 09942 1342 1680 391 0198 220 0573 232 0273 Marsala, California ... 1 0052 1606 20 33 642 428 353 06'>6 418 166 " Eclipse" Extra Dry Champagne . " Gold Seal"Champagne, New York Cook's " Imperial Champagne . . Sweet Catawba, Bass Island, Ohio . Sweet Catawba, Brocton, New York Sweet Catawba, Iowa, 1871 1.0174 1.0402 1.0207 10338 1.0512 1 0101 9.26 8.26 8.41 11.68 1071 989 11.87 10.82 10.82 15.21 14.18 1258 7.78 1331 8.47 14.49 16.71 723 0.149 0.110 0.130 0.152 0.113 0211 6.51 12.02 7.23 11.00 15.22 401 0.885 0.880 0.779 0.595 0.714 0668 0.295 0447 0.470 0.296 0.471 318 0.472 0.346 0.247 0.239 0.194 0280 Sweet Muscatel, California 10245 1733 1858 81 34 0371 25.37 753 0421 o 'ee 10440 896 11 79 14.41 0.196 12.48 0.489 0310 0143 Brocton Sweet Regina 10515 971 1287 1652 0101 1531 06 r >8 0465 130 Sweet Delaware, 1879 1 0320 873 11 35 1207 0118 1027 0799 355 355 Scuppernong, Sweet, 1878 1 0404 906 1187 1413 0.132 11 56 0758 03'>3 348 Scuppernong, Dry, 1879 0.9948 1072 13.43 3.39 0.108 1.31 0925 0346 0463 Side-products. The first of these is the marc of the grapes, sepa- rated from the must in the original pressing of the grapes, or left when the fermenting must is drained from it. This consists of the stems, skins, and stones of the grapes. If the marc instead of being washed out with water has been merely pressed, it still contains sufficient must to allow of its being used in the manufacture of petiotized wine. Be- sides this, the marc serves for a great variety of purposes. It is fer- mented for brandy; it is used with sheet-copper in the manufacture of verdigris; it is used to start the fermentation in vinegar-making; as cattle-food; when dried, as fuel or for fertilizing purposes; the tannic acid is extracted, or it is used direct in producing black colors, and for other minor applications. The second and more valuable side-product is the deposit formed on the bottom and sides of the casks in which the fermentation takes place. That on the bottom of the casks is called "lees." It contains from thirty to forty per cent, of vegetable matter (from the yeast-cells depositing), the remainder being tartrates, sulphates (in plastered wines), alumina, phosphoric acid, etc. Its composition is greatly altered by "plastering " the wine, in which case the tartrate exists chiefiV as the neutral calcium tartrate instead of the acid potassium salt. The crystalline crust that forms on the sides of the vessels used for fermentation is called "argol," or crude tartar. It varies somewhat in composition, the tartaric acid THE MANUFACTURE OF WINE. 235 ranging from forty to seventy per cent, and being always present, chiefly as the acid potassium tartrate. From this crude tartar is pre- pared, by extraction with boiling water, filtering, and crystallizing, "cream of tartar." This, however, still contains some calcium tartrate mixed with the acid potassium salt, the amount ranging from two to nine per cent. V. Analytical Tests and Methods. In 1884 the Imperial German Health Office appointed a commission of experts to report upon the best uniform methods for the analysis of wines. The methods agreed upon by that commission are very generally adopted now in Germany, and largely used elsewhere in guiding wine analysts. These official methods have been fully described and explained in a little work entitled "Weinanalyse," by Dr. Max Barth, Leipzig, 1884. The specific gravity of the wine is determined either by the pyk- nometer (specific gravity bottle) or by the Westphal balance (see p. 87), the readings of which have been compared with those of the specific gravity bottle. In the case of champagnes and effervescing wines, as was the case with beer, the carbonic acid must be got rid of as far as possible before taking the specific gravity readings. The alcohol is determined by the direct distillation, as described on p. 222. Wines that have a tendency to foam have a little tannin (.1 gramme) added. If one hundred cubic centimetres of the sample is taken, sixty cubic centimetres only need be collected, and will contain all the alcohol. This is then diluted to nearly one hundred cubic centi- metres, cooled, uniformly mixed, and then brought exactly to the 100- cubic centimetre mark, mixed again, and the specific gravity taken. The form of apparatus best adapted for this determination of alcoholic strength of wines and liquors is shown in Fig. 61. For the rapid deter- mination of the alcoholic strength of wines various forms of apparatus have been devised, such as the vaporimeter of Geissler, in which the vapor-tension of an alcoholic liquid exerted upon a column of mercury is made to indicate its percentage strength in alcohol, the ebullioscope of Tabarie, of Malligand and Vidal, and of Amagat, which depend upon the observation of the boiling-points of a spirituous liquor as determin- ing the amount of alcohol contained. None of these can be said to have scientific accuracy, as wine is not merely a mixture of alcohol and water, but contains other constituents which affect the results in either case. The extract detemi nation. Here the direct weighing of the residue after evaporation is preferred to the indirect method, fifty cubic centi- metres of the wine, measured at 15 C., are to be evaporated on the water-bath in a platinum dish (according to the German wine commis- sion, this dish should be eighty-five millimetres in diameter, twenty millimetres in height, seventy-five cubic centimetres in capacity, and should weigh about twenty grammes), and the residue dried for two and a half hours in a double-walled water drying oven. In the case of wines 236 FERMENTATION INDUSTRIES. containing more than .5 per cent, sugar, a smaller quantity must be taken and suitably diluted, so that the extract shall not weigh more than 1.0 to 1.5 grammes. In this method, the loss of glycerine by evap- oration is trifling. The indirect method for determining the extract is very like that described under beer (see p. 221) as 'Sullivan's method, except that with wine we divide the excess of specific gravity observed over 1000 by 4.6 instead of 4, as the solids of wine have a higher solu- tion density than those of extract of malt. Or with the specific gravity of the de-alcoholized liquid we may get the extract percentage from Hager 's tables, which are analogous to those of Schultze for malt extracts before referred to. FIG. 61. The ask percentage can be obtained by incineration of the evaporated extract above referred to. To determine the percentage of glycerine, one hundred cubic centi- metres of the wine are evaporated down to about ten cubic centimetres in a spacious porcelain dish ; some sand and milk of lime are then added till the reaction is strongly alkaline and the mixture evaporated almost to dryness. The residue is next treated with fifty centimetres of ninety- six per cent, alcohol, warmed and stirred on the water-bath, and the solution obtained then passed through a filter. The insoluble matter is washed with successive small portions of hot alcohol (ninety-six per cent.), of which fifty to one hundred and fifty cubic centimetres will as THE MANUFACTURE OF WINE. 237 a rule suffice, so that the entire filtrate will be from one hundred cubic centimetres to two hundred cubic centimetres. The alcoholic extract is now evaporated to a viscous consistency, and the residue taken up with ten cubic centimetres of absolute alcohol; this solution is mixed with fifteen cubic centimetres of ether in a stoppered flask and the mixture allowed to stand until clear. The clear liquid is decanted or filtered into a light tared glass vessel, carefully evaporated, and the residue dried for one hour in the water-bath. It is then cooled and weighed. In the case of sweet wines (containing more than five per cent, of sugar), only fifty cubic centimetres of the wine are taken for the estimation of the gly- cerine ; sand and lime are added, and the mixture is warmed on the water- bath. After cooling it is treated with one hundred cubic centimetres of ninety-six per cent, alcohol, the precipitate formed allowed to settle, the solution filtered, the insoluble matter washed with spirit, and the alcoholic filtrate treated as above described. To estimate the sugar in wine, Fehling 's solution is used, as the sugar should be only glucose. After neutralization of the wine with sodium carbonate, the determination is made (using the separately preserved solutions for Fehling 's mixture. See p. 175). Strongly-colored wines must be first decolorized. If the sugar percentage is low, it is done with purified bone-black ; if they contain over .5 per cent, of sugar, bone-black cannot be used because of its absorptive power, and basic acetate of lead must be substituted. After filtering, the wine is then treated with sodium carbonate and Fehling 's solution. If the polarization indicates the pres- ence of cane-sugar, the solution must be inverted (see p. 174) and then the Fehling 's test applied again, and the cane-sugar calculated from the difference in the two readings. The Fehling 's test is best carried out gravimetrically, and from the weight of reduced copper the correspond- ing amount of glucose can be obtained from the tables. The polarization, which is essential in the case of heavy wines to indi- cate the nature of the sugar contained, is carried out as follows : With white wines, to sixty cubic centimetres of the wine are added three cubic centimetres of the basic acetate of lead solution and the precipitate filtered off on a dry filter. To 31.5 of the filtrate is added 1.5 cubic centi- metres of a saturated solution of sodium carbonate and the solution again filtered and the polarization tube filled with the filtrate. The dilu- tion of the original wine in this case is 10 : 11. With red wines, sixty cubic centimetres of the wine are treated with six cubic centimetres of the lead solution, and to thirty-three cubic centimetres of the filtrate three cubic centimetres of the saturated sodium carbonate solution added, the solution filtered and polarized. The dilution here is 5:6. This diluted solution is observed in the 220-millimetre tube of the polariscope, and large and accurate instruments are necessary. The free acids (total acid-reacting constituents of the wine) are estimated in twenty-five cubic centimetres of the wine heated to incipient boiling by means of one-tenth normal alkali. Any considerable quantity of carbonic acid to be first removed by shaking. The ' ' free acids " to be calculated into and given as tartaric acid (C 4 H 6 6 ). 238 FERMENTATION INDUSTRIES. The volatile acids are determined by steam distillation and calculated as acetic acid (C 2 H 4 O 2 ). The quantity of non-volatile acids calculated as tartaric is found by subtracting the equivalent of the acetic acid in tartaric acid from the free acids previously determined. These three determinations are all that are usually made in wine analyses. If a special qualitative test for free tartaric acid is desired or, in case it be shown to be present in appreciable quantity, a quantitative method for its determination, they can be made by Nessler's method, for details of which the reader is referred to Earth's "Weinanalyse " before mentioned, or to a summary of its methods in the "Journal of the Society of Chemical Industry," 1885, p. 553. The tannin may be determined by Neubauer's method with perman- ganate of potash, or approximately by the following procedure : the free acids in ten cubic centimetres of the wine are neutralized with standard alkali, after which one cubic centimetre of a forty per cent, solution of sodium acetate is added, and finally a ten per cent, solution of ferric chloride, drop by drop, and avoiding excess. One drop of this solution suffices for the precipitation of every .05 per cent, of tannin. Salicylic Acid. To detect this acid, one hundred cubic centimetres of the wine are shaken repeatedly with chloroform, the latter is evap- orated, and the aqueous solution of the residue tested with very dilute ferric chloride solution. For the purpose of an approximate quantita- tive estimation, it is sufficient, on the evaporation of the chloroform, to once recrystallize the residue from chloroform and weigh it. One of the most important questions that arises in the examination of red wines is as to the genuineness of the coloring matter, as both vege- table and artificial dye colors have been used for years to imitate the natural coloring matter in the manufacture of factitious red wines. Very elaborate schemes for the recognition of foreign coloring matters, includ- ing both the vegetable coloring matters like dye-woods and color-yielding berries and the large number of the newer coal-tar colors, have been given by Gautier * and by Chas. Girard,f the director of the Laboratoire Municipal in Paris, to which we can only give references. The coloring matters most generally used to imitate the natural pigment of the grape- skins are fuchsine, cochineal, alder-berry, hollyhock, and logwood. Dupre tests the coloring matter as follows: Cubes of jelly are prepared by dis- solving one part of gelatine in twenty parts of hot water and pouring the solution in moulds to set. These are immersed in the wine under examination for twenty-four hours, then removed, slightly washed, and examined. Pure wine will color the gelatine only very superficially ; the majority of other coloring matters (fuchsine, cochineal, logwood, Brazil- wood, litmus, and indigo) penetrate more readily, passing to the very centre of the cube. The double dyeing test of Sostegni and CarpentieriJ is now very frequently employed. Take one hundred cubic centimetres * Wynter Blyth, Foods, Composition and Analysis, p. 464. t Deuxieme Rapport du Laboratoire Municipal, p. 272. $ Bulletin No. 107 (revised), Bureau of Chem., U. S. Dept. of Agric., p. 190. MANUFACTURE OF DISTILLED LIQUORS. 239 of the wine, acidify with from two to four cubic centimetres of a ten per cent, solution of hydrochloric acid. In this solution immerse a piece of woolen cloth which has been washed in a very dilute solution of boiling potassium hydroxide and then washed in water and boil for from five to ten minutes. Remove the cloth, thoroughly wash it in water and boil in a very dilute hydrochloric acid solution. After washing out the acid dissolve the color in a solution of ammonium hydroxide (1:50). Take the wool out, add a slight excess of hydrochloric acid to the solution, immerse another piece of wool and boil it again. With vegetable color- ing matter, such as the wine color, this second dyeing gives practically no color, and there is no danger of mistaking such a color for one of coal-tar origin which dyes the second piece of wool a bright shade. This test will detect minute quantities of fuchsine or aniline red. The fact that pure wine color is not changed or decolorized by nascent hydrogen (zinc and acid), while most of the aniline dyes are decomposed by it, is also used as a test. D. MANUFACTURE OF DISTILLED LIQUORS, OR ARDENT SPIRITS. This industry differs radically from the two fermentation industries already described, firstly, in that the effort is made to push the fermen- tation to the fullest possible limit, so that the maximum quantity of alcohol may be produced, and, secondly, in that this product of fermen- tation is then distilled, and it may be redistilled in order to get a dis- tillate richer in alcohol than the fermentation product itself can be. The end to be attained may be either the production of an alcoholic beverage as the product of distillation or of raw spirit, which takes name from the material used, as ' ' grain spirit, " " potato spirit, " ' ' corn spirit, ' ' etc. From this raw spirit by the processes of rectification is obtained the "rectified spirit " used as the basis of the manufacture of various alco- holic beverages and as a solvent in various manufacturing processes, and by purification and dehydration the absolute ethyl alcohol of the chemist. I. Raw Materials. These may be divided into three classes : First, alcoholic liquids, them- selves the product of fermentation, these require only to be submitted to distillation in order to yield the stronger spirit ; second, solid and liquid materials containing some variety of sugar, whether cane-sugar, grape- sugar, or maltose, which are directly or indirectly fermentable; and, third, starch-containing cereals and all materials capable under the influ- ence of diastase or dilute acids of hydrolysis and the production of a fermentable sugar. 1. ALCOHOLIC LIQUIDS (Wines}. The distillation of wines is followed for the production of an alcoholic beverage (brandy) which takes to some degree its flavor and bouquet from the wines used in the distillation. "While factitious brandies are largely made from grain or potato spirit, the true product from wine is always regarded as superior. 240 FERMENTATION INDUSTRIES. The manufacture of wine brandy has been chiefly carried out in France, and in minor degree in Spain and Portugal. Within recent years California wines have also been used for the manufacture of brandies. The French wines which are used are largely those of the departments Charente and Charente-Inferieure, in the southwest of France, and the product is all known as Cognac brandy. White wines are said to yield a superior spirit to that obtained from red wines, and older wines better than newer ones. About eight and a half hectolitres of wine are needed to produce one hectolitre of brandy. Because of the ravages of the Phylloxera insect, the manufacture of genuine wine Cognac has decreased enormously in France in recent years, while the manufacture of factitious Cognac has correspondingly increased. Thus we find it officially stated * that the production of alcohol from wine in France had decreased from 530,000 hectolitres in 1875 to 14,678 hectolitres in 1883. The marc of the grapes, as already stated (see p. 234), is also utilized in the manufacture of an inferior grade of brandy, known in France as eau de vie de marc. The lees, or sediment, of the wine-casks are also used in this same way. This brandy is not necessarily sold for consump- tion, but is used to strengthen the alcoholic percentage of wines in which fermentation is to be arrested. 2. SUGAR-CONTAINING RAW MATERIALS. The most important sugar- yielding materials cultivated on a large scale, it will be remembered, are the sugar-cane and the sugar-beet. The sugar-canes are not used directly for the production of spirits (except in the case of accidental souring), and the "bagasse," although still containing saccharine juice, is too bulky, and hence is at once burned as fuel, but the molasses obtained on so large a scale in the extraction of raw sugar is a most valuable material for the purpose. Throughout both the West Indies and the East Indies enormous quantities of this molasses are fermented and the resultant product distilled for rum. Even the sugar scums obtained in the defe- cating and concentrating of the sugar juice are fermented, and produce an inferior grade of rum. With the sugar-beet, both the beet itself and the beet-molasses are util- ized, the former being used in France and the latter in both France and Germany. Sweet fruits, the juice of which is rich in sugar, also serve as raw materials for the spirit industry. Thus peaches, plums, and cherries are much used in different countries for the manufacture of fruit brandy, and the fermented juice of the date-palm in the East Indies and of the plantain in the West Indies both serve for the distillation of an alcoholic beverage. 3. STARCH-CONTAINING RAW MATERIALS. This list includes the main sources for the distillation of spirits, as the high percentage of starch in many cereals, ranging from sixty to seventy-seven per cent., the ease with which the starch can be converted into fermentable sugar under the in- fluence of diastase or dilute acids, and the cheapness of these starchy products of nature all combine to make them for most countries the * Deuxi&me Rapport du Laboratorie Municipal, p. 272. MANUFACTURE OF DISTILLED LIQUORS. 241 cheapest and best materials for the spirit industry. In the United States, the three cereals used almost exclusively for the manufacture of distilled liquors are corn, rye, and malted barley; in England, barley, both raw and malted, rye, corn, and rice ; in Germany the potato is almost the only starchy material used. The composition of the several cereals showing their relative percentage of starch was given on p. 186. n. Processes of Manufacture. 1. PREPARATION OF THE WORT. In England and the United States, where grain spirit is mainly manufactured, the first process is that of saccharifying the starch of the grain. In the special cases where malted grain alone is used, the mash process somewhat resembles that already described under beer-brewing. Most distillers, however, use mixtures of raw and malted grain, in which the raw largely predominates, being often ten to one or even more, as a very small quantity of diastase can be made to convert a large amount of starch into maltose or fermentable sugar. It is stated, moreover, that the yield of spirit is larger when several kinds of grain are mixed than when one kind is used singly. The mixture of raw and malted grain, properly ground, is put into the mash-tub (see Fig. 59, p. 214) with water at 150 F. and agitated. This first mashing requires from one to four hours, the larger the quantity of raw grain used the longer being the time required for mashing. The temperature of the mixture is kept up to about 145 F. by the successive additions of water at a somewhat higher temperature (190 to 200 F.). The object of the distiller in this is somewhat different from that of the beer-brewer. He wishes to convert the whole of the starch, if possible, into maltose, which is directly fermentable by the action of yeast, while the dextrine is not, so he must mash at not much over 146, which it will be seen from Fig. 58 (p. 207) is the limit above which the maltose production begins to decrease. When the gelatinization of the starch is complete, the tem- perature of the mash may go slightly higher. By keeping within this limit of temperature, a minimum of diastase from the small admixture of malt will gradually change not only the starch, but bring about a hydration of the residual dextrine, converting it into maltose. When the wort has acquired its maximum density, as found by the saccharo- meter, it is drawn off, and fresh water at about 190 F. is run upon the residue in the mash-tub and allowed to infuse with it for one or two hours. This second wort is then added to the first. A third weak wort is often obtained, and used to infuse new lots of grain. The mash is then cooled down promptly to the temperature required for fermentation so that the acetous fermentation may not set in. It is stated that in this method of open-tub mashing ten per cent, of the starch escapes decomposition, even although the grain may be taken finely ground. Hence a preliminary warming with water to which a little green malt is sometimes added, followed by heating with water under a pressure of several atmospheres, now often precedes the addition of the main quantity of the malt, which is to complete the conversion of the 16 242 FERMENTATION INDUSTRIES. starch and dextrine into maltose. This treatment is carried out in so- called "vacuum cookers." In Germany potatoes constitute the chief raw material for the spirit manufacture. They contain from eighteen to twenty per cent, of starch only, however, while the cereals contain over sixty per cent. The amount of the malt needed for the saccharification of the starch can therefore be correspondingly reduced. Instead of mashing the ground, rasped, or chipped potatoes in open mash-tubs as was formerly done, they are now first steamed under a pressure of two to three atmospheres, whereby the starch-containing cells are thoroughly ruptured and the starch put in condition to be easily acted upon by the diastase. Among the forms of apparatus based upon this principle may be mentioned those of Holle- freund, Bohm, Henze, and Ellenberger. In that of Henze, which has been largely adopted, the potatoes, after steaming under a pressure of several atmospheres, are so disintegrated that on opening a valve in the bottom of the vessel the pulp is forced out through a grating in a thin stream. This is cooled, mixed with the requisite quantity of malt, and started to mashing. In the Hollefreund and in the Bohm cookers, the steaming, disintegrating, and mashing all take place in the same closed vessel, the malt being added after the disintegrated mass has been prop- erly cooled down. Green malt is found to work better in this case than air malt, and produces more alcohol. 2. FERMENTATION OP THE WORT, OR SACCHARINE LIQUID. In the case of mashing, as described above, either with grain or with potatoes, the wort must first be cooled down before adding the yeast and starting the fermentation. The yeast used is a surface yeast, and either fresh brewer's yeast or compressed yeast (previously softened in warm water) may be used. The procedure is now somewhat different, according as we have a grain-mash or a potato-mash to deal with. In the former case, using a thin wort drained from the exhausted grain, it has been found that the best results are obtained when the temperature during fermen- tation rises to about 33 or 34 C. (92 to 94 P.), as shown in Fig. 58 (see p. 207) ; in the latter case, where the entire mash, solid matter and all, is fermented, the fermentation begins at a much lower temperature, and the heat evolved in the fermentation of such a concentrated wort ultimately carries the temperature to the same maximum. In the English plan, considerable lactic acid forms because of the higher temperature, and this constitutes a sour yeast mash, while in the German plan, because of the low initial temperature of the fermentation, comparatively little lactic acid is produced, and when the higher temperatures are reached the mixture already contains so much alcohol that the lactic acid ferment grows with considerable difficulty. For one thousand litres of grain-mash, eight to ten litres of brewer's yeast or one-half kilo, of compressed yeast are used; for one hundred litres of potato-mash, one to two litres of brewer's yeast or three-fourths to one kilo, of compressed yeast are needed. The fermentation is sometimes divided into several stages: the pre- liminary fermentation, in which the yeast-cells grow without much alco- MANUFACTURE OF DISTILLED LIQUORS. 243 hoi formation ; the main fermentation, in which the maltose is fermented ; and the a/^er-treatment, in which the dextrine is gradually changed into maltose and this into alcohol. The time of fermentation varies from three to nine days, but it is car- ried on until the density of the liquid ceases to lessen or attenuate, which is determined by the saccharometer. The coefficient of purity of a fermentation is a term used to designate what percentage of the available starchy material in a substance has actually undergone the pure alcoholic fermentation. Thus, the reaction C H 10 5 -(- H 2 = 2C 2 H 6 -f- 2C0 2 demands from one kilogramme of starch a percentage of alcohol equal to 71.7 litres, and such a yield from one kilogramme of fermented material would indicate a purity coefficient of one hundred per cent. A percentage yield equal to sixty litres of alcohol from one kilo, of material would give a purity coefficient of 83.7 per cent. The use of hydrofluoric acid or ammonium fluoride, first proposed by Effront as an antiseptic and indirect aid to the alcoholic fermentation, has become quite important in the spirit industry. The advantages claimed for its use are : first, by preventing the losses due to secondary fermentation, the alcohol yield is increased; second, this yield is espe- cially maintained when raw materials of somewhat inferior quality are used, when without the hydrofluoric acid the yield would be diminished ; third, the development of foaming in the fermentation is in large degree prevented. In France, the juice from inferior beets instead of being worked for the extraction of sugar is often fermented and distilled. The juice is made slightly acid with sulphuric acid to prevent any viscous fermen- tation, and a small quantity of brewer's yeast is added. The tempera- ture of the fermentation is from 20 to 22 C., and the process is usually complete in from twenty-four to thirty-six hours. The use of the molasses obtained in the extraction of the raw sugar, whether from the sugar-beet or the sugar-cane, is, however, much more common. In France and Germany, where the beet-sugar molasses is pro- duced in large quantities, the molasses originally marking 40 to 48 Beaume is diluted to 8 or 10 Beaume, and sulphuric acid of 66 is added to the amount of 1.5 per cent, of the molasses taken. This neu- tralizes the bases of the beet-molasses and inverts the cane-sugar present, bringing it into fermentable form. Brewer's yeast is then added, and the fermentation proceeds rapidly. The temperature ranges from 22 C., that usually chosen in France, where more dilute solutions are fermented, to 25 to 30 C. in Germany, where the concentration is usually as much as 12 B. Two hundredweight of molasses at 42 B. will furnish about six gallons of pure spirit. In the West Indies, notably in Jamaica, the cane-sugar molasses is similarly utilized, but the procedure is somewhat different. In this case the addition of yeast is unnecessary, as the nitrogenous matters present suffice to start spontaneous fermentation. The best rum is that gotten from the molasses alone ; a second grade is obtained from the skimmings 244 FERMENTATION INDUSTRIES. and "sweet-waters " which accumulate in the extraction of the sugar. To these is added some "dunder " (fermented wash, deprived by dis- tillation of its alcohol and much concentrated by boiling), which acts as the ferment and starts the action. Molasses is then added in the pro- portion of six gallons to every hundred gallons of the fermenting liquid and the action allowed to go to completion. One hundred gallons of this mixture when distilled should yield twenty-five gallons of "low wines " or one gallon of proof rum for each gallon of molasses employed. 3: DISTILLATION OF THE FERMENTED MASH, OR ALCOHOLIC LIQUID. Upon the construction of apparatus for the distilling from the fermented mash of the alcohol which it contains much skill and ingenuity have been displayed, and some of the later forms of stills and rectifying apparatus employed in large distilleries are wonderfully adapted for obtaining in a continuous operation the purest and strongest alcohol from the crude fermentation products. We may distinguish some five main classes of distilling apparatus, of which the minor varieties are too numerous to be specially enumerated. These classes are: first, simple stills with worm condenser heated by direct firing ; second, simple stills with closed ' ' wash- warmer"; third, stills with rectifying "wash-warmer"; fourth, stills with " wash- warmer, " rectifying and dephlegmator apparatus for inter- mittent working ; and, fifth, similar forms of construction for continuous working. The first and simplest of these classes hardly needs any special description. The stills are usally of copper, flat-bottomed, and often of great size, especially in Irish and Scotch whiskey distilleries. It is obvi- ous that their use involves a great waste of fuel. Therefore one of the earliest devices for economizing the heat of distillation consisted in interposing between the still and the refrigerating apparatus a "wash- warmer, ' ' or vessel filled with the liquid ready for distillation. Through this vessel the pipe conveying the hot vapors to the refrigerator coil passed, and the vapors partly condensing there heated up the wash, which then went into the still quite hot. Dorn's apparatus, still some- what used in smaller establishments in Germany, accomplished the same thing, and effected a partial rectification of the distillate by having inter- posed between the still and the refrigerator a vessel divided horizontally into two compartments by a diaphragm of copper. The upper and larger compartment served as a wash-warmer, and through it the tube conveying the vapors from the still passed into the lower compartment, where at first the distillate condensed. As the wash becomes warmed up this distillate gives off alcoholic vapors, which then pass on and are con- densed in the worm, while the watery portion is allowed to flow back into the still by a side-connection. It is obvious that this rectifying action can be increased by the introduction of two or more such vessels between the still and the final condenser, and so a distillate much richer in alcohol be obtained. Another principle was now brought into play "in effecting a fractional condensation, that of dephlegmation, or chilling the vapor coming off by contact with metallic diaphragms so that a portion of it, and of course the most watery, is condensed and separated while the richly alcoholic MANUFACTURE OF DISTILLED LIQUORS. 245 rnnnnnnrnnnnnr : S IB [= ' 1= = 3 . [= . . = ft n" i ', j 1 ! ! ! ; ip IP f ; i r r r L 1 246 FERMENTATION INDUSTRIES. vapor passes on into the rectifier or condenser. Three types of these most elaborate apparatus may be briefly referred to : the Pistorius appa- ratus, used in Germany for the thick potato-mashes of that country, which is intermittent, the Coffey still, used in England and Scotland for the thinner worts from grain, and the column apparatus, first introduced by Savalle and improved by later inventors, which is used ?n Prance for distilling wines and in Germany to follow up the work of the Pistorius or similar apparatus. Both the Coffey still and the column apparatus are continuous in action. In the Pistorius apparatus, two boilers and a wash-warmer are used for the fresh mash, and are connected so that the vapors from the first boiler pass into the second boiler, heating it up and in time driving vapor from it, which then passes around the wash- warmer and goes through several dephlegmators placed one above the other. In these the watery alcohol is continually being condensed and running back to the second boiler, while the uncondensed vapor which escapes from the top dephlegmator goes finally to the refrigerating apparatus. The Pistorius apparatus has been improved upon by Gall, Schwartz, and Siemens. The Coffey still, illustrated in Fig. 62, consists of two columns placed side by side, made of wood and lined with copper. The analyzer, A, is divided into twelve small compartments by four horizontal plates of copper, a, perforated with numerous holes and fur- nished with valves opening upwards. Dropping-pipes, & &, are also attached to each plate, the upper end of the pipe being an inch or two above the plate and the lower end dipping into a shallow pan, c, placed on the lower plate. The second column or rectifier, B, receives the spirit- uous vapors passing from the column A through the pipe g. This column is also divided into compartments like A, but there are fifteen instead of twelve. The ten lower diaphragms, I, are pierced with small holes and furnished with drop-pipes, while the upper five have only one large opening surrounded by a ring to prevent the finished spirit from return- ing. Between each of these compartments passes a bend of a long zigzag pipe, n n', one end of which is attached to the pump m, whilst the other end discharges the contents of the pipe into the top of the column A, as indicated by the arrow. The following is the working of the appa- ratus. In the first place, the fermented liquor or wash is pumped up by the pump m until the zigzag pipe is filled and the wort flows over the compartments a a a. Steam is then admitted into the compartments of the analyzer by the pipe d and heats the wash, which is deprived of all its alcohol by the time it reaches the bottom of the clyinder and flows off by e f as spent wash. The strong spirituous vapor passes through g to the rectifier, and at last through the worm c of the refrigerator into the receiver. The Coffey still is recognized as the best and most economical device for preparing a highly-concentrated spirit in a single operation. It is specially adapted for preparing from grain-mashes what is called "silent spirit," which is almost entirely destitute of flavor, and of a strength ranging from fifty-five to seventy over proof. It is not so well adapted for the distillation of malt whiskey as fire-heated stills, because the peculiar flavor of the whiskey depends upon the retention by the MANUFACTURE OF DISTILLED LIQUORS. 247 alcoholic distillate of the volatile oils produced in the mash, and the Coffey still separates the alcohol from these as well as other impurities. The forms of apparatus used in France for the distillation of wines are illustrated in that of Cellier-Blumenthal as improved by Derosne, shown FIG. 63. in Fig. 63. The alcoholic vapors from A pass into B, and thence into the rectifying column C, which contains a series of perforated metal cups over which wine from the wine-warmer, E, is trickling. The vapors thus enriched go through the upper rectifying column, D, and thence to the wine-warmer, E, M'hich serves as a first condenser, and then to the cold 248 FERMENTATION INDUSTRIES. FIG. 64. FIG. 65. FIG. 66. MANUFACTURE OF DISTILLED LIQUORS. 249 condenser, F, and so to the collecting vessel. After the operation is well under way the supply of wine can be introduced from H through G, k, and E, while the de-alcoholized liquid can be run off from the lower side of A. Another form of still very largely used in France and Belgium, espe- cially for thin mashes like molasses and beet-mash, is that of Savalle, illustrated in Fig. 64. It is a continuous-working apparatus. B is the still proper heated by steam-pipes, A is the rectifying column, C is for catching froth, D is a warm tube condenser and E the cold condenser. The elements which form the condensing and rectifying parts of the column A are shown in Figs. 65 and 66. The vapors rising pass through the holes of the perforated plates, on which rests a layer of condensed liquid which can only drain down through d into th'e cup c placed below it. From these cups it overflows upon the perforated plate and is again drained off by the next connecting tube, d. The rising vapors are there- fore washed by the liquid upon each perforated plate. 4. RECTIFYING AND PURIFYING OF THE DISTILLED SPIRIT. The products from the preliminary distillation from the fermented grain- or potato-mash are not at first sufficiently strong, but must be strengthened by rectifying. In England, the spirits obtained by the first distillation from grain-mash are generally called low wines, and have a specific gravity of about .975. By rectifying, or doubling, a crude milky spirit, abounding in oil, at first comes over, followed by clear spirit, which is then caught separately. "When the alcoholic strength of the distilled liquid has considerably diminished, the remaining weak spirit that distils over, called faints, is caught separately and mixed with the low wines preparatory to another distillation. The rectifying is most rapidly and effectually done in the several forms of column apparatus, the best of which will yield a very pure alcohol in one or two operations. An improved Savalle rectifying colunm as used generally in French and Belgian distilleries is shown in Fig. 67. It consists of a still, A. heated by closed steam-coils, a rectifying column, B, two tubular con- densers, C and D, from the upper of which any condensed vapors flow back into the rectifying column as "low wines," while the lower con- denser takes the more volatile product and passes it on as high-grade alcohol to the receiving-vessel, F. The purifying of raw spirit, notably that from grain and potatoes, from what is called fusel oil (propyl, isobutyl, and amyl alcohols) is also a matter of great importance if the spirit is to be used as the basis of any manufactured liquors. This fusel oil sticks persistently to the alcoholic distillates, and alcohol rectified until it reaches a strength of ninety-five or ninety-six per cent, by volume contains fusel oil. Some acetaldehyde also remains dissolved in the alcohol, giving the raw spirit a bitter taste. The rectifier's method is to dilute the alcohol with water until it is about fifty per cent, strength, by which means the fusel oil separates out in- soluble in the dilute spirit, and then to filter through wood charcoal. Another method which has been experimented upon on a large scale, known as the Bang and Ruffin process, is to shake up the diluted spirit 250 FERMENTATION INDUSTRIES. with petroleum oils, which have the power of absorbing the fusel oil and so withdrawing it from the dilute alcohol. In this country the storage of the grain spirit in charred oaken barrels in warm rooms is extensively practised as a method of improving FIG. 67. the quality of the spirit. It was supposed that the fusel oil disappeared during this storage, but Crampton * has shown that it does not and is merely masked by the empyreumatic extractive matter taken up from the wood. Esters, however, are formed and the rawness disappears. 5. MANUFACTURE OF ALCOHOLIC BEVERAGES FROM RECTIFIED SPIRIT. . Much of the rectified spirit, from whatever source derived, is used in * Journ. Amer. Chem. Soc., Jan., 1908, p. 98. MANUFACTURE OF DISTILLED LIQUORS. 251 connection with the manufacture of wines for fortifying them and in arresting fermentation at any desired stage. The so-called "silent spirit " made in England by the use of the Coffey still from grain- wort is largely utilized in the manufacture of factitious brandies and wines, and the same thing applies to the spirit manufactured in France from beet-roots and beet-root molasses, where it is made to supply the deficien- cies in the wine and Cognac production. The composition of many of these factitious or imitation liquors will be spoken of in the next section in enumerating the products of this industry. m. Products. 1. RECTIFIED AND PROOF SPIRIT. "Rectified spirit " is the name often given to the most concentrated alcohol producible by ordinary distilla- tion. The British Pharmacopoeia describes rectified spirit as containing ninety per cent, by volume real alcohol and having a specific gravity of .834. The United States Pharmacopoeia under the name "alcohol " simply calls for a spirit containing 94.9 per cent, by volume of real alcohol and having a specific gravity of .816 at 60 F. The "spirit " of the German Pharmacopoeia has a specific gravity of .830 to .834, and hence corresponds more nearly to the British ' ' rectified spirit. ' ' ' ' Proof spirit " is a term in constant use in England for the purposes of excise, and its strength was defined by act of Parliament to be such that at 51 F. (10 C.) thirteen volumes shall weigh the same as twelve volumes of distilled water. The "proof spirit " so made will have a specific gravity of .91984 at 15.5 C. (60 F.) and contain, according to Fownes, 49.24 per cent, by weight of alcohol and 50.76 per cent, of water. Spirits weaker than proof are described as U. P. (under proof), stronger than proof as 0. P. (over proof) ; thus, a spirit of fifty U. P. means fifty water and fifty proof spirit, while fifty 0. P. means that the alcohol is of such strength that to every one hundred of the spirit fifty of water would have to be added to reduce it to proof strength. Tables are in use which give for alcohol of a given specific gravity at 15.5 C. (60 F.) the corresponding percentage by weight, percentage by volume, and percentage of proof spirit contained. (See Wynter Blyth, Foods, Composition and Analysis, 5th ed., p. 380.) 2. ALCOHOLIC BEVERAGES MADE BY DIRECT DISTILLATION OF THE FER- MENTATION PRODUCTS. Arrack. Any alcoholic liquor is called ' ' arrack ' ' in the East, but arrack proper is a liquor distilled either from toddy, the fermented juice of the cocoa-nut palm, or from malted rice. The arrack from Goa and Columbo is considered the best, and is made from toddy alone. This latter is gotten by the incision of the palm, arid is collected in pots hung to the tree under the cuts. It is then fermented and dis- tilled. In preparing the other variety, as carried out in Batavia and Jamaica, the rice is covered with water and allowed to germinate, dried at a temperature of 59 F., which arrests germination, and then a wort is made from the malted rice in the same manner as from malted grain, which is afterwards distilled. The commonest pariah arrack of India is 252 FERMENTATION INDUSTRIES. generally narcotic, very intoxicating, and unwholesome. It is prepared from coarse jaggery sugar, spoilt toddy, refuse rice, etc., and rendered more intoxicating by the addition of hemp leaves, poppy-heads, juice of stramonium, and similar deleterious substances. Brandy in its purest form (Cognac) is the direct product of the dis- tillation of French wines. Its peculiar flavor and aroma are due to the presence of ethyl pelargonate (osnanthic ether). The better qualities of Cognac are distilled from white wines, the inferior varieties from the dark-red Spanish and Portuguese wines or from the marc or refuse of the wine-press, and called eau de vie de marc. A great deal is also entirely factitious, being mixtures of grain spirit and water to which different coloring and aromatic substances have been added. When first dis- tilled, brandy, like other spirituous liquors, is colorless, when it is known as white brandy, and continues so if kept in glass- or stone-ware, but if stored in oak casks, as is usually the case, it gradually acquires a yel- lowish tint from the wood, and it is then termed pale brandy. The still deeper color which it frequently possesses is given it by the addition of caramel-color, which was originally designed to simulate the appearance of an old brandy long stored in casks. The coloring matter is also some- times prepared from catechu and similar astringent and aromatic sub- stances. Numerous recipes for factitious brandies are furnished for the use of rectifiers in making up imitations of Cognac. Two such recipes are given : No. 1. Powdered catechu, 100 grammes ; sassafras-wood, 10 grammes ; balsam of tolu, 10 grammes; vanilla, 5 grammes; essence of bitter almonds, 1 gramme; well-flavored alcohol (at 85), 1 litre. No. 2. Malt spirit (17 U. P.), 100 gallons; nitrous ether, 2 quarts; ground cassia-buds, 4 ounces ; bitter almond meal, 5 ounces ; sliced orris- root, 6 ounces; cloves in powder, 1 ounce; capsicum, iy 2 ounces; good vinegar, 3 gallons ; brandy-coloring, 3 pints ; powdered catechu, 2 pounds ; full-flavored Jamaica rum, 2 gallons. Mix in an empty Cognac-cask and macerate for a fortnight, with occasional stirring. Produces 106 gallons at 21 or 22 U. P. Kirschwasser is a spirituous liquor obtained in the Black Forest and in Switzerland by the distillation of cherries. These are picked free from the stalks and only the sound fruit taken. They are crushed for the extraction of the juice, and a portion of the cherry-stones are then sepa- rately crushed so as to bruise the kernels and returned to the juice. These bruised kernels impart the almond flavor to the product and give to it a small quantity of prussic acid (.15 gramme per litre in good kirsch and more in inferior kinds). After fermentation the liquor is drawn off and distilled by steam. The kirsch is colorless, of agreeable odor and flavor, which improves by keeping, and^equal in strength to the strongest spirit. Rum is a spirit obtained in the West Indies, notably in Jamaica, Mar- tinique, and Guadeloupe, from the molasses of the sugar-cane by fer- mentation and distillation. The process of fermentation of the molasses MANUFACTURE OF DISTILLED LIQUORS. 253 as carried out in Jamaica has already been described. When new, rum is white and transparent, and has when freshly distilled an unpleasant odor, due to oils contained. These are got rid of by treatment with charcoal and lime. It owes its characteristic flavor to butyric ether, which compound is also prepared artificially on a large scale, and as rum essence is used with "silent spirit " to make a factitious rum. Rum is always colored artificially with caramel-color. Whiskey is the spirit obtained from the fermented wort of corn, rye, and barley, either raw or malted. In Scotland and Ireland, malted barley, pure or mixed with other grain, is chiefly used ; in the prepara- tion of the Bourbon whiskey of Kentucky partially-malted corn and rye are taken, while for the Monongahela whiskey of Western Pennsylvania only rye (with ten per cent, of malt) is used. The difference between the Irish and the Scotch whiskeys lies mainly in the fact that the latter is distilled from barley malt dried by peat fuel, giving a characteristic smoky flavor to the spirit, while the malt of the Irish whiskey is destitute of this flavor. Both are in general pot-still whiskies, while the product of the Coffey still with less flavor is used for blending. The Irish "poteen " whiskey, however, has the smoky flavor and this is imitated by the addition of one or two drops of creosote to the gallon of spirits. 3. ALCOHOLIC BEVERAGES MADE FROM GRAIN SPIRIT BY DISTILLATION UNDER SPECIAL CONDITIONS. Gin is common grain spirit distilled and aromatized with juniper-berries, either when the "low wines " are con- centrated or later, using full-strength spirit. The proportion employed is variable, depending upon the nature of the spirit ; usually one kilo- gramme of berries is enough to flavor one hectolitre of raw grain spirit. The finest gin, known as ' ' Hollands, ' ' is made in the distilleries of Schie- dam, whence also the name "Schiedam Schnapps." Strassburg turpen- tine, oil of fennel, coriander and cardamom seeds are frequently sub- stituted either wholly or in part for the juniper-berries, particularly in the English-made gin. The quality and healthfulness of the gin depend largely upon the purity of the spirit used in the distillation, whether raw or rectified. It is obvious that many factitious brandies belong also in this class, being made by distillation of mixtures of which grain spirit is the basis and not by distillation of wine. These have already been described. 4. LIQUEURS AND CORDIALS. Liqueurs is the name now given to such spirituous drinks as are obtained by mixing various aromatic substances, such as anise, absinthe, essence of orange-peel, etc., with brandy or alco- hol. Most are obtained by steeping in pure brandy or spirit different fruits or aromatic herbs and submitting the resulting liquid to distilla- tion. They are then colored, and are usually sweetened with sugar. The best known of them, absinthe, contains a characteristic ingredient, oil of wormwood, to which its deleterious effects on the nervous system are supposed to be due. At the same time the amount of total essential oils held dissolved in the strongly alcoholic liquid is such that when diluted with water the solution becomes milky and turbid. 254 FERMENTATION INDUSTRIES. Among the liqueurs may be enumerated Absinthe (consumed chiefly in Paris), Anisette (made in the south of France), Chartreuse (made by the monks of the Grande Chartreuse Monastery near Grenoble), Curaqoa (originally made in Plolland of Curacoa oranges), Maraschino (made in Italy of Dalmatian cherries), Ratafia (made in France from a great variety of fruits), and Usquebaugh (a strong cordial made in Ireland. It furnishes the name from which the word whiskey is derived). The composition of the several alcoholic liquors enumerated cannot be given in great detail, as their differences depend so largely upon the flavoring and aromatic ethers and essential oils, which are present in very minute quantities. Their general differences in alcoholic strength and the extract and ash of several are, however, given on the authority of Konig : * Alcohol Alcohol Alcohol Alcohol by by by by volume. weight. volume. weight. Russian Dobry wutky 620 54.2 Gin ... 47.8 40.3 Scotch whiskey . . . 50.3 42.8 Ordinary German schnapps 45.0 37.9 49 9 42 3 Rum . 49.7 42.2 English whiskey . . 49.4 41.9 French Cognac brandy . . 55.0 47.3 American whiskey . . 60.0 52.2 And in one hundred cubic centimetres of the following: Specific gravity. Alcohol by volume. Alcohol by weight. Extract. Ash. 0.9158 60.5 52.7 0.082 0.024 Cognac 0.8987 69.5 61.7 0.645 0.009 Rum 0.9378 51.4 34.7 1.260 0.059 The composition of some of the well-known liqueurs is also given on the same authority : f Specific gravity. Alcohol by volume. Alcohol by weight. Extract. Cane- sugar. Other ex- tractions. Ash. Absinthe 0.9116 58 93 181 032 Bonekamp of Maag bitters Benedictine bitters . . . Ginger 0.9426 1.0709 1.0481 50.0 52.0 47 5 42.5 44.4 40 2 2.05 36.00 27 79 32.57 2592 3.43 1 87 0.106 0.043 0.141 Creme de menthe .... Anisette of Bordeaux . . Curaqoa 1.0447 1.0847 1.0300 48.0 42.0 550 40.7 35.2 47 3 28.28 34.82 28 60 27.63 3444 28 50 0.65 0.38 10 0.068 0.040 0040 Kummel liqueur .... Peppermint liqueur . . . Swedish punch 1.0830 1.1429 1.1030 33.9 34.5 26.3 28.0 28.6 21 6 32.02 48.25 36 61 31.18 47.35 0.84 0.90 0.058 0.068 * Konig, Nahrungs- und Genussmittel, 3te Auf., vol. i, p. 992. f Ibid., p. 997. $ Oil of wormwood. MANUFACTURE OF DISTILLED LIQUORS. 255 5. SIDE-PRODUCTS. The distiller's residue (Schlempe, vinasse) forms a side-product of considerable value as a cattle food because of its com- position. It is especially rich in protein matter, fat, and non-nitrogen- ous extractive, or carbohydrates. The residues from the beet- and cane- molasses distillation, moreover, yield an ash very rich in potash salts, so that they constitute, especially in France, a very important source of potashes. The constituents of several of these distillery residues in the moist state are here given on the authority of Konig : * Nitro- Non-nitro- Water. Fat. genous genous Cellulose. Ash. matter. extract. Kye-mash residues (ten analyses) . ... 93.48 0.22 1.40 4.05 0.52 0.33 Potato-mash residues (six analyses) .... 95.10 0.17 1.17 2.17 0.92 0.47 Molasses residues . . . 91.86 2.04 4.56 1.54 Two complete analyses of distillery residues dried by centrifugating and heating in kilns are given on the authority of Rosenbaum : f Water 11.62 7.83 Ash 6.50 16.40 Crude proteid matter 21.44 23.08 Crude fibre 10.54 8.60 Non-nitrogenous extractives 38.96 40.54 Crude fat 11.44 3.55 100.00 100.00 Of these constituents the following were assimilable as food: Albuminoids 17.20 Carbohydrates 37.40 Fat 9.10 18.50 39.40 2.85 IV. Analytical Tests and Methods. The most important determination in this class of beverages is the alcoholic strength. In the case of rectified or proof spirit, a simple specific gravity determination is all that is necessary, and then the per- centage strength can be found from the alcohol tables that have been prepared. The determination should be made at 15.5 C. (60 F.), or if at another temperature, a correction in the reading must be made. By multiplying the number of degrees above or below 15 by .4 and adding the product to the percentage given by the table when the tem- perature is lower than 15, or deducting it when the temperature is above, we get a correct result. In freshly-distilled and colorless whiskeys and brandies, in which the amount of extract is trifling, the alcoholic * Konig, Nahrungs- und Genussmittel, 2te Auf., vol. ii, p. 468. tJahresber. der Chem. Technol., 1887, p. 1058. 256 FERMENTATION INDUSTRIES. percentage can also be determined with sufficient accuracy by the specific gravity method. In such liquors as contain more extractive matter, like rum and the liqueurs and cordials, the alcohol must first be distilled off, and then made up to original volume with distilled water, as described on p. 235. The detection and determination of fusel oil, which is a persistent impurity in potato and grain spirit, is one of the most important tests to be made. To detect it, the greater part of the alcohol is distilled off at as low a temperature as possible, the residual liquid mixed with an equal amount of ether and well shaken. The ethereal layer is then sepa- rated and allowed to evaporate spontaneously, when amyl alcohol, if present, will be recognized in the residue by its smell and chemical characters. Petroleum-ether may be advantageously substituted for the ether in this test. Two quantitative methods are now in use, the Roese method in which the increase in volume of a measured amount of chloroform when shaken with a distillate from the sample in question is compared with that obtained in a blank experiment with fusel-free alcohol, and the Allen- Marquandt method in which the fusel oil extracted with a solvent (pref- erably carbon tetrachloride) is oxidized by bichromate of potash and sulphuric acid, the volatile acids produced distilled off and titrated with one-tenth normal sodium hydroxide solution. For full working direc- tions for the use of these processes see "Official and Provisional Methods of Analysis," Bulletin No. 107 (Revised) Bureau of Chemistry, Depart- ment of Agriculture. Caramel (burnt sugar) is used for coloring and flavoring spirits, and may be detected by the Crampton and Simons test. Evaporate fifty cubic centimetres of the sample nearly to dryness on the water-bath, wash into a fifty cubic centimetre flask, add twenty-five cubic centimetres of absolute alcohol, cool to a definite temperature and dilute to mark with water. Transfer twenty-five cubic centimetres to an apparatus such as is used in the Roese fusel oil determination, add ether (fifty cubic cen- timetres) and shake at intervals for half an hour and allow to settle. After withdrawing the water, the aqueous layer is compared with twenty- five cubic centimetres of the solution which have not been treated with ether. The amount of color removed is expressed on the percentage basis. The Amthor test, as modified by Lasche, is based upon the action of paraldehyde solution upon a sample of the liquor. A permanent tur- bidity after ten minutes indicates caramel. Tannin is often present in brandy and whiskey, being chiefly extracted from the casks used in storing. Sometimes, as in factitious brandies, it is purposely added in the form of tincture of oak-bark. It may be detected by the darkening produced on adding ferric chloride to the spirit, and any reaction thus obtained may be 'confirmed by boiling off the alcohol from another portion of the spirit and adding solution of gelatine to the residual liquid, when a precipitate will be produced if tannin be present. BREAD-MAKING. 257 E. BREAD-MAKING. Bread-making as ordinarily conducted is to be classed as one of the fermentation industries, as the swelling of the dough which must precede the baking is generally accomplished by the aid of the alcoholic fermen- tation brought about by the addition of ''leaven " or yeast. For every kilogramme of bread, on the average, 2.5 grammes of alcohol and 2.7 grammes of carbon dioxide gas are produced. Both are lost in the baking, but the carbon dioxide gas when first generated is caught in the thick and viscid dough and causes it to swell up and become spongy in structure. This not only gives to the bread when baked a porous and cellular structure, but allows the chemical changes to take place through- out its entire substance, whereby it is made more readily digestible. As the only effective result of the alcoholic fermentation is per- formed by the carbon dioxide, of course the addition of chemical mix- tures liberating carbon dioxide gas in the dough may be made to obviate the necessity of using leaven or yeast, and similarly aerated breads may be made by simply forcing carbon dioxide under pressure into the dough. A few varieties of bread are made from dough, baked without any aeration either natural or artificial, such as hard crackers, the unleavened bread of the Jews, the Scotch oat-cake, and the corn-cake of the Southern States. These exceptions are of relatively minor importance, and by far the largest amount of bread is prepared by the aid of a fermentation process. I. Raw Materials. 1. FLOTJK. This may be from either wheat, rye, barley, oats, maize, Indian corn, or rice, although wheat flour is used in far the largest amount. The average composition of the several cereals has already been given. (See page 186.) Wheat flour contains the following substances: starch, dextrine, cellulose, sugar, albumen, gliadin, or gluten, mucin, fibrin, cerealin, fat, mineral matters, and water. The first four are carbohy- drates, or non-nitrogenous substances, and they form nearly three-fourths of the entire weight of the flour. The nitrogenous matter consists of at least five principles, three of which, gluten (or gliadin), mucin (or mucedin), and fibrin, constitute the bulk of the material known as crude gluten, which is the substance left when flour is kneaded with water and afterwards washed to remove the starch and any soluble substance. The remaining two nitrogenous principles, albumen and cerealin, are soluble in water, and are carried away with the starch in the process of washing. Crude gluten possesses a peculiar adhesiveness, arising from the presence of gliadin, which is a highly tenacious body, and which is not present in the same form in other cereal flours. It is this adhesive property which gliadin imparts to gluten that renders wheaten flour so well adapted for bread-making purposes. The vegetable albumen mentioned above as soluble in cold water is accompanied also by small amounts of legumin, or vegetable casein, 17 258 FERMENTATION INDUSTRIES. which is also soluble in water. The cerealin is a soluble nitrogenized fer- ment occurring especially in the husk or bran of wheat and other cereals. It has a powerful fermentative action on starch, rapidly con- verting it into dextrine and other soluble bodies. The presence of cere- alin in bran renders "whole meal " unsuitable for making bread by fer- mentation with yeast, though it can be used with baking-powders, and "aerated bread " can be made from it. The cerealin acts like malt extract, causing a too rapid conversion of the starch into dextrine and sugar, and hence, although the bran is rich in nitrogenous food con- stituents and salts like phosphates, it is ordinarily separated from tho flour. The difference in the composition of the several parts of the wheat-grain is seen in the following table given by Church : * FINE WHITE FLOUR. COARSE WHE.VT BRAN. In 100 parts. In 1 pound. In 100 parts. In 1 pound. Water 13.0 10.5 74.3 0.8 0.7 0.7 2 ounces 35 grains. 1 297 " 11 388 " 57 " 49 " 49 " 14.0 15.0 44.0 4.0 17.0 6.0 2 ounces 105 grains. 2 175 < 7 17 < 280 ' 2 316 422 Fibrin, etc Starch, etc Fat Cellulose Mineral matter Of course, milling processes have to be specially adapted to the sepa- ration of these quite different parts of the wheat-grain, the white flour free from bran being sought. By the old-fashioned "low-milling " process, or grinding between stones placed very close together and bolt- ing, it was impossible to obtain a flour entirely free from contamination. The advance to "high-milling " with stones far apart, allowing the mid- dlings which were produced to be purified before grinding to flour, was a step which made it possible to make from winter wheat an excellent and pure flour. When, however, spring wheat with its hard and brittle outer coats became important commercially, it was necessary to resort to the roller methods of milling, which, in conjunction with peculiar purifying machinery, would furnish a flour free from all undesirable impurities. This latter process has now almost universally replaced the other in the newer mills. While most of the other cereals before mentioned may be found occa- sionally in admixture with wheat flour, very few are used alone as sub- stitutes for it. Rye flour is probably the only one. It makes a dark- colored, heavy and sourish bread, which, however, keeps moist a long time. It is much used in Germany and Northern Europe under the name of "black bread." A more palatable bread may be made from a mixture of two parts wheat flour and one part rye flour. This latter flour con- tains a slightly larger amount of fat and of mineral matter than wheat flour. It is never so white as wheat flour and the gluten has very little adhesive character. Ritthausen states that the gluten of rye flour con- * A. H. Church, Foods, etc., South Kensington Hand-book, pp. 63 and 64. BREAD-MAIQNG. 259 sists chiefly of mucin (mucedin) and vegetable casein, and that gliadin is absent entirely. 2. YEAST, OR FERMENT. The yeast is at present almost always added, either as brewer's yeast or compressed yeast. In former times (and to a considerable extent still in France) wheat bread was made by the use of leaven, which consists of a portion of dough left over from a previous baking, charged with the ferment and in part changed by its action. The leaven is originally gotten by allowing flour and water to start into spontaneous fermentation, the nitrogenous matters becoming soluble and attacking the starch and sugar. The leaven tends, however, to continue its decomposition and to pass from the alcoholic into the lactic fermen- tation. Hence, if the leaven is in the proper stage of decomposition, it will induce the alcoholic fermentation and generate carbon dioxide gas, raising the dough ; if it be, however, in a more advanced state of decom- position, lactic fermentation will be induced and the bread will not rise, but become heavy and sour. In domestic practice, to avoid this latter result, saleratus (bicarbonate of potash or soda) is added to the dough. This neutralizes the lactic acid as fast as formed, and at the same time liberates carbon dioxide gas to innate the dough. An excess of this salt, however, makes the bread alkaline to the taste and yellow in color. The black rye bread of Gfermany is also made with the aid of a leaven known as ''sour dough." In this both the alcoholic and the lactic fer- mentations are in progress, the latter, however, preponderating. Four parts of such sour dough are used for one hundred parts of flour. The brewer's yeast for bread-raising purposes must be a fresh and vigorous yeast-growth, as its value here depends largely upon the energy of the fermentation set up and the amount of gas given off. Its appear- ance and characters have been described before. (See p. 207.) Unless of the best quality, compressed yeast is to be preferred because of its reliability. The manufacture of this latter is carried out chiefly in con- nection with the spirit distilleries. At the time when the fermentation is most energetic, the yeast is skimmed off the surface and conveyed by wooden shoots to steam sieves, by which the husks are eliminated, the strained liquid passing on to the settling cisterns. When settled the surface liquid is drained off and sent for distilling purposes, and the yeasty sediment mixed with starch and put into the filter -presses, which squeeze out all the liquid, leaving a dough-like paste, which, when suffi- ciently dry, is packed into bags and packets and is ready for distribu- tion. Yeast from its peculiar slimy nature cannot be pressed well, hence the addition of starch, which permits the removal of more of the liquid from the yeast. Absolutely pure yeasts do not keep so well as the same yeasts with an addition of from five to ten per cent, of starch. In high- class yeasts the quantity added is about five or six per cent. ; it is often added in quantity beyond this as an adulterant. A good sample of com- pressed yeast has the following characteristics: It should be only very slightly moist, not sloppy to the touch; the color should be a creamy white ; when broken it should show a fine fracture ; when placed upon the tongue it should melt readily in the mouth; it should have an odor of 260 FERMENTATION INDUSTRIES. apples, not like that of cheese; neither should it have an acid taste or odor. Any cheesy odor shows that the yeast is stale and that incipient decomposition has set in. 3. BAKING POWDERS. To obviate the necessity of using yeast and waiting until the dough should rise sufficiently under the influence of fer- mentation, it was early sought to supply the necessary carbon dioxide to the dough by chemical reactions. The earliest proposal was that of Liebig to use sodium bicarbonate and hydrochloric acid, which should evolve carbon dioxide and leave sodium chloride (common salt) in the dough. Next was proposed sodium bicarbonate and tartaric acid, or acid potassium tartrate (cream of tartar). More generally satisfactory than either of these was acid calcium phosphate (either alone or with acid magnesium phosphate), which with, bicarbonate of soda formed Hors- ford's baking-powder. More objectionable was the introduction of alum with the sodium bicarbonate. Most of these baking-powder mixtures, then, have starch or flour added as "filling," and in amount varying from twenty to sixty per cent. Sesquicarbonate of ammonia is also used in many of the mixtures, replacing part of the bicarbonate of soda. Self-raising flours have these baking-powders already added to the flour in such proportions as will insure a spongy dough upon the simple addi- tion of water and kneading into loaves. n. Processes of Manufacture. 1. THE MIXING OF THE DOUGH AND ITS FERMENTATION. The mixing of the flour with water is not only for the purpose of bringing into solu- tion the dextrine, the sugar, and the soluble albuminoids, and of allowing these latter as peptones to act upon the insoluble consituents of the flour, such as the gluten, but also to penetrate and soften the starchy material. The yeast may be added directly along with the water to some of the flour to prepare a "sponge," from which the whole batch of dough is afterwards made, or a "ferment " may -be made from the yeast with potatoes, which then is used to prepare the "sponge." In the latter case, potatoes are boiled and mashed with water into a moderately thin liquor, to which the yeast is added, and the fermentation is allowed to proceed for some time. In either case, whether the yeast is used direct or a potato ferment is first made, it is worked up with a portion of the flour into a slack dough, which constitutes the sponge, and is set to rise in a warm place. When the sponge has risen sufficiently the remainder of the flour is worked in with sufficient water to which some salt has been added, and the dough is made, kneaded, allowed to stand again to rise, and then prepared for baking. The use of potato ferment is based upon the belief that the yeast-cells are strengthened by the soluble nitrogenous matter of the potato, which acts as a yeast stimulant and enables a smaller quantity of yeast to hydrolyze a larger amount of starch. The yeast-cells then act very rapidly upon the glucose so produced and develop the alcoholic fermen- tation. The albuminoids of the flour are also softened and partially pep- tonized, and these changed albuminoids in turn assist in the hydrolysis of the starch. BREAD-MAKING. 261 2. BAKING. For baking, the oven should have a temperature of 400 to 450 F. (200 6 to 230 C.). Before putting the loaves in, they are often wetted on the surface so as to assist in the prompt formation of a crust that shall prevent the dough from expanding too rapidly. The heat expands the gases throughout the loaf and so swells it and vaporizes; a portion of the moisture. The action of the heat and steam soon con- verts the starch on the surface of the loaf into dextrine and maltose, and these at the high temperature are slighly caramelized, thus giving; the crust its brownish color. At the temperature of the interior of the loaf (212 F. or slightly above) the starch-cells will have burst, the coagulable albuminoids will have been coagulated, and their diastatic power entirely destroyed. Steam is often injected into the oven during the baking. The effect is to produce a glazed surface on the outside of the crust. It not only dextrinizes and glazes the crust, but keeps the interior of the loaf moist by preventing too rapid evaporation. Of course, in perfectly tight ovens the steam resulting from the evaporation of the moisture of the bread is kept in, and soon acts in the same manner though in a lesser degree. One hundred kilogrammes of flour will yield, according to its quality, from one hundred and twenty-five to one hundred and thirty-five kilos, of bread. 3. USE OF CHEMICALS FOREIGN TO THE BREAD. Both alum and sul- phate of copper (and notably the former) have been used in baking bread from inferior or unsound flours in order to improve the appear- ance of the bread. This form of adulteration is rarely practised at present. Much more important in recent years is the practice of bleach- ing flour with nitrogen peroxide. If not used in excess this promptly whitens the gray or slightly yellowish flour and increases the whiteness of the bread baked from the same. In the Alsop process most generally employed the nitrogen peroxide is formed by a flaming electric discharge which causes nitrogen and oxygen of the air to combine. Other processes use chlorine or bromine or nitrosyl chloride. Liebig suggested the use of lime-water as a means of retarding too rapid decomposition of the starch during the fermentation of bread- making. The bread made with the proper amount of lime-water is said by Jago * to be more spongy in texture, pleasant in taste, and quite free from sourness. In the bread the lime exists as calcium carbonate, but in such quantities as to be perfectly harmless. in. Products. 1. BREAD. The nature of the change which the flour undergoes in the bread-baking process has already been indicated in part. The com- position of the finished bread can now be noted. A loaf of wheaten bread consists of two parts, the crumb and the crust, which differ somewhat in both physical and chemical character. The crumb is white in color, more or less vesicular in structure, soft when fresh, and of agreeable taste and sweet odor ; the crust is harder, more easily broken, of a chest- * Chemistry of Wheat, Flour, and Bread, etc., 1886, p. 326. 262 FERMENTATION INDUSTRIES. nut-brown color, and nearly destitute of all porous character, is sweeter in taste, because of the greater change of the starch into dextrine and maltose. The chemical differences between well-known forms of bread are shown in the following analyses from the U. S. Bureau of Chemistry, Bulletin 13, Part 9 : Number of analyses. Moisture. Proteids, N x 6.25. Proteids, N x 5.70. Ether extract. Vienna bread 10 38.71 887 8.09 1.06 Home-made bread 2 33.02 794 7.24 1.95 Graham bread 9 34.80 8.93 8.15 2.03 Rye bread 7 33.42 8.63 7.88 0.66 Miscellaneous bread 9 3441 760 693 1.48 48 ' 7.13 10.34 9.43 8.67 Rolls 11 2798 8.20 7.48 3.41 Crude fibre. Salt. Ash. Carbohy- drates, excluding fibre. Calculated calories of com- bustion. Vienna bread 062 0.57 1.19 5372 4435 0.24 0.56 1.05 56.75 4467 Graham bread 1.13 0.69 1.59 53.40 4473 Rye bread 0.62 1.00 1.84 56.21 4338 Miscellaneous bread 0.30 0.49 1.00 56.18 4429 Biscuits or crackers 047 099 1 57 73.17 4755 Rolls 060 069 131 5982 4538 The differences between wheat bread made by the usual fermentation process and wheat bread aerated by carbon dioxide under pressure (Dauglish system) are shown also in the following analyses by Dr. Bell:* CONSTITUENTS OP THE BREAD KEDUCED TO DBY STATE. AERATED BREAD. HOME-MADE BREAD. Tin loaf. Cob loaf (Paris bread). Tin loaf. Cob loaf (Paris bread). Crumb. Crust. Crumb. Crust. Crumb. Crust. Crumb. Crust. Starch, dextrine, cellulose, etc. 78.93 640 10.30 1.96 0.18 2.23 78.96 5.61 11.28 1.75 0.16 2.24 82.75 4.66 8.58 1.80 13 2.08 82.82 3.94 9.09 1.85 0.17 2.13 78.12 6.87 11.65 1.74 0.22 1.40 77.62 6.68 11.17 2.00 1.22 1.31 82.05 4.85 10.59 1.28 0.15 1.08 83.42 4.11 8.68 2.37 0.39 1.03 Nitrogenous matter, insolu- ble in alcohol Nitrogenous matter, soluble in Fat Inorganic matter or ash . . . Percentage of moisture in bread when new 44.09 19.19 41.52 16.48 42.02 22.92 41.98 20.02 Analyses and Adulteration of Foods, p. 131. BREAD-MAKING. 263 2. CRACKERS AND HARD BISCUIT are made from a dough composed of flour and water, with the addition in special cases of a great variety of sweetening and flavoring ingredients, such as milk, eggs, sugar, butter or lard, spices, and flavoring essences. The dough prepared in large masses is passed between rollers, and from the sheet of dough so obtained by other machines are cut out the various forms desired. Sheets or trays of these dough-forms pass by automatic machinery into and through long ovens at a regulated rate of speed, which can be so controlled as to give them exactly the requisite exposure to the heat needed for baking. IV. Analytical Tests and Methods 1. FOR THE FLOUR. The moisture is determined by drying five grammes of the flour in a water-oven until constant weight is obtained. The starch is estimated from the amount of glucose which is pro'duced from it by the action of dilute acid. Two grammes of the flour are boiled in a flask with inverted condenser for several hours with some twenty cubic centimetres of sulphuric acid suitably diluted. When the conver- sion of the starch is completed the solution is neutralized with soda, made up to definite volume with water, and the glucose determined with Feh- ling's solution either gravimetrically or volumetrically, as described under glucose. (See p. 175.) After deduction of the sugar found in a previous test to be contained in the sample, the difference is the amount produced from the starch, together with a small quantity from the dex- trine and traces of fibre. One hundred parts of glucose correspond to ninety of the starch. To determine the cellulose, a weighed quantity of the flour is boiled with rather dilute sulphuric acid for ten minutes to dissolve the starch. A large quantity of water is then added, and the undissolved part allowed to settle. The residue is thrown upon a filter, well washed with boiling water, and then digested with dilute potash solution to dissolve the albuminous matter. It is then washed upon a tared filter, dried, and weighed. It is now incinerated and the ash determined. This subtracted from the weight of material on the tared filter gives the cellulose or fibre. To determine the sugar, ten grammes of the flour or powdered grain are repeatedly digested in alcohol of seventy per cent, and the filtrate made up to a bulk of three hundred cubic centimetres. This solution is first tested directly for glucose, but generally with negative results. A known portion of the filtrate is then boiled for four minutes with five cubic centimetres of normal sulphuric acid, neutralized with soda and. tested with Fehling's solution, and the sugar present reckoned as cane is calculated from the result. The total nitrogenous compounds, and the portions soluble or in- soluble in alcohol, are generally determined. The total nitrogen is deter- mined by the Gunning or Kjeldahl method and the nitrogen figure mul- tiplied by 5.70 for wheat flour. For the alcohol soluble proteid ten grammes of the flour are completely exhausted with eighty per cent, alcohol at a temperature of 140 F. (60 C.) and an aliquot portion of 264 FERMENTATION INDUSTRIES. FIG. 68. 150 iflo the total filtrate evaporated to dryness and weighed. A known quantity of this residue is then analyzed for nitrogen by the Kjeldahl or Gunning process, using the same factor 5.70 as before. The flour left after treat- ment with alcohol is dried, and a weighed portion analyzed for nitrogen and similarly calculated for albuminoids (albumen and fibrin). The gluten is best determined as recommended by Wanklyn and Cooper.* Ten grammes of the flour are mixed on a porcelain plate with four cubic centimetres of water so as to form a compact dough. This is placed in a conical test-glass or measure, fifty cubic centimetres of water added, and the dough manipulated with a spatula so as to free it from starch. The water is decanted off, a fresh quantity added, and the kneading continued until the water remains colorless. The gluten mass is then removed, kneaded in a little ether, and spread out in a thin layer on a platinum dish, where it is dried by the aid of a water-oven until the weight is constant. The crude gluten contains ash equal to about .3 per cent, of the flour and fat equivalent to 1.00 of the flour. An examination of the crude gluten as to its power of dis- tending under the influence of heat is often made as a means of judging of the value of a flour for bread-making. This is done by the aid of the aleur- ometer of Boland, shown in Fig. 68. Some thirty grammes of the flour are kneaded as just de- scribed, and seven grammes of the freshly-separated crude gluten obtained is placed in the inner vessel as shown at a b. In the mean time, while the gluten is being prepared, the tube D is heated by means of an oil-bath until the thermometer T, which is at first sunk in the tube J>, registers 150 C. The thermometer is then withdrawn, and the aleurometer E, containing the gluten, put in its place. The spirit lamp under the oil-bath is allowed to burn for ten minutes longer and then extinguished. The piston G is graduated so that when pushed down it registers 25. When the gluten swells and fills the space from a & to c d it touches the bottom of the piston and is at 25. If it continues to swell the reading may be 30 or 35, as shown on the scale when the piston is pushed up. If the gluten does not indi- cate at least 25 on the aleurometer it may be considered unfit for bread- making. A similar instrument, termed an aleuroscope, has been invented by Sellnick. To determine the fat of the flour, four grammes are dried and re- * Bread Analysis, London, 1880, p. 43. BREAD-MAKING. 265 peatedly digested with ether until exhausted. The filtrates are evap- orated in a tared vessel and weighed. To determine the ash, ten grammes of the flour are incinerated in a platinum capsule to a white ash, which is then weighed. Among the adulterations of flour, besides the admixture of other starchy material of lesser value, which must be looked for with the micro- scope (see starches, p. 185), the most frequently occurring is alum. For the detection of this, one of the best known tests is based upon the prop- erty of alumina of forming a violet- or lavender-colored lake with the coloring matter of logwood. Ten grammes of the flour should be mixed in a wide beaker with ten cubic centimetres of water, one cubic centi- metre of the logwood tincture (five grammes of logwood-chips digested with one hundred cubic centimetres of strong alcohol) and an equal measure of a saturated aqueous solution of ammonium carbonate are then added, and the whole mixed together thorough^. If the flour is pure, a pinkish color, gradually fading to a dirty brown, is obtained; whereas if alum be present, the pink is changed to a lavender or actual blue. As a precaution, it is desirable to set the mixture aside for a few hours or to warm the paste in the water-oven for an hour or two and note whether the blue color remains. To determine whether flour has been bleached with nitrogen peroxide or not, two tests have been employed. The first is to shake up twenty- five grammes of the flour in a four-ounce wide-mouthed glass-stoppered bottle with gasoline. After the latter has settled, if the flour had been unbleached the gasoline will show distinctly yellow; if bleached, it will remain nearly colorless. The second test is with the reagents, sulphanilic acid and alpha-naph- thylamine chloride solutions, used to detect nitrites in water analysis. Ten grammes of the flour, one hundred cubic centimetres of distilled nitrite-free water, and four cubic centimetres of each of the reagents are shaken up in a wide-mouthed, glass-stoppered bottle. With bleached flour a pink or red tint will be developed. For the quantitative deter- mination of nitrites in flour, this latter test, known as the Griess-Ilosvay reaction, is carried out with special precaution, and the results compared with those obtained from a standard sodium nitrite solution. (See Leach, Food Inspection and Analysis, 2d ed., p. 321). 2. FOE BREAD. The methods just described under flour are almost all equally applicable to the baked bread. To test bread for adulteration from alum a slightly different procedure is to be followed. To about a wineglassful of water in a porcelain capsule five cubic centimetres of freshly-prepared tincture of logwood and the same quantity of the carbonate of ammonia solution are added. A piece of the crumb of the bread, say about ten grammes, is then soaked therein for about five minutes, after which the liquid is poured away and the bread is dried at a gentle heat. If alum be present the bread will acquire a lavender color or more or less approaching dark blue, according to the quantity of the alum which has been added; whereas if the color be a dirty brown, the bread may be regarded as pure. 266 FERMENTATION INDUSTRIES. F. THE MANUFACTURE OF VINEGAR. Under the general heading of fermentation mention was made of the acetic fermentation, which frequently follows the alcoholic fermentation. It is produced, it is true, by other species of ferments, but largely upon materials susceptible to the alcoholic fermentation or already changed by it into alcohol-containing products. The close association in nature of these two changes is readily understood when the chemical relation- ship of alcohol and acetic acid is looked at. The latter is the simple oxidation product of the former, and the processes for developing the alcoholic change in any sugary liquid, such as a beer-wort or a grape- must, have to be controlled carefully that they do not allow of this sup- plementary change whereby the alcohol goes over into acetic acid. The conditions under which the acetic fermentation sets in may be sum- marized as follows : 1. A liquid weak in alcohol, containing not more than twelve per cent, by weight of this compound. 2. Abundant access of air. 3. A temperature of from 20 to 35 C. (OS to 95 F.). 4. Acetic ferments (Mycoderma aceti, etc.), together with the food necessary for these organisms. Under this heading of acetic ferments Nageli distinguishes besides the Mycoderma aceti, the Mycoderma cere- visi(B and Mycoderma vini, although the latter of these is said by De Seynes to arrest the growth of the acetic ferment proper. Hansen also mentions a second ferment as found at times in beer along with the Mycoderma, or, as it is often termed now, Bacterium aceti, to which he gives the name Bacterium Pasteurianum. The acetic ferment, as before stated (see p. 203), develops not by the budding process characteristic of the yeast ferment, but by splitting or fissure of the elongated cell. When these germs, which originally drop from the air, like the yeast-cells, into the fermenting or sugary liquids, find a liquid specially suited for their growth, as, for example, a mixture of wine and vinegar, they develop rapidly over the surface of the liquid, where they have the necessary oxygen supply, and form a gelatinous skin, which thickens and falls to the bottom of the vessel because of its increasing weight. Another skin forms at once again, and this in turn is replaced by a third, and so on until the liquid is completely exhausted of assimilable material. This skin, called the "mother of vinegar," con- sists of a multitude of these minute fissure ferments. I. Raw Materials. Only such materials will be considered here as give rise to a vinegar by the normal acetic fermentation. The manufacture of acetic acid and technically important acetates will be spoken of later under pyroligneous acid as derived from the destructive distillation " of wood. The materials referred to as furnishing vinegar under the influence of the acetic fermentation are, first, wine; second, spirits; third, malt- wort or beer; fourth, fermented fruit juices other than wine; and, fifth, sugar-beets. THE MANUFACTURE OF VINEGAR. 267 The wines used are both red and white wines, and are such as are of inferior vintages, and considered unfit for drinking as wine. Such wines are gathered together from all sections and are made into vinegar largely in France at Orleans and at Paris. The wines do not exceed ten per cent, alcoholic strength. Wines about a year old are the best for vinegar- making, as the new wines are prone to undergo putrid or ropy fermenta- tion, and older wines do not contain sufficient extractive matter. The spirits used are chiefly the potato brandy of Germany and whiskey in this country, the vinegar in either case being made by the "quick- vinegar " process. These spirits, when used for vinegar-making, are so diluted with water and vinegar already formed that the alcoholic strength ranges between three and ten per cent. The malt-wort used for vinegar-making is exactly like that prepared for grain spirit manufacture, unmalted grain and malt being used ad- mixed, and the alcoholic fermentation being pushed so as to produce the maximum amount of alcohol from the converted starch of the grain. When the alcoholic fermentation is completed it is allowed to stand for some days in the fining- vats, where all dead yeast and cloudiness subside, and it is then made to pass through a filter-bed of wood-chips into the acetifier. The unmalted grain used in the preparation of the wort must be thoroughly dried in a kiln previous to crushing in order that many of the glutinous and albuminoid matters may be destroyed. These would otherwise interfere with the keeping qualities of the vinegar. Sour ale or beer is said not to yield good vinegar, but a product very liable to undergo putrid fermentation, a very disagreeable smell being imparted to the vinegar in consequence. Cider from apples and Perry from pears are about the only fruit juices besides wine fermented for the production of vinegar. Cider from good, sweet, and ripe apples serves for the manufacture of cider vinegar in this country. The cider is the product of a spontaneous alcoholic fer- mentation of the apple juice, and the vinegar formation may be merely a continuation of this spontaneous change, but much is now made by the quick-vinegar process, using casks containing beechwood shavings. Sugar-beets are used somewhat in France for vinegar-making. The beets are rasped to a fine pulp and pressed. The juice is diluted with water and boiled. After cooling, yeast is added and the alcoholic fer- mentation developed, and this product mixed with vinegar and treated as the other alcoholic liquids before mentioned for the development of the acetic fermentation. Artificial glucose, cane-sugar, and molasses have also been used in England for the production of vinegars which are used to adulterate malt vinegar. n. Processes of Manufacture. 1. THE ORLEANS PROCESS. This is the process by which wine vine- gar is made in France and Germany, and is the oldest in practical use of the several methods now employed. The wine which is to be acetified is allowed to stand for a time over wine-lees, and then clarified by being passed through vats containing beech-shavings. The oaken acetifying 268 FERMENTATION INDUSTRIES. vessels, holding from fifty to one hundred gallons, known as "mother- casks, ' ' are first steamed out and then soured with boiling vinegar, which is made to fill one-third of the cask. The wine is now added in instal- ments of ten litres every eight days until the cask has become more than half-full, when one-third of its contents are siphoned off into storage- vats and the periodical addition of wine continued as before. The "mother-casks," or acetifiers, can be used in this way continuously for years until the sediment of yeast, argols, and impurities makes it neces- sary to give them a thorough cleaning. The vinegar obtained in this way has a very agreeable aroma, that made from white wines being most esteemed. When the wines employed in the Orleans process are too weak it often happens that the vinegar is ropy and wanting in trans- parency. In such case it must undergo the firing process. The progress of the acetification is judged of by plunging in a rod and examining the froth upon it when withdrawn. This should be white and copious. The temperature that is found to answer best is between 24 and 26.6 C. (75 and 80 F.) Hengstenberg has proposed a modification of the Orleans process, whereby a series of the "mother-casks " are connected together at the base by short pieces of glass tubing. After the acetification of the first addition of wine in each cask the new wine is added only to the first cask, into which it runs slowly, while from the last cask of the series, by means of a siphon-tube fixed in the side, the excess flows off as finished vinegar. The increase of yield by this modification is, however, only slight. 2. THE QUICK-VINEGAR PROCESS. This process was first introduced by Schutzenbach in 1823, and has been considerably improved since. It is used exclusively in the case of spirit vinegar in Germany and in this country, and, with slight modifications, in England for malt vinegar. The vinegar-formers are upright casks from six to twelve feet in height and three to five feet in diameter. About a foot above the true bottom of the cask it has a false bottom perforated like a sieve. Upon this beech-wood shavings are heaped, extending nearly to the top of the cask. Between the true and false bottoms and just under the latter a series of holes is bored in the cask in a direction slanting downward and extend- ing around the entire cask. The beech-shavings are first boiled in water and dried. They are then soured or soaked in warm vinegar for twenty- four hours, filled into place and covered by a wooden disk perforated by fine holes in which pack-thread is loosely filled. This disk also is perforated by four larger glass tubes open at both ends, which serve as air- vents. The cask is then closed on top by a wooden cover with a single hole in the centre, through which the alcoholic liquid is to be poured and from which air may escape. The entire arrangement may be understood from Fig. 69. During the oxidation of the alcoholic liquid considerable heat is developed, and a current of air is thus made to enter through the circle of holes under the false bottom and rise through the wet shav- ings, escaping through the opening at the top. The diluted spirits or mixture to be acetified are poured into the top of each vat, and as they THE MANUFACTURE OF VINEGAR. 269 flow off, by the aid of a siphon arrangement from the base they are intro- duced into the top of the second vat. If not over four per cent, of alco- hol were contained in the original liquid, that drawn off from the second vat will be converted into good vinegar. The temperature of the vinegar- forming casks should be about 35 C. (95 F.). Above this there is too much loss of alcohol and aldehyde by evaporation; below it, the oxida- tion goes too slowly. If the minute organisms known as "vinegar eels " show themselves, hot vinegar is poured in on top until it shows a temper- ature of 50 C. (122 F.) on running off, which kills them. FIG. 69. Whiskey, brandy, and grain spirit properly diluted are all acetified by the aid of this quick-vinegar process. To these diluted spirits a small amount of malt infusion is generally added to furnish nutritive matter for the development of the acetic ferment, which in this process as in the preceding is the agency whereby the atmospheric oxidation becomes effective in changing alcohol into acetic acid. 3. MANUFACTURE OF MALT VINEGAR. This is effected by a process much resembling the quick-vinegar process. The acetifiers are, however, much larger, holding from eight thousand to ten thousand gallons. Their construction is shown in Fig. 70. Bundles of birch-twigs, B, are sup- ported upon a perforated bottom, from which the liquid trickles in fine streams. The malt-wort fed in below is warmed by a closed steam-coil of block-tin, and pumped to the top of the casks, where it is sparged, or 270 FERMENTATION INDUSTRIES. sprinkled, in fine streams over the birch-twigs, and the process repeated until the vinegar shows the requisite strength. These birch-twigs have been previously freed from all juice and coloring matter by repeated boiling with water, and are soured before starting the sparging. The entire process of making malt vinegar requires about two months. The temperature at the beginning of the process is about 43 C. (110 F.), and later is kept at 38 C. (100 F.). 4. THE MANUFACTURE OF CIDER VINEGAR. As before stated, this is largely a spontaneous fermentation. The fresh cider is allowed to fer- ment in barrels having the bung-hole open, which are exposed to the sun or placed in a warm cellar. The acetification is often made a pro- gressive change by adding fresh quantities of cider to the barrel every few weeks; the addition of "mother of vinegar " also is made to accel- erate the change. 5. PASTEUR'S PROCESS FOR VINEGAR-MAKING BY DIRECT USE OF THE VINEGAR FUNGUS. Pasteur takes an aqueous liquid containing two per cent, of alcohol and one per cent, of vinegar and small amounts of phos- phates of potassium, magnesium, and lime, and in this propagates the acetic ferment (Mycoderma aceti). The plant soon spreads out and covers the whole surface of the liquid, at the same time acetifying the alcohol. When one-half of the alcohol has been changed small quantities of wine or alcohol mixed with beer are added daily until the acetification slackens, when the vinegar is drawn off and the "mother of vinegar " collected, washed, and used again with a freshly-prepared mixture. When wine or beer is used, the addition of the phosphate salts as food for the plant is unnecessary, but when pure alcohol is used they are needed. Vinegar prepared by this process is said to possess the agree- able aroma of wine vinegar. m. Products. Wine Vinegar varies in color from light yellowish to red, according as it has been derived from white or red wines, that from the former being the most highly esteemed. The vinegar from red wines, however, can be decolorized by filtration through purified bone-black. Skimmed milk is also used for the same purpose. When thoroughly agitated with the vinegar the casein coagulates and carries down with it the greater part of the coloring matter of the vinegar, besides clarifying it. It is not used, however, so much as the filtration through charcoal. Wine vinegar has a specific gravity 1.014 to 1.022, and contains from six to nine per cent, (rarely twelve) of absolute acetic acid. When freshly made, it contains traces of alcohol and aldehyde. The amount of acid potassium tartrate (tartar) contained in wine vinegar averages .25 per cent. Its presence is peculiar to this variety of vinegar. Malt and Beer Vinegars have a higher specific gravity (1.021 to 1.025) and contain dissolved dextrine, maltose, soluble albuminoids, and similar constituents of the malt extract. This kind of vinegar on evap- oration leaves a glutinous residue only sparingly soluble in alcohol. It contains from three to six per cent, of acetic acid. THE MANUFACTURE OF VINEGAR. 271 Spirit Vinegar is colorless as produced, but is frequently colored with caramel-color to imitate the appearance of wine or cider vinegar. It contains from three to eight per cent, of acetic acid, although the so- called "vinegar essence " (double vinegar) may contain as much as fourteen per cent. Cider Vinegar is yellowish-brown, has an odor of apples, a density of 1.013 to 1.015, and contains from three and a half to six per cent, of acetic acid. It is distinguished from the other varieties by yielding on evaporation a mucilaginous extract smelling and tasting of baked apples and containing malic acid, which replaces the tartaric acid of the wine vinegar. The differences between cider vinegar and whiskey vinegar as manufactured in this country are shown in the accompanying analyses by Battershall : * Cider vinegar. Whiskey vinegar. Specific gravity 1.0168 1.0107 Specific gravity of the distillate from neutralized sample 0.9985 0.9973 Acetic acid 4.66 7.36 Total solids 2.70 0.15 Total ash 0.20 0.038 Potassa and phosphoric acid in ash . . Considerable. None. Heated with Fehling's solution Copious reduction. No reduction. Treated with basic lead acetate Flocculent precipitate. No precipitate. Glucose, or Sugar, Vinegar, prepared from different saccharine and amylaceous materials by conversion with dilute acid, followed by fermen- tation and acetification, contains dextrose, dextrine, and often calcium sulphate (from commercial glucose). It is said to be employed in France and England for adulterating wine or malt vinegars. Factitious Vinegars are often made from pyroligneous acid flavored with acetic ether and colored with caramel-color. Such a product differs from malt vinegar in containing no phosphates, and from wine or cider vinegar in the absence of tartaric or malic acids respectively. IV. Analytical Tests and Methods. The determination of the acetic acid is usually done by titration with standard alkali, using phenolphthalei'n as indicator. In the presence of free sulphuric acid, it is necessary to distil a measured quantity of the sample almost to dryness and titrate the distillate, it being assumed that eighty per cent, of the total acetic acid present passes over. The determination of the extract or solid residue in vinegar is exe- cuted in the same manner as described under beer or wine. The test for sulphuric acid is an important one. In England, the manufacturers were allowed by law to add one part of sulphuric acid by volume to one thousand of vinegar in order to protect weak vinegar from the putrid fermentation. This addition is not necessary in good vinegar and is not generally followed at present. Still, it may be present, and is to be looked for in all vinegars. The usual test with basic chloride is * Food Adulteration and Detection, New York, 1887, p. 230. 272 FERMENTATION INDUSTRIES. inoperative here, as sulphates may be present in the vinegar from the water used, etc. Hehner's test for free mineral acids (sulphuric and hydrochloric), now regarded as satisfactory in this case, is based on the fact that acetates and most other salts of organic acids are decomposed by ignition into carbonates, having an alkaline reaction to litmus, while sulphates and chlorides of the light metals are unchanged on ignition and possess a neutral reaction. To determine the amount of free mineral acid it is sufficient therefore to carefully neutralize the vinegar with standard solution of soda before evaporation to dryness (the same process serving for a determination of the total free acid), ignite the residue, and titrate the aqueous solution of the ash with standard acid. If the free acid originally present were wholly organic, the ash will contain an equivalent amount of alkaline carbonate, which will require an amount of standard acid for its neutralization exactly equivalent to the amount of standard alkali originally added to the vinegar. Any deficiency in the amount of standard acid required for neutralization is due to the free mineral acid originally present in the vinegar. The tartaric acid, a normal constituent of wine vinegar, may be tested for by evaporating to dryness and treating the extract with alcohol, which dissolves nearly everything but the tartar or acid potassium tar- trate. On pouring off the alcohol and dissolving this in a little hot water its nature can be easily shown by the usual tests for tartaric acid. Caramel is recognized by extracting the solid residue with alcohol and evaporating the solution to dryness; in its presence the residue now obtained will possess a decidedly dark color and a bitter taste. Metallic impurities, such as lead, copper, and zinc, are at times to be found arising from the use of metallic vessels for storing the vinegar. Arsenic has also been found as an impurity through the use of impure sulphuric or hydrochloric acid. They are all detected by the usual qualitative tests. V. Bibliography and Statistics. BIBLIOGRAPHY. OF FERMENTATION AND ITS INDUSTRIES IN GENERAL. 1879. Studies on Fermentation, M. Pasteur, translated by Faulkner and Robb, London. Theorie der Giihrurig, C. von Nageli, Miinchen. 1883. The Brewer, Distiller, and Wine Manufacturer, J. Gardner, Philadelphia. 1884. Falsifications des Mati&res alimentaires, Laboratoire Municipal, 2e Rapport, Paris. 1887. United States Department of Agriculture, Bulletin No. 13, Part iii. (Fer- mented Alcoholic Beverages), C. A. Crampton, Washington. Fermentation, P. Schiitzenberger (Inter. Science Series), New York. 1889. Les Fermentations, E. Bourguelot, Paris. Chemie der menschlichen Nahrungsmittel, J. Konig, 3te Auf., Berlin. 1892. Untersuchungen aus der Praxis der Gahrungs-Industrie, E. Ch. Hansen, zwei Hefte, Miinchen. 1893. Micro-organisms and Fermentation, A. Jorgensen, translated by A. K. Miller and E. A. Lennholm, London. 1896. Practical Studies in Fermentation, E. Ch. Hansen, translated by A. K. Miller, New York. BIBLIOGRAPHY AND STATISTICS. 273 1898. Technical Mycology, the Utilization of Micro-organisms, etc., F. Lafar, trans- lated by Chas. T. C. Salter, vol. i., Philadelphia. 1899. Les Enzymes et leurs applications, J. Effront, Paris. The Soluble Ferments and Fermentation, J. Reynolds Green, Cambridge, England. 1000. Die Diastasen und ihre rolle in der Praxis, J. Effront, iibersetzt bei M. Biicheler, Band i., Leipzig. 1905. Abriss der mykologischen Analyze, etc., Bauer, Braunschweig. 1907. Handbuch der technischen Mykologie, F. Lafar, 2te Auf., 5 Bde., Jena. 1908. Die Hefepilze, Kohl, Leipzig. 1910. Die Fermente und ihre Wirkungen, C. Oppenheimer, 3rd Auf., Berlin. ON MALTING AND BREWING AND THEIR PRODUCTS. 1876. fitudes sur la Bi&res, ses Maladies, etc., M. Pasteur, Paris. 1877. Hops: their Cultivation, Commerce, and Uses, P. L. Simmonds, London. 1878. Lehrbuch der Bierbrauerei, C. Lintner, Braunschweig. 1880. Die Fabrikation von Malz, Malzextract, and Dextrin, J. Bersch, Berlin. 1882. Preparation of Malt and Fabrication of Beer, Thaussing, edited by Schwarz and Bauer, Philadelphia and London. 1884. Handbuch der Bierbrauerei, L. von Wagner, 6te Auf., 2 Bde., Braunschweig. 1886. Die Malz-Fabrikation, K. Weber. 1888. The Theory and Practice of Modern Brewing, F. Faulkner, 2d ed., London. 1889. Manuel pratique de la Fabrication de la Biere, P. Boulin, Paris. The Microscope in the Brewery, Matthews and Lott, London. 1891. Handbuch der Bierbrauerei, E. Ehrich, 5te Auf., Halle. Text-Book of the Science of Brewing, edited by Morritz and G. H. Morris, London. 1892. Untersuchung des Maizes, Windisch, Berlin. 1893. La Biere, H. Boucheron, Paris. 1894. Die Bierbrauerei, Dr. B. von Posanner, Wien. 1895. Systematic Book of Practical Brewing, E. R. Southby, 3d ed., London. Handy-Book for Brewers and Practical Guide to Malting, H. E. Wright, 2d ed., London. 1897. The Principles and Practice of Brewing, W. J. Sykes, London. 1898. The Laboratory Text-Book for Brewers, L. Briant, 2d ed., London. 1907. Theorie und praxis der malzbereitung und bierfabrikation, Thausing, Leip- zig. The Brewer's Analyst A systematic hand-book of analysis of materials used for brewing and malting, R. D. Bailey, London. Das Chemische Laboratorium des Brauers, Wilh. Windisch, 5th Auf., Berlin. 1908. Hopfenbau und hopfenbehandlung, Fruwirth, Berlin. ON WINKS. 1872. Treatise on the Origin, Nature, and Varieties of Wine, Thudichum and Dupre", London. 1873. fetudes sur le Vin, ses Maladies, etc., M. Pasteur, 2me e"d., Paris. Die Kiinstliche Weinbereitung, F. J. Dochnahl, 3te Auf., Frankfort. 1878. Die Bereitung des Schaumweines, etc., A. von Regner, Wien. 1879. Die Bereitung des Schaumweines, etc., A. von Regner, Wien. Ueber die Chemie des Weines, C. Neubauer, Wiesbaden. 1881. Handbuch des Weinbaues, etc., A. von Babo, 2 Bde., Braunschweig. 1884. Die Weinanalyze, Max Earth, Leipzig. Anleitung zur chemischen Analyse des Weines, Eug. Borgmann, Wiesbaden. Die Chemie der Rothweine, E. Roth, 2te Auf., Heidelberg. A History of Champagne, H. Vizetelly, London. 1888. Die Praxis der Weinbereitung, J. Bartsch. 18 274 FERMENTATION INDUSTRIES. 1889. 'Manuel de 1'Analyze des Vins, E. Barillot, Paris. Chimie des Vins, A. de Saporta, Paris. Wines and Vines of California, F. E. Wait, San Francisco. Practische Anleitung feinste Desertweine, etc., darzustellen, L. Gall, 4te Auf., Wien. 1890. Trait6 theorique et pratique du Travail des Vins, 2 vols., 3me ed. E. Maumene", Paris. The Cider-Maker's Handbook, J. M. Trowbridge, New York. 1891. Sophistication et Analyse des Vins, A. Gautier, 4me 6d., Paris. 1892. Le Vin et 1'Art de la Vinification, Victor Cambon, Paris. Analyse des Vins, M. de la Source, Paris. Die Champagne-Fabrikation, Adal Piaz, Wien. L'Essai commercial des Vins et des Vinaigres, Dujardin, Paris. 1896. Manuel gn6ral des Vins, E. Robinet, 5me e"d., 3 vols., Paris. 1899. Proce"de"s modernes de Vinification, 2me 6d., Coste-Floret, Montpellier. Trait6 pratique d'Analyse chimixrue des Vins, J. Roussel, Paris. 1905. Lehrbuch der chemischen technologie der landwirthchaftlichen gewerbe, Ahrens, Berlin. 1908. Die Bereitung, Pflege und Untersuchung des weines, J. Nessler, 8th Auf., von Carl Windisch, Stuttgart. 1909. Die Wein bereitung und Kellerwirthschaft, by A. Dal Piaz, Wien. ON SPIRITS AND DISTILLED LIQUORS. 1879. Treatise on the Manufacture of Alcoholic Liquors, P. Duplais, translated by M. McKennie, Philadelphia. 1885. Practical Treatise on the Distillation, etc., of Alcohol, Win. T. Brannt, Phila- delphia. 1886. Die Fabrikation von Rum, Arrak, Cognac, etc., A. Gaber, Leipzig. 1889. Ueber Branntwein, seine Darstellung, etc., Dr. Eugen Sell, Berlin. 1890. Ueber Cognac, Rum and Arrak, etc., Dr. Eugen Sell, Berlin. La Fabrication de 1'Alcool, 7 Fascicules, J. P. Roux, Paris. 1891. Die Cognac und Weinspirit Fabrikation, A. del Piaz, Wien. Untersuchungs-Methoden der Spiritus Industrie, E. Bauer, Braunschweig. 1892. Nouveau traite" de la Fabrication des Liqueurs, etc., Fritsch et Fesq, Paris. 1893. Les Eaux-de-Vie et la Fabrication du Cognac, A. Baudoin, Paris. Manufacture of Liquors and Preserves, J. de Brevans, New York. The Manufacture of Spirit, J. A. Nettleton, London. 1894. Manuel des Fabricants d'Alcools, Barbet et Aracheguesne, Paris. Handbuch der Spiritus-Fabrikation, M. Maercher, 6te Auf., P. Parey, Berlin. Die Spiritus-Fabrikation, Essigerzeugung und Weinbereitung, Dr. B. von Posanner, Wien. 1895. La Chimie du Distillateur, M. P. Guichard, Paris. 1899. Trait6 complet de la Fabrication de PAlcool, etc., G. Dejaghe, Lille. Les Eaux-de-Vie et Liqueurs, X. Rocques, Paris. Manuel pratique de 1'Analyse, des Alcools et des Spiritueux, Girard et Cuniasse, Paris. 1900. Trait6 de la Fabrication des Liqueurs et de la Distillation, P. Duplais, 7me 6d., Paris. 1907. Industrial Alcohol, its Manufacture and Uses, J. K. Brachvogel, New York. Denatured or Industrial Alcohol, R. F. Herrick, New York. Industrial Alcohol, Production and Use, J. G. Mclntosh, London. 1908. Handbuch der spiritus-fabrikation, M. Maercker, 9th Auf., Herausgegeben von Dr. M. Delbruck, Berlin. ON THE MANUFACTURE OF VINEGAR. , 1868. fitudes sur le Vinaigre, M. Pasteur, Paris. 1876. Lehrbuch der Essigfabrikation, P. Bronner, Braunschweig. 1877. Die Essigfabrikation, J. C. Leuchs, 7te Auf. BIBLIOGRAPHY AND STATISTICS. 275 1880. Fabrication industrielle des Vinaigres, Claudon, Paris. 1885. Acetic Acid and Vinegar, John Gardner, Philadelphia. 1890. Vinegar: a Treatise on the Manufacture of Vinegar, etc., Wm. T. Brannt, Philadelphia. 1892. L'Essai commercial des Vins et des Vinaigre^ Dujardin, Paris. 1895. Die Essigfabrikation, Dr. J. Bersch, 4te Auf., Wien. 1907. Die Untersuchungs methoden, etc., des gab. rung-ess igs, Dr. Fritz Rothenbach, Berlin. ON FLOUR AND BREAD. 1878. Das Brodbacken, K. Birnbaum, Braunschweig. 1880. The Chemistry of Bread-Making (Lectures before Society of Arts), Chas. Graham, London. 1884. Die Fabrikation des Mehls und seine neben Producte, H. Meyer, 2 Theile, Leipzig. 1886. Bread Analysis, Wanklyn and Cooper, 2d ed., London. United States Department of Agriculture, Bulletins Nos. 1, 4, 9 (American Cereals), C. Richardson, Washington. The Chemistry of Wheat, Flour, and Bread, W. Jago, Brighton. 1889. Handbuch der Presshefe-Fabrikation, Otto Durst, Berlin. United States Department of Agriculture, Bulletin No. 13, Part v. (Bak- ing-Powders ) , C. A. Crampton, Washington. 1890. Presshefe, Kunsthefe und Backpulver, A. Wilfert, 2te Auf., Wien. 1892. Le Pain et la Viande, J. de Brevans, Paris. The Dietetic Value of Bread, J. Goodfellow, London. 1895. Text-Book of Science and Art of Bread-Making, W. Jago, London. 1897. Modern Flour-Milling, W. R. Voller, 3d ed., Gloucester, Eng. STATISTICS. I. PRODUCTION OF HOPS THROUGHOUT THE WORLD. From the U. S. Consular Keports the total crop of hops throughout the world for the last three years is given as follows: TOTAL CROP IN CWT. OF 110 LBS. Countries 1909 1910 1911 Germany 119,000 384,000 222,000 Austria-Hungary 164,000 297,000 178,000 France 27,000 54,000 45,000 Belgium and Holland 29,000 58,000 52,000 Russia 60,000 58,000 62,000 England 205,000 296,000 354,000 America 310,000 400,000 400,000 Australia 10,000 10,000 15,000 924,000 1,557,000 1,328,000 The United States imports a limited quantity of hops, but exports a much larger amount. The figures for recent years were : 1906. 1907. 1908. 1909. 1910. Imports in pounds 9,630,206 5,733,386 8,636,192 7,383,907 3,185,991 Valued at $2,266,333 $1,813,306 $1,911,602 $1,335,300 $1,492,779 Exports in pounds .. . 13,026,904 16,809.534 22,920,480 10,446,884 10,589,254 Value;! at $3,125,843 $3,531,972 $2,963,167 1.271.62:) $2,002,140 276 FERMENTATION INDUSTRIES. II. tt. BEEE PRODUCTION IN THE UNITED STATES. According to the reports of the Commissioner of Internal Revenue, there were brewed in the United States the following amounts of malt liquors : Bbls. (31 gallons or 117.3 litres). 1905 49,459,540 1906 54,724,553 1907 58,546,111 1908 58,747,680 1909 56,364,360 1910 ' 59,544,775 II. 6. PRODUCTION OF DISTILLED SPIRITS IN THE UNITED STATES (IN GALLONS). From grain and cereals. From fruit. 1906 145,666,125 4,444,072 1907 168,573,913 6,138,305 1908 126,989,740 6,899,823 1909 133,450,755 6,440,859 1910 156,237,526 7,656,433 Totals. 150,110,197 174,712,218 133,889,563 139,891,613 163,893,960 II. C. BEER PRODUCTION AND CONSUMPTION OF THE WORLD FOR 1904 AND 1905. Production 1904. Great Britain 56,395,360 Russia 6,560,140 Norway 295,020 Sweden 2,751,210 Denmark 2,451,460 Germany 69,538,590 Belgium 15,163,830 France 14,125,320 Switzerland 2,093,850 Italy 227,700 Austria 19,621,800 Hungary 1,500,840 Bulgaria 64,340 Servia 75,240 United States 57,546,310 in hectolitres. 1905. 54,842,670 307,890 2,415,010 72,027,450 15,592,500 13,283,820 235,620 10,908,010 1,485,990 88,110 63,591,840 Consumption per capita in litres. 1904. 1905. 129.60 124.65 4.54 13.05 13.50 52.20 92.25 92.25 115.65 118.35 216.90 219.60 34.45 33.75 64.35 0.90 0.99 68.40 64.35 8.10 8.10 1.67 2.21 2.97 68.80 75.60 248,410,000 245,778,910 58.25 68.48 (English Parliamentary Report on Alcoholic Beverages, 1905. ) III. WINE PRODUCTION OF THE WORLD FOR 1897 AND 1898. 1S<7. 1898. Hectolitres. Hectolitres. France 32,350,700 32,282,300 Algeria and Tunis 4,457,758 5,341,000 Italy 25,958,500 31,500,000 Spain 18,900,000 24,750,000 Portugal 2,500,000 2,100,000 Austria-Hungary 3,000,000 2,800,000 Russia 2,500,000 3,120,000 Switzerland 1,250,000 1,160,000 Germany 2,775,576 1,406,818 Roumania 3,200,000 3,900,000 United States 1,147,000 1,300,000 Other countries 10,261,000 9,975,000 108,300,534 119,635,818 BIBLIOGRAPHY AND STATISTICS. 277 IV. a. CONSUMPTION OF SPIRITS, WINES, AND MALT LIQUORS IN THE UNITED STATES. Distilled spirits (proof gallons). Wine (gallons). Malt liquors (gallons). Per cap. Per cap. Per cap. 1905 120,869,649 (1.45) 35,059,717 (0.42) 1,538,526,610 (18.50) 1906 127,851,583 (1.52) 46,485,223 (0.55) 1,700,421,221 (20.19) 1907 140,084,436 (1.63) 57,738,848 (0.67) 1,823,313,525 (21.24) 1908 125,379,314 (1.44) 52,121,646 (0.60) 1,828,732,448 (20.98) 1009 121,130,036(1.37) 61,779,549(0.70) 1,752,634,426(19.79) (Statistical Abstract of United States.) IV. 6. CONSUMPTION OF SPIRITS, WINES, AND BEER DURING 1901-1908 PER CAPITA IN DIFFERENT COUNTRIES (IN IMPERIAL GALLONS). Spirits. Wine. Beer. Australia 0.89 1.29 11.88 Belgium 1.06 1.02 47.75 Canada 0.86 0.09 5.01 Denmark 2.54 20.58 France 1.35 30.67 7.92 Germany 1.55 1.45 26.25 Holland 1.50 0.37 6.50 Italy 0.25 25.04 0.14 Norway 0.62 3.45 Russia 0.94 0.98 Sweden 1.46 12.60 Switzerland 0.97 13.65 13.88 United Kingdom 1.00 0.32 29.45 United States 1.45 0.52 18.50 (Webb, Dictionary of Statistics, 1910.) 278 MILK INDUSTRIES. CHAPTER VII. MILK INDUSTRIES. I. Raw Materials. MILK is the fluid secreted by the females of the mammalia for the nourishment of their young, and is therefore a food specially adapted for the needs of the animal organism at this stage, furnishing all the nutrients required and furnishing them in the proper proportion. As will be seen from its analysis, it occupies an intermediate position between the cereal and the strictly animal foods, approximating, of course, more nearly the latter, but showing in one important constituent, milk-sugar, its rela- tionship to the former. Milk is a secretion of the mammary glands, in which it is produced proximately by certain processes of diffusion from the blood and imme- diately by the breaking down of the gland-cells themselves, so that milk is described as cell-material liquefied. The milk of all mammalia is essentially the same in its constituents, although these vary somewhat iu their relative proportions. The essential constituents of milk are water, fat, casein, albumen, milk-sugar, and salts. The relative proportion of these constituents in the milk of different animals may be seen from the following table of analyses from Wynter Blyth : * Fat. Casein. Albu- men, Milk- sugar. Ash. Total solids. Water. Human milk 2.90 2.40 0.57 5.87 0.16 12.00 88.00 Cow's milk 3.50 3.98 0.77 4.00 0.17 13.13 86.87 Camel's milk 2.90 f~ 3. 1 , 84 5.66 0.66 13.06 86.94 Goat's milk 420 v 300 , * 062 400 056 12.46 87 54 Ass's milk 1 02 1.09 0.70 650 0.42 8-83 91.17 Mare's milk 2 50 2.19 0.42 5 50 0.50 11.20 88.80 Sheep's milk 530 6.10 1 00 420 1.00 17.73 82.27 In taking up milk as a raw material for industrial utilization, we shall refer to cow's milk exclusively unless otherwise specified. The fat exists in the milk in the form of minute globules suspended in a thin liquid, forming for the time a perfect emulsion with the aqueous solution of the -other constituents. The fat is essentially an intimate * Foods, Composition and Analysis, 1882, pp. 214, etc. RAW MATERIALS. 279 mixture of the glycerides of the fatty acids, palmitic, stearic, and oleic, not soluble in water, and of the glycerides of certain soluble volatile acids, such as butyric, caproic, caprylic, and capric. The casein of milk exists in the fresh milk as a diffused colloidal compound of albumen and calcium phosphate, which by the action of rennet (a ferment from the calf's stomach) is converted into the in- soluble one known as casein. The casein precipitated by rennet con- tains five to eight per cent, of ash, consisting almost entirely of calcium phosphate. If, however, this calcium phosphate compound of albumen is decomposed by mineral acids or acetic acid, the casein precipitated contains only traces of ash. Lactic acid gives the same result, so that the casein coagulated by the souring of the milk shows less ash than that precipitated by rennet from sweet milk. On the other hand, carbon dioxide will act like rennet. The soluble compound existing in the fresh milk is considered to be that of the tricalcium phosphate with- albumen, while the insoluble one precipitated by rennet is the acid calcium phos- phate with albumen. Pure casein is a perfectly white brittle crumbling substance, insoluble in water, but soluble in very dilute acids or very dilute alkalies. In the action of rennet and acids upon casein a portion is apparently altered into what are called peptones (lacto-protein or lacto-peptone) and remains dissolved in the whey of the milk. The albumen (or soluble nitrogenous matter) of milk seems to be analogous to the albumen of blood. It may be obtained by precipitation with basic acetate of lead or by dialysis as a yellowish flaky mass. The proportion of albumen in milk is always, according to Wynter Blyth, about one- fifth of the casein. Two additional nitrogenous compounds have been found by Blyth to exist in small amounts in milk, to which the names galactine and lacto- chrome have been given. Milk-sugar, which is an important and characteristic constituent of the milk, is obtained from the serum, or ' ' whey. ' ' After the separation of the curd has been effected by the addition of rennet the whey is evaporated on the water-bath, and yields the milk-sugar in hard crys- tals. These when purified by animal charcoal and recrystallized show the composition C^H^O^ -f- H 2 O. It is easily distinguished from other sugars of the same formula. It is converted by boiling with dilute acids into dextrose and galactose, which latter has one-fifth less copper-reducing power than dextrose. It undergoes the lactic fermen- tation readily but the alcoholic with some difficulty. The ash of milk consists of calcium citrate and the phosphates and chlorides of potassium, sodium, calcium, and magnesium, the salts that are specially needed for the growth of the bone-material in the young nourished by the milk. Cow's milk is a white or yellowish- white liquid nearly opaque, ex- cept in very thin layers, when it has a bluish opalescent appearance, and a specific gravity of from 1.029 to 1.035. It has a mild sweetish taste and a slight but characteristic odor, stronger when still warm from the 280 MILK INDUSTRIES. cow. Upon allowing milk to remain at rest for some time it undergoes two changes : First, a yellowish- white layer forms on the surface known as ' ' cream, ' ' due to the rising of the specifically lighter fat-globules from the body of the liquid where they were held back in emulsion with the aqueous liquid; and, second, the aqueous liquid after a time undergoes further separation into a thick coagulum or "curd " of casein and a thinner liquid or "whey," holding the sugar of milk, any lactic acid formed from it, and the salts in solution. Both of the changes are of the greatest importance, as upon them are based the great milk indus- tries, butter-making and cheese-making respectively. The rising of the cream is largely dependent ordinarily upon two conditions: First, the temperature, a low temperature being favorable to the separation; and, second, complete freedom from agitation. These conditions are not, however, indispensable, as will be seen later (p. 282) in speaking of the use of centrifugals for the separation of cream. The rising of the cream is generally allowed to be an entirely spon- taneous change on the part of the milk and the first one which it under- goes, but in some creameries a little sour milk (containing lactic acid) is added to the fresh milk, when first put in the cream-rising pans, so that the curdling of the casein may facilitate the escape of the fat- globules and the rising of the cream. In such a case what remains on removal of the cream is not ordinary skimmed milk, but a sour curdled milk. The second change mentioned, that of curdling, is really preceded by a change of some of the milk-sugar into lactic acid (due to lactic fermentation, which sets in very quickly in hot weather or if the milk has not been kept in clean vessels). This souring of the milk may be retarded by the addition of a little carbonate of soda or boric acid. The lactic acid as soon as liberated decomposes the soluble casein compound, before referred to (see p. 279), and the casein is thrown out or coagulated as ' ' curd. ' ' The separation of the curd is aided by heat. The liquor in which this coagulated casein floats, the serum of milk, or ".whey," con- tains about one-fourth of the nitrogenous matter of the milk, all of its sugar, and most of its mineral matter. The whey is "sour whey " in case lactic acid has formed as the antecedent of the coagulation, or "sweet whey " in case the casein is thrown out by the action of rennet without the formation of lactic acid. The composition of the several parts into which the milk is divided by these changes is thus given by Fleischmann: Water. Fat. Casein. Albumen. Milk-sugar. Ash. Whole milk 87.60 3.98 3.02 0.40 4.30 0.70 Cream 77 30 15.45 3.20 020 3.15 0.70 Skim-milk ........ 9034 1 00 2 87 * 45 4.63 0.71 Butter 14 89 8202 1 97 028 028 056 Buttermilk 91.00 0.80 3.50 0.20 3.80 0.70 Curd 59.30 6 43 2422 3.53 5.01 1.51 "Whey 9400 035 040 0.40 4.55 0.60 PROCESSES OF MANUFACTURE. 281 And the relative yield of these several constituents from one hundred parts of milk is thus given by the same author : . 100 parts of sweet milk will yield (by natural cream-raising or by centrifugal cream-separating) ' T 1 20 parts of cream, which 79.70 parts of skimmed milk, which 0.30 parts (churned into butter) (coagulated by rennet or acids) loss, will yield will yield 3.56 parts 16.30 parts 7.93 parts 71.45 parts butter. buttermilk. curd. whey. 0.14 loss. 0.32 loss. 0.30 loss n. Processes of Manufacture. 1. MANUFACTURE OF CONDENSED AND PRESERVED MILK. Condensed milk is milk from which a large portion of the water originally present has been driven off, increasing, of course, in a proportionate degree the percentage of the other constituents. This condensed product may or may not have cane-sugar added to it as a preservative. That to be pre- served with cane-sugar is made much more concentrated, and is that which is manufactured for export and preservation in sealed tin cans. In its preparation, the milk is first heated to 65.6 to 80 C. (150 to 175 F.) by placing the cans containing the milk in hot water, and is .then strained and conveyed to the evaporating vessels, which are usually vacuum-pans. Refined sugar is added during the boiling to the amount of one to one and a half pounds for every quart of the condensed milk produced. The product is drawn off into cans, cooled to about 70 F., and then weighed into tins, which are at once soldered down. Condensed milk free from cane-sugar is only concentrated to about one-half the degree attained in the other product, and is then cooled and filled into stone or glass flasks provided with ordinary air-tight stoppers. It will remain fresh for from one to two weeks, and requires only to be diluted with its own bulk of water in order to yield the counterpart of the original milk. Preserved milk is either prepared by Appert's process, which con- sists in boiling the milk to destroy ferments and keeping it then in her- metically-sealed vessels, or by Scherff's improved process, whereby the milk is filled into glass bottles which are stopped with corks previously steamed and then fastened in by clamps, and then heated in closed boilers under a pressure of from two to four atmospheres to about 120 C. The bottles are then taken out of the pressure-vessel and cooled down, with the corks covered with flannel soaked in paraffin, so that as they cool the air entering through the pores of the corks shall be filtered. "When cooled down, the cork, which has been drawn into the neck of the bottle considerably, is covered with a layer of paraffin. This kind of preserved milk is used largely in Germany for invalids and children. 2. OF BUTTER. The first operation in this connection is the separa- tion as completely as possible of the cream from the rest of the milk. This is generally a spontaneous process, it is true, but its completeness is dependent largely upon the conditions before referred to. There are 282 MILK INDUSTRIES. various ways in which, the raising of the cream is allowed to take place. We may mention the Holstein process, in which the fresh milk is at once set to raise cream in wide shallow pans at a temperature of 12 to 15 C. (53.6 to 59 P.), the Dutch process, in which it is first rapidly cooled down in large vessels immersed in cold water to about 15 C. (59 P.) and then transferred to the shallow pans for the raising of the cream, and the Schwartz process, largely used in Northern Europe, which differs from the Dutch process chiefly in using much deeper pans at a lower temperature, 4.4 to 10 FIG. 71. C. (40 to 50 P.). Very similar to this last mentioned are the Hardin and the Cooley methods, which also use deep cream-raising pans. In the former of these, ice and not ice-water is used to effect the cooling, the pans being exposed to the influence of air cooled by ice, the claim being made that the cream is obtained in more solid condition. In the FIG. 72. Cooley method, used largely in this country, the water not only sur- rounds the can outside as high as the milk inside, but is made to rise an inch or two above the lid, so that the can is completely submerged and all contamination from external sources prevented. The processes which use shallow pans give a larger yield of cream but take a longer time (thirty-six to forty-eight hours as against eighteen to twenty-four for those using deep pans). Within twenty years past the principle of the centrifugal has been applied to the separation of the cream from the milk, and this has proven itself so successful that in most large creameries it is now utilized. The milk is placed in a hori- zontal rotating vessel driven at a high rate of speed, which causes the heavier milk fluid to gravitate towards the circumference of the vessel, PROCESSES OF MANUFACTURE. 283 whilst the cream remains nearer the centre and rises towards the upper part of the rotating bowl, whence it is removed by a conveniently-placed aperture on the side of the vessel. An exit is also provided for the gradual removal of the skimmed milk, thus making room for fresh milk to be added to the apparatus and allowing the process to be carried on continuously. Figs. 71 and 72 show the Laval cream separator in gen- eral view and in section. The fresh milk is admitted through a funnel, the tube of which is prolonged so as to deliver the milk near the bottom of the revolving drum. The skim-milk flows out through an opening, t, and the cream through a higher opening, the relative position of which can be changed by an adjustable screw above. The cream obtained by these centrifugal separators seems to be freer from mechanically- enclosed casein than that gotten in any of the old separation processes, as is seen in the appended cream analyses by Bell,* where samples 2 and 6 were separated by the centrifugal separator: Water. Fat. Milk- sugar. Casein. Ash. I. Raw cream 54.02 39.40 1.85 3.76 0.57 2 Raw cream 60.66 33.60 2.43 2.90 0.41 8, 67.93 24.44 2.96 4.04 0.63 4 Raw cream 5807 35 67 220 3.55 0.51 5 Raw cream 63.07 30.74 2.61 3.04 0.54 6 Thick cream 37.62 58.77 1.46 1.83 0.32 7 Devonshire clotted cream 33 76 59.79 1.01 4.97 0.47 ! The composition of the skimmed milk of course varies according to the extent to which the cream has been removed. The following analyses by Voelcker represent its average composition as obtained in the ordinary way and as obtained by the Laval separator : Water. Butter- fat. Casein. Milk- sugar. Ash. Ordinary skimmed milk 89.25 1.12 3.69 5.17 78 Skimmed milk by Laval separator 90.82 0.31 3.31 4.77 0.79 The coalescence of the fat-globules separated in the cream layer is now to be effected to form the compact butter. This is almost univer- sally accomplished by mechanical agitation in the process called churn- ing. The churns may be of very diverse construction, either for hand or power. The cream may be taken as ' ' sweet cream ' ' freshly separated in the centrifugal or raised from deep pans where the skim-milk is still sweet, or it may be "sour cream," which has stood longer and has separated slowly in shallow pans. The sour cream is more easily churned, but the butter will contain more casein, while sweet cream yields a butter with pleasanter taste and better keeping qualities because containing less * Analysis and Adulteration of Food, p. 35. 284 MILK INDUSTRIES. casein. The temperature most favorable for churning is about 15.5 C. (60 F.). Sometimes cream is heated to a much higher temperature first, and then cooled down to 60 F. before being churned. Butter thus made keeps well. Butter has almost invariably some salt added to it even when for immediate consumption; the quantity in this case need not be large (five-tenths to two per cent.), but when it is to be packed for preser- vation or for export considerably more is added, so that it is known as "salt butter." Export butter has also a small addition of sugar, and sometimes saltpetre, added, as well as salt, to preserve it. Genuine FIG. 73. butter will always have a yellowish color, which, however, becomes deeper in summer when the cows have an abundance of fresh pasture. Most butter manufacturers now add a little vegetable coloring matter like annotto, arrot-color, or saffron, to give the butter this desired yellow tint in winter, when the butter would otherwise be very much lighter in color. All butter will in time become rancid and take a strong dis- agreeable odor. This is due to the gradual spontaneous decomposition of the butyric ether under the influence of air and light whereby free butyric acid is liberated. The composition of butter will be more fully spoken of later on in discussing the products of these industries. 3. OF ARTIFICIAL BUTTER (Butterine, Oleomargarine}. The manu- facture of substitutes for normal dairy butter began with the experiments of the Frenchman Mege-Mouries in 1870. He found that carefully- PROCESSES OF MANUFACTURE. 285 washed beef-suet furnished a basis for the manufacture of an excellent substitute for natural butter. The thoroughly- washed and finely-chopped suet was rendered in a steam-heated tank, taking for one thousand parts of fat, three hundred parts of water, one part of carbonate of potash, and two stomachs of pigs or sheep. The temperature of the mixture was raised to 45 C. After two hours, under the influence of the pepsin in the stomachs, the membranes are dissolved and the fat melted and risen to the top of the mixture. After adding a little salt, the melted fat is drawn off, stood to cool so as to allow the stearin and palmitin to crys- tallize out, and then pressed in bags in a hydraulic press. Forty to fifty per cent. .of solid stearin remains, while fifty to sixty per cent, of fluid FIG. 74. oleopalmitin (so-called "oleomargarine ") is pressed out. Mege then mixed the ' ' oleo oil ' ' with ten per cent, of its weight of milk and a little butter-color and churned it. The fat-cutting process of Mege-Mouries is shown in Fig. 73 and the churning of the "oleo oil " in Fig. 74. The product was then worked, salted, and constituted the "oleomargarine," or butter substitute. Various improvements have been made in the process of Mege, and it has been found that leaf-lard can be worked in the same way as beef-suet, and will yield an oleopalmitin suitable for churning up into a butter substitute. The processes now followed are given substantially as described by Mr. Phil. D. Armour in his testimony before a committee of Congress :* "The fat is taken from the cattle in the process of slaughtering, and after thorough washing is placed in clean water and surrounded with * Department of Agriculture, Bulletin No. 13, Part i. p. 16. 286 MILK INDUSTRIES. ice, where it is allowed to remain until all animal heat has been removed. It is then cut into small pieces by machinery and cooked at a tempera- aure of about 150 F. (65.6 C.) until the fat in liquid form has sepa- rated from the fibrin or tissue, then settled until it is perfectly clear. Then it is drawn into graining-vats and allowed to stand for a day, when it is ready for the presses. The pressing extracts the stearin, leaving a product commercially known as 'oleo oil,' which when churned with cream or milk, or both, and w r ith usually a proportion of creamery butter, the whole being properly salted, gives the new food product, oleomar- garine. In making butterine we use 'neutral lard,' which is made from selected leaf-lard in a very similar manner to oleo oil, excepting that no stearin is extracted. This neutral lard is cured in salt brine for forty-eight to seventy hours at an ice-water temperature. It is then taken and with the desired proportion of oleo oil and fine butter is churned with cream and milk, producing an article which when properly salted and packed is ready for the market. "In both cases coloring matter is used, which is the same as that used by dairymen to color their butter. At certain seasons of the year viz., in cold weather a small quantity of sesame oil or salad oil made from cotton-seed oil is used to soften the texture of the product," It will be seen that in this process a higher temperature is used in rendering the fat than w r as used originally by Mege. He obtained about fifty per cent, of oleo oil. The manufacturers now obtain sixty-two per cent, or more. The oleo oil from beef -suet and the neutral lard from leaf-lard are frequently mixed, the proportions varying according to the destination of the product; a warm climate calling for more "oleo," a cold one for more "neutral." In ordinary practice about forty-eight gallons of milk are used for churning with the oil per two thousand pounds of product. Plain oleomargarine is the cheapest product made. By adding to the material in the agitator or churn more or less pure butter what is known as butterine is produced, two grades of which are commonly sold, viz., "creamery butterine," containing more, and "dairy butterine," containing less, butter. Large quantities of oleo oil are now manufactured and exported as such from the United States to Europe, notably to Holland, where it is made up into oleomargarine butter. There are said to be seventy manu- factories of this kind in Holland which work up oleo oil from all parts of the world. 4. CHEESE-MAKING. The manufacture of cheese depends upon the property possessed by casein of being curdled by acids or ferments. In the case of sour milk, the milk-sugar has developed by the lactic fermen- tation some lactic acid, and this, as before stated, promptly throws out the casein in the insoluble form. In the case of sweet milk we usually accomplish the curdling of the casein not by the use of an acid, but with a ferment contained in the preparation called rennet. This is pre- pared from the fourth stomach of the calf by first cleansing the stomach, cutting and drying it, and then leaving some brine in contact with its lining membrane for a few days. The salt liquid will thus acquire very PROCESSES OF MANUFACTURE. 287 active properties, so that a small quantity will curdle a large quantity of milk. We would have then, according as one or the other method is followed, a sour-milk cheese or a sweet-milk cheese. The former have a very minor value commercially, being made mainly for immediate domestic consumption. The latter class include all the more valuable commercial varieties. Of these we may distinguish fat, half-fat (or medium), and lean cheeses, or as they are also designated to indicate their origin, cream cheeses, whole milk cheeses, and skim-milk cheeses. As these last names indicate, the material may differ. "We may have, moreover, all gradations or mixtures of cream, whole milk, and skim- milk used for the various grades manufactured. In cheese-making from sweet milk, the milk, whether whole, mixed with cream, or skimmed, is heated to about 30 C. (86 F.) and the rennet added. It curdles usually in from thirty to forty minutes. After the curd has formed and been cut, or "broken down," the heat is raised to 98 F. (36 C.) to insure the souring of the whey and its more com- plete separation from the curd. Or the curd produced at not over 86 F. (30 C.) is after being cut collected in a heap, covered with a cloth to preserve the heat, and allowed to stand an hour to develop the acidity which serves to harden the curd and promote its separation from the whey. The curd is now cut up, worked to free it from the whey, salted and pressed. After it has acquired sufficient coherence (which requires from twelve to fourteen hours) it is taken from the press and placed in the curing-room to "ripen." This ripening process is essentially a fermentative one, and during its progress the curd loses its insipidity and acquires the characteristic taste and flavor of cheese. In this process of ripening, the milk-sugar remaining in the cheese becomes transformed partly into lactic acid and partly into alcohol and carbon dioxide. In some varieties the carbon dioxide swells up ("huffs ") the cheese-mass and gives it the porous character so noticeable in the ripened cheese. Fresh cheese has an acid reaction, but this diminshes more and more in the ripening, as the casein is gradually altered, soluble albuminoids, peptone-like bodies, and organic bases like leucine, tyrosine, and amines being formed. Some cheeses, especially the cream cheeses, are not pressed, but come on the market as soft cheeses. In these the curdling by rennet has also been effected at a lower temperature than in the case of the hard cheeses. Cheese has also been manufactured extensively in this country from skimmed milk to which oleomargarine or "oleo oil " has been added so as to give the finished product the character of a whole-milk cheese. This product is now quite supplanted, however, by the "lard cheese," which, according to Caldwell,* was made in 1882 at over twenty factories in the State of New York. In this process an emulsion of lard is made by bringing together in a "disintegrator " lard and skimmed milk both previously heated to 140 F. in steam-jacketed tanks; the "disintegrator " * Second Annual Report New York State Board of Health, p. 529. 288 MILK INDUSTRIES. consists of a cylinder revolving within a cylindrical shell : the surface of the cylinder is covered with fine serrated projections, each one of which is a tooth with a sharp point; as this cylinder revolves rapidly within its shell the mixture of melted lard and hot skimmed milk is forced up into the narrow interspace ; and the lard becomes very finely divided and most intimately mixed, or ' ' emulsionized, ' ' with the milk. This emulsion consists of from two to three parts of milk to one of lard. In making the cheese, a quantity of this emulsion, containing about eighty pounds of lard, is added to six thousand pounds of skimmed milk and about six hundred pounds of butter-milk in the cheese-vat, and the lard that does not remain incorporated with the milk or curd, usually about ten pounds, is carefully skimmed off. These quantities of the materials yield from five hundred to six hundred pounds. of cheese containing about seventy pounds of lard, or about fourteen per cent. About one-half of the fat removed as cream in the skimming of the milk is thus replaced by lard. It is claimed that no alkali or antiseptic is used, and that only the best kettle-rendered lard can be employed, because of the injurious effect of any inferior article on the quality of the cheese, and that before even this lard is used it is deodorized by blowing steam under eighty pounds pressure through it for an hour. According to many witnesses the imi- tation is excellent, for experts have been unable to pick out lard cheeses from a lot of these and full-cream cheeses of good quality together. m. Products. 1. CONDENSED AND PRESERVED MILK. The distinction between con- densed milk prepared with the addition of cane-sugar and that prepared without sugar has already been referred to in speaking of the manu- facture of this class of products. The first of these classes forms a white or yellowish-white product of about the consistency of honey and rang- ing in specific gravity from 1.25 to 1.41. It should be completely soluble in from four to five times its bulk of water without separation of any flocculent residue, and then possess the taste of perfectly fresh sweetened milk. The second class of condensed milk preparations, those without addi- tion of cane-sugar, are not boiled down to the same degree and remain perfectly liquid, and are put up therefore in glass bottles instead of being sealed in cans. Analyses of both classes are given on the authority of Battershall.* Condensed Milk with Addition of Sugar. BRAND. Water. Fat. Cane- and milk-sugar. Casein. Salts. Alderney 30.05 10.08 46.01 12.04 1 82 Anglo-Swiss (American) .... Anglo-Swiss (English) .... Anglo-Swiss (Swiss) 29.46 27.80 25 51 8.11 8.24 8 51 50.41 51.07 53 27 10.22 10.80 10 71 1.80 2.09 200 Eagle 27.30 6.60 44.47 10.77 1.86 Crown 29.44 9.27 49.26 10.11 1.92 * Food Adulteration and its Detection, p. 53. PRODUCTS. 289 Condensed Milk without Cane-sugar. BRAND. Water. Fat Milk-sugar. Casein. Salts. American 52.07 15.06 16.97 14.26 2.80 New York 56.71 14.13 13.98 13.18 2.00 Granulated Milk Company . . Ea^le . 55.43 56.01 13.16 14.02 14.84 14.06 14.04 13.90 2.53 2.01 2. BUTTER AND BUTTER SUBSTITUTES. Commercial butter is more or less granular, and the more perfect the granular condition the higher is its quality considered. Special effort has been made in the case of oleomargarine or butterine to imitate this granulation, as the artificial product does not naturally tend to show such appearance. A good butter when fresh has a pleasant fragrant odor and agreeable taste, but the flavor, like the color, varies with the food of the cow, certain plants, like garlic, giving a quite pronounced flavor to both milk and butter. At ordinary temperatures butter is easily cut or moulded, and it readily melts to a transparent, light-colored oil. It always contains, according to the thoroughness with which it has been kneaded and washed, more or less casein, which is very liable to undergo decomposition, and hence the necessity for the addition of larger or smaller amounts of salt, which acts as a preservative. When the butter-fat is freed from curd and water by melting the butter and drawing off the oily layer it may be kept for a long time without change. This butter-fat is made up, as was stated in speaking of the fat of milk, of the glycerides of oleic, palmitic, and stearic acids (the so-called insoluble acids) and the glycerides of butyric, caproic, caprylic, and capric acids (the so-called soluble acids). The proportion in which they exist in butter-fat varies within very slight limits only, so that five to six per cent, may be called the average percentage of the soluble acids, and eighty-eight per cent, the average percentage of the insoluble acids present in butter-fat. This gives a very important means of distinguishing between a natural butter and oleomargarine or natural butter adulterated with the imitations. In such butter the glycerides of the soluble acids (butyric, etc.), are either wanting entirely or, if a little cream was used in the churning with "oleo oil," present in very much smaller amount than the normal. This distinction will be evident from the analyses of nor- mal butter and oleomargine butters, given on the authority of Dr. Bell. * Genuine Butter, showing Range of Variation in Composition of the Fat. Water. Salt Curd. Butter- fat. Specific gravity at 100 F. Percentage of fixed acids in fat. Percentage of soluble acids as butyric. Melting point, Fahren- heit. 1. 7.55 1.03 1.15 90.27 913.89 85.56 7.41 85 F. 2. 11.71 3.60 0.95 83.74 911.45 88.24 5.41 90 F. 3. 11.42 1.29 1.12 86.17 910.47 88.53 4.84 90 F. 4. 1255 0.89 0.74 85.82 910.20 89.00 4.57 90 F. 5. 14.62 1.48 1.88 82.02 910.70 89.00 4.50 91 F. Analysis and Adulteration of Foods, pp. 68 and 70. 19 290 MILK INDUSTRIES. Analyses of Oleomargarine Butter or Butterme. Specific Percentage .Percentage Melting Water. Salt. Curd. Fat. gravity at 100 F. of fixed acids. of soluble acids. point. Fah- renheit. 14.30 3.81 0.48 81.41 903.84 94.34 82 F. 11.21 1.70 1.73 85.36 902.34 94.83 0.66 78 F. 12.33 400 1.09 82.58 903.15 95.04 0.47 79 F. 5.32 1.09 0.67 9292 903 79 96.29 0.23 81 F. 13.21 3.99 1.07 81.73 901.36 95.60 0.16 78 F. The best grades of artificial butter do not differ in appearance from ordinary butter. To induce the proper granulation of the oleomargarine, it is chilled thoroughly with fragments of ice immediately after it is taken from the churn and before kneading or salting it. In color, con- sistence, and taste it may be made to imitate the natural butter so as to deceive most persons. A distinction, it is said, however, can always be noted in the taste when it is melted upon hot boiled potatoes, to which it imparts a peculiar taste recognizable as distinct from that of a true butter, 3. CHEESE. The general classification of the cheeses has been given in speaking of the methods of manufacture, and the distinctions between the fat and lean cheeses, between cream cheese, whole-milk and skimmed- milk cheeses given. The terms hard and soft cheeses are applied accord- ing as the curd has or has not been pressed in the process of manufac- turing. Most of the names which have been attached to the different varieties of cheese are those of localities. We will indicate the character of a few of these. Neufchatel cheese is a Swiss cream cheese. Limburger cheese is a soft fat cheese. Fromage de Brie is a soft French cheese rapidly ripening and devel- oping ammoniacal compounds. Camembert cheese is also a cream cheese. Roquefort cheese is a cheese made from the milk of the ewe. Gruyere cheese is a peculiarly flavored Swiss cheese. Cheddar cheese is a hard cheese made with whole milk. Single and double Gloucester are made, the first from a mixture of skimmed and entire milk, and the second from the entire milk. Parmesan cheese is a very dry cheese, with a large amount of casein and only a moderate percentage of fat. Eidam cheese is a Dutch cheese, also relatively dry, and covered with red coloring. In illustration of the chemical composition of these different varieties of cheese we will append three tables, the first of analyses from miscel- laneous sources, and the second and third from Bell,* giving a fuller study of the composition of the cheeses and r showing the difference between the fat normally belonging to the cheese and the fat added in the shape of lard or "oleo oil" in adulterated cheeses. * Analysis and Adulteration of Foods, pp. 79 and 82. PRODUCTS. 291 Water. Fat Casein. Non-nitro- genous and loss. Ash. Neufchatel (Fleischmann) 34.50 41.90 13.00 700 360 Emmenthaler (Fleischmann) 36.10 2950 28.00 330 810 Limburger (Fleischmann) 35.70 3420 2420 300 290 Brie (Wvnter Blyth) 51.87 24.83 18.30 500 Camembert (Wynter Blyth) 51.30 21 50 19.00 350 4 70 Parmesan (Wynter Blyth) 27.56 15.95 44.08 669 572 100 PARTS CONTAIN Proportion of fat in 100 parts of dry cheese. Proportion of fat in 100 parts of casein and fat. Salt percentage in cheese. PERCENTAGE COMPOSITION OF THE FAT. Water. J 03 a Free acid as lactic. 4 si i a Insoluble acid. Stilton 23.57 28.63 31.55 32.26 31.85 35.60 33.66 37.11 35.75 41.30 39.13 38.24 35.93 34.38 34.34 31.57 30.69 30.68 28.35 22.78 32.55 29.64 28.83 27.16 27.88 28.16 30.67 26.93 31.10 28.25 1.24 6.27 1.32 1.35 0.45 0.27 0.86 0.31 0.57 3.51 3.49 3.42 4.88 4.58 4.22 4.71 4.42 4.49 7.10 5119 53.57 52.49 50.75 49.02 46.26 48.78 48.78 44.12 38.80 52.50 54.12 53.34 54.24 53.08 50.49 47.02 50.84 45.24 42.41 0.67 0.72 0.82 3.04 2.11 1.43 0.81 1.69 1.28 4.45 4.42 4.26 4.81 4.91 4.40 4.55 4.41 5.55 6.68 5.84 88.96 89.06 88.49 88.70 89.18 8875 88.97 87.76 86.89 87.58 American (red) American (pale) Roquefort . . . Gorgonzola . . Cheddar (medi um) Gruyere Cheshire Single Gloucester Dutch (Eidam) . . Analyses of Oleomargarine and Lard Cheeses. 100 PARTS CONTAIN Per cent, of salt. 100 PARTS OF FAT CONTAIN Melting point of fat. Water. Fat. Casein and free acids. Ash. Insol- uble acids. Soluble acids. Oleomargarine cheese . . Lard cheese 30.95 31.30 28.80 24.66 36.27 38.87 3.98 5.17 1.14 1.55 92.43 92.88 2.16 1.55 77 F. (25 C.). 92 F. (33.3 C.). 4. MILK-SUGAR. The manufacture of crystallized milk-sugar (lac- tose) has developed greatly in recent years, and a perfectly white, well- crystallized product is now obtained. For its preparation, the sweet skim-milk as it comes from the cream separator is precipitated with acetic acid, filtered, and boiled either in open steam-heated evaporators or in vacuum pans. This first boiling should take several hours. The whey during the boiling becomes more cloudy, but suddenly clears, and the remaining albuminoids will separate in large flocks that can readily be filtered. It is to be filtered hot and boiled to crystallization in a vacuum pan. The raw sugar so obtained can be refined and made white exactly as described under cane-sugar. As the first crystallization is all that can be brought to satisfactory color and purity, the yield is not much over ten per cent, of the total sugar contained in the milk. 5. KOUMISS. Koumiss is an alcoholic drink made by the fermenta- tion of milk. As made by the fermentation of mare's milk it has long 292 MILK INDUSTRIES. been a favorite beverage with, the Tartars and other Asiatic tribes. Cow's milk has been used chiefly in making it in both Europe and Amer- ica. Mare's milk is the more suitable for fermentation because of the larger percentage of milk-sugar which it contains. The fermentation is started by mixing fresh milk with some already soured. Both the lactic and the alcoholic fermentations are set up, with the production of lactic acid, alcohol, and carbonic acid gas. Some of the albuminoids are also changed into peptones. The composition of the koumiss as prepared from both mare's and cow's milk is shown in the accompanying analyses from various sources: .S o-d i-s A OH isg o jj el & fifl g o B 2-2 oj'O 4 * S h-l * m * o * Koumiss from mare's milk (Fleischmann) Koumiss from cow's milk (Fleischmann) Koumiss from mare's milk (Konig) . . . 91.53 88.93 92.47 1.25 3.11 1.24 1.01 079 0.91 1.91 2.03 1.97 1.27 085 1.26 1.85 2.65 1.84 0.88 1.03 0.95 0.29 0.44 Koumiss from mare's milk (London, 1884) 91.87 0.79 1.04 1.91 1.19 2.86 Koumiss from cow's milk (Wiley) .... 89.32 4.38 0.47 2.56 2.08 0.76 0.83 6. KEPHIR. This is a Caucasian product somewhat similar to kou- miss, but prepared from cow's milk in leathern bottles by the aid of a peculiar ferment known as "kephir grains." According to Kern, as quoted by Allen (Commercial Organic Analysis, 2d ed., vol. iv, p. 242), the kephir ferment is an elastic cauliflower-like mass found below the snow line on certain bushes. The fungus consists of bacilli and yeast- cells, each cell containing two round spores, whence the name Dispora caucasina. When dried, the kephir fungus forms hard yellowish grains about the size of peas. By soaking these in water and adding them to milk, alcoholic fermentation ensues and the kephir is matured in a few days. The following figures show the comparative percentage composition of fresh milk, kephir, and koumiss : Fresh Milk. Kephir. Koumiss. Fat 3.8 2.0 2.05 Proteids 4.8 3.8 1.12 Sugar 4.1 2.0 2.20 Lactic acid Trace. 0.9 1.15 Alcohol None. 0.8 1.65 Water and salts 87.3 90.49 91.83 7. CASEIN PREPARATIONS. Casein is now utilized on a large scale, first, as a basis of food preparations ; second, as a fixing agent in calico printing instead of albumen; and third, as a substitute for glue in cements. For the first class of compounds, the casein salts of the alkalies and alkaline earths are used, and are obtained by ^dissolving casein in the calculated amount of caustic alkali, alkaline carbonate or phosphate or milk of lime, and evaporating the solution in vacua. The products are dry white powders. For the second class of compounds, casein is gen- ANALYTICAL TESTS AND METHODS. 293 erally dissolved in ammonia or in borax solution and used either with or without formaldehyde. A very superior paper size is thus made which is used on glazed cardboard. A mixture of casein with slaked lime sets to a hard insoluble mass, which is sometimes employed as a cement for earthenware and for similar purposes as a cheap substitute for glue. In making these casein cements the most important point that is to be noteH to insure success is the freeing of the casein from all oily matter. Therefore, when curd is prepared from milk, use only the most carefully skimmed milk quite free from cream, such as separator skimmed milk. When the casein has been separated and thoroughly washed it is uni- formly mixed with quicklime and applied quickly. It then sets very rapidly. Silicate of soda solution and borax are also used instead of quick-lime, and form excellent cements with casein. Kdseleim pulver, a ready-made Swiss preparation, will set when moistened. 8. WHEY. The aqueous liquid remaining after the separation of the butter-fat and the casein, or curd, is termed the whey. Its more im- portant constituent is milk-sugar, which in sour whey has been changed in part into lactic acid. It also contains soluble nitrogenous constitutents, such as milk-albumen and peptonized casein. On account of these con- stituents it is an easily digestible preparation and one assisting diges- tion. Hence the use of the "whey treatment " in medical practice for dyspeptics and those suffering from enfeebled digestion. The chief im- portance, however, of the whey is for the extraction of the milk-sugar, which has developed into an important article of manufacture. Other products of minor and local importance only are ' ' whey butter, " " whey alcohol," from which latter "whey champagne" is made, and "whey vinegar." For the analysis of whey see p. 280. IV. Analytical Tests and Methods. 1. FOR MILK. The specific gravity of milk is an indication of value, as it varies according to the content of fat, being higher for a skimmed milk than for a whole milk. However, when the cream has been removed, the specific gravity may be reduced to that of normal milk by the addi- tion of water, and then the specific gravity determination taken alone would be fallacious. Hence the detection of the adulteration of milk by addition of water cannot be made with entire accuracy by the lactometer or specific gravity hydrometer in use. The lactometer officially used by milk inspectors in New York and other States indicates specific gravities between 1.000 (the specific gravity of water) and 1.038. A specific gravity of 1.021 (taken as the minimum density of genuine milk) is also marked 100, while the specific gravity of water (1.000) is called 0. Hence if the lactometer read 70, the sample is supposed to contain seventy per cent, pure milk and thirty per cent, water. The average lactometric strength of about twenty thousand samples of milk examined by the New York State Dairy Commissioner in the year 1884 was 110, equivalent to a specific gravity of 1.0319. Another form of lactometer used abroad is the Quevenne-Miiller instrument, which is graduated in absolute specific gravity readings between the limits 1.014 and 1.042, and 294 MILK INDUSTRIES. then the limits of pure milk (1.029 to 1.034) indicated, and degrees of dilution with water also indicated as the specific gravity sinks below this. The degree of adulteration of skimmed milk is also indicated on the instrument in the same way. The total solids form an important element in the examination of milk. In some States the minimum percentage of total solids allowed in a milk is stated by law. (In Massachusetts thirteen per cent. ; in New York and New Jersey twelve per cent.) To determine the water and total solids, five grammes of milk are placed in an accurately weighed flat-bottomed platinum dish of not less than five centimetres diameter and dried on a steam bath until constant weight is obtained. Fifteen to twenty grammes of pure dry sand may be previously placed in the dish to facilitate drying. Cool in desiccator and weigh rapidly to avoid absorption of moisture. To determine the ash weigh about twenty grammes of milk in a weighed dish, add six cubic centimetres of nitric acid, evaporate to dry- ness and ignite at a temperature just below redness until the ash is free from carbon. Both fat and moisture may be determined with one weighing of the sample in the Babcock asbestos method. A hollow cylinder of perforated sheet metal sixty millimetres long and twenty millimetres in diameter, closed at one end by a disk of the same material, is taken. This is filled loosely with from 1.5 to 2.5 grammes of freshly ignited woolly asbestos free from fine and brittle material, cooled in a desiccator, and weighed. Then introduce a weighed quantity of milk (between three and five grammes) and dry at the temperature of boiling water to constant weight to obtain the moisture by loss. Extract the residue now by the aid of anhydrous ether until all the fat is removed, evaporate the ether, dry the fat at the temperature of boiling water and weigh. The fat may also be determined by difference, drying the extracted cylinders at the temperature of boiling water. The paper coil method of Adams is also often used. In this a coil of white blotting-paper (or thick filtering-paper) previously purified with ether and dried is made to soak up the milk to be analyzed from a weighed beaker or pipette. The paper coil is then dried in a hot-air oven and placed in a Soxhlet (see p. 86) or similar fat-extraction appa- ratus connected with an inverted condenser and the fat extracted by ether or petroleum-ether. The total nitrogen is estimated by evaporating a weighed portion of milk to dryness and making a combustion of the residue with soda-lime or by the Kjeldahl method of conversion into ammonia compounds and distillation from an alkaline solution. Casein may be determined in fresh milk as follows : Place about ten grammes of milk in a beaker with about ninety cubic centimetres of water at 40 to 42, C., and add at once 1.5 cubic centimetres of a ten per cent, acetic acid solution. Stir with a glass rod and let stand from three to five minutes longer. Then decant on to the filter, wash first by deeantation and then transfer the precipi- tate to the filter and complete the washing. The nitrogen is determined ANALYTICAL TESTS AND METHODS. 295 in the washed precipitate and filter paper by the Kjeldahl method, using 6.38 as the factor to calculate the casein. The estimation of the milk-sugar by the polariscope is rendered diffi- cult by the presence in milk of various albuminoids, all of which turn the plane of polarization to the left, and the ordinary means of removing these albuminoids by a solution of basic acetate of lead is far from being perfect. Professor Wiley after extensive experimentvS upon this has adopted a method of optical analysis, using acid mercuric nitrate to precipitate the albuminoids. He takes the specific rotatory power of milk-sugar as ()<* = 52.5. For details of his procedure the reader is referred to Bulletin 107.* Milk-sugar may also be determined either volumetrically or gravimetrically with the aid of Fehling's solution. (See p. 175.) In this case, it is also necessary to remove the albuminoids first, and this is done by Ritthausen's method of precipitation with copper sulphate, all excess of this reagent being removed with caustic potash solution. In calculating the results it will be remembered that the copper reducing power of milk-sugar is 70.5 as compared with dextrose at 100. The sugar is probably most accurately determined by extraction from the fat-free residue with weak boiling alcohol, filtering the alcoholic fluid, and evaporating to dryness. This leaves the sugar with some mineral matter. On burning and determining this matter as ash the amount of sugar can be gotten. The artificial coloring of milk is frequently practised to cover up the watering of the sample. The colors to be tested for are annatto, caramel and anilin-orange, an azo-dye. Leach f has given the following scheme for the detection of added colors in milk: SUMMARY OF SCHEME FOR COLOR ANALYSIS. Curdle one hundred and fifty cubic centimetres of milk in casserole with heat and acetic acid. Gather the curd in one mass, pour off whey, or strain, if curd is finely divided. Macerate curd with ether in corked flask. Pour off ether. Ether Extract. Extracted Curd. Evaporate off ether, treat with NaOH (1) If colorless indicates presence of and pour on wetted filter. After the solu- no foreign color other than in ether ex- tion has passed through, wash off fat and tract. dry filter, which if colored orange, indi- (2) If orange or brownish indicates rates presence of annatto. (Confirm by presence of anilin orange or caramel. SriCl 2 . ) Shake curd in test-tube with concentrated hydrochloric acid. If solution gradually If orange curd turns blue, indicative immediately of caramel. (Confirm turns pink, in- by testing for caramel dicative of ani- in whey of original lin orange, milk.) The examination of milk for preservatives is constantly necessary. The most important of these preservatives is formaldehyde. To detect U. S. Dept. of Agricult., Bureau of Chem., Bulletin 107 (Revised), p. 118. f Food Inspection and Analysis, 2d ed., 1909, p. 177. 296 MILK INDUSTRIES. it according to Leach add ten cubic centimetres of commercial hydro- chloric acid (specific gravity 1.2) containing two cubic centimetres of ten per cent, ferric chloride per litre to an equal volume of milk in a porce- lain casserole and heat slowly over the free flame, giving the vessel a rotatory movement while heating to break up the curd. The presence of formaldehyde is indicated by a violet coloration varying in degree with the amount present. With fresh milk, one part of formaldehyde in 250 of milk may be thus detected. Hehner's test may also be used. To five or ten cubic centimetres of milk in a wide test-tube add about half the volume of concentrated com- mercial sulphuric acid, pouring the acid carefully down the inside of the tube so that it forms a layer at the bottom without mixing with the milk. A violet zone at the junction of the liquids indicates formaldehyde. Ben- zoic, salicylic, and boric acids have also been used. The latter may be readily tested for by turmeric paper. Ten cubic centimetres of the milk are thoroughly mixed with six drops of concentrated hydrochloric acid. Turmeric paper moistened with this and dried will show a red color if boric acid were present in the milk. 2. FOR BUTTER. The water in butter is determined by drying five grammes of the butter in a platinum dish at a temperature of 100 C. (212 F.) or slightly higher. The melted butter is stirred from time to time to facilitate the escape of the moisture. The water will have been given off in three to four hours, and it has been found that longer heating sometimes causes the melted fat to gain in weight. To determine the salt, the dried butter just obtained is treated with warm ether or petroleum spirit, and the contents of the platinum dish poured on a weighed filter and washed with ether until all fat is removed. The residue and filter are dried and weighed. The salt is then dissolved out by warm water, and the chlorides in the solution estimated volumet- rically by titration with decinormal silver nitrate, using a few drops of potassium chromate as indicator. The difference between the weight of salt ascertained and the total weight of curd and salt on the weighed filter is regarded as the amount of the casein, or curd, present. If after washing out the salt the residue on the weighed filter be dried and then weighed, the amount of casein so obtained is a little less than that gotten by difference. This is partly due to the small amount of milk-sugar washed out along with the salt and undetermined, and partly to the slight solvent action of warm water on some of the curd. The percentage of fat may be obtained by evaporating the ether filtrate from the previous determination of salt and curd, but the butter- fat is liable to increase in weight by this treatment, and therefore the fat is usually gotten by difference after determining the water, casein, salt, and milk-sugar. N The adulteration of butter and the manufacture on a large scale of butter substitutes make an examination of the butter-fat one of great importance. This examination may be both qualitative and quantitative. The butter-fat is gotten for examination by melting a sample of butter ANALYTICAL TESTS AND METHODS. 297 and, after allowing the water and curd to settle, pouring the clear fat on to a dry warm ribbed filter and collecting the filtrate. The specific gravity of the butter-fat may be taken, as first suggested by Bell, in a specific gravity bottle at a temperature of 100 F. (37.7 C.), or, as suggested by Estcourt and endorsed by Allen, with the aid of the Westphal balance (see p. 87) at a temperature of 99 to 100 C. (210 to 212 F.). Bell found by this method that the specific gravity of true butter-fat varied from 909.4 to 914 (water 1000), while butterine showed a specific gravity of 901.4 to 903.8. Allen gives the limit for pure butter-fat tested at 99 C. as 867 to 870, while butterine at the same temperature was 858.5 to 862.5. The melting point of the butter-fat is also generally noted. Bell pro- posed determining the melting point by first suddenly cooling some melted butter-fat by floating the capsule containing it upon ice-water, and then taking a fragment of the congealed butter upon the loop of a platinum wire. This is then introduced close to the bulb of a ther- mometer in a beaker of water which is being heated from without. As the water becomes warmed the globule melts and the thermometer is read off. An improvement on the method insuring greater accuracy is recorded in Bulletin No. 107 (revised) of the Bureau of Chemistry, p. 133. The melting point of butter usually ranges between 29.5 C. and 33 C. (85 to 90 F.), while the melting point of butterine is stated to be between 25.5 C. and 28 C. (77.9 to 82.4 F.). The quantitative examination of the supposed butter-fat may be made by several methods, viz., the determination of the saponification equiv- alent by Koettstorf er 's method,* the determination of the percentage of insoluble fatty acids present as glycerides by Hehner's method, f and the determination of the volatile fat acids after distillation by Reichert 's method. \ To these most generally received methods may also be added the method of Hiibl of iodine saturation as determining the character of fatty acids, and the method of Morse and Burton, which combines the Koettstorfer and the Hehner processes, and determines the saponification equivalent of the soluble and the insoluble fat acids separately. The term "saponification equivalent " is used to indicate the number of grammes of an oil saponified by one equivalent in grammes of an alkali. Thus, tributyrin (the glyceride of butyric acid) has a saponification equivalent of 100.67, while tristearine (the glyceride of stearic acid) has a saponification equivalent of 296.67. Butter-fat, it will be remembered, is a mixture of the several glycerides of the lower or volatile fatty acids and the higher or non-volatile fatty acids. Its saponification equivalent ranges from 241 to 253, the average being 247 ; butterine has a saponi- fication equivalent ranging from 277 to 294, the average being 285.5. In Hehner's method, the weighed quantity of the fat is saponified by alco- holic potash, the soap solution evaporated down, taken up with water, * Allen, Commercial Organic Analysis, 2d ed., vol. ii, p. 40. t Bell, Analysis and Adulteration of Foods, Part ii, p. 56. J Allen, Commercial Organic Analysis, 2d ed., ii, p. 45. 298 MILK INDUSTRIES. and the fatty acids set free by an excess of hydrochloric acid. They are now brought upon a weighed filter, washed with boiling water until no longer acid, and then chilled into a cake by immersing the filter in cold water. The filter is then transferred to a weighed beaker-glass and the contents dried at 100 C. until constant in weight. The soluble fat acids can also be determined in this process by collecting the washings which were obtained with boiling water and making them up to one hundred cubic centimetres and then carefully titrating an aliquot portion with decinormal soda solution. This will give the amount of soluble fat acids plus the excess of standard hydrochloric acid used originally in liberating the fat acids. The amount of this excess can be ascertained by carrying through a blank experiment with alcoholic potash and hydrochloric acid, but without the fat. In the analysis of butter-fat the sum of the insoluble fatty acids and of the soluble fatty acids calculated as butyric acid should always amount to fully ninety-four per cent, of the fat taken. The soluble fatty acids calculated as butyric acid should amount to at least five per cent., any notably smaller proportion being due to adultera- tion. As an average, eighty-eight per cent, of insoluble and five and a half per cent, of soluble acids should be obtained. "While the true percentage of the volatile fatty acids cannot be easily obtained, the amount of alkali needed to neutralize them after distillation can be determined by Reichert's process. According to this, as improved by Meissl, five grammes of the fused and filtered fat are placed in a flask of about two hundred cubic centimetres contents with about two grammes solid caustic potash and fifty cubic centimetres of seventy per cent, alcohol, saponified on the water-bath and evaporated down until all alcohol is driven off. The thick soap-mass remaining is now dissolved in one hundred cubic centimetres of water, forty cubic centimetres of dilute sulphuric acid added, and, after adding a few fragments of pumice-stone, distilled with the aid of a Liebig condenser. About one hundred and ten cubic centimetres of distillate are collected, which requires about an hour. Filter and collect one hundred cubic centimetres in a graduated flask. Add phenol-phthalein as an indicator, and titrate with decinormal alkali. Increase the result by one-tenth, and reckon the result upon five grammes of the substance. It is found that two and a half grammes of butter-fat, examined by Reichert's method, require about thirteen cubic centimetres of the decinormal alkali, while butterine requires only one cubic centimetre. As the difference between these is twelve cubic centimetres, it may be calculatd that there is 8.5 per cent, real butter-fat present in a mixture for every cubic centimetre of alkali required over the one cubic centimetre required for ordinary butterine. Hiibl's method is founded on the fact that the three series of fatty acids (acetic, acrylic, and tetrolic) unite in different proportions with the halogens, like chlorine, bromine, and iodine, , to form addition prod- ucts. The number of grammes of iodine absorbed is calculated to one hundred grammes of fat, and this is Hiibl's "iodine number." Thus genuine butter has an iodine number from 30.5 to 43.0, while oleomar- garine has from 50.9 to 54.9. ANALYTICAL TESTS AND METHODS. 299 Morse and Burton * saponify the combined fatty acids, liberate the free acids, wash out the soluble portion of the mixture, and then saponify again the soluble and the insoluble acids separately. They thus combine the Koettstorfer and the Hehner processes and get a greater certainty as to the character of the fat mixture. Thus they find that with butter 86.57 per cent, of potassium hydrate is required to neutralize the insol- uble acids and 13.17 per cent, to neutralize the soluble acids, while with oleomargarine 95.40 per cent, of potassium hydrate is required for the insoluble acids and 4.57 per cent, for the soluble acids. A physical test frequently applied to distinguish oleomargarine and process (renovated) butter from true butter is the foam test. True butter melted in a spoon over a free flame will foam abundantly, while the other butter named will only burn and sputter like melted grease. The presence of annatto coloring in butter is shown by treating two or three grammes of the melted and filtered fat (freed from salt and water) with warm dilute sodium hydroxide and after stirring pouring the warm mixture upon a wet filter. If annatto is present the paper will absorb the color so that when the fat is washed off by a gentle stream of water the paper appears dyed straw yellow and on application of a drop of stannous chloride solution turns pink. For azo colors, melt a small amount in a test-tube and add an equal amount of a mixture of one part concentrated sulphuric acid and four parts glacial acetic acid and heat nearly to boiling, shaking the contents of the tube. Then set aside. The acid solution when settled will show a wine-red color in the presence of azo colors. 3. FOR CHEESE. The methods employed in cheese analysis are in most respects the same as those employed in the examination of butter. The fat is best extracted with light petroleum-ether, as common ether dissolves the free lactic acid as well as the fat. The remaining solids not fat can then be dried and weighed. The fat should be examined by Koettstorfer 's saponification equivalent method, as the oleomargarine and lard cheeses may be detected in this way. Genuine cheese-fat, accord- ing to Muter, f should not consume less than two hundred and twenty milligrammes of potassium hydrate for each gramme used. If the cheese should give unfavorable indications with Koettstorfer 's test, then the soluble and insoluble fatty acids are determined in the fat according to Hehner. The percentage of insoluble fat acids in genuine cheese, accord- ing to Muter, averages 88.5, while in oleomargarine cheeses it is from 90.5 to 92 per cent. The acidity, calculated as lactic acid, may be determined by treating the residue from the fat determination with water and titrating the washings with decinormal soda solution. The washed residue then is the non-fatty solids. The ash is determined by ignition of the dried cheese before extrac- tion of the fat. * Amer. Chem. Journ., x, p. 322. t Analyst, vol. x, p. 3. 300 MILK INDUSTRIES. V. Bibliography and Statistics. BIBLIOGRAPHY. 1878. Butter, its Analysis and Detection, Angell & Hehner, 2d ed., London. Illustrirtes Lexikon der Verfalschungen der Nahrungsmittel, H. Kluncke, Leipzig. 1882. Food Sources, Constituents, and Uses, A. H. Church, London. Chevallier's Dictionnaire dee Alterations et Falsifications, 6me eM., Baudri- mont, Paris. The Analysis of Milk, Condensed Milk, etc., N. Gerber, New York. 1884. Falsifications des Mati&res aliraentaires, Laboratoire Municipal, Paris. Die Conservirung von Milch, Eier, etc., C. Heinzerling, Halle. 1885. Fabrikation von Kunstbutter, V. Lang, 2te Auf., Leipzig. 1886. Ueber Kunstbutter, ihre Herstellung, etc., Eugen Sell, Berlin. Milk Analysis, J. Alfred Wanklyn, 2d ed., London. Die Analyse der Milch, E. Pfeiffer, 2d ed., Wiesbaden. Des Laits fermented et leurs Usages, Saillet, Paris. 1887. Food Adulteration and its Detection, J. P. Battershall, New York. United States Department of Agriculture, Bulletin No. 13, Part i. (Dairy Products), H. W. Wiley, Washington. United States Department of Agriculture, Bulletin No. 16 (Methods of Analysis of Dairy Products, etc.), C. Richardson, Washington. Le Lait, fitudes chimiques et Microbiologiques, Duclaux, Paris. Illustrirtes Lexikon der Verfalschungen, etc., Dammer, Leipzig. 1888. United States Department of Agriculture, Bulletin No. 19 (Analysis of Dairy Products), C. Richardson, Washington. Foods, their Composition and Analysis, 2d ed., A. W. Blyth, London. 1889. Chemie der Menschlichen Nahrungs- und Genussmittel, J. Konig, 3te Auf., Berlin. La Margarine et le Beurre artificiel, Girard et Brevans, Paris. 1891. Die Untersuchung landwirthschaftlich wichtiger Stoffe, J. Konig, Berlin. Handbuch der Milchwirthschaft, Kirchner, 3te Auf., Berlin. 1893. Trait gnral d'Analyse des Beurres, 2 tomes, A. J. Zune, Paris. Dairy Chemistry for Dairy Managers, H. D. Richmond, London. 1894. Milk, Cheese, and Butter: a Practical Handbook, J. Oliver, London. 1895. Dairy Bacteriology, E. von Freudenreich, translated by J. R. Davis, London. 1896. The Analysis of Milk and Milk Products, Leffman and Beam, 2d ed., Phila- delphia. The Book of the Dairy, W. Fleischmann, translated by Aikman and Wright, London. 1897. The Chemistry of Dairying, Harry Snyder, Easton, Pa. 1898. Testing Milk and its Products, Farrington and Woll, 3d ed., Madison, Wis. 1899. Milk, its Nature and Composition. A Handbook. C. M. Aikman, 2d ed., New York. Dairy Chemistry: a Practical Handbook, H. D. Richmond, London. 1903. Milk, its Production and Uses, E. F. Willoughby, London. 1906. Casein, its Preparation and Technical Utilization, R. Scherer, translated by Chas. Salter, London. 1909. Milk Analysis by J. Wanklyn, New Ed., by W. J. Cooper, London. The Science and Practice of Cheesemaking, L. L. van Slyke and C. A. Publow. 1910. Chemie und Physiologic der Milch, W. Grimmer, Paul Parey, Berlin. > STATISTICS. The only general statistics of the milk industry are those gathered for the Census Bureau in 1905, those for 1910 being not as yet avail- BIBLIOGRAPHY AND STATISTICS. 301 1900. Increase. $130,783,349 $37,399,400 420,126,546 111,351,595 $84,079,754 $29,109,699 281,972,324 35,172,548 $26,519,829 $2,091,931 186,921,787 121,563,395 $11,888,792 $8,260,490 $8,294,974 $2,062,680 able. The figures for the main products of the milk industry are as follows : 1905. Products, total value $168,182,789 Butter (Ibs.) 531,478,141 Value $113,189,453 Cheese (Ibs.) 317,144,872 Value $28,611,760 Condensed milk (Ibs.) 308,485,182 Value $20,149,282 All other products $6,232,294 (Report of Census Bureau, 1905.) The oleomargarine production, as reported by the Internal Revenue Bureau, has been: 1909. 1910. Uncolored oleomargarine (Ibs.) 86,572,514 135,685,289 Colored oleomargarine (Ibs.) 5,610,301 6,176,991 Total oleomargarine (Ibs.) 92,282,815 141,862,282 The exportation of dairy products from the United States has de- creased in recent years and was as follows: 1906. 1907. 1908. 1909. Butter (Ibs.) 27,360,537 12,544,777 6,463,061 5,981,265 Valued at $4,922,913 $2,429,489 $1,407,962 $1,268,210 Cheese (Ibs.) 16,562,451 17,285,230 8,439,031 6,822,842 Valued at $1,940,620 $2,012,626 $1,092,053 $857,091 Oleomargarine (Ibs.) . 11,794,174 5,397,609 2,938,175 2,889,058 Valued at $1,033,256 $520,406 $299,746 $293,746 Oleo oil (Ibs.) 209,658,075 195,337,176 212,541,157 179,985,246 Valued at $17,455,976 $16,819,933 $19,278,476 $19,126,745 Condensed milk (Ibs. ) Valued at $1,889,690 5,191,111 $2,455,186 $1,375,104 1910. 3,140,545 $785,771 2,846,209 $441,017 3,418,632 $349,972 126,091,675 $14,305,080 13,311,318 $1,023,633 Of miscellaneous products, there were produced in 1905, according to the Census Bureau, 1,161,414,457 pounds of skimmed milk valued at $1,368,738, and from this was extracted 11,581,874 pounds of casein, valued at $554,099. The whey from which sugar of milk is obtained amounted to 166,451,226 pounds, valued at $111,907. 302 VEGETABLE TEXTILE FIBRES. CHAPTER VIII. VEGETABLE TEXTILE FIBRES. General Characters. ALL the fibres which have been found of technical value for manu- facturing purposes may be divided into the two great classes, vegetable fibres and animal fibres, the few found in the mineral kingdom among fibrous minerals being of relatively" slight importance in textile manu- facturing. Moreover, the distinction is not merely, as the name chosen would indicate, one of origin, but fundamental structural and chemical differences also exist and make themselves evident upon the slightest examination. The vegetable fibres are exclusively cell-growths of rela- tively simple structure, which during their life form integral parts of the plant organisms, while the animal fibres may be either a hardened secretion like silk or a more complicated cell-growth like wool, distin- guished by its scale-like surface. Thus the vegetable fibres are without exception some form of cellu- lose (C H 10 5 ) n in more or less pure condition or an alteration product of the same, while the animal fibres are composed of protein matter, and hence are nitrogenous. The radical character of their chemical difference just referred to will be more thoroughly appreciated when we note the action of reagents upon the two classes respectively. The vegetable fibres are not dissolved or weakened by alkalies even at a boiling temperature, while the animal fibres are speedily disintegrated, with eventual liberation of ammonia from the nitrogenous material; on the other hand, sulphuric acid or hydrochloric acid rapidly causes a disintegration of the vegetable fibres by their action upon the cellulose, and nitric acid either oxidizes the cellulose or gives rise to nitrated derivatives, while the animal fibres are only slightly affected even when the acids are concentrated. These reactions will be referred to more fully in speaking of the analytical tests used for distinguishing the fibres in mixed goods. (See p. 353.) The several vegetable fibres may be classified according to botanical or morphological character into three groups: (1) Seed-hairs (filaments composed of individual cells) ; (2) bast fibres (filaments or fibre-bundles made up of individual fibre-cells aggregated together) ; and (3) fibro- vascular bundles. Sometimes the term bast fibres is made to include both the second and third classes as just given. Chemically, all vegetable fibres are composed "of cellulose. However, it has long been known that it is frequently more or less contaminated with altered products, which have been known as lignin, ligno-cellulose, adipo-cellulose, etc. The recent researches of Messrs. Cross and Bevan GENERAL CHARACTERS. 303 have given us a clear understanding of the nature of the lignin and the alteration products of cellulose. The combination of cellulose and lig- nin, to which they apply the name of bastose, may make up the whole bundle of fibres, as in jute, or may be merely a covering upon the unal- tered cellulose. By distinguishing between the cellulose and the bastose and mixtures of the two we may establish a chemical classification of the vegetable fibres. We are enabled to do this by the aid of the solutions of iodine (potassium iodide solution saturated with free iodine) and sul- phuric acid (concentrated glycerine and strong sulphuric acid), which were first proposed by Vetillart.* Pure cellulose when tested with the iodine and sulphuric acid solutions, one after the other, will give a pure blue color, while bastose shows under these conditions a yellow colora- tion. A complete classification, taking both botanical and chemical char- acters into account, is the following, which is that of Cross and Sevan 's f with some additions: A. B. c. Seed-hairs. Dicotyledonous Monocotolydonous fibres cor- bast fibres. responding to bast fibres. Linen. Straw. Hemp. Pineapple. Blue reaction with iodine < and sulphuric acid. Yellow reaction with iodine and sulphuric acid. Cotton. China-grass. Esparto. Kamie. Alfa. Nettle. Sunn fibre. New Zealand flax. Aloe. Hibiscus. Yucca. Jute. Manila hemp. Coir. 1. COTTON FIBRE. The cotton, as already noted, is a seed-hair and envelops the seeds, which are at first enclosed in a capsule. With the ripening of the plant this capsule bursts and the contents spread out widely, consituting the cotton-boll, which is easily picked. The separa- tion of the fibre from the enclosed seed is afterwards accomplished by the mechanical operation called "ginning," in which it is torn from the seed, so that while one end of an individual fibre is always closed the other is irregularly broken. The genus Gossypium, to which all cotton-plants are referred, in- cludes several well-marked varieties, the most important of which are G. Barbadense, or "sea-island cotton," grown off the coast of Georgia, South Carolina, and Florida, which yields the longest and strongest fibre or the finest ' ' staple ; ' ' the G. hirsutum, or upland cotton, grown inland in Georgia, Alabama, Louisiana, and Mississippi, which yields a shorter staple; the G. herbaceum, grown in Egypt, Asia Minor, and India; the G. Barbadense, or "sea-island cotton," grown off the coast of Georgia, China and India and yielding the so-called "nankin " cotton of brown- yellow color ; and the G. Peruvianum, yielding the long-stapled Brazilian and Peruvian cotton. The structure of the cotton fibre is very characteristic. It presents a * Vetillart, Etudes pur les Fibres, Paris, 1876. t Text-book of Paper-Making, p. 46. 304 VEGETABLE TEXTILE FIBRES. flattened and collapsed tube slightly twisted in spiral form, with com- paratively thick walls and a small central opening. This structure is illustrated in Figs. 75 and 76, in the first of which the fibre is magnified thirty times and in the second of which it is magnified two hundred times. The first illustration shows the spiral twist of the fibres distinctly, but the collapsed character of the tube only slightly ; this latter feature, however, is shown very distinctly in the second illustration. This flat- tening is not seen in the unripe fibre, which is a tube filled with liquid protoplasmic matter, but in the ripening of the plant this liquid dries up and the walls of the tube collapse and flatten out. The adhesion of the fibre to the seed also becomes less, so that the ripe cotton is easily separated in the ginning process. In some species (as in G. Barbadense] this separation of hair from the seed is so perfect that the seed shows FIG. 75. FIG. 76. after the ginning a lustrous black appearance, whence the name locally applied of " black-seed cotton " as distinguished from the upland variety, known as "green-seed cotton." The fibre must be picked when mature or it becomes ' ' over-ripe ' ' and deteriorates. The length of the "staple," or fibre, varies considerably with the different varieties of the cotton, the long-stapled sea-island cotton grown on the shores of Georgia and Florida attaining a length of nearly two inches (five centimetres), while the short native cotton of India scarcely exceeds three-quarters of an inch (eighteen millimetres) in length.* Chemically, the cotton fibre contains about ninety-one per cent, of pure cellulose, seven per cent, of moisture, and small amounts of fat, nitrogenous material, and cuticular substance. An ammoniacal solution of copper oxide causes the cellulose material of the fibre to soften and swell up, whereby the cuticle, which is not softened, takes the appearance of yellowish constricting rings binding the swollen cellulose at regular intervals. Prolonged action of the reagent dissolves the cellulose. When Bowman, Structure of the Cotton Fibre, p. 19. GENERAL CHARACTERS. 305 FIG. 77. 5 a i a 2 4 bleached by boiling with sodium carbonate or hydrate, the cuticle is decomposed and the fibre yields easily a very pure form of cellulose. 2. FLAX. The flax-plant, Linum usitatissimum, yields the best known and probably the most valuable of the bast fibres as well as other products, like the linseed oil and linseed cake. (See p. 54.) It is not grown for both fibre and seed together, however, as when the fibre is desired in best condition the plant is gathered before it is fully matured, while if the plant is allowed to ripen fully for production of seed, the fibre obtained is more stiff and coarse. The plant is grown through a wide range of climate, although that grown in the tropics, as in India, is chiefly used for seed, the fibre being of little value, while that grown in colder countries, as in the Russian East Sea provinces, yields the best fibre. When the plant is cultivated for the production of fibre, it is either sowed more thickly or, as in Hol- land and Belgium, forced to grow up through a net-w r ork of brushwood, thus yielding a more slender plant with a longer and finer fibre, known as tin rame. The plant is not cut, but is always carefully pulled up by the roots, and the freshly pulled-up flax is at once submitted to the process of seeding, or ' ' rippling, ' ' which is to remove the leaves and seed capsules. This is usually done by hand, drawing the bundles of the flax through upright metallic combs, or "ripples," the prongs of which easily catch the seed capsules, so that three or four drawings suffice to clean the stems or flax straws. This straw, as it is termed, contains in a dried condi- tion seventy-three or eighty per cent, of its weight of woody matter and encrusting material and twenty to twenty-seven per cent, of bast fibre. The distinction between the several parts of the stem in the flax and similar plants yielding bast fibres is shown in Fig. 77 by both transverse and longitudinal cross-sections, where 1 represents the pith, 2 the woody tissue, 3 the cambium or partially lignified tissue, 4 the bast fibre, and 5 the crust or rind. To free these several parts of the stem from each other so as to obtain in a clean state the bast fibre is the object of the process of "retting." This is done either by natural means, as in the case of dew retting and cold-water retting, or by the help of an artificial process, as in warm-water retting and chemical retting. The dew ret- ting, applied most largely in Russia, consists in leaving the flax thinly spread exposed to dew and rain, air and light, for eight or ten weeks, when, by the fermentation of the pectose matter of the rind, the bast fibre is thoroughly loosened. In cold-water retting either running or stagnant water may be used, the former being used in Belgium and the latter in Ireland. The bundles of flax are placed in crates and sub- merged, when actual fermentation ensues. The water must be soft, and care must be taken, especially in the stagnant-water method, to prevent 20 306 VEGETABLE TEXTILE FIBRES. undue heating up during the fermentation. The warm-water retting requires a temperature of 30 to 35 C., and can be carried to comple- tion in fifty to sixty hours, yielding an excellent product. The chemical process consists in the use of dilute sulphuric acid or hydrochloric acid, which allow of the completion of the process in a few days. After the retting process the flax is well washed and dried, and is then submitted to the mechanical processes of "breaking," "scutching," and "hack- ling" to thoroughly free the fibre from the woody layer and draw out the fibre-bundles into filaments. The flax fibre as seen under the microscope seems to be a long straight and transparent tube with thick walls and a minute central canal. Fig. FIG. 79. FIG. 78. Flax (3f). Heinp ( 78 shows these characters of the flax fibre. Characteristic transverse markings also are shown, which may be nodal divisions or slight breaks or wrinkles produced by bending. Longitudinal fissures also show after vigorous rubbing. The linen fibre when cleansed has a blonde or even white color, a fine silky lustre, and great strength. It is less pliant and elastic than cotton, but is a better conductor of heat, and hence seems colder than cotton. Chemically it is, like cotton, a pure cellulose, but when swollen by the action of ammoniacal cupric oxide solution does not show the same uniform series of constricting bands of cuticle. Linen is in many respects more readily disintegrated than cotton, especially under the influence of caustic alkalies, calcium^ hydrate, and strong oxi- dizing agents like chlorine and hypochlorites. 3. HEMP. The fibre known by this name is the product of the Can- ndbis sativa, which is grown for textile purposes chiefly in Russia and GENERAL CHARACTERS. 307 Italy, while the seed is grown in India. It is a bast fibre similar to that of the flax-plant, but coarser, stronger, of deeper color and less lustre. Fig. 79 shows the microscopical characters of the hemp fibre. Its culti- vation is very similar to that already described under flax, and differs according as the fibre or the seed are sought. The freshly-plucked hemp loses sixty per cent, of its weight in drying, and from the air-dried hemp straw twenty per cent, of bast fibre is obtained in the case of the male plant and twenty-two per cent, in the case of the female plant. It is used chiefly for ropes and cordage, and the fabric woven from it, known as canvas, is used in sail-making. Much of the finer fibre, however, is com- bined with linen fibre in weaving other goods. The iodine and sulphuric FIG. 80. FIG. 81. Jute, Corchorus capsularis (*!). acid test shows that the hemp fibre is not composed of pure cellulose, but is a mixture of cellulose and bastose. 4. JUTE is the bast fibre of two species of the genus Corchorus, and is grown chiefly in India and Ceylon. The fibre is separated from the plant by methods similar to those employed with flax and hemp, the process of cold retting in stagnant water being followed generally. The bast fibres attain a length of 2.5 metres or even more, are of a yellowish- white color, and have a fine lustre. It is seen under the microscope to consist of bundles of stiff lustrous cylinders with walls of very irregular thickness. These 'characters of the jute are shown in Fig. 80. Chem- ically, jute differs from the bast fibres hitherto mentioned in that it contains no free cellulose, but consists of the chemical compound of cellulose with lignin, to which Cross and Bevan, who investigated it, gave the name of bastose. It gives, treated with iodine and sulphuric acid, a deep brown color. Moreover, the bastose acts with basic dye 308 VEGETABLE TEXTILE FIBRES. colors, like the aniline dyes, as if it had been mordanted with tannin, and can therefore be dyed directly without previous treatment. It is much more easily affected by the action of acids and alkalies than flax or hemp. The influence of air and moisture will also rot the jute fibre. It cannot be bleached safely with chloride of lime because of the readi- ness with which the fibre is oxidized, but it may be bleached with a weak solution of sodium hypochlorite or by the successive action of potassium permanganate and sulphurous acid. It may be considered as showing more resemblance to the animal fibre in lustre and appearance than any of the other vegetable fibres, and is therefore frequently mixed with wool, mohair, and silk in certain classes of goods. Among the fibres of lesser importance which serve as substitutes for hemp and jute are Manila hemp, Sunn hemp, and Sisal hemp. The first of these is a tropical fibre, obtained on the Philippine Islands from the leaves of the wild plantain. The fibre is obtained by cutting open the leaf-stalks, which are from six to nine feet in length, and then scraping them free from pulpy matter. It furnishes a very superior rope-making fibre because of its combined lightness and strength, and the finer grades are used for woven goods. The color is yellowish or white, and the white variety has a fine silky lustre. It is shown in Fig. 81. The Sunn hemp is grown in India, and furnishes a fibre of light- yellowish color and resembles jute, although less lustrous. It is well adapated for cordage and netting. Sisal hemp (or henequen) is derived from the fleshy leaves of a species of agave grown in Yucatan, British Honduras, and the West Indies and Bahamas. It is used largely in the United States as a sub- stitute for jute in the manufacture of bagging and for cordage, being stronger and lighter than jute. Ramie fibre (China-grass}. The bast fibre from two varieties of Boehmeria nivea, known in India as Rhea, in the Malay Archipelago as Ramie, and to Europeans as China-grass, has in recent years attracted very favorable attention from all interested in textile industries. It seems to thrive best in the tropics and requires a great deal of moisture. The bast fibre cannot be removed from the woody stems by the retting process used for flax and hemp, as the intercellular substance is so easily decomposed that the water retting rapidly resolves the fibre into a magma of separated cells. The fibre must be removed from the woody stem while the plants are in the green state, as when dried, even by several hours' exposure to the sun, the fibre becomes difficult to remove from the woody portion. The length of the cells makes it possible to cut the ramie fibre into short lengths and to treat the cleansed fibre like cotton rather than like a long bast fibre. Hence the name "cottonized" ramie which has been applied to that exported from China. With improved methods it is found possible to cleanse it in full lengths, and the fibre is worked like flax rather than with cotton-spinning machinery. The machines for breaking and decorticating the ramie are numerous, but few if any are entirely satisfactory. The properly-prepared fibre is of fine silky lustre, soft, and extraordinarily strong. It is undoubt- GENERAL CHARACTERS. 309 FIG. 82. edly the most perfect of all the vegetable fibres, and will play a great part in the industries of the future, especially as the plant, being a perennial, can be grown continuously for years, spreading of itself very rapidly and yielding several crops yearly. Its cultivation has been begun successfully in Louisiana and Mississippi, and it can probably be extended through the Southern States and Mexico, where is has also been tried. The iodine and sulphuric acid test shows the ramie fibre to be composed of a pure cellulose, which swells easily and voluminously when treated with ammoniacal solution of cupric oxide. The appearance of the China-grass is shown in Fig. 82. Nettle Fibre. The bast fibres of the common nettle (Urtica dioica) were at one time prior to the development of the cotton industry used ex- tensively in spinning and weav- ing on the Continent of Eu- rope, the cloth made being known as grass-cloth, the name now given to the product of the China-grass, or ramie. The fibre when cleansed is soft, of good length and strength, and quite lustrous and white. The bast fibres of the linden (Tilia Europcea) and of the paper- mulberry - tree (Broussonetia papyrifera) are also used, the former for the manufacture of mats in Russia and the latter by the paper-makers of China and Japan. New Zealand Flax is a fibre obtained from the leaves of Phormium tenax, which acquires a length of one to two metres. The fibre as prepared by hand-scraping, the method of the native Maoris, is soft, white, and of silky lustre ; as pre- pared by machinery it is distinctly inferior in character. Its chief value is for rope-making and for coarse textiles. The rope made from this fibre is, however, weakened when wet by sea-water, and therefore must be kept well oiled. Pineapple Fibre. The leaves of the several varieties of Bromelia yield a fine, nearly colorless, fibre, which is worked, especially in Brazil, for the manufacture of the so-called "silk-grass." Esparto. This is a grass, cultivated especially in North Africa and Spain, where ropes and cordage are made from it. Its chief use, how- ever, is in connection with paper-making. (See p. 313.) Cocoa-nut Fibre (Coir}. The coarse fibrous covering of the nut of the coco palm is largely used for brooms, brushes, matting, and coarse China-grass ( 310 VEGETABLE TEXTILE FIBRES. carpeting. The fibre is coarse, stiff, very elastic, round, and smooth like hair. It also has great tenacity, and is well adapted for cordage. The classification of the vegetable fibres just enumerated has already been made upon the basis of the iodine and sulphuric acid reaction according to Vetillart. Two groups were thus established, the one com- posed essentially of unaltered cellulose and the other of lignified cellu- lose bastose. Other reactions of these two classes of materials are given in the accompanying table from 0. Witt : * Reagent. Cellulose. Bastose (compound of cellulose with lignin). Iodine and sulphuric acid. Sulphate of aniline with free sulphuric acid. Basic aniline dyes. Weak oxidizing agents. Ammoniacal cupric oxide. Produces blue color. Indifferent. Indifferent. Indifferent. Immediate solution. Produces a yellow or brown color. Colors deep yellow. Produces fast colors. Rapid disintegration. Swelling up, blue color, and slow solution. To distinguish the several more important vegetable fibres from each other when admixed, a number of chemical and physical tests have been proposed in addition to the microscopical study of the structural dif- ferences already mentioned under the individual fibres. Thus, according to Kindt's test, the presence of cotton fibre in linen goods can be distinguished, after first removing the size or dressing by thorough boiling with distilled water and drying again, by dipping them from one-half to two minutes, according to the texture of the goods, in concentrated sulphuric acid. They are then well washed with water, rubbed, dipped for a moment in ammonia-water, and dried. The cotton fibre is either dissolved or gelatinized and removed by the rubbing, while the linen fibre remains unchanged or but slightly attacked. By counting the flax fibres remaining for a given superficial area the relative pro- portion of cotton admixture can be determined. The different effect of strong caustic potash solution upon cotton and linen fibres is also taken as decisive at times, although the difference is not so marked. Both kinds of fibres shrink in size, the cotton fibres remain whitish or grayish yellow, while the linen fibres are colored deep yellow or orange. A very characteristic test is that given by Boettger. A piece of the mixed goods frayed out in three sides is first dipped in a one per cent, solution of fuchsine, then taken out, washed in running water until this runs off clear, and dipped in ammonia-water for from one to three minutes. The cotton fibre is quickly decolorized, while the linen fibre remains bright rose-red in color. A test easily applied and satisfactory is the oil test, but it is only applicable to white goods which are free from size. The well-dried sample is dipped into olive oil, and then well pressed. The linen fibres become translucent from the capillary action upon the oil, while the cotton fibres remain white and dull in appearance. * Chem. Technologie der Gespinnstfasern, p. 111. PAPER-MAKING. 311 An alcoholic cochineal solution (one part of powdered dyestuff di- gested with twenty parts of alcohol of .847 specific gravity for twenty- four hours) is also recommended by Bolley. Cotton fibres take a clear red color in this solution, while linen fibres are colored violet. A special test to distinguish the fibre of the Phormium tenax (New Zealand flax) from linen or hemp is given by Vincent. It is in the use of concentrated nitric acid, which colors the New Zealand flax distinctly red, but does not change the other fibres mentioned. (For tests to dis- tinguish the vegetable fibres as a class from the animal fibres, see p. 302.) The use of the microscope, however, is much the most reliable means of distinguishing the several fibres when occurring in admixtures, as the structural characters are sufficiently distinct to allow of easy recognition to those possessed of some practice. INDUSTRIES BASED UPON THE UTILIZATION OF VEGETABLE FIBRES. The great utilization of these fibres is of course in the manufacture of textile fabrics of all grades. Having described the fibres which consti- tute the raw materials of these industries, we shall pass the mechanical side of their treatment and shall note the chemical processes of bleach- ing, dyeing, and color-printing in a later section of the work (see p. 522), after the preparation of natural and artificial dye-colors has been de- scribed. Other industries based upon utilization of some one or more of the vegetable fibres are Paper-making, Pyroxylin and Gun-cotton, Col- lodion, Celluloid, and most recent Artificial Silk. A. PAPER-MAKING. I. Raw Materials. 1. RAGS. The first in order of use for paper-making and still the most important raw materials for the finer grades of paper are linen and cotton rags. As the cellulose of these rags has already undergone a process of purifying from the coloring and incrusting matter with which it was first associated in nature in its preparation for manu- facture into textile fabrics, it is well adapted for use in paper-making, the basis of which is also a cellulose fibre. Of course, the rags may be of all grades of cleanliness. They may be cuttings obtained in the course of manufacture of garments, and being unworn may be relatively clean, or they may be fragments of cast-off wearing apparel gathered from waste-heaps and reeking with filth. Indeed, so great is the demand for paper-making stock that rags are gathered from Japan, Egypt, and all parts of the world, and the bales generally require careful disinfection before they can be used. They may contain sizing and China clay and other loading materials, or they may be colored with various dyes and metallic salts. Rags considered as paper-making stock must therefore be assorted, and for trade purposes they are divided into a large number of grades or classes distinguished by different letters. 312 VEGETABLE TEXTILE FIBRES. Linen rags are distinctly superior for paper-making to cotton rags, as they make a stronger and more durable paper. 2. WOOD FIBRE. Two varieties of pulp for paper-making may be obtained from wood, viz., mechanically and chemically prepared pulp. Of these, the mechanical wood-pulp obtained by shredding the wood serves for the inferior grades of paper only, as its fibres are too short and do not "felt" or interlace sufficiently. It can therefore be used only as a filling material. Moreover, the resin present resists strongly the action of bleaching agents, and the paper becomes yellowish after a time. This mechanical wood-pulp is known to the trade as "ground wood" and it is obtained by forcing the barked timber cut in short lengths against rapidly revolving stones or grinders, keeping a steady stream of water in contact with it to prevent the development of heat. This fibre, although, as said, very short, is used in enormous quantities to "fill in" in the manufacture of newspapers. No attempt is made to bleach it before making paper, it being merely necessary to incorporate in the stock sufficient coloring matter to overcome the yellowish tinge which otherwise would be evident. On the other hand, what is termed chemical wood-pulp has met with great favor as a very pure and easily obtainable form of cellulose. Chemical pulp is made by three distinct processes, known to the trade as the sulphite, soda, and sulphate proc- esses. In all of these cases the timber is thoroughly denuded of bark and is then split and put through a "hog" or chipper which produces short, coarse heavy chips of about a half-cubic inch in volume. These are screened to obtain a fair degree of uniformity and separate the dust. In the sulphite process, there are two methods of cooking, known as the "quick cook" and the "slow cook" or Mitscherlich method. The former is now more extensively used by large manufacturers of news- paper and by book paper manufacturers to obtain their raw sulphite stock. The cooking liquor is made from a dolomitic milk of lime satu- rated with sulphur dioxide, thus forming a mixture of magnesium and calcium bisulphite; or by another method high wooden towers are kept packed with lime-stone while water is allowed to pass down over the stone against a counter current of sulphur dioxide which displaces the carbon dioxide in the limestone. The digestors in most common use are about forty feet high, vertical, with conical bottom,, and of boiler steel lined with rough or glazed firebrick set in an alkaline silicate cement. The "cook" lasts six to eight hours, during which time a steam pressure of about 120 pounds is maintained, while the excess of sulphur dioxide developing is frequently allowed to pass off through relief pipes. The pulp when "blown" from the digester is washed and if for book or writing paper is bleached with chloride of lime, or if for news, wrapping or bag paper is allowed to go to the beating engines unbleached. In the case of the "slow cook" or Mitscherlich process, a horizontal cylindrical digestor is used having the same kind of lining as above described, but in which the heating is indirect by leaden steam coils placed longitudinally on the bottom inside the digestor. This "cook" PAPER-MAKING. 313 lasts about forty hours under a comparatively low pressure. Although the resulting material has had the lignin dissolved from it, it retains the original form of the uncooked chips and though soft must be ground before beating. Cross and Bevan explain the efficacy of the bisulphite processes by saying, "The chief agency is the hydrolytic action of sul- phurous acid, aided by the conditions of high temperature and pressure ; and the subsidiary agencies are, (1) the prevention of oxidation; (2) the removal from the sphere of action of the soluble products of resolution in combination with the sulphite as a double compound, for it is to the class of aldehydes that we have shown that the non-cellulosic constitu- ents of wood belong; and (3) the removal of a portion of the constituents in combination with the base, i.e., with expulsion of sulphurous acid." At the present writing, the large consumption and rapidly dimin- ishing supply of timber adapted to the sulphite process will cause a search for new fibres and an abandonment of the sulphite process in favor of the other chemical processes of treatment. The soda process is used for the working of a variety of woods such as different kinds of long-leaf pine, spruce, hemlock, poplar, bass, etc. The cooking of the wood is comparatively simple. A vertical clyindrical welded digester is used without any lining. The cooking liquor is generally a caustic soda solution testing about 12 B. The time of di- gestion is the same as in the "quick cook" sulphite process. The soda takes up the ligneous and resinous portion of the wood, and, when sepa- rated from the pulp, is evaporated, incinerated, and recausticized, with a loss of ten to fifteen per cent, in recovery, for cooking purposes. In this country, a large proportion of the soda pulp mills use poplar, spruce, and hemlock for the production of a fine grade of pulp for book paper. Others, using the long-leaf pine, produce a long, coarse fibre for wrap- ping paper. The sulphate process, in large use in Sweden and Norway and to a small but increasing extent in the United States, produces what is known as a "kraft" pulp, which as the name denotes, has an extremely strong fibre and makes excellent wrapping paper. To obtain this, long-leaf pine is digested in soda digestors, and the process corresponds with the soda process except that before the incineration of the concentrated spent soda or "black liquor" sulphate of soda is introduced, which in the incineration causes the formation of a certain amount of sodium sulphide from the action of the carbon on the sulphate. This mixture of the caustic soda and sodium sulphide in cooking has the proper influ- ence on the chemical changes taking place and produces long strong fibre. 3. ESPARTO. This grass, mentioned under the vegetable fibres (see p. 309), is of great importance as a paper-making material, particularly in England. The Spanish variety, according to Hugo Miiller, contains 48.25 per cent, and the African variety 45.80 per cent, of cellulose, but the yield of bleached fibre obtained in practice probably does not much exceed forty per cent. The fibre is tough and it makes an excellent paper, whether used singly or in admixture with other materials. 4. STRAW. As a material for admixing with other fibres, straw- 314 VEGETABLE TEXTILE FIBRES. pulp is largely used. The varieties of straw so utilized are oat, wheat, rye, and barley. Of these, rye is the most suitable on account of its yielding the largest amount of fibre, and next in value is wheat. The amount of cellulose in winter rye is given by Hugo Miiller as 47.69 per cent, and in winter wheat as 46.60 per cent., but probably not more than thirty-five per cent, is actually obtained as pulp, much being lost in the treatment on account of the loose aggregation of the cellular tissue. Straw contains more silica than Esparto, and hence requires more soda in the after-treatment to free the cellulose and adapt it for use. 5. JUTE. The "butts" or "cuttings" rejected by the textile manu- facturer are largely used in the manufacture of the common grades of paper. It possesses a large percentage of cellulose (63.76 per cent, in the best fibre and 60.89 per cent, in the "butts"), but it cannot be economically bleached to a white color. 6. MANILA HEMP. This is very like jute in its adaptability for cheap and colored papers, and as the fibre is a lignified cellulose it requires considerable boiling with soda to prepare it for use. 7. PAPER-MULBERRY. In China and Japan, where the paper-makers excel the best European workmen in the making of some delicate but strong papers, the material chiefly used is the inner bark of the paper- mulberry-tree (Broussonetia papyrifera}, the leaves of which can be used in feeding silk-worms. The strength of this paper is due to the fact that in making the pulp the long bast-cells are not broken and torn as in European pulping-machines, but merely softened and separated by beating. In taking up the pulp in the mould the cells are made to lie in one direction, and the paper may be strengthened by taking one or more dips in which the cells are made to lie in other directions. Some gum is added to make the cells of the pulp adhere. II. Processes of Treatment. 1. MECHANICAL PREPARATION OF THE PAPER-MAKING MATERIAL. This differs, of course, according as the raw material is composed of rags or other cellulose-containing substance. "With rags, a preliminary sort- ing always takes place, more or less complete according to the make-up of the bales. Numerous commercial designations are in use for these different grades so obtained. We need only speak of white linen, blue or gray linen, white cotton, colored linen or cotton, sacking, half wool, etc. They are then cut into coarse fragments by hand, being passed rapidly over broad knives fixed at a set angle in tables, and all buttons and hard substances removed. A thorough dusting or "thrashing" is now necessary to remove the dust and detachable dirt. This is effected in large wooden boxes with revolving arms. A more thorough cutting now ensues with the aid of revolving knives, followed in most cases by a final and thorough dusting, so as to eliminate as" much dirt as possible and save in the amount of boiling necessary as the next operation. With Esparto a mechanical sorting or "picking" is also the first operation. The grass is spread out on tables and the weeds, root-ends, PAPER-MAKING. 315 etc., carefully removed, as these would be difficult to boil and bleach and would give rise to dark-colored specks in the finished paper known as "sheave." Machines for this cleansing of the Esparto are also used quite largely. The preparation of mechanical and chemical wood-pulp has already been referred to. FIG. 83. 2. BOILING. The boiling of the rags with caustic soda, caustic lime, or a mixture of soda ash and lime, which is the next operation, is designed to free them from grease, dirt, and coloring matter. This may be done either in rotating spherical or cylindrical boilers or in the so-called "vomiting" boilers described later. The boilers are often large enough to take two tons of rags at a charge. The amount of alkali usually ranges from five to ten per cent, on the weight of the rags. Soda is preferred by many paper-makers to lime on account of the greater solubility of the compounds it forms, although both are in gen- eral use. The time of boiling varies from two to six hours, according to 316 VEGETABLE TEXTILE FIBRES. FIG. 84. the quality of rags, the alkali employed, and the pressure. The use of high pressure is to be avoided as far as possible, as it may result in fixing the dirt and coloring matter instead of dissolving them. A pressure of from three to four atmospheres is com- monly employed. After the pressure has been allowed to fall, the liquor collected at the bottom of the boiler is drawn off and the water run in to give the rags a slight preliminary wash- ing. The charge is then drawn off. In the case of Esparto, the "vomiting" boiler or other form of apparatus for keeping up a continuous circulation of the liquor is used. A form of boiler in which this circulation is kept up by the use of a steam injector is shown in Fig. 83. The grass is put in through the man-hole C and rests upon the false bottom B. Circulation is set up by the steam from the pipe D passing through the in- jector E and drawing the liquor through the small pipe r. In order that this circulation may proceed uniformly, it is necessary that the steam shall enter at a pressure one atmos- phere higher than the pressure existing in the boiler. A mano- meter, M, shows the pressure, and a safety-valve, V, allows- of * the adjustment of the necessary conditions. The contents of the boiler are discharged through s at the end of the operation. The quantity of soda necessary de- pends upon the nature of the grass, Spanish requiring less than African, and the pressure employed varies from five to forty-five pounds per square inch. 3. WASHING. This operation, which must be a thorough one, takes place in a washer or "breaker." The name "hollander" is very gen- PAPER-MAKING. 317 erally given to this machine as well as to the similar one in which the beating or mixing is done. The hollander is an oval iron tube, from ten to twenty feet long, four to six broad, and about three feet high, divided for two-thirds or more of its length by an upright partition known as the "mid-feather." The details of its construction may be seen from Figs. 84 and 85. The roll A carries upon its circumference a number of steel knives and revolves on one side of the "mid-feather," or longi- tudinal division Q Q (Fig. 85). The floor on this side is raised in such a way as to bring the pulp well under the roll, as shown by the line J K (Fig. 84). Immediately under the roll is the "bed-plate," shown at 0, and provided with knives similar to those in the roll A, but set with their edges in the opposite direction. The distance between the roll and the bed-plate can be varied at will by means of the hand-wheel h and the mechanism shown at k and i (Fig. 85). After passing between the roll and the bed-plate, the pulp flows down the "back-fall" K K, and finds its way around to the other side of the mid-feather. On the in- clined part of the floor and immediately in front of the bed-plate a small depression is made at E, covered with an iron grating, for the purpose of catching buttons, small pieces of stone, and other foreign substances that may have found their way into the rags or other paper stock. The dirty water from the rags is removed by the ' ' drum- washers " R R. The ends of the drums are of wood, and the circumference is covered with fine copper or brass wire-cloth. The wash-water passes through the wire- cloth into the compartment shown in R, and passing towards the nar- rower end of the inner conical tub, flows out through the side of the drum into a trough placed to receive it. In washing the rags in this machine, the tub is partly filled with water, the rags from the boiler dumped in, and the operation begun. The action of the roll thoroughly mixes pulp and water and sweeps the rags up the incline and over the back-fall K. The dirty water then passes away through the drum-washer, the supply of pure water being so regulated as to keep the level constant. When the water begins to run off clear the supply is stopped, the washer still being kept in action. As the level falls, the drum is lowered by means of the handle h. When sufficiently drained, the pulp is discharged through the valves C C in the bottom of the washer. It is now ready to be bleached. This may be done in the washer itself or in separate engines called "potchers." If done in the washer, a solution of bleaehing-powder is run in after the withdrawal of the wash- water and the action of the roll continued. Esparto is generally washed in exactly the same way as that just described for rags, but in some mills the grass is washed in a series of connected lixiviating tanks like those used in alkali-works. Pure water flows in at one end, passes through fresh lots of grass in succes- sion, and issues at the farther end highly charged with the soluble prod- ucts of the grass. The washed and broken pulp now goes by the name of "half-stuff." 4. BLEACHING. This is done with the aid of chlorine or a solution of calcium or sodium hypochlorite. The use of chlorine gas, once largely practised, has been almost entirely superseded by the hypochlorite solu- 318 VEGETABLE TEXTILE FIBRES. PAPER-MAKING. 319 tions, as chlorine is liable to form difficultly removable compounds, and it also tends to attack and weaken the fibre of the pulp. When chlorine is used, 2.5 to 5 kilos, of salt are taken as needed for 100 kilos, of "half- stuff." The solution of calcium hypochlorite must be used perfectly clear and free from undissolved hydroxide or carbonate. A solution of 6 Twaddle, which contains about half a pound of bleaching-powder to the gallon, is commonly used. An addition of hydrochloric or sulphuric acid to the bleaching-liquor is sometimes made, but this must be done with care so as not to liberate chlorine instead of hypochlorous acid. This danger from free chlorine is greater when highly lignified fibres, such as wood or jute, are used. The bleaching is often effected by com- bining a preliminary treatment in the "potcher" or washer with a sub- sequent prolonged steeping in tanks. A process has been recently pro- posed by Professor Lunge involving the use of acetic acid. The quan- tity required is very small, as during the process of bleaching it becomes regenerated. Any free lime in the solution is first nearly neutralized with a cheaper acid, such as hydrochloric or sulphuric acid, followed by the addition of the acetic acid. The process is said by Cross and Bevan to give excellent results with high-class material, such as the best cotton and linen rags, but is not to be recommended for materials like straw or Esparto. A process invented by Thompson is also said to be very effective for the bleaching of rags. It consists in saturating the materials with a weak solution of bleaching-powder and then exposing them to the action of carbonic acid gas. The bleaching action is thus made very rapid and effective. One of the most recent innovations in bleaching is the application of electricity in this connection. The earliest process that attracted much attention was that of M. Ilermite. It is thus described by Cross and Bevan:* "This process is based upon the electrolysis of a solution of magnesium chloride, this salt having been found to give the most economical results. The solution, at a strength of about 2.5 per cent, of the anhydrous salt (MgCl 2 ), is electrolyzed until it contains the equiva- lent of about three grammes of chlorine per litre. This solution is then run into the 'potcher' containing the pulp to be bleached; a continuous stream is then kept up, the excess being removed by means of a drum- washer. This excess, which, after being in contact with the pulp in the engine, is more or less deprived of its bleaching properties, is then returned to the electrolyzing-vat, where it is again brought up to normal strength. It is claimed that the bleaching effect is much stronger than that of the corresponding amount of calcium hypochlorite solution. More- over, the bleaching is much more rapid and the loss of weight which the substances undergo is less for equal degrees of whiteness obtained." In this country several successful electrolytic bleaching processes have been introduced in connection with the paper and pulp industry, such * Text-book of Paper-Making, p. 115. 320 VEGETABLE TEXTILE FIBRES. as the Carmichael electrolytic process and the Whiting electrolytic process, both extensively used. The removal of any excess of chlorine or bleaching-liquor must now be looked to. This is done either by careful washing or by the use of an ' ' antichlor. ' ' The first method has the advantage of not only remov- ing the bleach but also of the chloride of calcium which has been formed from it. It, however, takes some time and consumes a large amount of water. Much more general is the use of an "antichlor." The com- monest of these is sodium thiosulphate (or hyposulphite, as it is com- monly called). This is ordinarily decomposed according to the reaction 2(Ca(C10) 2 ) -f Na.,S 2 8 -f H 2 = 2CaS0 4 -f 2HC1 + 2NaCl, but when the solutions are very dilute, sodium tetrathionate, Na 2 S 4 O 6 , and caustic soda and lime are formed. For the first equation two hundred and forty-eight parts of commercial thiosulphate are required to neutralize four hundred and nine parts of bleaching-powder of thirty- five per cent, available chlorine strength. The various sulphites are also in use as antichlors, sodium sulphite being the most important. A cheap anti- chlor is also made by boiling together lime and sulphur, the resultant calcium sulphide solution containing a mixture of calcium thiosulphate and calcium pentasulphide. This last-mentioned preparation is, how- ever, objectionable on account of the free sulphur formed, as this affects the pulp injuriously. Whatever antichlor is used, an excess should be avoided, as it may act upon the color or size added subsequently. The antichlor should therefore be added in successive small portions, and any hypochlorite solution still remaining be tested for from time to time with iodide of starch paper, which will be turned blue as long as hypochlorite remains. 5. BEATING. The bleached pulp, or " half-stuff ," is not yet in con- dition for making an even paper, as the fibre has not been sufficiently disintegrated. This is now effected in the beating-engine, which is a hollander very similar to the breaker already illustrated, except that the roll carries more knives and it is usually let down much nearer the bed-plate. The half-stuff is furnished in successive portions to the beater previously partially filled with water, each successive portion being allowed to mix thoroughly with the water before another lot is added. This is continued until the mass is so thick that it will only just turn round under the action of the roll. The operation of beating is designed to be a more complete breaking or tearing apart of the fibres rather than a cutting, as this latter result would interfere with the felting of the fibres so necessary in paper-making. Cotton and linen rags naturally take longer than most other paper-making material, taking often as much as ten hours; wood-pulp requires to be very gently and slowly beaten, so that it requires some six hours; while Esparto is sufficiently disintegrated in from two to four hours. In making the finer grades of paper, the roller bars or knives instead of being made of steel are made of bronze, so that contamination with oxide of iron is avoided. Beaters of a totally different form of construction are also largely in use. Thus, in the Jordan beater the roll is in the shape of a truncated PAPER-MAKING. 321 cone, fitted with knives and revolving in an iron box of corresponding shape, and also fitted with knives set at an angle. In the Kingsland engine and the Gould engine a circular plate furnished with knives revolves against one or more stationary plates similarly fitted, somewhat after the manner of millstones. The half-stuff is even more thoroughly disintegrated in these beaters than in the ordinary forms. 6. LOADING, SIZING, COLORING, ETC. Except in the very finest papers, some mineral loading material is incorporated with the pulp when in the beater. This is, of course, in the main for cheapening purposes, but also serves the useful purpose of filling the pores of the paper and enabling it to take a better surface in the subsequent operations of calendering. Such loading materials are China clay, or kaolin, sulphate of lime, or "pearl hardening," barium sulphate, precipitated chalk, bauxite, pre- cipitated magnesia, and magnesium silicate, or "agalite." The amount added varies from two or three per cent, to twenty per cent., or in rare cases even more. All papers except blotting-papers have also to be sized. This is for the purpose of filling the pores with some material that will, to some degree at least, resist the action of water. Thus, all writing-papers, and in general printing-papers also, are sized to prevent the ink applied to them from running. This is done either by what is termed "engine- sizing" that is, in the beating-engine itself or by "tub-sizing," when the paper as it goes through the Fourdrinier machine (see below) passes through a tub of gelatine size and takes a layer of the same on either surface. In "engine-sizing" a rosin soap is first added to the pulp in the beater, and when this is thoroughly incorporated a solution of alum is run in, forming, as it has been generally supposed, a resinate of alumina, which is water resistant when dried. Wurster * claims to have shown, however, that the sizing in this case is not due to the formation of a resinate of alumina but to a separation of free resin, and in this result he has been supported by Conradin.f With the resin soap is also added some starch, and the quantity of mixed rosin and starch is usually from three to four pounds to the one hundred pounds of pulp. The pulp although bleached is rarely white enough to produce a clear white paper, and the yellowish tint requires to be neutralized by the addition of small quantities of blue and pink coloring material. Ultramarine, smalt, and aniline-blue are used for the first color, and either cochineal, Brazil-wood, or aniline-red for the second. The paper may be colored throughout any desired color by using rags previously dyed, or by adding to the bleached pulp in the beater the necessary dyes or pigments. 7. MANUFACTURE OF PAPER FROM THE PULP. We have to consider here two different products, viz., hand-made paper and machine-made paper. The former is made by taking in the mould upon the ' ' deckel, ' ' or wire-cloth frame, just sufficient of the prepared pulp diluted with * Wagner's Jahresbericht, 1878, p. 1155. flbid., 1879, p. 1106. 21 322 VEGETABLE TEXTILE FIBRES. water to make a sheet of paper. As the water drains through the wire- cloth and leaves the fibres spread out upon the surface, the felting operation is assisted by shaking the frame gently from side to side. The mould with the sheet of paper is then turned over, and the sheet thus transferred from the wire to a piece of felt. When a number of sheets have been thus prepared, they are piled up with alternate sheets of felt and the whole subjected to strong pressure to expel water. They are then sized if required by dipping them into a solution of gelatine, again pressed, and hung up to dry. When dry they are calendered or pressed between hot metal rolls. Machine-made paper is made on what is universally known as the Fourdrinier machine, of which an improved form, as manufactured by the Pusey and Jones Company, of Wilmington, Delaware, is shown in Fig. 86. We cannot here describe the various mechanical details of this machine, but may summarize by saying that it consists of an endless mould of wire-cloth on to which the prepared pulp flows from the ' ' stuff- chest" through a " regulating-box " and over the li sand-table " and the "screen." From the deckel wire it now passes through a series of rolls, at first covered with felt and later of smooth heated metal known as the "dandy-roll," the "couch-rolls," the "press-rolls," the " drying cylin- ders," and, finally, the "calenders." The action of the machine is a continuous one, and the speed of the Fourdrinier is from sixty to two hundred and forty feet per minute, the latter for cheap newspaper, the former for the best paper requiring the most care. What is known as "tub-sizing" is applied to many machine-made papers in the course of their passage through the Fourdrinier. A filtered solution of gelatine is used to which about twenty per cent, of its weight of alum has been added. A certain quantity of soap is also often added, a white soap free from resin being used. Instead of the Fourdrinier, what are termed cylinder-machines are also in use, in which a large drum or cylinder covered with wire-cloth revolves in the vat containing the pulp. As it revolves the fibres attach themselves to the wire and the water is sucked through the meshes by a partial vacuum within. The sheet of paper thus formed is taken on to an endless felt passing over a couch-roll, which revolves in contact with the hollow drum, and thence passes to a large drying cylinder heated by steam. Paper made on such a machine is weaker, however, than that made on the Fourdrinier, because it has not been found pos- sible to give the shaking motion to the cylinder necessary to produce the felting of the fibres. IE. Products. The products are almost without number, and vary not only in dif- ferent countries, but even locally from time to time as different mills change their production. We will therefore attempt only a general classification of the main varieties. 1. BLOTTING- AND TISSUE-PAPER. These are unsized papers. Blot- ting-paper is a mass of loosely-felted fibres, which, however, is free from PAPER-MAKING. 323 324 VEGETABLE TEXTILE FIBRES. any loading or filling material, and therefore is capable of easily and quickly taking up water or other liquids. It may be white, gray, or colored to any shade by the addition of the proper dyes. Tissue-papers, which as the name indicates are the thinnest of all papers, are made from very strong fibres, such as that of hemp-bagging and cotton canvas, and on machines somewhat different from the ordinary Pourdrinier. 2. WRAPPING-PAPERS. These are partially-sized papers of coarse materials, such as straw, jute, Manila hemp, common rags, etc. They may show the natural color of the materials or may be colored, as in the case of the blue wrapping-paper commonly used for packing sugar. A more strongly sized and calendered wrapping-paper is made for use with linens and other textile goods. 3. PRINTING-PAPERS. These are -white papers, generally with filling and sizing material, although some special grades are given a smooth surface by calendering instead of sizing. The cheaper grades for news- paper use are frequently largely adulterated with filling material, and mechanical wood-pulp is also largely used in their manufacture. 4. WRITING-PAPERS. These are thoroughly-sized papers, for which the best materials are generally used, linen rags alone being taken for the finer grades. 5. CARDBOARD, PASTEBOARD, AND PAPIER-MACHE. Pasteboard may be made by pressing a number of sheets of freshly-formed unsized paper in powerful presses, or cementing them together by the use of glue or other cementing material, and then pressing the mass so formed. Cardboard is made direct upon machines adapted for heavy layers of pulp and pressed and calendered like similar grades of ordinary paper. Papier- mache is made chiefly from old paper by boiling to a pulp with water, pressing, mixing with glue or starch paste, and then pressing in moulds previously oiled. After drying, the articles are soaked with linseed oil and then dried at higher temperature. PARCHMENT-PAPER. If a pure unsized paper be dipped in sulphuric acid of 60 B. a portion of the cellulose is changed into amyloid (hydro- cellulose, according to Girard), which forms a gelatinous coating over the swollen fibres and effects in some degree a sizing of them. The paper is made hereby translucent and parchment-like, the strength is increased from three to fourfold, and the specific gravity by perhaps forty per cent. For the manufacture of this parchment-paper the long-fibred, unfilled paper is to be chosen. After treatment the paper is quickly washed, first with water, then with weak ammonia, and again with water. In place of sulphuric acid we have the treatment with ammoniacal cuprous oxide solution or zinc chloride. The former reagent furnishes the Willesden ware, which always retains the light blue-green color; the latter yields the valuable product known as indurated or hard fibre. In preparing this latter material the paper, which is either unsized or prepared with a rosin size and then nearly dried, is dipped or run while in the roll through a bath of zinc chloride of about 65 to 70 B. kept at a temperature of about 38 C. After passing through the zinc chlo- ride bath, the paper is passed over hot rolls and then cooled and washed in pure water to remove all excess of zinc chloride or rosin size. It is PAPER-MAKING. 325 then dried in a heated room, given a coating of paraffin oil, and calen- dered. The material so obtained is very strong, tough, and can be washed. 6. SIDE-PRODUCTS. Recovered Soda. The alkaline liquors in which rags, esparto, and other paper-making material have been boiled were at one time run off as waste products. This is no longer done in properly conducted mills, as the alkali used can be recovered in the form of carbonate by evaporation of the waste-liquor and ignition of the residues, and this carbonate can then be causticized and fitted for renewed use. The soda during the process of boiling with the paper-making materials takes up a large amount of non-cellulose fibre constituents, such as resin, coloring matter, and silica. These on evaporation and ignition become either carbonate or silicate. It will not be possible for us here to describe the forms of evaporators in use for this soda recovery. One of the best-known evaporators is that of Porion, used largely in Eng- land on the Continent. For a description of this and other forms, see Cross and Bevan's "Text-book of Paper-Making," p. 182. In this country the Swenson form of evaporator has been largely used for the "black liquor" of the soda pulp works. The recovered soda consists essentially of carbonate of soda, together with a certain amount of silicate of soda if the liquor had been obtained by boiling straw or esparto. The causticizing is done in the usual way with caustic lime and the clear alkali decanted from the separated cal- cium carbonate, which is then thoroughly washed. IV. Analytical Tests and Methods. 1. DETERMINATION OF THE NATURE OF THE FIBRE. This may be done in part, if not wholly, by either of two methods, viz., by the aid of the microscope or by the use of chemical tests for individuals fibres. The fibre is always torn or cut and often somewhat attacked. By some prac- tice, however, it is possible to distinguish between cotton and linen or to identify both in admixture. Wood and straw can also be identified. In making these tests, it is best to take strips of the paper in question and boil them in succession with alcoholic potash solution, with water, with two per cent, hydrochloric acid, and then again with water. If they are now shaken up with a little warm water, we obtain a fine magma of fibres, which when mixed with an equal volume of glycerine is well adapted for examination under the microscope. The distinctive char- acters of some of the chief paper-making materials as seen under the microscope may be thus summarized, according to Cross and Bevan : * Cotton, flat, ribbon-like fibres, frequently twisted upon themselves. The ends generally appear laminated. Linen, cylindrical fibres, similar to the typical bast fibre. The ends are frequently drawn out into numer- ous fibrillse. Esparto, the pulp consists of a complex of bast fibres and epidermal cells. The most characteristic feature of esparto pulp is the presence of a number of fine hairs which line the inner surface of the leaf, some of which still remain after the boiling and washing processes. * Text-book of Paper-Making, p. 199. 326 VEGETABLE TEXTILE FIBRES. The presence of these hairs may be taken as conclusive evidence of the presence of esparto. Straw, this closely resembles esparto pulp in microscopical features, except that the hairs are absent. On the other hand, a number of flat oval cells are always present in paper made from straw. Chemical wood-pulp, flat ribbon-like fibres, showing unbroken ends. The presence of pitted vessels is eminently characteristic of pulp prepared from pine-wood. Mechanical wood-pulp may be recognized by the peculiar configuration of the torn ends of the fibres and from the fact that the fibres are rarely separated, but generally more or less agglomerated. The pitted vessels of pine-wood also show, and usually more distinctly than in chemical wood-pulp. The chemical reagent most useful in testing paper-pulp is aniline sulphate. With most of the fibres which consist of cellulose simply it gives no reaction. Straw, esparto, and mechanical wood-pulp can, how- ever, be identified by its means. Thus, where paper containing straw or esparto is treated for some time with a boiling one per cent, solution Of aniline sulphate, a pink color is produced. Esparto gives the reaction with greater intensity than straw. Mechanical wood-pulp treated with this solution develops even in the cold a deep-yellow color. According to Bolley,* the moistening of paper containing mechanical wood-pulp with nitric acid will give the same result, and a naphthylamine salt produces a deeper orange color. According to Wiesner, phloroglucin is also a delicate reagent for wood fibre in paper. A drop of dilute solution of phloroglucin put upon the paper and this followed by mois- tening with hydrochloric acid develops an intensely red color. Fuch- sine also colors wood fibre red, but has no effect upon paper from linen fibre alone. M. Wurster in "Journ. de Pharm. et Chemie" has extended Wies- ner 's observation on phloroglucin to a number of the phenols, finding them as a class to serve as reagents for distinguishing between wood- pulp and other cellulose. The results are : Reagent. Wood-pulp. Cellulose paper. Orcin Dark red. No color. Resorcin Deep green. Violet. Pyrogallol Blue-green Violet. Phenol Yellow-green. Violet. Phloroglucin Blue-violet. No color. According to Godeffroy and Coulon, mechanical wood-pulp from pine-wood possesses the property, after it has been extracted with water, alcohol, and ether, of reducing gold solutions on boiling. This property is not possessed by wood-pulp prepared by the caustic soda or sulphite processes, after similar extraction with solvents, nor by the pulp pre- pared from linen or cotton fibres. This property depends upon the fact that in mechanical wood-pulp ligno-cellulose remains, and to this com- position is due the reducing power upon gold solutions. This ligno- cellulose is destroyed in the preparation of chemical wood-pulp, and does not exist at all in the linen or cotton fibre. It has been found that on the average one hundred parts of mechanical wood-pulp, extracted with * Handbuch der Technisch-Chem. Untersuchungen, Gte Auf., p. 1006. GUN-COTTON, PYROXYLINS, ETC. 327 solvents and dried at 100 C., will reduce fourteen thousand two hundred and eighty-five grammes of gold. It is thus made possible by weighing the reduced gold to estimate the amount of mechanical wood entering into the composition of the paper. For details of the analytical method based upon this gold reaction, see Bolley's "Handbuch der Technisch- Chem. Unterschungen, " 6te Auf., p. 1007. 2. DETERMINATION OF THE NATURE OF LOADING MATERIALS. The total amount of the mineral loading material is determined by igniting a weighed quantity of the paper until the ash is white or grayish and then accurately weighing this. The ash from a paper containing the China clay is insoluble in boiling dilute hydrochloric acid; that from paper containing calcium sulphate is soluble, and deposits on standing needle- shaped crystals of gypsum easily recognizable by chemical tests. 3. DETERMINATION AS TO NATURE OF THE SIZING MATERIALS. The iodine test serves to indicate the use of starch in the size, as it produces the well-known blue color. Extraction of the paper with alcohol con- taining a few drops of acetic acid serves to show the resin used in the size. The alcohol, after cooling, is poured into four or five times its bulk of water, when the resin separates, producing cloudiness or tur- bidity. Or, after extraction, the alcohol is evaporated, leaving the resin capable of being identified by its properties. Notable quantities of alumina in the ash also point to the use of resinate of alumina as sizing material. According to Wurster, if between two sheets of paper which have been sized with resin is pressed paper moistened with tetramethyl- paraphenylen-diamine solution, a bluish-violet color is produced, while paper free from resin is not affected. Boiling of the paper sample with distilled water, filtering, and adding a few drops of tannic acid solution will serve to show the presence of gelatine sizing. If present, a white curdy precipitate is formed on the addition of the tannic acid. 4. DETERMINATION OF THE NATURE OF THE COLORING MATERIAL. In deciding as to the presence of coloring matter, we must bear in mind the reactions of the commoner pigments used. Ultramarine is destroyed and decolorized on addition of acids; Prussian blue is decolorized by heating with alkalies; indigo is decomposed by heating with chlorine or nitric acid; smalt withstands the action of both acids and alkalies and remains in the ash as a blue glass ; the aniline colors are capable of extraction with alcohol as solvent. B. GUN-COTTON, PYROXYLINE, COLLODION AND CELLULOID. I. Raw Materials. The basis of these preparations is the class of nitrates formed from cellulose by the action of nitric acid, either taken singly or admixed with strong sulphuric acid, or as developed by the action of sulphuric acid upon a nitrate. Using the doubled formula C 12 H 20 10 , we may note the following five stages of nitration: Hexanitrate, C 12 H 14 O 4 (N0 3 ) 6 (trinitro-cellulose, C 6 H 7 (N0 2 ) 3 5 , of other writers), is the true gun-cotton. It is formed by the action of a 328 VEGETABLE TEXTILE FIBRES. mixture of the strongest nitric acid (specific gravity 1.52) with two or three parts of concentrated sulphuric acid, in which the cotton is im- mersed for twenty-four hours at a temperature not exceeding 10 C. (56 F.). The hexanitrate so prepared is insoluble in alcohol, ether, or a mixture of both, in glacial acetic acid, or in methyl alcohol. Ace- tone dissolves it very slowly. According to Eder, mixtures of nitre and sulphuric acid do not give this nitrate. It contains 14.14 per cent. nitrogen. Pentanitrate, C 12 H 15 O 5 (N0 3 ) 5 . It is difficult, if not impossible, to prepare this nitrate in a state of purity by the direct action of the acid upon cellulose. The best method (that of Eder) is to dissolve gun-cotton (hexanitrate) in nitric acid at about 80 to 90 C. (176 to 194 P.) and then precipitate as pentanitrate by concentrated sulphuric acid after cooling to C. ; after mixing with a larger volume of water and wash- ing the precipitate with water and then with alcohol, it is dissolved in ether-alcohol and again precipitated with water, when it is obtained pure. This nitrate is insoluble in alcohol, but dissolves readily in ether- alcohol and slightly in acetic acid. It contains 12.75 per cent, nitrogen. Strong potash solution converts this nitrate into the dinitrate. The tetranitrate and trinitrate (collodion pyroxyline) are generally formed together when cellulose is treated with a more dilute nitric acid and at a higher temperature and for a much shorter time (thirteen to twenty minutes) than in the formation of the hexanitrate. It is not possible to separate them, as they are soluble to the same extent in ether-alcohol, acetic ether, acetic acid, or wood-spirit. On treatment with concentrated nitric acid and sulphuric acids, both the tri- and tetranitrates are converted into pentanitrate and hexanitrate. Potash and ammonia convert them into dinitrate. The dinitrate, C 12 H 18 8 (N0 3 ) 2 , always results as the final product of the action of alkalies on the other nitrates, and also from the action of hot, somewhat dilute nitric acid upon cellulose. The dinitrate is very soluble in ether-alcohol, acetic ether, and in absolute alcohol. The chief raw material for the manufacture of these nitrates at present is the waste from cotton-spinning, which has already been freed from the impurities of the raw cotton. It is first picked clean by hand from admixture with foreign matter and then torn and opened up by machinery so as to fit it for easy action of the nitrating acids. It is then treated for a few minutes with boiling potash solution, thoroughly washed, and dried by steam. For the manufacture of celluloid a specially prepared and perfectly pure tissue-paper is now used, which is torn into shreds by machinery preparatory to the nitrating. II. Processes of Manufacture. 1. GUN-COTTON. The following is the procedure at Waltham Abbey, where gun-cotton is made for the English government under Sir F. Abel's improved method. A mixture of fifty-five parts of nitric acid (1.516 specific gravity) and one hundred and sixty-five parts of sul- phuric acid (1.842 specific gravity) is taken for one part of cotton. The GUN-COTTON, PYROXYLINE, ETC. 329 nitrating mixture is placed in cast-iron vessels, cooled from without by flowing water, and the cotton immersed. It may either remain in these until ready for washing, or may after a brief immersion be transferred to smaller stone-ware vessels, similarly cooled, in which it then remains for twenty-four hours, for the double purpose of completing the nitra- tion, so that the product shall contain a maximum of the highest, or hexanitrate, and of allowing the contents of the jar to cool down per- fectly. The nitrated cotton is then centrifugated, stirred up thor- oughly with cold water, again centrifugated, and then washed system- atically with warm water to which some soda has been added. The gun-cotton so obtained may either be used in the loose form or, when designed for manufacture into cartridges, is beaten in a hollander after the manner of paper-pulp, and then washed and pressed in the desired forms. The gun-cotton when finished is usually preserved in a moist state, and dried only when needed for use. It, however, does not require to be sharply dried, as with fifteen to twenty per cent, of moisture it can be made to develop its full explosive powers. 2. PYROXYLINE AND COLLODION. Pyroxyline of various grades of solubility can be prepared according to the strength of acids used and length of immersion given the cotton. In general, the nitric acid taken is less concentrated than that used for making gun-cotton, and a some- what higher temperature is employed. Potassium or sodium nitrate is also used along with the sulphuric acid as the nitrating mixture, as the presence of nitrous acid in the nitric acid generated is considered as playing some part in the result. A mixture of twenty parts pul- verized potassium nitrate with thirty-one parts of sulphuric acid of 1.835 specific gravity is given as a suitable pyroxyline mixture. After the nitre has entirely dissolved in the sulphuric acid and the mixture has fallen in temperature somewhat below 50 C. the cotton is put in, stirred around thoroughly, and then the vessel left covered for twenty- four hours at a temperature of from 28 to 30 C. The pyroxyline is then washed with cold water until it shows no acid reaction, and finally with boiling water to remove the last traces of potassium sulphate. A similar mixture, using sodium nitrate, is thirty-three parts of sul- phuric acid of 1.80 specific gravity, seventeen parts of sodium nitrate, and one-half part cotton. A special grade of pyroxyline for the manufacture of collodion, put upon the market by the Schering factory in Berlin, is made by immers- ing cotton for fifteen minutes in a mixture of equal volumes of sulphuric acid of 1.845 specific gravity and nitric acid of 1.40 specific gravity, taken at a temperature of 80 C. The pyroxyline made from tissue-paper for the celluloid manufac- turers is made by taking fifty cubic centimetres of nitric acid of 1.47 specific gravity, one hundred cubic centimetres nitric acid of 1.36 specific gravity, and one hundred cubic centimetres of sulphuric acid of 1.84 specific gravity. In this mixture eighteen grammes of the finely-shredded tissue-paper are immersed at a temperature of 55 C. for one hour. The paper gains about forty per cent, in weight in the nitration. The method of carrying out this nitration as proposed by Hyatt, the 330 VEGETABLE TEXTILE FIBRES. patentee of celluloid, is shown in the annexed illustration. (See Fig. 87.) The shredded paper is filled into the container //, in which has been placed a mixture of strong sulphuric and nitric acids heated to from 26 to 32 C. The mixture having been vigorously stirred by a mechanical stirrer which can be raised and lowered at will, it is allowed to remain at rest for twenty minutes to allow of the completion of the nitration. It is then swung around on the revolving table H 1 , caught by a crane from above, and emptied into the centrifugal K, which quickly drains off the excess of acid from the mass, the liquid flowing through the pipe K 1 into the reservoir O 1 . The container H can be filled from this reservoir through the pipe K 3 by the application of air pressure at M, as the lid of the acid reservoir is fitted on air-tight. O 2 is a reservoir for fresh acid mixture. The proportions of ether and alcohol used in dissolving pyroxyline to make collodion solutions vary very greatly. The United States Phar- macopoeia prescribes for four grammes of pyroxyline seventy-five cubic FIG. 87. centimetres of ether and twenty-five cubic centimetres of alcohol; the British Pharmacopoeia takes for one ounce of pyroxyline thirty-six fluid- ounces of ether and twelve fluidounces of rectified spirit; the German Pharmacopeia takes one part of pyroxyline to twenty-one parts of ether and three parts of alcohol. 3. CELLULOID. The conversion of pyroxyline into celluloid is accom- plished by effecting a thorough incorporation with the former of a certain amount of camphor. This may, however, be done in a number of waySj several of which have been carried out in practice. First, it is possible to effect it by heat alone, without the use of any solvent for either the camphor or the pyroxyline. The camphor at the temperature of its fusion becomes a sufficient solvent for tb^ pyroxyline to effect com- plete physical admixture. This process is essentially that used in this country. The weighed amount of camphor is added to the pyroxyline while the latter is still in a partially moist condition, some alcohol sprinkled upon the mixture to aid in the comminution of the camphor, and the materials carefully ground together in closed drums. The GUN-COTTON, PYROXYLINE, ETC. 331 mixture may now be put through heated rolls to effect the melting of the camphor and cause it to penetrate and take up the pyroxyline in every part of the mass. It is then put through a heated masticating machine to complete the admixing and make the mass of uniform com- position throughout. Coloring matter is added when desired to the materials before the camphor takes up the pyroxyline, so that it may be thoroughly distributed or dissolved as the case may be. A solution of camphor in either ethyl or methyl alcohol has also been used as the means of converting the pyroxyline into celluloid. This may be either with the aid of heat or, if sufficient of the solvent be used, it may be carried out at ordinary temperatures. A solution of camphor in ether has also been used in the celluloid factory of Magnus & Co. in Berlin. For fifty parts of pyroxyline are taken twenty-five parts of camphor dissolved in one hundred parts of ether to which five parts of alcohol have been added. The mixture is covered up and stirred from time to time. A gelatinous and glutinous mass results, which must be rolled between calender rolls until it acquires plastic characters. The process is distinctly more dangerous than the others mentioned, as the ether is all allowed to evaporate, and it does not yield anything better in the way of product. m. Products. 1. GUN-COTTON. The explosive variety of gun-cotton, whether in the form of loose fibre or as compressed cartridge or paper sheets, cannot be readily told by outward characteristics from untreated cotton. On close examination a slight yellowish tint is recognizable ; it is slightly rougher to the touch, and crinkles slightly when pressed ; when rubbed it is easily electrified and sticks to the fingers. When lighted it burns quickly without smouldering or leaving any residue. When heated slowly it begins to decompose with evolution of acid fumes, and above 130 C. it explodes. It is therefore necessary to exercise great care in the drying of it, and especially if all traces of acid have not been removed. It is much safer when wet than dry, although it is possible to explode it by con- cussion when it still contains from fifteen to twenty per cent, of water. The explosive variety of nitrocellulose is a mixed penta- and hexa- nitrate and contains from 12.6 to 13.4 per cent, of nitrogen. Gun-cotton is insoluble in water, alcohol, ether, chloroform, and acetic acid, in dilute acids and alkalies. It is somewhat soluble in ace- tone and wood-spirit. Gun-cotton is chiefly used in submarine mines and blasting and for naval torpedoes. The combination of it with nitro-glycerine, known as blasting gelatine, has been referred to under another section. (See p. 85.) 2. PYROXYLINE. This in most physical characters resembles per- fectly the explosive gun-cotton. The most important difference is the ready solubility of this variety of cellulose nitrate in a mixture of alcohol and ether, in which the higher nitrate is insoluble. The ordinary pyrox- yline is, moreover, only slightly explosive. When dissolved in the strength noted before (see preceding page) we obtain, 332 VEGETABLE TEXTILE FIBRES. 3. COLLODION. This is a colorless liquid, which rapidly evaporates on exposure to the air, leaving a transparent film of tetranitrate, or tetra- and trinitrate mixed, insoluble in water and alcohol. It is used as a dressing for wounds under the name of " liquid adhesive plaster," and very largely in photography as a means of covering the photographic plates with a transparent film which shall hold finely divided and dis- tributed the sensitive silver salt. 4. PYROXYLINE VARNISHES. In recent years a very important class of metal varnishes or lacquers have been introduced under trade-names, such as Zapon varnish, etc., in which pyroxyline is the basis. This is dissolved in either methyl alcohol, acetone, methyl and amyl acetates, or mixtures of these. Petroleum-naphtha is also added to these solvents to facilitate the drying. These varnishes are of special value for fine metal-work in brass or bronze, as they leave a perfectly transparent and flexible film of pyroxyline, which protects the metal and will not crack or peel when properly applied. 5. CELLULOID. This valuable product of the action of camphor upon pyroxyline is prepared under a great variety of forms, both transparent and opaque, colored uniformly, or mottled and striated in imitation of ivory, coral, amber, tortoise-shell, agate, and other substances. It cannot be caused to explode by heat, friction, or percussion. When brought in contact with flame it burns with a rustling flame, and continues to smoulder after the flame is extinguished, the camphor being distilled off with production of thick smoke, while the nitro-cellulose undergoes in- complete combustion. Celluloid dissolves in warm, moderately concentrated sulphuric acid, but is carbonized by the strong acid. It is readily soluble in glacial acetic acid, and on diluting the solution with water both camphor and pyroxyline are reprecipitated. It is rapidly soluble in warm, moderately concentrated nitric acid (four volumes of fuming acid to three of water), and is also dissolved with ease by a hot concentrated solution of caustic soda. Ether dissolves out the camphor from celluloid, and wood-spirit behaves similarly. Ether-alcohol (3:1) dissolves both the nitro-cellulose and camphor, leaving the coloring and inert matters as a residue. The density of celluloid ranges from 1.310 to 1.393. When heated to 125 C., it becomes plastic and can be moulded into any desired shapes. Sepa- rate pieces can also be welded together by simple pressure when at this temperature. The celluloid is easily cemented to wood, leather, etc., by the use of collodion or a solution of shellac and camphor in alcohol. IV. Analytical Tests and Methods. Pure hexanitrate of cellulose will keep indefinitely, but the presence of free acid, of lower nitrates, or of fatty and waxy matters renders it more or less unstable, and therefore unsafe. The most important deter- minations to make are the examination for free acid and for lower nitrates, and the valuation by means of the estimation of N0 2 liberated from any sample. ARTIFICIAL SILK. 333 1. EXAMINATION FOR FREE ACID. This may be detected by treating twenty grammes ' weight of the gun-cotton with fifty cubic centimetres of cold water. After twelve hours the water may be pressed out, filtered, and twenty-five cubic centimetres titrated with decinormal caustic alkali. With the remainder of the liquid the nature of the acid, whether sulphuric or nitric, may be ascertained by the usual tests. 2. EXAMINATION FOR LOWER NITRATES. These may be detected if present by treating five grammes of the sample, previously dried at 100 C., with one hundred cubic centimetres of a mixture of three parts of ether and one of alcohol. The mixture is shaken frequently during twelve hours, and then rapidly filtered through loosely-packed glass- wool, the filtrate evaporated at a gentle heat, and the residue weighed. 3. EXAMINATION FOR UNALTERED CELLULOSE. This may be estimated by treating the gun-cotton left undissolved by the ether-alcohol with acetic ether, which dissolves the hexanitrate and leaves the unchanged cotton. An alternative plan is to prepare a solution of sodium stannite by adding caustic soda to a solution of stannous chloride until the pre- cipitate at first formed is just redissolved. This solution when boiled with gun-cotton dissolves the cellulose nitrates without affecting the unchanged cellulose. Sodium sulphide is also used for the same purpose. 4. VALUATION BY DETERMINATION OF NO 2 . The nitrogen peroxide contained in gun-cotton and similar nitrated products is frequently determined by the aid of the reaction of sulphuric acid and mercury upon the nitrates as carried out in a Lunge's nitrometer. This is a burette provided at one end with stopcock and funnel-tube and nar- rowed at the other end, which is connected by a stout piece of rubber tubing with a simple graduated burette-tube. The burette with the stop- cock is filled with mercury through the rubber connection with the other tube and the stopcock closed. .35 gramme of gun-cotton, dissolved in five cubic centimetres of concentrated sulphuric acid, are then put into the funnel-tube, and by opening the stopcock and lowering slightly the connecting burette are drawn into the stoppered tube, washed out of the funnel with a little additional pure sulphuric acid, and the stopcock closed. The tube is then shaken vigorously until the reaction is complete and the volume of gas no longer increases. It is then allowed to attain constant temperature and the volume read off with correction for tem- perature and pressure. Allen (Commercial Organic Analysis, 2d ed., vol. i, p. 328) recommends that the volume be compared with that yielded by a standard sample or a nitre solution. ARTIFICIAL SILK. I. Raw Materials. The manufacture of an artificial silk (with the exception of one process, not now commercially followed that using gelatine) starts with cellulose, usually in the form of the cotton fibre. Three processes have been developed, until at present they have assumed what may be termed an international importance and are successfully supplying a 334 VEGETABLE TEXTILE FIBRES. product of great value and one that has created a field for itself in numerous special utilizations. While the raw material is primarily cellulose in all cases, in two of the processes it is first changed into a chemical derivative of cellulose which is afterwards decomposed in the process of manufacture. 1. NITROCELLULOSE OR CHARDONNET PROCESS. The starting-point of this process, the earliest of the commercial processes (1888) is a pure cellulose, usually cotton fibre, cleansed both mechanically and then by treatment with weak alkali solutions. This is then carded so as to open it up and nitrated, as already described in the manufacture of pyroxy- line or soluble cotton. The washing, of the nitrocellulose must be very thorough, so that every trace of acid is removed. When washed the wet nitrocellulose is pressed in hydraulic presses until the per cent, of water retained is reduced to thirty-six per cent., which amount remains in it until after the spinning. The solution of this is then effected in a mixture of equal parts of ninety-five per cent, alcohol and ether, using one hundred litres of solvent for twenty-two kilos, of nitrocellulose, reckoned on dry weight. This solution takes place in horizontal revolv- ing iron cylinders lined with tin and provided with mechanical agita- tion. From fifteen to twenty hours slow continued revolution of the cylinder is usually required and the solution, although appearing per- fectly clear, is nevertheless filtered to remove any imperfectly dissolved nitrocellulose. The solution after filtration is stored in large containers to "ripen," so that it may be suited for the spinning process. 2. THE CUPRAMMONIUM PROCESS. The raw material is here also a purified cellulose. Cotton is treated with an alkaline lye to bring it into a pure condition easily soluble in the solvent, which in this case is a copper-oxide-ammonia solution. Pauly, the first patentee of arti- ficial silk of this kind, prepared his solution by precipitating cupric hydroxide from copper sulphate solution with ammonia in required amount, washing the same and then dissolving it in aqua ammonia to clear solution, of which one litre contained from ten to fifteen grammes of copper. This is then allowed to act on the moist purified cellulose in a hollander, in which the cellulose solution is rapidly effected. Even after perfect solution seems to have been effected, this must be filtered in order to obtain that uniform solution needed for the spinning opera- tion. A later process (that of Bronnert, Fremery and Urban) pre- pares the cuprammonium solution by the action of strong ammonia water on metallic copper in the presence of a current of air. If the temperature is kept down to about 5 C. the ammonia in the presence of air has a rapid solvent action on the copper, and solutions containing eight and ten per cent, of copper are obtained. 3. THE VISCOSE PROCESS. Cross, Bevan, and Beadle in 1892 dis- covered the method of preparing a water-soluble cellulose xanthogenate by the reaction of carbon disulphide upon alkali-treated cellulose, which compound decomposes with the liberation of carbon disulphide, leaving behind a pure cellulose in gelatinous form mixed with the alkali. For the manufacture of filaments a short-fibre cellulose is chosen, ARTIFICIAL SILK. 335 which is mixed with the required amount of sodium hydroxide in solu- tion and allowed to react, producing a swollen mass of crumbling granu- lated texture, with the development of heat. The proportions usually taken are air-dried cellulose 25 to 33, sodium hydroxide 12.5 to 16, water 62 to 55. The carbon disulphide is made to act upon the soda-cellulose in the proportion of 1 to 10. The proper mixture being put into a wooden rotating drum which can be sealed, the reaction takes place rapidly at the ordinary temperature, a few hours sufficing for its com- pletion. The product of the reaction being transferred to a closed vessel provided with mechanical stirring attachment, water is gradually added, when the mass dissolves to a viscid jelly which, when filtered, is ready for the spinning. II. Processes of Manufacture. SPINNING OF THE ARTIFICIAL SILK FILAMENT. While in each case the spinning is effected by forcing a very viscid liquid through fine jets of glass or metal, the conditions are so dissimilar in the case of the three different raw materials that the process will be described as applying to each material in turn. 1. The Collodion or Chardonnet Process. The collodion filament solidifies almost in the moment that it is forced out of the jets. The passing of the filament into a bath of acidified water is no longer prac- tised, but the filament goes into the air, liberating the vapors of alcohol and ether which are carried along by a current of warm air and pass through condensation and absorption vessels, the first containing soda and the second sulphuric acid which absorbs the vapors of ether. The Chardonnet filament is, however, a nitrocellulose which when dried thoroughly is extremely inflammable, so that it is necessary to denitrate it. This is done by the action of alkaline sulphides, such as ammonium sulphide. Following this a slight bleaching is necessary, as the ammo- nium sulphide leaves the filament yellow. A very small amount of bleaching powder and muriatic acid suffices to bring the silk to a white color, when it is finally washed and dried. 2. The Cuprammonium Process. The material which is forced from the spinning jet in this case is cellulose in ammoniacal cupric-oxide solution. So to form the filament it must be delivered into a solution which will act at once to decompose it and liberate the cellulose, which then forms a filament semisolid at first but becoming stronger as it loses the water with which it is charged. Pauly first used fifteen per cent, sulphuric acid as the ingredient of the decomposing bath. This forms cupric and ammonium sulphates, both soluble, while the cellulose fila- ment when thoroughly washed free from acid is dried under tension and yields a product of silky lustre that requires no denitrating or bleaching to finish it. Bronnert, Fremery, and Urban later improved this procedure by using fifty per cent, sulphuric acid in the decomposing bath, which gave 336 VEGETABLE TEXTILE FIBRES. them a firmer filament, and then, after washing this, drying it in two stages, first in a current of air at the ordinary temperature and then in heated rooms at 40 C. 3. Viscose Process. The separation of cellulose from viscose solu- tions takes place so readily that at first it was sought to simply spin the filament from the fine jets into a vertical shaft or air-passage through which warm air was rising, but now it is effected according to the Stearns' process by spinning the filament into a solution of ammo- nium chloride, which causes a complete separation of the cellulose of the filament. It is left in a cold ammonium chloride bath for several hours, brought into boiling ammonium chloride for a few minutes and then thoroughly washed. m. Products. Artificial silk as a commercial product is of a uniform white color and possesses the characteristic lustre of natural silk. Chardonnet silk indeed possesses a higher lustre than the natural, although it does not have the rustle of true silk and is somewhat harder to the touch; cuprammonium silk (the German glanz-stoff), on the other hand, has more exactly the lustre as well as the rustle of natural silk; viscose silk resembles the collodion silk. Several points of difference in physical characters between natural and artificial silk are thus given by Silvern : * Absorption of moisture in Percentage moist room of Specific of moisture silk dried at gravity. at 99C. 110-115. Natural raw silk 1.36 7.97 20.11 Chardonnet silk (1) 1.52 10.37 27.46 Chardonnet silk (2) 1.53 11.17 28.94 Lehner silk 1.51 10.71 26.45 Cuprammonium silk ( Glanz-stoff ) 1.50 10.04 23.08 Gelatine silk 1.37 13.02 45.56 Viscose 11.44 That artificial silk fibres lose notably in strength on wetting is one of their distinguishing characters as compared with natural silk fibre. The average loss in strength on wetting is given as seventy per cent, for all varieties. A treatment of artificial silk with a formaldehyde bath to correct this defect has been proposed by Escalier and is known as "sthenosizing." It is claimed that fibres so treated lose very little of their strength on wetting. From the chemical point of view the most important difference between artificial silk (the gelatine silk excepted) and natural silk is that while natural silk contains some seventeen per cent, of nitrogen, the artificial silk contains only traces of this element. They therefore behave to chemical reagents like the vegetable cellulose fibres. * Die Kunstlicke Seide, Dr. Carl Silvern, 2te Auf., p. 220. BIBLIOGRAPHY AND STATISTICS. 337 IV. Analytical Tests and Methods. There are a number of reagents that will distinguish between natural and artificial silk. Strong potassium hydroxide, solution, which will dis- solve natural silk, will only swell more or less the artificial silks, with the exception, of course, of gelatine silk. Alkaline copper-glycerine solution will dissolve natural silk (both the true and the tussah silk) but does not attack the artificial silk con- sisting of cellulose. Diphenylamine sulphate, however, is one of the best of the reagents for the detection of artificial silk. Its reaction is as follows: With natural silk Brown coloration. With tussah silk Intense brown coloration. With Chardonnet and Lehner silk Intense blue. With Pauly or Thiele cupraramonium silk No reaction. With viscose silk No reaction. It is claimed that artificial silk is more easily affected by heat than either cotton, wool, or natural silk fibre. On heating a fabric containing mixed fibres to 200 C., the artificial silk will be destroyed and the dust can be beaten or brushed out and the loss in weight give the proportion of the artificial silk originally present. V. Bibliography and Statistics. BIBLIOGRAPHY. 1873. Die Gespinnstfasern, R. Schlesinger, Zurich. Die Pflanzenfasern, Hugo Mtiller, Leipzig. 1874. Etudes sur le Travail des Lins, A. Renouard, Paris. 1876. Etudes sur les Fibres v6g6tales textiles, M. Ve"tillard, Paris. 1877. Die Pflanzenfasern, Hugo Miiller (and Hofmann's Entwickelung der Chem- Ind. ) , Braunschweig. Die Fabrikation des Papiers, L. Miiller, Berlin. 1878. Cotton from Seed to Loom, William B. Dana, New York. 1881. Matieres premieres organiques, G. Pennetier, Paris. Die Gewinnung der Gespinnstfasern, H. Richard, Braunschweig. 1882. Structure of the Cotton Fibre, F. Bowman, Manchester. Chevallier's Dictionnaire des Falsifications, Baudrimont, Paris. Etude sur les Textiles tropicaux, A. Renouard, Lille. 1884. Ueber pflanzliche Faserstoffe, V. von Hohnel, Wien. Ramie, Rhea, Chinagras und Nesselfaser, Bouche und Grothe, Berlin. Cotton-Spinning, R. Marsden, London. Guide pratique de la fabrication du Papier, A. Proteaux, Paris. 1885. The Dyeing of Textile Fabrics, J. J. Hummel, London. 1886. Handbuch der Papierfabrikation, S. Mierzinski, Wien. The Manufacture of Paper, Charles T. Davis, Philadelphia. 1887. Report on Indian Fibres and Fibrous Substances, Cross and Bevan, London. Die microskopische Untersuchung des Papiers, J. Wiesner, Leipzig. Die Fabrikation des Papiers, Egbert Hoyer, Braunschweig. Microscopie der Faserstoffe, F. von Hohnel, Wien. The Practical Paper-Maker, J. Dunbar, 3d ed., London. 1888. A Text-Book on Paper-Making, Cross and Bevan, London. Die chemische Technolgie der Gespinnstfasern, Otto Witt, Braunschweig. Die Jute und ihre Verarbeitung, E. Pfuhl, Bd. i., Berlin. Papier priifung, W. Herzberg, Berlin. 22 338 VEGETABLE TEXTILE FIBRES. 1890. Report on Flax, Hemp, Ramie, etc., United States Department of Agriculture, Washington, D. C. The Cotton Fibre, its Structure, etc., Hugh Monie, Jr., Manchester. . The Art of Paper-Making, Alex. Watt, London. 1892. Explosives and their Powers, M. Bethelot, trans, by Hake and McNab, Lon- don. Index to Literature of Explosives, C. E. Munroe, Washington. Taschenbuch fur den praktischen Papier Fabrikanten, C. F. Dahlheim, 2te Auf., Miinchen. 1893. Textiles Vegetaux, E. Lecompte, Paris. Examen microscopique des textile fibres, R. Schlesinger, traduit par L. Gau- tier, Paris. Modern High Explosives, M. Eissler, 3d ed., New York. 1894. Das Celluloid, Dr. Fr. Bockmann, 2te Auf., Wien. The Chemistry of Paper-Making, Griffin and Little, New York. 1895. Cellulose, Cross and Bevan, London and New York. Die Baumwolle, Th. Otto Schweitzer, Bern. A Treatise on Paper-Making, C. Hoffman, New York. The Manufacture of Explosives, O. Guttmann, 2 vols., New York. 1896. Nitro-Explosives, P. Gerald Sanford, London. 1897. Hand-Book of Modern Explosives, M. Eissler, 2d ed., London. A Treatise on Paper, R. Parkinson, 3d ed., London. 1898. Cotton, its Uses, Varieties, Fibre, etc., C. P. Brooks, Lowell and New York. The Technical Testing of Yarns and Textile Fabrics, J. Herzfeld, trans, by Charles Salter, London. 1900. Die Rohstoffe des Pflanzenreiches, J. Wiesner, 2te Auf., Leipzig. 1904. Cellulose, Cellulose Production, etc., Dr. Josef Bersch, Wien. 1906. Researches on Cellulose, C. F. Cross and E. J. Bevan, vol. ii, London. Nitro-explosives, Smokeless Powders, and Celluloid, P. G. Sanford, 2d ed., London. Die Zellulose-fabrikation, Max Schubert, 3te Auf., von M. Knosel, Berlin. Die Viskose, ihre Harstellung, etc., Dr. B. Margosches, 2te Auf., Leipzig. 1907. Celluloid, its Raw Materials, Manufacture, etc., Fr. Bochmann, translated by Chas. Salter, London. Practical Paper-making, G. Clapperton, 2d ed., London. Papier priifung, Wilhelm Herzberg, 3te Auf., Berlin. 1908. The Paper-Mill Chemist, H. P. Stevens, London. 1909. The Textile Fibres, their Physical, Microscopical and Chemical Properties, J. Merritt Matthews, 2d ed., J. Wiley & Son, New York. The Manufacture of Paper, R. W. Sindall, London. 1910. Die Cellulosebearbeitung und chemischen Eigenschaften, C. Wiest, Stuttgart. Le Celluloid, Fabrikation, Application, Substituts, etc., Masselon, Roberts et Cillard, Paris. 1911. The Nitrocellulose Industry, E. C. Worden, 2 vols., Van Nostrand, New York. STATISTICS. I. a. PRODUCTION, CONSUMPTION AND EXPORTATION OF COTTON FROM THE UNITED STATES. Year. 1905 Domestic con- Production (in sumption (bales Exportations Value of bales of 500 Ibs.) of 500 Ibs.) ( bales of 500 Ibs.) exportations. 10,804,556 4,877,465 6,975,494 $401,005,921 1906 13,595,498 4,974,199 8,825,237 481,277,797 1907 11,375,461 4,493,028 7,779,508 437,788,202 1908 13,587,306 5,198,963 8,889,724 417,390,665 1909 . . 10.315,382 5.491,842 450,447,243 BIBLIOGRAPHY AND STATISTICS. 339 I. 6. COTTON CONSUMPTION BY COUNTRIES, 1905 AND 1900. (IN BALES OF 500 LBS.) Country. 1905. United States 4,310,000 United Kingdom 3,620,000 Continent of Europe 5,148,000 East Indies 1,350,000 Japan 875,000 Canada 130,000 Mexico 70,000 Other countries 35,000 Total 1900. 3,856,000 3,334,000 4,576,000 1,139,000 712,000 105,000 18,000 33,000 , 15,538,000 13,773,000 (Census Bureau, 1905.) II. FLAX. According to a United States consular report from Odessa (United States Consular Reports, March, 1891, p. 365), the total area sown in Europe with flax amounted to 5,700,000 acres, of which Russia alone had 3,700,000 acres. The total quantity of flax fibre pro- duced in Europe is there given as follows: Pounds. Russia 900,000,000 Austria-Hungary 104,400,000 Germany 97,200,000 France 79,200,000 Ireland 46,800,000 Pounds. Belgium 43,200,000 Italy 43,200,000 All other countries 36,000,000 1,350,000,000 The world's production of flax is thus stated by J. Scott Keltic (The Statistician's Year-Book, London, 1907) : Tons. Russia 350,000 Germany 44,000 France ( 1905) 20,645 North America 20,000 Tons. Great Britain and Ireland (1908) 9,080 Italy 5,200 The importation of flax into the United States was as follows : 1906. 1907. 1908. Amount in tons . . . 8,729 8,656 9,528 Value $2,327,300 $2,086,205 $2,514,680 1909. 1910. 9,890 12,761 $2,542,256 $3,417,321 III. a. The importations of other vegetable fibres have been : Hemp (dutiable) . Value 1906. 5,317 $906,808 1907. 8,718 $1,534,371 1908. 6,213 $1,086,805 1909. 5,208 $799,164 1910. 6,423 $1,039,833 Hemp (Manila) .. Value 58,738 $11,036,667 54,513 $10,876,107 52,233 $8,974,617 61,622 $7,156,091 92,507 $10,517,100 Jute ( tons ) .... 103,945 104,489 107,533 156,685 68,155 Value $6,449,684 $8,950,684 $6,504,920 $7,216,307 $3,728,448 Sisal grass (tons) Value . 98,037 $15,282.308 99,061 $14,959,415 103,994 $14,047,369 91,451 $10,215,887 99,966 $11,440,521 340 VEGETABLE TEXTILE FIBRES. III. &. Production and exportation of jute from India : Production in Export in 1000 cwts. 1000 cwts. 1905 29,075 12,875 1906 32,880 14,480 1907 35,064 15,970 1908 22,539 14,192 1908 17,880 (Statistical Abstracts for British Colonies, London, 1909.) IV. Paper and Pulp Statistics: The importations of crude paper stock (rags, etc.) and of wood-pulp in recent years have been : Crude paper stock. Wood-pulp. 1904 $2,900,713 289,592,000 Ibs., valued at $3,602,668 1905 3,796,595 335,008,000 " " 4,500,955 1908 3,675,926 532,031,360 " " 7,313,326 1909 3,638,034 614,244,972 " " 8,629,263 1910 5,206,877 847,440,759 " " 11,768,014 (Commerce and Navigation of U. S., 1910.) The production of wood-pulp, according to Census Reports, has been: Ground wood-pulp. Soda-fibre. Sulphite-fibre. Total. 1900 586,374 tons 177,124 tons 416,037 tons 1,179,535 tons 1905 968,976 tons 196,770 tons 756,022 tons 1,921,768 tons RAW MATERIALS. 341 CHAPTER IX. TEXTILE FIBRES OF ANIMAL ORIGIN. As before stated, the only animal fibres that have acquired technical importance are the wool fibre and silk. These will now be considered. I. Raw Materials. A. WOOL. Wool is undoubtedly a variety of hair, found in greater or less quantity on almost all mammals, on a few of which, as the domestic sheep, it forms the principal covering of the body. It is probable that while both hair and wool occur together in wild sheep, domestication has gradually caused the rank hairy fibres to disappear and the soft under- wool to develop until the fleece of wool becomes a thick and complete covering. From ordinary hair the wool is distin- guished by two important properties : First, while hair is almost smooth on the surface, the wool fibre is covered by minute overlapping scales arranged like roof-tiles. While these scales are so minute as not to be discernible to the eye, they can be felt if a woollen fibre is drawn between the fingers in the direction opposite to that in which the scales are set. Secondly, while a hair is perfectly straight, the woollen fibre is finely crimped or curled, so that it becomes longer when drawn out and shortens again when the strain is removed. The spring due to this curled structure gives woollen fabrics notable elasticity. Owing to the overlapping scale-like structure and the crimpled condition of the fibre, wool has also the power of felting, or becoming matted into a compact cloth under the fulling process without the necessity of weaving. These structural characters of the wool fibre are shown in Fig. 88. Sheep's wool varies from the long straight coarse hair of certain varieties of the English sheep (Leicester, Lincolnshire, etc.) to the com- paratively short wavy fine soft wool of the Spanish and Saxon Electoral sheep. According to the average length of the fibres or staples two principal classes of wool are established, the long-stapled (eighteen to twenty-three centimetres) and the short-stapled wools (two and five- tenths to four centimetres). The former class have hitherto been combed and then spun into worsted yarn, while the latter have been carded and spun, yielding woollen yarns. These processes will be re- ferred to again later. (See p. 350.) In general the long straight wools, like Lincoln and Leicester wools, possess a silky lustre, and are known as lustre wools, while the Merino, Colonial, etc., which are shorter and curly, are known as non-lustre wools. The worth of any grade of wool is determined by noting such prop- erties as softness, fineness, length of staple, waviness, lustre, strength, elasticity, flexibility, color and the facility with which it can be dyed. 342 TEXTILE FIBRES OF ANIMAL ORIGIN. Wool is very hygroscopic. In warm dry weather it may contain eight to twelve per cent, moisture but if kept for a time in a damp atmos- phere it may take up thirty to fifty per cent. This becomes an important item in the sale of wool, and hence in France and Germany the per- centage of moisture contained in wool to be sold must be officially deter- mined in "wool-conditioning" establishments. (See silk-conditioning, p. 348.) The legal amount of moisture allowed on the Continent is 18.25 per cent. The best kind of wool is colorless, but inferior grades are often yellowish, and sometimes even brown or black in color. The chemical composition of the wool fibre is, as already noted (see p. 302), nitrogenous, but we must at the same time distinguish between the true fibre and the encrusting matters. These latter, independent of mechanically adhering impurities or ' ' dirt, ' ' are of twofold character, the "wool-fat" (soluble in ether) and the "wool-perspiration" (soluble in water). These two are frequently included together under the name of the "yolk" or "suint" of the wool. The true wool fibre, when cleansed from these, has approximately the following composition : Car- bon, 49.25 per cent. ; hydrogen, 7.57 per cent. ; oxygen, 23.66 per cent. ; nitrogen, 15.86 per cent. ; sulphur, 3.66 per cent. The presence of sul- phur is very distinctive of wool and serves to distinguish it from silk, the other nitrogenous fibre. It can be removed in large part, but not without weakening the fibre and destroying its lustre, etc. Wool-fat is a mixture of a solid alcoholic body, cholesterine, together with isocholesterine and the compounds of these bodies with several of the fatty acids. These free higher alcohols are soluble in boiling ethyl alcohol, while the compounds they form with the fatty acids are insoluble in alcohol but soluble in ether. Wool-perspiration has been shown to consist essentially of the potas- sium salts of oleic and stearic acids, possibly other fixed fatty acids, also potassium salts of volatile acids, like acetic and valerianic acid, and small quantities of chlorides, phosphates, and sulphates. The wash- water of raw or greasy wool, it will be seen, therefore, would contain large amounts of potash salts, and when evaporated and ignited would yield an abundant product of potassium carbonate. This utilization of the wool wash-water as carried out at present in France and Belgium yields over one million kilos, of potassium carbonate. Another utiliza- tion of this yolk of wool is to submit it to dry distillation, when it yields a residue which is an extremely intimate mixture of carbonate of potash and nitrogenous carbon, of great value for the manufacture of yellow prussiate of potash. Wool is decomposed by heat at 130 C., ammoniacal vapors are given off, and at 140 to 150 C. sulphur compounds are also present in the vapors. When ignited by a flame, wool emits the disagreeable odor of burnt feathers and leaves a porous caked residue. Ammoniacal solu- tion of cupric hydroxide has no action upon wool in the cold, but dissolves it when hot. Dilute solutions of hydrochloric and sulphuric acids have little influence whether hot or cold. This fact is availed of in separating RAW MATERIALS. 343 cotton from wool in the process of "carbonizing" mixed cotton and woollen goods. The dilute sulphuric acid used attacks and disintegrates the cotton. They are then dried in closed chambers at 110 C., after which the disorganized cotton can be beaten out, while the wool remains but slightly altered. Nitric acid does not attack the wool seriously, but gives it a yellow color, hence sometimes used as a ' ' stripping ' ' agent for dyed woollen goods in case of re-dyeing. Sulphurous acid is the most satisfactory bleaching agent for woollens, as it removes the natural yellow tint of the ordinary wool. Caustic alkalies act rapidly and in- juriously upon wool. Alkaline carbonates and soap have little or no injurious action if not too concentrated and if the temperature is not above 50 C. Chlorine and hypochlorites act injuriously upon wool and cannot be used for bleaching. A very slight action of chlorine, on the other hand, causes wool to assume a yellowish tint and gives it an increased affinity for many coloring matters. FIG. 88. FIG. 89. Sheep's wool ( s f). Alpaca goat's hair ( 3 f ). Closely related to sheep's wool are a few varieties of animal hair, which are also utilized in some degree as textile fibres in similar classes of goods. Mohair is the product of the Angora goat of Asia Minor and Cape Colony, South Africa. It is a long silky hair, which is very soft and lustrous. Cashmere consists of the soft under-wool which grows in winter on the Cashmere goat. It furnishes the material for the costly Cashmere shawls of native manufacture, but is not exported at all as fibre. Alpaca, Vicuna, Llama, and Guanaco are the names of four closely- 344 TEXTILE FIBRES OF ANIMAL ORIGIN. related species of South American goats found on the western slopes of the Andes, which yield valuable hair-like fibres. Of these, the alpaca is exported in largest amount to Europe and the United States. It is a long silky fibre somewhat intermediate between true wool and hair and possessing a strong lustre. It is both white and of various colors. It is shown in Fig. 89. Camel's Hair is somewhat used in Africa, Asia Minor, and the Cau- casus, and latterly in Europe, for the manufacture of woven goods, which are made from the unbleached hair. B. SILK. The silk fibre is, morphologically, the simplest and at the same time, because of its properties, the most perfect of the textile fibres. It differs from all the other fibres in that it is found in nature as a continuous fine thread, so that the process of spinning is super- fluous in its case. In place of this we have the reeling process, whereby several of the natural threads are united into one thicker and stronger thread. Silk is the product of the silk-worm (Bombyx mori) and is simply the fibre which the worm spins around itself for protection when enter- ing the pupa or chrysalis state. From the eggs laid by the animal in the moth or butterfly state develops the caterpillar or silk-worm. The eggs are yellowish in color at first, changing to gray when dry. They are very light in weight, some thirteen hundred and fifty together weigh- ing one gramme. For the development of the caterpillar from them a certain amount of warmth and moisture is necessary, the temperature being raised in the incubation chamber during ten or twelve days from 18 to 25 C. The young worms are at once removed to larger chambers, where are lath frame-works strung across with threads and sheets of paper. The animals are placed upon these, and fed regularly during thirty to thirty-three days, till indeed they begin to spin. They are here fed upon mulberry leaves (Morus alba}, and during this period increase enormously in size, becoming at length about eight to ten centimetres long and about five grammes in weight. To allow of this increase in size it casts its skin some four times during this period (at intervals of from four to six days). When about the thirtieth day of its growth has been reached it ceases to take food and shows a decided restlessness. It is then placed on birch-twigs, and soon begins to spin. This spinning of the cocoon, or oval-shaped house in which the worm is to undergo the chrysalis state before emerging as the butterfly, involves the secretion of the fibre so much prized as silk. The silk substance is secreted by two glands, one on either side of the body of the caterpillar. The substance from these two glands unites in a capillary canal situated in the head of the animal, whence issues the silk as a double fibre only rarely separated, cemented throughout by the sericin, or silk-glue. ^The microscopical ap- pearance of the silk fibre is shown in Fig. 90. This fibre which goes to form the cocoon varies in length from three hundred and fifty to twelve hundred and fifty metres, and has a diameter which averages about .018 millimetre. The interlacing layers of the silk cocoon are at first loose, but become finer and denser towards the interior, while the inner- RAW MATERIALS. 345 FIG. 91. most layer which immediately surrounds the animal forms a thin parchment-like skin. The several stages of cocoon-spinning are shown in Fig. 91. The cocoons of the female are pure oval in shape, while those of the male are distinctly contracted in the centre. They are white or yellowish, and usually about three centimetres long and one and one- half to two centimetres thick. Some seven or eight days are allowed for the completion of the cocoon-spinning, and they are then gathered. A sufficient number of both males and females are taken for breeding pur- poses, and the rest put aside to be reeled for silk. Those chosen for breeding are kept for some twenty days at a temperature of from 19 to 20 C., when the silk-moth which has formed in the inte- rior from the pupa emits a peculiar saliva, which softens the sericin, or silk-glue, at FIG. 90. Silk fibre (|). one end of the cocoon and enables the animal to push its way out to day- light. The females within forty hours after their appearance lay their eggs, some four hundred in number, and shortly after die. The eggs are slowly dried, and stored in glass bottles in a dry dark place till the following spring. The cocoons put aside for the reeling of silk must be taken in hand promptly and the chrysalis contained in them killed, in order to prevent the development of the silk-moth and the injury to the cocoon by its pushing its way out. This is done either by heating them for several hours in an oven at 60 to 70 C., or more quickly by 346 TEXTILE FIBRES OF ANIMAL ORIGIN. steam heat. One hundred grammes of eggs produce under favorable conditions from ninety thousand to one hundred and seventeen thousand cocoons, weighing one hundred and fifty to two hundred kilos., and these yield twelve to sixteen kilos, of reeled silk. The silk fibre consists to the extent of rather more than half its weight of fibroin, C 15 H 23 N 5 6 , a nitrogenous principle. Covering this is the silk-glue, or sericin, C 1D H 25 N 5 8 . Whether this latter exists in the glands of the silk-worm along with the fibroin, as maintained by Duseig- neur-Kleber, or is produced exclusively by atmospheric change from the fibroin as asserted by Bolley, is still in debate. This sericin, how- ever, is easily dissolved off from the fibroin by warm soap-water and other alkaline liquids. This ' ' boiled-bff " liquid plays an important part in silk-dyeing operations. (See p. 544.) The most important physical properties of the silk fibre are its lustre, strength, and avidity for mois- ture. The regulation of the amount of moisture contained in raw silk as offered for sale, or "silk-conditioning," will be spoken of under the process of treatment. (See p. 348.) Besides the true silk, the product of Bombyx mori, we have several so-called "wild silks," the most important of which is the Tussur silk, the product of the larva of the moth Antheraa .mylitta, found in India. The cocoons are much larger than those of the true silk-worm, egg- shaped, and of a silvery drab color. They are also attached to the twigs of the food trees by a thread-like prolongation of the cocoon. The cocoon is very firm and hard, and the silk is of a drab color. It is used for the buff-colored Indian silks, and latterly largely in the manufacture of silk plush. Other wild silks are the Eria silk of India, the Muga silk of Assam, the Atlas or Fagara silk of China, and the Yama-mai silk of Japan. n. Processes of Manufacture. It will be beyond the province of this work to take up the manu- facture of woollen and silk goods from the mechanical side. Hence we shall only notice the preliminary processes of chemical treatment which the fibres undergo to prepare them for manufacture into goods, and then take up the several classes of manufactured textiles again in speak- ing of bleaching and dyeing of goods. A. WOOL. 1. Wool-scouring. The condition of the raw wool when first obtained from the back of the sheep has already been referred to. The fibre is covered with both natural and artificial impurities (yolk, dirt, etc.) to such an extent that mordanting and dyeing would be almost impossible. These are therefore to be removed by the process of scour- ing. It will be remembered, too, that the yolk was stated to be made up of the wool-fat (soluble in alcohol) and the wool-perspiration (soluble in water). Both of these have to be removed in the completed scouring operation. The full operation then must include three stages, viz., steeping, or washing with water (desuintage} ; cleansing or scouring proper with weak alkaline solutions (degraissage} ; rinsing or final wash- ing with water (ringage). The first operation may be omitted if the PROCESSES OF MANUFACTURE. 347 wool has been washed by the wool-grower. This is true, for instance, with Australian wools, while, on the other hand, most South American wools come into commerce unwashed and very rich in yolk. The wash- ing of these wools is largely carried on in France and Belgium, and, as has been stated (see p. 342), is made to yield large amounts of potas- sium carbonate by evaporating and igniting the wash-waters. The wool is systematically washed in tepid water (about 45 C.) in a series of tanks arranged so that the water passes from one to the other until completely saturated, when it is evaporated. According to M. Chan- delon, one thousand kilos, of raw wool may furnish three hundred and thirteen litres of yolk solution of specific gravity 1.25 (50 Tw.), having a value of fifteen shillings and sixpence, while the cost of extraction does not exceed two shillings and sixpence. The scouring and washing processes for loose wool are usually carried out in the well-known rake scouring-machines, consisting of a large cast-iron trough provided with an ingenious system of forks or rakes whereby the wool is gradually passed forward by the to-and-fro digging motion of the rakes. Two or three such scouring-machines are placed in series, so that the first may take the bulk of the impurities, the second complete the scouring, and the third effect a thorough washing in a stream of fresh water. The scouring liquid which has been longest in use is stale urine (lant), which is effective because of the ammonium carbonate it contains. It is now largely supplanted by ammonia, sodium carbonate, soaps, etc. The most injurious effects arise from the use of water containing lime or magnesia, because of the formation of the insoluble lime or magnesia compounds upon the fibre. In recent years volatile solvents, like petroleum-naphtha, carbon disulphide, and carbon tetrachloride, have also been introduced for scouring purposes, although not generally adopted on account of the expense and risk attending their use. They must be followed at all events by a washing with water, as, while they dissolve fatty matters, they do not take up the oleates, etc., of the wool-perspiration. The only treatment of this kind, known technically as a degreasing process, is that with petroleum-naphtha. This has been found prac- ticable and remunerative. The wool, freed from its grease and wax- like constituents by the naphtha and its potash salts, by a washing with water only is left in an excellent condition for the mechanical treatment, such as carding and combing. Woollen yarns and woollen cloth are also scoured to free them from the oil which has either purposely or by accident been put upon them in the spinning and weaving operations. The scouring of "union" goods that is, materials with cotton warp and woollen weft is a more difficult operation on account of the differences in elasticity, hygro- scopic character, etc., of the cotton and the wool fibre. It includes the operations of crabbing, steaming, and scouring. 2. Bleaching Wool. Wool is generally bleached either as yarn or cloth. The bleaching agent in general use is sulphur dioxide. It may of course be applied either as gas or as sulphurous acid solution, the 348 TEXTILE FIBRES OF ANIMAL ORIGIN. former method being generally followed, and the yarn or cloth suspended on poles in closed chambers, called sulphur-stoves, which can be charged with the gas. In liquid bleaching with sulphurous acid, a solution of sodium bisulphite is generally used, which is either mixed with an equivalent amount of hydrochloric acid or, what is better, the goods are passed through one solution after the other in separate baths. The bleaching of sulphur dioxide differs essentially from that effected by chlorine and hypochlorites in that it is not due to oxidation, but to reduction or possibly to the formation of colorless compounds with the natural yellow color of the wool. At all events, it is not permanent in character, and the yellow color gradually returns on exposure to atmos- pheric influences and repeated washings in alkaline solutions. The best liquid bleaching agent is hydrogen dioxide. The woollen material is steeped for several hours in a dilute and slightly alkaline solution of the commercial H 2 2 and then well washed, first with water acidified with sulphuric acid and afterwards with pure water. B. SILK. 1. Reeling of Silk. The unwinding of the long silk fibre from the cocoon and bringing it into condition for weaving is to be accomplished in the reeling process. The cocoons are thrown into a basin of warm water to soften the silk-glue and allow of the fibres being separated. From four to eighteen fibres, according to the quality, are taken, and two threads formed by passing the fibres together through two perforated agate guides. After being crossed or twisted together at a given point they are again separated and passed through a second pair of guides, thence through the distributing guides on to the reel. The temporary twisting or crossing causes the agglutination of the indi- vidual fibres of each thread. In order to form long threads a frequent adding on the fibre of a new cocoon is necessary. Care must be taken, also, that the thread remain as nearly as possible of uniform thickness, so that as the inner fine fibres of several cocoons come through the guides another cocoon is added to the number used for the thread. One cocoon gives .16 to .20 or at most .25 gramme of raw silk. The loss through removal of the external floss varies from eighteen to thirty per cent., according to the cocoons and the care bestowed by the worker. Before this raw silk can be used for weaving two of the threads are "thrown" together and slightly twisted. 2. Silk-conditioning. Raw silk kept in a humid atmosphere is capable of absorbing thirty per cent, of its weight of moisture without this being at all perceptible. It therefore becomes a matter of great importance for the buyer to know what weight of normal silk there is in any given lot. To ascertain this with accuracy, there have been estab- lished in a number of the European centres of silk industry conditioning establishments. The operation is carried out by means of the apparatus shown in Fig. 92, where a number of hanks of silk are shown in the drying chamber. A test hank of silk is taken from the bale, and having been suspended from the one arm of an accurate balance its initial weight is gotten. It is then dried in a current of air at 110 C. until constant weight is again obtained. The arrangement of the drying PROCESSES OF MANUFACTURE. 349 FIG. 92. chamber is shown in the illustration. To the final weight obtained for the dry silk eleven per cent, is added, and the result taken as a normal silk weight. The average loss of weight in this conditioning process is about twelve per cent. 3. Silk-scouring. By the scouring of silk the silk-glue is removed to a greater or less extent and the fibre is rendered lustrous and soft and able to take the dye-color. According to the amount of silk-glue removed in this operation the product is called boiled-off silk, souple silk, or ecru. In the first case, the loss of silk-glue amounts to twenty-five to thirty per cent, of the weight of the raw silk; in the second, to eight to twelve per cent. ; and in the third to three to four per cent, of the original weight of the silk. In preparing the first variety two operations are necessary, stripping or ungumming (degom- mage), and boiling off. The hanks of raw silk are sus- pended by wooden rods in a rectan- gular trough lined with copper and worked by hand in a thirty to thirty- five per cent, soap solution heated to 90 to 95 C. When the water is very hard it must be corrected or softened previously. Frequently two soap- baths are used one after the other as the first one becomes charged with the silk-glue. The silk at first swells up and becomes glutinous, but as the glue dissolves off it becomes soft and silky. The waste soapy and glutin- ous liquid obtained is called "boiled- off" liquor, and is a useful addition to the dye-bath in dyeing with coal- tar colors. (See p. 544.) For the purpose of removing the last portions of the silk-glue, it is now washed in water at 60 C., to which some soap and carbonate of soda have been added, then put in coarse hempen bags called "pockets" and boiled for half an hour to three hours, according to quality, in open copper vessels with a solution of ten to fifteen per cent, of soap. It is then rinsed with a weak tepid solution of sodium carbonate, and finally washed in cold water. Silk intended to remain white or to be dyed pale colors is then at once bleached while moist with gaseous sulphur dioxide for some six hours. The bleaching operation may be repeated from two to three times, according to the quality of the silk. Souple silk is that which has been prepared for dyeing with a loss of not more than eight per cent, of its weight. It is, however, not so strong as boiled-off silk, and is used only for tram. Its preparation 350 TEXTILE FIBRES OF ANIMAL ORIGIN. always includes two operations, and if the silk is to be dyed light colors, two additional operations have to be carried out. The raw silk is first " softened," and the small quantity of fatty matter present removed (degraissage) by working it from one to two hours in a ten per cent, soap solution at 25 to 35 C. It is then "bleached" by immersion for ten to fifteen minutes in a dilute solution of aqua regia (five parts hydro- chloric acid to one part nitric), or as a substitute for this nitrated sul- phuric acid (nitrosyl-sulphate). This is followed by "stoving, " or treatment with sulphur dioxide, and then, without removing the sul- phurous acid, by the treatment of soupling (assouplissage) proper. This consists in working the silk for about an hour and a half at 90 to 100 C. in water containing three to four grammes cream of tartar to the litre. This treatment makes the silk softer and causes it to swell up and become more absorbent. It is then finally washed in tepid water. Ecru silk is raw silk which has been washed with hot water, with or without soap, bleached with sulphur, and again washed. It is only used for a base for other silk fabrics like velvet or dyed in blacks. Artificial silk has already been described in detail under the vege- table fibres and the products therefrom (see p. 333.) HE. Products. A. WOOL. We have already alluded to the distinction between worsted and woollen yarns. Formerly all long-stapled wools were combed, that is, the fibres were brought as nearly as possible parallel to one another and were then spun into what was known as worsted yarn, used in hoisery and in the manufacture of fabrics which did not undergo fulling. All short-stapled wools, on the other hand, were carded and spun much as cotton is spun, and the yarns so obtained were the only ones capable of being used in making milled or fulled cloths, in which the felting property of wool is availed of to thicken the cloth after weaving and in which by teasels the nap of the cloth is raised so as to present a uniform surface. All kinds of wool, therefore, were formerly divided into combing and carding or clothing wools. Machines have been invented latterly, however, capable of combing wools having as short a staple as one inch, and, on the other hand, wools with a staple as much as five inches long may be used in making milled cloth. So the distinction between the several wools is no longer as absolute as it once was. Among the chief kinds of worsted fabrics are serges and merinos and mixed goods of wool and mohair, alpaca, and camel 's hair. Hosiery and carpets also belong here, although the best of these latter are made on a ground of strong linen or hemp. The principal varieties of woollen cloth are broadcloths, the finest variety of woollen cjoth, cashmeres, a fine thin twilled fabric, tweeds, fabrics of looser texture than broadcloth and less highly milled, doeskin, a strong twilled cloth, blankets, flan- nels, etc. Shoddy is a material made from fragments of cast-off woollen cloth- ing torn into fibres and re-spun into yarn. It is looser in texture than ANALYTICAL TESTS AND METHODS. 351 mungo, which is made from remains of finer fragments, such as old dress-coats, tailor's clippings, etc. A third grade of recovered wool, sometimes called extract wool, is obtained from union goods (mixed woollen and cotton goods) by the process of carbonizing the vegetable fibre and then beating it out. The carbonizing is done with dilute sulphuric acid, with aluminum chloride, or with gaseous hydrochloric acid. The last process is said to give the best results. B. SILK. The raw-silk threads obtained in the reeling process are not sufficiently strong for use in the loom, so several must be united. This may be done in different ways. By the union of two or more single threads, separately twisted in the same direction, which are then doubled and retwisted in the opposite direction, is obtained organzine. The best grades of silk are also taken for the organzine, which is to form the warp in silk-weaving. The product of the union of two or more simple un- twisted threads which are then doubled and singly twisted is tram, which forms the weft in w r eaving. Waste silk is that which proceeds from perforated and double cocoons and such as are soiled in steaming or in any other way. This waste silk is washed, boiled with soap, and dried. When carded and spun like cotton it yields the so-called flurt-silk. Satins are tissues so woven that almost the only threads appearing on the right side of the tissue are weft threads, which present a uniform glossy surface. Velvets are tissues in which the outer surface presents to view a short soft pile, made by passing the warp threads over fine wires, which are afterwards drawn out. The loops then remaining are either left as they are, in which case the tissue is called pile-velvet, or cut to form cut-velvet. This fabric is now largely imitated in cotton and mixed tissues. IV. Analytical Tests and Methods. GENERAL DISTINCTIONS BETWEEN VEGETABLE AND ANIMAL FIBRES. A general scheme for distinguishing between the several classes of fibres has been proposed by R. Schlesinger in his "Leitfaden fur die mikro- skopische und mikrochemische Analyse der technisch verwendeten Rohstoffe der Textil-Industrie. " It is in outline as follows : TREAT WITH CAUSTIC SODA. The fibre does not dissolve in ten per cent, caustic soda solution, and in burning, which takes place readily, does not develop any burnt horn odor. Vegetable fibres. The fibre dissolves in concen- trated caustic soda, and when treated with ammo- niacal cupric oxide shows scales upon its surface. Animal hairs or wool. The fibre does not dissolve in cold ten per cent, caustic soda, but dissolves per- fectly in concentrated sul- phuric acid ; shows neither scales nor medullary sub- stance. Silks. 352 TEXTILE FIBRES OF ANIMAL ORIGIN. The vegetable fibres are then to be studied by the aid of the iodine and dilute sul- phuric acid reaction, and the several groups already noted in the classification on p. 303 are established. The animal hairs are to be distinguished best by the microscopical characters and measurements. The several varieties of silk are also to be distinguished by a comparison of the diame- ters of the fibre as measured under the microscope. A scheme for distinguishing between the more important textile fibres, based upon their behavior to the two dyes malachite-green and Congo- red, and after examination under the microscope, has been proposed by Behrens ("Microchemische Analyse," 2te Heft, p. 51). The grouping thus established is as follows : Group A. Dyed fast to washing by malachite- green. Here belong, of the textile fibres, silk, wool, and jute. Aa. Not capable of supplementary dyeing by aromatic amines: silk and wool. Ab. Capable of supplementary dyeing by aromatic amines : jute. Group B. Dyed partially fast only by malachite- green. Hemp and manila. Ba. Strongly polarizing: hemp. Bb. Weak polarizing: manila. Group C. Fugitive dyeing with malachite- green; complete supplementary dye- ing with benzidine dyes. Here belong cotton and flax. Ca. Weak polarizing: cotton. Cb. Strongly polarizing: flax. Several of the simpler differences between the vegetable and the animal fibres as groups have already been alluded to in classifying the fibres. (See p. 302.) Other special tests are as follows : 1. Millon's reagent (mercurous and mercuric nitrate) colors the animal fibres red, but not the vegetable fibres. 2. Liebermann gives the following test: Prepare a fuchsine solu- tion, add potash solution drop by drop until it is decolorized, filter, and dip in the sample of goods. Wool or silk fibres are colored red, cotton remains colorless. 3. Ammoniacal cupric oxide solution dissolves cotton as well as silk. While cotton, however, is precipitated by certain salts as well as by sugar and gum, silk is only precipitated by acids. 4. As wool always contains sulphur, a sodium plumbate solution (made by boiling red lead with caustic soda solution and filtering) is at once blackened on contact with wool. This test may be interfered with in the presence of sulphur-treated silk. 5. Wool and silk may be distinguished by the use of hot hydro- chloric acid. Silk dissolves easily in this, while wool merely swells up but does not dissolve. 6. According to Hohnel, wild silks behave differently from true silks with chromic acid. If a cold saturated solution of chromic acid be diluted with an equal bulk of water and then boiled for one minute with the sample of silk, the true silk dissolves up, while the wild silk remains unattacked even after two or three minutes' boiling. Wool behaves like true silk in this. BIBLIOGRAPHY AND STATISTICS. 353 A. Eemont gives a process for determining wool, silk, and cotton when mixed in the same fabric. Four pieces of about two grammes' weight each are taken ; three of these are boiled for a quarter of an hour in two hundred cubic centimetres of three per cent, hydrochloric acid, which is renewed if the liquid becomes strongly colored, and the samples are then well washed. The dressing is thus removed and the coloring matter in the case of the cotton, but only slightly in the case of wool and silk; the weighting of the silk with iron salts is also completely removed by the hydrochloric acid if the weighting does not exceed twenty-five per cent, of the weight of the silk, leaving the fibres chest- nut-brown in color. Two of the samples thus treated are dipped for one to two minutes into a boiling solution of basic chloride of zinc of specific gravity 1.69 ; then thrown into water and washed first with acidified water and then with pure water. This removes the silk. The basic chloride of zinc solution is prepared by heating one thousand parts of zinc chloride, forty parts of zinc oxide, and eight hundred and fifty parts of water. One of the two samples freed from silk is then boiled gently for a quarter of an hour with sixty to eighty cubic centimetres of caustic soda solution of specific gravity 1.02. This is best done with inverted condenser, so that an injurious concentration of the soda solution is avoided. "Wash gently without too much rubbing and the wool is removed. All four samples are now washed for a quarter of an hour with distilled water, pressed out, dried in the air, and weighed. The first will weigh as before, two grammes or nearly, a slight difference of a few milligrammes being neglected; the difference in weight between the first and second samples gives the dressing ; that between the second and third gives the silk; that between the third and fourth the wool present, and the weight of the fourth sample the vegetable fibre present. This is slightly attacked by the soda solution, and in the case of cotton it is usual to reckon five per cent, as the loss from this cause. V. Bibliography and Statistics. BIBLIOGRAPHY. 1867. Einleitung in die technische Microscopie, J. Wiesner. 1869. Darstellung der Baues und der Eigenschaften der Merinowolle, M. Settegast, Berlin. 1873. Die Gespinnstfasern, R. Schlesinger, Zurich. 1874:. Die Wollgarnfarberei, Richter und Braun, Berlin. 1878. Le Conditionnement de la Soie, J. Persoz, Paris. 1880. The Woollen Thread: its Nature, Structure, etc., C. Vickerman. Hudders- field. 1881. Die Gewinnung der Gespinnstfasern, H. Richard, Braunschweig. Matieres premi&res organiques, Pennetier, Paris. The Wild Silks of India, Th. Wardle, London. 1882. Chevallier's Dictionnaire des Falsifications, 4me 6d., Baudrimont, Paris. 1885. The Dyeing of Textile Fabrics, J. J. Hummel, London. The Structure of the Wool Fibre, F. H. Bowman, Manchester. L'Art de la Soie, N. Rondot, Paris. Les Soies, N. Rondot, Paris. 23 354 TEXTILE FIBRES OF ANIMAL ORIGIN. 1886. The Catalogue of the Silk-Culture Court, Indian Exhibition, Th. Wardle, London. 1887. Microscopic der Faserstoffe, F. von Hohnel, Vienna. 1888. Chemische Technologic der Gespinnstfasern, Otto Witt, Braunschweig. Wool Manufacture, R. Beaumont, London. 1890. Les Industries de la Soie, Sericulture, etc., E. Pariset, Lyons. La Soie, L. Vignon, Paris. Industrie de la Soie, F. Dehaitre, Paris. 1895. Grundriss der Allgemeinen Waarenkunde, Erdman-Kb'nig, 12te Auf., Von Hanausek, Leipzig. 1902. The Textile Fibres of Commerce, Wm. T. Hannan, London and Philadelphia. 1907. Papier-prufung, Wilhelm Herzberg, 3te Auf., J. Springer, Berlin. STATISTICS. Wool. The following figures show the production, importation, and home consumption of wool for the United States in recent years : Production. Importation. Home consumption. Year. Pounds. Pounds. Pounds. 1905 295,488,428 249,135,746 542,062,536 1906 298,915,130 201,688,668 494,960,990 1907 298,294,750 203,847,545 498,695,547 1908 311,138,321 125,980,524 431,252,030 1909 328,110,749 266,409,304 590,996,078 (Statistical Abstract of U. S., 1909.) The importations of wool during the last few years are thus classified : 1908 1909 1910 Class L Clothing wool (Ibs.) 45,798,303 142,580,993 111,592,978 Valued at $10,278,199 $29,455,598 $27,231,052 Class II. Combing wool (Ibs.) 13,332,540 21,952,259 31,614,235 Valued at $3,624,617 $4,591,559 $7,931,145 Class III. Carpet wool (Ibs.) 66,849,681 101,876,052 120,721,019 Valued at $9,762,122 $11,124,837 $16,058,647 The world's production of raw wool in 1903 was estimated to be 2666 million pounds. The chief producing country, Australia, exported as follows : Raw wool. Scoured wool. Amount Value in Amount Value in in 1000 pds. in 1000 pds. 1000 Ibs. sterling 1000 Ibs. sterling 1904 339,395 13,147 55,911 3,975 1905 380,420 15,574 56,775 4,247 1906 415,353 17,547 64,889 5,099 1907 512,757 22,928 72,318 5,964 1908 471,846 18,028 70,915 4,886 (Statistical Abstract, 1909.) After the British Colonies of Australia, New Zealand, and Cape of Good Hope, the largest wool producing country is the Argentine Republic and La Plata. The exports in bales of one hundred and twenty-five kilos, were as follows: 1900 468,000 bales. 1905 403,821 bales. 1906 419,386 bales. 1907 384,971 bales. 1908 382,000 bales. BIBLIOGRAPHY AND STATISTICS. 355 Silk. The production of raw silk throughout the world at five-year intervals, as given in the Census Report of 1905, was: 1885. 1890. 1895. 1900. 1905. Italy (kilos) 2,810,000 3,033,000 4,661,900 4,528,500 4,900,000 France (kilos) 483,000 618,000 896,000 500,000 625,000> Austria (kilos) 142,000 267,000 266,000 276,000 315,000 Spain (kilos) . 85,000 65,000 90,000 78,000 77,000 The Levant ( kilos ) 730,000 707,000 1,244,000 1,760,000 2,186,000 Japan, exports (kilos) . 1,346,000 2,130,000 3,076,000 3,371,000 5,679,518 China, Shanghai (kilos) . 2,695,000 2,914,000 3,358,000 4,756,000 2,950,047 China, Canton (kilos) . 774,000 1,529,000 1,394,000 2,253,000 2,137,785 India, Calcutta (kilos) . 861,000 210,000 199,000 350,000 180,000 Total 9,926,000 11,473,000 15,184,900 17,932,000 19,050,350 The same report thus gives the raw silk consumption of the world by countries, taking an average of the years 1902, 1903, and 1904: Country. Kilograms. United States 6,128,000 France 4,327,000 Germany 2,846,000 Switzerland 1,595,000 Russia and Caucasus . . 1,271,000 Italy 966,000 Austria-Hungary 776,000 England 709,000 India 350,000 Egypt 200,000 Spain 183,000 Syria 110,000 Morocco 70,000 Algeria and Tunis 65,000 Other countries 152,000 19,748,000 Pounds. 13,512,240 9,541,035 6,275,430 3,516,975 2,802,555 2,130,030 1,711,080 1,563,345 771,750 441,000 403,515 242,500 154,350 143,325 335,160 43,544,340 100.0 Per cent, of total. 31.0 21.9 14.4 8.1 6.4 4.9 3.9 3.6 1.8 1.0 0.9 0.6 0.4 0.3 0.8 No data exist to show the consumption in China and Japan and they are not included. The importations of raw silk into the United States for the last few years have been as follows : 1905 22,357,307 pounds, valued at $61,040,053 1907 18,743,904 " " 71,411,899 1908 16,662,132 " " 64,546,903 1909 25,187,957 " " 79,903,586 1910 23,457,223 " " 67,129,603 (Commerce and Navigation of U. S., 1910.) 356 ANIMAL TISSUES AND THEIR PRODUCTS. FIG. 93. CHAPTER X. ANIMAL TISSUES AND THEIR PRODUCTS. A. LEATHER INDUSTRY. I. Raw Materials. 1. ANIMAL HIDES AND SKINS. The moist animal skin undergoes decomposition very rapidly; if dried it becomes stiff and horny, or if boiled with water is changed into soluble glue. The object of tanning is to bring the animal skin into such a condition that decomposition is arrested, and after drying it no longer forms a stiff horny mass, but an opaque tissue insoluble in water, distinctly fibrous and pliable. The product known as leather has properties which at once distinguish it from the untanned hide, such as greater or less impermeability to water and toughness and strength. Nevertheless, the best authorities on the subject believe that in the main tanning is a physical rather than a chemical pro- cess, and that the function of the tanning material is chiefly to penetrate the pores of the skin and envelop the indi- vidual fibres so that in drying they are prevented from ad- hering and so stiffening the whole mass. The power of the skins to fix tanning mate- rials upon the surface of its fibres varies considerably according to the nature of the material used, and in many ' grades of leather is undoubt- edly supplemented by a chemical combination of the coriin of the skin with the tannin. To understand the nature of the change wrought by tanning in the animal hide, it is necessary first to refer briefly to its anatomical structure. Fig. 93 shows a section of ox-hide cut parallel with the hair, magnified about fifty diameters. It consists essentially of three layers : the epidermis, which is itself made up of two layers, the outer horny layer or cuticle A, a dead layer which is continually wearing off and being renewed, and the inner mucous layer LEATHER INDUSTRY. 357 B, the rete Malpighii, a watery cellular layer, which rests upon the true skin and is continually renewing the outer layer ; the derma or corium, the true skin, C, which alone is the leather-tissue; and the fatty under tissue, shown in the illustration at D, in which the perspiratory and sebaceous glands are embedded. Both the epidermis and the under tissue are removed in the preparatory processes of tanning, so that the corium alone remains to combine with the tanning materials to form leather. The hair of the animal is enclosed in hair-sheaths, which pass down through the epidermis and rest upon the corium, from which in life the hair-glands draw their nourishment. The corium, or true leather- forming layer, is composed of bundles of interlacing fibres, between which is found an albuminoid substance, coriin, which as the skin dries cements the fibres together and stiffens the hide. This is in- soluble in water but soluble in lime-water, and hence removed in large part by the process of liming to which the hides are submitted. The animal skins which are utilized in the manufacture of leather are, first, those of the ox, cow, buffalo, horse, etc. These are known as hides, or if from younger animals of the same kind as kips. Second, those of the calf, sheep, goat, deer, etc. These are known as skins. For special purposes the skins of crocodiles, alligators, porpoises, and seals are also made into leather. The hides may come to the tannery according to the source whence obtained either as fresh or green hides, that is, direct from the slaughter-houses, as wet salted, as dry salted, and as dried hides. In addition to the domestic production, great numbers of hides are im- ported into the United States from the Argentine Republic and the River Plate in South America. England imports from India, the Cape of Good Hope, and Australia as well as from South America. Goat- skins for the morocco trade are brought mainly from India and the East. 2. TANNIN-CONTAINING MATERIALS. The conversion of the hides into leather is usually accomplished by the action of an extract or infusion of tannin or tannic acid. This powerful astringent acid is very widely distributed in nature, being found in barks, roots, leaves, seed-pods, flowers, and fruits, and in excrescences on trees. More accurately speak- ing, we find a number of varieties of tannic acid in these different vege- table sources, of which some are more valuable for tanning than others. As a class they are readily soluble in water, amorphous, of slight acid reaction, and astringent taste. They yield with iron salts bluish-black or greenish precipitates, throw gelatine and albumen out of solution, and change hides into leather. In tanning it is not necessary to extract the acid in a pure state, but infusions are made from the powdered barks as needed, or concentrated extracts prepared for this purpose are used. We will note briefly the more important tannin-containing materials used at the present time in leather manufactures. Oak-bark. The common English oak (Quercus Robur], which in- cludes the two varieties Q. pedunculata and Q. sessiliflora, is one of the most important materials. It contains from twelve to fifteen per cent, of tannic acid and produces an excellent quality of leather. Other varieties in use are Quercus coccifera (or kermes-oak), of which the 358 ANIMAL TISSUES AND THEIR PRODUCTS. bark, known as coppice-oak, is yellowish-brown in hue and very rich in tannin; Quercus suber (or cork-oak) and Quercus Ilex (or evergreen- oak), both of which are grown in Algiers, Italy, Spain, and the South of France. In the United States the most important varieties of oak are Quercus prinus or castanea (chestnut-oak) ; Quercus rubra (common red-oak); Quercus alba (or white-oak). The tannin of the several varieties of oak is known as quercitannic acid. According to the re- searches of Etti,* the main constituents of the oak-bark are quercitannic acid, with the formula C 17 H 16 O 9 ; its first anhydride, phlobaphene, C 34 H 30 17 ; its second anhydride, C 34 H 28 16 ; its third anhydride, Oser's oak-red, C 34 H 26 O 15 ; and its fourth anhydride, Lowe's oak-red, C 34 H 24 14 . Of these, the quercitannic acid and the phlobaphene are specially con- cerned in the tanning process. Hemlock-bark. The bark of the hemlock (Abies Canadensis) of Canada and the United States contains nearly fourteen per cent, of tannin. This is extensively used, either jointly with oak-bark (union tanned leather) or as a substitute for it, in the manufacture of sole- leather. It is said to produce a harder leather than oak-bark, but less pliable and more pervious to water. A solid extract from the hemlock- bark containing from twenty-five to thirty-five per cent, of a deep red tannin is prepared in large quantities for export. The production of this solid extract is said to be at present considerably over ten thousand tons per annum. Liquid extracts with fifty per cent, of solid matter are also largely sold. Pine-bark is much used in Austria, Bavaria, and Southern Germany. It contains from seven to ten per cent, of tannin and considerable resin- ous extractive matter. It does not yield so good a leather as oak-bark. Closely related and somewhat used are the barks of the White Spruce, the Larch, and the Fir. Willow-bark. Several species of the willow, notably Salix arenaria and 8. caproza, are used in Russia and Denmark for the tanning of lighter skins, for the manufacture of glove leather and the so-called Russia leather. It is stated that the yearly consumption of willow-bark in Russia at present is some six and a half million kilos, against two and a half million kilos, of all other tanning barks. The percentage of tannin in the willow is usually given at from three to five per cent., although Eitner f found over twelve per cent, in several species. Chestnut-wood. The wood of the chestnut (Castanea vesca) contains from eight to ten per cent, of a tannin which closely resembles gallo- tannic acid. The extract, containing from fourteen to twenty per cent, of tannin, is used largely to modify the color produced by hemlock extract and for tanning and dyeing. > Horsechestnut-bark. The bark of the horsechestnut (^Esculus hippo- cast anum) is also said to be used for the manufacture of an extract under the simple name of "chestnut extract," but such manufacture in the United States is very doubtful. * Wagner's Chemical Technology, 13th ed., p. 1051. t V. Hohnel, Die Gerbriende, p. 90. LEATHER INDUSTRY. 359 Catechu (or Cutch) is the name given the dried extract from Acacia Catechu, cultivated in India and Burmah, and containing forty-five to fifty-five per cent, of a special variety of tannic acid (catechu or mimo- tannic). The extract is evaporated until a semi-solid dark-brown pro- duct is obtained. This is exported in mats, bags, and boxes to European and American markets. Gambier or Gambir (Pale Catechu) is the dried extract from the leaves of Uncaria Gambler and U. acida. It contains thirty-six to forty per cent, of a brown tannin which rapidly penetrates leather and tends to swell it, but taken alone produces a soft, porous tannage ; it is largely used in conjunction with other materials for tanning both light and heavy leathers. It is exported from Singapore in pressed blocks and cubes. The catechutannic acids of cutch and gambier differ from gallo- tannic acid in giving a grayish-green precipitate with ferric salt and no reaction with ferrous salts ; by giving a dense precipitate with cupric sulphate and none with tartar emetic. They also contain catechin, which is said to be an anhydride of catechutannic acid. Kino is an extract somewhat resembling cutch, and is the dried juice from a variety of plants. Thus, the East Indian kino is obtained from Ptcrocarpus marsupium, the Bengal kino from Butea frondosa, the African from Pterocarpus erinaceum, and the Australian from the several species of Eucalyptus. It ordinarily forms small angular frag- ments of black lustrous appearance, brittle, and crumbling to brown-red powder. It contains thirty to forty per cent, of a tannin (kinotannic acid) analogous to catechutannic acid, together with phlobaphene. Sumach consists of the powdered leaves, peduncles, and young branches of Rhus coriaria, Rhus cotinus, and other species of Rhus. Thus, Sicilian sumach, the most esteemed variety, is from R. coriaria; Spanish sumach is from several species of Rhus, and comes in three varieties, Malaga, Molina, Valladolid ; Tyrolean sumach from R. cotinus; French from Coriaria myrti folia; American from R. glabra, R. Cana- dense, and R. copallina. The leaves are collected while the shrub is in full foliage and cured by drying in the sun. They are then ground under millstones and the product baled. The sumach contains from sixteen to twenty-four per cent, of a tannin which seems to be identical with gallotannic acid. The American variety contains usually six to eight per cent, more than the European, but also contains more of a dark coloring matter, which renders it inferior to the Sicilian sumach for white leathers. Myrobalans (or Myrabolans). The fruit of several species of Termi- nalia found in Hindostan, Ceylon, Burmah, etc. Myrobalans varies in size from that of a small hazel-nut to that of the nutmeg. The tannin occurs in the pulp which surrounds the kernel. It is generally used in combination with other tanning materials to modify the objectionable color w r hich some of the latter impart to the leather. By itself it pro- duces a soft and porous tannage. Valonia is the commercial name for the acorn cups of several species of oak, Quercus cegilops and Quercus macrolepis, coming from Asia 360 ANIMAL TISSUES AND THEIR PRODUCTS. Minor, Roumelia, and Greece. They are of a bright-drab color, and contain twenty-five to thirty-five per cent, of a tannin somewhat resem- bling that of oak-bark, but giving a browner color and heavier bloom. It is generally used in admixture with oak-bark, myrobalans, or mimosa- bark, because of itself it produces too brittle a leather. Mimosa-bark (Wattle). The bark of numerous species of Acacia (A. decurrens and A. dealbata) from Australia and Tasmania, contains from twenty-four to thirty per cent, of mimotannic acid. The bark comes into commerce chopped or ground and also in the form of an extract. It makes a red leather and is generally used in admixture. Divi-divi. The seed-pods of Ccesqlpinia Coriaria, a small tree found in the neighborhood of Maracaibo, South America. The pods are about three inches long, brownish in color, and generally bent by drying into the shape of the letter S. It contains thirty to fifty per cent, of a pecu- liar tannin somewhat similar to that of valonia, but is liable to fermen- tation. Quebracho. This is the name applied to several South American trees possessing hard wood. They are Aspidosperma Quebracho (Que- bracho bianco), Loxopterygium Lorentzii (Quebracho Colorado). The wood and bark of the latter contain from fifteen to twenty-three per cent, of a bright red tannin. Both the wood and the extract are used in tanning. Nutgalls is the term applied to the excrescences on plants produced by the punctures of insects for the purpose of depositing their eggs. The principal commercial kinds are oak-galls (or Aleppo galls) and Chinese galls. The first of these are the product of the female of an insect called Cynips, which pierces the buds on the young branches of the Quercus infectoria and other species of oak. In the centre of the gall thus pro- duced the larva is hatched and undergoes its transformation, boring its way out as a winged insect in five to six months. If the galls are gath- ered while the insect is in the larval state they are known as "blue" or "green" galls; if the insect has cut its way out they are known as "white" galls, and are of inferior character and less astringent. The best oak-galls contain from sixty to seventy per cent, of gallotannic acid. The Chinese gallnuts are the product from the Rhus semialata, the leaves of which are punctured by an insect, the Aphis Chinensis. The nuts are of irregular shape but are very rich in tannin, containing about seventy per cent. Knoppern are galls from immature acorns of several species of oak largely used for tanning in Austria. They contain from twenty-eight to thirty-five per cent, of tannin. > n. Processes of Manufacture. Leather may be manufactured from hides or skins by a number of methods, which may be summarized, however, under three heads, viz., tanning by the use of tannin-containing barks or extracts; mineral tan- ning, using either chromium salts to make an insoluble leather, or alum LEATHER INDUSTRY. 361 and salt, as in "tawing;" and the manufacture of soft leather by treat- ment of the skins with oils. We will note first the methods involving the use of tannin-contain- ing materials, and these again differ somewhat according to the grade of leather to be made and the character of the hides or skins used. A. MANUFACTURE OF SOLE-LEATHER. 1. Softening and Cleansing the Hides. This process differs according as the hides are taken in the fresh or green state or are salted or dried. For fresh hides, a washing with pure water to cleanse them from dirt and blood is all that is neces- sary to prepare them for the next or "swelling" process. For salted hides, a soaking in fresh water for from two to three days is necessary, while for hard dried hides a longer treatment is necessary, first in water which has been repeatedly used for softening and afterwards in fresh water. This involves often a slight putrefaction of the coagulated albu- men of the dry hide. To control this and prevent injury to the corium of the hide a weak salt solution (five per cent.) is often used in this pro- longed softening. "Stocking" or kneading the hides with heavy rolls or breaking weights is also needed for heavy hides which have been dried. 2. Unhairing and Swelling. These operations are carried out to- gether. As the swelling proceeds the cells in which the roots of the hair are embedded are softened, so that the hair is easily removed by mechan- ical means. The horny epidermis is similarly softened, so that it can be removed by the same means. The swelling may be effected by several different methods: (1) by sweating; (2) by treatment with acid tan- liquor; (3) by liming; (4) by treatment with sulphides of sodium and calcium, etc. The sweating process now in use is the so-called "cold sweating" method, and consists in hanging the hides in a moist cham- ber kept at a uniform temperature of 60 to 70 F. (15 to 21 C.), so that an incipient putrefaction ensues which attacks the soft parts of the epidermis and root-sheaths before materially injuring the corium or leather-forming material. This method is that generally followed for sole-leather in this country and on the Continent of Europe, while in England liming is more generally adopted. The swelling with acid tan- liquor depends upon the action of the acids which are present in con- siderable quantity in old tan-liquors and their effect upon the connective tissue. The swelling and unhairing by lime always adopted for small skins is also used for sole-leather hides in England. A view of the lime- pits and skins in process of softening by lime as carried out in morocco tanneries is shown in Fig. 94. The action of the lime upon the hide is in part a solvent one. The hair-sheaths are loosened and dissolved and the hardened epidermis swells up and softens, so that both come away more or less completely with the hair when scraped. The intercellular substance, or coriin, as before stated, is also soluble in the lime-water, and as this is removed the fibrous nature of the leather-forming skin becomes more evident. The hides are generally put into several lime- pits in succession, in the first of which is old liquor with the weakest alkaline reaction because of its partial saturation with organic material, and in the last the liquor is the freshest and strongest in alkaline reac- 362 ANIMAL TISSUES AND THEIR PRODUCTS. FIG. 94. LEATHER INDUSTRY. 363 tion. The hides require to be turned and changed in position during this liming process as well as removed from one pit to the other. The swell- ing and unhairing by the use of alkaline sulphides largely used upon the Continent of Europe consists in taking a solution of sodium sulphide (made from alkali- waste by Schaffner and Helbig's process) and bring- ing it to a thin pasty condition with lime. This is then spread upon the hair side of the hides and they are packed together for five to twenty hours, when the loosened hair and sulphide paste are washed off and the hides left in water a time longer to "plump" or swell. Another process uses the sulphide in solution only. The hair having been loosened by one or the other of the means just described, it is to be removed by mechanical means. This is usually done on the ' ' beam, ' ' a sloping frame of wood or metal, with a blunt two-handled knife, which pushes the hair downward and away from the workman. After the unhairing, the loose flesh and fat, the latter somewhat saponified by the lime, are next removed from the inner side of the hide by a sharp-edged knife. Hand "fleshing" is in many cases superseded by machine treatment, as the hide must not only be scraped but worked to force out the fat which remains in the loose tissue, as this would impede tanning. The hides after the fleshing are trimmed, and the inferior ends and edges are cut off with a sharp knife. They have still to be freed from the traces of lime which they have absorbed during the lime treatment before they can be put in the tan-liquors. This used to be done for sole-leathers, as it is still done for calf- and goat-skins, by means of ' ' bate. ' ' or dung of animals, mixed with water, but that is now almost entirely replaced by the use of dilute acids which shall combine with the lime, when the lime salts so formed are to be washed out. Dilute sulphuric, phosphoric, and hydrochloric acids have been used (the latter being best because its lime salt is soluble), as well as the acid tan-liquors containing gallic, acetic, and lactic acids. The organic acids are considered to be safer for the hide than the inorganic. 3. Tanning. The bark or other tanning material must be crushed and then ground to a state sufficiently fine to allow of the extraction of the tannic acid, and yet not so fine as to cause it to cake together in clayey masses. This is accomplished in bark-mills and disintegrators of various kinds, which need not be specially described here. The tan- house into which the cleansed and prepared hides or "butts" now come is provided with rows of pits running in parallel lines, which are to contain the butts during the treatment with the tan-liquor. The butts in most cases are first suspended in weak tanning infusions before they go into the first, or "handler," pits. The object of this is to insure the uniform absorption of tannin by the skins before subjecting them to the rough usage of "handling," which in the early stages of the process is liable to cause injury to the delicate structure of the skin. During this suspension the skins should be in continuous agitation to cause the tannin to be taken up evenly. Both the suspension and the agitation are accomplished generally by mechanical means. From the suspenders the butts are transferred to the "handlers," where they are laid flat in 364 ANIMAL TISSUES AND THEIR PRODUCTS. K W DC H < W J W O CO O fe CO CO M O o & b o 2 HH 2 2 < H fe O w H P O 2 d G d 3 3 c 1 35 S / a c ^ .5 CK> ^ 1 1 00 QJ 1 'S * a s I 5 | 1 *l P^ 3 a *3 -c "" C 3 fl> G C B 4 I " .a "? a a 3 4 ?H K "3 *s 2 bo o> * | .14 g o a ^ V* "S. } o c p Bfi t- & *B *& ^V a ! 1 ! ii i Q> g S ^ G fc" M * i O O 3 rt . "S ? s a *d 5 S "c 2 ,c 1 a oj .2 ^ 2 V CQ *H Q; a S w ^ w W c oc "1 "bo ffi - EH oj c < s ^ -*' -^ oS w a- D w a" _Q 50 -d w e S W^3 - a 3 RIMMED 1 ,an-liquor -a ^ P o'd g i e s! s ! -0 < K S H M _ 3 L.J 6, it gi i; ii sa if i i , "d 2;S * S;i W 03 Q J2 " S P*< @5 Wco-S e-g H s !s s .a si LEATHER INDUSTRY. 365 the liquor. They are here treated with weak infusion of bark, com- mencing at about 15 to 20 by the barkometer, and are handled twice a day during the first two or three days. This may be done by taking them out, turning them over, and returning them to the same pit, or more generally by running them, fastened together, from one handler-pit into another. The treatment of the butts in the handlers generally occupies about six to eight weeks, by which time the coloring matter of the bark and the tannin should have "struck" through about one-third of the substance of the skin. Many of the butts will have become covered, moreover, with a peculiar "bloom" (ellagic acid) in- soluble in water. They are now removed to the "layers," in which they receive the treatment of bark and "ooze," or tan-liquor, in progressive stages until the tanning is complete. Here the butts are stratified with ground oak-bark or valonia, which is spread upon each butt to the depth of about one inch, and a thicker layer finally on top. The pit is then filled up with ooze, which varies in strength from about 35 barko- meter at the beginning to 70 at the end of the treatment. For heavy tannages six to eight layers are required, the duration of each ranging from ten days at the beginning to a month in the later stages. Each time the butts are raised they should be mopped on the grain to remove dirt and loose bloom. With the use of strong prepared extracts, especially with the aid of heat, the tanning process can be carried out in much shorter time than that just indicated, but the leather produced though hard is deficient in toughness and is liable to crack on bending sharply. 4. Finishing. The butts after coming from the last layer are well brushed, washed in a clear liquor, and then thrown over a "horse" to drain before going to the drying-shed. They are then frequently oiled lightly on the grain so as to prevent too rapid drying out and hung on poles in the drying-loft. When about half dry, they are heaped upon the floor in piles and covered to sweat a little, which facilitates the operation of ' ' striking, ' ' which next follows. The "striking," which may be done by hand with a two-handled tool with triangular blunt edges or by machinery, is chiefly for the purpose of removing the deposit called bloom, although it somewhat flattens and stretches the leather. After a little further drying the butt is laid upon a flat bed of wood or metal and is rolled either by heavy hand-rollers or by the aid of machinery. The leather is then sometimes colored on the grain with a mixture of yellow ochre, with size and oil to give a gloss, and then brushed again, well rolled, and dried off gradually in a room slightly warmed by steam. The main outlines of sole-leather tan- ning are summarized on the accompanying diagram. B. UPPER AND HARNESS LEATHERS. For upper and harness leathers the hides of cows and smaller oxen are chosen. Fresh hides are, more- over, much better adapted for this class of leathers than dry salted or dry "flint" hides, as the utmost toughness and strength rather than hardness or weight are to be secured. The hides are cleansed, limed, and unhaired very much as already described for sole-leather. They are 366 ANIMAL TISSUES AND THEIR PRODUCTS. FIG. 95. LEATHER INDUSTRY. 367 then "bated" in a bate of hen manure or treated with sour bran-liquor to completely remove the lime from the pores of the skin. The remain- ing portions of hair-sheaths and fat-glands are at the same time so loosened that they are easily worked out by a blunt knife on the beam. This final cleansing process is called "scudding." The action of the "bate" is considered by the best authorities to be a fermentative one, and the weak organic acids produced neutralize and remove the lime and at the same time soften the hide by dissolving out the coriin and probably also portions of the gelatinous fibre. "Stocking" is also used to assist in the softening and cleansing. These lighter tannages are also carried out very largely by the aid of gambier in combination with bark, valonia, mimosa, and myrobalans. The tanning liquors are often used at temperatures of from 110 to 140 F. (43 to 60 C.). The finishing of the light leathers requires much care in order to give them the proper softness and strength. They are alternately worked with a stretching- iron, or "sleeker," and rubbed with oil or with a mixture of degras and tallow. C. MOROCCO LEATHER. This is generally made from goat-skins, although a cheaper variety is made from sheep-skins. The skins are softened and then unhaired by lime, to which a small quantity of arsenic sulphide is often added, whereby calcium sulphydrate and sulpharsenite are produced, which assist in softening the hair-sheaths and in giving the grain a higher gloss. A view of the unhairing machines and washing drums of a morocco tannery is given in Fig. 95. They are then bated with a mixture of dog's dung and water, known as the "puer." This is often followed by a treatment with bran to aid in removing the lime from the skins. A "scudding" or scraping with a blunt two-handled knife on both the grain and flesh sides then ensues to remove the last portions of lime salts and albuminoid matters. The tanning was for- merly done with sumach and gambier, either in revolving paddle "tum- blers," as shown in Fig. 96, or according to the English method, by sewing up the skins into bags partially filled with the sumach-liquor and then distended by air and floated in a large vessel of the same liquor. The bags are turned over constantly, and afterwards piled up in heaps. The sumach solution is thus forced through the pores of the skin, and the tanning is rapidly effected. The tanned skins are thoroughly washed and "struck," or scraped and rubbed, until smooth. After thorough drying they are again struck until thoroughly soft and smooth. This sumach tannage has been replaced in this country almost entirely by the chrome tanning, to be mentioned later. D. MINERAL TANNING OR "TAWING." Skins may be converted into a substance resembling leather, although in fact essentially different from it, by the action of alum and salt. There has been no chemical combination, however, analogous to that formed by the gelatine and tannic acid in the ordinary tanning processes, as the gelatine, alum, and salt can be again separated by treatment with water. The process of tawing is applied to goat, kid, sheep, and other small skins. The preliminary operations of steeping, breaking, liming, un- 368 ANIMAL TISSUES AND THEIR PRODUCTS. hairing, and fleshing, steeping in bran-water and working on the beam, are essentially the same as have been described already. The skins with the pores cleared of lime and sufficiently opened are then put into a kind of wooden drum or "tumbler," such as is used for washing skins and for treating morocco leather skins with sumach solution. For every two hundred skins some twelve pounds of alum and two. and a half pounds of salt with twelve gallons of water are used. The action is continued for a short time only, about five minutes. They are then put into an emulsion of yolk of eggs with flour and water, and tramped and worked in this until it has been thoroughly absorbed. The skins are now hung upon poles to dry, after which they are stretched and softened by drawing them to and fro upon the "stake," a blunt steel blade set in upright position. FIG. 96. "Combination tanning," in which the joint action of gambier and alum is used, is also extensively followed. Very different from this kind of mineral tanning is that introduced within the last few years under the name of "chrome tanning." It depends upon the power of chromium oxide (sesquioxide of chromium) of forming an insoluble compound with the gelatigenous fibre of the hide, furnishing a product which possesses in a high degree the water- proof character desirable for leather. The process generally in use at present in this country involves treat- ing the skins at first with a weak solution of bichromate of potash to which sufficient hydrochloric acid is added to liberate the chromic acid (of course pickled skins may be used without the necessity of adding free acid). After the skins have taken up a bright yellow color through their entire texture they are drained and transferred to a bath of sodium thiosulphate, to which some acid is added to liberate sulphurous acid, which reduces the chromic acid to green chromic oxide. The sulphur- ous acid is at the same time oxidized to sulphuric acid, which liberates a LEATHER INDUSTRY. 369 further portion of sulphurous acid, until the whole of the chromic acid is reduced. Hydrogen sulphide liberated from alkaline sulphides has also been used as the reducing agent for bichromated skins, and still more recently electrolytic hydrogen developed upon the bichromated skin itself. In any case the reduction must take place rapidly, so that the potassium bichromate may be reduced superficially before it can "bleed" or diffuse out of the skins into the water of the reducing bath. The leather so produced is of a pale bluish-green color, tough and flexible, and thoroughly resistant to water. Indeed, it is this latter property which distinguishes it from all other forms of leather, as the combination of the hide fibre or coriin with the chromium oxide is apparently more stable than its combination with tannin and yields less to boiling water, as has been shown in tests made by Professor Henry Procter, of Leeds. The leather can also be dyed and produced in a variety of colors, but the dyeing must be done before the leather dries, as its water-repellent character is such that once dried it cannot be wetted sufficiently to take up a full color. Chrome-tanning processes involving the use of chrome alum and other salts of the sesquioxide of chromium as the basis of the tanning vat have been used, but apparently the combination does not take place so readily as where the chromium oxide is obtained in statu nascendi by reduction from the bichromate under the influence of reducing agents. Basic chromium salts, such as the basic chromium chloride, have also been proposed as mineral tanning agents, it being claimed that the dis- solved chromium oxide is taken up by the hide-fibre at once and that a single bath only is necessary in this case. Such a basic salt is prepared by dissolving commercial chromium hydroxide (chrome green) in hydro- chloric acid, adding sal soda until precipitation of the hydrate begins again. The solution is then nearly neutral, and contains an oxychloride or basic chloride in solution. Common salt is also added to prevent injury to the grain of the leather and to facilitate tanning. After the absorption of the chromium oxide is completed the skins are agitated in water containing suspended carbonate of lime to neutralize all traces of acid. They are then washed and are ready for the fat liquor. At the present time the bulk of the glazed kid made in the United States is chrome-tanned, two establishments in Philadelphia each turning out at present three thousand dozen chrome-tanned goat-skins daily. Quite recently formaldehyde, applied either as gas or in aqueous solution, has been introduced as a tanning agent, the well-known coagu- lating power of the formaldehyde on animal tissue causing it to unite with the hide fibre to form an insoluble leather. All grades of leather, from sole leather to light morocco, it is asserted, can be made readily and very rapidly by this treatment. As yet, it is too early to judge con- clusively of its quality and durability. E. CHAMOIS AND OIL-TANNED LEATHER. The skins tanned in this way are sheep- and calf-skins, and formerly chamois- and deer-skins. The flesh splints of sheep-skins are now generally employed for ordinary- wash-leather. If heavy hides are taken, the grain side of the skin is 24 370 ANIMAL TISSUES AND THEIR PRODUCTS. shaved so that the oil can penetrate easily. The skins receive a thorough liming, so that the coriin is thoroughly removed from between the fibres, making them very soft. A bran-drench follows to remove the lime, and they are worked on the beam. The surplus water having been removed by pressing, while still moist they are oiled with fish, seal, or whale oil (to which some five per cent, of carbolic acid is often added). After being stocked for two to three hours, shaken out, and hung up for one- half of an hour to an hour to partially dry, they are again oiled and stocked, and this process is repeated until the skins lose their original smell of limed hide and acquire a peculiar mustard-like odor. The later dryings are frequently conducted in a heated room, and when the oiling is complete the skins are piled up, and the oxidation of the oil which has already commenced during the fulling and drying is completed by a sort of a fermentation, in which the skins heat considerably. This heat- ing must be controlled so that the leather is not injured, and if necessary the pile of skins is turned. When the oxidation is complete the skins are of the yellow chamois leather color. To remove the surplus oil, the skins are again oiled, then thrown into hot water and wrung out. The semi-solid fat obtained this way is the degras so much prized for currying purposes. Or the whole of the uncombined oil is removed by washing with soda or potash lye and then set free by neutralizing with sulphuric acid. The oil so obtained forms the "sod oil" of commerce. About half of the oil employed is retained by the skin, and cannot be removed even by boiling with alkalies. No gelatine is obtained by boiling with water, to which the chamoised skin is much more resistant than ordinary leather. The skins intended for gloves, etc., are bleached like linen, by sprinkling and exposure to the sun or with weak solution of potassium permanganate followed by sulphurous acid. HI. Products. 1. SOLE-LEATHER. This is the heaviest and firmest variety of leather produced. It is made from the heaviest and thickest hides, and is valued for its fine grain and toughness. It retains the whole thickness of the hide, and no part is split off, so that it is not weakened by the loss of the flesh side. The tanning process is protracted until the whole hide is of uniform color throughout and shows the completed action of the tannin upon the interior of the hide. 2. UPPER AND HARNESS LEATHERS. These are made from lighter hides, and are tanned for strength and flexibility rather than for weight, and are finished with care to give perfect pliability. They may be shaved or split leather. The black color and finish are put on upper leather by coating it with a mixture of lamp-black, linseed oil, and fish oil, to which tallow and wax and a little soap have been added. This is brushed on, allowed to dry, and then thoroughly rubbed in and the skin sized with a glue size. 3. MOROCCO LEATHER. The true morocco leathers are manufactured from goat-skins. A cheaper grade, known as French morocco, is pro- duced from sheep-skins. As they are to be dyed on one side only, two LEATHER PRODUCTS. 371 of the skins are fixed face to face with the flesh side inward, so that the dye acts upon one side of each skin only. After dyeing the skins are rinsed and drained, saturated with linseed oil to prevent too rapid drying, and then curried by repeated oiling or waxing and rubbing with a glass "slicker." 4. ENAMELLED OR PATENT LEATHERS. These are leathers finished with a water-proof and bright varnished surface similar to lacquered woodwork. The name "enamelled" is generally applied when the leathers are finished with a roughened or grained surface, and ' ' patent, ' ' or "japanned," when the finish is smooth. Thin and split hides are used. The skins after drying are prepared with a mixture of linseed oil and white lead and heated in closets to 160 F. (71 C.) or higher, then coated with a varnish of spirits of turpentine, linseed oil, thick copal varnish, and asphaltum, and heated again in closets or "stoves," as they are termed. This varnishing and heating are alternated, while the sur- face is meanwhile rubbed smooth with pumice, until the desired thickness is acquired. 5. RUSSIA LEATHER. This variety is peculiar in its characteristic odor and ability to withstand dampness without any tendency to mould, both of which qualities it owes to the currying with the empyreumatic oil of birch-bark. In Russia the skins are tanned with willow-bark, but the imitation Russia leather made largely in Germany and England is tanned in the ordinary way with oak-bark. The birch-bark oil is rubbed into the flesh side of the tanned skins with cloths, care being taken not to apply so much as to cause it to pass through and stain the grain side of the leather. The red color is given by dyeing with Brazil-wood or red saunders, and the diamond-shaped marking by rolling with grooved rollers. 6. CHAMOIS LEATHER is a soft felt-like leather originally prepared from the skin of the chamois goat, but now made from other goat-skins and from the "flesh-splits" of sheep-skins. In these leathers the grain has practically been removed by scraping or "prizing" before the oil is applied, so that it is uniformly porous and soft throughout. They acquire a yellow color and a peculiar odor, although they are often bleached whiter by subsequent treatment. (See preceding page.) The combination of oil with the hide makes chamois leather very resistant to water and allows it to be washed without any change of nature. 7. WHITE-TANNED OR "TAWED" LEATHER. Skins to be tanned with the hair on, as sheep-skin rugs, etc., are always alum-tawed, as well as light calf kid and glove leather. The glove leather obtained in this process has softness and considerable strength but is not thoroughly water-resistant, although the treatment with egg-yolk and flour-paste which follows the alum treatment tends to give it somewhat of this character. 8. CROWN LEATHER. This is a variety which is intermediate between oil-tanned and tawed leather, being stronger than the first and more water-resistant than the latter. The hides are first tawed with the alum and salt mixture, then washed to partially dissolve. out the tawing mate- rials, and now spread upon a table and the flesh side covered with a 372 ANIMAL TISSUES AND THEIR PRODUCTS. mixture of fat, ox-brain, barley-flour, and milk. They are then put into a revolving tumbler and rotated for a time, and again rubbed with the fat mixture and rotated if necessary. The leather readily becomes mouldy, but seems to be strong and specially adapted for belting. 9. PARCHMENT AND VELLUM. The first of these is prepared from the skins of sheep and goats and the second from the skins of calves. The skins are washed, limed, unhaired, and fleshed, again well washed, and then stretched either upon hoops or upon a square wooden frame called the herse. On these the skin while wet and soft is stretched thoroughly. It is then scraped again free from the fleshy matters, the flesh side dusted over with sifted chalk or slaked lime and rubbed in all directions with a flat piece of pumice-stone. The grain side is also scraped with a blunt tool and rubbed with pumice. The skin is then allowed to dry on the frame in 'the shade, care being taken to avoid sunshine or frost. Very fine vellums are prepared with the finest pumice-stone. 10. DEGRAS. Among the side-products of the leather industry is one which is quite valuable for after-use. Degras, originally obtained only as a side-product of the chamois-leather manufacture, is now also made specially on a large scale. The purest degras is essentially an emulsion of oxidized fish oil produced by soluble albuminoids. That which is squeezed out of the skins after completion of the fermentation and heating, which makes the last stage of the chamois-leather manufacture (see p. 370), is the finest grade of degras. That which is recovered by the aid of caustic alkalies and after-liberation with sulphuric acid is the second grade (sod oil). The great demand for degras for currying purposes has led to the manufacture of it as a special industry. The skins employed for this purpose are treated exactly as are those in the normal chamois-leather manufacture, but are used over and over until no longer capable of taking up the oil. An artificial degras has also been made from oleic acid, fat, and a little lime soap to which some tannic acid had been added. Degras is of semi-solid consistence and has a peculiar odor. Its specific gravity is higher than that of fish oil, and after dehydrating is from 0.945 to 0.955. Its characteristic constituent is the so-called degras- former, which in a genuine degras should range from twelve to twenty per cent. It is this which effects the ready emulsion with water. The degras-former is a brown resinous saponifiable substance, fusing at from 65 C. to 67 C., and is distinguished from fats in that it is not pre- cipitated when in alkaline solution by salt and is not soluble in petro- leum-ether. According to Fahrion, the degras-former is a mixture of oxy-fatty acids. IV. Analytical Tests and Methods. 1. QUALITATIVE TESTS FOR THE SEVERAL TANNING MATERIALS. H. R. Procter* has constructed the following table (see p. 373) showing the reactions of the several tanning materials. 2. ANALYSIS OF LIQUID AND SOLID TANNING EXTRACTS. The method * Text-book of Tanning, pp. 112 and 113. LEATHER INDUSTRY. 373 hn S^Ot^oJ^WGd td 5' p^B-e-Sr CLCE: g3g2.,3=. ? eP l ell Sl^'Pl GgOf 1 ii e - p iB'S5&SU=S^'B B> | g ||B.IB i |H:| P SrS'OiS'S'B o re o, 2.SJ-B I rfpi-lK I I f li5 pi M 2. c 2.C. 3.c ff 3 ^ 1:1 G^bdt) i i-'K'tt Hj II i M it 53 CO W 1 t TJ J O >S TJ *-< rV OW -^ t|||lf|||I I llP^!fll:pri|Il|lfl f HS t uu WjSjiZWtxi^o 2 i-i ftitfiin^iiP ^t "a ca~~g%P v s o-o S-- -O n S o " I P p'-'fo P^ "-(^^i-f' *^ V & V > s-s. S.B^ 3 s. o So 1 (t> C&-L- '^ .^? 1 ^?'^ 2.g^?p 2. g^ol - ttl _tz! o w a a rilliliti ^llfllltl <&"2 *^ * ^- r*- 2.c2 P^ J 11 ^ P^ all i 5 ^ a a 2.3 p "2.^ S-B - s a " ml xtr - i na ' 2 wSf ff -.^^o izj a 3 poggpo2.3^o S P^o? ?%'%.*?'% ~ ^B ^ .' & ~'A M* O 22 oo o DG^Z^ ^ 111 If SI pf Iff =fs I'illS SsS sjs5' 3 lii?i| s fls I I - &E-2.3 o -i o-o S - - .. ^ (p t^p z! I! 2.3 BogSajaS'a^ al | ||S|&3 I < S| "a -a! ?'? S 2. SoE- 2.3 c 2.5s o H> 3 ni-o So g-2 |l F fl^^P|ip|l w !! ~ og e S " 2 o 5 2. "SgS ^ _.. 50 c &3 2 H. o' 374 ANIMAL TISSUES AND THEIR PRODUCTS. prescribed by the "Official and Provisional Methods of Analysis" of the U. S. Department of Agriculture is as follows : Dissolve in nine hundred cubic centimetres of water at 80 C. such a quantity of the extract as will give from 0.35 to 0.45 gramme of tannin in one hundred cubic centi- metres of solution. Allow to cool slowly for from twelve to twenty hours at a temperature not below 20 C. and dilute to one litre. a. Thoroughly mix the solution, immediately pipette one hundred cubic centimetres into a tared dish, evaporate and dry for sixteen hours in a combined evaporator and dryer at from 98 to 100 C. The result is the total solids. b. Add seventy-five cubic centimetres of solution (kept at from 20 to 25 C. during filtration) to two grammes of kaolin (free from soluble salts), stir, let stand fifteen minutes, decant, and discard as much as possible of the supernatant liquid and again add seventy-five cubic cen- timetres of the tannin solution to the kaolin. Stir and pour immedi- ately on a fifteen centimetre folded filter. Keep the filter full and the funnel and receiving vessel covered. Reject the first one hundred and fifty cubic centimetres of filtrate, evaporate and dry the next one hun- dred cubic centimetres (which must be as clean as practicable) as before under total solids. The residue is the soluble solids. c. Non-tannins. Prepare a sufficient quantity of hide powder in the following manner : Digest with twenty-five times its weight of water until thoroughly soaked ; add three per cent, of chrome alum in solution, agitate occasionally for several hours and allow to stand over night. "Wash by squeezing through linen, until the wash water gives no pre- cipitate with barium chloride. Squeeze the hide, using a press if necessary, so that it contains from seventy to seventy-five per cent, of water and determine moisture (twenty grammes is a convenient quantity). Add to two hundred cubic centimetres of the tannic solution such a quantity of the cut hide as contains from twelve to thirteen grammes of dry hide, shake for ten minutes in a shaker and squeeze immediately through linen, add two grammes of kaolin to the filtrate, stir and filter through a folded filter, returning until clear. Evaporate and dry one hundred cubic centimetres as in previous section. Correct the weight of the residue for dilution caused by the water contained in the cut hide powder. This non-tannin filtrate must not give a precipi- tate with a gelatine salt solution (one per cent, of gelatine and ten per cent, of salt). d. The difference between the weight of the soluble solids and the corrected non-tannin residue is the weight of tannin in one hundred cubic centimetres of solution. s 3. QUANTITATIVE ESTIMATION OF TANNIN. Of the numerous pro- cesses that have been described for this purpose, the only one generally accepted as capable of sufficient accuracy is Lowenthal's permanganate method. This depends upon the oxidation of the tannin, etc., by per- manganate of potash in acid solution in the presence of indigo, which serves as indicator, as its oxidation shows the end of the reaction. As solutions of commercial tanning materials contain other oxidizable LEATHER INDUSTRY. 375 matters besides tannins, it is necessary to separate these and titrate a second time in order to ascertain the volume of permanganate actually required by the tannin present. This separation may be effected by digestion with hide-raspings, or more conveniently by a solution of gela- tine. In practice, a mixed solution of gelatine and common salt is used to which a small quantity of sulphuric or hydrochloric acid is added. Procter has also improved the process by adding kaolin, after the gela- tine and salt have removed the tannin, for the purpose of facilitating filtration. The special precautions and details of the process as generally prac- tised and as modified by the Commission of German Technical Chemists are given in Allen.* The results are always stated in terms of crystal- lized oxalic acid to which the tannin is equivalent in reducing power upon the permanganate solution, and are gotten by the aid of the pro- portion c: (a &) : : 63 : z, in which c represents the volume of per- manganate needed for ten cubic centimetres of decinormal oxalic acid, a and b the volume of permanganate needed for the tanning infusion before and after precipitation of the tannin. The shaking method with chromed hide-powder, as given on the preceding page, is that gen- erally used by American leather chemists. It is objected to, however, by European chemists, that the shaking introduces abnormal conditions so that some of the non-tannins are absorbed and that the result will vary somewhat with the degree of chroming of the hide-powder. Many workers, therefore, prefer the bell, as proposed by Procter, which is packed with the chromed hide-powder and the shaking is dispensed with. The most recent method adopted by the International Association of Leather Trade Chemists and officially promulgated by them is found in Trotman's Leather Trades Chemistry, p. 146. f 4. DETERMINATION OF ACIDITY OF TAN-LIQUORS. A method for the determination of volatile and non-volatile organic acids and the sul- phuric acid present in acid tan-liquors has been given by Kohnstein and Simand.J One hundred cubic centimetres of the tanning liquor are taken and eighty cubic centimetres distilled off, the residue diluted and again distilled with steam. The acidity of the distillate is determined, and the result is the volatile organic acids reckoned in terms of acetic acid. To determine the non-volatile organic acids, eighty cubic centi- metres of the tanning infusion is treated with three to four grammes of freshly-ignited magnesium oxide and the mixture left for some hours with frequent agitation, when the filtered liquid will be nearly colorless and perfectly free from tannin. The magnesia in solution is determined in an aliquot part of the filtered solution, and will be equivalent to the total free acids of the liquor exclusive of the tannic acid. Another portion of the filtrate is evaporated to dryness, the residue gently ignited, moistened with carbonic acid water, and dried. It is then boiled with distilled water and the solution filtered. The carbonate of magnesia * Allen, Commercial Organic Analysis, 2d ed., vol. iii, Part i, pp. 109-116. t Leather Trades Chemistry, S. R. Trotman. 1908, J. B. Lippincott Co., Phila. J Dingier, Polytech. Journ., 256, pp. 38 and 64. 376 ANIMAL TISSUES AND THEIR PRODUCTS. remaining insoluble represents the total organic acids, and can be more accurately determined by converting the magnesia into pyrophosphate and weighing. If these total organic acids be calculated in terms of acetic acid, and the previously found volatile acids, reckoned as acetic, be deducted, the difference represents the non-volatile organic acids. The magnesia remaining in the filtrate from the carbonate of magnesia is combined as sulphate, and when determined gives the sulphuric acid of the original liquors. 5. ANALYSIS OF LEATHER. It is possible in the case of a leather to determine the percentage of moisture, total fats, water-soluble matter, insoluble fibre, and ash. In the case of mineral tannages, the quantita- tive determination of the chief constituents of the ash is of special importance. The fats are determined by extraction in a Soxhlet appa- ratus, as described in a previous chapter, carbon disulphide or petro- leum-ether being used as solvent. The dry leather residue remaining after this extraction is digested for some hours with distilled water at 40 C. and then thoroughly extracted by fresh water at the same tem- perature. The washings are then brought to fixed volume and the resi- due determined in an aliquot portion. Uncombined tannin may also be determined in this aqueous extract by means of the hide-powder or Low- enthal method. The total ash is obtained by igniting a separate quantity of the leather. This is chipped in small fragments and ignited grad- ually in small portions in a platinum dish. After the leather swells and carbonizes, it can be burned completely at a dull-red heat without loss of the mineral salts. B. GLUE AND GELATINE MANUFACTURE. Glue is a decomposition product of many nitrogenous animal tissues. These lose on heating with water (analogous to starch-granules) their organized structure, swell up, and gradually go into solution. The solu- tions, even when very dilute, gelatinize on cooling, forming a jelly, which dries to a horny translucent mass. This mass is glue or gelatine, as the finer grades are termed. It dissolves in hot water to a liquid possessing notable cementing power. Neither the original solution obtained from the nitrogenous tissues nor the jelly formed from it on cooling have any cementing power. This is only acquired when the jelly has dried to the hard mass known as the glue. Two proximate principles seem to be present as characteristic in all preparations of glue: glutin, obtained chiefly from the hide and larger bones, and chondrin, from the young bones while yet in the soft state and the cartilage of the ribs, and joints. Of these, the former much exceeds the latter in adhesive power, and is therefore sought to be obtained predominantly in the glue manufacture. I. Raw Materials. 1. HIDES AND LEATHER. The corium of the animal hides (see p. 356) is the most important glue-yielding material to be had. Neither the epidermis nor the underlying fat-tissue contribute to the glue produc- tion, but have rather an injurious effect when present. "What is known GLUE AND GELATINE MANUFACTURE. 377 as ''glue-stock" is made up of the trimmings from the ox. sheep, and calf-skins, the refuse of the beam-house, and scraps of parchment, which have been softened and unhaired by liming and are in condition for immediate boiling. Of still greater value are the so-called calves' heads, which after liming and drying form a special article of commerce. The amount of glue obtainable from these various materials varies from fifteen to sixty per cent. According to Fleck,* the scraps from the alum-tawing process yield forty-five per cent., those from the ox-hides thirty per cent., hare- and rabbit-skins and parchment trimmings fifty to sixty per cent., foot and tail pieces of oxen fifteen to eighteen per cent., other scraps from the tanneries, such as ear-laps of sheep and cows, sheep's feet, etc., thirty-eight to forty-two per cent. Scraps of bark-tanned leather, such as shoemaker's and saddler's trimmings, are also available after a special treatment for the removal of the tannin. (See p. 379.) 2. BONES. The bones contain on an average nearly one-third (32.2 per cent.) of their weight of organic constituents, extracted by boiling and converted into glue, which, however, is inferior in adhesive power to that prepared from animal skins. The soft bones of the head, shoul- ders, ribs, legs, and breast, and especially deer's horns and the bony core of the horns of horned cattle, yield a larger quantity of glue than the hard thigh-bones and the thick parts of the vertebra, which are prin- cipally composed of calcium phosphate and require a more prolonged treatment to extract the glue-making constituents. 3. FISH-BLADDER. The inner skin of the air-bladders of the several varieties of sturgeon and cod furnishes a very pure glue substance, which on account of its purity is preferably used for culinary and medicinal purposes, and is known as "isinglass." It is inferior in adhesive power to hide-glue, but on account of its freedom from color, taste, and odor, and its almost perfect solubility in hot water, commands a higher price. It is used for food preparations, for clarifying wine, beer, and other liquids. The chief production of isinglass is from the sturgeon in Rus- sia, on the borders of the Caspian and the Black Sea. 4. VEGETABLE GLUE. Certain species of algae (Plocaria tenax and others) found in Chinese and Japanese waters when cleansed and boiled yield a product known under the several names of "Chinese isinglass" and ' ' agar-agar. ' ' Of similar character is no doubt the ' ' algin ' ' obtained from Scotch alga3 by E. C. C. Stanford. f n. Processes of Manufacture. 1. MANUFACTURE OF GLUE FROM HIDES. The hide trimmings and offal, if in the fresh state, must first of all be well limed, that, is, treated with milk of lime in pits for a period varying from ten to forty days, according to the character and source of the hides, the lime being fre- quently renewed. The lime softens and swells the hide-tissue, saponifies * Die Fabrikation Chemischer Producte, etc., p. GO. t Soc. Chem. Ind. Jour., 1884, p. 297. 378 ANIMAL TISSUES AND THEIR PRODUCTS. FIG. 97. the fats, and dissolves in large part the coriin, blood, and flesh-particles which do not form glue. The glue-stock is then thoroughly washed free from the lime, lime salts, and dirt, usually by putting it in nets or wicker baskets which are suspended in running water. The liming also serves to preserve the glue-stock in case it is not to be immediately worked up. After washing it is spread out to dry. The lime scum from the pits is often utilized in fertilizer manufacture. Caustic soda has also been used instead of milk of lime for this treatment. A short treatment with chloride of lime immediately after taking the stock out of the lime-pits has also been found to give the glue a bright color and excellent ad- hesive power. In recent years sulphurous acid has been used with advantage to cleanse and prepare the glue-stock, as it bleaches and at the same time swells the hide, at least as well as can be done by the lime. The boiling and conversion of the glue-stock into solution may be effected by heating with water or with steam. The use of steam, either from closed pipes or direct steam from per- forated pipes, greatly improves the extraction, shortening the time required and improving the quality of the product. Direct high-pressure steam blown into closed vessels has been found to be quite effective in rapidly melting down the glue-stock and producing a con- centrated solution. The use of vacuum-pans and the extraction by steam under reduced pressure and at lower temperatures has also been found very satisfactory in giving a good product in which the adhesive qualities of the gluten are in no way impaired. A form of vacuum pan designed for the evap- oration of thin glue extraction liquors is shown in Fig. 97. The solution must be freed from any melted fat and lime soaps by skimming and from suspended impurities by settling, by filtering through linen bags, or clarifying by the use of bone-black. The addition of alum as sometimes practised has an injurious effect upon the adhesive power of the product. The residue of the glue-stock left unextracted is pressed out, dried, and sold as a fertilizer containing about four per cent, of GLUE AND GELATINE MANUFACTURE. 379 nitrogen. The clarified glue solution is poured into shallow wooden moulds some six inches in depth, in which as it cools it gelatinizes to a brownish-yellow jelly containing from eighty to ninety per cent, of water. The block of jelly is then turned out upon a smooth table, pre- viously moistened to prevent adherence, and sawed by horizontal wires into thin slabs, which are again cut by vertical wires into strips of the proper width. The drying of the jelly is one of the most troublesome parts of the whole process, as it must take place rapidly so that the glue-making material may not spoil, as it is very prone to do while in the jelly form, and, on the other hand, the heat should not exceed 20 C. (68 F.). It may take place with this limitation of temperature in the open air, if the air is not too moist or too dry, both of which conditions are unfavor- able. It is now generally effected in drying-rooms in which a current of warm dry air at the right temperature is made to circulate. As the surface of the cakes after drying is generally rough and dull, it is improved in appearance by moistening with warm water, brushing with a soft brush, and again drying. 2. MANUFACTURE OF GLUE FROM LEATHER-WASTE. Before attempt- ing to boil the leather-waste to glue, the removal of all traces of tannic acid becomes absolutely necessary, since the retention of the smallest quantity prevents the animal tissue from dissolving in water. The waste must therefore be comminuted as thoroughly as possible to facilitate the complete removal of the tannic acid. This is done frequently in the "hollander" used for paper-pulp, and the washed and ground leather- waste then heated in a pressure-boiler under a pressure of two atmos- pheres with fifteen per cent, of its weight of slaked lime. After thor- ough washing, the residue is ready for use as glue-stock. 3. MANUFACTURE OF GLUE OR GELATINE FROM BONES. Two methods have been followed for the extraction of gelatine, as the product is generally called in this case, from bones. The bones are either boiled under pressure, or they are treated with hydrochloric acid to remove the calcium phosphate and afterwards boiled for the extraction of the gelatine. The bones in either case are with advantage deprived of their fat first, which is done either by heating them with water and steam in boiler-shaped vessels, when the fat rises and can be skimmed off from the water, or in closed vessels with volatile solvents like petroleum- benzine and carbon disulphide. The older process of extracting the gelatine by boiling the powdered bones with water under pressure decomposes a portion of the valuable material, and is now generally replaced by the method of treatment with hydrochloric acid for the removal of the calcium phosphate. The crushed bones are placed in wooden vats with dilute hydrochloric acid of specific gravity 1.05 (forty litres of acid to ten kilos, of bones) and allowed to remain for several days. They are then placed in lime-water for a time, well washed, and boiled eight to ten hours with a large excess of water, or converted more rapidly into gelatine solution by the aid of steam. The resulting solu- tion is filtered through cloth, bleached by sulphurous oxide, and poured 380 ANIMAL TISSUES AND THEIR PRODUCTS. into forms to gelatinize. The manufacture of bone gelatine is fre- quently combined with the fertilizer manufacture, as the calcium phos- phate extracted by the hydrochloric acid treatment contains from eighteen to twenty per cent, of phosphoric acid. The newer method of extracting the fat by volatile solvents yields five to six per cent, of fat without injury to the gelatine of the bones, while the older method of boiling out the fat yields from three to four per cent, only and tends to lessen the yield of gelatine. 4. MANUFACTURE OF FISH GELATINE. The swimming-bladders of the fish are taken and thoroughly washed in water from all fatty and bloody particles. They are then removed and cut longitudinally into sheets, which are exposed to the sun and air to dry, with the outer face turned down upon boards of linden or bass-wood. The inner face of the bladders is pure isinglass, which when partially dried can with care be removed from the outer muscular layer. The isinglass layer, possessing a silvery white lustre, is taken either in sheets, rings, or horseshoe-shaped strips, etc., bleached with sulphurous acid, and then thoroughly dried. A product distinct from isinglass and known as fish glue is prepared by boiling the sldn and muscular tissue of fish, and more resembles ordinary hide glue in its adhesive properties, but is offensive in odor. It is prepared from the scales and skins of large fish like the carp by acting on them with hydrochloric acid as upon bones and then extract- ing with water. m. Products. 1. HIDE GLUE is the variety which shows most strongly the adhesive property, and hence is that manufactured for joiner's and carpenter's use. Its color may vary considerably without any impairing of its adhe- sive power. It is rarely perfectly colorless or transparent. A gray to amber or brown-yellow color and translucent or partially opaque ap- pearance is more usual. It should be clear, dry, and hard, and possess a glassy fracture. It should swell up but not dissolve in cold water, but dissolve in water at 62.5 C. (144.5 F.). Inorganic substances (such as white lead) are intentionally introduced into some varieties, such as the Russian glue, without injury to their adhesive power. The variety known as "Cologne glue" is manufactured from scrap hide, which after liming is carefully bleached in a chloride of lime bath and then thoroughly washed. "Russian glue," as stated, contains some inorganic admixture. It is of a dirty-white color, and contains from four to eight per cent, of white lead, chalk, zinc-white, or barytes. "Size glue" and "Parchment glue" are both skin glues prepared with special care. 2. BONE GLUE (OR BONE GELATINE). Bones yield a product of less adhesive power than the glue of skins and tendons, but when carefully worked the product is clearer and is free from offensive odor. It is GLUE AND GELATINE MANUFACTURE. 381 therefore much used for culinary purposes and for medicinal applica- tions, and for fining or clarifying beer, wine, and other liquids it has largely superseded isinglass. The gelatine thus used must, however, be absolutely tasteless and free from odor. Bone gelatine is now made use of very largely in the manufacture of gelatine capsules, etc., for medicinal uses, of court-plaster for apply- ing to wounds, and of gelatine emulsions with bromide and chloride of silver for coating the photographic dry plates. Mixed with glycerine it makes an elastic mass used for printers' rollers, for hectographs, etc. "Patent Glue" is a very pure variety of bone glue of deep dark- brown color. It is very glossy and swells up very much in water. 3. ISINGLASS (OR FISH GELATINE). This is the finest and best of animal glues. The best isinglass should be pure white, nearly trans- parent, dry and horny in texture, and free from smell. It dissolves in water at from 35 to 50 C. (95 to 122 F.) without any residue, and in cooling should produce an almost colorless jelly. The com- mercial varieties of isinglass are the Russian (the best coming from Astrachan), North American (or New York}, East Indian, Hudson's Bay, Brazilian, and German (or Hamburg). 4. LIQUID GLUE. By the action of nitric or acetic acid upon a solu- tion of glue its power to gelatinize may be completely arrested while its adhesive power is not at all interfered with. Thus, if one kilo, of glue is dissolved in one litre of water and .2 kilo, of nitric acid of 36 B. be added, after the escape of the nitrous fumes we have a solution that will not gelatinize on cooling, although it has the full adhesive power of the glue. Four parts of transparent gelatine, four parts of strong vinegar, one part of alcohol, and a small amount of alum will also yield an excellent liquid glue. IV. Analytical Tests and Methods. The nature of glue makes it rather a question of physical and mechanical tests as to quality of a given sample than of chemical tests. 1. ABSORPTION OF WATER. Thus the relative amount of water that a given sample will take up when laid in cold water is regarded as a moderately fair criterion of its quality. A weighed sample is laid for twenty-four hours in cold water (not exceeding 12 C. (53.4 F.) in temperature), and at the expiration of that time the excess of water having been poured off, the jelly is weighed. Very good varieties (white gelatine prepared from bones) will take up thirteen times the quantity of water in gelatinizing, second quality glue ten times, and inferior grades only about six times the amount of water. At the same time the consistency of the jelly formed must also be taken into consideration. A firm jelly produced by the absorption of a large quantity of water indicates a glue of the best quality. Two observations are of value in this connection: first, glue twice dissolved and again dried is capable of drying out more thoroughly and of showing water-assimilating properties on redissolving more fully 382 ANIMAL TISSUES AND THEIR PRODUCTS. than glue obtained by a single drying; and, second, that hide glue on taking up smaller quantities of water becomes very soft and more dif- ficult to weigh accurately than bone glue, which, with larger amounts of absorbed water, still forms a firm jelly. This difference in behavior alone is capable of giving an indication of the source of the glue. 2. INORGANIC IMPURITIES. The presence of inorganic salts, as in the case of Russian glue, can be determined by the use of the appropriate reagents, and the amount also quantitatively determined. 3. ADULTERATION OP ISINGLASS WITH GLUE. Isinglass is sometimes adulterated by rolling up sheets of gelatine (bone gelatine) between the layers of true isinglass and drying them in this condition. Redwood and Letheby have observed that the ash of pure isinglass does not exceed .9 per cent., while glue contains from two to four per cent, of ash. An adulterated sample of isinglass gave Letheby 1.5 per cent, of ash. On heating with water, true isinglass gives only a peculiar fish or algae odor, while the adulterated isinglass gave a strong glue-like odor at once recognizable. V. Bibliography and Statistics. BIBLIOGRAPHY. ON LEATHER. 1873. Die Rohstoffe des Pflanzenreiches, J. Wiesner, Leipzig. 1876. Leather Manufacture, J. S. Schultz, New York. 1877. Die Weissgerberei etc., F. Wiener, Leipzig. Leder-Industrie-Bericht iiber die Austellung in Philadelphia, W. Eitner, Vienna. 1880. Classification de 300 Matidres tannantes, R. J. Bernardin, Gand. Die Gerberinden, F. R. von Hohnel, Berlin. The Culture of Sumach, Department of Agriculture, Special Report 26, W. McMurtrie, Washington. 1881. Matieres premieres organiques, Geo. PennetieT, Paris. 1882. Die Grundziige der Lederbereitung, Chr. Heinzerling, Braunschweig. 1885. Bericht der Commission der Gerbstoffbestimmung, etc., C. Councler, Cassel. Text-book of Tanning, H. R. Procter, London and New York. 1886. Cuirs et Peaux, Tannage, etc., H. Villain, 2me, Paris. 1888. Abriss der chemischen Technologic, Chr. Heinzerling, Berlin. 1889. Handbuch der technisch-chemischen Untersuchungen, 6te Auf., Bolley, Leipzig. Hand-book of Commercial Geography, Geo. Chisholm, London and New York. Traite pratique de la Fabrication des Cuirs, etc., A. M. Villon, Paris. 1890. Lehrbuch der technischen Chemie, H. Ost, Berlin. Die Lohgerberei, F. Wiener, 2te Auf., Leipzig, 1891. Leather Manufacture, J. W. Stevens, London. Praktisches Lehrbuch der Lohgerberei, S, Kas, Weimar. 1892. Industrie des Cuirs et des Peaux, T. Jean, Paris. The Tannins, vol. i., Henry Trimble, Philadelphia. 1893. Die Herstellung der Lohgaren Leder, L. Hoffmann, Weimar. 1894. Cuirs et Peaux, Voinesson de Lavelines, Paris. The Tannins, vol. ii., Heniy Trimble, Philadelphia. 1896. Anleitung zur Mikrochemischen Analyse, 2te Heft (Die wichtigsten Faser- stoffe), H. Behrens, Leipzig. BIBLIOGRAPHY AND STATISTICS. 383 1897. The Art of Leather Manufacture, Alexander Watt, 4th ed., London. The Manufacture of Leather, C. T. Davis, 2d ed., Philadelphia. 1898. Leather Industries Laboratory Book, H. R. Procter, London. 1900. Leather- Worker's Manual, H. C. Standage, London. 1901. Die Feinleder fabrikation, etc., Joseph Borgman, Berlin. 1903. The Principles of Leather Manufacture, H. R. Procter, New York. Die Chromgerburg, S. Hegel, J. Springer, Berlin. 1906. Leather Manufacturer, A Practical Hand-book, A. Watt, London. 1908. Leather Industries Laboratory Book, H. R. Procter, 2d ed., New York. Leather Trades Chemistry, S. R. Trotman, London. Practical Tanning, L. A. Fleming, H. Carey Baird & Co., Philadelphia. 1909. Tanners' and Chemists' Hand-book, L. E. Levi and E. V. Manuel, Milwaukee. Leder fabrikation, H. Kronlein, M. Janecke, Hanover. Die Pflanzlichen Gerbstoffe, H. Franke, Magdeburg. 1910. Praxis und Theorie der Leder-Erzeugung, J. Jettmar, J. Springer, Berlin. ON GLUE AND GELATINE. 1878. Die Fabrikation chemischer Producte aus thierischen Abfallen, H. Fleck, Braunschweig. 1884. Die Verwerthung der Knochen auf chem. Wege, W. Friedberg, Vienna. Glue and Gelatine, Davidowsky, translated by H. Brannt, Philadelphia. 1893. Cements, Pastes, Glues, and Gums, H. C. Standage, London. 1900. Glue and Glue-testing, S. Rideal, London. 1901. Glues and Gelatines, R. L. Fernbach, Van Nostrand Co., New York. Bone Products and Manures, Thomas, Lambert, London. 1907. Die Fabrikation von Leim und Gelatine, Dr. L. Thiele, Hannover. 1911. Die Kitte und Klebstoffe, W. Jeep, 5te Auf., Leipzig. STATISTICS. 1. IMPORTATIONS OF TANNING MATERIALS INTO THE UNITED STATES. 1908. 1909. 1910. Gambler or terra Japonica (pounds) 26,681,791 30,992,245 25,572,655 Valued at $894,752 $1,313,997 $1,255,296 Quebracho extract (pounds) 98,186,787 102,004,981 95,183,073 Valued at $2,260,304 $2,740,530 $3,021,902 Quebracho-wood (tons) 48,871 66,113 80,210 Valued at $612,971 $731,795 $1,058,647 Sumac (pounds) 8,576,091 10,974,613 13,632,861 Valued at $227,611 $293,299 $299,170 2. IMPORTATION OF SKINS AND HIDES INTO THE UNITED STATES. 1908. 1909. 1910. Goat-skins (pounds) 63,640,758 104,048,244 115,844,758 Valued at $17,325,126 $26,023,914 $30,837,590 Sheep-skins (pounds) 48,906,326 67,406,131 Valued at $8,276,637 $11,289,158 Calf-skins (pounds) 75,503,451 Valued at $17,922,051 Cattle-hides (pounds) 98,353,249 192,252,083 285,468,821 Valued at $12,044,435 $23,795,602 $42,306,943 Horse-skins (pounds) 19,512,397 Valued at $3,080,484 All others (pounds) 120,770,918 99,347,672 12,258,753 Valued at $25,400,575 $20,319,171 $2,418,414 Total (pounds) 282,764,925 444,554,325 608,619,028 Valued at $54,770,136 $78,487,324 $112,247,836 384 ANIMAL TISSUES AND THEIR PRODUCTS. 3. LEATHER INDUSTRY ACCORDING TO CENSUS OF 1905. Raw materials used Number. Value. Hides and skins of all kinds 17,581,613 $89,126,593 Tanning materials Hemlock bark (cords) 1,000,328 8,471,292 Oak bark (cords) 422,269 3,765,559 Gambier (bales) 80,610 752,347 Hemlock extract (barrels) 21,766 265,665 Oak-bark extract (barrels) 214,391 2,300,395 Quebracho 2,490,487 Sumac (tons) 7,958 "338,614 Chemicals 2,847,441 All other materials used in tanning 3,798,244 Oil, degras, tallow, etc., used in currying 3,807,186 Aggregate value of products 252,620,986 4. UNITED STATES EXPORTS OF LEATHER. 1908. 1909. 1910. Sole-leather (pounds) 31,189,897 33,002,746 38,332,247 Value $6,593,950 $6,887,298 $8,307,880 Upper leather Kid, glazed value 2,879,969 3,593,909 10,926,255 Patent or enamelled value 131,154 168,825 367,601 Splits, buff, grain, and other upper leathers value 15,342,497 17,623,525 15,620,336 All other leather 2,004,022 2,159,542 2,192,103 5. PRODUCTION OF GLUE AND GELATINE IN DIFFERENT COUNTRIES. United States (Census of 1905), 50,000 tons, valued at $10,034,685. Germany ( 1901 )' 32,000 tons, including 2000 tons of fine gelatine. England (1907), 30,850 tons, valued at $2,530,000. 6. EXPORTS OF GLUE AND GELATINE FROM THE UNITED STATES. 1908. 1909. 1910. Glue (pounds) 2,917,173 2,340,426 2,488,205 Valued at $289,441 $244,751 $261,756 7. IMPORTS OF GLUE AND GELATINE INTO THE UNITED STATES. 1908. 1909. 1910. Glue and gelatine (pounds) 6,731,943 6,610.894 8,821,554 Valued at $629,032 $655,127 $861.888 DESTRUCTIVE DISTILLATION OF WOOD. 385 CHAPTER XI. INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. DESTRUCTIVE distillation has been defined as "the decomposition of a substance in a close vessel in such a manner as to obtain liquid pro- ducts. ' ' It must be observed here that the word product is used to indi- cate something not originally present in the substance distilled. A body may be obtained in the liquid distillate which has merely been driven over by heat and which already existed in the original material in phys- ical or mechanical admixture. Such a body is, to speak exactly, an educt and not a product. The substances which are submitted to destructive distillation are in the main solids, as most classes of liquids are capable when heated with care of volatilization without decomposition, although such liquids as fatty oils, glycerine, etc., are decomposed if distilled under normal atmospheric pressure. (The cracking of petroleum is another illustra- tion of destructive distillation of a liquid purposely brought about.) With solids, on the other hand, it is the exception rather than the rule to find one capable of melting and vaporizing unchanged in composition when distilled under normal atmospheric pressure. The same solid, moreover, if of at all complex molecular composition, may decompose quite differently and yield different sets of products according to the conditions which govern the distillation. The most important of these modifying conditions is that of temperature. "Low temperature " dis- tillation and "high temperature" distillation as practised upon the same material (.wood or coal, for example) may yield quite different results. The physical condition or mechanical subdivision of the sub- stance also has an influence, although a subordinate one, upon the nature of the products. Solids, upon the destructive distillation of which important industries are founded, are wood, coal, shales, bones, and animal refuse. The distillation of shale has already been considered in connection with the mineral oil industry. (See p. 28.) The other in- dustries will now be noted in succession. A. DESTRUCTIVE DISTILLATION OF WOOD. I. Raw Materials. 1. COMPOSITION OF WOOD. The wood which is to be destructively distilled is composed, we may say in general terms, of woody fibre and plant-juice or sap, which is an aqueous solution of the substances, both nitrogenous and non-nitrogenous, which serve as the food for the living plant. The woody fibre is made up primarily of cellulose, which is in part changed into "lignin," as the incrusting substance is called. In percentage composition this latter substance differs from the pure cellu- 25 386 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. lose in containing more carbon and less oxygen and hydrogen. The amount of incrusting material varies, being more abundant in hard and heavy varieties than in light and soft kinds, and wood which contains it in the largest proportion gives the most acid and naphtha on distilla- tion. The amount of water present in wood also varies not only accord- ing to the season of the year, but also quite widely in different woods cut at the same season. Thus, the following table of Schiibler and Hartig shows the percentage of water of different trees taken at the period of minimum amount: Per cent, of water. Beech 18.6 Willow 26.0 Maple 27.0 Elder 28.3 Ash 28.7 Birch 30.8 White hawthorn 32.3 Oak 34.7 White fir . .37.1 Per cent, of water. Horsechestnut 38.2 Pine 39.7 Alder 41.6 Elm 44.5 Lime 47.1 Lombardy poplar 48.2 La.rch 48.6 White poplar 50.6 Black poplar 51.8 2. EFFECT OF HEAT UPON WOOD. The effect of heat upon wood in the absence of air is a matter which is to be carefully noted as throwing light upon the results obtained in destructive distillation. It of course differs radically from the result of heating with free contact of air. Violette * found that when wood was carefully and slowly heated no de- composition occurred under 150 C., water only being given off; between 150 and 160 C. the loss was two per cent, of weight of the water-free wood; between 160 and 170 C., 5.5 per cent.; between 170 and 180 C., 11.4 per cent., and so on until at 280 C. 63.8 per cent, of volatile products had been driven off and 36.2 per cent, only of the water-free wood remained in the retort. The products given off in this period of heating between 150 and 280 are the valuable liquid products known as pyroligneous acid (acetic acid and its homologues), wood-naphtha or methyl alcohol, methyl acetate, acetone, furfurol, the mixture of phenols known collectively as "wood-creosote," and all other bodies of empyreu- matic and tarry odor. Above 280 C., the decomposition proceeds some- what differently, hydrocarbons, both gaseous and liquid, being formed. The additional percentage of loss by weight between 280 and 350 C. is only 6.5 per cent, of the water-free wood, but it makes from eighty to ninety volumes of gas. The decomposition continues from 350 to 430 C., when the total loss by weight amounts to eighty-one per cent, of the water-free wood. The products obtained within these limits of temperature are largely solid hydrocarbons like paraffin and high tem- perature products like benzene and toluene, naphthalene, phenol and cresol. From 430 to 1500 C. the additional loss of weight is only 1.7 per cent. We may sum up these results by saying that three periods may be distinguished broadly for this decomposition of wood by heat: first, from 150 to 280 C., the period of watery acid products; second, *Dingler's Polytech. Journal, 123, 117. DESTRUCTIVE DISTILLATION OF WOOD. 387 from 280 to 350 C., the period of gaseous products; and, third from 350 to 430 C., the period of liquid and solid hydrocarbons. Violette found also great difference in the results according as the temperature was slowly raised or as the wood was rapidly brought up to a higher heat. Thus, one hundred parts by weight of wood slowly heated so that the temperature of 432 C. was only reached after six hours left 18.87 parts of charcoal, while one hundred parts of the same wood put into a retort previously heated to 432 C. left only 8.96 parts by weight of charcoal. n. Processes of Manufacture. 1. DISTILLATION OF THE WOOD. The primitive method of distilling wood devised by the charcoal-burners, in which the wood was piled up in large heaps covered in by clay and turf so as to form a circular dome- shaped mound, is still followed in some heavily- wooded districts. Of course the charcoal is the only product sought in this case, and the gase- ous and liquid products of the distillation are allowed to escape. In Russia and Sweden the charcoal-burning in mounds is now frequently combined with the collection of tar, which as it condenses is made to flow through inclined troughs, and is drawn off from below. In this way the valuable birch-bark tar (see p. 371) and kienoel (Russian tur- pentine oil) are obtained. For a proper collection of all the products of the destructive distillation of wood, however, it is essential that the distillation be carried out in retorts provided with proper condensation apparatus. These retorts may be either set in horizontal or vertical position, and may be either fixed or capable of removal for emptying and recharging. It is found convenient in large works where it is desirable to carry on the distillation continuously to have a series of retorts connected with one and the same condensation apparatus and heated by the same flues. This arrangement allows of the removal and re-charging of a single retort without interrupting the working of the others. In recent years the American and Canadian wood distilling plants have been built with large horizontal retorts of such size that material in wagons of light skeleton construction can be run in on a track prepared for them and the wood distilled without having to handle it until completely changed to charcoal. Several such wagons, each con- taining one cord of wood cut to suitable length, are run in one back of the other, and the doors of the horizontal retort closed and locked tight, when the heating is begun. When the distillation is finished these cars containing the glowing charcoal are pushed from the farther end of the retort into large cooling chambers of boiler iron, where they remain until cooled sufficiently to allow of their being brought into the air without ignition. The heating should be conducted slowly at first so that the maximum yield of the low temperature products, acetic acid and methyl alcohol, may be obtained, then increased until the gas comes off freely, and at the end of this stage of the decomposition again strengthened to drive over the high temperature products characteristic of the last period of distillation. As the maximum temperature needed 388 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. is beyond the record of the mercury thermometer, a pyrometer can be used or a small bar of metallic antimony which melts at 432 C. taken as indicator. Superheated steam has also been used as a means of accurately controlling the application of heat in the distillation, and it is said that the majority of European works manufacturing charcoal for gunpowder purposes use this method of distillation. The liquid which runs off. from the condenser is at first wax-yellow in color, but becomes dark-colored, reddish-brown, and eventually nearly black and quite turbid. When allowed to stand at rest it soon separates in two sharply distinct layers, the lower one of a thick tar, dark or perfectly black in color, and the upper one, which is much the larger in amount, is the crude pyroligneous acid and is reddish-yellow or reddish-brown in color. A light film of oil often covers, in part at least, this watery layer and represents the benzene hydrocarbons produced. We have already noted the fact that the yield of liquid products is affected greatly by the temperature used for distillation. Different, varieties of wood also vary somewhat in the results obtained, even when distilled under the same conditions of temperature. This is illustrated in the following few examples : * Charcoal. Tar. Crude pyro- ligneous acid. Containing actual acid. Gases. T> ^ v i, f slowly heated . Kedbeech { rapidly heated . . . D- v. f slowly heated . 26.7 21.9 29.2 21.5 34.7 27.7 30.3 24.2 5.9 4.9 5.5 3.2 3.7 3.2 4.4 9.8 45.8 39.5 45.6 39.7 44.5 42.0 41.0 42.0 5.2 3.9 5.6 4.4 4.1 3.4 2.7 2.4 21.7 33.8 19.7 35.6 17.2 27.0 24.4 24.1 Birch \rapidly heated ^ i f slowly heated . ' \ rapidly heated -p. ( slowly heated ' \ rapidly heated Beech-wood and foliage trees in general yield distinctly more acid than coniferous trees, but the latter yield more tar of terebinthinate char- acter. The figures given above, it must be remembered, however, were gotten in experiments with small portions. In practice, working with larger quantities, the yield of several of the products is notably larger. The yield of wood-spirit, or methyl alcohol, varies from five-tenths to one per cent, of the weight of the dry wood. The emptying of the retorts, if done as intended while the charcoal is yet glowing, involves the use of air-tight pits into which the charcoal can be emptied from the retorts and immediately covered with moist charcoal-powder to prevent loss by combustion. A form of apparatus for distilling the sawdust so abundantly produced in wood-working processes has been devised by Halliday, of Salford, England, and is said to work satisfactorily in practice. It is shown in Fig. 98. It con- sists of a horizontally placed cylindrical retort, A, within which revolves an endless screw, B. The sawdust is regularly fed in through the vertical pipe C, and falling upon the screw is kept moving at a uniform * Ost, Lehrbuch der technische Chemie, p. 294. DESTRUCTIVE DISTILLATION OF WOOD. 389 speed along the entire length of the heated retort. At the farther end the vapors and gaseous products of the distillation escape through an ascending pipe, K, leading to the condenser, while the powdered charcoal drops through the pipe D into water, where it is at once quenched. A general view of the products of the distillation of wood and their subsequent treatment is given in the accompanying diagram taken from Post.* 2. TREATMENT AND PURIFICATION OF THE CRUDE WOOD-VINEGAR. The brown aqueous solution poured off from the tarry layer (see above) has a strong empyreumatic odor, and contains, besides the acetic acid, FIG. 98 methyl alcohol, acetone, and homologous ketones, allyl alcohol, homo- logues of acetic acid (such as formic, propionic, butyric, and valerianic acids), methyl acetate, acetate of ammonia and of methylamine, alde- hyde, furfurol, phenols, and other empyreumatic and tarry bodies. It is not used in its crude condition except in the preparation of the crude pyrolignite of iron (iron-liquor} or in limited amount for impregnating wood. The first step towards purification is to separate the wood- naphtha (the fraction containing the methyl alcohol, acetone, and methyl acetate) from the wood-vinegar (crude acetic acid), which is done by distillation. Two procedures are possible here. Either to neutralize the crude pyroligneous acid with milk of lime and then distil off the volatile constituents only, using an iron still, or to distil the crude pyro- *Post, Chem. Technologie, p. 78. 390 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. S o j 3 S g& wo "1 3 A 2 w 2 a, ) ta4 L .2.5o 23 |S S ^ /\y p'S - W W S a> M H > ^^ t*> g^ S . H "5g I, Q i| ^g ll 5 ^ o B3 I O I -s - 2 ]S82 G jjj! 1 M "Sx; o o w ^ 2 ^5^ > 1 W ^ O H a .- - | I * S on S fi ss H w 1 a" P g 1 Q i S . t*. t B5 S H <- " S "S TTO B W H ^ n o O cc s =! 3 5 ^ < 5 S P -a ^ 3 a *. gS > OS DESTRUCTIVE DISTILLATION OF WOOD. 391 ligneous acid from a copper still without neutralizing with lime. In the former case, while the wood-naphtha distils off, the tarry impurities of the crude pyroligneous acid remain with the lime salt in the still, and on evaporation a dark mass is obtained known as "brown acetate of lime." In the latter case, after catching the wood-naphtha distillate, the receiver is changed and the crude acetic acid is also collected freed to a con- siderable extent from the tarry matter, so that on neutralizing with milk of lime and evaporating the product is a lighter salt known as "gray acetate of lime. ' ' The latter process is now more generally in use. The solution of the calcium acetate is evaporated in iron pans; the phenols and tarry products which volatilized with the acetic acid separate largely as scum and may be skimmed off, so that the residue of the evaporation is much purer than the product of the other method mentioned above. If the brown acetate of lime has been obtained and is to be further worked for acetic acid, it is found necessary to roast it at a temperature not exceeding 250 C. so as to drive off as much of the tarry impurity as possible without decomposing any of the acetate. If, on the other hand, the gray acetate is taken, it is distilled from copper retorts with concentrated aqueous hydrochloric acid, taking care to avoid an excess. The acetic acid distils over between 100 and 120 C., is clear in color and has only a slight empyreumatic odor. Its specific gravity usuall} 7 ranges from 1.058 to 1.061, and it contains about fifty per cent, of pure acetic acid. If some water is added with the hydrochloric acid so that the distilled acetic acid is more dilute, it tends to give a purer product, as the liberated acetic acid cannot decompose any of the calcium chloride before coming over. A good proportion is said to be one hundred parts of acetate of lime, ninety to ninety-five of hydrochloric acid of 1.160 specific gravity, and twenty-five parts of water. The acetic acid so obtained has a slight empyreumatic odor. It may be freed from this by distilling with from two to three per cent, of potassium bichromate, or by filtration through freshly ignited wood charcoal. The brown acetate of lime usually contains about sixty-eight to sixty-nine per cent, of pure acetate, while the gray acetate contains from eighty-five to eighty-six per cent, of true acetate. In recent years it has been found practicable to prepare pure acetic acid from the crude pyroligneous acid by making the sodium salt in- stead of the lime salt. The sodium salt allows of purifying by recrys- tallization, and can also be fused without decomposition. Glacial acetic acid is generally made by distilling the anhydrous and fused sodium acetate with concentrated sulphuric acid. Rohrmann has recently developed a process by which it is possible to make ninety per cent, or even glacial acetic acid direct from the crude acetate of lime in one operation. He uses a column still provided with Lunge-Rohrmann plates, over which concentrated sulphuric acid is made to trickle. This meets the ascending acetic vapors and dehydrates them. They pass over into a condenser, while the empyreumatic vapors are drawn off by a warm-air current which connects with the column. When hydrochloric acid is used to decompose the acetate the resulting acetic 392 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. acid can be brought to eighty per cent. ; when sulphuric acid is used, one hundred per cent, acid can be obtained. 3. PURIFICATION OF THE CRUDE WOOD-SPIRIT. The wood-spirit forms the first fraction when the crude pyroligneous acid is distilled, and amounts to perhaps one-sixth of the latter in bulk. It is usual to collect, however, until the hydrometer reading of the distillate, which begins at about .900, has risen to 1.000 or a little beyond. This distillate forms a greenish-yellow liquid of unpleasant odor and contains many impurities besides the acetone and methyl acetate, the chief substances which are present with the methyl alcohol. Milk of lime is first added and allowed to stand with the liquid for several hours. The mixture heats up quite distinctly as the lime combines with any free acid and begins to decom- pose the methyl acetate and other ethereal compounds of acetic acid, small quantities of ammonia often being given off. It is then distilled by connecting it with a column rectifying apparatus. (See p. 244.) The distillate thus obtained, of about .816 specific gravity, is colorless at first but gradually darkens in color, and if diluted with water becomes milky from separated oily hydrocarbons and ketones. It is therefore diluted down with water to about .935 specific gravity and allowed to stand until this oily impurity rises to the top in a distinct layer. The diluted spirit is again distilled over lime once or twice with a rectifying column and so brought to ninety-eight or ninety-nine per cent, strength. The acetone impurity, however, is not removed by any of these rectifica- tions, as the boiling-points of acetone (56.4 C.) and methyl alcohol (55.1 C.) do not allow of their separation in this way. To remove the acetone a number of methods have been proposed. The methyl alcohol may be converted into the solid chloride of calcium compound, or the oxalate of methyl and the acetone having been removed by careful heat- ing, the methyl compound is decomposed by water or alkali. Or the methyl alcohol is distilled over chloride of lime, which reacts with the acetone to form chloroform. The passing in of chlorine in order to con- vert the acetone into high-boiling chloracetones, which are then separated from the methyl alcohol by distillation, has also been proposed. 4. TREATMENT OF THE WOOD-TAR. The tar w r hich has separated from the crude pyroligneous acid by settling, and that which has risen and been skimmed off in the neutralizing of the acid, are united and sub- mitted to distillation in horizontally-placed iron retorts, which are set at a slight inclination. At first acid-water comes over, then light oils, and finally heavy oils until no more will distil. The pitchy residue is run out while hot, so that it does not adhere to the walls of the retort. The relative amounts of the several fractions from the tar depend upon the nature of the wood used in the original distillation and upon the way that distillation has been carried out. Hard woods usually give a tar which, according to Vincent, when redistilled yields as follows: Aqueous distillate (wood-spirit and pyroligneous acid) . .10 to 20 per cent. Lighter oily distillate (specific gravity .966 to .977... 10 to 15 " " Heavy oily distillate (specific gravity 1.014 to 1.021) ... 15 " ," Pitch ..50 to 65 " " DESTRUCTIVE DISTILLATION OF WOOD. 393 The oily distillates are washed with weak soda to remove adhering acid and hen carefully rectified, when the oils coming over under 150 C. are collected for solvent and varnish-making purposes, those between 150 and 250 C. collected as creosote oils, and those above 250 C. used for burnings oils. The creosote oil, which is the most valuable part, is thoroughly agi- tated with strong caustic soda solution, the aqueous layer drawn off, mixed with sulphuric acid, and allowed to stand for a time at rest, when the creosote oil separates out. This is best driven off by steam distilla- tion and again rectified finally from glass retorts. Stockholm tar, so largely used in ship-building, is the product of a rude distillation of the resinous wood of the pine. North Carolina pine-tar is also the product of a distillation of the pine. The billets of pine- wood are piled in heaps like a charcoal-burner's mound, though not so large, covered in with clay and turf, and lighted from the top. The resin or tar distils downward and runs off through inclined troughs previously fixed for it. It is obvious that the compo- sition of both the Stockholm and the North Carolina tar differs notably from that of wood-tar distilled in retorts from hard woods. This com- position will be referred to later. m. Products. 1. PYROLIGNEOUS ACID AND PRODUCTS THEREFROM. The crude acid as obtained in the distillation is a clear liquid of reddish-brown color and strong acid taste, with a peculiar penetrating odor described as empyreumatic, and now known to be due largely to the furfurol it con- tains. It possesses a specific gravity of from 1.018 to 1.030 and contains from four to seven per cent, of real acetic acid. Pyrolignite of iron (iron or black liquor) is a solution of ferrous acetate with some ferric acetate, prepared by acting upon scrap-iron with crude pyroligneous acid. It forms a deep-black liquid, and is concentrated by boiling to 1.120 specific gravity, when it contains about ten per cent, of iron. It is extensively used by calico-printers. Brown and gray acetate of lime have been already referred to. Other technically important acetates are lead ace- tate (sugar of lead), used in the preparation of the alum mordants and the lead pigments; copper acetate, the basic salt of which is known as "verdigris;" aluminum acetate, the solution of which is used in calico- printing under the name of ' ' red liquor. ' ' Pure acetic acid is a colorless acid liquid with pungent smell and taste. It crystallizes when chilled in large transparent tablets, melting at 16.7 C., whence the name "glacial acetic acid." Its specific gravity at 15 C. is 1.0553, and it boils under normal pressure at 119 C. 2. METHYL ALCOHOL AND WOOD-SPIRIT. As before stated, crude wood- spirit is a complex liquid and contains many impurities. The percent- age of real methyl alcohol may rise to ninety-five per cent., but more generally ranges from seventy-five to ninety per cent. Some impure wood-naphthas go much lower, however, than this. A large percentage of acetone does not interfere with its use as a solvent for resins and for 394 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. varnish-making, but does interfere with its use in the aniline-color in- dustry, where a very pure methyl alcohol is needed for the manufacture of dimethyl aniline. The methods of freeing methyl alcohol from the two chief impurities, methyl acetate and acetone, have already been referred to. Pure methyl alcohol has a purely spiritous odor, a specific gravity of .7995 at 15 C., and boils at 55.1 C. It is miscible in all proportions with water, ordinary alcohol, and ether. 3. ACETONE. This substance is of interest as always produced in the distillation of wood, and hence present in the crude wood-spirit. The acetates yield it as the chief product when submitted to dry distillation, and the vapors of acetic acid distilled over porous baryta at a tempera- ture of from 350 C. to 400 C., it has been found by Dr. Squibb, will also readily yield acetone. One hundred kilos, of forty per cent, acid will give from twelve to thirteen kilos, of acetone. At present it is made on a large scale by distilling the gray acetate of lime in iron stills pro- vided with mechanical agitation at a temperature of about 290 C. When purified, it is a colorless liquid of peculiar ethereal odor and burn- ing taste, and, like methyl alcohol, is miscible in all proportions with ether, alcohol, and water. It is an excellent solvent for resins, gums, camphors, fats, and pyroxyline, or gun-cotton. It does not form a com- pound with dry calcium chloride and can thus be separated from methyl alcohol when in admixture with this latter. Chlorine and iodine in the presence of an alkali react with acetone to form chloroform and iodoform. 4. CREOSOTE. Wood-tar creosote is a strongly refracting liquid, which is colorless when freshly distilled but gradually acquires a yellow or brown color. It has a smoky aromatic odor, which is very persistent and is quite distinct from that of carbolic acid. It has a specific gravity ranging from 1.030 to 1.080, and boils between 205 and 220 C. It is a powerful antiseptic, and is largely used to preserve meats, etc. It differs from coal-tar creosote in containing relatively little common phenol (carbolic acid) and relatively large amounts of higher phenols, such as phlorol, C 8 H 9 .OH, guaiacol, C 7 H 7 O.OH, and creosol, C 8 H 9 O.OII. 5. PARAFFIN. This mixture of solid hydrocarbons, as already said, occurs in the higher boiling distillate gotten from wood. It is of interest to recall that paraffin was first discovered by Reichenbach in beech-wood tar. At present, however, the extraction of paraffin from wood-tar is not to be thought of because of the cheapness of its production from petroleum and bituminous shales. It has been already described under the chapter on Petroleum. (See p. 33.) 6. CHARCOAL. We have already shown in the table of results of slow and rapid distillation of wood (see p. 388) that the relative amount of charcoal depends upon the manner of heating, being larger with gradual application of heat and smaller with rapicj. heating. The proper- ties and chemical composition of the charcoal are similarly dependent upon the temperature to which the wood is heated. Wood is stated to become brown at 220 C., at 280 C. it becomes a deep brownish.-bla.ck and begins to be friable, and at 310 C. forms an easily friable black mass taking fire easily. That prepared at higher temperatures is harder and less readily ignited, and it eventually becomes graphitic and rings DESTRUCTIVE DISTILLATION OF WOOD. 395 with a metallic sound when struck. The accompanying table from Vio- lette shows the gradual change in the composition of charcoal prepared at different temperatures from the same kind of wood (buckthorn) : Heated to Carbon, per cent. Hydrogen, per cent. Oxygen, nitro- gen, and loss. Ash, per cent. Dry wood 150 C. 47.51 6.12 46.29 0.08 Charred wood 260 C. 67 85 5.04 26.49 0.56 lied charcoal 280 C. 72.64 4.70 22.10 0.57 Brown charcoal .... 320 C. 73.57 4.83 21.09 0.52 Dull black charcoal . . . 340 C. 75.20 4.41 19.96 0.48 Lustrous black charcoal . 432 C. 81.64 1.96 15.25 1.16 Extreme white heat . . 1500 C. 96.52 0.62 0.94 1.95 IV. Analytical Tests and Methods. 1. ASSAY OF PYROLIGNEOUS ACID AND CRUDE ACETATES. The crude pyroligneous acid, as before stated, contains from four to seven per cent, of real acetic acid. Its strength may be ascertained by titration with standard alkali, using phenol-phthalein as an indicator. If the liquid is too dark to allow of the end reaction being readily seen, it can be diluted sufficiently, as the reaction will still be sufficiently delicate. In the absence of sulphates in the sample, the acetic acid can be determined by adding excess of pure precipitated barium carbonate to the solution, filtering, and determining the barium in the nitrate by the aid of sul- phuric acid. As the pyroligneous acid is largely converted into calcium acetate in th.e process of purifying, the analysis of the brown or gray acetate of lime as a common cemmercial product becomes of some importance. This commercial acetate may contain from sixty-five to eighty per cent, of true acetate of lime, with carbonate of lime, so-called "tar-lime," and empyreumatic matter as chief impurities. The acetic acid determination may be made by different methods, but the most accurate according to the experience of the author is the distillation method, as suggested by Stillwell and Gladding. One gramme of the sample of acetate of lime is placed in a small distillation bulb or flask with a long neck, a little distilled water added, and then a solution of five grammes of glacial phosphoric acid dissolved in ten cubic centimetres of water. The flask is then heated to distil off the acetic acid, care being taken to avoid spurting and mechanical carrying over of any of the phosphoric acid. When the contents have nearly gone to dryness, some twenty-five cubic centimetres of distilled water are introduced and the distillation re- peated. If this is done some three or four times, the distillate will be found to be free from -acid reaction. The combined distillate is then brought to definite volume and titrated with decinormal soda solution, using phenol-phthalein as indicator. 2. DETERMINATION OF METHYL ALCOHOL IN COMMERCIAL WOOD- SPIRIT. But one method, and that not capable of the most accurate working, is at present available. Five cubic centimetres of the sample 396 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. of wood-spirit are allowed to drop slowly upon fifteen grammes of phos- phorus di-iodide placed in a small flask of some thirty cubic centimetres capacity. This is connected with an inverted condenser and cooled exter- nally while the reaction takes place. Five cubic centimetres of a solu- tion of one part iodine in one part of hydrogen iodide of 1.7 specific gravity is then added and the mixture gently digested for a quarter of an hour, when the condenser having been turned downward the iodide of methyl formed is distilled off. It is collected in a graduated tube divided into one-tenth cubic centimetres, washed with some fifteen cubic centimetres of water with vigorous agitation, allowed to settle, and the volume read off. Five cubic centimetres of pure and perfectly dry methyl alcohol should give 7.45 cubic centimetres of iodide of methyl. 3. DETERMINATION OF THE ACETONE IN COMMERCIAL WOOD-SPIRIT. This may be done by either the Kraemer and Grodzki gravimetric method or the Messinger volumetric method, both of which depend upon its quantitative conversion in the presence of iodine and caustic alkali into iodoform. In the former case, one cubic centimetre of the sample of wood-spirit is mixed with ten cubic centimetres of a double normal solution of caustic soda (eighty grammes to the litre), and to the mixture, after thorough agitation, is added five cubic centimetres of a solution containing two hundred and fifty-four grammes of iodine and three hundred and thirty-two grammes of potassium iodide to the litre. The iodoform which separates on agitation is dissolved by the addition of ten cubic centimetres of ether free from alcohol. An aliquot portion of the ethereal layer is then pipetted off into a tared watch-crystal, and the iodo- form remaining after evaporation is weighed. Three hundred and ninety-four parts of iodoform correspond to fifty-eight parts of acetone. More accurate is the Messinger volumetric process. In this, twenty cubic centimetres (or thirty cubic centimetres in samples rich in acetone) of normal potash solution and one or two cubic centimetres of the wood- spirit in question are shaken together in a stoppered 250-cubic-centi- metre flask and a known quantity (twenty or thirty cubic centimetres) of a one-fifth normal iodine solution added. The mixture is shaken until the supernatant liquid clears perfectly on momentary standing, hydrochloric acid of 1.025 specific gravity is added in amount equal to the potash solution before used, and excess of decinormal sodium tliio- sulphate run in. Starch paste is then added, and the excess of sodium thiosulphate titrated with one-fifth normal iodine solution. If r be the volume in cubic centimetres of the iodine solution required to combine with the acetone, and n the volume in cubic centimetres of the methyl alcohol taken, then the quantity of acetone by weight in one hundred , . r X .193345 cubic centimetres of the sample is equal to n 4. QUALITATIVE TESTS FOR WOOD-TAR CREOSOTE. The U. S. Pharma- copoeia gives the following tests as enabling one to distinguish between wood-tar creosote and coal-tar creosote : 1. On stirring together equal volumes of wood-tar creosote and collo- dion in a dry test-tube no permanent coagulation should form. DESTRUCTIVE DISTILLATION OF COAL. 397 2. If one volume of creosote be mixed with one volume of ninety-five per cent, glycerine, a clear mixture will result from which a creosotic layer equal to or greater in volume than the creosote employed will separate on the addition of one-fourth volume of water. 3. On adding to ten cubic centimetres of a saturated aqueous solu- tion of creosote one drop of ferric chloride test solution, the liquid develops a clear violet-blue color, which is very transient ; it then clouds almost instantly, the color passing rapidly from a grayish-green into a muddy-brown, with finally the formation of a brown precipitate. 4. If one cubic centimetre of creosote be cautiously and gently shaken with two cubic centimetres of petroleum benzine and two cubic centi- metres of freshly-prepared barium hydroxide solution -until a uniform mixture is produced, upon complete separation three distinct layers are visible, the middle one of which contains the creosote, unaltered in ap- pearance ; while the petroleum benzine should not be blue or muddy and the aqueous layer should not have acquired a red tint (absence of coeru- lignol and other high-boiling constituents of wood-tar). B. DESTRUCTIVE DISTILLATION OF COAL. I. Raw Materials. Probably the most important industry involving the destructive dis- tillation of coal is the manufacture of illuminating gas. The classes of coals employed for the purpose are confined to those varieties which are bituminous in their nature, yielding when distilled volatile hydro- carbons in varying quantity. The uncombined or "fixed carbon," with the mineral constituents originally present in the coal, remaining, after the distillation comprise coke. Bituminous Coals have the property, not possessed by the anthra- cites, of softening and apparently fusing when subjected to a tempera- ture below that at which combustion would take place. This fusion indicates the commencement of destructive distillation, when both solid, liquid, and gaseous carbon compounds are formed. Bituminous coal is essentially a coking coal, and as such is, to a very great extent, employed in the coking regions of Western Pennsylvania. It is black or grayish- black in color, of a resinous lustre, and somewhat friable, being easily broken into cubical fragments of more or less regularity; upon ignition it burns with a yellow flame. When it is heated to bright redness in retorts or ovens, free from the access of air, the volatile matter, before mentioned, carbon compounds of hydrogen and of oxygen, with water, pass off. Coals having a large percentage of hydrogen will yield more volatile substances at the temperature of distillation and less carbona- ceous residue than others which may contain less hydrogen and more carbon, approaching anthracite in composition. Coking and Non-coking Coals are quite similar in chemical composi- tion ; the coking varieties contain less volatile matter, however, than the non-coking; the latter do not possess the property of fusing to a com- pact "coky" mass, but retain their original form, and yield a coke which 398 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. has no commercial value unless it is obtained from large pieces of the coal. Cannel Coal is much more compact than gas or coking coals, duller in appearance, possessing a grayish-black to brown color, and burning with a clean candle-like flame. It does not soil the hands, and is not readily fractured. It is capable of taking a high polish, and can be cut or turned into articles for use or ornamentation. Cannel coal occurs in large quantities in West Virginia, and near Glasgow, Scotland, in Lan- cashire, England, and at other localities. Destructively distilled, it- yields a larger amount of volatile matter and ash, with much less coke, than the bituminous coals. Brown Coal, or Lignite, appears to occupy an intermediate position between the bituminous coals and wood. It retains the ligneous struc- ture of the material from which it is formed, hence the name Lignite. The vegetable remains in a great many cases are quite distinct. The color varies from yellowish-brown in the earthy, to black in the more compact, coal-like varieties. The percentage of carbon contained is low, fifty to eighty per cent., though rarely exceeding seventy per cent., while the hydrogen is from 4 to 6.85 per cent. Oxygen and nitrogen are present in variable quantities from 7.59 to 36.1 per cent. The ash in good qualities is low, in earthy specimens is high, in many cases exceed- ing fifty per cent. Lignite does not yield coke. Aside from being utilized as fuel in the several localities where it is found, for both domestic and industrial purposes, it has been distilled for volatile con- stituents in Saxony. Peat, or Turf, occurring in large areas in Ireland and in some parts of Europe, consists of the decayed remains of certain forms of plants. It has been, according to Mills, destructively distilled for tarry prod- ucts, the industry, however, being no longer profitable. The following tables, taken from the Reports of the Second Geological Survey of Pennsylvania, show the analyses of some of the more im- portant varieties of American gas coals, coking coals, and non-coking, or block coals. I. Gas Coals. WESTMORELAND COAL COMPANY. PENNSYLVANIA GAS COAL COMPANY. South Side Mine. Foster Mine. Larrimer, No. 2. Irwin, No. 1. Irwin, No. 2. Sewickley. Water at 225 . . Volatile matter . Fixed carbon. . Sulphur .... Ash 1.410 37.655 54.439 0.636 5.860 1.310 37.100 55.004 0.636 5.950 1.560 39.185 54.352 0.643 4.260 1.780 35.360 59.290 0.680 2.880 1.280 38.105 54.383 0.792 5.440 1.490 37.153 58.193 0.658 2.506 Total .... 100.000 100.000 100.000 100.000 100.000 100.000 Coke, per cent. . Fuel ratio . . . 60.935 1:1.47 McCreath. 61.590 1:1.48 McCreath. 59.255 1 : 1.38 McCreath. 62.860 1 : 1.67 McCreath. 60.615 1:1.42 McCreath. 61.357 1:1.56 McCreath. DESTRUCTIVE DISTILLATION OF COAL. //. Coking Coals. 399 Connells- ville, . Frick & Co. Bennington, Cambria Iron Company. Broad Top, Baniet. Broad Top, Kelley. Cumber- land. Huntingdon County, Alloway Colliery. Moisture .... Volatile matter . Fixed carbon . Sulphur .... Ash 1.260 30.107 59.616 0.784 8.233 1.400 27.225 61.843 2.602 6.930 16.00 74.65 1.85 7.50 19.68 71.12 1.70 750 1.10 15.30 73.28 1.23 908 0.250 14.510 77.042 1.338 6860 Total. . . . 100.000 100.000 100.00 100.00 100.00 100.000 Coke, per cent. . Fuel ratio . . . 68.63 1:1.98 McCreath. 71.375 1:2.27 McCreath. 81.00 T.T.Morrell. 71.00 T.T.Morrell. 83.59 1 : 4.78 McCreath. 85.24 1 : 5.30 McCreath. HI. Non-coking Coals (Block Coal). Mercer County, Pa., Sharon Coal. Youngstown, Ohio. Mercer County, Pa. Straitsville, Ohio. Brazil, Ind. Moisture .... Volatile matter . . Fixed carbon . . Sulphur ..... 3.79 35.30 63.875 0675 3.60 32.58 62.66 (0 85^ 3.80 25.49 68.03 1 04 36'. 50 55.60 0.96 40J5 57.20 0.75 Ash 6.36 \\J.O-J) 1 16 1.70 6.94 1.90 Total .... 100.000 100.00 100.06 100.00 100.00 Coke, per cent. . . 60.91 McCreath. Wormley. Jno. Fulton. 61.00 Wormley. 58.00 Prof. Cox. Effects of High or Low Temperature in the Distillation of Coal. Coal when distilled at a low temperature yields products of a very dif- ferent nature from those obtained if the temperature employed had been high. On this subject Professor Edmund T. Mills, of Glasgow, in his little manual on "Destructive Distillation" (3d ed., p. 9), states that "at a very high temperature the products from coal and shales are carbon and carbonized gases of low illuminating power, with but little liquid distillate ; at a low temperature there is much liquid product and gas of high illuminating power. The greatest amount of liquid product of low boiling-point is found in American and Russian petroleums, which have probably been produced by the long-continued application of a very gentle natural heat. "When coal is slowly heated (as must be to a great extent the case when it is broken fine, or when a large retort is used), its oxygen is chiefly converted into water; when rapidly heated, the oxygen is ex- pelled as carbonic oxides." To show the verification of these principles in practice, the results of high and low temperature distillation upon three different coals may be quoted from the same authority : 400 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. Yield of Gas, Oil, etc., from Shales and Coals at High and Low Heats. GOOD SHALES. BOGHEAD COAL. GAS COAL. High heats. Low heats. High heats. Low heats. High heats. Low heats. * 32 if > a Coke Coke or c Speci coal f Gas . . . . 13.65 3.65 11.04 0.99 2.82 2.54 6.47 17.65 37.32 2.43 20.65 0.18 0.80 4.83 3.23 50.29 20.49 3.09 17.08 0.29 4.15 6.49 7.24 26.45 Ammonia-water . . Tar or oil Sulphur . Water at 212 .... t Fixed carbon . . . \ Sulphur ...... 32.15 4.16 1.05 62.64 26.66 10.81 62?53 61.38 9.01 0.06 29.55 58.35 12.40 29.25 45.10 45.00 0.34 9.56 40.18 49.93 '9.89* I Ash (dry) per ton of shale oal 67.85 73.34 38.62 41.65 54.90 59.82 100.00 100.00 100.00 100.00 100.00 100.00 1,520 Ibs. l.i 1,642.2 Ibs. 18 865 Ibs. U 934 Ibs. .24 1,230 Ibs. 1.5 1,340 Ibs. 96 ic gravity of shale or NOTE. The low heat results were gotten by distilling the sample in a two-inch iron tube in a gas- furnace. Lunge (Coal-Tar and Ammonia, 2d ed., p. 17) states that "The quantity, and to a much greater extent the quality, of the tar are influ- enced by the temperature at which the decomposition of the case is carried on. Low temperatures, with nine thousand cubic feet of gas per ton of coal, will yield, with some coals, sixteen gallons of tar; whilst at high temperatures the yield will be but nine gallons, with about eleven thousand cubic feet of gas, from the same coal."* If the temperature be a comparatively low one, mostly such hydrocarbons are formed as belong to a paraffin (methane) series, having the general formula C n H., n + 2 , along with the olefins, C n H 2n . The lower members of this series are liquid, and, furnished in the pure state, are lighting and lubricating oils ; the higher ones are solid and form commercial paraffin. They are always accompanied by oxygenized derivatives of the benzene series (phenols) ; but of these the more complicated ones predominate, in some of which methyl occurs in the benzene nucleus, in others replacing the hydrogen of hydroxyl, e.g., cresol, C G H 4 (CH 3 ) (OH) ; guaiacol, C 6 H 4 (OH)(OCH 3 ); creosol, CH,(CH 8 )(OH)(OCH t ), et c- Liquid products prevail; and among the watery ones acetic acid (which is again a compound of the fatty series) is paramount. Of course also permanent gases are always given off, though in comparatively small quantity. If, on the other hand, the coal has been decomposed at a very high temperature, the molecules are grouped quite differently. Whilst the olefins and members of the acetylene series-, still occur more or less, the hydrocarbons of the paraffin series disappear almost entirely; and from them are formed on the one hand compounds much richer in carbon, on the other hand more hydrogenized bodies. The latter always occur in the gaseous state ; hence the gas so produced contains methane, or marsh- * Davis, Journ. Soc. Chem. Ind., 1886, p. 5. Showing the most important of the products derived from manufad The direct products which can be separated as they come over from the still, by filtra- tion or other simple processes, are marked thus, | Those substances which are prepared by further chemical treatment are marked COAL GAS'. GAS-UQOOR. c< Liquid Ammonia Sulphate of Ammonia. Chloride Of Ammonia. Carbon- ate of Ammonia. Oils lighter than water or Crude Naphtha. Oils heavier than v or tar, commc BENZOL. TOLUOL. Nitrb- Benzol. Mtro- ToluoL TbLUl- DINE. XYLOL. CUMOL. Nitro- Xylol. PYRIDINE. CARBOLIC ACID. CRESYLIC ACID. CARBOLIC ACID. CRESYLIC ACID. Picric Acid. Aurinc. Nitro- Cumol. For the manufacture of pure carbolic, cresylic, and other tar acids, further and elaborate treatment is required. XYLIDINE. CUMIDINE. RAM twcastle Coal when carbonized by the usual method for the of coke. The direct products of the dead oils are arranged as nearly as possible according to 'their respective volatilities/ and to the order in which they come over from the still otherwise dead oil ailed Creosote. PITCH, in WILS, aistiiiing irom oso" to 750 F ^ r | n NAPHTHX LENE. Quinoline Series, 6.17.. Cryp- tidine. Phenan- threne. Carbazol. A CENE RA " Acri ^ n e. Pyrene Cbrysene. ** Nitro- Naphtha- lene Phenan- threne Quinone. Anthra- Pyrene Chryso- quinone Qyinone. Quinone. Naphthyl- amine. Diphenic Acid. Anthra- qninone Sulphonic Acid NAPH- THOU HHTHALTC ACID. ALIZA RINE. PORPU- RINE. ; - < DESTRUCTIVE DISTILLATION OF COAL. 401 gas, CH 4 , and free hydrogen as principal constituents, and is very much increased in quantity. The carbon thus set free is partly deposited in the retorts themselves, and then occurs in a very compact graphitoidal form ; another portion of the free carbon occurs in a state of extremely fine division in the tar, and forms a constituent of the pitch or coke remaining behind from tar-distilling; another portion contributes to the formation of compounds richer in carbon, belonging to the "aromatic" series, all of which are derived from benzene, C 6 H 6 . At the same time the action of heat effects further molecular "condensations," usually with separation of hydrogen, by which process compounds of a higher molecular weight are formed, as naphthalene, anthracene, phenanthrene, chrysene, etc. The never absent oxygen must also in this case cause the formation of phenols; but here phenol proper, or carbolic acid C H 5 (OH), predominates, whilst cresol and the other homologues are diminished in quantity, and the dioxy-benzenes, as well as their methylated derivatives, disappear altogether. The above will be better illustrated by the state- ment (from Stohmann-Kerl's "Chemie," 3d ed., vi. p. 1162) that Zwickau glance coal yielded the following quite different products, ac- cording to whether it was put into a cold retort and gradually brought to a red heat (a), or distilled quickly from a very hot retort (&) : a. b. Coke 60.0 50.0 Water 10.7 7.7 Tar 12.0 10.0 Gas and loss 17.1 32.1 The tar from (a) consisted of photogen, paraffin oil, lubricating oil, paraffin, and creosote; that from (&), of benzene, toluene, naphthalene, anthracene (together with heavy oils corresponding to the paraffin and lubricating oil), and much creosote. The annexed diagram, constructed by S. B. Boulton, and published in the Society of Chem. Ind. Journal, 1885, p. 471, represents the whole process of the destructive distillation of coal, including the subsequent treatment of the main fractions, and exhibits in their proper order the various products obtained therefrom. n. Processes of Treatment. 1. GAS-RETORT DISTILLATION OF COAL. The distillation of coal as carried out in retorts differs from distillations of other substances mainly in the apparatus employed and in the nature of the substances to be recovered. For gas purposes, retorts, wherein the decomposition of the coal used takes place, are made use of, which were originally constructed of cast iron, about one inch in thickness, twelve to fifteen inches in width, and about seven feet in length, closed at the rear end, and pro- vided at the front or mouth with a heavy shoulder or rim supplied with studs to which is attached a cast-iron extension, technically termed the "neck," which carries on its upper side a flange to which are secured upright pipes serving to lead the gases generated away from the retort. 26 402 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. The front of the neck is provided with a screw clamp to retain the lid or cap of the retort in position. Iron retorts are destroyed with great rapidity; the destruction being caused by the heat of combustion of the fuel used, the sulphur in the gas coal (an impurity always present in more or less quantity), which acts, forming sulphide of iron, and the carbon, which, as a carbide of iron, graphitic in appearance, forms layers within the retort from one to two inches in thickness. The oxygen of the air also has a very deleterious influence, especially upon retorts when heated to redness. In later years fire-clay retorts have been substituted for those made of cast iron, for the reason that they are more durable. These retorts are made of a mixture of clay and sand, and are furnished to the gas-works in several shapes, the semi-cylindrical being the one most generally employed. The sizes vary, six to nine feet in length, fifteen to twenty inches in width, and from ten to fifteen inches in height being the aver- age, and take a charge of one hundred and fifty to two hundred pounds of coal. Retorts have been made up to nineteen feet in length, being charged from both ends. The retorts, varying in number from five to seven, or even nine and more, are mounted in brick furnaces of special construction, in such a manner that the gases of combustion of the coal will pass around and over the retorts and out through a main flue leading to the chimney. The fuel employed can be either coal, coke, or a mixture of both. Gas as a means of firing has been used for the purpose, the method being based upon the well-known regenerative system of Sir William Siemens. The retorts are charged by hand, care being taken to evenly dis- tribute the coal over the sole, or bottom, and to close it quickly. Various attempts have been made to perform this laborious work with mechanical means, but at present no entirely satisfactory substitute has been found. The products of distillation pass from the retorts proper through the neck, and upward through cast-iron stand-pipes, which are provided with goose-neck outlets, dipping below the surface of water in what is termed the hydraulic main. It is in this part of the process that the main bulk of the tar is obtained, together with the ammonia-liquor. V The hydraulic main is provided with an overflow-pipe through which all the tarry matters pass, This overflow-pipe leads to the tar-well, wherein the liquid products collect. The gas having been freed from the tarry matters, etc., contained, passes from the hydraulic main with a considerably elevated tempera- ture, carrying in a vaporized state hydrocarbons that would separate as its temperature is lowered. It is necessarily very important to remove these volatile and condensable products, which is effected by causing the gas to pass through a series of pipes, which reduces its temperature very close to that of the atmosphere. The older form of condenser was a series of pipes completely covered with water, similar to the worms as at present employed in connection with spirit and other distillations. This arrangement was replaced, however, by the forms now universally DESTRUCTIVE DISTILLATION OF COAL. 403 FIG. 99. employed, and known as the atmospheric condensers, consisting of ver- tical pipes connected in pairs near the top by straight or curved pieces; the lower end of the upright pipes being connected to a box or trough containing water, divided by partitions, causing the gas to pass up and down alternately, as shown in Figs. 99 and 100. Tarry matters and more ammoniacal liquor are again obtained, w r hich find their way to the tar- well. The gas after circulating through the con- densers still contains impurities, which are re- moved by passing it through an apparatus known as the scrubber, consisting essentially of cylin- drical wrought-iron towers filled with coke, over and through which trickles a light flow of water, or better, weak ammoniacal liquor; the gas pass- ing upward meets this downward flow of liquid, and to it gives up the hydrogen sulphide con- tained, with the formation of ammonium sulphide, etc. Tarry matters again are separated, and in time cause the coke to become somewhat clogged. This apparent drawback has led to the introduc- tion of perforated iron plates in place of the coke, or, what has also proved equally efficient, wooden lattice screens. Anderson's rotating scrubber consists of brushes, which while rotating dip in a trough of ammoniacal liquor, and thereby perform functions similar to the means above mentioned. Another form of scrubber consists of a tower containing cast-iron plates provided with perforations, through which ammoniacal liquor passes in its downward course, meeting the gas. The liquid is continuously pumped to the top, when it again passes down, coming in contact with fresh gas. This is repeated until the liquor has taken up sufficient ammonia to make it available to the ammonia sul- phate manufacturer. From the scrubber the gas passes on to the purifiers, where the hydrogen sulphide still remaining, carbon-disulphide FIG. 100. vapor, and the carbonic acid are removed. The purifiers ordinarily used consist of a large shallow box, constructed of cast iron in sections, and bolted together, or of wrought-iron plates, provided with a cover, the edge of which dips in water contained in a channel provided at the 404 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. top of the box, acting as a seal and preventing the escape of gas at that point, as shown in Fig. 101. The purifying agent first employed was slaked lime, which was spread upon wood screens, within the box, from four to six in number, one above the other, and supported by ledges. Hydrogen sulphide and carbon dioxide are absorbed by the lime, while compounds of cyanogen are at the same time decomposed. Four purifiers are generally used, three being in service, while the fourth is reserved charged with fresh lime. Gas enters the one contain- ing the oldest lime, and when it is noticed that lead-acetate paper is dis- colored by some of the gas acting upon it, it is known that the purifying material is saturated; this purifier is discontinued, and the freshly- charged one placed in service. In this manner they are continually rotated. Ferric hydroxide (hydrated ferric oxide) is now largely employed in gas purification, Laming process. Gas charged with hydrogen sulphide coming in contact with the above causes a reduction to ferrous sulphide, FIG. 101. at the same time some sulphur is deposited, with the formation of water. This process does not absorb the carbon dioxide from the gas ; for this pur- pose lime is mixed with the ferric hydroxide, together with some cinders or sawdust, in order that the whole may be porous, and resist as little as possible the passage of the gas. When the purifying action has ceased, simply exposing the inert mixture to the action of the air for a while restores its properties, until after repeated use it becomes so charged with separated sulphur that it is no longer available. The introduction of free oxygen into the gas, previous to it entering the purifiers, has been found to lengthen the time during which the oxide of iron can remain without being changed, thereby saving much handling. It has also improved the illuminating power of the gas. (Journ. Soc. Chem. Ind., vol. viii, pp. 84 and 694.) From the purifiers the gas passes through the meter of the works, where the volume is registered, then on to the gas-holders, where it is stored and from which it is distributed. DESTRUCTIVE DISTILLATION OF COAL. 405 The following table illustrates the composition of illuminating gas taken from various stages of manufacture : Entering the air-con- denser. Entering the scrubber. Entering the Laming's purifier. Entering the lime- purifier. Entering the gas- holder. Hydrogen 37.97 37.97 37.97 37.97 37.97 Marsh-gas 39.78 38.81 38.48 40.29 39.37 Carbonic oxide 7.21 7.15 7.11 3.93 3.97 Heavy hydrocarbons 4 19 4.66 446 4.66 4.29 Nitrogen 4.81 4 99 6.89 7.86 9.99 0.31 047 0.15 0.48 0.61 Carbon dioxide 3.72 3.87 3.39 3.33 0.41 Hydrogen sulphide 1.06 1.47 0.56 0.36 Ammonia 0.95 0.54 2. COKE-OVEN DISTILLATION OF COAL. The burning of coke in pits, "meilers," or mounds, represents the first rough and wasteful method of converting bituminous coal into coke; involving, at the same time, the total loss of all the volatile matter of the coal. It allows, however, of the smothering the finished coke with fine dust, instead of requiring it to be quenched with water, as in other methods. The so-called "bee- hive" ovens allow of the volatilizing of a much greater amount of sulphur in the coal, and give a decidedly increased yield of coke over the pit-burning method. The charge can be run through, too, in less than half the time. Some air is admitted in both cases, with consequent loss of coke, and no attempt is made to save the residuals in either case. The distillation of coal in ovens differs materially from the older methods of production in piles or kilns in that the inflammable gases given off are to some extent utilized. Among the earlier forms of ovens planned for the collection of resid- uals (gas, tar, and ammonia) were the Appolt, which was a vertical oven surrounded by air spaces in which combustion took place, and the Coppee, which was a horizontal oven with vertical side canals for the combustion of gas and air. One of the most successful forms based upon the Coppee principle but using the Siemens regenerative firing is the Otto-Hoffmann oven, which has been extensively adopted in this country. The Simon-Carves oven, illustrated in Fig. 102, on the other hand, has horizontal heating chambers for gas combustion. Mr. Henry Simon, C.E., in an address before the British Iron and Steel Institute (Journ. Iron and Steel Inst., No. 1, 1880), states: "According to our system, the coal is rapidly carbonized by subjecting a comparatively thin layer of it to a high temperature in a closed retort-like vessel, and, whilst in the bee-hive ovens the volatile products are burned inside, we burn them around and outside of this retort-like vessel, and only after they are deprived of the tar and ammoniacal liquor. Each oven is in the form of a long, high, narrow chamber of brick-work, and a number of these are built side by side, with partition-walls between them sufficiently thick to contain horizontal flues. Flues are also formed under the floor 406 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. FIG. 102. DESTRUCTIVE DISTILLATION OF COAL. 407 of each oven, and at one end of these is a small fireplace, consisting of a fire-grate and ash-pit, with suitable door, the fire-door having fitted above it a nozzle, through which gas produced from the coking is ad- mitted to form a flame over some fuel burning on the grate. Only a very trifling amount of such fuel, consisting exclusively of the small refuse coke, is used here, its function being really more that of igniting the gas than that of giving off heat. These grates are not charged with fuel more than twice in each twenty-four hours when in regular work. The products of combustion pass from the fireplace along a flue under the oven floor to the end farthest from the fire. They return along another flue under the floor to the fire end; they then ascend by a flue in the partition-wall to the uppermost of several horizontal flues formed there- in, and descend in a zig-zag direction along these flues, finally passing into a horizontal channel leading to a chimney. The oven in consequence is evenly heated at the bottom and sides, and the coal con- tained is rapidly and completely coked. No air enters the chambers, the only openings being for the escape of the volatile products. The im- proved ovens are fed with coal by openings in the roof, over which coal- trucks are run on rails ; and the coal is evenly distributed by rakes intro- duced at end openings, provided with doors faced with refractory mate- rial, which doors are closed and kept tightly luted while the oven is in operation. The feed-holes in the roof are also provided with covers. Through the middle of the roof rises a gas-pipe provided with a hy- draulic valve, which closes the passage by a lip projecting down from it into an annular cavity surrounding its seating, in which it is immersed in a quantity of tar and ammoniacal liquor, lodged there during previous distillations. The volatile products of the coal distillation rise by the gas-pipe, and are led through a range of pipes kept cool by external wetting, so that the tar and ammoniacal liquor become condensed and separated from the combustible gas. ' ' When the charge of coal has been converted to coke, it is removed from the ovens by means of a piston worked by an engine traversing rails in front of the battery. The yield of coke has been stated to be from seventy-five to seventy-seven per cent, of the coal. During a run of two hundred and fifteen days, the yield of residuals averaged 27.70 gallons of ammoniacal liquors per ton of coal carbonized, and 6.12 gallons of tar per ton of coal carbonized. An improved form of oven analogous to the Simon-Carves but with improved utilization of heat and greater yield of residuals is the Semet- Solvay, which has practically divided the field in this country with the Otto-Hoffmann oven. While the regenerative heating is not used in the Semet-Solvay oven, the air for combustion and sometimes the gas is heated by the waste gases of combustion. It is claimed that by the horizontal flue for the burning of the fuel gas a more uniform and higher temperature is obtained. Considerable difference exists between the tars obtained from the different coking processes above referred to. The Simon-Carves tar has a specific gravity of 1.106, and closely resembles, chemically, the tars produced in the illuminating (retort) gas process, both being obtained 408 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. at a high temperature. The Simon-Carves tar is rich in naphthalene and anthracene, but low in naphtha, benzene, phenols, etc. Analogous to this, as might be expected, is the Semet-Solvay tar. A sample from Glassport, Pa., gave 3.7 per cent, light oils, 9.8 per cent, middle oils, 12 per cent, heavy oils and 4.3 per cent, anthracene oil, and had a specific gravity 1.170. On the other hand, a sample of Otto oven oil (Lunge, Die Industrie des Steinkohlentheers und Ammoniaks, 4te Auf., p. 87) gave light oil 3.4, creosote oil 14.5 per cent., crude naphthalene 6.7 per cent., and 27.3 per cent, anthracene oil. Much of the gas pro- duced in the by-product coke oven contains benzol vapor and this is washed out of it, so that much more is obtained than the percentage of light oils in the tar would indicate. The following comparison of Otto-Hoffmann coke oven tar with gas retort tar from Dammer's Chemische Technologic der Neuzeit, vol. ii, p. 98, 1910) is instructive : Distillation temperature. Tar from Otto-Hoffmann oven. Gas-tar. |rf "gcd 5>5 . a 02 O03 Q L s >, i o >, i o 1 CO s D Light oil 80-170C. 170-230 230-270 Above 270 1.26 14.76 7.07 21.38 53.03 1.52 1.01 1.38 11.46 8.56 20.63 53.68 1.93 2.36 6.55 10.54 7.62 44.35 30.55 trace 0.39 3.0 7.5 33.5 10.5 45.5 2.5 2.5 25.0 10.0 60.0 1.65 10.66 8.18 14.05 61.16 1.81 2.49 Middle oil Heavy oil Anthracene oil . . Pitch Water Loss , Specific gravity 100.00 1.188 100.00 1.140 100.00 1.155 100.00 1.155 100.00 1.155 100.00 3. FRACTIONAL SEPARATION OF CRUDE COAL-TAR. Following gas retort distillation, in point of technical importance is certainly the dis- tillation of the coal-tar obtained from the former processes and the separa- tion therefrom of certain constituents which have a wide application in several industries. The same general mechanical arrangement, though somewhat simplified, is employed, consisting of a still, a condenser, and a receiver. The still should be constructed entirely of wrought iron, and can be either horizontal or vertical. Horizontal stills are, accord- ing to Lunge, far less economical than the vertical. Fig. 103 is a ver- tical section of a tar-still showing the construction and fittings. The heat from the fire on the grate & is prevented from impinging against the concave bottom of the still by means of the arch g, but passes through the openings h in the circular wall k into vertical flues i, from which it enters the annular space I and through flues in the front of the still to the upper space n, finally entering the flue p, which leads to the DESTRUCTIVE DISTILLATION OF COAL. 409 chimney. The supply pipe r is for feeding the still, the pipe s is an overflow, and serves to indicate when the tank is full. The cock a is for drawing off the pitch. The still-head t is for conducting the vapors, and is connected with the condenser. The system of pipes x y z indi- cated is for conducting superheated steam into the still for finishing the distillation; the pipes conforming to the shape of the bottom, are pro- FIG. 103. vided with a number of jets for a more equal distribution of the steam. The remaining attachments require no further mention. The condenser consists of a coil of pipe immersed in water contained in an iron tank. In England, the pipe used is from six to nine feet in length, and from four to six inches in diameter ; the total length for one still is calculated at from one hundred and forty to two hundred feet. In Germany, preference is given to worms of iron (or lead, in which case 410 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. the pipe from the still must be continued below the surface of the water in the condenser and join the worm there, in order to obviate the possi- bility of it being melted), made of two-inch pipe, and mounted in cir- cular tanks provided with a steam-pipe for heating the water, and also with a small pipe connected with the worm for blowing in steam when- ever it is necessary to clean it. Connected with the condenser, and located at a safe distance from the still, is the receiver, which can be of any convenient shape, and of such a size as to contain the whole of one fraction; or a number can be em- ployed, each acting as a store-tank and receiver. For the receivers to contain the volatile fractions, tight-closing covers must be supplied to guard against evaporation and fire," and the one containing the first fraction must have means for separating the oily from the watery layer. The receivers for the oils which deposit crystalline matter must be so arranged that they can be easily cleaned. Coal-tar (Allen, Commercial Organic Analysis, 3d ed., vol. ii, Part ii, p. 47), ''as obtained as a by-product in the manufacture of illuminat- ing gas, is a black viscid fluid of a characteristic and disagreeable odor. The specific gravity ranges from 1.10 to 1.20, being usually between 1.12 and 1.15. "As coal-tar is always more or less mixed with ammcniacal liquor, the consituents of the latter liquid are present in addition to those of the tar proper, and the constituents of the illuminating gas itself are also present in a state of solution. ''The first treatment of coal-tar on a large scale consists in distilling it in iron retorts and collecting the distillate in three or four fractions. The temperatures at which the receivers are charged vary considerably with the practice of different works, and hence the products are far from being strictly parallel." The annexed table indicates the three most important methods of f ractionation : A. B. C. Product. Distilling- point C. Product. Distilling- point C. Product. Distilling- pointC. Crude naphtha, or light oils . Heavy oils, dead oils, or creo- sote oils . . . Anthracene oils to 170 170 to 270 above 270 First runnings, or first light oils .... Second light oils Carbolic oils . Creosote oils to 110 110 to 210 210 to 240 240 to 270 Light naphtha Light oils . . . Carbolic oils . Creosote oils . Anthracene oils Pitch .... Oto 110 110 to 170 170 to 225 225 to 270 270 to 360 Pitch .A nthracene oils above 270 Pitch .... \ The principal constituents of coal-tar are separated, one from the other, by means of fractional distillation, a process depending upon the fact that, if a mixture of liquids, each having a different boiling-point, be heated, the one having the lowest will pass over first, and if the tern- DESTRUCTIVE DISTILLATION OF COAL. 411 perature is not increased beyond that point at which the distillation of this fraction takes place, no other constituent will come over ; if the tem- perature be gradually increased the others will follow in the order of their boiling-points. In cases where the boiling-points are close, and even in others where they are widely differing, the action of one sub- stance upon another often prevents exact separations. The hot stills (from the previous working) are charged with fresh tar, all the openings are then closed, and the fire carefully watched in order that no undue rise in temperature, and consequent boiling over of the contents, may take place. Gases, ammonia-liquor, and light oils distil over at 170, the whole being designated "first runnings." This fraction is collected and allowed to stand, when the watery portion sep- arates more or less completely from the oils, which are redistilled, yield- ing ammonia boiling under 70, crude benzol at 140, which is subse- quently purified with sulphuric acid and distilled, naphtha, 140 to 170, treated as the benzol, yielding "solvent naphtha." This whole fraction has a specific gravity nearly equal to that of water. The second fraction "middle oil," or "carbolic oil" distils over from 170 to 230, and contains the impure phenols or carbolic acid and naphthalene. It is crystallized and pressed; the mother-liquor is agitated with caustic soda in an iron tank, the alkaline liquor (carbolate of soda) decomposed with sulphuric acid, separating crude carbolic acid, which is distilled and crystallized, yielding liquid and pure carbolic acid in crystals. The unchanged oil from the soda treatment is returned to the second fraction for re- working. The press-cake from the first treatment of this fraction is purified with sulphuric acid, distilled, and yields naphthalene. The third fraction constitutes the heavy or dead oil, so called from the fact that the specific gravity is greater than water, and boils from 230 to 270, occupying a position between middle oil and the anthracene frac- tion. It is subjected to no further treatment, but is employed chiefly for preserving timber, varnish manufacture, burning for lamp-black, etc. The fourth fraction, or anthracene oil, boiling over 270, constitutes the green oil or green grease, from which, upon subsequent treatment, the commercial anthracene is obtained. This fraction is allowed to stand for some time, in order to cool and to separate the crystallizable sub- stances, when the mass is drained from the excess of oil and pressed. The press-cake is crude anthracene, which is dissolved in naphtha and known as fifty per cent, anthracene. The mother-liquor from the first pressing and the drainings are redistilled, crystallized and pressed, yielding crude anthracene, treated as above, and anthracene oil. The residue in the still constitutes pitch, which is withdrawn and employed for making pavements, varnish, etc. The annexed diagram from Ost's "Lehrbuch der Technischen Chemie ' ' graphically represents the preceding outline of the tar distilla- tion process. 4. TREATMENT OP AMMONIACAL LIQUOR. The ammoniacal liquor of the gas-works is that which passes out continuously from the scrubbers and other parts of the process, and is the chief source of nearly all the 412 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. S5 S' H 3^ !5 4) C ANTHR boilin ystalliz S oj _Q ^ O WO w o QL. o S MI ;_> w QL, H H I 02 "* ft'3'' w < < J5 -2 4- o, <0 * * S C 5 e ~ S H - 1 oJ j i~"l I s 5 2*2 o| *rt u l ! ! t 1 _ Cr-> 2o f~ & *1 O J3 cS J2 S ** O g|-g * s ag v^S " _CJ~c^'^_ > WJ3. Q3 -|-c|S-l|- ^J9 o o . '|il| 2 l | fi| 6 M bJO ^" r " < |lli 3 j sfi fed 5 ^ "^cT o3 " K LH 0> >- "^ o < g 1 sl-a COfc 1 * 5 a S' s 3 .5 ^ *) to 4 d > -39* O o-gS-o I-QJ S -5 S ^"8 H S **'% & & 'g c ^ c "8 " K ^2 "^ O J2 g! Cfl SfT-l. '-g n^SS^S-oSS w ^ o M <: S Q .S'C'S.'O c < *j Q.5 ^ * i5 ** ''v-.^ft be P r^ ^ --^ a PocOt^aQ ^^S5 SKOP.SOS . ( 169.5 C. .895 at C. Mesitylene, J ^Hj-CCHj), j 165 <> c 865 at 14 o c Durene, C 6 H 2 .(CH 3 ) 4 . (Fuses at 79-80 C.) 192 C. Pentamethylbenzene, C 8 H.(CH S ) 5 . (Fuses at 5.5 C.).. 231 C Hexamethylbenzene, C 8 (C'H 3 ) 8 . (Fuses at 166 C.) 265 C. Of which only the first three are employed to any extent. Benzene has been described in a previous chapter (see Tar Distilla- tion), but for the manufacture of colors an explanation is necessary; the name benzene, chemically speaking, does not refer to the light frac- tions obtained from petroleum, but applies solely to the substance dis- tilled from coal-tar; boiling at 80.4 to 81 C., having a specific gravity of .899 at 0, with the definite composition C 6 H 6 . The term benzol, on the other hand, is not given to a definite compound, but to a mixture of benzene with variable quantities of toluene and xylene, with the other homologous of the same series. The quantity of these homologous bodies contained has an influence upon the use to which the aniline oil obtained (by subsequent treatment of the benzol) can be put. The pure benzene, free from the high-boiling homologues, is succes- sively converted through several processes to dimethylaniline, which is the base of the valuable methyl-violets. For the fuchsine process, ben- zol, seventy-five per cent, of which distils between 80 and 100 C. (con- taining toluene), is employed, producing aniline, seventy-five per cent, of which distils between 180 and 190 C. High-boiling 'benzol, 115 to 120 C., yields aniline, which is the starting-point for the production of the beautiful series of xylidine scarlets; the introduction, however, of pure xylene has served to displace the above. Allen states (Commercial Organic Analysis, 2d ed v vol. ii, p. 489), "Ninety per cent, benzol is a 28 434 THE ARTIFICIAL COLORING MATTERS. product of which ninety per cent, by volume distils before the ther- mometer rises above 100 C. A good sample should not begin to distil under 80 C., and should not yield more than twenty to thirty per cent, at 85, or much more than ninety per cent, at 100 C. It should wholly distil below 120 C. An excessive distillate e.g., thirty-five to forty per cent, at 85 C. indicates a larger proportion of carbon disul- phide or light hydrocarbons than is desirable. "The actual percentage composition of a ninety per cent, benzol of good quality is about seventy of benzene, twenty-four of toluene, in- cluding a little xylene, and four to six of carbon disulphide and light hydrocarbons. The proportion of real benzene may fall as low as sixty or rise as high as seventy-five per cent. Ninety per cent, benzol should be colorless and free from opalescence. " "Fifty per cent, 'benzol, often called 50/90 benzol, is a product of which fifty per cent, by volume distils over at a temperature not exceed- ing 100 C., and forty per cent, more below 120. It should wholly distil below 130." ' ' Thirty per cent, benzol is a product of which thirty per cent, distils below 100, about sixty per cent, more passing over between 100 and 120. It consists chiefly of toluene and xylene, with small proportions of benzene, cumene, etc." The following table from Schultz (Steinkohlentheers) indicates the general properties of the three commercial benzols above described when subjected to distillation: Thirty per cent. Fifty per cent. Ninety per cent. To 85 25 90 2 4 70 95 12 26 83 100 30 50 90 105 42 62 94 110 70 71 97 116 82 82 98 120 90 90 99 The theoretical quantities of commercially applicable products from benzol are: For 100 parts, 157.6 parts nitrobenzol. " " " 119.2 " aniline. " " " 215.3 " dinitrobenzol. " " " 155.1 " dimethylaniline. " " 191.0 " diethylaiiiline. Toluene, or Methylbenzene, C 6 H 5 .CH 3 , is obtained by careful distilla- tion of coal-tar benzols, and can be obtained from the balsam of tolu and other sources. It is quite similar in its properties to benzene; fluid at ordinary temperatures, and when pure boils between 110 and 111 C. Specific gravity .869. It is employed for the production of RAW MATERIALS. 435 nitrotoluene, toluidine, benzylchloride, benzalchloride, and benzalde- hyde, the base of a valuable series of green colors. The theoretical yield of commercial products from toluene is as follows: For 100 parts, 148.9 parts nitrotoluene. ' " " " 116.3 " toluidine " " " 115.3 benzaldehyde. Xylene, or Dimethylbenzene, C 6 H 4 . (CH 3 ) 2 , exists under similar con- ditions to tqluene, and is found in coal-tar. There are three xylenes, the ortho-, meta-, and para-, the second being most abundantly obtained. Owing to the slight difference between their respective boiling-points, a commercial separation by distillation is practically impossible. The annexed table gives the nature and behavior of the three iso- meric hydrocarbons mentioned. Ortho-xylene. Meta-xylene. Para-xylene. Melting point Fluid. Fluid. 15 C Boiling-point 141 to 142 C. 139 C. 137 5 to 138 C Specific gravity .... .8668 at 19 C. 8621 at 19 5 C r^ f Dilute nitric acid v 26 1 S'S i x ^ \ Permanganate ^ [ Chromic acid . . Sulphuric acid (66 Be.) Sulphuric acid (fuming) Melting point of the sul- phochloride o-Toluic acid, melting point 102 C. Phthalic acid. Decomposed. Sulphonic acid. Sulphonic acid. 62 C. w-Toluic acid, melt- ing point 160 C. i Isophthalic acid. Two sulphonic acids. Two sulphonic acids. (a) 34 C , (b) liquid p-To\u\c acid, melting point 178 C. Terephthalic acid No change. Sulphonic acid. 26 C Melting point of the sul- phamide 144 C (a) 137 C (6) 96 C 148 C From Schultz, " Steinkohlentheers." Naphthalene Series. Naphthalene, C 10 H 8 , as a raw material, enters largely into the production of the extensive series of azo-coloring mat- ters, and for such use it is converted into intermediary products, of which the alpha- and beta-naphthols are the most familiar. The occur- rence, properties, and production of naphthalene are referred to on page 419. Methyl-naphthalene, C 10 H 7 CH 3 . Two isomers exist in coal-tar, and can be separated from that fraction of the distillate boiling at from 220 to 270 C. The first of these is a liquid boiling at 243 C. ; specific gravity 1.0287 at 11.5. The second is a solid, looking like naphthalene, melting at 32.5 C. and boiling at 242 C. Ethyl-naphthalene, C 12 H 12 . Two isomers, a- and /?-, are known. a-Ethyl-naphthalene, produced from a-brom-naphthalene and ethyl- bromide, and distilled in vacuum, boils a.t from 257 to 259.5 C. iS-Ethyl-naphthalene, from /?-brom-naphthalene, ethyl bromide, and sodium, boils at from 250 to 251 C. Diphenyl, C 12 H 10 , has been found in coal-tar, and is readily obtained when benzene vapors are passed through a red-hot tube. It is insoluble 436 THE ARTIFICIAL COLORING MATTERS. in water, soluble in hot alcohol and in ether. It forms large colorless scales, melting at 71 C. and boiling at 254 C. Oxidized by chromic acid, it yields benzoic acid. Stilbene, C 14 H 12 . This compound, which is diphenylethylene (C 6 H 3 .CH = CH.C 6 H 5 ), is formed when toluene or dibenzyl is led over heated lead oxide. It crystallizes in colorless scales, melting at 125 C. Forms the basis of numerous important dyes. Anthracene Series. Anthracene, C 14 H 10 , reference to which has been made in the previous chapter, is employed for the production of ali- zarine and allied bodies, the successful introduction of which caused a revolution in the processes of dyeing, and made useless for the time great areas of land which were devoted to the culture of madder. An- thracene, as it occurs in commerce, is rarely pure, being made up of a very large number of hydrocarbons, several of which have not been investigated. The following may be mentioned: Methyl-anthracene, C 15 H 12 , closely resembles anthracene. It differs from that body in having a methyl group substituted for an H atom of one of the benzene rings. It occurs in coal-tar in small quantity, and owing to the high boiling-point, over 360 C., it is found in the anthra- cene. Crystallizes in pale-yellow leaflets, melting at 199 to 200. Phenyl-anthracene, C 20 H 14 , is formed when phenyl-anthranol or coerulem is heated with zinc-dust. Slightly soluble in hot alcohol, ether, benzene, carbon disulphide, and chloroform, and, upon cooling, crys- tallizes from the above solvents in yellow plates, melting at 152 to 153 C. The solutions have a blue fluorescence. Fluorene, or Diphenylen-methane, C 13 H 10 , is found in coal-tar, and can be obtained by passing diphenylmethane through a combustion-tube heated to redness ; it can also be obtained by distilling diphenyleneketone over heated zinc-dust, or by heating the same substance with hydriodic acid and phosphorus from 150 to 160. Very soluble in hot alcohol, less in cold; crystallizes in colorless plates having a violet fluorescence. Melts at 113 C., boils at 295 C. Phenanthrene, C 14 H 10 . This hydrocarbon is isomeric with anthra- cene, is found with it, and forms a large part of, the last fraction of coal-tar. Compared with anthracene, the melting point is considerably lower, while the boiling-points are somewhat closer. It is much more soluble in alcohol, by which means a separation is effected ; the low melt- ing point materially assisting. Crystallizes in colorless, shining plates, melting at 100 and boiling at 340, insoluble in water, but soluble in fifty parts of alcohol in the cold, and in ten parts on boiling; easily soluble in ether and benzene. It imparts a blue fluorescence when dis- solved. When oxidized, phenanthrenquinone is formed. Technically, but little use is made of it, being chiefly employed in the oil baths for alkali melts, heating autoclaves, subliming phthalic anhydride, etc. Fluoranthene, C 15 H 10 , occurs in the highest boiling tar fractions; crystallizes in needles; melts at 109. Pseudophenanthrene, C 16 H 12 , is found in crude anthracene, and crys- tallizes in large glistening plates, which melt at 115. Pyrene, C 16 H 10 , RAW MATERIALS. 437 Retene, C 18 H 18 , Chrysene, C 18 H 12 , and Picene, C 22 H 14 , are bodies which occur in the highest fractions with fiuoranthene, and cannot be classed as raw materials, no technical importance being attached to them. 2. HALOGEN DERIVATIVES. From Benzene. The following table of the halogen derivatives of benzene indicates those whose constitution is known. They are produced by the action of the halogens upon the hydrocarbons directly, or through the action of the halogen compounds of phosphorus upon phenols and aromatic alcohols. Two classes are produced, substitution and addition compounds. The former occur under ordinary conditions, while the latter are formed when the reaction takes place in direct sunlight. Of the two, the substitution products are the more stable, the addition products being easily decomposed. The following table gives the formulas of the several halogen deriva- tives of benzene and the boiling-points of the more important of the several isomeric compounds: Halogen substitution products of benzene. C 6 H 6 C.H, C 6 H< C e H, C 6 H 2 cX C 6 Cl C1 2 CL Cl 01, C1 6 133 179 213 246 276 332 Br f Br 6 154 224 276 329 219 278 219 J! 185 277 285 172 208 246 173 218 254 } From Toluene. (1) Benzyl-chloride (Chlorbenzyl} , C 6 H 5 CH 2 .C1, results from the action of hydrochloric acid upon benzyl alcohol (C 6 H .CH 2 .OH), or by acting on boiling toluene with chlorine, this method being the one most generally used; the product is washed with water containing a little alkali, when it is freed from impurities by dis- tillation. It is a colorless fluid, specific gravity 1.113, boils at 179, insoluble in water, but soluble in alcohol and ether, and possesses an exceedingly penetrating odor, acting upon the eyes and mucous mem- brane of the nose. Technically, it finds considerable application in the color industry. (2) Benzol-chloride, CeHg.CH.Cl^. Formed when chlorine acts upon boiling benzyl-chloride, or when phosphorus penta-chloride acts upon benzaldehyde. It is a. colorless liquid, having ordinarily but little odor, but upon the application of heat gives off a vapor producing effects similar to the preceding. Boils at 206 to 207 ; specific gravity at 16 1.295. (3) Benzo-trichloride, C H 5 .C.C1 3 , is obtained by acting with chlorine upon boiling toluene until no further increase in weight takes place, when it is washed in water containing alkali, dried, and distilled in a vacuum. Boils at 213 to 214 ; specific gravity 1.38 at 14. It has a penetrating odor, and is highly refractive. Bromine Derivatives of Xylene. These are obtained when bromine is allowed to act upon the hydrocarbon or its isomers, or upon bromi- 438 THE ARTIFICIAL COLORING MATTERS. nated compounds of the same, with or without the presence of iodine. They find no application industrially. Halogen Derivatives of Naphthalene. (1) Naphthalene Dichloride, C 10 H 8 C1 2 , is a liquid, easily decomposed; produced as an addition com- pound by the action of chlorine gas upon naphthalene. (2) Naphthalene Tetrachloride, C 10 H 8 C1 4 . This substance is manu- factured in large quantities by passing chlorine gas through the melted hydrocarbon in a suitable apparatus, or by grinding the naphthalene to a paste with water and intimately kneading therein sodium or potas- sium chlorate, moulding into balls, and drying, after which they are immersed in concentrated hydrochloric acid. It crystallizes from chloro- form in large rhombohedra, melting at 182, and when boiled with nitric acid is converted into phthalic acid, which is the chief product obtained from it. (3) a-Brom-naphthalene, C 10 H 7 .Br. Formed by the direct bromi- nation of the hydrocarbon, or by the substitution of bromine for the ami do group in a brom-a-naphthylamine. It is a liquid, boiling at 277 ; specific gravity 1.503 at 12. Insoluble in water, soluble in acohol and ether. (4) (3-Naphthyl-chloride, C 10 H 7 .CH 2 C1, is formed when chlorine acts upon /?-methyl-naphthalene at a temperature of 240 to 250. Melts at 47, boils at 168. (5) fS-Naphthyl-jbromide, C 10 H 7 .CH 2 Br. Formed when the vapor of bromine with C0 2 gas is brought in contact with ^-methyl-naphtha- lene, heated to 240. Crystallizes from alcohol in white plates, which melt at 56. Anthracene Derivatives. (1) Monochlor-anthracene, C 14 H .C1. When dichlor-anthracene is heated, hydrochloric acid is evolved, having the monochlor derivative. Soluble in alcohol, ether, carbon disulphide, and benzene. Crystallizes in yellow needles, melting at 103. (2) Dichlor-anthracene, C 14 H 8 .C1 2 , is produced when anthracene is allowed to remain in contact with chlorine, or when the monochlor deri- vative is similarly treated, being maintained at a temperature of 100. Freely soluble in benzene, but not readily in alcohol or ether. Forms beautiful yellow lustrous needles, which melt at 209. Treated with sulphuric acid at a low temperature, dichlor-anthracene-sulphonic acid occurs in solution ; this, when heated, yields sulphurous acid, hydro- chloric acid, and the anthraquinone-disulphonic acid, which is the imme- diate base of the artificial alizarine. (3) Dibrom-anthracene, C 14 H 8 Br 2 . Upon agitating bromine with a solution of anthracene in carbon disulphide, this derivative is formed. Difficultly soluble in alcohol, ether, and benzene; hot toluene or xylene answer best. Crystallizes in gold-yellow needles, melting at 221, and subliming without decomposition. 3. NITRO- DERIVATIVES. By the action of nitric acid upon the hy- drocarbons nitro- derivatives are obtained, and one of the most important of these nitrobenzene is manufactured in very large quantities for use in the color industry. RAW MATERIALS. 439 (1) Nitrobenzene, C 6 H 5 .N0 2 , was discovered by Mitscherlich, who obtained it by heating benzene or benzoic acid with fuming nitric acid. It was first brought into trade, bearing the name "oil of mirbane" (artificial oil of bitter almonds), by Collas, and in 1847 a patent for its manufacture from coal-tar was granted to Mansfield. It is obtained by adding a cooled mixture of concentrated sulphuric acid and nitric acid (150: 100) to the hydrocarbon and agitating, taking care that the tem- perature does not go above 50 C. After the addition of the acid is complete, heat is applied, and it is again agitated. The oily layer is removed, washed with dilute alkali, dried, and distilled. Nitrobenzene, when pure, is a pale-yellow fluid, strongly refractive, having the odor of bitter almonds, and a sweet, though burning, taste. Specific gravity 1.208 at 15; boils at 206 to 207, and when the temperature is re- duced it crystallizes in large needles, which melt at-}- 3. Nearly in- soluble in water, though with alcohol, ether, and benzene it is readily soluble. It is exceedingly stable, and even at a boiling temperature it is not acted upon by either bromine or chlorine. It is poisonous, and, according to Roscoe and Schorlemmer (vol. iii, pt. iii), "especially when the vapor is inhaled; it produces a burning sensation in the mouth, nausea and giddiness, also cyanosis of the lips and face, and in serious cases, which frequently end fatally, symptoms of a general depression." (2) Dinitrobenzene, C 6 H 4 (N0 2 ) 2 . Three isomers of this derivative exist, being obtained when benzene is nitrated with the concentrated acids, as in the preceding case, but instead of being cooled is boiled for 4 short time, when the product is washed with water, pressed, dissolved in alcohol, from which the meta-nitro body crystallizes, followed upon standing by the paranitro compound. Upon distilling the alcohol re- maining in the mother-liquors from the para- compound, a further yield of the meta- body is obtained, finally the ortho-dinitrobenzene, which occurs in small quantity, crystallizes, and is purified by treatment with acetic acid, from which it is deposited in needles, having a melting point of 117.9. The para- compound occurs in monoclinic needles, melting at 172, and subliming. The meta- compound finds technical application in the production of chrysoidine and Bismarck brown, and is manufac- tured on a large scale by adding a mixture of one hundred kilos, nitric acid (specific gravity 1.38) and one hundred and fifty-six kilos, sul- phuric acid (specific gravity 1.84) to one hundred kilos, of benzene. When the reaction is over, a separation of the acids (which can be used again) from the product occurs; commercially, the product is washed with warm and cold water, further purification being unnecessary. It crystallizes in needles or rhombic tables, which melt at 98.8, boiling at 297. Difficultly soluble in warm water, easily in ether and alcohol. Nitrotoluene. (1) Nitrotoluene, C 6 H 4 (N0 2 )CH 3 , occurs in three isomers. The ortho- derivative is a liquid boiling at 223, and at 23.5 has a specific gravity of 1.162. Does not become solid at 20. The meta- derivative melts at 16, boils at 230 to 231. Specific gravity at 22 1.168. Para- nitrotoluene, melting point 54, distilling unchanged at 236, occurs in colorless prisms. Nitrotoluene, consisting more or 440 THE ARTIFICIAL COLORING MATTERS. less of a mixture of the three, is manufactured in large quantities and in the same manner as nitrobenzene. Ten parts of toluene are mixed, and continually agitated with eleven parts of nitric acid (specific gravity 1.22) and one part sulphuric acid (specific gravity 1.33). The product is treated with water, and afterwards with caustic alkali; dis- tilled to remove uncombined toluene, and finally distilled with super- heated steam. When fractionated, that part passing over at 230 yields, when purified, para-nitrotoluene, and is employed in the production of toluidine, tolidine, and fuchsine. The fraction between 220 and 223 is nearly all ortho-nitrotoluene. (2) Dinitrotoluenes, C 6 H 3 (N0 2 ) 2 -CH 3 a- or ordinary dinitrotoluene is produced when toluene is added to a mixture of fuming nitric and sulphuric acids and boiled; ortho-nitrotoluene is employed for the man- ufacture also. Crystallizes in needles, which melt at 70.5 ; insoluble in water, little soluble in alcohol, ether, or carbon disulphide. /2-dinitro- toluene, isomeric with the above, is produced under similar conditions; or it can be made by replacing the amido group of dinitroparatoluidine with hydrogen. Crystallizes in golden-yellow needles; melting point 61.5. Trinitrotoluene, C e H 2 .(N0 2 ) 3 CH 3 . Produced by the action of nitric and sulphuric acids upon toluene, or dinotrotoluene, and heating for several days. a-Trinitrotoluene is soluble in alcohol, crystallizing from it in beautiful needles, which melt at 82. /^-Trinitrotoluene crys- tallizes from acetone in transparent prisms, which melt at 112, while from alcohol it forms plates or flat white needles. ^-Trinitrotoluene is deposited from acetone in small hexagonal crystals, melting at 104. Mononitronaphthalene, C 10 H 7 .NO 2 . Two isomers exist; the a- com- pound is produced when ten parts naphthalene, eight parts nitric acid (specific gravity 1.4), and ten parts sulphuric acid (specific gravity 1.84) are combined in a nitrobenzene apparatus. The naphthalene is added in small portions and continually stirred. The product is washed with water, and freed from acid by treatment with alkali. Insoluble in water, easily in benzene, carbon disulphide, ether, and alcohol. Crys- tallizing in yellow needles, melting at 61, boiling at 304. The ft- com- pound is produced when /?-nitronaphthylamine is melted with nitrate of potassa. Soluble in alcohol, ether, or glacial acetic acid. Crystallizes in yellow needles; melts at 79. a-Dinitronaphthalene, C 10 H 6 (NO 2 ) 2 , obtained in a similar manner to the above. Difficultly soluble in cold, easily in warm, benzol. From glacial acetic acid it crystallizes in needles, melting at 217. /3-Dinitro- naphthalene, isomeric with the above, crystallizes in rhombic plates, melting at 170. 4. AMINE DERIVATIVES. The amine derivatives of benzene, toluene, and xylene can be regarded as forming one of the most important groups of raw materials from which are obtained the basic coloring matters, all of which contain nitrogen. The structure of the amines can readily be seen if we employ ammonia, NH 3 , as the type ; in this case there are three atoms of hydrogen. If one of these be replaced by an organic RAW MATERIALS. 441 radical, a primary amine is produced; if two or all three are replaced, a secondary or tertiary amine respectively is formed. Aniline, or Amido-benzene, C 6 H 5 .NH 2 . This substance was discov- ered by Unverdorben in 1826, who noticed its property of combining with acids to form salts. Runge, subsequently, experimenting upon coal- tar, found a volatile substance which, when treated with a solution of bleaching-powder, produced a blue coloration, giving rise to the name kyanol. It was he who noticed that when a drop of the "nitrate of kyanol" was brought in contact with dried cupric chloride, a black spot was formed. Fritsche, later, examined the distillation products of indigo, and found a body to which he gave the name aniline. Aniline was for- merly obtained in large quantities by reducing the nitrobenzene with iron fillings or scrapings and acetic acid, but now it is wholly produced with hydrochloric acid, the following reaction showing the change that occurs : (Nitrobenzene.) C 6 H 5 .NO 2 -f 3Fe -f 6HC1 = (Aniline.) C 6 H 5 .NH 2 + 3FeCl 2 + 2H 2 0. The quantity of acid represented by the above equation is more than sufficient for the purpose, from the fact that ferrous chloride, (FeCl 2 ), a reducing agent itself, will act in the reduction of a further quantity of nitrobenzene : C 6 H 5 .N0 2 + 6FeCl 2 + 6HC1 = C 6 H 5 .NH 2 + 3Fe 2 Cl 6 + 2H 2 0. Aniline is a liquid, fluid at ordinary temperatures, but when frozen melts at 8; boils at 182 w r hen pure; specific gravity 1.036; colorless when freshly distilled, but becomes reddish-brown upon exposure to light and air; impurities hasten discoloration. Soluble in alcohol, ether, and benzene in all proportions; in water it is soluble to a slight extent, one hundred parts of water dissolving three parts aniline, while it, in turn, dissolves water to the extent of five per cent. Aniline forms a series of well-crystallized salts, among which are the hydrochloride, C 6 H 7 .N.C1H, known as "aniline salt," largely em- ployed in the production of black upon cotton; and the sulphate, (C 6 H 7 N) 2 H 2 S0 4 , of considerable importance. Methylaniline, C 6 H 5 .NH(CH 3 ), is obtained by heating aniline hydro- chloride or a mixture of aniline and hydrochloric acid with rather more than a molecule of methyl alcohol at 200 C. The product is then con- verted into sulphate and the easily soluble sulphate of methylaniline separated from the sparingly soluble aniline sulphate. The sulphate is decomposed by an alkali and the free base obtained by distillation. The commercial product contains from ninety to ninety-five per cent, of pure methylaniline. It is a colorless oil, boiling at 192 C., and has a specific gravity 0.976 at 15 C. Dimethylaniline, C H 5 .N(CH 3 ) 2 , is obtained by heating a mixture of 442 THE ARTIFICIAL COLORING MATTERS. aniline (seventy-five parts), aniline hydrochloride (twenty-five parts), and methyl alcohol, free from acetone (seventy-five parts), in a cast-iron autoclave at from 230 to 270 C. The product is rectified. The yield is about one hundred and twenty parts from the above proportions. It is a colorless oil, boiling at 192 C., and specific gravity 0.96 at 15 C. Solidifies at -f- 5 C. to a crystalline solid. The commercial product is usually nearly pure. Nitramline, C 6 H 4 (N0 2 )NH 2 . Both the ra- and the p- nitraniline are used technically. The former is made by the partial reduction of dini- trobenzene; the latter from acetanilid, which is nitrated and then freed from the acetyl group by treatment with steam. Toluidine, or Amido-toluene, C 6 H 4 (CH 3 )NH 2 , occurs in three iso- mers, according to the extent to which the nitration of the toluene was originally carried. Ortho-toluidine is produced by the reduction of ortho-nitro-toluene, by the same means as was applied in the case of aniline. It is a fluid, colorless at first, but becoming brown upon expo- sure. Specific gravity 1.000 at 16, boiling point 197 ; soluble to a slight extent in water (2 : 100) and in alcohol. Meta-toluidine, occurring similarly to the preceding, is a liquid. Specific gravity .998, boiling at 197, little soluble in water, but freely in alcohol and ether. Para-toluidine is obtained in the form of large colorless leaflets, crys- tallizing from alcohol. Specific gravity .973, melting point 45, and boiling at 198 ; slightly soluble in water, readily in alcohol and ether. Commercial toluidine consists chiefly of a mixture of the ortho- and para- bodies, and containing very little aniline ; it is of considerable importance in the color industry. Xylidine, or Amido-xylenc, C 6 H 3 (CH 3 ) 2 .NH 2 , homologous with ani- line and toluidine, is produced from xylene, as aniline is from benzene, nitration followed by reduction. Six isomers are obtainable, but the xylidine industrially employed consists of a mixture of five. At ordi- nary temperature it is a liquid, specific gravity .9184 at 25, boiling point 212. From this derivative the beautiful series of xylidine scarlets are produced. Naphthylamine, C 10 H 7 .NH 2 . Two isomers exist. For a-Naphthylamine naphthalene is converted into the nitro- derivative as has been described, and equal parts of this body and water are heated to 80, incorporated with an equal part of iron filings, and reduced with hydrochloric acid. The product is distilled with lime, and finally rectified by further dis- tillation. Nearly insoluble in water, soluble in alcohol and ether; crys- talizes in colorless needles or prisms, which melt at 50, and boil at 300. Upon contact with the air it acquires a red color, and oxidizing agents cause a blue precipitate to form in solutions of its salts. It finds exten- sive application in the preparation of several colors of importance. j3-Naphthylamine is produced when gaseous ammonia combines with /3-naphthol in the fused state; commercially it is obtained by the action of ammonio-chloride of calcium, or ammonio-chloride of zinc, upon the same body, assisted by heat, and the subsequent separation of by-pro- RAW MATERIALS. 443 ducts. It occurs in white or pearly leaflets, odorless, difficultly soluble in cold, freely in hot water, and in alcohol and ether. Melting point 112, boiling at 294. Unlike the a-naphthylamine, it is not acted upon by oxidizing agents. Phenylendiamine, C G H 4 (NH 2 ) 2 . Both the m- and the p- compounds are used in practice. The former is obtained by the reduction of m-dini- trobenzene with iron and hydrochloric acid; the latter by the reduction of amidoazobenzene with zinc-dust in aqueous solution. C G H 4 .NH 2 Benzidim (diamido-diphenyl), | . This base is manufac- C G H 4 .NH 2 tured on a large scale as the basis of the substantive cotton dyes (see p. 464). For its preparation nitrobenzene is reduced by zinc-dust and caustic soda in the presence of alcohol. The hydrazobenzene so obtained is heated in the presence of hydrochloric acid to boiling and the benzi- dine precipitated from the solution by the addition of sulphuric acid. It forms a grayish- white crystalline solid, fusing at 122 C., and rather difficultly soluble in water. Diphenylamine, (C 6 H 5 ) 2 NH, is made on a large scale by heating aniline with aniline chlorhydrate in autoclaves to between 220 and 230. It forms a white or slightly yellowish solid, melting at 54, and has a pleasant odor of flowers. 5. PHENOL DERIVATIVES. Phenol, C 6 H 5 OH. The occurrence of this body has been mentioned under tar products, page 418. It crystallizes in needles, which have the well-known odor of ' ' carbolic acid. ' ' Specific gravity 1.08, and melting at 37.5, boiling at 132 to 133 ; soluble in water (1: 15) and readily in alkalies, alcohol, and ether. It finds exten- sive application in the color and other industries, large quantities being consumed in the manufacture of picric acid. Resorcin, or m-Dioxy~benzene, C 6 H 4 (OH) 2 , is obtained from benzene by fusing the sodium sulphonate of the latter with caustic soda. (See page 444.) Occurs in sweetish, colorless crystals, which, however, event- ually become dark colored, melting at 110, boiling-point, 271; readily soluble in water, alcohol, and ether. Specific gravity 1.28. Pyrogallol, or Trioxy-benzene, C 6 H 3 (OH) 3 , is readily obtained from gallic or tannic acid when the same are heated to 210 to 220. It can be obtained from benzene, but the above method is more generally adopted. Processes for its manufacture are detailed on page 452. Pyro- gallol occurs in white leaflets, which melt at 115 and boil at 210 ; soluble in water, alcohol, and ether. Naphthols, C 10 H 7 .OH. The two derivatives of naphthalene, a- and /2-naphthol, find extensive application in the manufacture of artificial coloring matters. They are prepared from the two isomeric naphtha- lene sulphonic acids, a and /?, which are discussed under Processes, page 452. a-Naphthol occurs as lustrous needles, which melt at 94, boil at 278 to 280; specific gravity 1.224; sparingly soluble in hot, insoluble in cold, water; soluble in alcohol, ether, benzene, and in solution of caustic alkalies. /3-Naphthol occurs in leaflets, melting at 122, boiling 444 THE ARTIFICIAL COLORING MATTERS. from 285 to 290 ; solubilities same as for the preceding. Allen (Com- mercial Organic Analysis, 2d ed., vol. ii, p. 511) gives the following table of the distinguishing characteristics of the two naphthols: x-Naphthol. 0-Naphthol. Crystallizes in small monoclinic needles. Melting point 94 ; boils at 278 to 280. Faint odor, resembling phenol. Volatilizes readily with vapor of water. Aqueous solution becomes dark violet, changing to reddish-brown on adding solution of bleaching-powder. Aqueous solution becomes red, and then violet, on adding ferric chloride. Crystallizes in rhombic laminae. Melting point 122 ; boils at 285 to 290. Almost odorless. Scarcely volatile with vapor of water. Aqueous solution colored pale yellow by solution of bleaching-powder. Aqueous solution becomes pale green on adding ferric chloride. 6. SULPHO- ACIDS. This group constitutes an interesting and techni- cally valuable series of bodies, which are obtained by the action of con- centrated sulphuric acid upon the hydrocarbons, or upon coloring mat- ters already formed. (1) Benzene-sulphonic Acid, C 6 H..SO ; ,H, is readily obtained by heat- ing two parts benzene with three parts sulphuric acid to 100 C., diluting with water, saturating with carbonate of lead, and decomposing with sulphuric acid to liberate the sulphonic acid. The acid is soluble in water and alcohol, and crystallizes in small plates. (2) Benzene-disulphonic Acids, C 6 H 4 (SO 3 H) 2 , are (mainly the meta variety) produced when benzene is heated with fuming sulphuric acid to 275. Employed in the production of resorcin. (3) Toluene-sulphonic Acid, C 6 H 4 (CH,)S0 3 H. No importance. (4) Naphthalene-sulphonic Acids, C 10 H 7 .SO 3 H. Two isomeric bodies are obtained when naphthalene is submitted to the action of sulphuric acid. At temperatures ranging from 80 to 100 the a - derivative is largely obtained, and at temperatures from 160 to 170 the /3-derivative is produced. Their separation is based upon the different degrees of solubility of the lead salts upon concentrating their aqueous solutions, a-naphthalene-sulphonic acid being soluble in twenty-seven parts water, while the /3-acid requires one hundred and fifteen parts. (5) Anthracene-sulphonic Acid, C 14 H n .SO 3 H, is produced similarly to the above, or by the reduction of sodium anthraquinone-sulphonate with zinc-dust and ammonia. Phenol-sulpkonic Acid, C fi H 4 (OH)S0 3 H. Three isomers are known, two, the ortho- and para-, being produced by the direct action of sul- phuric acid upon phenol, while the meta- compound must be produced by other means. The ortho- acid is largely obtained when one part of phenol is slowly mixed with one part of sulphuric acid, care being taken to keep the temperature from rising. The para- acid will be obtained if the mixture be heated to 100. These bodies are much employed as anti- septics under various names; the para- compound, also, in the produc- tion of picric acid. RAW MATERIALS. 445 Naphthol-sulphonic Acids. The two naphthols are easily converted into mono-sulphonic acids upon being heated to 100 C. with concen- trated sulphuric acid; disulphonic acids being produced if the tempera- ture reaches 110 C. (3-naphthol-sulphonic add, C 10 H 6 .SO,H.OH. One hundred parts of /?-naphthol are added to two hundred parts of sulphuric acid (specific gravity 1.84) and carefully heated to 50 or 60, when two acids result, ordinary p-naphthol-sulphonic acid (known also as "Schaffer's acid," or "acid S") and fi-naphthol- a -sulphonic acid ("Bayer's acid," or "acid B"). When converted into their sodium salts they can be separated by treatment with alcohol, in which men- struum the latter acid is more soluble than the former. They are exten- sively used for the production of the crocei'n scarlets ; and upon nitration yield other colors of importance. If the mixed acid and naphthol is heated to about 20 C. Bayer's acid will be formed, while the employ- ment of a temperature about 90 will cause the formation, as the chief product, of Schaffer's acid. Disulphonic Acids of (3-Naphthol, C 10 H 5 (S0 3 H) 2 OH, are obtained when the naphthol is subjected to a temperature of 100 to 110 with three times its weight of sulphuric acid (specific gravity 1.84). Upon dilution milk of lime is added, the precipitated calcium sulphate filtered off, carbonate of soda added, and the whole evaporated to dryness, and lixiviated with alcohol, when "salt G" (yellow shade) is dissolved from "salt R," red shade). Ordinarily, after the addition of the carbonate of soda, the solution is used without further treatment. Anthraquinone-sulphonic Acid, C 6 H 4 (CO) 2 C 6 H 3 .S0 3 H, is formed when anthraquinone is treated with fuming sulphuric acid at 160 C. The unaltered anthraquinone is separated, the solution neutralized with soda, when the white soda salt settles out. The free acid occurs in yellow plates, soluble in water and in alcohol. When fused with either caustic soda or potash alizarin is obtained (when anthraquinone-disulphonic acid is used, either by itself or in the melt, purpurin is produced along with alizarin) ; anthraquinone-sulphonic acid being employed directly for the production of this most valuable coloring matter. Sulphanilic (p-amidobenzene-sulphonic) Acid, C e H 4 (HS0 3 )NH 2 , is made by the action of sulphuric acid upon aniline at about 190 C. Is used very largely as basis of the manufacture of dye-colors. Naphthylamine-sulphonic Acids are prepared from naphthylamine by treatment with sulphuric acid and the application of heat. Several derivatives are produced, which, however, find limited application, mainly in some patented specialties. 7. PYRIDINE AND QUINOLINE BASES. Pyridine, C 5 H 5 N, is regarded as a benzene nucleus (C 6 H e ) with one of the CH groups replaced by an atom of nitrogen. It is obtained w r hen bone oil or other nitrogen-contain- ing organic bodies are distilled. It possesses a pungent odor, is liquid, boils at 116.7, and is soluble in water; specific gravity .986. A large number of the pyridine derivatives bear a relationship to the alkaloids. Quinoline (Chinoline), C H 7 N, differs from pyridine in that naphtha- lene is the base, C 10 H 8 , one nitrogen atom replacing, as before, one of 446 THE ARTIFICIAL COLORING MATTERS. the CH groups. Quinoline is readily prepared by carefully heating in a flask one hundred and twenty grammes glycerine, thirty-eight grammes aniline, twenty-four grammes nitrobenzene (oxidizing agent), with one hundred grammes concentrated sulphuric acid; when the reaction is over, boil for two or three hours, dilute with water, and remove the unchanged nitrobenzene with steam, saturate with caustic alkali, distil, add sulphuric acid and sodium nitrite (NaNO 2 ) to destroy any aniline present, make alkaline, and again distil. Quinoline is a colorless fluid, having a penetrating odor, highly refractive, becoming brown upon ex- posure to the air; boils at 238 ; specific gravity 1.094 at 20. Quinaldine (a-Methyl-quinoUne) , C 9 H 6 (CH 3 )N. Obtained by the action of hydrochloric acid upon paraldehyde and aniline, for several hours, with the aid of heat. It has a faint odor, is fluid, and boils at 238 to 239. Technically employed, mainly for the production of "quino- line yellow," cyanine blue, quinoline red, etc. Acridine, C 13 H 9 N. Anthracene is the base from which this deriva- tive is obtained by a substitution of a nitrogen atom for one of the CH groups. As in the previous instances many derivatives of the above bodies exist, which have considerable interest, but no technical import- ance is attached to them as raw materials. 8. DIAZO- COMPOUNDS. These form the most extensive, and probably the most thoroughly investigated of the several groups of coal-tar colors. They are produced when nitrous acid (obtained from starch and nitric acid) is allowed to act upon the primary amines of the aromatic series, in which case the following change is noted, assuming aniline nitrate to be acted upon : C G H 5 NH 2 .HNO 3 + HO.NO = C 6 H.N=:N.N0 3 + 2H 2 O. (Diazo-benzene nitrate.) Aniline hydrochloride, treated in the same manner, will yiel 1 diazo-ben- zene chloride: C 6 H 5 .NH 2 .HC1 + HO.NO = C B H B N=N.C1 + 2H 2 0. The diazo-compounds differ from those of the azo-group in that one of the bonds of the diatomic nitrogen group N=N is satisfied with a hydrocarbon radicle, while in the latter it is saturated with an atom of oxygen, nitrogen, bromine, chlorine, etc., or with an acid or basic group. The annexed list of diazo- bodies illustrates the above : C a H 5 N NCI Diazo-benzene chloride. (C 6 H S .N=N) 2 SO 4 " " sulphate. C 8 H 5 N=N.Br " " bromide. CH B N=N.NH.C H 5 Diazo-amido-benzene. The azo- compounds have the two nitrogen atoms ( N = N ) united, each to a hydrocarbon group; mixed azo- compounds result if these hydrocarbon groups are not identical. (1) Diazo-benzene Chloride, C 6 H..N 2 C1, is formed when nitrite of RAW MATERIALS. 447 soda (NaN0 2 ) is added to a solution of aniline chloride in the presence of an excess of hydrochloric acid, the solution being kept cool by means of ice. The product finds application in the manufacture of aniline yellow and other colors. Diazo-amido Compounds result from the action of salts of the diazo- derivatives upon the primary and secondary amines. Diazo-amido-benzene, C G H..N 2 .NH.C 6 H 5 , occurs when nitrous acid is passed through a solution of aniline in alcohol ; or by adding a solution of sodium nitrite to a mixture of aniline hydrochloride and aniline. Crystallizes in golden-yellow prisms or scales, insoluble in water, easily in ether, benzene, and alcohol; melting point 91, exploding at a higher temperature. (2) Diazo-benzene-sidphonic Acid, C 6 H 4 .N 2 .S0 3 (the anhydride of the sulphonic acid of diazo-benzene). Sulphanilic acid, C 6 H 4 NH 2 .S0 3 H (see p. 445), is dissolved in water, and sodium nitrite added, when the whole is poured into dilute sulphuric acid, which causes a precipitation of the crystals. 9. AROMATIC ACIDS AND ALDEHYDES. The aromatic acids form a class of bodies of considerable importance, derived from benzenes by substituting the carboxyl group CO. OH for hydrogen. The simplest of the series is Benzoic Acid (Benzene-carl) oxylic Acid), C H 5 .CO.OH, which, besides finding extensive application in medicine, is also used in the color manufacture. It can be prepared by a number of methods, chiefly by the sublimation of gum benzoin; by treating the urine of herbivorous animals with hydrochloric acid, which causes the hippuric acid to break up, yielding the acid and glycocoll ; and from benzotrichlo- ride with water under pressure. It crystallizes in needles or scales, lus- trous, and odorless when pure. Specific gravity 1.291, melting at 121, and boiling at 249 ; soluble in alcohol, ether, benzene, etc., sparingly in water. Phthalic acid (Benzene-dicarb oxylic Acid}, C 6 H 4 .(CO.OH) 2 . Three isomers of the above are known, but only the ortho- acid will be consid- ered. It is obtained from naphthalene tetrachloride by heating with nitric acid or more generally at present by treating naphthalene with strong sulphuric acid in the presence of mercury. It occurs in rhombic crystals, specific gravity 1.585, and melting at 213 ; upon being heated, it is liable to split up into water and the anhydride; soluble in hot water, alcohol, and ether. When a phenol is heated with the phthalic anhydride phthale'ms result; of these, the resorcin and pyrogallol- phthale'ins are the most important, being the bases of the eosins and galle'ms and ccerulems. Gallic Acid (Trihijdroxybenzoic Acid), C 6 H 2 (OH) 3 .CO.OH. This acid occurs in several vegetable substances, chiefly gallnuts, sumach, tea, etc. It is ordinarily prepared by heating gallo-tannic acid with dilute mineral acid, or by allowing crushed galls to remain exposed in a moistened state to the action of the atmosphere for some time, when a fermentation takes place, after which boiling with water removes the gallic acid. It yields needle-shaped crystals, sometimes white, but mostly 448 THE ARTIFICIAL COLORING MATTERS. light brown in color. Specific gravity 1.70. When heated to 220 it decomposes, forming pyrogallol (Trihydroxybenzene, C 6 H 3 (OH) 3 ) and C0 2 . Gallic acid is the chief source of pyrogallol, reference to the appli- cation of which has been made under phthalic acid. Benzaldehyde (Benzoic Aldehyde}, C 6 H 5 .CO.H. This body, also known as "Bitter Almond Oil," is a colorless liquid, possessing an agree- able odor, and high refracting power. Specific gravity 1.063, boiling at 180, difficultly soluble in water (1:300), easily in alcohol and ether. Several methods are employed for the production of this substance; for industrial purposes, benzyUchloride is boiled with nitrate of copper and water, half of the contents are distilled, when the oil layer is sepa- rated from the distillate and purified. Mercuric oxide has been used instead of the copper salt. It finds extensive application in the color in- dustry, also for the production of cinnamic and benzoic acid, and several derivatives of value. 10. KETONES AND DERIVATIVES, ANTHRAQUINONE. The ketones are closely related to the aldehydes, as will be seen from their structure, CH 3 CO H, Aldehyde, CH 3 CO CH 3 , Dimethyl-ketone (ace- tone). The CO group carbonyl is possessed by both classes, but in the aldehydes is united, on the one hand to an alcohol radical, and on the other to an atom of hydrogen. The ketones, however, are distinguished by having two alcohol radicals (alkyls) linked by the CO group. Benzophenone, C 6 H 5 .CO.C 6 H 5 , is a ketone of the benzene series, and can be obtained by distilling calcium benzoate, or by heating benzoyl chloride with aluminum chloride and benzene. It occurs in crystals hav- ing an aromatic odor, and which melt at 48 to 49, subliming at 300. Insoluble in water, soluble in alcohol and ether. It is of some import- ance, together with the amido- and oxy- derivatives, in the manufacture of certain colors. Acetophenone (Phenyl-methyl-ketone} , C 6 H r ,.CO.CH ?> . This is a mixed ketone, and contains two residues of different hydrocarbons united to the carbonyl group. Acetophenone can be obtained by distilling a mixture of the benzoate and acetate of calcium. It occurs in crystalline plates, melting at 14 to 15, and boils at 198. Anthraquinone, C 6 H 4 /^ \C G H 4 . This substance is of the utmost importance in the manufacture of alizarine. It can be obtained by sev- eral processes, the simplest of which is probably the distillation of cal- cium phthalate, or by oxidizing anthracene (C 10 H S ) with bichromate of potash and sulphuric acid. Anthraquinone is very stable, oxidizing agents having but little effect upon it. When heated it sublimes, yielding yellowish rhombic crystals. Specific gravity 1.425, melting point 273 ; insoluble in water, but somewhat in alcohol and ether. Upon fusion with caustic alkalies it yields benzoic acid. For use in the alizarine process, it must be converted into the sulphonic acid, and this fused with caustic alkali, dissolved in water, and the coloring matter precipitated by a mineral acid, and sublimed. (See Process of Manufacture, p. 453.) PROCESSES OF MANUFACTURE. 449 II. Processes of Manufacture. 1. OF NITKOBENZENE AND ANILINE. The commercial production of nitrobenzene is carried out essentially in the following manner, although the details may vary in the different works. Sulphuric acid, 66 Be., and nitric acid, 42 Be ( = seventy per cent. HNO 3 ), are mixed together, in the proportion of fifteen parts by weight of the former to ten parts of the latter, in a lead-lined wood tank (preferably situated above the nitrating apparatus) and allowed to become cold. Three hundred pounds of this "nitrating acid" are run into the nitrating apparatus, either by gravity or by pressure, when the benzene is allowed to flow in in a slow, steady stream. During the admission of the benzene the temperature, which should be maintained between 80 C. and 90 C., is regulated by means of water kept at about 50 C. circulating around the vessel, or stopping the inflow, should the temperature give indication of rising, thereby producing the dinitro- derivative. About one hundred pounds of benzene are used, although this quantity is subject to change, accord- ing to quality. After the nitration is finished, the contents of the vessel are emptied slowly into large tanks, the acid layer being drawn off first, and the nitric acid recovered therefrom, and the nitrobenzene, insoluble in the acid, coming last, is immediately poured into a tank containing water, and washed, followed by a wash with caustic alkali, and finally agitated with water. The quantities by weight of the two acids to effectually nitrate either benzene, toluene, or xylene, are shown below: 100 kilos, benzene. ... 120 kilos, nitric acid. 180 kilos, sulphuric acid. 100 " toluene.... 150 " " " 175 " " " 100 " xylene 90 " " " 150 " Or, of a standard mixture of one hundred kilos, nitric acid and one hun- dred and fifty kilos, sulphuric acid, there will be required for the effect- ual nitration of one hundred kilos, of the above tabulated hydrocarbons three hundred, two hundred and sixty, and two hundred and twenty-five kilos, respectively. The form of nitrating apparatus in use is usually cylindrical, with a flat or round bottom. Fig. 109 illustrates the latter form. The cover is provided with several openings: f is for general charging; e is for the gas exit, while provision is made for the intro- duction of the thermometer, and for carrying the agitator shaft. The opening for withdrawing the charge is at g. The best plan in arranging the plant is to provide for the acid mixing and nitrating on one floor, on the floor below the washing, and, if desirable, a steam still employed to separate the benzene which has not been acted on by the acids, and which is always found dissolved in the nitrobenzene. On the lowest floor, the alkali and final water-wash. If all the operations are performed on one level, a "monte-jus" should be used for the transportation of liquids. Aniline ("Aniline Oil" of commerce). Aniline is obtained by the treatment of nitrobenzene with iron filings or scrapings and hydrochloric 450 THE ARTIFICIAL COLORING MATTERS. acid. The apparatus employed are generally of two kinds, vertical and horizontal, the method of working being in each case the same. In the former, the agitator is attached to an upright hollow shaft, so constructed as to provide for the admission of steam to the bottom of the vessel. The cover supports the gearing, and gooseneck for leading the vapors to the condenser, etc. The horizontal form is shown in Fig. 110 ; the construc- tion provides for agitators attached to a horizontal revolving shaft pass- FIQ. 109. ing through boxes in the heads. Steam enters through the pipes under- neath. A steady supply of fine iron is maintained by means of the mechanical feed on the cover. The operation is conducted by adding some of the iron fillings with water, followed by the acid and nitro- benzene; steam is turned on, and, the agitators set in motion, at once the reaction begins, and a mixture of nitrobenzene, aniline, and water appears in the condenser, which is continually returned to the main body in the apparatus; after the reaction has commenced and the dis- PROCESSES OF MANUFACTURE. 451 FIG. 110. tillate comes over regularly, the iron can be fed steadily, or at uniform intervals. If all the iron is added at once, serious loss is occasioned by a reduction of aniline to benzene and ammonia. For a charge of six hun- dred kilos, of nitrobenzene, about seven hundred kilos, of iron filings will be required and sixty kilos, of 21 Be. hydrochloric acid. The solu- bility of the distillate in hydrochloric acid is noted, until a point is reached at which no nitrobenzene separates in an unaltered condition. Formerly it was the general practice to add lime to the tank, and distil off the aniline by means of steam; now the contents are emptied into large tanks containing water and allowed to subside for a day or more, when the lower layer, consisting of aniline, is drawn off and pumped into a large iron still mounted over an open fire and rectified. One hundred parts of nitrobenzene will yield about seventy-five parts of aniline if the process is carefully attended. Ordinarily, the yield will be from seventy-one to seventy-four parts. 2. OF PHENOLS, NAPHTHOLS, ETC. Phenol See Chapter XL, " Coal- tar Distillation," p. 418. Besorcin is manufactured commer- cially from the soda salt of meta- benzene-disulphonic acid, by fusing with caustic soda and subsequent ex- traction with ether. One hundred kilos, of fuming sulphuric acid are contained in a large cast-iron vessel provided with means for agitating the contents, and into it is gradually al- lowed to flow twenty-eight kilos, of benzene; the whole is maintained at a moderate temperature for sev- eral hours, and finally raised to about 270 C. to 275 C v after which the contents are transferred to a large volume of water and boiled. Lime is added, the precipitated sulphate removed, and the soluble lime salt decomposed by the addition of the requisite quantity of carbonate of soda ; carbonate of lime is precipitated, filtered, and the precipitate freed from the excess of solution in the filter-press. This solution is evap- orated to dryness in iron pans. For the resorcin melt, sixty kilos, of the above salt and one hundred and fifty kilos, of 76 caustic soda are fused together for about eight hours at a temperature near 270 ; when fusion is finished the melt is cooled, leached out with boiling water, and boiled with hydrochloric acid for some time, when the heat is withdrawn, and the solution allowed to become cold, and subjected to the action of ether or benzene in an extraction apparatus, which removes the resorcin. The benzene is distilled off and recovered, while the crude resorcin remaining is dried at about 210. Pure resorcin is obtained from the above by distillation. Pyrogallol. Several processes are employed for the production of 452 THE ARTIFICIAL COLORING MATTERS. this substance, all being based upon the use of an aqueous extract of gallnuts or of gallic acid. One process is carried out by heating a gly- cerine solution of gallic acid to about 200 C., diluting with an equal volume of water, and extracting therefrom the pyrogallol with ether, which is evaporated off and recovered. Another process is to heat one part of gallic acid and two parts water in a closed vessel to 200 to 210 C. for half an hour, when it is cooled, and heated with bone-black, the solution filtered, and evaporated to the crystallizing-point. The crystals are further purified by being distilled in a vacuum. Alpha- and Beta- Naphthols. a-Naphthol is manufactured on a large scale in the same general manner as resorcin. a-Naphthalene-sulphonic acid is first prepared by heating naphthalene with fuming sulphuric acid to 90 C., diluting with water, and completely neutralizing with milk of lime, filtering from the magma of sulphate which is passed through a filter-press, the solution of the soluble lime salt decomposed with carbonate of soda, filtered and pressed again and the solutions finally evaporated to crystallization, when, on cooling, the /3-naphthalene-sul- phonate separates out and is removed. The a- salt is fused with caustic soda, when the corresponding naphthol is obtained. (3-Naphthol, of much more commercial importance than the preceding, is manufactured similarly. The naphthalene-sulphonic acid is made as above, but at a temperature of 200 C., in order to obtain a large yield of the ^-derivative. This is converted into the soda salt, dried, and one part by weight fused with two parts of caustic soda dissolved in the smallest quantity of water, at a temperature of 270 to 300 C. ; when the reaction is over, the melt is treated with water, the /?-naphthol sepa- rated by the addition of hydrochloric acid, filtered, dried, melted, and poured into cylindrical moulds. 3. OF AROMATIC ACIDS AND PHTHALEINS. Benzoic Acid can be man- ufactured by several processes and from different sources. For technical purposes the manufacture from benzoin resin and from hippuric acid need not be considered, as it is made almost exclusively on a large scale from the chlorine derivatives of toluene, such as benzal chloride, C 6 H 5 .CHC1 2 , and benzo-trichloride, C 6 H 5 CC1 3 . The former, when heated with water or milk of lime under pressure, is changed into benzaldehyde, C 6 H 5 CHO, which, however, always has some benzoic acid formed with it as a side-product. The benzo-trichloride, similarly with water or milk of lime, yields benzoic acid according to the reaction C P ,H 5 .CC1 3 -f- 2H 2 C 6 H 5 .COOH 4- 3HC1. The benzoic acid so obtained is almost always contaminated by some chlorbenzoic acid. Phthalic Acid and Phthalic Anhydride. The process for their manu- facture at present preferred is to heat one hundred parts of naphthalene with fifteen hundred parts of concentrated sulphuric acid and fifty parts of mercuric sulphate. The naphthalene at first goes into solution as a sulpho acid, which, on heating gradually to 300 C., is decomposed with liberation of sulphur dioxide, carbon dioxide, and water, phthalic acid then distilling over. On cooling a mixture of phthalic acid and phthalic anhydride separates out, which is drained and purified. The anhydride PROCESSES OF MANUFACTURE. 453 is obtained by acting upon phthalic acid, heated to about 200 C., with carbon dioxide and subliming. Phthale'ins. When phthalic acid or its anhydride acts upon phenols a class of bodies termed "phthaleins" are formed with elimination of water. Phenolphthalein is manufactured by heating the anhydride, phenol, and sulphuric acid for ten to twelve hours at 120 C. ; the sul- phuric acid acts only as a dehydrating agent. The melt is boiled with water, the residue dissolved in caustic soda, and the phthalem is pre- cipitated upon the addition of an acid. Resorcin-phthale'in, or Fluor- escein, is obtained by heating three parts of phthalic anhydride with about four parts of resorcin until the fusion yields no more vapors, and becomes solid at a temperature not exceeding 210 C. The melt is dis- solved in dilute caustic soda, with an addition of phosphate of soda and chloride of calcium to remove impurities. The fluoresce'in is precipitated from the solution by the addition of dilute hydrochloric acid. 4. OF ANTHRAQUINONES, ETC. Anthracene in a finely-divided state is suspended in water by agitation, and oxidized by means of potassium bichromate and sulphuric acid at a boiling temperature ; allowed to cool, and the anthraquinone is collected on filter-frames, washed with water and dried, and for further purification is treated with concentrated sulphuric acid, and heated to 110 to 120 C., when the dark mass obtained is treated with steam, which causes a dilution, followed by a gradual separation of the anthraquinone in crystals. These are washed with hot water, and afterwards with hot dilute soda to remove organic acids. The yield is about fifty to fifty-five per cent, of the weight of the anthracene used. Anthraquinone-monosulphonic Acid. (See p. 445.) This is manu- factured by heating one hundred kilos, anthraquinone with one hundred kilos, fuming sulphuric acid (containing forty-five to fifty per cent, anhydride) to 160 C. in an enamelled cast-iron vessel mounted in an oil- bath. By varying either the quantity of sulphuric acid or the tempera- ture the alpha- or beta-disulphonic acid will result. The separation of the two latter from the monosulphonic acid is effected by converting the sulphonic acids into lead salts, decomposing these with carbonate of soda, and acting upon the resulting soda salts with dilute sulphuric acid, which has but a slight solvent action upon the monosulphonic acid. Alizarin. The alizarin process is carried on in large vessels or auto- claves, mounted as shown in Fig. 111. To the central shaft Z> agitators are attached, so that the charge may be constantly mixed. F is a ther- mometer, and the openings in the top to the right are for introducing the charge, and the small one on the left for admitting steam and water. The process is commenced by melting two hundred and fifty to three hundred parts of caustic soda in a small quantity of water, and then adding twelve to fifteen parts of chlorate of potash and one hundred parts of the sodium anthraquinone-sulphonate, when the vessel is closed and the agitator put in motion, the whole being kept at a temperature of 180 C. for two days, when it is allowed to cool, dissolved in a large quantity of water, and the alizarin precipitated by the addition of hydro- 454 THE ARTIFICIAL COLORING MATTERS. chloric acid. The alizarin is washed to free it from soda salts, passed through filter-presses, and is ready to be either dried and ground, or ground in glycerine to a paste. Neutralizing the soda solution with sul- phurous acid instead of with hydrochloric acid enables a recovery of the caustic soda. The yield from one hundred kilos, anthraquinone is one hundred and five to one hundred and ten kilos, alizarine (Schultz). Sev- eral processes are employed, varying mainly in the duration of the melt and in the proportion of materials used. Instead of soda, lime is em- ployed, in which case a ' ' lake ' ' is formed. FIG. 111. 5. OF QUINOLINE (CHINOLINE) AND ACRIDINE. Quinoline is pro- duced from nitrobenzene and aniline. Twenty-four grammes of the former and thirty-eight grommes of the latter, with one hundred and twenty grammes of glycerine, are placed in a flask (provided with a return condenser) containing one hundred grammes of concentrated sul- phuric acid; when the reaction is over, the contents are boiled for some time, diluted, and the unconsumed nitrobenzene is distilled off ; an excess of alkali is added to the solution, and the quinoline distilled off with a current of steam. It can also be obtained from crude quinoline from coal-tar with phthalic anhydride and zinc chloride. Acridine is found along with crude anthracene, from which it is separated by treatment with dilute sulphuric acid, precipitating with chromate of potash, recrys- tallizing, precipitating by ammonia, dissolving in hot water, from which it separates in crystals on cooling. 6. SULPHONATING. This general process consists in dissolving the PRODUCTS. 455 compound to be changed in fuming sulphuric acid, whereby one or more H atoms are replaced by HSO 3 groups, producing mono-, di-, or trisul- phonic acids. Examples of this process are given under Resorcin (see p. 451), the Naphthols (see p. 452 ), and will frequently be referred to in classifying the artificial dye-colors. 7. DIAZOTIZING. By the action of nitrous acid upon primary aromatic amines a diazo- compound is formed, as in the following reaction: C 6 H 5 .N! H 2 H ! N0 3 = C H 5 .N=N.N0 3 -f 2H 2 0. + NJ O.H! These diazo- compounds are susceptible of a great variety of reactions whereby other groups or atoms of elements may be substituted. Thus, by the aid of the diazotizing reaction it is possible to replace a N0 2 or a NH 2 group by OH, H, Cl, Br, I, CN, etc. It is therefore of the greatest importance in synthetic organic chemistry. The process is carried out in one of two general ways: (a) by con- ducting a current of nitrous acid gas through a solution of the substance to be diazotized, the nitrous acid in this case being most conveniently obtained by acting upon starch with concentrated nitric acid in a suitable generator, or (&) by diazotizing in a bath together with the nitrous acid- yielding substance (nitrite of soda generally). In this case the gas is evolved by adding an acid, usually sulphuric, to the solution. Diazo- tizing is always conducted at a low temperature. The development of productive values from coal by distillation and working up of the intermediate products to those classed as final pro- ducts is thus shown by Ost (Lehrbuch der Chem. Technol., 6th ed., p. 555): 1000 kilos, of coal valued at 10 marks yield 700 kilos, of coke, valued at 10.5 marks ; 30 kilos, of coal-tar valued at 0.7 mark ; 6 kilos, of impregnating oils valued at 0.25 mark ; 15 kilos, of pitch valued at 0.6 mark; 1.1 kilos, of ammonium sul- phate valued at 2.75 marks; and 1 kilo, of potassium cyanide valued at 1.3 marks. 30 kilos, of coal-tar valued at 0.7 mark yield 5 kilos, of benzol valued at 1.1 marks; 2 kilos, of naphthalene valued at 0.16 mark; 0.25 kilo, of anthracene valued at 0.07 mark; and 0.15 kilo, of carbolic acid. From these intermediate products are obtained: 2.5 kilos, of fuchsine valued at 16 marks; 0.75 kilo, of indigo val- ued at 6 marks; 0.2 kilo, of alizarine valued at 1.4 marks; and 0.2 kilo, of picric acid valued at 0.35 mark. m. Products. It would be impossible in the space of this chapter to do more than give a classification of the artificial dye-colors and enumerate a few of the more important under each group. The number of distinct products has already run far into the thousands, and the trade-names by which many 456 THE ARTIFICIAL COLORING MATTERS. are exclusively known frequently bear so little relation to the chemical names that it would be idle for us to attempt to cover the ground in any other way than by a simple outlining at present. But before taking up this classification it will be well to examine what general principles, if any, underlie the production of a dye-color. O. N. Witt * has proposed a theory which explains in a very simple way this color formation in the aromatic series. He names a series of radicals or groups which by their entrance alone or with others change a colorless hydrocarbon into a colored compound. These radicals, which he calls ' ' chromophor " groups, are only capable of producing the ' ' chromogens, " or parent substances of dye-colors, which chromogens, however, are at once changed into dye- colors of distinct basic or acid character when a salt-forming group enters. Thus, from two molecules of benzene by the entrance of the chromophor group N=N is formed azo-benzene, an orange-colored chromogen, but not capable of dyeing silk or wool. When the NH, group enters there results, however, amido-azo-benzene, a real dyestuff. Or from benzene by the entrance of the chromophor group NO, is formed the chromogen trinitro-benzene, which by the entrance of the salt-form- ing group OH becomes trinitro-phenol (or picric acid), a yellow dye- color. Witt indicates some eleven of these chromophor groups, to which we shall refer under the appropriate heads in our classification. Of salt- forming groups which change the chromogens to dyestuffs, two are specially to be noted, the amido group NH 2 , which imparts a basic char- acter to the dye-color, and the hydroxyl group Oil, which gives the dye- color an acid character. Almost all dye-colors are changed to colorless compounds by the action of reducing agents. The nitro- compounds are changed into the corresponding amido- derivatives, the azo- compounds into hydrazo- or even amido- compounds, while more complex dye-colors are changed by careful reduction into bodies richer in hydrogen, which are known as "leuco" compounds. From these "leuco" compounds the corresponding dye-colors are then formed more or less easily by oxida- tion. In some cases atmospheric oxidation alone suffices, as with indigo, in others more energetic oxidizing agents, such as lead peroxide, are needed. Again, the study of dye-colors soon shows that they possess different characters with reference to the ease with which they may be fastened upon the fibre to be dyed or the kind of mordant needed to effect such fastening upon the fibre. We therefore distinguish between basic, acid. and indifferent or neutral dyestuffs. Basic dyes like magneta fasten upon the animal fibre at once, and upon the vegetable fibres after treat- ment with tannic acid and similar acid mordants. They are used in the form of their salts. The acid dyes are frequently sparingly soluble, and are either brought into soluble condition by forming alkaline salts and sulphonic derivatives, which are then used for dyeing, or they are used with fibres previously mordanted with metallic hydroxides or salts, as in * Berichte der Chem. Ges., ix, p. 522. PRODUCTS. 457 the case of alizarin. In the latter case, however, the color acid forms a variety of different colored compounds (lakes) with the different bases. To the third class (indifferent or neutral bodies) belong indigo-blue and some other substances. The classification which is now generally accepted is that based in the main upon Witt's chromophor groups, and we will simply note a few illustrative compounds under each group. 1. ANILINE OR AMINE DYE-COLORS. / Q _. (&) TRIPHENYL-METHANE DYES ( Chromophor group, ^_J N ) Benzaldehyde Green (or Malachite Green), known also under a variety of other names, is made by the action of benzaldehyde upon dimethyl- aniline. The commercial dye is the oxalate or zinc chloride double salt. Brilliant Green (or Solid Green) is the corresponding derivative from diethyl-aniline. The sulphate or zinc chloride salt is used as dye. Magenta (Aniline Red, or Fuchsine) is a mixture of the chlorhydrates of para rosaniline and rosaniline, and is obtained by oxidizing aniline oil with arsenic acid or nitrobenzene. A large number of side-products are obtained in the manufacture of magenta, and have been used under the names of cerise, cardinal, amaranth, chrysaniline, phosphine, maroon, mauvaniline, etc. Acid Magenta (Fuchsine S) is the sodium or ammonium salt of para- rosaniline and rosaniline trisulphonic acids, and is prepared by sulpho- nating the ordinary magenta. Aniline Blue (spirit soluble Blue) is a salt of triphenylated para- rosaniline, and is made by the action of a large excess of aniline upon rosaniline. If magenta is used instead of rosaniline a reddish-blue is obtained. Diphenylamine Blue (spirit soluble) is probably the chlorhydrate of triphenylated para-rosaniline, and is made, as the name indicates, from diphenylamine, which is heated with oxalic acid to 120 to 130 C. Alkali Blue (Nicholson's Blue, Soluble Blue) is the sodium salt of the mono-sulphonic acid of a spirit soluble blue, and is made by sulpho- nating the latter. Patent Blue is the disulpho salt of m-oxymalachite green. It colors wool a very fast greenish-blue and resists alkalies. Is much used as a substitute for indigo carmine. Hofmann's Violets consist of salts of the ethyl and methyl derivatives of rosaniline and pararosaniline, and are made by the action of methyl or ethyl chloride or iodide upon magenta in the presence of caustic soda. It is of historic interest, but has been replaced almost completely by methyl violet. Methyl Violet is a salt of pentamethyl pararosaniline, and is pro- duced by the direct oxidation of the purest dimethylaniline with copper chloride. Crystal Violet is the chlorhydrate of hexa methyl pararosaniline. Methyl Green. This dye is formed by the action of methyl chloride upon methyl violet. The commercial dye is the zinc double chloride. 458 THE ARTIFICIAL COLORING MATTERS. (b) DIPHENYL-METHANE DYES. Auramino, an important yellow dye, is prepared by heating tetramethyl diamido diphenylmethane with sul- phur, ammonium chloride and common salt in a current of ammonia gas. Pyronine is a red dye obtained by condensing formaldehyde with dimethyl-m-amidophenol and oxidizing the product. (c) AZINES (EURHODINES AND SAFRANiNEs). Chromophor group = N N =. Neutral Red (Toluylen Red) is a basic dye-color prepared by the action of nitroso-dimethyl-aniline upon w-toluylen-diamine. It is used with cotton after mordanting with tannic acid and tartar emetic. Safranine (Aniline Rose) is prepared by the oxidation of amido- azotoluene and toluidine, or of p-tbluylen-diamine, ortho-toluidine, and aniline. The commercial salt is the chlorhydrate of the safranine base. Naphthalene Red (Magdala Red) is the compound in the naphtha- lene series corresponding to the preceding. It is obtained by fusing the chlorhydrate of a-naphthylen-diamine, a-naphthylamine, and amidoazo- naphthalene. It forms a dark-brown powder, soluble in alcohol with strong red fluorescence. It is used largely in silk-dyeing and for velvet because of its fine color and fluorescence. Mauve'in (Perkin's Violet) is of historic interest mainly as the first aniline color. It was obtained by W. II. Perkin in 1856 by the oxidation with sulphuric acid and bichromate of potash of a mixture of aniline and toluidine. Methylene Violet is a reddish-violet dye obtained by the action of hydrochloride of nitroso-dimethyl-aniline upon a mixture of the hydro- chlorides of m- and p-xylidine. Indoines are basic coloring matters dyeing cotton deep shades from dark violet to indigo-blue, fairly fast to light and washing. They are made by combining diazotized safranines with a- and /?-naphthol and conversion into hydrochlorides. (d) INDULINES AND NIGROSINE. Induline, spirit soluble ( Coupler's Blue, Guernsey Blue, etc.) is prepared by heating amidoazobenzene with aniline to 160 C. Induline, water soluble (Indigo substitute), is the sodium salt of the disulphonate of the preceding, and is extensively used for silk and wool. Paraphenylene Blue is a dark blue dye of the induline class obtained by the action of p-phenylene-diamine upon hydrochloride of amidoazo- benzene. Naphthyl Blue is the sodium sulphonate of anilido-phenyl-naphthin- duline. Dyes silk blue with a red fluorescence, and is faster to light than the ordinary indulines. Nigrosine is prepared by heating nitrophenol with aniline and aniline chlorhydrate. The alcohol soluble compound is the simple salt of the base, while the sodium sulphonate forms the water soluble compound. (e) ANILINE BLACK. For the preparation of aniline black, aniline chlorhydrate is very carefully oxidized. The dyestuff is not prepared for dyeing or printing, but is fixed on the fibre by an oxidation process PRODUCTS. 459 which develops it gradually. It is a very fast black. Quite a variety of oxidizing agents may be used. Potassium chlorate and copper sul- phate are frequently used in admixture, and vanadate of ammonia is also of special serviceableness in connection with the chlorate. Electrolysis of a concentrated solution of an aniline salt will also produce aniline black. 2. PHENOL DYE-COLORS. (a) NITRO-DERIVATIVES. Picric Acid (Trinitrophenol) is made by nitrating carbolic acid direct with strong nitric acid, or, better, by acting upon phenol-sulphonic acid with strong nitric acid. Forms light yellow leaflets or scales, and has been used as a dye for silk and wool. Naphthol Yellow (Martius Yellow, Manchester Yellow, etc.) is the sodium, potassium, or calcium salt of dinitro-a-naphthol, and is prepared by the nitration of a-naphthol either directly, or after conversion into the mono-sulphonic acid. Naphthol Yellow 8 is & sulphonate of the preceding, and is made by nitrating the a-naphthol-trisulphonic acid. The color is faster than picric acid or the simple naphthol yellow and is more extensively used. Aurantia is the ammonium salt of hexa-nitro-diphenylamine, and is made by the nitration of diphenylamine. It was formerly used for wool and silk, but is now used only for leather coloring. (6) ROSOLIC ACIDS. Eosolic Acid and Aurin (Pararosolic Acid) may be prepared from rosaniline and pararosaniline respectively by treatment with sodium nitrite followed by boiling in the presence of sul- phuric acid. These two coloring matters are no longer of commercial importance. Yellow Corallin is prepared by heating pure phenol with concen- trated sulphuric acid and oxalic acid for some hours until the evolution of gas nearly ceases. The crude product of the reaction obtained by pouring the melted mass into water is changed into the commercial dye by dissolving it in caustic soda solution and evaporation to dryness. Red Corallin (Paeonin) is obtained by the action of ammonia under pressure upon the yellow corallin, and represents an intermediate pro- duct between aurin and para-rosaniline. (c) PHTHALEINS. Phenol-phthalein is not used as a dyestuff, but as an indicator in alkalimetry. Fluorescein (Resorcin Phthalein) is made by heating molecular pro- portions of resorcin and phthalic anhydride to 195 to 200. Fluor- escein is not used as such for dyeing, but is converted into the eosins. The sodium salt of the fluorescein comes into commerce under the name of uranine. Eosins. The several halogen substitution derivatives of fluorescein form the class of dyes known as eosins. Thus, the potassium or sodium salt of tetrabrom-fluorescein is the eosin yellow shade, while the cor- responding salts of tetraiodo-fluorescein constitute eosin blue shade. Methyl and Ethyl Eosin (Primrose) are the methyl and ethyl ethers of tetrabrom-fluorescein. Aureosin is a chlorinated fluorescein. Saffrosine is the potassium or sodium salt of dibrom-dinitrofluorescein. Erythrosin 460 THE ARTIFICIAL COLORING MATTERS. is the potassium salt of di-iodo-fluorescein. Rose Bengale is the sodium salt of tetraiododichlor-fluorescein. Phloxin is the potassium salt of tetrabromdichlor-fluorescein, and Cyanosine is the potassium salt of 'the methyl ether of phloxin. Rhodamine is the phthalein of diethyl-meta- amidophenol. Cyclamine is obtained by the action of iodine upon thi- onated dichlorfluorescein. Violamine is obtained by the action of o-tolui- dine upon fluorescein chloride and sulphonation of the product. Wool and silk especially are dyed with the eosins, and cotton after mordanting with various metallic salts. Gallein is the phthalein of pyrogallol, and is prepared by an analo- gous method to that described under fluoreseein. It is very little used in dyeing, but serves for the preparation of Ccerulein. This dye is obtained by heating gallein with twenty times its weight of strong sulphuric acid. Forms a dark amorphous mass, which dissolves in alkalies with a beautiful green color. Coerulein forms a colorless compound with sodium bisulphite, which is known as Ccerulein 8, and is much used in dyeing, as it is easily decomposed by steaming. 3. NlTROSO AND OXYAZINE COLORS. (a) NITROSO COLORS (Chromophor group = N OH). Gambine is obtained by the action of nitrous acid upon a-naphthol. It dyes iron- mordanted fabrics green. Dinitrosoresorcin is obtained by the action of nitrous acid upon resorcin. Dyes like the previous color. Dioxine is obtained by the action of nitrous acid upon dioxynaph- thalene. Dyes bright green or brown shades on metallic mordants. (&) INDOPHENOLS AND INDAMINE ( Chromophor, N = ). Indo- V U__J ' phenol (a-Naphthol Blue) is prepared by oxidizing dimethyl-parapheny- lene-diamine and a-naphthol with bichromate of potash and acetic acid Indophenol may be reduced by glucose and caustic soda to a leuco- compound known as Indophenol white, which is also sold commercially. When cotton goods are printed with leuco-indophenol, the blue color may be developed in dilute bichromate of potash solution. Indamines are obtained by heating the indulines with p-phenylene : diamine and p-phenylene-diamine hydrochloride. Dyes deep indigo- blue shades on cotton mordanted with tannin and tartar emetic. (c) OXYAZINES I Chromophor <^ ^> j. Azurine is obtained by V x (y / the action of nitrosodimethyl-aniline hydrochloride upon si/m-dioxy- benzoic acid. Dyes a violet blue on chrome-mordanted wool or cotton. Gallocyanine is obtained by the action of nitrosodimethyl-aniline upon gallic acid. It is a gray paste, insoluble in water, but soluble in alcohol with bluish-violet color. Prune Pure is the methyl-ether of gallocyanine. Gallanilic Indigo is the sodium bisulphite compound of gallocyanine- anhydride-anilide. Meldola's Blue is obtained by the action of nitrosodimethyl-aniline PRODUCTS. 461 hydrochloride upon /3-naphthol. Dyes cotton mordanted with tannin and tartar emetic indigo-blue. Nile Blue, Capri Blue, and Gallamine Blue are all oxyazine colors obtained by analogous reactions of nitrosodimethyl-aniline or the cor- responding amidophenol. Resorcin Blue. By the action of nitrous acid upon resorcin is pro- duced diazoresorcin, which by the action of concentrated sulphuric acid is changed into diazoresorufin. This yields a hexabrom-derivative, the ammonium salt of which is the commercial dye. It is used for dyeing silk and wool a blue color, which has a red fluorescence, especially by artificial light. By combining with yellow dyes it yields a fluorescent olive color. (d) THIAZINES Chromophor ^g 5 o 7 g^ g 1 s i i ^ c- oj > '- ijo.2 g '3 H H I j-fa.^ I-D S '"go 1*3 ' ll 1 i " i * i* ^ i s 5! 1 ? * i ^ o 2 * i 3 _e 55 58 A o^; n > cr^~~ 2 ^ ~ 2 * ? 5 * ' 1 3 & OS o. ^S 11 8 ^ S" ^* 5 ^ d 1 5| i S*i ! 3:3 IT & 1 i b "o. "ti < o ft, o PS w 1 *o ! C ^ ai 11* s g| |||:3, ||i po & O xi o3 5 ^ 2-2,2 H " "S'^'SS ""^S 3^0 rf e tn-p.S ~ 8 > 3 a * Of O * 3 <"" S o 8 not reappei ig matter, wh ns without de iece of unmoi on of the orig in ojH 3-s O aj O. . <1> Oj M >>j2 9 C -as m> 3 {si iw 1 11 o o O c 5 as 2*0 8 MnS'S wOM"So-3 S'-2~2 a'5 J 9 Z 3 8 M H o < w Q "3 1 toj,^ -T38 J3rt. . O o <" -d">d B < o 5 < I e original 1 ll II o x * 'S S g g! ^-2* a> oj a) o- g x;'3. e '3* * 5 .J^s i-^^-o^ 2 o-.2u H ^ .20." F i ae"^ 5 o XI s^ O^ *hft ^feC J -2"o ^*v O^H^^OJ a H OH 2 o S Bjo'a W 'C!3 3 ^ ^^ ^SS^p, SIOCHLO ll 03 O S 8 .2 ^c ! Bji KO'Sfl &gal^ Slli^lS* S^*S *-2 S 33SI& a "^S^SQ^ol < <'f2 5 < o.'S .S os S ^ o SH n S Sz; < a E N H o B o" i _o "C .5 'S . N is ?/S lL if li K! glslll 1 _o 2 O jj f 2 jg 3 PH 5 aj' 1 ' a>S "oO'SS 5 S" 1 ^ S N 3 r* o M i o o t- a) o 43 l i^-suM 8-0 5s 3".* S .. .- 2 ^ls A o is |Q s _x>.g_ s _ |a g -g mgo og-OEg. 5 v 3^ if** 2 & El S 3 2.2 2 he'filter y SJ ^"S ofj A H l illtll .sl ill ill el If 11 itllll < < < c i c t. * a-e'S fi-rfB O o3 >^ . .t-^jO 1 *& F ^'rt *!To.5 *~~'"S ^- " Q "3-0 J; S^^W 3^iiO ^>> o fc'C S C ^ 8 8 ^* S oS O _e c -2* S i7? S^ foxJ c*^^ vo P a 15 "3 o ?$*& S "s-e aifJ * &. Ji-3^ i-? ^ ^ o 5 K ^ S .- oi A "*"* 'c5 * '3 o ^ "^ 'S o '~ S " - u3 B C-O S - ^*Q^ tj?^^ xi Q^S *^*2t2 'r- ^J O C D. _o S 03 3 :W 3 -s: '-' Ci S fe '" > ,wd "" '.' ai 'O > S> "fe.2 3 . ^-3 0) "o M M 2: ? S*^3 ^* cc^^tf^ ^tt ^^"o CQ"^t2 "~ ^ co ** _, ^ o :- *o . tj ^* ^ > "* '3. tf -c~S f< 3 fc w xs > '2'^' u >2~ =si"d jSt-' 1 * S'o'S ^ ."S u ^ O ' o> P"t .^c'^So C^^oj ^ Q,*3 <^*^^ ^"^0^^ ^ t" t & 0} t^^^^-^ K^^?'!- oj O'^'Sb ^^-n. - 1 *"" ^* s" 0* "55 x-2 8 ".2 ~~^" 5 " .2 B. ^OQS S ^'- 03 o . P ^- i) X _1 P,C^ X*^^ CQuOJO o^ "^ ^* Ij C ?S" ) M> K^ ^ " "S K'S^' ' 1 "" "* 5' = 'S H O *3 X! ft! oi 5 6* ^55 aS"" o^5* < = 'oS S ^>o W w OH o ANALYTICAL TESTS AND METHODS. 473 II. The Dye is Insoluble in Water. Treat with a five per cent, solution of caustic soda. B C g g pC ** 3 5 e ft ft.o g ij "O W Sag fill 1 | rj C =S O 5 o>x: ;- "-" O CJ ^ > 58 2tfi *g ** -j^ ^ yi ^ Sv< O oj O P. 01 M -Ofti> B-a-S SaS S |G __ H ^^ olution inc-dus the sol ry, t char e im ginal colo reappear. o ft >H g o ii ec colo pape the a nec olo a he original c the solution pears. ll ill! 474 THE ARTIFICIAL COLORING MATTERS. Dextrine. This substance is estimated by weighing one or two grammes of the dye in a small tared beaker, provided with a glass rod. The dye is dissolved in a little water, and absolute alcohol added, when the dextrine will be thrown down, and adheres closely to the glass. The contents are emptied, and the glass rinsed two or three times with alco- hol, dried, and weighed. Starch. The presence of this substance must not be taken as an adulterant in every case it is found; owing to its peculiar properties it acts as a drier or absorber of moistness, and hence prevents the caking of the dye. By dissolving a quantity of the dye in water, and allowing the solution to stand in a conical glass for a while, any starch present will subside, the clear liquid is poured off, and the residue repeatedly washed with distilled water and alcohol until no color remains, it can then be examined with the microscope ; a drop is placed on a slide with a drop of water, the cover-glass put on, and a drop or two of iodine solution placed on the edge, and allowed to displace the water by the aid of a piece of filter-paper opposite the iodine, will, if starch is present, develop the characteristic reaction, blue. /S^ar. Estimated as for dextrine; the alcohol used should be satu- rated with sugar. Sugar can be estimated in dyes by precipitating the coloring matter with basic acetate of lead, and proceeding as for raw sugar with the polariscope (see page 173), or by inverting and estimat- ing with Fehling's solution (page 175). Sand and Iron Filings are gross adulterations occasionally met with in dyes from unprincipled dealers. Their presence would have been noticed under the insoluble matter determination. Iron filings can be easily determined with a magnet. A careful microscopic examination of ground and crystallized dyes will throw much light on their preparation; bronze-powder and sugar crystals have been thus found. Paste-dyes, etc., are best estimated by evaporating a weighed quan- tity to absolute dryness in a small glass mortar, grind thoroughly, add water, and filter through a tared filter, wash with water, dry, and weigh. If this is not done, trouble will be met; paste-dyes not filtering well if simply diluted with water. The Examination of Dyed Fibres can well be accomplished by the aid of the following table, which is adapted from those of Hummell,* of R. Lepetit,f and of Lehne and Rusterholz,J and embraces a majority of the more important coloring matters which have found application. The reagents employed are Hydrochloric acid (HC1), concentrated, 21 Beaume, and dilute, one part of acid 21 B. and three parts water; sul- phuric acid (H 2 S0 4 ), concentrated, 66 B., and dilute, one part of acid 66 B. and five parts of water; nitric acid (HNCK,), concentrated., specific gravity 1.40, dilute one part of the strong acid and two parts of water; caustic soda solution (NaOH), concentrated, 38 B., and dilute, one * Hummell, The Dyeing of Textile Fabrics, London, 1885. fR. Lepetit, Journ. Soc. Chem. Ind., vol. viii, p. 773 (from Zeits. f. angew. Chem., 1888, 535). $ Farber-zeitung, 1891, Hefte 11, 13, etc. ANALYTICAL TESTS AND METHODS. 475 part of the strong solution and ten parts of water; ammonia, specific gravity .960; alcohol, ninety-six per cent.; stannous chloride, tin salt (SnCl 2 + 2H 2 O), and concentrated hydrochloric acid equal parts; acetate of ammonia solution, by neutralizing ammonia with pure acetic acid and bringing exactly to 5 B. The initials or names in parentheses following the names of the dye- colors are those of the manufacturers who furnish the particular dye- stuff, and will be readily understood by those accustomed to handle these wares. A separate column has not been made for nitric acid, but where its action is distinctive it is noted under the head of remarks. Method of Procedure. For the testing with concentrated acids and caustic alkalies small watch-crystals are most advantageously used. These are then placed upon white paper in order to be able to observe carefully the changes of color. The concentrated acids are most con- veniently dropped from small dropping tubes or pipettes, so that they can be added drop by drop until the fibre is completely covered. After addition of the acids four to five minutes are allowed, and the action is then noted. The watch-crystals are then heated carefully by using a very small flame or placing them upon a steam-coil, but the liquids upon the watch-crystals should not be allowed to boil. After waiting a few minutes and allowing them to cool, water is added to the contents of the watch-crystals. All the other reactions of the tables are carried out in test-tubes. The fibre is placed in the test-tube, covered with the reagent, and al- lowed to stand for several minutes, then heated without quite bringing the liquids to the boiling-point, when the action is carefully noted. Finally the liquids are boiled for a short time. The solution is then poured off and caustic alkali or acid, as the case may be, is added, and any change carefully noted. After the tests with concentrated hydro- chloric or sulphuric acids the fibres are well washed with water in order to observe whether the original color is thereby restored. 476 THE ARTIFICIAL COLORING MATTERS. CO W h- 1 W o CO P. .S ^ o> o nJ O ^ I o < I I aj j, a I 22 - oO*t S ci 45 CJ *^ s .| 1 II l^-o 1 B '| w o.^ *3 b ^1 c 1 ^ ' fl ^ 3S"1 li^a j; t. o ^9|S ^4 S ^ 2 Remarks. ^T~ S 5^ *" O t* 3 " CM a> ,^$5 S'S'C fn v> r ~,'O 71 >; << s) i&s HIS 'Illillli >i'Z Cju cs -5 .a .2^o3 .sScgS-?-; S 55=- s S s -g.I i|8ri|||s| o,-BS : 5tc" i |..2: Ji|ll& ? ill lisHiiijiii tljlijiili! itrous acid, fibre brow icric acid, fibre reddis 11 these dyes which r are attached by a ho tion. itrous acid, fibre blu< violet, icric acid, fibre dark b O - - <; O H K2-< .< On d . S 1 2 u o o a a 1 ~t; d _o o fl .2 M Vj O o o < 23 t> 2| "8 S ''3 g Bj 9 6 ^< o H z o o , ' T3 5 B 4- II ft c ^w C 'i 5-5^8 IN* A||J 6 a *1 4>; W> X s g-o'l-^ lip "o 3 t r*i.'* > ^ "^ (-. CC O ^ ^o be c? IE l-l 5 h W o go ^ ...-C < . 3 i ^o d _o B K p 1] s 1 1 K'l 2 So I .s 5 S d d W 4)j 'O'S ^ _0 _o o "Co _0 > c ,0 i 1 K o 'S 2 I 5 s s "o ^ o 5 1 ^IgJ 5 |||| c d c-g - 3. s ill lllll 1 1 ^'11 .1 5 ill s 11^ g, f 2 ** t< ^ * S "3 ^ _N "p p,C "O 4) ' g c o g S s B S ^ S ^ S * QJ ^ C j O ^ ^5 B 1 S ".2 _LT W) 2*2 .. 03 1 S c c CO! a "tug sS'f.ffS'SSi o sSOWSS o "s illlil 0M ^ ?* < 03 S c; 2-^5 ^SSu i|l| S^sS o a. S J* . a' B^ ^ i a "3 gjj .2* A .-o->> S2! o! . ||||| l^ll^ d H ilglslfl^ - u fc. M G S Q ~ a> slspls^s: g 8^1-S ggljj s ^|g|l ?> w s .2 o> =c s ^ Wt3tJ_r&: 1 KS S w cu i c S -T s c^ -SScoW Q M ft ft o g K 5 . g MB g H | M M O- "^ O Ed OH h fe & ** s *3 1.5 :< 2 ^hrO g S'E- ^S 03 ' a I ^-03 ...5 *> 3 .o Xi g>| _g o' S Q J 5*3 ? S |g jj| 1 l| * 11 l!i fci C ?5-S g -S SS S'S : Jin | ill t~ C '** *S rf >-^ (_, r> y >" ft'U flj ^ ^ *3 ^ 4) r^ ^ fc O" S ^ 2 *3 5^2 3 fc > - * i- . t- ^-^i c3! CC,Q O oj O 5 a'S'-c > P 'o'" - ro" . P-ji en 'Sio 5 Sa3'S rgtSta S "2 '!2-o" 2 03 ^"5 S "3.2 c C .2 T3 fQ 2 '? 11 2 'v bC'O' > tu o "*~>'3 '& ta - ic -i S eoS 1> 3 Q O Js2 2.2'E 2 5? 11 *!.2U8 |sl1*| 3 >S'3 M g=s gga.H IB^S ill D9 X PH 1 2 X X ^x " "* J5 P4 2 S . . 3 *o S o d d a* S B N _o _o .2 kg s . o C o *? o S3 a ^5 "t o . S *pi ^*rt u . _q> a oj O S ts ^^ _aj-43 g a> 0) v 85 l< 8 o glS o tJ'o' o o 3 fl X X 3 H fc K 4 n p _ "U'd decolor- L sa^ ill 2 < o 2 fl M nj l|-| S^J bo-i u "o 5 111 I lilt -o l| 3 u 3| 1 5 S rj 'i'S 2 B S 8 jU'O'aJw o o 5ft o o o w"3 K S fe K 8 S p B . 2s al ft _o _i a -2 E2 "5 T3^ T3 O g sj boai'7? ,5Sf8 ftc3c rf a B" o B fiftl & c 2 -2 a T^ C '^ v OT ^ cfl *^ -2 fli tS "Q rrt a C3 ^ 1 g^3 a 1 -5 Q> 50 O S f3 8 5*3 2 c ^5 ^" 2 2 SJ'S.H'-s 2 ^ J3 '^ ^j Q ^ *M ^ '-2 ft -Q ^Q i-j o o ** S *2J M o o -O gj ^ ^~ Q E 6 S E 3 K 8 S g a -i lit ^ 11 S3 2< * il ^^SS a"o 1| Lrfl B B O Q) 1^1 g 93 o. s'? ^"44 ^"B "^ ^ w * ! 'O' _ Jf'o'" S 73 23 s3>3 "c 5 00 "S3 JS '3 gS tc O, -*- oj 03 .2 ' " B Jgg^v g J? If fii> 52 S S3 0) S3 S_o llsl jo gS3 | 3 ra bCjo; ,0 * s * 52 4 3J S 3j Cfi Q B 5^9 pt< PS, G fc, E f R fa fa d-s A M , .aj Jioa i A * Ssoa . tf..l B si-s 3 Kbre violet, liqui colorless : liaui> S5 3 2 0^-C xi^s^'-SoW-2 Q ^ 3 o ? 03 ol 5S'o c Q ~ C o-sis^ Q 111 fa el a r=so. E oecomes oiue, liquid greenish blue. Dilute, fibre red- dish-brown ; co centrated, fibre olive black. Dilute, fibre brow red. solution col less;concentrat fibre greenish- black. Dilute, fibre black violet; concen- trated, fibre blu solution colorle H d 9 ffl bj 1 S^ fe .4 H c H S K^; t * """ o co ri 2 5 pi CL, ^ OH -B a EBRICH i Si II Si 11 KM Si g it s I! h at n pq o ^ o O Q 10 P 5 478 THE ARTIFICIAL COLORING MATTERS. (B-O .- c - "O -Ofl ^ ijl, WO)- W H fe ^0 , S'3 1 S ^ ji-'C r- ^ Q; 03 ^3 tH O 2 <5 "s* 2 S P "^ b^S -*- 1 oi o>.5 og . S'" 2*8 li ^x**^ |q| |s 5 . 'K^ 5 a is 5 Remarks. ot water containin NH 4 OH extracts a p from soluble eosins. itrous acid, fibre v brown -red with amnn eric acid, fibre brown |M .11 .5 '1 1 |l |'B S-oS aj o >S-c 2-S 2 ' S sSS l-l Sl^.B-g g= S^S.2-5. lll'glg*^ .s'S'S 1*5 ^S N 3 9)-B'2 o-r; oi fc.S- c iliilf i c Ji 'S W g o? itric acid gives a bri spot, leaching powder bleac Mled with a solution and cooling, gives an orescent solution. H 55 S e ccH "^ c-aoOgo fa 55 WPQ o . M j 0JM Alcohol. .s*?^ o *j? IIP ttle extracte solution pin fluorescent. a P , r . ^aj^ ||| 2gfi | o reaction. d o e q CO a < 55 55 CO to i -a . . ! ift I go | o s S=2bL a) o d5 5 J2 - sic -> ill i ssjf. III! _03 JB.9 s ill T3 t-S M **^* O $5 PI 2--H S 3 3 J5 ?S "C I ^Ife s III o O 3 T3 g so e* fa E s "< CO ?H fa N . . o T) o O K O la 1 1 d 1 a) ft ft .2 ll-d s 55 |ll 1 o B o o I a> 9 a> bb s 1 O bj)l> rill fa 55 55 Q CO CO 55 d I ibre yellow, solution pink, fluorescent. o reaction. o reaction. tT-O 111 II! "Si-- jjjj 'eated, fibre and solution cherry-red. h 55 55 fa fa fa fa _o 3|| _j 2 o'> -w- bb a c "33 *'>, W "3 * -o ? s> ... "S""'- '3 '? S 2 S 9 e 2 |fi5S 3 fe i 0$ ^ ,M "^ ti 0) ^ be . .^- QJ ^3 c .2 p oca l ^g gS, H *S a .0 Qi oj a 3s ^ u I o 0> O 3) C S 3 a 1* S , W QJ QJ 3 D ^ a> s * S9 3 1 51s 3JXJ .ol %% a fa E 55 CO fa fa fa CO 'to P d 1 - . d . "S ID _o * o S c ?& s td ^~6J A si 03 o fn'S OJS^ 2 (t3*T 6 ^" uj"? "d 3 JS 111? ^"i 55 * .-j'3'3 S s" 55 fa E fa fa m 5 S5 K M 3 S ^ * E d g 5g H H j N _ o Cu ^~* "^ 4 ^ So S5 ^ ^ o . ? s "3 1 ft n S H S? *" <2 aS aj 1 IB o . a II bis B g o 2 4^>3 a) ** ^ *-*^ OQ 8 1 | _ a> .2 o> ' Se -3.0 B >- u * M "" p T< X 'O o 3 * * ** ^ -*J o O "3 4) O o * H o ^ H> & iz; S5 3 !z; sig - js . "d S= 5 S 3 o o ^ ' s s-l . >.N bD C. 8 1 N till '"o'o "o ^g8 S | P| d * ^ o g c .c S'C S ' . ^'C ^^ 5 flfS . ^ * > O" I g!e5 : 3 3'n Sill! W Q 1 11 Q fa a) S"o 5 ^'O'oS W)0 fa PH ' >vS 13 >.o g "o^ li B o a o 3^? s^S w ^ x . bo - ti S t,~ os a :H ^^ O, " S p. o> 1 'g'o ****s s lal 3 .2 s . 1| 1 ft? to d M fl 03 KA V (jj C3 dj 3 C O .0 >c 'C "5. o fa as"* 03 a O a I-" 8 oT E* 1 1 3 W fa " s ~ a 'ft c 1 1 O 0) q S 1 llj. g||; -g d >. _a> a <6a & . M g| ^^ *""" -^ .S2 'S ^ _o > >> K^ t "O- *. t- ^ JH 3 ^ JH ^* QJ O O C .J O >^ 'O -^ ty? Jllll "o ll ll Illil illf l ji> oS'aJjaj i|i ill, fa CO ^ Jz; fa~ fa fa &i 03 03 fa M I ^ S nrs *%Z~** 8l|sl ^ fo 'Eo.il go 5B fa 2 tf.lia gS 3-Sg.2 C " aj 010*30 S2 U 3 2fe c-^oo-d 3 5-3 w O.-2 5^2 m o> a S^3 fa U P4 Q s I ^ n K g w ' S ts~ g .fa fJ"O QJ'O j,. 2fa H "g Bad 2 N aS " z s"ZT 2 ^* W* l? E WJ WJ y -< < 5 S f >HJ ^ J . O3 O3 H < K B~ w o o o fa" K~" 480 THE ARTIFICIAL COLORING MATTERS. * ' 5 a ' -a 'O A SjS ** M H d) S 3J* 1 1 , lg 1 %~ oJg fell -a 5o S-o ^j c g o o a> 3 " 03 " 5 ._, O ^ * p t o G ^ o fe 'S ** '" > ** ^ O ^j CO. xl ,4 Jj f2J wT-^ > ~ S -^ 3 sf^s's S'S o M 8 "2 * 'S a T? 4> 9 os 5 "o"* S3 : u. ^ 1 52 S 3^-0^5 -o"S *=a S g S SJ^B M 2 -! -E 1* ! 1*1 J B Ji fl fi S ^ QQ. S Mj d . ^ """* g 3 S3 o c g ^ M H 4, g H "3^3 5 S5 >< 3*" CO fc !? ^ g "S- i (-. o o . * G ^ i o > o o H + C S o jolorized. 1 i|||si | | 8*^w I Hl^llfl d i % o 1 >re orang( irown, the lecolorizei C *,O !~! colorized leating. QQ ^9tD J9 Q\ )T gj t.^^IS SC O 4>*-* *X *^ = C oo OtCr-. 4>JS fa fl o - c H C & * C & oS O O.G O OJ3 is Is|| d _o B g 5 i S a P. 3 K si^ 'p? c'g'5 C 'EI Jill 1 G* B* v*i o -r >> 3*T? >> S ^ o o S s3 '** fa ^ en en fa fa 55 S5 hJ en . , , c *" *L 4) d o ij deep red. ^ , " S "5V 5 (3 Hi 51- Si.- Ill u -^-t o i o> S :i >" scarcely . ,3 fl fe o ^ fl .| 8 .l Hills 6^1 ^5 c'S ^ Q)*> OJ L* rr *" .O O o * 5 <- 5 o |H ^ O *^3 J= .= gill ^13 *|1i fa fa s fa S fa fa H 60 bb .2 sTg; to bo 2 d g jj _O o _B fl 3 *2 * <3 a ,2 4)^ V b u i S (V) C ^* ? O W i p. i. 'S ^ 5 o< 1. 1 c 13 o>> s** * I w 1 5 1 5 S o_o o o | ^! B 03 V PI i 3*3 s* 3 || a 03 o) 5 | 0) en CO W en CD 5 fa fa tn ce C -if C B -M bo 9 * o 5 S O 2 s Q ^ S'E-S r-> I "3 * .2 I 'S5 .0 .2-2 o* 3 , O3 ^ ^> ^ W bl u? j^ ^* O O fr5 be ^ d w 11 11 "3 a I *d *^ C3 0> ^30 Sfs "3 a> Cs sle re reddi rown, so line. G Q; O ^ -, O *- rj r*,S 2 o3"^ S V O X J id O M J H PH 2 CO ^ j M >. fH w'S" 2* & < 2 O H I J5 55 K B 3 g p 3 i * \4 H S3 X ^S M S * *^ o /vs H S E ^ ^! ^ o H >-< Q ^ S P5 PQ 4 < H 55 * OH 5 ^ cy H -."^ ** 1) ,2 g.3 3xi o o III I ^ ft xi 00 (sn *-^ fcl 03 p t 1 i if a is 2 1 > C 05^ 2 "3 rf .Sxi X! 5 - *o" S ^"3 XI S> >> _o bCj4 X! *O j3 *7l gj 2* 2 "3 "3 _r ^ rt *^ irT r '3 jj'O '^ 3 '^ '^ M 5 W fl ^ a) aS .2^| so gig! 2 .2 ^ * a ufj 'tn i 2 1 '^ 'C -t< '^ .ti il.ti-2 .-5 as >> ^H -tn .t^ ^ 'z *~*? u *^ 55 55 55 55 55 55 a! -55 S 55 d li a a o o a' a* g .2 .2 5 a a 8 B4 ft o o ^ ' *. ' a oS OS as as *> oj ^"3 o o3 O rt ; 2 2 0) 0> h M MO 2 Sx-g 2 33 p o o o "3 55 55 8 o 3x1 o o -ax 55 55 w ^3 ig|| ||| 2 II j| j a 3 ^. >> -^ la Si * * 1> 'O . "3 . o *- .S *^ 0> *-< "o 0} *^ 2 2 o d 2 "3 2 ~ 2 55 55 S 55 55 Q 5J 2 'ft o 55 O fa 55 t. a .2 t. .2 -i S .2 i ili . 4S' >.o t' *M .* (Jn t) ^*"^ K " Q? O 3 *-^ C u r q W>' 2 j * c M'c^'g'S^S ^ aj ^ 3^f3 ^ "* U M * O **'o S o a o 2 -O b* ^$ CJ t-2 "uS^'^^'S'SS E 10 ' s 88100 55 fa O *^tX -J2^?o^M p t ^3 fa E E S a -o bo a ^-* - s - -j.i O 0> JH* 3 a 3 *rt; gS g si ...a ai . M'>*Q S ='1" o ~< 'o ^ t*. a a g'O (0 S rS 1 -^ 33 '>_byS-2 _3o "^O.^So 3 O . ^~~i aa . -08 S" xi c a"S -o^ 5P -|5 2-c5 3 a S oj Q C w i. g-2| 5^ a'SS ^.2 8-g i--^ S M 3a"2 < a)_3^3 4)^3 oiN^ftp 2 a r-f^^ 4>r2a c^2 i>^*'>'a xl S. xl" ? E"? S" 5-" 1 xl'^S s3o)"" b^5 fc"^ 2oo2 fa s wu c^ fa"* fa Q E fa fa o -i - QJ . i (B -5>>^xl 56 3. g..g i , Its s .i s -l c"^a'^a'w fc g^^>.- 3 3JXI tcis S3 ,Q'^3 X!bio.-2j3!C^ ill Hi S"" Q ^^^ fa fa fa E E o E U td ^^ y 0) > 1? _> 1) rn w W W a? Q-G Q^3 i? I s 2 z < "? w g 2 2 S ^ ^ H p5" o^3 5 S ^s a HOJ SSo > i 111 13 i-J N < 31 482 THE ARTIFICIAL COLORING MATTERS. 00 tH >. ' O ' tr* ' O i 2, -a S N^S S 8 M 3 'm ' J S 2 K $ oj a< 3 J g W M js -a 1 & 5 jd a> *- p ^? ." (*- '5-SJi 3 Remarks. Boiled with soap, soluti blue. Heated with olive oil, pu extracted. Induline NN is not ch{ bleaching-powder. Nitric acid gives a dar green spot. C'o S e t. ^jSgjSoS a"^r'3 s a . Sstfl-a if lilsfl I-? &ofl S f|a?ll 11 Ss^^- &8 "oSo*^3 fc ;>43 E as o c beg-. .tS^MgSS'OOoS 55 O W Destroy color by boiling ^ wash, and add NaOH; i rin on the fibre isdisso purple color. Picric acid, fibre black. Dilute acetic acid, fibre bl H *> a 2 *o a *> 3 . s g "^ a' a fl tG T3 "S S *O *H .1-1 3 I fl|t] (-< t *3 O t^ W , QJ ^ ** .-H M ^5 C 03 fi O o - ^-H S*3 S "p.o "S O O ^ ^J2 O*3 i_, o ^-i '75^' o o 55 mm co 55 55 d w . l O -C > i 1 3 >. + "c 'c s i *c ^ S^ N ,_2f o o o 2. O "O w 'n CO 1 1 fis o ' N ^o ^ o EK .D 1 Q Q W Q fa'" w fa ^ i i i W *l 1 1 o a a tj> v a ^T A w-SS 5 CJ , fj a a; 3 C . ^ J2 ^- ^ o o a i 3 Sg jj g ^ fO f-l Q> 3 c * a o 3a 6" ^4 bjt/^ CO gj 2 ^X! 3 2 C 'S '5 O< "^ "2 o G "- * " W lljij 1 S a -s |B a; a" ^ fa CO CO fa fa 00 fa"' d - ^ . W t-. f*> -o A . S ^3 ^ o a^S 53 S - QJ" ^ u a o a fO *3 Q u? tuD 3 P '03 "^ ^32 ' 5 lg 11 a >'Sj'?'i 6 i 'P. & 3 g "* ^.-.2 " S ~ A 2*^ A c *^ *c c '22 o f0 1^ DC fc* ^ C'S'w -O M gj ^* . flj 4^ T3 II Illl s m fa fa fa" ! siziJ fa o g w H ? 3 o- s W PQ 5 HJ? o^ o- i a < KM i ^ S g S' 5 2 H g& g g S S3 < !> S A 5 SS P o 1 < w S S 55 W MM ^ ?5 o O ;6 a oS ^. X lg ss-S II 3 '?, 55 c 55 2 g H d 1 H b o M d i 13 1 V .0 o I a o 1 H i | H t3 gg || 2 L rj .2 i i o 55 s sf o 1 M "55 |ia | !| ^-H gigllJlft! | if _o |||^ ft O . P l-t c8 >VQ ||||| pi si S . ^bc'S.C ^H >* C s^- 8 ^5 M^j |1|| P-S^ fa^ 2 (-1 O '^ a -So fa |all .s|S O . fa s.s cfl **"' 00 | fa I s * S S a fa S ^' S fa H o 00 43 ' S S d S S d g'o'o ofc o a a llsl fc- ^ CH OJ 'S |S0 AH Oi '^ JpSfl jj "S ^ l"sb ^H_J fcl . O 0> ^ '^ i ^r'rSjJ oj_O g S^wd ""S S ,-g is .0 jll |1|1 111 fli OJ~ i^ N ^"3.2 ^'E ll ||1 3 S || slj-S s fa S """ fa fa < *. E^ 1 E ^ . Ma bb e - bb J- bo bb ' 'Q G? LH Q o fl o n .2 lji ||J Sa> j 43-2^1 1 I! li || 2 a. 8-So e P. 11 fl . P. 1 l^SlliIgil fa s S S as sill 23 Sb'? fa a ill !| J 5 3 a S m w A C <- ** , i o A . S i lifl It ^! a if H .2 ^ sl^fd il Fibre blue- Unchanged Slli Q lllfill I|IS? fa 111^ g-SgS fa !fi E S " s|ilil|ii|iill|ti w i o' S M g z ^ ^ . FAST VIOLET GALLOCYANI: HELIOTROPE. METHYL Vi< MUSCARINE. ALIZARIN. BENZO-BROW (Bayer.) BlSMARCK-Bl FAST BROWN (Berlin. Act NAPHTHYLAI BROWN. 484 THE ARTIFICIAL COLORING MATTERS. (M D 5 o S3 | 'o 2 OS O S 1 3 60 ft g ^ S"^ ^ "5 5 1 CO J9 03 sl Is 3 ID Remar 1 03 2 C3 reen spot. g-powder mish-red ; have no ac id. brown s is a mixtu a E o 'O' a s 03 60 pl oi , 'S oS 1 O * 0,0 3 C* ^-3 o .^ 1 "o IsSP II 1 i "o a B f- , a .0 1 o o 2 "S o s goo rt s s 3 ^3 2 B B o B * o o 55 _a i .fa _a d 4) "c > .^4 u Cj a" S _o a c 2 c w ^s j.2 >> ^ S o ^ 3 9 5 CO o ill ^M'-'O O t- g O 8IUOUI jN 3 S *" si ill 2 2-- V "3 . oj e^t-S" 5fft P- ^-- ^- S3 _0) * 1 1 5 oS O 3 ^5 QJ o o M 6 s A m E ft 1! ft a S 3 a o 3S a ol B S a Q) 0)^3 ^ a) o v i S 60 O.S 3 cc cc S S ci CO o a unchanged. u% 1.3 e-3 s'S tion, or color miesgreenish- k ; restored by .lies; acid tion brownish. unchanged, tion reddish. drab, solution ige-brown. unchanged, tion light :, pink on dilu- a) 3 S o 2 ^ o>5 * 3 0) 3 u; r* 3 3 tn 60 o- Q 3'oi 3 5 S 5 o |a E S E N E C5 B j u: M M o^ K S O c; ui *** ft"! u % * eg OH >j * o pa 1 pq S^ fc < z co' w 2 . 2 S S . They differ as a class from the Brazil-woods in their more resinous characters, and are often known as " close woods " RAW MATERIALS. 489 in contrast to the others as " open woods." The Sandal-wood (Red Sanders), from Pterocarpus santalinus, is grown in the East Indies, Ceylon, and Madagascar, and is a very hard and heavy wood, dark brown on the surface and blood-red in the interior. Caliatur-wood comes also from the East Indies, and though used as a substitute for the sandal- wood is considered as a distinct variety. Sandal-wood is said to contain some sixteen per cent, of santalin. Bar-wood, from Baphia nitida, comes from Sierra Leone, Africa,, and is a dark-red wood, containing Fia. 112. twenty-three per cent, of santalin. Cam-wood (or Gaban-wood) is sup- posed by many to be the same as bar-wood, but by others is ascribed to species of Peterocarpus. It comes, like bar-wood, from the west coast of Africa. Madagascar-wood is a minor variety resembling Caliatur- wood. 3. Madder (syn. Krapp, Racine de Garance) is the dried and broken root of the Rubia tinctorium and allied species. It grows wild in Asia Minor, Greece, and the Caucasus, and has been cultivated in France, Alsace, Silesia, Hungary, Holland, etc. The appearance of the plant may be seen from Fig. 112, in which it forms the right-hand illustra- tion. 490 NATURAL DYE-COLORS. In the Levant, the five- to six-year-old plants are plucked, in Europe, those two to three years old. While the Turkish madder (known as Lizari or Alizari) was the earliest in use, the French variety grown in the neighborhood of Avignon, in part upon marshy soil (palus) and in part upon soil containing lime (rosee), has long been considered the best. Other varieties are the Dutch or Zealand madder, the Alsatian, the Silesian, and the Russian madder. That which has not been freed from the brown outer crust before grinding is inferior to that which has been so freed, and which is known as " crop-madder," while the im- purest variety, obtained by grinding the rootlets, crusts, and woody parts of the roots, is called " mull-madder." From the madder-roots are also -prepared by fermentation and filtra- tion of the separated dye-colors the commercial extracts known as " madder flowers " and " guarancine." One hundred kilos, of madder will yield fifty-five to sixty kilos, of madder flowers. The tinctorial value of the madder depends upon the existence of the two coloring matters, alizarin, C 14 H 8 O 4 , and purpurin, C 14 H 8 5 , both of which have been mentioned under the artificial dye-colors derived from anthracene. (See p. 466.) These are not found free in the growing plant, but combined as glucosides and other compounds easily decom- posable by fermentation. As a nitrogenous and soluble ferment erythrozym is present; so soon as the solutions of madder extract are exposed to the air the ruberythric acid (or alizarin glucoside) is decom- posed into alizarin and dextrose and the pseudo-purpurin (or naturally occurring purpurin-carboxylic acid) is decomposed into purpurin and carbon dioxide. Two other anthracene derivatives also occur in madder, both probably as decomposition products of pseudo-purpurin, munjistin, C 15 H 8 6 , and xanthopurpurin, C 14 H 8 O 4 (the latter of which is isomeric with alizarin). The importance of madder and madder preparations has almost en- tirely disappeared with the development of the artificial alizarin manu- facture. The colors obtainable from alizarin, isopurpurin or anthra- purpurin, and flavopurpurin, which are the products of the synthetical methods, have almost entirely replaced those formerly obtained from madder. 4. Safflower (syn. Safflor, Fleurs de Carthame) consists of the dried flowers of the Carthamus tinctorius, a plant first grown in Egypt and the East Indies, but now grown in Asia Minor, Spain, Alsace, Austria, and Central Germany. The flowers are of a deep reddish-orange color, and contain, besides a yellow coloring matter of no technical value, carthamin, or carthamic acid, C 14 H 1(i 7 , a red dye of considerable im- portance for silk- and cotton-dyeing. It forms from .3 to .6 per cent, of the weight of -the flowers. " Safflower carmine " is a solution of the carthamin in soda, and " plate carthamine " is a pure preparation of the dye which has been dried in crusts upon glass or porcelain plates. The most important commercial varieties of safflower are the Egyptian, which is the richest in dye-color, the East Indian, the Spanish, and the German. Safflower comes from Spain and France, the production hav- RAW MATERIALS. . 491 ing amounted in recent years to 400,000 pounds. However, it is now almost entirely displaced from use as a dye by the artificial dyes. 5. Orseille, or Archil (syn. Orseille, Persia, Cudbear). The various species of lichens, as Rocella tinctoria and Rocella fuciformis from Angola, Zanzibar, Ceylon, and Mozambique, as well as from the Azores and South American coast, contain a mixture of phenols, phenol-ethers, and phenol-acids, such as orcin (or orcinol), erythric, orcellinic and lecanoric (or diorcellinic) acids. These by the action of air and am- monia yield orcein, contained in the orseille (archil) extract as a red dye, and on drying the extract the cud-bear or persio as a reddish-violet powder. Archil extract occurs in commerce in two forms, paste and liquor. The solid matter consists mainly of the impure orcein in combination with ammonia. Its preparation will be referred to later. Cudbear (or Persio) differs mainly from the orseille extract in being free from all excess of ammonia and moisture and in being reduced to a fine powder. An illustration of the orseille-yielding lichens is given in Fig. 112 (see page 489) in the lower left-hand figure. 6. Cochineal (syn. Cochenille) is the dried female insect Coccus Cacti, which lives and grows on the plants of the Cactus family, espe- cially the " nopal," or Cactus opuntia. The nopal-plant is indigenous to Mexico, but is also cultivated largely in Central America, the Canary Islands, the Island of Teneriffe, Algeria, and the East Indies. The commercial varieties of cochineal are known as the silvery-gray and the black cochineal. These varieties are apparently produced ac- cording to the method adopted for killing the insects when they are swept off the leaves of the nopal-plant. If killed by immersion in hot water or by steam they lose the whitish dust with which they are covered and constitute the black variety (zaccatila) ; if killed by dry heat in ovens this dust remains and they yield the silvery-gray variety (bianco}. This latter is considered the better, and is sometimes simulated by dust- ing the black variety with powdered talc, gypsum, barytes, or stearic acid. The natural gray powder is a variety of wax known as coccerin. The coloring matter of the cochineal is carminic acid, C 17 H 18 10 , and may amount to fifteen per cent, of the weight of the dried cochineal, although Liebermann states that the average is from nine to ten per cent. Carminic acid is a purple substance soluble in water and alcohol, but only slightly so in ether. Chlorine readily destroys the carminic acid and nascent hydrogen reduces it to a leuco body, which again be- comes red on exposure to the air. Chemically it is a glucoside, being capable of decomposition into carmine-red, C U H 12 O 7 , and a sugar, C 6 H 10 O 5 . Carminic acid dissolves in caustic alkalies with a beautiful red color, forms purple precipitates with barium, lime, lead, and copper, and a fine red lake with alumina. A decoction of cochineal behaves with re- agents somewhat differently from a solution of the pure carminic acid owing to the presence of phosphates, tyrosine, etc. The addition of alum or stannic chloride to it yields the fine red pigment known as ' ' cochineal 492 NATURAL DYE-COLORS. r carmine." This as well as other preparations from cochineal will be referred to again under products. (See p. 507.) 7. Kermes (syn. Kermes, Alkermes) is a corresponding substance to cochineal, and consists of the dried female insects Coccus Ilicis, which burrow under the epidermis of the leaves or young shoots of the kermes oak (Quercus coccifera), growing in the south of France, Spain, and Algeria. The coloring matter of the kermes insect has not been suffi- ciently investigated; it is said to be identical with that of cochineal. It is not used any longer in dyeing. 8. Lac dye (syn. Farberlack) is the product of the Coccus Lacca, an East Indian insect which lives on the branches of the fig and other trees. The female insects exude a resinous substance which encloses them and attaches them to the twig. This constitutes the "stick-lac" (see p. 108), which contains about ten per cent, of coloring matter. This latter may be obtained by treating the stick-lac with carbonate of soda. The coloring matter of lac dye has been studied by Schmidt, who terms it laccainic acid, C 1G H 12 O S , and found it to be very similar to carminic acid in most of its reactions. Many writers consider the two to be identical. B. YELLOW DYES. 1. Old Fustic (syn. Gelbholz, Bois jaune} is the trunk wood of Morus tinctoria, indigenous to the West Indies and South America. It is also yielded by the Madura tinctoria and Broussonetia tinctoria. The wood is hard and compact and has a pale citron-yellow color. It contains two coloring principles, morin, or moric acid, C 15 H 10 O 7 , which occurs in the wood combined with lime, and maclurin, or moritannic acid, C 13 H 10 C , both of which are yellow dyes and are contained in the com- mercial extract. 2. Young Fustic (syn. Fisetholz, Bois de fustet) is the bark-free wood of the Rhus cotinus, a variety of sumach growing in the Levant, Spain, Hungary, Tyrol, and Italy. The coloring matter is stated by Schmidt to occur as a soluble compound of fustin and tannic acid. This fustin is a glucoside, and is decomposed by dilute sulphuric acid into fisetin, C 15 H 10 O 6 , and isodulcite. A decoction of young fustic .gives a fine orange color with alkalies and bright orange precipitates with lime and baryta-water, stannous chloride and lead acetate. It also gives a fine orange color with alumina mordants. Is largely used in the dyeing of glove-leathers. 3. Quercitron is the crushed or rasped bark of the Quercus nigra or Quercus tinctoria, indigenous to North America, and grown also in Germany and France. It forms a brownish-yellow powder, from which an extract is also made. The coloring principle is quercitrin, C 21 H 22 12 , a glucoside, which is decomposed by dilute sulphuric acid into quercetin, C 15 Hj O 7 , and isodulcite. Besides quercitm, the bark contains quercitannic acid, C 17 H 10 6 . Quercitin is difficultly soluble in water, but easily soluble in alkalies with golden-yellow color. '"Flavine " is the commercial name of a preparation of quercitron obtained by acting upon the bark first with alkalies and treating this extract with sulphuric RAW MATERIALS. 493 acid; it is a varying mixture of quercitrin and isodulcite, having some sixteen times the coloring power of the bark. Flavine and quercitron bark are used chiefly for dyeing cottons and woollens with tin mordants. 4. Persian Berries, or Avignon Berries (syn. Gelbbeeren, Graines jaunes), are the dried fruit of different buckthorn (Rhamnus) species. The different commercial varieties are the Persian (from Rhamnus amygdalinus and Rhamnus-oleo'idiis) , coming from Aleppo and Smyrna, regarded as the richest in dye color and the best in use, the French, or Avignon (from Rhamnus infectoria and Rhammts saxatilis), the Levan- tine, or Turkish (from Rhamnus infectoria and Rhamnus saxatilis), and the Spanish (from Rhamnus saxatilis} and the Hungarian (from Rham- nus amygdalinus, etc.). The coloring matter of the Persian berries is called by Liebermann xanthorhamnin, or chrysorhamnin, and is a glucoside, yielding under the influence of dilute acids rhamnetin, C 16 H 12 7 (or methyl-quercetin, C 18 H,O T CH,), and isodulcite. Persian berries are used for yellows on wool and cotton with alumina or tin mordants. 5. Weld (syn. Wau, Gelbkraut, Gaude) consists of the leaves and other parts of the Reseda luteola, a variety of mignonette. It is culti- vated in almost all parts of Europe, notably in the south of France, Germany, and England. The coloring matter is known as luteolin, C ir ,H 10 6 , and forms yellow crystals of silky lustre, insoluble in water, soluble in alcohol. It dissolves in alkalies with deep yellow color. It is used especially in silk-dyeing. 6. Annatto (syn. Orlean, or Roucou) is prepared from the fleshy pulp of the seed-shells of the Bixa orellana, indigenous to the West Indies and South America, but cultivated also in the East Indies. The commercial annatto forms a soft reddish-yellow paste of buttery con- sistency, or sometimes it is dried in hard cakes. It contains two color- ing matters, bixin, C 28 H 34 O 5 , and orellin, the former of which the more important is a red dye and the latter a yellow. The bixin dissolves in alkalies with yellow color. It is but little used in silk-dyeing. Orellin is as yet only slightly studied, and is considered by some to be simply an oxidation product of bixin. By far the largest amount of annatto is used not in dyeing but in coloring butter and cheese. (See p. 295.) 7. Turmeric (syn. Gelbwurz, Curcuma) is the tuber of the Curcuma tinctoria and Curcuma rotunda. The roots are usually grayish-yellow on the exterior but deep yellow in the interior. The plant is indigenous to Central Asia. The varieties of it are the Chinese, Java, and Bengal, of which the latter is considered the best. The coloring principle is curcumin, C 21 H 20 (t , which acts like a weak acid. The pure color is bright orange-red, but it dissolves in alkalies with a red-brown color. It is seldom used as a dye, and then only for shading blacks on silk. C. BLUE DYES. 1. Indigo (syn. Indig-blau, Indigo). This is by far the most im- portant of all the vegetable dyes. It has been known from very early times in the East, but was not introduced into Europe until the six- 494 NATURAL DYE-COLORS. teenth century, where its use was at first prohibited because of the gen- eral culture of the woad, and indeed it was only in 1737 that its employ- ment was legally permitted in France. However, in time it displaced the woad almost entirely, so that the latter is used now only in a few special cases. The indigo-plant is an Indigofera, the more important varieties of which are the Indigofera tinctoria, cultivated in India, particularly in Bengal, Coromandel, Madras, Java, and Manila; the Indigofera Anil, cultivated in Guatemala, Caracas, Brazil, and the Antilles; the Indigo- fera Argent ea, cultivated in Egypt, Senegal, and the Isle of France. Of lesser importance are the Indigofera disperma and the Indigofera pseudotinctoria, both cultivated in" the East Indies. The Indigofera tinctoria is shown in Fig. 112 (see p. 489) to the left of the illustration above. The indigo dye does not exist as such in the plant but as the result of fermentation, whereby the naturally occurring indican, a glu- coside, is decomposed, most probably according to the reaction : 2C 26 H 31 N0 17 + 4H 2 = C 16 H 10 N 2 8 + 6C 6 H 10 6 . Indican. Watr. Indigo-blue. Indiglucin. The plants are cut at two or three different periods in the year when they have just come into bloom. They are at once packed into bundles and put into the soaking-vats covered with water. A fermentation here ensues, which is completed in from ten to eighteen hours, according to the temperature of the air and the ripeness of the plants. When the supernatant liquid has taken a yellowish-green color and has a pleasant sweetish taste, the fermentation is stopped and the liquid is run off into vats placed at a lower level. Here it is beaten vigorously with sticks or paddles for from one and a half to three hours by men who enter the vats for the purpose. The liquid is changed by this treatment to a deep-blue color and becomes covered with froth of like color. When the men leave the vat to rest, the separated indigo rapidly settles, and in some two to three hours the supernatant liquid can be run off from stopcocks placed in the side of the vat at levels above the indigo pre- cipitate. Milk of lime is often added to hasten the settling of the separated indigo, and more recently dilute ammonia has been used. The addition of this latter reagent is said to increase the yield of indigo and to improve its quality, as it contains less indigo-brown and resinous impurities. The thin paste of indigo and water is then drawn off, boiled to prevent subsequent fermentation, and strained through a sheet. It is then put into square press-boxes lined with cloth and pro- vided with holes in the sides and bottom for thorough drainage of the indigo. Pressure is then applied, gentle at first but stronger as the indigo hardens and acquires a firmer consistency. The mass is then cut into cubical blocks, which are stamped with the name of the factory and put on shelves in the drying-house to slowly dry out, great care being taken to avoid drafts of air, which might cause the cakes to crack in drying. Three hundred kilos, of indigo-plants yield an average of one kilo, of indigo. The commercial product contains from twenty to eighty per cent, of the indigo-blue (averaging about forty-five per cent.), RAW MATERIALS. 495 and with this two other coloring matters, indigo-brown and indigo-red, besides 'indigo-gluten, moisture, and a variable amount of mineral matter. The commercial varieties of indigo are, first, the Asiatic, of which the Bengal indigo is the best, followed by the Java, Madras, Coroman- del, and Manila varieties; second, the American, of which the Guate- mala is the best, followed by the Caracas and the Brazilian varieties; and, third, the African, including the Egyptian, Senegal, and Isle de France varieties. Indigo-blue is insoluble in water, alcohol, ether, dilute acids, and alkalies, soluble in fuming sulphuric acid, aniline, nitrobenzene, chloro- form, and glacial acetic acid. It may be sublimed by heat, although with partial decomposition when the sublimation is carried out at ordi- nary atmospheric pressure. By the action of alkaline reducing agents it is changed to indigo-white, C 16 H 12 N 2 2 , and dissolved. Upon this reaction and the subsequent change of the indigo-white, when deposited upon the textile fibre, by atmospheric oxidation back again into indigo- blue, is based the use of indigo in vat-dyeing. (See p. 536.) Indigo has been extensively used for cotton and wool dyeing, but is being largely replaced by the artificial indigo. 2. Woad (syn. Waid, Pastel). The leaves of the Isatis tinctoria and Isatis lusitanica moistened, slightly fermented, and then compacted and dried into balls constitute the woad of commerce and furnish an additional source of indigo. As before stated, the use of the woad for dyeing antedated the use of the indigo-plant, and the cultivators of the woad, particularly in Central Germany, long fought against the intro- duction of the richer tropical indigo-yielding material, but in vain. The woad-culture is still carried on in different parts of Europe, particularly in France and Germany, but in small degree compared with its former development. The woad contains only .3 per cent, of indigo reckoned on the weight of the fresh leaves, or as it is often calculated, one hun- dred kilos, of woad have the same coloring power as two kilos, of indigo. The woad balls improve in quality by keeping for some years, the best variety coming from the south of France under the name of Pastel. The woad is rarely used by itself in dyeing operations, but along with indigo as a means of inciting the fermentation in the " woad- vat " process of dyeing. A few other plants, such as Polygonum tinctorium, indigenous to China, and Eupatorium tinctorium, indigenous to Brazil, have been found to contain indigo, and have been used locally for blue-dyeing. 3. Logwood (syn. Blauholz, Bois de Campeche). This is the heart- wood, freed from bark and sap-wood, of the Hcematoxylon Campe- chianum, a tree indigenous to Campeachy Bay, Central America, but grown now in various parts of Central and South America and the West Indies. The commercial varieties are the Campeachy, Yucatan, Laguna, Honduras, Jamaica, Haiti, St. Domingo, Monte Christo, Fort Liberte, and Guadeloupe logwoods. The principal sources now are Jamaica, Haiti, and St. Domingo. Of these, the first commands the highest price on account of the 496 NATURAL DYE-COLORS. large yield of coloring matter obtainable from it and the readiness with which it " bronzes " when submitted to the " curing " process. The wood comes in logs or sticks of smaller size, and is then chipped or rasped by the makers of extracts, who sell it in the chipped or rasped condition as well as in the form of prepared extract. The wood has a dark-red color on the exterior but is yellowish-red in the interior, has a weak odor of violets and a peculiar sweetish but astringent taste. On moistening the wood or chips with ammonia it takes a dark-violet color. Logwood contains some nine to twelve per cent, of the chromogen, hcBmatoxylin, C 16 H 14 O 6 , which is present in the wood partly in the free state but mainly as glucoside. It forms colorless prismatic crystals difficultly soluble in water, easily soluble in alcohol and ether. From the hasmatoxylin by oxidation in the presence of alkalies, and particu- larly ammonia, is produced hcematein, C 1G H 12 O 5 , the true dye-color. This forms small crystals or crystalline scales of dark-red color and greenish metallic lustre, which show plainly upon the wood, especially after the fermentation or curing. It is difficultly soluble in water, alcohol, and ether. Hgematein forms a crystalline compound with ammonia, C 16 H 11 (NH 4 )O 6 -f H 2 0, which, however, is decomposed by acids or by heating to 130 C., leaving pure hoematein. Zinc and sul- phuric acid readily reduce the hcematein to hasmatoxylin again. Log- wood is used on an extended scale in dyeing wool, silk, cotton, and leather. It is used for deep blues, blacks, and jointly with other color- ing matters for composite shades of color. 4. Litmus (syn. Lakmus, Tournesol). This is a dyestuff very simi- lar in character to orseille and persio (see p. 491), and also derived from the class of lichens. For its preparation the same lichens may be used, although at present the different species of Lecanora serve as the chief material, such as Lecanora orcina, L. dealbata, L. parella, which occur in the French Pyrenees, and the Lecanora tartarea, occurring in Iceland and Scandinavia. The lichens are allowed to ferment after the addi- tion of stale urine or ammonia and carbonate of potash. When the mass has assumed a deep-blue color, chalk or gypsum is added, and it is shaped into small cubes and dried. The coloring matter is azolitmin, C 7 H 7 N0 4 , which differs by one atom of oxygen only from the orcein of orseille extract, C 7 H 7 N0 3 . It acts like a weak acid, the salts of which are blue in color (the potassium compound existing in the com- mercial litmus), and which when set free by acids is reddish in color. D. GREEN DYES. We have practically nothing here that has assumed practical value as yet. The only ones needing mention at all are : 1. Chlorophyll. This is the green coloring matter of fresh vegeta- tion, and is abundantly present in nature, but it has not been found possible hitherto to isolate it in a pure state adapted for use. Schiitz has, however, separated it from the yellow coloring matter accompany- ing it, xanthophyll. It is stated that chlorophyll forms a beautiful green color with zinc as mordant which is adapted for dyeing, but it has not as yet been used in practice. PROCESSES OF TREATMENT. 497 2. Lokao, or Chinese Green, is a green pulverulent deposit from the decoction of the bark of Rhamnus chlorophorus and Rliamnus utilis, both indigenous to China. Kayser, who has investigated the lokao, states that the coloring matter is lokaonic acid, C 42 H 48 O 27 , which is combined in the commercial preparation as the alumina lake. This lokaonic acid is decomposed by acids into lokanic acid, C 3B H 36 21 , and lokaose, an in- active sugar. Lokao has been used for cotton- and silk-dyeing, but is practically displaced by the cheaper artificial colors. E. BROWN DYES. 1. Catechu (or Cutch). This has already been spoken of as one of the raw materials of the tanning industry. (See p. 359.) It finds, however, an equally extended use in dyeing as an adjective color. The explanation of this is that catechu contains two principles, catechin, C^H^Og -f- 5H 2 O, a yellow dye forming brown precipitates with copper, alumina, and tin mordants, and catechutannic acid, C 13 H 12 O 5 . The former is present in amount from twenty to thirty per cent., the latter, however, from forty-eight to fifty-two per cent. The best variety of catechu is the Pegu catechu, and after this the Bombay and the Bengal catechu. Catechu is extensively used in both cotton- and silk-dyeing for browns and for composite shades. 2. Kino is a natural dyestuff very similar to catechu and comes from a variety of sources, as Butea frondosa and Butea superba, yielding the Bengal kino; Pterocarpus erinaceus, yielding the West African kino; Eucalyptus corymbosa and other Eucalyptus species, yielding the Aus- tralian kino. The important principles are kinoin, C 14 H 12 6 , and its anhydride, kino-red, C^H^On. It is used like catechu for dyeing. n. Processes of Treatment. 1. CUTTING OF DYE-WOODS. Whether the dye-woods are to be used for the manufacture of extracts or used as wood by the dyer, they must be reduced to powder or cut into chips of small size. This process varies with different manufacturers. In America, it is usually one of cutting with powerful knives, in which whole logs are brought with their ends against rapidly-revolving cylinders, on the circumference of which are heavy steel knives, which cut off flat chips directly across the grain about one-eighth inch in thickness. This method is a very rapid one, as but little previous splitting of the logs is necessary. In Europe, where labor is cheaper, the logs are frequently sawed and split into billets about two feet long, and two to three inches in thickness, and these are then brought by hand diagonally against toothed knives on a rapidly-revolving cylinder, by which means the wood is torn or rasped into a much finer condition, or these billets are put into a machine which presses them in this way against the revolving knives. Such a machine of German design is shown in Fig. 113, where a rotating drum, D, carry- ing on its circumference a series of knife-blades, is continuously cutting the billets of wood which are pressed against it. 32 498 NATURAL DYE-COLORS. 2. FERMENTATION OR CURING OF DYE-WOODS. As has already been stated in several cases, the dye-woods in the fresh condition contain not the finished dye-color, but a chrom-ogen capable of passing into the former under the influence of oxidizing or other agents. Notably is this the case with logwood, and the chips or rasped wood are therefore sub- mitted to a curing treatment by moistening them with water and expos- FIG. 113. ing them to the air in heaps some three feet in depth for from four to six weeks. The chips heat up, and the pile must then be turned with shovels to regulate the temperature and allow contact with the air. More water is then added, and the process continued until the chips assume a rich reddish-brown color or become coated with a bronze pow- der (haematein). Various chemicals have been suggested to hasten the operation, such as ammonium carbonate and chloride, stale urine, sodium carbonate, potassium nitrate, chalk, and glue. None of these are known certainly to be of benefit. The alkalies give the chips a fine red color at first, but unless great care is taken they cause them to become black from PROCESSES OF TREATMENT. 499 over-oxidation before the action can be checked. Glue has been used because it is said to combine with the tannin of the wood, and by remov- FIG. 114. 500 NATURAL DYE-COLORS. ing it to open up the pores of the wood to the oxidizing influence and so facilitate the curing. But the existence of tannin in logwood has not been at all certainly established. Curing is of value to the dyer because it enables him to rapidly obtain the color from the chips and gives him a liquor containing a more highly oxidized coloring matter, which " goes on " the goods more rap- idly. It must be remembered, however, that curing the chips enables the manufacturer to sell twenty to thirty per cent, of water with them, while uncured chips contain only ten to fifteen per cent, of moisture. "When the chipped logwood is intended for the manufacture of ex- tract it is usually conveyed directly to the extractors without curing, which is, no doubt, the better procedure, since all oxidation in the first part of the process is objectionable. 3. MANUFACTURE OF DYE-WOOD EXTRACTS. As dye-woods contain generally only a tenth or less of their weight of dye-color, it becomes a matter of great economy in transportation and storage to prepare from them extracts, either as concentrated liquids or solids representing the active coloring principle. This is done by manufacturers who make a specialty of this extracting, and apply to it the best designed and most improved machinery. The operation may be divided into two stages, the extraction and the concentration. For extraction a rasped wood such as is made in France has many advantages over the chipped, since it yields its color- ing to a smaller quantity of water and at a lower temperature than the chips. The extraction consists in heating the wood with water under various conditions and then drawing off the liquor into tanks for set- tling or treatment. The conditions refer to the kind of vessels, the amount and quality of the water, and the temperature. Many European manufacturers use open wooden vessels for extractors, so that the tem- perature does not get above 100 C. As this method was first used in France, it is known as the French process. The use of closed extractors, however, allows of increase in the pressure, and this within limits much facilitates the perfect extraction. A closed extractor of German de- sign, in which a pressure not exceeding two atmospheres is used, is shown in Fig. 114. (See preceding page.) It will be seen that the vessel, A, is provided with a false bottom, D, to allow of the draining off the extract liquor, a perforated steam-pipe, g, to rapidly bring up the contents of the extractor to the required temperature, and a drainage- pipe, h, to draw off the thin extraction liquors. In America closed copper or iron vessels are used, arranged in bat- tery form very much like the diffusion apparatus now used in the ex- traction of sugar. One cell of such an extraction battery is shown in Fig. 115. This method allows of continuous working, as one cell of the series can be emptied of exhausted dye-wood and loaded with fresh chips while the extraction liquors are passing successively through the other cells of the battery and acquiring the maximum strength. The temperature or pressure varies with different manufacturers, but most writers on the subject agree that a pressure not exceeding fifteen to PROCESSES OF TREATMENT. 501 FIG. 115. twenty pounds excess over atmospheric pressure should be used. An increase in the pressure is always attended with an increase in the yield, and after a certain point with a decrease in the coloring value of the resulting extract. When the liquors from the extractors are run into large tanks and allowed to cool much wood-fibre and some resinous mat- ter separates. The clear liquor is then drawn into the evaporators, which in this country almost invariably consist of vacuum-pans, but in Europe often consist of open pans or vessels in which heated disks revolve so as to favor the evaporation. While the liquor is still thin, double- or triple-effect pans are used, and of recent years the Yaryan evaporators (see Fig. 38, p. 144) have been applied with great suc- cess to the evaporation of dye-wcod ex- tracts. As the liquors become thicker the concentration is continued in vacuum-pans more analogous to the strike-pans of the sugar refinery. Such a vacuum-pan designed for use in the manufacture of dye-wood extracts is shown in Fig. 116. When the gravity of the liquid becomes 42 or 51 Tw., it is drawn off into barrels for shipment, or if the solid extract is desired the concen- tration is continued in a vacuum-pan. Various methods of treatment have been suggested at different stages of the process with a view of improving the extract, but it is an open question whether anything better than pure water has yet been used. The addition of solu- tions of glue and of different salts to the wood before extraction has been frequently recommended. Chalk sus- pended in water and dilute lime- water have also been recommended to be similarly used. Such processes could only result in an over-oxidized product. Borax has also been used, but without notable advantage in the case of logwood, although it serves very well in the case of the red- woods. The use of chlorine, hypochlorites, and chlorates has been patented in connection with logwood extract for addition either to the wood or the liquor after extraction, but it is doubtful if any of these are used on a large scale at the present time. That these substances and many others develop the color of logwood there can be no ques- tion, but to be of value to the dyer that development must take place in the presence of the goods. The yield of logwood extract by the American process of manufac- 502 NATURAL DYE-COLORS. ture is said by Soxhlet* to be twenty or twenty-one per cent, of solid extract, while that by the French process is sixteen and a half per cent. The latter is superior in quality, and is therefore almost invariably re- duced by the addition of such substances as molasses, glucose, and ex- tract of chestnut. In America, in addition to the above, extract of FIG. 116. hemlock and extract of quercitron (after the removal of the flavine) are considerably used to adulterate logwood extract. 4. MISCELLANEOUS PROCESSES. (a) Preparation of Guarancine and Madder Flowers. For the preparation of guarancine, the pulverized madder-root is warmed gently with dilute sulphuric acid (one part acid and two parts water) for some time, whereby the glucosides of the madder are decomposed. The sugary liquid is drained off and the resi- * Textile Colorist, xiii, p. 125. PROCESSES OF TREATMENT. 503 due heated with concentrated sulphuric acid, which decomposes the woody fibre and other organic substances present and decomposes any lime compounds that may have been in the madder. The whole mixture is now thrown into water, the precipitate collected, washed, and dried. The guarancine now contains the alizarin and purpurin in uncombined form. The yield is from thirty-four to thirty-seven per cent. For the preparation of ." madder flowers " the powdered madder is set to fer- ment with warm water to which a little dilute sulphuric acid had been added. After some days, the liquid is filtered and the residue washed, pressed, and dried. The flowers of madder can be used more readily than crude madder in dyeing at low temperatures, and give finer and purer violets. (&) Preparation of Ammoniacal Cochineal and Carmine. Five parts of powdered cochineal are mixed with fifteen parts of ammonia-water, and the mixture is allowed to stand in a warm place with frequent stir- ring for some four weeks. Some two parts of alumina are then added, and the mixture carefully evaporated in a porcelain dish until the odor of ammonia has disappeared. The preparation so obtained, known as ammoniacal cochineal, yields its color more readily than cochineal and produces brighter shades of color. Cochineal-carmine is a brilliant red pigment prepared from decoc- tion of cochineal by the action of alum under certain conditions. The details of its preparation vary and are kept by different manufacturers as trade secrets. The following process has been published : * Five hundred grammes of finely-powdered cochineal are boiled for one-quar- ter of an hour with thirty times the weight of distilled water, thirty grammes of acid tartrate of potassium added, boiled for ten minutes longer, fifteen grammes of alum added and boiled for two minutes longer. The clear liquid is allowed to stand in shallow glass vessels, when the carmine separates in a very fine state. It is washed with water and dried in the shade. Or, by another process, f one pound of cochineal and one-half ounce of potassium carbonate are boiled with seven gallons of water for fifteen minutes. The heat having been withdrawn, one ounce of powdered alum is added, and the liquid stirred and allowed to settle. The clear liquid is decanted, one-half ounce of isinglass added, and heat applied until a coagulum forms, when the liquid is briskly stirred and allowed to settle. (c) Preparation of Flavine. As stated before (see p. 492), flavine is a preparation containing the coloring matter of the quercitron bark in purer and more concentrated form. The method for its preparation is not generally known, although it is found to contain quercetin as well as quercitrin, and frequently the former in larger amount. A procedure that has been published J is the following : Two hun- * Schiitzenberger, Die Farbstoffe, ii, p. 338. f Allen, Commercial Organic Analysis, 2d ed., iii, p. 367. j Gerb- und Farbstoffe-Extracte, Mierzinski, p. 208. 504 NATURAL DYE-COLORS. dred and fifty kilos, of the powdered quercitron are boiled for fifteen minutes with, fifteen kilos, of crystallized soda and two hundred kilos, of water, there is then added to the liquid sixty-one kilos, of sulphuric acid of 66 B., and the boiling continued for three-quarters of an hour longer, when the whole is allowed to cool and settle, the liquid poured off, and the separated color drained and dried. (d) Preparation of Indigo-carmine, Soluble Indigo, etc. It was stated in an earlier section (see p. 495) that indigo-blue was soluble in strong sulphuric acid. The solubility depends, however, upon the chemical action of the acid, whereby sulphonic acids of indigo are formed. Two such acids, indigo-monosulphonic acid (sulpho-purpuric acid), C 1C H 9 (HS0 3 )N 2 O 2 , and indigo-disulphonic acid (sulphindigotic acid), C 16 H 8 (HS0 3 ) 2 N 2 2 , are formed. Of these, the first is insoluble in water or dilute acids, while the second is soluble with deep-blue color. Both are formed together in practice when indigo is dissolved in strong sulphuric acid, although if not more than four parts of sulphuric acid to one of indigo be used and too prolonged heating be avoided, the mono- sulphonic acid will be formed predominantly, while if some fifteen parts of ordinary concentrated sulphuric acid or seven parts of fuming sul- phuric acid be taken to one of indigo and the heating be continued, the disulphonic acid will be the sole product. After treatment with the acid the dissolved mass of indigo is allowed to cool down and then strained to remove any lumps that may have escaped grinding; salt is thrown in, which precipitates the indigo-sulphonic acids, which are re- moved by filtration through felt. For finer grades of " indigo ex- tract " the precipitate is redissolved in water and reprecipitated with salt several times, each precipitation removing a greater quantity of the objectionable green coloring-matter. Whatever be the process or proportion of acid used, the indigo must be very finely ground. This is done in indigo-mills, which are of various forms, known as " ball- mills," in which rotating cannon-balls gradually grind the color, as " cylinder-mills," in which heavy iron rolls accomplish the same work, and other forms. An illustration of such an indigo-mill with conical rolls, taken from a form in current use, is shown in Fig. 117. Indigo grinding for " extract " making is of little importance since the intro- duction of dry synthetic indigo. The direct use for dyeing of the product obtained by the action of sulphuric acid upon indigo is no longer common. The preparation and sale by the color manufacturers of pure preparations, known as Indigo Extract, Soluble Indigo, or Indigo- carmine, has replaced them. The sodium salt of the monosulphonic acid constitutes " indigo-purple " or " red indigo-carmine," the sodium salt of the disulphonic acid the true " indigo-carmine," which comes into commerce in paste form under that name or as a dry powder known as " Indigotin." This indigo-disulphonic acid fixes itself on the animal fibre like other acid colors, and is dyed in an acid bath containing sulphuric acid. PRODUCTS. m. Products. 505 1. FROM RED DYESTUFFS. (a) Brazil-wood Extracts are made by the diffusion process, three varieties coming into commerce, a liquid extract of 20 B., a liquid one of 30 B., and a solid one. One kilo, of the dry extract corresponds on the average to twelve kilos, of the wood. Brasilin is also manufactured on a large scale almost pure by Geigy, of Basle. This brasilin often separates in the form of a crystalline crust on the surface of the commercial extract liquors. These crusts contain the FIG. 117. brasilin mixed with the lime compound of the same. If this crude product is boiled with very dilute alcohol with the addition of zinc dust and hydrochloric acid, and the solution stood aside to crystallize, a very pure product is obtained. Brasilin is relatively easily soluble in water, alcohol, and ether. In alkalies it is soluble with carmine-red color. Zinc dust will decolorize the solution, but on exposure to the air it speedily takes up the red color again. Acetate of lead precipitates a colorless crystalline com- pound which gradually turns red. Brasilein bears the same relation to brasilin that hsematein bears to hsematoxylm, and can be prepared by the oxidation of the alkaline solution of brasilin in the air. Brazil-wood extracts are used in wool- and cotton-dyeing. With alumina mordants they produce shades resembling the alizarin lakes, 506 NATURAL DYE-COLORS. but inferior in character. On wool mordanted with bichromate of potash they produce a fine brown. The insolubility of the coloring matters in sandal-wood prevents their being used in the form of extracts. (6) Madder Preparations. We have already referred to Quarantine and Flowers of Madder. Guaranceux is the name applied to the impure purpurin recovered from the sediment of the waste-liquors in madder- dyeing. Pincoffin (Alizarine commerciale) is a preparation from guarancine, in which the purpurin has been decomposed by superheated steam, leav- ing the alizarin unchanged. It has twenty-five per cent, less coloring power than the guarancine, but gives finer violets than can be obtained with the former. (c) Safflower Preparations. These are practically more or less pure preparations of carthamin, and the names Safflower Extract, Safflower- carmine. Safflower-red, and Plate-red refer to different concentrations of the carthamin solution. For the preparation of the pure safflower-red, the safflower-yellow must be removed by washing the crushed flowers with water until this runs off colorless. The residue is then treated with water and fifteen per cent, of its weight of crystallized soda salt. The solution is strained from the residue, filtered, and after acidulating with acetic or citric acid, cotton yarn is immersed in it to take up the color. The dyed cotton is stripped of the color by a five per cent, soda solution, and from this solution the color is again precipitated by citric acid. It is now drained, and comes into commerce as a paste known as ' ' Safflower Extract." The color must be kept in sealed flasks, protected from the light. This paste dried upon plates at a gentle heat yields the so-called " plate-red." It then forms a red powder with greenish reflex, almost insoluble in water and ether, but easily soluble in alcohol. It is also soluble in alkalies with yellowish-red color. The " safflower-carmine, " on the other hand, is prepared from the extract paste by washing the insoluble color and dissolving it in alcohol, which is then left to slowly evaporate. For dyeing purposes the safflower-carmine is dissolved by addition of soda, and the bath is then made slightly acid with citric acid; or the soda-extraction liquors from the flowers, which have been washed with water, may be used directly, acidifying the bath as before. Safflower-red is fixed in a weak acid bath both upon the animal fibre and upon the unmordanted cotton. On silk it produces a fine rose-red color. (d) Orseitte Preparations. These come into commerce both as paste and liquor. The solid matter consists essentially of the impure orcein in combination with ammonia. It is liable to be adulterated with the spent weeds from the manufacture of the orseille liquor or with other vegetable coloring matters. It is also at times adulterated with aniline dyes, such as magenta, acid magenta, and methyl violet. Various azo dyes, producing colors ranging from crimson to claret-red, are now sold as substitutes for the orseille extract, and, being cheaper, are used to adulterate it. These are known as " orchil extract," " orchil-red," ' ' orselline, " etc. They may be detected when so admixed by their PRODUCTS. 507 behavior with salt solution and basic acetate of lead. The liquid extract is usually brought to 25 B., and is frequently adulterated with logwood or Brazil-wood extract. Orseille Purple (French Purple) is a pure orseille dye, obtained by extraction of the lichens with a fifteen per cent, ammonia solution, precipitation with hydrochloric or sulphuric acid, and redissolving in ammonia. This solution is then left exposed to the air in shallow vessels until it becomes dark purplish-violet. The color is then precipitated by addition of sulphuric acid, washed, and dried. Orseille Carmine is a similar preparation, in which the ammoniacal solu- tion, after exposure to the air until it becomes cherry-red, is heated with alum or calcium chloride. Cudbear, or Persia, as before stated, is a dry powder obtained by evaporation of the extract, or prepared direct from the lichens by the action of ammonia or urine and then evaporated to the condition of a powder. It is often adulterated with common salt and other mineral matters, and is liable to much the same organic impurities or adulterants as orseille. (e) Cochineal Preparations. Ammoniacal cochineal and cochineal- carmine have already been referred to. Ammoniacal Cochineal is dis- tinguished from carminic acid by giving a purple precipitate (instead of scarlet) with oxymuriate of tin. The crimson, purple, and mauve colors it yields with mordants are not affected by acids so readily as those produced directly by cochineal. Ammoniaeal cochineal is used in admixture with ordinary cochineal for producing the bluer shades of pink. Cochineal-carmine requires for its production a decoction of cochineal itself and not of carminic acid, the nitrogenized matters being essential to its formation. Liebermann,* who has investigated care- fully the nature of the cochineal coloring matter, found it to contain 3.7 per cent, of nitrogen, of which only .25 per cent, could be expelled by boiling with dilute alkali, the remainder existing apparently as pro- teids. He gives the following as the composition of the commercial sam- ple of carmine , examined by him: Water, seventeen per cent.; nitrog- enous matter, twenty per cent. ; ash, seven per cent. ; coloring matter, fifty-six per cent.; wax, traces. Liebermann considers cochineal-car- mine to be no ordinary compound of a coloring matter with alumina, but as an alumina-albuminate of the carmine coloring matter, compar- able in some respects to the product from alizarin and alumina with " Turkey-red oil." Carmine forms red, porous, relatively light masses, which are easily rubbed up to a fine red powder. It is insoluble in water and alcohol, but readily soluble, when pure, in aqueous ammonia. Cochineal-carmine is liable to adulteration with starch, kaolin, vermilion, red-lead, chrome-red, etc. These admixtures may be detected by treat- ing the sample with dilute ammonia, in which a pure sample should be completely and readily soluble. M. Dechan f has published a series of analyses of commercial car- mine, which are here given : * Ber. Chem. Gea., xviii, p. 1971. t Pharm. Journ. [3], xvi, p. 511. 508 NATURAL DYE-COLOES. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Moisture 22.1 16.1 2.0 22.3 20.2 23.5 8.5 10.0 21.2 13.0 Soluble in f Coloring matter . ether. \ Alumina, lime, etc. T i T.I ( Organic matter . 46.1 8.0 21.8 69.2 9.8 2.5 34.1 11.4 18.5 65.7 12.0 608 9.0 9.8 69.5 7.0 26.1 0.4 72.0 8.1 8.0 18.4 4.4 52.4 67.5 10.0 9.5 Insoluble) Y g E 2.0 2.4 34.0 Trace. 0.2 Trace. 14.6 1.9 3.6 Trace. in ether. \ Ve nnilion. '.'.'.'. 50.4 Cochineal is not used in cotton-dyeing. In dyeing silk it has also been almost entirely superseded by aniline reds, and in wool-dyeing the azo colors have to a great extent replaced it. Two distinct shades of red are obtained with cochineal, according to the mordant used, cochineal-crimson with cream of tartar and alum, and cochineal-scarlet with stannous chloride and cream of tartar or oxalic acid. 2. FROM YELLOW DYESTUFFS. (a) Old Fustic Extracts. Both a liquid extract of about 20 B. and a solid extract have been prepared. The latter forms large yellowish-brown blocks of a waxy lustre, which dissolve in water with yellow color. They are prepared from the wood by diffusion. The name morin has been given to a commercial product obtained by boiling the rasped wood with a two per cent, soda solution and evaporating the solution so obtained to a specific gravity of 1.041, when on cooling the morin and moritannic acid separate out. (&) Quercitron Extracts, etc. Both liquid and solid extracts are used commercially. The former of 20 and 30 B. respectively, and the latter as a dark-brown mass of waxy lustre. The extracts contain, as a rule, mixtures of quercitrin and quercetin. Flavine has already been referred to. It is a preparation in which the quercitrin of the bark has been extracted, and in large part changed by subsequent treatment with sulphuric acid into quercetin, which is superior in coloring power. The tannic acid of the bark extract has also been removed and the lime salts, so that it gives much purer colors than the original extract. Flavine is largely used in connection with cochineal or lac-dye for producing scarlet. A quercitron extract to which stannite of soda or sulphate of zinc has been added is said to be used under the name of " Fustic Sub- stitute." It can be told from genuine extract of fustic by the test with ferric chloride, which produces a brown precipitate, turning olive-green with fustic, but a greenish-black with quercitron extract. (c) Persian Berries. A thick extract is prepared from Persian ber- ries, soluble in water with yellow color shading into brown. The solu- tion becomes clearer on addition of hydrochloric or nitric acids and deposits a dirty-yellow precipitate. Ammonia or caustic soda colors it a reddish-yellow, stannous chloride gives at once, and stannic chloride after the addition of carbonate of soda, a golden-yellow precipitate, iron salts a dark olive-green to greenish-black color.. 3. FROM BLUE DYESTUFFS. (a) Commercial Indigo occurs in lumps or fragments of a deep-blue color, usually showing a bronze or purple- red streak when rubbed with any hard substance, or in the case of the better kinds with the friction of the thumb only. The fracture of indigo is dull and earthy, it sticks to the tongue, is odorless and tasteless. The PRODUCTS. 509 specific gravity varies from 1.324 to 1.455. Helen Cooley* has given the following determinations of indigotin, ash, and specific gravity in a number of samples of commercial indigo : DESCRIPTION. Specific gravity. Ash. Indigotin. Kurpah blue 1.129 17.54 55.11 Watson's best 1.292 6.50 59.53 Bengal red 1.391 6.41 54.03 Oude 1 427 7.02 52.90 Bengal blue 1.431 7.50 67.60 Kurpah red 1.529 21.20 45.28 Guatemala 1.559 14.49 47.04 Indigo preparations have been referred to under processes (see p. 504), and it was then noted that the salts of the indigo-sulphonic acids constituted the several so-called indigo extracts. Indigo-carmine is the potassium or sodium sulphindigotate (C 16 H 8 (SO 3 K) 2 N 2 O 2 ). It comes into commerce in both paste and solid form. It is soluble in one hun- dred and forty parts of cold water, readily soluble in dilute sulphuric acid. It dyes animal fibres direct, but with a much lighter shade than indigo, and is not at all so fast to light, while to vegetable fibres it shows no affinity. An analysis of the several grades of carmine-paste by Mierzinski f gave : DESCRIPTION. Water. Indigo. Salt. Carmine I 89.0 4.96 5.7 85.0 10.02 4.8 Carmine III 73.7 12.04 13.9 Saxony Blue (Chemic Blue} is the free sulphindigotic acid, C 16 H 8 N,(X(S0 3 H) 2 , and forms a deep-blue solution. It is prepared as in the making of indigo-carmine, except the acid is not saturated with alkali. It was largely used in dyeing wool, but is not adapted for silk. Indigo- purple is a reddish-violet powder, which mixed with varying amounts of orseille can be used for dyeing wool directly without mordants. For its preparation, powdered indigo is covered with ordinary (not fuming) sulphuric acid, and having been cooled is left for half an hour. In this way is obtained a blue solution of sulphindigotic (indigo-disulphonic) acid, which can be worked up into indigo-carmine and a violet powder. This latter is the monosulphonic acid, which is washed first with water and then with dilute soda solution until the washings are no longer acid, then dried for use as above. A product of analogous composition, known as Boiley's Blue, is prepared by gradually adding one part of finely- powdered indigo to ten or twenty parts of acid sodium sulphate, HNa S0 4 , in a state of fusion. The product is dissolved in water, precipi- tated with common salt, and washed with brine. Boiley's blue is a crystalline light-purplish mass, soluble in water with beautiful blue- violet color. Its solution in strong boiling acetic acid deposits on cool- * Amer. Journ. Anal. Chem., ii, p. 130. f Ganswindt, FJirberei, p. 150. 510 NATURAL DYE-COLORS. ing large prismatic crystals exhibiting a coppery reflection. It is in- soluble in alcohol or ether, but readily soluble in hot water. The light transmitted by the solution is red. With barium and strontium salts it yields violet precipitates. The fact that indigo had been obtained artificially by several differ- ent methods was mentioned under the artificial dye-colors. (See p. 465.) A synthesis of indigo-carmine has also been effected within re- cent years. The process, due to B. Heymann,* is as follows: One part of phenyl-glycocoll (C 6 H 5 .NHCH 2 .COOH) is rubbed up with ten to twenty times its volume of clean sand (which simply acts in the way of reducing the temperature of the reaction), and slowly added to fuming sulphuric acid, with eighty per cent, anhydride strength, warmed to 20 to 25 C. Care is to be taken that the temperature does not thereby exceed 30 C. After the solution of the phenyl-glycocoll, which takes place with evolution of sulphurous oxide, concentrated sulphuric acid of 66 B. is added to remove the excess of anhydride. It is then diluted with ice and common salt added, when indigo-carmine (indigo-disul- phonic acid) at once separates out. Experiments on dyeing with the new product show it to be better and purer than the commercial indigo- carmine. Its identity was established in a number of ways. The yield amounts to sixty per cent, of the theoretical, but this may be improved by further study of the conditions of the reaction. (6) From, Logwood. Logwood Extracts are prepared as liquids of 12, 42, and 51 Tw. (for equivalents of the Beaume scale, see Ap- pendix) and as a solid. This latter forms a dry black, lustrous and resin-like mass, which is quite brittle and easily powdered, taste sweet- ish astringent, and yields a reddish-brown solution. The specific gravity ranges from 1.45 to 1.51. The specific gravity is not a reliable indica- tion of the strength of the fluid extract, as it is liable to be raised by the addition of salt, glucose, molasses, etc. The extracts are also sometimes adulterated with starch, dextrin, chestnut-bark extract, hemlock extract, etc. The following table by Bruhl f gives the yields of extracts ob- DESCRIPTION OF WOOD. Yield of extract Soluble in ether. Soluble in absolute alcohol. Residue. Yucatan 2020 60 12 37 46 2 42 Yucatan, E. J 17.34 58.34 38 51 3 15 Laguna 21.00 51 37 47 95 68 St. Domingo 1402 44 95 53 47 1 58 19.30 43 81 50 32 5 87 Monte Christo, 1884 18.75 3200 60 32 7 68 Monte Christo, 1887 14 00 34 72 54 10 11 18 Fort Liberte, 1886 20 33 41 89 54 11 4 00 Fort Liberte, 1887 1600 50 00 47 92 2 08 Fort Liberte, 1885-86 17 45 59 7.2 35 17 5 21 Fort Liberte, J. B., 1887 18.00 59 24 34 81 5 95 18 70 43 20 60 50 6 30 Jamaica 18.00 43 05 50 71 6 24 Jamaica wood roots 1070 52 99 30 12 16 89 * Ber. Chem. Ges., xxiv, p. 1476. t Textile Colorist, x, p. 148. ANALYTICAL TESTS AND METHODS. 511 tained by himself from different woods and the percentage solubility of the resulting extracts in ether and alcohol. The portion dissolved by ether represents roughly the hasmatoxylin percentage, while that dis- solved by absolute alcohol represents the haematein and decomposition products of the hcematoxylin. Indigo Substitute (Noir imperial, or Kaiser schwarz] . Under these names are known oxidized logwood extracts, made by boiling logwood extract with copper, iron, or chromium salts with the addition of oxalic acid. They may be in liquid form, or pastes, or dry powders. The preparations are almost insoluble in water, but completely soluble in acids with yellowishrbrown color. A commercial preparation of this class, known as " direct black," for cotton forms a brownish, viscid liquid, composed of fifty per cent, water, forty-five per cent, of a sub- stance soluble in alcohol and ether (hgematoxylin and haematein), and 3.5 per cent, of copper sulphate. Hcematein (Hematin) is a commer- cial preparation of French origin, which claims to consist of nearly pure dyestuff. It forms a granular, reddish-brown powder, completely soluble in water, and dyes the same shades as those obtained from the wood. Fifteen kilos, of hsematein are said to be equivalent to one hundred kilos, of the logwood. Hematine crystals is a solid logwood extract made porous by the addition of nitrite of sodium just before solidifying. (c) Litmus, as has been said, is a mixture of the lichen dye of that name with chalk or gypsum as inert material. It is made in different numbered grades, containing different amounts of the mineral matter. Litmus in the dry form has a violet-blue color, is quite friable, and dis- solves in water and dilute alcohol, leaving a residue of chalk, gypsum, alumina, silica, etc. 4. FROM BROWN DYES. (a) Catechu has been described already in part under the raw materials of the tanning industry. (See p. 359.) It is not unfrequently adulterated with starch, sand, clay, and blood. Good catechu should yield at least half its weight to ether and should be entirely soluble in boiling water, the latter solution depositing catechu on cooling. Catechu does not wholly dissolve in cold water unless it has been previously modified by age or exposure to damp. It should not yield more than five per cent, of ash. Prepared Catechu has been merely purified by mechanical means. For this purpose, the commer- cial catechu is fused on the water-bath, whereby sand, earth, and simi- lar impurities settle out, and then it is strained to remove leaves, etc. The material so obtained is again melted on the water-bath, and to every one hundred parts of the catechu three-fourths per cent, of potas- sium bichromate is added, when it is allowed to cool down again. IV. Analytical Tests and Methods. 1. FOR DYE-WOODS. Here the question of adulteration does not come notably in play. The compact woods are not capable of much adultera- tion of any kind. When chipped or rasped; however, they may be adul- terated quite considerably. The examination with the microscope or simple lens will often suffice to indicate the nature of this adulteration. 512 NATURAL DYE-COLORS. A special case of cheapening is that of the cured or fermented logwood chips, which, as has already been stated, may take up as the result of this fermentative process as much as thirty to forty per cent, of water. In this case a moisture determination will show the change, allowance being made for the fourteen per cent., which is the average moisture of the unfermented wood. To determine the comparative dyeing value of different samples of woods, the only thoroughly reliable test is an actual dyeing test made with definite weights of the wood, thoroughly extracted, and using definite amounts of mordants upon the wool or other fibre used. This test, as applied to logwood, for example, would be carried out as fol- lows : Ten gramme portions of clean wool are separately mordanted for li/2 hours at the boil with 3 per cent, of potassium bichromate and 2y 2 per cent, of cream of tartar, washed, and dyed for 1 hour at the boil in the logwood bath, containing a definite amount of decoction or extract of each sample to be tested, afterwards washing and dyeing for the final comparison of shade. This method of logwood assay takes cognizance both of the actual and the potential coloring matter present (hasmatein and haematoxylin), and is a more rational method of examination than any based on the color produced on cotton mordanted with alumina or tin salts. The dye test in other cases must be made upon a normal pre- pared extract of known strength and purity, and the result compared with those obtained with a corresponding weight of the supposed adul- terated sample. 2. FOR DYE-WOOD AND OTHER EXTRACTS. (a) Orseille Extract. This may be adulterated with logwood or Brazil-wood extract. They may be detected, according to Leeshing, as follows : A solution of orseille extract, much diluted and acidified with acetic acid, will, if pure, when boiled with a freshly prepared solution of stannous chloride, become pale yellow or almost colorless, while logwood extract solution under similar circumstances will show a violet color and Brazil-wood solution a red color. If, therefore, the orseille is adulterated with logwood ex- tract a permanent grayish-blue color will show, if with Brazil-wood extract, a reddish color. Orseille is also found frequently to have been adulterated with aniline dyes, especially magenta, acid magenta, and methyl violet. For the detection of magenta and methyl violet Knecht* employs cotton yarn dyed with chrysamin (p. 464). This does not take up the color- ing matter of the orseille, but is dyed red by magenta and brownish-red by methyl violet. To detect the acid magenta, Kertesz f treats the orseille preparation with benzaldehyde and adds to the solution tin salt and hydrochloric acid, shaking up the mixture thoroughly. If acid magenta was present a red color will remain, while with pure orseille the solution remains colorless. One part of acid magenta in one thousand parts of orseille it is said can be thus detected. For other tests for the artificial dye-colors when present as adulterants in orseille, * Journ. fiir Prakt. Chem., 71, p. 19. f Berichte der Chem. Ges., xviii, p. 1970. ANALYTICAL TESTS AND METHODS. 513 see Allen, "Commercial Organic Analysis," 2d ed., iii, pp. 322 and 323. (&) Quercitron Extracts. The dyeing value of the extract, as well as a possible adulteration of the same with dextrine, glue, etc., can be best determined by an actual dye test. For this purpose, wool is boiled with 1.5 per cent, of tin salt and three per cent, of oxalic acid, then washed. One gramme of the wool is now dyed with twenty cubic centi- metres of a solution of ten grammes of the quercitron extract in one thousand cubic centimetres of water. Similarly several portions of one gramme each of mordanted wool are dyed with solutions of pure bark or pure extract of definite strength, and the results compared. (c) Annatto (Orlean). Annatto possesses only a slight importance as a dyeing agent, but special importance as the basis of most butter colorings. (See p. 299.) It is, therefore, a commercial article of com- mon use and liable to be adulterated. The common adulterants are starch, dextrine, chalk, silica, alumina compounds and common salt, together with ochre, brick-dust. Most of these increase notably the percentage of ash, which in a pure sample it is said should not exceed ten to twelve per cent. Wynter Blyth gives the following two analyses as illustrating the nature of its adulteration: DESCRIPTION. Water. Resin. Extractive matter. Ash. Fair commercial sample . . Adulterated sample .... 242 134 28.8 11.0 245 27.3 22.5 40 o f Oxide of iron, alumina, ' 1 silica, chalk, and salt. For dyeing purposes the only satisfactory test is an actual dyeing test in comparison with an authentic unadulterated sample. For the analysis of the many butter-coloring mixtures containing annatto as the basis the reader is referred to Allen, " Commercial Organic Analysis," 2d ed., iii, pp. 353-356, and Wynter Blyth, "Foods, Com- position and Analysis," p. 306. (d) Logwood Extract. Both the liquid and the solid extracts are liable to be adulterated, the former with glucose, molasses, dextrine, salt, and other extracts of lesser value, the latter with starch and in- ferior extracts. Notably are the French and German logwood extracts adulterated in the way just referred to. The following analyses of some of the commercial extracts as currently sold in France and Germany are given by V. H. Soxhlet : * DESCRIPTION OF EXTRACT. Molasses. Dextrine Chestnut extract. Salt. Guaranteed Pure, 30 B. . . Prima, 30 B 5 per cent. 10 Secunda, 30 B 20 10 per cent. 10 per cent. Secunda, Solid 20 15 " " Saaford Brand, I 25 15 per cent. Sanford Brand, II Sanford Brand, III 35 35 10 " " 15 " " 10 " " 15 " " Farber-Zeitung, Aug. 1, 1890, p. 368. 33 514 NATURAL DYE-COLORS. The Sanford Brand here referred to is a French extract made in imitation of the original American Sanford Extract. The extracts may be tested for purity either by the colorimetric assay or by comparative dye tests. The colorimetric test is carried out, according to Henry Trimble,* as follows: A volume of solution corre- sponding to .001 gramme of the dry extract is treated with ten cubic centimetres of water naturally or artificially containing traces of cal- cium carbonate and a solution of .002 gramme of crystallized copper sul- phate. The mixture is brought quickly to the boiling-point and diluted with distilled water to one hundred cubic centimetres. The color of this solution is then compared with one of pure hcematoxylin similarly used, or with a standard sample of logwood extract. The method of carrying out the dye test for logwood with bichro- mate of potassium mordant has already been given in speaking of dye- woods. The same test is, of course, equally applicable to the extracts. Cotton strips are sometimes used for these dye tests instead of wool. The cotton strips must be boiled in dilute soda solution and well washed. They may then be mordanted with nitrate of iron solution instead of the chromium salt, following the nitrate of iron with a rinsing in car- bonate of soda solution and thorough washing. They are then put in the dye-bath cold, and this gradually heated to boiling. In this dye- testing with iron solution, the hsematoxylin of the solution is oxidized by the ferric oxide to hgematein, so that the full coloring value of the logwood is obtained in the test. For the discovery of adulterations like chestnut extract, which con- tain almost nothing soluble in ether, Houzeau proceeds as follows: One gramme of the extract to be investigated is dried at 110 C., exhausted with ether, and the weight of the dissolved material determined. The undissolved material is then exhausted with absolute alcohol, and the weight of the portion dissolved by this also determined. The compari- son of the figures so obtained with those yielded when a pure extract is treated with the same solvents will show clearly the presence or absence of adulterating extract. Dye tests may also be carried out with the material which has been extracted by ether and alcohol respectively in the two cases, and the difference more fully established. (e] Catechu Extract. Catechu is frequently adulterated, not only with mineral matter like sand and clay, but with starch, dextrine, sugar, blood, etc. The mineral matters will, of course, remain in the ash. This in normal catechu should not exceed five per cent. The starch may be detected by extracting the sample with alcohol, boiling the insoluble residue with water, and testing the cooled liquid with iodine, which will show by the blue color any starch present. An addition of alcohol to the aqueous solution will show by the production of a turbidity any notable quantity of dextrine. Blood may be' detected by treating the sample with alcohol, and drying and heating the residue in a tube, when ammonia and offensive decomposition products will be given off, or the coagulation of the blood albumen when the aqueous solution is boiled. * Journ. Soc. Dyers, etc., i, p. 92. ANALYTICAL TESTS AND METHODS. 515 The value of catechu for dyeing purposes can only be determined by a dye test. For this purpose strips of cotton-stuff are immersed for half an hour in a catechu solution (for each gramme of the cotton fifty cubic centimetres of a catechu solution containing five grammes to the litre of water are taken and diluted with water if necessary). The strips are pressed out, and then the color developed by oxidizing in a hot solution of one to two grammes of potassium bichromate to the litre of water. 3. FOB COCHINEAL. The adulteration of cochineal may be effected in various ways. A very common adulteration is to admix with the fresh cochineal insects others from which the coloring power has already been in large part extracted. To give the exhausted cochineal insects the appearance of fresh ones, they are shaken up with talc, barytes, and white lead, and thus given a coating resembling the silvery insects. Either a washing or an ash determination will serve to detect this adul- teration. The valuation of the cochineal as to coloring power may be made by several methods. The one best known is that of Penny,* in which one gramme of the cochineal is treated with fifty grammes of dilute potassium hydroxide, twenty-five grammes of water added, and to this is then added drop by drop a solution of ferricyanide of potassium containing five grammes to the litre. The solution loses its purplish- red color and becomes brownish-yellow. The action of the ferricyanide of potassium solution is tested in comparison on the solution of one gramme of a cochineal of known purity. Liebermann f extracts the cochineal with boiling water, and determines the coloring matter by the addition of a slightly acid solution of lead acetate. After filtering and washing the lead precipitate, a lead determination is made in an aliquot portion, and from this the percentage of coloring matter calculated. Allen does not consider either of these methods to be perfectly satisfac- tory. An actual dye test is therefore in the end to be regarded as the most reliable method of valuation. For this purpose strips of woollen stuff of about five grammes in weight are put into the bath until the color is all taken up. A portion of the strips may then be dyed scarlet- red by immersing them in a tin solution (for one gramme of cochineal two grammes of cream of tartar, two grammes of tin salt, and as much water as is needed to thoroughly immerse the strips), and the other portion of the strips may be dyed a cherry-red by the use of an alum solution (for one gramme of cochineal, three-fourths gramme of cream of tartar and one and a half grammes of alum). These strips are then to be compared with others obtained from similar treatment of a nor- mal or pure cochineal sample. 4. FOR INDIGO AND ITS PREPARATIONS. Indigo may be of very varying value as it comes into commerce, partly because of the differences natural to such a product and dependent upon the differences in cultiva- tion of the plant, care in extracting and drying the indigo, and the fact that the natural product is at best a mixture, and partly from inten- tional adulteration. Thus starch colored with iodine, Prussian blue, * Journ. fur Prakt. Chem., 71, p. 119. f Berichte der Chera. Ges., xviii, p. 1970. 516 NATURAL DYE-COLORS. smalt, and logwood-powder are said to be used as adulterants of com- mercial indigo. In order to detect the starch, the suspected sample is rubbed up in a mortar with chlorine-water until it is completely decolor- ized, when a drop of potassium iodide is added. If starch be present the blue color of iodide of starch will be seen. To detect the smalt or Prussian blue, the sample is oxidized with nitric acid, when if a blue residue is shown in the yellowish solution adulteration is indicated. If the adulterant were Prussian blue, the color fades too after a time, if smalt, it is permanent. To detect logwood-powder, mix the sample with oxalic acid, place it upon filter-paper, and moisten it; in the presence of logwood the paper will be colored red, if the sample were pure it is unchanged. In the assay of commercial indigo the moisture is generally to be determined. This should not exceed some seven per cent, in a genuine sample. The ash similarly is an important criterion of the quality of the indigo sample. In the purest kinds it is sometimes as low as two per cent., but from five to eight per cent, is more usual. Some of the inferior grades of indigo, such as Kurpah and Madras, may contain from twenty-five to thirty-five per cent, of ash. The methods for the determination of the percentage of indigo-blue are, of course, the most important things to be considered in connection with indigo as a dyeing material. They are very numerous. We may summarize the more important of them under .three heads, viz., oxida- tion methods, reduction methods, and sublimation of the pure indigo- blue from the commercial product. The oxidation of the indigo-blue takes place in acid solution, the indigo being previously dissolved in strong sulphuric acid. Potassium permanganate, bichromate, and ferricyanide have all been recommended and used in this connection. All the processes are open to the objec- tion that the oxidizing agents act on the indigo-gluten and ferrous salts as well as on the indigo-blue and indigo-red, but the errors due to this cause may be practically avoided, as pointed out by Rawson, by pre- viously precipitating the sulphindigotic acid in the form of the sodium salt by adding common salt to the solution. The method with per- manganate of potassium, modified in this manner by the use of common salt, is as follows : * One gramme of the sample of indigo in the form of an impalpable powder is mixed in a small mortar with its own weight of ground glass. This mixture is gradually added with constant stir- ring to twenty cubic centimetres of concentrated sulphuric acid (specific gravity 1.845), which is then heated to about 85 C. for an hour. The product is then cooled, diluted with water to one litre, and filtered from indigo-brown and other soluble matter. Fifty cubic centimetres of the filtered solution are now taken, diluted with fifty cubic centimetres of water, and thirty-two grammes of common salt added, which quantity is almost sufficient to saturate the liquid. After standing for two hours, the solution is filtered, and the precipitate washed with about fifty cubic centimetres of brine of 1.2 specific gravity. This sodium sulphindi- * Allen, Commercial Organic Analysis, 2d ed., iii, p. 308. ANALYTICAL TESTS AND METHODS. 517 gotate is dissolved in hot water, the solution cooled, mixed with one cubic centimetre of sulphuric acid, and diluted to three hundred cubic centi- metres. This solution is then titrated in a porcelain dish with a solution of potassium permanganate containing .5 gramme of the solid salt per litre, the exact oxidizing power of which has been ascertained by experi- ment with a solution of pure indigotin. The oxidation is regarded as complete when the liquid which at first takes a greenish tinge changes to a light yellow with a faint pink color on the margin. The reduction of indigo-blue may take place in alkaline solution or with a solution of the sulphindigotic acid or its salts. Ferrous hydrox- ide and hyposulphites are among the, reducing agents used to effect the reduction in alkaline solutions. C. Rawson considers the hyposulphite reduction method the better one of the two. In carrying it out, one gramme of the finely-powdered sample is made into a paste with water and placed in a flask with about six hundred cubic centimetres of lime- water. The flask is closed by a cork having four perforations, two of which serve for the passage of coal-gas, a third carries a siphon, while to the fourth is fitted a tap-funnel. The contents of the flask are heated to 80 C. and one hundred to one hundred and fifty cubic centi- metres of a strong solution of sodium hyposulphite (NaHS0 2 ) intro- duced through the tap-funnel. In a few minutes the liquid assumes a yellow tint, and is maintained at a temperature near the boiling-point for half an hour. After allowing the insoluble matters to subside, an aliquot portion of the solution should be removed, and a current of air drawn through it for about twenty minutes, when it is acidulated with hydrochloric acid. The precipitate, which consists of indigotin and indigo-red, is collected on a weighed filter, washed with hot water, dried at 100 C., and weighed. It is then exhausted with boiling alcohol, whereby the indigo-red is dissolved out and the difference again weighed as indigo-blue. Rau reduces the indigo in alkaline solution with glu- cose, and L. M. Norton uses milk of lime and zinc-dust as reducing agent, and then takes an aliquot portion of the reduced solution to re- duce a solution of iron-alum. The ferrous salt formed corresponds to the reduced indigo in the volume taken, and is determined by titration with a standard solution of potassium bichromate. (For details, see Helen Cooley's article, Amer. Journ. Anal. Chem., ii, p. 133.) For the reduction of the indigo in acid solution, Bernthsen and Drew* recommend the use of hyposulphite of soda (NaHS0 2 ), and claim that the reaction is a quantitative one: C 10 H 8 N 2 2 (S0 3 H) 2 -f- NaHS0 2 + H 2 O = C 16 H 10 N 2 O 2 (S0 3 H) 2 -f NaHSO 3 . C. Rawson f considers that of all the volumetric methods which have been devised for estimating indigotin the hyposulphite process is capable of giving the most rapid and accurate results, but that considerable care and delicacy are required in its manipulation. Lee I has proposed the sublimation of the indigo-blue as a method for determining its percentage in commercial indigo. Other writers, * Chem. News, xliii, p. 80. f Allen's Com. Org. Anal., 2d ed., iii, p. 309. J Chem. News, 1, p. 49. 518 NATURAL DYE-COLORS. ~-*i = 3 a 2 n a S 3 3 S GO Jit ff; aJ k . Sg i ca e 5 03 s - 2,9 o *.s . a 3 t ^i pq sl '5 If -2 S-Co-6 tfjs o ~ . . '3 > -- " r* ~ ip ( - .^. ^ fij 2 ^ fe Q ^ ^ O O d5 d> i< o o 1 -u -2 9 e 8 o o o ^ 3 PH W M rt ^ ^ Pd PH H ^ pq H P^ M c chloride, 1 : 10. i 4) a a B .M olution. 3recipitate. 3. 'S. a '3 S S ft ft -3 a> O a; ^ S ft i ft 1 "o '3 J 1 precipitate, color. !i ^ 3 u o 1 red color. ^'as'e S'Sg'S 1 M | -I'll ;-,&- c^n 4P n l| 34^ -w 1 3 a-g -3 ^,; ft SSi? a be c ft ffl pq ft ft JH ft n pq pq pq M C5 a A a 73 . i M a Aluminum sul- phate and sodiui carbonate, 1:10. II Reddish-violet lution. Yellow solution. Reddish-yellow s lution. Yellow precipitat Yellow precipitat Yellow s o 1 u t i o when p o u r e 1 Yellow color. Light yellow colo Yellow color. Red color. Light yellow pr cipitate. Red color. 8.1 a 0_3 ^ , d i a d y o m 4) S o o oS -*? "S li ^ ^H ft 33 H fl 2 O rt a ^ ^ : 3 3 "S . 1 1 1 CjrH O T3 fi 8 ^ frn >H" 3 'S f 3 ^-, ^^2 "3 ai"^ "O 1 J3 ^ '3 '3 B, "S "o a "o ^ O O S 8 8 133 k ^ "8 II ?> ai;as 1111 ||| J3 pq M " P pq PH H o w pq 3 pq pq jl i . 45 . I) o |! O 1 d k > d S |-2 |-2 s li _o 0) S d 1 "o i*i i> o >,5 c -s o 13 ca cy C B a 3 ^ * 00 a C o ^ t. 33 o ! fcl Q fc S Reddis S.2 ^ -0 | S _0 ig s* EH S ft 'g '3 S S Color] e Red co A 5 S 1 a 2 ' ' H 3 p : D 03 ij P A - S W 3 o o P S H-* E C5 t ! W 55 K S o H K 1 z a Q -KM S5 J a 55 O a O O P p >" & H * 3S Pi < P 02 O H H) i CO fc fc D HH CO D H < 2 H 2 < H W O CO o S O CO H O BIBLIOGRAPHY AND STATISTICS. 519 however, do not agree that, unless the indigo has previously been some- what purified, the results can be depended upon. C. Rawson * has given the following results with commercial sam- ples, using the several processes just detailed: METHOD USED. Java. Bengal. Bengal. Oude. Kurpah. Madras. 2.99 522 6 17 7 50 8 05 5 71 Ash 1.99 3.91 4 86 8 21 25 72 33 62 Indigotin, by sublimation .... Indigvjtin, volumetric, by hypo- sulphite GO. 84 68 78 57.50 59 26 49.36 55 66 41.60 43 18 41.92 42 52 39.66 36 80 Indigotin, gravimetric, by ferrous sulphate and NaOH 68.24 58.84 54 34 44 50 41 50 34 50 Indigotin, gravimetric, by hypo- sulphite and lime 68.97 \ 59 12 \ 56 20 \ 43 42 > 42 68 \ 35211 Indirubin, separated by alcohol . Indigotin and indirubin, titration with KMnO 4 direct 4.23 / 76.18 3.50 / 66.71 2.80 / 6266 3.65/ 5004 2.45 / 47 15 3.98/ 39.50 Indigotin and indirubin titration after precipitation with salt . . 73.55 63.50 57.50 44.90 43.10 37.40 The table from Dammer's Chem. Technologic, Band iv, p. 591 (see opposite page), shows the characteristic reactions of the important nat- ural dyestuffs. V. Bibliography and Statistics. BIBLIOGRAPHY. 1877. Tropical Agriculture, P. L. Simmonds, London and New York. 1880. Lexikon der Farbwaaren, F. Springmiihl, Berlin. 1881. Les Matidres premieres, Georges Pennetier, Paris. 1882. Dictionnaire des Alterations, etc., Ed. Baudrimont, 6me ( sumach, galls, etc.) for several hours, then worked in dilute iron solutions as above, this pro- duces a tannate of iron, followed by a passage through weak lime-water, and dye in a separate kettle. Acetate of alumina can be used with the iron, somewhat modifying the shade. A " chrome black " can be ob- DYEING. 537 tained by dyeing in a single bath of bichromate of potash, hydrochloric acid, and logwood ; many modifications of this process are known. Gray shades can be obtained by first working in logwood, and afterwards in the copperas or bichromate of potash baths. Of the red dye-woods little need be said, as they are now but seldom used; their coloring matters are fixed in the usual manner with tin, alumina, or iron mordants. Of the yellows, Quercitron Bark and Fustic are the most important; the former, used chiefly as an extract, is avail- able for the production of greens, etc., in combination with other color- ing matters. Fustic is used to shade logwood black. Turmeric is no longer used in dyeing. Application of the Artificial Coloring Matters to Cotton* In this section only the individual colors will be referred to, any attempt to discuss the production of shades by compounding would be beyond the scope of this publication. Fuchsine is dyed upon tannin-prepared cotton, or upon cotton that has been worked in small quantities at a time in a bath of ten per cent, of neutral soap or Turkey-red oil, followed by an immersion in a warm bath of two hundred and fifty gallons water and one gallon acetate of alumina (9 Tw.). Work half an hour, wash, pass through a soap- bath for fifteen minutes, wash, squeeze, and dye. The color is added in successive portions until the required shade is obtained. Safranine is dyed upon a tannin mordant, or the tanned material is worked in a 3 Tw. bath of stannous chloride for an hour, washed, and passed through a two per cent, soap solution, and dyed at 140 F. Methyl and allied Violets can be dyed upon tannin as above, or pass the untanned cotton through a one per cent, olive-oil bath, squeeze, and dye at 100 F., or with the assistance of acetate of tin, or with alum and soda. The basic greens, including Victoria Green, Methyl Green, Brilliant Green, etc., are easily dyed upon cotton in the ordinary manner with a little (.5 per cent.) acetic acid. The Eosins, with Phloxin, etc., are dyed in several ways: first, by passing the cotton through a two per cent, soap-bath, followed by an immersion for two hours in from two to three per cent, acetate of lead, washing well, and dyeing, cold, with a little acetic acid; or, second, by working in a dye-bath with eight to ten per cent, sulphate of soda, or the cotton can be worked in 5 Tw. bath of stannate of soda for an hour, worked for thirty minutes in a ten per cent, alum solution, rinsed, and dyed cold. Rhodamin is dyed on acetate of alumina exactly as for fuchsine. Brilliant, Cotton, and Soluble Blues. The cotton is tanned and dyed with five per cent, alum and one per cent, soda; or the tanned cotton can be worked in a 3 Tw. stannous-chloride bath for an hour, rinsed, and dyed at 150 F. If light shades are to be produced, work the cotton in a five per cent, soap-bath for an hour, squeeze, and work in a three per cent, tannin-bath, wring out, and dye with the assistance * Reference has been made in the preparation of this and subsequent sections on its application to several of the published trade circulars issued by the coal- tar color manufacturers, and also to information from private sources. 538 BLEACHING, DYEING, AND TEXTILE PRINTING. of tartaric acid and alum. Victoria Blue. Cotton is mordanted with tannin; dye with one per cent, acetate of alumina. Methylene Blue. This is an exceedingly valuable color to the cotton-dyer, as with it he can produce indigo shades. The cotton is mordanted with twenty-five per cent, sumach at 160 F. Give several turns, and allow to steep ten hours, wring* out, and work for twenty minutes in two and one- half per cent, tartar emetic, wash, and dye in a bath prepared with acetic acid (three per cent.) at 75 F., gradually raising the tempera- ture to 160 F. Croce'in Scarlets are dyed on cotton by working the untanned yarn in stannate of soda, wring, and pass for half an hour through sulphate of alumina, rinse, and dye. Cotton can also be dyed by passing first through stannic chloride, and then through acetate of alumina. Dye cold, or dye direct, with sulphate of alumina. Auramin, of considerable value, is dyed in the same manner as methylene blue. Bismarck Brown and Chryso'idine. Dye same as safranine; tempera- ture 100 F. Induline and Nigrosine. Dye in same manner as for the cotton blues. Paraphenylene Blue is dyed upon tin or antimony, and tannin. The shades produced are very dark, and extremely fast; treated with bichromate of potash, the shade closely imitates, and is faster than, indigo. The substantive colors of the Congo and parallel groups are exceedingly valuable, for the reason that they are easily dyed upon unmordanted cotton, and that they are of exceptional fast- ness. The several Congos, Benzo- and Delta-purpurin, and Rosazarin, are dyed with two and one-half per cent, soap and ten per cent, sul- phate of soda, or phosphate of soda, boil for one hour. Hessian Purple is dyed at a boil for half an hour with ten per cent, common salt, fol- lowed by a passage through dilute soda. Chrysamin is dyed with ten per cent, sulphate of soda and two and one-half per cent, soap at a boil. Hessian Yellow is dyed with ten per cent, of salt and a little Turkey-red oil. Brilliant Yellow and Chrysophenin are dyed with ten per cent, salt and two per cent, oxalic acid, work half an hour, squeeze, rinse, and dry. Azo Blue, and Benzoazimine, Heliotrope, etc., are dyed with ten per cent, sulphate or phosphate of soda and two and one-half pounds of soap, let stand, and skim the surface, add the dye, boil, and put in the yarn, and work for an hour, boiling, rinse the yarn, and dry at as low a temperature as possible. Indigo shades from Benzoazimine are obtained as above, but for every one hundred parts of color add three parts Chrysamin. All the substantive dyes act as mordants for a very large number of other colors, no other fixing agent being required. Diazotized and developed colors for cotton, of which primuline is the type are dyed in the usual way for a substantive color, then "diazo- tized " in a bath of nitrite of soda and a mineral acid, and afterwards " developed " by passing through a bath containing a developer, e.g., /3-naphthol, which develops and fixes the colors.- Dark blues and blacks are largely dyed by this process specially for hosiery, on account of the fastness. CSee p. 541.) The important group of sulphur colors dye cotton various shades, the most important being the blacks, blues including indigo shades, DYEING. 539 cutch shades and olives. Cotton is dyed from alkaline dye baths pre- pared with sodium sulphide, common salt, and the necessary color. The shades are noted for their fastness except to chlorine. Another important group of cotton colors are the so-called " vat dyes " which dye cotton from baths containing the coloring matter in a reduced state, similar to indigo. The range of shades is very exten- sive, possessing very good fastness to general influences, including chlorine. Aniline Black. This color is produced directly upon the fibre dur- ing the dyeing by means of aniline oil in the presence of oxidizing agents ; to obtain good results it is necessary that the oil used should be as pure as possible. Two methods are in general use, warm (Grawitz patent) and the cold. In the former method, two thousand four hun- dred litres of water, thirty-two kilos, hydrochloric acid, sixteen kilos, bichromate of potash, and eight kilos, aniline oil are taken. The acid and aniline are each diluted with water and carefully mixed, the solu- tion thus obtained being added to the main volume of water. The bi- chromate of potash is previously dissolved and added after the aniline. Immerse the cotton, and work for three-quarters of an hour in the cold, and then gradually raise the temperature to 60 or 70 C. In the cold method take eighteen kilos, hydrochloric acid, eight to ten kilos, aniline oil, twenty kilos, sulphuric acid, 66 Be., fourteen to twenty kilos, bichromate of potash, and ten kilos, copperas. This bath is made up similarly to the previous one, with the exception that much less water is used. Aniline salts in solid form are often used instead of aniline oil and acid. The yarn is worked in one-half of the materials for an hour or so, after which the remainder is added, and the operation carried on for about one and a half hours longer, followed by a wash- ing, and a boiling in a soap solution. In either case, the cotton after dyeing is subjected to a further oxidization with bichromate of potash, copperas, and sulphuric acid, this having a tendency to prevent green- ing. Chlorate of soda is used considerably as an oxidizing agent in the dye-bath. Vanadium chloride, or vanadate of ammonia, has been recommended to be used with a chlorate in place of bichromate of potash; the proportion of the vanadium salt being to the displaced bichromate as 1 : 4000. Another method is to produce the aniline black in powder form, purify it, liberate the base, which is dissolved in sul- phuric acid, poured into water, and the precipitate formed thereby dis- solved in caustic soda. This is reduced as in the case of indigo, and dyed in a similar manner. Alizarin-dyeing, Turkey-red Process. J. J. Hummel, in his " Dye- ing of Textile Fabrics," 1886, p. 427, et seq., details the emulsion process, which need not be described here. It may be stated, however, that beautiful results have been obtained from its use; the yarn passes through fourteen operations, as follows: boiling in soda and drying, worked in an emulsion of oil, dung, and carbonate of soda; passed through the previous process twice again; worked four times in car- bonate of soda, steeped in water, and in carbonate of soda, suma~ched. 540 BLEACHING, DYEING, AND TEXTILE PRINTING. mordanted with alumina, dyed with alizarin (ten per cent.), sumach, and blood, cleared with carbonate of soda, final clearing with soap and tin crystals. To finish the dyeing requires about three weeks, but a real Turkey-red is produced. Except for some grades of goods, it is doubtful whether such a lengthy process would be profitable. The following scheme of a process represents the type of a reason- ably short one ; it is well to remember that it can be modified to a con- siderable extent without altering its product. It is used in several establishments essentially as given. Boil the cotton for two hours in a 1.04 specific gravity solution of caustic soda, wash well in water, dry, and work in seven to ten per cent, solution of Turkey-red oil, squeeze, dry at about 115 to 120 F., steam in a chest, mordant with acetate of alumina (red liquor) at 80 Tw., and dry as before; work for an hour in a hot bath of five pounds of dung and eight to ten pounds of chalk, followed by a good wash, and pass to the dye-bath, made up of eight per cent, of alizarin, two per cent. Turkey-red oil, and about one per cent, of ground sumach, or equivalent in pure extract. Enter cold, and slowly FIG. 120. increase the temperature to and maintain it at 160 F. for over half an hour. Dry, and steam in the chest as above. The final operation is a soaping with carbonate of soda and stannous chloride as in the above emulsion process. An almost unlimited number of processes could be given, but it is hardly necessary, the principle remaining the same in every case. For full information reference is made to Hummel, Sansone, and Knecht, Rawson, and Lowenthal. The apparatus used for alizarin-dyeing is not special, with the exception of the machines for " padding," the material to be dyed with the oils and for working in the liquors; the most important is the steam-chest, which is essentially a large cylindrical wrought-iron drum with cast ends, one of which is provided with a well- closing door. The chest, or steamer, is provided with a steam-supply pipe, gauge, and safety-valve. The yarn or cloth is hung on sticks supported on rods inside, or, as shown in Fig. 120, mounted on iron carriages. Some chests are so built that the yarn contained can be turned while closed and with the steam pressure on, which seldom ex- ceeds four or five pounds. DYEING. 541 Ingram Red, a color obtained from primuline or polychromine, is for some purposes a perfect substitute for Turkey-red, being fast to light, soap, and acids. Primuline is dissolved in warm water, common salt or sulphate of soda added, and the yarn worked in the bath until a good full yellow is obtained, when the material is washed, and im- mersed in a cold solution of nitrite of soda slightly acidulated with either hydrochloric or sulphuric acid, this causes a diazotizing of the yellow color, with the production of an unstable orange shade ; the yarn is lifted out, washed rapidly, and at once dipped in a warm solution of fi-naphthol in caustic soda, when a deep-red color is developed. The yarn is worked for a while, and afterwards well washed in water. If phenol or resorcin is substituted for the /8-naphthol, a fast yellow or orange color, respectively, will be obtained. The diazotized yarn is very sensitive to the light: if it is not in a reasonable time developed, no color will be obtained; this fact is at the present time experimented upon with a view to its possible use in photography. A more recent and still better substitute for Turkey-red is the azo- para-nitraniline obtained by diazotizing para-nitraniline C and devel- oping with /?-naphthol and red developer C. The cotton yarn is pre- ferably first impregnated with the caustic soda solution of the developer, made with the addition of castor-oil soap, and then put in the diazotized solution. Linen. The uses to which fabrics made of this fibre are put demand colors that shall be fast to washing, light, and air ; this requirement being satisfied by alizarin and indigo. The coal-tar colors, as a rule, are not applied, although they can be by treating the fibre in the same manner as cotton. Jute, owing to its peculiar chemical structure, does not require any mordanting; all basic colors can be applied by simply boiling in a neu- tral bath. Some scarlets and a few of the acid colors are fixed with the assistance of a little acetic acid in the dye-bath, sometimes with a little sulphuric acid and alum. Wool-dyeing. Raw wool is dyed in the same manner as raw cotton, in open kettles, or in machines made for the purpose. Woollen yarns and cloth are similar in their manipulation to cotton, the apparatus be- ing in both cases nearly the same. Dyeing-machines for carpet yarns are coming slowly into use, several forms being capable of handling a large quantity in comparison with hand labor. Some classes of goods, i.e., plushes, have cotton backs, these being previously dyed in the hank and warp and then woven, the face, or pile, is afterwards dyed in proper shade, care being taken to select such colors as will have no modifying effect upon the cotton color. For this purpose cottons dyed with aniline black, indigo, or alizarin are best suited. Natural Coloring Matters applied to Wool. Indigo, as extract, is now but little employed for dyeing wool on account of its fugitiveness, when now used it is only for its cheapness. If other coloring matters are to be used in connection with the above for the production of com- 542 BLEACHING, DYEING, AND TEXTILE PRINTING. pound shades, a neutral extract had better be used, and the dyeing done without the use of acid. Wool is dyed in a vat, where exception- ally fast and full shades are demanded, especially for army cloth. Loose wool is dyed in the so-called fermentation-vat, the wool being kept below the surface of the liquor, worked about by means of long rakes for a sufficient time, and taken out and put in large cord bags, or placed upon rope screens to drain and oxidize. It is finally dipped in very dilute acid to remove soluble impurities, well washed, and dried. Woollen yarn is worked in vats exactly as in the case of cotton. Cloth is worked in the vat below the surface of the liquid, by means of poles with hooks. The best indigo-dyed cloth is that made from wool which has been previously dyed in the raw state, dyed in the wool. Logwood. This dyestuff is the real base of the blacks upon wool, the most generally followed method being with bichromate of potash as a mordant. Boil the wool in a bath of three per cent, bichromate and one per cent, sulphuric acid for an hour, lift out, rinse, and boil in a bath (made with a decoction of about forty per cent, chipped log- wood) for an hour, lift the wool, and add a little extract of fustic, con- tinue the boiling for a half-hour. Frequently blacks of the anthracene groups are used in combination with logwood to give increased fastness. To prevent a " greening," or development of greenish tinge on exposure of the goods to the light, a coal-tar color, such as " cloth red," is dyed on first, so as to neutralize the effect of the green shade which may form. For cheap work " one-dip blacks " are used, these consist chiefly of a mixture of logwood and a mineral mordant, iron or copper. Wool can be mordanted with copperas, copper, and cream of tartar, etc., followed by dyeing in the logwood, or it can be worked in the logwood first, fol- lowed by a " development " in a bath of ferrous sulphate of iron and copper. Logwood Blue, for some kinds of work, is an excellent substitute for indigo, full shades being obtained by direct dyeing, or by dyeing upon a light indigo bottom. Hummel gives the following method. Mordant the wool for one to one and a half hours at 100 C. with four per cent. of aluminum sulphate, four to five per cent, of cream of tartar; wash well, and dye in a separate bath for one to one and a half hours at 100 C., with fifteen to thirty per cent, of logwood and two to three per cent, of chalk. The addition of a little alizarin or tin crystals to the bath at the termination of the dyeing will cause the appearance of " bloom," peculiar to indigo. The red woods are fast losing ground, although before the introduc- tion of the artificial scarlets and cardinals they were much used. Mad- der, likewise, has been superseded by artificial alizarin. Wool was mor- danted for browns with bichromate of potash as for logwood; for reds, mordant with alum, or sulphate of alumina, with cream of tartar (argols), and boil. Tin crystals and tartar produce a reddish-yellow. These colors were not brilliant, but the value of them depended upon their fastness. The use of Cochineal is mainly for the scarlets obtained therefrom. The wool is mordanted with tin crystals and cream of tar- DYEING. 543 tar, washed, and dyed in a bath with five to ten per cent, of cochineal (ground) for an hour. Another method is to boil the unmordanted wool in a bath of cochineal, tin crystals, and potassium oxalate for an hour. For scarlets with a bluish cast (crimsons) the wool is mordanted with aluminum sulphate and cream of tartar, or the wool can be mor- danted in a bath containing tin crystals, tartar, and aluminum sulphate, followed by the dyeing in a separate bath. Copper, or iron, as a mor- dant will produce dark shades, and as impurities in the dye-baths will have a saddening effect upon the color obtained. Fustic is largely used in wool-dyeing, chiefly, however, in combination with other colors, i.e., indigo extract to produce greens, olives, sages, etc., and always upon mordanted wool, using tin crystals, sulphate of alumina, bichromate of potash, iron, and copper. Quercitron Bark is used for the same pur- pose as fustic and under the same conditions. Flavin, a production of the latter, is used in the same manner, its chief advantage is that it is much more concentrated. Archil (Orchil) as " extract," liquor, or paste is extensively used in the dyeing of carpet yarns; it is applied by simply boiling the yarn in a bath with the color, sulphuric acid, and sulphate of soda. It is exceedingly difficult to remove from yarn once dyed with it ; a process which will economically accomplish this is much sought after by manufacturers. Application of the Coal-tar Colors. As a general rule, it may be stated that nearly all the soluble artificial colors can be dyed upon wool without any special treatment, by boiling in a bath with ten per cent, of sulphate of soda and two to four cent, of sulphuric acid. A few excep- tions may be given: Alkali Blue (Nicholson's Blue). The color is dis- solved in carbonate of soda, poured into the dye-bath, the wool entered, and the temperature raised to the boil, keep boiling for a while, lift, rinse well, and immerse in a bath of very dilute sulphuric acid, when the color will be at once developed. The Violets (Hofmann's, etc.) are dyed neutral, or with a little soap. Methyl Green is applied to wool with borax, after having been mordanted with hyposulphite of soda, and hydrochloric acid. Auramine is dyed both neutral and acid. The Indulines are dyed neutral, and then boiled in dilute sulphuric acid. Gallein and Coerulein are dyed upon wool mordanted with potas- sium bichromate and a small quantity of acetic acid. The application of Alizarin to wool is exactly as for madder, the general mordant being sulphate of alumina and tartar for reds; tin crystals and tartar for orange; potassium bichromate and sulphuric acid for red-browns; iron and tartar yield violet; and copper, shades of brown. The addition of a little lime to the dye-bath is necessary in case none is naturally present in the water. Nitro-alizarin (Alizarin Orange) produces with several metallic mordants, applied as above, a range of shades, which have not reached commercial importance. Alizarin Blue is dyed upon a chromium mor- dant, and yields a durable blue, of some value, for wool, the price of the dye is against it. Alizarin blues, such as Alizarin Blue H R, which are made by com- 544 BLEACHING, DYEING, AND TEXTILE PRINTING. birring alizarin or a derivative of the same with a base, such as aniline, give various fast shades, and are dyed nearly the same as the older alizarin blue and alizarin blue S, except that the bath may be exhausted with very little or no acid. The constant tendency to do away with the mordanting processes for wool dyeing has caused the development of certain groups of dye- stuffs, which yield shades of extreme fastness, and which are produced by dyeing the wool in the presence of the chrome salt, or by dyeing first and " fixing " the color by adding the chrome to the extracted dye baths, or after chroming in a separate dye bath. It is instructive to note that some of the dyes which produce such shades on wool are old and well known cotton substantive "dyes. The mineral colors are dyed upon fibres through the decomposition of metallic salts, for example, to dye Prussian Blue, the wool is worked in a bath of red prussiate of potash and sulphuric acid, and gradually brought to a boil, squeezed, rinsed, and dried. Silk-dyeing. Silk has a great affinity for the coal-tar colors, with which it can be dyed without any mordant, although it is customary to employ a soap-bath (boiled-off liquor) with or without the addition of a weak acid, usually acetic. If soap is not used the colors will appear streaky or spotted. For ribbons, fancy dress goods, plushes, etc., the above colors are solely employed, with the possible exception now and then of recourse to some natural coloring matter, the use of the latter being almost restricted to logwood for blacks and modified shades, in- cluding browns. Silk is dyed in skeins or hanks, warps, or pieces, this latter including plushes. The machinery is of the simplest kind, em- bracing the kettles, with and without winches, washing-machines, etc., and need not be especially described. Silk is not dyed with indigo (vat process), but indigo shades are ob- tained by using indigo-carmine. Black is obtained by several processes. "Work the silk in acetate of iron and wash, then in a warm soap solution, followed by an immersion in ferrocyanide of potash, washed, and worked again in the iron-bath, rinsed well, and steeped in a solution of catechu or gambir for ten or twelve hours and washed. This preliminary process is necessary in order to insure a good result if systematically carried out and not forced. The material is dyed in a logwood decoc- tion containing soap. To obtain heavily weighted goods, for blacks, the process of dipping in iron solution and then in tannin-containing liquors is often repeated several times. A method giving excellent results, and which is consider- ably used, is as follows: Wash the goods, and pass through a bath of nitrosulphate of iron, wash, and then through a solution of carbonate of soda. These two operations are repeated several times, each time causing the precipitation of more iron upon the fibre, and consequently " weighting " the silk. "Work for some time in a bath of ferroprussiate of potash and then in a bath of catechu, followed with a little "muriate of tin " or tin crystals, wash, and transfer to the logwood-bath, which may contain a little extract of fustic to modify the shade required, TEXTILE PRINTING. 545 then to a soap-bath. Every locality is not suited to black silk-dyeing on account of impurities in the water, careful purification of which is a special requisite. Seal plushes are dyed, first in a dye-bath in the ordi- nary manner, a dark-brown shade, followed by the application of a black, blue-black, or other color, in the form of a paste thickened with starch, gum, or other medium, the application of this being done on a machine provided with revolving brushes, and so regulated that only the tip or face of the piece of goods is coated. One important feature in plushes of this character, and also in other kinds of silk goods which have been heavily iron-mordanted, is that the natural lustre of the fibre is some- what destroyed; this loss is supplied by means of a mixture of vege- table oils made into a paste with starch or other substance, applied as in the case of the tip, and steamed in an apparatus similar to that used for alizarin red (p. 540). The oil, usually a definite amount, is ab- sorbed by the silk fibre under the influence of steam, imparting a per- manent lustre. The goods, when removed from the steamer, are washed to remove the starch, excess of oil, etc., when they are ready for other operations. "Dynamited " silk is silk weighted with stannic chloride (dynamite) and fixed with silicate and phosphate of soda, and for full fibres with sulphate of alumina. Weighting may be as high as 400 per cent. A class of fabrics similar to plush, but with the pile of two or even three colors, much used for carriage-robes, etc., and dyed to imitate the skins of animals, are prepared in the following manner: The material (cotton in black with silk pile, the former previously dyed a fast color) is dyed, say a brown, in the ordinary manner; upon the fibre is then ap- plied a discharge made of stannous chloride solution and permanganate of potash. This is so controlled that only one-half of the fibre is acted upon. When the effect is produced the excess is washed off, rinsed, dried, and, if necessary, a tip is applied, which only dyes the very face of the pile. In this manner three colors are obtained on each thread of the face. After treating as above, the whole may be dyed a very light shade, thereby producing modified effects. The artificial coloring matters are applied to silk as previously stated. Nicholson's Blue (Alkali Blue) is applied as directed for wool, and seldom for the production of mixed shades. Picric Acid is much used for compounding, especially for greens, faster colors can be ob- tained by using naphthol yellow and indigo-carmine. The Eosins yield beautiful colors, and are applied in a soap-bath followed by a brightening in dilute acid. The Azo dyes are applied with a neutral soap-bath. The use of Alizarin with silk is only in cases where fastness is of more importance than brilliant shades. Alizarin Black is being much used in dyeing mohair goods (astrachans), and is applied in the ordi- nary manner. E. PRINTING TEXTILE FABRICS. A brief outline of the more im- portant " styles " in use is all that will be attempted in this section, from the fact that the subject is too extensive to enter into the details satisfactorily. The processes in general are conveniently divided into 35 546 BLEACHING, DYEING, AND TEXTILE PRINTING. FIG. 121. two main groups, differing in the manner of applying the colors, namely, Direct Printed Colors and Dyed Colors. Direct Printing is done by mixing the desired color with the proper fixing agents and applying directly to the fabric by means of blocks engraved with the design, or in a machine provided with a cylinder upon which the design is likewise engraved; for each color to be applied a separate cylinder is needed. From the above it is obvious that the color so applied will appear only on those portions of the fabric brought in contact with the design. Dyed Colors are obtained by printing different mordants upon the cloth, as above, and fixing as for ordi- nary cloth, and then dyeing the whole, or, by printing upon the cloth resists, substances which will prevent the dye from becoming fixed at those places so printed, or, again, by dyeing the Avhole pieces first, and then producing patterns or designs by means of substances which will destroy the ground-color whenever brought in contact; these substances are called discharges. This broad definition is deemed sufficient for the purpose in- tended ; the principle of each style will be apparent upon following the methods hereafter given. The operations conducted in a print- works embrace as a preliminary bleach- ing, the details of which are referred to on p. 524. Then the preparation of the colors, which is always done in copper pans mounted in such a manner that they can be emptied easily, and that their contents can be boiled by steam, and cooled by water, facilities for this being done by means of steam and water trunnions connecting with the double bottom of each pan. From five to eight pans are supplied in a " bat- tery," although it is often convenient to have one or more pans separately mounted, and without steam taps. The agitation of the contents is performed either by means of wooden paddles or, preferably, by mechanical agitation, which can be raised clear above the top of the pan, and without interfering with the working of the others. As the majority of colors used are made with either search or flour for thicken- ing, it is necessary, to insure good results, that they are strained or fil- tered; for this purpose it is well to have wooden frames made, over which is tacked brass or copper wire cloth (iron is inadmissible). The most important piece of apparatus is the printing-machine, an idea of TEXTILE PRINTING. 547 the construction and operation of which may be had from Fig. 121. A is a cylindrical " bowl " or drum, covered with several thicknesses of felt cloth, c; around this drum, and passing over a smaller one, U, is an endless band, d (full width of the machine) ; over this band, and acting as a guide to the fabric to be printed, is another band, e, which serves to keep d clean, being, in fact, a piece of cloth yet to be bleached and printed; the piece being printed is indicated by /. The means for applying the color are shown in the figure below the large drum, viz., the printing rollers or engraved cylinders h t , 7i 2 , h 3 , which are fed with color through coming in contact with the wooden rollers %, n 2 , n s , which dip in the color contained in the troughs fc t , & 2 , fc 3 . Pressing against each of the rollers, h, is shown a small strip of metal, r, tech- nically termed the " doctor," the purpose of which is to remove the excess of color from the face of the printing-rollers before they come in contact with the cloth. These ' ' doctors ' ' are best made of bronze or gun-metal, or some of the newer aluminum-copper alloys, capable of better resisting weak acid. Before the cloth is printed upon it passes over a "lint doctor," the office of which is to remove any loose hair or fibres from the cloth. Printing-machines are built w T ith any number of color boxes and rollers up to twelve or fourteen, each being for a sepa- rate color. Sansone mentions one for use with twenty colors. Great nicety is required in adjusting the machines in working to have no over- lapping of colors or mordants, perfect " registration " being sought. For drying the printed goods revolving cylinders, or " cans " of large diameter, are used, or the goods are passed over heated plates, in no case allowing the printed face to come in contact with any part of the apparatus. Steaming follows to fix the colors, the apparatus being a steamer, as shown on p. 540, or one constructed of brick and iron, act- ing continuously, thereby turning out much more work than the former. The dyeing- and washing-machines are similar to those already described. Mordants, Resists, Discharge, etc. All the various substances used in printing must be applied in the form of pastes, the consistency of which must be such that whenever applied they will not run or spread, which impairs the sharpness of outline of the printed pattern. For the purpose the color-mixer has recourse to the starches and gums, the most important of which are corn or wheat starch, and flour, usually made up into ten per cent, pastes. The gums include gum arabic, dex- trine (British gum), and tragacanth. The first is used in several degrees of consistency, from a fifty to a one hundred and fifty per cent, solution, dextrine the same, and the last in a ten per cent, paste. The propor- tions are by no means uniform, but they represent the average strengths used in the color house. Blood albumen is considerably used, large quantities being manufactured cheaply in Chicago and other Western localities. The mordants used embrace the acetates of alumina of vari- ous strengths, basic sulphate, and others of less importance. The ace- tates and nitrates of iron are the most prominent salts of this element, and of chromium there may be mentioned the acetates and nitrates; others, including salts of tin, calcium, manganese, are also used. Owing 548 BLEACHING, DYEING, AND TEXTILE PRINTING. to the great number of recipes published for preparing mordants, and of the difficulty in selecting those which may be called representative, only a few will be given of the more important. Acetate of Alumina, or " Red Liquor " (Crookes). Water 45 gallons. 45 gallons. Alum 100 pounds. 200 pounds. Acetate of lead 100 " 200 " Soda crystals 10 " 10 Or the same result can be had by substituting acetate of calcium for the lead salt. In either case the alumina salt is dissolved in about half the quantity of water, and the acetate in the remainder, when the two solutions are mixed and allowed to settle, the precipitated lime or lead sulphate being removed. The addition of soda is to neutralize any free acetic acid. Acetate of Iron, or " Black Iron Liquor," can be obtained either by double decomposition as above, or by dissolving scrap-iron or precipi- tated oxide of iron in crude acid. In the former method sulphate of iron and acetate of lead are used as follows : Water, forty pounds, sul- phate of iron, twenty-four pounds, acetate of lead, twenty-four pounds. Dissolve each separately, mix, and filter. The oxide of iron above men- tioned is obtained by precipitating a solution of copperas with am- monia or soda, filtering and washing, and dissolving the moist precipi- tate in ordinary acetic acid to make a twenty-five per cent, solution. In the event of using soda, much longer washing is required. Nitrate of Iron is made as above ; copperas and nitrate of lead being used for the decompositions in equal proportions. Nitrates made by direct solution are obtained by several methods, the best being nitric acid nearly saturated with scrap-iron and diluted to about 80 Tw. Some of the so-called nitrates of iron are mixtures of sulphate and nitrate of iron and some are composed entirely of sulphate of iron, while others are waste liquors, such as are obtained by dissolving iron out of " tin scrap " by means of sulphuric acid. Others may contain hydro- chloric acid, with or without the addition of copperas. Chromium Ace- tate is similarly prepared with chrome alum and lead acetate, or by precipitating chrome alum with an alkali, and dissolving the washed precipitate in acetic acid, or in nitric acid if the nitrate is wanted. This latter mordant can be made by using lead nitrate and chrome alum. The tin mordants are used to brighten the color with madder and cochineal dyeing. The first is Stannous Chloride, SnCL -f- 2H 2 O. It is made by dissolving tin in hydrochloric acid and evaporating the solu- tion. It is used somewhat in wool-dyeing, but more largely in calico- printing. Stannic chloride, SnCl 4 , is also used, and its combination with sal ammoniac known as "Pink Salt," and Sodium Stannate, Na 2 Sn0 3 , known as " Preparing Salt." The principal styles of printing tissues are given in the following scheme., condensed from a tabular view given in Sansone's excellent work on " Cotton-Printing." TEXTILE PRINTING. 549 PRINTED (DIRECT) COLORS. 1. Steam or Extract Styles. (a) Coal-tar Colors. Alizarin, Basic Aniline Colors, Acid Colors, and Neutral Azo Colors. (6) Dyewood Extracts (natural organic coloring matters). Logwood, Quercitron Bark, Sapan and other Red Woods, Catechu, Annatto, Cochineal. (c) Steam Mineral Colors. 2. Pigment Styles (fixed by albumen). 3. Oxidation Colors. 4. Direct Indigo-printing (alkaline styles). DYED COLORS. 5. Alizarin Dyed Styles. 6. Turkey-red Styles. 7. Indigo Styles. 8. Manganese Bronze Styles. 1. Steam Styles. Here the colors and proper mordants are mixed, and applied to the fabric in one operation, followed by air drying and steaming, or by immediate steaming, drying, and again steaming, the object in each case being to fix and develop the colors. Several condi- tions are to be noted in this style, chiefly the humidity of the steam, temperature, pressure, and the duration of the steaming, in order that the same shades may be again obtained with the same colors. Before being printed the cloth is passed through a solution of stannate of soda, also called " preparing salt," and then through sulphuric acid (1.005 to 1.015 specific gravity), washed, and dried. The colors best suited are the basic, that is, those which form insoluble lakes with tannin in combination with a metal, and the general method of applying the same is given in the following extract from Sansone (" Printing "), p. 208: " A color is formed consisting of thickening, the solution of coloring matter, and acetic acid. The acetic acid is added in the preparation of the color in order to prevent the tannic acid from combining with the dyestuff; in other words, the acetic acid keeps both the coloring matter and the tannin in solution in the thickened color, and prevents their combining with each other; but when the color is printed and the cloth is dried and steamed, the acetic acid is expelled, and the coloring mat- ter and the tannin then go into combination to form the insoluble col- ored lake. This lake, however, not being sufficiently fast to stand by itself, a metallic mordant is necessary to give additional fastness to the colors; for this reason the cloth, after printing, dyeing, and steaming, is passed into a solution containing tartar emetic." The antimony of which at once unites with the " tannate " of the color already on the fabric, thereby producing a more insoluble body. The steaming opera- tion must be conducted with such a volume of steam that the acetic acid volatilized can be carried away, or else the colors may be injured. Of the colors employed may be mentioned the Fuchsines, Methyl Violets and Greens, Bismarck Brown, Naphthylene Blue, etc. 550 BLEACHING, DYEING, AND TEXTILE PRINTING. Alizarin, without exception, is the most important coloring matter used in cotton-printing, for which purpose the goods are previously treated with alizarin oil and dried. With alizarin in printing, as in dye- ing, the color obtained depends upon the selection of the mordant, which can, however, be a mixture; for reds, alumina, with or without tin; purples, iron; browns, with either ferricyanide of potassium or acetate of iron, and acetate of alumina, or with chromium mordants. When the fabrics have been printed they are steamed for one or two hours, and passed through a heated chalk-bath, washed, and soaped. The following indicate the methods of preparing several colors: Red. (Standard.) Alizarin paste (fifteen per cent.) 6 pounds. Starch paste 2 gallons. Acetate of alumina (11 Be.) 1^ pints. Acetate of lime (15 Be. ) 1 pint. Nitrate of alumina ( 13 Be.) % " Purple. ( Standard. ) Alizarin 2 pounds. Starch paste 1 gallon. Acetate of iron ( 13 B6.) 1 quart. Acetate of lime (13 Be\) 1 pint. Acetic acid 1 Brown. ( Standard. ) Alizarin ( fifteen per cent. ) 4 pounds. Starch paste 1 gallon. Nitro-acetate of chromium (25 Be".) 3 pounds. Acetate of lime (13 B6.) % pound. Since the introduction of the alizarin greens and violets, their use in connection with chromium in cotton-printing has been most rapid. Dye-woods, with the exception of logwood, have been nearly super- seded by the tar colors. The method of applying the color is nearly the same as for other steam colors, viz., print, dry in the air, steam, and wash, and is made up with chromium as the mordant, and an oxidizing agent, with or without the presence of another coloring matter to modify the shade. The following recipes illustrate the color as made for blacks: Steam Logwood Black. Water ( Sansone. ) 1 gallon. Acetic acid (6 TV ) ... 1 H Logwood extract ( 30 Tw. ) 1 Quercitron bark extract ( 30 Tw. ) 2 pounds. Starch 5 U Dextrine .\ . . 2.5 U Olive oil 5 pound. 75 Boil, stir until cold, then add Acetate of chromium (20 Tw. ~\ . . 1 gallon. TEXTILE PRINTING. 551 Steam Logwood Black. (Sansone.) Starch 6 pounds. Flour 6 Acetic acid (6 Tw. ) 2.5 gallons. Logwood extract (20 Tw.) 3.5 " Acetate of iron ( 15 Tw.) 3.5 " Olive oil 1.5 pounds. Of. the other natural coloring matters there may be mentioned Cochi- neal, applied with tin or alumina; Sapan, in the same manner, and Quercitron Bark, with alumina or chromium. Catechu, most used for browns, may be applied with acetate of chromium or with logwood and fuchsine. The Mineral Colors are to some extent made use of, their application depending upon the principle of double decomposition upon its fibre when subjected to steaming. The following examples will make the principle clear: Yellows are obtained by the decomposition of nitrate of lead and a soluble chromate, the insoluble chromate of lead (" chrome yellow ") being formed. For Blues, both prussiates of potash are used. Brown is obtained by means of chloride of manganese and bichromate of potash. 2. Pigment Styles. For this style effects are produced by means of insoluble color lakes and the mineral colors, which are fixed upon the cloth by steaming, the action of which coagulates the albumen with which the colors are invariably mixed for printing. The colors are gen- erally supplied to the color-mixer in a dry condition, and include Ultra- marine of various qualities, Vermilion (sulphide of mercury) , the Chro- mates of Lead and Barium, Cadmium Yellow (cadmium sulphide), Chrome Green (oxide of chromium), the Ochres, yellow and red, and Lamp-black. A familiar example of this style is seen in cheap flags and decorative muslins. 3. Oxidation Colors. The most important of this class is Aniline Black, and will be briefly outlined as follows : Aniline oil is made into a paste with a chlorate (soda generally) and a metallic salt, with the proper amount of starch paste. This is printed upon the fabric, " aged " for forty-eight hours, or passed through a " steam ager," then passed through a warm bath of bichromate of potash, washed well, and finally worked through a soap-bath. The metallic salt mentioned acts as a carrier of oxygen, and for the purpose vanadate of ammonium, sulphide of copper, bichromate of potash, etc., are used. For the prep- aration of the color paste the following methods are given: 1. Water '. . 1 gallon. Aniline salt 2 pounds. Aniline oil 2 " Starch 2 " Dextrine y 2 pound. 552 BLEACHING, DYEING, AND TEXTILE PRINTING. The paste is made first with the starch and dextrine, then the aniline is added. 2. Chlorate of soda (8 B6.) 1 gallon. Starch 2 pounds. Dextrine */ 2 pound. Chloride of ammonium % " These are made separately, but when wanted are mixed, and two pounds of sulphide of copper paste are added, and the whole well mixed and strained. (Crookes.) The use of vanadium is shown by the following method (Sansone, "Printing," p. 275): Water 1 gallon. Starch 1% pounds. Dextrine % pound. Boil, cool down to 120 F., then add Aniline oil 1 % pounds. previously neutralized with Hydrochloric acid (32 Tw.) \y z pounds. Stir until cold, then add a cold solution of Chlorate of soda % pound. Boiling water 1 " Before printing add further Vanadium solution % " Print, dry not too hard, age two days, then pass through two per cent, solution of bichromate of potash at 160 F., wash and soap. The vanadium solution is made with vanadate of ammonia, hydro- chloric acid, glycerine, and water, and contains about .15 gramme per litre. Other colors are produced by oxidation, namely, Brown (with phenylendiamine, Sansone), by simply printing with a chlorate, dry- ing, and steaming, Yellow, Grays, Olives, Blues, etc. To obtain white patterns on goods printed with aniline black, a " resist " or " reserve " is first applied of the desired pattern, consisting of white arsenic as the base, with caustic soda, and the proper thickening. For discharging the aniline black after it is printed, permanganate of potash is used; the goods are afterwards passed through a solution of oxalic acid. 4. Indigo-printing. Indigo is printed upon cotton fabics in two ways, one of which is known as the ' ' Glucose, ' ' and the other the ' ' Re- duced Indigo " Process. The former is carried out as follows: Indigo is finely ground, and made into a paste with water, to which is added caustic soda; this is now kept in a closed vessel in order to prevent as much as possible the absorption of carbonic oxide from the atmosphere. "When used in printing, it is thickened with dextrine and starch; the following table (from Sansone, " Cotton-Printing," p. 284) showing the proportions used for several shades: TEXTILE PRINTING. 553 Light calcined starch 3 parts. 3 parts. 3 parts. Indian corn starch iy 2 " iy 2 " iy a " Water 3% " 3% " 3% " Caustic soda lye (70 Tvv.) . 16 " 28 " 40 " Indigo paste 30 " 18 " 6 " The cloth, before being printed upon, is worked through a twenty- five per cent, solution of glucose and dried. After printing, the cloth must be again dried and passed through an atmosphere of wet steam, in an apparatus shown in Fig. 122, to effect the reduction of the indigo, which now takes place. The cloth is now washed in water, being re- peatedly, during the washing, exposed to the air, when the reduced indigo is oxidized and its real color appears. The reason for rapidly steaming is to act upon the caustic alkali while it is still in that state, FIG. 122. as if it should become carbonated through delay little reduction will take place. This method is employed in printing indigo upon alizarin- dyed goods and in other combinations with resists, etc. The ' ' Reduced Indigo Process ' ' is based upon the fact that indigo, when finely ground and mixed with lime and thiosulphate of soda in suitable thickening agents, is reduced ; if, with this reduced indigo paste, patterns are printed upon cotton fabrics, and then exposed to the air, the indigo is oxidized with a regeneration of the blue color. The pieces are then washed and dried. Instead of using indigo in printing, one of the newer colors, 7m- medial Blue, is now very extensively used and printed with suitable mordants directly upon the goods. 5. Dyed Alizarin. This process differs from all those previously mentioned in that the colors are produced by first printing upon the fabric the thickened mordants suited to alizarin, ageing, during which the mordants so printed are decomposed and more firmly fixed upon the cloth, dunging, an operation which removes the thickening no longer 554 BLEACHING, DYEING, AND TEXTILE PRINTING. needed, followed by a washing, and then dyeing with alizarin, and, finally, brightening. The mordants used for Reds are generally made with acetate of alumina, thickened with starch or flour, and dextrine, while by the addition of tin to such a mixture blue shades will be ob- tained. For Purples or Violets, acetate of iron is used diluted with paste, if used strong, blacks can be produced. Browns are obtained with catechu and copper acetates. Mixtures of the acetates of iron and alumina yield varying shades of Chocolate. Following the printing operation, the fabric is allowed to dry, when it is aged by being caused to pass through the continuous steamer; here the acetates are decom- posed, basic salts remaining fixed upon the cloth. Formerly the opera- tion w r as conducted in large rooms, and often required a week to finish ; now long chambers provided with a series of rollers, and with requisite means for steam control, are used; it must be remarked that colors ob- tained upon cloth rapidly aged do not compare in fastness with those ob- tained upon cloth slowly aged. Dunging is merely a transmission of the aged cloth through solutions of phosphate, arseniate, or silicate of soda, these chemicals having displaced the somewhat offensive cow-dung in the operations of precipitating the mordant upon the fibre, and also tc remove the thickening and excess of mordant, after which the cloth is well washed and then dyed. The dye-bath is made up with alizarin, alizarin oil, tannin, etc., in a similar manner to that described under Dyeing (p. 539), after which the cloth is washed, worked in alizarin oil, dried, and steamed, then washed and soaped. In case reds have been dyed, and it is desirable to reduce their tone, " cutting " is resorted to after the soaping, by means of a solution of stannic chloride. Resists are substances printed upon the fabric which will prevent the fixation of color at those places, and are of two kinds, chemical and mechanical ; the former are composed chiefly of citric acid, while the latter are made up of some inert substances, such as pipe-clay, beeswax, etc. Thus a resist (or reserve) of citrate of soda (lime- juice and soda lye) when applied to the cloth prevents the fixation of the oxides of iron or alumina on the fibre, and therefore when the cloth is afterwards dunged and dyed in the alizarin bath the reserved spots remain white, while the colors will be formed where the mordant has been fixed. In this way not only reds and pinks can be reserved, but purples, chocolates, and blacks also. Discharges are substances printed upon goods the whole of which had been mordanted, the object being to remove the mordant from places where whites are to appear, consequently when the piece is dyed only where the mordant is intact will the cloth be colored ; these discharges are made principally with citric, tartaric, or acetic acid. This acid-containing discharge having been printed on, the goods are then taken through a solution of bleaching-powder (chloride of lime). The result is that where the acids have been printed on chlorine gas is liberated, which destroys the dye-color, leaving in the simplest cases a white design upon a colored ground. 6. Turkey-red Styles. This process is simply printing upon cloth which has previously been dyed Turkey-red (see p. 539) by means of TEXTILE PRINTING. 555 discharges, which may or may not be made so as to yield colored pat- terns. The base is citric or tartaric acid, thickened with a suitable paste, and if for colors, containing a salt of lead if for a yellow dis- charge, or ferro-prussiate of potash for a blue discharge, or iron and logwood for a black discharge. After printing on the discharges, the goods are passed through a bath of bleaching-powder, well washed, and then, if lead has been printed on, passed through a bath of bichromate of potash, when chrome yellow will be produced. If the prussiate of potash has been printed, a blue color will be developed. Green is ob- tained by mixing both discharges first. 7. Indigo Styles are similar to the above; resists are printed on the cloth, which is then dyed in the vat in the ordinary manner, when, upon a removal of the resist by suitable means, white patterns are had upon a blue ground. By the system of discharges various colors may be put on by means of lead and other metallic salts. Vermilion is applied directly with albumen. For a discharge which has to be afterwards dyed red with alizarin, bromide of manganese and an aluminum salt are used. 8. Manganese Bronze Style, or Bistre Style. This process has for its object the production of hydrated peroxide of manganese upon the fibre, and the subsequent printing of colors by means of discharges. The goods are worked in a solution of manganous chloride, dried, and worked in soda lye, washed and passed through a solution of chloride of lime until a brown color is produced. Wash, dry, and the goods are ready for printing. A discharge for white is made with muriate of tin (120 Tw.) ; for blue, yellow prussiate of potash with an organic acid; for yellow, a lead salt, developed with bichromate of potash. Green and black as in the previous style. Woollen- and Silk-printing. Wool, either as yarn or fabric, is gen- erally printed with the tar colors, and according to the steam style pre- viously described. The goods are dried after printing, steamed for one hour, and well washed. Silk is printed in the same style after being prepared by suitable agents, such as tin with or without an acid. Pre- vious to being printed both silk and wool must be entirely free from grease. Silk warps for ribbon and veiling are often printed by hand blocks, and with aniline colors dissolved and thickened with Irish moss. After printing, the warps are simply air dried being neither washed nor steamed. Such colors are not fast, but they are much used for so- called " Dresden " and " Persian effects." 556 BLEACHING, DYEING, AND TEXTILE PRINTING. The following table from Rupe's " Cliemie cler Naturliehen FarbstofFe" (Braunschweig, 1900) shows the artificial dye-colors which have replaced or are in practical use competing with the natural dyestuifs named : NATURAL DYESTUFFS. Is displaced for cotton. Is displaced for wool and silk. QUERCITRON PERSIAN BERRIES . WELD FUSTIC LOGWOOD BRAZIL-WOOD COCHINEAL ARCHIL ANNATTO Mainly by substantive dye-colors : Diamine fast yellow B A (C.), Chlora- mine yellow (C.), Chrysophenine (C.), Auramine (H. G.), Diamine yellow (H.), Chrysamine (H.), Thioflavine (G.). For printing along with log- wood it is still used as before. Are still much used in cotton-print- ing and in connection with tin salts. For direct printing compete : Auramine, Thioflamne T (C.), the latter exclusively for discharges; in addition. Chrysophenine (H.), Chloramine yellow (H.), Oriol (G.). Important are also the yellow sal- icylic acid azo colors, such as Alizarin yellow (H.), etc. Is hardly ever used for cotton. Almost entirely displaced by the sub- stantive yellow dyes, as with quer- citron. In addition, Sun yellow (G. ), Diphenyl fast yellow (G.), Cresolin yellow (G.), also by Alizarin yellow and its homologues ( H. ) . For print- ing in connection with logwood it is still unreplaced. In cotton dyeing (for black) is about given up. For better goods is re- placed by Aniline black, Diaminogen black (C.), for cheaper goods by the direct dyeing and diazotizable blacks: Diamine black (C.) , Oxydia- mine black (C. ), Columbia black (C.). Direct deep black (C.), also by Vidal black, Iminedial black (G. H.), and similar sulphated products. For cotton scarcely used now, being replaced by the substantive dye- ing reds : Diamine fast red F (C.), Congorubine (C.), Diamine bordeaux (C.), Benzopurpurine (G. H.), Dia- mine red (H.), also by Fuchsine (G. H.), Hessian purple (G.), Safra- mine, (H.), Paranitraniline red (H.), Alizarin red (H.). For cotton is replaced by the dif- ferent artificial orange colors, as Chrysophenine (H. ), Chrysamine (H.), Mikado yellow and orange (H.). Is not much used now, the dif- ferent mordant coloring yellows haying taken its place. In ad- dition, Naphthol yellow S (H.), Tartrazine, Quinoline yellow (H.). Little used for wool, For silk re- placed by Tartrazine, Fulling yel- (ow (C.), Naphthol yellow S (H.). Is little used for wool, but, on the other hand, largely for silk. Is replaced by Naphthol yellow S, Hist yellow (C.), Tartrazine, Failing yellow (C.), Citronine (G.), Jasmine (G.), Azo yellow (G.), Alizarin yel- low (H.). Is still much used in wool-dyeing, although strongly pushed by the different mordant-attracting yel- lows: Anthracene yellow C (C. G.), Chrome yellow (C. G.), Mordant yel- low (C. G.), Fulling yellow (C.), Azo yellow (H.), Fast yellow (H.), Alizarin yellow (H.). With wool the case is the same as with cotton. It is still used for dyeing, but is losing ground rap- idly. The substitutes are : Naph- thol and Kaphthylamine black (C. G. H.), Brilliant black (C. G.), Dia- mond black (C. G. H.), Wool black (C. ), Alizarin black (G. H.), An- thracene black (C. G.), Azo acid black (H.), Chromotrope S (H.). For silk, still used enormously and with no substitute. Also for wool and silk almost en- tirely replaced by Cloth red (C. Wool red (C.), Acid fuchsine (G. Fast red ( H. ) , Arch U substitute ( G. , . Ponceau (H.), Apollo red (G.), Ro- cellin (G.); in the fulling industry by Alizarin red (C. H.), Diamine fast red (C.), Chromotrope (H.). Is still used somewhat for wool and silk, but is being displaced by vivid acid wool colors, such as Azoeosin (G.), Chromazon red (G.), Palatine scarlet (H. C.), Brilliant crocein (H.), Brilliant cochineal (C.), and the different Ponceaux, etc. Has practically been entirely dis- placed for wool and silk by the readily levelling red acid wool dyes: 'Acid fuchsine (C.), Azocar- mine (C. G. H.), Archil substitute CO. G. PI.), Azoftichsine (C. G. H.K Lana/uchsine (C.), Azorubine (C.), Azo acid fuchsine (H.), Rosindu- line (G.), Apollo red (G.), Chromo- trope (H.). BIBLIOGRAPHY. 557 NATURAL DYESTUFFS. Is displaced for cotton. 19 displaced for wool and silk. SAFFLOWER BERBERINE CATECHU. . Was first replaced for cotton by the Eosines, Phlpxine (C. G.) ; later these were displaced by Rhodamine (C. G.), Erica (C.), JDiamine rose (C.), Geranine (C.), Safranine (H.), etc. INDIGO Still used for cotton, although a whole series of excellent substan- tive dyes have appeared. Espe- cially have the Diamine colors, Benzo and Congo colors with sup- plementary treatment with chrome and copper, recently competed suc- cessfully (C.), and Chrysoidine (H.), Vesuvine ( H. ) , etc. For calico-print- ing, catechu is still very largely used, although the different Aliza- rin colors are seeking to displace it in part (C.). Despite the many seriously com- peting products is still much used for cotton. These competing prod- ucts are : Synthetic indigo, Indoin (C. G. H.), Naphthindon (C.), Fast cotton blue (C.), Methylene blue (C. H.), Jndamine blue (H.), Janus blue (H.), and the direct coloring and diazotizable blues of the Dia- mine, Diphenyl, and Benzo color groups. [Diamine blue and related colors (H.), Diaminogen blue (C. H.).] A new product, Immedial blue (C. H.), belonging to the sul- phated colors, which has recently appeared, seems to be among the most important substitutes. In calico-printing, Indigo has been in part replaced by the Synthetic in- digo preparations and by the dif- ferent basic blues, including Nitroso blue, Alizarin blue, etc. (C.). Is not used for wool, but still some- what for silk. Substitutes are the same as those mentioned for Weld. Still used for silk in combination with logwood in large amount without any competing products (C.). For weighting of silk. On wool, is replaced on the one hand by Alizarin blue (C. G. H.), Synthetic indigo, Alizarin cyanine (C. G. H.), Anthracene blue (G. H.), Chromotrope F B (H.), Gattamine blue (G.), Gattocyanine (G.), and on the other hand by Sulpho- cyanine (C.) and Lanacyl blue. However, the application of In- digo to wool still holds out rela- tively well. The communications upon which this table is based were from the firms of Leopold Casella & Co., of Frankfurt-am-Main (C.), Joh. Rud. Geigy & Co., of Basel (G.), and Farbwerke, vormals Meister, Lucius and Briining, of Hochst (H.). Bibliography. 1875, 1876. 1877, 1878, Manual of Dyeing and Dyeing Receipts, Napier, London. Dyeing and Calico-Printing, Grace C'alvert, Manchester. Cantor Lectures on Wool-Dyeing, G. Jarmain, London. -Traite de la Teintures des Soies, M. Moyret, Lyons. Die chemische Bearbeitung der Schafwolle, V. Joclet, Vienna. -Le Conditionnement de la Soie, Jules Persoz, Paris. Handbuch der Bleichkunst, Victor Joclet, Vienna. Calico-Printing, Bleaching, and Dyeing, C. O'Neill, London. The American Dyer, by Gibson, Boston. 1879. Die Woll- und Seidendruckerei, Victor JoclSt, Vienna. Handbuch der Seidenfiirberei, Philip David. Bleicherei, Farberei und Appretur, C. Romen, Berlin. A System of Chemistry applied to Dyeing, Jas. Napier, Philadelphia. The Art of Dyeing, Cleaning, and Scouring, Thos. Love, 2d ed., Philadelphia. Die Technologic der Gespinnstfasern, 2 Bde., H. Grothe, Berlin. Die Wascherei, Bleicherei und Farberei von Wollengarnen, R. Sachse, Leipzig. Manual of Colors and Dye-wares, J. W. Slater, London. Dyeing and Tissue-Printing, W. Crookes, London. 1880 1881 1882 558 BLEACHING, DYEING, AND TEXTILE PRINTING. 1883. La Teinture du Coton, A. Renard, Paris. TraitS pratique du Degraissage, etc., A. Gillet, Paris. 1884 Bleaching, Dyeing, and Calico-Printing, J. Gardner, London. Bleaching, Dyeing, and Calico-Printing, F. J. Bird, London. Die Bleicherei, Druckerei, Farberei, etc., der baumwollenen Gewebe, G. Stein, Braunschweig. 1885 Die praktische Anwendung der Theerfarben in der Industrie, E. J. Hodl, Vienna. The Dyeing of Textile Fabrics, J. J. Hummel, London. Die Beizen, ihre Darstellung, etc., H. Wolff, Vienna. Die Gesammte Indigo-Kupenblau Farberei, E. Rudolf. 1886. Praktische Anleitung zur Bleicherei, etc., von Jutestoffen, R. Ernst. Die Appretur-Mittel und ihre Anwendung, F. Polleyn, Vienna. 1887. Teinture et Apprets des Tissus de' Coton, L. Lefebre, Paris. The Printing of Cotton Fabrics, A. Sansone, Manchester. L'Art la Soie, N. Rondot, 2 vols., Paris. 1888. Dyeing, A. Sansone, 2 vols., Manchester. Des Couleurs et de leurs Applications, 2me ed., E. Chevreul, Paris. 1889. Handbuch der Farberei, Dr. A. Ganswindt, Weimar. Les Matieres Colorantes et la Chemie de la Teinture, C. L. Tassart, Paris. The Guide for Piece-Dyeing, F. W. Reisig, New York. 1890. L'Industrie de la Teinture, C. L. Tassart, Paris. Trait6 de Teinture sur Laine, P. F. Levaux, Liege. Ueber das Fiirbe der Strangseide, W. Vollbrecht, Berlin. Bleicherei, Wiischerei, Carbonisation, J. Herzfeld, Berlin. Farberei der Baumwolle mit Substantiven Farbstoffe, Soxhlet, Stuttgart. Anilin Fiirberei und Druckerei auf Baumwolle, Soxhlet, Stuttgart. 1891. Traite" de la Teinture et de I'lmpression, lere partie, J. Depierre, Miilhausen. Chemische Technologic der Gespinnstfasern, O. Witt, Berlin. 1892 Silk-Dyeing, Printing, and Finishing, J. H. Hurst, London. 1893. Traite pratique de la Teinture et de I'lmpression, 2me ed., M. de Vinant, Paris. 1894. Manual of. Dyeing, Knecht, Rawson, and Lowenthal, 3 vols., London. Teinture et Impression, Prud'homme, Paris. 1895. Bleichen und Fiirben der Seide und Halbseide, C. H. Steinbeck, Berlin. Les Industries Textiles, Guignet, Dommer, et Grandmougin, Paris. 1896. Bleaching and Calico-Printing, Duerr and Turnbull, Philadelphia. 1897. La pratique Teinturier, J. Garcon, 3 tomes, Paris. Printing of Textile Fabrics, C. F. Rothwell, London. Wool-Dyeing, Part i, W. M. Gardner, Philadelphia. Recent Progress in the Industries of Dyeing and Calico-Printing, A. Sansone, 3 vols., Manchester. 1898. Technologic der Gespinnstfaser, v. Georgievics, Wien. 1903. The Principles of Dyeing, G. S. Fraps, The Macmillan Co., New York. 1905. Hypochlorite und Electrische Bleiche, Abel. 1906. The Chemistry and Physics of Dyeing, W. P. Dreaper, Philadelphia. The Chemistry and Practice of Sizing, etc., P. Bean and F. Scarrsbrick, Man- chester. Theorie und Praxis der garnfarberei mit Azoentwicklern, Franz Erban, Berlin. Blanchissage et 1'appret du ligne, L. Verefel. 1907. Farbereichemische Untersuchungen, Dr. Paul Hermann, 2te Auf., Berlin. 1908. The Methods of Textile Chemistry, F. Dannerth, London. Die Technologic der appretur, A. Ganswindt, Wien. BIBLIOGRAPHY. 559 1909. The Dyeing and Bleaching of Textile Fabrics, F. A. Owen, J. Wiley & Son, New York. Laboratory Manual of Dyeing and Textile Chemistry, J. Merritt Matthews, John Wiley & Son, New York. Farbereichemisches Practicum, etc., Richard Mohlau und Hans Bucherer, Viet & Co., Leipzig. Handbvich der Farben-lehre, E. Berger, 2te Auf., Leipzig. Modern Bleaching Agents and Detergents, Max Bottler. Translated by Chas. Salter, Scott & Greenwood, London. A Manual of Dyeing, etc., by E. Knecht, 2 vols., 2d ed., C. Griffin, London. 1910. Das Farben und Bleichen von Baumwolle, Seide, etc., J. Herzfeld, 3te Auf. 1911. The Principles of Bleaching and Finishing of Cotton, S. R. Frohman and E. L. Thorp, London. Anleitung zur qualitativen Appretur und Schlichte- Analyse, Wilhelm Massot, Berlin. APPENDIX. I. The Metric System. THE French metric system is based upon the idea of employing, as the unit of all measures, whether of length, capacity, or weight, a uni- form unchangeable standard, adopted from nature, the multiples and subdivisions of which should follow in decimal progression. To obtain such a standard, the length of one-fourth part of the terrestrial meridian, extending from the equator to the pole, was ascertained. The ten- millionth part of this arc was chosen as the unit of measures of length, and was denominated meter. The cube of the tenth part of the meter was taken as the unit of measures of capacity, and denominated liter. The weight of distilled water, at its greatest density, which this cube is capable of containing, was called kilogram, of which the thousandth part was adopted as the unit of weight, under the name of gram. The multi- ples of these measures, proceeding in a decimal progression, are distin- guished by employing the prefixes, deca, hecto, kilo, and myria, taken from the Greek numerals ; and the subdivisions, following the same order, by deci, centi, milli, from the Latin numerals. Since the introduction of this system it has been adopted by the principal nations of Europe, excepting Great Britain, and in many of them its use is compulsory. It is in general use in France, Germany, Austria, Italy, Spain, Norway, Sweden, Netherlands, Switzerland, Greece and British India. It was legalized in Great Britain in 1864, and in the United States by an act of Congress in 1866. The meter, or unit of length, at 32, = 39.370432 inches. The liter, or unit of capacity, = 33.816 fluidounces. U. S. The gram, or unit of weight, = 15.43234874 Troy grains. Upon this basis the following tables have been constructed: MEASURES OF LENGTH. English inches. Millimeter (mm.) = .03937 Centimeter (cm.) = .39370 Decimeter (dm.) 3.93704 Meter (m.) = 39.37043 English inches. Decameter (Dm.) = 393.70432 Hectometer (Hm.) = 3937.04320 Kilometer (Km.) 39370.43200 Myriameter (Mm.) = 393704.32000 36 561 562 APPENDIX. MEASURES OF CAPACITY. Milliliter (ml.) Centiliter (el.) Deciliter (dl.) Liter (1.) Milligram (mg.) Centigram (eg.) Decigram (dg.) Gram (gm.) English cubic inches. .061028 .610280 6.102800 61.028000 Decaliter (Dl.) Hectoliter (HI.) Kiloliter (Kl.) Myrialiter (Ml.) MEASURES OP WEIGHT. Troy grains. .0154 .1543 1.5432 15.4323 Decagram (Dg.) Hectogram (Hg.) Kilogram (Kg.) Myriagram (Mg.) English cubic inches. 610.280000 6102.800000 61028.000000 610280.000000 Troy grains. 154.3234 1543.2348 15432.3487 154323.4874 EQUIVALENT WEIGHTS AND MEASURES. 1 kilometer = 1093.61 yards or 0.621 statute mile 1 square meter = 10.764 square feet 1 cubic meter = 35.3 cubic feet 1 liter = 1 quart and J gill U. S. measure or 1 pint and 3 gills Imperial measure 1 cubic centimeter = .061 cubic inch or 0.03381 fluidounce 1 hectoliter = 26.4 U. S. gallons or 22.01 Imperial gallons 1 kilogram = 2.204 Ibs. avd. or 2 Ibs. 3 ozs. 4| drams 1 inch = 25.4 millimeters 1 foot = 0.3048 meter 1 yard = 0.9144 meter 1 square foot = 0.0929 square meter 1 cubic inch = 16.3872 cubic centimeters 1 cubic foot = 0.02832 cubic meter 1 pound avd. = 453.5925 grams 1 ounce avd. = 28.3495 grams 1 grain = 0.0648 gram 1 U. S. gallon = 3.78543 liters 1 Imperial gallon = 4.54346 liters 1 U. S. quart = 0.94636 liter 1 fluidounce = 28.396 cubic centimeters I. Tables for Determination of Temperature. RELATIONS BETWEEN THERMOMETERS. In Fahrenheit's thermometer, the freezing-point of water is placed at 32, and the boiling-point at 212, and the number of intervening degrees is 180. The Centigrade or Celsius's thermometer, which is now recognized in the U S. Pharmacopeia and has been adopted generally by scientists, marks the freezing-point zero, and the boiling-point 100. From the above statement, it is evident that 180 degrees of Fahren- heit are equal to 100 of the Centigrade, or one degree of the first is equal to f of a degree of the second. It is easy, therefore, to convert the 'degrees of one into the equivalent number of degrees of the other; but in ascertaining the corresponding points upon the different scales, it is necessary to take into consideration their different modes of gradua- tion. Thus, as the zero of Fahrenheit is 32 below the point at which that of the Centigrade is placed, this number must be taken into account in the calculation. 1. If any degree on the Centigrade scale, either above or below zero, be multiplied by 1.8, the result will, in either case, be the number of degrees above or below 32, or the freezing-point of Fahrenheit. 2. The number of degrees between any point of Fahrenheit's scale and 32, if divided by 1.8, will give the corresponding point on the Centigrade. APPENDIX. 563 THERMOMETKIC EQUIVALENTS. ACCORDING TO THE CENTIGRADE AND FAHRENHEIT SCALES. P. C. P. C F. C. F. C. F. 39.4 39 17.2 1 5 41 27.2 81 49.4 121 39 38.2 17 1.4 5.5 42 27.7 82 50 122 38.8 38 16.6 2 6 42.8 28 82.4 50.5 123 38.3 37 16.1 3 6.1 43 28.3 83 51 123.8 -38 36.4 16 3.2 6.6 44 28.8 84 51.1 124 37.7 36 15.5 4 7 44.6 29 84.2 51.6 125 37.2 35 15 6 7.2 45 29.4 85 52 125.6 37 34.6 14.4 6 7.7 46 30 86 52.2 126 36.6 34 14 6.8 8 46.4 30.5 87 52.7 127 36.1 33 13.8 7 8.3 47 31 87.8 53 127.4 36 -32.8 13.3 8 8.8 48 81.1 88 53.3 128 35.5 32 13 8.6 9. 48.2 31.6 89 53.8 129 35 31 12.7 9 9.4 49 32 89.6 54 129.2 34.4 -30 12.2 10 10 50 32.2 90 54.4 130 34 29.2 12 10.4 10.5 51 32.7 91 55 131 33.8 29 11.6 11 11 61.8 33 91.4 55.5 132 33.3 28 11.1 12 11.1 62 33.3 92 56 182.8 33 27.4 11 12.2 11.6 53 33.8 93 56.1 133 32.7 27 10.5 13 12 53.6 34 93.2 56.6 134 32.2 26 10 14 12.2 54 34.4 94 57 134.6 32 25.6 9.4 15 12.7 55 35 95 57.2 135 31.6 25 9 15.8 13 55.4 35.5 96 57.7 136 31.1 24 8.8 16 13.3 56 36 96.8 68 136.4 31 23.8 8.3 17 13.8 57 36.1 97 58.3 137 30.5 23 8 17.6 14 57.2 36.6 98 58.8 138 30 22 7.7 18 14.4 58 37 98.6 59 138.2 29.4 21 7.2 19 15 69 37.2 99 59.4 139 29 20.2 1 19.4 15.5 60 37.7 100 60 140 28.8 20 6.6 20 16 60.8 38 100.4 60.5 141 28.3 19 6.1 21 16.1 61 38.3 101 61 141.8 28 18.4 6 21.2 16.6 62 38.8 102 61.1 142 27.7 18 5.5 22 17 62.6 39 102.2 61.6 143 27.2 17 5 23 17.2 63 39.4 103 62 143.6 27 16.6 4.4 24 17.7 64 40 104 62.2 144 26.6 16 4 24.8 18 64.4 40.5 105 62.7 145 26.1 15 3.8 25 18.3 6.5 41 105.8 63 145.4 26 14.8 3.3 26 18.8 66 41.1 106 63.3 146 25.5 14 3 26.6 19 66.2 41.6 107 63.8 147 25 13 2.7 27 19.4 67 42 107.6 64 147.2 24.4 12 2.2 28 20 68 42.2 108 64.4 148 24 11.2 2 28.4 20.5 69 42.7 109 66 149 23.8 11 1.6 29 21 69.8 43 109.4 65.5 150 23.3 10- -1.1 30 21.1 70 43.3 110' 66 150.8 23 9.4 1 30.2 21.6 71 43.8 111 66.1 151 22.7 9 0.5 31 22 71.6 44 111.2 66.6 152 22.2 8 32 22.2 72 44.4 112 67 152.6 22 7.6 0.5 33 22.7 73 45 113 67.2 153 21.6 7 1 33.8 23 73.4 45.5 114 67.7 154 21.1 6 1.1 34 23.3 74 46 114.8 68 154.4 21 5.8 1.6 35 23.8 75 46.1 115 68.3 155 20.5 5 2 35.6 24 75.2 46.6 116 68.8 156 20 4 2.2 36 24.4 76 47 116.6 69 156.2 19.4 3 2.7 37 25 77 47.2 117 69.4 157 19 2.2 3 37.4 25.5 78 47.7 118 70 158 18.8 2 3.3 38 26 78.8 48 118.4 70.5 159 18.3 1 3.8 39 26.1 79 48.3 119 71 159.8 18 0.4 4. 39.2 26.6 80 48.8 120 71.1 160 17.7 4.4 40 27 80.6 49 120.2 71.6 161 564 APPENDIX. Thermometric Equivalents. Continued. c. F.- C. F. C. F. C. F. C. F. 72 161.6 95.5 204 118.8 246 142.2 288 166 830.8 72.2 162 96 204.8 119 246.2 142.7 289 166.1 331 72.7 163 96.1 205 119.4 247 143 289.4 166.6 332 73 163.4 96.6 206 120 248 143.3 290 167 332.6 73.3 164 97 206.6 120.5 249 143.8 291 167.2 333 73.8 165 97.2 207 121 249.8 144 291.2 167.7 334 74 165.2 97.7 208 121.1 250 144.4 292 168 334.4 74.4 166 98 208.4 121.6 251 145 293 168.3 335 75 167 98.3 209 122 251.6 145.5 294 168.8 336 75.5 168 98.8 210 122.2 252 146 294.8 169 336.2 76 108.8 99 210.2 122.7 253 146.1 295 169.4 337 76.1 169 99.4 211 123 253.4 146.6 296 170 338 76.6 170 100 212 123.3 254 147 296.6 170.5 339 77 170.6 100.5 213 123.8 255 147.2 297 171 339.8 77.2 171 101 213.8 124 255.2 147.7 298 171.1 340 77.7 172 101.1 214 124.4 256 148 298.4 171-6 341 78 172.4 101.6 215 125 257 148.3 299 172 341.6 78.3 173 102 215.6 125.5 258 148.8 300 172.2 342 78.8 174 102.2 216 126 258.8 149 300.2 172.7 343 79 174.2 102.7 217 126.1 259 149.4 301 173 343.4 79.4 175 103 217.4 126.6 260 150 302 173.3 344 80 176 103.3 218 127 260.6 150.5 303 173.8 345 80.5 177 103.8 219 127.2 261 151 303.8 174 345.2 81 177.8 104 219.2 127.7 262 151.1 304 174.4 346 81.1 178 104.4 220 128 262.4 151.6 305 175 347 81.6 179 105 221 T28.3 263 152 305.8 175.5 348 82 179.6 105.5 222 128.8 204 152.2 306 176 348.8 82.2 180 106 222.8 129 264.2 152.7 307 176.1 349 82.7 181 106.1 223 129.4 205 153 307.4 176.6 350 83 181.4 106.6 224 130 266 153.3 308 177 350.6 83.3 182 107 224.6 130.5 267 153.8 309 177.2 351 83.8 183 107.2 225 131 267.8 154 309.2 177.7 352 84 183.2 107.7 226 131.1 268 154.4 310 178 352.4 84.4 184 108 226.4 131.6 269 155 311 178.3 353 85 185 108.3 227 132 269.6 155.5 312 178.8 354 85.5 186 108.8 228 132.2 270 156 312.8 179 354.2 86 186.8 109 228.2 132.7 271 156.1 313 179.4 355 86.1 187 109.4 229 133 271.4 156.6 314 180 356 86.6 188 110 230 133.3 272 157 314.6 180.5 357 87 188.6 110.5 231 133.8 273 157.2 315 181 357.8 87.2 189 111 231.8 134 273.2 157.7 316 181.1 358 87.7 190 111.1 232 134.4 274 158 316.4 181.6 359 88 190.4 111.6 233 135 275 158.3 317 182 359.6 88.3 191 112 233.6 135.5 276 158.8 318 182.2 360 88.8 192 112.2 234 136 276.8 159 818.2 182.7 361 89 192.2 112.7 235 136.1 277 159.4 819 183 361.4 89.4 193 113 235.4 136.6 278 160 320 183.3 362 90 194 113.3 236 137 278.6 160.5 321 183.8 363 90.5 195 113.8 237 137.2 279 161 821.8 184 363.2 91 195.8 114 237.2 137.7 280 161.1 822 184.4 364 91.1 196 114.4 238 138 280.4 1<51.6 823 185 365 91.6 197 115 239 138.3 281 162 323.6 185.5 306 92 197.6 115.5 240 138.8 282 162.2 324 186 366.8 92.2 198 116 240.8 139 282.2 162.7 825 186.1 367 92.7 199 116.1 241 139.4 283 163 325.4 186.6 368 93 199.4 116.6 242 140 284 163.3 826 187 368.6 93.3 200 117 242.6 140.5 285 163.8 327 187.2 369 93.8 201 117.2 243 141 285.8 164 327.2 187.7 370 94 201.2 117.7 244 141.1 286 164.4 828 188 370.4 94.4 202 118 244.4 141.6 287 165 329 188.3 371 95 203 118.3 245 142 287.6 165.5 330 188.8 372 APPENDIX. Themnometric Equivalents. Continued. 565 c. F. C. F. C. F. C. F. C. F. 189 372.2 211.6 413 233.8 453 256.1 493 278.3 533 189.4 373 212 413.6 234 453.2 256.6 494 278.8 534 190 374 212.2 414 234.4 454 257 494.6 279 534.2 190.5 375 212.7 415 235 455 257.2 495 279.4 535 191 375.8 213 415.4 235.5 456 257.7 496 280 536 191.1 376 213.3 416 236 456.8 258 496.4 280.5 537 191.6 377 213.8 417 236.1 457 258.3 497 281 537.8 192 377.6 214 417.2 236.6 458 258.8 498 281.1 538 192.2 378 214.4 418 237 458.6 259 498.2 281.6 539 192.7 379 215 419 237.2 459 259.4 499 282 539.6 193 379.4 215.5 420 237.7 460 260 500 282.2 540 193.3 380 216 420.8 238 460.4 260.5 501 282.7 541 193.8 381 216.1 421 238.3 461 261 501.8 283 541.4 194 381.2 216.6 422 238.8 462 261.1 502 283.3 542 194.4 382 217 4226 239 462.2 261.6 503 283.8 543 195 383 217.2 423 239.4 463 262 503.6 284 5432 195.5 384 217.7 424 240 464 262.2 504 284.4 544 196 384.8 218 424.4 240.5 465 262.7 505 285 545 1961 385 218.3 425 241 465.8 263 505.4 285.5 546 196.6 386 218.8 426 241.1 466 263.3 506 286 546.8 197 386.6 219 426.2 241.6 467 263.8 507 286.1 547 197.2 387 219.4 427 242 467.6 264 507.2 286.6 548 197.7 388 220 428 242.2 468 264.4 508 287 548.6 198 388.4 220.5 429 242.7 469 265 509 287.2 549 198.3 389 221 429.8 243 469.4 265.5 510 287.7 550 198.8 390 221.1 430 243.3 470 266 510.8 288 550.4 199 390.2 221.6 431 243.8 47 1 - 266.1 511 288.3 551 199.4 391 222 431.6 244 47. 2 266.6 512 288.8 552 200 392 222.2 432 2444 472 267 512.6 289 552.2 200.5 393 222.7 433 245 473 267.2 613 289.4 553 201 393.8 223 433.4 245.5 474 267.7 514 290 654 201.1 394 223.3 434 246 474.8 268 514.4 290.5 555 201.6 395 223.8 435 246.1 475 268.3 515 291 555.8 202 395.6 224 435.2 246.6 476 268.8 516 291.1 556 202.2 396 224.4 436 247 476.6 269 516.2 291.6 557 202.7 397 225 437 247.2 477 269.4 517 292 657.6 203 397.4 225.5 438 247.7 478 270 518 292.2 558 203.3 398 226 438.8 248 478.4 270.5 519 292.7 559 203.8 399 226.1 439 248.3 479 271 519.8 293 559.4 204 399.2 226.6 440 248.8 480 271.1 520 293.3 560 204.4 400 227 440.6 249 480.2 271.6 521 293.8 561 205 401 227.2 441 249.4 481 272 521.6 294 561.2 205.5 402 227.7 442 250 482 272.2 522 294.4 562 206 402.8 228 442.4 250.5 483 272.7 523 295 563 206.1 403 2283 443 251 483.8 273 523.4 295.5 564 206.6 404 228.8 444 251.1 484 273.3 524 296 564.8 207 404.6 229 444.2 251.6 485 273.8 625 296.1 565 207.2 405 229.4 445 252 485.6 274 525.2 296.6 566 207.7 406 230 446 252.2 486 274.4 526 297 566.6 208 406.4 230.5 447 252.7 487 275 627 297.2 567 208.3 407 231 - 447.8 253 487.4 275.5 528 297.7 568 208.8 408 231.1 448 253.3 488 276 528.8 298 568.4 209 408.2 2316 449 253.8 489 276.1 529 298.3 669 209.4 409 232 4496 254 489.2 276.6 530 298.8 570 210 410 232.2 450 254.4 490 277 530.6 299 570.2 210.5 411 232.7 451 255 491 277.2 531 299.4 571 211 411.8 233 451.4 255.5 492 277.7 532 300 572 211.1 412 233.3 452 256 492.8 278 532.4 566 APPENDIX. HI. Specific Gravity Tables. 1. Baume's Scale for Liquids Lighter than Water. The following table is calculated for a temperature of 17.5 C. 140 = specific gravity and (63.5 F.), and is based on the formulas 140 1Qn loU ^ - - specific gravity 130 = B.. Degree Baum6. Specific gravity. Degree BaumtJ. Specific gravity. Degree Baum6. Specific gravity. Degree Baum6. Specific gravity. 10 1.0000 33 0.8588 56 0.7526 79 0.6698 11 0.9929 34 0.8536 57 0.7486 80 0.6666 12 0.9859 35 0.8484 58 0.7446 81 0.6635 13 0.9790 36 0.8433 59 0.7407 82 0.6604 14 0.9722 37 0.8383 60 0.7368 83 0.6573 16 0.9655 38 0.8333 61 0.7329 84 0.6542 16 0.9589 39 0.8284 62 0.7290 85 0.6511 17 0.9523 40 0.8235 63 0.7253 86 0.6482 18 0.9459 41 0.8187 64 0.7216 87 0.6452 19 0.9395 42 0.8139 65 0.7179 88 0.6422 20 0.9333 43 0.8092 66 0.7142 89 0.6393 21 0.9271 44 0.8045 67 0.7106 90 0.6363 22 0.9210 45 0.8000. 68 0.7070 91 0.6335 23 0.9150 46 0.7954 69 0.7035 92 06306 24 0.9090 47 0.7909 70 0.7000 93 0.6278 25 0.9032 48 0.7865 71 0.6965 94 0.6250 26 0.8974 49 0.7821 72 0.6931 95 0.6222 27 0.8917 50 0.7777 73 0.6896 96 0.6195 28 0.8860 51 0.7734 74 0.6863 97 0.6167 29 0.8805 52 0.7692 75 0.6829 98 0.6140 30 0.8750 53 0.7650 76 0.6796 99 0.6113 31 0.8695 54 0.7608 77 0.6763 100 0.6087 32 0.8641 55 0.7567 78 0.6731 The coefficient of expansion of petroleum oils for increase or decrease of 1 .0. in temperature has been determined for both Russian and American oils. For the latter the following figures have been given (Iron Age, xxxviii, No. 7) : Specific gravity Coeflicient of at 15 C. (59 F.). expansion for 1 C. UnderO.700 0.00090 0.700 to 0.750 0.00085 0.750 to 0.800 0.00080 0.800 to 0.815 s 0.00070 Over 0.815 0.00065 As stated in the text (p. 39), it is customary in practice to take as the coefficient of expansion 0.004 for every 10 F. (0.00072 for 1 C.). APPENDIX. 567 2. Comparison of Various Baume Hydrometers for Liquids Heavier than Water with Specific Gravities. (Lunge's Technical Methods of Chemical Analysis, vol. i, p. 935.) Degrees. Rational Hydrometer . 144.3 a== Baum6's Hydrometer according to Gerlach's scale. Baume 1 American scale . 145 I Rational Hydrometer d U4 ' 3 Baum6's Hydrometer according to Gerlach's scale. Baum6 American scale 145 144.3 ' 145-n 144.3 n d 145-n 1 1.007 1.0068 1.005 34 1.308 1.3015 1.309 2 1.014 1.0138 1.011 35 1.320 1.3131 1.317 3 1.022 1.0208 1.023 36 1.332 1.3250 1.334 4 1.029 1.0280 1.029 37 1.345 1.3370 1.342 5 1.037 1.0353 1.036 38 1.357 1.3494 1.359 6 1.045 1.0426 1.043 39 1.370 1.3619 1.368 7 1.052 1.0501 1.050 40 1.383 1.3746 1.386 8 1.060 1.0576 1.057 41 1.397 1.3876 1.395 9 1.067 1.0653 1.064 42 1.410 1.4009 1.413 10 1.075 1.0731 1.071 43 1.424 1.4134 1.422 11 1.083 1.0810 1.086 44 1.438 1.4281 1.441 12 1.091 1.0890 1.093 45 1.453 1.4421 1.451 13 1.100 1.0972 1.100 46 1.468 1.4564 1.470 14 1.108 1.1054 1.107 47 1.483 1.4710 1.480 15 1.116 1.1138 1.114 48 1.498 1.4860 1.500 16 1.125 1.1224 1.122 49 1.514 1.5012 1.510 17 1.134 1.1310 1.136 50 1.530 1.5167 1.531 18 1.142 1.1398 1.143 51 1.540 1.5325 1.541 19 1.152 1.1487 1.150 52 1.563 1.5487 1.561 20 1.162 1.1578 1.158 53 1.580 1.5652 1.573 21 1.171 1.1670 1.172 54 1.597 1.5820 1.594 22 1.180 1.1763 1.179 55 1.615 1.5993 1.616 23 1.190 1.1858 1.186 56 1.634 1.6169 1.627 24 1.200 1.1955 1.201 57 1.652 1.6349 . 1.650 25 1.210 1.2053 1.208 58 1.671 1.6533 1.661 26 1.220 1.2153 1.216 59 1.691 1.6721 1.683 27 1.231 1.2254 1.231 60 1.711 1.6914 1.705 28 1.241 1.2357 1.238 61 1.732 1.7111 1.727 29 1.252 1.2462 1.254 62 1.753 1.7313 1.747 30 1.263 1.2569 1.262 63 1.774 1.7520 1.767 31 1.274 1.2677 1.269 64 1.796 1.7731 1.793 32 1.285 1.2788 1.285 65 1.819 1.7948 1.814 33 1.297 1.2901 1.293 66 1.842 1.8171 1.835 What is known as the " Rational " Baume scale is calculated by tak- ing water at the temperature chosen at B. and sulphuric acid of 1.842 144 3 specific gravity at 66 B. and using the formula - = d. (See J. 4:4.o n Lunge's " Sulphuric Acid and Alkali," vol. 1, p. 20.) 568 APPENDIX. 3. Twaddle's Scale for Liquids Heavier than Water. Degrees ~] Twaddle. | l 3 > O> at oo'Sb Degrees Twaddle. <& 'S'> g & Degrees Twaddle. P.2 MM Degrees Twaddle. g& '3 > 2Lfi 00 "> Degrees Twaddle. "3 > Q> at &E oa w> Degrees Twaddle. * P *> Degrees Twaddle. X tC ;*~* 'oV &! K M 1.000 29 1.145 58 1.290 87 1.435 116 1.580 145 1.725 173 1.865 1 1.005 30 1.150 59 1.295 88 1.440 117 1.585 146 1.730 174 1.870 2 1.010 31 1.155 60 1.300 89 1.445 118 1.590 147 1.735 175 1.875 3 1.015 32 1.160 61 1.305 90 1.450 119 1.595 148 1.740 176 1.880 4 1.020 33 1.165 62 1.310 91 1.455 120 1.600 149 1.745 177 1.885 5 1.025 34 1.170 63 1.315 92 1.460 121 1.605 150 1.750 178 1.890 6 1.030 35 1.175 64 1.320 93 1.465 122 1.610 151 1.755 179 1.895 7 1.035 36 1.180 65 1.325 94 1.470 123 1.615 152 1.760 180 1.900 8 1.040 37 1.185 66 1.330 95 1.475 124 1.620 153 1.765 181 1.905 9 1.045 38 1.190 67 1.335 96 1.480 125 1 625 154 1.770 182 1.910 10 1.050 39 1.195 68 1.340 97 1.485 T2G 1.630 155 1.775 183 1.915 11 1.055 40 1.200 69 1.345 98 1.490 127 1.635 156 1.780 184 1.920 12 1.060 41 1.205 70 1.350 99 1.495 128 1.640 157 1.785 185 1.925 13 1.065 42 1.210 71 1.355 100 1.500 129 1.645 158 1.790 186 1.930 14 1.070 43 1.215 72 1.360 101 1.505 130 1.650 159 1.795 187 1.935 15 1.075 44 1.220 73 1.365 102 1.510 131 1.655 160 1.800 188 1.940 16 1.080 45 1.225 74 1.370 103 1.515 132 1.660 161 1.805 189 1.945 17 1.085 46 1.230 75 1.375 104 1.520 133 1.665 162 1.810 190 1.950 18 1.090 47 1.235 ! 76 1.380 105 1.525 134 1.670 163 1.815 191 1.955 19 .095 48 1.240 77 1.385 106 1.530 135 1.675 164 1.820 192 1.960 20 .100 49 1.245 78 1.390 107 1.535 136 1.680 165 1.825 193 1.965 21 .105 50 1.250 79 1.395 108 1.540 137 1.685 166 1.830 194 1.970 22 .110 51 1.255 80 1.400 109 1.545 138 1.690 167 1.835 195 1.975 23 .115 52 1.260 81 1.405 110 1.550 139 1.695 168 1.840 196 1.980 24 .120 53 1.265 82 1.410 111 1.555 140 1.700 169 1.845 197 1.985 25 .125 54 1.270 83 1.415 112 1.560 141 1.705 170 1.850 198 1.990 26 1.130 55 1.275 84 1.420 113 1.565 142 1.710 171 1.855 199 1.995 27 1.135 56 1.280 85 1.425 114 1.570 143 1.715 172 1.860 200 2.000 28 1.140 57 1.285 86 1.430 115 1.575 144 1.720 The uniform division of the Twaddle scale makes the degrees very easily convertible into specific gravity readings It is only necessary to multiply the degree as read off by five and add this to 1.000 in order to obtain the specific gravity. Again, as the gallon of distilled water at ordinary temperatures weighs ten pounds avoirdupois, it is possible to determine the weight of a gallon of an acid or lye by the aid of the Twaddle scale. Thus, if an acid shows 50 Twaddle, corresponding to the specific gravity 1.250, it weighs twelve and a half pounds per gallon. Or, as a liter of distilled water weighs one thousand grams, a liter of a liquid showing 20 Twaddle will weigh eleven hundred grams. APPENDIX. 569 4. Comparison of the Twaddle Scale with the Rational Baume Scale. Twaddle. Baume. >l O*J * > 8 |a 03 Twaddle. Baume. 1 at O oS O (_ 460 02 Twaddle. Baume. o *? Is &> 00 Twaddle. <0 i i 1 > 2> t> oj &M X 1.000 44 26.0 1.220 88 44.1 1.440 131 57.1 1.655 1 0.7 1 .005 45 264 1.225 89 44.4 1.445 132 57.4 1.660 2 1.4 1.010 46 26.9 1.230 90 44.8 1.450 133 57.7 1.665 3 2.1 1.015 47 27.4 1.235 91 45.1 1.455 134 57.9 1.670 4 2.7 1.020 48 27.9 1.240 92 45.4 1.400 135 58.2 1.675 5 3.4 1.025 49 28.4 1.245 93 45.8 1.465 136 58.4 1.680 6 4.1 1.030 50 28.8 1.250 94 46.1 1.470 137 58.7 1.685 7 4.7 1.035 51 29.3 1.255 95 46.4 1.475 138 58.9 1.690 8 5.4 1.040 52 29.7 1.260 96 46.8 1.480 139 59.2 1.695 9 6.0 1.045 53 30.2 1.265 97 47.1 1.485 140 59.5 1.700 10 6.7 1.050 54 30.6 1.270 98 47.4 1.490 141 59.7 1.705 11 7.4 1.055 55 31.1 1.275 99 47.8 1.495 142 60.0 1.710 12 8.0 1.060 56 31.5 1.280 100 48.1 1.500 143 60.2 1.715 13 8.7 1.065 67 32.0 1.285 101 48.4 1.505 144 60.4 1.720 14 9.4 1.070 58 32.4 1.290 102 48.7 1.510 145 606 1.725 15 10.0 1.075 59 32.8 1.295 103 49.0 1.515 146 609 1.730 16 10.6 1.080 60 33.3 1.300 104 49.4 1.520 147 61.1 1.735 17 11.2 1.085 61 33.7 1.305 105 49.7 1.525 148 61.4 1.740 18 11.9 1.090 62 34.2 1.310 106 50.0 1.530 149 61.6 1.745 19 12.4 1.095 63 34.6 1.315 107 50.3 1.535 150 61 8 1.750 20 13.0 1.100 64 35.0 1.320 108 50.6 1.540 151 62.1 1 755 21 13.6 1.105 65 35.4 1.325 109 50.9 1.545 152 62.3 1.760 22 14.2 1.110 66 35.8 1.330 110 51.2 1.550 153 62.5 1.765 23 14.9 1.115 67 36.2 1.335 111 51.5 1.555 154 62.8 1.770 24 15.4 1.120 68 36.6 1.340 112 51.8 1.560 155 63.0 1.775 25 16.0 1.125 69 37.0 1.345 113 52.1 1.565 156 63.2 1.780 26 16.5 1.130 70 37.4 1 350 114 52.4 1.570 157 63.5 1.785 27 17.1 1.135 71 37.8 1.355 115 52.7 1.575 158 63.7 1.790 28 17.7 1.140 72 38.2 1.360 116 53.0 1.580 159 64.0 1.795 29 18.3 1.145 73 38.6 1.365 117 53.3 1.585 160 64.2 1.800 30 18.8 1.150 74 39.0 1.370 118 53.6 1.590 161 64.4 1.805 31 19.3 1.155 75 39.4 1.375 119 53.9 1.595 162 64.6 1.810 32 19.8 1.160 76 39.8 1.380 120 54.1 1.600 163 64.8 1.815 33 20.3 1.165 77 40.1 1.385 121 54.4 1.605 164 65.0 1.820 34 20.9 1.170 78 40.5 1.390 122 54.7 1.610 165 65.2 1.825 35 21.4 1.175 79 40.8 1.395 123 55.0 1.615 166 65.5 1.830 36 22.0 1.180 80 41.2 1.400 124 55.2 1.620 167 65.7 1.835 37 22.5 1.185 81 41.6 1.405 125 55.5 1.625 168 65.9 1.840 38 23.0 1.190 82 42.0 1.410 126 55.8 1.630 169 66.1 1.845 39 23.5 1.195 83 42.3 1.415 127 56.0 1.635 170 66.3 1.850 40 24.0 1.200 84 42.7 1.420 128 56.3 1.640 171 66.5 1.855 41 24.5 1.205 85 43.1 1.425 129 56.6 1.645 172 66.7 1.860 42 25.0 1.210 86 43.4 1.430 130 56.9 1.650 173 67.0 1.865 43 25.5 1.215 87 43.8 1.435 570 APPENDIX. 5. Comparison between Specific Gravity Figures, Degree Baume and Degree Brix (as used for sugar solutions). Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Baume. Percentage of sugar ac- cording to Balling or degree Brix Specific gravity. 0) .1 3 MlM o>W ft Percentage of sugar ac- cording to Balling or degree Brix Specific gravity. aj *s o> 3 j- ri Sw 0.0 1.00000 0.00 5.0 1.01970 2.84 10.0 1.04014 5.67 0.1 1.00038 0.06 5.1 1.02010 2.89 10.1 1.04055 572 0.2 1.00077 Oil 5.2 1.02051 2.95 10.2 1.04097 5.78 0.3 1.00116 0.17 5.3 1.02091 3.01 10.3 1.04139 5.83 0.4 1 00155 0.23 6.4 1.02131 3.06 10.4 1.04180 5.89 0.5 1.00193 0.28 5.5 1.02171 3.12 10.5 1.04222 5.95 0.6 1.00232 0.34 5.6 1.02211 3.18 10.6 1.04264 6.00 0.7 1.00271 0.40 5.7 1.02252 3.23 10.7 1.04306 6.06 08 1.00310 0.45 6.8 1.02292 3.29 10.8 1.04348 6.12 0.9 1.00349 0.51 6.9 1.02333 3.35 10.9 1.04390 6.17 1.0 1.00388 0.57 6.0 1.02373 3.40 11.0 1.04431 6.23 1.1 1.00427 0.63 6.1 1.02413 3.46 11.1 1.04473 6.29 1.2 1.00466 0.68 6.2 1.02454 3.52 11.2 1.04515 6.34 1.3 1.00505 0.74 6.3 1.02494 3.57 11.3 1.04557 6.40 1.4 1.00544 080 6.4 1.02535 3.63 11.4 1.04599 6.46 1.5 1.00583 0.85 6.6 1.02575 3.69 11.5 1.04641 6.51 1.6 1.00622 0.91 6.6 1.02616 3.74 11.6 1.04683 6.57 1.7 1.00662 0.97 6.7 1.02657 380 11.7 1.04726 6.62 1.8 1.00701 1.02 6.8 1.02697 3.86 11.8 1.04768 6.68. 1.9 1.00740 1.08 6.9 1.02738 3.91 11.9 1.04810 6.74 2.0 1.00779 1.14 7.0 1.02779 3.97 12.0 1.04852 6.79 2.1 1.00818 1.19 7.1 1.02819 4.03 12.1 1.04894 6.85 2.2 1.00858 1.25 7.2 1.02860 4.08 12.2 1.04937 6.91 2.3 1.00897 1.31 7.3 1.02901 4.14 12.3 1.04979 6.96 2.4 1.00936 1.36 7.4 1.02942 4.20 12.4 1.05021 7.02 2.5 1.00976 1.42 7.5 1.02983 4.25 12.5 1.05064 7.08 2.6 1.01015 1.48 7.6 1.03024 4.31 12.6 1.05106 7.13 2.7 1.01055 1.53 7.7 1.03064 4.37 12.7 1.05149 7.19 2.8 1.01094 1.59 7.8 1.03105 4.42 128 1.05191 7.24 2.9 1.01134 1.65 7.9 1.03146 4.48 12.9 1.05233 7.30 8.0 1.01173 1.70 8.0 1.03187 4.53 13.0 1.05276 7.36 3.1 1.01213 1.76 8.1 1.03228 4.59 13.1 1.05318 7.41 3.2 1.01252 1.82 8.2 1.03270 4.65 13.2 1.05361 7.47 3.3 1.01292 1 87 8.3 1.03311 4.70 13.3 1.05404 7.53 3.4 1.01332 1.93 8.4 1.03352 4.76 13.4 1.05446 7.58 3.5 1.01371 1.99 8.5 1.03393 4.82 13.5 1.05489 7.64 3.6 1.01411 2.04 8.6 1.03434 4.87 13.6 1.05532 7.69 3.7 1.01451 2.10 8.7 1.03475 4.93 13.7 1.05574 7.75 3.8 1.01491 2.16 8.8 1.03517 4.99 13.8 1.05617 7.81 3.9 1.01531 2.21 8.9 1.03558 5.04 13.9 1.05660 7.86 4.0 1.01570 2.27 9.0 1.03599 5.10 14.0 1 05703 7.92 4.1 1.01610 2.33 9.1 1.03640 5.16 14.1 1.05746 7.98 4.2 1.01650 2.38 9.2 1.03682 5.21 14.2 1.05789 8.03 4.3 1.01690 2.44 9.3 1.03723 5.27 14.3 1.05831 8.09 4.4 1.01730 250 9.4 1.03765 5.33 14.4 1.05874 8.14 4.5 1.01770 2.55 9.5 1.03806 5.38 14.5 1.05917 8.20 4.6 1.01810 2.61 9.6 1.03848 5.44 14.6 1.05960 8.26 4.7 1 01850 2.67 9.7 1.03889 5.50 14.7 1.06003 831 4.8 1.01890 2.72 9.8 1.03931 5.55 14.8 1.06047 8.37 4.9 1.01930 2.78 9.9 1.03972 561 14.9 1.06090 8.43 APPENDIX. 571 Comparison between Specific Gravity Figures, Degree Baume and Degree Brix. Continued. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Baume. 1 Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Baum6. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. aj $3 Q) 3l a 15.0 1.06133 8.48 20.0 1.08329 11.29 25.0 1.10607 14.08 15.1 1.06176 8.54 20.1 1.08374 11.34 25.1 1.10653 14.13 15.2 1.06219 8.59 20.2 1.08419 11.40 25.2 1.10700 14.19 15.3 1.06262 8.65 20.3 1.08464 11.45 25.3 1.10746 14.24 15.4 1.06306 8.71 20.4 1.08509 11.51 25.4 1.10793 14.30 15.5 1.06349 8.76 20.5 1.08553 11 57 25.5 1.10839 14.35 15.6 1.06392 8.82 206 1.08599 11.62 25.6 1.10886 14.41 15.7 1.06436 8.88 20.7 1.08643 11 68 25.7 1.10932 14.47 15.8 1.06479 8.93 20.8 1.08688 11.73 25.8 1.10979 14.52 15.9 1.06522 8.99 20.9 1.08133 11.79 25.9 1.11026 14.58 16.0 1.06566 9.04 21.0 1.08778 11.85 26.0 1.11072 14.63 16.1 1.06609 9.10 21.1 1.08824 11.90 26.1 1.11119 14.69 . 16.2 1.06653 9.16 21.2 1.08869 11.96 26.2 1.11166 14.74 16.3 1.06696 9.21 21.3 1.08914 12.01 26.3 1.11213 14.80 16.4 1.06740 9.27 21.4 1.08959 12.07 26.4 1.11259 14.85 16.5 1.06783 9.33 21.5 1.09004 12.13 26.5 1.11306 14.91 16.6 1.06827 9.38 21.6 1.09049 12.18 26.6 1.11353 14.97 16.7 1.06871 9.44 21.7 1.09095 12.24 26.7 1.11400 15.02 16.8 1.06914 9.49 21.8 1.09140 1229 26.8 1.11447 15.08 16.9 1.06958 9.55 21.9 1.09185 12.35 26.9 1.11494 16.13 17.0 1.07002 9.61 22.0 1.09231 12.40 27.0 1.11541 15.19 17.1 1.07046 9.66 22.1 1.09276 12.46 27.1 1.11588 15.24 17.2 1.07090 9.72 22.2 1.09321 12.52 27.2 1.11635 15.30 17.3 1.07133 9.77 22.3 1.09367 12.57 27.3 1.11682 15.35 17.4 1.07177 9.83 22.4 1.09412 12.63 27.4 1.11729 15.41 17.5 1.07221 9.89 22.5 1.09458 12.68 27.5 1.11776 15.46 17.6 107265 9.94 226 1.09503 12.74 27.6 1.11824 15.52 17.7 1.07309 10.00 22.7 1 09549 12.80 27.7 1.11871 15.58 178 1.07358 10.06 22.8 1.09595 12.85 27.8 1.11918 15.63 17.9 1.07397 10.11 229 1.09640 12.91 27.9 1.11965 15.69 18.0 1.07441 10.17 23.0 1.09686 12.96 28.0 1.12013 15.74 18.1 1.07485 10.22 23.1 1.09732 13.02 28.1 1.12060 15.80 18.2 1.07530 10.28 23.2 1.09777 13.07 28.2 1.12107 15.85 18.3 1.07574 10.33 23.3 1.09823 13.13 28.3 1.12155 15.91 18.4 1.07618 10.39 23.4 1.09869 13.19 28.4 1.12202 15.96 18.5 1 07662 10.45 23.5 1.09915 13.24 28.5 1.12250 16.02 18.6 1.07706 10.50 23.6 1.09961 13.30 28.6 1.12297 16.07 18.7 1.07751 10.56 23.7 1.10007 13.35 28.7 1.12345 16.13 18.8 1.07795 10.62 23.8 1.10053 13.41 28.8 1.12393 16.18 18.9 1.07839 10.67 23.9 1.10099 13.46 28.9 1.12440 16.24 19.0 1.07884 10.73 24.0 1.10145 13.52 29.0 1.12488 16.30 19.1 1.07928 10.78 24.1 1.10191 13.58 29.1 1.12536 16.35 19.2 1.07973 10.84 24.2 1.10237 13.63 29.2 1.12583 16.41 19.8 1.08017 10.90 24.3 1.10283 13.69 29.3 1.12631 16.46 19.4 1.08062 10.95 24.4 1.10329 13.74 29.4 1.12679 16.52 19.5 1.08106 11.01 24.5 1.10375 13.80 29.5 1.12727 16.57 19.6 1.08151 11.06 24.6 1.10421 13.85 29.6 1.12775 16.63 19.7 108196 11.12 24.7 1.10468 13.91 29.7 1.12823 16.68 19.8 1.08240 11.18 24.8 1.10514 13.96 29.8 1.12871 16.74 19.9 1.08285 11.27 24.9 1.10560 14.02 29.9 1.12919 16.79 572 APPENDIX. Comparison between Specific Gravity Figures, Degree Baume and Degree Brix. Continued. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. a! w a Is g> ft Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Baum6. 1 Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Baum6. 30.0 1.12967 16.85 35.0 1.15411 19.60 40.0 1.17943 22.33 30.1 1.13015 16.90 35.1 1.15461 19.66 40.1 1.17995 22.38 30.2 1.13063 16.96 35.2 1.15511 19.71 40.2 1.18046 2-J.44 30.3 1.13111 17.01 35.3 1.15561 19.76 40.3 1.18098 22.49 30.4 1.13159 17.07 35.4 1.15611 19.82 40.4 1.18150 22.55 30.5 1.13207 17.12 35.5 1.15661 19.87 40.5 1.18201 22.60 30.6 1.13255 17.18 35.6 1,15710 19.93 40.6 1.18253 22.66 30.7 1.13304 17.23 35.7 1.15760 19.98 40.7 1.18305 22.71 30.8 1.13352 17.29 35.8 1.15810 20.04 40.8 1.18357 22.77 30.9 1.13400 17.35 35.9 1.15861 20.09 40.9 1.18408 22.82 31.0 1.13449 17.40 36.0 1.15911 20.15 41.0 1.18460 22.87 31.1 1.13497 17.46 36.1 1.15961 20.20 41.1 1.18512 22.93 31.2 1.13545 17.51 36.2 1.16011 20.26 41.2 1.18564 22.98 31.3 1.13594 17.57 36.3 1.16061 20.31 41.3 1.18616 23.04 31.4 1.13642 17.62 36.4 1.16111 20.37 41.4 1.18668 23.09 31.5 1.13691 17.68 36.5 1.16162 20.42 41.5 1.18720 23.15 31.6 1.13740 17.73 36.6 1.16212 20.48 41.6 1.18772 23.20 31.7 1.13788 17.79 36.7 1.16262 20.53 41.7 1.18824 23.25 31.8 1.13837 17.84 36.8 1.16313 20.59 41.8 1.18887 23.31 31.9 1.13885 17.90 36.9 1.16363 20.64 41.9 1.18929 23.36 32.0 1.13934 17.95 37.0 1.16413 20.70 42.0 1.18981 23.42 32.1 1.13983 18.01 37.1 1.16464 20.75 42.1 1.19033 23.47 32.2 1.14032 18.06 37.2 1.16514 20.80 42.2 1.19086 23.52 32.3 1.14081 18.12 37.3 1.16565 20.86 42.3 1.19138 23.58 32.4 1.14129 18.17 37.4 1.16616 20.91 42.4 1.19190 28.63 32.5 1.14178 18.23 37.5 1.16666 20.97 42.5 1.19243 23.69 32.6 1.14227 18.28 37.6 1.16717 21.02 42.6 1.19295 23.74 32.7 1.14276 18.34 37.7 1.16768 21.08 42.7 1.19348 23.79 32.8 1.14325 18.39 37.8 1.16818 21.13 42.8 1.19400 23.85 32.9 1.14374 18.45 37.9 1.16869 21.19 42.9 1.19453 23.90 33.0 1.14423 18.50 38.0 1.16920 21.24 43.0 1.19505 23.96 33.1 1.14472 18.56 38.1 1.16971 21.30 43.1 1.19558 24.01 33.2 1.14521 18.61 38.2 1.17022 21.35 43.2 1.19611 24.07 33.3 1.14570 18.67 38.3 1.17072 21.40 43.3 1.19663 24.12 33.4 1.14620 18.72 38.4 1.17122 21.46 43.4 1.19716 24.17 33.5 1.14669 18.78 38.5 1.17174 21.51 43.5 1.19769 24.23 33.6 1.14718 18.83 38.6 1.17225 21.57 43.6 1.19822 24.28 33.7 1.14767 18.89 38.7 1.17276 21.62 43.7 1.19875 24.34 33.8 1.14817 18.94 38.8 1.17327 21.68 43.8 1.19927 24.39 33.9 1.14866 19.00 38.9 1.17379 21.73 43.9 1.19980 24.44 34.0 1.14915 19.05 39.0 1.17430 21.79 44.0 1.20033 24.50 34.1 1.14965 19.11 39.1 1.17481 21.84 44.1 1.20086 24.55 34.2 1.15014 19.16 39.2 1.17532 21.90 44.2 1.20139 24.61 34.3 1.15064 19.22 39.3 1.17583 21.95 , 44.3 1.20192 24.66 34.4 1.15113 19.27 39.4 1.17635 22.00 44.4 1.20245 24.71 34.5 1.15163 19.33 39.5 1.17686 22.06 44.5 1.20299 24.77 34.6 1.15213 19.38 39.6 1.17737 22.11 44.6 1.20352 24.82 34.7 1.15262 19.44 39.7 1.17789 22.17 44.7 1.20405 24.88 34.8 1.15312 19.49 39.8 1.17840 22.22 44.8 1.20458 24.93 34.9 1.15362 19.55 39.9 1.17892 22.28 44.9 1.20512 24.98 i APPENDIX. 573 Comparison between Specific Gravity Figures, Degree Baume and Degree Brix. Continued. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. XU 3 ft* Percentage of sugar ac- cording to Balling or degree Brix Specific gravity. oJ t i y |B 60.0 1.28989 32.99 65.0 1.31989 35.57 700 1.35088 38.12 60.1 1.29048 33.04 65.1 1.32050 35.63 70.1 1.35155 38.18 60.2 1.29107 33.09 65.2 1.32111 35.68 70.2 1.35214 38.23 60.3 1.29166 33.14 65.3 1.32172 35.73 70.3 1.35277 38.28 60.4 1.29225 33.20 65.4 1.32233 35.78 70.4 1.35340 38.33 60.5 1.29284 33.25 65.5 1.32294 35.83 70.5 1.35403 38.38 60.6 1.29343 33.30 65.6 1.32355 35.88 70.6 1.35406 38.43 60.7 1.29403 33.35 65.7 1.32417 35.93 70.7 1.35530 38.48 60.8 1.29462 33.40 65.8 1.32478 35.98 70.8 1.35593 38.53 60.9 1.29521 33.46 65.9 1.32539 36.04 70.9 1.35050 38.58 61.0 1.29581 33.51 66.0 1.32001 30.09 71.0 1.35720 38.63 61.1 1.29646 33.56 66.1 1.32662 36.14 71.1 1.35783 38.68 61.2 1.29700 33.61 66.2 1.32724 36.19 71.2 1.35847 38.73 61.3 1.29759 33.66 66.3 1.32785 36.24 71.3 1.35910 38.78 61.4 1.29819 33.71 66.4 1.32847 30.29 71.4 1.35974 38.83 61.5 1.29878 33.77 66.5 1.32908 30.34 71.5 1.30037 38.88 61.6 1.29938 33.82 66.6 1.32970 36.39 71.6 1.30101 38.93 61.7 1.29998 33.87 66.7 1.33031 36.45 71.7 1.36164 38.98 61.8 1.30057 33.92 66.8 1.33093 36.50 71.8 1.36228 39.03 61.9 1.30117 33.97 66.9 1.3315-3 30.55 71.9 1.36292 39.08 62.0 1.30177 34.03 67.0 1.33217 36.60 72.0 1.36355 39.13 62.1 1.30237 34.08 67.1 1.33278 36.65 72.1 1.36419 39.19 62.2 1.30297 34.13 67.2 1.33340 36.70 72.2 1.36483 39.24 62.3 1.30356 34.18 67.3 1.33402 36.75 72.3 1.36547 39.29 62.4 1.30416 34.23 67.4 1.33464 30.80 72.4 1.36611 39.34 62.5 1.30476 34.28 67.5 1.33526 36.85 72.5 1.36675 39.39 62.6 1.30536 34.34 67.6 1.33588 36.90 726 1.36739 39.44 62.7 1.30596 34.39 67.7 1.33650 36.96 72.7 1.36803 39.49 62.8 1.30657 34.44 67.8 1.33712 37.01 72.8 1.36867 39.54 62.9 1.30717 34.49 67.9 1.33774 37.06 72.9 1.36931 39.59 63.0 1.30777 34.54 68.0 1.33836 37.11 73.0 1.36995 39.64 63.1 1.30837 34.59 68.1 1.33899 37.16 73.1 1.37059 39.09 63.2 1.30897 34.65 68.2 1.33961 37.21 73.2 1.37124 39.74 63.3 1.30958 34.70 68.3 1.34023 37.26 73.3 1.37188 39.79 63.4 1.31018 34.75 68.4 1.34085 37.31 73.4 1.37252 39.84 63.5 1.31078 34.80 68.5 1.34148 37.36 73.5 1.37317 39.89 63.6 1.31139 34.85 68.6 1.34210 37.41 73.6 1.37381 39.94 63.7 1.31199 34.90 68.7 1.34273 37.47 73.7 1.37446 39.99 63.8 1.31260 34.96 68.8 1.34335 37.52 73.8 1.37510 40.04 63.9 1.31320 35.01 68.9 1.34398 37.57 73.9 1.37575 40.09 64.0 1.31381 35.06 69.0 1.34460 37.62 74.0 1.37039 40.14 64.1 1.31442 35.11 69.1 1.34523 37.67 74.1 1.37704 40.19 64.2 1.31502 35.16 69.2 1.34525 37.72 74.2 1.37768 40.24 64.3 1.31563 35.21 69.3 1.34648 37.77 > 74.3 1.37833 40.29 64.4 1.31624 35.27 69.4 1.34711 37.82 74.4 1.37898 40.34 64.5 1.31684 35.32 69.5 1.34774 37.87 74.5 1.37962 40.39 64.6 1.31745 35.37 69.6 1.34836 37.92 74.6 1.38027 40.44 64.7 1.31806 35.42 69.7 1.34899 37.97 74.7 1.38092 40.49 64.8 1.31867 35.47 69.8 1.34962 38.02 74.8 1.38157 40.54 64.9 1.31928 35.52 69.9 1.35025 38.07 74.9 1.38222 40.59 APPENDIX. 575 Comparison between Specific Gravity Figures, Degree Bourne and Degree Brix. Continued. Percentage -5 Percentage o Percentage 4> of sugar ac- cording to Balling or Specific gravity. i -.aJ w of sugar ac- cording to Balling or Specific gravity. a>S - S 3 4 of sugar ac- cording to Balling or Specific gravity. *s o 3 m degree Brix. p degree Brix. o degree Brix o 75.0 1.38287 40.64 80.0 1.41586 43.11 85.0 1.44986 45.54 75.1 1.38352 40.69 80.1 1.41653 43.61 85.1 1.45055 45.59 75.2 1.38417 40.74 80.2 1.41720 43.21 85.2 1.45124 45.64 75.3 1.38482 40.79 80.3 1.41787 43.26 85.3 1.45193 45.69 75.4 1.38547 40.84 80.4 1.41854 43.31 85.4 1.45262 45.74 75.5 1.38612 40.89 80.5 1.41921 43.36 85.5 1.45331 45.78 75.6 1.38677 40.94 80.6 1.41989 43.41 85.6 1.45401 45.83 75.7 1.38743 40.99 80.7 1.42056 43.45 85.7 1.45470 45.88 75.8 1.38808 41.04 80.8 1.42123 43.50 85.8 1. 45539 45.93 75.9 1.38873 41.09 80.9 1.42190 43.55 85.9 1.45609 45.98 76.0 1.38939 41.14 81.0 1.42258 43.60 86.0 1.45678 46. 0'-' 76.1 1.39004 41.19 81.1 1.42325 43.65 86.1 1.45748 46.07 76.2 1.39070 41.24 81.2 1.42393 43.70 86.2 1.45817 46.12 76.3 1.39135 41.29 81.3 1.42460 43.75 86.3 1.45887 46.17 76.4 1.39201 41.33 81.4 1.42528 43.80 86.4 1.45956 46.22 76.5 1.39266 41.38 81.5 1.42595 43.85 86.5 1.46026 46.26 76.6 1.39332 41.43 81.6 1.42663 43.89 86.6 1.46095 46.31 76.7 1.39397 41.48 81.7 1.42731 43.94 86.7 1.46165 46.36 76.8 1.39463 41.53 81.8 1.42798 43.99 86.8 1.46235 46.41 76.9 1.39529 41.58 81.9 1.42866 44.04 86.9 1.46304 46.46 77.0 1.39595 41.63 82.0 1.42934 44.09 87.0 L 46374 46.50 77.1 1.39660 41.68 82.1 1.43002 44.14 87.1 1.46444 46.55 77.2 1.39726 41.73 82.2 1.43070 44.19 87.2 1.46514 46.60 77.3 1.39792 41.78 82.3 1.43137 44.24 87.3 1.46584 46.65 77.4 1.39858 41.83 82.4 1.43205 44.28 87.4 1.46654 46.69 77.5 1.39924 41.88 82.5 1.43273 44.33 87.5 1.46724 46.74 77.6 1.39990 41.93 82.6 1.43341 44.38 87.6 1.46794 46.79 77.7 1.40056 41.98 82.7 1.43409 44.43 87.7 1.46864 46.84 77.8 1.40122 42.03 82.8 1.43478 44.48 87.8 1.46934 46.88 77.9 1.40188 42.08 82.9 1.43546 44.53 87.9 1.47004 46.93 78.0 1.40254 42.13 83.0 1.43614 44.58 88.0 1.47074 46.98 78.1 1.40321 42.18 83.1 1.43682 44.62 88.1 1.47145 47.03 78.2 1.40387 42.23 83.2 1.43750 44.67 88.2 1.47215 47.08 78.3 1.40453 42.28 83.3 1.43819 44.72 88.3 1.47285 47.12 78.4 1.40520 42.32 83.4 1.43887 44.77 88.4 1.47356 47.17 78.5 1.40586 42.37 83.5 1.43955 44.82 88.5 1.47426 47.22 78.6 1.40652 42.42 83.6 1.44024 44.87 88.6 1.47496 47.27 78.7 1.40719 42.47 83.7 1.44092 44.91 88.7 1.47567 47.31 78.8 1.40785 42.52 83.8 1.44161 44.96 88.8 1.47637 47.36 78.9 1.40852 42.57 83.9 1.44229 45.01 88.9 1.47708 47.41 79.0 1.40918 42.62 84.0 1.44298 45.06 89.0 1.47778 47.46 79.1 1.40985 42.67 84.1 1.44367 45.11 89.1 1.47849 47.50 79.2 1.41052 42.72 84.2 1.44435 ! 45.16 89.2 1.47920 47.55 79.3 1.41118 42.77 84.3 1.44504 45.21 89.3 1.47991 47.60 79.4 1.41185 42.82 84.4 1.44573 45.25 89.4 1.48061 47.65 79.5 1.41252 42.87 84.5 1.44fi41 45.30 89.5 1.48132 47.69 79.6 1.41318 42.92 84.6 1.44710 45.35 89.6 1.48203 47.74 79.7 1.41385 42.96 84.7 1.44779 45.40 89.7 1.48274 47.79 79.8 1.41452 43.01 84.8 1.44848 45.45 89.8 1.48345 47.83 79.9 1.41519 43.06 84.9 1.44917 45.49 89.9 1.48416 47.88 576 APPENDIX. Comparison between Specific Gravity Figures, Degree Baume and Degree Brix. Continued. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. M> .1 || Q Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Baume. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Baume'. 90.0 1.48486 47.93 94.0 1.51359 49.81 98.0 1.54290 51.65 90.1 1.48558 47.98 94.1 1.51431 49.85 98.1 1.54365 51.70 90.2 1.48629 48.02 94.2 1.51504 49.90 98.2 1.54440 51.74 90.3 1.48700 48.07 94.3 1.51577 49.94 98.3 1.54515 51.79 90.4 1.48771 48.12 94.4 1.51649 49.99 98.4 1.54590 51.83 90.5 1.48842 48.17 94.5 1.51722 50.04 98.5 1.54665 51.88 90.6 1.48913 48.21 94.6 1.51795 50.08 98.6 1.54740 51.92 90.7 1.48985 48.26 94.7 1.51868 50.13 98.7 1.54815 51.97 90.8 1.49056 48.31 94.8 1.51941 50.18 98.8 1.54890 52.01 90.9 1.49127 48.35 94.9 1.52014 50.22 98.9 1.54965 52.06 91.0 1.49199 48.40 95.0 1.52087 50.27 99.0 1.55040 52.11 91.1 1.49270 48.45 95.1 1.52159 50.32 99.1 1.55115 52.15 91.2 1.49342 48.60 95.2 1.52232 50.36 99.2 1.55189 62.20 91.3 1.49413 48.54 95.3 1.52304 50.41 99.3 1.55264 52.24 91.4 1.49485 48.59 95.4 1.52376 50.45 99.4 1.55338 52.29 91.5 1.49556 48.64 95.5 1.52449 50.50 99.5 1.55413 52.33 91.6 1.49628 48.68 95.6 1.52521 50.55 99.6 1.55487 52.38 91.7 1.49700 48.73 95.7 1.52593 50.59 99.7 1.55562 52.42 91.8 1.49771 48.78 95.8 1.52665 60.64 99.8 1.55636 52.47 91.9 1.49843 48.82 95.9 1.52738 50.69 99.9 1.55711 52.51 92.0 1.49915 48.87 96.0 1.52810 50.73 100.0 1.55785 52.56 92.1 1.49987 48.92 96.1 1.52884 50.78 92.2 1.50058 48.96 96.2 1.52958 50.82 92.3 1.50130 49.01 96.3 1.53032 50.87 92.4 1.50202 49.06 96.4 1.53106 50.92 92.5 1.50274 49.11 96.5 1.53180 50.96 92.6 1.50346 49.15 96.6 1.53254 51.01 92.7 1.50419 49.20 96.7 1.53328 51.05 92.8 1.50491 49.25 96.8 1.53402 51.10 92.9 1.50563 49.29 96.9 1.53476 51.15 93.0 1.50633 49.34 97.0 1.53550 51.19 93.1 1.50707 49.39 97.1 1.53624 61.24 93.2 1.50779 49.43 97.2 1.53698 51.28 93.3 1.50852 49.48 97.3 1.53772 51.33 93.4 1.50924 49.53 97.4 1.53846 51.38 93.5 1.50996 49.57 97.5 1.53920 51.42 93.6 1.51069 49.62 97.6 1.53994 51.47 93.7 1.51141 49.67 97.7 1.54068 51.51 93.8 1.51214 49.71 97.8 1.54142 51.56 93.9 1.51286 49.76 97.9 1.54216 51.60 APPENDIX. 577 6. Table of Weight and Volume Relations. Degrees Baume. Specific gravity 25 C. Specific volume (volume of 1 kilogram in liters).* Weight of 1 U. S. gallon in pounds avoirdupois.f Volume in U. S. gallons of 100 Ibs. avoirdupois.! Weight of 1 fluidounce in grains. 25 C. 70 0.700 1.4286 5.819 17.185 318.2 67 0.710 1.4085 5.902 16.943 322.8 64.5 0.720 1.3889 5.985 16.707 327.3 61.8 0.730 1.3699 6.068 16.479 331.9 59 0.740 1.3514 6.151 16.256 336.4 56.5 0.750 1.3333 6.235 16.039 341 54 0.760 1.3158 6.318 15.828 345.5 51.8 0.770 1.25)87 6.401 15.623 350 49.5- 0.780 1.2821 6.484 15.422 354.6 47 0.790 1.2658 6.567 15.227 359.1 45 0.800 1.2500 6.650 15.037 363.7 43 0.810 1.2346 6.733 14.851 368.2 41 0.820 1.2195 6.817 14.670 372.8 38.8 0.830 1.2049 6.900 14.494 377.3 36.8 0.840 1.1905 6.983 14.321 381.9 318 0.850 1.1765 7.066 14.152 386.4 33 0.860 1.1628 7.149 13.988 391 31 0.870 1.1494 7.232 13.827 395.5 29 0.880 1.1364 7.315 13.670 400.1 27.7 0.890 1.1236 7.398 13.516 404.6 25.5 0.900 1.1111 7.481 13.366 409.1 24 0.910 1.0989 7.565 13.219 413.7 22 0.920 1.0870 7.648 13.075 418.2 20.5 0.930 1.0753 7.731 12.935 422.8 19 0.940 1.0638 7.814 12.797 427.3 17.5 0.950 1.0526 7.897 12.663 431.9 15.5 0.960 1.0417 7.980 12.531 436.4 14.2 0.970 1.0309 8.063 12.401 441 13 0.980 1.0204 8.147 12.275 445.5 11.5 0.990 1.0101 8.230 12.151 450.1 10 1.000 1.0000 8.313 12.029 454.6 3 1.020 0.9804 8.479 11.794 463.7 5.7 1.040 0.9615 8.645 11.567 472.8 8.6 1.060 0.9434 8.812 11.348 481.9 10.5 1.080 0.9259 8.978 11.138 491 13 1.100 0.9091 9.144 10.936 500.1 16 1.120 0.8929 9.310 10.741 . 509.2 17.6 1.140 0.8772 9.477 10.552 518.3 20 1.160 0.8621 9.643 10.370 527.4 22 1.180 0.8475 9.809 10.194 536.4 24 1.200 0.8333 9.975 10.025 545.5 26.5 1.220 0.8197 10.142 9.860 554.6 28 1.240 0.8065 10.308 9.701 563.7 29.8 1.260 0.7937 10.474 9.547 572.8 31.6 1.280 0.7813 10.640 9.398 581.9 34 1.300 0.7692 10.807 9.253 591.0 35.2 1.320 0.7576 10.973 9.113 600.1 36.8 1.340 0.7463 11.139 8.977 609.2 38 1.360 0.7353 11.305 8.845 618.3 39.6 1.380 0.7246 11.472 8.717 627.4 41 1.400 0.7143 11.638 8.592 636.4 43 1.420 0.7042 11.804 8.471 645.5 44 1.440 0.6944 11.970 8.354 654.6 45.5 1.460 0.6849 12.137 8.239 663.7 47 1.480 0.6757 12.303 8.128 672.8 48 1.500 0.6667 12.469 8.020 681.9 49.5 1.520 0.6579 12.635 7.914 691.0 51 1.540 0.6494 12.802 7.811 700.1 37 578 APPENDIX. Table of Weight and Volume Relations. Continued. Degrees Baume. Specific gravity 25 C. Specific volume (volume of 1 kilogram in liters).* Weight of 1 U. S. gallon in pounds avoirdupois, t Volume in U. S. gallons of 100 Ibs. avoirdupois. J Weight of 1 fluidounce in grains. 25 C. 52 1.560 0.6410 12.968 7.711 709.2 53.4 1.580 0.6329 13.134 7.614 718.3 54.4 1.600 0.6250 13.300 7.519 727.4 55.4 1.620 0.6173 13.467 7.426 736.5 56.6 1.640 0.6098 13.633 7.335 745.6 58 1.660 0.6025 13.799 7.247 754.6 59 1.680 0.5952 13.966 7.160 763.7 60 1.700 0.5882 14.132 7.076 772.8 61 1.720 0.5814 14.298 6.994 781.9 61.7 1.740 0.5747 14.464 6.913 791.0 62.8 1.760 0.5682 14.631 6.835 800.1 63.5 1.780 0.5618 14.797 6.758 809.2 64.2 1.800 0.5556 14.963 6.683 818.3 65.1 1.820 0.5495 15.129 6.610 827.4 66 1.840 0.5435 15.296 6.538 836.5 67.6 1.860 0.5376 15.462 6.467 845.6 68.7 1.880 0.5319 15.628 6.399 854.7 69.5 1.900 0.5263 15.794 6.331 863.8 70.5 1.920 0.5208 15.961 6.265 872.8 71.2 1.940 0.5155 16.127 6.201 881.9 72 1.960 0.5102 16.293 6.137 891.0 73 1.980 0.5051 16.459 6.075 900.1 74 2.000 0.5000 16.626 6.015 909.2 * Or of 1 gram in cubic centimeters ; strictly true only at C. in vacuo. t Multiply these figures by 2 for weight of one U. S. pint in ounces avoirdupois. J Divide these^figures by 2 for volume in pints of 100 ounces avoirdupois. APPENDIX. 573 IV. Alcohol Tables. Percentage of Alcohol by Weight and by Volume from the Specific Gravity (at 15.5 C.), by Otto Hehner. Specific gravity a 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol b volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol b weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol b weight. Percent- age of absolute alcohol by volume. 1.0000 0.00 0.00 0.9999 0.05 0.07 0.9949 2.89 3.62 0.9899 5.94 7.40 8 0.11 0.13 8 2.94 3.69 8 6.00 7.48 7 0.16 0.20 7 3.00 3.76 7 6.07 7.57 6 0.21 0.26 6 3.06 3.83 6 6.14 7.66 5 0.26 0.33 5 3.12 3.90 5 6.21 7.74 4 0.32 0.40 4 3.18 3.98 4 6.28 7.83 3 0.37 0.46 3 3.24 4.05 3 6.36 7.92 2 0.42 0.53 2 3.29 4.12 2 6.43 8.01 1 0.47 0.60 1 3.35 4.20 1 6.50 8.10 0.53 0.66 3.41 4.27 6.57 8.18 0.9989 0.58 0.73 0.9939 3.47 4.34 0.9889 6.64 8.27 8 0.63 0.79 8 3.53 4.42 8 6.71 8.36 7 0.68 0.86 7 3.59 4.49 7 6.78 8.45 6 0.74 0.93 6 3.65 4.56 6 6.86 8.54 6 0.79 0.99 5 3.71 4.63 5 6.93 8.63 4 0.84 1.06 4 3.76 4.71 4 7.00 8.72 3 0.89 1.13 8 3.82 4.78 3 7.07 8.80 2 0.95 1.19 2 3.88 4.85 2 7.13 8.88 1 1.00 1.26 1 3.94 4.93 1 7.20 8.96 1.06 1.34 4.00 5.00 7.27 9.04 0.9979 1.12 1.42 0.9929 4.06 5.08 0.9879 7.33 9.13 8 1.19 1.49 8 4.12 5.16 8 7.40 9.21 7 1.25 1.57 7 4.19 5.24 7 7.47 9.29 6 1.31 1.65 6 4.25 5.32 6 7.63 9.37 5 1.37 1.73 6 4.31 5.39 6 7.60 9.46 4 1.44 1.81 4 4.37 6.47 4 7.67 9.54 3 1.50 1.88 3 4.44 5.55 3 7.73 9.62 2 1.56 1.96 2 4.50 6.63 2 7.80 9.70 1 1.62 2.04 1 4.56 5.71 1 7.87 9.78 1.69 2.12 4.62 5.78 7.93 9.86 0.9969 1.75 2.20 0.9919 4.69 5.86 0.9869 8.00 9.95 8 1.81 2.27 8 4.75 5.94 8 8.07 10.03 7 1.87 2.35 7 4.81 6.02 7 8.14 10.12 6 1.94 2.43 6 4.87 6.10 6 8.21 10.21 5 2.00 2.51 5 4.94 6.17 5 8.29 10.30 4 2.06 2.58 4 5.00 6.24 4 8.36 10.38 3 2.11 2.62 3 5.06 6.32 3 8.43 10.47 2 2.17 2.72 2 5.12 6.40 2 8.50 10.56 1 2.22 2.79 1 5.19 6.48 1 8.57 10.65 2.28 2.86 5.25 6.55 8.64 10.73 0.9959 2.33 2.93 0.9909 5.31 6.63 0.9859 8.71 10.82 8 2.39 3.00 8 5.37 6.71 8 8.79 10.91 7 2.44 3.07 7 5.44 6.78 7 8.86 11.00 6 2.50 3.14 6 5.50 6.86 6 8.93 11.08 5 2.56 3.21 5 5.56 6.94 5 9.00 11.17 4 2.61 3.28 4 5.62 7.01 4 9.07 11.26 3 2.67 3.35 3 5.69 7.09 3 9.14 11.35 2 2.72 3.42 2 5.75 7.17 2 9.21 11.44 1 2.78 3.49 1 5.81 7.25 1 9.29 11.52 2.83 3.65 5.87 7.32 9.36 11.61 580 APPENDIX. Percentage of Alcohol by Weight and by Volume from the Specific Gravity (at 15.5 C.), by Otto Hehner. Continued. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. 0.9849 9.43 11.70 0.9799 13.23 16.33 0.9749 17.33 21.29 8 9.50 11.79 8 13.31 16.43 8 17.42 21.39 7 9.57 11.87 7 13.38 16.52 7 17.50 21.49 6 9.64 11.96 6 13.46 16.61 6 17.58 21.59 5 9.71 12.05 5 13.54 16.70 5 17.67 21.69 4 9.79 12.13 4 13.62 16.80 4 17.75 21.79 3 9.86 12.22 3 13:69 16.89 3 17.83 21.89 2 9.93 12.31 2 13.77 16.98 2 17.92 21.99 1 10.00 12.40 1 13.85 17.08 1 18.00 22.09 10.08 12.49 13.92 17.17 18.08 22.18 0.9839 10.15 12.58 0.9789 14.00 17.26 0.9739 18.15 22.27 8 10.23 12.68 8 14.09 17.37 8 18.23 22.36 7 10.31 12.77 7 14.18 17.48 7 18.31 22.46 6 10.38 12.87 6 14.27 17.59 6 18.38 22.o6 5 10.46 12.96 5 14.36 17.70 5 18.46 22.64 4 10.54 13.05 4 14.45 17.81 4 18.54 22.73 3 10.62 13.15 3 14.55 17.92 3 18.62 22.82 2 10.69 13.24 2 14.64 18.03 2 18.69 22.92 1 10.77 13.34 1 14.73 18.14 1 18.77 23.01 10.85 13.43 14.82 18.25 18.85 23.10 0.9829 10.92 13.52 0.9779 14.90 18.36 0.9729 18.92 23.19 8 11.00 13.62 8 15.00 18.48 8 19.00 23.28 7 11.08 13.71 7 15.08 18.58 7 19.08 23.38 6 11.15 13.81 6 15.17 18.68 6 19.17 23.48 5 11.23 13.90 5 15.25 18.78 5 19.25 23.^8 4 11.31 13.99 4 15.33 18.88 4 19.33 23.68 3 11.38 14.09 3 15.42 18.98 3 19.42 23.78 2 11.46 14.18 2 15.50 19.08 2 19.50 23.88 1 11.54 14.27 1 15.58 19.18 1 19.58 23.98 11.62 14.37 15.67 19.28 19.67 24.08 0.9819 11.69 14.46 0.9769 15.75 19.39 0.9719 19.75 24.18 8 11.77 14.56 8 15.83 19.49 8 19.83 24.28 7 11.85 14.65 7 15.92 19.59 7 19.92 24.38 6 11.92 14.74 6 16.00 19.68 6 20.00 24.48 5 12.00 14.84 5 16.08 19.78 5 20.08 24.58 4 12.08 14.93 4 16.15 19.87 4 20.17 24.68 3 12.15 15.02 3 16.23 19.96 3 20.25 24.78 2 12.23 15.12 2 16.31 20.06 2 20.33 24.88 1 12.31 15.21 1 16.38 20.15 1 20.42 24.98 12.38 15.30 16.46 20.24 20.50 25.07 0.9809 12.46 15.40 0.9759 16.54 20.33 0.9709 20.58 25.17 8 12.54 15.49 8 16.62 20.43 8 20.67 25.27 7 12.62 15.58 7 16.69 20.52 7 20.75 25.37 6 12.69 15.68 6 16.77 20.61 6 20.83 25.47 6 12.77 15.77 5 16.85 20.71 5 20.92 25.57 4 12.85 15.86 4 16.92 20.80 4 21.00 25.67 3 12.92 15.96 3 17.00 20.89 3 21.08 25.76 2 13.00 16.05 2 17.08 i'0.99 2 21.15 25.86 1 13.08 16.15 1 17.17 21.09 1 21.23 25.95 13.15 16.24 17-25 21.19 21.31 26.04 - APPENDIX. 581 Percentage of Alcohol by Weight and by Volume from the Specific Gravity (at 15.5 C.\ by Otto Hehner. Continued. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. 0.9699 21.38 26.13 0.9649 25.21 30.65 0.9599 28.62 34.61 8 21.46 26.22 8 25.29 30.73 8 28.69 34.69 7 21.54 26.31 7 25.36 30.82 7 28.75 34.76 6 21.62 26.40 6 25.43 30.90 6 28.81 34.83 5 21.69 26.49 5 26.50 30.98 5 28.87 34. 9U 4 21.77 26.58 4 25.57 31.07 4 28.94 34.97 3 21.85 26.67 3 25.64 31.15 3 29.00 35.05 2 21.92 26.77 2 25.71 31.23 2 29.07 35.12 1 22.00 26.86 1 25.79 31.32 1 29.13 35.20 22.08 26.95 25.86 31.40 29.20 35.28 0.9689 22.15 27.04 0.9639 25.93 31.48 0.9589 29.27 35.35 8 22.23 27.13 8 26.00 31.57 8 29.33 35.43 7 22.31 27.22 7 26.07 31.65 7 29.40 35.51 6 22.38 27.31 6 26.13 31.72 6 29.47 35.58 5 22.46 27.40 6 26.20 31.80 5 29.53 35.66 4 22.54 27.49 4 26.27 31.88 4 29.60 35.74 3 22.62 27.59 3 26.33 31.96 3 29.67 35.81 2 22.69 27.68 2 26.40 32.03 2 29.73 35.89 1 22.77 27.77 1 26.47 32.11 1 29.80 35.97 22.85 27.86 26.53 32.19 29.87 36.04 0.9679 22.92 27.95 0.9629 26.60 32.27 0.9579 29.93 36.12 8 23.00 28.04 8 26.67 32.34 8 30.00 30.20 7 23.08 28.13 7 26.73 32.42 7 30.06 36.26 6 '/3.15 28.22 6 26.80 32.50 6 30.11 36.32 6 23.23 28.31 5 26.87 32.58 5 30.17 36.39 4 23.31 28.41 4 26.93 32.65 4 30.22 36.45 3 23.38 28.50 3 27.00 32.73 3 30.28 36.51 2 23.46 28.59 2 27.07 32.81 2 30.33 36.57 1 23.54 28.68 1 27.14 32.90 1 30.39 36.64 23.62 28.77 27.21 32.98 30.44 36.70 0.9669 23.69 28.86 0.9619 27.29 33.06 0.9569 30.50 36.76 8 23.77 28.95 8 27.36 33.15 8 30.56 36.83 7 23.85 29.04 7 27.43 33.23 7 30.61 36.89 6 23.92 29.13 6 27.50 33.31 6 30.67 36.95 6 24.00 29.22 6 27.57 33.39 5 30.72 37.02 4 24.08 29.31 4 27.64 33.48 4 30.78 37.08 3 24.15 29.40 3 27.71 33.56 3 30.83 37.14 2 24.23 29.49 2 27.79 33.64 2 30.89 37.20 1 24.31 29.58 1 27.86 33.73 1 30.94 37.27 24.38 29.67 27.93 33.81 31.00 37.34 0.9659 24.46 29.76 0.9609 28.00 33.89 0.9559 31.06 37.41 8 24.54 29.86 8 28.06 33.97 8 31.12 37.48 7 24.62 29.95 7 28.12 34.04 7 31.19 37.55 6 24.69 30.04 6 28.19 34.11 6 31.25 37.62 6 24.77 30.13 5 28.25 34.18 5 31.31 37.69 4 24.85 30.22 4 28.31 34.25 4 31.37 37.76 3 24.92 30.31 3 28.37 34.33 3 31.44 37.83 2 25.00 30.40 2 28.44 34.40 2 31.50 37.90 1 25.07 30.48 1 28.50 34.47 1 31.56 37.97 25.14 30.57 28.56 34.54 31.62 38.04 582 APPENDIX. Percentage of Alcohol by Weight and by Volume from the Specific Gravity (at 15.5 C.), by Otto Hehner. Continued. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. 0.9549 31.G9 3S.11 0.9499 34.57 41.37 0.9449 37.17 44.24 8 31.75 38.18 8 34.62 41.42 8 37.22 44.30 7 31.81 38.25 7 34.67 41.48 7 37.28 44.36 6 31.87 38.33 6 34.71 41.53 6 37.33 44.43 5 31.94 38.40 5 34.76 41.58 5 37.39 44.49 4 32.00 38.47 4 34.81 41.63 4 37.44 44.55 3 32.06 38.53 3 34.86 41.69 3 37.50 44.61 2 32.12 38.60 2 34.90 41.74 2 37.56 44.67 1 32.19 38.68 1 34.95 41.79 1 37.61 44.73 32.25 38.75 35.00 41.84 37.67 44.79 0.9539 32.31 38.82 0.9489 35.05 41.90 0.9439 37.72 44.86 8 32.37 38.89 8 35.10 41.95 8 37.78 44.92 7 32.44 38.96 7 35.15 42.01 7 37.83 44.98 6 32.50 39.04 6 35.20 42.06 6 37.89 45.04 5 32.56 39.11 5 35.25 42.12 5 37.94 45.10 4 32.62 39.18 4 35.30 42.17 4 38.00 45.16 3 32.69 39.25 3 35.35 42.23 3 38.06 45.22 2 32.75 39.32 2 35.40 42.29 2 38.11 45.28 1 32.81 39.40 1 35.45 42.34 1 38.17 45.34 32.87 39.47 35.50 42.40 38.22 45.41 0.9529 32.94 39.54 0.9479 35.55 42.45 0.9429 38.28 45.47 8 33.00 39.61 8 35.60 42.51 8 38.33 45.53 7 33.06 39.68 7 35.65 42.56 7 38.39 45.59 6 33.12 39.74 6 35.70 42.62 6 38.44 45.65 5 33.18 39.81 5 35.75 42.67 6 38.50 45.71 4 33.24 39.87 4 35.80 42.73 4 38.56 45.77 3 33.29 39.94 3 35.85 42.78 3 38.61 45.83 2 33.35 40.01 2 35.90 42.84 2 38.67 45.89 1 33.41 40.07 1 35.95 42.89 1 38.72 45.95 33.47 40.14 36.00 42.95 38.78 46.02 0.9519 33.53 40.20 0.9469 36.06 43.01 0.9419 38.83 46.08 8 33.59 40.27 8 36.11 43.07 8 38.89 46.14 7 33.65 40.34 7 36.17 43.13 7 38.94 46.20 6 33.71 40.40 6 36.22 43.19 6 39.00 46.26 5 33.76 40.47 5 36.28 43.26 5 39.05 46.32 4 33.82 40.53 4 36.33 43.32 4 39.10 46.37 3 33.88 40.60 3 36.39 43.38 3 39.15 46.42 2 33.94 40.67 2 36.44 43.44 2 39.20 46.48 1 34.00 40.74 1 36.50 43.50 1 39.25 46.53 34.05 40.79 36.56 43.56 39.30 46.59 0.9509 34.10 40.84 0.9459 36.61 43.63 0.9409 39.35 46.64 8 34.14 40.90 8 36.67 43.69 8 39.40 46.70 7 34.19 40.95 7 36.72 43.75 7 39.45 46.75 6 34.24 41.00 6 36.78 43.81 6 39.50 46.80 5 34.29 41.05 5 36.83 43.87 5 39.55 46.86 4 34.33 41.11 4 36.89 43.93 4 39.60 46.91 3 34.38 41.16 3 36.94 44.00 3 39.65 46.97 2 34.43 41.21 2 37.00 44.06 2 39.70 47.02 1 34.48 41.26 1 37.06 44.12 1 39.75 47.08 34.52 41.32 37.11 44.18 39.80 47.13 APPENDIX. 583 Percentage of Alcohol by Weight and by Volume from the Specific Gravity (at 15.5 C.}, by Otto Hehner. Continued. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. 0.9399 39.85 47.18 0.9349 42.33 49.86 0.9299 44.68 52.34 8 39.90 47.24 8 42.38 49.91 . 8 44.73 52.39 7 3995 47.29 7 42.43 49.96 7 44.77 52.44 6 40.00 47.35 6 42.48 50.01 6 44.82 52.48 5 40.05 47.40 5 42.52 50.06 5 44.86 52.53 4 40.10 47.45 4 42.57 50.11 4 44.91 52.58 3 40.15 47.51 3 42.62 50.16 3 44.96 52.63 2 40.20 47.56 2 42.67 50.21 2 45.00 52.68 1 40.25 47.62 1 42.71 50.26 1 45.05 52.72 40.30 47.67 42.76 50.31 45.09 52.77 0.9389 40.35 47.72 0.9339 42.81 50.37 0.9280 45.55 53.24 8 40.40 47.78 8 42.86 50.42 70 46.00 53.72 7 40.45 47.83 7 42.90 50.47 60 46.46 54.19 6 40.50 47.89 6 42.95 50.52 50 46.91 54.66 5 40.55 47.94 5 43.00 50.57 40 47.36 55.13 4 40.60 47.99 4 43.05 50.62 30 47.82 55.60 3 40.65 48.05 3 43.10 50.67 20 48.27 56.07 2 40.70 48.10 2 43.14 50.72 10 48.73 56.54 1 40.75 48.16 1 43.19 50.77 00 49.16 56.98 40.80 48.21 43.24 50.82 0.9379 40.85 48.26 0.9329 43.29 50.87 0.9190 49.64 57.45 8 40.90 48.32 8 43.33 50.92 80 50.09 57.92 7 40.95 48.37 7 43.39 50.97 70 60.52 58.36 6 41.00 48.43 6 43.43 51.02 60 50.96 58.80 6 41.05 48.48 6 43.48 51.07 60 51 -38 59.22 4 41.10 48.54 4 43.52 51.12 40 51.79 59.63 3 41.15 48.59 3 43.57 51.17 30 52.23 60.07 2 41.20 48.64 2 43.62 51.22 20 52.58 60.52 1 41.25 48.70 1 43.67 51.27 10 53.13 60.97 41.30 48.75 43.71 51.32 00 53.57 61.40 0.9369 41.35 48.80 0.9319 43.76 51.38 0.9090 54.00 61.84 8 41.40 48.86 8 43.81 51.43 80 54.48 62.31 7 41.45 48.91 7 43.86 51.48 70 54.96 62.79 6 41.50 48.97 6 43.90 51.53 60 55.41 63.24 5 41.55 49.02 5 43.95 51.58 60 55.86 63.69 4 41.60 49.07 4 44.00 51.63 40 56.32 64.14 3 41.65 49.13 3 44.05 51.68 30 56.77 64.58 2 41.70 49.18 2 44.09 51.72 20 57.21 65.01 1 41.75 49.23 1 44.14 51.77 10 57.63 65.41 41.80 49.29 44.18 61.82 00 58.05 65.81 0.9359 41.85 49.34 0.9309 44.23 51.87 0.8990 58.50 66.25 8 41.90 49.40 8 44.27 51.91 80 58.95 66.69 7 41.95 49.45 7 44.32 51.96 70 59.39 67.11 6 42.00 49.50 6 44.36 52.01 60 59.83 67.53 5 42.05 49.55 5 44.41 52.06 50 60.26 67.93 4 42.10 49.61 4 44.46 52.10 40 60.67 68.33 3 42.14 49.66 3 44.50 52.15 30 61.08 68.72 2 42.19 49.71 2 44.55 52.20 20 61.50 69.11 1 42.24 49.76 1 44.59 52.25 10 61.92 69.50 42.29 49.81 44.64 52.29 00 62.36 69.92 584 APPENDIX. Percentage of Alcohol by Weight and by Volume from the Specific Gravity (at 15.5 C.\ by Otto Hehner. Continued. Specific gravity at 15.5 C. Percent- age of absolute alcr ho: by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. 0.8800 62.82 70.35 40 77.71 83.60 0.8190 91.36 94.26 80 63.26 70.77 30 78.12 83.94 80 91.71 94.51 70 63.70 71.17 20 78.52 84.27 70 92.07 94.76 60 64.13 71.58 10 78.92 84.60 60 92.44 95.03 50 64.57 71.98 00 79.32 84.93 50 92.81 95.29 40 65.00 72.38 40 93.18 95.55 30 65.42 72.77 0.8490 79.72 85.26 30 93.55 95.82 20 65.83 73.15 80 80.13 85.59 20 93.92 96.08 10 66.26 73.54 70 80.54 85.94 10 94.28 96.32 00 66.70 73.93 60 80.96 86.28 00 94.62 96.55 50 81.36 86.61 0.8790 67.13 74.33 40 81.76 86.93 0.8090 94.97 96.78 80 67.54 74.70 30 82.15 87.24 80 95.32 97.02 70 67.96 75.08 20 82.54 87.55 70 95.68 97.27 60 68.38 75.45 10 82.92 87.85 60 96.03 97.51 60 68.79 75.83 00 83.31 88.16 50 96.37 97.73 40 69.21 76.20 40 96.70 97.94 80 69.63 76.57 0.8390 83.69 88.46 30 97.03 98.16 20 70.04 76.94 80 84.08 88.76 20 97.37 98.37 10 70.44 77.29 70 84.48 89.08 10 97.70 98.59 00 70.84 77.64 60 84.88 89.39 00 98.03 98.80 50 85.27 89.70 0.8690 71.25 78.00 40 85.65 89.99 0.7990 98.34 98.98 80 71.67 78.36 30 86.04 90.29 80 98.66 99.16 70 72.09 78.73 20 86.42 90.58 70 98.97 99.35 60 72.52 79.12 10 86.81 90.88 60 99.29 99.55 50 72.96 79.50 00 87.19 91.17 50 99.61 99.75 40 73.38 79.86 40 99.94 99.96 30 73.79 80.22 0.8290 87.58 91.46 20 74.23 80.60 80 87.96 91.75 0.7939 99.97 99.98 10 74.68 81.00 70 88.36 92.05 Absolute Alcohol. 00 75.14 81.40 60 88.76 92.36 0.7938 100.00 100.00 50 89.16 92.66 0.8590 75.59 81.80 40 89.54 92.94 80 76.04 82.19 30 89.92 93.23 70 76.46 82.54 20 90.29 93.49 60 76.88 82.90 10 90.64 93.75 50 77.29 83.25 00 91.00 94.00 APPENDIX. 585 V. Physical and Chemical Constants of Fixed Oils and Pats. (FROM LEWKOWITSCH AND OTHER AUTHORITIES.) Specific gravity at 15C. Specific gravity at 100C. Melting-point. C. Solidifying-point. C. Linseed oil 0.931-0.938 0.880 _16to 26 16 Hemp-seed oil .... 0.925-0.931 27 Walnut oil .... 0.925-0.926 0.871 27 Poppy-seed oil . . 0924-0.927 0873 18 Sunflower oil 924-0 926 0919 17 Fir-seed oil .... 0.925-0.928 27 to 30 Maize oil 0.921-0.926 10 to 15 Cotton-seed oil . . 0.922-0.930 0.867 12 Sesame oil 0.923-0.924 0.871 5 Rape-seed oil .... 0.914-0.91 7 0.863 2 to 10 3 Black mustard oil . 0.916-0.920 17.5 Croton oil . 0.942-0.955 16 Castor oil 960-0 966 0910 12 to 18 Apricot-kernel oil 915-0 919 14 Almond oil 0.915-0.920 10 to 20 Peanut (arachis) oil 0.916-0.920 0.867 30 to _7o Olive oil 0.914-0.917 0.862 2 Menhaden oil . . 927-0 933 4 922-0 927 0874 to 10 Seal oil 0.924-0.929 0.873 3 Whale oil 0.920-0.930 0.872 2 Dolphin oil 0.917-0.918 5 to 3 Porpoise oil . . 0926 0.871 16 Neat's-foot oil .... 0.914-0.916 0.861 to 1.5 Cotton-seed stearine . Palm oil 0.919-0.923 0.921-0.925 0.867 0.856 40 27 to 42 31 to 32.5 Cacao butter 0.950-0.952 0.858 30 to 33 25 to 26 Cocoa-nut oil 0.925-0.926 0.873 20 to 26 16 to 20 Myrtle wax 0.995 0.875 40 to 44 39 to 43 Japan wax 0.970-0.980 0.875 51 to 54.5 46 Lard 0.931-0.938 0.861 41 to 46 29 Bone fat 0.914-0.916 21 to 22 15 to 17 Tallow 0.943-0.952 0.860 42 to 46 35 to 37 Butter fat , 0.927-0.936 0.866 29.5 to 33 19 to 20 Oleomargarine . . 0.924-0.930 0.859 Sperm oil . . 0.875-0.884 0.833 25 Bottle-nose oil 0.879-0.880 0.827 Carnauba wax .... Wool-fat 0.990-0.999 0.973 0.842 0.901 84 to 85 39 to 42 80 to 81 30 to 30.2 Beeswax 0.958-0.969 0.822 62 to 64 60.5 to 62 Spermaceti 0.960 0.812 43.5 to 49 43.4 to 44.2 Chinese wax 0.970 0.810 80.5 to 81 80.5 to 81 Tun <* (Chinese wood oil) 0.936-0.942 below 17 Soya-bean oil 924-0 927 8 to 15 586 APPENDIX. V. Physical and Chemical Constants of Fixed Oils and Fats. Continued. (FROM LEWKOWITSCH AND OTHER AUTHORITIES.) Saponiflcation value. Maumen6 test. Iodine value. Hehner value. Reichert value. Linseed oil 190-195 104-111 175-190 Hemp-seed oil .... 190-193 95-96 148 Walnut oil 195 96-101 144_147 Poppy-seed oil .... Sunflower oil 195 193-194 86-88 72-75 134-141 120-129 95.38 95 Fir-seed oil 191.3 98-99 118.9-120 Maize oil 188-193 56-60.5 117-125 89-95.7 2.5 Cotton-seed oil . . . . Sesame oil 191-195 189-193 68-77 64-68 104-110 105-109 96-17 95.8 0.35 Rape-seed oil 170-178 51-60 95-105 95 Black mustard oil . . . Croton oil 174-174.6 210.3-215 430.440 96-110 101.7-104 95.05 89 13.5 Castor oil 178-186 46_47 83.4-85.9 1.4 Apricot-kernel oil . . . 192.2-193.1 42.5-46 100-107 Almond oil 190.5-195.4 51-54 93-97 96.2 Peanut (arachis) oil . . Olive oil 190-197 191-196 45-49 41.5-45.5 85-98 80.6-84.5 95.86 95.43 0.3 Menhaden oil 189.3-192 123-128 140-170 1.2 Cod-liver oil 182-187 102-103 154-180 95.3 Seal oil 190-196 92 127-140 94.2 0.22 Whale oil 188-193 91-92 110-136 93.5 2.04 197.3 99.5 93.07 5.6 Dolphin oil j j aw QJI 200 32.8 66.28 65.92 Porpoiseoill^yoj 1 - 216-218.8 253.7 50 119.4 49.6 6841 23.45 65.8 Neat's-foot oil 1943 47-48.5 69.3-70.4 Cotton-seed stearine . Palm oil 194.6-195.1 196.3-202 48 88.7-92.8 53-57 96.3 95.6 0.5 Cacao butter Cocoa-nut oil 192.2-193.5 250-253 32-41 8.5-9.3 94.59 88.6 1.6 3.7 Myrtle wax Japan wax 205.7-211.7 220-222.4 2.9 4.2-8.5 90.6 Lard 195.3-196.6 27-32 57-70 96 Bone fat 190.9 46.3-49.6 Tallow 195-198 36-47 95.6 0.25 Butter fat 221.5-227 26-35 87.5 28.78 Oleomargarine .... 194-203.7 55.3-60 95-96 2.6 Sperm oil 132.5-147 47-51 84 1.3 Bottle-nose oil .... Carnauba wax .... 126-134 80-84 41-47 77.4-82 13.5 1.4 Wool-fat 98 2-102 4 25-28 Beeswax 91-96 8.3-11 Spermaceti 128 Chinese wax 63 Tung (Chinese wood oil) 193 150-165 Soya-bean oil 190.6-192.9 59-61 121-.3-124 95.5 INDEX. Abel tester for oils, 40 Absinthe, 253 Acetate of alumina, 548 Acetate of iron, 533, 548 Acetates, analysis of, 395 Acetic acid production, 391 ferment, 266, 270 Acetin method of glycerine analysis, 94 Acetone, 394 in wood-spirit, 392 Acetophenone, 448 Achroodextrine, 187 Acid brown G, 463 dyes, 456, 471 magenta, 457 process for starch, 189 violet, 412 yellow, 461 Acidity of beer, 223 of tan-liquors, 374 Acridine, 454 yellow, 465 Adams' method for fat in milk, 294 Adjective dyeing, 531 Adulteration of beer, 223 Adulteration of butter, 296 Aerated bread, 262 After-fermentation of beer, 217 Agalite, 321 Agar-agar, 377 Albertite, 18 Albuminoids in milk, 294 Alcohol in beer, 222 tables of Hehner, 579 Alcoholic beverages, manufacture of, 239 fermentation, 205, 208 Ale, 218 Aleurometer of Boland, 264 Algin, 377 Alizarin, 453, 466, 550 black S, 468, 551 blue, 467 S, 468 bordeaux B, 467 cyanine R, 467 dyeing, 539 green S, 468 indigo-blue S, 468 manufacture, 453 maroon, 467 on cotton, 550 orange, 467 red, 467 saphirol, 467 Alizarin, yellow, 462 A, 468 C, 468 Alkali blue, 457 process for starch, 189 Almond oil, 54 Alpaca fibre, 344 Alum tawing, 366 in bread, 261, 265 Alumina mordants, 532 Aluminum acetate, 532 Amaranth, 462 Amber, 107 malt, 209 American grades of benzol, 417 Amidoazo dyes, 463 p-Amidobenzene-sulphonic acid, 445 Amine dye-colors, 457 Ammonia liquor, valuation of, 428 recovery of, from gas-liquor, 413 Ammoniacal cochineal, 503, 507 Amylodextrine, 187 Analysis of dyes, 471 of fats, scheme for, 92 Aniline, 441 black, 458, 539 dyeing, 539 blue, 457 hydrochloride, 441 manufacture, 449 red, 457 rose, 458 salt, 441 still, 450 sulphate, 441 Animal fibres, bibliography of, 353 hide, structure of, 356 Anim^, 107 Anisette, 254 Anisol red, 462 Annatto, 295, 493 Anthracene, 422, 436, 453 brown, 468 oil, 421 series, 436 sulphonic acid, 444 yellow, 468 Anthracite black, 463 Anthragallol, 468 Anthranilic acid, 466 Anthrapurpurin, 467 Anthraquinone, 448, 453 sulphonic acid, 445, 453 Anthrarufine, 467 " Antichlor " in paper-bleaching, 320 Antimony mordants, 533 Application of artificial colors to cotton, 537 587 588 INDEX. Appolt's coke-oven, 405 Arachis oil, 56 Archil, 491 substitute, 461 Ardent spirits, manufacture of, 239 raw materials of, 239 Argols, 226, 234 Arrack, 251 Artificial asphalts, 28 butter, 284, 289 camphor, 106 coloring matters, bibliography of, 485 dye-colors, statistics of, 486 indigo, 465, 466 rubber, 123 silk, 333 Asboth method for starch, 199 Ash of raw sugars, composition of, 176 Asphalt paving composition, 35 residue in lubricating oils, 45 occurrence of, 17 Asphalts, analysis of, 47 artificial, 28 composition of, 18 Assouplissage, 350 Atlas powder, 84 Auramine, 458, 538 Aurantia, 459 Aureosin, 459 Aurin, 459 Autoclave process for fats, 64 Avignon berries, 493 Azines, 458 Azo blue, 464, 538 dye-colors, 461 mauve, 464 Azococcin, 2E, 462 7B, 463 Azolitmin, 496 Azorubin S, 462 Azurine, 460 B Babcock method for fat in milk, 294 Bacterial fermentation, 204 Bagasse, 170 Bahia-wood, 488 Baking, chemistry of, 261 powders, 260 Balata, 110 Balling sugar degrees and Baume scale, 570 Balsams, 107 Bar-wood, 488 Barlow's high pressure kiers, 524 Basic dyes, 456, 471 Bast fibres, 302 Bastards, 169 Bastose, 303 Bate, use of, 366 Baume's scale for liquids heavier than water, 567 for liquids lighter than water, 566 Bavarian thick-mash process, 213 " Bayer's acid," 445 Beating machine for paper-pulp, 320 Becchi's test, 90 " Bee-hive " coke-ovens, 405 Beer, analysis of, 221 fall, 216 ferment, 205 production in the United States, 276 Beeswax, 58 Ben oil, 55 Benedictine, 254 Benzal-chloride, 437 Benzaldehyde, 448 green, 457 Benzene, 433 disulphonic acid, 444 hydrocarbons, 433 sulphonic acid, 444 Benzidine, 443 dyes, 464 Benzine distillate, 24 properties of, 32 Benzoaurine, 464 Benzo-azimine, 538 Benzoic acid, 447, 452 aldehyde, 448' Benzo-indigo-blue, 464 Benzol, tests for, 424 Benzophenone, 448 Benzopurpurin, 464 Benzo-trichloride, 437 Benzyl chloride, 437 Bermudez asphalt, 17 Betaine, 169 Biebrich scarlet, 463 Bichromate of potash, 533 of soda, 533 Bismarck brown, 463 Bisulphite process for wood-pulp, 312 Bituminous coal, 397 shales, 28 Bixin, 493 Black dyes, recognition of, on fibre, 484 bread, 258 iron liquor, 548 liquor in papermaking, 325 seed cotton, 304 Blasting gelatine, 85 Blauholz, 495 Bleached flour, 261 Bleached lac, 108 Bleaching agents, 529 dyeing, and textile printing, bibliog- raphy of, 557 kiers, 524 of paper-pulp, 317 of wool, 347, 528 processes, 522 Block coal, 399 Bloom in petroleum oils, 32 Blotting-paper, 322 Blown oils, 81 Blue dyes, recognition of, on fibre, 481 Bock-beer, 218 Boettger's test for vegetable fibres, 360 Boiled oil, 80 INDEX. " Boiled-off " liquid, 346, 349 silk, 349 Boiley's blue, 509 Boiling of linseed oil, 113 Bois de Br6sil, 488 de Campeche, 495 Bone-black, analysis of, 179 exhausted, 171 filters for sugar, 150 revivifying of, 164 Bone fat, 59 glue, 379, 380 Bordeaux B, 462 G, 463 Borneol, 106 Bottom fermentation, 205 Brandy, 252 Brasilein, 488 Brasilin, 488, 505 Brazil-wood, 488 Bread, adulteration of, 265 analyses of, 262 method of analysis of, 267 Brewer's yeast, 259 Brie cheese, 290 Briquettes for fuel, 423 Brix degrees compared with Bailing scales, 570 Bread-making, 257 Brilliant Congo G, 464 croce'in, 463 green, 457 ponceau, 4E, 462 British gum, 196 Bromine absorption of fats, 88 a-Brom-naphthalene, 438 Brown acetate of lime, 391, 393 coal, 398 dyes, recognition of, on fibre, 483 malt, 212 Burmese lacquer, 111 Burning naphtha, 417 Butter, 289 analysis of, 296 coloring matter of, 299 fat, 56, 289 manufacture of, 281, 284 yellow, 461 Butterine, 284, 289 Button : lac, 108 By-product coke-ovens, 405, 431 Byerlite, 28 c Cacao butter, 55 Cachou de Laval, 468 Calcium acetate, 391 Caliatur-wood, 488 California wood, 488 Calorisators, or juice-warmers, 152 Camel's-hair fibre, 344 Camembert cheese, 290 Camphors, 104, 106 Cam-wood, 488 Candle manufacture, 74 Candle-making materials, 76 Cane-sugar, bibliography of, 182 Cannel coal, 398 Caoutchouc, 108, 117, 122 statistics of, 133 Capri blue, 461 Caramel coloring, 194 in spirits, 256 Carbazol yellow, 464 Carbolic acid, 418, 426 Carbonatation process, 146, 156 Carbonate of potash, 530 Carbonizing mixed cotton and wool, 343 Cardboard, 324 Carded wool, 350 Carmichael electrolytic process, 320 Carmine, analyses of, 508 naphte, 46 i preparation of, 503 red, 491 Carminic acid, 491 Carmosin, 462 Carnauba wax, 56 Carthamic acid, 490 Carthamin, 490 Casein of milk, 279 preparations, 292 Cashmere wool, 343 Casing-head gas, 19 Castile soap, 69 Castor oil, 53 Catechin, 497 Catechu, 359, 497, 534 extract, 359, 514 Catechutannic acid, 359, 497 Caustic soda, 530 Celluloid, 330, 332 Cellulose nitrates, 327 xanthogenate, 334 Centigrade and Fahrenheit scales, 562, 563 Centrifugals, 145 Cerasine, 462 Cereals, composition of, 186 Ceresine, 27, 35 Chamois leather, 369, 371 Champagnes, 231 manufacture of, 229 Chaptalization of wines, 228 Charcoal from wood, 394 Chardonnet process for artificial silk, 334 CTiar-kilns, 164 Chartreuse, 254 Cheddar cheese, 290 Cheese, analysis of, 299 making, 286 varieties of, 290 Chemic blue, 509 Chemical wood-pulp, 312 Chestnut-wood in tanning, 358 Chicle, 110 China-grass, 308 Chinese green, 497 isinglass, 377 lacquer, 111 wax, 58 590 INDEX. Chinoline, 454 Chipping of dyewoods, 497, 500 Chloracetic acid, 466 Chloride of lime bleaching, 525 Chlorophyll, 496 " Chlor-ozone," 529 Chondrin, 375 Chromatropes, 463 Chrome alum, 533 tanning, 368 " Chroming " of wool, 531 Chromium mordants, 533 Chromogens, 456 Chromophor groups, 456 Chrysamine, 464, 538 Chrysaniline, 465 Chrysene, 437 Chrysoidine, 401 Chrysophenine, 464, 538 Chrysorhamnin, 493 Cider vinegar, manufacture of, 270 Cineol, 106 Cingalese lacquer, 111 Citral, 104 Clark's water purification process, 535 Clayed sugars, 167 Cleansing of fibres, 522 Clerget's process of inversion, 174 Cloth brown, 464 dyeing, 536 red G, 463 Coal distillation, statistics of, 431 Coals, composition of, 398 Coal-tar colors on wool, 543 diagram of distillation, 412 dyes, identification of, 471 fractions, 410 pitch, 423, 428 statistics, 432 still, 408 Coccerin, 491 Cochineal, 491 analysis, 515 carmine, 491, 507 dyeing, 542 red A, 462 scarlet 2R, 461 Cocoa-nut fibre, 309 oil, 55 Cod-liver oil, 57 Coefficient of expansion of petroleum oils, 566 Coerulein, 460 S, 460 Coffey still, 246 Cognac, 252 Coir fibre, 309 Coke-oven distillation of coal, 405 Coking coals, 397 Cold process of soap-making, 70 test for oils, 43 vulcanization process, 117 Collodion, 328, 329 Cologne glue, 380 Colophony resin, 105, 108 Color analysis in milk, 295 Colorimetric tests for oils, 46 Coloring for paper-pulp, 321 matter in wines, 238 recognition of, in paper, 327 Colza oil, 55 Combed wool, 350 Combination tanning, 368 Commercial indigo, composition of, 509 Comparative dye trials, 469 Comparison of Twaddle scale with rational Banine" scale, 569 Composition of gas-liquor, 413 Compressed yeast, 259 Compression test for paraffin, 46 Concrete sugar, 167 Condensed milk, 281, 288 Conditioning of wool, 342 silk, 348 Congo Corinth G, 464 G and P, 464 group of dyes, 464, 538 red, 464 yellow, 464 Consumption of malt liquors in the United States, 277 Copal, 157 varnish, 114 Coppee coke-oven, 405 Copper mordants, 533 nitrate, 533 sulphate, 533 wall in sugar extraction, 141 Copperas vat, 506 Cordials, 253 Cordite, 85 Coriin, 357 Corn oil, 55 syrup, 195 Cotton bleaching, 523 dveing, 535 fibre, 303 scarlet, 465 seed oil, 53 products from, 80 statistics of, 338 Cow's milk, 279 Crackers, 26 Cracking of petroleum, 20 Cracklings process of melting fats, 60 Crampton's test for caramel, 256 Cream separators, 282 Creme de menthe, 2'54 Creosote, 394 oil, 419, 427 Creosoting of timber, 420 Creydt's method for raffmose, 178 Crocein orange, 462 scarlet 3B, 463, 538 Crop-madder^ 490 Crown leather, 371 Crude petroleum, analysis of, 36 Crystallized grape-sugar, 192 Cudbear, 491 Cumidine red, 462 Cuprammonium process for artificial silk, 334 INDEX. 591 Curacoa, 254 Curcuma, 493 Curcumin, 493 Curd of milk, 280 Curing of logwood, 496 sugar crystals, 145 Cut soaps, 82 Cutch, 497 in tanning, 359 Cutting of dye-woods, 497 Cyanine, 465 Cyanosine, 460 Cyclamine, 460 Cylinder oils, 32 Cymogene, 31 D Dammar resin, 107 Decoction process of mashing, 212, 213 Defren's method, 175 Defecation of sugar- juice, 141 Degommage, 349 Degraissage, 346, 350 Degras, 370, 372 Degreasing of wool, 346 Delta-purpurin 5B, 464 Demerara crystals, 167 Dephlegmators, 244 Destructive distillation, bibliography of, 430 of coal, 397 of wood, 385 theory of, 385 D6suintage, 346 Dextrine, analyses of, 196 manufacture of, 194 Dextropinene, 105 Diagram of coal-tar distillation, 412 of distillation of coal, 401 Diamidoazobenzene hydrochloride, 461 Diamine black, 464 blue, 464 brown, 464 gold, 464 green, 464 scarlet, 464 Diastase, 204, 208 Diastatic power of malt, 220 Diazo-amido-benzene, 446 Diazo-benzene chloride, 446 Diazo-benzene-sulphonic acid, 447 Diazo-compounds, 446 Diazotizing, 455 Dibrom-anthracene, 438 Dichlor-anthracene, 438 Diffusion cells, 152 process in extracting sugar, 151 Dimethylaniline, 441 orange, 461 Dimethyl benzene or xylene, 435 ketone, 448 Di nitrobenzene, 396 Dinitrocellulose, 328 o-Dinitronaphthalene, 440 /3-Dinitronaphthalene, 440 Dinitrosoresorcin, 460 Dinitrotoluenes, 440 Dioxine, 460 Diphenyl, 435 Diphenylamine, 443 blue, 457 orange, 461 Diphenyl-methane dyes, 458 Direct printing processes, 549, 546 Discharges in calico-printing, 554, 555 Diseases of wines, 226 Distillation of essential oils, 103 of fermented mash, 244 of petroleum, 20, 22 of sawdust, 388 of wood, 387 Distilled spirit, rectification of, 249 spirits, production of, in the United States, 276 Distiller's residues, 255 Distinctions between two naphthols, 443 between artificial and natural silk, 337 between vegetable and animal fibres, 351 Disulphonic acids of /3-naphthol, 445 Diterpenes, 104 Divi-divi, 360 Double-effect vacuum-pans, 144 Doubling, 249 Dough, preparation of, 260 Dry wines, 231 Dryers for oils, 80 Drying oils, 54 Dunder, 244 Dyed fabrics, examination of, 474 Dyeing and textile printing, bibliography of, 557 processes, 534 Dye-wood extracts, manufacture of, 500 Dye-woods, curing of, 498 Dynamite, 79, 84, 532 analysis of, 95 " Dynamited silk," 545 extraction of, 501 E Eau de vie de marc, 252 Ebonite or hard rubber, 123 Ecru silk, 349, 350 Effervescing wines, manufacture of, 229 Eidam cheese, 290 Electrolytic bleaching, 527 Elution process for molasses, 162 Enamelled leather, 371 Enfleurage, 103 Engine-sizing for paper, 321 Engler viscosimeter, 44 Enzymes, 203, 204 Eosins, 459, 537 Equivalent English and metric weights and measures, 562 Erythrodextrine, 187 Erythrosin, 459 592 INDEX. Erythrozym, 490 Esparto, 313, 314 Essential oils, adulteration of, 124 bibliography of, 129 classification of, 104 extraction of, 103 statistics of, 131 Ethyl eosin, 459 naphthalene, 435 Eurhodines, 458 Evrard process, 60 Examination of dyed fabrics, 474 Extract determination in beer, 221 wool, 351 Extraction of oil seeds by solvents, 62 Factitious brandy, 252 vinegars, 271 Fahrenheit and Centigrade scales, 562, 563 Faints, 249 Fast brown, 463 N, 462 red A, 462 B, 462 C, 462 D, 462 violet, 463 yellow, 461 Fastness of dyes to light, 469 to soaping, 469 Fat determination in milk, 294 Fats and oils, analysis of, 85 bibliography of, 95 statistics of, 96 Fatty oils, composition of, 58 Fehling's solution, preparation of, 174 use of, 175 Feldman's ammonia still, 414 Fermentation, bibliography of, 272 nature of, 203 of dyewoods, 498 of grape juice, 225 of mash for spirits, 242 of wort, 216 Ferments, soluble, 203 Ferrous acetate, 533 sulphate, 533 Fibre, recognition of, in papers, 325 Fibroin, 346 Fibro-vascular bundles, 302 "Fifty per cent, benzol," 416, 434 Filled soaps, 70 Fire test of oils, 39 Fischer viscosimeter, 44 Fisetin, 492 Fish-bladders, 377 gelatine, 380 Fixed oils and fats, physical and chem- ical constants of, 585, 586 Flash-point of oils, 39 Flavaniline, 465 Flavine, 492, 503 Flavopurpurin, 467 Flax, 305 statistics of, 339 Flour, 257 adulterations of, 265 and bread, bibliography of, 275 Fluoranthene, 436 Fluorene, 436 Fluorescein, 453, 459 Fluoride of antimony and potassium, 533 Forcite, 84 Formaldehyde in milk, 296 in tanning, 369 Fortified wines, manufacture of, 229 Fourdrinier machine for paper, 322 Fractional generation of coal-tar, 408 Fromage de Brie, 290 Fryer concretor, 147 Fuchsine, 457, 537 S, 457 Fuel gas, 30 oil, 34 Fuller's earth for oil clarifying, 63 Fusel oil, determination of, 256 Fustic, 492 Fustin, 492 Gaban-wood, 489 Gallamine blue, 461 Gallanilic indigo, 460 Gallein, 460 Gallic acid, 447 Gallipoli oil, 80 Gallisin, 187, 197 Gallization of wines, 228 Gallocyanine, 460 Galloflavin, 468 Gambier in tanning, 359 Gambine, 460 Gas analysis, 429 coals, composition of, 398 liquor, constituents of, 413 oils, 33 purifiers, 403 retort distillation of coal, 401 tar and coke-oven tar, 408 Gasolene, 31 Gelatine, 379, 380 dynamite, 85 Gelbbeeren, 493 Gilsonite, 17 Gin, 253 Glacial acetic acid, 391 Glance pitch, 17 Gloucester cheese, 290 Glucose, analyses of, 195 determination of, 174 manufacture of, 190 method for analysis of, 199 vinegar, 271 Glue, analysis of, 381 and gelatine manufacture, 375 stock, 377 Gluten in bread, 257 Glutin, 375 INDEX. 593 Glycerine manufacture, 77 in wines, 236 properties of, 83 refining of, 77 statistics of, 102 Golden syrup, 169 Graham's method for glucose analysis, 201 Grain mash, 241 Grape, composition of, 223 sugar and glucose statistics, 201 manufacture of, 190, 192 varieties of, 224 Gray acetate of lime, 393 Green dyes, recognition of, on fibre, 48 hides, 357 seed cotton, 304 syrup, 169 Gruyfire cheese, 290 Guanaco fibre, 343 Guarancine, 490, 502 Gum arabic, 107 resins, 107 Gun-cotton, 327, 328 analysis of, 333 Gutta-percha, 110, 119, 123 statistics of, 133 vulcanization of, 119 H Haematein, 496, 511 Hsematoxylin, 496 "Half-stuff" paper-pulp, 317 Halogen derivatives of benzene, 437 Halphen's test for cotton-seed oil, 90 Hand-made paper, 321 Hansen's yeast cultures, 207 Hanus method for iodine figure, 90 Hard biscuit, 263 fibre, 324 rubber, 118 soaps, 68 water, 535 Harness leather, 365, 370 Heat, effect of, on wood, 386 Heavy oil, 411, 419 Hehner's method, 297 Helianthin, 461 Heliotrope, 464 Hemiterpenes, 104 Hemlock bark in tanning, 358 Hemp fibre, 306 Hemp-seed oil, 53 Henequen fibre, 308 Hercules powder, 84 Hermite bleaching process, 319, 527 Hessian purple, 464 violet, 464 yellow, 464 Heumann's tester, 42 Hexanitrate of cellulose, 327 Hide glue, 377, 380 Hides, varieties of, 357 High and low heat, effect of, on coal, 399, 400 milling process, 258 Hofmann's violets, 457 Hollander for paper stock, 316 " Hollands," 253 Hop production, statistics of, 275 Hops, 209, 210 in manufacture of beer, 215 Horsechestnut-bark in tanning, 358 Hiibl's method, 89, 297 Huile tournante, 80 Hydrated soap, 68 Hydrochloric acid, 530 Hydrogen peroxide, 529 bleaching, 528 Hydrolysis of starch, results of, 187 Hydrosulphite vat for indigo, 536 Identification of coal-tar dyes, 471 Illuminating gas, analysis of, 429 composition of, 405 Imitation wines, manufacture of, 230 Immedial black, 468 blue, 468 Indamines, 460 Indanthrene X, 468 Indian lacquer, 111 India-rubber, 108, 117, 122 Indican, 494 Indiglucin, 494 Indigo, 493 analysis of, 516 artificial synthesis of, 465, 466 blue, 495 carmine, 504, 509 synthesis of, 510 commercial varieties of, 509 disulphonic acid, 504 extract, 504 monosulphonic acid, 504 plant, treatment of, 494 printing, 552 purple, 509 salt, 466 substitute, 458, 511 vat dyeing, 536 white, 495 " Indigo pure," 466 Indoines, 458 Indophenol, 460 white, 460 Indulines, 458 Indurated fibre, 324 Infusion process of mashing, 212, 213 Ingrain colors, 464 red dyeing, 540 Insect wax, 58 Invert sugar, determination of, 174 Invertase, 204 Iodine absorption of fats, 89 compound with starch, 187 number, 298 Iron mordants, 533 Isinglass, 377, 381 adulteration of, 382 Isopurpurin, 467 594 INDEX. Jaggery sugar, 167 Japan wax, 56 Japanese lacquer, 111 Japans, 121 Jordan beater for paper pulp, 320 Juice-warmers, 152 Jute bleaching, 528 dyeing, 541 fibre, 307, 314 statistics of, 340 K Kaiserschwarz, 511 Kalle's artificial indigo, 466 Kaseleim pulver, 293 Kauri resin, 108 Kephir, 292 Kerm.es, 492 Kerosene, 32 Ketones, 448 Kindt's test for vegetable fibres, 310 Kino, 497 in tanning, 359 red, 497 Kinb'in, 497 Kips, 357 Kirschwasser, 252 Kjeldahl method for nitrogen, 294 Knoppern, 360 Koettstorfer's method, 297 Koumiss, 291 Kraft paper, 313 Krapp, 489 Lac dye, 492 resin, 108 Laccainic acid, 492 Lacquers, 103, 111, 114 Lactometer, use of, 293 Laevo-pinene, 105 Lager-beer, 218 Laming gas purifying mixture, 404 Lamp-black, 31 Lanolin, 57 Lard, 56 cheese, 287, 291 oil, 56 Lead acetate, 393 Leather, analysis of, 375 and glue, bibliography of, 382, 383 industry, statistics of, 383 Leed's scheme for soap analysis, 93 Lees of wine, 234 Leguminous starches, 185 " Leuco " compounds, 456 Levulose, manufacture of, 192 Light oil of tar, 415 Lignite, 398 Ligroine, 32 Lillie evaporator, 144 Lima oil, refining of, 25 wood, 488 Limburger cheese, 290 Lime and copperas vat for indigo, 536 sucrate process for molasses, 162 use of, in defecating sugar juice, 141 Liming of hides, 361 Linen-bleaching, 527 dyeing, 541 Linoleum, 116, 122 Linseed oil, 54 caoutchouc, 122 varnishes, 113, 120 -Liqueurs, 253 Liquid adhesive plaster, 332 glue, 381 Litho-carbon, 18 Litmus, 496, 511 Llama fibre, 343 Loading material for paper-pulp, 321 Logwood, 495 blue on wool, 542 dyeing, 536 extracts, 510, 513 Lokanic acid, 497 Lokao, 497 Lokaonic acid, 497 Lokaose, 497 Long-stapled wool, 341 Low wines, 244, 249 Lubricating oils, 32 Lunge's bleaching process, 526 nitrometer, 94 Lupulin, 209 Lustre wools, 341 Luteolin, 493 Lyddite, 85 M Maceration process for sugar-beets, 151 Machine-made paper, 322 Maclurin, 492 Madagascar-wood, 489 Madder, 489 bleach, 524 flowers, 490 Magdala red, 458 Magenta, 457 Maize oil, 55 Malachite green, 457 Malt, analysis of, 219, 220 composition of, 208 liquor industry, 208 substitutes, 215 vinegar, manufacture of, 269 Maltha, 17 Malting and^ brewing, bibliography of, 273 process, 210 Maltodextrine, 187 Maltose, manufacture of, 192 properties of, 196 Manchester yellow, 459 INDEX. 595 Mandarin, 462 Manganese bronze styles, 555 Manila hemp, 308 Manufacture of vinegar, bibliography of, 274 Maraschino, 254 Marc of grapes, 234 Marine soap, 68 Marseilles soap, 69 Martin's process for wheat starch, 189 Martius yellow, 459 Mash process, 212 Masse-cuite, 142, 145 Mastic, 108 Mather-Thompson process, 526 Mauvein, 458 Mechanical malting apparatus, 211 wood-pulp, 312 Melassigenic salts, 168 Meldola's blue, 460 Melinite, 85 Melis, or lump-sugar, 168 Melting-point of fats, method for, 86 Menhaden oil, 57 Menthol, 106 Mesitylene, 433 Metanil yellow, 461 Methyl alcohol, 393 in wood-spirit, 395 purification of, 392 aniline, 441 anthracene, 436 benzene, 434 eosin, 459 green, 457 naphthalene, 435 quercetin, 493 violet, 457 Methylene blue, 461, 538 violet, 458, 537 c-Methyl-quinoline, 446 Metric system, 561, 562 Mica powder, 84 Middle oil, 417 Milk analysis, 293 components of, 278, 280 composition of different varieties of, 278 industries, bibliography of, 300 statistics of, 301 sugar, 279, 291 Milling of soaps, 73 Millon's reagent, 352 Milly process of saponification, 64 Mimosa-bark, 360 Mineral tanning, 366 Mitscherlich method for wood pulp, 312 Mixing syrup, 170 Mohair, 343 Molasses, analyses of, 169 from sugar-beet, 159 from sugar-cane, 159 Monochlor-anthracene, 438 Monohydrated sodium carbonate, 530 Mononitronaphthalene, 440 Mordanting, 531, 547 Moric acid, 492 Morin, 492 Moritannic acid, 492 Morocco leather, 366, 370 Morse and Burton's method, 299 Mother of vinegar, 266, 270 Mottled soaps, 69 Mould growth fermentations, 204 " Mull-madder," 490 Mungo, 351 Munson and Walker's method, 175 Muriatic acid, 530 Muscovado sugar, 167 Must of grapes, 224 Mycoderma aceti, 266 Myrobalans in tanning, 359 Myrtle wax, 56 N Nankin cotton, 303 Naphtha from petroleum, 31 Naphthalene, 419, 426, 435 red, 458,, 464 sulphonic acids, 444 tetrachloride, 438 Naphthion red, 461 Naphthol black, 463 blue-black, 464 sulphonic acids, 445 yellow, 459 S, 459 a-Naphthol, 443, 452 a-Naphthol blue, 460 a-Naphthol orange, 462 -Naphthol, 443, 452 /3-Naphthol orange, 462 Naphthyl blue, 458 /3-Naphthyl-bromide, 438 /3-Naphthyl-chloride, 438 Naphthylamine black, 463 brown, 462 sulphonic acid, 445 a-Naphthylamine, 442 /3-Naphthylamine., 442 Natural dye-colors on wool, 541 dyestuffs, bibliography of, 519 reactions of, 518 replaced by artificial, o56, 557 statistics of, 520 gas, composition of, 14 occurrence of, 13 uses of, 18, 19 varnishes, 111, 119 Neat's-foot oil, 56 Nettle fibre, 309 Neufchatel cheese, 290 Neutral oils, 32 red, 458 New Zealand flax, 309 Nicaragua-wood, 488 Nicholson's blue, 457 Nigrosine, 458 Nile blue, 461 596 INDEX. "Ninety per cent, benzol," 415, 433 Nitraniline, 442 Nitrate of iron, 548 Nitrating acid, 449 Nitration of cellulose, 328 Nitrites in flour, 265 Nitroalizarin, 467, 543 a-Nitrobenzaldehyde, 466 Nitrobenzene, 439 manufacture, 449 Nitro-cellulose, analysis of, 332 Nitro-glycerine, 78, 83 analysis of, 94 Nitrometer, 333 Nitroso colors, 439 Nitrotoluene, 439 Non-coking coals, 397 drying oils, 55, 59 lustre wools, 341 Nopal-plant, 491 North Carolina pine tar, 393 Nutgalls, 360 in dyeing, 534 Oak-bark for tanning, 357 red, 358 Oil-cloth, 116, 122 manufacture of, 116 Oil-seed cake, 79 crushing, 61 Oils and fats, analysis of, 85 physical and chemical con- stants of, 585 statistics of, 96 Oil-tanned leather, 371 Old fustic, 492 Oleomargarine, 284, 2S9, 299 cheeses, 287 Oleo-resins, 107 Olive oil, 55 Orange IV, 461 G, 462 Orcein, 491 Orchil extract, 506 Orellin, 493 Orlean, 493 Orleans process of vinegar manufacture, 267 Orseille, 491 carmine, 507 purple, 507 Orselline, 506 Ortho-toluidine, 442 Osmose process for molasses, 160 Otto coke-oven, 405 Otto-Hoffmann ovens, 407 Oxidation colors, 551 Oxidized oils, 81 Oxyazine colors, 460 Oxyazo dyes, 461 Oxychloride of antimony, 533 Ozokerite, occurrence of, 17 treatment of, 27 Padded soaps, 70 Paeonin, 459 Pale brandy, 252 malt, 212 Palm oil, 56 Paper and pulp, statistics of, 338 making, 311 mulberry fibre, 314 pulp testing, 325, 326 sizing, 321 washing machine, 316 Papier-mache, 324 Paraffin, crude, occurrence of, 16 from bituminous shales, 29 oil, 26, 32 properties of, 33, 394 Paraphenylene blue, 458, 538 Para-toluidine, 442 Parchment, 372 glue, 380 paper, 324 Parmesan cheese, 290 Pasteboard, 324 Paste-dyes, 474 Pasteur's process of vinegar manu- facture, 270 Pasteurizing of beer, 218 of wine, 227 Patent fuel (briquettes), 423 glue, 381 leather, 371 Pauly artificial silk, 334, 335 Peach-wood, 488 Peanut oil, 56 Pearl-hardening for paper, 321 Peat, 398 Penta-nitrate of cellulose, 328 Peptones from malt, 209 Perfumes, manufacture of, 111 Perkin's violet, 458 Permanganate of potash, 529 Pernambuco-wood, 488 Perry for vinegar, 267 Persian berries, 493 Persio, 491 Petiotization of wines, 228 Petrolatum, 27, 34 Petroleum, bibliography of, 48 Canadian, 15 ether, 31 Ohio, nature of, 15 Pennsylvania, nature of, 15 Russian, 16 statistics, 49 Phenanthrene, 436 Phenetol red, 462 Phenol, 400, S 418, 443 dye-colors, 459 Phenol-phthalein, 459 sulphonic acid, 444 Phenols in tar, tests for, 425, 426 Phenyl-anthracene, 436 methyl-ketone, 448 INDEX. 597 Phenylene brown, 469 Phenylenediamine, 443 Phenylglycerine-o-carboxylic, 466 Phenyl-glycocoll, 510 Phlobaphene, 358 Phloxin, 460 Phosphine, 465 Phosphotage of wines, 22S Photogene, 35 Phthalamide, 466 Phthaleins, 447, 453 Phthalic acid, 447, 452 anhydride, 452 Physical and chemical constants of fixed oils and fats, 585, 586 properties of fixed oils, 58 Picene, 437 Picric acid, 459 Pigment brown, 461 styles of tissue-printing, 551 Pincoffin, 506 Pineapple fibre, 309 Pine-bark in tanning, 358 tar, 393 Pinene of oil of turpentine, 105, 156 Pinoline, 122 Pitch from coal-tar, 428 Plastering of wines, 227 Plate carthamine, 490 red, 506 Plumping of hides, 363 Pneumatic malting, 211 Polarization of sugars, 172 Polymerizing of turpentine oil, 126 Polyterpenes, 104 Pomades, 111 Ponceau B, 463 2R, 462 3R, 462 4GB, 462 4KB, 463 Poppy-seed oil, 54 Porter, 218 Potassium carbonate, 530 Potato group of starches, 185 mash, 242 yeast, 260 " Poteen " whiskey, 253 Preservation of timber, 420 Preserved milk, 281, 288 Press for oil seeds, 62 Pressure flask for hydrolysis, 198 Primary disazo colors, 463 Primrose, 459 Primuline colors, 464, 541 Printer's ink, manufacture of, 115 Printing-paper, 324 textile fabrics, 545 Proof spirit, 251 Propiolic paste, 466 Prune pure, 460 Prune wine, 230 Pseudo-phenanthrene, 436 Puer, use of, 366 Purifiers for gas, 403 Purification of water for dyeing, 534 Purpurin, 467, 490 Pyrene, 436 Pyridine, 445 Pyrogallol, 443, 448 manufacture, 451 Pyrol igneous acid, 393 Pyrolignite of iron, 393 Pyronine, 458 Pyroxyline for collodion, 331 manufacture of, 32Q varnishes, 332 Quebracho-wood in tanning, 360 Quercitannic acid, 358, 492 Quercitin, 492 Quercitrin, 492 Quercitron, 492 Quick-vinegar process, 268 Quinaldine, 446 Quinoline, 445, 454 blue, 465 red, 465 yellow, 465 R Raffinade, 168 Raffinose sugar, 169 Rags for paper-making, 311 Raisin wine, 230 Ramie fibre, 308 Rape oil, 55 Ratafia, 254 Rational BaumS scale, 567 Raw sugars, analyses of, 168 analysis of, 172 refining of, 148 Recognition of dyes on the fabric, 476 Recovered soda from paper-making, 325 Rectified spirit, 251 Rectifying distilled spirit, 249 Red corallin, 459 dyes, recognition of, on fibre, 476 liquor, 532 oil, 71 sanders, 489 Reduced oils, 19 indigo process, 553 Reeling of silk, 348 Refining of vegetable oils, 63 Reichert-Meissl figure, 298 Reichert's method, 298 Rendeinent or refining value, 177 Rendering of tallow, 60 Residuums, oil, 26 Resin acids, 107 separation of, 94 Resins, nature of, 106, 107 statistics of, 132 tests for, 126, 127 598 INDEX. Resists in calico-printing, 547, 554 Resorcin, 443 blue, 461 brown, 463 manufacture, 451 phthalein, 453 Retene, 437 Retting of flax, 305 Revivifying bone-black, 164 Rhamnetin, 493 Rhigolene, 31 Rhodamine, 460 Ripening of cheese, 287 Rice group of starches, 185 Rincage, 346 Rocelline, 462 Rock asphalt, 17 Rolls for sugar-mills, 138 Roquefort cheese, 290 Rose Bengale, 460 Rosin, 108 grease, 122 oil, 122 in mineral oils, 127 soaps, 69 spirit, 122 Rosolic acids, 459 Rothholz, 488 Roxamine, 463 Rubber substitute, 123 vulcanization of, 117 Ruberythric acid, 490 Ruffigallol, 468 Rum, 252 Russia leather, 371 Russian glue, 381 Saccharomyces, 205, 206 Safflower, 490 carmine, 490, 506 extract, 506 red, 506 Saffrosine, 459 Safranine, 458, 537 Sago group of starches, 185 Sal soda, 530 Salicylic acid in beer, 223 in wine, 238 Sandal-wood, 488 Santalin, 488 Santa-Martha-wood, 488 Sapan-wood, 488 Saponification equivalent, 89, 297 of fats, 64 value of fats, 88 Sarco asphalt, 28 Sawdust, distillation of, 388 Saxony blue, 509 Saybolt tester for oils, 39 " SchafFer's acid," 445 Scheelization of wines, 229 Schenk-beer, 218 Schiedam schnapps, 253 Schlempe, 171, 255 Scrap rubber, working of, 119 Scrubber for gas washing, 403 Sea-island cotton, 303 Seal plushes, 545 Sealing-wax, 121 Secondary disazo dyes, 463 Seed-hairs, 302 Seed-lac, 108 Self-raising powders, 260 Semet-Solway coke-ovens, 407 Sericin, 346 Sesame oil, 55 Sesquiterpenes, 104 . Shark oil, 57 Sheibler-Seyferth elution process, 162 Shellac, 108 Shoddy, 350 Short-stapled wood, 341 Silent spirit, 246, 251 Silk bleaching, 529 cocoons, 344 conditioning, 348 dyeing, 544 fibre, 344, 351 glue, 346 scouring, 349 statistics of, 355 worm, development of, 344 Simon-Carve's coke-oven, 405 Sisal hemp, 308 Size glue, 380 Sizing materials, recognition of, in paper, 327 Skimmed milk, 283 Sludge acid, 25 Smokeless powder, 85 Soap analysis, scheme for, 93 coppers, 68 frames, 71 making, 66 Soaps, classification of, 81 composition of, 82 in bleaching operations, 530 Sod oil, 370, 372 Soda ash, 530 crystals, 530 process for wood-pulp, 313 Sodium chloride in dye-colors, 469 peroxide, 530 sulphate in dye-colors, 469 zincate, 548 Soft soaps, 82 water, 535 Solar oil, 35 Soldaini's solution, 175 Sole-leather, 361, 370 Solid green, 457 Soluble blue, 457 indigo, 504 starch, 193 Solvent naphtha, 417 Sorghum cane, analysis of juice of, 137 plant, 134 INDEX. Soudan brown, 461 G, 461 Souple silk, 349 Soxhlet extraction apparatus, 85 Specific gravity tables, 566 Sperm oil, 57 Spermaceti, 57 Spindle oils, 32 Spirit production of the world, 271 soluble blue, 457 varnishes, 115, 121 vinegar, 271 Spirits and distilled liquors, bibliography of, 274 Sprengel specific gravity tube, 86 Stannate of soda, 532 Stannous chloride as mordant, 532 Stannic chloride as mordant, 532 Starch and products, bibliography of, 201 composition of, 186, 195 extraction of, from corn, 188 of, from potatoes, 189 of, from wheat, 189 method for analysis of, 197 statistics of, 202 Starches, classification of, 185 Steam distillation of essential oils, 125 styles of tissue-printing, 549 Stearic acid manufacture, 74 Steffen's substitution process, 162 Sthenosizing, 336 Stick-lac, 108, 492 Stilbene, 436 Stockholm tar, 393 Stoddard tester, 42 Stout, 218 " Stoving " of woollen yarns, 528 Straw for paper-making, 313 Strength of tanning infusions, determi- nation of, 372, 373 Stripping of silk, 349 Strontium process for molasses, 163 Styles of tissue-printing, 548, 549 Substantive cotton dyes, 464 dyeing, 531 Sucrates, analysis pf, 182 Sucrose, determination of, 172, 174 Sugar beet, 134 analysis of juice of, 137 composition of, 135 beets, analysis of, 134 cane, analysis of juice of, 136 composition of, 133 canes, analysis of, 133 coloring, manufacture of, 194 maple, 136 of lead, 393 production of, from sugar-cane, 137 statistics of, 183, 184 yielding materials, 133 Sugars, analysis of, 176 Sulphanil yellow, 464 Sulphanilic acid, 445 Sulphate of ammonia statistics, 432 Sulphate of magnesia in dye-colors, 469 process for wood pulp, 313 Sulphindigotic acid, 504 Sulpho-acetate of alumina, 532 ricinoleic acid, 80 Sulphonating, 454 Sumach in tanning, 359 Sunflower oil, 54 Sunn hemp, 308 Surface fermentation, 205 Sweet wines, 231 Swelling of hides, 361 Swenson evaporator for black liquor, 325 Sylvestrene, 105 Table of artificial dye-colors replacing natural dyes, 556 of reactions of natural dyestuffs, 518 of specific gravity figures, degree Baume' and degree Brix, 570 Table of weight and volume relations, 577 Tables for determination of temperature, 562 Tabular view of beet-sugar working, 157 of production of sugar from cane, 139 Tagliabue tester for oils, 39 Tallow, 57 extraction of, 60 oil, 57 Tannin as mordant, 553 containing materials, 357 determination of, 374 in brandy, 256 in wines, 238 Tanning extracts, reactions of, 373 liquors, 363 of sole-leather, diagram of, 364 Tar from Otto-Hoffmann coke-ovens, 408 Tar-stills in petroleum refining, 23 Tartar emetic as mordant, 533 Tartrazin, 464 Tawed leather, 371 Tawing processes, 366 Temper-lime in sugar juice, 144 Temperature effects of, on distillation of coal, 399 Terebene, 106 Terpenes, 104 Terpin hydrate, 106 Terpineol, 106 Terra-firma-wood, 488 Tetrabrom-fluorescein, 459 Tetranitrate of cellulose, *328 Theory of tanning, 356 Thermometer scales, comparison of, 563 Thiazines, 461 Thick-mash process, 212 Thin-mash process, 212 " Thirty per cent, benzol," 434 600 INDEX. Thymol, 106 Tin crystals, 532 mordants, 531 spirits, 532 Tissue-papers, 322 Toddy, 251 Toilet soaps, 83 Toluene, 434 sulphonic acid, 444 Toluidine, 442 Toluylen red, 458 Tournesol, 496 Train oil, 57 Transparent soaps, 83 Treacle, 169 Tribromphenol as test, 426 Trinidad asphalt, 17 Trinitro-cellulose, 328 phenol, 459 toluene, 440 Triphenyl-methane dyes, 457 Triple-effect vacuum-pan, 144 Tropseolin OO, 461 OOO, No. 1, 462 OOO, No. 2, 462 Tub-sizing for paper, 321 Turkey-red process, 539 Turmeric, 493 Turpentine oil, 105 analysis of, 125, 126 varnishes, 115, 121 Tussur silk, 346 Twaddle's scale for liquids heavier than water, 568 TwitchelFs method for resin acids, 91 U Unfermentable carbohydrates, 197 Unhairing of hides, 361 Upland cotton, 303 Upper leathers, 365, 370 Usquebaugh, 254 Utilization of fat, scheme for, 67 Vacuum-pan in sugar refining, 143 Valonia, 359 Valuation of tar samples, 423 Vanadium in calico printing, 552 Varnishes, analysis of, 128 manufacture of, 112 varieties of, 113 Vaseline, 28, 34 Vegetable fibres, bibliography of, 337 classification of, 303 glue, 377 oils and fats, 53 textile fibres, 302 Vellum, 372 Vesuvine, 461 Vicuna fibre, 343 Vigorite, 84 Vin de raisin sec, 230 Vinasse, 171, 255 Vinegar, analysis of, 271 Vinegar, manufacture of, 266 Violamine, 460 Violet dyes, recognition of, on fibre, 482 Viscose, 334, 336 Viscosity test, 43 Volatile oils, 103 Volume and weight relations, tables of, 577 " Vomiting " boiler for paper stock, 316 Vulcan powder, 84 Vulcanite, 118 Vulcanization of rubber, 117 W Walnut oil, 54 Water for dyeing, 534 Wau, 493 Weight and volume relations, table of, 577 " Weighting " of silk, 544 Weingartner's dye-testing tables, 471 Weiss-beer, 218 Weld, 493 Westphal balance, 86 Wetzel pan, 147 Whale oil, 57 Wheat group of starches, 185 Whey, 293 alcohol, 293 butter, 293 champagne, 293 of milK, 279 vinegar, 293 Whiskey, 253 White brandy, 252 White-tanned leather, 371 Wild silks, 346 Wiley's method for glucose analysis, 200 Willesden ware, 324 Willow-bark in tanning, 358 Wilson-Gwynne process for fats, 65 Wine, consumption of, in the United States, 277 ferment, 208 production of the world, 276 vinegar, 270 Wines, analyses of, 232, 233 analysis of, 235 bibliography of, 273 Woad, 495 Wood, composition of, 385 fibre, 312 naphtha, 389 pulp, recognition of, in paper, 326 spirit, 393 purification of, 392 tar, creosote tests for, 396 production and treatment, dia- gram of, 390 treatment of, 392 vinegar, purification of, 389 INDEX. 601 Wood paving specifications, 420 Wood turpentine, 106 Wool, 341, 346, 350 black, 463 bleaching, 528 dyeing, 541 fat, 342 grease, 57 perspiration, 342 scarlet R, 462 scouring, 346 statistics of, 354 yolk, 346 Worsted fabrics, 350 Wort, preparation of, 212 of, for spirits, 241 Wrapping-papers, 324 Writing-papers, 324 Xanthophyll, 496 Xanthopurpurin, 490 Xanthorhamnin, 493 Xylene, 435 Xylidine, 442 red, 462 Yaryan evaporator, 144 Yeast, use of, in bread, 259, 260 Yeast-plant, 205 Yellow and orange dyes on the fibres, 479 corallin, 459 Yield from distillation of wood, 388 Young fustic, 492 Zapon varnish, 332 Zinc chloride treatment of paper, 324 powder vat for indigo, 536 Zucker-couleur, 194 Zymase, 204 UNIVERSITY OF CALIFORNIA LIBRARY BERKELEY Return to desk from which borrowed. This book is DUE on the last date stamped below. MINERAL TECHNOLOGY L1BRAR/ ' 1954 LD 21-100m-ll,'49(B7146sl6)476 YD 07578 ^15803 rip s ( ^ ( c