UC-NRLF 
 
 tED MEb 
 
GIFT OF 
 
 PROF. W.B. RISING 
 
-v- 
 
THE 
 
 STUDENTS' GUIDE 
 
 QUANTITATIVE ANALYSIS 
 
 INTRNDED AS AN AID TO THE STUDY OF 
 
 FRESENIUS' SYSTEM. 
 
 BY 
 
 H. CARRINGTON BOLTON, Ph.D., 
 
 PROFESSOR OF CHEMISTRY IN TRINITY COLLEGE, 
 HARTFORD, CONN. 
 
 ILLUSTRATED. 
 
 NEW YORK : 
 JOHN WILEY & SONS. 
 
 1882. 
 
COPYRIGHT, 
 
 1881, 
 BY H. CARKINGTON BOLTON. 
 
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PREFA CE. 
 
 A portion of the following pages originally appeared in 
 the columns of the American Chemist, under the title: 
 "Schemes of Analyses executed in tJie School of Mines, 
 Columbia College!' Numerous applications for copies in 
 book form have induced the author to publish the Schemes 
 under a more general title. 
 
 Since writing the articles the author has been called to 
 another sphere of labor, and the circumstances which led 
 to their compilation are explained in the following para- 
 graphs, quoted from the prefatory remarks accompanying 
 the original publication. 
 
 " The system of instruction in Quantitative Analytical 
 Chemistry, organized in the School of Mines, Columbia 
 College, by Dr. C. F. Chandler, has been developed by the 
 Assistants, who have had charge of the Laboratory for 
 Quantitative Analysis, Mr. Alexis A. Julien, Dr. Paul 
 Schweitzer, and the writer. 
 
 The practical examples and the methods of analysis were 
 originally selected by Prof. Chandler ; the latter have been 
 modified by the Assistants, and from time to time they 
 have introduced new processes, conforming to the advances 
 made in this department of chemical science. 
 
VI PREFACE. 
 
 The plan of the STUDENTS' GUIDE is similar to that 
 in the excellent papers of Mr. Alexis A. Julien entitled : 
 "Examples for Practice in Quantitative Analysis," the 
 details, however, are the result of observing the needs of 
 students during my five years' experience in teaching 
 large classes. 
 
 The fragmentary character of many portions of the 
 notes is accounted for by the fact that they are intended 
 to serve in part as lecture notes, and to indicate to the 
 student the points to be ' studied. FRESENIUS' " System of 
 Instruction in Quantitative Chemical Analysis" (American 
 edition, edited by Prof. S. W. Johnson; New York, 1870) 
 is placed in the hands of each student on entering the 
 laboratory, but many students are perplexed by the peculiar, 
 though systematic, arrangement of this classic work, and 
 are at a loss to know how to begin work, what to study, and 
 where to find the information appropriate to particular 
 cases. To aid the student in the study of Fresenius' work, 
 and not to displace it, is one of the objects of the STUDENTS' 
 GUIDE. It is then scarcely necessary to state that very 
 free use has been made of Fresenius System; acknowl- 
 edgment is, however, made in all cases. By occasional 
 references to original papers the student's attention is 
 directed to methods, as detailed by their authors, with the 
 hope of encouraging the student in research." 
 
 H. C. B. 
 
 Trinity College. , 
 
LIST OF ANALYSES. 
 
 List of Analyses. 
 
 1. Baric chloride, 
 
 2. Magnesic sulphate, 
 
 3. Ammonio-ferric sulphate, 
 
 4. Potassic chloride, 
 
 5. Hjdrodisodic phosphate, 
 
 6. Silver coin, 
 
 7. Dolomite, 
 
 8. Bronze, 
 
 9. Coal, 
 
 10. Copper pyrites, 
 
 11. Alkalimetry, 
 
 12. Acidimetry, 
 
 13. Chlorimetry, 
 
 14. Type metal, 
 
 15. Zinc ore, 
 
 16. Chromic iron ore, 
 
 17. Pyrolusite, 
 
 1 8. Feldspar, 
 
 19. Slag, 
 
 20. Hematite, 
 
 21. Titaniferous iron ore, 
 
 22. Pig iron, 
 
 23. Nickel ore, 
 
 24. Arsenopyrite, 
 
 Constituents to be determined. 
 
 Ba, Cl, H 2 0. 
 
 MgO, SO 3 , H 2 O. 
 
 SO 3 , NH 3 , Fe 2 O 3 by ignition, by pre- 
 cipitation and volumetrically. 
 
 K, Cl, 
 
 Na 2 O, P 2 O 6 , H a O by direct weight. 
 
 Au, Ag, Cu, Pb. 
 
 CaO, MgO, SiO 2 , Fe 2 O 3 , CO 2 by loss 
 and by direct weight. 
 
 Cu, Sn, Zn. 
 
 H 2 O, volatile matter, fixed carbon, 
 ash, S. 
 
 Cu, in duplicate. 
 
 Soda ash, pearl ash. 
 
 Vinegar, hydrochloric acid. 
 
 Bleaching powder. 
 
 Pb, Sn, Sb, Zn. 
 
 Zn. 
 
 Cr,0 8 . 
 
 MnO,. 
 
 Si0 2 , A1 2 8 , K,0, Na 2 0. 
 
 SiO 2 , A1,O 3 , CaO, MgO, FeO, MnO, 
 S, P 2 8 . 
 
 SiO 2 , Fe, S and P. 
 
 Complete analysis. 
 
 Fe, Mn, graphite, combined C, P, 
 S, Si. 
 
 Ni, Co. 
 
 As. 
 
 vii 
 
Vlll 
 
 LIST OF ANALYSES. 
 
 List of Analyses. Constituents to be determined. 
 
 P 2 O 5 , CaO, MgO, Fe 2 O 3 , SiO 2 , H 2 O, 
 NH 3 , SO 3 , organic matter. 
 
 P 2 O 5 soluble, precipitated, and in- 
 soluble. 
 
 CaO, MgO, Na 2 0, K 2 O, SO 3 , Cl, 
 
 SiO 2 , organic matter. 
 28. Specific gravity of a solid, Heavier, lighter than, and soluble in 
 
 water, minerals and alloys. 
 
 " liquid, By the flask, by hydrometer, and by 
 weighing a s6lid in the liquid. 
 
 C, H, O. 
 
 N by Willand Varrentrapp's, and 
 Melsens' methods. 
 
 C, H. 
 
 Qualitative and quantitative. 
 
 Water, butter, casein, sugar, ash. 
 
 Water, crystallizable cane sugar 
 grape sugar, ash. 
 
 Fractional distillation, specific grav 
 itjr, fire test. 
 
 25. Guano. 
 
 26. Superphosphate of lime, 
 
 27. Water, 
 
 29 
 
 30. Sugar, 
 
 31. Potassic ferrocyanide, 
 
 32. Oil of turpentine, 
 
 33. Urine, 
 
 34. Milk, 
 
 35. Raw sugar, 
 
 36. Petroleum, 
 
INTRODUCTORY NOTES. 
 
 By means of Chemical Analysis we determine the com- 
 position of any substance. 
 
 The object of Qualitative Analysis is to determine the 
 natiire of the constituents of a body. 
 
 The object of Quantitative Analysis is to determine the 
 amount of these constituents. 
 
 Quantitative Analysis includes two methods, Gravimetric 
 and Volumetric Analysis. 
 
 In Gravimetric Analysis we convert the known constitu- 
 ents of a compound into such forms as will admit of their 
 exact determination by weight. This is done chiefly in 
 two ways : 
 
 ist. By separating one of the constituents of a body as 
 such (e.g., Cu by the battery). 
 
 2nd. By converting an existing constituent into a new 
 form by exchange of elements (e.g., AgNO 3 -[-HCl AgC 
 -j-HN0 3 ). 
 
 The forms must fulfil two conditions: 
 
 ist. Must be capable of being weighed exactly. 
 
 2nd. Must be of known and fixed composition. 
 
X INTRODUCTORY NOTES. 
 
 The choice of form of precipitate depends on two consid- 
 erations. The most preferable are 
 
 ist. Those most insoluble in the surrounding liquid. 
 
 2nd. Those in which the proportion of the constituents 
 to be determined is very small compared with the weight 
 of the precipitate (e.g., S in BaSO 4 is only 13.7 per cent.). 
 
 In Volumetric Analysis the amount of a constituent is 
 estimated by the action of reagents in solutions of known 
 strength and of determined volumes. (See Notes on Vol- 
 umetric Analysis, p. 40). 
 
WORKS FOR REFERENCE AND FOR STUDY. 
 
 Eresenius. A System of Instruction in Quantitative Chem- 
 ical Analysis. Editions: Johnson's American, 1870; last 
 English ; last German. 
 
 Thorpe. Quantitative Chemical Analysis. New York, 
 1874. 
 
 Rose, H. Traite* Complet de Chimie Analytique. Paris, 
 185962. 2 vols. 
 
 Rose H., and Finkener. Handbuch der Anatytischen 
 Chemie. Leipzig, 1867. 
 
 Mohr. Lehrbuch der Chemisch-analytischen Titrirmeth- 
 ode, vierte Auflage. Braunschweig, 1874. 
 
 Sutton. Systematic Handbook of Volumetric Analysis. 
 London, 1871 (2d ed.). 
 
 Rammelsberg. Leitfaden fur die Quantitative Chemische 
 Analyse. Berlin, 1863. 
 
 Crookes. Select Methods in Chemical Analysis. London, 
 1871. 
 
 Bolley and E. Kopp. Handbuch der Technisch-chemischen 
 Untersuchungen. Vierte Auflage. Leipzig, 1876. 
 
 Wohler. Die Mineral Analyse in Beispeilen. Gottingen, 
 1861. Also translation by Henry B. Nason. Philadelphia, 
 1871. 
 
 Prescott. Outlines of Proximate Organic Analysis. Van 
 Nostrand, N. Y, 1875. 
 
 Caldwell. Agricultural Qualitative and Quantitative Chem- 
 ical Analysis. New York, 1869. 
 
Xll WORKS FOR REFERENCE AND FOR STUDY. 
 
 Wanklyn. Water Analysis, last edition. London. 
 
 Bunsen. Anleitung zur Analyse der Aschen und Mineral- 
 wasser. Heidelberg, 1874. 
 
 Ricketts. Notes on Assaying and Assay Schemes. New 
 York, 1876. 
 
 Storer. First Outlines of a Dictionary of Solubilities of 
 Chemical Substances. Cambridge, 1864. 
 
 Heppe. Die Chemische Reactionen der wichtigsten anor- 
 ganischen und organischen Stoffe. (Tabellen, etc.) Leipzig, 
 
 1875- 
 
 Zeitschrift fur Analytische Chemie, Fresenius. Wiesbaden, 
 1862-1879. 
 
 Jahresbericht iiber die Fortschritte der Chemie. Giessen, 
 1847-77. 
 
 Bulletin de la Socie'te' Chimique de Paris. Paris, 1864-79. 
 Chemical News. Crookes. London, 1860-79. 
 American Chemist. Chandler. New York, 1870-79. 
 
 American Journal of Science and Art. J. D. and E. S. 
 Dana. New Haven, 1819-1879. 
 
THE 
 STUDENTS' GUIDE 
 
 IN 
 
 QUANTITATIVE ANALYSIS, 
 
 Analysis No. i. BARIC CHLORIDE. 
 BaCl 2 + 2H 2 0. 
 
 A. Determination of Chlorine. 
 
 See Fres. Quant. Anal., 141, I, a, and pages 564 to 
 568. (References are to Fresenius' Quantitative Analysis, 
 American edition, 1870.) 
 
 Weigh out 0.8 to i grm. of powdered BaCl 2 + 2H 2 O and 
 dissolve in cold water in a beaker ; add a slight excess of 
 AgNO 3 previously acidulated with HNO 3 ; stir well, and 
 warm. When the precipitate of AgCl has entirely settled, 
 and the supernatant liquid is quite clear, pour off through 
 a No. 2 filter; then add boiling water slightly acidulated 
 with HNO 3 , to the precipitate in the beaker; stir, and, 
 after the precipitate has settled again, pour off through 
 the filter. Continue this washing by decantation three or 
 four times ; then bring the precipitate on the filter by 
 means of a glass rod or a feather ; wash it down into the 
 point of the filter; wash lastly with a little non-acidified 
 water ; cover the funnel with paper ; label properly, and set 
 aside to dry. Weigh a clean porcelain crucible ; transfer 
 
14 QUANTITATIVE ANALYSIS. 
 
 the precipitate to this crucible, removing the AgCl from 
 the paper as completely as possible. Wrap a clean plati- 
 num wire around the rolled-up filter, forming a "cradle" 
 burn the filter in the cradle over the inverted crucible 
 cover ; do not let the ashes fall into the crucible. Moisten 
 the ashes with cone. HNO 3 (one drop); heat one minute; 
 add a drop of cone. HC1; evaporate cautiously, and heat 
 the contents of the crucible and cover until the AgCl is 
 partly fused, avoiding carefully a higher temperature than 
 necessary. See Fres., 82, b. Weigh the crucible and 
 contents. For calculation, see D. 
 
 AA. SECOND METHOD. Compare Fres., 115, 1, a, /?. 
 Take to 0.2 to 0.5 grm. BaCl 2 -l- H 2 O; dissolve in warm 
 water; acidulate with HNO 3 (free from chlorine); pour 
 into a "parting flask;" add AgNO 3 in slight excess; cork 
 the flask, and shake well. When well settled, wash the 
 precipitate in the flask by decantation with warm water, 
 without filtering. Invert the flask, covered with a watch- 
 glass, over a weighed porcelain crucible, placed in a large 
 porcelain dish, and filled with water. Withdraw the watch- 
 glass carefully, allow the precipitate of AgCl to fall into the 
 crucible, and remove the parting flask. Pour the water out 
 of the crucible, remove the last portions with filter paper, 
 and dry on a water-bath. Ignite to incipient fusion, and 
 weigh. 
 
 Note. The precipitate settles best in presence of an 
 excess of AgNO 3 . 
 
 B. Determination of Barium. 
 
 See Fres., 132, 1, i, and 101, I, a. Dissolve i to 1.5 
 grm. substance in warm water ; acidulate with HC1 ; dilute 
 to about 250 c.c.; heat to boiling ; when boiling hard, add 
 dilute H a SO 4 in slight excess ; boil some minutes and then 
 
CALCULATION OF ANALYSIS 15 
 
 keep warm while the precipitate settles. Test with a 
 drop of H 2 SO 4 ; wash with boiling water by decantation ; 
 then bring the precipitate on a No. 2 filter ; wash well ; dry 
 and ignite precipitate in a platinum crucible ; burn filter in 
 a cradle as above, and add ashes to contents of crucible. 
 See Fres., 71, a. 
 
 Note. Wash until the filtrate gives no precipitate with 
 AgNO 3 . When estimating barium in the presence of 
 nitrates, chlorides, etc., these salts are sometimes carried 
 down with the BaSO 4 . Since it is impossible to remove 
 these by washing with water alone, treat the precipitate 
 with very dilute HC1, or ammonic acetate. Cf. Crookes' 
 Select Methods, page 3 1 2. 
 
 C. Determination of Water (by Ignition). 
 
 In a weighed crucible weigh out I to 1.5 grms. substance ; 
 heat very gently at first over a small flame, and increase 
 the temperature very gradually ; finally, heat to low redness ; 
 then cool, weigh, and repeat the operation until the weight 
 remains constant. Caution : avoid too high a temperature, 
 else the Cl will be expelled. When substances contain large 
 percentages of water, as magnesic sulphate, hydrodisodic 
 phosphate, alum, etc., begin to expel the water at 100 C. 
 in an air-bath. 
 
 D. Calculation of Analysis. 
 
 See Fresenius, page 568, also 196. Make two state- 
 ments, the first to determine the amount of the desired 
 constituent in the precipitate obtained : 
 
 TVT i \\T4- f ) At. Wt. of the 1 Actual ) Actual ) 
 
 Mol.Wtof I . constituent I = weight of V : weight of [ 
 precipitate J degired J precipitate j constituent.! 
 
l6 QUANTITATIVE ANALYSIS. 
 
 The second statement determines the percentage of the 
 desired constituent in the substance taken : 
 
 Wt. of sub- 
 stance taken 
 
 }. Actual weight of ] _ . Percentage of the 
 constituent constituent. 
 
 To check work, compare with theoretical percentages 
 when possible. 
 
 Theoretical composition of crystallized barium chloride. 
 
 C1 2 = 29.09 
 2H 2 O= 14.76 
 
 IOO.OO 
 
 Use of Presetting Tables for the calculation of analyses. 
 Compare Table III, Fres., page 608. 
 
 Examples: Fe 2 O 3 X 0.7 = 2Fe. 
 
 BaOSO 3 X 0.34335 = 
 
 Consult Table IV, Fres., pages 610, et seq., also page 464. 
 
 Example: 1.2685 grms. MgSO 4 yielded a precipitate 
 of BaSO 4 , which weighed 1.2074 grms. From the table 
 we have: 
 
 .2 
 
 0.06867 
 
 .OO 
 
 o.ooooo 
 
 .007 
 
 . 0.00240 
 
 .0004 0.00013 
 
 1.2074 
 
 0.41455 
 
 =32.78 per cent. SO 3 
 
 1.2685 
 
REPORTING ANALYSES. 1 7 
 
 E. Reporting 1 Analyses. 
 
 Analyses may be reported on blank forms printed on let- 
 ter paper 8" x 10", having following headings : 
 
 HARTFORD, , 188 . REPORT OF . ANALYSIS 
 
 OF . DETERMINATION OF . GRAMMES TAKEN 
 
 . METHOD OF ANALYSIS . These headings are 
 
 printed in vertical column ; in one horizontal line 
 are placed following headings : PRECIPITATES, ACTUAL 
 WEIGHTS, CONSTITUENTS, CALCULATED WEIGHTS, PER- 
 CENTAGES, THEORETICAL PERCENTAGES ; under each a blank 
 space is left of 2 1-2 inches. Under " precipitates " place 
 formulae of precipitates obtained ; under " actual weights " 
 place actual weights of precipitates ; under " constituents " 
 place formulae of constituents to be reported ; under " cal- 
 culated weights " place the amounts of constituents existing 
 in precipitates; under "percentages" place percentages of 
 constituents actually obtained in short, the results of 
 analyses. The last column, " theoretical percentages," can 
 be filled only in the case of few pure chemical salts. 
 
 The words SPECIAL REMARKS are printed about two inches 
 from the bottom of the sheet, leaving room for remarks on 
 processes employed, etc.* 
 
 Notes to the Analysis of Barium Chloride. 
 
 Reactions, (i) BaCl 2 + H 2 SO 4 = BaSO 4 -f 2HC1. 
 
 (2) BaCl 2 + 2AgNO 3 = 2AgCl + Ba(NO 3 ) 2 . 
 
 The chloride of silver precipitate changes color on expos- 
 ure to light, losing chlorine and forming Ag 2 Cl ; the change, 
 however, is only superficial, but Mulder says the loss of 
 weight is appreciable. 
 
 * See specimen blank at the end of this book. 
 
1 8 QUANTITATIVE ANALYSIS. 
 
 When one part of silver is thrown down as AgCl in 
 1,000,000 parts of water, a slight bluish milkiness may still 
 be seen. This cloudiness disappears on adding an excess 
 of HC1. 
 
 Barium sulphate requires more than 400,000 parts of 
 water for solution. The solubility is not perceptibly 
 increased by the presence of NaCl, KC1O 3 or Ba(NO 3 ) 2 , 
 but HC1 produces a sensible increase. (Cf. Storer's Diction- 
 ary of Solubilities^) 
 
 Barium sulphate thrown down in a solution containing 
 ferric salts is often contaminated with iron. This becomes 
 evident by the reddish color of the precipitate after ig- 
 nition. The precipitate may be purified by washing with 
 ammonium acetate, or by solution in cone. PLSO 4 , and re- 
 precipitation by pouring into water. BaSO 4 dissolves in 
 cone. H 2 SO 4 in the ratio of 5.7 parts to 100, and in Nord- 
 hausen sulphuric acid as 15.9 to 100. 
 
 Analysis No. 2. MAGNESIC SULPHATE. 
 MgS0 4 +;H 2 0. 
 
 A. Determination of Sulphuric Acid. 
 
 See Fres., 132, I, I. Dissolve i to 1.5 grm. of sub- 
 stance in warm water, acidulate with HC1, dilute to about 
 250 c.c. ; boil hard ; add BaCl 2 carefully, avoiding a large 
 excess ; boil a few minutes ; let the precipitate of BaSO 4 
 settle ; wash by decantation and on the filter, and continue 
 as in Analysis I, B. 
 
 B. Determination of Magnesium. 
 
 Fres., 104, 2. Dissolve about 1.2 grm. of substance 
 in 150 c.c. cold water, in a beaker; add 30 c.c. NH 4 C1, 
 
DETERMINATION OF WATER. IQ 
 
 10 c.c. NH 4 HO, and a slight excess of HNa 2 PO 4 . (Should 
 a precipitate form on adding NH 4 HO, add NH 4 C1 until it 
 redissolves.) Stir the contents of the beaker well, avoiding 
 touching the sides with the glass rod. Cover, and set aside 
 for 12 hours, without warming. Filter and wash with cold 
 water, to which one-fourth its volume of NH 4 HO has 
 been added, until the filtrate acidified with HNO 3 gives 
 only a slight opalescence with AgNO 3 . Dry thoroughly on 
 the filter, ignite in a platinum crucible, gradually increasing 
 the heat ; burn the filter on a cradle until quite white before 
 adding the ashes to the contents of the crucible. If the pre- 
 cipitate or ash is not white, moisten with a drop or two of 
 cone. HNO 3 , evaporate, and ignite cautiously. (See Fres., 
 74, b and c.) Weigh the precipitate as Mg 2 P 2 O 7 . 
 
 C. Determination of "Water. 
 
 Heat i to 1.5 grm. salt in a weighed platinum crucible, 
 and proceed exactly as in Analysis I, C. 
 
 Notes to Analysis of Magnesia Sulphate. 
 
 On the solubility of ammonio-magnesic phosphate in 
 water and saline solutions. Cf. Fres. page 587, paragraphs 
 
 31-35. 
 
 f 1 5300 parts of pure water. 
 
 One part of | 443 " " ammoniated water, 
 precipitate 4 7548 " " strong sol. of NH 4 C1. 
 dissolves in 15600 " " water containing NH 4 HO 
 
 [ ' andNH 4 Cl. 
 
 Fresenius's proposed correction of o.ooi grm. magnesic 
 pyrophosphate for every 54 c.c. of filtrate is stated to be 
 incorrect. 
 
2O QUANTITATIVE ANALYSIS. 
 
 Reactions. By precipitation we have : 
 
 2MgSO 4 + NH 4 C1 + 2NH 4 HO + 2HNa 2 PO 4 = 
 Mg 2 (NH 4 ) 2 P 2 8 + NH 4 C1 + 2Na 2 S0 4 + 2H 2 O. 
 
 On heating we have : 
 
 (NH 4 ) 2 Mg 2 P 2 8 = Mg 2 P 2 7 + 2NH 3 + H 2 O. 
 
 Theoretical Composition 
 
 so, . 
 
 . 12 ^2. 
 
 7H 2 O 
 
 . ^1.22 
 
 
 
 IOO.OO 
 
 Analysis No. 3. AMMONIA-! RON- ALUM. 
 Fe 2 (NH 4 ) 2 (S0 4 ) 4 +2 4 H 2 0. 
 
 A. Determination of Sulphuric Acid. 
 
 Dissolve I gr. to 1.5 grms. in water, add 5 c.c., dilute 
 HC1 to prevent ferric hydrate from precipitating with the 
 BaSO 4 , heat to boiling, add BaCl 2 and proceed exactly as 
 in Analysis 2, A. 
 
 B. Determination of Ammonium. 
 
 (Fres., 99, b, 2, 0.) 
 
 (i.) Dry the salt, if necessary, before weighing, by press- 
 ing the powder between folds of bibulous paper. Dissolve 
 about 1.5 grms. in a little cold water in a casserole, add a 
 little dilute HC1 and an excess of PtCl 4 . Evaporate nearly 
 to dryness on a water-bath scarcely heated to boiling. Add 
 
DETERMINATION OF IRON 21 
 
 50 to 80 c.c. alcohol to the casserole while still warm ; do 
 not stir ; let stand several hours. The supernatant liquid 
 should be colored by an excess of PtCl 4 . 
 
 (2.) Place a No. I Swedish filter in a small funnel, wash 
 with very dilute HC1, then with water thoroughly; dry in 
 the funnel, then remove the filter and place it on watch- 
 glasses with clip; dry in an air bath 100 C. exactly, for 
 one hour precisely ; then close glasses and weigh the whole. 
 
 (3.) Bring the yellow crystalline precipitate on the 
 weighed filter by means of a clean feather, wash with al- 
 cohol carefully, not too much, dry on funnel. Then trans- 
 fer to clip, dry at 100 C. as before, and weigh. Dry and 
 weigh again, repeating until constant ; calculate results. 
 
 Precipitate has the composition (NH 4 ) 2 PtCl 6 . 
 
 [In the case of potassium determinations, wash with a 
 mixture of alcohol and ether ; also concentrate filtrate and 
 washings, filter from the secondary precipitate and add to 
 the former.] 
 
 (4.) Transfer the precipitate to a weighed crucible, burn 
 the filter and add the ashes ; ignite gradually and strongly. 
 Weigh the Pt remaining as a check on the first determi- 
 nation. 
 
 [In the case of potassium, add a little oxalic acid in pow- 
 der to the contents of the crucible, ignite, wash residue 
 with water, dry on water-bath, ignite, and weigh. (See 
 Fres., 97, 3, ft.)] 
 
 For solubility of ammonio-platinic chloride, see Fres. 
 p. 584, paragraph 16. 
 
 <J. Determination of Iron. 
 
 I. By Ignition, (Fres., 113, i, e.) Expose i.o grm. of 
 the salt in a weighed covered platinum, or porcelain 
 
22 QUANTITATIVE ANALYSIS. 
 
 crucible, to a moderate heat, gradually raise the temper- 
 ature till all the water is expelled ; then heat intensely be- 
 fore the blast-lamp. Weigh the residue as Fe 2 O 3 ; heat 
 and weigh again. Test the residue for H 2 SO 4 . 
 
 II. BY PRECIPITATION. (Fres., 113, i, a.) Dissolve 
 about I grm. of the salt in question in a large beaker with 
 about 250 to 300 c.c. of water, acidify with HC1, heat nearly 
 to boiling, add NH 4 HO in excess; let settle after stirring; 
 wash hot by decantation. (N.B. Wash out NH 4 C1 com- 
 pletely, lest on subsequent ignition a portion of the iron 
 volatilize as chloride. One grm. of ferric hydrate requires 
 nearly one gallon of water.) Bring precipitate on filter, dry 
 thoroughly on funnel, ignite and weigh. Burn filter and 
 precipitate separately. (See Fres., 53.) 
 
 Ammonia acts on the ferric solution in accordance with 
 the equation : 
 
 2[Fe 2 (S0 4 ) 3 ] + I2NH 4 HO = 2Fe 2 O 33 H 2 O + 
 6[(NH 4 ) 2 S0 4 ] + 3 H 2 0. 
 
 III. DETERMINATION OF IRON BY MARGUERITE'S METH- 
 OD. See Fres., 1 12, 2, a. Compare Mohr's Titrirmethode, 
 pages 1 80 to 204, also Crookes' Select Methods, page 73. 
 
 (i.) Standardisation of the Solution of Potassium Per- 
 manganate. Dissolve 13 grms. K 2 Mn 2 O 8 in two litres of 
 distilled water, shake, let settle over night, and siphon off 
 into a bottle. Fill a Gay-Lussac burette with this solution 
 up to the zero mark. 
 
 Dissolve exactly 0.2 grm. of piano-forte wire, previously 
 cleaned with sand-paper, in a closed flask with cone. H 2 SO 4 
 and sufficient water. Boil until dissolved ; cool suddenly 
 under the faucet, but to avoid collapse of flask wait a few 
 
DETERMINATION OF IRON. 23 
 
 moments before allowing the cold water to fall upon it. 
 The flask should be provided with a Kronig caoutchouc 
 valve. This is made by inserting a short glass tube through 
 a cork in the neck of the flask, and fitting to the projecting 
 end of the tube a piece of caoutchouc tubing about 10 cm. 
 long. A slit 4 to 5 cm. long is cut lengthwise in the 
 caoutchouc tubing, and the open end stopped with a piece 
 of glass rod. The valve is then complete. (Fig. i.) 
 
 FIG. x. 
 
 FIG. 2. 
 
 In place of the Kronig valve, another form may be used. 
 The projecting end of the glass tube, fitted to the cork in 
 the neck of the flask, is passed through another cork until 
 just even with its surface. Over the end of the cork and 
 tube a small piece of sheet caoutchouc is fastened by means 
 of pins, the rubber acting as the valve. (Fig. 2.) Having 
 effected the complete solution of the iron wire in one of 
 
24 QUANTITATIVE ANALYSIS. 
 
 these flasks, pour the solution into a large beaker contain- 
 ing about 300 to 400 c.c. H 2 O, placed upon a sheet of 
 white paper ; wash flask carefully, and add to beaker. Now 
 pour the solution of K 2 Mn 2 O 8 from the burette, drop by 
 drop, stirring continually, and continue until the pink hue 
 first permanently colors the whole liquid. Read the burette 
 and calculate as follows for the standard : 
 
 c.c. used : I c.c. = grms. Fe : x, or standard. 
 
 Repeat the titration until two concordant results are ob- 
 tained. Correction : To allow for the impurities in the 
 iron, multiply the amount taken by 0.997. 
 
 (2.) Reduction of the Ferric Solution. Dissolve 4.0 
 grms. ammonia-iron-alum in water, dilute to exactly 500 
 e.c. ; mix well, and divide in halves. 
 
 Place a piece of amalgamated zinc and a strip of plat- 
 inum foil in each reduction bottle ; pour in the solutions 
 and washings ; add a little cone. H 2 SO 4 , and cover the 
 bottles with watch glasses. The reduction requires six to 
 eight hours. If the platinum foils are new, scour them 
 with silica, rub them with KHO solution, then with HNO 3 , 
 and wash carefully. Removal of the polished and possibly 
 greasy surface hastens the evolution of hydrogen and con- 
 sequently the reduction. 
 
 Reaction : 
 Fe 2 (S0 4 ) 3 +Zn+H 2 S0 4 ^2(FeS0 4 )+ZnS0 4 +H 2 S0 4 . 
 
 (3.) Performance of the Analysis. When the reduction 
 is complete, ascertained by testing a few drops with am- 
 monium sulphocyanide, pour the contents of each reduction 
 
DETERMINATION OF IRON. 2 5 
 
 bottle into a large beaker, add H 2 SO 4 , and K 2 Mn 2 O 8 from 
 the burette until a permanent pink color is obtained. (See 
 Fres., 112, 2, a.) The two determinations, one in each 
 bottle, should not vary more than 0.2 per cent. 
 
 (4.) Calculation of tJie Analysis. No. of c.c. used X 
 standard = a or amount Fe. 
 
 a X ioo r . 
 
 = per ct. of iron. 
 
 wt. of salt taken 
 
 IV. THE STANDARD OF THE SOLUTION of potassium 
 
 permanganate may be determined in several ways. 
 
 (a.) Mohrs Method. Weigh out 1.4 grm. ainmonio- 
 ferrous sulphate, dissolve and titrate as usual. One-seventh 
 of its weight = iron. Ammonio-ferrous sulphate = FeSO 4 
 + (NH 4 ) 2 S0 4 + 6H 2 0. 
 
 In both this and the preceding method the reaction is 
 the same. 
 
 ioFeS0 4 +8H 2 S0 4 +K 2 Mn 2 8 ^5Fe,(S0 4 ) 3 +K 2 S0 4 + 
 2MnS0 4 + 8H 2 0. 
 
 (.) HempeVs Method. Weigh out 6.3 grms. pure, 
 dry oxalic acid, dissolve in one litre of water, making 
 
 N 
 
 a decinormal ( -} solution. Dilute 50 c.c. of this solu- 
 V 10' 
 
 tion, add 6 to 8 c.c. cone. H 2 SO 4 , warm and titrate. 
 The reaction in this case is as follows : 
 
 5H 2 C 2 4 + 3H 2 S0 4 + K 2 Mn 2 8 = ioCO 2 + 2MnSO 4 
 K 2 SO 4 +8H 2 O. 
 
26 QUANTITATIVE ANALYSIS. 
 
 D- Determination of Water. 
 Water may be determined by difference. 
 
 Theoretical composition : 
 
 (NH 4 ) 2 0= 5-39 
 Fe 2 O 3 =i6.6o 
 
 100.00 
 
 Analysis No. 4. POTASSIUM CHLORIDE. 
 KC1. 
 
 Expel hydroscopic moisture carefully by heating and 
 stirring in a porcelain dish over a Bunsen burner, before 
 filling the weighing tube. 
 
 A. Determination of Chlorine. 
 
 Dissolve about 0.8 grm. in warm water and proceed ex- 
 actly as in Analysis No. I, A. 
 
 B. Determination of Potassium. 
 
 See Fres., 97, 3, a, and Crookes' Select Methods, page i. 
 
 Dissolve about 0.5 grm. in a little cold water in a casse- 
 role, and proceed exactly as in the determination of ammo- 
 nia, Analysis No. 3, B, paying especial attention to tlie sen- 
 tences in brackets. 
 
 For solubility of potassio-platinic chloride, see Fresenius' 
 Quant. Analysis, p. 583, paragraph No. 8. 
 
DETERMINATION OF SODIUM. 27 
 
 Theoretical composition : 
 
 K 52-41 
 
 Cl 47-59 
 
 IOO.OO 
 
 Analysis No. 5. HYDRODISODIC PHOSPHATE. 
 Na 2 HPO 4 +i2H 2 O. 
 
 A- Determination of Sodium. 
 
 Cf. Fres., 135, a, /?. Dissolve about i grm. salt in 200 
 c.c. water in a large beaker. 
 
 Weigh off about 0.6 grm. clean piano-forte wire, place in 
 a flask, add cone. HC1 with some HNO 3 , boil hard (undei 
 a hood); when fully dissolved, continue boiling until excess 
 of HNO 3 is removed, then dilute, and, if necessary, filter 
 through a filter previously washed with dilute HC1. 
 
 Add this solution of pure Fe 2 Cl 6 to that of the hydrodiso- 
 dic phosphate, and immediately an excess of NH 4 HO. 
 Heat and let the precipitate stand some hours ; wash by 
 decantation with boiling water very thoroughly. Evap- 
 orate the filtrate with a slight excess of dilute HC1 on 
 a water-bath to dryness. Heat with care until fumes 
 of NH 4 C1 cease to come off; dissolve the residue in 
 water ; filter through a very small filter into a small 
 weighed dish, platinum preferred. Add a few drops 
 of dilute HC1; evaporate to dryness on a water-bath; 
 ignite very cautiously, not too long, and weigh the NaCl. 
 If the residue is not perfectly white and soluble in water 
 without residue, dissolve, filter through a very small filter 
 into another weighed dish. Evaporate and ignite again. 
 Test residue. 
 
28 QUANTITATIVE ANALYSIS. 
 
 B. Determination of Phosphoric Acid. 
 
 Fres., 134, I, b, a. Dissolve about 1.2 grms. of the 
 salt in question in cold water ; add " magnesia mixture " in 
 excess and NH 4 HO; set aside for twelve hours, and then 
 continue exactly as in Analysis No. 2. Consult Fres., 
 Exp. 32, p. 587. 
 
 C. Determination of "Water. 
 
 (1) By ignition. Weigh out about 0.8 gramme; place 
 it in a weighed crucible, in an air-bath, until partially de- 
 hydrated ; then heat cautiously over a Bunsen burner, ig- 
 nite eventually to redness, and weigh. 
 
 (2) By direct weight. Weigh out about 0.7 gramme 
 substance, and introduce it into the weighed ignition bulb 
 by means of a very narrow piece of folded paper. Weigh 
 CaCl 2 tube, and 'arrange apparatus, as shown in Fig. 25, 
 page 45>of Fres. Quant. Analysis (American edition, 1870), 
 substituting aspirator for gasometer if more convenient. 
 Heat cautiously, aspirating continually, and raise the tem- 
 perature to a low red heat for three minutes. In driving 
 the water into the CaCl 2 tube be careful not to burn the 
 cork. Aspirate while cooling, not too rapidly. Weigh 
 CaCl 2 tube after cooling and the ignition bulb as a check. 
 Consult Fres., 36, page 45. 
 
 Theoretical Composition : 
 
 When water is determined by heating to redness, the 
 calculation must be based on two molecules of the salt. 
 
 2Na 2 O 17.32 
 P a 5 = 19.83 
 
 =: 62.85 
 
 100.00 
 
SILVER COIN. 
 
 3 cu O 
 
 U o 
 
 ge 
 
 
 ia"! 
 
 S "" 
 
 1^ 
 
 CD t- 
 
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 81 
 
 
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 11 
 
 '5 w c 
 
 JI 
 
 il.s u 
 
 ^ ~.=rO 
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 V- C <U Ts 
 
 e d. 
 d weigh 
 CuO is 
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 , evap- 
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 119, i, 
 
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 f some 
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 f H NOs 
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 F 
 
 Dry, ig 
 s CuO. 
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 te an 
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 C 
 
 as 
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 a 
 or 
 m 
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 ilM 
 
QUANTITATIVE ANALYSIS. 
 
 
 
 
 
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ANALYSIS OF DOLOMITE. 3! 
 
 Note 2. If it is desirable to determine the SiO 2 in the 
 silicates present, " Residue a" must be treated as follows : 
 Dry and ignite (with filter), mix in a platinum crucible with 
 about six parts of Na 2 CO 3 (anhydrous), and fuse at a red 
 heat. Cool, remove the fused mass with boiling water, add 
 an excess of HC1, evaporate to dryness on a water-bath, 
 heat in an air-bath until the HC1 is completely expelled ; 
 again moisten with HC1, dissolve in water, and filter from 
 the residue. The residue which is now pure hydrated SiO 2 , 
 is dried, ignited, and weighed. The filtrate must be added 
 to "Filtrate a" Examine Fres., 140, II, b, a, and 93, 9. 
 
 Note 3. Heat the filtrate from " Residue a" add NH 4 C1, 
 and NH 4 HO in slight excess. (The NH 4 C1 may be omit- 
 ted if the " Filtrate a " is very acid.) Heat until excess of 
 NH 4 HO is expelled, filter quickly, and wash hot. See Fres., 
 113, \,a,and\ 105, I, a. 
 
 Note 4. " Precipitate b " is partly washed, and then, while 
 moist, dissolved in a little warm dilute HC1 on the filter, the 
 solution is reprecipitated by NH 4 HO and the precipitate 
 brought on the same filter, washed thoroughly, dried, and 
 ignited. Weigh as Fe 2 O 3 +Al 2 O 3 . The second filtrate is 
 added to " Filtrate &" 
 
 Note 5. Concentrate " Filtrate b" add some NH 4 C1 un- 
 less present already, add (NH 4 ) 2 C 2 O 4 in considerable ex- 
 cess, and some NH 4 HO. Let stand 12 hours in a warm 
 place. Wash partially and filter. See Fres.,\ 154, 6, #; 
 also 103, 2, b, a. 
 
 Note 6. Dissolve the partially washed " Precipitate c " 
 in HC1, reprecipitate with NH 4 HO and a little (NH 4 ) 2 C 2 O 4 . 
 Filter and wash hot, add filtrate and washings to " Filtrate 
 c? Dry precipitate on funnel, transfer to crucible, burn fil- 
 ter, add ashes, add a few drops of cone. H 2 SO 4 to contents of 
 
32 QUANTITATIVE ANALYSIS. 
 
 crucible, ignite cautiously to low redness, and weigh as 
 CaSO 4 . Compare Fres., 103, 2, b, a. 
 
 Note 7. If care has been taken to avoid undue excess of 
 NH 4 C1 in the preceding steps, the magnesium may be 
 thrown down in " Filtrate c" immediately. Otherwise the 
 NH 4 C1 must be expelled as follows : Concentrate the liquid, 
 add 3 grms. of HNO 3 for every grm. of NH 4 C1 supposed 
 to be in the solution, warm gently (60 C.) and eventually 
 heat to boiling. 
 
 Concentrate " Filtrate c" add NH 4 HO and Na 2 HPO 4 
 and proceed as in Analysis 2. B. See Fres., 104, 2, and 
 74- 
 
 Notes on the Decomposition of NH 4 C1 by HNO 3 in solu- 
 tion. Comptes Rendus, October 13, 1851 (Maumene). 
 J. Lawrence Smith in American Chemist, Vol. Ill, p. 201. 
 Also Am. Jour. Sci. (2), Vol. 15, note, page 240, which is as 
 follows : " The character of the decomposition which takes 
 place is somewhat curious and unexpected : it was first 
 supposed that equal volumes of Cl, N 2 O, and N were given 
 off, but it is shown that nearly all the NH 4 HO, with its 
 equivalent of HNO 3 , is converted into N 2 O, the liberated 
 HC1 mixing with the excess of HNO 3 . A little of the 
 NH 4 Cl-f-HNO 3 does not undergo the decomposition first 
 supposed, and in this way only can the small amounts of N 
 and Cl be accounted for." " Some nitrous or hyper-nitrous 
 acid forms during the whole process if cone. HNO 3 is used, 
 little or none if dilute HNO 3 ." 
 
 The action of NH 4 NO 3 on NH 4 C1 is theoretically as 
 follows : 
 
 2(NH 4 NO 3 )+NH 4 Cl=5N+Cl+6H a O. 
 
ANALYSIS OF DOLOMITE. 33 
 
 The following are possible reactions : 
 
 8NH 4 Cl+ioHNO 3 = 9N 2 O+8Cl + 2iH 2 O, 
 
 2HN0 3 +2NH 4 C1=N 2 0+2C1+2N+5H 2 0, 
 
 HN0 3 +NH 4 C1=HC1+N 2 0+2H 2 0, 
 
 and 
 2 HN0 3 +NH 4 C1=N 2 0+C1+N0 2 +3H 2 O, 
 
 and 
 =NO + C1+NOC1 2 +N0 2 +4C1+5H 2 0. 
 
 Note 8. Determination of CO 2 . /. By loss. Fres., 139, 
 II., d, bb, and cc. 
 
 Weigh out i.o to 2.0 grms., place 
 in the Geissler apparatus, fill the 
 proper portions of the apparatus with 
 HC1 (dil.) and with H 2 SO 4 (cone.) 
 respectively. Weigh apparatus. Cau- 
 tiously let the HC1 flow on the min- 
 eral, warm gently, heating at the last 
 till the solution begins to boil. ' Cool 
 apparatus and weigh. For details 
 consult Fresenitts, as above. Do not 
 hurry this process too much. Fi 
 
 //. By direct weight. Consult Fres., 139, II., c. 
 
 Arrange apparatus as in Fig. 4. Suspend tubes by wire 
 t loops on nails. 
 
 a contains soda-lime. 
 c is a flask of about 200 c.c. capacity. 
 d contains cone. H 2 SO 4 . 
 
 e contains pieces of pumice-stone saturated with cone. 
 H 2 SO 4 ; avoid much liquid in the bend. 
 /contains pumice-stone saturated with anhydrous CuSO, 
 
34 
 
 QUANTITATIVE ANALYSIS. 
 
 N.B. Make a strong hot solution of CuSO 4 -j-5H 2 O, add 
 pieces of pumice-stone, Soil hard, evaporate to dryness and 
 ignite well. The product should be nearly white. 
 
 g contains in outer tube, soda-lime ; in inner tube, (h) 
 pumice-stone saturated with H 2 SO 4 ; weigh these together 
 both before the absorption and after. 
 
 Fig. 4 . 
 
 Place i.o to 1.5 grms. mineral in c, weigh g and h, and 
 connect apparatus ; a is not attached at first. Pour a little 
 water through the funnel tube into c, then add gradually 
 HC1, diluted one-half with water. Attach a, and aspirate 
 gently. Heat cautiously to incipient ebullition ; maintain 
 this a few moments, and let cool while the aspiration 
 continues. Weigh increase of weight gives CO 2 . 
 
 Note 9. Calculation. Normal dolomite contains : 
 
 30.4 per cent. CaO. 
 47.8 CO,,. 
 21.8 " MgO. 
 
 i oo.o 
 
 Having estimated these constituents, calculate the 
 
ANALYSIS OF BRONZE. 35 
 
 amounts of CaCO 3 and MgCO 3 , and report under " Special 
 Remarks," thus : 
 
 CaO : CO 2 = CaO found : CO 2 required or M. 
 MgO : CO 2 = MgO found : CO 2 required or N. 
 and M -f- N must CO 2 found, nearly. 
 
 Analysis No. 8 BRONZE. 
 To be determined, Sn, Pb, Cu, Zn. 
 
 A. Determination of Tin. 
 
 Dissolve about 0.6 grm. bronze filings, carefully freed 
 from accidental impurities, in moderately dilute HNO 3 , in 
 a flask in the neck of which is placed a small glass funnel. 
 After complete solution (except the SnO 2 ), transfer con- 
 tents to a porcelain dish, evaporate to dryness, moisten 
 with HNO 3 , add H 2 O, and filter from the SnO 2 . Dry this 
 residue, ignite in porcelain, and weigh. Fres., 126, I., a, 
 and 91. 
 
 B. Determination of Lead- 
 To filtrate from A add dilute H 2 SO 4 , evaporate until 
 fumes of H 2 SO 4 appear, or the residue is nearly dry, let 
 the dish cool, then add water, and filter from the PbSO 4 . 
 See Fres., 163, 2, and 116, 3, a, p. Dry, ignite, and 
 weigh precipitate. See Fres., 83, d. 
 
 C. Determination of Copper. 
 
 The filtrate from B. should not measure more than 100 
 c.c. Place the solution in a large platinum dish, arrange 
 the Bunsen cells of a galvanic battery, connect the zinc 
 
36 QUANTITATIVE ANALYSIS. 
 
 element with the platinum dish, and the carbon element 
 with a small piece of platinum foil which is immersed in 
 the liquid. Let the battery run four or five hours. Take 
 out a drop of the solution with a pipette, place on a watch 
 glass and test for Cu with H 2 S. Pour out the solution 
 when the precipitation is completed, and wash thrice with 
 small quantities of water. Then wash the copper film 
 with alcohol twice, dry in the hand, over a Bunsen burner, 
 at a very gentle heat, and weigh quickly. 
 
 N.B. It is advisable to test solution for Cu before 
 proceeding further. 
 
 D. Determination of Zinc. 
 
 Heat the filtrate and washings from C to boiling, add 
 excess of Na 2 CO 3 , boil a few minutes, wash by decantation 
 hot, then on filter, Dry, ignite, and weigh as ZnO. Fres., 
 108, I, a, and 77. 
 
 Analysis No. 9. COAL. (PROXIMATE ANALYSIS.) 
 
 To be determined, Moisture, Volatile and Combustible 
 Matter, Fixed Carbon, Sulphur, and Ash. 
 
 A- Determination of Moisture. 
 
 Pulverize the coal very finely, heat one to two grms. in a 
 half ounce platinum crucible for fifteen minutes at 115 C. 
 in an air-bath, cool and weigh. Repeat this desiccation in 
 the air-bath, weighing at intervals of ten minutes, until the 
 weight is constant or begins to rise. Loss of weight gives 
 moisture. In reporting, give exact temperature at which 
 it was determined. N.B. The increase in weight is due 
 to oxidation of the coal ; it generally begins after heating 
 
ANALYSIS OF COAL. 37 
 
 thirty to ninety minutes in the air-bath. Anthracite coal 
 may be heated an hour or more. See Chem. News, Am. 
 Repr., Vol. V., p. 80. 
 
 B. Determination of Volatile Combustible Matter. 
 
 Heat the same crucible with contents, closely covered, 
 to bright redness over a Bunsen burner, exactly three and 
 one-half minutes, and then without allowing the crucible 
 to cool, heat strongly before the blast-lamp, exactly three 
 and one-half minutes more. Cool and weigh. The loss 
 gives the volatile and combustible matter, and includes half 
 the S in the FeS 2 . See F below. 
 
 C. Determination of Fixed Carbon. 
 
 Heat crucible and contents, uncovered, over Bunsen 
 burner, until all carbon is burned off and the weight is 
 constant. This takes from one to four hours or more. 
 Loss in weight = fixed carbon, including half the S. 
 
 D- Determination of the Ash. 
 
 The difference between the weight last obtained and that 
 of the crucible gives the weight of the ash. Note color of 
 the ash. 
 
 B. Determination of Sulphur. 
 
 Secure a sample of anhydrous Na 2 CO 3 , shown to be ab- 
 solutely free from S by the silver test. 
 
 Weigh out about two grms. coal in fine powder, mix 
 with about ten grms. NaNO 3 and ten grms. Na 2 CO 3 on 
 glazed paper. The sodium salts need not be weighed ac- 
 curately ; KNO 3 may be used in place of NaNO 3 . Deflag- 
 rate in a covered two-ounce platinum crucible, heating over 
 
38 QUANTITATIVE ANALYSIS. 
 
 a Bunsen burner ; add the mixed coal and sodium carbonate 
 little by little, replacing the cover of the crucible quickly 
 each time. Do not expect to effect a perfect fusion. Place 
 the crucible and contents in a casserole, add water, and 
 digest until the mass is disintegrated, and the crucible can 
 be removed. Add cautiously an excess of HC1, heat to 
 boiling, and throw down the H 2 SO 4 with BaCl 2 as usual. 
 If flocks of SiO 2 remain insoluble in HC1, evaporate to 
 dryness on water-bath, heat until HC1 is expelled, add 
 water, filter, and proceed as above. If the BaSO 4 is red- 
 dish after ignition, wash with solution NH 4 C 2 H 3 O 2 and 
 then with pure water, dry, ignite, and weigh again. The 
 BaSO 4 may also be purified by solution in cone. H,SO 4 and 
 reprecipitation with water. 
 
 Second Method for Determining Sulphur. Put two to 
 five grms. powdered coal in a flask holding a litre ; add 
 100 c.c. HNO 3 and five grms. powdered KC1O 3 , heat to 
 boiling, adding more reagents as needed ; continue until all 
 the carbon is oxidised. Transfer to a dish, evaporate to 
 dryness, add HC1 and water, throw down H 2 SO 4 with 
 BaCl 2 , and proceed as usual. Consult Hayes's article in 
 Am. Chem., Feb., 1875, also Wittstein's article in Am. 
 Chem., April, 1876. 
 
 P. Calculations. 
 
 Theoretically we should deduct half S from the volatile 
 combustible matter (because iron pyrites loses one-half its 
 sulphur at a red heat), one-eighth S from the fixed car- 
 bon, and three-eighths from the ash. (2FeS become Fe 2 O 3 , 
 or 8 X 4== 32 reduces to 8 X 3 24.) 
 
 Practically half the amount of sulphur is deducted from 
 the volatile combustible, and half from the fixed carbon ; 
 reports should be made out accordingly. 
 
ANALYSIS OF COPPER PYRITES. 39 
 
 G-, Estimation of Carbon and Hydrogen. 
 
 Ignite one grm. of coal with PbCrO 4 in a hard glass 
 tube 0.25 metre long. Pass the H 2 O, CO 2 and H 2 SO 4 
 formed through two U-tubes, one containing ignited CaCl 2 , 
 and the other a solution of Pb(NO 3 ) 2 , and through a potash 
 bulb. The increase in weight of the first U-tube gives the 
 H 2 O, and that of the potash bulb the CO 2 . 
 
 Calculation of Calorific Power. One part of carbon in 
 burning yields 8,080 calorific units, and one part of hydrogen 
 in burning 34,460 calorific units. Hence to calculate total 
 calorific units in a coal, multiply the percentage of C by 
 8,080 and divide by 100; also multiply the percentage of 
 H by 34,460 and divide by 100. Add the quotients. 
 
 (A calorific unit is the amount of heat necessary to raise 
 one grm. of water from o to i C.) See Chem. News, 
 XXXIV, p. 233. 1876. 
 
 Analysis No. 10. COPPER PYRITES. 
 Determination of Copper. 
 
 Pulverize very finely. Weigh out exactly 2 grms., place 
 it in a flask of about 300 c.c. capacity and covered with a 
 small funnel, the stem of which is slipped into the neck of 
 the flask. Add 20 c.c. cone. HNO 3 , 5 c.c. cone. HC1, mix- 
 ing these in flask under the hood. Digest some minutes, 
 then add cautiously 20 c.c. cone. H 2 SO 4 and boil hard un- 
 til fumes of H 2 SO 4 appear abundantly. Cool, add water 
 with caution, dilute not too largely, filter from residue (SiO 2 , 
 CaSO 4 , etc.), and wash. Test residue for copper before 
 the blow-pipe. Dilute filtrate to 200 c.c. exactly, mix well 
 by pouring into a dry beaker and back again three or four 
 times ; divide in halves by taking out 100 c.c. with a pipette 
 
4O QUANTITATIVE ANALYSIS. 
 
 and place in a platinum dish previously weighed. (N.B. 
 Volumetric apparatus as sold is rarely reliable, therefore 
 test pipette and flask before measuring as above.) Arrange 
 two cells of a Bunsen battery, placing the " battery acid " 
 (one part of H 2 SO 4 diluted with 8 to 10 of water) in the 
 outer cell and "battery fluid" (K 2 Cr 2 O 7 +H 2 SO 4 +H 2 O) in 
 the inner. Connect the zinc (-(-) pole with the platinum 
 dish, and the carbon ( ) pole with a piece of platinum 
 foil which is immersed in the liquid. Cover the platinum 
 dish with two pieces of glass plate, one each side of the 
 platinum foil, to prevent loss by spattering. Or use the 
 cone or spiral described in Chem. News, XIX, p. 222 (1869). 
 See also Crookes Select Methods, pages 187-200. 
 
 It is best not to let the battery run all night ; prepare 
 the solutions on one day and start the battery the next 
 morning. Four hours or more usually suffice for complete 
 precipitation. 
 
 Test a few drops of the solution with H 2 S. 
 
 When precipitation is complete, pour off liquid, wash 
 copper with distilled water three or four times (work rap- 
 idly), then with strongest alcohol twice ; drain the alcohol 
 off, dry the copper at a very low heat, holding the plati- 
 num dish in the hand over a small flame, which must not 
 touch the dish, and weigh immediately. Next treat the 
 remaining 100 c.c. solution likewise ; the two determina- 
 tions should agree to about 0.2 per cent. 
 
 Analyses No. 11 and No. 12. 
 Introductory Note 3 on Volumetric Analysis. 
 
 Definition. " Volumetric Analysis is a form of quantita- 
 tive analysis in which we seek to estimate the amount of 
 a substance from the determinate action of reagents in 
 
VOLUMETRIC ANALYSIS. 41 
 
 solutions of known strength, the amount of the reacting 
 substance being calculated from the volume of the liquid 
 used." The first principles and method of procedure have 
 been foreshadowed in Analysis No. 3, III., Determination 
 of Iron by Marguerite's method. For explanation of gen- 
 eral volumetric methods, see Fres. 54, and consult Sut- 
 ton s Handbook of Volumetric Analysis, also Mohr's Lehr- 
 bnch der cJiemisck-analytisdien Titrirmethode. 
 
 Principles. When volumetric analysis first came into 
 use, the standard solutions were so prepared as to give 
 results in percentages ; thus in Alkalimetry, one standard 
 solution of acid was used for potash, another for soda, etc. 
 The modern system is based on the fact that acids and 
 alkalies (as well as other reagents) neutralize each other in 
 the proportion of their molecular weights, or of simple 
 multiples of the same ; consequently standard solutions are 
 so prepared that one litre contains one-half or the whole 
 of the molecular weight of the reagent weighed in grms. 
 For example, the molecular weight of HC1 being 36.5 and 
 that of KHO 56.1, 36.5 grms. of HC1 exactly neutralize 
 56.1 grms. of KHO, and if these respective amounts be 
 dissolved in one litre of water, the whole of one solution 
 will not only neutralize the whole of the other, but any 
 aliquot part of one will exactly neutralize a similar aliquot 
 part of the other. And by using graduated vessels, (bu- 
 rettes,) the amount of reagent used is determined by the 
 volume of the solution. (Before employing burettes, 
 pipettes, and graduated flasks, care should be taken to test 
 the accuracy of the graduation.) 
 
 Standard Solutions. Solutions containing the molecu- 
 lar weight of the reagent expressed in grms. per litre are 
 called normal solutions ; in the case of di-basic acids 
 (H 2 SO 4 , H 2 C 2 O 4 etc.) and of " di-acid " alkalies (Na 2 CO.) 
 
42 QUANTITATIVE ANALYSIS. 
 
 one-half the molecular weight of each is taken, making 
 half normal solutions. 
 
 The standard solutions of the following reagents are 
 made with the quantities indicated : 
 
 Oxalic acid H 2 C 2 O 4 -f-2 aq. 63 grms. per litre 
 
 Sulphuric acid H 2 SO 4 49 " " 
 
 Hydrochloric acid HC1 36.5 " 
 
 Sodium carbonate Na 2 CO 3 53 " " 
 
 Potassium hydrate KHO 56.1 " " 
 
 Ammonia NH 3 17 " 
 
 The point of neutralization or end reaction is determined 
 by adding to the solutions some organic coloring-matter 
 which changes in hue under the influence of an alkali or 
 an acid. The " indicators " commonly used are litmus 
 solution and cochineal solution. 
 
 ALKALIMETRY. 
 (Cf. Sutton's Handbook.) 
 
 1. Preparation of Litmus Solution. Digest 5 to 6 
 grms. litmus with about 200 c. c. water for half an hour or 
 more ; decant the clear liquid or filter ; add very dilute 
 HNO 3 drop by drop, until the color is changed to violet. 
 If properly neutralized less than one-tenth c.c. of stand- 
 ard acid should distinctly redden one c.c. litmus in 100 
 c.c. of water. 
 
 2. Sulphuric Acid. Mix about 60 grms. cone. C.P. 
 
ALKALIMETRY. 43 
 
 H 2 SO 4 of sp. gr. 1.840 with three or four times its volume 
 of distilled water ; cool and dilute to one litre. The ex- 
 act standard of this solution is determined by testing with 
 sodium carbonate, as below. 
 
 3. Sodium Carbonate Solution. Weigh off about 12 
 grms. anhydrous C.P. Na 2 CO 3 ; heat in a porcelain dish 
 to low redness, stirring until moisture is expelled ; place in 
 a desiccator to cool. Weigh out accurately 10.6 grms. of 
 this, and dissolve in distilled water. Dilute to exactly 200 
 c.c. This gives a half normal solution, each c.c. of which 
 contains 0.053 grm. of sodium carbonate, as shown by this 
 simple calculation : 
 
 Na 2 = 46 
 
 C = 12 
 
 3 = 48 
 
 Mol. wt. of Na 2 CO 3 106 ' 
 One-half the mol. wt. = 53 
 
 200 c.c. : i c.c. = 10.6 grms.: 0.053 grms. 
 This solution serves to standardize the sulphuric acid. 
 
 Standardizing the Sulphuric Acid. Take of the Na 2 CO 3 
 solution, 20, 30, or 40 c.c., accurately measured, place in a 
 wide-mouthed flask of about 300 c.c. capacity ; add litmus 
 solution, and run in H 2 SO 4 solution from a burette until 
 a wine-red color is obtained ; boil hard to expel CO 2 , and 
 add more acid until the color is permanent. Read off the 
 c.c. used. Repeat the process. Suppose 30 c.c. Na 2 CO 3 
 solution required 25 c.c. H 2 SO 4 solution. Then 5 c.c. 
 (30 2 5) water must be added to every 25 c.c. of the acid 
 solution to make it normal. Measure, therefore, the 
 H 2 SO 4 solution carefully and add the necessary amount of 
 water. Suppose the H 2 SO 4 solution measures 900 c.c., 
 since 900=25X36, then 36 X 5, or 180 c.c. water must 
 be added. Add the water, mix well, and again determine 
 
44 QUANTITATIVE ANALYSIS. 
 
 the standard : one c.c. of the Na 2 CO 3 solution should ex- 
 actly neutralize one c.c. of the H 2 SO 4 solution. In case of 
 difficulties the exact standard of the acid should be deter- 
 mined gravimetrically by precipitating 10 or 20 c.c. with 
 BaCl 2 , and calculating from the BaSO 4 obtained the 
 amount of H 2 SO 4 in one c.c. 
 
 Carminic acid being stronger than carbonic acid, a solu- 
 tion of cochineal is sometimes substituted for litmus, in 
 which case boiling may be dispensed with. The dyestuff 
 tropaeoline has recently been proposed as an indicator in 
 alkalimetry. Cf. Ber. d. chem. Ges. XI, 460 (1878). 
 
 Deci-normal Solution of Acid. Call the above normal 
 solution "No. I ;" take 100 c.c. of No. i, put into a litre 
 flask, and dilute to one litre. Call this deci-normal solution 
 
 " No. 2." 
 
 A. Valuation of Soda Ash. 
 (Determination of Na 2 CO 3 .) 
 
 Place about 12 grms. powdered sample in a platinum 
 crucible or porcelain dish ; heat moderately for some min- 
 utes over a Bunsen burner, until all moisture is expelled ; 
 cool, weigh out exactly 10 grm. ; dissolve in water; dilute 
 to one-half litre and mix well. Take out 50 c.c. solution 
 (which contains one grm. soda ash), and determine the 
 amount of normal acid needed to neutralize, adding litmus 
 as before, and boiling to expel CO 2 . 
 
 Suppose 50 c.c. solution soda ash required i 5 c.c. stand- 
 ard acid, then 9 - 53 * g ^* I0 = 79-5 per cent. Na 2 CO 3 . 
 See Fres., 207, p. 500. These results are only 
 approximative and preliminary, and the operation must 
 be repeated, finishing with the deci-normal solution No. 
 2, as below. Take another 50 c.c. of soda ash solution; 
 run from a burette 12 c.c. of solution " No. i," and then 
 
ACIDIMETRY. 45 
 
 finish with solution " No 2." Of course, in calculating, 10 
 c.c. of No. 2 equals one c.c. of " No. i." 
 
 B. Valuation of Pearl Ash. 
 
 Proceed as before; weigh quickly the salt cooled in a 
 desiccator, for it is very hydroscopic. In calculating, use 
 the factor 0.0691. 
 
 The Residual Method of Titration. This method has 
 great advantages over the foregoing method, especially 
 when carbonates are in question ; the sharpness of the end 
 reaction being much increased by the absence of CO 2 . 
 The process is as follows : Super-saturate the soda ash 
 solution with normal acid in excess ; then add normal pot- 
 assic hydrate (and decinormal also) until the neutral point 
 is reached. (The normal KHO is mentioned in the next 
 paragraph.) Since one c.c. acid= one c.c. alkali, substract 
 the number of c.c. of standard alkali from the number c.c. 
 of standard acid added in the first place, and then calculate 
 as usual. 
 
 ACIDIMETRY. 
 
 Generalities. The value of strong acids, especially HC1, 
 HNO 3 , H 2 SO 4 , is frequently deduced from the Specific 
 Gravity as determined by the hydrometer. See tables in 
 Fres., pp. 488, 491, showing percentages of acids in solu- 
 tions of different densities. When titration is desirable, 
 standard KHO solution is used, and in accordance with 
 the principles already stated. 
 
 Preparation of Standard Alkali. Take about 60 grms. 
 KHO, dissolve in I litre of water, add Ca(HO) 2 to throw 
 clown carbonates, boil, let settle, and syphon off. Deter- 
 mine the exact standard of this with normal and deci- 
 normal acid. 
 
46 QUANTITATIVE ANALYSIS. 
 
 A. Valuation of HC1. 
 
 Take 5 to 50 c.c. acid, according to strength, dilute to a 
 definite volume, take an aliquot part, add litmus and run in 
 the standard KHO as described. 
 
 In calculating multiply the number of c.c. of KHO 
 added by .0365 X 100, and divide this product by the num- 
 ber of c.c. of acid taken X Specific Gravity of the solution 
 as determined by the hydrometer. 
 
 Example. Took 10 c.c. HC1 solution, having a Specific 
 Gravity = 1.025 ; since I c.c. of water weighs I grm., the 
 weight of acid taken 10.25 grms. 
 
 The acid solution required 8 c.c. KHO, whence 
 
 8 X .0365 X ioo 
 
 - - = 2 - 8 4 Per cent. 
 
 B. Analysis of Vinegar. 
 
 A. Determine the acetic acid by titration, using cochi- 
 neal solution, or with methylaniline violet, as in the " Witz 
 method" (Am. C/iem.,Vo\. VI, page 12), or use Mohrs 
 method, as follows : 
 
 Add to a known quantity of acid a weighed quantity 
 (in excess) of pure precipitated dry CaCO 3 . After de- 
 composition is nearly complete in the cold, boil to expel 
 CO 2 , filter, and wash the excess of CaCO 3 in hot water. 
 Dissolve the CaCO 3 in excess of normal HC1, and deter- 
 mine the HC1 remaining by means of normal KHO, or 
 NaHO and litmus solution. The results with dark 
 colored vinegars are good. 
 
 B. Determine water by drying at 100 C. to constant 
 weight, and allow for alcohol and acetic acid. 
 
CHLORIMETRY. 47 
 
 C. Determine alcohol by neutralizing about 300 c.c. 
 vinegar with CaCO 3 and distilling off some measured 
 amount, say 150 c.c. Then determine specific gravity by 
 weighing, and from this calculate the per cent, of alcohol. 
 
 D. Determine the grape sugar. (See Analysis No. 33.) 
 
 Analysis No. 13. CHLORIMETRY. 
 
 Constitution of Bleaching Powder. 
 Bleaching powder is formed thus : 
 
 2CaH 2 O 2 + 2C1 2 = 2H 2 O + CaCl 2 O 2 ,CaCl 2 . 
 
 The composition of bleaching powder is variously given. 
 The following are some of the formulae. 
 
 " Quelques Chimistes," CaCl 2 + H 2 O 2 . . 
 Watts, CaCIO + CaCl, Ca 2 O + 2H 2 O. 
 Bloxam, CaO C1 2 O + CaCl 2 2CaO +4H 2 O. 
 Roscoe, CaCl 2 O 2 . 
 Muspratt, CaO C1 2 2H 2 O. 
 Fownes, CaCl 2 -f- CaCl 2 O 2 . 
 Calvert, 2CaCl 2 + CaCl 2 O 2 . 
 
 Thorpe, Ca 3 H 6 O 6 Cl 4 = CaCl 2 O 2 + CaH 2 O 2 + CaCl 2 + 
 2H 2 O. 
 
 Kolb, ( 2 CaO,Cl 2 H 2 0), CaH 2 O 2 . 
 
 Rose, (CaCl 2 , Ca 2 O 2 ) CaO 2 Cl 2 + 4H 2 O. 
 
 Stahlschmidt's theory of its formation : Bericht D. 
 CJtcm. Ges., 1875 : 
 
 3CaH 2 2 + 4 C1 = CaCl 2 + CaCl 2 O 2 + CaH 2 O 2 + 2H 2 O. 
 
 See paper on Constitution of Bleaching Powder, by Dr. 
 Lunge in American Chemist, Vol. V, page 454. 
 
48 QUANTITATIVE ANALYSIS. 
 
 When allowed to stand in contact with air and light, it 
 decomposes, CaCL increasing, and the CaCIO decreas- 
 ing. Dry chloride of lime, at 50 C., decomposes thus : 
 (THORPE.) 
 
 3 Ca 3 H 6 6 Cl 4 = 5CaCl 2 + Ca(ClO 3 ) 2 + 3CaH 2 O 2 + 6H 2 O. 
 
 By the action of water chloride of lime decomposes 
 thus : 
 
 Ca 3 H 6 6 Cl 4 = CaH 2 O a + CaCl 2 + CaCl 2 O 2 + 2H 2 O. 
 
 The value of the commercial article depends wholly 
 upon the amount of " available chlorine," viz. : the Cl in 
 the hypochlorite, which is thus constantly varying. 
 
 The strongest contains 38.5 per cent, available chlorine. 
 One or two per cent, of this is present as calcium chlorate, 
 which is without bleaching power. 
 
 Action of Acids on Bleaching Powder. Action of hy- 
 drochloric acid : 
 
 (CaQ 2 2 + CaCl 2 ) + 2HC1 = 2CaCl 2 + 2(HC1O). 
 Action of dilute sulphuric acid : 
 
 (CaCl 2 2 + CaCl 2 ) + H 2 SO 4 = CaSO 4 + CaCl 2 + 
 2(HC10). 
 
 Further action of concentrated sulphuric acid : 
 
 CaS0 4 + CaCl 2 + 2(HC1O) + H 2 SO 4 == 2(CaSO 4 ) + 
 4C1 + 2H 2 O. 
 
CHLORIDE OF LIME. 49 
 
 Valuation of Chloride of Lime. 
 
 Penofs Method. From Fresenius' Quant. Analysis, 
 212. Based on the conversion of an alkaline arsenite, 
 into an arseniate by a solution of chloride of lime. 
 
 As 2 O 3 + CaCl 2 O 2 As 2 O 5 + CaCl 2 . 
 
 The end reaction is determined by KI and starch, un- 
 decomposed hypochlorite turning this mixture blue. 
 
 (a.) Preparation of KI Starch Paper. Boil three grms. 
 starch, in 250 c.c. water, add one grm. KI, one grin. 
 Na 2 CO 3 + aq. ; dilute to 500 c.c. Moisten paper with 
 this solution and dry. 
 
 (b.} Preparation of Solution of As 2 O r Dissolve ex- 
 actly 4.95 grms. pure sublimed As 2 O 3 with 25 grms. 
 Na 2 CO 3 -\- aq. (free from S) in 200 c.c. water. Boil until 
 
 N 
 dissolved and dilute to one litre. Make a solution. 
 
 Since it is difficult to weigh out exactly this amount, take 
 any number and dilute proportionately. If 5.013 grms., 
 then 
 
 4.95 : i ooo = 5.013 grms. : 1012.7. 
 
 Add then 12.7 c.c. to the litre. One c.c. of this solu- 
 tion = 0.00355 Cl. 
 
 (c.) Process of the Determination. Mix sample well ; 
 weigh out 10 grms., rub in mortar with 50 or 60 c.c. water ; 
 settle; decant turbid liquid into a litre flask. Repeat. 
 Fill up to mark, and mix. 
 
 Fill a burette, take 50 c.c., run it into a beaker, add the 
 standard As 2 O 3 solution, stirring until a drop of the so- 
 
5O QUANTITATIVE ANALYSIS. 
 
 lution no longer gives a blue mark on the KI starch paper. 
 Repeat on fresh amount. Caution : Shake, and draw off 
 turbid liquid. 
 
 (d.) Calculation. 
 
 c.c. As 2 O, solution used X 0.0035 5 X 100 
 
 : = per cent. Cl. 
 
 Amount taken 
 
 [French chlorimetrical degrees represent the number of 
 litres of Cl at o.C. and 760 m.m., which one kil. of sample 
 should yield. Now one litre of Cl weighs 3.177 grms. ; 
 hence 31.77 per cent. = 100 degrees. See foot-note on 
 p. 505 of Fres. Quant. Anal.'] 
 
 The amount of calcium chloride present may be de- 
 termined by first estimating the hypochlorite as above, and 
 then adding to the second portion of 50 c.c. a slight excess 
 of NH 4 HO and warming. 
 
 3 CaCl 2 O 2 + 4 NH 3 = 3CaCl 2 + 6H 2 O + 4N. 
 
 Neutralize the solution with HNO 3 and determine the 
 Cl by AgN0 3 . 
 
 The amount of chlorate may be determined by heating 
 a third portion with ammonia, then acidulation with pure 
 H 2 SO 4 and digesting with Zn. 
 
 Ca(C10 3 ) 2 + I2H = CaCl 2 + 6H 2 O. 
 
 Again determine the Cl by AgNO 3 , and the increased 
 amount over the second determination gives the Cl exist- 
 ing as chlorate. (THORPE.) 
 
TYPE METAL. 
 
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52 QUANTITATIVE ANALYSIS. 
 
 Note I. Some of the tin may go into solution as 
 nitrate of tin, if the nitric acid be dilute, and thus appear 
 in Precipitate c mixed with the sulphide of antimony ; in 
 this case they should be separated by F. W. Clarke's 
 method, which is based on the solubility of the sulphide 
 of tin in oxalic acid, and details of which may be found in 
 Crookes' Select Methods, page 249. For another method 
 see Fres., 165, 4, a, also 165, 7, a. 
 
 Note 2. On the other hand, some of the antimony 
 and lead may refuse to dissolve and remain with Residue a, 
 in which case proceed as follows : after igniting and weigh- 
 ing the SnO 2 + Pb ? + Sb ? fuse with Na 2 CO 3 and sulphur 
 in a porcelain crucible. Dissolve in warm water and filter 
 from the residue of PbS, which may be treated with HNO 3 
 in a porcelain crucible and weighed as PbSO 4 . To the 
 alkaline solution add slight excess of HC1 and collect 
 precipitate of SbS 3 -f- SnS 2 + S on filter ; dry and remove 
 excess of S by washing with CS 2 , transfer to porcelain 
 capsule, oxidize with HNO 3 evaporate to dryness, fuse 
 with NaHO in a silver dish, dissolve the mass in a mixture 
 of three volumes of alcohol and one of water, and filter 
 from the antimoniate of sodium. For details, see Fres., 
 165, 4, a To the solution containing stannate of sodium, 
 add HC1, saturate with H 2 S, and treat the precipitated 
 SnS 2 as usual. See Fres., 126, I, c, and 91. 
 
 Consult article on the Estimation of Antimony, by E. 
 H. Bartley, in American Chemist, Vol. V, page 436; also 
 paper by Dr. Clemens Winkler, in Fresenius' Zeitschrift 
 fur Analytische Chemie, Heft 2, 1875. 
 
DETERMINATION OF ZINC. 
 
 53 
 
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 C 
 
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 ETERMINATION OF ZlNC. 
 
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 arm and filter, wash thoroug 
 
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 Filtrate 
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 Iter, carefully covering the fu 
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 > 7} M-.S? 
 
 solution must be very car 
 and striking as deep brown- 
 
 f determining Zn, see artic 
 
 Filtrate d. 
 Examine carefully for 
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54 
 
 QUANTITATIVE ANALYSIS. 
 
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$6 QUANTITATIVE ANALYSIS. 
 
 Analysis No. 17. PYROLUSITE. 
 Determination of MnO 2 . 
 
 Employ Fresenius and Will's method as described in 
 Fres. Quant. Analysis, edition of 1870, pages 509-12, 
 215, A. See also Mohr's Titrirmethode 215, pp. 617-638 
 (ed. 1874). 
 
 Take 3.955 grms. of ore, and use Geissler's carbonic 
 acid apparatus if available. 
 
 Consult also the following article : " On the Estimation 
 of Peroxide of Manganese in Manganese Ores," by E. 
 Scherer and G. Rumpf, Chemical News, American Re- 
 print, Vol. VI, page 82, February, 1870. 
 
 Analysis No. 18. FELDSPAR. 
 
 A- Determination of Alkalies. 
 
 Prof. J. Lawrence Smith's method. See Am. J. Sci. 
 [3] I, 269. Also Fres., 140, II, b, r> 
 
 Pulverize well in an agate mortar. Weigh out one grm. 
 of the silicate. Mix well in an agate mortar, first, with 
 about one grm of NH 4 C1 (pure enough to sublime without 
 residue), and, secondly, with about eight grms. C. P. pre- 
 cipitated CaCO 3 ; add the latter in three or four portions, 
 mixing well after each addition. Transfer the mixture by 
 means of glazed paper to a platinum crucible. 
 
 Apply the heat of a Bunsen burner to the upper portion 
 of the crucible first and gradually carry the flame toward 
 the lower part, until the NH 4 C1 is completely decomposed, 
 
DETERMINATION OF ALKALIES. 
 
 57 
 
 which ensues in four or five minutes. Then heat before 
 the blast-lamp, not too intensely, for thirty to forty min- 
 utes. 
 
 This operation is greatly 
 facilitated by using a special 
 apparatus devised for the pur- 
 pose by Prof. J. Lawrence 
 Smith, and represented in 
 
 Fig- 5- 
 
 The stand H supports on 
 its rod G a cast-iron plate B 
 perforated by a hole large 
 enough to admit the some- 
 what elongated crucible A; 
 the bottom of the crucible 
 projects within the sheet iron 
 chimney C which is held in 
 its place by the hook N. 
 When heat is applied to the 
 bottom of the crucible by the 
 flattened burner F the decom- 
 position proceeds regularly and is completed in about one 
 hour. 
 
 Cool the crucible, place it in a porcelain casserole, and 
 digest the semi-fused mass with boiling water until tho- 
 roughly disintegrated. This may take some hours. Then 
 filter from the residue (SiO 2 , Fe 2 O 3 , A1 2 O 3 , Mn 2 O 3 (?), 
 CaO, etc.), and wash well with about 200 c.c. of water. 
 All the alkalies of the silicate are converted into chlorides 
 and are now in the water solution. Add to this solution 
 NH 4 HO and (NH 4 ) a CO 3 with a few drops of (NH 4 ) 2 C 2 O 4 . 
 Evaporate without filtering, on a water-bath, to about 50 
 c.c., add a little NH 4 HO, and filter through a small filter 
 (No. 2) into a weighed platinum dish. Evaporate to dry- 
 
 FIG 5. 
 
58 QUANTITATIVE ANALYSIS. 
 
 ness on a water-bath, ignite very gently to drive off a little 
 NH 4 C1, and weigh. If the residue is not perfectly soluble 
 in water, and quite white, dissolve, filter off, evaporate, 
 ignite, and weigh again. This gives the weight of the 
 KC1 + NaCl. 
 
 Next determine the K, either by separating it with PtCl 4 
 and alcohol in the usual manner, or by gravimetric or vol- 
 umetric estimation of the total Cl in the weighed chlorides. 
 For calculation, see Fres., 197, a. Consult also Crookes' 
 Select Methods, pages 13 and 14. 
 
 B. Determination of SiO 2 , A1 2 O 3 , Pe 2 O 3 , CaO, 
 and MgO. 
 
 Fuse two grms. mineral with six grms. K 2 CO 3 -f- six 
 grms. Na 2 CO 3 . Moisten with water, digest, add excess of 
 HC1, evaporate to dryness, expel HC1 in air-bath, add 
 water and HC1, and filter from SiO 2 . Continue exactly as 
 in Analysis No. 7. 
 
SOLUBLE SILICATES. 
 
 59 
 
 I ? 
 
 s * 
 
 3 
 O rt 
 
 || 
 
 Q"| 
 
 r ^ 
 
 r^ o 
 
 91.1 
 
 pt, T3 
 
 'c-^3 tT 
 
 X r T3 <u 
 
 * 
 
 3-S^s 
 
 c u ti 
 
 8s * 
 
 rt 
 
 .t; ^o 
 
 JH' 
 
 
 
 1 1 
 
 II 
 
 a* 
 5 
 
 1 
 
 ft I 5 
 
 > > c 
 
 Wo" 
 
 r . 
 
 I 
 
 
 
 ^os:*** * > o"'.2 
 
 - e 
 
 U 
 
 o> 
 
 Sfg 
 
 3 5 S 
 
 ^ 9 ~ 
 
6O QUANTITATIVE ANALYSIS. 
 
 Analysis No. 19. IRON SLAG. 
 
 To be determined: SiO 2 , FeO, MnO, A1 2 O 3 , CaO, 
 MgO, S, P 2 5 . 
 
 Pulverize finely; weigh out exactly five grms. ; mix 
 on glazed paper, by means of a horn spatula, with 
 fifteen grms. anhydrous Na 2 CO 3 and fifteen grms. K 2 CO 3 , 
 together with one grm. NaNO 3 . These fluxes need not 
 be accurately weighed. Put one-third the mixed slag 
 and fluxes into a two-ounce platinum crucible, and heat 
 over a Bunsen burner until by settling down room is 
 made for more. Heat twenty minutes or more before 
 the blast-lamp. Cool suddenly, place in a casserole, 
 and treat with boiling water until thoroughly disinte- 
 grated. Remove the crucible and add excess of HC1 
 little by little, avoiding loss of liquid by violent efferves- 
 cence ; evaporate to dryness on water-bath, expel HC1 
 completely by drying (not above 1 15 C.) in an air-bath. 
 
 Moisten with water, add HC1, digest, and proceed as per 
 scheme on following page. 
 
IRON SLAG. 
 
 61 
 
 p 
 
 18 
 
 > ^ 
 
 j ^ > 
 
 U .M <^ l> 
 
 jj- rt 
 
 t - 
 < - ^ 
 
 Precip 
 
 solve in strong HC 
 two unequal portion 
 
 Ckrt 
 
 c 
 
 .5 <L> C/) > M - 
 
 IcT^ 
 
 rtC/} 3 
 
 5: 
 
 ^ t.s 
 
 ^) ^^ CJ 
 
 ^N rn nT 
 
 bjo,o. 
 
 
 
 :QS 
 
 a x 
 
 o c II 8 
 
 :c o~ m 
 
 
 
 - 
 
 
 8*1 !" 
 
 .s a 
 
 *-> c " 
 
 -Jolt 
 
 ', 0) C T3 
 
 ^g SoS" 
 
62 
 
 QUANTITATIVE ANALYSIS. 
 
 J^ ,0 C 
 
 "y 'G 3 
 
 OS 3 _, 
 
 g & 
 
 fi J5 ~ o c 
 
 ttf " rO S 
 
 N ^ ^J 
 
 * O **H kj 3 
 
 M 
 
 H 
 
 I 
 
 b 
 
 ffi ^ 
 
 8 I 
 
 | 8 g d 
 
 i 
 
 J5 C , ^ 
 
 u ( j 
 
 ! 1 
 
 o-8 
 
 o <u 
 
 
 S 
 
 er. 
 from 
 ed fo 
 
 Sol 
 
 1 
 
 Determine S 
 the usual man 
 The filtrate 
 may be reserv 
 eating the Fe. 
 
 - 
 
 S 
 
 }- - *O 
 
 bo > c 
 
 g 
 2 I 
 
 .2 2 
 
 ver 
 asse 
 d, 
 
 l 
 a 
 c 
 
 ample, pu 
 er in a c 
 xcess of a 
 
 til 
 
 !!?. 
 
 :s 
 
 g.sx 
 
 r 2 S 
 
 vn S 
 
 rt ^ 
 
 J* 
 
 rt ri 
 
 s*; 
 
 it 
 
 S 
 
 OS TTl 
 
 tJ3 ^ 
 
 15 5 
 
 s , 
 
 II 
 
 ^ ,/- 
 
 rt ^ ^ . t? 
 
 nat 
 
 ible 
 
 apes) 
 halve 
 the l 
 
 II 
 
 I 5 
 gS 
 
 51 
 
 o 
 
 , e 
 e i 
 
 n 
 o 
 
 (CO 
 vi 
 
 d 
 eta 
 
 y 
 d 
 
 careful 
 oo c.c.. 
 See for d 
 
 j_> J3 fl) "* 
 
 " O <U 3 x 
 
 ^ ^3 C S cS 
 
 Iff ft 
 
 I J3 S W 
 
TITANIFEROUS IRON ORE. 
 
 63 
 
 j <U 
 
 O w 
 
 OH ' 
 
 3 S 
 
 oS co 
 
 I s 
 
 o ^ 
 
 S 02 
 
 It 
 
 s 
 
 oS 
 
 g 8 -o 
 
 g ' 
 
 W ^ 03 
 
 I ! 
 
 t!s 
 
 *S, S 
 
 s -S 
 
 11 g 
 
 8, E 
 
 I a 
 
 pare 
 qualita 
 
 73 ,5 ^""^ 
 
 dirt 
 
 ,jj s. va oo 
 
 "? 9' e 
 
 C/3 
 
 a M 
 
 .s 3 
 
 1 1 
 
 1 
 
 a 
 
 * 
 
 1 
 
 1 
 
 
 
 T3 
 
 rt 
 
 S 
 
 <3 
 
 c 
 
 UH 
 
 ~^^ 
 
 
 
 1 
 
 o" 
 u 
 
 TS 
 
 C 
 rt 
 
 1 
 
 1 
 
 OS" 
 
 j^ 
 
 *j 
 
 
 05 
 
 53 
 
 
 
 
 
 CO 
 
 X! 
 
 1" 
 
 gramm 
 
 CO 
 
 oS 
 O 
 
 oS 
 G 
 
 ,d 
 
 X! 
 
 1 
 
 
 
 o 
 
 
 
 CO 
 
 cS 
 
 fe 
 
 3 
 
 "E, 
 
 TD 
 
 1 
 
 
 
 
 C 
 
 rt 
 
 Q 
 
 S 
 
 c 
 
 u 
 
 IN 
 
 -M 
 
 !s 
 
 C 
 
 'e ^ 
 
 s ^ 
 
 bJO ^ 
 
 . NJ W 
 
 ^ & 
 
 Pre 
 
 I c3 If 
 
 i 1 1 
 
 x! b >-. 
 
 S c 2 
 
 g | ^ 
 
 * -S 8 
 
 o 
 02 
 
 *o 
 
 M ^ 
 
 7:. I 
 
 I rt -O 
 
 d 
 
 02 tS 
 
 I .b ^ 
 o" * 3 
 
 .TH C oi 
 
 QQ rt _r 
 
 contain 
 , heat i 
 
 c O 
 
 iH S 
 
 -5 5 
 
 e a 5 
 
 .!_> OS vj/ 
 
 ! I- 
 
 S 1 
 
 *Q _ 7 p, 
 
 *y 
 
 t! E o3 
 
 <U CO <U 
 
 o, ; bfl 
 
 rt co 
 
 B 
 -|l 
 
 (U HH 
 
 <u 
 
 E 
 
 o 
 e 
 
 <a t! O 
 Co o '-3 
 
 3 
 
 5J D 'o 
 
 ^ 
 
 o *as 
 
 (u *2 
 fO bo's 
 
 1 jS O 
 
 Put into a 
 be afterwards 
 Filtrate/. 
 
 02 
 
64 
 
 QUANTITATIVE ANALYSIS. 
 
 C 
 
 O 2 
 
 
 OQ 
 
 n 
 i 
 
 a O C 
 
 : I-'S 
 8= 
 
 Hei 
 s i! 
 
 U O 
 
 
 II 
 
 ^3 73 
 
 ^ g 
 
 S 
 
 ^ 5 
 
 ^5 
 
 Fi 
 Fi 
 
 8 HS 
 
 M O ' 
 
 o 
 
 ij55 
 
 ^ 
 
 QJ O 
 
 rt oo rt 
 
 
 
 
 
 
 o 
 
 6Q 
 
 . 
 
 to o 
 
 
 
 Filtrate f. 
 h Solutions a 1 and 
 almost to neutral 
 ic acetate, dilute 
 inutes. (Note n 
 
 3 
 
 od 
 
 '1, combine w 
 Add Na 2 C 
 20 grammes 
 and boil ten 
 
 I, A) 
 
 , 
 
 I? 2 
 
 JSP*! 
 
 .^ <u ^ 
 
 
 
 S a 
 
 uju, 
 o 
 
 fe, S isS 
 
 co O O ^2 
 
 to 
 
 v> 
 
 s oj 
 
 > 
 
 '-Z'f* 
 
 O ^3 
 
TITANIFEROUS IRON ORE. 
 
 6 5 
 
 2 ^ 
 
 H 
 
 IpSiSfcitSrficSii, 
 
 ^i*giFsi.^Pi s ii*F^iai 
 
 ,0^5 4S O 4-g b .8*r^ 
 
 s -s g e ; E -o g I 3 53 -CL-O .^ ^9, s ^ 
 
 B^gS ^ * !^^M ^ '"^S^^ 
 
 t^ 
 
 I s 
 
 
 ^0 >* w 
 
 1 5. a 
 
 &s * 
 
 - 
 
 Q r &* rC- 
 
 oe SS.2.-' 
 ^aSulot 
 
 < ^^ *- s ^ 
 
 C" C T3 
 
 O C 
 
 ^J ^J 
 k "** 
 
 O w -M -3 n>^ ca - < -^.ti , o M , 
 
 i-g w e <i ^ (-TT3 
 
 *>-> <n .tj i - ff 'O LJJ OJ 
 
 
 
 "c 13 
 
 ;T3.5 3 
 
 I -I 
 
 r 
 
 M ^ C/) 
 
 s 
 
66 QUANTITATIVE ANALYSIS. 
 
 Notes to the Preceding- Scheme. 
 
 Note i. SAMPLING THE ORE. Break up in an iron mortar 
 forty or fifty pounds into pieces that will pass through a tin 
 sieve with half-inch holes. Thoroughly mix the fine and 
 coarse. Break up about ten pounds of average quality, so 
 that it will pass through a tin sieve with quarter-inch holes. 
 Mix well, take one pound, and pulverize in the iron mortar 
 until it will pass through a brass sieve of 60 meshes to the 
 linear inch. Mix well, take out about 50 grammes, pul 
 verize in agate mortar, pass through muslin bolting cloth, 
 and put into a small bottle, tightly corked, for analysis and 
 special determinations. It is yet necessary that every 
 portion of this required for the main analysis or a special 
 determination should be further pulverized, as needed, in 
 an agate mortar, to an impalpable powder. 
 
 Note 2. PRELIMINARY FUSION. Thoroughly mix the ore 
 and its fluxes on glazed paper, put about a third of the 
 mixture in a two-ounce platinum crucible, the lower portion 
 of whose interior surface has been previously lined with a 
 thin layer of Na 2 CO 3 , and heat over a common Bunsen 
 burner with strong flame until the greatest violence of the 
 effervescence has ceased. Then add and treat the two- 
 thirds remaining successively and with the same precaution. 
 Finally, heat strongly over the blast-lamp until the mass is 
 in complete and quiet fusion, adding a little more Na 2 CO 3 , 
 should it not readily fuse. The time required for this 
 fusion varies fron 30 to 50 minutes. 
 
 Certain highly aluminiferous ores obstinately resist this 
 method of attack ; in such cases mix with the flux a known 
 weight (two or three grammes) of chemically pure precipi- 
 tated silica which has been strongly ignited just before 
 weighing. The amount of silica added is afterwards 
 deducted from the total amount found in Residue d. 
 
NOTES TO THE PRECEDING SCHEME. 6/ 
 
 Note 3. REMOVAL OF THE FUSED MASS. Let the crucible, 
 cool until just below red heat, then chill it suddenly by 
 plunging it into cold water contained in a porcelain cas- 
 serole, lay the crucible on its side and digest with boiling 
 water. The fused mass will generally become detached 
 from the crucible and come out in a cake. Then remove 
 the crucible, wash it, treat in a small beaker with a little 
 cone. HC1 to remove any adhering particles of the mass, 
 and add this solution to that of the INSOLUBLE RESIDUE 
 (2). Should any portion of the fused mass, thicker than a 
 film, obstinately resist solution in the hot water, it ought to 
 be removed only by patience and long boiling ; and no 
 attempt should be made either to dig it out or to dissolve 
 it in HC1; lest by the formation of Aqua Regia or free Cl 
 (in the presence of NaNO 3> or Mn 2 O 3 ) the crucible be 
 attacked and injured. 
 
 Note 5. SEPARATION OF SiO 2 . In order to render the 
 SiO 2 entirely insoluble, it must be perfectly dehydrated. 
 The evaporation should be carried to dryness, the residue 
 heated until odors of HC1 can no longer be detected, and 
 the mass is hard and crumbly. Since the residue is to be 
 re-fused with Residue b, the drying may be completed, at a 
 temperature somewhat higher than 100 C., in an air-bath. 
 
 Note 8. PRECIPITATION OF BaSO 4 . Avoid the addition 
 of a large excess of BaCl 2 solution. Add only 5 c.c. at first, 
 and then after complete subsidence of precipitate, add a 
 few drops to determine if any H 2 SO 4 remains unprecipi- 
 tated, etc. Then proceed as in Fres., 132, I, i. After 
 decanting the clear supernatant liquid, boil the precipitate 
 with water, allow to subside, decant, filter, and wash with 
 hot water. These precautions are necessary to dissolve 
 out any other salts of barium, which are always carried 
 down on the first precipitation. If the precipitate of BaSO 4 
 is dark colored after ignition, dissolve in the crucible in 
 
68 QUANTITATIVE ANALYSIS. 
 
 Jiot cone. H 2 SO 4 , pour into cold water, and collect the pre- 
 cipitate as before. 
 
 Note 9. SEPARATION OF SiO 2 . Evaporate as in Note 5. 
 Then add HC1 quite freely and warm for some time before 
 adding any water, as the high heat may have produced 
 anhydrous Fe 2 O 3 , forming an oxychloride which is very 
 slow to dissolve, especially in dilute acid. Should the acid 
 already added be too dilute, .concentrate by evaporation, 
 add cone. HC1, and digest at a moderate heat. 
 
 Note ii. PRECIPITATION OF THE BASIC ACETATES. Fil- 
 trate f combined with Solutions ct and d v must be very 
 carefully neutralized with sodium carbonate. (If ammonium 
 carbonate were used, bromide of nitrogen might form in 
 Filtrate g.) To neutralize the greater portion of the acid 
 use crystallized sodium carbonate, and complete the neu- 
 tralization with a very dilute solution of the carbonate, add- 
 ing it drop by drop, agitating to dissolve the precipitate, 
 until the liquid assumes a deep mahogany-red color. If a 
 permanent precipitate forms, add a little hydrochloric acid, 
 and repeat as above. Then dilute the solution to about i 
 litre for each gramme of the sesquioxide present, add about 
 20 grammes sodium acetate dissolved in a small quantity of 
 water, and heat the whole to boiling. 
 
 It is sufficient to boil from ten to fifteen minutes for the 
 complete precipitation of the acetates. The filtering should 
 be done rapidly on a ribbed filter, keeping the fluid hot, and 
 disturbing the settled precipitate as little as possible. 
 When available the Bunsen pump may here be used with 
 advantage. After the supernatant fluid has been poured 
 through the filter, throw on the precipitate and wash it with 
 boiling water containing a little sodium acetate. Should 
 any basic acetate separate upon concentrating the filtrate, 
 add some sodium acetate, boil, filter, dissolve the precip- 
 itate in HC1, and unite to the solution cf the main body. 
 
NOTES TO THE PRECEDING SCHEME. 69 
 
 In boiling Filtrate e with KC1O 3 to oxidize FeO, be 
 careful to decompose the whole of the chlorate by heat- 
 ing with excess of HC1. 
 
 Note 1 2. DETERMINATION OF P 2 O 5 . To remove the HC1 
 in Solution g 1 add NH 4 HO in large excess, wash the pre- 
 cipitates of ferric hydrate and ferric phosphate by decanta- 
 tion two or three times, and redissolve in hot cone. HNO 3 . 
 Evaporate this solution down to small bulk (i5oc.c. to 100 
 c.c.), partially neutralize with NH 4 HO, and add about 50 
 c.c. of solution of ammonium molybdate in nitric acid. If 
 the solution is very acid, ammonium nitrate is formed by 
 the partial neutralization as above, otherwise add a small 
 quantity of the salt. Warm the solution, do not boil, and 
 let stand 24 hours or more. Then filter from the yellow 
 granular precipitate of ammonium phospho-molybdate with- 
 out bringing it all on the filter, and wash the precipitate 
 with a solution prepared by mixing 100 parts of the precipi- 
 tant with 20 parts of HNO 3 (sp. gr.= i.2) and 80 parts of 
 water. Dissolve the yellow precipitate by pouring a small 
 quantity of dilute NH 4 HO through the filter into the 
 original beaker, and determine the phosphoric acid in the 
 ammoniacal solution by means of magnesia mixture (5 c.c.) 
 in the usual manner. Magnesia mixture is preferably made 
 with magnesium chloride. If the crystalline ammonio- 
 magnesium phosphate falls mixed with flocculent magne- 
 sium hydrate, add HC1 until dissolved and reprecipitate 
 with NH 4 HO. 
 
 Reserve the filtrate and washings of the yellow precipi- 
 tate, and test for phosphoric acid by adding a little more 
 of the ammonium molybdate solution, heating and allowing 
 to stand 12 hours. If a yellow precipitate forms, pour 
 through a separate filter, dissolve in dilute NH 4 HO and 
 add to the ammoniacal solution. 
 
 If the yellow precipitate first obtained was not suf- 
 
7O QUANTITATIVE ANALYSIS. 
 
 ficiently washed, a red residue of oxide of iron may remain 
 on the filter, in which case pour dilute HNO 3 upon it, 
 allow it to pass into the ammoniacal solution, acidulate 
 that with HNO 3 , warm, add more of the precipitant, and 
 set aside as before; filter and wash several times with the 
 diluted precipitant, then dissolve the precipitate on the 
 filter and that adhering to the beaker in as little dilute 
 NH 4 HO as possible. 
 
 The yellow granular precipitate of ammonium phospho- 
 molybdate is not sufficiently constant in composition to 
 admit of directly weighing it in exact analysis ; it is there- 
 fore dissolved in NH 4 HO and the phosphoric acid thrown 
 down with magnesia mixture as just detailed. According 
 to Nuntzinger's analysis, after drying at 100 C., it contains 
 
 3-577 P er cent - NH 4 HO 
 3.962 " P 2 5 
 92.461 " MoO 3 
 
 100.000 
 
 Lipowitz says the precipitate dried at 20 to 30 C. con- 
 tains 3.607 per cent, of P 2 O 5 , and Eggertz 3.7 to 3.8 per 
 cent. P 2 O S . When dried at 120 C., Sonnenschein found 
 about 3 per cent. For properties of this precipitate see 
 also Fres., 93, i, foot-ncte. Consult also Finkener's 
 paper in Bericht d. d. chem. Ges XI, p. 1638 (1878), and 
 Chem. News, XXXVIII, p. 63, (1878). 
 
 Note 13. WASHING OF FE 2 O 3 3H 2 O. Wash this precipi- 
 tate by boiling up with water and decanting until the wash 
 water shows very little alkaline reaction with litmus paper, 
 and gives very little precipitate with solution of AgNO 3 . 
 Then transfer to filter, and wash thoroughly with boiling 
 water. 
 
 Note 1 6. DETERMINATION OF MN. (Gibbs' process, Am. 
 
NOTES TO THE PRECEDING SCHEME. /I 
 
 your. Sci. [2] XLIV, p. 216.) To the HC1 solution add 
 NH 4 HO in excess and solution of Na 2 HPO 4 in large 
 excess. Then add dilute H 2 SO 4 or HC1 until the white 
 precipitate redissolves, heat to boiling, and add NH 4 HO in 
 excess. Digest near the boiling point about an hour, when 
 the precipitate, at first white and gelatinous, becomes 
 rose-colored and forms crystalline scales. Filter and wash 
 with hot water. If tinged red, redissolve the precipitate in 
 dilute HC1, and repeat the process. On ignition the pre- 
 cipitate is converted into Mn 2 P 2 O 7 , a nearly white powder. 
 
 If Zn is present, it must first be separated as in 
 SCHEME I, Am. Chem., Vol. I, p. 323. 
 
 Note 1 8. VOLUMETRIC DETERMINATION OF FE. Put 
 Solution k l , which must be completely free from the KC1O 3 
 used to oxidize Filtrate k, into a wide-mouthed reduction 
 bottle holding about 250 c. c. Carefully let down into the 
 bottle a lump of amalgamated zinc, free from iron, and a 
 strip of platinum foil resting upon it, add about 10 c. c. 
 cone. H 2 SO 4 , cover with a watch-glass and set aside over 
 night. To ascertain if the reduction is complete test the 
 solution with ammonium sulpho-cyanide, which should 
 give only a trace of pink color. 
 
 Then introduce into a flask holding about 200 c. c., and 
 fitted with a Kronig valve, exactly 0.2 gramme iron piano- 
 forte wire, add dilute H 2 SO 4 , and heat until complete 
 solution of iron. Cool the flask, pour and wash out the 
 contents of the flask into a large beaker containing about 
 400 c. c. cold water, add a little concentrated H 2 SO 4 and 
 titrate with a solution of K 2 Mn 2 O 8 (13 grms. in 2 litres 
 water) to determine its strength. Repeat, and average 
 
 results. 
 
 Now pour and wash out the contents of the reduction- 
 bottle into a large beaker, add cone. H 2 SO 4 , and titrate 
 with the standard K 2 Mn 2 O 8 as before. If the HC1 was not 
 
72 QUANTITATIVE ANALYSIS. 
 
 properly removed from Solution fa the dark brown-red 
 ferric chloride formed will interfere with the end reaction 
 of the permanganate. In such a case reprecipitate with 
 NH 4 HO, wash thoroughly, and proceed as with Solution k*. 
 
 Treat Solution & in exactly the same manner, and aver- 
 age the results. Cf. Analysis No. 3, C. III. 
 
 For method of repeating the titration in the same solu- 
 tion, see Crookes' Select Methods, p. 74. 
 
 SUNDRY SUGGESTIONS. i. Solution a* may be used for 
 duplicating the determination of S, provided the absence 
 of Fe is proved by the proper tests. Duplicate determina- 
 tions of Ca and Mg can be made, if desired, in the filtrate 
 from the precipitate formed by ammonium hydrate in 
 Solution b z , provided this precipitate be thoroughly washed. 
 
 2. Duplicate determinations of Ti and of Fe can be 
 made in Solution b l \ the Fe can also be estimated volu- 
 metrically by dissolving in acid the weighed precipitate 
 resulting from the treatment of Solution g 2 . In the latter 
 case, however, the presence of TiO 2 will impair the results. 
 
 3. The purity of the SiO 2 obtained in Residue d may be 
 tested, after weighing, by heating with fluoride of ammon- 
 ium and concentrated sulphuric acid in a platinum crucible, 
 whereby all the SiO 2 is expelled and is determined by the 
 loss in weight, the residue being TiO 2 probably colored by 
 Fe. 
 
 4. In fusing Residue c or Precipitate k, hydro-sodium 
 sulphate may be substituted for KHSO 4 , but since the for- 
 mer contains water of crystallization it should be heated 
 until the water is expelled before using in fusions. In 
 either case avoid expelling the whole of the H 2 SO 4 , or if 
 the mass is heated to redness, partially cool, add cone. 
 H 2 SO 4 and heat again at a lower temperature. In this 
 
NOTES TO THE PRECEDING SCHEME. 73 
 
 way the TiO 2 will be held in solution by the excess of acid, 
 and the resulting acid sulphate will dissolve out readily. 
 
 For Special Determinations see NOTES TO SCHEME I in 
 American Chemist, Vol. I, pp. 323 et seq. 
 
 REACTIONS. A full discussion of the many and complex 
 reactions which take place in the preceding scheme for the 
 analysis of iron ores is superfluous. 
 
 We add a few remarks and equations which may serve 
 to throw light upon some points. 
 
 A. The action of potassium permanganate on ferrous 
 sulphate has already been formulated in connection with 
 the notes to Analysis No. 3. This action, however, may be 
 regarded as taking place in two stages, as follows : 
 
 ist stage. 2KMnO 4 +H 2 SO 4 =K 2 SO 4 +2HMnO 4 . 
 2d stage. 2HMnO 4 +7H 2 SO 4 +ioFeSO 4 =2MnSO 4 . 
 
 + 5 (Fe 2 (S0 4 ) 3 )+8H 2 0. 
 
 Solution b z is treated with excess of NH 4 HO and the 
 precipitate dissolved in H 2 SO 4 in order to remove the 
 larger part of the HC1 which might vitiate the results of 
 the titration as indicated in Note 18. The presence of HC1 
 is injurious also because it exerts a reducing action on the 
 permanganate as shown in the equations following : 
 
 2HMnO 4 +i4HCl=2MnCl a +8H 2 O+ioCl, 
 and 2FeSO 4 +H 2 SO 4 +2Cl=Fe 2 (SO 4 ) 3 +2HCl. 
 
 B. When KC1O 3 is employed in acid solution as an 
 oxidizing agent (as in the case of Filtrate e), the reaction 
 which takes place depends upon the acid used and partly 
 upon the strength of said acid. Concentrated sulphuric 
 acid is said to act thus : 
 
 6KC1O 3 +3H 2 SO 4 ^2HC1O 4 +2C1 2 O 4 +3K 2 SO 4 +2H 2 O 
 and nitric acid thus : 
 
74 QUANTITATIVE ANALYSIS. 
 
 8KC1O 3 + 6HNO 3 = 2KC1O 4 + 6KNO 3 + 6C1 + 130 
 
 + 3H 2 0. 
 
 The action of hydrochloric acid on potassium chlorate is 
 variously formulated ; Bottger gives the equation (i) and 
 Odling (2): 
 
 (1) 2KC1O 3 +6HC1=2KC1+C1 2 O 3 +4C1+3H 2 O. 
 
 (2) 4KC1O 3 +I2HC1=4KC1+3C1O 2 +9C1+6H 2 O. 
 
 In any of these cases the powerful oxidizing agency of 
 KC1O 3 is evident. 
 
 Appendix to Analysis No. 21. 
 A. Method for the Estimation of Fe and Ti only. 
 
 Sample, pulverize, fuse i grm. ore with 3 grms. NaFl-(-i2 
 grms. KHSO 4 . Dissolve in large quantity of cold water; 
 if there is any considerable residue re-fuse. Neutralize 
 with Na 2 CO 3 until a slight precipitate forms, then add 
 H 2 SO 4 until the ppt. redissolves and the liquid is slightly 
 acid. Saturate with H 2 S gas, boil some hours, occa- 
 sionally adding H 2 S water. Filter from the precipitate 
 of TiO 2 -f-S, dry, ignite, and weigh, if dark colored re- 
 fuse, etc. To filtrate add a little KC1O 3 , boil to oxidize 
 H 2 S. Reduce the iron with amalgamated zinc and plat- 
 inum foil, and titrate with K 2 Mn 2 O 8 as usual. As a result 
 of the fusion we have 
 
 4NaFl+SiO 2 +4H 2 SO 4 =4NaHSO 4 +SiFl 4 +2H 2 O. 
 
FLIGHT'S METHOD. 
 
 c -o 
 
 c 
 
 . "c * 
 
 *rt o ^ 
 
 iH U -^ 
 
 3 | H 
 
 C 3 
 
 
 
 ight's M 
 
 PQ 
 
 S ^ 
 
 S 
 co 3 
 
 II 
 
 s^ 
 
 g( C 
 
 PJ 5 c 
 
 I ^ 
 
 ^ 11 
 
 fl I | 
 
 *H "o 
 
 A g 
 
 OT^ 
 
 2 1 o 
 
 03 r i VC 
 
 2 S 
 
 s *? 
 
 J o 
 
 s. "C j 
 
 S 3 2 
 
 ^ .S fcJD 
 
 si t3 3 
 
 ^00 
 
 3tl 
 
 ^^x 
 
 rsj (]J OQ 
 
 I ^ > 
 ^ w ^ 
 s *-> 
 
 M| 
 
 ,0 C 
 
 a 
 
 .2'C o 
 
 Q e = 
 
 I? 
 
 o rt ^ 
 
 p 
 
 S^IJ 
 
 ESS* 
 
 T3^ O 
 C d, ,- 
 
 rt SS'S 
 
 Cf8i*fc 
 
 <" 5 q,8 
 ^a = 
 
 S^ ^ o 
 
 2 y ^ 
 
 4J S *"U c 
 
 Xi ^ 
 
 <S 03 
 
 .s 
 
 Si's 
 
 c 
 
 I 
 
 l 
 
 O 8 in II C 
 and filter. 
 
 Pre 
 
 e Ba 
 O 4 b 
 
 ^ S c$ 
 i'Ss SB 
 
 fc; o SrJ'3 S 
 
 ^-^ w C (^ D"O 
 
 05 
 
 ll 
 
 O 73 
 
7 6 
 
 QUANTITATIVE ANALYSIS. 
 
 & S 
 
 S c8 
 
 C rt CS 3 
 
 tuo 5 ^ .2 
 
 60^3 
 
 
 
 c 
 
 8 
 
 
 1 , 
 ^ 
 
 til 
 
 S | 
 
 
 
 g 
 
 a 
 
 1 
 
 o 8 * 
 
 T3 
 3 <L) ^ 
 
 n 
 
 g 
 
 a% 
 
 - 
 
 8-9 
 
 O Si ^^ 
 
 ,0 3 W 
 
 7\? be dete 
 
 A. Deter 
 
 g g ' 
 
 r= 
 r:i 
 
 x-^v ^ c/3 
 
 0) 4) 
 
 S .SP 
 
 S s Q 
 
 3^ 
 
 n 
 
 m 
 NS. 
 
 ttle 
 i 
 
 . 
 
 e 
 
 (By 
 KC1O 
 about 
 
 rate to d 
 100 C 
 
 po 
 
 eva 
 dried 
 
 o 
 
 C X 
 
 O Q) 
 
 tSo 
 
 ^ 2^, 
 
 fa S 
 
 C X 
 O 4) 
 
 'S-g -v 
 
 CD ^ 
 
 6 8 .1 
 
 
 
 
NOTES TO THE PRECEDING SCHEME. 77 
 
 Note i. Care must be taken in dissolving the pig-iron in 
 HC1-|-KC1O 3 not to add the oxidizing agent all at once, nor 
 too rapidly, otherwise some of the iron may remain unoxi- 
 dized. Should a small portion of ferrous chloride remain 
 in the solution, the subsequent precipitation of the iron as 
 basic acetate (as in Filtrate f, Analysis No. 21) will be 
 imperfect ; instead of an orange red flocculent precipitate 
 resembling ferric hydrate, the iron will fall as a brick-red 
 pulverulent precipitate, (anhydrous ferric oxide ?) which 
 has the property of running through niters. 
 
 Note 2. SiO 2 obtained in this manner, and dried at 
 100 C., contains 6 per cent. H 2 O, which is expelled on 
 ignition, and must be deducted from graphite after the 
 SiO 2 has been determined. According to Allen (see 
 Chemical News, Vol. XXIX., p. 91, Feb., 1874) the Si of 
 the pig-iron is converted by the action of dilute HC1 into 
 leucone, 3SiO.2H 2 O. By fusing the mixture of leucone and 
 graphite with KHO, the former goes into solution, and both 
 may be estimated directly. 
 
 AA. Determination of Graphite and Silicon. 
 
 Second Method. (EGGERTZ, Ckem. News, XVI 1 1., p. 
 232. Mix 10 c.c. H 2 SO 4 with 50 c.c. H 2 O, cool, add 5 
 grms. fine borings, boil half an hour, evaporate one-third 
 and cool. The reaction is as follows : 
 
 2Fe 4 C+8H 2 SO 4 :=8FeSO 4 +C 2 H 4 +H I2 . 
 
 This equation, however, but imperfectly formulates the 
 reaction, the S forming H 2 S and the P forming PH 3 . A 
 large number of compounds of C and H are evolved in 
 addition to the C 2 H 4 of the equation ; according to Dr. 
 
78 QUANTITATIVE ANALYSIS. 
 
 Hahn (Annalen der Chemie und Parmacie, Vol. 129, p. 57, 
 1864) they include the following : 
 
 Gaseous. 
 
 Ethjlene. C 2 H 4 . 
 Propjlene, C~H 6 . 
 Butylene, C 4 H 8 . 
 
 Liquid. 
 
 ( Amylene, C K H in . 
 Liquid. { _ J 
 
 I Caproylene, C 6 H 12 . 
 
 (Enanthene, C 7 H M 
 Caprylene, C 8 H lf 
 Elaene, C 9 H 
 
 Paramylene, C 10 H 20 . 
 Cetylene, C lfi H 32 . 
 etc. etc. 
 
 18- 
 
 Next add 10 c. c. HNO 3 and boil 15 minutes. 
 
 6FeS0 4 +8HN0 3 =2(Fe 2 (S0 4 ) 3 )+Fe 2 (N0 3 ) 6 +N 2 2 
 
 +4H 2 0. 
 
 Evaporate on a water-bath until vapor ceases to come off 
 and the mass is nearly dry. 
 
 Add 75 c. c. H 2 O+i3 c. c. HC1 and boil 15 minutes; 
 add more HC1 if any Fe 2 O 3 remains undissolved. Filter 
 through a filter washed with HC1, dried and weighed; wash 
 first with cold water until no more iron appears in wash- 
 ings, then with boiling water containing 5 per cent. HNO 3 . 
 Dry at 100 C., and weigh the residue consisting of SiO 2 + 
 graphite. Ignite and weigh again; the loss in weight gives 
 the amount of graphite. Lest the residue contain some- 
 thing besides SiO 2 it is well to determine the latter by 
 heating with NH 4 F1 and H 2 SO 4 , which expels the SiO 2 in 
 accordance with the following equation : 
 
 4 NH 4 Fl+Si0 2 +2H 2 S0 4 =SiFl 4 +2(NH 4 ) 2 S0 4 +2H 2 0. 
 
 The loss in weight gives the amount of SiO 2 ; consult, 
 however, Note 2 of A. 
 
 AAA. Graphite determination according to F. A. CAIRNS. 
 
 Dissolve 5 grms. borings in dilute HC1, boil, filter, wash 
 with hot water, then with KHO solution, then with boiling 
 
DETERMINATION OF TOTAL CARBON. 79 
 
 water, then with () alcohol, ($) ether and (<:) hot water. 
 Dry and transfer to flask and determine as in B. 
 
 In this process the combined carbon goes off in volatile 
 hydrocarbons, and graphite -)-SiO 2 together with certain 
 liquid hydrocarbons, remain. The SiO 2 is removed by the 
 KHO, the hydrocarbons dissolve out in the alcohol and the 
 ether, while the latter is removed at last by boiling water. 
 
 B. Determination of Total Carbon. 
 
 A. H. ELLIOTT'S modification of ROGER'S Process. See 
 Journal of Chemical Society, London, May, 1869; also 
 CAIRNS' article in Am. Ckem., Vol. II, p. 140. 
 
 To 2.5 grms. of borings add 50 c.c. of a neutral solution 
 of CuSO 4 , containing one part of sulphate to 5 parts of 
 water; heat gently for 10 minutes; the iron dissolves; 
 copper is precipitated, and the silica, graphite, and com- 
 bined carbon remain : 
 
 Fe+CuS0 4 =Cu+FeS0 4 . 
 
 The cupric sulphate should be as neutral as possible, in 
 order to avoid loss of combined carbon, in the form of 
 volatile hydrocarbons, as shown in AA. 
 
 Add 20 c.c. CuCl 2 (i part of chloride to 2 parts of water), 
 with 50 c.c. strong HC1, and heat for some time nearly to 
 boiling, until the copper dissolves : 
 
 CuCl 2 -f-Cu=:Cu 2 Cl 2 . 
 
 Prepare an asbcstus filter as follows : select a glass tube 
 of about 3 to 4 cm. diameter, and 18 to 20 cm. in length. 
 Draw out this tube to taper at one end, and place broken 
 glass and asbestus, lightly packed, in the narrowed portion 
 of the tube. (See Fres., 229, I, a, Fig. 100.) Filter the 
 cuprous solution through the asbestus, wash thoroughly 
 
8O QUANTITATIVE ANALYSIS. 
 
 with boiling water, and transfer contents of filter to a flask 
 holding about 200 c.c. In making this transfer, the carbon, 
 asbestus, and broken glass may be blown into the flask 
 together, in order to use as little water as possible. Add 
 to the contents of the flask about 3 grms. of CrO 3 , (or if 
 this is not available, about 5 grms. K 2 Cr 2 O 7 ), and arrange 
 apparatus as in the determination of CO 2 by direct weight, 
 Analysis No. 7, note 8, II (page 34). Avoid adding more 
 water than absolutely necessary to transfer the carbon. 
 'Add 30 c.c. to 40 c.c. concentrated H 2 SO 4 , little by little, 
 shaking constantly, and closing cock of funnel-tube each 
 time. Finally, heat gently to boiling, not allowing more 
 than three bubbles of CO 2 gas to pass per second : 
 
 3 C+4Cr0 3 +6H 2 S0 4 ^ 3 C0 2 +2Cr 2 (S0 4 ) 3 +6H 2 0. 
 
 Boil one minute, attach guard tube of soda lime, and 
 aspirate slowly, three bubbles per second. Weigh the 
 soda-lime tube for amount of CO 2 absorbed, and calculate 
 the amount of carbon. 
 
 Note The carbon separated from cast-iron by treatment 
 with sulphate of copper contains H and O, and cannot 
 therefore be determined by weighing directly. 'Schutzen- 
 berger and Bourgeois assign to it the composition expressed 
 by the formula C ir 3H 2 O, and consider it related to graphitic 
 acid. Bulletin de la Societe Chimique de Paris, Vol. 23, 
 No. 9. 
 
 BB. Other Methods for determining Total Carbon. 
 
 A great number of methods have been devised for deter- 
 mining total carbon, some of which we will briefly outline, 
 remarking, however, that the foregoing is entirely satis- 
 factory. 
 
DETERMINATION OF TOTAL CARBON. 8 1 
 
 1. Method of ALVARGONZALEZ. See Am. Chem., Vol. V., 
 p. 437. Place 10 grms. of borings in a beaker and treat 
 with a solution of cupric sulphate (40 grms. CuSO 4 in 200 
 200 c.c. H 2 O), stirring until the reaction ceases. Add di- 
 lute HNO 3 gradually, and let stand until the copper has dis- 
 solved. Dilute the solution and filter through one of Roth- 
 ers half filters (described in Chem. News, Jan. 30, 1874, 
 p. 57), wash thoroughly, and dry on funnel at 100 C. 
 Detach ppt. from filter carefully, place in a weighed cru- 
 cible (throw away filter), dry at 100 C., and weigh. Ignite * 
 and weigh again ; the difference between two weighings 
 gives total carbon. 
 
 This method is not free from objections, but will answer 
 when great accuracy is not indispensable, and speedy results 
 are desirable. 
 
 2. Method employed by I. LOWTHIAN BELL. See Chemical 
 Phenomena of Iron Smelting, London, 1872. Digest 3 grms. 
 borings from 24 to 48 hours with a solution of CuSO 4 in 
 excess, collect the spongy Cu-|-C -(-graphite on an asbestos 
 filter, and burn the carbon in a stream of oxygen gas, as in 
 the ultimate analysis of organic bodies collecting the CO 2 
 in KHO solution. Cf. Analysis No. 30. 
 
 3. Method of REGNAULT and BROMEIS. See Crookes' 
 Select -Methods, p. 74. Heat borings in a combustion tube 
 with a mixture of plumbic chromate and KC1O 3 , collecting 
 the CO 2 in KHO. 
 
 4. Methods for the liberation of Combined Carbon are also 
 numerous. 
 
 (a) BOUSSINGAULT triturates the iron in a porcelain mor- 
 tar with 15 to 20 parts of HgCl 2 and sufficient water to 
 make a thin paste : 
 
 Fe+2H g Cl 2 =FeCl 2 +Hg 2 Cl a . 
 
82 QUANTITATIVE ANALYSIS. 
 
 Then dilute with 200-250 c.c. HC1 and warm for an hour; 
 filter from the SiO 2 -j-C, wash and dry. Transfer to a 
 platinum boat, and heat in a current of pure H, volatilizing 
 the Hg 2 Cl 2 . Weigh the C, heat again in a current of O, 
 burning off the C, and weigh again. 
 
 (b) WEYL dissolves the pig-iron under the influence of 
 a galvanic current. Attach a weighed piece of cast-iron to 
 the positive pole of a Bunsen cell, and suspend it in dilute 
 HC1. The iron dissolves, H being given off at the negative 
 pole, and the carbon is separated. 
 
 Weyl has also devised another method based upon the 
 following reaction : 
 
 Fe 2 +K 2 Cr 2 7 +7(H 2 S0 4 )-Fe 2 (S0 4 ) 3 +Cr 2 (S0 4 ) 3 
 +;H 2 0+K 2 S0 4 . 
 
 See Crookes' Select Methods, p. 76. 
 
 (c) MCCREATH'S Method. See Engineering and Mining 
 Journal, March 17, 1877. The author uses double chloride 
 of ammonium and copper to dissolve out the iron, while the 
 precipitated copper dissolves in excess of this reagent; 
 he then oxidizes the carbon by means of CrO 3 in an appar- 
 atus somewhat similar to Elliott's, collecting the CO 2 in a 
 Liebig potash-bulb. 
 
 5. EGGERTZ Colorimetric Method. See Crookes' Select 
 Methods, pp. 81 to 84; also Britton's paper in Journal of 
 the Franklin Institute, May, 1870. 
 
 C. Other Methods for the Determination of Sulphur 
 and Phosphorus. 
 
 i. EGGERTZ'S Method. See Chem. News, Vol. XVII, 
 p. 207. 
 
DETERMINATION OF SULPHUR, ETC. 83 
 
 A. Dissolve 10 grms. KC1O 3 in 200 c.c. H 2 O, place in a 
 500 c.c. flask, add 5 grms. fine borings, boil and add 60 c.c. 
 HC1, little by little, boiling until the Fe dissolves : 
 
 4KClO 3 +i2HCh=4KCl+3ClO 2 +9Cl+6H 2 O, 
 and 
 
 2Fe+C10 a +Cl+4HCl=Fe a Cl 6 +2H a O. 
 
 Evaporate, dry on water-bath to insure oxidation of sul- 
 phur. Thorough dryness is unnecessary, since SiO 2 does 
 not interfere in acid solution with the precipitation of 
 BaSO 4 . Then add 10 c.c. HC1-|-3O c.c. H 2 O, and digest 
 on water-bath until all the Fe 2 Cl 6 is dissolved. Then add 
 20 c.c. H 2 O, filter, and wash thoroughly. Add 2 c.c. of a 
 saturated solution of BaCl 2 (enough to precipitate the 
 H 2 SO 4 from o.i grm. S); after cooling add 5 c.c. NH 4 HO, 
 stir and let stand 24 hours. Filter, and wash by decanta- 
 tion with cold water two or three times, and then tho- 
 roughly with hot water. Dry, ignite, and weigh. If the 
 precipitate shows traces of iron after ignition, purify by so- 
 lution in H 2 SO 4 . 
 
 B. For the determination of phosphorus dissolve the 
 pig-iron in the same manner, and dry at 140 C ; some 
 anhydrous Fe 2 O 3 will remain with the SiO 2 ; add water, 
 filter, fuse residue with a little KHSO 4 , soften with H 2 SO 4 , 
 and dissolve in water. Filter from the SiO 2 , and determine 
 it as a check on the main analysis. Add filtrate to main 
 one, and determine the P 2 O 5 by means of ammonium molyb- 
 date, as in Analysis No. 21. 
 
 2. Method of DR. T. M. DROWN. See Am. C/tem., Vol. 
 IV, p. 423. 
 
 Treat 5 grms. of borings in a flask with HC1, and pass 
 the H 2 S and PH 3 formed through a series of three bottles 
 containing a solution of K 2 Mn 2 O 8 (i grm. to 200 c.c. H 2 O). 
 Avoid a very rapid evolution of the gas ; when this ceases. 
 
84 QUANTITATIVE ANALYSIS. 
 
 aspirate for some time, and then pour the contents of the 
 bottle into a beaker, rinse with water, and add sufficient 
 HC1 to decompose the K 2 Mn 2 O 8 . Filter the colorless so- 
 lution, add BaCl 2 , to throw down the H 2 SO 4 , and proceed 
 as usual. 
 
 3. Method employed by ]. LOWTHIAN BELL. 
 
 Dissolve in HC1 as above, and pass the gases through a 
 solution of potassic plumbate (lead nitrate super-saturated 
 with KHO). Boil half an hour, or until the evolution of 
 gas has ceased. Wash the PbS formed, oxidize it with 
 HNO 3 , and throw down the S as BaSO 4 by means of 
 Ba(NO 3 ) 2 . Let stand 24 hours, collect on a filter, dry, 
 ignite, and weigh. This method is said to give higher 
 percentages of S than that of Eggertz. Compare Fres., 
 229, 2. 
 
 4. Method of ARTHUR H. ELLIOTT. See Am. Chem., 
 Vol. I, page 376. 
 
 5. Method employed by KONINCK and DIETZ. See Prac- 
 tical Manual of Chemical Analysis and Assaying applied 
 to Iron. Translated by Robert Mallet. London, 1872. 
 
 Dissolve 3 to 5 grms. borings in HC1 in a flask connected 
 with four bottles, the first a condenser, the three following 
 containing solution of AgNO 3 (i part of nitrate to 20 parts 
 of water). Boil, and when gas ceases to evolve, aspirate 
 Pour contents of flask on one filter, and wash the Ag 2 S. 
 Wash out the flask and cleanse the ends of the tubes witn 
 bromine water, and expel excess of Br by heat; the follow 
 ing reaction ensues : 
 
 Ag 2 S+8Br+4H 2 O=H 2 SO 4 +2AgBr+6HBr. 
 
 The phosphide is also converted into phosphoric at-tr 
 Filter from AgBr, and ppt. H 2 SO 4 with BaCl 2 as U.MUU. 
 
DETERMINATION OF IRON MANGANESE, ETC. 85 
 
 6. Method of BOUSSINGAULT for determination of Phos- 
 phorus. See Annales de Chimie et de Physique, June, 
 
 1875, and abstract in American Chemist, Vol. VI, p. 275. 
 
 7. For additional methods consult also papers by Alfred 
 H. Allen, Chem. News, XXIX, p. 91, and paper by 
 Hamilton, Chem. News, Vol. XXI, p. 147. Compare 
 Crookes' Select Methods, pp. 84-89. 
 
 D. Determination of Iron Manganese, etc. 
 
 The iron may be determined by difference or by Margue- 
 rite's method, in which case dissolve 0.2 grms. of pig-iron 
 in H 2 SO 4 , and proceed as usual. It is advisable to use a 
 rather dilute solution of K 2 Mn 2 O 8 towards the close of the 
 oxidation. 
 
 For the determination of the bases of Groups II, III, 
 and IV, dissolve 10 or 20 grms of pig-iron in HC1, remove 
 the SiO 2 by drying thoroughly, and proceed as in Analysis 
 No. 21. 
 
 The manganese may be thrown down in the filtrate, from 
 the basic acetate of iron by means of bromine, or in the 
 absence of calcium, magnesium, etc., by hydrodisodic phos- 
 phate. See Fres., 109, 3, also 229, 5. For other methods 
 of estimating manganese see articles by Samuel Peters in 
 Chem. News, Vol. XXXIII, p. 35, and by William Gal- 
 braith, in Chem. News, Vol, XXXIII, p. 47. 
 
 See also paper by Charles H. Piesse in Chem. News, 
 Vol. XXIX., pp. 57 and no. 
 
 For testimony as to the condition in which silicon exists 
 in pig-iron, see paper by E. H. Morton, Chem. News, 
 Vol. XXIX., p. 107. 
 
86 
 
 QUANTITATIVE ANALYSIS. 
 
 IS 
 
 Z 
 
 Mn, Zn 
 
 fc 
 
 H 
 
 C/3 33 
 Cd < 
 
 l 
 
 80 c 
 rt "* 
 
 BO 
 
 AS 6 
 
 2 g 
 ce 
 lt 
 
 finely; heat 
 dissolved, expt 
 , warm and filte 
 
 8 If! 
 
 g I8g 
 
 - ,? .2 -5 
 
 
 .- 
 
 fl C 
 
 . 43 j 
 
 
 
 s? 
 
 s-l 
 
 9= 
 
 II 
 
 U3 
 
 Ig 
 
 as 
 
 l 
 
 ffi 
 
 5* 
 
 CJ COB 
 
 p 
 
 rt 
 
 icarly to dryne 
 11 hot. 
 
 X 
 
 o 
 
 
 2 
 
 Si 
 
 6 
 
 T* 
 
 8 il? -gs 
 
 !! 
 
 2^ u rtO. 55 JS 
 
 * -s s*a 
 
 * 
 
 5* o S 
 
 8 . 00 a= 
 
 
 i 
 
 .-5. 3 
 ' 
 
 cT3 
 
ARSENICAL NICKEL ORE. 
 
 a^^ 28 
 
 ."Si P T3 i ,2 
 
 > a .2 ,5 * s 
 5 5 c g 
 
 ^ C^ -^'^ cc]^ 
 
 013 
 
 73 <u -* 
 
 ill 
 
 a; G 
 *J*-' 
 
 
 ' y O ^ g . 
 
 - 
 
88 QUANTITATIVE ANALYSIS. 
 
 Analysis No. 25. GUANO. 
 
 Consult Fres., Quant. Analysis 233, 235, and 236; 
 also article by F. A. Cairns, Am. Chem., Vol. I, p. 82. 
 
 To be determined: SiO 2 , CaO, MgO, Fe 2 O 3 , P 2 O 5 , SO 3 , 
 H 2 O, NH 3 , total N, organic and volatile matter. 
 
 A. Determination of Moisture. 
 
 Heat i grm. at 100 C. until constant weight and loss 
 H 2 0[+(NH 4 ) 2 C0 3 ]. 
 
 In cases where great accuracy is required, a correction 
 for the (NH 4 ) 2 CO 3 counted as water must here be made. 
 Heat the substance in a U tube in a water-bath and aspirate, 
 collecting the (NH 4 ) 2 CO 3 in normal H 2 SO 4 . Titrate with 
 KHO as usual. Subtract (NH 4 ) 2 CO 3 found from H 2 O 
 [+(NH 4 ) 2 CO 3 ] determined by heating at 100 C. as above. 
 B. Organic and Volatile Matter. 
 
 Determine loss by ignition in open crucible, and correct 
 for H 2 0, (C0 2 ) and (NH 4 ) 2 CO 3 ). 
 
 C. Ammonia. 
 
 Use Schldsings method, Fres., 99, 3, b. Mix the guano 
 with milk of lime and place under bell-jar over a dish of 
 normal H 2 SO 4 . A large surface of acid in proportion to 
 the guano solution is desirable. Let stand, cold, 48 hours 
 or more, and titrate with normal KHO as in acidimetry. 
 (Cf. Analysis No. 1 1.) 
 
 D. Total Nitrogen. 
 
 Use Varrentrapp and Will's Method, as detailed in Fres., 
 185. Heat the guano in a combustion tube with soda 
 lime, converting it into NH 3 . Absorb the NH 3 in a stand- 
 ard solution of H 2 SO 4 , aspirate and disconnect bulb. Add 
 litmus and titrate with standard KHO. 
 
 B. Sulphuric Acid. 
 
 Dissolve in hot HC1, filter and precipitate with BaCl 2 , or 
 follow the Scheme F. 
 
GUANO. 
 
 8 9 
 
 i 
 
 a + 
 
 A 
 
 O ^ 
 
 5 o 
 
 <j . 
 o s f 
 
 02 2 
 
 3 o 
 
 d c 
 
 g rt 
 < > 
 
 " 
 
 u-i 
 
 5 .3 
 
 ^ *g 
 
 k-s ^ 
 6 
 
 a 
 
 o 
 
 <u -^ c 
 
 uj 
 
 ^ c/J * O 
 
 S> ^ 
 
 N .S3 6 .< 3 
 
 " '5 c/. ^' ^3^. 
 
 *> P rt Q r^ " CJ ^ 
 
 jrf *%* \** w . i c3 *u 
 
 <u c 
 
 M C 
 
 E o 
 
 .(S rlT 3 Qk fc fg 
 
 ^: c o o -o 
 
 : s 
 
 O <u -o 
 
 2 S'S 
 
QUANTITATIVE ANALYSIS. 
 
 Analysis No. 26. SUPERPHOSPHATE OF LIME. 
 
 To be determined: Moisture, reduced (or reverted) 
 P 2 O 5 , soluble P 2 O 5 and available P 2 O S . 
 
 A. Determination of Moisture. 
 Dry I grm. at 100 and weigh loss of weigh t^moisture. 
 
 B. Determination of Total P 2 O 5 . 
 
 Weigh out i grm. accurately, mix with 2 grm. KNO 3 and 
 4 grms. Na 2 CO 3 , fuse in platinum crucible, dissolve in 
 HNO 3 , evaporate in a casserole to dryness (to dehydrate 
 SiO 2 +aq.), add water and filter. Wash thoroughly and 
 dilute filtrate to 500 c.c. ; take 50 c.c. of this solution 
 (n^o.i grm. of superphosphate) and determine P 2 O S with 
 (NH 4 ) 2 MoO 4 as usual. Consult Note 12, Analysis No. 21. 
 
 C. Determination of Insoluble P 2 O S . 
 
 Digest i grm. with about 400 c.c. of water in 8 to 10 
 different portions successively, rubbing the superphosphate 
 with water in a porcelain mortar. Filter and treat residue 
 (filter included) with about 50 c.c. solution of ammonium 
 citrate containing 30 grm. of salt to 100 c.c. of water, and 
 carefully neutralized if acid. Digest at about 7oC. for 40 
 minutes or longer, filter and wash. Dry residue and fuse 
 exactly as in B. Estimate the P 2 O 5 in same manner using 
 100 c.c. (=0.2 grm. of superphosphate) of the solution 
 (500 c.c.) for each determination. 
 
 D. Determination of Reduced and Insoluble P 2 O S . 
 
 Leach another sample (i grm.) with water as in C 
 (omitting the use of ammonium citrate), dry the residue 
 and fuse as in B. Continue as in B, taking 150 c.c. of the 
 solution for each determination. 
 
POTABLE WATER. 91 
 
 B. Calculation. 
 
 The reduced P 2 O S is found by subtracting the P 2 O 5 in 
 C from that in D. The soluble P 2 O 5 =B-D and the avail- 
 able P 2 O S =B-C. 
 
 Note. Reduced or reverted P 2 O 5 forms thus : 
 Ca 3 P 2 O 8 +CaH 4 P 2 O 8 =2Ca 2 H 2 P 2 O 8 . 
 Consult Bolleys Handbuch, pages 802-806. 
 
 Analysis No. 27. POTABLE WATER. 
 
 To be determined: K; Na; Mg; Ca; Cl; SO 3 ; SiO 2 ; 
 organic and volatile matter, total 
 solids ; hardness (soap test) ; oxy- 
 gen required to oxidize organic mat- 
 ter (permanganate test). 
 
 Quantity required, three to four gallons ; collect in clean 
 demijohns. 
 
 A- Determination of Total Solids and Loss by Ignition. 
 
 Measure out 250 c.c. of the water, evaporate to dryness 
 on a water bath, in a weighed platinum dish of 100 c.c. ca- 
 pacity. During the evaporation cover the dish with a 
 paper screen. Dry in an air bath I2O-I3O C. and 
 weigh. Weight of residue gives "Total Solids." Ignite 
 gently over a Bunsen burner, moisten with a solution of 
 CO 2 in distilled H 2 O, dry on water-bath, heat in air-bath 
 I2O-I3O C. as before and weigh; difference between 
 second and first weights* gives organic and volatile mat- 
 ter, also called " Loss by Ignition." For further treatment 
 of residue see F. Compare Chapter II of Wanklyn's 
 " Water Analysis;' 3rd edition, 1874. 
 
9?, QUANTITATIVE ANALYSIS. 
 
 B. Determination of SiO 2 , Fe 2 O 3 , A1 2 O 3 , CaO, MgO. 
 
 Evaporate 4 to 6 litres of water (according to the 
 proportion of total solids) to small bulk in porcelain 
 dish. Add HC1, transfer to platinum dish, washing care- 
 fully the porcelain dish, evaporate to dryness, filter from 
 SiO 2 and follow scheme for Dolomite, Analysis No. 7. 
 
 C. Determination of H 2 SO 4 . 
 
 Take I litre (or less) of the water, boil down to 
 200 c.c. with a few drops of HC1, and determine SO 4 
 as BaSO 4 in the usual manner. If the water contains 
 sufficient H 2 SO 4 (as sulphates) to give a feeble precip- 
 itate with BaCl 2 before concentration, one-half or one- 
 quarter litre will suffice. 
 
 D. Determination of Cl. 
 
 Test the water with AgNO 3 for Cl, and if no cloud 
 is formed evaporate i litre to small bulk ; otherwise 25 
 to 50 c.c. suffice. Add a slightly acid solution of AgNO 3 , 
 and proceed as usual. 
 
 Second method. Determine the Cl volumetrically by 
 a standard solution of AgNO 3 , using potassium chromate 
 as an indicator. See Fres. 141,!, b, . 
 
 B. Determination of Na and K. 
 
 Evaporate 6 litres to dryness in a large porcelain dish, 
 finishing on a water bath. Boil the residue with dis- 
 tilled water several times, filter into a platinum dish 
 and wash. Add Ba(HO) 2 to filtrate. Evaporate to dryness, 
 heat to low redness, let cool, take up with water, add 
 (NH 4 ) 2 CO 3 and a little (NH 4 )C 2 O 4 , wash the precipitate, 
 filter, add HC1 to filtrate, evaporate to dryness, ignite 
 and weigh. Dissolve in water and if not clear, filter, 
 evaporate, dry, ignite cautiously, and weigh again. This 
 
POTABLE WATER. 93 
 
 residue of NaCl-)-KCl must be perfectly white and sol- 
 uble without residue in water. Determine the Cl in the 
 weighed NaCl-{-KCl and calculate the Na and K as in 
 Fres. 197, a. Compare Wanklyn, ^rd edition, page 63. 
 
 F. To check determination of Na and. K. 
 
 Moisten the weighed "Total Solids" of A with dilute 
 H 2 SO 4 , dry and ignite with a little powdered (NH 4 ) 2 CO 3 
 to constant weight. By deducting from this weight, 
 calculated fot one gallon, the combined weights of SiO 2 , 
 Fe 2 O 3 , A1 2 O 3 , CaO, MgO (the latter four reckoned as sul- 
 phates), the weights of Na 2 SO 4 and K 2 SO 4 are obtained. 
 
 G. Dr. Clark's Soap Test. 
 
 Consult Button's Volumetric Analysis, 83,10: or Wank- 
 lyn's Water Analysis, 3rd edition, page 125. 
 
 Principle. Hard water, so called, destroys much soap 
 before a lather is formed, owing to the formation of insol- 
 uble salts, viz. : stearates, palmitates, and oleates of cal- 
 cium and magnesium. 
 
 Preparation of Soap Solutions. Dissolve 10 grms. of 
 good white Castile soap (which should contain about 
 12 per cent, of water) in I litre of alcohol 90 to 95 
 per cent. Let stand and siphon off from the residue. 
 Label this solution "No. I." Take of solution No. I, 
 ico c.c.; of 56 per cent, alcohol, 65 c.c. ; of distilled water, 
 75 c.c., and mix. Label this soap solution " No 2." 
 
 Preparation of Standard Calcium Solution. Dissolve 
 i grm. of precipitated CaCO 3 in HC1, evaporate until 
 neutral, take up with water and dilute to 1000 c.c. I c.c. 
 of this solution contains grm. o.ooi CaCO 3 . 
 
 Standardization of Soap Solution. Fill a burette with 
 soap solution No. 2. Place 10 c.c. of calcium solution 
 
94 QUANTITATIVE ANALYSIS. 
 
 in a glass stoppered bottle. Add it to 100 c.c. of distilled 
 water, run in soap solution from the burette and shake 
 well, and continue adding soap solution until a lather 
 is formed of sufficient consistence to remain for five 
 minutes on the surface of the water. Read burette and 
 calculate. Repeat. 
 
 In certain cases allowance should be made for the 
 amount of soap solution destroyed by water itself ; 100 
 c.c. destroys 0.8 c.c. soap solution. 
 
 Performance of Analysis. Same as above. Report mil- 
 ligrammes per litre and grains per gallon of CaCO 3 . 
 
 Example. loc.c. of the standard solution of chloride of 
 calcium required 23 c.c. of soap solution 
 
 But 10 c.c. of CaCl 2 solution is equivalent to .01 grm. 
 of CaCO 3 , hence 
 
 c.c. used) 
 23 
 
 ) ) .01 ) 
 
 [ i c.c. [ = [. : * = .00043 grms. 
 
 ) J grm. CaCO 3 ) 
 
 And if 100 c.c. of water under examination require 
 33 c.c. of CaCl 2 solution, we have 33 X. 00043 X IO = grms. 
 per litre of CaCO 3 . This gives .1419; and .i4i9X.O583i8 
 gives grains per gallon. For the factor .058318 consult 
 I, Calculation of Results. 
 
 H. Permanganate Test for Organic Matter. 
 
 Principle. Permanganate of potassium in solution oxi- 
 dizes putrescible organic matter. 
 
 Preparation of solution of permanganate. Dissolve 
 0.320 grms. of permanganate in I litre of water. Dis- 
 solve 0.7875 pure oxalic acid in I litre of water, weighing 
 very accurately. Of this solution i c.c.=o.oooi grm. oxy 
 
POTABLE WATER. 95 
 
 gen. To standardize the permanganate, take 10 c.c. of 
 oxalic acid solution ; dilute to 100 c.c. with distilled water, 
 add 5 c.c. dilute H 2 SO 4 , heat nearly to boiling and run in 
 from a burette the permanganate solution. 10 c.c. of 
 oxalic acid will require 12 to 15 c.c. permanganate. Cal- 
 culate value of I c.c. of latter in milligrammes of oxygen. 
 
 Testing water. Take 100 c.c. potable water add H 2 SO 4 , 
 add standardized permanganate, little by little in the 
 cold, until the water retains a pink tinges after one-half 
 hour's standing. Report amount of oxygen required to 
 oxidize organic matter. 
 
 Example. 10 c.c. of standard solution of oxalic acid 
 required 14 c.c. of solution of K 2 Mn 2 O 8 
 
 But 10 c.c. of H 2 C 2 O 4 solution is equivalent to o.ooi 
 grms. of oxygen, hence 
 
 c.c. used^l ^1 I. mgm. 1 
 
 \ : i. c.c. >= > : a = .0713 mgms. 
 
 14. J J oxygen J 
 
 And if 100 c.c. of water under examination required 
 0.8 c.c. of K 2 Mn 2 O 8 , we have O.8X.O/I3X 10 = mgms. per 
 litre of oxygen required to oxidize organic matter. This 
 gives .5704 milligrammes and . 5 704 X. 05 831 8 gives grains 
 of oxygen per gallon. See I, Calculation of Results. 
 
 I. Calculation of Results. 
 
 To convert grms. in a litre \X\\JQ grains in a gallon, multi- 
 ply the number of milligrammes of each constituent by 
 0.058318; or use Dr. Waller's Table, published in Am. 
 CJtcm., Vol. V, p. 278. Report results in two ways : the 
 grains per gallon of uncombined constituents, viz., SiO 2 , 
 Fe 2 O 3 , A1 2 O 3 , CaO, MgO, Na 2 O, K 2 O, Cl, SO 3 , together 
 with " Loss by Ignition " and " Total Solids ; " and secondly 
 
96 QUANTITATIVE ANALYSIS. 
 
 report the grains per gallon of the bases combined with 
 acids in accordance with the following scheme. 
 
 Combine " " Na as Na 2 SO 4 
 
 " excess of Cl " Mg C1 2 
 
 " SO 4 " Ca SO 4 
 
 " " " Mg " Mg CO 3 
 
 " " " Ca " Ca CO 3 
 
 " " " K " K 2 SO 4 
 
 " K " K Cl 
 
 " " " Cl " Na Cl 
 
 The sum of the combined salts -f- " Loss by Ignition " 
 should equal the " Total Solids " very nearly. 
 
 Example, showing method of calculation. A sample of 
 potable water yielded on analysis the following results : 
 
 Cl .215 grains per gallon. 
 
 Na .291 " " " 
 
 SO 3 .340 
 
 CaO .804 " " " 
 
 etc. etc. 
 
 Begin by calculating the amount of Na required to 
 saturate the Cl found, thus : 
 
 (i) I'd : Na = f Amount j J Amount of Na 
 
 [of Cl found.} : {needed for the Cl. 
 _35-5 23 = 0.215 : w 
 
 w = 0.139 grains, 
 hence 0.215 -f- 0.139 = 0.354 grains NaCl. 
 
 But the water contains .291 grains Na, hence we have 
 .291 .139 = .152 grains Na left over to combine with 
 S0 3 . 
 
POTABLE WATER. 97 
 
 0.152 grains Na corresponds however to 0.204 grains 
 Na 2 O making then a proportion similar to (i) we have 
 
 (2) f Na 2 O : SO 3 = f Amount 1 f Amount of SO 3 1 
 
 j of Na 2 O - : j needed 
 
 [ remaining, j [ for the Na 2 O. 
 62 : 80 = 0.204 : x 
 
 x = 0.263 grains, 
 hence 0.204 -f- 0.263 = 0.467 grains Na 2 SO 4 . 
 
 But the water contains 0.340 grains SO 3 hence we have 
 0.340 0.263 = 0.077 grains SO 3 left over to combine 
 with CaO. 
 
 Accordingly we have the proportion 
 
 (3) fSO 3 :CaO = f Amount of SO 3 | f Amount of CaO 1 
 
 { remaining, j ' [needed for the SO 3 . j. 
 1 80 : 56 = 0.077 : y \ 
 
 y = 0.0539 grains CaO, 
 hence 0.077 + 0.0539 = 0.130 grains CaSO 4 . 
 
 Proceeding in like manner the CaO remaining is regarded 
 as combined with CO 2 . 
 
 0.804 0.0539 = 0.7501 grains CaO ; and since. 
 
 (4)J CaO : CaCO 3 = 0.7501 : z 
 
 whence z = 1.34 grains CaCO 3 . j 
 
 Collecting the results of the calculation we have (thus 
 far) the following figures for the constituents combined: 
 
 NaCl 0.354 grains per gallon. 
 Na 2 S0 4 = 0.467 " 
 CaS0 4 =0.130 " 
 CaC0 3 = 1-34 " 
 etc., etc. 
 
98 QUANTITATIVE ANALYSIS. 
 
 The following will serve as a further example of the 
 manner of reporting similar analyses. 
 
 ANALYSIS OF CROTON WATER BY DR. C. F. CHANDLER. 
 
 Grains per gallon. 
 
 Soda 0.326 
 
 Potassa 0.097 
 
 Lime 0.988 
 
 Magnesia 0.524 
 
 Chlorine 0.243 
 
 Sulphuric acid . . . . . . 0.322 
 
 Silica 0.621 
 
 Alumina and oxide of iron trace 
 
 Carbonic acid (calculated) . . . 2.604 
 
 Water in bicarbonates (calculated) . . 0.532 
 
 Organic and volatile matter . . . 0.670 
 
 6.927 
 Less oxygen equivalent to the chlorine . .054 
 
 Total . . . 6.873 
 These acids and bases are probably combined as follows 
 
 Chloride of sodium . 
 Sulphate of potassa . 
 Sulphate of soda 
 Sulphate of lime 
 Bicarbonate of lime . . . 
 Bicarbonate of magnesia . 
 Silica . 
 
 Alumina and oxide of iron 
 Organic matter 
 
 6.8/3 
 
SPECIFIC GRAVITIES OF SOLIDS AND LIQUIDS. 99 
 
 Analyses No. 28 and No. 29. SPECIFIC GRAVITIES OF 
 SOLIDS AND LIQUIDS. 
 
 A Sp. gr. of a solid by direct weight. 
 Weight of solid in the air = w 
 " " " " water = w 1 
 w 
 
 Sp. gr. = 
 
 w w 1 
 
 B. Sp. gr. of a solid by the flask. 
 
 Weight of solid = w 
 
 " flask + water = w 1 
 
 " " " " " + solid = w" 
 w 
 
 Sp. gr. = 
 
 (w -f- w 1 ) w 11 
 
 C. Sp. gr. of a body soluble in water. 
 
 Weight of body in air w 
 oil _ w , 
 
 Sp. gr. of oil = a 
 
 " " " water = i 
 
 The liquid displaced being 
 w w 1 w 11 
 
 then 
 
 a: i = w 11 : w 1 " 
 w 
 
 Sp. gr. = 
 
 w 111 
 
 D. Sp. gr. of a body lighter than water and insoluble 
 in it, e.g., Cork. 
 
 Weight of cork in air = w 
 
 " " lead " water w 1 
 
 " " " and cork in water = w" 
 
IOO QUANTITATIVE ANALYSIS. 
 
 W 
 
 Q 
 
 w /_ 
 
 E. Sp. gr. of a Body lighter than Water and soluble in it. 
 
 Weight of body in air = w 
 
 " " " naphtha = w' 
 
 w w' = w" 
 
 Sp. gr. of naphtha = A 
 " " " water = i 
 
 A : w"= i : w'" 
 
 c w 
 
 S P- S r - - jnr 
 
 P. Determination of the Proportion of two Metals in an 
 
 Alloy. 
 
 Sp. gr. of the alloy = S 
 
 Weight of the alloy = A 
 
 Sp. gr. of one of the metals = s' 
 Sp. gr. of the second metal = s" 
 Weight of one metal = w' 
 
 Weight of the second metal = w" 
 
 (s' s")S 
 
 w" = A w' 
 
 For proofs of this formula, see Galloways First Step in 
 Chemistry, p. 74. 
 
 G. Sp. gr. of a liquid by the flask. 
 
 Weight of flask = F 
 
 " " " and water = w 
 " " " liquid = w' 
 
ORGANIC ANALYSIS. IOI 
 
 H. Sp. gr. of a Liquid by weighing a Substance in it. 
 
 Weight of substance = w 
 
 " " " in liquid = w' 
 
 Sp. gr. of the substance A 
 
 w : (w w') = A : sp. gr. 
 
 or Sp. gr. = ( w ~ w ) 
 w 
 
 Analysis No. 30, 31, and 32. Organic Analysis. 
 
 INTRODUCTORY NOTES. The analysis of organic bodies 
 comprises two branches ; PROXIMATE ANALYSIS which deals 
 with the separation of proximate principles of organic bodies 
 without altering them, and ULTIMATE ANALYSIS, by which 
 the nature and quantity of the elements composing the 
 organic bodies are determined. 
 
 No systematic course of proximate analysis is possible 
 in the present state of the science ; animal chemistry is in 
 this respect more advanced than vegetable ; for a course of 
 zoo-chemical analysis see article by Gorup-Besanez in the 
 Neues Handworterbuch der Chemie, I, 551, and compare 
 Watt's Dictionary, I, 249. See also Heintz Lehrbuch der 
 Zoochemie and LeJimaris Physiological Chemistry. For 
 general principles of proximate organic analysis, consult 
 Dr. Albeit B. Prescotfs " Outlines of Proximate Organic 
 Analysis" a most useful manual, and the only one of its 
 kind. For special methods of analyzing organic bodies, 
 especially of commercial articles, consult " Bolleys Hand- 
 buck der TechniscJi-cJiemischen Untersuchungen" of which 
 the second edition by Emil Kopp is most valuable. 
 
TO2 QUANTITATIVE ANALYSIS. 
 
 The method of conducting an ultimate analysis is suffi- 
 ciently detailed in Fresenius* System, 171-189, yet the 
 following summary may be of service in calling attention 
 to the chief points. 
 
 A. Determination of C, H, and O, in Sugar. 
 
 Select a very pure well crystallized sample of sugar, rock- 
 candy will do, but small crystals from a vacuum pan are 
 better. Dry at 100 C, in powder. 
 
 Provide the following articles : 
 
 (1) The dried substance in a tared watch glass. 
 
 (2) Combustion tube of hard glass drawn out as shown 
 in Fres. 174, cleaned and carefully dried. 
 
 (3) Liebig potash bulb filled with a KHO solution of 
 Sp. gr. 1.27, or a U-tube filled with soda-lime. 
 
 (4) Chloride of Calcium tube ; that of the form described 
 by Thorpe in his Quant. Chem. Analysis page 347, fig. 80 is 
 advantageous. 
 
 (5) Small U-tube containing potash-pumice in one limb 
 and CaCl 2 in the other. 
 
 (6) Rubber tubing. 
 
 (7) Fine wire for binding the tubing. 
 
 (8) Good corks, free from holes, rolled and pressed. 
 
 (9) Cupric oxide, granulated preferred, chemically pure, 
 freshly ignited to remove organic matter and moisture, and 
 contained in a corked holder. 
 
 (10) A platinum boat to contain the substance, or if 
 another process be followed, a mixing wire. 
 
 (11) Combustion furnace. 
 
 (12) If oxygen is to be employed, a cylinder of this gas 
 and a system of drying U-tubes must be provided. 
 
ORGANIC ANALYSIS. IO3 
 
 (13) Sundry articles, such as glazed paper, agate mortar, 
 towel, asbestus, a ramrod for cleaning combustion tube. etc. 
 
 Process of the Combustion. 
 
 (a) Weigh the substance (sugar) and preserve in a des- 
 iccator until ready for use ; weigh also the KHO bulb to- 
 gether with the U-tube (5), CaCl 2 tube. 
 
 (b) Dry the combustion tube and fill with cupric oxide ; 
 the substance may be inserted on a platinum boat if the 
 combustion is to be conducted with oxygen, otherwise it 
 must be intimately mixed with some powdered CuO in 
 the agate mortar and transferred by the glazed paper to 
 the combustion tube. Stir also with the iron mixer. Avoid 
 introducing moisture. 
 
 (c) Connect the apparatus, arranging it as shown in the 
 cut on page 433 of FrescniuJ System. Test the joints by 
 heating the air in that bulb of the KHO apparatus which 
 is between the solution and the combustion tube ; drive 
 out a few bubbles of air and let cool, if an unequal level 
 of the solution is maintained, the joints are tight. 
 
 (d) Conduct the ignition, heating gradually, and begin- 
 ning at the end next to the CaCl 2 tube ; do not apply heat 
 to the substance until several inches of CuO are red hot. 
 Pass oxygen gas through the tube if that method is em- 
 ployed. Fres. 178. The combustion of sugar may be 
 completed in about half an hour, other substances require 
 more time, especially those rich in Carbon. 
 
 (/-) Aspirate air, or pass oxygen through the apparatus 
 
 slowly. 
 
 (/) Disconnect the weighed tubes, cool and weigh. From 
 the CO 2 and the H 2 O found, calculate the C and the H 
 respectively. The O is found by difference. 
 
IO4 QUANTITATIVE ANALYSIS. 
 
 Theoretical Composition of Cane Sugar. 
 
 Ci 144 .... 42.11 
 
 H.,2 22 .... 6.43 
 
 O u 176 .... 51.46 
 
 342 100.00 
 
 In the case of nitrogenous bodies introduce copper turn- 
 ings or a spiral of sheet copper in the end of the combus- 
 tion tube next to the absorption tubes ; the metallic copper 
 at a red heat reduces any nitric oxide which may form, and 
 the inert nitrogen passes through the absorption tubes 
 without increasing their weight. See Fres. 183.2. 
 
 The difficulty of effecting a complete oxidation of the 
 carbon in organic substances increases, other things being 
 equal, with the percentage of carbon contained in the sub- 
 stance ; the richer the substance in carbon, the smaller the 
 amount should be taken for combustion. Moreover, it is 
 desirable to graduate the quantity used, to prevent the for- 
 mation of too large a quantity of carbonic anhydride to 
 admit of complete absorption by the potash solution ; hence 
 the following Table, used in Prof. A. W. Hoffman's Labo- 
 ratory, University of Berlin, is of service in determining 
 the amount of substance which may be conveniently em- 
 ployed. 
 
 Table showing amount of Substances to be used in 
 Ultimate Analysis. 
 
 Of substances containing 80 percent carbon take o.2oogrms. 
 " " 75 " " " 0.225 " 
 
 " " 70 " " " 0.250 " 
 
 " " 65 " " " 0.275 " 
 
 " " 60 " " " 0.300 " 
 
 U jj C ft O.32"5 " 
 
DETERMINATION OF NITROGEN. 105 
 
 Of substances containing 50 percent carbon take 0.350 grms. 
 
 " " 45 " " " 0.375 " 
 
 " " 40 " " 0.400 " 
 
 " " 35 " " " 0.425 " 
 
 " " 30 " " " 0.450 " 
 
 " " 25 " " " 0.475 " 
 
 " 20 " " " 0.500 " 
 
 C. Determination of Nitrogen in Potassium Ferrocy- 
 anide by Conversion into Ammonia. 
 
 Method of Varrentrapp & Will. See Fres. 185. 
 
 Purify about 50 grms. of the commercial salt by recrys- 
 tallization ; dry the crystals on filter paper and preserve in 
 a desiccator. The crystallized salt contains 3 molecules 
 of water. 
 
 Principle: When organic substances are heated with 
 hydroxides of the alkaline metals the carbon is oxidized by 
 the oxygen of the hydroxide, and hydrogen is set free ; if, 
 however, nitrogen is present it combines with the nascent 
 hydrogen, forming ammonia. (For an exception, see D.) 
 By conducting the operation in such a way as to complete 
 the reaction, and collecting all the ammonia by absorption 
 in acid of known strength, the amount of nitrogen is 
 easily calculated. 
 
 Requisites : The apparatus needed is, in general, the 
 same as that used in determination of C and of H, but 
 a somewhat shorter tube (40 cm.) may be used ; the am- 
 monia is absorbed by normal sulphuric acid placed in pear- 
 shaped bulbs of the form shown in Fig. 92, or Fig. 94, 
 pages 443 and 445 of Fres. System. The substance used 
 to oxidize the carbon is soda-lime, at present a commercial 
 
IO6 QUANTITATIVE ANALYSIS. 
 
 article ; it should be heated in a porcelain dish to expel 
 water and ammonia before using. 
 
 Operation : Fill the combustion tube about one-third full 
 of warm soda-lime and let it cool ; then mix this in an 
 agate mortar with 0.2 to 0.4 grms. of the dry ferrocyanide 
 of potassium, and introduce the mixture again into the 
 tube ; rinse the mortar with a little soda-lime, and then 
 fill the tube with the same nearly to the open end. Insert 
 a small plug of asbestos loosely, attach the absorption bulb 
 containing the sulphuric acid by a well-fitting cork, and 
 place the tube in the combustion furnace. Begin to heat 
 the tube at the end nearest the cork, and proceed gradu- 
 ally towards the other end. 
 
 The gas evolved should bubble quietly through the ab- 
 sorption tube, and when it ceases to pass break the tail- 
 piece of the combustion tube, and aspirate gently through 
 the whole apparatus. 
 
 Detach the absorption tube, empty its contents into a 
 beaker, rinse well, add a little litmus, or cochineal solu- 
 tion, and determine, by means of normal KHO, the 
 amount of acid remaining unneutralized by the ammonia. 
 For details of this process see Analysis No. 12. 
 
 Theoretical Composition of Potassium Ferrocyanide : 
 
 C 6 ; . . . 17-1 
 
 N 6 19.9 
 
 Fe 13.3 
 
 K 4 37.0 
 
 3H 2 12.7 
 
 IOO.O 
 
DETERMINATION OF NITROGEN. IO/ 
 
 D. Determination of N from the Volume. 
 
 Dumas' method modified by Melsens, Cf. Fres. 184. 
 See also Watts' Dictionary, I. 242. 
 
 When nitrogen exists in an organic substance in the form 
 of an oxide, e. g. nitro-benzol CK 5 (NO 2 ), Varrentrapp & 
 Will's method cannot be employed because the oxides of 
 nitrogen are not completely converted into ammonia on 
 heating with soda lime. Dumas' method consists in heat- 
 ing the substance with oxide of copper, and measuring the 
 nitrogen evolved by collecting over mercury. The process 
 originally devised by Dumas necessitated the use of an air- 
 pump to exhaust the combustion tube, but this may be 
 obviated by following Melsens, who introduces hydro- 
 sodium carbonate into the tube which gives up carbonic 
 anhydride on heating, and drives out the nitrogen before it. 
 
 For Melsen's process provide the following articles : 
 (i) A combustion tube 70 cm. long. 
 
 (2) Mercury trough. 
 
 (3) Graduated cylinder. 
 
 (4) Copper oxide. 
 
 (5) Solution of potassium hydrate. 
 
 (6) Hydrosodium carbonate. 
 
 (7) Connecting tube. 
 
 (8) Corks, asbestos, rubber tubing, etc. 
 
 (9) Combustion furnace. 
 
 In filling the combustion tube observe the following 
 order: Insert, first, 15 cm. of hydrosodium carbonate, then 
 5 cm. of copper oxide, then 15 cm. of copper oxide mixed 
 with the substance to be analyzed, next add about 28 cm. 
 of copper oxide, insert a copper spiral 5 cm. long, and 
 lastly a plug of asbestos in the remaining 2 cm. Insert 
 cork with connecting tube, and arrange apparatus as shown 
 in Pig. 91, page 441, of Fres. System. 
 
108 QUANTITATIVE ANALYSIS. 
 
 Conduct the operation as follows : Heat a portion of the 
 NaHCO 3 until all the air is expelled ; test with a solution 
 of KHO in an inverted test-tube ; then heat CuO to red- 
 ness, arrange the graduated cylinder containing KHO solu- 
 tion over mercury, and heat the mixed CuO and substance 
 until gas ceases to come off; lastly, expel the nitrogen in 
 the combustion tube by again heating the NaHCO 3 , some 
 of which must have been left undecomposed. (Oxalic acid 
 may be substituted for the HNaCO 3 . See Thorpe, page 
 332.) Transfer the graduated cylinder to a vessel of 
 water, hold it so that the level of the water within the 
 cylinder and without is equal, then read off the volume of 
 the gas in cubic centimeters, and simultaneously the tem- 
 perature of the water and the height of the barometer. 
 
 Calculation of Results. To obtain the weight of nitro- 
 gen from its volume employ the following formula : 
 
 Let V = Volume of N observed, expressed in cubic centi- 
 meters. 
 
 And t= Temperature of the gas. 
 
 " B = Height of the barometer expressed in millimeters. 
 " f = Tension of aqueous vapor at the temperature t, 
 
 expressed in mm. of mercury. 
 Then if W = weight of nitrogen we have : 
 
 W = .001 2566 V l - -^- 
 i +.003671 760 
 
 The constant 0.0012566 is the weight in grammes of 
 I c. c. of N at C and 760 mm. The constant 0.00367 is 
 the coefficient of expansion of gas. 
 
 Example : In an analysis of Butyramide 
 
 C 4 H 7 ) 
 
 H v N, the following data were obtained : 
 H 
 
ANALYSIS OF URINE. 
 
 0.315 grms. of substance gave 43.9 c. c. N at /=i73 C 
 and B = 753.2 mm. 
 
 First look out in a table the value of /at I7 .3. (Fres. 
 ! 95> P a e 4^1.) We find (calculating for the tenths of a 
 degree) /= 14.7. 
 
 Now V = 43.9 c. c. 
 
 B f =753.2 mm. 14.7=738.5 mm. 
 
 And i + .00367 X t= 1.0635. 
 
 Substituting in equation : 
 
 W = .0012566 V 1+-o ; 367t o we have : 
 
 = .0012566x43.9x738.5 = . 0504 grms . 
 
 1.0635X760 
 
 . 0.0504 x 100 , 
 
 And - = 1 6.00 per cent nitrogen. 
 0.315 
 
 Theoretical Composition of Butyramide : 
 
 H 9 
 
 DD-* 
 IO.3 
 
 O 
 
 1 8.4 
 
 N 
 
 . . 16 1 
 
 
 
 IOO.O 
 
 Analysis No. 33. URINE. 
 
 For brief methods of analysis consult Dr. George B. 
 Fowler's " Urine Analysis," Thudicutn's " Manual of Chem- 
 ical Physiology," pages 178-192, and Button's " Systematic 
 Handbook of Volumetric Analysis," part vi. 78. For 
 figures of sedimentary deposits examine Ultzmann & Hof- 
 mann's "Atlas der Physiologischen und Pathologischen 
 Harnsedimente." (44 plates.) 
 
 The following works may also be studied : Legg's 
 " Guide to the Examination of Urine," Attfield's " Chem- 
 
IIO QUANTITATIVE ANALYSIS. 
 
 istry," F. Hoppe-Seyler's " Handbuch der Physiol. and 
 Pathol. Chem. Analyse," Neubauer & Vogel's " Anleitung 
 zur Qualitative und Quantitative Analyse des Harns," 
 Gorup Besanez' " Lehrbuch der Physiologischen Chemie," 
 pages 576-580, Ultzmann & Hofmann's "Anleitung zur 
 Untersuchung des Harns." 
 
 Constituents of Urine. 
 
 Urine, the secretion of the kidneys, in a healthy individ- 
 ual, is a clear, yellowish, fluorescent liquid of a peculiar 
 odor, saline taste, with a mean sp. gr. 1.020. The follow- 
 ing are its normal constituents : 
 
 1. Water. H 2 O. 
 
 2. Inorganic Salts. K, Na, NH, Ca, Mg, combined with 
 
 HC1, H 3 P0 4 , H 2 S0 4 , C0 2 , (HNO*) and SiO 2 . 
 
 3. Nitrogenous crystalline bodies. Urea, uric acid, hip- 
 
 puric acid, creatine, creatinine, xanthine, (ammonia,) 
 cystine. 
 
 4. Non-nitrogenous organic bodies. Sugar, lactic, succinic, 
 
 oxalic, formic, malic, and phenylic acids, all in small 
 quantities. 
 
 5. Pigments. Urochrome, urohaematin. 
 
 6. Albumenoid matters. 
 
 7. Matters derived directly from the food. 
 
 Besides these, urine may contain, under varying cir- 
 cumstances, as in disease, a large number of 
 
 8. Abnormal constituents. Blood, pus, mucus, albumen, 
 
 fibrin, casein, fats, cholesterin, leucine, tyrosine, allan- 
 toin, taurine, biliary pigments, indigo-blue, melanin, 
 glucose, inosite, acetone, butyric acid, benzoic acid, 
 oxaluric acid, taurocholic acid, glycocholic acid, and 
 many others. (See Watts' Dictionary, vol. v. p. 962.) 
 
ANALYSIS OF URINE. Ill 
 
 These substances do not occur simultaneously in all 
 urine, and many of them but rarely. Only those com- 
 monly determined are considered in the Scheme 
 (page 112). 
 
 Chemical Composition of Urine. (DALTON.) 
 Healthy. Numbers Approximate. 
 
 Water 938.00 
 
 Urea ." 30.00 
 
 Creatine 1.25 
 
 Creatinine 1.50 
 
 Urate of soda \ 
 
 " potassia > 1.80 
 
 " ammonia ) 
 
 Coloring matter and mucus 30 
 
 Bi-phosphate of soda 
 Phosphate of soda 
 
 potassa 
 
 12.45 
 
 magnesia 
 
 lime 
 
 Chlorides of sodium and potassium .... 7.80 
 Sulphates of soda and potassa 6.90 
 
 1000.00 
 
 Morbid urine may contain, also : 
 
 Albumen, (Bright's disease.) 
 
 Sugar, (Diabetes.) 
 
 Bile, 
 
 Excess of Urea, 
 
 Oxalate of calcium. 
 
112 QUANTITATIVE ANALYSIS. 
 
 Action of Reagents on Urine. 
 
 Boiling acid urine effects no change. 
 
 Boiling alkaline urine makes it turbid if rich in earthy 
 phosphates. 
 
 HNO 3 or HC1 darkens the color, and throws down uric acid 
 on standing. 
 
 KHO or NH 4 HO throws down earthy phosphates. 
 
 BaCl 2 or PbA, in acidified urine, yield a white ppt. of sul- 
 phates. 
 
 AgNO 3 white ppt. of chlorides, also coloring matter and 
 some organic substances. 
 
 Murexid Test. Collect some of the uric acid thrown 
 down by HC1, remove supernatant liquid, add cone. HNO 3i 
 and evaporate to dryness. When cold add a drop of NH 4 - 
 HO. A purplish-crimson color shows formation of mur- 
 exid (C 8 H N 6 6 ). 
 
 Reactions of Urea. Hg (NO 3 ) 2 throws down a gelati- 
 nous white ppt. containing COH 4 N 2 .2HgO. 
 
 Boiling with KHO converted into NH 4 HO ; test with 
 Nessler reagent. 
 
 HNO 3 , nitrate of urea precipitates. 
 
 NaCIO or NaBrO decomposes urea with evolution of N. 
 
 Scheme for Analysis of Urine, 
 i. PHYSICAL CHARACTERS. 
 
 (a) Odor. Certain peculiarities in odor indicate either 
 nature of food or symptoms of disease. 
 
 (b) Consistence. Viscous or fluid. 
 
 (c) Color. When healthy, urine is amber-colored; when 
 bilious, brown or greenish. 
 
 (d) Specific Gravity. By the urinometer, 1015 to 1025 
 is marked H. S., signifying Healthy State. 4 c. makes a 
 difference of about i in the reading. 
 
ANALYSIS OF URINE. 1 13 
 
 2. TEST WITH LITMUS PAPER, and note whether acid or 
 alkaline. 
 
 3. POUR A SAMPLE into a stop-cock funnel, and let stand 
 12 hours. If a deposit forms, filter, and examine the filtrate 
 and sediment separately. Filtered urine leaves a scum of 
 mucus. (For sediments, see Schemes, page 117 and 118.) 
 
 4. DETERMINE TOTAL SOLIDS. Evaporate 4 to 6 c. c., 
 weighed, to dryness in a weighed dish. Dry at 115 c. (In- 
 accurate). 
 
 5. ASH. Evaporate 100 c. c. urine and ignite residue. 
 
 6. DETERMINATION OF UREA. CH 4 N 2 O. 
 
 A. Liebigs Method. 
 
 Principle : Mercuric nitrate added to a solution of urea 
 gives a white, gelatinous ppt. containing i molecule urea, 
 and 2HgO. (Absence of NaCl necessary.) 
 
 Requirements : 
 
 (a) Standard solution Hg (NO 8 ) 2 . 
 
 (b) Baryta solution. 
 
 (c) Carbonate of soda test paper. 
 
 (a) Standard solution of mercuric nitrate. Dissolve 
 72 grms. pure dry HgO in strong HNO 3 , (50 grms.,) 
 evaporate until syrupy, and dilute to I litre. If a yellow 
 ppt. is produced by dilution, too little acid is present. It 
 must be evaporated down, fresh acid added, and again di- 
 luted, i c. c. = o.oi grm. urea. To test the strength of 
 the mercuric nitrate dissolve 2 grms. cryst. urea in 100 c. c. 
 water, i c. c. mercuric solution should equal o.oi grm. urea. 
 
 (b) Solution of Ba(NO 3 ) 2 +BaH 2 O 2 . Mix i part cold 
 saturated solution Ba(NO 3 ) 2 with 2 parts cold saturated 
 solution BaH 2 O 2 , and add 3 parts distilled water. 
 
 (c} Soda test paper. Dip a sheet white filter paper into 
 cone. sol. Na 2 (CO 3 ) and dry. 
 
114 QUANTITATIVE ANALYSIS. 
 
 Process: Collect the urine passed during 24 hours, and 
 measure carefully. Place 20 c. c. in a small beaker, add 
 20 c. c. barium solution, filter from the sulphates and phos- 
 phates. Of the filtrate 20 c. c. (containing 10 c. c. urine) 
 are measured off, a drop of AgNO 3 added to precipitate 
 excess of chlorides, and then standard solution of mercuric 
 nitrate is added until a drop of the mixed solutions gives a 
 yellow stain (of mercuric hydrate) on the test paper. 
 Byasson adds some of a solution of KHO (25 grms. to I litre 
 water) from time to time to partly neutralize the acid set 
 free. The solution must not be rendered alkaline, 
 
 Calculation : Amount urine passed in 24 hours = A ; 
 c. c. mercuric solution used = C ; each c. c. being equal 
 
 A x C 
 to o.oi grm. urea ; then - = grms. urea passed in 24 
 
 hours. 
 
 Caution : The urine must be free from phosphoric and 
 hippuric acids. Consult Caldwell's " Agricultural Analy- 
 sis," page 220. Urine must contain 2 per cent. urea. Cf. 
 Watts' Diet. vol. v. p. 967. 
 
 B. Daveys Method of Estimating Urea. 
 
 Pour a small quantity of urine into a graduated glass 
 tube one-third full of mercury. Fill the tube with a solu- 
 tion of sodic hypochlorite, close tube, and invert quickly 
 over a saturated solution of NaCl. Let stand several hours 
 while the following reaction ensues : 
 
 CH 4 N 2 O+3(NaClO)=CO 2 +2H 2 O + 3NaCl+N 2 
 
 Read off the quantity of N. 1.549 cubic inches of N at 
 60 Fah. and 30" bar. = i grain urea. 
 
 Method inaccurate since ammonia, uric acid, &c v are 
 likewise decomposed. 
 
ANALYSIS OF URINE. 1 15 
 
 C. Heintz and Ragskys Method. 
 
 First determine ammonia by precipitation with PtCL. 
 
 Heat 2 to 5 c. c. with equal vol. H 2 SO 4 in a covered cap- 
 sule to i8o-2oo. Cool, dilute with water, filter, and de- 
 termine NH 3 formed by PtCl 4 . Calculate both amounts for 
 100 c. c., and take the difference ; this multiplied by 0.13423 
 gives per cent, of urea. 
 
 Results very accurate. 
 
 D.Apjokris Method. 
 
 See "American Chemist," V. 431. 
 
 Provide the following apparatus : 
 
 (1) A glass tube 30 cm. long, subdivided into 30 equal 
 parts, whose aggregate volume is 55 c. c. The end of the 
 tube is drawn out like a Mohr's burette. 
 
 (2) A wide-mouthed gas bottle of 60 c. c. capacity. 
 
 (3) A test tube of 10 c. c. capacity, and long enough to 
 be slightly inclined when introduced into the gas bottle. 
 
 The principle of the process is based upon the following 
 equation : 
 
 H 4 ) + 3(CaBr 2 O 2 )=3CaBr 2 -f-2CO 2 +N 4 
 
 To make the hypobromite solution take loogrms. NaHO, 
 250 c. c. H 2 O, and add 25 c. c. bromine ; agitate and set 
 aside for use. 
 
 Process : Into a glass cylinder containing water the tube 
 (i) is depressed till the zero mark and surface of water 
 coincide. 15 c. c. hypobromite solution (100 grms. NaHO, 
 250 c. c. H 2 O, 25 c. c. Br) are placed in (2) and the test- 
 tube containing the urine is introduced carefully to avoid 
 spilling its contents. The flask is closed by a perforated 
 
Il6 QUANTITATIVE ANALYSIS. 
 
 stopper which is connected by tubing with the measuring 
 tube. The urine is now mixed with the hypobromite, and 
 the disengaged nitrogen is driven into the measuring tube. 
 The tube is now levelled to relieve hydrostatic pressure, 
 and the volume of nitrogen read off. Since 55 c. c. equal 
 
 0.15 grm. of urea, a single division corresponds to 
 
 =0.005 g rm - urea. 
 
 (0.15 grm. urea gives 55 c. c. nitrogen at 60 Fah. and 
 30 bar.) 
 
 7. DETERMINATION OF ACTUAL AMMONIA. Take 20 c. c. 
 filtered urine and treat by Schlosing's method. 
 
 The NH 3 is expelled by milk of lime, and absorbed by 
 standard acid, in the cold under a bell jar. For details see 
 Fres. 99, 3 b. p. 158. (Human urine contains 0.078 to 
 0.143 per cent.) 
 
 8. DETERMINATION OF ALBUMEN. Measure urine 
 passed in 24 hours. Drop 50 c. c., one c. c. at a time, 
 into I ounce boiling distilled water in a porcelain dish. 
 If the urine was alkaline add a drop of acetic acid, avoid 
 excess. Allow the coagulated albumen to settle, filter 
 through a weighed filter, and wash well. Dry at 100 C, 
 and weigh. 
 
 9. DETERMINATION OF SUGAR. Dilute urine 5 or 10 
 times, and apply Fehling's solution as in grape sugar. See 
 Analysis No. 35, Raw Sugar. 
 
 10. DETERMINATION OF PHOSPHORIC ACID. To 50 c. c. 
 filtered urine add 5 c. c. sodic acetate and titrate with 
 uranic acetate. For details see Sutton's " Volumetric 
 Analysis." 
 
 11. DETERMINATION OF URIC ACID. To 200 c. c. 
 urine add 10 c. c. HC1, stand 48 hours in a cool place, 
 
DETERMINATION OF URINE. 
 
 117 
 
 filter on a very small weighed filter. Wash-water should 
 not exceed 30 c. c. If more is necessary add 0.045 mgm. 
 uric acid for each c. c. additional. (Albumen must first be 
 removed by coagulation.) Dry at iooc. and weigh. 
 
 12. TESTS FOR BILE. 
 
 (1) Place a little urine on a white plate, add HNO 3 . A 
 peculiar play of colors green, yellow, violet, &c. occurs 
 if coloring matter of bile is present. 
 
 (2) Agitate concentrated urine with boiling ether. If 
 bile is present the ether solution will be greenish-yellow. 
 
 (3) Add baric acetate to urine, treat the ppt with alco- 
 hol, decompose it with HC1, and evaporate the liquid to 
 dryness. Water will dissolve out in the residue coloring 
 matter of the bile. 
 
 (4) Pettenkofers Test. Mix fluid with one-half vol. H 2 SO 4 , 
 avoiding rise of temperature ; add a little powdered cane 
 sugar ; mix and add more H 2 SO 4 . Liberation of cholalic 
 acid produces a purplish-red coloration ; this gives a pecul- 
 iar absorption spectrum. See Thudichum's " Manual." 
 
 Scheme for analysis of Urinary Sediments. (ATTFIELD.) 
 
 Warm the sediment with the supernatant urine, and filter. 
 
 INSOLUBLE. 
 
 Phosphates, oxalate of calcium and uric acid. 
 Warm with acetic acid, and filter. 
 
 SOLUBLE. 
 
 Urates of Ca, N;i, 
 and NH 4 , 
 chiefly of Na. 
 They are re-depos- 
 ited as the liquid 
 cools, and if suffi- 
 cient in quantity 
 may be exam- 
 ined for uric 
 acid and bases 
 by usual tests. 
 
 INSOLUBLE. 
 
 Oxalate of calcium and uric acid. 
 Warm with HC1, and filter. 
 
 SOLUBLE. 
 
 Phosphates. 
 AddNH 4 HO, 
 and exam- 
 ine ppt. 
 for P 2 O 5 , 
 CaO and 
 MgO. 
 
 INSOLUBLE. 
 
 Uric acid. Apply 
 murexid test. 
 
 SOLUBLE. 
 
 Oxalate of cal- 
 cium. May 
 be pptd. by 
 N!! 4 HO. 
 
 Note. Urates are often of a pink or red color, owing to the pig- 
 ment purpurine. This is soluble in alcohol. 
 
QUANTITATIVE ANALYSIS. 
 
 Scheme for Determination of Urinary Sediments by Chemi- 
 cal Tests. (ATTFIELD.) 
 
 The sediment is white; warm 
 with the supernatant urine 
 and filter. 
 
 The sediment is colored 
 
 and 
 crystalline 
 uric acid. 
 
 and amorphous 
 easily soluble 
 on heating 
 urates. 
 
 and 
 amorphous, 
 slowlv solu- 
 ble on heat- 
 ing. Urates 
 colored by 
 purpurine. 
 
 Solution 
 contains 
 urates. 
 
 Residue 
 Treat with ammonia. 
 
 Solution Residue 
 contains Treat with 
 cystine. acetic acid. 
 
 Residue 
 oxalate and 
 oxa lit rate 
 of calcium. 
 
 Solution. 
 Add NH 4 
 HO white 
 ppt. of 
 earthy 
 phos- 
 phates. 
 
 Analysis No. 34. MILK. 
 
 A. Determination of Water. 
 
 Wash quartz sand thoroughly with HC1 and water, and 
 ignite. Put about one-quarter inch of this sand in a plati- 
 num pan, weigh, and pour on 3 to 5 grms milk. Dry at 100 
 C. to constant weight. 
 
 B. Determination of Butter. 
 
 Break up the cake from residue A and wash the butter 
 out with ether into a weighed beaker, evaporate the ether 
 and weigh the butter. 
 
 C. Determination of Sugar. 
 
 Collect the residue from B on a dried and weighed filter, 
 dry it at 100 C., boil it four or five times with fresh por- 
 tions (i5oc. c. each) of 80 per cent, alcohol, and dry the 
 insoluble residue at iocT C. and weigh on a tared filter. 
 The loss of weight gives the sugar approximately. Or 
 determine sugar as under grape sugar, Analysis No. 35. 
 
DETERMINATION OF SUGAR. 119 
 
 A convenient apparatus for the extraction of sugar is 
 described by Prof. S. W. Johnson, in Am. J. of Sci. (3)xiii. 
 page 196(1877). 
 
 D. Determination of total Non- volatile Matter. 
 
 Evaporate 10 to 20 grms. milk to dryness, with the 
 addition of a little acetic acid, and ignite the residue in a 
 muffle furnace, at the lowest possible temperature. 
 
 E. Determination of Protein Compounds. 
 
 Subtract the sum of the butter, sugar, and ash from the 
 total dry substance, and the remainder is chiefly casein. 
 
 For other methods, see " A Method for the Analysis of 
 Milk," by E. H. von Baumhauer, Am. Chem., Vol. VII., 191. 
 
 Analysis No. 35. RAW SUGAR. 
 
 A. Determination of Moisture. 
 
 Heat a weighed amount of sugar at 1 10 until it no 
 longer loses in weight. Loss = moisture. 
 
 B. Determination of Ash. 
 
 Weigh off ten grms. in a platinum dish. Either burn the 
 sugar direct, or add a few drops of cone. H 2 SO 4 and heat 
 very cautiously in a gas muffle. Weigh the ash. 
 
 The two methods do not give results at all concordant ; 
 the latter is the French method, and the results are called 
 " the salts," after subtracting one-ninth, but this is seldom 
 correct, though the ash burns very white. 
 
 C. Determination of Grape Sugar. 
 C 6 H 12 6 , H 2 
 
 (i) Qualitative reactions. Glucose is colored dark- 
 
I2O QUANTITATIVE ANALYSIS. 
 
 brown when heated with a strong solution of sodic hy- 
 drate. It dissolves in cold cone. H 2 SO 4 without being 
 blackened. [Cane sugar blackens.] 
 
 If a cone, solution of glucose is mixed with cobaltic 
 nitrate, and a small quantity of fused NaHO, the solution 
 remains clear on being boiled ; if very concentrated it de- 
 posits a light-brown ppt. 
 
 [Cane sugar solutions similarly treated give a violet ppt., 
 which turns green on standing]. 
 
 BaH 2 O 2 added to an alcoholic solution of glucose forms 
 a white ppt. 
 
 If a little caustic soda is added to a solution of glucose, 
 and then drop by drop a dilute solution of CuSO 4 , a deep- 
 blue liquid forms ; after some time in the cold, but imme- 
 diately if heated, a yellowish or red ppt. of hydrated cuprous 
 oxide is deposited. yooVoo f glucose may be easily de- 
 tected ; y/oo^/oTo st ^ gives a red tint to the solution. 
 
 Cupric acetate is similarly reduced. Potassio-tartrate of 
 copper acts likewise. 
 
 (2) Quantitative estimation, i eq. glucose will reduce 
 10 eq. of cupric oxide to cuprous oxide. 
 
 Preparation of Fehlings Solution. (Fres., 250.) 
 
 Dissolve exactly 34.639 grms. pure dry CuSO 4 in about 
 200 c. c. water. In another vessel dissolve 173 grms. C. P. 
 Rochelle salts (C 4 H 4 K NaO 6 -f-4H 2 O) in 480 c. c. pure sodi- 
 um hydrate solution having a sp. gr. 1.14. 
 
 Mix the solutions and dilute to exactly 1000 c. c. loc. c. 
 of this solution contains 0.34639 grms. CuSO 4 and corre- 
 sponds to 0.050 grms. anhydrous glucose. Keep in the 
 dark. On boiling with four vols. of water, it should give 
 no precipitate. 
 
DETERMINATION OF GRAPE SUGAR. 121 
 
 The solution of glucose should not contain more than 
 | per cent, glucose ; if stronger, dilute. 
 
 Performance of Analysis : 
 
 Run exactly 10 c. c. of the copper solution into a small 
 flask, add 40 c. c. water, (or a dilute solution of NaHO.) 
 heat to boiling and run into the solution the liquid con- 
 taining the glucose, slowly and gradually, from an accurate 
 burette. Continue until the last shade of bluish green 
 disappears, and a small portion of liquid filtered, gives no 
 reaction with H 2 S, nor with HC 2 H 3 O 2 and K 4 Fe 2 Cy 6 . 
 
 Calculation. Since we took 10 c. c., Fehling's solution, 
 corresponding to 0.050 grms. anhydrous glucose, we read ofif 
 the number of c. c. of glucose solution taken ; this shows us 
 how much of the substance contains 50 grms. grape sugar. 
 
 Example. Used 9. 5 c. c. solution containing glucose : 
 
 9.5 : .05 = loo : x 
 If solution was diluted, then .rX^=per cent, glucose. 
 
 This method may be applied to cane sugar, by first con- 
 verting it into grape sugar by boiling one to two hours 
 with dilute H 2 SO 4 (i part acid 5 parts water). This is not 
 very accurate, owing to formation of caramel. Milk sugar 
 reduces Fehling's solution direct, but in another propor- 
 tion, 100 glucose = 134 milk sugar. 
 
 D. Determination of Crystalizable Cane Sugar. 
 Weigh out x grms.* of sugar or syrup, add water so that 
 the whole will form about 80 c. c. Dissolve and add for 
 
 * The value of # depends upon the instrument employed. Instruc- 
 tions usually accompany a sacchari meter. 
 
122 QUANTITATIVE ANALYSIS. 
 
 syrup 5 to 10 c. c. basic acetate of lead ; for raw sugar less ; 
 for pure sugar, none. Dilute to 100 c. c. ; pour into a 
 beaker, and add pulverized bone-black, and filter ; do not 
 wash. Fill the tube of a Soleil or Dubosq Saccharimeter 
 with this solution, perfectly full, insert the tube, and 
 observe the transition tint. For details, see Atkinson's 
 translation of Ganot's Physics, '613. Cf. Fownes' Chem- 
 istry, p. 84, and Watts' Diet. iii. 673-5. 
 
 Analysis of a sample of RAW SUGAR. 
 
 Water, ... . 2.07 
 
 Ash, 1.58 
 
 Grape Sugar, . . . . . 1.82 
 Cane Sugar, 86.00 
 
 Analysis No. 37. PETROLEUM. 
 
 For information as to the composition and refining of 
 petroleum, the products which it yields by distillation, and 
 the methods of testing kerosene, see Dr. C. F. Chandler's 
 " Report on Petroleum Oil " in the " American Chemist," 
 Vol. II. pp. 409, 446, and Vol. III. pp. 20 and 41. 
 
 A. Distillation of Petroleum. 
 
 The method of examining crude petroleum for determi- 
 nation of its commercial value, is not that of fractional 
 distillation in its true, scientific sense, but consists in a 
 process of distillation which separates the liquid into a 
 certain number of al'quot parts, having determinable den- 
 sities, and flashing points ; and the value of the sample 
 depends upon the proportion of the light and heavy pro- 
 ducts. 
 
 The process of distillation is conducted as follows. Se- 
 lect a tubulated retort of strong glass, free from flaws, and 
 
DISTILLATION OF PETROLEUM. 123 
 
 of about 500 c. c. capacity ; connect this with a Liebig's 
 condenser, and arrange for distilling in the usual manner. 
 Through the tubulus of the retort insert a thermometer. 
 Provide ten glass cylinders of 50 to 75 c. c. in capacity, 
 and mark each with a file, so as to show the volume occu- 
 pied by 25 c. c. of liquid. These cylinders are to serve as 
 recipients of the distillate. 
 
 Pour 250 c. c. crude petroleum into the retort, and apply 
 heat very gently at first, increasing gradually, and finally 
 heating until the residue in the retort is coked. Collect 
 25 c. c. of the distillate in the first cylinder, and note the 
 temperature indicated by the thermometer in the retort ; 
 collect the second 25 c. c. in another recipient, note also 
 temperature, and continue in this manner, changing the 
 recipient for every 25 c. c. until the whole liquid has dis- 
 tilled over. 
 
 B. Examination of the Distillates. 
 
 Determine the sp. gr. of each distillate by floating in it 
 a small Baumo Hydrometer, note the color of each sam- 
 ple, and determine its flashing point by means of Taglia- 
 bue's "Open Tester," a figure and description of which are 
 found on page 41, Vol. III. of the "American Chemist." 
 
 To test the flashing point, proceed as follows : pour a 
 small quantity of the sample to be examined into the open 
 cup, which is surrounded by a vessel of water. Light the 
 lamp beneath and apply heat very gradually ; the tempera- 
 ture should not rise faster than two degrees a minute. 
 The thermometer bulb should dip beneath the surface of 
 the oil. . From time to time test the inflammable vapors 
 which arise from the surface of the oil, using a small flame, 
 flitting it quickly across the surface, and noting simultane- 
 ously the height of the thermometer at the moment of 
 Record results with each distillate. 
 
124 
 
 QUANTITATIVE ANALYSIS. 
 
 Example. The following report of an actual distilla- 
 tion shows how the results may be reported. This distilla- 
 tion was accompanied with the phenomena technically 
 called " cracking," by which the heavier hydrocarbons split 
 up into lighter ones. 
 
 No. of 
 fraction. 
 
 I. 
 
 2. 
 
 3- 
 4- 
 5- 
 6. 
 
 7 
 8. 
 
 9- 
 10. 
 
 Colorless, 
 
 Light yellow, 
 
 Yellow, 
 Dark yellow, 
 Deeper " 
 Green, 
 Black, 
 
 Temperature 
 
 Sp. Gr. 
 
 Flashing Point. 
 
 Fahr. 
 
 Beaume". 
 
 Fahr. 
 
 I42-224 
 
 64 
 
 20 
 
 22 4 -2 9 8 
 
 60 
 
 48 
 
 298 -404 
 
 55 
 
 102 
 
 404 -458 
 
 51 
 
 147 
 
 458 -532 
 
 45 
 
 208 
 
 532- ? 
 
 42 
 
 254 
 
 
 40 
 
 20 4 
 
 42 
 
 44 
 
 The tenth product was coke left in the retort. 
 
 82 
 
 Fig. 6 shows the disposition of apparatus at the commencement of the distillation ; so soon 
 as the lighter products have passed over, the bulb tube a c must be removed and connection 
 made with the condenser by a short bent tube. 
 
APPENDIX. 
 
 TABLE I. 
 
 THE ELEMENTS, THEIR SYMBOLS, AND ATOMIC 
 WEIGHTS. 
 
 Name. 
 
 Symbol. 
 
 Atomic 
 Weight. 
 
 Name. 
 
 Symbol. 
 
 Atomic 
 Weight. 
 
 Aluminium . . . 
 Antimony .... 
 Arsenic .... 
 Barium .... 
 Bismuth .... 
 Boron . . 
 
 Al 
 Sb 
 As 
 Ba 
 Bi 
 Bo 
 
 274 [ 
 
 122. ; 
 75- 
 137- 
 
 210. 
 1 1 
 
 Manganese . . . 
 Mercury .... 
 Molybdenum . . 
 Nickel .... 
 Nitrogen .... 
 Osmium 
 
 Mn 
 Hg 
 Mo 
 Ni 
 N 
 Os 
 
 55- 
 
 2OO. 
 9 6. 
 58.8 
 14. 
 TOO ""> 
 
 Bromine .... 
 Cadmium .... 
 Caesium .... 
 Calcium .... 
 Carbon ..... 
 
 Br 
 Cd 
 
 Cs 
 Ca 
 
 c 
 
 80. 
 112. 
 
 133- 
 40. 
 12. 
 
 Oxygen .... 
 Palladium . . . 
 Phosphorus . . . 
 Platinum . . . 
 Potassium . 
 
 
 Pd 
 P 
 Pt 
 
 K 
 
 yy* 
 
 1 6. 
 106.6 
 
 31- 
 197.4 
 
 3Q T 
 
 Cerium .... 
 Chlorine . . . 
 Chromium . . . 
 Cobalt 
 
 Ce 
 Cl 
 Cr 
 Co 
 
 92. : 
 
 35-5 
 52.2 
 58 8 ! 
 
 Rhodium . . . 
 Rubidium . ." . 
 Ruthenium . . . 
 Selenium . . . 
 
 Rh 
 Rb 
 Ru 
 
 Se 
 
 JV -1 
 1044 
 
 854 
 1044 
 
 Columbium . . . 
 Copper 
 
 Cb 
 
 Cu 
 
 94- 
 
 hi A 
 
 Silicon .... 
 Silver 
 
 Si 
 Ag 
 
 28. 
 
 108 
 
 Didymium . . . 
 Erbium . ' . 
 Fluorine .... 
 Gallium .... 
 Glucinum . . . 
 Gold . . 
 
 D 
 E 
 F 
 Ga 
 Be 
 Au 
 
 . u j 4 
 
 95- 
 170.5 
 19. 
 69.9 
 94 
 
 IQ7 
 
 Sodium .... 
 Strontium . . . 
 Sulphur .... 
 Tantalum . . . 
 Tellurium . . . 
 Thallium 
 
 Na 
 Sr 
 S 
 Ta 
 Te 
 Tl . 
 
 23- 
 87.6 
 
 32. 
 182. 
 128. 
 
 1Q A 
 
 Hydrogen .... 
 I ndiuiYi 
 
 H 
 In 
 
 y/' 
 
 T -7-j A 
 
 Thorium .... 
 Tin . . . . . 
 
 Th 
 Sn 
 
 235- 
 
 118 
 
 Iodine 
 Iridium .... 
 Iron ...... 
 
 Lanthanum . . . 
 Lead . . 
 
 T 
 
 Ir 
 Fe 
 La 
 Pb 
 
 127. 
 198. 
 56.. i 
 93-6 
 
 O7 
 
 Titanium 
 Tungsten . 
 Uranium .... 
 Vanadium . . . 
 Yttrium . 
 
 Ti 
 W 
 U 
 
 V 
 Y 
 
 50. 
 184. 
 240. 
 51.2 
 61.7 
 
 Lithium .... 
 Magnesium . . . 
 
 Li 
 Mg 
 
 7- 
 24. 
 
 Zinc 
 Zirconium 
 
 Zn 
 Zr 
 
 65.2 
 89.6 
 
APPENDIX. 
 
 TABLE II. 
 PRECIPITATING VALUE OF COMMON REAGENTS. 
 
 Solutions of reagents being prepared of the strength recommended 
 by Fresenius (see Fres. Oual. Anal, 17 to 85, b, Johnson's edition 
 of 1875), the amount of a reagent required for precipitation may be 
 calculated from the following table : 
 
 One cubic centimetre of Will precipitate 
 
 Dilute sulphuric acid 0.231 grm. Ba. 
 
 Barium chloride 0.032 " SO 3 . 
 
 Hydrodisodic phosphate .... o.ou " MgO. 
 
 Magnesia mixture 0.024 " P-Oj 
 
 Ammonium molybdate o.ooi " PoO;. 
 
 Ammonium oxalate 0.016 " CaO. 
 
 Argentic nitrate o.oio " Cl. 
 
 TABLE III. 
 
 DIAMETER OF FILTERS AND WEIGHTS OF FILTER 
 ASHES; SWEDISH PAPER. 
 
 Weight of Ash. 
 
 Filter No. 
 
 Diameter. 
 
 Acid. 
 
 Alkaline. 
 
 I . . . 
 
 70 mm. 
 
 0.0004 grm. 
 
 0.0014 
 
 2 . . . 
 
 104 " 
 
 0.0007 " 
 
 O.OO27 
 
 3 
 
 , 122 " 
 
 0.00 1 1 " 
 
 0.0043 
 
 147 " 0.0016 " 0.0062 
 
APPENDIX. 
 
 TRINITY COLLEGE. 
 
 HARTFORD,.... ... 188 
 
 Report of 
 Analysis of 
 
 Determination of 
 Grammes taken : 
 Method of Analysis. 
 
 Actual Calculated Theoretical 
 
 Precipitates. Weights. Constituents. Weights. Percentages. Percentages. 
 
 Special Remarks. 
 
 [This is a reduced fac-simile of the reporting blank, measuring S by 10 inches, de- 
 scribed on page 17.] 
 
ERRATA. 
 
 First table on page 96 should read as follows : 
 
 Combine K as K, SO 4 
 
 " excess of K i; KC1 
 
 Cl " Na Cl 
 
 Na " Na,SO 4 . 
 
 " '< Cl " Mg CL 
 
 S0 4 " Ca SO,. 
 Ca " Ca CO,. 
 " Mg " Mg CO 3 . 
 
 Page 9, line 16, for Ag C read Ag Cl. 
 
 Page ii, line 20, for Beispeilen read Beispielen. 
 
INDEX. 
 
 Acidimetry, 45. 
 
 Albumen, determination of, in urine, 116. 
 Alkalies, determination of, in potable water, 
 92. 
 
 in feldspar, estimation of, 56. 
 Alkalimetry, 42. 
 
 Alloys, determination of two metals in, 100. 
 Alum, ammonia-iron, analysis of, 20. 
 Alumina, iron and phosphoric acid, 75. 
 Alvargonzalez, determination of total car- 
 bon, 81. 
 
 Ammonia-iron-alum, analysis of, 20. 
 Ammonia, determination of, in guano, 88. 
 Ammonio-magnesic phosphate, properties 
 
 of, 19. 
 Ammonium, gravimetric determination of, 20. 
 
 phospho-molybdate, properties of, 70. 
 Analysis, organic, 101. 
 Analyses, calculations of, 15. 
 
 reporting of, 17. 
 
 Antimony, determination of, 51. 
 Apjohn's method of estimating urea, 115. 
 Arsenical nickel ore, analysis of, 86. 
 Ash, estimation of, in coal, 37. 
 
 Baric chloride, analysis of, 13. 
 Barium, determination of, 14. 
 
 sulphate, properties of, 18. 
 Bell's determination of total carbon in pig- 
 iron, 81. 
 
 Bile, tests for, in urine, 117. 
 Bleaching powder, constitution of, 47. 
 
 reactions of, 48. 
 
 valuation of, 49. 
 Bronze, analysis of, 35. 
 Butter, determination of, in milk, 118. 
 Butyramide, estimation of nitrogen in, 107. 
 
 Cairns' determination of graphite in pig-iron, 
 
 78. 
 
 Calcium, determination of, 31. 
 Calculation of results of analyses, 15. 
 
 Calorific power of coal, 39. 
 Cane sugar, analysis of, 101. 
 
 determination of, 121. 
 Carbon, estimation of, in coal, 39. 
 
 total, determination of, in pig-iron, 79. 
 
 ultimate determination of, in sugar, 102. 
 Carbonic anhydride, determination by direct 
 weight, 34. 
 
 determination by loss, 33. 
 Chandler's analysis of Croton Water, 98. 
 Chloride of lime, valuation of, 49. 
 Chlorimetry, 47. 
 Chlorine, determination of, 13. 
 
 determination of, in potable water, 92. 
 Chromic iron ore, analysis of, 54. 
 Clark's soap test for potable water, 93. 
 Coal, proximate analysis of, 36. 
 Cobalt, determination of, in nickel ore, 86. 
 Combustions, process of conducting, 103. 
 Copper, electrolytic estimation of, 35, 39. 
 
 estimation of, in a silver coin, 29. 
 
 pyrites, analysis of, 39. 
 
 Davey's method of estimating urea, 114. 
 Distillation of petroleum, 122. 
 Dolomite, analysis of, 30. 
 Drown's determination of sulphur in pig- 
 iron, 83. 
 
 Eggertz' determination of graphite in pig- 
 iron, 77. 
 
 determination of sulphur and phosphorus 
 in pig-iron, 82. 
 
 Elliott's determination of total carbon in 
 pig-iron, 79. 
 
 Fehling's solution, preparation of, 120. 
 
 Feldspar, analysis of, 56. 
 
 Ferrocyanide of potassium, determination of 
 
 nitrogen in, 105. 
 Flight's method of separating iron, alumina, 
 
 and phosphoric acid, 75. 
 Fusion of an iron ore, 66. 
 
 125 
 
126 
 
 INDEX. 
 
 Glucose, estimation of, 119. 
 Grape sugar, determination of, 119. 
 Graphite, determination of, in pig-iron, 76. 
 Guano, analysis of. 88. 
 
 Heintz and Ragsky's method of estimating 
 
 urea, 115. 
 
 Hematite, analysis of, 62. 
 Hydrochloric acid, valuation of, 46. 
 Hydrodisodic phosphate, analysis of, 27. 
 Hydrogen, determination of, in sugar, 102. 
 
 Iron and titanium, determination of, 74. 
 basic acetate of, 53, 68. 
 determination of, in ammonia-iron-alum, 
 
 21. 
 
 determination of, in a titaniferous ore, 68, 
 
 7- 
 
 determination of, by precipitation, 22. 
 determination of, in hematite, 62. 
 ore, titaniferous, analysis of, 63. 
 slag, analysis of, 60. 
 volumetric determination of, 22, 71. 
 
 Koninck and Dietz' determination of sulphur 
 in pig-iron, 84. 
 
 Lead, estimation of, in a silver coin, 29. 
 Liebig's method of estimating urea, 113. 
 Liquids, specific gravity of, 99. 
 Litmus solution, preparation of, 42. . 
 
 Magnesic sulphate, analysis of, 18. 
 Magnesium, separation from calcium, 30. 
 Manganese, estimation of, 56. 
 
 Gibbs' method of estimation, 70. 
 Marguerite's method for determination of 
 
 iron, 22. 
 
 Melsens' determination of nitrogen, 107. 
 Milk, analysis of, izS. 
 Moisture, determination of, in coal, 36. 
 Molybdenum, use of, in estimation of phos- 
 phoric acid, 69. 
 
 Nickel ore, arsenical, analysis of, 86. 
 Nitrogen, determination of, by Varrentrapp 
 
 and Will's method, 105. 
 Melsens' determination of, 107. 
 Normal solutions, 41. 
 
 Organic analysis, 101. 
 matter in potable water, 94. 
 
 Pearl-ash, valuation of, 45. 
 
 Penot's method for valuation of chloride of 
 
 lime, 49. 
 Permanganate of potassium, standardization 
 
 of, 25. 
 
 Petroleum, distillation of, 122. 
 Phosphoric acid, determination of, 28. 
 determination of, in guano, 89. 
 determination of, by molybdenum, 69. 
 Flight's method of separation from iron, 
 
 75- 
 
 insoluble, determination of, in superphos- 
 phates, 90. 
 
 reduced, determination of, in superphos- 
 phates, 90. 
 Phosphorus, determination of, in pig iron, 
 
 76, 82. 
 
 Pig-iron, analysis of, 76. 
 Potassium chloride, analysis of, 26. 
 ferrocyanide, determination of nitrogen in, 
 
 105. 
 
 gravimetric estimation of, 26. 
 permanganate, solution of, 22. 
 Pyrolusite, analysis of, 56. 
 
 Raw sugar, analyses of, 119. 
 Reporting analyses, 17. 
 Reverted phosphoric acid, determination of, 
 91. 
 
 Salammoniac, action of nitric acid on, 32. 
 Schlosing's determination of ammonia, 88. 
 Silica, determination of, in soluble silicates, 
 
 59- 
 
 determination of, in slag, 61. 
 
 separation of, from titanium, 64. 
 Silicates, analysis of soluble, 59. 
 Silver coin, analysis of, 29. 
 Slag, analysis of iron, 60. 
 Soap test for potable water, 93. 
 Soda ash, valuation of, 44. 
 Sodium, determination of, 27. 
 Specific gravities of solids and liquids, 99. 
 Standard solutions, 42. 
 
 Sugar, determination of ash in raw sugar, 
 119. 
 
 determination of, in milk, 118. 
 
 ultimate analysis of, 101. 
 Sulphur, determination of, in pig-iron, 82. 
 
 estimation of, in coal, 37. 
 Sulphuric acid, gravimetric determination 
 of, 18. 
 
INDEX. 
 
 127 
 
 Sulphuric acid in potable water, determina- 
 tion of, 92. 
 Superphosphate of lime, analysis of, 90. 
 
 Testing petroleum, 122. 
 
 Tin, determination of, in type metal, 51. 
 
 determination of, in bronze, 35. 
 Titaniferous iron ore, analysis of, 63. 
 Titanium, estimation of, in iron ore, 74. 
 Titration, residual method of, 45. 
 Type metal, analysis of, 31. 
 
 Urea, determination of, Liebig's method, 113. 
 
 Apjohn's method, 115. 
 
 Davey's method, 114. 
 Urinary sediments, scheme for analysis of, 
 
 117. 
 Urine, analysis of, 109. 
 
 composition of, in. 
 
 Varrentrapp and Will's estimation of nitro- 
 gen, 105. 
 
 Vinegar, analysis of, 46. 
 Volatile matter, estimation of, in coal, 37. 
 Volumetric analysis, general notes on, 40. 
 estimation of nitrogen, 107. 
 
 Water analysis, calculation of results, 95. 
 
 determination of, by direct weight, 28. 
 
 determination of, by ignition, 15, 28. 
 
 determination of, in milk, 118. 
 
 potable, analysis of, 91. 
 Weyl's determination of total carbon in pig- 
 iron, 82. 
 
 Zinc, determination of, in bronze, 36. 
 ore, analysis of, 53. 
 
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