HAND-BOOK OF ADAPTED FOR THE USE OF MANUFACTURERS, CHEMISTS, AND ALL INTERESTED IN THE UTILIZATION OF ORGANIC MATERIALS IN THE INDUSTRIAL ARTS. BY 1 SAMUEL P. SADTLER, PH.D., AUTHOR OP "A HAND-BOOK OF CHEMICAL EXPERIMENTATION," AND CHEMICAL EDITOR OF THE "UNITED STATES DISPENSATORY," FELLOW OF THE CHEMICAL SOCIETIES OF LONDON AND BERLIN, OF THE SOCIETY OF CHEMICAL INDUSTRY, PROFESSOR OF ORGANIC AND INDUSTRIAL CHEMISTRY IN THE UNIVERSITY OF PENNSYLVANIA, AND OF CHEMISTRY IN THE PHILA- DELPHIA COLLEGE OF PHARMACY, ETC., ETC. PHILADELPH I A : J. B. LIPPINCOTT COMPANY. 1892. Copyright, 1891, by SAMUEL P. SADTLER. All rights reserved. PRINTED BY J. B. LIPPINCOTT COMPANY, PHILADELPHIA. i- PREFACE. THE literature of Applied Chemistry is reasonably voluminous. We have dictionaries and encyclopaedic works upon the subject, a series of small hand-books for individual industries, and a mass of technical journals of both general and special application. Works, however, in which the effort is made to give within the bounds of a single volume a general view of the various industries based upon the applications of chemistry to the arts are much rarer, and especially is this true of works printed in the Eng- lish language. In German we have Wagner's " Chemische Technologic," brought down to date by its present editor, Ferd. Fischer ; Post's " Chem- ische Technologic," Bolley's " Technische-Chemische Untersuchungen," Heinzerling's " Technische Chemie," Ost's " Chemische Technologic," and others ; in French, Payen's " Chimie Industrielle" and Girardin's " Chimie applique aux Arts Industriels," etc. ; while in English we have only the now antiquated translations of Wagner and Payen. In speaking thus, the writer wishes to be understood as referring only to general works on chemical technology of moderate size. The excellent " Dictionary of Applied Chem- istry," in three volumes, now being published by Longmans & Co., does not therefore come into the consideration, for the twofold reason of its size and of its encyclopaedic and disconnected method of treatment. Similarly, works which cover only a single side of the subject, like Allen's " Commercial Organic Analysis," are not referred to in the above statement. The author has endeavored within the compass of a moderate-sized octavo to take up a number of the more important chemical industries or groups of related industries, and to show in language capable of being under- stood even by those not specially trained in chemistry the existing conditions of those industries. The present volume, it will be noticed, is limited to "Industrial Organic Chemistry." This field, while covering many very important lines of manufacture, does not seem at present to be so well pro- vided for as the inorganic part of the subject. A companion volume, covering this other side of industrial chemistry, is in contemplation. In taking up the several industries for survey, it has been thought de- sirable first to enumerate and describe the raw materials which serve as the basis of the industrial treatment ; second, the processes of manufacture are given in outline and explained ; third, the products, both intermediate and final, are characterized and their composition illustrated in many cases by tables of analyses ; fourth, the most important analytical tests and methods iv PREFACE. are given, which seem to be of value either in the control of the processes of manufacture or in determining the purity of the product ; and, fifth, the bibliography and statistics of each industry are given, so that an idea of the present development and relative importance of the industry may be had. The author has endeavored in a number of cases to give a clearer picture of the lines of treatment for an industry by the introduction of schematic views of the several processes through which the raw material is carried until it is brought out as the finished product. A number of these dia- grams have been taken from German and English sources, and several have been constructed by the author specially for this work. A list of these diagrams will be found appended. A large number of the illustrations have been drawn specially for this work, and others have been procured from the best German and American sources. Frequent foot references are made to authorkies and sources of informa- tion, although this may not have been done in all cases. The author has in the analytical section made frequent use of Allen's " Commercial Organic Analysis," and hereby desires to acknowledge his special indebtedness to that most valuable work. He has also made frequent use of Wagner's "Chemische Technologic," thirteenth edition, and Stohmann and Kerl's " Angewandte Chemie." Besides these works of a general character he has also consulted a large number of special works, the titles of which will be found in the bibliographical lists appended to each chapter. The author desires here to acknowledge his indebtedness to the many friends who have aided him by information and helped him especially in the collating of the statistics of the several industries. His special indebtedness is due to his friend and former pupil, Mr. Louis J. Matos, M.E., who aided him in the completion of Chapters XI. and XII., and to whom Chapter XIV. in its entirety belongs. To his colleague, Professor Henry Trimble, of the Philadelphia College of Pharmacy, he is also indebted for information upon the subject of Tannin and Dye.-woods, as treated in Chapter XIII. The original drawings made for this work and the index are also due to Mr. L. J. Matos. The author hopes that this work may prove of some value to those en- gaged in the several lines of manufacturing industry touched upon by show- ing the chemical nature of the materials which are handled by them, and of the change which these materials undergo in the course of treatment and preparation as marketable commodities ; that it may be suggestive to those engaged in research or invention in connection with chemistry ; and, lastly, that it may be found to possess some interest for the general reader or the student of scientific or economic topics. PHILADELPHIA, August 3, 1891. TABLE OF CONTENTS. CHAPTER I. PETROLEUM AND MINERAL OIL INDUSTRY. PAGES I. Raw Materials 13-16 1. Natural Gas, 13. 2. Crude Petroleum, 14-16. 3. Crude Paraffine, 16. 4. Bitumen and Asphalt, 16. II. Processes of Treatment 16-28 1. Of Natural Gas, 16-18. 2. Of Crude Petroleum, 18-25. 3. Of Ozokerite and Natural Paraffine, 25, 26. 4. Of Natural Bitumens and Asphalts and of Bituminous Shales, 26-28. III. Products 28-32 1. Prom Natural Gas (a, Fuel Gas ; b, Illuminating Gas ; c, Lamp- black ; and, d, Electric-light Carbons), 28, 29. 2. From Petro- leum, 29-31. 3. From Ozokerite and Natural Paraffine, 31. 4. From Bitumens, Asphalts, and Bituminous Shales, 31, 32. 5. Vaseline, 32. IV. Analytical Tests and Methods 32-41 1. For Natural Gas, 32. 2. For Petroleum, 32-41. 3. For Ozokerite, 41. V. Bibliography and Statistics 42-45 CHAPTER II. INDUSTRY OF THE FATS AND FATTY OILS. I. Raw Materials 46-55 1. Occurrence of the Materials (a, Vegetable Oils, Fats, and Waxes ; b, Animal Oils, Fats, and Waxes), 46-49. 2. Physical and Chemical Characters of the Different Oils and Fats, 49-51. 3. Extraction of the Raw Materials and Purification of the same, 51-55. II. Processes of Treatment 55-68 1. Saponification of the Fats, 55-57. 2. Practical Soap-making, 57-62. 3. Stearic Acid and Candle Manufacture, 62-66. 4. Oleomar- garine or Artificial Butter Manufacture, 66. 5. Glycerine Manu- facture (5, Nitro-glycerine and Dynamite), 66-68. III. Products . 68-72 1. Purified Oils, Fats, and Waxes, and Products from the same, 68-70. 2. Soaps, 70, 71- 3. Candles, 71. 4. Oleomargarine or Butterine, 71. 5. Glycerine and Nitro-glycerine, 71, 72. IV. Analytical Tests and Methods 72-82 1. For Oils and Fats, 72-78. 2. For Soaps, 78-80. 3. Glycerine, 81, 82. V. Bibliography and Statistics 82-88 CHAPTER III. INDUSTRY OF THE ESSENTIAL OILS AND RESINS. I. Raw Materials 89-94 1. Essential Oils, 89-91. 2. Resins, 91-93. 3. Caoutchouc, 93. 4. Gutta- percha and Similar Products, 93, 94. 5. Natural Varnishes, 94. v vi TABLE OF CONTENTS. II. Processes of Treatment . 94-102 1. Manufacture of Perfumes and Similar Products, 94, 95. 2. Manufac- ture of Varnishes, 95-98. 3. Manufacture of Printer's Ink, 98, 99. 4. Manufacture of Oil-cloth, Linoleum, etc., 99. 5. Processes of Treatment of Caoutchouc and Gutta-percha, 99-102. III. Products 102-106 1. Perfumes, 102. 2. Varnishes, 102-104. 3. Printing Inks, 104. 4. Miscellaneous Products from Resins and Essential Oils, 104, 105. 5. India-rubber and Gutta-percha Products, 105, 106. IV. Analytical Tests and Methods 106-110 1. For Essential Oils, 106-108. 2. For Kesins, 108-110. 3. For Var- nishes, 110. 4. For Caoutchouc and Gutta-percha, 110. V. Bibliography and Statistics 110-112 CHAPTER IV. THE CANE-SUGAR INDUSTRY. I. Raw Materials 113-117 1. The Sugar-cane, 113. 2. Sugar-beet, 113, 114. 3. Sorghum Plant, 114. 4. The Sugar-maple, 114. II. Processes of Treatment 117-145 1. Production of Sugar from the Sugar-cane, 117-130. 2. Production of Sugar from the Sugar-beet, 130-138 3. The Working up of the Molasses, 138-143. 4. Revivifying of the Bone-black, 143-145. III. Products of Manufacture 145-149 1. Raw Sugars, 145, 146. 2. Refined Sugars, 146. 3. Molasses and Cane-sugar Syrups, 146, 147. 4. Miscellaneous Side-products, 147-149. IV. Analytical Tests and Methods 149-159 1. Determination of Sucrose, 149-162. 2. Determination of Glucose, or Invert Sugar, 152, 153. 3. Analysis of Commercial Raw Sugars, 153, 154. 4. Analyses of Molasses and Syrups, 154, 155. 5. Analyses of Sugar-canes and Sugar-beets and Raw Juices there- from, 155, 156. 6. Analyses of Side-products, 156-159. V. Bibliography and Statistics 159, 160 CHAPTER V. THE INDUSTRIES OF STARCH AND ITS ALTERATION PRODUCTS. I. Raw Materials 161-163 II. Processes of Manufacture 163-169 1. Extraction and Purifying of the Starch, 163-165. 2. Manufacture of Glucose, or Grape-sugar, 165-167. 3. Manufacture of Maltose, 167, 168. 4. Manufacture of Dextrine, 168. 5. Manufacture of Sugar-coloring, 168, 169. III. Products 169-171 1. Starch, 169. 2. Glucose and Grape-sugar, 169, 170. 3. Maltose, 170. 4. Dextrine, 170, 171. 5. Unfermentable Carbohydrates, 171. IV. Analytical Tests and Methods 171-175 1. For Starch, 171-173. 2. For Glucose, or Dextrose, 173. 3. For Maltose, 173. 4. Dextrine, 173. 5. Commercial Glucose and Similar Mixtures derived from Starch, 173-175. V. Bibliography and Statistics 175 TABLE OF CONTENTS. vii CHAPTEK VI. FERMENTATION INDUSTRIES. A. Nature and Varieties of Fermentation, 176-179. B. Malt Liquors and the Industries connected therewith. PAGES I. Raw Materials 179-181 1. Malt, 179, 180. 2. Hops, 180, 181. 3. Water, 181. II. Processes of Manufacture 181-187 1. Malting of the Grain, 181-183. 2. Preparation of the Wort, 183, 184. 3. Boiling and Cooling, 184-186. 4. Fermentation of the Wort, 186, 187. III. Products 187, 188 IV. Analytical Tests and Methods 188-192 1. For Malt, 188-190. 2. For Beer-worts, 190. 3. For Beer, 190-192. C. The Manufacture of Wine. I. Raw Materials 192-194 1. The Grape, 192, 193. 2. The Must, 193, 194. II. Processes of Manufacture 194-199 1. Fermentation, 194, 195. 2. Diseases of Wines and Methods of Treat- ing and Improving them, 195-197. 3. Manufacture of Efferves- cing Wines, 197, 198. 4. Manufacture of Fortified, Mixed, and Imitation Wines, 198, 199. III. Products 199-203 IV. Analytical Tests and Methods 203-206 D. Manufacture of Distilled Liquors, or Ardent Spirits. I. Raw Materials 207, 208 1. Alcoholic Liquids, 207. 2. Sugar-containing Raw Materials, 207, 208. 3. Starch-containing Raw Materials, 208. II. Processes of Manufacture 208-217 1. Preparation of the Wort, 208, 209. 2. Fermentation of the Wort, or Saccharine Liquid, 209, 210. 3. Distillation of the Fermented Mash, or Alcoholic Liquid, 211-214. 4. Rectifying and Purifying of the Distilled Spirit, 214-217. 5. Manufacture of Alcoholic Beverages from Rectified Spirit, 217. III. Products 217-221 1. Rectified and Proof Spirit, 217, 218. 2. Alcoholic Beverages made by Direct Distillation of the Fermentation Products, 218, 219. 3. Alcoholic Beverages made from Grain Spirit by Distillation under Special Conditions, 219. 4. Liqueurs and Cordials, 219, 220. 5. Side-products, 221. IV. Analytical Tests and Methods 221, 222 E. Bread-making. I. Raw Materials 223-225 1. Flour, 223, 224. 2. Yeast, or Ferment, 224, 225. 3. Baking-pow- ders, 225. II. Processes of Manufacture 226, 227 1. The Mixing of the Dough and its Fermentation, 226. 2. Baking, 226. 3. The Use of Chemicals Foreign to the Bread, 226, 227. III. Products . , 227, 228 1. Bread, 227, 228. 2. Crackers and Hard Biscuit, 228. IV. Analytical Tests and Methods 228-230 1. For the Flour, 228-230. 2. For Bread, 230. viii TABLE OF CONTENTS. F. The Manufacture of Vinegar. PAGES I. Raw Materials 231, 232 II. Processes of Manufacture 232-235 1. The Orleans Process, 232, 233. 2. The Quick-vinegar Process, 233, 234. 3. The Manufacture of Malt Vinegar, 234. 4. The Manu- - facture of Cider Vinegar, 234. 5. Pasteur's Process for Vinegar- making, 234, 235. III. Products 235, 236 IV. Analytical Tests and Methods 236 V. Bibliography and Statistics for Fermentation Industries 237-240 CHAPTER VII. MILK INDUSTRIES. I. Raw Materials 241-243 II. Processes of Manufacture 243-250 1. Manufacture of Condensed and Preserved Milk, 243, 244. 2. Of Butter, 244-246. 3. Of Artificial Butter (Oleomargarine), 246- 248. 4. Cheese-making, 248-250. III. Products 250-254 1. Condensed and Preserved Milk, 250, 251. 2. Butter and Butter Substitutes, 251, 252. 3. Cheese, 252, 253. 4. Koumiss, 253, 254. 5. Whey, 254; IV. Analytical Tests and Methods 254-259 1. For Milk, 254-256. 2. For Butter, 256-259. 3. For Cheese, y 259. V. Bibliography and Statistics : 259-261 CHAPTER VIII. VEGETABLE TEXTILE FIBRES. I. General Characters 262-270 1. Cotton Fibre, 263, 264. 2. Flax, 264-266. 3. Hemp, 266. 4. Jute, 266, 267. 5. Miscellaneous Vegetable Fibres, 267-269. 6. Clas- sification of the Vegetable Fibres, 269, 270. INDUSTRIES BASED UPON THE UTILIZATION OF VEGETABLE FIBRES. A. Paper-making. I. Raw Materials 270-272 1. Rags, 270, 271. 2. Esparto, 271. 3. Straw, 271. 4. Jute, 271. 5. Manila Hemp, 271. 6. Wood Fibre, 271, 272. 7. Paper-mul- berry, 272. II. Processes of Treatment 272-281 1. Mechanical Preparation of the Paper-making Material, 272, 273. 2. Boiling, 273. 3. Washing, 273, 275. 4. "Bleaching, 275-278. 5. Beating, 278. 6. Loading, Sizing, Coloring, etc., 278, 279. 7. Manufacture of Paper from the Pulp, 279-281. III. Products (Different varieties of paper) 281,282 IV. Analytical Tests and Methods 282-284 1. Determination of the Nature of the Fibre, 282, 283. 2. Determina- tion of the Nature of the Loading Materials, 283. 3. Determina- tion as to Nature of the Sizing Materials, 283, 284. 4. Determi- nation of the Nature of the Coloring Material, 284. B. Gun-Cotton, Pyroxyline, Collodion, and Celluloid. I. Raw Materials 284, 285 II. Processes of Manufacture 285-287 1. Gun-cotton, 285. 2. Pyroxyline and Collodion, 285, 286. 3. Cel- luloid, 286, 287. TABLE OF CONTENTS. ix PAGES III. Products 287,288 1. Gun-cotton, 287. 2. Pyroxyline, 287. 3. Collodion, 287. 4. Py- roxyline Varnishes, 287. "5. Celluloid, 287, 288. IV. Analytical Tests and Methods 288, 289 V. Bibliography and Statistics of Vegetable Fibres and their Indus- tries 289-291 CHAPTER IX. TEXTILE FIBRES OF ANIMAL ORIGIN. I. Raw Materials 292-296 A. Wool and Animal Hairs, 292-294. B. Silk, 294-296. II. Processes of Manufacture or Treatment . . . 297-300 A. Wool. I. Wool-scouring, 297, 298. 2. Bleaching of Wool, 298. B. Silk. I. Reeling of Silk, 298. 2. Silk-conditioning, 298, 299. 3. Silk-scouring, 299, 300. III. Products ; . . . 300,301 A. Woollen Products, 300. B. Silken Products, 300, 301. IV. Analytical Tests and Methods ". . 301, 302 V. Bibliography and Statistics 302-304 CHAPTER X. ANIMAL TISSUES AND THEIR PRODUCTS. A. Leather Industry. I. Raw Materials 305-309 1. Animal Hides and Skins, 305, 306. 2 Tannin-containing Materials, 306-309. II. Processes of Manufacture 309-317 A. Manufacture of Sole-leather, .309-314. B. Upper and Harness Leather, 314. C. Morocco Leather, 314. D. Mineral Tan- ning or " Tawing," 314-316. E. Chamois and Oil-tanned Leather, 316, 317. III. Products 317-319 1. Sole-leather, 317. 2. Upper and Harness Leathers, 317. 3. Morocco Leather, 317. 4. Enamelled or Patent Leathers, 317. 5. Russia Leather, 317, 318. 6. Chamois Leather, 318. 7. White-tanned or " Tawed" Leather, 318. 8. Crown Leather, 318. 9. Parch- ment and Vellum, 318. 10. Degras, 318, 319. IV. Analytical Tests and Methods 319-321 1. Qualitative Tests for the several Tanning Materials, 319. 2. Deter- mination of Strength of Tanning Infusions, 319. 3. Quantitative Estimation of Tannin, 319-321. 4. Determination of Acidity of Tan-liquors, 321. B. Glue and Gelatine Manufacture. I. Raw Materials 322 1. Hides and Leather, 322. 2. Bones, 322. 3. Fish-bladders, 322. 4. Vegetable Glue, 322. II. Processes of Manufacture 322-325 1. Manufacture of Glue from Hides, 322-324. 2. Manufacture of Glue from Leather-waste, 324. 3. Manufacture of Glue or Gelatine from Bones, 324, 325. 4. Manufacture of Fish Gelatine, 325. III. Products .' 325, 326 1. Hide Glue, 325. 2. Bone Glue (or Bone Gelatine), 325, 326. 3 Isinglass (or Fish Gelatine), 326. 4. Liquid Glue, 326. X TABLE OF CONTENTS. IV. Analytical Tests and Methods 326, 327 1. Absorption of Water, 326. 2. Inorganic Impurities, 326. 3. Adul- teration of Isinglass with Glue, 326, 327. V. Bibliography and Statistics of Leather and Glue and Gelatine . . . 327, 328 CHAPTER XL INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. A. Destructive Distillation of Wood. I. Raw Materials ' 329,330 1. Composition of Wood, 329, 330. 2. Effect of Heat upon Wood, 330. II. Processes of Manufacture 331-337 1. Distillation of the Wood, 331-333. 2. Treatment and Purification of the Crude Wood-vinegar, 333-335. 3. Purification of the Crude Wood-spirit, 335, 336. 4. Treatment of the Wood-tar, 336, 337. HI- Products . . 337, 338 1. Pyroligneous Acid and Products therefrom, 337. 2. Methyl Alcohol and Wood-spirit, 337. 3. Acetone, 337, 338. 4. Creosote, 338. 5. Paraffine, 338. 6. Charcoal, 338. IV. Analytical Tests and Methods 338-340 1. Assay of Pyroligneous Acid and Crude Acetates, 338, 339. 2. Deter- mination of Methyl Alcohol in Commercial Wood-spirit, 339. 3. Determination of the Acetone in Commercial .Wood-spirit, 339, 340. 4. Qualitative Tests for Wood-tar Creosote, 340. B. Destructive Distillation of Coal. I. Raw Materials 34O-344 1. Varieties of Coal, 340-342. 2. Effects of Temperature in the Dis- tillation of Coal, 342-:J44. II. Processes of Treatment 344-356 1. Gas-retort Distillations of Coal, 344-347. 2. Coke-oven Distillation of Coal, 347-350. 3. Fractional Separation of Crude Coal-tar, 350-353. 4. Treatment of Ammoniacal Liquor, 353-356. III. Products .... 356-363 1. First Light Oil, 356-359. 2. Middle Oil, 359, 360. 3. Creosote Oil (or Heavy Oil), 360-361. 4. Anthracene Oil, 361-363. 5. Pitch, 363. IV. Analytical Tests and Methods 363-369 1. Valuation of Tar Samples, 363, 364. 2. Special Tests for Tar Con- stituents, 364-368. 3. Valuation of Ammonia-liquor, 368. 4. Analysis of Illuminating Gas, 368, 369. V. Bibliography and Statistics of Destructive Distillation Industries . 369-371 CHAPTER XIT. THE ARTIFICIAL COLORING MATTERS. I. Raw Materials 372-385 1. Hydrocarbons, 372-375. 2. Halogen Derivatives, 375-377. 3. Nitro- Derivatives, 377-379. 4. Amine Derivatives, 379, 380. 5. Phenol Derivatives, 380, 381. 6. Sulpho- Acids, 381 , 382. 7. Pyri- dine and Quinoline Bases, 382, 383. 8. Diazo- Compounds, 383, 384. 9. Aromatic Acids and Aldehydes, 384, 385. 10. Ketones and Derivatives (Anthraquinone), 385. II. Processes of Manufacture 385-391 1. Of Nitrobenzene and Aniline, 385-387. 2. Of Phenols, Naphthols, etc., 387, 388. 3. Of Aromatic Acids and Phthaleins, 388, 389. 4. Of Anthraquinone and Alizarin, 389, 390. 5. Of Quinoline and Acridine, 390. 6. Sulphonating, 390, 391. 7. Dia/otizing, 391. TABLE OF CONTENTS. xi PAGES III. Products 391-400 1. Aniline or Amine Dye-colors, 392, 393. 2. Phenol Dye-colors, 393- 395. 3. Azo Dye-colors, 395-398. 4. Quinoline and Acridine Dyes, 398. 5 Artificial Indigo, 398, 399. 6. Anthracene Dye- colors, 399. 7. Miscellaneous Colors, 399, 400. IV. Analytical Tests and Methods 400-416 1. Fastness of Colors to Light and Soap, 400. 2. Comparative Dye- trials. 400-402. 3. Identification of Coal-tar Dyes, 402-404. 4. Chemical Analysis of Commercial Dyes, 405, 406. 5. Examina- tion of Dyed Fibres, 407-416. V. Bibliography and Statistics 417, 418 CHAPTER XIII. NATURAL DYE-COLORS. I. Raw Materials 419-427 A. Red Dyes, 419-422. B. Yellow Dyes, 422-424. C. Blue Dyes, 424-426. D. Green Dyes, 426, 427. E. Brown Dyes, 427. II. Processes of Treatment 427-434 1. Cutting of Dye-woods, 427. 2. Fermentation or Curing of Dye- woods, 427, 428. 3. Manufacture of Dye-wood Extracts, 429-432. 4. Miscellaneous Processes, 432-434. III. Products 434-439 1. From Red Dyestuffs, 434, 435. 2. From Yellow Dyestuffs, 435, 436. 3. From Blue Dyestuffs, 436-439. 4. From Brown Dyes, 439. IV. Analytical Tests and Methods 439-445 1. For Dye-woods, 439. 2. For Dye-wood and other Extracts, 439-442. 3. For Cochineal, 442, 443. 4. For Indigo and its Preparations, 443-445. V. Bibliography 445-446 CHAPTER XIV. BLEACHING, DYEING, AND TEXTILE PRINTING. I. Preliminary Treatment 447 II. Bleaching 447-453 1. For Cotton, 448-451. 2. For Linen. 451, 452. 3. For Jute, 452. 4. For Wool, 452, 453. 5. Silk, 453. III. Bleaching Agents and Assistants 453, 454 IV. Mordants employed in Dyeing and Printing 455-458 1. Mordants of Mineral Origin, 455-457. 2. Mordants of Organic Origin, 457, 458. V. Dyeing 458-467 1. Cotton-dyeing, 459-463. 2. Linen-dyeing, 463. 3. Jute-dyein-, 463, 464. 4. Wool-dyeing, 464-466. 5. Silk-dyeing, 466, 467. VI. P*rinting Textile Fabrics 467-475 VII. Bibliography ' 475 xii TABLE OF CONTENTS. APPENDIX. PAGES I. The Metric System 477, 478 II. Tables for Determination of Temperatures 478-481 Kelations between Thermometers, 478. Thermometric Equivalents, 479-481. III. Specific Gravity Tables 482-493 1. Baume's Scale for Liquids Lighter than Water, 482. 2. Baume's Scale for Liquids Heavier than Water, 483. 3. Twaddle's Scale for Liquids Heavier than Water, 484. 4. Comparison of the Twaddle Scale with the Rational Baume Scale, 485. 5. Com- parison of Gay-Lussac Scale with Absolute Specific Gravity Figures, 486. 6. Comparison between Specific Gravity Figures, Degree Baume and Degree Brix, 487-493. IV. Alcohol Tables 494-499 LIST OF ILLUSTRATIONS. FIGURE PAGE 1. Carburetting Natural Gas .... 17 2. Crude Oil Still, Cylindrical Shape 20 3. Crude Oil Still, "Cheese-box" Shape 21 4. Oil-still with Superheated Steam . 22 5. Still for Continuous Distillation, I. 22 6. Still for Continuous Distillation, II 23 7. Distillation of Bituminous Shales 27 8. Taglia hue's Open-cup Oil- tester . 34 9. Saybolt's Open-cup Oil-tester . . 35 10. Abel Oil-testing Apparatus ... 36 11. Heumann Oil-test Apparatus . . 37 12. Stoddard Flash-test Apparatus . . 37 13. Tagliabue Cold-test Apparatus . . 38 14. Fischer's Viscosimeter 39 15. Engler's Viscosimeter 39 16. Thurston's Lubricating Oil-tester . 40 17. Wilson's Chromometer, I. ... 40 18. "Wilson's Chromometer, II. ... 41 19. Rendering of Tallow by Steam . . 51 20. Oil-seed Mill 53 21. Oil-seed Press 54 22. Autoclave for Saponifying Fats . . 56 23. Distillation of Free Fatty Acids . 57 24. Wilson and Gwynne Apparatus for Decomposing Fats 57 25. Soap-coppers 60 26. Wooden Soap-frames 62 27. Iron Soap-frames 62 28. Soap-cutting Machine 63 29. Crystallization of Solid Fatty Acids 63 30. Stearic-acid Press 64 31. Candle-moulding Frame 66 32. Soxhlet Extractor 73 33. Thorn's Extractor 73 34. Westphal Specific Gravity Balance 74 35. Boiling Linseed Oil over Free Fire 96 36. Boiling Linseed Oil with Steam . 97 37. Distillation of Copal and Amber Resins . 97 38. Vessel for Vulcanizing Caoutchouc 101 39. Three-roll Sugar-mill' 118 40. Cane-shredder 119 41. Vacuum-pan 123 42. Yaryan Evaporator 124 43. Yaryan Evaporator (sectional view) 125 44. Centrifugal for Sugars 126 45. Wetzel-pan 127 46. Sectibnal View of Sugar Refinery (full page) 129 47. Centrifugal for Sugar-cones . . . 131 FIGURE PAGE 48. Diffusion Battery Elevation . . 132 49. Diffusion Battery Plan 133 50. Circular Diffusion Battery (full page) 135 51. Filter-press for Sugar-scums . . . 137 52. Osmogene 140 53. Steffen Process for Molasses . . . 141 54. Char-kiln for Sugar Refineries . . 142 .55. Klusemann Washer (full page) . 144 56. Polariscope Scheibler Form . . 150 57. Payen's Rendement Method . . . 155 58. Scheibler's Apparatus for Analvsis of Char ". . 158 59. Hoffmann's Converter for Glucose Manufacture 166 60. Maubre's Converter for Glucose Manufacture 167 61. Lintner's Pressure-flask 172 62. Varieties of Yeast, after Hansen (full page) 178 63. Effect of Temperature upon Fer- mentation 179 64. "Thick-mash" Process for Beer (full page) .,185 65. Pasteurizing Wine in Casks . . . 196 66. Apparatus for Determining Alco- holic Strength 203 67. Coffey Still (full page) 213 68. Derosne Still 214 69. Savalle Still 215 70. Element, in Column Still, I. ... 215 71. Element in Column Still, II. . . 215 72. Savalle Rectifying Column ... 216 73. Aleurometer o'f Boland 229 74. Quick-vinegar Process 233 75. Malt-vinegar Cask 234 76. Laval Cream Separator, I. ... 245 77. Laval Cream Separator, II. ... 245 78. Fat-cutting Machine for Oleomar- garine 247 79. Churning-machine for Oleomar- garine 248 80. Cotton Fibre magnified Thirty Times 264 81. Cotton Fibre magnified Two Hun- dred Times 264 82. Sectional View of Stems and Bast Fibres 265 83. Flax Fibre under the Microscope . 266 84. Hemp Fibre under the Microscope 266 85. Jute Fibre under the Microscope . 267 86. Manila Hemp under the Micro- scope ... 267 87. China-grass under the Microscope 268 xiii XIV LIST OF DIAGRAMS. FIGURE PAGE 88. Vomiting Boiler for Paper-makers 274 89. Hollander, 1 275 90. Hollander, II. (full page) ... 276 91. Poudrinier Machine (full page) . 280 92. Wool Fibre under the Microscope 292 93. Alpaca Hair under the Microscope 294 94. Silk Fibre under the Microscope . 295 95. Spinning of the Silk Cocoon . . 295 96. Silk-conditioning 299 97. Magnified Section of Ox-hide . . 305 98. Lime-pits and Liming Process (full page) 311 99. Unhairing Machines and Wash- ing Drums (full page) .... 315 100. Revolving Tumblers for Morocco- tanning 316 101. Steam-boiler for Glue Manufac- ture 324 102. Distillation of Wood from Retorts 331 103. Distillation of Sawdust from Re- torts 333 104. Tar-condensers of Gas-works, I. . 346 105. Tar-condensers of Gas-works, II. 346 106. Lime-purifiers of Gas-works . . 347 107. Simon-Carve's Coke-oven (full page) 349 FIGURE PAGE 108. Tar-still 351 109. Gfiineberg and Blum Ammonia- still 356 110. Benzene Rectification Column . . 358 111. Naphthalene Subliming-chamber 360 112. Anthracene-press 362 113. Sublimation of Anthracene . . . 362 114. Manufacture of Nitrobenzene . . 386 115. Horizontal Aniline-still .... 387 116. Autoclave for Alizarin Manufac- ture 390 117. Madder, Indigo, and Archil . . 420 118. Cutting of Dye-woods 428 119. Extractor for Dye-woods .... 429 120. Cell of Dye-wood Extraction-bat- tery 430 121. Vacuum-pan for Dye-wood Ex- tracts 431 122. Indigo Grinding-mill 433 123. Madder Bleach 448 124. Injector-kier 449 125. Steaming-chest for Turkey-red Yarn 463 126. Calico Printing-machine .... 468 127. Steaming Indigo Prints .... 473 LIST OF DIAGRAMS. General View of the Refining of Crude Petroleum 19 View of the Practical Utilization of a Fat 58 Outline for the Analysis of Fatty Oils ; 79 Leed's Scheme for Soap Analysis 80 General View of the Composition of the Sugar-beet 115 Outline showing the Production of Sugar from the Sugar-cane 121 Outline showing the Production of Sugar from the Sugar-beet 136 Outline of Tanning Process for Sole-leather 313 Qualitative Tests for Tanning Materials 320 General View of the Treatment of Wood-tar 334 General View of the Products of the Distillation of Coal 344 Scheme for the Distillation of Coal-tar 354 Tables for the Identification of Coal-tar Dyes 402-404 Tables for the Detection of Coloring Matters upon the Fibre 407-416 UHIVERSIT7 INDUSTRIAL ORGANIC CHEMISTRY CHAPTER I. PETEOLEUM AND MINERAL OIL INDUSTRY. I. Raw Materials. THE raw materials of this industry are hydrocarbons and products derived from them by alteration, which occur associated together in nature. They may be gaseous, liquid, or solid, and very frequently all three of these physical modifications are found admixed in the same crude material. As, on the other hand, they occur at times separate and distinct, they will be separately noted. 1. NATURAL GAS. Under this name is generally known now the mixture of inflammable gases that is found issuing from the earth in various localities. While it is chiefly in connection with the boring of wells for oil or salt, or as a constantly-forming product of decomposition in coal-mines, that it has been obtained, we find that it often occurs entirely independently of these. "Burning springs," as they have been termed, have been known from the earliest historical times. Those of Baku, on the Caspian Sea, are supposed to have been burning as early as the sixth century before Christ, and to have been a sacred shrine of the Persian fire- worshippers. The Chinese have employed natural gas for centuries in their salt-mines as a source of illumination. In the United States it was employed already in 1821, at Fredonia, New York, as a source of illumi- nation, and for fifty years past has served as the fuel for the evaporation of brine at the salt-wells of the Kanawha Valley, West Virginia. In chemical composition, natural gas is relatively uniform. It consists essentially of methane (marsh-gas), the first member of the paraffin series of hydrocarbons, which may be accompanied by ethane, propane, and the members of the paraffin series next following methane. Small quantities of hydrogen, carbon monoxide, and dioxide have been found to be present at times, while nitrogen is apparently an invariable impurity. The following table gives the results of analyses of natural gases, made in 1886, by Prof. F. C.* Phillips for the Second Geological Survey of Pennsylvania. The localities chosen are all in Western Pennsylvania, with the exception of Fredonia, New York, which is introduced because of its historical interest : 13 14 PETROLEUM AND MINERAL OIL INDUSTRY. & (2 a .' cj C 8 6 ScS Sfi _ - ^ ~s ar% so Sw c * & CO * M 03 ^ m W Paraffin hydrocarbons 90.05 90.64 90.38 90.01 95.42 97.70 90.09 87.27 84.26 Olefine hydrocarbons Carbon dioxide . . . 0.41 0.30 0.21 0.20 0.05 0.20 Trace. 6.41 0.44 Hydrogen 0.02 Oxygen . Trace. Trace. Trace. Trace. Trace Trace Trace Trace Trace Nitrogen 9.54 9.06 9.41 9 79 4 51 202 9 91 12 32 15 30 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 The paraffins contained in these gases have the following composition by weight : Carbon 78 14 76 69 76 52 76 77 77 11 74 96 76 42 76 48 76 68 Hydrogen 21.86 23 31 23 48 23 23 22 89 25 04 23 58 23 52 23 32 100.00 100.00 100.00 10000 100.00 100.00 100.00 100.00 100.00 With these may be compared the natural gas from two important petro- leum-yielding localities in Europe, viz., Pechelbronn, in Alsace, and Baku, on the Caspian. Pechelbronn Pechelbronn Pechelbronn Baku Baku I. II. III. I. II. * (Engler.) (Engler.) (Engler.) (Schmidt.) (Schmidt.) Methane .... 73.6 68.2 77.3 92.49 93.09 Olefines .... 4.0 3.4 4.8 4.11 3.26 Carbon dioxide . 2.2 2.9 3.6 0.93 2.18 Carbon monoxide 3.0 3.7 3.4 . . Hydrogen . . . . . 0.34 0.98 Oxygen .... Nitrogen .... 17.2 4.3 16.9 2.0 9.0 2.13 0.49 100.00 99.6 100.10 100.00 100.00 2. CRUDE PETROLEUM (syn. Erdoel, Naphtha, etc.). Under this heading is included the liquid product which is obtained so abundantly in various parts of the earth, either issuing from the ground naturally or gotten by the boring of wells, through the overlaying rocks to the oil- bearing strata. At the present time the most important petroleum district of the world is that of Western Pennsylvania and New York, covering about three hundred and seventy square miles, and stretching southwesterly from Alleghany County, New York, to Beaver County, Pennsylvania, on the Ohio River, the development centring about Bradford, in McKean County, Pennsylvania. While the oils found in this district may differ considerably in gravity, color, and undoubtedly in chemical composition, KAW MATERIALS. 15 the differences are not fundamental, and with certain special exceptions the crude oils from various localities are all brought together by the pipe-lines and become mixed before going to the refineries. None of these Pennsyl- vania and New York oils contain any appreciable amount of sulphur or other impurity which would require a modification of the general refining methods. The heavy oils of Franklin and Smith's Ferry, Pennsylvania, and some few other localities are so valuable for the manufacture of lubricating oils that they are collected and worked separately. The Penn- sylvania crude oil has in general a dark greenish-black color, appearing claret-red by transmitted light, and varies ordinarily in specific gravity from 0.782 to 0.850, or, as it is frequently expressed, from 49 B. to 34 B. Exceptions to this are the Washington County amber oil, the light-colored Smith's Ferry oil, and some other natural yellow or amber oils. In chemi- cal composition it is essentially composed of hydrocarbons of the paraffin series C n H 2n + 2 , the gaseous and the solid members of the series being alike held dissolved in the liquid ones, and smaller amounts of the hydrocarbons of the olefine series C n H 2n , and the benzene series C n H 2n _ 6 . According to Markownikow, Pennsylvania petroleum also contains hydrocarbons of a series, C n H 2n , which he terms " naphthenes," which are probably hydrogen addition compounds of the aromatic series. Within the last few years a second important field has developed, viz., Ohio, which includes the two dis- tinct districts, the Lima oil district and the Macksburg district. The former is by far the more important, but the product is peculiar in that it contains sulphur, and has an offensive odor similar to Canadian crude oil. Careful analyses made in the author's laboratory have shown that it contains on an average 0.42 per cent, of sulphur, combined in relatively stable forms not decomposed by simple distillation.* Reference will be made to it in speak- ing of refining methods. The most important localities in the United States, outside of the Pennsylvania and Ohio oil-fields, are West Virginia, where a very heavy natural lubricating oil is obtained from shallow wells, Kentucky, Tennessee, Colorado, and California, in which latter State a blackish petroleum of rather heavier consistency than Pennsylvania petro- leum is found quite abundantly. Closely related to the Pennsylvania and New York oil-fields is the oil district of Canada. This is in the neighborhood of Enniskillen, in the western section of the province of Ontario. The Canadian petroleum, however, is distinctly different from that of Pennsylvania. It is darker in color, heavier in gravity, and is of a very offensive odor on account of sulphur impurity, and is therefore more difficult and expensive to refine. As before stated, it finds a counterpart in the oil of Lima, Ohio. Second in importance to the Pennsylvania oil-fields, and even more pro- lific in the yield of individual wells, is the Russian petroleum district of Baku, on the Caspian. For detailed accounts of the extraordinary pro- duction of these wells, the reader is referred to Crew's " Treatise on Petro- leum," p. 96, to Boverton Redwood's article in the Jour. Soc. Chem. Ind., iv., p. 70, or to Engler's articles in Dingler's Polytechnisches Journal, Bd. 260 and 261. The Russian petroleum has a higher gravity than the American, averaging 0.873, or 31 B., and has been found to be entirely different in its chemical composition, consisting for the most part of hydro- * Mabery (Am. Chem. Jour., April, 1891) has identified in Ohio petroleum methyl, ethyl, normal propyl, iso- and normal butyl, pentyl, ethyl-pentyl, and tiexyl sulphides. 16 PETROLEUM AND MINERAL OIL INDUSTRY. carbons of the series C n H 2n , isomeric with the olefine series, and called " naphthenes." As will be seen later, this difference in chemical composi- tion involves a difference in the refining results. The most important of the other European petroleum-fields are those of Galicia, which produce a variety of oils, both light and heavy, either accompanying or independent of the ozokerite of the region, those of Hanover, which yield thick oils, varying in specific gravity from .862 to .910, and those of Alsace, which also yield oils predominantly heavy, and used chiefly for lubricants. The Asiatic petroleum-fields are those of Burmah, which have long been known to be very rich, and which, under British control, will now be developed, and those of Rangoon, -in India, the oils from which are thick and heavy, yielding much lubricating oil and paraffin, and those of Japan. 3. CRUDE PARAFFINE. Under this head may be understood the more or less compact solid material which often accompanies crude petroleum, is deposited from it on standing, and in some cases is found in extensive deposits independently of it. Thus, a deposit of buttery consistency separates from some crude oils, such as Bradford oil, and adheres to the pumping machinery and derrick, forming a crust which has to be scraped off from time to time. The same oils deposit crude paraffine in the pipe-lines, necessitating a periodical scraping of the interior of the pipe-lines. Much of the deposit which accumulates in the storage-tanks of crude oil is of the same material. More important, however, is the occurrence of solid native paraffine, under the name of " ozokerite," or earth-wax. The best-known locality for this native paraffine is Boryslaw, in Eastern Galicia, although it is found also in the Caucasian oil district, and in Persia under the name of " neft- fil," and a few years ago was found in Southern Utah, in the United States. n color it varies from dark green to black, and possesses a lamellar or conchoidal fracture, according to the variety. It fuses between 56 and 74 C., or even higher. In chemical composition it does not differ much from the separated paraffine of petroleum oils. 4. BITUMEN AND ASPHALT. These names are usually made to include the various alteration products of hydrocarbon oils, products which have resulted from evaporation and oxidation, and vary in consistency from thick tars to hard black lustrous solids. Among the bitumens or liquid tars, the best known is that of the Island of Trinidad, where it forms a large lake fluid in the centre, but hardening and becoming solid around the border. Of the hard asphalt, important occurrences are the Cuban as- phalt, or " chapapote," the Albert mineral, at the Albert Mines, New Bruns- wick, and in Ritchie County, West Virginia. The Albert mineral or coal was distilled for hydrocarbon oils already in 1857, but is used now chiefly as a gas-coal enricher. The Torbane mineral, from Bathgate, Scotland, and Boghead coal, and other bituminous shales belong to this class, and form the crude material for the Scotch paraffine distillation. n. Processes of Treatment. 1. OF NATURAL GAS. If we refer to the composition of natural gas, as already stated, it will be seen that it is largely made up of methane and its homologues, with some nitrogen as impurity. The defines, or " illumi- nating hydrocarbons" of ordinary coal-gas, are practically absent in most PROCESSES OF TREATMENT. 17 FIG. 1. cases. This at once indicates quite clearly the value of natural gas as a fuel and its lack of value in the natural state for illuminating purposes. But that it can be readily converted into an excellent illuminating gas has been shown, and in Western Pennsylvania, where natural gas is abundant, it is being used for illumination as well as for fuel. To illustrate the treat- ment that is necessary for the purpose we may describe the McKay and Critchlow process, which is among the most successful in practice. The apparatus, as shown in Fig. 1, consists essentially like the water-gas gen- erators of a combustion-chamber filled with coal brought to a white heat by an air-blast and a fixing-chamber above filled with fire-brick, where the gas- eous products of the first reac- tion combine with oil vapors to form a permanent illuminating gas. The procedure is as follows : The fuel having been rendered thoroughly incandescent, and the fire-brick structure, as observed through the sight-valve, having been heated to a light orange tint, the air-blast is shut off, the lid of the cupola closed, and the gas outlet opened. Natural gas is then introduced into the ash- pit and forced up and through the incandescent fuel-bed, de- positing its carbon on the sur- faces of the fuel as decomposition is effected, and hydrogen gas is thus liberated, which, passing up through the open chamber, meets the vapors of the hydro- carbon, which is projected into the chambers by means of a steam- or gas-injector. The candle-power of the gas may be regulated as desired by intro- ducing more or less of the hy- drocarbon oil. All of these products of decomposition pass- ing together into the upper or fixing chamber, a part of the hydrogen unites with the heavy hydrocarbons, producing the lighter hydrocarbons, while an intimate mixture of all the gases is effected, forming a completely permanent illuminating gas, which passes off through the water-seal, con- densers, scrubbers, and purifiers, to the holder in the ordinary way. Natural gas is also burned for the production of a very pure grade of lamp-black. This manufacture, first carried out at Gambier, Ohio, is now introduced at various places in the oil regions of Pennsylvania. The gas is burned from rows of burners placed in such position that the flame im- pinges upon slate or metallic slabs or revolving cylinders, and there deposits 2 PETROLEUM AND MINERAL OIL INDUSTRY. its carbon. In one building at Gambier, eighteen hundred burners have been used, consuming two hundred and seventy-five thousand cubic feet of gas per twenty-four hours. 2. OF CRUDE PETROLEUM. As petroleum has been shown to be a mixture of hydrocarbons of different volatility, the first operation would naturally be to effect a partial separation of these hydrocarbons by a process of fractional distillation. But, in fact, simpler lines of treatment were first tried. It was found that crude oils spread out over warm water in tanks and exposed to the sun were much improved in gravity and con- sistency. This process was chiefly employed for the production of lubri- cating oils, and the products were called " sunned oils." This was followed by the application of methods of partial evaporation or concentration in stills, either by direct application of heat or by the use of steam coils, care- fully avoiding overheating. The products are called " reduced oils," and form the best material for the manufacture of high-grade lubricating oils. They will be referred to again. The process to which the great bulk of crude petroleum is submitted, however, is that of fractional distillation continued to the eventual coking of the residue. As the most valuable of the several distillates is that which is to be used as illuminating oil, the percentage of that distillate obtainable is an important item in an oil refinery. A normally-conducted fractional distillation of Pennsylvania petroleum will give from thirty-five to fifty-five per cent, of oil suitable for illuminating purposes, and from twenty to thirty per cent, of lubricating oils. About 1865, however, it was found that if during the distillation the heavy vapors were made to drop back upon the hot oil in the still they became superheated and were decomposed. This process of destructive dis- Tke Results of a Normal Distillation of One Hundred Cubic Centimetres of Crude Oils are thus given by Engler : CRUDE OIL FROM Sp. gr. at n 8 c. Began to boil. Came over under 150 C. Between 150 C. and 300 C. Over 300 C. Pennsylvania (I.) Pennsylvania (II.) Galicia (Sloboda) . Baku (Bibieybat) . Baku (Balakhani) Alsace (Pechelbronn) Hanover (Oelheim) 0.8175 0.8010 0.8235 0.8590 0.8710 0.9075 0.8990 82 C. 74 C. 90 C. 91 C. 105 C. 135 C. 170 C. 21 per cent. 31.5 per cent. 26.5 per cent. 23 per cent. 8.5 per cent. 3 per cent. 38.25 per cent. 35 per cent. 47 per cent. 38 per cent. 39.5 per cent. 60 per cent. 32 per cent 40.75 per cent. 33.5 per cent. 26.5 per cent. 39 per cent. 52 per cent. 47 per cent. 68 per cent The Commercial Results usually obtained, on the other hattd, are thus stated by the same Authority (Wagner's Jahresbericht, 1886, p. 1077). CRUDE OIL FROM Benzine and volatile oils. Burning oil, first quality. Burning oil, second quality. Residuum. Pennsylvania 10 to 20 3 to 6 60 t 55 t 35 t 60 t 40 27 to 33 o 75 o65 a45 o 70 135 5 to 6 5 to 10 30 to 40 65 to 60 25 to 35 36 60 to 60 Alsace Roumania . 4 10.5 5 to 6 Baku (Bibieybat) Baku (Balakhani) tillation or " cracking" allowed of a notable increase of the illuminating oil fraction at the expense of the lubricating oil. So at present some PROCESSES OF TREATMENT. 19 seventy-five to eighty per cent, of burning oil is obtained, while the re- siduum from which the lubricating oil is gotten is reduced to six per cent. A general outline of the petroleum refining process as at present con- ducted is presented in tabular form on the accompanying diagram. The process is generally divided into two quite distinct parts. The benzine and burning oil distillate are run from the same still, when the fluid residuum is transferred to what are usually called " tar-stills," in which the rest of the distilling operation is conducted. FIG. 2. Lateral vertical section of cylindrical still. Transverse vertical section of cylindrical still. The crude-oil stills are of two forms, the cylindrical still and the "cheese-box" still, as illustrated in section in Figs. 2 and 3, although the latter is little usecLany more. The former consists of a cylinder of boiler- plate, the lower half being generally of steel, thirty feet in length by twelve feet six inches in diameter. This still is set horizontally, as shown in the sectional view, jn a furnace of brick-work, usually so constructed that the upper part of the still is exposed to the air. The " cheese-box" still has a body and dome-shaped top of boiler-plate and a double-curved bottom of steel plate. It is thirty feet in diameter and nine feet in height, and is 20 PETROLEUM AND MINERAL OIL INDUSTRY. 6-050 j 8 sl^'C S i|- g Irf to EESIDUUM. iation has been carried on esiduum is known as a " re< rety for the manufacture < .seline. e residuum is redistilled fror i .llsll I 1 ^lll s 1 -Ja s s1l J- * 4 s r ^ tw 9 S'sftfeos - <- ^ c^ o S ^ o oS. ^ rr, W--bn ScS fcl 'O StT>-i 'O S ^M'OoS-S- ri -iS'-S m fillill^ si ^i i * g^a-s i 8.^g|a as i fts g l?||ll 1 f s gill El Itffll I 1 5 53 a P^ o^^o ^ 2'^ca.G *^* J3 Q> e ^ l^s-g s E M *" L 1 ^ g N S .S 3 '^ M .-3 sl'^s .S-o ? o.s'o ^ e e G O M O BSaS SB *H ^ fr* ^ to 8S - 3 w ^0, S ' ?|lsl 1 & - _- gg _i-i gwflgo ^ ^ w s2CS Sg M e*^'c 2 M E Ou " 5 J 3 .s-s.s5 2"" 02^-2 % **o ^-o.-S3 5 g ~ H C'S S'^^-nS v cS ^ ;< M Q 5 KH s S^S^^-d | &H!||y > ^ ^-,5 ^ m rt O >^ y O 9 ** ^ r o".'S Sri -3 "S o 5 E 5DO -tn'S ^ 3 .S*^ ^ ^ i C cfi oj o M P 111 1 -t_a O *f. <-> CA T 55? ' K o s "2 ^3 "^ c s PROCESSES OF TREATMENT. 21 set on a series of brick arches. The working charge of the cylindrical stills is about six hundred barrels, and of the cheese-box stills about double that quantity. Both forms of stills are usually provided with coils of steam-pipes, both closed and perforated. The steam, issuing in jets from the perforated pipe, has been found to facilitate distillation by carrying over mechanically the oil vapors. The condensing apparatus varies somewhat in the details of its construc- tion, but consists essentially of long coils of pipe immersed in tanks, through which water is kept flowing. The terminal portions of the con- densing pipes all converge and enter the receiving house within a few FIG. 3. inches of each other. Near the extremity of each a trap in the pipe is made for the purpose of carrying away the incondensable vapor. This may be allowed to escape, or is burned underneath the boilers or stills, effecting thereby a large saving in fuel. The condensing pipes generally deliver into box-like receptacles, with plate-glass sides, through which the running of the distillate can be observed, and from which test portions can be taken from time to time for the proper control of the process. The tar-stills are usually of steel, cylindrical in shape, holding about two hundred and sixty barrels, and are set in groups of two or more, sur- rounded by brick -work. They are either upright or horizontally placed, usage inclining now to the latter position. Vacuum-stills have been and 22 PETROLEUM AND MINERAL OIL INDUSTRY. are still used to some extent, especially in the preparation of reduced oils for the manufacture of lubricants and products like vaseline. Of course, the evaporation in these stills takes place rapidly, and at the lowest temper- ature possible, insuring a fractional distillation and not a decomposition. If superheated steam be used, moreover, instead of direct firing, it is pos- sible to reduce oils to 26 B. without any production of pyrogenic products. A still arranged with superheated steam is shown in Fig. 4. Continuous distillation has not proved commercially successful in the United States. In Russia, on the" other hand, continuous dis- tillation has been emi- nently s u c c e s s f u 1, being especially suited to Baku petroleum, as the quantity of burn- ing oil separated being comparatively small, the residuum is not very much less fluid than the crude oil. The stills, each of the capacity of four thou- sand four hundred gal- lons, are arranged in groups or series of not more than twenty-five, as shown in Figs. 5 and 6, one of which is a front view, and the other a section, and a stream of oil is kept continuously flowing through the entire number. The crude oil, entering the first still, parts with its most volatile constituent^; passing into the next still, has rather less volatile hydrocar- bons distilled from it, and, finally, flows from the last still in the condition of residuum, which in Russia is termed as- tatki, or masut. The several stills are maintained at temper- atures corresponding with the boiling-points of the products to be volatilized. Super- heated steam is used for all the stills, the steam being de- livered partly under the oil and partly above the level of the oil, that is, in the vapor space above. The fuel used under all the stills in Baku is petroleum residuum, or astatki. To recur, now, to the products of the first rough distillation of crude oil, the first fraction, known as the " benzine distillate," and amounting usually to twelve per cent, of the crude oil, is redistilled by steam heat in cylindrical stills, holding five hundred barrels, and is sometimes separated PROCESSES OF TREATMENT. 23 into the following products: cymogene, 100 to 110 B. gravity; rhigo- lene, 90 to 100 B. gravity ; gasolene, 80 to 90 B. gravity ; naphtha, 70 to 76 B. gravity ; benzine, 62 to 70 B. gravity. The time occupied in working the charge is about forty-eight hours. The percentage of these products varies, but, as a rule, amounts to about twenty-five per cent, of the first three collectively, rather more than twenty- five per cent, of the naphtha, and about forty per cent, of the benzine. The deodorization of the benzine which is to be used for solvent purposes in pharmacy or the arts is effected somewhat after the manner to be described under burning oils by the action of sulphuric acid. Only the proportion of acid used is much smaller and the agitation is effected by revolving paddles instead of by an air-blast. One-half of one per cent, is sufficient FIG. 6. in this case. Other processes have been proposed for the deodorization, such as the use of mixtures of sulphuric and nitric acids with alcohol, which produce ethereal products which are said to neutralize and destroy the benzine odor. The treatment of the illuminating oil fraction is a more important process. It must be freed from the empyreumatic products resulting from the distillation, which give it both color and disagreeable odor. To effect this it is subjected to a treatment with sulphuric acid, washing with water and a solution of caustic soda. This operation is conducted in tall cylin- drical tanks of wrought iron, lined with sheet-lead, which are called " agi- tators." The bottom is funnel-shaped, terminating in a pipe furnished with a stopcock for drawing off the refuse acid and soda washings. The distillate to be treated must be cooled to at least 60 F., and before the main body of acid is added for the treatment, any water .present must be carefully withdrawn. This is done by starting the agitation of the oil by the air-pump and introducing a small quantity of acid. This is allowed to settle, and withdrawn. The oil is now agitated, and about one-half of the charge of acid is introduced gradually from above. The agitation is now to be continued as long as action is indicated by rise of temperature, when the dark " sludge acid" is allowed to settle, and withdrawn. The remaining portion of acid is added, and a second thorough agitation takes place. The whole charge of acid needed for an average distillate is about one and one-half to two per cent., or about six pounds of acid to the barrel of oil. The acid, as drawn off, is dark-blue or reddish-brown in color, and is charged with the sulpho-compounds of the defines, while free sulphur 24 PETROLEUM AND MINERAL OIL INDUSTRY. dioxide gas is present in abundance. The oil, after treatment, consists of the paraffin hydrocarbons almost freed from admixture with olefines. In color it has been changed from brownish-yellow to a very light straw shade. The oil is now washed with water introduced through a perforated pipe running around the upper circumference of the tank. This water perco- lates through the body of the oil, removes the acid, and is allowed to escape in a constant stream from the bottom. When the wash-water shows no appreciable acid taste or reaction, the washing is stopped, and about one per cent, of a caustic soda solution of 12 B. is introduced, and the oil is again agitated. When this is drawn oif, the oil is ready for the settling tanks. A washing with water after the soda treatment is sometimes followed, but it is not general. A washing with dilute ammonia is also sometimes used to remove the dissolved sulpho-compounds. The settling tanks are shallow tanks, exposed to air and light on the sides, and here any water contained in the oil settles out, and the oil becomes clear and brilliant. They are provided with steam-coils for gently warming the oil in cold weather to facilitate this separation. A spraying of the finished oil to raise the fire-test by volatilizing a small quantity of the lighter hydrocarbon present was formerly practised at this stage, but exacter control of the dis- tillation has rendered it no longer necessary. The Lima oil and Canadian oil, which, as before stated, contain sulphur impurity, cannot be refined and good illuminating oils obtained by this simple treatment with acid and alkali. Various methods of treatment have been proposed and patented for these oils, such as the alternate treatment with litharge and caustic soda, distillation over finely-divided copper and iron, and other substances tending to combine with the sulphur. It is stated that processes now in use are successfully purifying the Lima oil distillates, but the oil is mostly sold for fuel purposes. This latter utilization is becoming one of great importance. Considered at first as unsalable, because of the diffi- culty of refining it, much attention was directed to the fuel possibilities of the oil. A pipe-line now conducts the Lima oil to Chicago, where it is used in all classes of manufacturing establishments as a substitute for solid fuel with great success and economy. With the aid of injector burners, it has been found pos- sible to use it in smelting and annealing furnaces, in all kinds of forges, in burning brick, tiles, and lime, and for raising steam with all forms of boilers. It is used in these burners in connection with either steam or compressed air. The residuum of the original crude-oil distillation is, as was said, dis- tilled from the " tar-stills." The first runnings, constituting from twenty to twenty-five per cent., will have a gravity of 38 B., and are returned to the crude-oil tank for redistillation, or are treated and purified as burning oil. The paraffine oil which now runs over may be caught in separate lots as it deepens in color and increases in density, or it may be all received together to be treated in the paraffine agitator with acid and purified for the separation of paraffine wax. The agitator in this case must be provided with steam-pipes, so that its contents can be kept perfectly liquid, and the charge of acid is larger, amounting to three, four, or even five per cent. The treatment includes the usual washing with water and soda all at the proper temperature.* The " sludge" becomes quite solid on standing, and is * With the lubricating oils from certain crude petroleums, it is found advantageous not to wash after the acid treatment, but to treat immediately with a strong caustic lye (of 33 B.), and then to wash as a final step. This is said to prevent the emulsifying of the oil and water which sometimes takes place and greatly retards the separating out of the oil. PROCESSES OF TREATMENT. 25 not worked over. After settling, the paraffine oil goes to the chill-rooms, where, by the aid of the ammonia refrigerating machines and the circulation of cooled brine, the whole mass is brought to a semi-solid condition. This is pressed between bagging by hydraulic pressure, and the refined heavy oil which drains off is collected as lubricating oil. Its gravity should be about 32 B., fire-test, 325 F., and cold test, 30 F. The press-cake may be broken up, melted, and recrystallized, and then submitted to still greater pressure at a higher temperature (70 F.) than before, when it is gotten as " refined wax." To convert it into block paraffine, it must be washed with benzine, pressed, melted, and filtered through bone-black, when it is gotten perfectly colorless and solidifying to a hard, translucent block. The char- acters of paraffine will be referred to farther on. The distillation of residuum is continued until the bottom of the still becomes red-hot, when yellow vapors issue from the tail-pipe, and a dense resinous product, of a light-yellow color, and nearly solid consistency, dis- tils over. This " yellow wax" contains anthracene, chrysene, picene, and other higher pyrogenic hydrocarbons. Its only use at present is to add it to paraffine oils to increase density and lower cold test. Its chemical char- acter will be referred to again. The coke remaining in the tar-still at the end of the process amounts to about twelve per cent., and is largely used in the manufacture of electric- light carbons. Reduced oils gotten by careful driving off of the light fractions of the crude petroleum, without cracking, as stated before, are of great value as lubricants. They are generally made by vacuum distillation and the use of superheated steam instead of direct firing. They are either brought into the market at once, without further treatment, or after a bone- black filtration. This production of filtered oils is usually combined with the manufacture of vaseline, or "petrolatum" as it is now known in the " United States Pharmacopoeia." Taking a vacuum residuum as the raw material, this is melted and run on to filters of fine granular well-dried bone-black. The filters are either steam-jacketed or are placed in rooms heated by steam- coils to 1 20 F. or higher. The first runnings are colorless, and all up to a cer- tain grade of color go to the manufacture of vaseline. Beyond that the filtrate is known as " filtered cylinder oil," and is used as a lubricant exclusively. 3. OF OZOKERITE AND NATURAL PARAFFIXE. The Galiciau ozoker- ite is in the main a natural paraffine, but contains some oil in mechanical admixture. Until within ten to twelve years ago it was worked exclusively for the production of paraffine, but now not more than one-third of the annual production is so worked. The most of it is distilled, yielding five per cent, of benzine, fifteen to twenty per cent, of illuminating oil, fifteen per cent, of " blue oil," and about fifty per cent, of paraffine. The " blue oil" is a buttery-like mixture of heavy oils with paraffine crystals, and cor- responds to a paraffine oil as distilled from petroleum. It is run into filter- presses and pressed, first cold, and then the press-cake broken up and pressed warm to remove the adhering oils. If the paraffine scale so obtained is to be worked up into block paraffine, it is repeatedly treated with benzine of not over .785 specific gravity, and pressed, then melted and filtered through bone-black, as before described under petroleum paraffine. If the ozokerite is to be worked up as a whole into the wax-like product known *as Ceresine, the operation may be conducted in one of two ways. The older method was, after a preliminary melting of the ozokerite, to free it from earthy impurities, and continuing the heating until all water 26 PETROLEUM AND MINERAL OIL INDUSTRY. was driven out of the melted mass to treat it with ten per cent, of sulphuric acid as long as sulphurous oxide was evolved. This was followed by treat- ment with water and soda solution. To more thoroughly separate out the black carbonaceous matter produced by the action of the sulphuric acid, one-half to one per cent, of stearic acid is added, and this then saponified with caustic soda. The soap so formed carries down all carbonaceous matter with it, and allows the ceresine to be filtered clear by using filter- paper. The product is the Yellow Ceresine, much resembling beeswax. The White Ceresine, resembling bleached beeswax, is gotten by melting the yellow ceresine by the aid of steam, digesting it with bone-black, with frequent stirring, and filtering through paper. The newer method, more frequently followed now, is to extract the ozokerite with benzine and ligroine. The forms of apparatus devised for this purpose allow of a complete exhaustion of the ozokerite mass and a subsequent recovery of the solvent used in the extraction. The natural paraffine that separates spontaneously from crude petroleum, and accumulates at times, as before mentioned, in pipe-lines, etc., is chiefly used as a basis for the manufacture of vaseline and similar products, being melted and filtered through bone-black, as already described. 4. OF NATURAL BITUMENS AND ASPHALTS AND OF BITUMINOUS SHALES. The pitch or natural bitumen from the Island, of Trinidad is exported largely to the United States, where it is used in the manufacture of roofing materials and of asphalt pavements. It yields from one and three-fourths to two and a half per cent, of paraffine on distillation, and contains sulphur as an invariable constituent. Efforts made to manufacture illuminating and other oils from the pitch have failed of practical results. The use of the Albertite, from New Brunswick, in 1857, prior to the discovery of Pennsylvania petroleum, when it was distilled by the Downer Kerosene Company, of Boston, for illuminating oils, and its present use as a gas-coal enricher have been referred to. Very much more important are the industries based upon the distillation of bituminous shales. As these shales do not contain either liquid or solid hydrocarbons as such, but much more complex compounds called bitumens, the distillation is exclusively a destructive one, and the character of the distillation products becomes dependent upon the conditions of the opera- tion, temperature being the most important consideration. The theory of destructive distillation will be entered upon at length later (see p. 329), and we will here only say that for paraffine and illuminating oil production the distillation is essentially a low-temperature one. The material originally used in Scotland was Boghead coal, or the Torbane Hill mineral from Bathgate, near Glasgow, which was exhausted in 1872. This yielded thirty-three per cent, of tar or oily distillate and one to one and one-half per cent, of crude paraffine. At present shales are used, which furnish about thirteen per cent, of tar. The material for the German paraffine production is an earthy brown coal, which, when dry, is of a light-brownish or yellowish color and crumbling character ; it yields on an average 8.1 per cent, of tar and .6 per cent, of paraffine. The shales are usually distilled with some steam, which increases the amount of the tar, as well as the ammonia from the shale. The distillation may be intermit- tent, but in Scotland is now carried on in a continuous process by the two methods devised by Henderson and by Young & Beilby respectively, the ex- hausted shale being dropped from the bottom of the upright retort into a PROCESSES OF TREATMENT. 27 FIG. 7. combustion-chamber beneath. As the spent shale sometimes contains as much as twelve to fourteen per cent, of carbon, this, with the uncondensed gas of the distillation, suffices for fuel. The accompanying illustration shows the form of still introduced by Young & Beilby for shale distil- lation. (See Fig. 7.) The several products of the distillation are (1) gas, which is freed from gasolene vapors by passing through a coke tower, down which heavy oil is trickling ; (2), watery or ammoniacal liquor, which is obtained to the amount of sixty-five to eighty gallons per ton of shale, and yields from fourteen to eighteen pounds of sulphate of ammonia per ton worked ; (3), oily liquor, or tar proper, of dark-greenish color, and ranging from .865 to .880 in specific gravity, varying in amount from thirty to thirty-three gallons per ton of shale used. This is distilled in cast-iron stills holding from two hun- dred to two thousand gallons, for the purpose of purifying it, until only coke amounting to five to ten per cent, of the tar is left. The mixed distillates (the paraffine magma being added to the others), according to the usage of the German paraf- fine-works, are stirred with two per cent, by volume of caustic soda solution in or- der to take up phenols and " creasote," together with other acid products; the soda washings drawn off below, and the supernatant liquid, after washing with water, is agitated with five per cent, of sulphuric acid. The refined oil is now frac- tionally distilled. The first fraction (specific gravity .60 to .68) is a gasolene used for carburetting illuminating gas; the second (specific gravity .68 to .76) is naph- tha, used as a solvent ; the third (specific gravity .81 to .82) is illuminating oil; the fourth lubricating oil (specific gravity .865 to .900). The next distillate solidifies on cooling, yielding brown crystals of hard paraffine, whose mother-liquor, removed by a filter-press, is " blue oil," whence more but soft crystals can be obtained by artificial refrigeration. The mother- liquid of these is again treated with vitriol and soda and distilled ; the earlier fractions constitute heavy illuminating oil, the later lubricating oil. The percentage of solid paraffine gotten from the crude shale oil is from eleven to twelve and a half per cent. The shale oil does not yield any 28 PETROLEUM AND MINERAL OIL INDUSTRY. product corresponding to vaseline. B. Hiibner, a German paraffine manu- facturer, believing that the distillations of the process just described act injuriously upon the quantity and hardness of the paraffine obtained, has modified the process as follows : He treats the crude shale oil with sulphuric acid, and, after the separation of this, distils the oil over several per cent, of slacked lime. After the crystallization of the paraffine from the distillate, it is purified by washing with shale oils and pressing. He thus avoids one distillation and obtains a larger yield of paraffine, distinctly harder in char- acter than the usual product. In the Scotch shale-works the distilled oil is treated first with sulphuric acid and then with caustic soda, as in the purifying of petroleum oils, and then fractionally distilled. These fractions are again treated with acid and alkali before being considered pure enough for the market. In some works (as those at Broxburn) continuous distillation is practised, so that a set of three boiler stills and two residue- or coking-stills, used together, can put through thirty-five thousand gallons of crude oil per day. The solid paraffine, by careful processes of extraction, can be brought up to twelve and a half per cent. m. Products. 1. FROM NATURAL GAS. (a) Fuel Gas. The great value of natural gas as fuel for manufacturing and industrial purposes has only been realized in the last few years, but with that realization its introduction as cheap fuel has been extraordinarily rapid. In Western Pennsylvania and Ohio, par- ticularly in Pittsburg and its vicinity, it has for manufacturing purposes almost entirely displaced coal and coke. That a gaseous fuel, the admix- ture of which with air can be perfectly effected and controlled, should be superior to solid fuel is, of course, readily conceded. That natural gas, largely made up of methane and similar hydrocarbons, is one of the best of gaseous fuels is seen from the accompanying table, prepared by a com- mittee of the American Society of Mechanical Engineers : Table showing Comparative Effects of Different Gas Fuels. Heat units viPldpd hv Number of cubic feet needed one r\ihir foot to evaporate 100 pounds ^ of water at 212 F. Hydrogen 183.1 293 Water gas (from coke) 153.1 351 Blast-furnace gas 51.8 1038 Carbonic oxide 178.3 313 Marsh gas 571.0 93.8 The comparison of its work with that accomplished with solid fuel, as carried out at the works of Carnegie, Bros. & Co., in Pittsburg, is also given by the same committee. Using the bes1>selected coal, and charging the furnace in such manner as to obtain the best results, the maximum with coal was nine pounds of water evaporated to the pound of coal con- sumed. " In making the calculations, the standard seventy-six-pound bushel of the Pittsburg district was used ; six hundred and eighty-four pounds of water were evaporated per bushel, which was 60.90 per cent, of the theoretical value of the coal. When gas was burned under the same boiler, but with a different furnace, and taking a pound of gas to be equal to 23.5 cubic feet, the amount of water evaporated was found to be 20.31 pounds, or 83.40 per cent, of the theoretical heat-units were utilized." (6) Illuminating Gas. The processes for converting natural gas into PRODUCTS. 29 illuminating gas have already been referred to, and the McKay & Critehlow process described in detail. The production by this process of a permanent gas, showing no condensation of vapors at the drips, and of eighteen to twenty candle-power, is said to have been demonstrated at Beaver Falls, Pa., and elsewhere. (c) Lamp-black. The burning of natural gas so as to cause separation of carbon, which is then collected as lamp-black, has been referred to. The lamp-black. so manufactured has been shown to be of great purity. It is miscible with water, does not color ether, and is free from oily matter. A sample of it analyzed by Professor J. W. Mallet, of the University of Vir- ginia, gave the following results : Specific gravity at 17 C., after complete exhaustion of air, 1.729. The percentage of composition was as follows : Carbon 95.057 Hydrogen . 0.665 Nitrogen 0.776 Carbon monoxide 1.378 Carbon dioxide 1.386 Water 0.622 Ash (Fe 2 O 3 and CuO) 0.056 99.940 (f?) Electric-light Carbons. Still another use for carbon from natural gas is the manufacture of carbons for electric arc-lights, the purity of the material making a very pure and uniform carbon pencil possible. 2. FROM PETROLEUM. The names of commercial products obtained from petroleum have, of course, been almost infinitely varied, as each manufacturer has his trade names for his special products. We shall only designate the generally-accepted classes of products. Beginning with the lightest, we ha*ve : Cymogene, gaseous at ordinary temperatures, but liquefiable by .cold or pressure. Boiling-point, C. (32 F.). Specific gravity, 110 B. Used in the manufacture of artificial ice. Rhigolene, condensable by the use of ice and salt. Boiling-point, 18.3 C. (65 F.). Specific gravity, 0.60 or 100 B. Used as an anes- thetic for medical purposes. Petroleum Ether (Sherwood oil). Boiling-point, 40 to 70 C. Specific gravity, .650 to .660, or 85 to 80 B. Used as a solvent for caoutchouc and fatty oils, and for carburetting air in gas-machines. Gasolene (canadol). Boiling-point, 70 to 90 C. Specific gravity, .660 to .690, or 80 to 75 B. Used in the extraction of oil from oil-seeds and in carburetting coal-gas. Naphtha (Danforth's oil). Boiling-point, 80 to 110 C. Specific gravity, .690 to .700, or 76 to 70 B. Used for burning in vapor-stoves and street-lamps, as a solvent for resins in making varnishes and in the manufacture of oil-cloths. Ligroine. Boiling-point, 80 to 120 C. Specific gravity, .710 to .730, or 67 to 62 B. For solvent purposes in pharmacy and for burning in sponge-lamps. Benzine (deodorized). Boiling-point, 120 to 150 C. Specific gravity, .730 to .750, or 62 to 57 B. Used as a substitute for turpentine, for cleaning printers' type, and for dyers', scourers', and painters' use. Burning Oil, or Kerosene. The different burning oils are known often by special names, of which the number is legion, but they are graded by the American petroleum exporters chiefly accordina^aifaeatattkstandards of 30 PETROLEUM AND MINERAL OIL INDUSTRY. color and fire-test. The colors range from pale-yellow (standard white) to straw (prime-white) and colorless (water-white). The fire-tests (see p. 33), to which the commercial oils are mostly brought, are 110 F., 120 F., and 150 F. ; that of 110 going mainly to the continent of Europe and to China and Japan, and that of 120 to England. An oil of 150 F., fire- test, and water-white in color, is known in the trade as " headlight oil." An oil of 300 F., fire-test, and specific gravity .829, is known as " mineral sperm," or " mineral colza oil." " Pyronaphtha" is a product from Rus- sian petroleum, somewhat similar to mineral sperm oil. It has a specific gravity of .865, and fire-test of 265 F. Lubricating oils from petroleum have assumed an importance which is increasing every year. Some crude petroleums, like those of Franklin and Smith's Ferry, Pa. ; Mecca, Ohio ; Volcano, W. Va., and other local- ities, are natural lubricating oils, requiring little or no treatment to fit them for use. The other petroleum lubricating oils are gotten in one of two ways. Either by driving off the light hydrocarbons from the crude oil, yielding what is called a " reduced oil" (see p. 25), or they are the oils gotten by distilling the petroleum residtiums in tar-stills (see p. 25). The lightest of the lubricating oils, varying in gravity from 32 B. to 38 B., are frequently called " neutral oils." They are largely used for the purpose of mixing with animal or vegetable oils, and it is therefore neces- sary that they should be thoroughly deodorized, decolorized, and deprived of the blue fluorescence or " bloom" characteristic of petroleum distillates that contain paraffine. The first two results are accomplished by bone- black filtration, the last in various ways, such as treatment with nitric acid, addition of small quantities of nitre-naphthalenes, etc. Heavier lubricating oils are called "spindle" and " cylinder" oils. The most important characters to be possessed by these oils is high fire-test, low cold-test, and a high viscosity. (See analytical tests, p. 33.) In the matter of lubricating oils the Russian products are, it is now admitted, distinctly superior in most respects to the American. This is be- cause of the entire difference in the chemical composition of the two, the hydrocarbons characteristic of the Russian oil being heavier and showing less tendency to solidify at low temperatures than those of the American oils. The following statement from Boverton Redwood will illustrate this : Viscosity Viscosity Loss in viscosity, at 70 F. at 120 F. per cent. Kussian oil (sp. gr. .913) 1400 166 88 American oil (sp. gr. .914) 231 66 71 Russian oil (sp. gr. .907) 649 135 79 American oil (sp. gr. .907) 171 68 66 Russian oil (sp. gr. .898) 173 66 67 American oil (sp. gr. .891) 81 40 60 Refined rape oil (for comparison) 321 112 65 It is true that the disproportion is chiefly at lower temperatures, the Rus- sian oil losing its body relatively faster than the less viscous American oil. Paraffine differs somewhat in its hardness and melting point according to the source from which it is derived. The petroleum paraffine is manu- factured generally in three qualities, fusing at 125 F. (51.6 C.), 128 F. (53.3 C.), and 135 F. (57.3 C.), respectively, paraffine from shales melts at 56 C., while that from Rangoon tar melts at 61 C. and that from ozokerite at 62 C. The harder varieties are bluish-white, translucent, and glassy on the surface, while the softer varieties are alabaster-white, dull PRODUCTS. 31 in lustre and only translucent when heated. The harder varieties are resonant. Paraffine is readily soluble in ether, benzene, and all light hydro- carbons, ethereal and fatty oils and carbon disulphide, not entirely in abso- lute alcohol ; while ordinary alcohol only takes up 3.5 per cent, of it. It mixes with stearine, spermaceti, and wax in all proportions. Exposed for some time under a slight pressure to a temperature below its melting point, paraffine wax undergoes a molecular change and becomes trans- parent ; but upon a change of temperature, or upon being struck, the original translucent appearance returns. The harder variety of paraffine is used chiefly in candle-making, for which purpose, however, a small proportion (five per cent.) of stearic acid must be added to it to prevent the softening and bending of the candle. It is also used for finishing calicoes and woven goods, to the surface of which it imparts lustre. The softer varieties are used for mixing with wax and stearic acid in candle-making, for the preparation of translucent and water- proof paper of all grades, for impregnating Swedish matches, for the adul- teration of " chewing-gums," and, in recent years, for " enfleurage" or extract- ing delicate perfumes from flowers. 3. FROM OZOKERITE AND NATURAL PARAFFINE. The character of several of the products now obtained from Galician ozokerite, viz., illuminat- ing and lubricating oils and paraffine, has been sufficiently described under other heads. The peculiar product known as Ceresine, gotten from ozokerite without distillation, remains to be described. It resembles beeswax very greatly in appearance, but is of lower specific gravity, ranging from .915 to .925, while wax is from .963 to .969. The fusing point of ceresine varies from 68 C. to 80 C. Ceresine, with a fusing point of over 75 C., shows a fracture and structure like that of wax. Its behavior to water, alcohol, ether, chloroform, fatty and ethereal oils is exactly like that of paraffine. Ceresine is extensively used as a substitute for wax as well as for most of the uses before given for paraffine. It is commended especially for the formation of matrices for galvano-plastic work, proving in this respect superior to gutta- percha. It is also being used instead of gutta-percha for hydrofluoric acid bottles. 4. FROM BITUMENS, ASPHALTS, AND BITUMINOUS SHALES. It is only from the latter of these that products of commercial importance are derived. From the crude shale oil, already described, the following products are obtained : Shale Oil, Benzine. Specific gravity .77 to .79, boiling-point 80 to 90 C., is colorless, of ethereal odor, and slightly peppermint-like taste. It is used somewhat as a cleansing benzine, but mainly in the purifying of the shale paraffine. Photogene (shale naphtha). Specific gravity .800 to .810, boiling-point 145 to 150 C., has a slight ethereal odor and peppery taste. It dissolves sulphur, phosphorus, iodine, fats, resins, caoutchouc, etc. It is used some- what for illuminating purposes and for dissolving the fat from bones and bleaching them in the preparation of artificial ivory. Solar oil comes into the market, according to Grotowski, in two grades, known as jyrima and secunda oils, one with specific gravity .825 to .830 and a boiling-point 175 to 180 C., and the other with specific gravity .830 to .35 and a boiling-point 195 to 200 C. The oils are of slight, yellowish color, and on exposure to air and light lose their free burning qualities, somewhat through the resinifying of the trace of creosote which 32 PETROLEUM AND MINERAL OIL INDUSTRY. may remain in them. The fire-test of the solar oil is generally above 100 C., and they are in general both cheap and excellent burning oils. Paraffine Oil. The paraffine itself has been described under a previous heading. The expressed paraffine oil is used considerably as a lubricating oil, but is of greatest importance for gas-making. The gas from this paraffine oil is especially rich in illuminating hydrocarbons and is free from the ordinary impurities of coal-gas. It is extensively manufactured in Germany, in the Hirzel and Pintsch forms of apparatus, and in England by the Pintsch, Keith, and Alexander & Patterson processes, and compressed for use in railway carriages, etc. Its characters will be referred to more especially under the heading of illuminating gases. 5. VASELINE. This product (petrolatum of the United States Phar- macopoeia and unguentum paraffini of the German Pharmacopoeia) may be obtained from several of the raw materials already mentioned. In the United States, as the name petrolatum indicates, it is a petroleum product and may be called " natural vaseline," as it is merely a purified preparation of naturally existing petroleum constituents ; in Germany, and elsewhere in Europe, it is either extracted from other sources (pomade ozokerine), or, as the name unguentum paraffini indicates, it is an " artificial vaseline" made by the solution of paraffine in paraffine oil. American vaseline, as made by the Chesebrough Company and others, is gotten by taking a vacuum residuum (see p. 25) and, without any treatment with sulphuric acid or other chemicals, simply filtering it through heated bone-black. In this way the amorphous character of the hydrocarbons is not changed and no crys- talline paraffine is produced, as would be the case if it were a distillation product, and, moreover, no traces of sulphonic acids can remain from the acid treatment to interfere with its use as a basis of medicinal ointments. The petrolatum of the United States Pharmacopoeia may be either a soft variety, melting at 40 C. (104 F.), or a firmer variety, melting at 51 C. (125 F."). The German vaseline, or unguentum paraffini, is made by taking one part of ceresine (parqffinum solidum) and dissolving it in three parts of a paraffine shale oil, known as "vaseline oil" (paraffinum liquidum). This artificial vaseline, as Engler and Bohm have shown,* easily becomes granular on chilling, and shows its composite nature moreover by readily separating on distillation into ceresine and oil. The natural vaseline has greater homo- geneity and is more viscous, although at high temperatures it seems to. absorb more oxygen then the artificial preparation. At temperatures not exceeding 30 C. the oxygen absorption seems to be practically nothing in either ease. Vaseline is largely used in pharmacy and medical practice as a basis of ointments and pomades. IV. Analytical Tests and Methods. 1. FOR NATURAL GAS. These are the methods employed for the analysis of all varieties of illuminating gas, and will be referred to under that heading. (See p. 368.) 2. FOR PETROLEUM. For liquids in general, the two constants most characteristic are specific gravity and boiling-point. For commercial petroleum products, which are, of course, mixtures of hydrocarbons, the second becomes of only secondary importance, while, with reference to their uses as illuminants, the element of safety comes into consideration, so * Dingier, Polytech. Journal, 262, p. 468. ANALYTICAL TESTS AND METHODS. 33 that what is called " flash-point" and " burning point," together included in what is known as " fire-test," becomes important. For lubricating oils, the consistency or body determined in the viscosity -test and the " cold-test," or point to which they can be chilled without separating paraffine, are impor- tant. For paraffine and solid products the melting point and amount of oil enclosed are important. And for all classes the color is a not unim- portant gauge of purity. So that the analytical tests for petroleum products may be summed up under the following heads : Specific gravity. Fire-test, including flash-point and burning point. Cold-test. Viscosity. Melting point. Compression-test. Colorimetric tests. (a) Specific Gravity Determinations. While, of course, the methods of the specific gravity bottle and the specific gravity balance are available, the determinations are, in the case of the liquid petroleum products, almost uni- versally made with hydrometers, and these may be of two kinds, either graduated so that specific gravities are read oft' direct in decimal fractions less than one, or graduated in the arbitrary scales of Beaume, Brix, Gay- Lussac, or Twaddle, the relations of which to simple fractional specific gravity numbers is known. In America and Russia the BeaumS scale is universally adopted ; in Germany, the Brix spindle is used officially by customs officers ; in France, the Gay-Lussac ; and in England, the Beaum6 scale for liquids lighter than water, and the Twaddle for liquids heavier than water. For the formulas for conversion of readings of these scales into specific gravity figures and for a complete table of BeaumS degrees in comparison with the corresponding specific gravity figures, see Appendix. The use of direct specific gravity hydrometers is gradually extending, especially in Germany, as they do away with the necessity of all reduction tables. The specific gravity tables for liquids lighter than water are calcu- lated for a temperature of 60 F., and in practice it is customary to add to or subtract from the observed specific gravities .004 for every 10 F. above or below 60 F., and this is found to afford a sufficiently close approximation to the truth for all commercial purposes in the case of all . the ordinary petroleum products. (6) Fire-test. Just as crude petroleum is dangerous because of the dis- solved gases, although its specific gravity may be relatively high, so illuminating oils may give off, at temperatures far below their boiling- point, small amounts of inflammable vapors, which might make these oils dangerous for use in lamps where the oil reservoir gradually becomes warm. This does not necessarily presuppose designed admixture of ben- zine or volatile distillates with the burning oils. Fractional distillation must be very often repeated to give sharp separations of liquids with gradually increasing boiling-points. What is gotten may be predominantly of one compound, but a little of higher and lower boiling-point is carried over with it. Two points may be determined with a petroleum oil, the flashing point, or the temperature at which the oil gives off vapors which, mixing with air, cause an explosion or flash of flame, dying out, however, at once, and the burning point, or the temperature at \vhich a spark or lighted jet will ignite the liquid itself, which then continues to burn. The 3 34 PETROLEUM AND MINERAL OIL INDUSTRY. later point is usually 6 to 23 C. higher than the former, but there is no fixed relation between them. The danger, of course, begins when an oil will flash, so the flash-point is generally taken as the basis of legal prescription ; Austria and the New York Produce Exchange alone recog- nize formally the burning-test instead of the flash-test. Most European countries and most of the States in the United States prescribe a flash-test. The United States have no national regulation on the subject. The different forms of apparatus in use to determine the safety of oils are based upon either one of two principles, the direct determination of flash or burning point, or the determination of the increased tension of vapor which the oil shows as the temperature rises. The second class is represented by a single form FIG. 8. of apparatus, that of Salleron- Urbain, used to some extent in France ; the first class is rep- resented by a dozen or more dif- ferent forms, chiefly of Ameri- can, English, and German invention. The earliest form, that of the Tagliabue open- cup tester, is shown in Fig. 8, in which the glass cup I), holding the oil to be tested, is heated by the water-bath A. When the thermometer, the mercury of which is just immersed, indicates 90 F. (32 C.), the spirit lamp is withdrawn and the tempera- ture allowed to rise more slowly to 95 F. (35 C.), when a lighted splinter of wood is passed to and fro over the surface of the oil. If the gas rising from the oil does not ignite, the water-bath is heated again and tests are made when the thermometer indicates 100 F. (38 C.), 104 F. (40 C.), and 108 F. (42 C.). A flash at 108 F. is considered as marking the oil at 110 F.. flash-test. This form was the first one offi- cially adopted in the United States, and is still used some- what in Germany and Aus- tria. The New York Produce Exchange and the American petroleum inspectors have now adopted an open-cup tester, known as the Saybolt tester, in which the electric induction-spark is made to pass over the top of the open oil-cup. It is shown in Fig. 9. F is a water-bath, the ANALYTICAL TESTS AND METHODS. 35 temperature of which is noted by an independent thermometer. Although this was a decided improvement on the first Tagliabue apparatus, it was found that, like the other open-cup apparatus, it gave readings which were variable and higher than if the top of the cup were covered. This led to the study of the whole subject by Sir Frederick Abel, at the request of the English governmsnt, and the adoption by the English government as their official standard of the Abel tester. This has since been adopted by the German government as well, and is considered by many to be the most exact now in use. It is shown in Fig. 10. The following is a de- scription of the details of the apparatus : " The oil-cup consists of a FIG. 9. cylindrical vessel, two inches in diameter, two and two-tenths inches high (internal), with outward projecting rim five-tenths inch w r ide, three-eighths inch from the top, and one and seven-eighths inches from the bottom of the cup. It is made of gun-metal or brass (17 B. W. G.), tinned inside. A bracket, cons'sting of a short, stout piece of wire, bent upward, and terminating in a point, is fixed to the inside of the cup to serve as a gauge. The distance of the point from the bottom of the cup is one and a half inches. * The cup is provided with a close-fitting, overlapping cover, made of brass (22 B. W. G.), which carries the tin rmometer and test-lamp. The latter is suspended from two supports from the side by means of trunnions, PETROLEUM AND MINERAL OIL INDUSTRY. FIG. 10. upon which it may be made to oscillate ; it is provided with a spout, the mouth of which is one-sixteenth of an inch in diameter. The socket which is to hold the thermometer is fixed at such angle, and its length is so ad- justed, that the bulb of the thermometer, when inserted to full depth, shall be one and a half inches below the centre of the lid. The cover is provided with three square holes, one in the centre, five-tenths inch by four- tenths inch, and two smaller ones, three-tenths inch by two-tenths inch, close to the sides and opposite each other. These three holes may be closed and uncovered by means of a slide moving in grooves and having perforations corresponding to those on the lid. In moving the slide so as to un- cover the holes, the oscillating lamp is caught by a pin fixed in the slide and tilted in such a way as to bring the end of the spout just below the surface of the lid. Upon the slide being pushed back so as to cover the holes, the lamp returns to its original position." Not only are all the dimensions of parts in the Abel apparatus prescribed most minutely, but the method of carrying out the test must be followed in minute particulars in order to get accu- rate results. The opening and closing of the slide must be regu- lated either by a seconds pendu- lum or, as in the official German apparatus, by exact clock-work. It gives a flash-test which, on the average, is 27 F. lower than that of the open-cup apparatus, so that 73 F. Abel test is taken as the equivalent of 100 F. open- v cup test. A German apparatus, which seems to be fully as exact, and simpler in its construction and operation, is Heumann's tester, shown in Fig. 11. In it the results are to a considerable degree independent of the dimensions of the oil-cup, size of flame, temper- ature of the water, etc. This apparatus shows to what temperature a speci- men of petroleum must be heated through and through in order that the vapor given off may suffice to make an explosive mixture with a volume of air exactly equal to the volume of oil. The glass oil-vessel, g, is set direct in the metallic water-bath, 6, and is exactly half-filled with oil with the aid of a measure accompanying the instrument. The agitating paddles, c, agitate the oil and the air-and-vapor mixture independently. The little flame or lamp for igniting the explosive mixture is attached to a button at d, and here is a small hole through which the gas-and-air mixture escapes, ANALYTICAL TESTS AND METHODS. 37 and, when ignited, yields a flame about five millimetres high. In making the test, after agitation of the mixture, the button, k, is pressed down until the little flame is pushed below the surface, when, if the temperature of flashing has been reached, it ignites the explosive mixture of air and vapor, and is blown out in turn by the slight puif of the explosion. The appa- ratus is said to give results agreeing perfectly with those gotten with the more complicated but official Abel tester. Other forms of apparatus are those of Engler (a closed test apparatus with the Saybolt electric spark attachment), of Parrish, used in Holland, and of Bernstein. Victor Meyer first adopted the principle that the true flash-point of a petroleum is that temperature at which air, shaken with petroleum, can be ignited by a small flame, and proposed the thorough agitation of the warmed oil to be tested with air be- fore applying the flame. The simplest form of apparatus in which this prin- ciple is applied is the flash-tester of Stoddard, shown in Fig. 12. The air-current escapes from a fine-drawn opening in the glass tube, and must raise a foam several millimetres in height on the surface of the oil. The cylinder containing the oil may be a small Argand lamp-chimney, and the FIG. 12. whole apparatus is lowered into a water-bath. The little jet of flame is passed to and fro over the opening at the top of the chimney, while the ther- mometer, immersed in the oil, is read. (c) Cold Test. This is applied chiefly to lubricating oils. The execution of it with Tagliabue's standard oil-freezer is shown in Fig. 13. The glass oil-cup, four inches in depth and three inches in diameter, is adjusted to a rocking shaft, seen at the side of the cup, so as to show by its motion whether the oil is congealing or not. Surrounding the oil-cooling chamber is the ice-chamber, and outside of this is a non-conducting jacket filled with mineral wool. Three thermometers are used : one in the oil-cup and the other two in the ice-chamber to either side. Two stopcocks below, communicating with the cooling-chamber, allow of the forcing in of warm atmospheric air to raise the temperature within when necessary. A glass door in the side opposite the oil-cup allows of the reading of the ther- 38 PETROLEUM AND MINERAL OIL INDUSTRY. mometer without opening the cooling-chamber. The cold-test is also fre- quently applied by simply taking the oil in a sample bottle, the diameter of which is about one and a half inches, chilling it in a freezing mixture, and noting the temperature at which, on inclining the tube, the oil no longer flows, or that at which the separation of paraffine commences. (d) Viscosity Test. As before stated, the " viscosity" or body of a lubri- cating oil is one of its most important characters. Its determination is, therefore, to be made with great care. The earlier forms of apparatus consisted simply of glass tubes, of pipette form, which, being filled with oil to a certain mark, were allowed to empty while the time was accurately noted. The pipette was set in a hot-water funnel or similar vessel, and FIG. 13. the water in this outer vessel brought to 60 F., so that the observation on the oil might be at a standard temperature. Other forms are those of Coleman, Mason, and Redwood, in England, and F. Fischer and C. Engler, in Germany. The Redwood viscosimeter, a very accurate instrument, will be found described and illustrated fully in " Allen's Commercial Organic Analysis" (2d ed., vol. ii. p. 1 98). The Fischer viscosimeter is shown in Fig. 14. The outer vessel, B, having been filled with warm water, the oil- vessel, A, has placed in it about sixty-five cubic centimetres of the oil sample, filling it to a mark on the inside. When the thermometer, immersed in the oil, shows the proper temperature, fifty cubic centimetres are allowed to run into a graduated flask placed below and the time required for its flow noted. The exit-tube, , consists of a platinum tube 1.2 millimetres wide and 5 millimetres long, which is surrounded by a wider copper tube. This exit-tube is enlarged conically at either end, ANALYTICAL TESTS AND METHODS. 39 above to allow of the closing by the conical plug, 6, and below to allow of better flow of the escaping oil. In the Engler instrument, illustrated in Fig. 15, still greater care is taken to insure accurate measurement of the volume of oil operated upon, and that it shall flow under exactly similar conditions in comparative tests. Two hundred and forty cubic centimetres of water fill the inner vessel just to the mark c, and when the temperature of 20 C. (68 F.) is reached, two hundred cubic centimetres are run out into the vessel below. The oil to be tested is similarly filled in to the mark, and when the temperature 20 C. is reached, after keeping the oil at this for some three minutes, the plug, 6, is withdrawn, and two hundred cubic centi- metres are run into the vessel below, while the time required is accurately FIG. 15. FIG. 14. noted. This time in seconds, divided by the time in seconds required for the running of the same volume of water, gives the specific viscosity or viscosity- grade, as Engler terms it. The lubricating value of oils can be determined best by actual use upon the surfaces where friction is felt, and instruments to determine such value are, therefore, based upon experimental trials of the diminution of friction on moving surfaces, when covered by the oils to be compared. Such an instru- ment is the well-known Thurston lubricating oil-tester, shown in Fig. 16, in which both the resistance in the speed of revolution of a rotating axis due to friction and the heating of the axis and the bearing in which it rotates are measured. (e) Melting, Point. The "melting point" of paraffine should rather be called the congealing point, as what is taken usually is the temperature at which the sample, after having been melted, and while in the process of cool- 40 PETROLEUM AND MINERAL OIL INDUSTRY. thermometer bulb, occurs. FIG. 16. ing, begins to solidify. The American test is conducted by melting sufficient of the samples to three-fourths fill a hemispherical dish three and three- fourths inches in diameter. A thermometer with a round bulb is suspended in the fluid so that the bulb is only three-fourths immersed, and the ma- terial being allowed to cool slowly, the temperature is noted at which the first indication of filming, extending from the sides of the vessel to the The English test is made by melting the sample in a test-tube about three-quarters of an inch in diameter, and stirring it with a thermometer as it cools, until a temperature is reached at which the crystallization of the material produces enough heat to arrest the cooling, and the mercury remains stationary for a short time. The results afforded by this test are usually from 2J to 3 F. lower than those furnished by the American test. The melting point is also sometimes determined by observing the temperature at which a minute quantity of the sample previously fused into a capillary tube, and allowed to set, becomes transparent when the tube is slowy warmed in a beaker of water. (/) Compression Test. Paraffine scale usu- ally contains oil and sometimes water. The percentage of oil is determined by subjecting a weighed quantity of the material to a given pressure for a specified time and noting the loss in weight. The test is made at 60 F., the quantity of material employed five hundred grains, the pressure is nine tons over the whole surface of the FIG. 17. circular press-cake, five and five-eighths inches in diameter, and this pressure is maintained for five minutes, the oil expressed being absorbed by blotting- paper. ANALYTICAL TESTS AND METHODS. 41 (g) Colorimetric Tests. The color of petroleum oil is determined in the United States (as regards oil for export), in England, and in Russia (in the case of oil for export) mainly by the use of the Wilson chromometer. In Germany they use both a modification under the name of the Wilson- Ludolph chromometer and Stammer's colorimeter. The Wilson instrument, shown in Fig. 17 and Fig. 18, is fitted with two parallel tubes, furnished with glass caps, and at the lower end of the tubes is a small mirror by means of which light can be reflected upward through the tubes with an eye-piece. One of these tubes is completely filled with the oil to be tested, and beneath the other tube, which remains empty, is placed a disk of stained glass of standard color. On adjusting the mirror and looking into the eye- piece the circular field is seen to be divided down the centre, each half being colored to an extent corresponding with the tint of the oil and of the FIG. 18. glass standard respectively. An accurate comparison of the two colors can thus be made. The glass disks, which for the English trade are of five shades of color, termed good merchantable, standard white, prime white, superfine white, and water white, are issued by the Petroleum Association of London. In Germany, the Bremen Exchange recognizes seven shades of color, straw, light straw, prime light straw to standard white, prime light straw to white, standard white, prime white, and water white. 3. FOR OZOKERITE. The physical tests are the same as those for paraffine scale. 42 PETROLEUM AND MINERAL OIL INDUSTRY. BIBLIOGRAPHY. The following list of titles is not meant to be complete, but only gives the more important published works of the last thirty years. It does not cover periodical literature, which is very voluminous: 1862. Die Fabrikation der Mineralischer Oele, etc., von Theod. Oppler, Berlin. 1865. The Oil Regions of Pennsylvania, W. Wright, New York. 1868. Die Industrie der Mineral Oele, von H. Perutz, Part I., Vienna. 1874. Das Paraffin und die Mineral Oele, M. Albrecht, Stuttgart. 1876-86. Repi-rts of the Second Geological Survey of Pennsylvania on Oil Regions, Harrisburg, Pa. 1877. Petroleum Industrie Nord Amerikas, H. Hofer, Berlin. Geological Survey of the Oil Lands of Japan, B. S. Lyman, Tokio. 1880. Die Industrie der Mineral Oele, H. Perutz, Part II., Vienna. 1881. Petroleum und Erdwachs, Burgmann, Vienna. 1883. Petroleum Central-Europas, J. L. Piedboeuf, Diisseldorf. 1884. Petroleum Distillation, A. N. Leet, New York. Naphtha und Naphtha Industrie, V. Ragosine, St. Petersburg. The Region of Eternal Fire, Chas. Marvin, London. 1885. Lecons sur le Petrole et ses Derives, Chas. Augenot, Antwerp. Census Report of 1880 on Petroleum and its Products, S. F. Peckham, Washington. Destructive Distillation. Ed. J. Mills, third edition, London. 1887. Das Erdoel von Baku, C. Engler, Stuttgart. Verarbeitung der Naphtha oder des Erdoeles, F. A. Rossmassler, Leipzig. Cantor Lectures on Petroleum and its Products, B. Redwood, London. Practical Treatise on Petroleum, B. Crew, Philadelphia. 1886-88. Mineral Resources of the United States for 1886-88 (Petroleum, by J. D. Weeks), Washington. 1887. Preliminary Report on Petroleum and Inflammable Gas, E. Orton, Columbus, Ohio. England as a Petroleum Power, Chas. Marvin, London. Fette und Oele der Fossilien (Mineral Oele), C. Schaedler, Leipzig. Petroleum, its Production and Uses, B. Redwood, New York. 1888. Das Erdoel und seine Verwandten, H. Hofer, Braunschweig. Die Deutschen Erdoele, C. Engler, Stuttgart. 1890. Aux Pays du Petrole Histoire, Origines, etc., F. Hue, Paris. STATISTICS. 1. FOR NATURAL GAS. The wonderful rapidity with which the natural gas production and utilization has been pushed in the last five years in Pennsylvania, Ohio, and adjacent States makes it difficult to present any figures that represent present values or show the varied industries with which its uses has been associated. The figures given in the reports of the United States Geological Survey on " Mineral Resources of the United States" represent the approximate value of the coal displaced in use by natural gas. The industrial utilization may be said to have begun in 1882, and for the first three years values only are given, while from 1885 on both quantities and values are given as taken from the reports on " Mineral Resources of the United States." Years. Location. Amount. Amount. Total. 1882. Pittsburg region . . $75,000 elsewhere. .$140,000 $215,000 1883. Pittsburg region . . 200,000 elsewhere . . 275,000 475,000 1884. Pittsburg region . . 1,100,000 elsewhere . . 360,000 1,460,000 Short tons. Valued at 188o. Pennsylvania ... 3 000,000 $4,500,000 Elsewhere .... 131,600 357,200 4,857,200 1886. Pennsylvania . . . 6,000,000 9,000,000 Elsewhere .... 453,000 1,012,000 10,012,000 1887. Pennsylvania . . . 8,883,000 13,749.500 Elsewhere .... 984,000 2,0(58,000 15,817,500 1888. Pennsylvania, 12,443,830 short tons ; Ohio, 750,000 short tons ; Indiana, 660,000 short tons ; elsewhere, 210,000 short tons ; total coal displaced, 14,063,830 tons, valued at $22,629,878. ANALYTICAL TESTS AND METHODS. 43 2. FOR PETROLEUM. The oil-fields of Pennsylvania and New York were almost the only producing ones prior to 1886, when the Ohio and California production began to develop, so the figures^up to 1886 are not given in detail ; after that the producing States are indicated. The annual production, according to the "Report on Mineral Resources of the United States," has been in barrels (forty-two gallons) : Barrels. Valued at 1882 30,053,500 $23,705,698 1883 23,400,229 25.740,252 1884 24,089,758 20,476^294 1885 21,842,041 19,193,694 1886. Pennsylvania and New York, 25,798,000 barrels ; West Virginia, 152,- 000 barrels; Ohio, 1,782,970 barrels; California, 377,145 barrels ; other States, 50,000 ; total, 28,110,115 barrels : valued at $20,028,457. 1887. Pennsylvania and New York, 22,356,193 barrels ; West Virginia, 145,000 barrels; Ohio, 5,018,015 barrels; California, 678,572 bar- rels; other States, 51,817 barrels; total, 28,249,597 barrels: valued at $18,856,606 1888. Pennsylvania and New York, 16,491,083 barrels ; West Virginia, 119.448 barrels; Ohio, 10,010,868 barrels: California, 704,619 bar- rels; other States, 20,000 barrels; total, 27,346,018: valued at $24,598,559. The production in the Pennsylvania, New York, West Virginia, and Ohio fields (exclusive of Lima) for the year 1889 and the first half of 1890, on the authority of the National Transit Company, was as follows : Total Daily Average, barrels. Barrels. 1889. In Pennsylvania, New York, West Virginia, and Ohio (outside of Lima field). . . . 21,994,261 60,258 In the Lima (Ohio) field 11,837,189 32,431 First half of 1890. Pennsylvania, New York, West Virginia, and Ohio (outside of Lima field) 13,941,213 77,023 In the Lima (Ohio) field 6,116,244 33,791 During the second half of 1890 the production in the Pennsylvania and New York fields increased so that, according to Stowell's Petroleum Re- porter, the daily average for the year 1890 was 78,588 barrels, or a pro- duction for the year 1890 of 27,984,620 barrels. In an estimate of the present cond t'ons of the petroleum industry account must be taken of the accumulated stocks of petroleum held by the pipe-line companies, as that can be drawn upon to compensate for deficien- cies in present production. The figures given below are the stocks held by the companies at the dates assigned. They are for Pennsylvania and New York oil only, and are from Stowell's Petroleum Reporter : January 1, 1885, 37,366,126 barrels January 1, 1889, 18.995,814 barrels. January 1, 1886, 34.428.841 barrels. January 1, 1890, 11,502,593 barrels. January 1, 1887, 34,156.605 barrels. January 1, 1*91, 10,682,807 barrels. January 1, 1888, 28,006,211 barrels. April ' 1, 1891, 10,939,163 barrels. At the same time the stocks of Lima (Ohio) oil are increasing, so that the deficiencies in Pennsylvania and New York oil are about made up, although the oil is not of the same refining value. These stocks were : January 1, 1890 14,105,149 barrels. January 1, 1891 20,971.395 barrels. April 1, 1891 ' 21,957,948 barrels. The exportations of petroleum and petroleum products from the United States for the last five years, according to the United States Bureau of Sta- tistics, have been as follows : 44 PETROLEUM AND MINERAL OIL INDUSTRY. Year end- ing June 30, 1886. Year end- ing June 30, 1887. Year end- ing June 30, 1888. Year end- ing June 30, 1889. Year end- ing June 30, 1890. Crude petroleum (gallons) 76,346 480 80650286 77 549 452 72 987 383 95 350 653 Valued at 85.068,409 85,141,833 85 454 705 85 083 132 86'744'235 Naphtha and light oils (gallons) .... Illuminating oils (gallons) 14,474,%! 485 120 680 12,382,213 485,242 107 13,481,706 455 045 784 14.100,054 502 257 455 12,937,433 523 295 090 Lubricating oils (gallons) 13 948 367 20,582,613 24 510 437 25 166 913 30 16 9 522 Residuum and tar (gallons) 1,993,908 2,989.098 1 ,870,596 1 683R54 2 222 47 Value of refined products $43,076,795 846,898,842 848,105,703 1 814 830 545 844 658864 The value of the paraffine and paraffine wax exported from the United States for the last five years has been as follows: 1886, $1,729,313; 1887, $2,032,713; 1888, $2,168,247 ; 1889, $2,029,602 ; 1890, $2,408,709. The quantities exported during the last two years above quoted were : For year ending June 30, 1889, 33,826,575 pounds ; for the year ending June 30, 1890, 48,552,551 pounds. Next in importance to the oil-fields of the United States are those of Russia. The production of crude oil in the Baku district, according to Hofer, has been in metric centners (100 kilos., or 220.4 pounds), and in barrels (1 barrel = 1.38 metric centners). 1882. 8,190,400m. c., or 5,934,556 barrels. 1883. 9,828,480m. c., or 7, 121 ,468 barrels. 1884. 14,578,912 m. c., or 10,563,510 barrels. 1885. 18,018,880 m. c., or 13,056,024 barrels. 1886. 20,148,384 m. c., or 14,599,008 barrels. 1887. 22,666,500 m. c., or 16,425,000 barrels. The production for 1888 and 1889 is given in the United States Con- sular Reports as 21,000,000 barrels and 24,000,000 barrels respectively, and for the first ten months of 1890, on the authority of the Baku Caspia (as quoted by Stowell's Petroleum Reporter, January, 1891), 24,408,770 barrels. The shipments from Baku for the years 1888 and 1889 are thus re- ported in the United States Consular Reports for May, 1890 : 1888. To Russia. Gallons. Illuminating oils 125,270,660 Benzine and gasolene . . . 456,042 Crude oil 33,616,955 Kesiduum for fuel 269,253,638 Lubricating oils 5,925.920 Soft pitch 4, 788 Totals 434,528,003 For Export. Gallons. 132,929,333 5,205 2,087,475 4,040,330 8,387,764 26,827 147,476,934 Total. Gallons. 258,299,993 461,247 35,704,430 273,393,968 14,313,684 31,615 682,004,937 To Russia. For Export. Total. 1889. Gallons. Gallons. Gallons. Illuminating oils .... 122,315,075 194,434,846 316,749,921 Benzine and gasolene . . . 517,368 8,334 525,702 Crude oil 19,059,757 715,917 19,775,668 ' Kesiduum for fuel . . . . . 409,947,502 8,236,863 418,184,365 Lubricating oils 1,840,667 14,237,177 16,077,744 Soft pitch 639,483 391,612 1,031,096 Totals 654,319,752 218,024,743 772,344,495 The petroleum production of Galicia, the third most productive source, been, according to Hofer, as follows for the last few years : 1883. 510,000 m. c., or 392,308 bbls. 1884. 570,000 m. c., or 438,461 bbls. 1885. 650,000 m. c., or 500,000 bbls. 1886. 750,000 m. c., or 571,538 bbls. BIBLIOGRAPHY AND STATISTICS/ 45 Pizzala ( W. Oesterr. Gewerbe, 1891, p. 58) gives other figures as follows 1882. 200,000 hectolitres or 5,283,400 gallons. 1883. 250,000 ' 6,604,250 1884. 350,000 9,245,950 1885. 500,000 13,208,500 1886. 650,000 17,171,050 1887. 800,000 21,133,600 1888. 1,000,000 26,417,000 1889 1,120,000 29,587,040 1890. 1 ,225,000 32,360,825 3. FOR OZOKERITE AND NATURAL PARAFFINE. The entire produc- tion of ozokerite in Galicia for the year 1883 was 105,200 metric centners. As the crude, ozokerite has a value of twenty-nine to thirty gulden per metric centner at the mines, this production represented a value of three and a quarter to three and a half million gulden ($1,300,000 to $1,400,- 000). In 1884 the production was stated to be 110,000 metric centners (11,000 tons). 4. FOR BITUMINOUS SHALE AND SHALE OIL INDUSTRY. The figures given a few years ago for the Scottish mineral-oil trade are as follows : Amount of oil shale mined daily Annual production of crude oil Annual production of sulphate of ammonia Burning oil distilled from crude oil ... Lubricating oil (upward of 800,000 gallons) Paraffine Annual value of the trade 5,000 tons. 50,000,000 gallons. 14,000 tons. 500,000 barrels. 30,000 tons. 19,000 tons. 1,750,000 Persons engaged in the industry 9500 to 10,000 The following are the figures of the German mineral-oil trade for 1888 : In eleven oil-works there were distilled 2,547,246 hectolitres of coal (or shale), 43,656 tons of tar produced in the works, and 5881 tons of purchased tar, and from these obtained 4448 tons of hard paraffine and 2356 tons of soft paraffine, 4297 tons of paraffine candles, 4298 tons of solar oil, 4905 tons of yellow and 13,604 tons of dark paraffine oil. The value of all products was 6,761,930 marks. 46 INDUSTRY OF THE FATrf AND FATTY OILS. CHAPTER II. INDUSTRY OF THE FATS AND FATTY OILS. I. Raw Materials. 1 . OCCURRENCE OF THE MATERIALS. The fats and fatty oils are of both vegetable and animal origin. They occur not only widely spread through these two kingdoms of nature, but constitute often the larger proportion by weight of the material in which they are found. No part of the plant seems to be entirely wanting in fat, although that found in the leaves is more of a wax-like character than the oil obtained from the seeds and fruit ; in the animal, fats are present in all tissues and organs and in all fluids with the exception of the normal urine. In plants the percentage of fat seems to be in inverse ratio to the percentage of starch and sugar, and ranges from sixty-seven per cent, in the Brazil nut to one per cent, in barley. While the oil-bearing plants are far too numerous to allow of a complete enumeration here, it will ba desirable to state first the occurrence of those technically most important, and afterwards to examine those physical and chemical differences which lie at the basis of their different uses. Similarly the most important animal oils and fats will first be enumerated. (a) VEGETABLE OILS, FATS, AND WAXES. Castor oil (oleum ricini, ricinus-oel) is extracted by pressure or heat from the seeds of the Ricinus communis, originally from the East. It is a thick oil, of specific gravity .9667 at 15 C., colorless or yellowish, transparent, of mild taste, but be- coming rancid on long exposure to air, miscible with alcohol and ether, and easily saponifiable. The shelled seeds yield from fifty to sixty per cent, of the oil. Cotton-seed oil (oleum gossypii seminum, baumwollen-samen-oel) is obtained by pressure from the hulled seeds of the several species of Gossyp- ium, or cotton-plant. The raw oil is brownish-yellow in color, somewhat viscid, of specific gravity .922 to .9306 at 15 C., and separates some palmitin at from 6 C. to 12 C. The refined oil has a straw-yellow color, or is colorless, of pleasant nutty flavor; specific gravity, .9264 at 15 C. ; boils at about 600 F., and congeals at about 50 F. for summer- and 32 F. for winter-pressed. It possesses slight drying properties, and is saponifiable, but is chiefly used in adulterating olive, lard, sperm, and other oils. The hulled seeds yield from eighteen to twenty per cent, of the crude oil. Hemp-seed oil (oleum cannabis, hanf-oel) is obtained from the seeds of the Cannabis saliva, or common hemp. It has a mild odor but mawkish taste, and greenish-yellow color, turning brown with age. Its specific gravity at 15 C. is .9276. It is freely soluble in boiling alcohol. Has weaker drying properties than linseed oil, but is used in paint and varnish manufacture and in making soft soaps. The seeds contain some thirty per cent, of the oil. RAW MATERIALS. 47 Linseed oil (oleum lini, lein-oel) is pressed from the seeds of the Linum usitatissimum, or flax-plant. The oil differs in quality according to the method of its production. By cold pressure is obtained twenty to twenty- one per cent, of a pale, tasteless oil, which is used in cooking as a substi- tute for lard or butter in Russia and Poland. By warm pressure is obtained twenty-seven to twenty-eight per cent, of an amber-colored or dark-yellow oil. It is, when fresh, somewhat viscid, but as a drying oil it gradually absorbs oxygen and becomes thick and eventually dry and hard. The specific gravity of the fresh oil is .935 at 15 C. It is used almost exclu- sively in the preparation of paints, varnishes, printer's ink, and " oil-cloth." (See p. 95.) Poppy-seed oil (oleum papaveris, mohn-oel) is obtained from the seeds of the opium poppy by pressure, is of pale-yellow color, and slightly sweetish taste. Specific gravity, .925 at 15 C. It is used for salads, paints, soaps, and to adulterate olive and almond oil. The seeds yield from forty-seven to fifty per cent, of oil. Almond oil (oleum amygdalae, mandel-oel) is the fixed oil obtained from both the sweet and the bitter almond. The former contains the more oil, but the latter is cheaper, and the residual cake can be utilized for the prep- aration of the essential oil of bitter almonds. The oil is odorless, agreeable to the taste, and of yellow color. Specific gravity, .919 at 15 C. It is used in pharmacy and medicine and in soap-making. Ben oil (oleum balatinum, behen-oel) is obtained by expression from the seeds of the several species of Moringia. Colorless, odorless oil, not readily turning rancid. It is used by perfumers for extracting odors and for lubri- cating clocks and light machinery. Cacao butter (oleum theobromatis) is obtained from seeds or nibs of Theobroma cacao. Pure white fat, with pleasant odor and taste. Fuses at 86 F. (30 C.). Specific gravity, .945 to .952. It is used for cosmetics and for pharmaceutical preparations. Cocoa-nut oil (oleum cocdis, cocos-oel) is obtained from the dried pulp (copra) of the cocoa-nut by expression. An oil of the consistency of butter, fusing at 73 to 80 F. (22.7 to 26.6 C.). When fresh, is white in color and of sweet taste and agreeable odor, but easily becomes rancid. It is easily saponified, even in the cold. It is used in the manufacture of candles and padded soaps. (See p. 61.) Colza and rape oils (oleum brassicse, oleum rapse) are practically identical. They are extracted from the several varieties of Brassica campestris. The seeds are called cole-seed or rape-seed. The term " colza oil" is generally applied to refined rape oil. The crude oils are used as lubricating oils, and are of dark, yellow-brown color. Refined and freed from albumen and mucilage, they become bright-yellow. The specific gravity of the refined oil is .9132 at 15 C. Rape oil is used for lamps, for lubricating machinery, and for adulterating both almond and olive oils. Olive oil (oleum olivarum, oliven-oel) is expressed from the fruit of Olea Europcea. It differs greatly in quality according to the method by which it is obtained. The purest is nearly inodorous, pale-yellow, with pure oily taste. Specific gravity, .918 at 15 C. Does not decompose or become rancid easily, and congeals at 32 F. to a granular solid mass. The percentage of oil amounts to thirty-two per cent., of which twenty-one per cent, is furnished by the pericarp, and the remainder, which is inferior, by the seed and woody matter of the fruit. It is used extensively as an article of food 48 INDUSTRY OF THE FATS AND FATTY OILS. or condiment, in pharmacy, as an illuminant and lubricant, and in soap- making. Palm oil (oleum palmse, palm-oel) is obtained from the fruit of several species of palm. The fresh palm oil has an orange-yellow tint, a sweetish taste, and an odor resembling violets. Its specific gravity is about .968. Its consistency is that of butter or lard. It ordinarily becomes rancid rapidly, and hence usually contains free acid. It is used in candle- and soap-making, and also to color and scent ointments, pomades, soap, powders, etc. Carnauba wax is obtained from the leaves of the carnauba palm, Copernicia cerifera of Brazil. Its specific gravity is .999 and its melting point 185 F. (84 C.). It is brittle and of yellowish color. It is exten- sively used in the manufacture of candles. Japan wax is obtained by boiling the berries of several trees of the genus Rhus, from incisions in the stems of which flows the famous Japan lacquer varnish. It is properly a fat, as it consists almost entirely of glyceryl palm- itate. Its specific gravity is .999 and melting point 120 F. (49 C.). When freshly broken, the fractured surface is almost white or slightly yellowish-green and the odor tallow-like. It is used for mixing with beeswax in the manufacture of candles and in the manufacture of wax- matches. Myrtle wax, a solid fat obtained by pressure from the berries of myrica cerifera. Specific gravity 1.005 at 15 C. ; fusing point 45 to 46 C. It is used as a substitute for beeswax and particularly in candle-making. (6) ANIMAL, OILS, FATS, AND WAXES. Neat's-foot oil. Prepared from the feet of oxen collected from the slaughter-houses. It is a clear, yellowish oil of specific gravity .916 at 15 C. It does not congeal until below 32 F., and is not liable to become rancid. Of great value as a lubricant, and used for softening leather and grinding of metals. Butter fat is the oily portion of the milk of mammalia, but in practice the term is restricted to that obtained from cows' milk. The pure fat con- stitutes from eighty-five to ninety-four per cent, of the finished butter. The pure fat has a specific gravity of .910 to .914, and its melting point varies from 85 to 92 F. For fuller account of manufactured butter, see under milk (p. 244). Lard and lard oil (adeps, schweine schmalz) is the fat of the pig melted by gentle heat and strained. The crude lard is white, granular, and of the consistency of a salve, of faint odor and sweet, fatty taste. Its specific gravity is .938 to .940 at 15 C. Exposed to the air it becomes yellowish and rancid. When pressed at 32 F., it yields sixty-two parts of colorless lard oil and thirty-eight parts of compact lard. The lard is used in cooking, the lard oil for greasing wool, as a lubricant and an illuminant. Tallow and tallow oil (sevum, talg). Tallow is the name given to the fat extracted from " suet," the solid fat of oxen, sheep, and other ruminants. The quality of the tallow varies according to the food of the cattle and other circumstances, dry fodder inducing the formation of a hard tallow. Its melting point varies from 115 to 121 F. The best qualities are whitish, but it has in general a yellowish tint. Beef tallow contains about sixty-six per cent, of solid fat and thirty-four per cent, of olein or tallow oil ; mutton tallow contains about seventy per cent, of solid fat and thirty per cent, of tallow oil. The oil is used chiefly in the manufacture of soaps and the harder tallow for candle-making. RAW MATERIALS. 49 Bone fat is a whitish-yellow fat obtained by boiling bones, and is used in soap-making. Cod-liver oil (oleum jecoris ceselli, leberthran) is an oil ranging in color according to the method of its preparation from pale-straw to dark-brown, and of specific gravity .923 to .924 or even .930 at 15 C. The finer qualities are used for medicinal purposes, the darker for tanners' and curriers' use. Menhaden oil is obtained from the Alosa menhaden, a kind of herring. Is used for soap-making and tanning, and, when pure, as a substitute for cod-liver oil. Shark oil is prepared from the livers of various species of shark. It is the lightest of the fixed oils, the specific gravity ranging from .865 to .876. It is used in the adulteration of cod-liver oil and for tanning. WJiale oil (train oil) is extracted from the blubber of the common or Greenland whale. Is yellow or brownish in color and of disagreeable odor. Specific gravity .920 to .931. It is used for illumination and for soap- making. Sperm oil is procured from the deposits in the head of the sperm whale. In the living animal, the solid spermaceti is held in solution in the liquid sperm oil ; when the liquid becomes cold the spermaceti separates out. The oil is very limpid, relatively free from odor, and burns well in lamps. Specific gravity, .875. It is used as a lubricant on account of its low cold test and its viscosity, and as an illuminant. Spermaceti (cetaceum, walrath) is the solid wax separated out from the accompanying oil. It is yellowish at first, but when purified is white, brittle, and scaly. Its specific gravity is .943 at 15 C. ; melting point, 43 to 49 C. It is only slightly soluble in alcohol, benzene, and petroleum- ether, but easily soluble in ether, chloroform, and carbon disulphide. It is used in the manufacture of candles and in pharmaceutical preparations. Beeswax (cera flava, bienenwachs) is the substance of which the cells of the honey-bee are constructed. The crude melted wax is a tough, compact mass of yellow or brownish color, granular structure, faint taste, and honey- like odor. When bleached it becomes white. Specific gravity .959 to .969 ; melting point 62 to 64 C. It is used in making candles, ointments, and pomades. Chinese wax (insect wax) is deposited by an insect, Coccus cerifera, upon the Chinese ash-tree. It is a white, veiy crystalline, and brittle wax, resem- bling spermaceti in appearance. Specific gravity .973 at 15 C. ; fuses at 82 to 83 C. It is slightly soluble in alcohol and ether, very soluble in benzene. It is used in candle-making. 2. PHYSICAL, AND CHEMICAL CHARACTERS OF THE DIFFERENT OILS AND FATS. (a) Physical Properties. Most of the vegetable fats are liquid at ordinary temperatures, because of the relatively high percentage of olein they contain. Cocoa-nut oil, palm oil, cacao butter, and a few others have a buttery consistence on account of the palmkin present. The fats of animals feeding on straw and hay are solid, because of the stearin present ; the fats of carnivorous animals are all softer ; the fat of fishes is liquid at ordinary temperatures, and somewhat differently constituted chemically. The solid waxes, both vegetable and animal, are in general differently constituted from the softer fats. The fats and oils are almost insoluble in water (if the water contains albumen, gum, or alkaline carbonates in solution they readily form an 50 INDUSTRY OF THE FATS AND FATTY OILS. emulsion with it on shaking) ; alcohol only dissolves them sparingly ; ether, carbon disulphide, chloroform, benzene, turpentine oil, fusel oil, and acetone dissolve them readily. On exposure to the air, the fats, and particularly the fatty oils, absorb oxygen. The heat developed by this oxidation at times suffices to inflame wool and cotton tissues soaked with the oil. The oils which absorb oxygen in this way become thick, and finally dry to translucent resinous masses. Such oils are called " drying oils," and are used in painting and varnish-making. (See p. 95.) The specific gravity of all the fats and oils is less than unity, although the vegetable waxes are only very slightly less. ' The boiling-points of the oils and fats cannot in general be taken as distinctive, as many of them begin to decompose when distilled under ordi- nary pressure. Their fusing and congealing points are more important; particularly in the case of oils used as lubricants does the latter denote the different value of the oil for use at low temperatures. (6) Chemical Composition of the Oils, Fats, and Waxes. The fatty oils, as distinguished from the mineral oils (see p. 13) and the volatile oils (see p. 89), belong to the class of compound ethers. They are salt-like bodies, composed of characteristic acids (oleic, palmitic, and stearic), known as fatty acids, in combination with an alcohol or base. In most cases the base is the triatomic alcohol glycerine, so that the oils are said to be glycerides of the several fatty acids. Some few, known as waxes, do not contain glycerine, but a. monatomic alcohol in combination with the fatty acid. Most of the animal and vegetable fats contain the three proximate .constituents, olein, palmitin, and stearin, the combinations of oleic, palmitic, and stearic acids respectively with glycerine. In the more liquid oils the olein predominates, in the more solid palmitin or stearin. The so-called " drying oils" contain a different acid linoleic acid in combination with glycerine. The fish oils contain a variety of the lower fatty acids and some solid unsaponifiable alcohols like cholesterin. The most satisfactory classification of the oils and fats is that of A. H. Allen,* which is here given in abstract. I. Olive Oil Group. Vegetable oleins. Vegetable non-drying oils. Lighter than Groups II., III., and IV. Yield solid elaidins with nitrous acid. Includes olive, almond, earth- nut, ben, rape-seed, and mustard oils. II. Cotton-seed Oil Group. Intermediate between drying and non-drying oils. Un- dergo more or less drying on exposure. Yield little or no elaidin. Includes cotton-seed, sesame, sunflower, hazel-nut, and beech-nut oil. III. Linseed Oil Group. Vegetable drying oils. Yield no elaidin. Of less viscosity than the non-drying oils. Includes linseed, hemp-seed, poppy-seed, niger-seed, and walnut oils. IV. Castor Oil Group. Medicinal oils. Very viscous and of high density. Includes castor and croton oils. V. Palm Oil Group Solid vegetable fats. Do not contain notable quantities of flycerides of lower fatty acids. Includes palm oil, cacao butter, nutmeg butter, and shea utter. VI. Cocoa-nut Oil Group. Solid vegetable fats, in part wax-like. Several contain notable proportions of the glycerides of lower fatty acids. Includes cocoa-nut oil, palm- nut oil, laurel oil, Japan wax. and myrtle wax. VII. Lard Oil Group. Animal oleins. Do not dry notably on exposure, and give solid elaidins with nitrous acid. Includes neat's-foot oil, bone oil, lard oil, and tallow oil. VIII. Tallow Group. Solid animal fats. Predominantly glycerides of palmitic and stearic acid, although butter contains lower glycerides. Includes tallow, lard, bone fat, wool fat, butter fat, oleomargarine, and manufactured stearin. * Commercial Organic Analysis, 2d ed., vol. ii. p. 63. RAW MATERIALS. 51 IX. Whale Oil Group. Marine animal oils. Characterized by offensive odor and reddish-brown color when treated with caustic soda. Includes whale, porpoise, seal, men- haden, cod-liver, and shark-liver oil>. X. Sperm Oil Group. Liquid waxes. Are not glycerides but ethers of monatomic alcohols. Yields solid elaidins. Includes sperm oil, bottle-nose oil, and dolphin oil. XI. Spermaceti Group. Waxes proper. Are compound ethers of higher monatomic alcohols, with higher fatty acids in free state. Includes spermaceti, beeswax, Chinese wax, and carnauba wax. 3. EXTRACTION OF THE RAW MATERIALS AND PURIFICATION OF THE SAME. The method of extraction of the oils and fats is, of course, deter- mined to a considerable degree by their physical condition. Solid fats, like tallow and lard, are obtained free from the enclosing membranes by melting the finely-chopped material and drawing off the fat in the melted state; FIG. 19. lfiiliSiiiii.1- I animal oils are extracted mainly by boiling out with water ; oil fruits and seeds are ground fine, and then the oil obtained by submitting the meal to pressure, either cold or with the aid of heat, or the oil is extracted by solvents like carbon disulphide and petroleum ether. In the extraction of fats by the process of melting, three forms of procedure are followed: (1), the so-called "cracklings" process, a melting over direct fire, known, too, as the " dry melting ;" (2), the melting over direct fire with the addition of dilute sulphuric acid, known as the " moist melt- ing ;" and (3), the melting by the aid of steam. In the first process, a 52 INDUSTRY OF THE FATS AND FATTY OILS. little water is added and the tallow or other chopped fat is heated in open vessels. The mixture of fat globules and water at first gives it a milky appearance, but, as soon as the water is driven off, the cell membranes shrivel more and more together, forming the cracklings, and the fat appears as a clear, fused liquid. A constant stirring is required in order to prevent the fragments of membrane from sticking to the sides or bottom of the vessel and burning. The melted fat is drained from the cracklings by passing through metallic sieves, and cracklings afterwards pressed in suitable presses to recover the adhering fat, which forms a second quality tallow. A raw tallow yields on the average eighty to eighty-two per cent, of drained oil and ten to fifteen per cent, of cracklings ; a very pure kidney fat will yield, however, ninety per cent, and over of drained fat. In the second process, now generally followed, to one hundred kilos, of tallow, twenty kilos, of water mixed with one-half to one and one-half kilos, of concentrated sulphuric acid is added. The sulphuric acid attacks and destroys the cell-membranes rapidly when heated, and so allows of the liber- ation of the fat. In this process, as in the last, provision must be made for preventing the escape into the air of the unhealthy and offensive odors coming from the melting of the impure tallow. The escaping vapors are in part condensed and part burned under the kettles. In the third process, that of melting by steam, the steam may be directly introduced into the fat mass or indirectly used by the aid of coils of pipes. The tallow rendering by steam is illustrated in the apparatus of Wilson, shown in Fig. 19. The steam enters through the perforated pipe 6r, under the perforated false bottom. The plate F having been shut down tight upon the opening E, the vessel is two-thirds filled with the tallow and steam applied. The pressure is allowed to rise to three and a half atmos- pheres (fifty-two and a half pounds per square inch) and kept at this for some ten hours. The condensed water collects under the false bottom and can be drawn off when necessary. The melted tallow is then run off from the stopcocks, PP, and the cracklings finally discharged through the opening E. Some acid may be added to the fat or in the Evrard process, instead of acid, caustic soda, which has the advantage of combining with the noxious volatile acids evolved. The extraction of lard takes place by similar methods to those employed for tallow, but at lower temperatures and more readily. For the extraction of animal oils, like fish oils, the method of boiling out with water is generally employed, elevation of temperature and prolonged heating being avoided as much as possible in the case of the finer medicinal oils. For oil-bearing fruits and seeds, the methods of obtaining oil, as already mentioned, are expression, either cold or by the aid of heat, and that of extraction by solvents. For the expression of oils, the carefully cleansed seeds are first crushed to break the shells or kernels and then ground to fine meal. The crushing is done very generally in oil-seed mills of the construction shown in Fig. 20, where the two stones or metal wheels are made to revolve on a stone founda- tion on which the oil seeds are placed, and from which any excess of oil may flow. A much more perfect crushing is possible in this mill than in those in which stamps are used They arc then slightly heated for the double purpose of coagulating any plant albumen and making the oil more liquid. EAW MATERIALS. 53 In the case of the best medicinal or table oils all heat is avoided and cold- pressed oils only taken. The meal is then repeatedly pressed. The result of the first pressing is often called " virgin oil," and is of better color and taste than the later lots. The pressing is done chiefly with hydraulic presses, as shown in Fig. 21, although the old wedge presses may still be used on a small scale. The crushed oil seed is placed in woolen or cotton cloths, usually covered in by bags of horse-hair, and then placed between the press-plates. The other process, that of extraction of the oil by solvents, is capable of yielding a much larger amount of oil than pressure, but has FIG. 20. been more or less opposed on several grounds. The solvents employed are carbon disulphide and petroleum -ether. The former is the better solvent, is used at a lower temperature, and is easily recovered from the solution after- wards without leaving any appreciable odor adhering to the oil. It, how- ever, dissolves coloring matter and resin from the seed as well as oil, and so introduces impurity, and when not perfectly pure, it leaves sulphur impuri- ties also in the oil. The other solvent does not dissolve so much coloring matter or resin, communicates no odor, and leaves no sulphur or other residues in the oil, and so can be used for fine table oils, if necessary. It 54 INDUSTRY OF THE FATS AND FATTY OILS. FIG. 21. requires a higher temperature, however, and, condensing on the surface of water instead of under it, like carbon disulphide, requires more complicated distil- ling and condensing apparatus. At the present time the carbon disulphide is more generally used. The objection first urged against the extraction of oil by solvents, that they left the oil-cake valueless for cattle food because of the too complete extraction of the oil, is now met by the oil men, who leave eight to ten per cent, of fat or oil in palm-nut or other oil-cake. The expressed or extracted oils are in many cases in quite a crude condition, containing both sus- pended and dissolved impurities of various kinds. To purify them for use, even in soap-making, some treatment is generally necessary. Often simple but prolonged subsidence suffices if the impurities are only suspended. Instead of subsidence, it may be necessary at times to use filtration through cotton wadding or animal charcoal. If both subsidence and filtration fail to clear the oils, it is necessary to adopt chemical treatment as the impurities in time ferment and develop N a permanent rancidity or de- terioration of the oil. The first process to note is that of Thenard, to add gradually one to two per cent, of sulphuric acid to oil previously heated to about 100 F. and mix by thorough agitation. The sulphuric acid both takes up the water that holds the impurities in solution and chars the impurities them- selves. The treatment with acid is to be followed by a thorough washing with warm water and final filtra- tion. Cogan's process follows the addition of sulphuric acid by that of steam. Instead of sulphuric acid, caustic alkalies are sometimes used as in the Evrard process (see p. 51), which is chiefly applied to colza and rape oils. In this case, the caustic soda saponifies a small quantity of the oil, and the soap carries down, mechanically, all impurities, leaving the oil perfectly clear. Too pro- longed agitation may, however, make an emulsion of soap and oil, which separates with difficulty. R. von Wagner proposed the use of zinc chloride instead of sulphuric acid, as this chars the impurities without attacking the oil. The zinc chloride is used in concentrated solution of 1.85 specific gravity, about one and one-half per cent, being taken and thoroughly agitated with the oil. After the zinc chloride solution is withdrawn, the oil is well washed with w r ater and filtered. Tannin is also used to clear some oils, which it effects by coagulating the albumen. Cotton-seed oil is always colored by some resin, which is removed by treatment with alkali, which saponifies the resin and the free acids of the crude oil. A recent patent proposes to replace the sodium hydrate, which in its action causes a loss of from three to seven per cent, of the oil, by sodium carbonate, which is capable of acting upon the coloring matter, although not upon the oil. A subsequent filtration through fuller's earth is also recommended. Still more energetic methods for purifying oils are th n oxidation methods, ushig " chloride of lime" or bichromate of potash, and sulphuric or hydrochloric acids as applied to palm oil. PROCESSES OF TREATMENT. 55 The use of hydrogen peroxide solution has recently been tried for the bleaching of oils, with the best of results. Four or five per cent, of a ten per cent, solution will generally suffice if repeatedly shaken up with the oil to be treated. Ozone-carriers, like ferrous sulphate solution, will also bleach in the presence of sunlight. This method is often applied with linseed oil. IE. Processes of Treatment. 1. SAPOXIFICATIOX OF FATS. The composition of the proximate principle, olein, palmitin, and stearin, which make up the bulk of the fats proper, was first established by the researches of Chevreul in 1823. Their decomposition can be effected in a number of ways, by the action of bases like the alkalies and some metallic oxides, by the action of sulphuric acid liberating the fatty acids, and by the action of water alone, when aided by heat and pressure. Chevreul at first used alkalies, patenting that process in 1825, in con- junction with Gay-Lussac, but this procedure was given up already in 1831, when Ad. de Milly replaced the alkalies by lime. This was used exclusively for a number of years, but was followed in 1854 by the inde- pendent discovery of Tilghman and Berthelot of the method of decom- posing by the use of hot water superheated by high pressure. Melsens also proposed the same process substantially a little later. In consequence of the danger connected with the high temperature and pressure, this pro- cess is not carried out any longer in its original shape, but is now replaced by the "autoclave" process, mentioned later. In 1841 Dubrunfaut found that if neutral fats were treated first with sulphuric acid, and then boiled with water, the fatty acids might be distilled in an atmosphere of super- heated steam without decomposition. This constituted the distillation pro- cess. It was extensively used in England. Wilson and Gwynne found it possible, with proper application of the superheated steam and regulation of the temperature (290 to 315 C.), to dispense with the sulphuric acid, and to decompose the fats and then distil them without any decomposition. This process is now used on a large scale by the Price Candle Company in England. Still later, Bock, of Copenhagen, found that if the membranous cellular tissue that enclosed the fat be decomposed by a preliminary treat- ment with sulphuric acid and the charred tissue, which by oxidation becomes heavier than the fat and sinks through it, be removed, the pure fat could be decomposed by boiling with water in open tanks. The sepa- rated fatty acids are so pure in color that washing suffices, and no distilla- tion is necessary. These several processes have been in time modified and amalgamated until now only three or four processes are practically followed on a large scale : (1) The saponification by alkalies used exclusively in soap-making and yielding a soda or potash salt of the fatty acid. (See SOAPS, p. 59.) (2) A combination of the lime and hot-water processes, known as Milly's " autoclave process," in which two to four per cent, of lime is made to do the work of saponification, for which 8.7 per cent, is theoretically needed, and for 'which fourteen to seventeen per cent, was at first used. The saponification is carried out in the presence of water in strong, closed, metallic vessels, at a temperature of 172 C. One form of such vessel for 56 INDUSTRY OF THE FATS AND FATTY OILS. FIG. 22. the saponification by lime under pressure, that of Leon Droux, is shown in Fig. 22. At present the form of the vessel in use is more generally that of a sphere, which stands the eight to ten atmospheres internal pressure better. The lime soap, technically called " rock," after its separation is decomposed by sul- phuric acid, four parts of acid to each three parts of lime used being taken. After the complete sub- sidence of the calcium sulphate the free fat acids are thoroughly washed with water and steam. (3) The sulphuric acid sapon- ification, followed by distillation. This process is almost exclusively followed in England. The amount of sulphuric acid used has grad- ually been diminished, as it is found that a relatively smaller per- centage will suffice. For offal fats some twelve per cent, is now used, for tallow nine per cent., and for palm oil six per cent. The decom- position generally requires some hours at a temperature varying from 1 20 to 1 70 C. Milly mod- ified this process by using a smaller quantity of sulphuric acid (two to three and a half per cent.), which he allows to act at a temperature of 150 C. for two to three min- utes only, and then boils with water. In this way the larger portion of the fat acids are white enough to be used for candle- making without previous distil- lation, while some twenty per cent, only of them needs to be distilled. The form of apparatus for the distillation of the free fatty acids produced in the sulphuric acid saponification is shown in Fig. 23. T is the super- heater, from which steam at 300 C. is passed into the retort D, which is previously filled to three-fourths of its capacity with melted tallow through the supply-pipes V V. The fatty acids distil out of the tube U, are con- densed by the worm 8, and collected by the receiver K. (4) The superheated-steam process of Wilson and Gwynne, before al- luded to. This is at present carried out in both England and Germany. The apparatus devised by Mr. G. F. Wilson, of the Price Candle Com- pany, of London, is shown in Fig. 24. The fat, previously heated in the flat vessel, A, by the waste-heat from the superheater below, flows into the retort C. This retort must be kept at from 290 to 315 C., and to this end is covered entirely above; the superheated steam at 315 C. conies PROCESSES OF TREATMENT. 57 into the retort by the tube to the side, and some twenty-four to thirty-six hours is necessary to decompose and distil off a charge of fat. If the temperature falls below 310 C., the decomposition is extremely slow, while much above 315 C., acrolein forms from the decomposition of the glyc- erine. Before proceeding with the special processes of soap-making, stearine- FIG. 23. candle manufacture, oleomargarine and glycerine production, it will be well to present in schematic way the complete treatment of a fat such as tallow. The accompanying scheme is taken from Post's " Chemische Technologic," and shows the processes applicable and the products resulting from the tech- nical utilization of tallow. FIG. 24. 2. PRACTICAL SOAP-MAKING. In the application of the first method of saponification of fats, that of the use of alkalies, we have, of course, always a potash or a soda salt of the fatty acid formed, which, singly or admixed, constitute the products known as soaps. A very great variety of soaps are known, the appearance and properties of which vary according to the method of manufacture. We may classify the several methods of manufacture as follows : 58 INDUSTRY OF THE FATS AND FATTY OILS. ' 9 W ^.^ qj j-S E S;^ ^ ^gs S o S * O3 *~^ . "3 o' -c p2 s S w < o os _ JS*3 Be Soa * w^ 1 S S > o 55 \$"tt '- ~. S cj *S *O A U f ~~ l 5 E 9 *c O M B E TALLOW (ab< ing sulphuric steam. J GLYCERINE ( kilos.) of T7*TO T\I.O t/1 i i j' CRUDE GLY (about 2.5 k: 30 B. d J O fiirt OS'S 113 o- CL, QiSF 1 i* 03 I 1 S i || H a J.e ^ s? fe "* i O 1 ttil . 1 J 3 1 2^ g ^1 ! < e 1 H ~S *j '^ " s -^ Ol . X _Q p ; fli O 'oj 8> S if o 5-bfi o "S M rf O P, ft ll-g j 2 2 x.^- u co 5? m ^ d. P< ILIZATION [eld of one Ox), Su! )f. the fleshy and impu 2ta "O -a Iting point, 46.5 C. under a pressure of ith sulphuric acid. ] LIQUID FATTY Aci Filtered and i O SOLID FAT ACID (about 4 kilos.). i added to H. ntually about i kilos. Oleic Acid. P' 1 P and P' OLEIC ACID (about 23.1 brought into comme Oleic Acid. Olein Soaps (Soda Soa] Soft Soaps (Potash Soa H ^ a g S S ~o> > ci ID -2 o s"2 . "" p S " ^ 93 ' ^ fc, ^. mJZ o 5 . c ^ PRACTICAL e Tallow (approxim Careful separ 1 28 kilos.). F SCRAP (about 3 Added to 'v \ E - 1 FALLOW (about 50 kilos, composed by water am atmospheres, and was H TTY ACIDS (about 47.5 ki Pressed cold. it 32.5 kilos.). arm. N So-called RETURNED i (about 18.5 kilos. i Nand They yie kilos. Stearic Acid. M' 1 d M' .bout 24 kilos.), ommerce as : > mmixed). (mixed with g JJSo OJ--I < -a i *% p 03 O ^ y. 03 "Xo K *> E O S- S H,oi.O ? S- g> S s.~s^'2^ e !< o. H,c8 i 5 (M 5 "'H' si o 1 S" S S 3 S J W TT g*S S K ^ o ^ w P- CO 00 s I O "^ C/2 CA f^ X ' x fe W3 H fe ^ rf-S s O! < _w c-^ V a < a i __^T3C MO esooo PROCESSES OF TREATMENT. 59 (1) Boiling the fats in open vessels (coppers) with indefinite quantities of alkaline lyes until products of definite character are gotten. These are (a), soft soaps, in which the glycerine is retained, potash being the base ; (6), the so-called " hydrated soaps," with soda for a base, in which the glycerine is retained, and of which " marine" soap may be taken as the type ; (c), hard soaps, with soda for a base, in which the glycerine is eliminated, com- prising three kinds, curd, mottled, and yellow soaps. (2) Acting upon the fats with the precise quantity of alkali necessary for saponification without the separation of any waste liquor, the glycerine being retained in the soap. This includes (a) soaps made by the " cold process," and (6) soap made under pressure. (3) Direct union of the fatty acids, as in " red oil" and caustic alkali, or alkaline carbonate. The general outlines of these methods may be indicated : In the manufacture of soft soaps the drying oils are preferably used. In England whale, seal, and linseed oil are chiefly used, in Continental Europe hemp-seed, linseed, rape-seed, poppy, and train oils, and in the United States cotton-seed oil and oleic acid. A potash lye containing some carbonate is used, and frequently a portion of the potash is replaced by soda. The soft soaps, after being boiled to the necessary degree, are not salted, so that the glycerine and any excess of alkali remains in the soap. For use in wool-scouring this excess of alkali is, however, unsuited, so that neutral soft soaps are specially sought to be obtained. The method of making " hydrated" or " filled" soaps is very similar to that of soft soaps. Fatty matter and soda lye are run into the copper, and the whole is boiled together, care being taken to avoid an excess of alkali at first ; when saponification has taken place, lye is cautiously added until the soap tastes very faintly of alkali, when the soap is ready to be transferred to the frames, without any salting or separating of the mixture. Marine soap, for use with sea-water, is made in this way, and is entirely cocoa-nut oil soap. The well-known Eschweger soap is also made by this general method from a mixture of cocoa-nut oil and other fats, saponified either separately or together, and containing the glycerine and water in the soap mass. The manufacture of true hard soaps, which still constitute the great bulk of those made in England and the United States, requires more time and care than the varieties just mentioned. Melted fat and a quantity of soda lye of about 11 B., equal to one-fourth that needed for complete saponifi- cation, are simultaneously run into the copper and steam turned on. The " soap-copper," as shown in Fig. 25, is an iron kettle, or series of kettles, set in masonry, and equipped with pipes for both open and closed steam, and provided with an outlet for the discharge of the waste lyes when required. They may be used in series, or extra large single ones used. Strong lye should not be used at this first stage, or saponification will not take place. When the mixture becomes homogeneous, lye of 20 to 25 B., in amount equal to that taken before, may be cautiously added. It is now boiled until a sample taken out has a firm consistence between the fingers. Common salt or a brine of 24 B. is now run in. A small sample removed on a spatula or trowel should now allow clear liquor to run from it. The boiling is then stopped, and the copper should be allowed to stand at least two to three hours. * The 'contents now divide themselves into two portions, the upper consisting of soap-paste, containing water, and the lower consisting of " spent lye," holding in solution common salt and all the impurities of the 60 INDUSTRY OF THE FATS AND FATTY OILS. liquors, together with glycerine. It should contain no caustic soda and no soap. After removing the spent lye from below, the rest of the caustic soda lye is run in and the soap boiled up again. At this stage the rosin is usually added for rosin or yellow soaps. The boiling is now continued until the frothing mixture boils quietly and becomes clear, the process being known as " clear boiling." The copper is then boiled with open steam and a small quantity of lye of 12 B. allowed to run in until the soap separates in flakes and feels hard when cold, technically called "making the soap." Boiling is still continued for several hours to insure complete saponification, and it is then allowed to separate and harden. This procedure yields a curd B<5 soap if no rosin has been added. If, after a soap is " made," the lye in which it is suspended is concentrated to a point short of that necessary to produce hard curd soap, and it is then transferred to the cooling frames with a certain quantity of lye entangled in it, these insoluble particles will, during the solidification of the soap, collect together and produce the appear- ance known as " mottling ;" and the effect is heightened by the partial crys- tallization of the soap. The lye remaining in the cavities between the curds makes mottled soaps, the most suitable and really economical for washing clothes, etc., in hard waters, although not for toilet purposes. Mottling is sometimes added, as the peculiar greenish mottle, which becomes red on exposure, characteristic of Marseilles and Castile soaps, is produced by adding some solution of ferrous sulphate to the copper when the soap is nearly finished (about four ounces of the salt to one hundred pounds of the fat) ; the precipitated iron protoxide suspended in the soap is greenish, but it becomes peroxide in contact with air, to which the change to a red color on exposure is due. Yellow soaps are made from tallow and rosin, the pro- portion of rosin varying from one-sixth of the total fat to an equal weight, or even more, according to the quality of the soap desired. In the presence of the sodium oleate from the tallow, the rosin acids saponify readily and coalesce to form a very uniform soap. In smooth or " cut" soaps water or thin lye is added to the contents of the copper before the soap separates finally to form the curd, and is taken PROCESSES OF TREATMENT. 61 up in considerable amount, giving a smooth yet firm surface to the soap, instead of the hard, granular surface of the curd soap. The so-called " cold process" requires the use of exact weights of well- refined fats and of caustic soda of a given specific gravity, the quantities being such that only just enough soda is present to completely saponify the fat. The materials are allowed to stand together for a short time and then thoroughly mixed in a copper provided with steam, agitating paddles, and kept at a temperature of not over 120 F. The reaction proceeds rapidly, and after some fifteen minutes the materials have so far united that they will not separate on standing, although the complete saponification of the materials may require days. They are then run out into the cooling-frames. It is obvious that soaps made in this way retain all the glycerine originally combined with the fatty acids disseminated through the particles of soap, and belong to the class known as " filled" or " padded" soaps, mentioned before. (See p. 59.) When cocoa-nut oil alone is used, the temperature of working in this cold process need not be higher than 75 F. for summer and 90 F. in winter ; if one-half tallow, 104 to 108 F. ; and if two-thirds tallow, 113 to 120 F. is necessary. Mixtures of cocoa-nut oil and other fats are frequently saponified in this way, the free acid of the cocoa-nut oil readily starting the process of saponi- fication. A well-refined tallow can, however, be saponified in this way too, and mixtures of tallow and rosin worked up also into yellow filled soaps. This combination of cocoa-nut oil with tallow and rosin can also take up in its saponification large quantities of water-glass and similar " filling" material, so that a very large yield of a smooth filled soap is obtained. Thus a mixture of one hundred kilos, of cocoa-nut oil, seventy-five to eighty kilos, of rosin, three hundred kilos, of water-glass, one hundred to one hun- dred and fifty kilos, of tallow, and two hundred and forty kilos, soda lye of 33 B., will make eight hundred kilos, of a finished soap. Saponification under pressure has also been frequently tried, the object being to shorten the time required for open boiling. In this case the quan- tity of alkali used must be accurately adjusted to the fat to be saponified, the glycerine is retained in the ultimate product. The process is carried out in an autoclave or pressure-boiler, the temperature is allowed to rise to about 310 F. (154.4 C.), equivalent to a steam-pressure of sixty-three pounds to the square inch, and kept at this for an hour, when the contents are discharged into a cooling-frame. There remains to be noted the process of soap-making, in which we start not with a fat, but with the free fatty acid, as in the " red oil" or crude oleic acid obtained in stearine candle manufacture. (See p. 63.) These oleine soaps, as they are called, are made preferably from the oleic acid resulting from the saponification of tallow or palm oil by the lime process. That obtained in the distillation process is not so well adapted for use here. The oleic acid may be saponified either with carbonate or with caustic alkali. The former process has the disadvantage that the escaping carbonic-acid gas causes a strong frothing which easily leads to boiling over. One hundred kilos, of the oleic acid obtained in the lime-saponification yield one hundred and fifty to one hundred and sixty kilos, of soap. The acid obtained by distillation always yields somewhat less. Frequently the oleic acid before saponifying is changed by nitrous acid into the isomeric elaidic acid, which is as hard as tallow, and from which a very fine soap can then be made resembling tallow 62 INDUSTRY OF THE FATS AND FATTY OILS. soap, and capable of being worked at will into a curd soap or a cut soap. If to be made with carbonate of soda, the copper is filled to one-third its capacity with the oleic acid and the calculated amount of half-crystallized and half-calcined soda added, little by little, while the heating and thorough agitation of the liquid is kept up. Whe'n the soap becomes thick and all foam- ing has ceased, the soap is filled at once into the forms to cool. The portion of crystallized soda used supplies all the water needed for the saponification. In saponification with caustic alkali, a strong lye (25 B.) is taken. No emulsion forms, but a lumpy, mortar-like mass, which, however, as the alkali is more fully taken up and the lye becomes weaker, gradually goes over into ordinary soap-paste. The soap is separated by the addition of a strong lye instead of salting it. After the finishing of the soap in the copper, it may either be put direct into the cooling frame, or it may be transferred to mixing tanks, where various solutions or substances are incorporated with it prior to its being allowed to solidify. Soap-frames are of two kinds, according as it is desired to cool the soap slowly or quickly. 26 - When slow cooling is required, as is always the case with mottled soap, wooden frames, usually of pine, are employed. These are built up in horizon- tal sections, nine to twelve inches deep, each section lined with thin sheet - iron, as FIG. 27. shown in Fig. 26. Most curd and all yellow soaps are cooled rapidly in cast-iron frames of any desired shape and size. Such an iron soap-frame is illustrated in Fig. 27. The sides and ends of the frame are easily removed after the thorough so- lidification of the soap, and the block is then left upon the truck, which served as the bottom of the frame. It is now ready for the cutting into slabs and bars. This is now almost universally done by machinery, and the truck con- taining the hardened block is run at once into the large frame con- taining the cutting wires. Such a frame, although of smaller size, and used for slabs of soaps only, is shown in Fig. 28. The best piano-forte wire is necessary for these cutting frames, as the tension is very great when the soap is pressed through the wires. 3. STEARIC ACID AND CANDLE MANUFACTURE. For the extrac- tion of stearic acid, the washed fatty acids (see p. 56) are heated to the PROCESSES OF TREATMENT. FIG. 28. 63 FIG. 29. melting point and run into dishes or troughs made of tin, as shown in Fig. 29. These are placed in a room, the temperature of which is kept at 68 to 86 F. (20 to 30 C.), and left for two to three days, or until the contents have granulated, as the palmitic and stearic acids crystallize, when the dishes are emptied into canvas or woollen bags, which are carefully deposited between the plates of an upright hydraulic press, as shown in Fig. 30. Pressure is now exerted, increasing in degree until the flow of the liquid oleic acid ceases. The hard, thin cakes of crude stearic acid so obtained are then melted down again with steam, and after settling, the melted acid run into the tin dishes and placed aside to cool. The temperature of the cooling-room in this case should be higher than before, or about 86 F. (30 C.). The blocks of stearic acid gotten are ground to meal, filled in bags of hair or wool, and then sub- mitted to a second pressure in a hori- zontal hydraulic press, the plates of which can be heated. In this press, a pressure of six tons per square inch, at temperatures of from 104 to 120 F. (40 to 49 C.), is reached. The cakes so obtained are melted by 64 INDUSTRY OF THE FATS AND FATTY OILS. steam, a little wax being sometimes added to destroy the crystalline struc- ture of the stearic acid, which somewhat unfits it for candle-making. The yield of stearic acid obtained varies according to the fat used and the process of saponification employed. F. A. Sarg's Sons (Vienna) use three per cent, of lime under a pressure of ten atmospheres, and get ninety-five per cent, of crude fat acids and thirty per cent, of glycerine water (5 to 6 B.), and a final yield of forty-five per cent, stearic acid, fifty per cent, of oleic acid, and five to six per cent, of glycerine. In England, with the sulphuric acid and distillation process, they get sixty to seventy or even seventy-five per cent, of fat acids suitable for candle- making, although inferior to that obtained in the lime process. FIG. 30. Palm oil is now used in enormous quantities for the production of palmitic acid at Price's Candle Company's works, as well as by almost every candle manufacturer in Great Britain, about twenty-five thousand tons being annually consumed. In many continental countries a prohibi- tive duty prevents its employment. From this palmitic acid the finest composite candles are made by hot-pressing the distilled palmitic acid. Palmitic acid for candle-making is also made commercially, according to a process of St. Cyr-Radisson, by fusing oleic acid with a great excess of caustic potash, the products of the reaction being potassium palmitate, potassium acetate, and hydrogen. As carried out in Marseilles, the oleic acid and potash lye of 41 B. are put into an autoclave provided with PROCESSES OF TREATMENT. 65 mechanical agitator, and heated until steam ceases to be given off, when the open manhole is closed, and the heat continued until 554 F. (290 C.) is reached. Decomposition now commences, and much hydrogen is given off through an escape-tube set in the lid of the boiler. At 608 F. (320 C.) the odor of the evolved gas suddenly changes, and destructive distillation begins. This is arrested by blowing in steam at once, and the contents are run out. The potassium palmitate is then washed, decomposed with sul- phuric acid, the free acid washed and distilled. The product of the dis- tillation is white, and burns excellently when made into candles. In the manufacture of candles, the first operation is the preparation of the wick. For dip-candles the wick is twisted, for others it is plaited, and the kind of plaiting must also vary according to the material used. Stearine candles require a moderately tightly-braided wick, paraffine candles an extra tight braid, and for spermaceti and wax, on the other hand, the braids are measurably loose. After being twisted, or plaited, the wicks are dried and then dipped into a pickling liquor, which is to retard combustion and help in the destruction of the ash. The pickle usually consists of a solution of boracic acid, ammonium phosphate, or ammonium chloride. Three plans of candle-making are at present in use, dipping, moulding, and pouring. The first is employed for common tallow candles, which are accordingly called " dips." Under a frame holding the suspended wicks are placed troughs containing melted tallow, into which the wicks are repeatedly dipped. After each dipping the adherent fat is allowed to cool sufficiently to retain a fresh coating on immersion. When the candles have thus grown to the proper thickness they are left to cool and harden. These cheap " dips" are, however, now being replaced by small, moulded " com- posite" candles, as well as candles made from the softer, paraffine scale. Pouring is used only with wax candles, which cannot be moulded because of the adhering or cracking of the wax in removing it from the moulds. A well-made wax candle should show rings like a tree, where the different layers have been superposed. By far the greater number of candles are moulded, by which process they acquire a much more finished appearance. A form of frame in common use is represented in Fig. 31. The materials in general use for candle-making are tallow, palmitic and stearic acids, paraffine, ozokerite or ceresine, spermaceti, and beeswax. Very generally, several of these materials are admixed. Stearic candles have a small quantity of paraffine added to obviate the crystalline structure of the stearic acid ; paraffine candles always have five to ten per cent, of stearic acid in them, to prevent the softening and bending of the paraffine when warmed. Spermaceti and beeswax are more expensive than the other materials, and are only used now for special purposes, as for church- candles and carriage-lights. Ozokerite gives the paraffine candle of highest fusing point, being some six degrees higher than any other variety of paraffine. Colored paraffine candles are made by dissolving the coloring matter (vege- table or aniline dyes, not mineral colors) in stearic acid, and then mixing this with the paraffine, which itself does not take up the color. Paraffine and other transparent candles must be filled in the mould very hot, and after all air- bubbles have escaped, the moulds must be rapidly cooled by a large flush of cold water to prevent the paraffine, efo., from crystallizing and thus causing opacity. Of interest in this connection is the table of illuminating equivalents, or quantities of different illuminating materials necessary to produce the same amount of light, prepared by Frankland. 5 66 INDUSTRY OF THE FATS AND FATTY OILS. Young's paraffine oil .... 1.00 gallons. American petroleum, No. 1 . 1.26 gallons. American petroleum, No. 2 . 1.30 gallons. Paraffine candles 18.60 pounds. Sperm candles 22.90 pounds. Wax candles 26.40 pounds. Composite (stearine) . . . .29.50 pounds. Tallow 36.00 pounds. 4. OLEOMARGARINE, OR ARTIFICIAL BUTTER MANUFACTURE. The manufacture of a butter-substitute from the solution of palmitin in olein, which is known as oleomargarine, is a fat industry, but, because of its close relations to natural butter made from cows' milk, it will be FIG. 31. considered as supplementary to the description of butter under milk indus- tries. (See p. 246.) 5. GLYCERINE MANUFACTURE. For many years after the development of the soap and candle industries, no attempt was made to recover the glycerine which was liberated in the saponification. Its applications in medicine and for technical purposes have made it important to extract and purify it, however, and it has now assumed almost equal importance with the other fat constituents. The two methods of saponification, by which glycerine has been obtained on a large scale, are the process of Wilson & Payne, of decomposing the fats by superheated steam and after distillation (see p. 56), and the lime autoclave process of Milly. (See p. 55.) In the distillation process, moreover, by suitable arrangement for fractional conden- sation, it is found possible to concentrate the aqueous glycerine in the process of distillation. Care must be taken that the temperature of 600 F. (315 C.) is not exceeded, and that plenty of steam is present, otherwise some glycerine is decomposed and acrolein is formed. In the Milly process, after PROCESSES OF TREATMENT. 67 the decomposition of the fat is completed in the autoclave, the contents are blown out into a tank and the " sweet water" (glycerine) is run off. This is then concentrated in a modification of the Wetzel evaporating pan, origi- nally introduced for sugar-boiling. (See p. 127.) The concentrating may be done in contact with air or the apparatus may be worked in vacuo. Evap- oration is continued to 26 B. (1.220 specific gravity), when the glycerine is of a brownish color, and is known as " raw," in which state it is sold for many purposes. At Price's Candle Company's works the further purifica- tion is conducted as follows : The raw glycerine, specific gravity 1.240 to 1.245, is heated in a jacketed pan with that kind of animal charcoal known as ivory-black, and is then distilled ; this alternate treatment is repeated as often as is necessary. The distillation is performed with superheated steam in a copper still provided with copper fractional condensers, the still being also heated externally ; the operation is performed at as low a temperature as is consistent with distillation, usually about 440 P F. (227 C.). It is obvious that in soap-making, as enormous quantities of the fats are decomposed, corresponding quantities of glycerine go info the spent lyes. It is only very recently that it has been attempted to recover this glycerine, and no perfectly satisfactory process seems, as yet, to have been adopted. More practical, in the opinion of those qualified to judge, seems to be the idea recently put forward to deglycerinize all fats before saponifying them. The process of Michaud Freres, of Paris, as carried out by the Continental Glycerine Company, of New York, realizes this idea very successfully. According to their patent "the fatty matter is subjected in a close vessel to the action of the steam, at a pressure of one hundred to one hundred and thirty pounds per square inch, and at corresponding temperature in presence of one-fourth to one-third part its weight of water and one-fifth to three-fifths per cent, of its weight of the oxide of zinc, known commercially as zinc white, or a like proportion of zinc powder or zinc gray, which is a residue in the treat- ment of zinc, being a mixture of zinc with its oxide. . . . The very small pro- portion of mineral substance used is sufficient for dispensing with the acid treatment applied for decomposing lime soap, and the product obtained, con- sisting almost exclusively of acid fat, can be converted by the acids usually employed into soap or candles. In soap-making, the dissolving powers of the caustic alkalies remove all objections to the presence of the zinc if it should be used in excess. The reducing power of the zinc powder prevents discoloration of the acid fats such as results from the ordinary treatment." The glycerine thus produced finds a ready sale, as it runs from the evaporators, and from it, as " crude," ninety-six per cent, of pure glycerine can be obtained. 5a. NITRO-GLYCERINE AND DYNAMITE. In 1847 Sobrero discovered a very interesting derivative of glycerine, and in 1862 A. Nobel gave it to the world as a technical product of the greatest importance. When strong glycerine is gradually added to a well-cooled mixture of very strong nitric and sulphuric acids, it is converted into glyceryl nitrate, or nitro-glycerine. For the manufacture of nitro-glycerine on a large scale, Nobel recommends that one part of good glycerine be allowed to flow in a thin stream into a well-cooled mixture of four parts of concentrated sulphuric acid and one part of the very strongest nitric acid (1.52 specific gravity), the mixture being contained in a wooden vessel lined with lead. Means should be provided by which the mixture can at once be run into a large quantity ofj^aieLghpuld the action threaten to become too violent. Oil standing 68 INDUSTRY OF THE FATS AND FATTY OILS. rates as a layer on the surface of the acid, and is skimmed off and washed with water and solution of sodium carbonate to get rid of every trace of free acid. Or, according to the same authority, a mixture is made of one part nitre with 3.5 parts of sulphuric acid (1.83 specific gravity), the mixture cooled to 32 F. (0 C.), and the liquid poured off from the acid potassium sulphate, which separates out ; into this liquid the glycerine is slowly dropped, the mixture poured into water, and the separated nitro-glycerine washed thoroughly and dried. The yield is two hundred and twenty-three per cent, of the glycerine used. It has been suggested to mix the glycerine beforehand with the sulphuric acid, and then run this mixture into the nitric acid, and it is claimed that the elevation of temperature is less than when the ordinary method is fol- lowed ; but the process does not seem to have been satisfactory in practice when tried in England. When absorbed by infusorial earth, " kieselguhr," sawdust, mica powder, or other inert porous material, nitro-glycerine forms the different varieties of dynamite, and, when combined with gun-cotton, it constitutes the explosive known as " blasting gelatine." ffl. Products. 1. PURIFIED OILS, FATS, AND WAXES, AND PRODUCTS FROM THE SAME. Most of the important oils, fats, and waxes have already been described as raw materials, and the methods of purifying them have been noted. The purified oils are in some cases the final products sought, and, in some cases, only improved raw materials for the main industries, like soap-making, candle- making, and glycerine extraction. These purified oils having, therefore, been referred to as raw materials, will not be further noted. A number of side- products, obtained with or produced from these oils, remain to be mentioned. One of these minor products of great value is the oil-cake, or compacted mass of crushed seeds or nuts, from which the oil has been expressed or extracted. This contains all of the woody fibre and mineral matter of the seed or nut, the residue of oil or fatty matter not extracted, and, what gives it special value, the proteids or nitrogenous constituents. The oil-cake thus becomes a most valuable cattle food and a basis for artificial fertilizers. The following table gives the composition of a number of the most important oil-cakes : Water. Fat. Non-Nitrogen- ous Materials. Woody Fibre. Ash. Protein Material. Nitrogen. Per Cent. Earth-nut cake 11.50 8.80 31.10 7.25 41.35 6.80 Cotton-seed cake 13.00 7.50 61.00 8.50 20.00 2.90 Rape-oil cake . 10.12 9.23 41.93 6.48 31.88 6.00 Colza-oil cake . 11.35 9.00 42.82 ,28 30.55 4.50 Sesame-oil cake 10.35 10.10 38.80 9.80 31.98 5.00 Beech-nut cake 11.40 8.50 49.80 5.30 24.00 3.20 Linseed cake . 10.56 9.83 44.61 6.50 28.50 4.25 Camelina cake . 9.60 9.20 50.90 7.00 23.30 3.60 Poppy-oil cake 9.50 890 37.67 11.43 32.50 ' 5.0D Sunflower-oil cake 10.20 8.50 48.90 11.40 21.00 2.40 Hempseed cake 10.00 8.26 48.00 12.24 21.50 3.30 Palm-nut cake . 9.50 8.43 40.95 10.62 30.40 4.50 Cocoa-nut cake 10.00 9.20 40.50 10.50 30.00 4.50 PEODUCTS. 69 It will be seen in this table that they vary in proteids or flesh-forming constituents quite widely. All of these cakes, however, are too rich in these proteids and in fats to be used unmixed as fodder. They are, in practice, mixed with cereals, hay, and straw, and then constitute a valuable food. The ash is, moreover, very rich in phosphoric acid and in potash, and this explains its value for fertilizer manufacture. Thus it is stated that, as a fertilizer, one ton of cotton-seed-hull ashes has as much value as four and one-half of average hard-wood ashes, or fifteen of leached hard-wood ashes. The amount of oil-cake obtained from the expression of the diiferent vegetable oils is enormous. Thus it is stated that one ton of hulled cot- ton-seed (constituting forty per cent, of the raw cotton) will yield eight hundred pounds of cotton-seed cake and forty-five gallons of crude cotton- seed oil. The amount of crude cotton-seed annually obtained in the United States is estimated at four thousand million pounds, half of which only is j f required tor sowing. The accompanying table, prepared by Grimshaw, will show how thor- oughly the cotton-seed is now utilized : Cotton-seed, 2000 pounds. Meats, 1089 pounds. Lint, 20 pounds. Hulls, 891 pounds. Cake, Crude oil, Fibre. 800 pounds. 289 pounds. i 1 High-grade Meal. Summer Soap stock. paper, yellow. I Ashes. Soap. Salad oil Summer white- Lard Cottoline Miners' oil Winter Cotton-seed Fertilizer, yellow. stearine. An important manufactured oil is what is known as " Turkey-red oil," used in the process of alizarin dyeing. (See p. 462.) There are, in fact, two entirely distinct oils known under this name. One is simply an inferior grade of olive oil, that known as " Gallipoli oil," and for this particular use is pre- pared from somewhat unripe olives, which are steeped for some time in boil- ing water before being pressed. This treatment causes the oil to contain a large proportion of extractive matter, and hence it soon becomes rancid. This preparation has long been used in the old process of Turkey-red dye- ing, under the name huile tournante. The other, used for producing alizarin reds by the quick process, is the ammonium salt of sulpho-ricinoleic acid (C 18 H 33 (HSO 3 )O 3 ), a body which is obtained mixed with unaltered glycerides and with products of its decomposition by the action of sulphuric acid upon castor oil. From linseed oil, as the most important of the class of drying oils, is prepared a product of great value for paint and varnish manufacture. (See p. 95.) What is called " boiled oil" is linseed oil, which has been heated to , a high temperature (130 C. and upward), while a current of air is passed through t>r over the oil, and the temperature increased until the oil begins to effervesce from evolution of products of decomposition. By adding litharge, red-lead, ferric oxide, or manganese dioxide, or hydrate, during the process 70 INDUSTRY OF THE FATS AND FATTY OILS. of boiling, the oxidation and consequent drying of the product is still further facilitated. The nature, proportion, and mode of adding these substances is usually kept jealously secret. Lead acetate and manganous borate are among the most approved. The action of some, at least, of these "dryers" (e.g., compounds of manganese) seems to be that of car- riers of oxygen, while litharge dissolves in the oil and acts partly as a carrier of oxygen and partly as the base of certain salts which oxidize very rapidly. 2. SOAPS. In noting the processes for practical soap-making, the follow- ing classes of soaps were indicated : (1), compact soaps, including () curd soaps, (6) mottled soaps, and (c) yellow soaps ; (2), smooth or cut soaps ; (3), filled or padded soaps ; and (4), soft or potash soaps. The most important difference between the compact, cut, and filled soaps is the amount of water present in the soap. In the compact soap it may vary from ten to twenty-five per cent., in the cut soap from twenty-five to forty-five per cent., and in the filled soap from forty-five to seventy-five per cent. In addition, the filled soap contains the glycerine, spent lye, and other impurities of the soap copper. The following table of analysis, by Mr. C. Hope, as quoted by Allen,* will illustrate the composition of a variety of soaps belonging to these sev- eral classes : NAME OF SOAP. MATERIALS. Fatty and resin an- hydrides. s '3 V 0i 03 g 1 tn .01 .06 .03 7.02 1.07 2.34 .06 .06 .42 6.40 .02 5.64 .04 .42 .62 .02 .03 9.00 Soda as silicate. Sodium carbonate and hydrate. Neutral salts, lime, and iron oxide. Water. 1 H White, No. 1 Tallow Tallow and cocoa-nut oil . . Tallow and cocoa-nut oil . . Tallow and cocoa-nut oil . . Tallow, rosin, and cotton- seed oil Tallow, rosin, and cotton- seed oil 69.06 60.50 55.71 44.27 71.30 49.95 71.20 62.66 59.28 38.89 59.92 42.41 60.69 48.20 39.92 63.06 10.90 19.42 8.98 6.82 6.90 6.23 7.98 7.00 7.58 7.27 6.65 ~..76 6.76 4.14 7.22 5.00 4.70 7.25 1.36 3.11 2.36 .48 1.01 .03 .03 .01 1.29 1.59 '.18 .25 3.98 .27 .06 .92 .75 .75 .33 .22 .77 .39 1.62 .92 2.76 .10 .15 .20 .10 Trace 3.00 .72 .39 .26 1.00 .82 1.01 1.03 1.22 .76 2.53 1.70 .51 .60 .90 1.81 1.90 3.27 5.64 21.14 32.20 36.54 38.14 17.44 38.18 19.70 28.20 32.35 38.70 31.30 42.88 31.22 45.00 52.40 27.47 84.00 53.32 100.18 100.03 100.36 99.77 99.84 99.82 99.82 100.21 99.86 95.19 99.75 99.93 100.00 99.80 99.90 100.00 99.56 97.47 White, No. 2 White No 3 White No 4 Cold water No 1 Olive oil No 1 Olive oil Marseilles No. 1 Chiefly olive oil Palm oil, No. 1 Mottled . . Palm-nut oil Satinet Tallow and rosin Tallow and rosin Glasgow almond Tallow and rosin Tallow and rosin Pale Rosin No. 2 Pale Rosin, No. 3 Tallow and rosin Not mentioned Not mentioned Palm-nut oil " " Milling Yellow (for foreign markets) Marine (for emigrants) . . Two of these samples, those designated as " mottled" and " marine," were prepared by the "cold process" (see p. 60), which accounts for the totals being appreciably less than 100.00, as the glycerine was retained in the soap. The chief soaps of pharmacy, as analyzed by M. Dechan,f are composed as follows : * Allen, Commercial Organic Analysis, 2d ed., vol. ii. p. 272. | Pharmaceutical Journal [3], xv. p. 870. PRODUCTS. 71 , S , "3 5 B j j * M - 6 JQ e "3 M 0) 0) 8*ri5s |g liR|sBg| S a a ? o a pr"* il 5. 5* P B o w S S P < . 5? ffi _ f . a L, P <" o > s- O M 0. M ^ " 13 3 o 3 lO ft p o a ~> <- M | ^ o" M 3 P z 5- a. S. 5' S i 2 W g 1 S = 3 S 'i> a a | 3s c r 1 ^. ^ l|ls|l>|l|'i-Sp SOLUTION OF with alcohol and a f ting the whole, bet\v the volume of soda so will determine the ne holic liquid, evaporat off solvent, and add a CON. Agitate with dil uid no longer reddens n a stoppered separato tiaken with water if tlx 3 c= R - n> a, Sra32,'<2 ) S.a;w3'.?>3a C S T f* as ^ H" S ^ ^ 3 -s 31 3" 3 ^ ^ O ^ I! | =*< 5 p 3 ^ ^ a 2. 3 = "3 5' P 3 "> ,0 r < S on y < y o' < % I JT" ^* -j ^3 p" s o 9 o' p .8 ET *" ^* >w & o* *-! ^1 3* 3 ^* ^ ~ r^ "p 3' 3* n 3 3 'iiiiilf i aP =? 5 ^"3 *^ s - o' o 3" P -1 3- S P (^ CfQ ZZ> (to 3 2. s 2 Z a s. o g a p a o a S CD t^ o a 3 ' . S 5" O ^ cf fr S r< =^2 a 3 P s fy with alcoholi cooled solution time with ethe I. s l i p v * IrKme I? s^ s- ai- ls !i at i a p g 3. a= - * ' separate.* Wa; , or recent! y-dii s found to remo F 1 *C3 <^ 5? S* O O* T3 n 2 ^ "**^ 3 5 &5" 5* ^ E* P a5 - 2. ; I e? 71 w CR T p 2. a 1 II- 1 J f 1 1 a o * ^3 C 3 -r e )> S n ? E| ^ 5 P - _. P i* p X 3- - ? f sh I ~p ^ i" 1 a 5 a I ? I ff >O on p r. s" S " ~ P C ** n* M* f 5 5* ta* 3 c s 3- n =" H y S ^*" -^ J3 s S a >o o *o A O ?S ' ? 'A tn ' - i 1 " 1 s I ^ 1 1 1 " 8- i 3- 11 ** ^ 2. fjQ C?* "53 ^ 73 ffi p n ^ ^S. jc C_ a 7 1 2 ? I a 3 1? al?. & o a i-h 1 > * 3 SL 1 S I : 3- 5 CTQ O n n I > o. ; i. a M 80 INDUSTRY OF THE FATS AND FATTY OILS. "" ^ O Q) *0 a, o> a> 0) V c 83 o 3 w H 3 fl f 8 a 5 | **" *** r* "S g 3 'o c i 03 g .Q W ^* fr, g .Is P< 1 cc ,P -2 (,5 O M M . 4 | ^j *0) * p "f 8 -Sg S3 | K ^ 62 "C 2 p- 132?? 3 , .- * -C o P 'S -o ~ S pj "So 5 fi - c S H C .22 o> W -2 "^ *^ .5 i 5 K % s s 1 S "c -g 'BDins aqj ptiB ajBOiiis ui pauiqraoo Bpos at(j auira g S sl " " * -aajap puB IOH HUM asodraooaa -a^Boms utnfpog S a) jr 3 -3 ? -2 g .2 03 Q< 13 xi aj *OS^N SB a}[no[BQ fl f g 1 'Wqdtn s uinuBq SB nSpAV 'a^Btiding uinfpog L 83 B^r "- B'f 'O - ^! o *P 'lO'BN s ^ ajBtnojBO -apiaoiqa aaA^is SB qStaAi. 21 p* 2 ic.wuj U U3AIJS L JIM ajBjjix -epiaomo mnipog Ij "o 53 W "^ Cj U 1 8 o I "3 *if ^OO^N s^ a)t?inoiBO PUB 'ppB o S ounqdms TBUIJOU miM a^Bj^ix e^mioqaua uinipog _Q rf> w X! ' ~ c 9 "d *S M d C a S -0 ^^.^.g .o^^^^j-. o P ,5 3 I 5 fl 'en -2 S o3^^c> O 'S, ^ 'fa Ej 'S H 5 1 U X >>o 2 5. * F8 M a fe .S -S 8 |||||^1|1|^ o 1 "3 OJ -* ^ 5 fe ^ ^3 *^ ^$SS*c'S*"*^ o ,_! o f S jfl 3 . " fj l I 1 1 & Q s, i p, 5 s * e c xi w o 2 -s ^ 2 fe o 9 " 9 ft 1> Q "* , 4* * E 60 2 ta o islj f o" >| a 2 | O H p- (-> J3 '-^ 'o 5s rj52J 'S 03 ,2 _ & I ^ Xi o 2 "j s S r J3 "3 c ^ s Q 14 n to .: : M ^ .2 o. as "S 'S 03 ^ M B ^ c > ^ x J V C 83 -o ' fe w "o o T* ^ .* ' xi .2 c M c" H T. ~ S ^ i i i * u" 1 ^ B e ^ 'S'" a)03 ' c j '^"^''2' , aT o 2 2 ^ Set g> a o g B a 2 e w S g a; 2 C a o ? C 1 ' 1 2 ' S a 5 "3 ^Igxi'Se'-S'a?, 5 ^. oS fl . r~. a HB O C v 0) C X a 5 e a 1 w -3 2 5 >. ? go ^ ^ "S O ,L O 5 i Q, M 11 - i, M 1- "2 C o ~ -J so c ^ 03 s o S a) _2 w H |^ 3 OJ O 5| h = "3 fill lid .2 M P. o c 3 S 03 u j .5 O 5 H ? S u i S ^) a) E o * ~ * Qj O go e H x! X! O x ** ^ W ^ 5 3 s e 1 a 03 5. u ^j o I if 131 q/SiaA pUB oOTI ?B Xid ;/ pamquioaun si XDVHXXSI ANALYTICAL TESTS AND METHODS. 81 Commercial glycerine is seldom free from contamination, and a variety of impurities are liable to be present. The impurities of raw glycerine are much greater in number and amount than those present in the distilled product, and of the former, glycerine from soap lyes is much more impure than the product resulting from the autoclave process. Thus the mineral matter remaining as ash in the case of a distilled glycerine never amounts to more than .2 per cent., while in raw glycerine from soap lyes the ash usually ranges from seven to fourteen per cent., and in that from the auto- clave process considerably less. The ash will contain common salt, and with it may be the chlorides and sulphates of lead, iron, zinc, magnesium, and calcium. In glycerine from soap lyes, sulphates particularly are present. They may be accompanied by thiosulphates, sulphites, and sul- phides resulting from the sulphuric acid saponification of fats. Such glycerines are purified only with great difficulty. Precipitation with basic acetate of lead often serves to distinguish be- tween a distilled and an undistilled glycerine. This treatment removes rosin, while rosin oil and free fatty acids are removed by shaking up the sample with chloroform. The direct determination of the amount of true glycerine in commercial samples can be effected with moderate accuracy by the method of oxidation with potassium permanganate in alkaline solution, whereby the glycerine is oxidized to oxalic acid, which is then determined as calcium salt. For details, the reader is referred to Allen's " Commercial Organic Analysis," 2d ed., ii. p. 289. More accurate is said to be the " acetin" method of Benedikt & Cantor, which depends upon the quantitative formation of glyceryl triace- tate when glycerine is heated with acetic anhydride. It is carried out as follows: 1 to 1.5 grammes of the crude glycerine is heated with seven or eight grammes acetic anhydride and about three grammes anhydrous sodium acetate for one to one and a half hours with inverted condenser; it is allowed to cool, fifty cubic centimetres of water are added, and the heating with inverted condenser continued until it begins to boil. When the oily deposit at the bottom of the flask is dissolved the liquid is filtered from im- purities, allowed to cool, phenol-phthalein added, and dilute caustic soda (about twenty grammes per litre) run in until neutrality is obtained. Care must be taken not to exceed that point, or glyceryl triacetate is easily saponified. Twenty-five cubic centimetres of strong caustic soda (about ten per cent, strength) are now added from a pipette. The mixture is then heated for fifteen minutes and the excess of alkali titrated back with normal or half-normal hydrochloric acid. The strength of the alkali used is then determined by measuring twenty-five cubic centimetres with the same pipette and titrating it with the same acid. The difference in the two titrations gives the amount of alkali consumed in saponifying the glyceryl triacetate, and from this the glycerine can be calculated. Various methods have been proposed for the analysis of nitro-glycerine, based upon its decomposition by different reagents. One of the simplest and most satisfactory is that proposed by Lunge, who uses for this purpose his nitrometer. (See p. 288.) An accurately-weighed quantity, varying from .12 to .35 gramme, according to the proportion of nitro-glycerine and the capacity of the apparatus, is introduced into the cup of a nitrometer filled with mercury. About two cubic centimetres of concentrated sulphuric acid is then added, and when the nitro-glycerine is dissolved the solution is allowed to enter the nitrometer through the tap. The cup is rinsed with 6 82 INDUSTRY OF THE FATS AND FATTY OILS. successive portions of two cubic centimetres and one cubic centimetre of strong sulphuric acid, which are allowed to enter as before, and the contents of the nitrometer are then thoroughly agitated in the usual way, and the volume of nitric oxide evolved read off after standing about fifteen minutes. The volume of gas in cubic centimetres at the standard pressure and tem- perature, multiplied by 3.37, gives the weight of nitro-glycerine in milli- grammes. Hempel states that the total volume of five cubic centimetres of sulphuric acid must not be departed from ; with less than that volume the reaction proceeds too slowly, and with more the results are too low. In the analysis of dynamite, the nitro-glycerine may be conveniently determined by exhausting the dried sample with anhydrous ether, prefer- ably in a Soxhlet tube (see p. 73), and weighing the insoluble residue. The nitro-glycerine is estimated from the loss, and, in the absence of other substances soluble in ether, such as camphor, resin, etc., this is the most satisfactory way. A complete scheme for the analysis of all nitro-glycerine preparations will be found in Allen, ii. p. 310. V. Bibliography and Statistics. BIBLIOGRAPHY. 1862. La Connaissance et 1'Exploitation des Corps Gras Industrials, T. Chateau, 2me ed., Paris. 1864. Industrie der Fette und fette Oele, H. Perutz, Berlin. Das Beleuchtungswesen, P. Bolley, Braunschweig. 1867. Die Chemie der Austrocknenden Oele, G. J. Mulder, Berlin. Die Darstellung der Seifen, Perfumerien, und Cosmetica, C. Deite, Braunschweig. 1869. The Manufacture of Soaps, H. Dussance, Philadelphia and London. 1871. Soaps, Campbell Morfit, New York. 1872. The Olive and its Products, and the Manufacture of the Oil, L. A. Bernays, Brisbane. 1873. Die Rohstoffe des Pflanzenreiches, J. Wiesner, Leipzig. 1876. The Oil Seeds and Oils in the India Museum, M. C. Cooke, London. 1877. Tropical Agriculture, P. L. Simmonds, London. 1878. Die Industrie der Fette, C. Deite, Braunschweig. 1879. Commercial Products of the Sea, P. L. Simmonds, London. Die Nutzpflanzen aller Zonen, L. Wittmack, Berlin. Die Seifen-Fabrikation, F. Wiltner, Leipzig. 1880. Corps Gras, A. Renard, Rouen. Die Fettwaaren und fetten Oele, C. Lichtenberg, Weimar. 1881. Matieres Premieres Organiques, G. Pennetier, Paris. Soap and Candles, R. S. Christiani, Philadelphia and London. Die Fette und Oele, F. Thalmann, Leipzig. 1882. Die Trocknenden Oelen, L. E. Andes, Braunschweig. 1883. Technologic der Fette und Oele, C. Schaedler, Berlin. Analysis and Adulteration of Foods, Jarnes Bell, London. Das Glycerin, Koppe, Vienna. 1885. Soap and Candles* W. L. Carpenter, London and New York. 1886. Oils and Varnishes, J. Cameron, London. Analyse der Fette und Wachsarten, R. Benedikt, Berlin. ]887. The Art of Soap-making, A. Watt, London. 1888. Soap and Candles, J. Cameron, London. Manufacture of Soap and Candles, W. T. Brannt, Philadelphia and London. Animal and Vegetable Fats and Oils, W. T. Brannt, Philadelphia and London. 1889. Lard and Lard Adulteration, H. W. Wiley (Bulletin No. 13), Washington, D.C. Die fetten Oele des Pflanzen- und Thierreiches, Bornemann, Weimar. 1890. Die Untersuchungen der Fette, Oele, Wachsarten, etc., C. Schaedler, Leipzig. STATISTICS. 1. OF OILS, FATS, AND WAXES. Of the production of the various vegetable and animal oils, fats, and waxes, the figures are fragmentary. While they do not give any proper view of these industries, they will suffice BIBLIOGRAPHY AND STATISTICS. 83 to indicate in a general way the degree of their development. These will be given with the authorities where known. Cocoa-nut Oil. Ceylon exports annually 150,000 metric centners (quintals) ; British India, 40,000 to 60,000 metric centners ; Dutch India, about 13,000 metric centners ; other countries smaller amounts. Besides the oil itself, the dried pulp of the cocoa-nut is sent to European markets in large amounts under the name of " copra." The expert of copra from Ceylon amounts to 50,000 metric centners annually ; from Tahiti, to 40,000 metric centners ; from Samoa, to 30,000 metric centners, and from Singa- pore, to 40,000. (Heinzerling.) Palm Oil. The exportation of palm nuts from Southern Africa, accord- ing to Dr. von Scherzer, reaches 1,300,000 metric centners annually, of which the greater part goes to France. The exportation of nuts from British India, Siam, Cochin-China, China, South-Sea Islands, and Brazil together amount to 600,000 metric centners. The English importations of cocoa-nut oil and palm oil for the last few years have been as follows : 1887. 1888. 1889. 1890. Cocoa-nut oil (hundredweight) 183,766 197,773 213,470 184,409 Valued at 251,989 251,327 278,057 261,683 Palm oil (hundredweight) . . . 966,536 955,369 1,019,077 873,923 Valued at 941,622 947,839 1,078,605 1,000,535 The United States importations of cocoa-nut oil and palm oil for the last few years have been as follows : 1888. 1889. 1890. Cocoa-nut oil (pounds) . . 14,966,609 14,577,207 (For cocoa-nut and Valued at $703,135 $498,991 palm oils jointly.) Palm oil (pounds) .... 7,335,659 3,498,490 20,323 677 Valued at $207,962 $107,679 $923,223 Olive Oil is produced chiefly in Mediterranean lands and in the East. The figures as to the production of olives and olive oil given by different authorities are very conflicting. Mulhall, in his " Dictionary of Statistics," 1884, gives figures which are undoubtedly too low, and therefore unre- liable. The following is a fairer statement : In 1877, France had 317,800 acres of olives under cultivation, and produced 7,318,352 bushels of fruit and 392,618 hundredweight of oil ; Spain is calculated to have 2,500,000 acres planted in olives, of which 468,335 acres were in the Province of Cordoba, and these produced over 2,750,000 gallons of oil ; Italy, in 1874, had 2,223,768 acres covered by olives, and produced 9,310,375 bushels of fruit. The total Italian exports of olive oil in 1878 were 51,413,000 kilos., and in 1879, 88,655,000 kilos. The total Greek export in 1875 was 12,244,- 615 okes (of 2.83 pounds). The Algerian production in 1877 was 55,239,- 000 kilos, of fruit, yielding 1,543,400 hectolitres (of twenty-two gallons) of oil. (Spon.) The exportation of Turkey and the Turkish provinces is estimated at 900,000 metric centners annually. (Heinzerling.) The importations of olive oil into France is estimated at 20,000,000 kilos, annually, and the exportation at 5,000,000 kilos. (Schaedler.) The English importations of olive oil for recent years have been as follows : ' 1887. 1888. 1889. 1890. Olive oil in tuns 20,756 18,580 22,954 20,187 Valued at 757,040 674,472 818,352 785,787 84 INDUSTRY OF THE FATS AND FATTY OILS. The United States importations of olive oil for recent years have been as follows : 1888. 1889. 1890. Olive oil in gallons 685,611 893,338 893,684 Valued at $628,666 $696,065 $819,110 Of the production of olive oil in California no reliable statistics can be obtained at present. Rape or colza oil is cultivated in Germany, France, Austria, Hun- gary, Russia, and Roumania. The area in Germany planted with the dif- ferent varieties of brassica amounted in 1882 to 445,000 acres, the crop of rape seed to 1,882,000 metric centners, valued at 50,500,000 marks. The importations of rape seed into Germany were in 1882, 681,000 metric centners, and in 1883, 1,154,290 metric centners. After deducting the seed for sowing, some 2,500,000 metric centners were available for oil produc- tion, and from this 900,000 to 1,000,000 metric centners of oil, valued at 48,000,000 to 56,000,000 marks, and 1,300,000 metric centners of oil-cake, valued at 17,000,000 marks, were obtained. England imports some 800,000 metric centners of rape seed annually, and produces quite an amount. Austria presses for oil about 550,000 metric centners of rape seed annually, obtaining 200,000 to 225,000 metric centners of oil. The total consumption of rape and colza oil in Europe is estimated at 2,800,000 to 3,000,000 metric centners per annum, valued at 170,000,000 to 175,000,000 marks. (Heinzerling.) The exportation of rape seed from Russia in 1879 amounted to 1,294,728 bushels, and from Roumanian ports, on the Danube, in 1878, to 938,376 bushels. The shipments from India in 1877-78 amounted to 3,193,488 hundredweight. (Spon's " Encyclopedia.") Sesame Oil. The seeds come chiefly from the East Indies and the Levant, and the oil is pressed in Marseilles and Trieste. British India exports 1,300,000 metric centners; Turkey, 120,000 metric centners, and Siam about 30,000 metric centners, annually. France imports somewhat more than 1,000,000 metric centners of the seeds ; England imports 250,000 metric centners; Italy, 150,000 metric centners, and Germany, 140,000 metric centners of sesamS seeds. (Heinzerling.) Cotton-seed Oil. In the United States, it is reckoned that for each one pound of ginned cotton there are three pounds of seed. As the cotton crop of 1889-90 was 7,313,726 bales of 470 pounds, or 3,437,451,220 pounds, the production of seed must have been about 10,000,000,000 pounds (or about 4,464,000 tons). About half of this is required for sowing. The amount of cotton seed crushed in recent years is officially stated to have been as follows : Tons. Tons. 1879-80 294,512 1880-81 . . . . 340,600 1881-82 411,200 1882-83 486,300 1883-84 475,200 1884-85 534,000 1885-86 590,000 1886-87 610,000 1887-88 720,000 1888-89 814,750 1889-90 1,058,200 The amount and value of the cotton-seed products for the last three years have been as follows : 1887-88. Crude oil in gallons 25,340,000 = $11,009,700 Cake in tons 271,500= 4,922,750 Lint in bales Hulls in tons 360,000 = 540,000 BIBLIOGRAPHY AND STATISTICS. 85 . 1888-89. Crude oil in gallons 31,775,250 = $12,074,505 Cake in tons 305,456= 6,414,575 Lint in bales 48,885= 1,466,550 Hulls in tons 407,375= 511,106 1889-90. Crude oil in gallons 41, 287,300 = $12,886,855 Cake in tons 383,759= 7,867,054 Lint in bales 63,519= 1,905,570 Hulls in tons 529,375= 1,587,970 Of this annual production of crude cotton-seed oil about 9,000,000 gal- lons go into the production of " compound lard," and the rest is partly ex- ported as cotton-seed oil, partly used in admixture with drying oils, and partly as soap-stock. The exportations of cotton-seed oil from the United States for the last five years have been as follows : 1885-86. 1886-87. 1887-88. 1888-89. 1889-90. Cotton-seed oil in gallons . 6,240,139 4,067,138 4,458,597 2,690,700 13,384,385 Valued at $2,115,674 $1,578,935 $1,925,739 $1,298,609 $5,291,178 In Europe, England is the chief country extracting the oil from the cotton seed, which comes chiefly from Egypt. The imports of seeds into England for 1881 were about 2,300,000 metric centners, valued at 1,783,- 100 ; in 1882, 2,100,000 metric centners, valued at 1,585,850, and in 1883, 2,500,000 metric centners, valued at 1,845,000; France imported in 1882, 205,754 metric centners, and in 1883, 234,796 metric centners of cotton seed ; Italy imported in 1881, 200,500 metric centners, and in 1882, 252,835 metric centners of cotton seed. (Heinzerling.) Hemp-seed ail is produced chiefly in Russia. The exports of hemp seed from Riga in 1878 were 629,520 bushels, and in 1879, 725,809 poods (of thirty-six pounds) of seed and 573 poods of the oil. (Spon's " Encyclo- pedia.") Linseed OIL The supplies of linseed come from all countries, but most largely from Russia and India. In 1890, European Russia had 3,780,000 acres sown in flax, and the total harvest of flaxseed amounted to 1,800,- 000,000 pounds, or about 21,000,000 bushels. Of this, the quantity exported has been for recent years as follows: 1887, 13,000,000 bushels; 1888, 14,000,000 bushels ; 1889, 13,500,000 bushels ; and 1890 (estimated), 12,000,000 bushels. The total Indian exports of flaxseed for the year ending March 31, 1890, were 7,146,896 hundredweight, of which 4,342,962 hundredweight went to Great Britain. (" U. S. Consular Reports," March, 1891.) In Germany about 292,500 acres are under cultivation for the pro- duction of linseed and about 332,500 acres for fibre production ; the yield in linseed being about 500,000 metric centners (50,000 tons). The impor- tations of linseed oil into the German empire for the last several years have been as follows : 1885. 1886. 1887. 1888. 1889. 383,130 m.c. 397,430 m.c. 414,930 m.c. 440,702 m.c. 439,730 m.c. The importations of linseed into the United States for the last few years have been : 1888. 1889. 1890. 1,461,41 8 bushels. 3,259,460 bushels. 2,391,175 bushels. Valued at ... $1,505,499 $3,851,685 $2,839,057 86 INDUSTRY OF THE FATS AND FATTY OILS. At the same time the American production of flaxseed is considerable, the crop for 1889-90 having been 9,000,000 bushels and that for 1890-91 is estimated as likely to amount to 12,000,000 bushels. Oil-cake and Oil-cake Meal. The exportations of vegetable oil-cake from the United States, three-fourths of which went to Great Britain, have been during recent years as follows : 1886. 1887. 1888. 1889. 1890. Pounds. Pounds. Pounds. Pounds. Pounds. 585,947,181 622,295,233 562,744,209 588,317,880 711,704,373 Valued at . . $7,053,714 $7,309,691 $6,423,930 $6,927,912 $7,999,9:>6 Fish Oils. The amounts of sperm, whale, and fish oils of all kinds ob- tained annually, according to Mulhall,* are : Sperm and whale oil, 1,485,- 000 hectolitres (32,670,000 gallons); fish oils of other kinds, 1,170,000 hectolitres (25,740,000 gallons), and oil from sea birds, 58,500 hectolitres (1,287,000 gallons). The English importations of train and other fish oils during the last few years were : 1888. 1889. 1890. Amount in tuns 16,861 21,051 20,302 Valued at . . 323,579 442,699 419,296 The exportations from the United States of whale and fish oils for the last two years have been : 1889. 1890. 483,208 gallons. 1,844,041 gallons. Valued at $127,412 $440,773 Cod-liver Oil. The annual production of Newfoundland is said to amount to 1,250,000 gallons, valued at 200,000. The Norwegian fisher- ies exported in 1877, 130,600 barrels, valued at 386,600. The total exports of cod-liver oil from Sweden and Norway in 1879 were 143,165 hectolitres (3,149,630 gallons). (Spon's " Encyclopedia.") Spermaceti and Sperm Oil. The production of spermaceti in the Ameri- can whale-fisheries was 1,300,959 gallons in 1878, and 1,285,454 gallons in 1879. The exports of sperm oil from New York in 1878 were 912,603 gallons, and in 1879, 1,089,137 gallons. (Spon's " Encyclopedia.") The exportations of sperm oil have much diminished in more recent years. Thus the exports for 1889 and 1890 are given as 98,823 gallons and 162,565 gallons respec- tively, valued at $69,628 and $124,601. The exportations of spermaceti from the United States in recent years have been as follows : 1889. 1890. 425,479 pounds. 447,384 pounds. Valued at $111,386 $116,757 Lard and Lard Oil. The production of lard in the United States during recent years is thus given by the Cincinnati Price Current : 1884-85. 1885-86. 1886-87. 1887-88. 1888-89. 1889-90. Pounds. Pounds. Pounds. Pounds. Pounds. Pounds. 480,405,000 514,230,000 527,032,000 487,179,000 483,902,000 624,227,000 * Mulhall, Production and Consumption, p. 142. BIBLIOGRAPHY AND STATISTICS. 87 Of this production from one-third to one-half is " compound lard," or lard admixed with cotton-seed oil and beef stearine. The production of com- pound lard has reached as much as 300,000,000 pounds per annum, but diminished last year to about 225,000,000 pounds. The exports of lard from the United States during recent years have been as follows : 1886. 1887. 1888. 1889. 1890. Pounds. Pounds. Pounds. Pounds. Pounds. 331,509,570 321,523,746 270,245,146 318,242,990 471,083,598 Valued at . .$22,523,197 $22,703,921 $23,516,097 $27,329,173 $33,455,520 Of this amount approximately one-third goes to Great Britain and Ireland. Of the exports of lard, about forty per cent, are stated to be " com- pound lard" and about sixty per cent, pure lard. (Testimony before the House Committee on Agriculture.) Tallow. The production of tallow for all European countries for the year 1882, according to Mulhall,* amounted to 355,700 tons, for the United States to 330,000 tons, and all other countries, 60,000 tons, making a total of 745,700 tons. The exportations of Russian tallow have greatly dimin- ished in recent years ; they were 40,300 tons in 1860, 21,100 tons "in 1870, and 10,400 tons in 1880. The exportations from the United States, River Plate in South America, and Australia, on the other hand, have increased, especially the first and the last of these. In the year 1883 the exporta- tions of tallow were as follows : From the United States, 45,000 tons ; from Australia, 28,000 tons ; from Argentine Republic, 10,500 tons, and from Uruguay, 12,000 tons. (Heinzerling.) The exportations from the United States in recent years have been : 1886. 1887. 1888. 1889. 1890. Pounds. Pounds. Pounds. Pounds. Pounds. 52,699,115 84,099,951 75,470,826 77,844,555 112,745,370 Valued at . $2,435,349 $3,772,837 $3,736,488 $3,942,024 $5,242,158 Chinese or Insect Wax. The amount annually produced is valued by Professor Thistleton Dyer, of Kew Gardens, England, at 600,000. Carnauba Wax. The exportation of this wax from Brazil was esti- mated in 1876 at 871,400 kilos., valued at 162,500. Japan Wax. The exportations from Japan were in 1872, 1,230,588 kilos.; in 1873, 1,520,751 kilos., and in 1874, 1,302,465 kilos. The London importations in 1880 were 564,000 kilos., and in 1881, 666,660 kilos. Soaps. Sir Henry Roscoe stated, in 1881, in his inaugural address before the Society of Chemical Industry, that the annual production of soap in Great Britain and Ireland was about 250,000 tons. In a report on the exhibits at the Paris Exposition of 1878, it was stated that the French soap- trade had been for some time stationary at about 220,000 tons per annum, but was then declining. In the United States, the census report for 1880 gives the production for that year as 446,296,138 pounds, or 199,239 tons. It has undoubtedly increased greatly since that time, but the figures for the census year 1890 are not, as yet,, available. * Mulhall, Dictionary of Statistics, p. 434. 88 INDUSTRY OF THE FATS AND FATTY OILS. Candles. The exports of candles of all kinds from England, in 1883, are given as 5,285,600 pounds, valued at 147,961. (Carpenter.) The con- sumption of wax and spermaceti candles in England and Ireland alone, at present, is given as 400 tons. The manufacture of stearic acid candles for the census year 1880, in the United States, was 18,363,066 pounds, valued at $2,281,600. Glycerine. The total European production of glycerine in 1878 was estimated by Riche, in a report on the Paris Exposition of that year, to be 10,000,000 kilos. According to another authority, quoted by Heinzerling,* the European production was only 9000 tons instead of 10,000, distributed as follows : England, 300 tons ; France, 4000 ; Germany and Austria, 1500; Holland, 900; Russia, 900; Belgium, 800; Italy, 400 ; and Spain, 200 tons. That these figures are in some cases much too low is seen from the fact that the exports- of raw and refined glycerine from Germany alone for the last few years have been : 1887. 1888. 1889. 2040 tons. 2109 tons. 2200 tons. Valued at. . . . 2,327,000 marks. 2,032,000 marks. 2,018,000 marks. In the United States, there was produced in 1880, 7,117,825 pounds, or 3178 tons, of which almost one-half was made into nitro-glycerine. The importations of glycerine into the United States during recent years have been as follows : 1888. 1889. 1890. 10,695,742 pounds. 10,563,240 pounds. 11,147,684 pounds. Valued at . .$1,107,692 $910,925 $928,935 * Heinzerling, Abriss. der Chemischen Technologic, p. 179. RAW MATERIALS. 89 CHAPTER III. INDUSTRY OF THE ESSENTIAL OILS AND RESINS. I. Raw Materials. 1. ESSENTIAL OILS. The essential or volatile oils, as they are termed, are found extensively distributed throughout the vegetable kingdom. They occur in almost all parts of the plants except the cotyledons of the seeds, in which, in general, the fixed or fatty oils are contained. The essential oils impart the peculiar and characteristic odors to the plants ; they furnish us our perfumes, spices, and aromatics, and many of them possess valuable medicinal properties. The essential or volatile vegetable oils are procured in several ways : (1) by distillation ; (2) by absorption or " enfleurage" ; (3) by means of solvents ; (4) by expression ; and (5) by maceration. In the distillation method the plants are put into the still along with about an equal weight of water, either with or without previous soaking, and the distillation carried on rapidly. If necessary, the water that sepa- rates from the oil in the receiver is returned to the still and driven over a second or third time. The separation of the oil and water is effected in what is termed a " Florentine receiver," from the bottom of which the water can be siphoned off without disturbing the oily layer. The odors of some flowers, such as jessamine and mignonette, are too delicate to bear heat, and for these the process of absorption, or " enfleurage," as it is called in the south of France, is employed. Sheets of glass in wooden frames, called chassis, are coated on their upper and lower surfaces with grease about a tenth of an inch in thickness. The flowers are spread upon this grease, and a number of frames are superimposed on each other. After a day or two the flowers are carefully removed and replaced by fresh ones, and this is continued for two or three months, till the fat is impregnated with the odors. It is then removed and extracted with alcohol. Recently the grease has been replaced in some cases by soft paraffine, glycerine, or vaseline. For the extraction by solvents, alcohol, ether, petroleum-naphtha, and notably carbon disulphide are employed, and the solvent recovered by distillation. The essential oils of lemons and oranges of commerce, and of some other fruits, are chiefly obtained by submitting the rind to powerful pressure. The oils are more fragrant but not so white as when distilled, and the process is only adapted for substances which are very rich in essen- tial oils. Flowers with very delicate perfume, such as those of the bitter orange, violets, etc., which would be spoiled by distillation, are treated by this method. The medium used for infusion is clarified beef or mutton suet or lard. The fat is melted, the flowers immersed, and the mixture stirred occasionally for a day or so. The exhausted flowers are removed and fresh ones introduced, and such renewals are continued till it is judged that the fat is sufficiently charged with the oil. 90 INDUSTRY OF THE ESSENTIAL OILS AND RESINS. The essential oils are usually more limpid and less unctuous than the fixed oils, but some of them, when in the crude state, may be quite thick or even semi-solid from admixtures of solid and crystalline ingredients with the more liquid portion. Their odor is that of the plants which yield them, and is usually powerful ; their taste is pungent and burning. They mix in all proportions with the fixed oils, dissolve in both alcohol and ether, and are sparingly soluble in water, forming "perfumed" or "medicated water." They are not saponifiable. Their boiling-points usually range from 310 to 325 F. (154.5 to 162.7 C.), although in some oils the hydrocarbons boil at 356 F. (180 C.) or even higher. They are, how- ever, capable in most cases of being distilled in a current of steam. In specific gravity they vary from oil of citron .850 to oil of winter-green 1.185 at 15 C. Chemically, essential oils are often divided roughly into three classes, oils composed ef hydrocarbons only ; oils containing hydrocarbons mixed with oxygenated products, and oils containing sulphur compounds. A more exact, but still quite general, chemical division is given below : 1. Oils consisting chiefly of terpenes (C 10 H 16 ) and oxidized products allied thereto : examples, oil of turpentine, oil of lemon, oil of camphor. 2. Oils consisting chiefly of cedrenes (C^IL^) and oxidized products allied thereto : examples, oil of cedar, oil of cubebs, oil of cloves. 3. Oils consisting chiefly of aromatic aldehydes and allied bodies : exam- ples, oil of bitter almonds, oil of cinnamon. 4. Oils consisting chiefly of ethereal salts. These may be either (a) oxygen salts, as in oil of winter-green, and (6) sulphur salts, as in oil of mustard, oil of garlic. Special mention of but two substances from the essential-oil class need be made, as the bulk of them are raw materials only to the special industries of the pharmacist and the manufacturer of perfumes. Oil of Turpentine. This oil is produced by all the Com/era in greater or less amount. It flows from cuts in the tree as a balsam (see p. 91), known as turpentine. This, on distillation with steam, yields the volatile oil of turpentine, and there remains behind the resin (colophony resin) commonly known as " rosin." While a number of minor varieties of turpentine are known, such as Venetian, Hungarian, Strasburg, Chios turpentines, and Canada balsam, which are of pharmaceutical value, but three commercially important varieties of oil of turpentine need be noted. They are English or American oil of turpentine, from Pinus australis and Pinus tceda, col- lected in North and South Carolina and Georgia ; the French oil of tur- pentine from Pinus maritima, collected in the neighborhood of Bordeaux ; and the Russian or German oil of turpentine, from Pinus sylvestris. Of the American oil, only seventeen per cent, is obtained on distillation of the crude turpentine balsam ; of the French, as much as twenty-five per cent, of oil may be obtained ; and of the Russian, thirty-two per cent. The essential composition of all three of these oils, when rectified, is C 10 H 16 , but distinct hydrocarbons, differing in physical if not in chemical characters, are considered to be present in each of the three oils. Thus the terpene C, H 16 of French oil of turpentine is laevo-rotatory, and is known as tere- benthene, while that of the American oil is dextro-rotatory, and is known as australene. Otherwise they are practically identical in properties. Russian oil of turpentine consists mainly of a hydrocarbon, sylvestrene, which boils some sixteen to twenty degrees Centigrade higher than the others, and shows some other minor differences. The commercial oil of turpentine is a color- RAW MATERIALS. 91 less, very mobile, highly refracting liquid, of pleasant odor when freshly rectified, but becoming disagreeable by exposure to the air, as it absorbs oxygen and becomes resinous. It is almost wholly insoluble in water, glycerine, and dilute alkaline and acid solutions. It is soluble in absolute alcohol, ether, carbon disulphide, benzene, petroleum spirit, fixed and essen- tial oils. It is itself a solvent for sulphur, phosphorus, resins, fats, waxes, caoutchouc, etc. Camphor. This is one of the most important of the oxidized principles which were referred to as accompanying the hydrocarbons in the crude essen- tial oils. While the name is frequently used to designate a class of com- pounds, it is commercially restricted to the laurel camphor, C 10 H 16 O, which is obtained from the wood of the Japan camphor-tree (Camphora qflicinarum) by distillation with water and after purification with sublimation. It forms a colorless, translucent, tough, fibrous mass, but may be obtained crystal- lized in prisms. It has a peculiar, fragrant odor and burning taste. It melts at 347 F. (175 C.), and boils at 399.2 F. (204 C.). It is nearly insoluble in water, but readily soluble in alcohol, ether, acetone, carbon disulphide, chloroform, and oils. 2. RESINS. The resins are products of the oxidation of the terpenes, and either accompany them in the crude essential oils or occur as exudations from trees hardening on exposure to the air. The classification of resins usually adopted at present is into (1) true resins, (2) gum resins, and (3) oleo-resins or balsams. The true resins are hard, compact products of oxidation, made up chiefly of what are termed " resin acids," which, admixed with fatty acids, are capable of saponifying with alkalies and yield " rosin soaps" (see p. 61) ; the gum resins differ from the true resins only in con- taining some gum capable of softening in water ; and the oleo-resins include the mixtures of essential oil and resin of whatever consistency and the mix- tures of benzoic and cinnamic acid and salts of these acids. This last class is obviously much the largest of the three. To the first class belong the hard resins, which serve for the manufacture of varnishes, such as copal, dammar, mastic, sandarach, dragon's blood, gum lac, and amber ; to the second class, olibanum or frankincense, myrrh, ammoniacum, asafbetida, galbanum, and tragacanth ; and to the third class, crude turpentine, benzoin, storax, copaiba, Peru and Tolu balsams. Brief mention will be made of a few of the commercially more important. Amber is a fossil resin found in detached pieces on the sea-coast, and particularly in the blue earth along the Baltic coast of Prussia, between Konigsberg and Memel. Its applications are chiefly as an article for the manufacture of mouth-pieces of pipes and cigar-holders and for beads, for the preparation of a superior varnish, and for the production of amber oil and succinic acid. Gum Arabic. This is included among gum resins because an exuda- tion analogous to other resins, but is almost wholly a gum, soluble in water, and closely related chemically to the starch group. (See p. 161.) It is yielded by the different species of Acacia, and, at present, comes chiefly from Central and North Africa, by way of Egypt, Senegal, and the Red Sea. It varies greatly in purity and color, and is used, because of its mucilaginous character, for a multitude of applications, as in medicine, confectionery, preparation of. textile fabrics, manufacture of inks, etc. Copal and Anime. These terms include a number of related resins, which are of both fossil and recent origin. The Zanzibar copal or anime is chiefly 92 INDUSTRY OF THE ESSENTIAL OILS AND RESINS. fossil, and is dug, out of the soil by the natives for some distance along the southeastern coast of Africa. Some freshly-exuded copal resin is also gathered here. On the west coast of Africa, for a distance of seven hundred miles, copal resin is also dug as a fossil. When of good quality it is too hard to be scratched by the nail, has a conchoidal fracture, and a specific gravity ranging from 1.059 to 1.080. Unlike others, the copal resins are soluble with difficulty in alcohol and essential oils, and this property, combined with their extreme hardness, renders them very valuable for making varnishes. Dammar is obtained from the Dammara orientalis, a coniferous tree, indigenous in the East Indies and Moluccas, and also from Dammara australis, in New Zealand. The two varieties are known as East Indian and Australian dammar, the latter being also known as Kauri resin. The former is that commonly met with in commerce under the simple name of dammar. The resin occurs in masses, coated on the exterior with white powder from mutual attrition, while the interior is pale amber-colored and transparent. It is scratched by copal, but is harder than rosin. The resin splits and cracks at the temperature of the hand. The Kauri variety is chiefly fossil in its origin. The dammar is extensively used in the manufacture of varnishes. LOG is a resinous incrustation produced on the bark of the twigs and branches of various tropical trees, by the puncture of the female " lac in- sect" (Coccus laced). This crude exudation constitutes the stick-lac of com- merce. Shell-lac or shellac is prepared by spreading the resin into thin plates after being melted and strained. In the preparation of the shellac, the resin is freed from the coloring matter, which is formed into cakes, and is known as " lac-dye." " Button-lac" differs from shellac only in form. Instead of being drawn over a cylinder, the melted lac is allowed to fall upon a flat surface, and assumes the shape of large cakes about three inches in diameter and one-sixth inch thick. Bleached lac is prepared by dis- solving lac in a boiling lye of pearl-ash or caustic potash, filtering and pass- ing chlorine through the solution until all the lac is precipitated. This is then collected, well washed, and pulled in hot water, and finally twisted into sticks and thrown into cold water to harden. Seed-lac is the residue obtained after dissolving out most of the coloring matter contained in the resin. The common shellac is used in varnishes, lacquers, and sealing-wax ; the bleached lac in pale varnishes and light- colored sealing-wax. Mastic is the resin flowing from the incised bark of the Pistacia lentiscus, and comes exclusively from the Island of Chios, in the Mediter- ranean. It comes into commerce in pale, yellowish, transparent tears, which are brittle, with conchoidal fracture, balsamic odor, and softens be- tween the teeth. It is soluble in alcohol, oil of turpentine, and acetone. It is used in varnish-making. Colophony Resin (rosin) is the solid residue left on distilling off the volatile oil from the crude turpentine. The resins from the Bordeaux tur- pentine and that from the American turpentine are substantially identical. Rosin is a brittle, tasteless, very friable solid, of smooth, shining fracture, specific gravity about 1.08. It softens at 80 C. (176 F.), and fuses com- pletely to a limpid yellow liquid at 135 C. (275 F.). It is insoluble in water, difficultly soluble in alcohol, but freely soluble in ether, acetone, benzene, and fatty oils. With boiling alkalies it takes up RAW MATERIALS. 93 water to form abietic acid, and then unites with the alkali to form a rosin soap. (See p. 61.) 3. CAOUTCHOUC (India-rubber). This is the chief substance contained in the milky juice which exudes when a number of tropical trees belonging to the natural orders Euphorbiacece, Artocarpacece, and Apocynacece are cut. This juice is a vegetable emulsion, the caoutchouc being suspended in it in the form of minute transparent globules. The emulsion is easily coagulated, and the caoutchouc caused to separate by the addition of alum, salt solutions, and other means Caoutchouc belongs in the same general category as the essential oils, as it possesses the general formula (C 10 H 16 ) n , and is, hence, a polymer of the terpene formula C 10 H 16 . On submitting it to destructive distillation it yields caowtchin, C 10 H 16 , boiling at 171 C., and isoprene, C 5 H 8 , boiling at 38 C. The different species of rubber-trees are cultivated in Mexico, South America, and the West Indies, in the East Indies, Borneo, Sumatra, and the African coast. The commercial varieties of caoutchouc may be grouped under four heads, the relative value of which accords with the order in which they are placed : South American : Para, Ceara, Carthagena, Guayaquil ; Central American : West Indian, Guatemala ; African : Madagascar, Mozambique, West African ; Asiatic : Assam, Borneo, Rangoon, Singapore, Penang, and Java. The Para rubber (from the Hevea Brasiliensis or Siphonia elastica] is the best of the many varieties, and commands the highest price. Caoutchouc, when pure, is nearly white, but the commercial varieties are discolored by smoke in the drying of the freshly-exuded juice in the methods usually followed. At ordinary temperatures caoutchouc is soft, elastic, and so glutinous that two freshly-cut surfaces pressed strongly together will permanently adhere. At low temperatures it is harder, is less elastic and adhesive, while, on heating it, the elastic property disap- {>ears also, and it becomes perfectly soft and can be kneaded. In water caoutchouc swells up without dissolving ; in ether, petroleum-naphtha, benzene, carbon disulphide, oil of turpentine, rosin oil, and oils gotten by the dry distillation of the rubber itself, the caoutchouc s\vells up rapidly, and after a time dissolves to a greater or less degree. The best solvents are carbon disulphide and chloroform, and Payen recommends carbon disul- phide, to which five per cent, of absolute alcohol has been added, as excel- lent. Caoutchouc is quite indifferent to most chemical reagents, but is attacked by strong nitric and sulphuric acids. Fatty matters present in the solvents used seem to have a deleterious action upon the caoutchouc, causing it to become first soft and afterwards hard and brittle. Caoutchouc softens at 120 C., melts at about 150 C., and decomposes at 200 C. 4. GUTTA-PERCHA AND SIMILAR PRODUCTS. Gutta-percha is ob- tained from the milky juice of different trees of the genus Isonandnt, belonging to the natural order Sapotacece. By the coagulation of the col- lected juice the gutta-percha globules mass together and can be kneaded into lumps. The localities in which the gutta-percha is cultivated are Borneo, Sumatra, and the Malayan Archipelago. It comes into commerce in irregularly- and fancifully-formed blocks. It forms a fibrous mass, vary- ing in color from nearly white to reddish or brownish, looking something like leather clippings cemented together, and has a specific gravity of .979. At ordinary temperatures it is hard and somewhat elastic, at 25 C. (77 F.) 94 INDUSTRY OF THE ESSENTIAL OILS AND RESINS. it becomes soft, and at 50 C. (122 F.) it can be kneaded or rolled out into plates. Between 55 C. and 60 C. it is so thoroughly plastic as to be drawn into tubes, thread, plates, and at 120 C. (248 F.) it melts. Its elasticity seems distinctly greater in the direction of its fibre than in an opposite one, while caoutchouc is equally elastic in all directions. Gutta- percha is a poorer conductor of electricity than caoutchouc, and hence its extensive use in insulating wires and cables. Its power of softening at 45 C. is partly overcome by the process of vulcanization or union with sulphur. Chemically, gutta-percha seems to be composed, like caoutchouc, of a hydro- carbon (C 10 H 16 ) n , but is always accompanied by a certain amount of oxida- tion products. Payen found that the crude gutta-percha, after thorough exhaustion with alcohol, left seventy-eight to eighty-two per cent, of a pure hydrocarbon, that he termed gutta, which, at from 1 5 C. to 30 C. (59 to 86 F.), was tenacious and ductile > but not very plastic. Batata is the dried, milky juice of the bully-tree (Sapota Milleri), which flourishes in Guiana. The balata is obtained from the juice in a manner similar to gutta-percha. In its properties it is intermediate to caoutchouc and gutta-percha ; it is more plastic and readily kneaded than the former and more elastic than the latter. At ordinary temperatures it is compact and horny, but at 49 C. already it becomes soft, and can be shaped. Towards solvents it behaves like gutta-percha. It is used chiefly in England as a substitute for gutta-percha and caoutchouc, and is also used as an addition to these. Towards chloride of sulphur and metallic sulphides it acts like caoutchouc and gutta-percha. 5. NATURAL VARNISHES. This term is applied to a class of natural products which are resinous exudations, capable of direct use as varnishes or lacquers. The most important are : (1) Burmese lacquer, a thick, grayish terebinthinous liquid, collected from the Melanorrhcea usitatissima of Burmah. It dissolves in alcohol, turpentine oil, and benzene, assuming greater fluidity. Locally, it is used in enormous quantities in lacquering furniture, temples, idols, and varnishing vessels for holding liquids. (2) Cingalese and Indian lacquer, a black varnish obtained in Ceylon and India from Semicarpus anarcardium, and in Madras, Bombay, and Bengal, from Holigarua longifolia. It forms an excellent varnish, adhering strongly to wood and metal. (3) Japanese and Chinese lacquer is derived from several species of Rhus, whose fruits form the Japan wax of commerce. (See p. 48.) It is purified by defecation and straining, and mixed with coloring matter, if needed. It is most extensively used in Japanese and Chinese lacquer-work. IE. Processes of Treatment. 1. MANUFACTURE OF PERFUMES AND SIMILAR PRODUCTS. In the use of essential oils or mixtures of them, as the basis of agreeable smelling preparations or perfumes, several classes of preparations may be distin- guished : (1) Perfumed waters or alcoholic solutions of mixed essential oils ; (2) odoriferous extracts or alcoholic extracts from fatty oils charged with odors by " enfleurage" or maceration ; and (3) pomades and per- fumed soaps. In the manufacture of the first class of preparations, the alcohol to be used must be free from fusel-oil and thoroughly deodorized. The essential oils may be in part dissolved separately in the alcohol or PROCESSES OF TREATMENT. 95 added together to the proper quantity of the solvent according to the nature of the materials. Long-continued standing of the alcoholic solutions is now considered sufficient to effect a thorough amalgamation and development of the desired perfume, and distillation is dispensed with. As examples of such perfumes we have the well-known cologne waters and eau de mille fleurs. The odoriferous extracts are gotten by treating with alcohol the fatty oils and fats which have been charged with the perfumes of flowers by the " enfleurage" process. Glycerine, soft paraffine, and vaseline have latterly been used too in the extraction of the odors. On chilling the alcohol by freezing mixtures or other means to 18 C., the fat is separated out and gotten rid of. Pomades are made from fatty oils, the basis usually being oil of almonds, oil of ben, or olive oil. The processes for preparing these scented fats are those of infusion with warm fatty oils or melted fats at a temperature of about 65 C., and of " enfleurage/' or cold perfuming, as already described. The analogous class of compounds, perfumed soaps, have been spoken of under another heading. (See p. 71.) 2. MANUFACTURE OF VARNISHES. Very much more important, in an industrial sense, is this application of essential oils and resins. Under the name varnish is generally understood either a solution of a resin or a rapidly resinifying oil, which, when applied to solid bodies, becomes dry and hard, either by evaporation of the solvent or a drying and oxidation of the same, while the film of resin left behind makes a hard, glossy coating, impervious to air and moisture. Varnishes may be of three classes, ac- cording to the character of the solvent used for the resin : (1) Linseed-oil varnishes, in which boiled linseed oil is used ; (2) spirit varnishes, in which alcohol or petroleum spirit is used ; (3) turpentine-oil varnishes. Linseed-oil Varnishes. Linseed oil itself, as a drying oil (see p. 47), is capable of forming a varnish without the addition of a resin. For the preparation of varnish, the oil must first be boiled. When heated to 130 C. it begins to boil, but the heat is continued until it shows about 260 C. (500 F.), which temperature should not be much exceeded. It absorbs oxygen in this process and becomes thick and glutinous. The ab- sorption of oxygen and the thickening of the oil are much accelerated by the use of driers like litharge, manganese dioxide, lead acetate, manganese borate, etc. (See p. 70.) Boiling linseed oil over free fire, as it is generally carried on, is illustrated in Fig. 35. Care should be taken that the kettle is not filled so full as to allow it to boil over when strongly heated. The lid e, ordinarily raised, can be lowered upon it if the escaping decomposi- tion products catch fire. In Fig. 36 is shown a pair of kettles arranged for boiling the linseed oil by steam. Pressures of four and a half to five atmospheres are used for the steam in this case, and a temperature of 132 C. (269.6 F.) yielding a perfectly clear, light-colored varnish. When boiled so as to have lost one- twelfth of its weight it yields the ordinary boiled oil varnish ; if heated until it loses one-sixth of its weight it becomes thicker and yields a stiff varnish, which is used as the basis of printer's ink. (See p. 98.) The specific gravity of boiled linseed oil of good quality varies from .940 to .950, and, on ignition it leaves a mineral residue of from .2 to .4 per cent. Experiment has taught that oxidation proceeds the more rapidly when it is pushed rapidly ; or, in other words, in order to change linseed oil into var- nish by atmospheric exposure, it must be brought to boiling as rapidly as 96 INDUSTRY OF THE ESSENTIAL OILS AND RESINS. possible. What takes place in this case is not an evaporation simply, but a decomposition of the linolein (glyceride of linoleic acid) takes place, whereby glycerine separates, and a portion of the linoleic acid changes into linoleic anhydride, C^fl^f)^ an elastic and caoutchouc-like mass (see p. 103), which then dissolves in the undecomposed linseed oil and gives the oil its valuable varnish-forming and drying character. Another part of the FIG. 35. linoleic acid, liberated by the boiling, absorbs oxygen and changes into oxylinoleic acid, C^H^O,;, which at first is of turpentine-like character, while all undecomposed glyceride of linoleic acid dries up to elastic linoxyn, C^H^OH. A good varnish, therefore, is made up of three factors : (1) Lino- leic anhydride, (2) oxylinoleic acid, and (3) linoxyn. These views of Mulder as to the changes which occur in the boiling of PROCESSES OF TREATMENT. 97 linseed oil are controverted by Bauer and Hazura,* who consider that the liquid fatty acids of linseed oil consist of eighty per cent, of linolenic and isolinolenic acids (C 18 H 30 O 2 ), together with nearly twenty per cent, of linoleic acid (C^H^O-j), and small quantities of oleic acid (C 18 H 34 O 2 ). They con- Fio. 36. sider Mulder's oxylinoleic acid to have been a mixture, and state that the more linolenic acid an oil contains, the more quickly it dries. The pure linseed-oil varnish so prepared may then serve for the prepa- ration of what are termed lacquers or solutions of resins in linseed-oil var- nish, thinned out ordinarily with turpentine oil or benzine. Of the resins, amber, copal, anime, dammar, and asphalt are used for these lacquers. In order to prepare these varnishes, the resins, amber, copal, etc., are fused in a kettle placed over a coal-fire in such a way that it sinks into the fire-chamber but a slight distance, and the flame can touch the bottom of the kettle only. After the resin has fused, the proper amount of boiling linseed-oil varnish is added, care being taken that the mixture does not fill the kettle to more than two-thirds at the most, and the contents then boiled for ten minutes. When the kettle has cooled down to about 140 C., the necessary amount of tur- pentine oil is added. In the case of the FlG - 37 - two resins, amber and copal, something more than a fusion is essen- tial. They are sub- mitted to a dry distil- lation, and only after they have given off from ten to twenty per cent, of their weight in oily distillation prod- ucts does the residue become perfectly solu- ble. A form of still in which this distillation of resins is carried out is shown in Fig. 37. The cop- per still B, which is heated in this case over the direct fire, is provided with * Zeit. fur Angew. Chem., 1888, pp. 455-458. 98 INDUSTRY OF THE ESSENTIAL OILS AND RESINS. mechanical agitation, R, and a tube, A, for drawing off the melted residue. This tube is covered where it projects through the fire by fire-brick to protect it from the flame. The distillation products escape through I) and are condensed by the worm K. The dry distillation of copal proceeds best at a temperature of 340 to 360 C., while that of amber requires 380 to 400 C. If heated higher than these temperatures the resins become dark. As the melting-point of lead is 334 C., a lead bath is recommended for the copal distillation. These lacquers are the hardest and most durable of varnishes, but they dry more slowly than simple linseed-oil varnish. Spirit varnishes are solutions of resins, such as sandarach, mastic, dammar, gum-lac, and shellac, in alcohol, although this is sometimes replaced by other solvents, such as methyl alcohol, acetone, and petroleum spirit. The spirit varnishes dry rapidly, leaving a brilliant surface, but are more apt to crack and peel off than turpentine varnishes. Turpentine is often added to these varnishes to diminish this brittleness. Among the most important varnishes of this class are shellac varnish, of which the finest grade is pre- pared from bleached shellac dissolved in alcohol, and copal varnish. In the preparation of this latter, the copal must be first fused, or rather sub- mitted to dry distillation in the manner already described. (See p. 97.) The fused copal residue is afterwards powdered, mixed with sand and covered with strong alcohol, heated to boiling for some time and then filtered. The addition of elemi resin imparts a toughness to the copal varnish. Colored spirit varnishes are made by the addition of alcoholic extracts of annatto, dragon's blood, gamboge, turmeric, cochineal, or even solutions of the different coal-tar colors. Turpentine-oil Varnishes. These are prepared in the same way as the spirit varnishes. They dry more slowly, but are more flexible and durable. The most important are copal varnish and dammar varnish. Turpentine and linseed oil are frequently used jointly in the preparation of varnishes, so as to obtain the best results. Thus, in the manufacture of copal and amber varnishes, described before (see p. 97), the relative amounts of ma- terials are : Ten parts of copal or amber (or the residue from the distil- lation of amber oil), twenty to thirty parts of linseed-oil varnish, and twenty-five to thirty parts of oil of turpentine. 3. MANUFACTURE OF PRINTER'S INK. Printer's ink, of whatever grade, whether for newspaper print, for book, lithographic, or copperplate printing, is a very stiff, rapidly-drying linseed-oil varnish, to which has been added lamp-black or charcoal in the finest state of division. For its prepara- tion, linseed, poppy, or nut oil is heated in copper vessels, over a free fire to a temperature beyond the boiling-point, so that inflammable vapors are given off. These are frequently ignited, or, as is now preferred, they may be allowed to escape into a draught chimney. The heating is continued until the oil becomes quite thick and a film forms on the surface, which causes it to swell up with escaping bubbles of vapor. A sample taken out and tested between the fingers should draw out in long filaments. In this condition, with the addition of about sixteen per cent, of lamp-black, the varnish will dry very easily and rapidly. If the varnish has not been boiled long enough, the printed characters will run together and oil will be absorbed in the paper fibre, so that the printed letters will show a yellowish border. For the ink to be used in book-printing, an addition of soap is absolutely PROCESSES OF TREATMENT. 99 necessary ; it allows the inked type to be withdrawn from the moist paper clear and sharp without any adhering or smearing. The finer the printed work required the stiffer and more thoroughly boiled the varnish must be, so that for copperplate and lithographic inks a much stiifer ink is needed than that which is used for newspaper or even book printing. The ex- pensive linseed oil is frequently replaced by hemp-seed, poppy, or nut oil. In order to obviate the necessity of boiling the oil down so thick, rosin is sometimes added to the varnish. Thus, to one hundred and twenty parts of linseed oil forty to fifty parts of rosin are added and twelve to fourteen parts of soap. Rosin oil is also used in place of a part of the linseed oil ; indeed, cheap printing ink can be made composed of rosin oil, rosin, soap, and lamp-black alone, without the addition of linseed oil at all. Colored printing inks are obtained by adding to the boiled-oil varnish vermilion, Prussian blue, indigo, and other colors. 4. MANUFACTURE OF OIL-CLOTH, LINOLEUM, ETC. In the manufac- ture of oil-cloths, the basis is a coarse canvas, of jute or cotton stuff usually, which is coated with repeated layers of linseed oil, which has been pre- viously boiled sufficiently with litharge, and to which the coloring matter has been added, or, in other words, a linseed-oil paint. Before putting on the coatings of paint, the canvas is primed with a coating of size. The object of this is not only to give a body to the cloth, but also to protect the fibre from the injurious action of the acid products generated during the oxidation of the linseed oil which is subsequently applied. Cloth which is covered with paint without a protective coating of size soon becomes rotten and brittle. Both sides of the canvas are painted in this way. After thor- ough drying of this layer a second coat is applied to both sides. This suffices for the back of the oil-cloth. The painting of the face side is con- tinued until it is sufficiently built up for the printing of the pattern. Most of the printing is hand-printing done by blocks, the number of which cor- respond to the number of colors to be used. Linoleum is a name often given to a form of oil-cloth in which powdered cork is incorporated with the boiled oil, or, rather, alternated with it in layers. A pattern is then printed on and a transparent varnish to cover all. The oxidized oil used in linoleum manufacture has a certain quantity of rosin and kauri gum added to it to give it toughness. The proportions for ordinary linoleum are : Oxidized oil, eight and one-half hundredweight ; rosin, one hundredweight; kauri gum, one-half hundredweight. A variety of linoleum containing wood fibre instead of ground cork has of late years been introduced as a substitute for wall-papering under the name of " lincrusta." 5. PROCESSES OF TREATMENT OF CAOUTCHOUC AND GUTTA-PERCHA. The crude rubber as brought into commerce is quite impure from acci- dental causes, and, in many cases, from intentional adulteration. It, there- fore, must undergo a thorough mechanical cleaning before being submitted to any chemical treatment. It is first boiled with w r ater (to which a little slaked lime is advantageously added) until thoroughly softened, then cut into slices and passed repeatedly between grooved rollers, known as washing rollers, wjiile a stream of cold water flows over it. This crushes and carries away any solid impurities as well as those which are soluble. Under this treatment Para rubber loses from twelve to fifteen per cent, of its weight ; the African variety, twenty-five to thirty-three per cent. After this wash- 100 INDUSTRY OF THE ESSENTIAL OILS AND RESINS. ing, the rubber is carefully and thoroughly dried. Neglect of this frequently causes the wares when subsequently vulcanized to appear spongy. The caoutchouc is now to be worked over and agglomerated thoroughly, which is done either by passing it repeatedly between rollers heated to 70 or 80 C., or by the aid of the so-called masticating or kneading machine, which consists of a hollow cylinder within which revolves another cylinder with a fluted or corrugated surface. The rubber being placed in the annular space between the two cylinders, the inner one is made to revolve, whereby the mass is worked over and over and thoroughly kneaded. The rubber is now to be mixed with the sulphur needed for its vulcanization and with whatever coloring or weighting materials are to be used. This mixing is effected by the aid of horizontal rollers heated internally with steam, and so geared as to move in contrary directions at unequal speed. This mixed rubber so obtained can readily be softened by heat, and can now be shaped, moulded, or rolled into any desired shape, and then submitted to the heat necessary for vulcanization. The vulcanization of rubber consists in effecting a combination of the caoutchouc with sulphur or sulphides whereby the behavior of the caout- chouc towards heat and towards solvents is changed. Its value for tech- nical purposes is greatly increased by this change. Two methods of vulcanization are to be noted : (1) the vulcanizing by mixing with sulphur or metallic sulphides and heating to 125 to 140 C. ; (2) the cold vulcanization process of Alexander Parkes, consisting of immersing the rubber articles in a solution of chloride of sulphur in carbon disulphide or benzene. The latter process is only used for small articles or those consisting of thin layers of caoutchouc, as the action of the chloride of sulphur, even in the two and one-half per cent, solution usually em- ployed, is very rapid, while at the same time it is superficial, so that it is difficult to control the action properly. In vulcanizing by the first process, that of " burning/' as it is termed, the crude caoutchouc is mixed with varying amounts of sulphur ; for soft rubber goods with about ten per cent., for hard rubber or vulcanite with thirty to thirty-five per cent., of sulphur. Instead of sulphur, metallic sulphides are used, such as alkaline sulphides, sulphide of lead, and sulphide of antimony. For red rubber goods the latter is always used. For soft rubber articles the proper temperature for vulcanization lies between 120 and 136 C.; for hard rubber, from 140 to 142 C. In vulcanizing, only a part of the sulphur is chemically com- bined, a part remaining mechanically mixed. This can be largely removed by boiling the finished articles in a solution of caustic soda. Both air-baths and steam-baths are in use for heating, the latter at present in the majority of cases. A form of vulcanizing vessel for smaller articles is shown in Fig. 38. The lid can be removed by the mechanism shown at a, and the manometer m shows the pressure existing in the vulcanizer A. This final heating which effects the change in the rubber is frequently called the "curing" of the rubber. Vulcanized rubber goods can be manufactured in the greatest variety of shapes and for a multitude of uses, the rubber being in almost all cases " cured" after the shaping. In the manufacture of hard-rubber -articles, the East Indian, and spe- cially the Java and Borneo, caoutchouc is used, the Para rubber being too expensive, and besides not so well adapted. While in the manufacture of soft rubber, the burning or curing was the last process, following the shaping of the articles, in the manufacture of the hard rubber the curing is PROCESSES OF TREATMENT. 101 generally done before the articles are finally shaped. Only in the manufac- ture of moulded goods is the curing done last. Gutta-percha, balata, and colophony resin are often added to modify the hardness and elasticity, while a large number of mineral substances, such as chalk, gypsum, calcined mag- nesia, zinc oxide, asphalt, etc., are added chiefly for cheapening purposes. FIG. 38. A kind of vulcanite or hard rubber which contains a very large proportion of vermilion is used, under the name of dental rubber, for making artificial gums. The working over of scrap rubber has in recent years assumed much importance. Although scraps of raw caoutchouc can easily be kneaded or rolled together, vulcanized rubber cannot be. The insolubility of the vul- canized rubber in ordinary solvents presents another difficulty. Although the problem is not yet solved, numerous proposals have been made. These all involve one of three lines of treatment: (1) mechanical subdivision of the scrap and the adding of the powder so obtained to fresh caoutchouc ; (2) heating the vulcanized scrap to fusion and use of the pitchy mass so obtained as mixing material ; (3) partial desulphurization of the caoutchouc, solution in suitable solvents, driving off the solvent, and use of the residuum so obtained. Treatment of Gutta-percha. This is quite similar to that described under caoutchouc. The crude gutta-percha must be thoroughly washed and freed from dirt and mechanically mixed impurities. It is then cut or torn into fine shreds, which are, after washing, heated so as to ball them together. It is now kneaded and compacted so as to drive out the air- bubbles. Gutta-percha is used both in the vulcanized and unvulcanized condition. The vulcanization is carried out, as in the case of caoutchouc, by the addi- tion of sulphur and curing. The amount of sulphur varies from six to ten per cent., and the temperature for vulcanization lies between 135 and 102 INDUSTRY OF THE ESSENTIAL OILS AND RESINS. 150 C. The gutta-percha scraps are worked up generally by desulphurizing the vulcanized material by boiling for five to six hours in a six to eight per cent, solution of caustic soda, washing, drying, dissolving in carbon disulphide, benzene, or turpentine, and then distilling off the solvent. in. Products. 1. PERFUMES. The general character of the several classes of perfumes has already been indicated in the previous section, while the products are so extremely numerous and special in character that any attempt at detailed description would be beyond the province of this work. 2. VARNISHES. We have to note here both the natural varnishes, already referred to (see p. 93), and manufactured varnishes. The classi- fication of manufactured varnishes, already given, was: (1) Linseed-oil varnishes, including both plain boiled linseed-oil varnish and solutions of resins in the boiled oil, or lacquers, as they are often called ; (2) spirit varnishes, including not only alcoholic solutions of resins, but solutions of the latter in benzol, petroleum spirit, wood-naphtha, and other volatile liquids, and (3) turpentine-oil varnishes. Natural Varnishes. With regard to the Burmese and Indian lacquers, little is known except as to their production as crude materials. The Japanese lacquer has been more fully described, and the methods of ap- plying it attentively followed. As the varnish flows from the incisions in the trees of the Rhus species it is a milky juice, which, on exposure, quickly darkens and blackens in color. After resting in tubs for some time the juice becomes thick and viscous, the thicker portions settle at the bottom of the vessel, and from it the thinner top stratum is separated by decanting. Both qualities are strained to free them from impurities, and when ready for use they have a rich brown-black color, which, however, in thin layers presents a yellow, transparent aspect. This varnish, when applied to any object, becomes exceedingly hard and unalterable, and with it as a basis all the colored lacquers of Japan are prepared. The black variety of the lacquer is prepared by stirring the crude varnish for a day or two in the open air, by which it becomes a deep brownish-black. Towards the completion of the process, a quantity of highly ferruginous water, or of an infusion of gall-nuts darkened with iron, is mixed with the varnish, and the stirring and exposure are continued till the added water has entirely evaporated, leaving a rich jet-black varnish of proper consistency. In preparing the fine qualities of Japanese lacquer, the material receives numerous coats, and between each coating the surface is carefully ground and smoothed. The final coating is highly polished by rubbing, and the manner in 'which such lacquered work is finished and ornamented presents endless variations. The durability of Japanese lacquer-w r ork is such that it can be used for vessels to contain hot tea and other food, and it is even unaffected by highly-heated spirituous liquors. Linseed-oil Varnishes. The method of burning linseed or similar drying oil in order to develop its varnish-forming character has been described (see p. 95). The use of metallic oxides and salts as driers has also been referred to. In this connection an additional word may be had. While litharge and lead acetate are commonly used, they must be replaced by manganese or other driers when the boiled oil is to be used as the basis of zinc PRODUCTS. 103 oxide paint. Lately, manganous borate has been strongly recommended as a drier, and it is claimed that it is capable of giving rapid drying qualities to linseed oil when it is heated a sufficient length of time (ten to fourteen days) at a temperature of only 40 C. Such a boiled oil would be, of course, lighter in color than if treated at a higher temperature. Boiled oil is often bleached by sunlight, and always improves by keeping, as impurities gradually settle out, and its drying qualities develop by age. According to F. Sacc, linseed-oil varnish in drying absorbs atmospheric oxygen to the extent of almost fifty per cent, of its own weight. The most important of the linseed-oil resin varnishes are : Amber var- nish, the most durable and resisting oil varnish, but unfortunately of dark color ; copal varnish, the finest of all the oil varnishes, nearly as hard and durable as amber varnish, much paler in color, and drying more quickly ; and kauri resin and colophony resin for inferior varnishes. The best oil varnishes are made from " fused" copal or amber, with boiled linseed oil, subsequently thinned out with oil of turpentine. Spirit varnishes are easily obtained perfectly clear ; they dry very rapidly, and leave smooth, lustrous films, which appear at first unexcep- tionable. But slight vibrations and changes of temperature soon develop innumerable small cracks, in consequence of which it loses its lustre, and if the varnish layer was thick it begins to peel off. The reason of this is that the film consisted simply of unaltered resin, spread in a thin layer, and as most of the resins are brittle by nature, slight shocks or changes of temperature, inducing contraction or expansion of the article varnished, will cause the resin film to break. What is true of alcoholic varnishes applies, of course, also to all varnishes where the solvent of the resin takes no part in the formation of the film. The more volatile the solvent the quicker the film is deposited and the easier it cracks. Two methods of obviating this difficulty are in use : first, to mix with the brittle resin a soft, balsam-like resin, and, second, to mix spirit varnish with one prepared with turpentine oil. The resins chiefly used in spirit varnishes are lac, which is the best because of its hardness and toughness, copal, sandarach, and for coloring, chiefly gamboge, dragon's blood, gum acaroides, aloes, and benzoin. Turpentine varnishes are seldom used exclusively as such because of the strong" and persistent turpentine odor. When used alone they give films as perfect as those gotten by the use of spirit varnishes, but tougher and drying more slowly than these latter. Usually, however, turpentine oil is used in connection with boiled linseed or other drying oil in varnish manufacture, as in the case given of copal varnish, before described (see p. 97). The resins used for turpentine-oil varnishes are the varieties of copal, amber, sandarach, dammar, mastic, and coniferous resins. Japans are simply varnishes that yield, on drying, very hard, brilliant coatings upon paper, wood, or metal, analogous to the natural lacquer of Japan, before described. The effecting of this result is gotten in general by exposing the articles to high temperatures in stoves or hot chambers subsequent to the application of the varnish. This supplementary heating process is called "japanning." It is done with clear, transparent varnishes, in black and in colors, but black japan is the most characteristic and com- mon style of \vork. Black japan varnish contains asphaltum as the basis, and when applied in several layers, each of which is separately dried in the stove at a heat rising to 300 F. (149 C.), is susceptible of a high polish. 104 INDUSTRY OF THE ESSENTIAL OILS AND RESINS. Japanning may be regarded as a process intermediate between ordinary painting and enamelling. It is very extensively applied in the finishing of ordinary hardware goods and domestic iron-work, deed-boxes, clock-dials, and papier-mach6 articles. The process is also applied to blocks of slate for making imitation of black and other marbles for chimney-pieces, etc., and a modified form of japanning is employed for prepared enamel, japan, or patent leather. 3. PRINTING INKS. The character of printing inks has been suffi- ciently indicated in the description of its manufacture. (See p. 98.) 4. MISCELLANEOUS PRODUCTS FROM RESINS AND ESSENTIAL OILS. (1) Sealing-wax is a valuable product of manufacture from shellac. Venice turpentine is always added to the shellac to make it more fusible and less brittle, and some mineral coloring matter, which, in the case of the common red variety, is always vermilion. For black sealing-wax the best ivory-black is used, for golden-colored wax, " mosaic gold" (stannic sul- phide), for green wax, powdered verdigris. For the commoner varieties, earthy materials, like chalk, magnesia, burnt plaster, barytes, or infusorial earth, are added for the double purpose of making it less fusible and to weight it. Perfumed sealing-waxes are scented with benzoin, Peru and Tolu balsams, and storax. As a substitute for, or adulterant of, shellac in the manufacture of sealing-wax, gum acaroides has recently come into use. (2) Rosin Oil. In recent years great importance has attached to the products of the dry distillation of common colophony resin or " rosin." It yields, on distillation, two valuable products : first, from three to seven per cent, of a light fraction known as rosin spirit, or " pinoline," and, second, from seventy to eighty-five per cent, of rosin oil, a violet-blue fluorescing liquid, varying in specific gravity from .98 to 1.1. The pinoline is used as an illuminant and as a substitute for turpentine oil in varnish manufacture. The rosin oil has a large use as a lubricant, especially for machinery and wagon-wheels. It is used in the condition of " rosin grease" (made by stirring rosin oil with milk of lime), and largely as a substitute for linseed oil in the manufacture of printer's ink. (See p. 98.) Moreover, as it can be deprived of its fluorescence or " bloom" in various ways (exposure to sun- light, treatment with hydrogen peroxide, nitro-benzene, dinitro-naphtha- lene, etc.), it can be used in adulterating olive, rape, and sperm oils. The best mineral lubricating oils are also adulterated with it at times. (3) Oil-doth and Linoleum. The general outlines of the manufacture of these products as given on page 99, allow one to form an idea of the character of them. Oil-cloth is a firm but flexible fabric, which by its treatment has been made water-proof and impervious to atmospheric influences. It can be washed and cleansed, and, under ordinary wear, retains for a considerable time its lustre and brilliancy of printed pattern. It is, however, cold and hard, and, unless well seasoned, the pattern is liable to wear off. The covering film will not stand much bending without cracking, and then it rapidly disintegrates. Linoleum is softer and more elastic to the feet, and, if the composition has been properly made, shows great elasticity and toughness, so that its wearing powers are notably greater than those of oil-cloth. In laying down linoleum, the edges may be cemented to the floor by using a thick solution of shellac in methylated spirit. PRODUCTS. 105 (4) Linseed-oil Caoutchouc. For the preparation of this substitute for caoutchouc, linseed oil is heated to a high temperature for a considerable time until it becomes dark and has changed into a tough mass. For ten kilos, of linseed oil about twenty-four hours' heating is necessary. The tough mass obtained is then heated for several hours with nitric acid until it becomes plastic and hardens on exposure to the air. It is then taken from the nitric acid and put into a lukewarm, slightly alkaline bath, where it is kneaded for a time to free it from adhering acid. The oil-caoutchouc is soluble in turpentine, carbon disulphide, and caustic alkalies ; on addition of acid it is precipitated unchanged from the alkaline solution. It is stated that when vulcanized by the acid of sulphur chloride it can be used as a substitute or adulterant of genuine caoutchouc. 5. INDIA-RUBBER AND GUTTA-PERCHA PRODUCTS. In noting the properties of crude caoutchouc it was stated that the raw caoutchouc, while elastic at ordinary temperatures, did not show the same character when chilled, as it became hard, and when heated it lost the elastic feature en- tirely. On the other hand, vulcanized caoutchouc or manufactured rubber shows no change in its elasticity, even within very wide limits of tempera- ture. Freshly-cut surfaces, on being pressed together, will not adhere as was the case with raw caoutchouc ; it swells up only slightly in bisulphide of carbon, oil of turpentine, and other solvents, while the raw caoutchouc swells up greatly and even dissolves in part. The vulcanized rubber is much more impervious to water than the raw material. As stated before, not all of the sulphur present in the vulcanized rubber is chemically com- bined. A large excess of uncombined sulphur is, however, deleterious to the goods, as it causes them to lose their elasticity when they are stored for a few years. If such goods are treated with alkaline solutions, the free sulphur can be removed without impairing the elastic character of the vul- canized caoutchouc. Hard rubber, prepared, as described before, from crude caoutchouc, with a larger percentage of sulphur, has a black color and takes a high degree of polish. Articles of this material can also be gotten of any desired color, as in the case of the dental rubber previously referred to. Resins, like shellac, are often added to give elasticity to the hard rubber, the amount of resin capable of being taken up being consider- able, equalling at times fifty per cent, of the combined weight of the caoutchouc and sulphur. Hard rubber becomes strongly electrified by rub- bing, and hence is used in various plate electrical machines, while its non- conducting qualities make it valuable for insulators in various forms of tele- graphic apparatus. Hard rubber is unacted upon by strong mineral acids and other chemicals, and hence is used for acid-pumps and connections, for spatulas, photographic dishes, etc. Gutta-percha, in the pure as well as the vulcanized condition, has been adapted to a multitude of uses. One of the most important uses of gutta- percha is as a material for the matrices or moulds for coins, medals, smaller art castings, etc., and all forms of galvano-plastic work. The pure gutta- percha serves very well to take imprints, but for overlaying matrices or moulds compositions of gutta-percha and caoutchouc must be used, to unite plasticity when heated with sufficient elasticity to allow of the matrix being removed without injury to the impression. The chief use for gutta-percha, however, is for telegraphic cable insulation (every nautical mile of cable re- quiring about one-half of a ton of gutta-percha), and the chief purchaser and worker in gutta-percha, therefore, is the " Telegraph Construction and 106 INDUSTRY OF THE ESSENTIAL OILS AND RESINS. Maintenance Company," of London, who buy up the crude gutta-percha through their agents in Singapore. The gutta-percha is covered upon the wires by pressing. The partly vulcanized and warm gutta-percha mass is forced out of a powerful press along with and around the wire or wires to be covered. The gutta-percha must have previously been well kneaded to remove the air thoroughly from it, so that it may pack uniformly. Gutta-percha is also incorporated with powdered wood and sawdust, making a composition which is very hard and can be worked by means of the saw and turning-lathe into a variety of shapes. IV. Analytical Tests and Methods. 1. FOR ESSENTIAL OILS. Essential oils are extremely liable to adul- teration, the high price of many of the finer ones lending to this tendency. The usual adulterations are with alcohol, chloroform, oil of turpentine, fixed oils, both vegetable and mineral, and spermaceti, and by mixing the cheaper essential oils with the more expensive. In addition to the above intentional adulterants, volatile oils are apt to contain water and resinous and other oxygenated bodies, produced by their exposure to air. The detection of fatty oils, resins, or spermaceti can often be effected by simply placing a drop of a suspected oil upon a piece of white paper and exposing it for a short time to heat. If the oil is pure it will entirely evaporate ; but if one of these adulterants be present, a greasy or translu- cent stain will be left on the paper. These substances will also remain undissolved when the oil is agitated with thrice its volume of rectified spirit. Alcohol in essential oils may be detected by agitating the oil with small pieces of dry calcium chloride. These remain unaltered in a pure essential oil, but dissolve in one containing alcohol, and the resulting solution sepa- rates, forming a distinct stratum at the bottom of the vessel. When only a very little alcohol is present, the pieces merely change their form and exhibit the action of the solvent on their angles or edges, which become more or less obtuse or rounded. If the experiment be performed in a graduated tube and a known measure of the oil employed, the diminution in its vol- ume will give that of the alcohol mixed with it. Dragendorff recommends the use of metallic sodium, which does not act on hydrocarbons, and but slightly in the cold on oxygenated essential oils if pure and dry, but in the presence of ten or even five per cent, of alcohol a small piece of the sodium is dissolved, while a brisk evolution of gas takes place. Aniline-red (ma- genta) is insoluble in essential oils if pure and dry, but in the presence of a small proportion of alcohol they acquire a pink or red color. This adul- teration with alcohol is said to be very common, as it is a frequent practice of druggists to add a little of the strongest rectified spirit to their essential oils to render them transparent, especially in cold weather. Oil of cassia is a notable example of an oil treated in this way. The adulteration of essential oils with fixed oils is best distinguished by what is termed " steam distillation." The essential oils all distil over with steam at 100 C., while resinous matters and fixed oils, added as adulterants, will remain in the retort. The adulteration of the finer essential oils with cheaper essential oils is constantly met with. Thus, the expensive oil of cassia is adulterated with oil of cedarwood ; oil of rose with oil of geranium ; ANALYTICAL TESTS AND METHODS. 107 and oil of geranium with oil of turpentine. Noting the specific gravity carefully where that is characteristic, and noting the odor on evaporating, are methods most generally resorted to for the detection of these fraudulent admixtures. The adulteration of essential oils with oil of turpentine is, unfortunately, one of those difficult of detection, and no method of testing has as yet been suggested that will always show it. The test of Land- beck * on the solubility of salicylic acid in the different essential oils as a means of detecting their adulteration seems to have given good results. He has observed that salicylic acid is soluble in essential oils, but most freely in oils containing oxygen. An adulteration of five or ten per cent, of oil of turpentine is generally indicated tolerably distinctly by the reduced solvent power of the oil for* salicylic acid. The examples in the accompanying table will suffice to indicate the differences observed. The number of parts of the various oils other than turpentine required to dissolve one part of salicylic acid rarely exceeds eighty, so that there is in all cases a very considerable difference. The age of an oil materially affects its solvent power. NATURE OF OIL. NUMBER OF PARTS BY WEIGHT OF OIL REQUIRED FOR SOLUTION OF ONE PART OF SALICYLIC ACID. Pure oil. + 5 per cent, of turpentine oil. + 10 per cent, of turpentine oil. Oil of anise (fresh) . . . ... 74 30 17 80 12 625 540 159 94 94 36 22 104 18 116 42 36 125 24 Oil of bergamot (one year old) Oil of lemon (six months old) Oil of rosemary (fresh) . . Oil of turpentine (fresh) Oil of turpentine (three months old) . . . Oil of turpentine (two years exposed to sunlight) ... Oil of turpentine (partly resinified) . . . In using the test, Landbeck employs flat-bottomed test-glasses, two inches long by five-sixteenths inch in diameter. Each glass is fixed in a cork to serve as a stand, and .050 gramme of salicylic acid is placed in it. The oil to be tested is then added drop by drop, and the tube shaken until a clear solution is obtained, when, from the increase in weight, the parts of oil added can be calculated. The essential oils give a variety of color-tests with such reagents as con- centrated sulphuric acid, fuming nitric acid, bromine, picric acid, etc., which, however, are not sufficiently characteristic to allow of their being used to recognize adulterations. The purity of oil of turpentine, as commercially the most important of the essential oils, is often a question to be deter- mined. The most usual adulterants of oil of turpentine are light petro- leum-naphtha, known as " turpentine substitute," " rosin spirit," and of late a so-called " light camphor oil," gotten as a side-product in the manufacture of safrol. The following tabular statement of Allen f shows the characters of oil of turpentine, rosin spirit, and petroleum-naphtha under the influence of different reagents : * Phar. Journ. [3], xv. 309. f Allen, Commercial Org. Anal., 2d ed., ii. p. 439. INDUSTRY OF THE ESSENTIAL OILS AND RESINS. Turpentine oil. Rosin spirit. Petroleum-naphtha. 1. Optical activity . . . Active. Usually none. None. 2. Specific gravity . . .860 to .872. .856 to .880. .700 to .740. 3. Temperature of dis- 156 to 180. Gradual rise. Gradual rise. tillation, C. . 4. Action in the cold on coal-tar pitch. Readily dissolves pitch to a deep-brown solu- Readilv dissolves pitch to a deep-brown solu- Very slight action, lit- tle or no color. tion. tion. 5. Behavior with abso- Homogeneous m i x- Homogeneous m i x- No apparent solution. lute phenol, 3 of ture. ture. sample to 1 of phe- nol, at 20 C. 6. Behavior on shak- Homogeneous m i x- Homogeneous m i x- Liquid separates into ing 3 parts of cold ture. ture. two layers of nearly sample with 1 part equal volume. castor oil. 7. Bromine absorption. 203 to 236. 184 to 203. 10 to 20. 8. Behavior with sul- phuric acid. Almost completely polymerized. Polymerized. Very little action. It will be seen that the presence of petroleum spirit can be indicated by almost all of these reagents, while that of rosin spirit would hardly be shown. H. E. Armstrong * recommends a process which consists of agi- tating the suspected turpentine sample first with sulphuric acid and water (2 : 1), carefully avoiding too high a rise of temperature. This gradually polymerizes the genuine oil of turpentine, changing it to a viscid non- volatile oil. The sample is then distilled with steam, and that which is volatile at this temperature is now treated with 4:1 sulphuric acid and water. The polymerization of the turpentine is usually completed by this treatment, while any petroleum-naphtha present is not affected, and remains as volatile as before. A final steam distillation will give the petroleum- naphtha originally present in the turpentine sample. Rosin spirit is partly polymerized in this treatment, while volatile hydro-carbons remain, but its presence is much harder to indicate certainly than that of petroleum. The bromine absorption of oil of turpentine (see p. 77) is higher than that of any of these adulterants, and that may in many cases serve to indi- cate its purity. The iodine absorption percentages with Hiibl's reagent (see p. 77) for a large number of essential oils have been determined by R. H. Davies,f who finds that the differences in absorption power are very much greater in the case of essential than in that of fixed oils. Some volatile oils do not absorb any appreciable amount of iodine, while others will remove from solution four times their weight, or four hundred per cent. Thus, oil of turpentine shows an absorption equivalent of three hundred and seventy- seven per cent. 2. FOR RESINS. The tests for resins or resin acids, when admixed with fats or fatty oils, have been referred to under the discussion of the latter. (See p. 78.) From admixture with the neutral fixed oils resins may be separated by treating the mixture with alcohol of about .85 specific gravity. The alcohol is subsequently separated, and the dissolved resin recovered by evaporating it to dryness. Acid resins, such as common colophony, may be separated from the neutral fats by boiling the substance with a strong solu- tion of sodium bicarbonate or borax. After cooling, the aqueous liquid is * Journ. Soc. Chem. Ind., i. p. 480. f Phar. Journ. and Trans., April, 1889, p. 821, and Amer. Journ. of Phar., 1880, p. 301. ANALYTICAL TESTS AND METHODS. 109 separated from the oil and the resin precipitated from its solution in the sodium salt by adding hydrochloric acid. Resins may be separated from the essential oils and camphors in admix- ture with which they so frequently occur by distilling in a current of steam. The resins show some considerable differences when examined by the two methods of bromine absorption and saponification equivalent, before referred to under the fatty oils. (See p. 75.) Mills and Muter * have determined the bromine absorptions, and E. J. Mills f the proportions of potash neu- tralized by various resins. The following table gives a summary of their results : KIND OF RESIN. KOH neutralized per cent. Saponification equivalent. Bromine absorp- tion. Hydrobromic acid formed. Rosin (refined) .... Shellac 18.1 23.0 308.6 242.7 112.7 5.2 Shellac (bleached) . . Benzoin 18.2 22 3 306.9 256.0 4.6 38.9 Some. Amber 16.1 347 & 53.5 Some. Anime ........ 9 5 r >85 5 60.2 Much. Gamboge 15.5 361 1 71 6 Much Copal 12.4 450.8 89.9 Much. Copal (reduced to by boiling) 129 433 4 845 Much. Sandarach i 16.4 340.6 96.4 Very much. Kauri 12.9 433.4 108.2 Thus 21 340 6 108 5 5.2 1068 1 117 9 Much Elerni 3 3 1697.9 1222 Very much Mastic . 11 7 478 6 124 3 Much The chief feature attracting attention is the low bromine-absorption figure gotten with shellac. Mills's method could probably be used to ad- vantage for the analysis of varnishes after evaporating off the volatile solvent. Hirschsohn J has elaborated a systematic scheme for the identification of resins, gum-resins, and balsams analogous to the schemes for plant analysis, in which he uses a succession of solvents and reagents. It is too lengthy to be given here in detail. The constantly-widening use of rosin oil makes the tests for its presence of considerable importance. Rosin oil gives a character- istic violet color, with anhydrous stannic chloride or bromide. If it is mixed with fatty oils, A. H. Allen points out that the test may still be suc- cessfully applied by distilling the mixture and applying the test to the first fraction which passes over. Demski and Morawski recommend the use of acetone for the detection and rough determination of rosin oil in mineral oils. According to these chemists, rosin oils are miscible with acetone in all proportions, while mineral oils require several times their volume of acetone to effect solution. The test is applied by agitating fifty cubic centimetres of the sample with twenty-five cubic centimetres of acetone. If, on allowing the mixture to stand, it separates into two layers, ten cubic centimetres of the upper or acetonic layer should be removed with a pipette and evaporated, and the residual oil weighed. In the case of pure American or Galician lubricating oil the residue will weigh about two grammes, but only half this quantity * Journ. Soc Chem. Ind., iv. p. 97. J Watts's Diet, of Chem., viii. p. 1743. f Journ. Soc. Chem. Ind., v. 221. \ Ding. Polytech. Journ., cclviii. p. 82. 110 INDUSTRY OF THE ESSENTIAL OILS AND RESINS. will be obtained from Wallachian or Caucasian oil. It is stated that mix- tures of rosin oil with the lubricating oils from American and Galician petroleum are permanently soluble in half their volume of acetone, if the proportion of rosin oil exceeds thirty-five per cent, of the mixed oil, but that complete solution is not eifected in the case of Wallachian and Caucasian oils unless the rosin oil constitutes at least fifty per cent, of the mixture. Ragosine cylinder oil requires an addition of rosin oil equal to fifty-three per cent, of the mixture to become soluble in half its volume of acetone. 3. FOR VARNISHES. The most important constituent which enters into the manufacture of varnishes is undoubtedly the linseed or other drying oil. Linseed oil (see p. 147) is liable to be adulterated with other vege- table oils, with fish oils, with mineral and rosin oils, and with rosin itself. As mineral and foreign seed oils are lighter in specific gravity than linseed oil, while rosin and rosin oil are much heavier, by the judicious use of a suitable mixture of mineral and rosin oils extensive adulteration can be eifected without alteration of the density. The analysis of a linseed oil sup- posed to be adulterated would be made according to the scheme given be- fore (see p. 79) for the analysis of a fatty oil containing foreign admixtures. A. H. Allen gives also a rather elaborate method, which he states is better adapted for a boiled linseed oil, for the details of which the reader is re- ferred to Allen's " Commercial Organic Analysis," 2d ed., ii. p. 125. 4. FOR CAOUTCHOUC AND GUTTA-PERCHA. The adulterations of caoutchouc are both mineral, or inorganic, and organic in character. A careful incineration of a given specimen in a porcelain crucible will leave any mineral admixture, as ash. Oxide of zinc, gypsum, and such admixtures are thus recognized. To determine the amount of sulphur, the specimen is burned in a current of oxygen, the gaseous products of combustion passed through water acidulated with nitric acid, so that the sulphurous acid re- tained is changed into sulphuric acid, which is then determined by chloride of barium in the usual way. If the mass contain metallic sulphide, this pro- cedure does not answer. The mass must be deflagrated in a crucible with saltpetre and acid, then the sulphur determined in the sulphate of potassium produced. V. Bibliography and Statistics. BIBLIOGKAPHY. 1862. Die Aetherische Oele, J. Maier, Stuttgart. 1874. Gums, Resins, Oleo-resins, etc., of India, M. C. Cooke, London. 1875. Notice sur la Fabrication et 1'Emploi du Caoutchouc, L. Ogier, Paris. 1877. Die Fabrikation der Aetherische Oele, Askinson, Vienna. Perfumery and Kindred Arts, Christiani, Philadelphia. 1879. The Art of Perfumery, S. Piesse, London. Pharmacographia, Fluckiger and Hanbury, 2d edition, London. Die Kautchuk Industrie, F. Clouth, Weimar. Die Harze und ihre Producte, G. Thenius, Leipzig. 1880. Die Fabrikation des Wachstuches, R. Esslinger, Leipzig. Kautchuk und Gutta-percha, R. Hoffer, Leipzig. 1883. Die Rohstoife des Pflanzenreiches, J. Wiesner, Leipzig. Die Fabrikation der Lacke, Firnisse, etc., E. Andres, Vienna. Caoutchouc and Gutta-percha. Hoffer, Philadelphia and London. Die Fabrikation der Kaoutchuc und Gutta-percha Waaren, Heinzerling, Braun- schweig. 1884. Handbuch fiir Anstreicher und Lackirer, L. E. Andes, Leipzig. 1885. Die Fabrikation der Siegel- und Flaschenlacke, L. E. Andes, Leipzig. 1886. Oils and Varnishes, James Cameron, London. 1888. Pharmaceutist-he Chemie, Fluckiger, 2te Auf., Berlin. BIBLIOGRAPHY AND STATISTICS. Ill STATISTICS. No attempt will be made to take up the essential oils in detail. The statistics of the entire class will he given, and only such specially important substances, like oil of turpentine and camphor, will be separately considered. Essential Oils. The importations of essential oils as a class into the United States for the last few years have been : 1888. 1889. 1890. Free of duty (Ibs.) 1,418,433 2,065,316 1,437,216 Valued at $1,048,593 $1,036,524 $904,991 Dutiable (Ibs.) 604,525 630,232 682,180 Valued at $138,972 $146,481 $156,640 The exportations of turpentine spirit from the United States during the same years were : 1888. 1889. 1890. Gallons 10,585,942 9,681,759 11,248,920 Valued at $3,580,106 $3,777,525 $4,590,931 The British importations of turpentine during recent years have been : 1885. 1886. 1887. 1888. 1889. 1890. Cwt. . . 308,442 294,914 359,202 359,067 408,074 424,453 Value 387,986 392,259 472,016 517,897 662,681 644,886 The German importations of turpentine during recent years have been : 1885. 1886. 1887. 1888. 1889. Metric centners . . . 98,160 104,810 115,590 107,792 133,110 Valued at (marks) . 4,908,000 5,450,000 6,010,000 6.252,000 6,922,000 . Camphor. The total exportations of camphor from Japan during the last five years have been : 1885. 1886. 1887. 1888. 1889. Kilos. . . . 1,331,424 2,114,596 2,913,922 1,717,837 2,487,458 The quantities imported into the United States for the last three years have been : 1888. 1889. 1890. Pounds 2,779,719 1,961,018 2,055,287 Valued at $304,460 $287,333 $420,331 Resins. The exportation of rosin (colophony resin) from the United States for the last three years has been as follows : 1888. 1889. 1890. Barrels 1,492,314 1,420,218 1,601,379 Valued at $2,273,952 $2,120,422 $2,762,385 The English importations of rosin for 1888, 1889, and 1890 were : for 1888, 1,314,740 cwt., valued at 268,490 ; for 1889, 1,337,844 cwt, valued at 295,451 ; and for 1890, 1,627,446 cwt., valued at 376,841. The value of all gums and gum-resins imported into the United States for the last three years was: 1888, $5,494,712; 1889, $5,277,516 ; 1890, $5,697,280. Of these resins, the most important were shellac, cutch (or catechu), and gambier. The English importations of these resins were also among the most important of this list. They were as follows for the years 1887, 1888, 1889, and 1890: 1887. 1888. 1889. 1890. Lac (seed, shell, stick, and dye) (.cwt.) 114,685 103,364 78,602 91,834 Valued at 299,114 271,946 276,274 389,538 Cutch and gambier (tons) . 27,258 28,135 25,107 27,445 Valued at 658,364 704,731 678,548 717,820 112 INDUSTRY OF THE ESSENTIAL OILS AND RESINS. Gutta-percha and Caoutchouc. The entire world's production of caout- chouc for the year 1865, according to a report of the jury of the Paris Exposition of 1867, was: Brazil, 3773 tons; India, 2250 tons; Central America, 1125 tons, and Africa, 75 tons ; or a total of 7223 tons. The pro- duction had grown in 1882 to the following figures: Para, Brazil, 11,020 tons ; Central America, 3000 tons; Assam, Java, etc., 2000 tons; Mozam- bique, 1000 tons ; Borneo, 600 tons ; Madagascar, 250 tons ; AVest Coast of Africa, 2500 tons; or a total of 20,370 tons, valued at about $35,000,000. (Heinzerling.) The exportation of rubber from Brazil in 1887 amounted to more than fifteen million kilos. The largest came from the province of Para. The production of Brazil during recent years is stated to have been as follows : 1883-84 10,463,000 kilos. 1884-85 11,885,000 kilos. 1885-86 12,835,000 kilos. 1886-87 13,395,000 kilos. 1887-88 15,766,000 kilos. 1888-89 15,500,000 kilos. 1889-90 16,500,000 kilos. The importations and exportations of crude caoutchouc and gutta-percha for the chief countries of the world were, for the years specified, as follows : United States, 1882-83 . . Great Britain, 1883 . . . German Customs Union, 1883 France, 1883 Austria-Hungary, 1882 . . Importations in met. cent. 110,000 148,000 Exportations in met. cent. 8,000 55,000 Net imports. 102,000 m. c. 93,000 m. c. 20,020 1,320 18,700m. c. 23,654 6,232 17,422m. c. 4,000 100 3,900 m. c. (Heinzerling.) The United States importations of crude caoutchouc and gutta-percha in more recent years have been as follows : 1888. 1889. 1890. Pounds 36,639,401 32,418,563 33,842,374 Valued at $16,077,262 $12,387,427 $14,854,512 The English importations of caoutchouc and gutta-percha have been for recent years : 1888. 1889. 1890. Caoutchouc (cwt.) . . . 218,171 236,274 264,009 Valued at 2,529,436 2,612,704 3,265,088 Gutta-percha (cwt.) . . . 22,483 48,042 70,176 Valued at 181,660 576,896 798,296 The exportations of gutta-percha from Singapore in 1879 amounted to 36,400 metric centners; in 1880, 32,500 metric centners; in 1881, 40,400 metric centners, and in 1882 to 42,400 metric centners. The entire amount which comes into commerce now is approximately 45,000 metric centners annually, worth about $3,250,000. (Heinzerling.) BAW MATERIALS. 113 CHAPTER IV. THE CANE-SUGAR INDUSTKY. I. Raw Materials. ALTHOUGH sucrose, or cane-sugar, is present in a great many plants, it is usually accompanied by relatively large quantities of other carbohydrates, such as glucose, starch, etc., so that its extraction on a commercial scale is practically impossible. In order to extract the cane-sugar advantageously, glucose, invert sugar, and other dissolved solids must not be present in amount relatively large as compared with the sucrose. If this ratio of sucrose to total dissolved solids, called the " coefficient of purity," falls below a certain percentage (usually put at sixty-five), the plant-juice can- not be economically worked for the extraction of crystallized cane-sugar. At the present time the sucrose is extracted from four different sources, and on what may be termed a commercial scale from two only. 1. THE SUGAR-CANE. The sugar-cane belongs to the family of grasses, growing, however, to an exceptionally large size. The plant is known as Saccharum officinarum, and the best known varieties are called by such names as Bourbon cane, Otaheite purple cane, ribbon cane, crystalline cane, and Java cane. It has a wide range, succeeding in almost all tropical and sub-tropical countries, and requires a warm, moist climate, developing most luxuriantly on islands and sea-coasts in the tropics. It is the richest in sugar of all the plants cultivated for this purpose. Under ordinary favor- able conditions it yields about ninety per cent, of juice, which contains eighteen to twenty per cent, of cry stall izable cane-sugar. The following analyses of sugar-canes from several sources illustrate its composition : Martinique. (Peligot.) Guadeloupe. (Dupuy.) Mauritius, (leery.) Martinique. (Popp.) MiddleEgypt. (Popp.) Upper Egypt. (Popp.) Water . . Sucrose . . Glucose 72.1 18.0 72.0 17.8 69.0 20.0 72.22 17.80 028 72.15 16.00 2 30 72.13 18.10 025 Cellulose . Salts . . . f 9.9 9.8 0.4 10.0 0.7 to 1.2 9.30 040 9.20 35 9.10 042 100.00 100.00 99.7 to 100.2 100.00 100.00 100.00 The most successful cultivation of the sugar-cane is at present carried on in Cuba and other West Indian islands, although largely produced in almost all tropical countries. 2. S.UGAR-BEET. The sugar-beet is a source of sucrose that, while first mentioned as long ago as 1747, when Marggraf called the attention of the Berlin Academy of Sciences to its importance as a sugar-yielding material, has only in the last few decades advanced to great importance and 114 THE CANE-SUGAR INDUSTRY. taken position as a commercial rival of the sugar-cane in the matter of pro- duction. It has been greatly improved by careful selection and cultivation, and its richness in sugar notably increased. Marggraf could only extract 6.2 per cent, of sugar from the white and 4.5 per cent, from the red beet ; it has now been brought to an average of eleven per cent., and in excep- tional cases has been found to contain sixteen per cent. Some six varieties are now cultivated in Germany, where the beet-sugar industry has reached its highest development : the white Silesian, the Quedlinburg, the Siberian, the French, the Imperial, and the Electoral. (The beet is relatively much more complex in its chemical composition than the sugar-cane, and the ex- pressed juice contains a number of organic impurities not present in the juice of the cane, notably of the class of nitrogenous or albuminoid sub- stances. On the other hand, glucose, or invert sugar, which is frequently present in the cane, is practically absent in the juice of fresh beets.) The detailed composition of the sugar-beet is seen from the accompanying scheme of Scheibler.* At the same time the three accompanying analyses by R. Hofmann gives the composition of three types of beets : those poor in sugar, those of medium richness, and those containing the largest percentage. First type. Second type. Third type. "Water 8920 83.20 75.20 Sugar 4.00 9.42 15.00 Nitrogenous compounds 1.00 1.64 2.20 Non-nitrogenous ? soluble 4.13 3.34 4.23 compounds \ insoluble (cellulose) 1.01 1.50 2.07 Ash 0.66 0.90 1.30 100.00 10000 100.00 3. SORGHUM PLANT. The sorghum plant (Sorghum saccharatum and other species) has been known and valued in China for ages, and small quantities have been cultivated in the United States for the sake of the syrup for a number of years past. It is only of recent years, however, that attention has been drawn to it as a source of crystallized sugar, chiefly by the experiments of the United States Bureau of Agriculture, and its systematic cultivation has been attempted in several parts of the United States. The composition and saccharine strength of the juice seems to be quite variable, and dependent upon conditions of cultivation to a much greater extent than is the case with either the sugar-beet or the sugar-cane. Thus, in 1883 the mean per cent, of sucrose in the sorghum juice, analyzed by the chemists of the department, was 8.65, in 1884 the mean was 14.70 per cent, in 1885 it was 9.23, and in 1886 it was 8.60 per cent. The sorghum plant grows easily over a very wide ra"nge of climate, and if its cultivation can be established definitely upon correct principles, it may prove to be a most valuable addition to the world's sugar-producing materials. 4. THE SUGAR-MAPLE. The sap of Acer saccharinum and other species of the genus Acer is a source of sugar and syrup more esteemed for confectionery and table use than because of its commercial importance. The sugar is never refined, and only comes into use as a raw, small-grained * Bericht iiber Entwick Chem. Ind., von Hofmann, 1877, 3te Heft, p. 187. RAW MATERIALS. 115 t 2 C? O en ^ tt _. . o-O-o o H W n w H K O O >0 o w o 25 A su Etc., Arabic a Dextrine Soluble p Coloring Colorless (Chromo Fats. (beet-gum), Ci 2 H HooO) . tic bodies. atters (chlorophyll ompounds takin same meta lic, and oth ombined cids. BOBS- "?' CT fP CD C" H- a no . g I P B 3 (5 (t - B C 3 O ?" & B- C c = 3 M *" C g, B & S? ^35 B-S B o ^ - -" S 8, B. 5i & c^ 5 ; s g W CO C O > td w w H 50 2. Solid substance of the juice. 116 THE CANE-SUGAR INDUSTRY. sugar of peculiar and characteristic flavor; the syrup is a thin, sweet syrup of the same characteristic maple flavor, differing considerably, too, in its composition from both cane- and beet-sugar syrups. The freshly-collected sap contains from two to four per cent, of sucrose, with traces of glucose. We may now compare the chemical composition of the freshly-expressed juice from the three sources of sugar manufacture above described, and note those differences which are of importance in determining the successful ex- traction and crystallization of the cane-sugar. The composition of the fresh juice of the sugar-cane is illustrated in the following table. The first four analyses are by the United States Bureau of Agriculture and were made in connection with its experimental work, and the last six from experimental cultivation of certain varieties of cane in Cuba on the Soledad estate of Mr. E. Atkins. LOUISIANA. CUBA. 1884. 1885. 1886. 1887. Crystalline cane. Red ribbon cane. Black Java cane. Specific gravity . Total solids . . . Sucrose 1.068 16.54 13.05 0.67 0.19 78.97 15.80 12.11 1.02 0.16 76.64 1066 16.20 13.50 0.61 0.167 83.33 1.066 16.37 13.69 0.77 83.48 11.6 B. 20.9 19.2 0.66 Non- sugar. 1.04 91.8 12.5 B. 22.6 20.5 0.20 Non- sugar. 1.90 907 11 2 B. 20.2 18.5 0.14 Non- sugar. 1.56 91.5 12.1 B. 21.9 20.0 0.31 Non- sugar. 1.69 91.3 12.2 B. 22.0 21.3- Trace. Non- sugar. 0.70 96.8 11.8 B. 21.4 20.6 0.08 Non- sugar. 071 96.3 Glucose Albuminoids . . Coefficient of purity The average composition of the fresh beet juice is shown in the follow- ing analyses, the method of obtaining the juice being also indicated. The first four are from " Stammer's Lehrbuch," and represent each the average of a German beet-sugar factory for the season ; the fifth is from beets culti- vated at Washington, D. C., by the Bureau of Agriculture ; the sixth the average of a week's work at Alvarado, California, in 1888, and the last from a beet grown at Grand Island, Nebraska, and analyzed at the State Agricultural Experiment Station. German. By press- ure. German. By diffu- sion. German. By cen- trifugat- ing. German. By ma- ceration. Washing- ton. By press- ure. Alvarado, Cal.* By diffu- sion. Grand Island, Neb.f H. H. Nichol- son. Total solids (degree Brix.) 16.27 17.20 14.99 18.77 11.78 17.20 23 70 Sucrose 1302 14.63 11.98 14 64 761 1480 21 41 Reducing sugar . . 39 138 Non-sugar .... Coefficient of purity 3.25 80.02 2.57 85.14 3.01 79.92 4.13 77.99 3.78 64.60 2.4 85.5 2.152 90.3 The composition of the sorghum juice of different seasons, as cultivated by the United States Department of Agriculture, is shown in the following table: * Many beets grown near Alvarado in the fall of 1888 polarized twenty per cent., and the average coefficient of purity for the season was estimated to be from eighty-five to eighty-seven per cent. f Individual beets grown in Nebraska have shown a percentage of 22.08 sucrose, and a coefficient of purity of ninety-three per cent. PROCESSES OF TREATMENT. 117 1883 1884 1885. 1886. 18 87. Fort Scott. Rio Grande. Total solids 13.59 19.75 15.07 17.08 16.14 14.02 8.65 14.70 9.23 9.59 9.54 8.98 4.08 1.27 3.04 4.25 3.40 3.24 Non-su'j'ar 0.86 3.78 2.80 3.24 3.20 1.80 Coefficient of purity 63.65 74.43 61.25 56.15 59.11 64.05 Analyses of fresh maple-sap made at Lunenburg, Vermont, by one of the chemists of the Department of Agriculture, in the spring of 1885, shows that it contains an average of 3.50 per cent, of sucrose, traces only of glu- cose, about .01 per cent, of albuminoids, and has a mean coefficient of purity of 95. n. Processes of Treatment. 1. PRODUCTION OF SUGAR FROM THE SUGAR-CANE. As the cultiva- tion of the sugar-cane is chiefly carried on in the tropical countries, parts of which are dependent upon totally unskilled labor, there is very great diversity in the development which the industry has reached. In some countries the work is still done by hand or with the simplest kind of ma- chinery, with corresponding small yield of inferior products, while, in others, as in Louisiana, Demerara, Cuba and other West Indian islands, there are many sugar plantations equipped with the very latest and best of sugar-making machinery, and producing direct from the juice raw sugars that are almost equal to the refined product. In general, however, the sugars produced on the plantation are not in a sufficiently pure condition for consumption and are termed " raw sugars," having therefore to undergo a process of refining, by which the impurities are eliminated and the sucrose obtained in a pure, well-crystallized state. We shall note first the method of producing raw sugar, and afterwards the methods of refining the same at present in use. The canes must be cut when they have arrived at maturity, and must be promptly used to prevent the fermentation of the albuminoid constituents and other non-sugar of the cane, which in turn rapidly change sucrose into invert sugar and lessens the possible yield of crystallizable sugar. At least this immediate use of the cut cane is necessary in Cuba, Demerara, and dis- tinctly tropical countries, where the juices must be expressed within forty- eight hours after the cutting to prevent an excessive inversion taking place. In Louisiana, the experiments of the Department of Agriculture have shown * that sound canes can be kept stored under cover for two or three months without appreciable diminution in the sucrose per cent, or loss in the coefficient of purity. The expression of the juice has been, and in most cases still continues to be, effected by the process of crushing the canes between heavy rolls, which may vary from the crude stone or iron rolls, driven by water or horse-power, to the perfected sugar-mills now in use, in which enormous, hollow, steam-rheated rolls, driven by steam, are used to do the same work. * Bulletin No. 5, p. 57. 118 THE CANE-SUGAR INDUSTRY. Large, slow-moving rolls have been found in practice to yield better results than smaller, rapid-moving rolls. While four, five, and even nine-roll mills have been constructed, the mill in general use is a three-roll mill, an example of which is shown in Fig. 39. The canes pass by the earner, down the slide, through the rolls, and the " bagasse" (exhausted canes) emerging below is carried away for fuel purposes, while the juice as expressed collects in a receptacle and is run to the evaporators. While the analyses of sugar-canes, given on a previous page, show that the cane contains ninety per cent, of juice, the percentage of extraction of juice by this roller-crushing process on the best-managed Cuban estates does not exceed seventy or seventy-one, and generally ranges from sixty to sixty-five, per cent. This imperfect liberation of the cane juice by the crushing process has led to experiments in other directions. One result has been the frequent introduction of a second or supplementary crushing of the cane in a two-roll mill following the use of the three-roll mill before FIG. 39. described. These second rolls are heavier, and the pressure is greater than in the first crushing. The total percentage of juice, and consequently of sugar extracted from the cane, is raised, although the juice from the second and heavier pressure is less rich in sucrose than the first juice, which came from the softer pulp of the cane. Another result has been the invention of machines for effecting a more thorough mechanical disintegration of the cane-tissue. A preliminary shredding by means of a " defibrator" is one of the means which seems to have been of advantage. A cane-shredder, such as was used on the Magnolia plantation, Louisiana, by the Department of Agriculture in its recent experiments, is shown in Fig. 40. The two cylinders, the teeth of which are shown in the cut, revolve in opposite directions and at different rates of speed. The cylinder on the right turns at one hundred and thirty-eight revolutions per minute, and the one on the left at three hundred. The canes falling into the hopper from the carrier are caught by the teeth of the cylinders and crushed and torn into a pulp. PROCESSES OF TREATMENT. 119 From the bottom of the apparatus this pulp falls upon the carrier, which conveys it to the rolls. In this state of pulp a more even distribution of the material is secured, and the working of the mill is thereby made more uniform and effective. With this improvement in the preparation of the canes for the rolls the percentage of extraction is increased. The total crop on the Magnolia plantation for the season 1886-87, where a shredder, a three-roll mill, and a supplementary two-roll mill were used, showed an average extraction of juice amounting to 78.17 per cent., a very material improvement upon ordinary results. It has also been sought to increase the yield of saccharine juice by sub- mitting the cane to the action of hot water or steam at an intermediate stage FIG. 40. between the two crushings. It is stated that a "maceration" process of this kind, known as Duchassing's, has been in quite successful use in Gua- deloupe, raising the yield of sugar from 9.40 per cent, on the cane to 11.04 per cent. All the processes hitherto described for extracting the juice from the cane have depended for success upon the rupture of the juice-containing cells. " Diffusion," which has been so successful in the extraction of the juice of the sugar-beet, differs from them essentially in dispensing with the breaking up of the cells, and in substituting therefor a displacement by osmosis or diffusion of the saccharine juice by pure water. As a descrip- tion of this method follows when speaking later of the treatment of the 120 THE CANE-SUGAR INDUSTRY. sugar-beet, we will at this stage speak only of the advantages and disad- vantages of its application to the sugar-cane work. It has not met at all with general favor from sugar-cane planters. Difficulties were met with in cutting the chips needed for the diffusion-cells. The sugar-cane differs so radically in its structure from the sugar-beet that totally different forms of slicing apparatus had to be used. The cane-chips tended to pack in the cells, and so impeded the circulation of the warm water. When this took place, fermentation and inversion of the sucrose rapidly followed. The cane-chips, after exhaustion, do not make as good a fuel as the bagasse of the cane-mill. The first of these difficulties has been overcome both in the use of diffusion apparatus in Guadeloupe and by the United States Department of Agricul- ture in its experiments on diffusion, as applied to the sugar-cane made at Fort Scott, Kansas, in 1886. The second difficulty has in part been over- come by using hotter diffusion water (at 90 C.), and working more rapidly with a sufficient pressure. But it is more effectually prevented by the use, in the diffusion-cells, of either carbonate of lime, as proposed and patented by Professor M. Swenson, or of dry-slacked lime, as proposed by Professor H. W. Wiley, the chemist of the Department of Agriculture. Of these, the latter seems to meet with more general approval of those who have tried diffusion with either the sugar-cane or the sorghum-cane. In answer to the third difficulty, it is remarked that the bagasse burns better largely be- cause of the notable quantity of sugar left in it, and that when the diffusion- chips are dried they will burn fairly. They can also be used to great ad- vantage for paper stock and for manure, as they still contain most of the nitrogenous constituents of the cane. On the other hand, if successfully carried out, it undoubtedly effects a more complete extraction of the sugar than any other process. At Monrepos, Guadeloupe, with Bouscaren's ap- paratus, consisting of six diffusors, juice having a density nearly equal to that of the natural juice is obtained, one and a half hours being sufficient for extracting the sugar. The yield of white sugar amounts to twelve and a half to thirteen per cent, of the weight of the cane.* At Fort Scott, Kansas, the chemists of the Department of Agriculture, f in their experiments with diffusion as applied to sugar-canes, succeeded in obtaining a yield the highest ever got from sugar-cane. The mean loss of sugar in the chips at Fort Scott was .38 per cent., and the quantity of sugar present was 9.56. The percentage of extraction was, therefore, ninety-six per cent., or, reckoned on the weight of cane, 86.4 per cent, of a possible ninety, which, if compared with the best figures obtained in mill-crushing, shows a decided advantage for diffusion. The treatment of the expressed juice is next to be noted. This has also undergone considerable improvement in recent years, although on small isolated sugar plantations the primitive and wasteful methods of the "cop- per-wall," or open-pan, boiling are still in use. The general outlines of the treatment of the juice which is followed in the main, if not always in detail, is given in the accompanying scheme. The juice of the sugar-cane must be properly "defecated," or treated with milk of lime, in order to neutralize the organic acids of the juice, and so prevent their starting a fermentation and consequent inversion of the sucrose when the juice is heated. This has the effect, as soon as the juice is heated, of bringing to the surface a thick scum of lime salts, holding * Spon's Encyclopedia, p. 1881. f Bulletin No. 14, p. 63. PROCESSES OF TREATMENT. 121 "S 8 "5 C c- O o 2 <~t ' y~r rS2. O ^ g| X3 M i! r i ^ O3 $ i? !_, o 1 ||- oo M "' _i -p"B e O o ' ij II j 1 " '* r 3- eg- K M O *< - ~ 3 o p o* " j _ * cr^-- oo 03 O, o c C3 M . 2, B o, 5- JO ? - a S" O ~o3~] O ffi O O C BK- M Illo fit E 115 |!| : 1 iflH l|l- 1 ^ ! CANES cut and transported to the m DUCTION OF SUGA IP gg&a | 5 ' 5.1 ^SS g^ & asiS 1 2 = "* ^5-g 'Sg i SS5- ilslj r ^ |s_ Ills i Ls 1 ^ || s- .9 SsiS ? Pi g . |li| 3 =o-g g- >?? p & n 1 & > co-3'2? *g = p i. ^"Ig 1 - ^1 1 B.I 3 * ^ ** P 5' -p^s, ?">; P- 5 50 / * l^ B ^ p | ^3 o, o ^5 g- r^ ?o l5^ > ? a ^^i O >_j I ii K G ^ S w Isi 'Is CO ^^i PS: C 1 ^> i - H s >^ a * JO 1 o -j W 00 J> C!D ^ * 1 1 o. CD 2 w .'" i" i & f- ? & M ^ D* 122 THE CANE-SUGAR INDUSTRY. mechanically entangled much of the albuminoids and suspended particles of fibre of the juice. This is known as the " blanket-scum." This is removed by skimming, and the boiling continued, when additional greenish scum forms, which is similarly removed. When the scum ceases to form, the steam is shut off and the sediment allowed to settle, and the clarified juice gradually drawn off. The amount of lime to be added in the case of cane juice is usually .2 to .3 per cent., or about four ounces of quicklime to the gallon of juice, but is always carefully controlled, so that the acids of the juice are not entirely neutralized and a faint acid reaction still remains. Should the lime be in excess, the glucose almost always present in the cane juice is rapidly acted upon and decomposed, yielding dark-colored products. An excess of lime is always corrected before further treatment by the addi- tion of sulphurous, sulphuric, or phosphoric acids. In the older process of open-pan boiling, this defecating and clarifying takes place in the first of five connected kettles or pans, walled in and heated by the same fire, and known technically as the " copper-wall." From this first pan the juice, after the removal of the blanket-scum, goes to the second, in which it receives more heat. After it is thoroughly clarified and both scum and sediment removed, the juice goes to the third and fourth pans successively, in which it is concentrated to 30 B., and then goes to the fifth, or " strike-pan," to be brought to the crystallizing point. It may still require some treatment here, as it first becomes thick. If " sticky" or sour, some buckets of lime- water are let in, or if too dark-colored, dilute sulphuric acid is added to clear it. When the " masse-cuite," or thick mass, full of separating crys- tals, has been sufficiently heated, it is " struck out" into large, shallow, crys- tallizing vessels and allowed to cool, and so complete the crystallization. The older open-pan sugars are generally " cured," or freed from syrup, simply by draining in vessels with perforated bottoms, or, in a limited number of cases, by the process of "claying," or covering the sugar in cones with a batter of clay and water, through which water percolates, slowly displacing the darker syrup. The first method gives the common " muscovado" sugar, a moist, brown sugar, which goes from the West Indies to the United States and Europe for refining ; the second method gives a lighter-colored but soft-grained sugar, which similarly must be refined for use. This older and cruder method has given place most generally now to improved methods, whereby the yield is notably increased and grades of raw sugars are produced that are much purer and finer in appearance. The chief improvements consist in the use of vacuum-pans for concentration of the juice and centrifugals for curing the crystallized sugar. At the same time other minor improvements contribute no little to the better results. The juice, unless it has been gotten by diffusion, is generally run through a strainer into the clarifier. In addition to very careful and exact measuring of the amount of " temper-lime" needed, sulphurous acid or sulphites are often used now to bleach the juice. In case sulphurous acid is used, more lime is needed for tempering. The thin clarified juice is then filtered through bone-black filters before it goes to the vacuum-pan. This filtra- tion removes the vegetable coloring matters as well as the finely suspended impurities that remain. The use of powdered lignite as a means of clarifying and improving the raw-sugar juices, first introduced by Kleeman, has been tried in recent years, and, it is claimed, with success and profit. It is added after the juice has been limed and defecated, and the juice, together with the accumulated PROCESSES OF TREATMENT. 123 skimmings and bottoms and the lignite, are thoroughly mixed and then im- mediately filter-pressed. A clear, bright juice is thus obtained, which needs no sulphuring or bone-black filtration, but can be at once concentrated, and FIG. 41. the press-cakes, after washing, make excellent fertilizer material. Lignite filtration has also been tried in the clarifying of molasses, but with little success as far as cane-sugar molasses is concerned. UNIVERSITY 124 THE CANE SUGAR INDUSTRY. The most important improvement in the preparing of a better-grade sugar, however, consists in the use of the vacuum-pan, by means of which the concentration can be effected with the least heating, and hence least discoloring of the sugar-containing juice. The vacuum-pan, invented in 1813 in England by Howard, allows of the concentration, or "boiling to grain," being effected at temperatures varying from 130 to 170 or 180 F., instead of the 240 or 250 F. reached in the open-pan. They are of vary- ing forms, but consist essentially of a spherical, cylindrical, or dome-shaped copper or iron vessel, such as is shown in Fig. 41. The contents of this vessel are heated by the steam-coils shown in the cut, and the vacuum is maintained by the connection with an injector air-pump, as shown. The vacuum-pan is connected first with an overflow vessel, or " save-all," to FIG. 42. collect saccharine juice thrown over, and thence with the exhaust-pump. Through suitable openings in the side of the pan the interior can be illu- minated and the operations watched ; samples can be withdrawn by the aid of the " proof-stick" for examination, and fresh juice can be admitted when the grain is to be built up. In concentrating the raw juice, considerable use is made of what are called " triple effect" vacuum-pans, a series of three connected pans, in the first of which the thin juice boils under a slightly-reduced pressure and, of course, at a slightly lower temperature than in the air ; the vapor from the boiling juice here passes into the steam-drum of the second pan, and readily boils the liquor here, which, though denser, is under a greater vacuum, and similarly the vapor from this liquor boils the most concen- PROCESSES OF TREATMENT. 125 FIG. 43. trated juice in the third pan, in which, by the aid of the condensing-pump, a very perfect vacuum is maintained. Thus large quantities of juice are evaporated with great economy of fuel. " Double effects" are also used in the same way. These triple effects have been much improved in the last few years by the modifications introduced by Yaryan and Lillie, both of whom adopt the plan of sending the sugar juice to be concentrated through the series of coils while the steam circulates around these tubes. A general view of a Yaryan quadruple effect is given in Fig. 42, in which the com- pact arrangement of the evaporators is well shown, while the action of the Yaryan apparatus will be understood from Fig. 43, giving a simplified section through one of the pans and " catch-alls." The heating-tubes, sur- rounded by steam, are divided into units or sections, consisting of five tubes coupled at the ends so as to form one passage. Of such sections there may be any number. The liquor enters the first tube of the coil in a small but continuous stream, and immediately begins to boil violently. It is thus formed into a mass of foam, which contains, as it rushes along the heated tubes, a constantly- increasing portion of steam. The mixture is thus propelled forward at a high velocity, and finally escapes into an end chamber known as a " sep- arator," which is provided with baffle-plates. The " masse-cuite" having been brought to sufficient thickness, the whole or a part of the contents of the pan are " struck off." If half the contents of the pan are discharged and fresh syrup then admitted to be concentrated, the crystals obtained at first grow by the deposit from the new portion of syrup. This process of admitting successive portions of fresh syrup after the " grain" has once formed is used in the development of large crystals. It must be used with judgment though, or the new syrup starts a new set of minute crystals, making what is called " false grain." The large yellow Demerara crystals are given the light yellow bloom by admitting sulphuric acid in small amount after the grain is complete and just before the " strike." It destroys the gray-green color of the raw-sugar crystals and gives instead a pale straw color. After the " masse-cuite" has left the pan, the crystallization, except in the case of the large crystals, is completed by cooling, and the sugar must then be " cured." This is now generally effected in centrifugals or rotary perforated drums. A form in common use for sugar-work is shown in Fig. 44. Over each centrifugal is a discharge-pipe from the coolers ; the brown or yellow magma is let in, the inner drum is started revolving, and the mass heaping against the perforated sides becomes rapidly lighter in color as well as more compact ; the syrup flies off, and from the space between the inner and outer drums runs off below into the proper receptacle. The centrifugal is emptied through the bottom of the drums by raising the cen- tral spmdle and with it the detachable plates around it, so that a circular opening is made in the middle of the apparatus. A serious loss of sugar in the usual method of working is in the scums, 126 THE CANE-SUGAR INDUSTRY. FIG. 44. which are frequently thrown away. Professor Wiley, the chemist of the Department of Agriculture, has shown * that in working a crop of 9063 tons of cane the loss of sugar in the scums, if thrown away, would have amounted to 120,316 pounds, of which 94,- 545 pounds would have gone in the blanket-scums, and 25,771 pounds in the subsequent scums. To save this sugar, the scums are steamed and then pressed and washed in a filter- press (see p. 137), whereby, practically, the whole of the sugar can be recovered. The scums are generally filter-pressed now in the best Cuban and Louisiana sugar- houses, although a cruder method of pressing them in bags is used on some plan- tations. The applica- tion to cane juice of the method so gener- ally followed in the case of beet-sugar of adding an excess of lime, which, after the the first boiling up, is removed by the pro- cess of carbonatation or saturating with car- bonic acid gas, has generally been consid- ered to be impossible, because, as was stated before, an excess of lime acts injuriously upon any glucose present and darkens the juice. But if the juice is from sound canes in which the glucose percentage is not large, the advantages of the carbonatation process may exceed the injurious effects. This seems to have been shown by the experiments of the Department of Agriculture at Fort Scott, Kansas, in the fall of 1886.f The yield of sugar in the ex- periments in which both diffusion and carbonatation were followed was, as mentioned before, larger than had ever been gotten from sugar-canes. * Bulletin of Department of Agriculture, No. 5, p. 59. f Ibid., No. 14, pp. 52 and 63. PROCESSES OF TREATMENT. 127 Professor Wiley suras up the advantages of the process as follows : " The process of carbonatation tends to increase the yield of sugar in three ways : (1) It diminishes the amount of glucose. This diminution is small when the cold carbonatation, as practised at Fort Scott, is used ; yet to at least one and a half its extent it increases the yield of crystallized sugar. (2) By the careful use of the process of carbonatation there is scarcely any loss of sugar. The only place where there can be any loss at all is in the press- cakes, and when the desucration of these is properly attended to the total loss is trifling. The wasteful process of skimming is entirely abolished, and the increased yield is due to no mean extent to this truly economical proceeding. (3) In addition to the two causes of increase already noted and which are not sufficient to produce the large rendement obtained, must be mentioned a third, the action of the excess of lime and its precipitation by carbonic acid on the substances in the juice which are truly melassigenic. Fully half of the total increase which the experiments have demonstrated is due to this cause. It is true, the coefficient of purity of the juice does not seem to be much affected by the process, but it is evidence that the treatment to which the juice is subjected increases in a marked degree the ability of the sugar to crystallize. This fact is most abundantly illustrated by the results obtained. Not only this, but it is also evident that the proportion of first sugars to all others is largely increased by this method. This is a fact which may prove of considerable economic importance." It only remains to notice in connection with raw sugars two forms of apparatus for concentrating raw-sugar juice which have had considerable use FIG. 45. in the tropics. The first of these is the " Wetzel pan," an apparatus shown in Fig. 45. As seen, it consists of a pan containing the liquor, in which dip pipes heated by steam passing through them ; while the cylinder, formed by these pipes, is caused to revolve by power applied from the end as shown in the cut. The large heating surface enables steam at very low pressure to be used, exhaust steam from the cane-mill engine being sometimes used for the purpose. Such pans are used on some plantations, in the absence of a vacuum-pan, to finish the concentration begun in the battery or copper- wall. The liquor is brought to them at a density of 26 to 27 B. The other form of apparatus referred to is the " Fryer Concretor," in which no 128 THE CANE-SUGAR INDUSTRY. attempt is made to produce a crystalline article, but only to evaporate the liquor to such a point that when cold it will assume a solid (concrete) state. The mass is removed as fast as formed, and being plastic while warm it can be cast into blocks of any convenient shape and size, hardening as it cools. In this state it can be shipped in bags or matting, suffering neither deli- quescence nor drainage. The " concretor" consists of a series of shallow trays placed end to end and divided transversely by ribs running almost from side to side. At one end of these trays is a furnace, the flue of which runs beneath them, and at the other end a boiler and an air-heater, which utilize the waste heat from the flue, employing it both to generate steam and to heat air for the revolving cylinder. The clarified juice flows first upon the tray nearest the furnace, and then flows down the incline towards the air-heater, meandering from side to side. While flowing thus it is kept .rapidly boiling by means of the heat from the furnace, and its density is raised from about 10 B. to 30 B. From the trays it goes into a hollow revolving cylinder full of scroll-shaped iron plates, over both sides of which the thickened syrup flows as the cylinder revolves, and thus exposes a very large surface to the action of hot air which is drawn through by a pan. In this cylinder the syrup remains for about twenty minutes and then flows from it at a temperature of about 91 to 94 C., and of such consistency that it sets quite hard on cooling. Raw sugars are often gotten now of sufficient purity to allow of their immediate use without further treatment. Such is not the usual rule, how- ever, but they have to undergo a purifying or refining in order to bring them to the requisite purity for consumption. The sugar-refining process is simpler in its theory than the process of preparing the raw sugars, but requires more exactitude in its execution, and more elaborate and costly ma- chinery and equipment. The problem as stated is a much simpler one than was that of handling the raw cane juice ; it is now simply a redissolving of the impure crystalline mass of raw sugar, freeing the solution from impuri- ties, and then crystallizing afresh the pure sugar from it. The sugar refinery located in a large commercial centre is almost always a building of consid- erable height, so as to allow of the descent by gravity of the sugar solutions from floor to floor as the process of treatment proceeds. The general out- line of the treatment will be easily followed with the aid of the diagram in Fig. 46. The raw sugars as they arrive are discharged from hogsheads or bags in the mixing room on the ground floor through wide gratings into the melting tanks, or " blow-ups," just below, where boiling water and steam rapidly dissolve all that is soluble in the sugars. These tanks hold from three thousand to four thousand five hundred gallons, and treat from nine to thirteen tons of sugar at a time. The hogsheads and bags are similarly cleaned out by live steam. The crude-sugar solution, run through a coarse wire strainer to remove mechanically-mixed impurities, is then pumped to the defecating tanks at the top of the building. The defecating is not done, as was the case with raw juice, with lime, but with some form of albumen, as bullock's blood, which, coagulating by the heat, encloses and carries with it much of the fine suspended impurities. Fine bone-black is also some- times added along with the blood. The contents of these defecating tanks are boiled up and agitated thoroughly for from twenty minutes to half an hour, when the clear liquor is run off in the troughs leading to the bag- filters. These are of coarse, thick cotton twill, four or five feet long, and but a few inches through. These filters collect the fine suspended slime PROCESSES OF TREATMENT. 129 FIG. 46. 130 THE CANE-SUGAR INDUSTRY. which would not settle in the defecating tanks. It has been found impossi- ble to replace them by filter-presses in the working of the raw cane sugars at present in the market, on account of the slimy character of the separated matter. The liquor, now containing soluble impurities only, has a brown color. It goes from the storage-tanks below the bag-filters to the bone- black-filters. These filters, immense iron tanks, twenty feet high and eight feet in diameter, open through man-holes at the top to the filter-room floor. They have false bottoms, perforated, over which a blanket is fitted to pre- vent the bone-black from flowing through with the liquid. The largest filters hold thirty to forty tons of the bone-black. When they are filled with bone-black the man-hole is closed, and the syrup from the cisterns below the bag-filters is turned on. It percolates slowly down, is allowed some time to settle, and after about seven hours the drawing off begins through a narrow discharge-pipe. The filtered syrup is caught in different tanks as it becomes deeper in color, and the colorless syrup first obtained used for the finest sugars, and so on. When the charge has run out, the sugar remaining in the charcoal is washed out by running through fresh or " sweet" water, and the bone-black must be reburned before it can again be used. From three-quarters to one and a quarter tons of black are needed per ton of sugar decolorized, according to the quality of the raw sugars. The liquor is now ready to be concentrated in the vacuum-pan and brought to the crystallizing point. This vacuum-pan boiling has already been de- scribed under raw sugars. The processes of boiling are somewhat different for " mould" and for " soft" sugars. The best grades of syrup boiled to an even, good-sized grain are used for the former, whether loaf, cut, crushed, or pulverized. As the " masse-cuite" cools it is run into conical moulds with a small aperture at the bottom, or smaller end, through which the un- crystallized liquid may drain off. After this has been allowed to drain, water or white syrup is poured in at the top, which washes the crystals as it slowly filters through. After a sufficient time allowed for drainage, the moulds are turned over, so that the small quantity of syrup in the point of the cone shall distribute itself through the mass. The result is the hard white " sugar-loaf/' or conical form of sugar. The process of draining in moulds is, however, very generally replaced by the use of large centrifugals, in which several cones can be dried at a time in a few minutes, saving enor- mously in time and in the room previously occupied by the large number of moulds needed for several days' working. Such a hydro-extractor for cones is shown in Fig. 47. The " soft" sugars, the crystallization of which is completed in the cooler after the " masse-cuite" leaves the vacuum-pan, are cured mostly by centrifugals, and are ready for barrelling on leaving them. 2. PRODUCTION OF SUGAR FROM THE SUGAR-BEET. In considering the question of the production of sugar from the sugar-beet, two things must be noticed : first, the soft, pulpy character of the beet, which allows of much more complete extraction of the juice, and, second, the more complex composition of the juice, which necessitates more elaborate methods of puri- fication of the juice. The cultivation and working of the sugar-beet has been developed to so much greater an extent in Germany than any other country that we shall, in describing the extraction of sugar from the beet, notice German methods chiefly. The beets are first washed, brushed and deprived of the tops, and then made to yield their juice by one of four methods : (1) by pulping them and pressing the pulp either in hydraulic presses or between rolls ; (2) by PROCESSES OF TREATMENT. 131 centrifugating the pulp ; (3) by the maceration process, in which the pulp is exhausted with either warm or cold water, and the residue pressed ; and (4) by the diffusion process, in which the beets are not pulped at all, but are cut into thin transverse sections, known in Germany as " schnitzel," in France as " cosettes," and in English as " chips." These are then put into a series of vessels, in which a current of warm water is made to displace the sugar juice by the principle of " osmosis," or diffusion, as it is more generally called. The first three processes are now almost entirely displaced in Germany by the diffusion process. It is stated that in the season of 1881-82, of the three hundred and forty-three German sugar-houses, all FIG. 47. but nineteen used the diffusion process; of these nineteen, sixteen used the press method, two the maceration method, and one the centrifugation method. In the season of 188485 the number not using the diffusion method had fallen to six. In France the diffusion method has not become so generally popular. As, however, it yields a purer juice and a higher per- centage of the same than the older methods, and is, as just stated, the one that is displacing the others, we shall confine ourselves to this. In, the diffusion method of Robert, the fresh beets are cut into slices or " chips" of about one millimetre thickness, which are digested with pure water at 50 to 60 C. This allows the saccharine beet juice to pass through the cell-walls and mix with the water and the water to replace it THE CANE-SUGAR INDUSTRY. in the cells, while the colloid non-sugar remains behind. The vessels used for this diffusion are mostly upright iron cylinders, as shown in Fig. 48, which are provided with a man-hole above for charging them with the chips. A series of these diffusors connected together is known as a battery. They are brought to the proper temperature either by a small steam-coil on the bottom of the vessel or by so-called " calorisators," or juice-warmers, de- tached upright heating vessels inserted between every two diffusors. A FIG. 48. diffusion-battery of ten cells, with juice-warmers, .is shown in plan in Fig. 49. From the bottom of each cell, I to X, goes a delivery-tube, 5, to the bottom of the juice-warmer, where it divides into seven tubes. From the top of each juice- warmer a tube, a, bent at right angles, connects with the next cell. The connection of the opposite cells, V and VI, as well as the cells X and / at the other end, is effected, as shown in the ground-plan, by longer tubes making these bends at right angles. By suitable valves in the supply- and delivery-tubes each cell can be shut off from the others* The upper man-holes of the cells are all reached from the platform e, which runs along just above them ; the valves 1, 2, 3 are reached from the platform /, which runs along lower down, supported on cross-pieces, as shown in Fig. 48 ; and the third platform, g, gives access to the lower valves. A sunken canal, A, in this lowest platform allows of the exhausted chips being dis- charged from the lower man-holes on to an endless band, which passes PROCESSES OF TEEATMENT. 133 around two wheels and delivers them into ascending buckets, whence they go to the chip-press, which dries them. The filling of the cells is effected FIG. 49. by means of a swinging trough, not shown in the cut, connecting with a chip-cutter placed on a higher level. 134 THE CANE-SUGAR INDUSTRY. In operating the battery, water at 66 C. is run into the first cell, which has been previously filled with fresh chips. For every cubic metre of space four hundred and fifty kilos, of chips and five hundred kilos, of water are to be reckoned. The cell remains quiet for twenty minutes, during which time the temperature falls to 45 C. The connection with the neighboring juice-warmer is now opened, and the thin juice made to pass into this by forcing fresh cold water into the first diffusion-cell. The juice, brought in the warmer to 66 C., is then passed into the second cell, which has been filled with chips. After twenty minutes the juice in No. 2 is passed into the adjoining juice-warmer, while the cell fills up with the juice from No. 1, and this in turn with fresh water. No. 3, which had been filled meantime with chips, is now brought into the connection. After the juice has been kept in contact, at 66 C., with the contents of each of the three cells in turn for twenty minutes, it is sufficiently concentrated to go to the defecating pan. This juice is therefore sent to be purified, while No. 3 fills up with the thin juice from No. 2. In twenty minutes this is displaced, and, after being warmed to 66 C., goes to No. 4, a freshly-filled cell. After suitable action here it goes direct to the defecating pan, as it is the second diifusate of three cells and the first of a fourth. From this time on, as a new cell comes into operation the juice from one cell goes to the defecating pan until the ninth is in connection, when the first cell is disconnected and emptied of the exhausted chips and then filled with fresh. While this is going on the tenth cell has been connected ; and then the second is to be emptied, while the first cell is brought into connection with the tenth. Thus nine cells are always working together in the battery, while the tenth is disconnected for emptying and filling. The diffusion-cells are sometimes arranged in a semicircle or a circle instead of a straight line, as this arrangement is thought to be more con- venient when the cells are to be filled and emptied. Such a circular diffusion- battery is shown in Fig. 50, and the method of filling the cells with the chips or slices is shown, as well as the endless belt carrying up the buckets of exhausted chips to be emptied. A continuous diffusor, consisting of one long cell, in which the chips and \vater move in opposite directions, so that as the juice becomes more concentrated it shall meet chips richer and richer in sugar, has also been devised. As stated, the percentage of extraction by these methods is higher and the juice is purer than by any other method, while the dried chips also serve as most valuable fertilizer material or for cattle food. Their average com- position is : ash, 5.67 ; fat, .49 ; crude fibre, 23.36 ; crude protein, 8.70 ; and non-nitrogenous extractives, 61.78. A modification of this diffusion process by Bergreen, already found advantageous in practice, is to exhaust the cells of air after filling them with fresh beet-chips, and then to alloAv expanded steam to enter, so as to coagulate the albuminoids. The usual procedure then follows. The exhausted chips gotten this way make a good cattle food, as they are richer in nitrogenous matter. The beet juice, by whichever of the four methods before mentioned it may be gotten, is now to be purified. The general outlines of the method of working up the juice is shown on the accompanying diagram, based on that of Post,* but modified to accord with recent improvements. Except in the case of the diffusion juice of Bergreen's process mentioned above, the crude juice is heated by * Post, Chemische Technologic, ii. p. 274. PROCESSES OF TREATMENT. FIG. 50. 135 136 THE CANE-SUGAR INDUSTRY. H 3 aTi^ K a q iifi S GO K S o^o o'' D S _Q r o K Q *O ca o *- a> 55 g c -< 3 3 < ^ 8 ^ rf rl|~ 5 & 00 -.2 ej a o5 |j 5 I l 2 ^ fj JiS 3 ^ , p O M fe^< <* a-~- W S P- "O fc 11 -aS- -3- 5 u'-o B* M o a O " -a s o pn o ^ 9 & e gS ' oS 8 2 ^ rrt o* ^ 3 ^ 1 ^ HH 37 ^330 3 M^ ,3 ft 5 '3 o LJ| ^3 A -9 53 ^^ g5 ^jjj* ^j ^-'^5 Q j-j r O 5^ai *TJ O "rt O^OQ SaT^ "'Ihfir 1 o^ 1 O *0 e c ill B g| 5 Ml ^ f^ fl'3 A c6 .^ J3 r/i 1 . si 9 fl a S-CSrrtS^'^^^ 0) w DC d5 2 ai as c 2^ J I ! W &,T-( /- O S'O rl P O H^ o | ill S g| J a j5S S H H . isJi c 5 a M f% 3 *O ^ *O ^ o3 a? ^1 a> i *-a.^, w g;5 os 3^ 1^ B C '^ 'C tF- ^ A ^S H 2 ** W UEIFI rd "III f 1 Jfesj s' d i w l t Pi 1 S'. T2 "S fQ ^..2 a> ^ tc ^ M [ > d 5 si S ~ v O " -*- < * :! S S ' -^2 "8 B o i ' rt o "5 o M O 1 i gi;i i> i i J 1 o o 'I > M 1^" W 5 ^| _ 2* fi fli ** 3 M PQ 5 oJ bo s- bl 18 M ^ S H T3 " c "fl 01 * ^ M tj^. ft3 *3'rt * ^ rf Q^ 2 2 B "C ft K A 31? H S J .0 to s~ So 3 S<2 F ^ o. as o " ^^ r/f H 9yZj O X PH 2 aS S o 5 pLl ! feS PL,_ Q O So 1 Li pq PROCESSES OF TREATMENT. 137 indirect steam to 80 C. to coagulate the albuminoids, and then two to three or even four per cent, of caustic lime, in the form of milk of lime, is added. This lime saturates the free acids and throws out nitrogenous com- pounds as in the case of cane juice, and, because of its excess, forms soluble calcium saccharates with some of the sugar. Carbonic acid gas is then added until the precipitated carbonate of lime becomes granular and settles readily. At this time there still remains a slight excess of free lime, about .1 to .2 per cent. The contents of the saturation-pan are now pumped into the filter-presses and the press-cakes washed free from sugar by steam. A filter- press, such as is adapted for sugar-scums and carbonatation press-cakes, is shown in Fig. 51 . This treatment is called the first carbonatation. The juice may be filtered now at once through bone-black, which will withdraw the remaining lime as well as decolorize it, but in most German sugar-houses it is subjected, boiling hot, to a second treatment with one-half per cent, of lime, and then completely neutralized with carbonic acid. This is called the second carbonatation, or the saturation. After again going through the filter- press the juice goes to the bone-black-filters. In many of the newer German sugar-houses the filtration of the thin juice through bone-black is no longer FIG. 51. practised, as repeated saturations with lime and carbonic acid or treatment with sulphurous acid and sulphites have so clarified it as to make bone-black unnecessary. It is stated that at Watsonville, California, in the beet-sugar factory of Spreckels, bone-black filtration is thus dispensed with. The thin filtered juice is concentrated in double or triple effect vacuum-pans to 24 or 25 B., and then filtered again as thick juice through bone-black. This second filtration takes the last traces of nitrogenous materials out, and the remnant of lime which remained in solution. It is then concentrated in the vacuum-pan to crystallization. In the preparation of raw sugar, the " masse-cuite" is dropped from the vacuum-pan into small coolers of about two hundred kilos, capacity, in which it becomes cold and crystallization is completed. The contents of these coolers are then mixed and broken up and rubbed to a paste with the aid of some syrup, and the whole centrifugated. The sugar so obtained is the raw beet-sugar of commerce. The syrup obtained is concentrated in a vacuum-pan, and the sugar from this forms the second product, which some- times goes into commerce and sometimes is returned to the thick juice to be worked up with it. 138 THE CANESUGAR INDUSTRY. As was stated before, raw cane-sugar can be obtained by care and with the best vacuum-pan practice so nearly pure as to be directly available for use without any special refining. In the case of raw beet-sugar this is much more difficult. The raw beet-sugar, though it may be well crystal- lized, usually contains substances of decidedly unpleasant odor and taste, chiefly decomposition products of the betaine of the juice (see composi- tion of the beet, p. 115), which are in the syrup adhering to the crystals. The production of a well-crystallized sugar for consumption direct from the beet juice requires, therefore, a thorough cleansing of the crystals in the centrifugating process. This is accomplished by the purging of the crystals with a clear white syrup, which displaces the impurer syrup adhering, or very generally by the use of steam of low tension either admitted into the inner drum of the centrifugal or to the space between the revolving drum and the mantel. In this last case the steam does not so much cleanse the crystals as it warms the mass and liquefies thoroughly the syrup in the spaces between the crystals. The production for direct consumption of a commoner sugar, known in Germany as " melis," or lump-sugar, is an im- portant branch of the raw sugar-working. In this case the contents of the vacuum-pan brought to grain, but without the special building of crystals, are discharged into shallow vessels with false bottoms, which may be called " warmers," in which the " masse-cuite" is heated up from 60 to 90 C., which has the effect of redissolving most of the small crystals. The warmed syrup is now filled into the moulds, in which it crystallizes uni- formly to a compact whole. This grade of sugar would have as so pro- duced a light yellow color, which is usually corrected by the addition of ultra-marine blue. Of course, raw beet-sugar can be most advantageously purified by a complete refining process, analogous to that described under cane-sugar, in which they are redissolved, clarified, decolorized, and again crystallized. The procedure is so similar to that described under the refining of cane- sugar that it need not be specially noticed here. 3. THE WORKING UP OF THE MOLASSES. It is stated in the tabular view of the working of cane-sugar on p. 121, that the molasses is used for syrup or worked over into molasses sugars. We should distinguish, however, between the several grades of molasses. In working up the raw sugar reference was made to first, second, and third sugars. Corresponding to each of these three grades, of course, is a different molasses, sometimes known as first, second, and third molasses, and sometimes as second, third, and fourth molasses. The average percentage of sucrose and of reducing sugars in these is shown from the analyses of the United States Department of Agriculture * made at Magnolia, Louisiana, in 1884. First molasses . . Sucrose, 37.97 per cent. Eeducing sugar, 8.13 per cent. Second molasses . Sucrose, 41.23 per cent. Reducing sugar, 18.82 per cent. Third molasses . . Sucrose, 21.87 per cent. Reducing sugar, 21.06 per cent. The percentage of solid non-sugar in the first and second of these rnolasses will nearly, if not quite, equal that of the sucrose, while in the third it considerably exceeds it. The " first molasses" is sufficiently pure to be mixed with syrup sugar in the pan for the production of a second product sugar; the "second * Bulletin No. 5, p. 52. PROCESSES OF TREATMENT. 139 molasses" can be refined as such for brown or grocery sugars, and the " third molasses" is so sticky and impure that it can only be sent to the rum-distillery, where it is fermented for rum. (See p. 210.) With respect to beet-root molasses the case is different. It is very impure from mineral salts and nitrogenous materials, but is nearly pure from the invert or reducing sugar so abundant in cane-sugar molasses, and in recent years it has been found possible to work it specifically for the extraction of the sucrose, of which over ninety per cent, is now extracted, thus reducing the loss of sugar to a minimum. The average composition of beet-sugar molasses is given at fifty per cent, of sucrose, thirty per cent, of non-sugar, and twenty per cent, of water. Of these thirty non-sugar, ten are made up of inorganic salts, chiefly potash compounds, and twenty of organic non-sugar (see composition of the sugar-beet, p. 115). As the amount of beet-sugar molasses produced in Continental Europe annually is estimated at 250,000 tons, the fifty per cent, of sucrose represents 125,000 tons of sugar which it was certainly desirable to extract if possible. The processes for accomplishing this depend upon either one or the other of two principles: either to withdraw from the molasses the potash and other mineral salts which prevent the crystallization of the sucrose, or to pre- cipitate out the sucrose in combination with calcium or strontium as an insoluble sucrate, which is then mixed with water and decomposed by carbon dioxide or used in the defecation of beet juice instead of lime. The elimination of the potash salts may be effected, according to Newland's proposal, by the addition of aluminum sulphate so as to form potash alum, which is crystallized out, or by the "osmose" process, in which the principle of diffusion already referred to (see p. 131) is again made use of. In this case advantage is taken of the fact that the potash salts are the most crystalline constituents of the molasses, and hence will pass through a sheet of vegetable parchment more rapidly than the other constituents. So if the molasses warmed to 80 or 90 C. be made to pass in a stream on the one side of such a membrane while pure water passes on the other, the potash salts diffuse through, and are to that degree elimin- ated from the molasses. However, the difference in the rapidity of diffusion of the salts and the sucrose is not sufficiently great to allow of a very perfect separation, so that to avoid loss of sugar the operation must be stopped before the elimination of salts is complete. A little more than half of the sugar can be recovered from the molasses in this way. The apparatus in which this treatment of the molasses is carried out is known as an osmogene, and is illustrated in Fig. 52. It consists of a number of very narrow but high and deep cells adjoining each other, the sides of which are of parchment paper. Through alternate cells in this system goes the heated molasses, and through the intervening cells the water at the same temperature, each connecting with lateral canals for the supply and withdrawal of the respective liquids. The ordinary osmose apparatus of the German sugar-houses is capable of working 1000 kilos, or upwards of molasses per day, and at a cost of 1.60 marks (38.4 cents) per 100 kilos, of molasses. The osmose sugar is somewhat darker in color than ordinary second or third sugar, but is of pleasanter and sweeter taste. The yield of the osmose process varies with the grade of the molasses taken ; a molasses with a purity coefficient of fifty-eight to sixty will yield ten to twelve per cent, of the molasses taken, and one of a coefficient of sixty to sixty-five will yield seventeen, or sometimes as high as twenty, per cent. By repeating the 140 THE CANE-SUGAR INDUSTRY. osmose process thrice the yield can be raised to thirty per cent, out of the possible fifty per cent, of sucrose contained in the molasses. Of the methods depending upon the formation of a lime or strontia sucrate, the most important are the Scheibler-Seyferth elution process, the Steffen substitution and separation processes, and the strontium processes. In the first of these processes, finely powdered quicklime is added to the molasses, which has been previously concentrated in vacuo to 84 or 85 Brix, in the proportion of about twenty-five parts of the former to FIG. 52. one hundred parts of the latter. The lime slakes at the expense of the water of the molasses, and leaves the tribasic calcium sucrate in the form of a dry porous mass. This is then broken up and put into the " elutors," vessels which are somewhat similar in design to the cells of a diffusion- battery. The impure sucrate is here systematically washed with thirty-five per cent, alcohol, which dissolves away from it most of the adhering im- purities. The washed sucrate is then brought to the condition of a fine paste with water, and either decomposed with carbon dioxide or used instead of lime in treating fresh beet juice. This process takes out eighty- five to ninety per cent, of the sugar contained in the molasses, but the cost is somewhat greater than in the case of the osmose process. The alcohol is recovered from the washings by distillation. Steffen's substitution process depends upon the difference in solubility of the tricalcium sucrate at high and low temperatures. The molasses is first diluted so that it shall contain about eight per cent, of sugar, and then caustic lime added until some two to three per cent, has been used. The whole mass is then heated to 115 C., when the tricalcium sucrate is precipitated and separated by the use of a filter-press. The sucrate is ground up, again filter-pressed, and then can be used in defecating sugar juice. The washings from the filter-press are used to dilute a fresh quantity of molasses to the degree mentioned before, PROCESSES OF TREATMENT. 141 which, treated with lime in the proper proportion and heated up, separates the sucrate, which is treated as before. After about the twentieth operation, the cooled mother-liquors and wash-waters are treated with lime alone, and the residual liquors after this treatment are then rejected. In the Steffen separation process, on the other hand, the molasses solution is kept cold, the temperature not being allowed to rise over 30 C. (86 F.). The molasses is diluted until the density shows 12 Brix, the percentage of sugar being then from seven to eight. This solution is cooled down to 15 C. (59 F.), and finely-powdered quicklime is added in small portions at intervals of about a minute, the temperature rising a little each time and being again cooled down. The mixing of the molasses and the lime, in the proportion of fifty to one hundred of powdered lime, according to quality, to one hundred of dry sugar, in the solution takes place in a closed mixing- vessel of iron provided with tubes through which cold water is kept circu- lating, and with a mechanical agitator to mix the contents uniformly. The insoluble sucrate separates out rapidly in the cold, and the contents of the mixer A (see Fig. 53) are pumped to the filter-press E y where the sucrate is washed, the mother-liquor, containing all the impurities of the molasses, being put aside for fertilizing purposes, the wash-water, however, being collected in F for use in diluting new quantities of molasses. The washed sucrate drops from the filter-press into the sucrate-mill G, where it is mixed to a thin paste with water, and then pumped, by means of the monte-jus H, to the receptacle J. From here it can be sent into the first saturation- vessel K, and to the filter-press M, and to the second saturation-vessel S, and the filter-press 0. The process which at the present time is attracting veiy favorable attention and seems to give considerable promise is the strontium process. In this the sugar is precipitated either as monostrontium sucrate, which is quite difficultly soluble in the cold, or as bistrontium sucrate separating from hot solution. According to Scheibler's monosucrate procedure, tho molasses" is well mixed with hot saturated strontium hydrate solution, and the mixture passed over cooling apparatus into crystallizing tanks, where a few crystals of the monosucrate are added to start the crystallization. After 142 THE CANE SUGAR INDUSTRY. some hours the whole mass is changed into a crystalline magma, which is broken up and put through a filter-press. The white cakes of strontium sucrate go, as in the case of calcium sucrate, to the treatment of crude beet juice, while the mother-liquor is treated with more caustic strontia and boiled, when bistrontium sucrate is precipitated. This is dense enough to be washed by decantation, and then can be used instead of strontia solution FIG. 54. with fresh molasses for the formation of monostrontium sucrate. The excess of strontia is recovered from all the mother-liquors and worked over into caustic strontia. By the other strontium process the molasses is added to a twenty to twenty-five per cent, strontium hydrate solution, both taken hot, in such amount that for one part of sugar about two and one-half parts of strontium hydrate are present. The precipitated bistrontium sucrate separates rapidly, and the mother-liquor can be decanted from it. The PROCESSES OF TREATMENT. 143 sucrate is washed with hot water or with a ten per cent, hot strontium solution. In order to decompose the sucrate, it is brought in a refrigerating chamber and cooled to 10 to 12 C., when, after twenty-four to seventy- two hours' standing, according to temperature, etc., it decomposes into crystallized strontium hydrate and sugar solution, containing something less than half of the strontia. After filtering off the crystallized strontium hydrate, the sugar-liquor is decomposed with carbon dioxide in the usual way. In Germany, in 1881-82, out of 188 sugar-houses extracting the sugar from molasses, 135 used the osmose process, and 44 the elution, while in 1884-85, out of 162 sugar-houses working over molasses, but 79 used the osmose process, 51 used the elution process, 23 the substitution and separa- tion processes, and 4 the strontium process. 4. REVIVIFYING OF THE BONE-BLACK. The bone-black, or " char," after use in the filters, becomes charged with impurities and loses for the time its decolorizing power. It can, however, be restored to activity, or " revivi- fied," by suitable treatment so as to be used again for filtration, and this pro- cess can be repeated many times before, by the gradual loss of its porous character and change of composition, it becomes unfit for use. In working sugars from the cane this revivification is a much simpler process than in the case of beet-sugars. In the former case, water as hot as possible is run in at the top of the filter, which displaces the sugar solution remaining in the pores of the char and forms a dilute solution of sugar and the soluble impurities taken up from the liquor. This dilute solution is known as " sweet-water," and is usually boiled down in triple eifects and run in with the lower-grade products. After running additional hot water through, the filters are drained, and the moist char, after a partial drying, is put into the top of the vertical retorts, in which it is to be heated out of access of air for the decomposition of the organic matter still remaining in the pores and the restoration of its absorbent power. Various forms of char-kilns are in use in different refineries. That shown in Fig. 54 represents one of the simpler forms of char-kilns. The moist spent black from the filters in which it was washed goes on to the floor H, where it is dried by the waste heat passing through G and F, and then goes into the openings at J, which are kept always heaped up. The black descends in the retort-pipes A from the upper cooler portions into the middle hottest part, and then, as portions are withdrawn below, into a cooler section again. The black drawn off below is protected from the air by being received into closed receptacles or at once filled into the bone-black-filters. In other forms of kilns, the retorts are rotated slowly by mechanism so as to heat all parts equally. In beet-sugar refineries the revivifying of the char, as before stated, is a more tedious process. This is in part because the juices and syrups have been limed in such excess in the preliminary stages of treatment, and in part because the beet juice contains much more albuminoid and organic non-sugar, which is absorbed in the pores of the char and cannot be gotten rid of by simple washing. The first step in the revivifying, then, in this case, is a treatment with a calculated amount of hydrochloric acid to remove the excess of carbonate of lime ; after this a thorough washing of the black in special washing-machines, t such as the Klusemann washer, shown in Fig. 55 ; ttfen a fermentation to decompose into simpler and soluble constituents the absorbed albuminoids and other organic matter. The fermentation may be either what is termed the dry fermentation, in the presence of a very 144 THE CANE-SUGAR INDUSTRY. FIG. 55. PEODUCTS OF MANUFACTURE. 145 small quantity of water, or the moist fermentation in the presence of a larger amount. The first takes from twelve to twenty hours, while the latter re- quires from six to seven hours only. The black, after the fermentation, is treated with boiling alkaline solutions, washed, and then burned in char-kilns as already described. The char seems to improve in filtering power at first, as a consequence of revivifying, but soon loses again and runs down steadily in value. This is in large part due to the separation out in the pores of car- bonized residue from the burning. This carbon has no decolorizing power like the nitrogenized carbon of the original bone-black, but simply clogs the pores of the char and mechanically obstructs its action. m. Products of Manufacture. 1. RAW SUGAKS. The composition of the juice from both the sugar- cane and the sugar-beet has been stated, and the processes for preparing the raw sugar from each of these sources. We may now examine more closely the character of the products obtained. The raw cane-sugar, made as it is chiefly in the tropics under a variety of conditions of working, from the most primitive to the most highly improved, has come into commerce under a great variety of names as well as of varying grades of purity. The raw beet-sugar is usually known as first, second, or third product sugar. (See p. 136.) Muscovado is a brown sugar produced in the West Indies, generally by open-pan boiling, which has been drained in hogsheads or perforated casks, and so freed in large part from the accompanying molasses. Cassonade is a name formerly applied in the French colonies to musco- vado sugars. Melada is a moister brown sugar, produced like the muscovado, but not drained free from molasses. Concrete, or concreted sugar, is the product of the Fryer concretor (see p. 128) or similar form of apparatus, and is a compact, boiled-down mass, containing both the crystallizable sugar and impurities which ordinarily go into the molasses. It shows little or no distinct grain. Clayed sugars have been freed from the dark molasses by covering them in moulds by moist clay, which allows of a gradual washing and displace- ment of the adhering syrup. Bastards is the name given to an impure sugar gotten by concentrating molasses and allowing to crystallize slowly in moulds. Jaggery is the name given to a very impure East Indian palm-sugar, sometimes refined in England, but chiefly consumed in the country of its production. Demerara crystals are the product of the best vacuum-pan boiling and have been well purged in the centrifugals. They have the light yellow bloom due to treatment with sulphuric acid. (See p. 125.) These Demerara crystals have also been brought to the United States with very dark brown color. This, however, was only superficial, and was capable of removal by centrifugating with a lighter-colored syrup. The dark color was imparted like the yellow bloom by the action of sul- phuric cid added in the vacuum-pan before discharging the contents of the same. The composition of a variety of raw cane- and beet-sugars is given in the accompanying table : 10 146 THE CANE-SUGAR INDUSTRY. DESCRIPTION OF SUGAR. Sucrose. Glucose. Organic non- sugar. Ash. Water. Authority. Cane, Cuba (centrif.) . . . 91.90 2.98 2.70 0.72 1.70 Winner and Harland. Cuba (muscovado) . 92.35 3.38 0.66 0.77 2.84 Wallace. Jamaica 90.40 3.47 1.55 0.36 4.22 Wigner and Harland. Trinidad 88.00 5.14 1.67 0.96 4.23 Wigner and Harland. Porto Rico 87.50 4.84 2.60 0.81 4.25 Wigner and Harland. St Vincent 92.50 3.61 2.45 0.63 0.81 Wigner and Harland Demerara . . . . . . 90.80 4.11 077 1.12 3.20 Wallace. Benares 94.50 2.63 0.39 1.50 0.98 Wigner and Harland. Unclayed Manila . . 82.00 6.79 3.24 2.00 5.97 Wigner and Harland. Concrete 84.20 8.45 1.70 1.10 4.55 Wallace. Melada 67.00 11.36 1.93 0.91 18.80 Wallace. Bastards . . . 6830 15.00 120 150 14.00 Wallace. Palm East Indian 86.00 2.19 2.89 2.88 6.01 Wigner and Harland. Beet, First product .... 94.17 2.14 1.48 2.21 Bodenbender. " Second product . . . 91.68 2.49 2.92 2.91 Bodenbender. 2. REFINED SUGARS. The commercial designations of refined sugar are very varied. We may distinguish in general between hard sugars and soft sugars, the former of which are more thoroughly and carefully dried by the aid of artificial heat, while the latter are merely centrifugated, and so retain from three to four per cent, of water in the traces of syrup ad- hering to the sugar. To the former class belongs sugar " crystals," or sugar in well-formed individual transparent crystals, which are as pure as rock- candy, as well as loaf-sugar in the forms of pulverized, crushed, granu- lated, and cube sugars. To the latter belong what are called grocery sugars, of which the finest grades are called A sugars, the next B sugars, and so on. In Germany the finest white-beet-sugars are known as " raftinade," inferior grades as " melis" (or Brodzucker), as " pile/' and as " farin," the last of which is of inferior grain and color. The hard sugars in general all show a sucrose percentage of ninety-nine or over, while the soft cane-sugars and the second grade beet-sugars show from ninety-six to ninety-eight per cent. 3. MOLASSES AND CANE-SUGAR SYRUPS. The molasses may be termed the mother-liquor of the crystallized product, the sugar. It is never found possible in practice, however, to crystallize all the sugar out or to get a molasses which shall not contain sucrose. The potash salts, and in a lesser degree the calcium salts, which are present in the crude juice are " melassigenic," that is, prevent the crystallization of a certain amount of the sucrose ; the invert sugar, or glucose, operates in the same way, and the long-continued heating of the sugar solutions also has the effect of increas- ing the molasses. In France, for instance, the rendement, or amount of crystallized sugar obtainable in refining of raw sugars, is calculated by deducting from the total sucrose twice the glucose, and from three to five times the ash. In the case of cane-sugars the ash is not so melassigenic, not being so largely composed of potassium compounds as with the beet, and a deduction of one and a half times the glucose is considered sufficient to allow for that impurity. The experience of the last few years with sorghum-sugar, as manu- factured by the United States Bureau of Agriculture and several sorghum- sugar factories in Kansas, has shown that this rule does not apply to sorghum. Professor Swenson, the chemist of the Parkinson Company at Fort Scott, Kansas, finds that in the case of sorghum juice the glucose and other solids, known as " non-sugar," prevent only two-fifths of their weight PRODUCTS OF MANUFACTURE. 147 of cane-sugar from crystallizing, so that in the season of 1887, instead of there being only 61.6 pounds available sugar per ton of cane worked as the analyses indicated according to the old rule, as a matter of fact, 130.5 pounds were obtained. But with the sugar-cane and the sugar-beet the percentage of sucrose, in both the raw molasses produced in the extraction of the sugar from the juice and " refined molasses," the syrup produced in the process of refining is quite large. The composition of the first, second, and third molasses of the Louisiana cane-sugar plantation has already been given (see p. 138), as well as the average composition of beet-root molasses. The following analysis of a variety of molasses will further illustrate the differences in the several grades : Sucrose. Glucose. Ash. Organic non- sugar. Water. Authority. From sugar-cane : Green syrup 62.7 80 10 06 27.7 Wallace. Golden svmp 39.6 33.0 25 2.8 22.7 Wallace. Treacle 32.5 372 35 3.5 234 Wallace West Indian molasses . Dark molasses 47.0 35.0 20.4 10.0 2.6 5.0 2.7 10.0 27.3 20.0 Wallace. J. H. Tucker. Prom beets : Beet-sugar molasses . . Beet-sugar molasses . . Beet-sugar molasses . . 46.7 50.0 55.0 0.6 Trace. 13.2 10.0 12.0 15.8 20.0 13.0 23.7 20.0 20.0 Wallace. Wigner and Harland. J. H. Tucker. It will be seen from these analyses that the percentage of sucrose is usually much higher in the beet-root molasses, which is explained by the large percentage of ash and organic non-sugar. On the other hand, the glucose, or invert sugar, is large in the cane-sugar molasses, but almost entirely wanting in the beet-sugar molasses. The latter, however, always contains raffinose, another variety of sugar always present in the beet juice, betaine, a nitrogenous base, and proteids. The proportion of salts con- tained in beet-root molasses is usually ten to fourteen per cent., whereas refiner's molasses from cane-sugar rarely contains half that proportion. The term green syrup, used above, is given to the syrup centrifugated from the second products in the refining process. Golden syrup is produced from a refiner's molasses by diluting, filtering through bone-black, and then concentrating. Treacle is the name formerly given to the drainings from the dark molasses sugars called bastards. (See p. 145.) Cane-sugar molasses, when refined and brought to the condition of light-colored syrups, forms a common article of domestic consumption under the general name of table syrup. The table syrups of the present day, however, cannot, as a rule, claim to be simple products of the refining process, as they are almost always largely admixed with the cheaper glucose syrup, and the cane-sugar product in them is often entirely replaced by this latter. A glucose product, known as " mixing syrup," is quite openly sold for this purpose. Beet-sugar molasses is not adapted for use as table syrup on account of the unpleasant taste and odor, due to the nitrogenous principles present. It is, as before described, worked for the extraction of the sugar, or it is fermented for alcohol. 4. MISCELLANEOUS SIDE-PRODUCTS. (1) Exhausted Residue from the 148 THE CANE-SUGAR INDUSTRY. Sugar-cane or Sugar-beet. The character of this residue differs very greatly according to the method of juice extraction which lias been followed. The common sugar-cane residue from the roll-mills, known as " bagasse," con- sists of the fibre and cellular material of the cane still enclosing some six per cent, of sucrose, or about one-third of the total eighteen per cent, which the fresh-cut cane contains. It is very largely used as fuel on the sugar plantations, and the ash serves to some extent as fertilizing material for the soil. The cane-fibre, when freed more fully from the sugar by the diffusion process, has been proposed as a source of paper-stock. (See p. 120.) Both the pressed pulp and the exhausted diffusion-chips from the sugar- beet are recognized as valuable cattle food. Marcker found in the dried press-cake 1.227 per cent, of nitrogen. The exhausted chips of the diffusion- cells are still richer in nitrogen, as the diffusion process does not extract as much nitrogenous matter as the method of crushing. (2) Scums and Saturation Press-cakes. In describing the production of raw cane-sugar mention Avas made of the scums, which had at one time been thrown away, but which when filter-pressed yielded a very considerable additional amount of sugar. The press-cake obtained in this treatment has also a value. It contains on an average as taken from the press 45.17 per cent, of water, 15.67 per cent, of ash, 3.49 per cent, of phosphoric anhy- dride, and 1.14 per cent, of nitrogen, or, reckoned on the dry material, 28.56 per cent, of ash, 6.33 per cent, of phosphoric anhydride, and 2.10 per cent, of nitrogen. Its value, as taken from the press, at the ruling rates for fer- tilizing materials, would be $10.64 per ton.* Where the carbonatation process is used, and the excess of lime removed by carbon dioxide, the scums and carbonate of lime are found together in the press-cake gotten by filtering. In the experimental tests of the carbonatation process as ap- plied to cane-sugar made by the United States Department of Agriculture at Fort Scott, Kansas, in 1886,f the press-cake obtained after saturation and filtering when dried was found to contain 9.585 per cent, of albuminoids and 17.45 per cent, of other organic matter. The saturation press-cake of the beet-sugar process does not contain so high a percentage of albuminoids, but a much larger amount of nitrogenous compounds remains in the clari- fied juice, giving rise to the escape of ammonia on concentration in the vacuum- pan and showing itself in the molasses. (3) Exhausted Bone-black. The bone-black after repeated revivifying (see p. 143) becomes at last valueless for filtration purposes and passes out of the sugar-refinery, going to the manufacturer of fertilizers, for whom it is a very valuable material. The more calcium phosphate, and the less calcium carbonate it contains, the more valuable it is for superphosphate manufac- ture, as, on the addition of sulphuric acid, the liberated phosphoric acid re- mains, adding to the value of the product, while the carbonic acid is driven off. The exhausted bone-black contains on an average thirteen per cent, of calcium carbonate, sixty to seventy-four per cent, of calcium phosphate, four per cent, of carbon, and four-tenths to six-tenths per cent, of nitrogen. (4) Vinasse, or Molasses Residues. When the beet molasses is fermented for the production of alcohol, the residual liquor, which contains all the potash salts of the molasses, is known in French as " vinasse," or in German as "schlempe." It is of about 41 B. and acid in reaction. It is neutral- * Bulletin of Department of Agriculture, No. 11, p. 16. t Ibid., No. 14, p. 54. ANALYTICAL TESTS AND METHODS. 149 ized with calcium carbonate and then evaporated down to dryness and cal- cined. The black porous residue so obtained contains thirty to thirty-five per cent, of potassium carbonate, eighteen to twenty per cent, of sodium carbonate, eighteen to twenty-two per cent, of potassium chloride, six to eight per cent, of potassium sulphate, and fifteen to twenty-eight per cent, of insoluble matter. It is exhausted with hot water, and the extract evap- orated down, when potassium sulphate and afterwards sodium carbonate separate out. On cooling, potassium chloride and potassium sulphate crys- tallize out, and the mother-liquor contains potassium carbonate admixed with some sodium carbonate. It is possible by this gradual evaporation and fractional crystallization to bring the crude potashes to a purity of ninety per cent. In this production of the solid potashes from the molasses residue all the nitrogen of the molasses is lost. To prevent this, C. Vincent, a French chemist, has proposed to submit the evaporated vinasse to a dry distillation instead of calcination in the air. The residue of this distillation is an open and very porous coke containing all the mineral salts of the molasses, which can then be extracted as before. The products of distilla- tion are an illuminating and heating gas, ammonia water, and a small amount of tar. The ammonia water is the most interesting product. It contains besides carbonate, sulphide and cyanide of ammonium, methyl alcohol, and notable quantities of trimethylamine. This latter can be de- composed at 320 C. by dry hydrochloric acid gas into methyl chloride and ammonia, and on passing the products through aqueous hydrochloric acid, the methyl chloride goes through unabsorbed, while the ammonia is taken up. The methyl chloride is of great value for ice machines and for the manu- facture of methylated aniline colors. (See p. 393.) The process was quite largely introduced, but as in recent years the molasses is Avorked over for sugar in increasing amounts, less molasses is fermented, and hence less viuasse is obtained. IV. Analytical Tests and Methods. 1 . DETERMINATION OF SUCROSE. (A) Optical Methods. Among the most important physical properties of many of the varieties of sugars is the power possessed by their solutions of rotating the plane of polarization to the right or the left. They are accordingly classified as dextro-rotatory, la?vo- rotatory, or optically inactive in case no power of circular polarization is manifested. This property as possessed by solutions of cane-sugar, of deviating the polarized ray in a fixed and definite degree, has been made the basis of the method of analysis by means of polariscopes. The funda- mental idea involved in these instruments is to compensate for and so de- termine the optical rotatory power of sugar solutions of unknown strength by the corresponding circular polarizing action of quartz plates of known thickness, and hence of known power. The earliest of polariscopes was the Mitscherlich instrument, but those now in use for sugar analysis are either the Soleil-Ventzke-Scheibler, the Soleil-Dubosq, the Laurent shadow instrument, or the Schmidt and Haensch, which last claims to combine the best features of the Soleil and the Laurent instruments. A general view and a longitudinal section of this instrument is given in Fig. 56. The glass tube containing the sugar solution is shown lying in the axis of the tele- scope and the polarizing prisms. To the right below is shown the polar- izing prism (the so-called Jellet-Cornu prism), to the left is the analyzing prism, a quartz plate, quartz wedges of opposite rotatory power, and the lenses 150 THE CANE-SUGAR INDUSTRY. of the telescope, with a plate of bichromate of potash to correct for any color in the field. In this instrument, which uses white light, the field of view is a circle, which, with the instrument at and nothing intercepting the light, is of a uniform gray tint. When a sugar solution is interposed, one-half of the circle becomes darker than the other, and the quartz wedges, controlled by the screw shown underneath, must be moved to compensate for the rotation due to the sugar solution and to restore the uniformity of tint. The instrument is so graduated that one degree of displacement on the scale corre- sponds to .26048 gramme of cane-sugar dissolved in 100 cubic centimetres of water and viewed through a 200-millimetre tube. Therefore 26.048 grammes of the sugar to be analyzed are weighed out. If chemically pure and anhydrous, the solution of the strength stated should read one hundred FIG. 56. degrees of displacement, or one hundred per cent, of sugar, and if impure, correspondingly less. In the application of polariscope analysis to cane-sugars two cases may arise : first, when no other optically active substance is present, and, second, when glucose or invert sugar is also present. (a) Absence of other Optically Active Substances. The weighed sample is dissolved in about fifty cubic centimetres of water in a flask marked for one hundred cubic centimetres. As soon as the sugar is all dissolved, a few cubic centimetres of a solution of basic acetate of lead are added, and two or three cubic centimetres of cream of hydrated alumina. The liquid is well agitated, and then the flask is filled nearly to the mark on the neck with water and the froth allowed to rise to the surface, when it is flattened by the addition of a drop of ether. Water is now added exactly to the mark, the contents of the flask thoroughly agitated, and the liquid filtered through a dry filter. In the case of very dark sugars, purified and perfectly dry bone- ANALYTICAL TESTS AND METHODS. 151 black has been added for clarifying purposes. However, it is generally acknowledged to introduce error by its absorption of small amounts of sugar, so that it is now dispensed with, or if used on the dry filter, the first third of the filtrate is rejected and the later portions only used. Allen * recommends instead the use of sodium sulphite, or sulphurous acid solu- tions. The tube of the polariscope is now rinsed with the clear sugar solution and then filled with the same, the open end closed with a smooth glass plate held in place by a brass cap, which is screwed on. The tube containing the sugar solution is then placed in the instrument, and the lower thumb-screw turned until the uniformity of shade in the two halves of the field is restored, whe.i the number of degrees (or percentage of cane- sugar in the sample) is read oif on the scale. (6) Presence of Glucose, Invert Sugar, or other Optically Active Substance. The action of acids upon cane-sugar has already been stated to cause in- version, i.e., change of the sucrose into dextrose and levulose. Both these varieties of sugars differ from sucrose in their optical power. If, then, these alteration products accompany the sucrose in a cane-sugar sample, the results of the polariscope reading may be vitiated. Some writers have held that the invert sugar present in raw cane-sugars and syrups is optically inactive, but the statement seems to have been disproved by Meissl. Besides, in raw beet-sugars and syrups, ramnose, a very strong dextro-rotatory sugar, is found vitiating the readings for cane-sugar. The correction of the original polarization in such cases is most generally made by the method of inver- sion proposed by Clerget. The direct polarization is taken in the usual way, and a part of the solution remaining from the one hundred cubic centimetres prepared for this test is put into a 50-cubic-centimetre flask, which has also a 55-cubic-centimetre mark on the neck. Fifty cubic centimetres having been taken, five cubic centimetres of concentrated hydrochloric acid is added, and the whole heated on a water-bath to 70 C. for some ten minutes. This suffices to completely invert the cane-sugar present, while the original invert sugar is unacted on. The flask is then cooled, and part of the liquid is filled into a 220-millimetre tube, closed by glass plates at both ends and provided with a tubulure in the side so that a thermometer may hang suspended in the liquid when the observation is made. The reading will generally be much reduced from the original dextro-rotatory reading, and may even be some degrees to the left. If, then, S represent the sum or difference of polariscope readings before and after inversion (difference if both are to the right, sum if the second reading is to the left), T the temperature of the inverted solution when polarized, and R the correct percentage sought, R=^ Clerget has also prepared an elaborate set of tables which make the use of the formula unnecessary. (See also under molasses, p. 155.) (B) Chemical Methods. The only chemical method for the determination of cane-sugar ever resorted to is the inversion of the cane-sugar, neutralizing with sodium carbonate, and determination of the reducing sugar so obtained by the method to be described under the next head. The inversion takes place in definite proportions, so that nineteen parts of sucrose produce twenty parts of the invert sugar. When invert sugar is also present in the solution * Commercial Organic Analysis, 2d ed., vol. i. p. 201. 152 THE CANE-SUGAR INDUSTRY. of which the cane-sugar is to be determined by inversion, the former is first estimated as a separate operation, and then a portion of the original solution is inverted, and the total invert sugar, including that formed from the cane- sugar, is determined. 2. DETERMINATION OF GLUCOSE, OR INVERT SUGAR. The oldest method is that based on Trommer's reaction as applied to sugar analysis by Barreswill and Fehling. This depends upon the fact that an alkaline solu- tion of copper oxide containing a fixed organic acid, as tartaric, is reduced with the separation out of insoluble cuprous oxide by dextrose, or invert sugar, while cane-sugar has no eifect. The composition of a standard Fehling's solution, as it is called, is thus given by Tollens : * 34.639 grammes crystallized copper sulphate are dissolved in water and brought to 500 cubic centimetres ; 173 grammes Rochelle salt and 60 grammes sodium hydrate are also dissolved in water and brought to 500 cubic centimetres. Equal volumes of these solutions are mixed when required for use and con- stitute the correct Fehling's solution. The ready-prepared Fehling's solution changes in the course of some days in effective power even when kept in a cool place and in the dark. Ten cubic centimetres of the Fehling's solution given above correspond to .05 gramme dextrose, or invert sugar, or .0475 gramme cane-sugar made active by inversion. For technical determinations merely the work with the solution can be volumetric ; for more exact scien- tific purposes it must be gravimetric, weighing the copper as metal or as cupric oxide. In carrying out the volumetric test, the sugar solution in which glucose is to be determined is placed in a burette. If dark, it may be previously cleared with a small quantity of bone-black, or if it be some of the solution prepared for polarization, it is prepared without lead solu- tion, an aliquot portion taken out for this glucose determination, and the remainder treated with a measured quantity of the lead solution, for which allowance is made. Any lead in this glucose solution must be eliminated thoroughly. This is best done with sulphurous acid, the change of strength in the liquid being noted. Ten cubic centimetres of the mixed Fehling's solution are now measured into a porcelain dish, diluted with twenty or thirty cubic centimetres of water and brought quickly to boiling, when the sugar solution is run in two cubic centimetres at a time, boiling between each addition. When the blue color has nearly disappeared the sugar solution should be added, in small amount but still rapidly. The end of the reaction is reached when a few drops of the supernatant liquid filtered into a mixture of acetic acid and dilute potassium ferrocyanide give no brown color. In carrying out the gravimetric method the Fehling's solution remains in excess, while the precipitated cuprous oxide is carefully filtered off and further treated. The procedure is as follows : Sixty cubic centimetres of the mixed Fehling's solution and thirty cubic centimetres of water are boiled up in a beaker glass, twenty-five cubic centimetres of the dextrose solution of approximately one per cent, strength added, and the mixture again boiled. It is then filtered with the aid of a filter-pump upon a Soxhlet filter (as- bestos layer in a tared funnel of narrow cylinder shape), quickly washed with hot water, and then with alcohol and ether, and dried. The as- bestos filter, with the cuprous oxide, are now heated with a small flame, while a current of hydrogen is passed into the funnel, so that the precipitate * Handbuch der Kohlenhydrate, 1888, p. 71. ANALYTICAL TESTS AND METHODS. 153 is reduced to metallic copper. It is allowed to cool in the current of hydro- gen, placed for a few minutes over sulphuric acid, and then weighed. A table has been constructed by Allihn which gives in milligrammes the dextrose corresponding to the weight of copper found. Other methods for the determination of dextrose are those of Pavy, using an ammoniacal solution of the Fehling reagent ; of Knapp, who uses an alkaline solution of cyanide of mercury ; of Sachsse, who uses an alkaline solution of potassio-mercuric iodide ; and of Soldaini, who uses a solution of basic carbonate of copper dissolved in potassium bicarbonate. This last reagent has been recently strongly commended as better than Fehling's solution, in that it is more sensitive to glucose and is much less aifected by cane-sugar even after prolonged boiling.* 3. ANALYSIS OF COMMERCIAL RAW SUGARS. Raw sugars contain, besides the cane-sugar, invert sugar, moisture, mineral salts, organic non- sugar, and insoluble matter. Raw beet-sugars contain, in addition to the sucrose and glucose just mentioned, small quantities of raffinose, a variety of sugar found in the beet juice and present in all the products from it. The cane-sugar present is partly crystallized and partly uncrystallizable. Both are, of course, counted together in the polarization figures, but only the first is capable of extraction in the refining process. The method of esti- mating the crystallized cane-sugar for itself will be described later on. The polarization methods have already been described. In raw sugars containing much invert sugar, such as those from the cane, the double polarization (be- fore and after inversion) is alone to be relied upon. The methods for glucose have also been described. The determination of moisture is made by taking five grammes of the sample and drying it spread out on a weighed watch-crystal in an air-bath at 100 to 110 C. until it ceases to lose weight. As sugars containing much glucose cannot stand the heat without some alteration, in their case a lower temperature (60 to 90 C.) is used. For very syrupy sugars and melados it becomes necessary to dry with the addition of a weighed amount of clean sand. Drying in a vacuum is also practised in many cases, as the operation is shortened and less risk of alteration exists. The mineral salts are determined as ash. The following analyses give the average composition of raw cane- and beet-sugar ash according to Monier : Cane-sugar. Beet-sugar. Potassium (and sodium) carbonate 16.5 82.2 Calcium carbonate 49.0 6.7 Potassium (and sodium) sulphate 16.0 \ 111 Sodium chloride 9.0 J Silica and alumina . . . 9.5 None. 100 100.0 Owing to this decided difference, it is much easier to get the ash of cane- sugars completely burned and in weighable condition than that of beet- sugars, which contain so much of the deliquescent and alkaline carbonates. To obviate this difficulty, Scheibler proposes to treat the sugar with sulphuric acid before igniting it, by which means the ash obtained contains the bases as non-volatile, difficultly fusible and non-deliquescent sulphates instead of as carbonates. A deduction of one-tenth of the weight of the sulphated ash must be 'made in this case for the increase due to the sulphuric acid. * Bodenbender and Scheller, Zeitschrift fiir Riibenzucke-, 1887, p 138 154 THE CANE-SUGAR INDUSTRY. The soluble and insoluble ash are often distinguished in addition to total ash. In ordinary commercial analyses of sugars, the sum of the cane-sugar, glucose, ash, and water is subtracted from one hundred, and the difference called organic or undetermined matters. This would include both the solu- ble organic impurities and the insoluble impurities, such as fibre and parti- cles of cane. Two processes have been proposed for determining the solu- ble organic impurities separately : Walkoff's method of precipitation with tannin, and the basic acetate of lead method. Neither method is in very general use. As before stated, the full analysis of a raw sugar will not give any exact measure of its refining value, that is, of the amount of crystallized cane-sugar that can be extracted from it. The so-called method of co- efficients adopted in France, whereby five times the ash, plus once or twice the glucose percentage subtracted from the cane-sugar percentage, is taken to represent the crystallized cane-sugar obtainable, is not much to be depended upon. The true refining value, or rendement, of a raw sugar can, however, be determined by a special procedure first proposed by Payen and afterwards improved by Soheibler. The process depends upon the fact that if raw sugars be treated with a saturated alcoholic solution of cane- sugar acidified with acetic acid, the coloring matter and other impurities, together with the syrup and other uncrystallizable constituents, are removed, while the crystallized sugar remains unchanged. The sugary alcoholic liquids are then displaced by absolute alcohol. Fig. 57 shows the arrange- ment of vessels. The bottle I contains eighty-five per cent, alcohol, to which 50 cubic centimetres of acetic acid is added per litre, and the mixture allowed to stand in contact with an excess of powdered white sugar for a day, being shaken at intervals ; bottle II, alcohol of ninety-two per cent, saturated as the other, but without acetic acid ; bottle III, alcohol of ninety- six per cent., also saturated with sugar ; and bottle IV, a mixture of two- thirds absolute alcohol and one-third ether. Of the sugars to be examined, weights are taken corresponding to the polariscope used, placed in the up- right tubes, washed with the successive solutions, and dried by the aid of a filter-pump ready for use in the polariscope test. In carrying out the process, the alcohol and ether mixture is first run in that it may take up any moisture and throw out the sugar that such moisture may have dis- solved, then successively down to No. I, which is the effective washing solution. This is then displaced by Nos. II, III, and IV in succession. The method is thoroughly reliable, but great care must be taken to keep the alcoholic solutions just saturated with sugar through all changes of temperature. 4. ANALYSES OF MOLASSES AND SYRUPS. The composition of both the cane-sugar and the beet-sugar molasses have already been given (see p. 147), and it was seen that they differed notably. Both still contain con- siderable quantities of sucrose, but for different reasons. With the cane- sugar molasses because of the invert sugar, with the beet-sugar molasses because of the melassigenic salts. In either case the polariscope reading for sucrose must be corrected by inversion. The glucose is determined as described under raw sugars. The water is determined by weighing out a sample, thinning it with water, putting it into a weighed dish with clean sand, and drying it at a temperature of 60 C. until constant. Drying in a partial vacuum also facilitates the drying off of the moisture. The ash is determined as with raw sugars, sulphuric acid being added, and the bases ANALYTICAL TESTS AND METHODS. 155 weighed as sulphates instead of as carbonates, the proper correction being made. The organic non-sugar is simply taken by difference as with raw sugars. The determination of raffinose in raw beet-sugars, and particularly in beet-molasses, has attracted much attention in recent years. Creydt* has suggested a way for determining it in the presence of cane-sugar in con- nection with the method of inversion. He finds that while cane-sugar polarizing 100 to the right before inversion polarizes 32 to the left after inversion, a change of 132, raffinose changes from 100 to 50.7 Fm. 57. only, a change of 49.3. He proposes two formulas : -4=2+1.57 R, and c=1.322 + 1.57 RX .493, in which A is the direct polarization, c the polarization after inversion, z the percentage of cane-sugar, and R that of raffinose. From these formulas, A and c being known, z and R can be found. The reading after inversion must be taken uniformly at 20 C. 5. ANALYSES OF SUGAR-CANES AND SUGAR-BEETS AND RAW JUICES* THEREFROM. The very different physical characters of the sugar- * Zeitschrift fur Kubenzucker, vol. xxxvii. p. 163. 156 THE CANE-SUGAR INDUSTRY. cane and the sugar-beet, the one a bamboo-like shell enclosing a woody pith, and the other a soft root easily brought into pulpy consistency, make the work upon them quite different. In the case of the cane, the samples to be analyzed are weighed and then pressed between rolls, moistened with hot water and again pressed, and this repeated several times. The ex- hausted stalk, or " bagasse," is usually not further examined, but in the juice the sucrose, glucose, ash, and organic non-sugar are determined as before described. In all analyses of raw cane juices the percentage of total solids is determined by the Brix saccharometer or " spindle." The form of hydrometer in most general use is known as the Balling or Brix, and its readings indicate directly the percentage of impure sugar or solid matter dissolved. Sets of tables also allow of the conversion of the Brix scale into direct specific gravity figures. (See Appendix, p. 487.) With the aid of the specific gravity determination it is possible to make a rapid analysis of raw juice without weighing. The method adopted by Crampton,* one of the chemists of the United States Bureau of Agriculture, for this analysis is to measure out a certain volume of the juice, add lead solution, make up to another definite volume, polarize, and apply the correction for specific gravity to the reading obtained. A set of tables for this correction and the factor needed in the glucose determination are given by Crampton. In the examination of sugar-beets, the system of pressing and moisten- ing with hot water can be followed for the extraction of the juice, but the method proposed by Scheibler of extracting the sugar from a weighed quantity of the pulp by the aid of alcohol is much better. This is accomplished by the aid of a Soxhlet or other extractor (see p. 73) con- nected with an upright condenser. After complete extraction and cooling the necessary amount of lead solution is added, and the liquid brought up to the mark with absolute alcohol and then polarized. Degener has de- scribed a still simpler form of extraction, originally suggested by Rapp, in which the pulp remains in the alcoholic solution until after it is cleared with the lead solution and brought to the mark, when it is filtered and polarized. A correction must in this case be applied to the reading on account of the volume occupied by the pulp in the measured liquid. The amount of dry residue, or " mark," of the beet can be determined in the Scheibler extraction method at the same time by taking the exhausted residue, drying it in a current of air, and weighing it. The moisture and ash of the beet are determined as with raw sugars. The organic non-sugar is gotten by difference or by one of the methods mentioned under raw sugars 6. ANALYSES OF SIDE-PRODUCTS. (a) Of Bone-black. Careful anal- yses of both fresh char and that which is in use are needed to allow of the proper control in filtration. The most important determinations are those of water, carbonate of lime, carbon, and specific gravity, as upon the changes in these depend in the main its efficiency. The water is determined by dry- ing for several hours at 140 C. The sample should not be powdered. The carbon is determined by treating a weighed quantity of the char with pure hydrochloric acid, with the aid of heat, on a water-bath until the soluble portions have been dissolved, diluting and filtering upon a weighed quanti- tative filter. After thorough washing with hot water, the filter and contents are dried at 100, placed between watch-glasses and weighed, again heated and weighed as long as any loss of weight is shown. The filter and carbon * United States Bureau of Agriculture, Bulletin No. 15, pp. 31-31. ANALYTICAL TESTS AND METHODS. 157 are then transferred to a weighed crucible and ignited. The insoluble resi- due, taken from the previous weight, minus the weight of the filter, gives the amount of carbon. The estimation of carbonate of lime in case the char is used with cane-sugar or juices is of much less importance than when the char is used with beet-sugars or juices. In the former case, the per- centage decreases at first, and then remains nearly stationary, in the repeated use of the char, while in the latter case it would increase steadily, because of the more thorough liming and carbonatation to which the beet juices are subjected, were it not for the treatment with hydrochloric acid in the revivi- fying of the char. (See p. 143.) To allow of the proper judgment in this use of hydrochloric acid, it becomes necessary in beet-sugar working to determine carefully the amount of carbonate of lime taken up by the char in using before starting the revivification. It is almost universally done at present by the aid of the Scheibler apparatus, shown in Fig. 58. The nor- mal quantity of pulverized char (1.702 grammes) is placed in A, and the tube 8 filled with acid to the mark is carefully placed in the bottle. E is then filled with water, and the operator, by means of the compression-bulb, forces the liquid into D and C, which connect at the base, until it reaches a little above the zero-point in (7, when it is allowed to flow out by opening the pinchcock at p until the level in C is at zero. The stopper now being placed in A, a connection with B is made by the tube r. If the level of the liquid in D and C are then unequal, the equality may be restored by opening the cock q for a few seconds, and which for the rest of the opera- tion remains closed. The vessel A is now held, as shown in the cut, so that the acid may come in contact with the char, and the bottle gently shaken to cause the acid to thoroughly mix with the assay. The pressure of the gas evolved distends the rubber bag in B and depresses the column of water in (7. The stopcock p is now opened to allow the water in D to flow out suffi- ciently rapidly to keep the level in C and D as near the same as possible during the progress of the determination. When all the gas has been given off and the level of the liquid in C becomes stationary, p is closed, after bringing the water in D to the same level as that in (7, and the volume and temperature read off. A set of tables accompanying the instrument gives the percentage of carbonate of lime from the volume and temperature read- ings. Assuming seven per cent, to be the normal amount of carbonate of lime in the char, any excess, as shown in this determination, can have its equivalent in hydrochloric acid of known strength calculated, and thus the acid treatment in the revivifying process can be made accurate. In determining specific gravity, both apparent and real specific gravity (the latter after boiling the char with distilled water to displace air) are to be taken. (6) Of Scums, Press-cakes, and Sucrates. In the case of the scums and press-cakes obtained in the manufacture of raw sugars, their chief value is in the lime salts they contain, which, notably in the case of beet-sugars, adapt them for use as fertilizing materials. They, however, contain such amounts of sugar, either mechanically held, or, where the carbonatation process has been used, as sucrates, as make it necessary to regularly determine the sucrose in them. In the case of the thin scums from cane-sugar working, the determina- tion can be made exactly as with an impure juice before described. In the case of the' heavier press-cakes from beet-sugar working, resulting from car- bonatation, the procedure is different. Here the sucrate of lime is to be de- composed if possible without decomposing the large amount of accompanying 158 THE CANE-SUGAR INDUSTRY. carbonate of lime. This is done by careful addition of acetic acid, con- trolling the reaction with phenol-phthale'in. For details of this process, first proposed by Sidersky, see Friihling and Schultz, "Anleitung ziir Zucker Untersuchungen," 3d ed., p. 171. FIG. 58. Sucrates, resulting from the working of molasses for sugar by either of the lime or strontium processes (see p. 140), are analyzed by a somewhat similar procedure, using strong acetic acid to set the sugar free from its combination with the lime or strontia and phenol-phthalei'n as an indicator. BIBLIOGRAPHY AND STATISTICS. 159 The excess of acid is afterwards neutralized, lead solution added, the solution brought to strength, and polarized. (Ibid., p. 155.) V. Bibliography and Statistics. BIBLIOGRAPHY. 1861. Guide pratique du Fabricant du Sucre, Basset, Paris. 1872. Der praktische Kiibenzuckerfabrikant und Raffinadeur, L. "Walkhoff, Braunschweig. 1872-88. Jahresbericht der Zuckerfabrikation, etc., C. Stammer, Braunschweig. 1876. Food and its Adulterations, Hassall, London. 1877. Tropical Agriculture, P. L. Simmonds, London. Die Chemie der Kohlenhydrate, etc., R. Sachsse, Leipzig. 1879. Das Optische Drehungsvermosien, Landolt, Braunschweig. 1880. The Sugar- Beet, L. S. Ware/Philadelphia. 1881. Manual of Sugar Chemistry, J. H. Tucker, New York. The Analysis and Adulteration of Foods, James Bell, London. 1881-90. Bulletins of the United States Department of Agriculture on Sugar Experi- ments, Washington. 1882. Die Zuckerarten und ihre Derivate, E. von Lippmann, Braunschweig. Report on Sorghum-Sugar by the National Academy of Sciences, Washington. Foods, Composition and Analysis, A. W. Blyth, London. Traite de la Fabrication du Sucre, Horsin-Deon, Paris. 1885. Anleitung zur Untersuchungen der Zuckerindustrie, Friihling und Schultz, 3te Auf., Braunschweig. 1887. Lehrbuch der Zuckerfabrikation, C. Stammer, 2te Auf., Braunschweig. Food Adulteration and Detection, J. P. Battershall, New York. 1888. Handbuch der Kohlenhydrate, B. Tollens, Breslau. 1888. Hand-book for Sugar Manufacturers, etc., G. L. Spencer, New York. Handbuch der Zuckerfabrikation, F. Stohmann, 2te Auf., Berlin. Die Chemie der Menschlichen Nahrungs und Genussmittel, J. Konig, 3te Auf., Berlin and New York. Sugar : a Hand-book for Planters and Refiners, Lock and Newlands, London. 1890. Sugar Analysis, for Refineries, Sugar-Houses, etc., F. G. Wiechmann, New York. STATISTICS. 1. PRODUCTION OF SUGAR FROM THE CANE. The total production of raw sugar from the sugar-cane for the last five years is thus estimated by Willet and Gray. (Louisiana Planter and Sugar Manufacturer, April 5, 1890.) 1885-86. 1886-87. 1887-88. 1888-89. 1889-90. Cuba Tons. 705,400 Tons. 608,900 Tons. 610,000 Tons. 530,000 Tons. 600,000 Porto Rico 64,000 86,000 50,000 55,000 70,000 Trinidad 49,200 69,000 60,000 60,000 60,000 44,000 65,000 60,000 50,000 60,000 Jamaica 17,000 21,000 30,000 28,000 30,000 Antigua and St. Kitt's . . Martinique 25,000 33,000 25,000 41,000 26,000 39,000 25,000 38,000 28,000 40,000 Guadeloupe 37,000 55,000 50,000 45.000 50,000 Demerara 111,800 135,000 110,000 108,000 125,000 Reunion 35,000 32,000 32,000 25,000 30,000 114,200 101,800 120,000 132,000 125,000 Java 365,950 363,950 396,000 364,000 310,000 British India 50,000 50,000 55,000 60,000 60,000 Brazil 186,000 260,000 320,000 220,000 150,000 Manila, Cebu, and Iloilo . Louisiana 186,000 127,900 180,000 80,900 174,000 158,000 210,000 145,000 180,000 125,000 Peru 27,000 26000 30,000 30,000 30,000 Esrvpt . 65,000 50,000 35,000 35,000 35,000 Sandwich Islands .... 96; 500 95,000 100,000 120,000 120,000 2,339,950 2,345,550 2,465,000 2,254,000 2,228,000 160 THE CANE-SUGAR INDUSTRY. The sugar production of Louisiana for 1890-91 is stated to have been 324,528,000 pounds, or 162,264 tons. 2. Production from the /Sugar-beet. The world's production of beet- sugar for the five years beginning 1885 has been as follows : 1886-86. 1886-87. Tons. Tons. Germany 838,105 1,023,734 Austro- Hungary 369,000 555,300 France 298,407 506,384 Russia 526,200 480,854 Belgium 48,420 118,455 Holland, and other countries 37,500 69,552 Tons. 955,400 408,000 405,750 435,361 121,643 70,538 1888-89. 1889-90 (estimated). Tons. Tons. 978,484 1,260,000 525,000 760,000 474,000 780,000 500,000 430,000 124,400 220,000 68,746 60,000 2,117,632 2,754,299 2,396,692 2,670,630 3,510,000 (Zeitsch. fur Angewandte Chemie, April 15, 1890.) Licht's circular (January, 1891) gives the following figures for beet- sugar production : 1889-90. 1890-91 (estimated). German Empire 1,264,607 tons. 1,335,000 tons. Austro-Hungary 787,989 " 760,000 France ..." 753,078 " 700,000 Russia 456,711 " 530,000 Belgium 221,480 " 200,000 Holland 55,813 " 65,000 Other countries 80,000 " 80,000 3,619,678 " 3,670,000 The beet-sugar production of the United States is thus given in Ware's " Sugar-Beet" (May, 1891) : 1887 200 tons. 1888 1,800 " 1889 3,000 tons. 1890 12,000 " 3. The sugar consumption of different countries for the year 1887, as well as the consumption per capita, are thus stated : * England Consumption. . 1,179 000 tons Per capita. 66 57 pounds United States of America . . . . . . 1,397,000 ' 47.19 France . . . 423,000 ' 22 83 Germany 445 000 ' 18 64 Austro-Hungary . . . 250,000 ' 11 08 Russia . . . 360 000 ' 8 64 Italy . . . 100 000 ' 7 19 Spain 50 000 ' 7 40 Turkey . . . 45,000 ' 4 33 Belgium ... 46 000 ' 1832 Holland . 45 000 ' 19 94 Norway and Sweden ... 44 000 ' 1742 Switzerland . . . 40,000 ' 21 37 Denmark . . . 36,000 " 19.05 Portugal . . . 16,000 " 9.00 Roumania . . . 13,000 " 3.86 Greece . . . . 9,000 " 10.00 ' Servia ... 4 000 " 2 94 ' Montenegro 1 000 " Bulgaria 3 30 " * Stammer, Dingier Polyt. Journ., 271, p. 266. RAW MATERIALS. 161 CHAPTER V. THE INDUSTRIES OF STARCH AND ITS ALTERATION PRODUCTS. I. Raw Materials. STARCH is one of the most important, as well as most widely occurring, productions of the vegetable kingdom. It constitutes, either when extracted from vegetable raw materials, or more generally in admixture with the other plant constituents, the staple article of food for the great bulk of the human race. It is only necessary to call attention to the fact that the prin- cipal cereal grains used throughout the world for food contain starch as their chief ingredient, and that the tubers of many plants and the stems and roots of some trees also yield starch in great abundance. The most complete enumeration and classification of starches is that of Muter as amplified by Allen* and Blyth,f by which they are divided into five groups on the basis of their physical and microscopical diiferences, as follows : I. The potato group includes such oval or ovate starches as give a play of colors when examined by polarized light and a selenite plate and having the hilum and concentric rings clearly visible. It includes tout les mois, or canna arrow-root, potato starch, maranta, or St. Vincent arrow-root, Natal arrow-root, and curcuma arrow-root. II. The leguminous starches comprise such round or oval starches as give little or no color with polarized light, have concentric rings all but invisible, though becoming apparent in many cases on treating the starch with chromic acid, while the hilum is well marked and cracked, or stellate. It includes the starches of the bean, pea, and lentil. III. The wheat group comprises those round or oval starches having both hilum and concentric rings invisible in the majority of granules. It includes the starches of wheat, barley, rye, chestnut, and acorn, and a variety of starches from medicinal plants, such as jalap, rhubarb, senega, etc. IV. The sago group comprises those starches of which all the granules are truncated at one end. It includes sago, tapioca, and arum, together with the starch from belladonna, colchicum, scammony, podophyllum, canella, aconite, cassia, and cinnamon. V . The rice group. In this group all the starches are angular or polyg- onal in form. It includes oats, rice, buckwheat, maize, dari, pepper, as well as ipecacuanha. In addition to the differences in form and marking mentioned above, the starch-granules differ in size according to their different sources, so that under the microscope they can be distinguished by the measurement of the average diameter of the granule. This ranges, according to Karmarsch, from .01 to J 85 millimetre, or from .0004 to .0079 inch. * Coin. Org. Anal., 2d ed., vol. i. p. 335. f Blyth, Foods, Compos, and Anal., p. 139. 11 162 INDUSTRIES OF STARCH AND ITS ALTERATION PRODUCTS. For practical purposes we may now speak of two classes only of these starch-containing materials, viz., the cereals and the plants in which the starch is extracted from tubers, roots, or stems, such as potatoes on the one hand, and the West Indian starch preparations, like arrow-root, sago, and tapioca, on the other. As before stated, starch is the chief ingredient in the cereals, but not at all the only one. The composition of the more impor- tant cereals is thus given by Bell :* CONSTITUENTS. Wheat. Winter sown. Wheat. Spring sown. Long- eared barley. English oats. Maize. Rye. Carolina rice (without husk). Fat 1.48 1.56 1.03 5 14 358 143 19 Starch 6371 6586 6351 4978 64 66 61 87 77 66 Sugar (as sucrose) 257 224 1 34 2 36 1 94 4 30 038 Albumen (insoluble in alcohol) 1070 7 19 818 1062 967 978 794 Nitrogenous matter (soluble in alcohol) . Cellulose 4.83 303 4.40 293 3.28 7 28 4.05 1353 4.60 1 86 509 323 1.40 Mineral matter 1 60 1 74 232 266 1 35 1 85 028 Moisture 1208 1408 1306 11 86 1234 1245 12 15 Total 10000 10000 10000 10000 10000 10000 10000 The chemical formula of starch is (C 6 H 10 O 5 ) n . According to Tollens, confirmed by Mylius, it is C^H^Oa, ; according to Brown soluble starch is C^HgooOjoo, while for the ordinary variety he proposes C^H^O^. Nageli stated that by subjecting the starch-granules to the slow action of saliva, salt solutions, and dilute acids two substances could be shown to be present, granulose, w^hich dissolved, and cellulose (or, as it has been called, farinose], which remained. Arthur Meyer considers that there is only a single sub- stance originally present, and that the cellulose, or farinose, which remains is a decomposition product of the starch. Air-dried starch always retains from eighteen to twenty per cent, of water. It is soluble in cold water, alcohol, ether, ethereal and fatty oils. When it is heated with twelve to fifteen times its bulk of water to 55 C., it begins to show signs of change, swelling up, and at a temperature of from 70 to 80 C. (or even below 70 C. with some pure starches) the granules burst and it becomes a uniform translucent mass, known as " starch-paste," which is not, however, a solution, as the water can be frozen out of it. Boiled with water for a long time it goes into solution, one part dissolving in fifty parts of water. The action of heat upon starch is to change it gradually into dextrine, which is soluble in cold water. One of the best known of the reactions of starch is the formation of a blue color with iodine. This is supposed by some to be merely a physical combination, but more generally believed now to be a chemical compound. Mylius finds that it contains about eighteen per cent, of iodine, partly as hydrogen iodide, and gives it the formula (C^H^O^I^m. Seyfert, accept- ing the same formula for starch, considers that the iodine compound pos- sesses the formula (C^tl^O^gly, which requires 18.61 per cent, of iodine. It is not very stable, being decomposed by water on heating. Neverthe- less, the blue coloration is constantly availed of to note the presence or gradual disappearance or alteration of starch in many technical processes. * Bell, The Analysis and Adulteration of Foods, Part ii. p. 86. PROCESSES OF MANUFACTURE. 163 The action of dilute acids upon starch brings about the change known as "hydrolysis," and there is produced dextrine, C 12 H 20 O 10 , and dextrose, C 6 H 12 O 6 , the latter eventually as sole product. Many ferments, like saliva, the pancreatic ferment, and especially the diastase of malt, produce in starch a somewhat similar change, and yield maltose, C^H^Ojj, and a number of intermediate products between this and stareh. A great deal of investi- gation has been devoted to these intermediate products, and as yet no abso- lute agreement has been reached on the subject. The following is the series of products obtained in this hydrolysis of starch as stated by Tollens : * Starch gives a blue iodine reaction. Soluble starch (amylodextrine) .... gives a blue iodine reaction. C erythrodextrine gives a violet and red iodine reaction. Dextrines -I achroodextrine gives no iodine reaction. (maltodextrine gives no iodine reaction. Maltose reduces Fehling's solution, but not Barfoed's reagent. Dextrose reduces Fehliug's solution, and also Barfoed's reagent. Other chemists notably increase the list of these intermediate products. The existence of erythrodextrine as a distinct compound is doubted by some investigators, who consider it to be merely a mixture of achroo- or maltodextrine with a little soluble starch, such a mixture giving a violet reaction with iodine. By over-treatment with acids unfermentable carbo- hydrates, of a character differing from any of the products named, appear to form. The name gallisin has been given to a compound of this kind, and the formula C 12 H 24 O 10 ascribed to it. For a description of the con- ditions of its formation see later (p. 171). Strong nitric acid in the cold acts upon starch, producing nitro deriva- tives, such as mono-, di-, and tetra-nitro-amylose, collectively known as xyloi'din. Alkalies and alkaline earths form combinations with starch, the barium and calcium compounds being insoluble, of which advantage is taken in the Asboth method for determination of starch. (See p. 173.) n. Processes of Manufacture. 1. EXTRACTION AND PURIFYING OF THE STARCH. Of the various starch-containing materials before enumerated, only a limited number are actually utilized for the extraction of the starch in a pure condition, viz., maize, wheat, rice, potatoes, and arrow-root. In the United States by far the greater amount is obtained from maize, or Indian corn, a limited amount only being extracted from wheat. In Europe, on the Continent, potatoes serve as the chief starch-producing material, some also being extracted from wheat and some from rice, while in the West Indies arrow-root starch is manufactured at St. Vincent and elsewhere. In the manufacture of corn starch, after Avinnowing or cleansing the corn by powerful fans, it is placed in large wooden steeping-vats, holding from one thousand to six thousand bushels. It remains here covered with water at a temperature not exceeding 140 F. for from three to ten days, the water being, however, renewed every six hours, and care being taken to prevent any development of fermentation. In the Durgen system, as practised at the Glen Cove Starch Works, a continuous stream of water, * Tollens, Kohlenhydrate, Breslau, 1888, p. 177. 164 INDUSTRIES OF STARCH AND ITS ALTERATION PRODUCTS. heated to 140 F., flows for three days at the rate of ten thousand gallons per day through eat'h tank, after which the corn is sufficiently softened. The softened corn is now ground between burr-stones, a stream of water running continuously into the hopper of the mill. As it is ground, the thin paste is carried by the stream of water upon the shakers, or sieves. These are either revolving sieves or horizontal square shaking sieves. The starch-con- taining magma is generally reground, and then the paste is passed over the starch-separators. These are inclined sieves of silk bolting-cloth, which are kept in constant motion and are sprayed with jets of water. The starch passes through the bolting-cloth with water as a milky fluid, while the coarser cellular tissue, or husk, of the corn is left behind. This residue is pressed to remove water, and sold as cattle food. The water from the shakers holding the starch in suspension is run into wooden vats, where the starch settles, and the water is drawn off and discarded. The starch is next thoroughly agitated with fresh water, to which a caustic soda solution of 7 to 8 Baume has been added, until the milky liquid has changed to a greenish-yellow color. The object in adding the alkali is to dissolve and remove the gluten and other albuminoids, oil, etc. After sufficient agita- tion and treatment with alkali, the separated starch and glutinous matter is allowed to deposit, the supernatant solution of gluten, oil, etc., is allowed to run to waste, and the impure starch washed and agitated with water. It is allowed to stand at rest for fifteen to twenty minutes to permit insoluble gluten to subside, when the top one of a series of plugs arranged in the side of the vat is withdrawn, and the starch suspended in water allowed to flow by means of a gutter into subsiding-vats placed below ; then the next lower plug is drawn, and so on until the last plug has been drawn. The plugs are replaced and the vats again filled with water, and the operation repeated as before. This operation, called the siphoning process, is gener- ally repeated three times, and the three runnings of starch are collected in three separate vats, forming the three grades of starch of the factory. These three grades of factory starch are again agitated with water, sieved through bolting-cloth, and run finally as purified starch into wooden "settlers." After it has been compacted sufficiently, which is effected in boxes with perforated bottoms, it is cut into blocks and dried upon an absorbent sup- port of plaster of Paris while heated in a current of warm air. In drying out thoroughly, any remaining impurities come to the surface with the escaping moisture and form a yellowish crust. When this is removed, the interior is found to be perfectly white. The Results on a bushel of fifty- six pounds of corn are thus stated by Archbold : * Starch recovered 28.000 pounds. Dry refuse for cattle food 13.700 " Bran (in cleansing process) 0.728 " Moisture of the corn 5.626 " Loss (albuminoids, oil, etc.) 7.946 " 56.000 " In the Jebb process for the manufacture of starch from Indian corn, recently introduced, the use of alkali is entirely avoided, and the treatment shortened and simplified by effecting a mechanical separation of both the husk and the germ of the corn before the starchy part of the corn is ground. *Journ. Soc. Chein. Ind., 1887, p. 82. - PROCESSES OF MANUFACTURE. 165 The ground husk and germ containing the gluten, albuminoids, and oil are sold for cattle food, while the starch in a high state of purity is sepa- rately ground and prepared. In manufacturing starch from wheat two quite diiferent processes are followed, according as the gluten is to be obtained as a side -product or not. In the process generally known as the " sour," or fermentation, process, the gluten is wasted. In this process the wheat is steeped in tanks until thor- oughly softened, then crushed in roller-mills, and placed for fermentation in large oaken cisterns. The temperature is here maintained at about 20 C., and the operation lasts some fourteen days, the mass being well stirred dur- ing its continuance. The sugar of the wheat and a part of the starch are converted into glucose, which undergoes alcoholic fermentation, and passes by oxidation into the acetous fermentation also, acetic, propionic, and lactic acids being formed. These rapidly attack and dissolve the gluten, liberating the starch-granules. The impure liquor is drawn off from the starch mass, and the latter is washed, either in hempen sacks while being trodden under foot or in drums with perforated sides. After repeated washings and set- tlings and renewed sieving through fine hair sieves the starch is sufficiently purified. Wheat starch is also obtained from wheat flour without fermenta- tion by what is known as Martin's process, in which a stiff dough is made of the flour. This is then washed in a fine sieve under a jet of water till all the starch has escaped as a milky fluid. This leaves the gluten, of which about twenty-five per cent, of the weight of the flour is gotten suitable for use in the manufacture of macaroni, or to be used instead of albumen or casein in calico-printing. In the manufacture of potato starch, the potatoes are washed and then pulped by a grating or rasping machine. The grated mass, made into a paste with water, then goes at once into the sieving machine, where it is rubbed by revolving brushes against the wire or hair sides of the rotating cylinder, while a current of water is continuously washing out the fine starch from the pulp. The sifted and washed starch deposits in large tanks, where it is repeatedly washed by agitation and settling with fresh waters. It is then spread out on absorbent slabs to dry, or is dried in centrifugals or filter- MANUFApruRE OF GLUCOSE, OR GRAPE-SUGAR. As stated on a preceding page^ the action of dilute acids converts starch into dextrine, maltose, and dextrose, the last of which becomes by continued action the sole product. I As it is also the most important product of this action of acids, we shall take it up ftnst. The purified starch obtained as described in the preceding section, while yet moist, is taken for the treatment with acids. The " conversion" is accomplished in either open or closed converters, or partly in"o"fie and partly in the other. The open converters are wooden vats, generally of three thousand to four thousand gallons capacity, and serve to treat the starch from one thousand bushels of corn^ They are pro- vided with copper steam-coils, either closed or perforated.il Sulphuric acid is generally employed in the conversion, though other acids nave been used. The quantity of the acid employed varies with the object of the manufac- turer. For the production of " glucose," a liquid product which contains much dextrine, a smaller quantity is used than w r hen solid " grape-sugar" is to be produced, in which the conversion into dextrose is mucn more com- plete. The proportion varies from one-half pound oil of vitriol to one and a quarter pounds per hundred pounds of starch. When the open converter . 166 INDUSTRIES OF STARCH AND ITS ALTERATION PRODUCTS. FIG. 59. is used, a few inches of water is introduced and the acid added, or half the acid may be added to the starch mixture. The acid water is brought to a boil, and the starch, previously mixed with water to a gravity of from 18 to 21 Baume, is slowly pumped in, keeping the liquid constantly boiling. When all the starch has been introduced, the whole is boiled until the iodine test ceases to give a blue color and shows a dark cherry color. . The boiling is usually continued for about four hours. The closed converters may be made from strong wooden vats or may be of copper ; they are provided with safety-valves, and are made of sufficient strength to stand a pressure of six atmospheres. Fig. 59 shows the form first introduced in this country by T. A. Hoffmann, while Fig. 60 shows the form proposed by Maubre in L o n- don. In this case the starch is mixed with water to a gravity of from 11 to 16 Baume. This with the acid is intro- duced into the con- verter, and the whole is heated under a pressure of from forty-five to s e v- enty-fi ve pounds per square inch. The time required for the conversion i s much shorter than in the open con- verters. The use of open and closed con- verters successively is often resorted to. The starch and water of a gravity of 15 or 16 Baume is first boiled in the open converter for from one to two hours, then transferred to the closed converter and boiled under a press- ure of from forty-five to seventy-five pounds per square inch. The time of this boiling varies from ten minutes to half an hour. When the starch has been sufficiently converted, according to the product desired, the liquor is run into the neutralizing-vats. Here a sufficient quan- tity of marble-dust is added to completely neutralize the sulphuric acid. A little fine bone-Black is generally added at the same time. It is then allowed to cool and deposit the sulphate of lime. The liquor having a gravity of 12 to 18 Baume, and known as " light liquor," is next filtered through bag filters of cotton cloth or filter-presses. In many establishments the liquor is now treated with sulphurous acid gas to prevent fermentation, and prob- ably to some extent to act as a bleaching agent. It is then filtered through bone-black, by which it is decolorized and at the same time freed from vari- ous soluble impurities. Concentration is then effected in the vacuum-pan at PROCESSES OF MANUFACTURE. 167 a temperature of about 140 F. until it has a gravity of from 28 to 30 Baume, when it is called "heavy liquor." A second bag or filter-press filtration is now resorted to in many factories to remove the sulphate of lime, which separates out at this degree of concentration. It is then filtered a second time through bone-black to secure complete decolorization and puri- fication. The final concentration is effected by boiling the liquor in the vacuum-pan until it reaches 40 to 42 Baum6. That product in which the conversion has been least complete remains liquid, and is called " glu- FIG. 60. cose" in the trade ; that which is ready to solidify is known as " grape- sugar." Dr. Arno Behr has patented a process for obtaining the solid grape- sugar in pure crystals. While it is still liquid there is added to it a small quantity of crystallized anhydrous dextrose. The mixture is filled into moulds, and in about three days it is found to be a solid mass of crystals of anhydrous dextrose. The blocks are then placed in a centrifugal machine to throw out the still liquid syrup, and the anhydrous dextrose remains as a crystalline mass. 3. MANUFACTURE OF MALTOSE. By the action of the diastase of malt upon starch is formed mainly maltose. Dilute sulphuric acid will convert this by prolonged boiling into dextrose, but diastase alone will not so convert it. The manufacture of maltose on a large scale as a prepara- tion for use in beer-brewing to simplify the preparation of a suitable wort has been attempted by several. Dubrunfaut and Cuisinier patented a pro- cess in 1883 for preparing maltose, either as syrup or crystallized, by the following procedure : One part of green or partially dried malt is warmed with two to three parts of water, digested for several hours at 30 C., and afterwards filter-pressed to obtain an " infusion" of malt. One part of starch-flour is then suspended in two to twelve parts of water, and five to ten per cent, of infusion added, the whole gradually warmed to 80 C., then heated under a pressure of one and a half atmospheres for thirty minutes, quickly cooled to 48 C., and treated with five to twenty per cent, of infu- sion and hydrochloric acid (from six to twenty-five cubic centimetres of acid per one hundred litres). After one hour the mass is filtered through filter- paper fastened upon linen cloth. The solution is allowed to stand at 48 C. for twelve to fifteen hours, then concentrated to 28 B., filtered, again concen- trated to 38 B., filtered through animal charcoal, and allowed to crystallize. A sample of the syrup made from corn-starch by the Brussels Maltose Com- 168 INDUSTRIES OF STARCH AND ITS ALTERATION PRODUCTS. pany working under this patent was analyzed by Marcker,* and found to contain 19.8 per cent, water, 78.7 per cent, maltose, 1.5 percent, non-sugar, and no dextrine. The process is, however, said to have failed as yet of commercial success. Saare,f who has recently investigated it, shows that the complete conversion into maltose only takes place with weak mashes, and he concludes from his results that the process is not suitable for German distilleries under the present conditions. O'Sullivan and Valentin J have also patented a process for producing from starch, or starch-yielding sub- stances, preferably from rice, a compound solid body, which the inventors term " dextrine-maltose," consisting of the same proportional quantities of dextrine and maltose as are ordinarily obtained from malt by a properly-con- ducted mashing process, and which it is intended should replace a portion of the malt used in brewing. For details, see original article. Perfectly pure maltose can be obtained by Herzfeld's process of repeatedly extracting with alcohol from the syrupy product of the action of malt upon starch. The alcohol precipitates the dextrine, but dissolves the maltose, which can then be obtained in crystalline condition. 4. MANUFACTURE OF DEXTRINE. This may be effected by acting upon starch with heat alone, by the action of dilute acids and heat, or by the action of diastase. The first and second of these methods are followed in preparing the solid product. In the manufacture by heat alone the limits of temperature are 212 to 250 C., although Payen says that 200 to 210 C. produces the most perfectly soluble dextrine. The starch is heated in revolving drums, which are frequently double-jacketed, and contain oil in the outer space in order to insure uniform heating. After the moisture is given off, the loss of weight in roasting is small, two hundred and twenty pounds of starch giving one hundred and seventy-six pounds of finished dextrine. In the manufacture by the aid of acids the starch is mixed with dilute nitric or hydrochloric acid so as to form a damp powder. This is exposed to a temperature of 100 to 120 C. until the transformation is complete, which can be determined by applying the iodine test from time to time. The process must be arrested promptly when the starch is all changed, or the dextrine will pass rapidly into glucose. Oxalic acid is also sometimes employed in the manufacture of dextrine. 5. MANUFACTURE OF SUGAR-COLORING (Caramel, or Zucker-couleur). Very considerable quantities of an artificial coloring material for use in coloring beer, rum, cognac, and high wines is made on the Continent of Europe from starch. For the manufacture of rum and cognac coloring, starch is treated with dilute sulphuric acid, as before described for the manu- facture of dextrose and dextrine mixtures, but the heating is continued until all the dextrine has been changed into dextrose, as determined by taking a sample from time to time and testing it with an excess of ninety-six per cent, alcohol. When no longer any turbidity from separated dextrine shows, the reaction is considered as finished. The sulphuric acid is then neutralized with carbonate of lime, and after sufficient standing the clear liquor is run off from the precipitated sulphatfe of lime. It is now concentrated to 36 B. and filtered. The hot filtrate is then run into a vessel provided with * Jahresber. der Chein. Tech., 1886, p. 613. f Dingier, Polytech. Journ., *266., p. 418. j Journ. Soc. Chem. Ind., 1888, p. 446. PRODUCTS. 169 mechanical agitation and heated to boiling, when crystallized soda salt (three kilos, of soda to one hundred kilos, of sugar solution) is added in small por- tions at a time. The contents of the kettle froth and must be continuously stirred. White and inflammable vapors are given off and the color rapidly deepens. The heat is now gradually lessened to prevent carbonizing of the contents of the vessel, and the color is tested. A drop chilled by being dropped into water should harden and be brittle and should taste bitter. The contents of the. kettle are then cooled at once by running in hot water. When the production of the color is completed, the contents of the kettle are extracted with water, filtered to remove carbonized particles, and then tested as to quality. The coloring is made in several grades or depths of color, which are also differently soluble, the one in seventy-five per cent, alcohol and the other in eighty per cent, alcohol. For beer- or wine-coloring it is not necessary to be so careful to use a sugar freed perfectly from dex- trine, nor is the treatment with soda necessary. Simple caramelizing by heat will suffice to produce the necessary color. HI. Products. 1. STARCH. The properties and action of reagents upon starch have already been noted in speaking of it as a raw material. It is only necessary to subjoin a few analyses of commercial starches in order to show the char- acter of that usually obtainable. Those of potato and wheat starch are by J. Wolff, as quoted in " Wagner's Chemical Technology," and those of corn starch are by Dr. Archbold, as given by him in the " Journal of the Society of Chemical Industry," 1887, p. 188. PERCENTAGE COMPOSI- TION. Potato starch. (Wolff.) Wheat starch, I. (Wolff.) Wheat starch, II. (Wolff.) Corn starch, I. (Archbold.) Corn starch, II. (Archbold.) Corn starch. III. (Archbold.) Starch 83 59 83.91 79 63 98 50 9'' 88 90.33 Gluten 10 ] 84 ) Cellulose 0.50 1.44 3.77 | 2.38 | 4.25 Ash "WaUT 0.63 15 38 0.03 14.52 -0.55 14.20 0.30 1 20 0.60 4 14 0.65* 4.77 Total 100.00 100.00 100.00 100.00 100.00 100.00 2. GLUCOSE AND GRAPE-SUGAR. Starch-sugar appears in commerce in a great variety of grades and under a similar variety of names. As already said, in the United States the name glucose is in .general applied to the liquid products, while that of grape-sugar is given to the solid products. In France, where large quantities of similar products are manufactured, the liquid product is known as " sirop cristal" and the solid product "glucose mass6." The following analyses show the composition of the commercial products, the first five being American products as examined by the Com- mittee of the National Academy of Sciences,* and the last two being French as exarnined by L. von Wagner : f * Report on Glucose, Washington, 1884, p. 22. | Dingier, Polytech. Journ., 266, p. 470. 170 INDUSTRIES OF STARCH AND ITS ALTERATION PRODUCTS. PERCENTAGE COMPO- SITION. I. Glucose solution. II. Glucose solution. III. Glucose solution. Solid grape-sugar. Crystallized grape-sugar. "Sirop cristal." " Glucose masse." Dextrose 36.5 86.5 39.0 72.1 99.4 640 64 66 Maltose . 19.3 7.6 Dextrine 29.8 40.9 41.4 9.1 21.0 18 22 "Water 14.2 15.3 19.3 16.6 0.6 15.0 15-18 100.00 100.00 100.00 100.00 100.00 100.00 100.00 3. MALTOSE. Maltose forms fine white crystalline needles aggregating in warty groups, which have a faint sweetish taste. It is soluble in water and methyl and ethyl alcohol, but more difficultly in the last than dextrose. Its formula is C^H^Oj,, and it crystallizes with one molecule of water, which it loses slowly at 100 C. in a vacuum. Its specific rotatory power is, according to Meissl, (S) D = 140.375 .01837 P .095 T, where P equals the percentage strength of the solution and T the temperature. A ten per cent, solution at 20 C. would then be 138.3. O'Sullivan takes it as 139.2 for a ten per cent, solution. Its reducing power with Fehling's solution is frequently stated to be two-thirds that of dextrose, but Brown and Heron as well as O'Sullivan make it more exactly sixty-two per cent, of that shown by dextrose. It has no action, however, upon Barfoed's reagent (see p. 173), which is reduced by dextrose. Maltose is said to be directly and completely fermentable without previous change into dextrose, but more slowly than this latter, so that if a mixture of maltose and dex- trose be fermented with yeast, the whole of the dextrose disappears before the former sugar is acted upon. 4. DEXTRINE. Pure dextrine is a white amorphous solid. It is taste- less, odorless, and non-volatile. It is completely soluble in cold water, but the commercial varieties usually leave from twelve to twenty per cent, or even more of starch and other insoluble residue when dissolved. Heated with dilute acids it yields maltose and ultimately dextrose. It is nnferment- al^e if free from sugar. It has no reducing power on Fehling's solution. Probably what is called dextrine is a mixture of products obtained in the breaking down of the complex starch-molecules. Some investigators claim to have obtained sixteen distinct modifications or varieties of dextrine in this way. We have before (see p. 163) alluded to amylodextrine, erythro- dextrine, achroodextrine, and maltodextrine. Commercial dextrine, or " British gum," gives a brown coloration with iodine, and probably consists largely of erythrodextrine. The following analyses by R. Forster give an idea of the composition of the dextrines usu- ally obtainable : PERCENTAGE COMPOSITION. First quality dextrose. Dark- burned starch. Brown dextrine. Gommel- ine. Old dextrine. Light- burned starch. Dextrine 72.45 7043 63 fiO 59.71 49.78 5.34 Sugar 8 77 1 92 7 67 5 76 1.42 0.24 Insoluble 13 14 19 97 14 51 20.64 3080 86.47 "Water 564 7 68 14 22 13 89 1800 7.95 100.00 100.00 100.00 100.00 100.00 100.00 ANALYTICAL TESTS AND METHODS. 171 Dextrine is used as a substitute for natural gums, especially for gum arabic. It is thus used in calico-printing and in the mordanting and print- ing of cold's upon most other classes of textile goods, for mucilage, for glazing cards and paper, as warp-dressing, and in the manufacture of beer. It forms the crust on bread by the change of the starch of the flour in baking, and is present in most products from starch or starch-sugar. 5. UNFERMENTABLE CARBOHYDRATES (Gallisin). The presence of an unfermentable carbohydrate in starch-sugar was long since pointed out by O'Sullivan. The compound which has been specially studied is known as gallisin, and is prepared by fermenting a twenty per cent, solution of starch-sugar with yeast at 18 or 20 C. for five or six days. The resultant liquid was filtered, evaporated to a syrup at 100 C., and shaken with a large excess of absolute alcohol. The treatment with alcohol was repeated several times until the unaltered sugar and other impurities were removed, the syrup being converted into a yellowish crumbling mess, which, by pound- ing in a mortar with a mixture of equal parts of alcohol and ether, was obtained as a gray powder. After purifying with animal charcoal and dry- ing over sulphuric acid, the gallisin was obtained as a white amorphous extremely hygroscopic powder. Its taste is at first sweet, but afterwards becomes insipid. It is easily decomposable by heat, even at 100 C. It is readily soluble in water, nearly insoluble in absolute alcohol, and but slightly more soluble in methyl alcohol, in which respect it differs from dextrose. Gallisin is stated to have the composition C 12 H 24 O ]0 . Its concentrated aque- ous solution is distinctly acid to litmus and a sparingly soluble barium compound may be obtained therefrom by adding alcoholic baryta. It reduces nitrate of silver on heating, especially on addition of ammonia, reduces bichromate and permanganate, and precipitates hot Fehling's solu- tion. Its cupric oxide reducing power (dextrose = 100) is stated to be 45.6. Gallisin is dextro-rotatory, the value for S D being stated to be 80.1 in twenty-seven per cent., 82.3 in ten per cent., and 84.9 in 1.6 per cent, solutions. By heating with dilute sulphuric acid for some hours gallisin yields a large proportion of dextrose, but its complete conversion has not so far been effected. It is doubtful whether "gallisin" as hitherto obtained is really a definite compound, but the possibility of isolating a reducing or optically active body from the liquid left after fermenting solutions of many specimens of starch-sugar cannot be ignored in considering the composition of commer- cial glucose. IV. Analytical Tests and Methods. 1. FOR STARCH. The usual method for the determination of starch is to invert by the action of dilute acid, and then determine the dextrose produced by the aid of Fehling's solution. In this case one hundred parts of dextrose are taken as indicating ninety of starch. It has been found, however, that the change to dextrose by the aid of dilute sulphuric acid is not complete, that other non-reducing bodies are formed, and that but ninety-five per cent, of the starch is converted into dextrose. The hydrol- ysis is more completely effected by the aid of hydrochloric acid, as carried gut in Sachsse's method. 2.5 to 3 grammes of dry starch (or so much of the starch-containing substance as would correspond to this amount of starch) are placed in a flask with two hundred cubic centimetres of water and twenty cubic centimetres of hydrochloric acid and heated on the water- 172 INDUSTRIES OF STARCH AND ITS ALTERATION PRODUCTS. FIG. 61. bath with inverted condenser for three hours. (Marcker states that heating for three hours with this amount of hydrochloric acid does not give more than ninety-six to ninety-seven per cent, of the starch as sugar, as some of the latter is destroyed. He recommends using fifteen cubic centimetres of acid and heating for two hours.) The contents of the flask are then neutralized with potassium hydrate or sodium carbonate, filled to the mark, and the dextrose determined by Fehling's solution. If other carbohydrates or cellulose are present, which would be also converted into dextrose by hydrochloric acid, the starch must be previously brought into the soluble form, which may be done by heating with water to 130 C. in a pressure- flask like that of Lintner, shown in Fig. 61. Or the starch may be hydro- lyzed in part by infusion of malt or diastase at 62.5 C., filtered from cellulose, etc., and then treated with hydrochloric acid for complete hydrol- ysis as above. In this latter case, the process of Reinke* is the simplest. Three grammes of the sample as finely powdered as possible are heated to boil- ing with fifty cubic centimetres of water, cooled to 62.5 C., and hydrolyzed for an hour at this temperature with .05 gramme of diastase. This is prepared according to Lintner's procedure, by making an alcoholic twenty per cent, extract (1 : 3) of raw malt, adding to the filtrate two volumes of ninety- six per cent, alcohol, separation of the precipitated diastase, washing with alcohol and ether, and drying in a des- iccator. The mixture is then cooled, diluted with water to two hundred and fifty cubic centimetres, and filtered. Of the filtrate, two hundred cubic centimetres are taken and hydrolyzed, as before described, with fifteen cubic centimetres of hydrochloric acid of 1.125 specific gravity for two and a half hours, when the solution is neutralized and the dextrose determined. A more elaborate course of treatment, following in the main the same lines as the procedure of Reinke just described, but stopping with the action of the diastase, has been published by O'Sullivan, and is given at length by Allen. f In this case the filtered liquid, assumed to contain noth- ing but maltose and dextrine, is made up to one hundred cubic centimetres, and the density determined. It is then tested with Fehling's solution for the maltose, and the dextrine deduced from the rotatory power of the solution. The maltose found, divided by 1.055, gives the corresponding weight of starch, which, added to the dextrine found, gives the total number of grammes of starch represented by one hundred cubic centimetres of the solution. The method for the determination of starch in cereals most generally used in Germany at present is that of Marcker.J Three grammes of sub- * Jahresher. Chem. Technol., 1887, p. 863. f- Commercial Organic Analysis, 2d ed., vol. i. p. 343. j Jahresber. Chem. Technol.*, 1885, p. 863. ANALYTICAL TESTS AND METHODS. - 173 stance are placed in a small beaker (preferably of metal), which is placed as one of several in a Soxhlet pressure-boiler, or the test is carried out in the Lintner pressure-flask, figured on the preceding page, and heated to the tem- perature of boiling water. It is then cooled to 60 to 65 C., five cubic centi- metres of thin malt infusion are added, and it is digested at this temperature for some twenty minutes. It is then made faintly acid (one cubic centi- metre of tartaric acid suffices) and heated under a pressure of three to four atmospheres. It is then cooled down and an additional five cubic centi- metres of malt infusion added, with which it is digested an half-hour. The solution is then brought up to one hundred cubic centimetres, filtered, and determined with Fehling's solution, either by titration or by weighing the reduced copper. Of other methods proposed for starch determinations it is only neces- sary to notice the Asboth method, proposed in 1887. It depends on the fact that starch forms a compound with baryta-water, C 24 H 40 O 20 BaO, con- taining 19.1 per cent, of BaO, which is insoluble in forty-five per cent, alcohol. The baryta-water is used in excess, and the free alkaline earth determined by titration with decinormal hydrochloric acid. Numerous experimenters have taken exception to the method that the results were variable, and that starch combined with varying amounts of barium oxide. To these objections the author has recently replied,* and claims that the presence of fat in the cereals interferes with the accuracy of the determina- tion, and that if the fat be previously extracted by ether, the determinations in the fat-free residue are accurate and concordant. J. Napier Spence, in the " Journal of the Society of Chemical Industry" for 1888, p. 77, has also come to the defence of the Asboth method and shown the conditions under which it yields accurate results. 2. GLUCOSE, OR DEXTROSE. For the determination of dextrose alone the Fehling's solution affords the most accurate means. For its use, see analysis of raw sugars, p. 152. In the absence of any other optically active body its examination with the polariscope will also suffice. For mixtures like com- mercial glucose, which contains dextrose, maltrose, and dextrine, see later. 3. MALTOSE. This variety of sugar, as before stated, has optical activity and reducing power on Fehling's solution. It can, however, be distinguished from dextrose by its failure to reduce Barfoed's solution, which is reduced by dextrose and invert sugar. This reagent is made by dissolving one part of neutral copper acetate in fifteen parts of water, to two hundred cubic centimetres of which five cubic centimetres of thirty- eight per cent, acetic acid is added. Boiled for several minutes with maltose solution it shows no reduction. 4. DEXTRIXE. Pure dextrine differs from dextrose and maltose in showing no reducing power with either Fehling's solution or with Knapp's mercuric cyanide solution. It can, indeed, be freed from admixture with dextrose and maltose by heating with an excess of an alkaline solution of mercuric cyanide, which oxidizes these two varieties of sugar, leaving the dextrine unaffected. (See Wiley's method on next page.) 5. COMMERCIAL GLUCOSE AND SIMILAR MIXTURES DERIVED FROM STARCH. As commercial glucose is likely to be a mixture of the three compounds, dextrose, maltose, and dextrine, its analysis and the determina- tion of the several constituents becomes a frequently-recurring problem. * Chemiker Zeitung, 1889, pp. 591 and 611. 174 INDUSTRIES OF STARCH AND ITS ALTERATION PRODUCTS. Three methods have been proposed. The first, by Allen,* requires the determination of moisture and ash in the sample, which, subtracted from 100, leaves the total organic solids, O. The apparent specific rotatory power, S, and the cupric oxide reducing power (in terms of dextrose re- duction =100), Kj are now determined. Then, if m be the maltose, g the dextro-glucose, and d the dextrine, Allen determines the respective per- , ,, f ,, f , / 52.7 K+ 198 (OK)\ centagee by the use ot the formulas m=|/o '1-4- V 100 / .313, g = K.Q2 m, and d = (g + m). The author states that the presence of gallisin or other tin fermentable sugar may vitiate the values of K and S, as observed, and so make the results inaccurate. The second method is that of Wiley, f which is based upon the theory that boiling with an alkaline solution of mercuric cyanide will destroy the optical activity of maltose and dextrose, leaving that of dextrine unchanged. The cupric oxide reducing power of the sample is ascertained in the usual way by Fehl ing's solution. The specific rotatory power is determined by polarizing a ten per cent, solution (previously heated to boiling) in the ordinary manner. Ten cubic centimetres of this solution used for polar- izing are then treated with an excess of an alkaline solution of mercuric cyanide, and the mixture boiled for two to three minutes. It is then cooled and slightly acidulated with hydrochloric acid, which destroys the reddish- brown color possessed by the alkaline liquid. The solution is then diluted to fifty cubic centimetres, and the rotation observed in a tube four decime- tres in length. The angular rotation observed will be due simply to the dextrine, the percentage of which may then be calculated by the formula rotation X 1000 X cubic centimetres of solution polarized = per- 198 X length of tube in centimetres X weight of the sample taken centage of dextrine. The percentages of dextrose and maltose may be deduced from the reducing power of the sample, or from the difference in specific rotatory power before (S) and after (s) the treatment with alkaline mercuric cyanide. Thus, 7^=1.00 g -f .62 m, =.527 (7 4-139.2 m-f 1.98 d and s=1.98 d, whence m== ' ' ' g can now be found l.Obo^b from the first of the three equations, and then d in the second. Wiley's process was employed by the Committee of the National Academy of Science in their investigation of commercial glucose from corn starch. It is, however, based upon several assumptions that have not been specifically proven, and especially in the presence of any considerable quantity of maltose are its results open to doubt. (See Allen, Commercial Organic Analysis, 2d ed., vol. i. p. 305, foot-note.) The third method of estimating the constituents in commercial glucose is due to C. Graham, and is probably more exact than either of those before mentioned. Dissolve five grammes of the sample in a small quantity of hot water and add the solution drop by drop to one litre of nearly absolute alcohol. Dextrine is precipitated, and on standing becomes attached to the sides of the beaker, while maltose, gallisin, and dextrose are soluble in the large quantity of alcohol employed. If the solution be then decanted from the precipitate, the dextrine in the latter can be ascertained by drying and weigh- ing, or by dissolving it in a definite quantity of water and observing the * Commercial Organic Analysis, 2d ed.. vol. i. p. 309. | Chemical News, xlvi. p. 175. BIBLIOGRAPHY AND STATISTICS. 175 solution, density, and rotation. The alcohol is distilled off from the solution of the sugars and the residual liquid divided into aliquot portions, in one of which the gallisin may be determined after fermentation with yeast, while others are employed for the observation of the specific rotation and reducing power, which data give the means of calculating the proportions of maltose and dextrose in the sample. V. Bibliography and Statistics. BIBLIOGRAPHY. 1867. Einleitung in die Tec-hnisehe Microscopic, J. "Wiesner, Vienna. 1873. Die Rohstott'e de-s Ptianzenreicb.es, J. Winner, Leipzig. 1874. Die Starkegruppe, W. Nageli, Leipzig. 1877. Die Chemie der Kohlenhyarate, etc., R. Sachsse, Leipzig. Fortschritte der Chemische Industrie, A. W. Hofmann, Heft iii., Braunschweig. Die Starkefabrikation, Rehwald, Vienna. 1879. Die Starkefabrikation, F Stohmann, Berlin. 1881. Starch, Glucose, and Dextrine. Friinkel and Hutter, Philadelphia. Manual of Sugar Chemistry, J. H. Tucker, New York. 1882. Foods, their Composition and Analysis, A. W. Blyth, London. Die Starke- und die Mahlproducte, F. von Hohnel, Berlin. 1884. Report on Glucose by the National Academy of Sciences, Washington. 188*. Die Starkefabrikation, F. Rehwald. 1886. Die Starkefabrikation, Dextrin und Traubenzucker, L. von Wagner, 2te Auf., Braunschweig. 1887. Die Fabrikation der Starke, K. Birnbaum, Braunschweig. 1888. Handbuch der Kohlenhvdrate, B. Tollens, Breslau. 1891. Die Untersuchung Landwirthschaftlich wichtiger Stoffe, J. Konig, Berlin. STATISTICS. 1. PRODUCTION OF STARCH-SUGAR AND GLUCOSE IN GERMANY. 1886. 29 factc rics produced 14,962,000 kilos, starch-sugar (solid) and 7,200 kilos, crystal 'ed. 1887. 30 1888. 29 1889. 30 '1886. 29" 1887. 30 1888. 29 1889. 30 13.903,700 11,010,500 17,580,200_ 30,000,000 33,515,800 24.481,400 34,084,100 glucose syrup jand 340,000 130,000 208,800 2,522,500 2,180,500 2,306,000 2,748,000 couleur. 2. EXPORTATIONS OF STARCH AND GLUCOSE FROM THE UNITED STATES. 1888. 1889. 1890. Glucose (pounds) 6.263,750 31,285,220 38,256,116 Value $163,573 $748,560 $855,176 StarchTpounds) 5,755,806 7,228,193 9,168,097 * 3. PRODUCTION OF GLUCOSE IN THE UNITED STATES. The report of the Committee of the National Academy of Science in January, 1884, gave the following statement of the glucose industry at that date : 29 glucose factories, with estimated capital of $5,000,000, consuming 40,000 bushels of corn per day, and producing grape-sugar and glucose of the annual value of nearly $10,000,000. In December, 1889, according to an address of E. Richards, chemist of the Internal Revenue Bureau (Washington, 1890), the figures were, 12 facto- ries, wHh estimated capital of from $12,000,000 to $15,000,000, consuming about 50,000 bushels of corn per day, and having an annual production of 450,000,000 pounds, valued at $10,500,000. 176 FERMENTATION INDUSTRIES. CHAPTER VI. FERMENTATION INDUSTRIES. A. NATURE AND VARIETIES OF FERMENTATION. THE word fermentation in the broader sense is applied to those changes whereby in the presence of a body called a ferment many organic bodies, notably the carbohydrates, are decomposed into simpler compounds, although not necessarily into the ultimate products of decomposition. The ferments which seem to determine the decomposition may be either soluble unorganized ferments, or insoluble organized ferments, which are, in fact, minute vegetable growths. With the soluble ferments, such as diastase invertin (or invertase), emulsine, or myrosine, pepsine, trypsine, and papaine, which act upon carbohydrates, glucosides, and albuminoids, we are not now concerned, although the first and second of those mentioned play a very important part in the hydrolysis of starch and cane-sugar. The organized ferments or vegetable growths may be divided into three classes : first, mould-growths ; second, yeast-plants, or the different species and varieties of Saccharomyces ; and, third, bacteria, belonging to the two genera Schizomycetea and Schizophycetes. The most important fermentations from an industrial point of view are the alcoholic, which is brought about mainly* by the presence of ferments of the second class, and the acetic and lactic, which are brought about by ferments of the third class. Upon the alcoholic fermentation depend three important groups of industries, viz., the manufacture of malt liquors, the manufacture of wines, and the manu- facture of ardent spirits, or distilled liquors. Upon the acetic fermentation depends the manufacture of different varieties of vinegar, and upon the lactic fermentation the manufacture of cheese and other milk products. The alcoholic fermentation is always meant when we use the word fer- mentation in the narrower sense, as with reference to the change which starch and saccharine bodies most generally undergo. In this fermentation, the action of the yeast-plant seems to differ according to the variety of sugar presented to it. Dextrose is most immediately acted upon, the main re- action being C 6 H 12 O 6 = 2C 2 H 6 O -f- 20O 2 , although, as Pasteur first showed, side-products like glycerine and succinic acid are also formed, and in practice only about ninety-five per cent, of the dextrose is decomposed by the main reaction. Cane-sugar is not immediately fermentable. If it has been previously exposed to the action of dilute acids, it is changed into invert sugar, which then acts like dextrose. The yeast-plant can effect the same change itself. Invertin (or invertase, as it is also termed) is a soluble fer- ment existent in yeast. It has the property of rapidly and completely effecting the transformation of cane-sugar into invert sugar, but is without * Hansen finds that several varieties of the genus Muco?-, belonging to the third class, can develop a feeble alcoholic fermentation. NATURE AND VARIETIES OF FERMENTATION. 177 sensible action on dextrose, levulose, maltose, or milk-sugar. Towards dextrine its action is not so certainly negative. The conditions of the activity of the yeast-plant have been studied by many chemists, but notably by Pasteur. It has been found that if an abundance of air is supplied the plant grows and multiplies but fermenta- tion proceeds very slowly, when the supply of air is limited, the fermenta- tion proceeds more rapidly while the growth of the cells is largely arrested, and that in the absence of air the fermentation proceeds with greatest rapidity, although the plant-cells do not grow any longer, but gradually disintegrate and die. Pasteur's dictum, that " fermentation is the conse- quence of life without air," is no longer taken as strictly accurate, as with the cessation of the growth and extension of the yeast-plant (which is dependent upon air like the life of any other plant), although its fermenta- tive activity then becomes greatest, it begins at the same time a decay which leaves it after a time dead and inactive. The genus Saccharomyc.es has already been alluded to as the active agent in the alcoholic fermentation. The species Saccharomyces cerevisice is generally known as the special beer ferment and the Saccharomyces eUipsoideus as the wine ferment. Moreover, of the Saccharomyces cerevisice, two well-marked varieties have been recognized. The one is the most active at the ordinary temperature (16 to 20 C.), and carries through its fermentative work in from three to four days ; the other works at a lower temperature (6 to 8 C.) and the fermentation is much slower. The first, placed in a saccharine liquid, is carried by the carbon dioxide which it liberates to the surface of the liquid, where it continues its activity ; it is therefore known as a surface or top yeast. The second, on the contrary, is not carried up, and rests during its entire activity on the bottom of the fermenting vessel, and is hence called a bottom yeast. Two quite distinct methods of beer-brewing are practised (see p. 183), depending upon the use of the one or the other of these varieties of yeast. It has been found, how- ever, in practice that, even when a top yeast is used exclusively or a bottom yeast exclusively, the results are not always uniform. These anomalies are now made clear through the researches of E. Ch. Hansen, of Copenhagen, who has applied the methods of pure cultivation introduced by bacteriolo- gists to the study of the yeast-plant. He has found that if a single yeast- cell of one of the better varieties of Saccharomyces be cultivated with the precautions needed to exclude what is called " wild yeast" (germs present in the air, notably in the summer months), absolutely uniform results can be gotten in brewing. Beginning in 1883, he has developed the study, and it has now been accepted by most of the leading authorities on fermenta- tion. He first described six species : Saccharomyces cerevisice I., Saccha- romyces Pastorianus I., II., and III., Saccharomyces ellipso'uleus I. and II., of which the second, fourth, and sixth cause bitterness and turbidity (so- called " diseases" in beer). He has since * increased the list of varieties of ferments studied to forty, including both top and bottom yeasts, ferments similar to yeast but not belonging to the genus Saccharomyces, and forms of mould-growth. He divides the representatives of each genus into two groups according as they secrete invertin or not. Fresh yeast resembles a dirty yellowish-gray sediment of unpleasant odor a*nd acid reaction, made up of an immense number of vegetable cells. * Journ. Soc. Chem. Ind., 1889, p. 471. 12 178 FERMENTATION INDUSTRIES. FIG. 62. Saccharomyces cerevisiee. (After Hansen.) Saccharomyces cerevisise. Ascospores. (After Hansen.) Saccharomyces ellipsoideus. (After Hanseu.) Saccharomyces ellipsoideus. Ascospores. (After Hansen.) Saccharomyces Pastbrianus. (After Hansen.) Saccharomyces Pastorianus. Ascospores. (After Hansen.) RAW MATERIALS. 179 YEAST... LACTIC ACETIC Three of the pure culture varieties of yeast-plant as obtained by Hansen are shown in the illustration, Fig. 62, together with the special appearance of the ascospores of the same. Of these, the Saccharomyces cerevisiw and Saccharomyces Pastonamis are beer ferments, while the Saccharomyces ellip- soideus is the wine ferment. For many purposes (bread-baking, use in dis- tilleries, etc.) it is prepared as compressed yeast in cakes, generally with the addition of potato starch. The special conditions of the alcoholic fermentation are : first, an aqueous solution of sugar of the strength of one part sugar to four to ten parts water; second, the presence of a yeast ferment. FIG. 63. If this is not added already de- veloped and active, or if the fermentation is to be sponta- neous, that is, brought about by spores from the air, the conditions for the development of these spores must also be present. There must be protein compounds and phosphates of the alkalies and alkali earths. Thirdly, the tenij>erature must remain within the limits 5 to 30 C., or, more generally, from 9 to 25 C. Above 30 C. the alcoholic fermentation readily passes into the butyric and other decomposition. The effect of temperature upon the several different fer- ments is shown in the graphic illustration of Fig. 63, which represents also the influence of temperature upon the decom- position of starch by diastase. On the right side of the figure, the regularly-dotted line represents the yeast curve. A slight fermentation is already induced at a temperature very little over the melting point of ice. As the temperature rises its activity increases until the maximum is reached, at about 33 C. (92 F.), when it diminishes down to nothing again, and at 50 C. (122 F.) or thereabouts it is killed. The activity of the acetic fer- ment is repeated at the same time by the irregularly-dotted line, and that of the lactic ferment by the uniform black line. R MALT LIQUORS AND THE INDUSTRIES CONNECTED THEREWITH. I. Raw Materials. 1. MALT. Malt is prepared by steeping barley or other grain in water, and allowing it to germinate in order to change the character of the albumi- noids and develop the ferment diastase, which then begins t( the germination and change being stopped at a certaij a kiln. The composition of the unlimited barley GRAIN MASH. POTATO MASH ENGLISH BECH. 1.A6ER BEEft. 180 FERMENTATION INDUSTRIES. cereals on p. 1 62. The changes which it undergoes in composition by the process of malting will be seen by comparing this with the two analyses of pale malt following, which are by O'Snllivan : c . , No. I. No. II. Starch 44.15 45.13 Other carhohycl rates (of which sixty to seventy per cent, consist of fer- mentable sugar), inulin and similar bodies soluble in cold water 21.23 19.39 Cellular matter 11.57 10.09 Fat 1.65 1.96 Albuminoids soluble in water 6.71 5.31 Albuminoids insoluble in water 6.38 8.49 Ash 2.60 1.92 Water . 5.88 7.47 100.00 100.00 O'Sullivan states that malt contains no ready-formed dextrine, but that it does contain from sixteen to twenty per cent, of fermentable sugars, of which about one-half is probably maltose, and due to the transformation of starch in the malting process, while the remainder exists ready formed in the barley, and is not identical with the sugar produced in the malting. Besides the diastase, a second soluble ferment is formed during the malt- ing process, the so-called peptase, which in the mash process changes the proteids of the malt into peptones and para peptones, which give nutritive value to the beer. A high percentage of starch in the barley to be used for brewing is desirable in order that when malted it may yield a large amount of " extrac- tive matter." According to Lintner and Aubry,* a good malt should yield at least seventy-one per cent, of extract reckoned on the weight of dry substance. This determination of the value of a sample of malt is one of the most necessary of analytical tests for the malsteror brewer. (See p. 187.) Well-malted barley is always yellow or amber-colored, shading to brown. On breaking the grain, the interior should be of a pure white color and floury appearance, except when the drying has been intentionally carried so far as to partially caramelize the sugar. Malted wheat, corn, and rice are at times used as partial substitutes for the barley malt, as well as potato starch and starch-sugar. The use of patented maltose and maltose-dextrine preparations has already been referred to. (See p. 167.) 2. HOPS. Hops are the female unfructified blossoms (catkins) of the hop-plant (Humulus lupulus). Under the thin membranous scales of the strobile or catkin is an abundance of a yellowish resinous powder, consist- ing of minute sessile grains, to which the name lupulin has been given. The active principles of the hops, contained mainly, but not exclusively, in the lupulin, are : First, the ethereal oil, which is present to the amount of .8 per cent, in the air-dried hops. This is yellowish, of strong odor and of burning taste. It consists of a hydrocarbon, C 5 H 8 , and an oxygenized oil, C 10 H 18 O 2 , which by atmospheric oxidation becomes valerianic acid, C 5 H 10 O 2 , to which old hops owe their odor. Second, the lupulin also contains a resin- ous bitter principle, which is easily soluble in alcohol, but difficultly solu- ble in water, and extremely bitter. This is supposed to be an oxidation product of lupulinic acid, which can be gotten in white crystals, speedily becoming resinous. Both the acid and its oxidation products seem to be * Jahresber. Chem. Tech., 1882, pp. 840 and 851. PROCESSES OF MANUFACTURE. 181 held dissolved in the ethereal oil. Hops also contain tannic acid of a variety allied to moritannic acid and turning iron salts green. Analyses of two well-known Bohemian varieties of hops are given.* A d Residue from .S3 a S) .H S alcohol solu- | S J3 _ ble in water. c S o s PERCENTAGE COMPOSITION. o> o CO u S ^u B 'S a 11 p Organ- ic. Ash. It A O ^ m CO O H> Is i o of o ~5 ^ . 5 "S "5 '3 o"3 * fl -> 4 H u 03 i-l 3 ^ 'go ^"^ K Burton pale ale .... 1.75 2.48 0.21 0.55 5.13 0.02 0.14 5.37 1:1.05 Burton bitter ale .... 1.62 2.60 0.16 0.87 5.42 0.01 0.17 5.44 1:100 Mild X ... 1.87 1.88 0.20 1.30 5.39 0.04 0.14 4.60 1:0.85 XXX 2.88 204 030 148 6.80 0.02 650 1-096 Scotch export, bitter . . 1.62 2.50 0.30 0.70 5.21 0.16 o!(J9 5.00 l r : 0.96 Dublin stout, XX ... 3.45 3.07. 0.26 1.76 8.71 0.01 0.17 5.50 1 : 0.63 Dublin stout, XXX . . . 535 2.09 0.43 1.40 9.52 0.04 0.25 6.78 1:0.71 Vienna lager 1.64 2.74 0.36 1.12 5.90 002 0.13 469 1:0.78 Pilsen lager ...... 0.69 2.65 020 0.59 4/22 0.02 0.09 3.29 1 : 0.80 Munich lager 1.57 315 0.40 1.82 7^08 0.01 0.14 4.75 1 : 0^67 The composition of various American beers and ales as analyzed by C. A. Crampton, of the United States Department of Agriculture, is also given.* 2 i V C o " * o "t "c cr* *^* E a "?J*^ a S-d 03 .5 .tn "3 M I 03 "S 01 sS o o S

eer to one-half at a gentle heat and shaking the cooled liquid with ether, or a mixture of ethylic ether and petroleum-ether. The ethereal layer is then separated, evaporated to dryness, and the residue dissolved in warm Avater. On adding ferric chloride, a violet coloration is produced if salicylic acid be present. Other chemists recommend dialyzing, when the salicylic acid will readily dialyze into the pure water and can then be tested. For the detection of the bitter principles used as substitutes for hops elaborate schemes have been proposed by Enders (given in Allen, vol. ii. p. 97) and Dragendorff (Gerichtliche-Chemische Ausmittelung der Gifte). (7. THE MANUFACTURE OF WINE. I. Raw Materials. 1. THE GRAPE. While the name wine is often used to include the products of the spontaneous alcoholic fermentation of any sweet fruit or berry, it is usually limited to the product of the fermentation of the grape, which alone is cultivated on an extensive scale throughout the civilized world purely for the manufacture of wine. The cultivation of the grape-vine and the production of wine therefrom dates back to the earliest historic times. Beginning in the East and the Mediterranean lands, it extended northward and westward until at present France is the chief wine-producing country, while Germany, Austria, Spain, and Portugal have all established flourishing wine industries indigenous to their soil. In this country, the wine industry is mainly established in the States of Ohio, New York, Virginia, and California. The varieties of the vine (estimated to number almost two thousand) hitherto cultivated in Europe are all said to be derived from the single species, Vitis vinifera. In this country four or five wild species have yielded varieties which when cultivated have proven adapted to wine production. Thus Vitis riparia, or " frost-grape," has yielded as cultivated varieties the Taylor and the Clinton grapes ; the Vitis cestivalis, or " summer-grape," has yielded as varieties Norton's Virginia, Cythiana, and Herbemont ; the Vitis Labrusca, or " Northern fox-grape," has yielded as varieties the Catawba, Isabella, Concord, and Delaware grapes ; the Vitis vulpina or rotimdifolia, or " Southern muscadine," has yielded as varieties the black, red, and white Scuppernong. Numerous varieties of the European vine, the Vitis vinifera, RAW MATERIALS. 193 have also l)een cultivated successfully in California, among which may be mentioned the Mission, Riesling, Traminer, Rulander, Gutedel, and Zin- fandel. The grapes owe their wine-producing value in the first place to the grape (or invert) sugar which they contain, and in the second place to the free acids, which in the later ripening of the wine are to develop the fra- grant ethers, and to the albuminoids, which exert a great influence on the fermentation. The composition of the grape varies of course in different localities and even from year to year in the same locality, but its mean com- position is thus stated by Konig : Grape-sugar, 14.36 per cent. ; free acid (tartaric), .79 per cent. ; nitrogenous material, .59 per cent. ; non-nitrogen- ous extract, 1.96 per cent. ; skins and kernel, 3.60 per cent. ; ash, .50 per cent. ; and w r ater, 78.17 per cent. The grapes are taken for wine-making only when they are fully ripe, and in many localities it is even customary to wait until the grape shows a slight appearance of over-ripeness or evidence of wilting, so that the maxi- mum of sweetness may be attained. In some cases the grapes are plucked from the stems, either by hand or by the aid of three-pronged forks, while in other cases the stems are left when they are crushed in order that the tannin so obtained may aid in the clearing of the fermenting juice. This juice is known as " must," and the pressed pulp and skins as the " marc." 2. THE MUST. This may properly be considered as still a raw mate- rial, as its expression from the grapes is purely a mechanical process. This is now generally effected by power-presses of various forms, although at one time largely effected by trampling the grapes under feet. (This method is still followed in the Oporto and the Madeira wine districts.) The first portion of must that runs from the presses is often collected separately, as it is the juice of. the ripest and sweetest grapes ; that which comes later is richer in acid and in tannin, as it comes partly from unripe grapes and partly from the stems and skins. The amount of must that is obtained usually ranges from sixty to seventy parts in the one hundred of grapes. The composition of this must is of the greatest importance, as upon it depends the character of the wine that will be produced, whether it shall ferment normally throughout and develop the perfect flavor and aroma de- sired, or whether it shall be thin and sour and show tendencies tow r ards alteration or " disease." The proportions of its constituents, especially the grape-sugar, may vary within quite wide limits from year to year, and in grapes grown in the same year under different conditions of soil, exposure, etc. Thus, two different musts of 1868 are given and two musts of the same variety of grape in two succeeding years, the first of which was a favorable year and the second an unfavorable year. The analyses are all by Neubauer. Sugar. Free acid. Albumi- noids. Ash. Non-nitro- genous extract. Water. Neroberger Rieslin^, 1868 1806 042 022 047 4.11 76.72 Steinberger Auslese, 1868 24 24 043 18 045 3 92 70.78 Hattenheimer, 1868, (good year) . . . 23.56 0.46 0.19 0.44 5.43 69.92 Hattenheimer, 1869, (bad year) . . . 16.67 0.79 0.33 0.24 5.17 76.80 The percentage of grape-sugar in the must sinks at times to twelve per cent., and may rise as high as twenty-six to thirty per cent. The ratio 13 194 FERMENTATION INDUSTRIES. between acid and sugar, according to Fresenius, ranges from 1 : 29 for good varieties of grapes in good years to 1 : 16 for inferior varieties in medium years. If the ratio falls as low as 1 : 10, the grapes are unripe and taste acid. This ratio of acid to sugar is now generally taken as the criterion for the quality of the must in any year or special locality. In bad seasons the free acid is more generally malic than tartaric, which is the normal constituent. n. Processes of Manufacture. 1. FERMENTATION. The fermentation of the must is a spontaneous one following exposure to the air, and due to the spores which drop upon the surface of the must as exposed in the fermenting-tubs. It may be a surface fermentation, taking place at temperatures of 15 to 20 C., as is the practice in Italy, Spain, and the south of France, or a bottom fermen- tation, taking place in cooler cellars at 5 to 12 C., as is the practice in Germany and with the finer French wines. The first method produces a fiery wine rich in alcohol, but without bouquet or aroma ; the second method, lighter wines with delicate bouquet, due to the formation of wine ethers. In either case the fermentation can be divided, as was the case with malt liquors, into three stages : the first, or main fermentation, which, according as the surface or the bottom fermentation method is followed, lasts from three to eight days, or from two to four weeks ; the second, or still fermentation, which lasts until the following spring ; and the third, the storage fermen- tation, which lasts for several years, until by the gradual development of its bouquet it becomes perfectly ripe. In the case of red wines, the main fermentation is allowed to take place with the marc added to the must, so that as the alcohol is developed it may dissolve out the coloring matter (cenocyanin) of the skins as well as some of the tannin, which latter is of benefit in effecting a more rapid separation of the protein materials. To prevent this pulpy mass from rising to the surface and starting a souring of the wine, perforated covers are often used in this case to hold it down. In the main fermentation, the casks are usually freely exposed to the air Many wine experts recommend in addition the aeration of the fermenting must or a whipping of the liquid, so as to induce a fuller and more vigorous fermentation On the other hand, other authorities consider that this excessive exposure to air injures the quality and aroma of the wine, and recommend only a partial exposure to the air after the main fermentation has begun. As the main fermenta- tion comes to an end, the yeast (with more or less tartar, gummy matter, and albuminoids) settles to the bottom, the liquid clears and is ready to be racked off into casks, under the name of young wine ( Jungwein), to undergo the after- or still fermentation. If the racking off does not take place promptly with the ending of the more energetic main fermentation, the young wine, of which a considerable surface is exposed to the air, is very apt to start into the acetic fermentation. The casks into which it is now put are kept quite full in order to prevent this undesirable change, slight additions being made every few days if necessary, and the bungs are set loosely in place. During this after-fermentation there deposits upon the inner walls of the cask argots, or impure acid potassium tartrate (Wein- stein), with some yeast and albuminoid matter. This fermentation lasts from three to six months, and then the wine is racked off again into smaller PROCESSES OF MANUFACTURE. 195 casks to undergo the final ripening, in which the bouquet of the wine is especially developed by the formation of ethers, while it clears more thor- oughly from the remaining particles of yeast, etc. The duration of this ripening may be two, four, or with rich wines even eight years or more, when it is considered " bottle-ripe." During this ripening fungous vegeta- tion is very apt to start, and must be arrested in order to prevent the spoiling of the wine. 2. DISEASES OF WINES AND METHODS OF TREATING AND IM- PROVING THEM. The souring of wine, due to the beginning of the acetic fermentation, is one of the commonest of these so-called diseases, especially with light wines, poor in alcohol and tannic acid, and hence commoner with white than with red wines. It arises from too free an exposure to the air and too high a temperature during fermentation. If just begun, it can be cured by the addition of a small quantity of potashes, which form potassium acetate, or by starting the alcoholic fermentation afresh by add- ing a new quantity of sugar. If the souring is very pronounced it cannot be cured, and the wine is made into wine-vinegar. The gumminess or ropiness of wine frequently arises from a premature filling into bottles, and is due to the beginning of the mucous fermentation of sugar. It takes place in wines poor in tannic acid, and hence more readily with white than with red wines. It can be cured by addition of tannic acid, treatment with sulphurous oxide, or starting a new fermenta- tion by addition of grape-sugar. The development of a stale or flat taste in the wine is due, according to Pasteur, to the growth of a thread-like ferment. The wine becomes cloudy, diminishes in alcohol and increases in acid percentage, it darkens in color, and often has a disagreeable odor. The wine is racked off and put into a cask which has been filled with sulphurous oxide fumes, which destroy the ferment. The turning bitter of red wines is due also, according to Pasteur, to a plant-growth, according to others to the formation of a bitter aldehyde resin. Neubauer has found that the tannic acid and the coloring matter both decrease in percentage in this disease. It can be cured completely by heating the wine to 60 to 64 C., or by starting the fermentation anew by adding fresh quantities of grape-sugar. The mouldiness of wine is due to the development of a fungoid growth in the form of a white film on the surface of wines poor in alcohol, and always precedes the souring of the wine. It is to be obviated by treat- ment with sulphur dioxide or more effectual protection of the young wine from the air. Of, the general lines of treatment adopted to prevent the development of these various diseases, we notice first the clarifying with isinglass (finings) or other form of gelatine. This is particularly applied to the sweet and heavy white wines, which often remain turbid and have to be cleared by the coagulating of the albuminoid which is added. With red wines which contain tannic acid, casein or blood albumen is used instead of gelatine. Fine clays are also used, especially in Spain, for this clarifying. The most important process, however, which is applied for the preser- vation and protection of wine against diseases is that known as " Pasteur- izing." It consists in heating the wine either in casks or in bottles to a temperature of 60 C., and then preserving it without exposure to the air. 196 FERMENTATION INDUSTRIES. This temperature is found to be sufficient to kill most of the germs which bring about the diseases before mentioned. A form of cask much used for this " Pasteurizing" process is shown in Fig. 65. FIG. 65. The use of salicylic acid for preserving wines has been extensively tried, but its use here is open to the same objection as before stated in speaking of beer, and it is now forbidden in most countries. Of the methods of " improving" wines, as it is termed, that known as " plastering" is probably most largely practised, its use for red wines ex- tending to Spain, Portugal, Italy, and the South of France. It consists in adding plaster of Paris (burnt gypsum) either to the unpressed grapes or to the must. The plaster takes up water and so increases the alcoholic strength of the fermenting must, which in turn allows of a greater extraction of the coloring matter from the skins. At the same time the wine is given bet- ter keeping qualities as well as deeper color. However, the sulphate of lime changes the soluble potash salts of the wine into insoluble tartrate of lime and soluble acid sulphate of potash, which latter remains dissolved along with some of the gypsum, and undoubtedly has an injurious effect upon the consumers of the wine. The process has hence had to be con- trolled by law, and in France the sale of wine containing over .2 per cent, of potassium sulphate is prohibited. The ash of pure wine does not exceed .3 per cent., but in the samples of sherry usually met with it reaches .5 per cent., and is almost entirely composed of sulphates. Hugonneng recommends adding dicalcium phosphate instead of gypsum. This process, called " phosphotage," is said to have all the good effects ob- tainable from plastering without increasing, as the latter does, the percentage of sulphuric acid and decreasing that of phosphoric acid. Chaptalization consists in neutralizing the excess of acidity in the must by the addition of marble-dust, and increasing the saccharine content by PROCESSES OF MANUFACTURE. 197 the addition of a certain quantity of cane-sugar, which the vintners some- times replace by starch-sugar. In this process the quantity of the wine is not increased, but it becomes richer in alcohol, poorer in acid, and the bouquet is not injured. It is much used in Burgundy. Gallization, as proposed by Dr. Gall, has for its object the bringing of the must of a bad year up to the standard found to belong to a good must (he takes as standard 24 per cent, of sugar, .6 per cent, of acid, and 75.4 per cent, of w T ater) by correcting the ratio of acid to sugar. This he does by adding sugar and water in sufficient quantity, and tables have been pre- pared to indicate the quantity needed according to the acid ratio shown by analysis. In both these processes, starch-sugar ought never to be used as a cheaper substitute for cane-sugar, as commercial starch-sugar will always introduce dextrine, an entirely foreign constituent, into the must. Petiotization is a process which takes its name from Petiot, a proprietor in Burgundy, and is carried out as follows : The marc from which the juice has been separated as usual by pressure is mixed with a solution of sugar and water and the mixture again fermented, the second steeping con- taining, like the first, notable quantities of bitartrate of potash, tannic acid, etc., which are far from being exhausted by one extraction. The process may be repeated several times, the diiferent infusions being mixed. This process is very largely used in France, and is said to produce wines rich in alcohol, of as good bouquet as the original wine, and of good keeping quali- ties. It is not allowed to be sold there, however, as natural wine. Scheelization consists in the addition of glycerine to the finished wine so as to improve the sweet taste without injuring its keeping qualities. The limits of the addition of glycerine lie between one and three litres to the hectolitre of wine. If the wine has not fully fermented, however, and if yeast-cells are present, the glycerine may yield propionic acid by decompo- sition. 3. MANUFACTURE OF EFFERVESCING WINES (Champagnes). For the manufacture of champagne the blue sweet grapes are preferred. They must be pressed promptly after picking in order that the least possible amount of color be taken up by the must. The first pressing only is used for the cham- pagne, and a second pressing of the marc yields a reddish wine, which is differ- ently utilized. The must is first put into vats that impurities may settle and then filled into casks for the main fermentation, which is retarded as much as possible by being carried out in cool cellars. Cognac is also added to the amount of about one per cent., so as to increase the alcohol percentage and thus moderate the fermentation. After the main fermentation is finished the wine is racked oif into other casks and left stopped until winter (end of December). It is then fined (or cleared) with isinglass and transferred to other casks, and this operation is repeated in a month's time. Towards the beginning of April it is ready to be transferred to bottles. The wines of different growths are now mixed and the amount of sugar in the wine de- termined, when a calculated additional quantity is added in the form of " liqueur" (a mixture of alcohol and pure cane-sugar). The bottles which are to receive the champagne must be specially chosen and be sufficiently strong to stand the pressure, which rises later to four to five atmospheres. They must also, have sloping sides, so that the sediment may not adhere to the sides in the after-process. The wine after being corked is thoroughly secured by an iron fastening called an agrafe, and the bottles are arranged in piles in a horizontal position in the large champagne-vaults, where they 198 FERMENTATION INDUSTRIES. remain throughout the summer months. Previous to the wine l>eing pre- pared for shipment, the bottles are placed in a slanting position, neck down- ward, in frames, and the incline is gradually increased day by day until the bottle is almost perpendicular. With the sediment thus on the cork it goes into the hands of a workman called a " disgorger," who, holding the bottle still neck downward, proceeds to liberate the cork by slipping off the agrafe, and when the cork is three-fourth parts out he quickly inverts the bottle. The cork is thus forcibly ejected with a loud report by the froth, which car- ries with it the greater part of the yeast and other solid matters, what re- mains of these being got rid of by the workman working his finger round the neck of the bottle, whereby they are detached and forced out by the still rising froth. The wine is now dosed again with liqueur, the bottles filled up, wired, and the neck wrapped with foil ready for ship- ment. 4. MANUFACTURE OF FORTIFIED, MIXED, AND IMITATION WINES. All the SAveet heavy wines, like sherry, malaga, and port, are characterized by a high alcohol percentage, ranging from sixteen to twenty or twenty-two. This they cannot acquire through fermentation alone, as twelve to thirteen per cent, seems to be the limit of alcohol developed in a wine by direct fer- mentation. They have the additional alcohol added to them directly in order to give them keeping qualities. With some sweet wines the alcohol is added to the must before the fermentation in order that the fermentation shall be arrested, while a certain amount of sugar remains in the wine unchanged. The quality of wines is often improved by blending. Light wines with too little alcohol are mixed with stronger wines with the forma- tion of an excellent product with better keeping qualities, which can then be transported to long distances without injury. These mixtures can best be made when the wines are new, in order that after mixing they may undergo an insensible fermentation and take a character distinctive of the new product. The practice of adding flavoring substances totally foreign to the con- stituents of the must to new and inferior wines in order that they may take the flavor and appearance of older and more valuable wine has also become very wide-spread. Such practices are of course illegal in all countries where laws against adulteration are enforced. Thus, elder flowers, orris-root, iris, cloves, oil of bitter almonds, and numerous perfumes, such as oil of orange flowers, of neroli, of petit-grain, and of violet, are used, as well as coloring infusions like raspberries and walnuts. The heavy wines are the ones most generally imitated. Port is frequently flavored with a mixture of elderberry juice, grape juice, brown sugar, and crude brandy. Sherry often consists of the cheaper Cape wine mixed with honey, bitter almonds, and brandy. In Spain and Southern France a wine prepared from the vine known as the Teinturier and possessing an intense bluish-red color is extensively used for coloring of other wines. In recent years, because of the deficiency in the wine crop of France due to the ravages of the Phylloxera, the production of wine from dried raisins or prunes has enormously increased. This product, known as " vin de raisin sec," is said to be a very close imitation of natural French wines. Spon* gives the following as the components of such a raisin wine : * Spoil's Encyclopedia of Industrial Arts, vol. ii. p 444. PRODUCTS. 199 White sugar 6 kilos. Raisins 5 kilos. Common salt 125 grammes. Tartaric acid 200 grammes. Common brandy .... 12 litres. River water 95 litres. Gall-nuts (bruised) ... '20 grammes. Brewer's yeast (in paste) . 200 grammes. To make this wine of a reel color it is necessary only to add to the above ingredients two hundred and fifty to three hundred grammes of dry picked hollyhocks, taking care to keep them at the bottom of the cask. The reports of the United States consular agents show that the manu- facture of this raisin wine has become an industry of large proportions in France at the present time. A significant additional indication of the devel- opment of this artificial wine industry and of the similar one of petiotiz- ing in France is found in the statement of the amounts of cane-sugar used by French wine manufacturers in recent years. In 1885 there was used in France for the manufacture of grape wines 7,933,887 kilos, of cane-sugar; in 1886, 27,856,592 kilos.; for the manufacture of fruit wines in 1885, 24,142 kilos, of sugar ; in 1886, for the same purpose, 145,555 kilos. Most of this fruit wine forms the basis of factitious champagne. m. Products. The normal constituents of a natural wine agree of course with those contained in the must, except in so far as new compounds have been devel- oped by the fermentation process and previously existing ones have been decomposed or made to separate out. We may divide the constituents of wine into two classes, volatile and fixed. The volatile matters are as follows : Water (eighty to ninety per cent.) ; alcohol (five to fifteen per cent.) ; glycerine (tAvo to eight per cent.) ; volatile acids, acetic, oenanthic, etc., constituting one-fourth to one-third of the total acidity ; aldehyde, compound ethers, together with other fra- grant indefinite constituents, which give the wine its flavor and bouquet. The fixed matters are glucose, or grape-sugar, in small quantities in most wines ; bitartrate of potash, tartaric, malic, and phosphoric acid, partly free and partly combined with various bases, of which compounds phosphate of lime is the most abundant, constituting from twenty to sixty per cent, of the weight of the ash, the remainder being chiefly carbonate of potash, result- ing from the calcination of the bitartrate, with a little sulphate and traces of chlorides; coloring matters; pectin and analogous gummy matters ; tannin, one to two per cent, in red wines and traces only existing in white wines. No very simple scheme of classification is possible, as the methods and products of most countries are not fixed by rule, but vaiy widely according to the season and market. Still, we may distinguish between the red and white, and the sweet and the dry, wines; between the light and delicately- flavored German and French wines and the more fiery but coarser Italian and Swiss wines ; between natural wines and those fortified by addition of alcohol, as port, sherry, and madeira ; between still wines and effervescing or champagne wines. Most of these terms have already found their explanation in the descrip- tion of the processes of manufacture. We may add that a sweet wine is one in which a notable portion of the original grape-sugar of the must has escaped fermentation, or to which an addition of sugar has been made sub- sequent to the main fermentation. A dry wine, on the contrary, is one in which the sugar, whether originally present or subsequently added, has 200 FERMENTATION INDUSTRIES. almost all undergone change in the processes of fermentation. Champagnes are wines in which a supplementary fermentation is purposely developed subsequent to the bottling, whereby quantities . of carbon dioxide gas are developed and held dissolved under pressure. On opening the bottles and thus relieving the pressure a brisk effervescence follows, due to the escape of the absorbed gas. Champagne-makers distinguish three grades of effer- vescence. In mousseux the pressure in the bottle amounts to from four to four and a half atmospheres ; in grand mousseux it reaches five atmospheres ; and less than four atmospheres' pressure constitutes cremant (from la crerne, " cream"), a wine which throws up a froth, but does not give off carbonic acid violently. Some manufacturers also distinguish a grade demi-mousseux. Of natural and unfortified foreign wines the following analyses from Eisner * refer to German wines exclusively : = 5 a> so OB "3 0> 11 Percentage of extract. 0) 1 f Percentage of phosphoric acid. Rhine wines, Riidesheimer . . . " " Rauenthaler .... " " Johannisberger . . " " Hochheimer .... " " Niersteiner .... Moselle wines, Brauneberger . . . 0.9960 0.9960 0.9958 0.9935 0.9956 9.30 9.25 8.60 8.00 7.54 1.97 210 2.20 1.50 1.75 2.60 0.50 0.54 0.52 0.72 0.62 0.20 0.19 0.19 0.16 0.18 0.18 0.020 0.023 0.023 6.012 0.041 " " Pisporter. . 2.40 0.15 0.038 Zeltinger 2.40 0.16 0.039 Hessian wines> Bodenheimer . . . " " Laubenheimer . . " " Liebfrauenmilch . Palatinate wines, Deidesheimer . " " Oppenheiiner . " " "Wachenheimer . Franconian wines, white .... " " red 0.9930 0.9934 0.9940 0.9968 0.9936 0.9954 0.9943 0.9932 7.54 6.83 8.00 9.60 8.87 8.65 6.65 8.00 1.25 1.00 1.96 2.12 1.50 1.72 1.20 1.50 0.63 0.60 0.62 0.50 0.60 0.65 0.60 0.47 0.14 0.10 0.20 0.18 0.16 0.17 6.20 0.015 The following analyses of French wines are from the official report of the Laboratoire Municipal at Paris for 1 883 : f GRAMMES PER LITRE. >> 1 e 09 ^ A c 3 I gu -w O o 3 isl 'So S? If || So ^ OS d D S so "So M M ** H tf 03 ** Bordeaux wines, St. Estephe, 1878 11.1 10.3 22.4 19.0 28.3 23.7 2.20 1.31 2.05 1.42 1.50 0.9 0.49 0.76 2.96 3.% " Medoc, 1880 '. " Latour, 1878 9.5 17.0 22.8 2.14 2.07 1.1 0.50 4.06 " Chateau Margaux, 1878 10.2 23.6 1.5 0.48 " Larose 1877 . . . 11.2 23.0 30.1 2.34 2.44 1.3 0.63 " (white,) Sauterne, 1880 10.4 16.0 3.6 0.53 Burgundy wines, Chambertin, 1882 11.5 23.3 29.5 1.77 3.57 1.4 0.55 . . (white,) Chablis, 1878 11.0 16.7 . . 0.6 0.38 Lower Burgundy, average of 7 analyses ..... Upper Burgundy, average of 25 analyses 7.8 9.1 20.2 20.7 1.2 1.1 0.37 0.48 * Praxis des Nahrungsmittels Chemiker, 1880, p. 103. f Deuxieme Rapport du Laboratoire Municipal, Paris, 1884. PRODUCTS. 201 Of sweet and fortified or treated wines the following analyses are given by Konig.* bj .tJ '3 2 8.6 05 Alcohol by weight. Extract. g 60 t Tartaric acid. Glycerine. Albuminoids. J3 < _o *u C as I s s Sulphuric acid. Tokay 1868 1.0879 9.80 26.36 22.11 0.509 0.212 0.427 0.343 0.050 0.061 Tokay Ausbruch 1866 10588 10.29 18.34 14.99 0.517 0.234 0.389 0.300 0.074 0.022 Ruster, Ausbruch, 1872 1.0849 8.% 23.64 21.74 0.512 0.162 0.231 0.409 0.057 0.035 Malaga, 1872 1.0691 13.23 21.23 16.57 0.416 0.248 0.217 0.239 0.042 0.026 Muscat wine 1872 1 0574 10.02 16.91 15.52 0.555 0.298 0.151 0312 0.036 0.073 Port wine (white), 1860 1.0126 16.28 8.83 4.88 0538 0.168 0.094 0.208 0.035 0.039 Port wine (red), 1865 1.0125 17.93 8.83 6.42 0.451 0.145 0.200 0.236 0.032 0.019 Marsala (Ingham) 09966 16.73 4.94 3.48 : 0.3% 0.298 0.150 0.270 0.024 0087 Marsala (Woodhouse) 1.0111 15.52 5.45 3.78 0.470 0.457 0.231 0.418 0.024 0.155 Madeira, 1868 1.0018 15.34 5.33 3.39 i 0.489 0.291 0.144 0.376 0.082 0.081 Sherry, 1870 09952 18.66 3.78 1.88 i 0.438 0.506 0.200 0.483 0.032 0.184 Sherry, Amontillado, 1870 0.9924 16.34 2.68 0.52 0490 0.560 0.200 0.650 0.038 0.268 Samos wine. 1872 1.0519 10.97 14.46 11.82 , 0.502 0.237 0.563 0.058 0.044 Two analyses of champagne and effervescing wine are also given by Konig :f 2 T; ^ 9 or; 2 > IS J i* _o a a o/d gsj . o g o < 2o 2 'i ** P 3 J3 o| s a) oi'E 0> o oo o .2 'C ^ w t3 *U 33 8"c? 8*^ 2 y ""* ^ 4> " $ SO ^ ^ > t< "x a "c -S X * _ GO ' ' N * 3 H S Dry red wines : Concord Virginia 1879 0.9953 883 11.08 210 0174 Trace. 0.709 0.452 0.206 Clinton Virginia 1879 0.9950 9.82 12.31 2.36 0^238 None. 0.784 0.513 0.217 Norton's Virginia, 1879 0.9937 10.21 12.77 2.88 0298 Trace. 0.772 0.377 0.316 Ives's Seedling, Virginia, 1879 .... 0.9944 8.68 10.82 2.18 0.247 Trace. 0.723 0.512 0.169 Sonoma Red Mission, California, 1879 0.9968 7.99 10.03 2.42 0.428 None. 0.722 0.301 0.337 Sonoma Red Zinfandel, California, 1879 09%2 780 9.78 2.43 0255 Trace. 0693 0.391 0242 Concord Bouquet, New Jersey .... 0.9928 9.84 12.31 2.18 0.141 0.71 0.741 0.272 0.375 * Nahrungs- uud Genussmittel, vol. ii. p. 463. f Ibid., p. 464. J United States Bureau of Agriculture, Bulletin No. 13, pp. 334-338. 202 FERMENTATION INDUSTRIES. o.ti > "S rl 03 Alcohol by weight. Alcohol by volume. Extract. A < Glucose. Total acid as tartaric. Fixed acids as tartaric. Volatile acid as acetic. Dry white wines : Brocton Catawba New York .... 09890 12 8 1530 209 121 0542 0470 OOfiS Missouri Catawba, Missouri Ohio Catawba, Ohio 0.9911 9892 888 1025 11.08 1277 1.67 1.63 0.129 0113 Trace. Trace 0.772 728 0.387 0424 0.3U8 43 Rulander. Virginia, 1880 9914 10.46 13.05 1.90 0.199 Trace 545 0302 194 Delaware, Virginia, 1880 0.9932 9.35 11.70 1.88 0.255 Trace O.a62 332 184 Taylor Virginia 1880 09921 1037 12% 1.99 185 Trace 0732 317 332 Herbemont, Virginia, 1880 9928 7.78 9 80 1.60 0.146 None 0562 0302 008 Dry Muscat, California 0.9928 9.14 11.44 1.82 0150 Trace 0619 0248 0'>89 White Zinfandel, California 0.9911 9.52 11.26 1.47 0.139 Trace. 0590 0227 ''90 Riesling, California 09918 964 1205 1.72 0221 Trace 0696 210 0389 Gutedel, California 09920 936 11.70 J.58 1% Trace 0726 0212 0411 Sonoma Mission, California, 1879 . . . Sweet wines : Brocton Port, New York 0.9935 1 0508 8.30 1000 10.38 1324 1.67 17.04 0.193 139 Trace. 11 80 0.619 0828 0.317 0600 0.242 182 Speer's Port, New Jersey 1 0213 1367 17.59 10.69 03(19 744 0705 347 0286 Port, Los Angeles, California 1.0339 1268 16.52 14.18 0345 11.39 0508 0348 128 New York Sherry 1.0074 13.87 17.59 6.83 0.166 4.84 0.689 0209 0323 Speer's Sherry, New Jersey 0.9949 1762 22.09 4.89 0.219 3.33 0.476 0.271 0164 California Sherry 9942 1342 1680 3.91 0198 2.20 0573 023 -) 0273 Marsala, California 10052 16.06 2033 6.42 0.428 3.53 0.626 0418 0166 " Eclipse" Extra Dry Champagne . " Gold Seal"Champagne, New York Cook's " Imperial" Champagne . . Sweet Catawba, Bass Island, Ohio . Sweet Catawba, Brocton, New York Sweet Catawba, Iowa, 1871 1.0174 1.0102 1.0207 10338 1.0512 1.0101 9.26 8.26 8.41 11.68 1071 9.89 11.87 10.82 10.82 15.21 14.18 12.58 7.78 1331 8.47 14.49 16.71 7.23 0.149 0.110 0.130 0.152 0.113 0.211 6.51 12.02 7.23 11.00 15.22 4.01 0.885 0.880 0.779 0.595 0.714 0.668 0.295 0447 0.470 0.2% 0.471 0.318 0.472 0.346 0.247 0.239 0.194 0.280 Sweet Muscatel, California 1 0245 1733 1858 31 34 0371 25.37 0753 0421 0266 California Angelica 1 0440 896 11 79 14.41 0.1% 12.48 0.489 0310 0143 Brocton Sweet Regina 10515 971 12.87 16.52 0.101 15.31 0.628 0.465 0.130 Sweet Delaware, 1879 1.0320 8.73 11.35 12.07 0.118 10.27 0.799 0.355 0.355 Scuppernong, Sweet, 1878 1.0404 9.06 11.87 14.13 0.132 11.56 0.7;>8 0.323 0.348 Scupperiioug, Dry, 1879 09948 1072 1343 3.39 0.108 1.31 0.925 0.346 0463 Side-products. The first of these is the marc of the grapes, separated from the must in the original pressing of the grapes, or left when the fer- menting must is drained from it. This consists of the stems, skins, and stones of the grapes. If the marc instead of being washed out with water has been merely pressed, it still contains sufficient must to allow of its being used in the manufacture of petiotized wine. Besides this, the marc serves for a great variety of purposes. It is fermented for brandy ; it is used with sheet-copper in the manufacture of verdigris ; it is used to start the fermen- tation in vinegar-making ; as cattle-food ; when dried, as fuel or for fertil- izing purposes ; the tannic acid is extracted, or it is used direct in producing black colors, and for other minor applications. The second and more valuable side-product is the deposit formed on the bottom and sides of the casks in which the fermentation takes place. That on the bottom of the casks is called " lees." It contains from thirty to forty per cent, of vegetable matter (from the yeast-cells depositing), the re- mainder being tartrates, sulphates, (in plastered wines), alumina, phosphoric acid, etc. Its composition is greatly altered by " plastering" the wine, in which case the tartrate exists chiefly as the neutral calcium tartrate instead of the acid potassium salt. The crystalline crust that forms on the sides of the vessels used for fermentation is called " argol," or crude tartar. It varies somewhat in composition, the tartaric acid ranging from forty to seventy per cent, and being always present, chiefly as the acid potassium tartrate. From this crude tartar is prepared, by extraction with boiling water, filtering, and crystallizing, "cream of tartar." This, however, still ANALYTICAL TESTS AND METHODS. 203 FIG. 66. contains some calcium tartrate mixed with the acid potassium salt, the amount ranging from two to nine per cent. IV. Analytical Tests and Methods. In 1884 the Imperial German Health Office appointed a commission of experts to report upon the best uniform methods for the analysis of wines. The methods agreed upon by that commission are very generally adopted now in Germany, and largely used elsewhere in guiding wine analysts. These official methods have been fully described and explained in a little work entitled " Weinanalyse," by Dr. Max Barth, Leipzig, 1884. The specific gravity of the wine is determined either by the pyknometer (specific gravity bottle) or by the Westphal balance (see p. 74), the readings of which have been compared with those of the specific gravity bottle. In the case of champagnes and effervescing wines, as was the case with beer, the carbonic acid must be got rid of as far as possible before taking the specific gravity readings. The alcohol is determined by the direct distillation, as described on p. 191. Wines that have a tendency to foam have a little tannin (.1 gramme) f added. If one hundred cubic centimetres of the sample is taken, sixty cubic I centimetres only need be collected, and will contain all the alcohol. This j is then diluted to nearly one hundred cubic centimetres, cooled, uniformly ' mixed, and then brought exactly to the 100-cubic-centimetre mark, mixed again, and the specific gravity taken. The form of apparatus best adapted for this deter- mination of alcoholic strength of wines and liquors is shown in Fig. 66. For the rapid determination of the alcoholic strength of wines va- rious forms of appa- ratus have been de- vised, such as the vaporimeter of Geiss- ler, in which the va- por-tension of an al- coholic liquid exerted upon a column of mercury is made to indicate its percentage strength in alcohol, the ebullioscope of Tabarie, of Malligand and Vidal, and of Amagat, which de- pend upon the obser- vation of the boiling-points of a spirituous liquor as determining the amount of alcohol contained. None of these can be said to have scientific accuracy, 204 FERMENTATION INDUSTRIES. as wine is not merely a mixture of alcohol and water, but contains other constituents which affect the results in either case. The extract determination. Here the direct weighing of the residue after evaporation is preferred to the indirect method, fifty cubic centimetres of the wine, measured at 15 C., are to be evaporated on the water-bath in a platinum dish (according to the German wine commission, this dish should be eighty-five millimetres in diameter, twenty millimetres in height, sev- enty-five cubic centimetres in capacity, and should weigh about twenty grammes), and the residue dried for two and a half hours in a double-walled water drying oven. In the case of wines containing more than .5 per cent, sugar, a smaller quantity must be taken and suitably diluted, so that the extract shall not weigh more than 1.0 to 1.5 grammes. In this method, the loss of glycerine by evaporation is trifling. The indirect method for deter- mining the extract is very like that described under beer (see p. 191) as O'Sullivan's method, except that with wine we divide the excess of specific gravity observed over 1000 by 4.6 instead of 3.86, as the solids of wine have a higher solution density than those of extract of malt. Or with the specific gravity of the de-alcoholized liquid we. may get the extract percentage from Hager's tables, which are analogous to those of Schultze for malt extracts before referred to. The ash percentage can be obtained by incineration of the evaporated extract above referred to. To determine the percentage of glycerine, one hundred cubic centimetres of the wine are evaporated down to about ten cubic centimetres in a spacious porcelain dish ; some sand and milk of lime are then added till the reaction is strongly alkaline and the mixture evaporated almost to dryness. The residue is next treated with fifty centimetres of ninety-six per cent, alcohol, warmed and stirred on the water-bath, and the solution obtained then passed through a filter. The insoluble matter is washed with successive small por- tions of hot alcohol (ninety-six per cent.), of which fifty to one hundred and fifty cubic centimetres will as a rule suffice, so that the entire filtrate will be from one hundred cubic centimetres to two hundred cubic centimetres. The alcoholic extract is now evaporated to a viscous consistency, and the residue taken up with ten cubic centimetres of absolute alcohol ; this solution is mixed with fifteen cubic centimetres of ether in a stoppered flask and the mixture allowed to stand until clear. The clear liquid is decanted or filtered into a light tared glass vessel, carefully evaporated, and the residue dried for one hour in the water-bath. It is then cooled and weighed. In the case of sweet wines (containing more than five per cent, of sugar), only fifty cubic centimetres of the wine are taken for the estimation of the glycerine ; sand and lime are added, and the mixture is warmed on the water-bath. After cooling it is treated with one hundred cubic centimetres of ninety-six per cent, alcohol, the precipitate formed allowed to settle, the solution fil- tered, the insoluble matter washed with spirit, and the alcoholic filtrate treated as above described. To estimate the sugar in wine, Fehling's solution is used, as the sugar should be only glucose. After neutralization of the wine with sodium car- bonate, the determination is made (using the separately preserved solutions for Fehling's mixture. See p. 152). Strongly-colored wines must be first decolorized. If the sugar percentage is low, it is done with purified bone- black ; if they contain over .5 per cent, of sugar, bone-black cannot be used because of its absorptive power, and basic acetate of lead must be substi- ANALYTICAL TESTS AND METHODS. 205 tuted. After filtering, the wine is then treated with sodium carbonate and Fehling's solution. If the polarization indicates the presence of cane- sugar, the solution must be inverted (see p. 151) and then the Fehling's test applied again, and the cane-sugar calculated from the difference in the two readings. The Fehling's test is best carried out gravimetrically, and from the weight of reduced copper the corresponding amount of glucose can be obtained from the tables. The polarization, which is essential in the case of heavy wines to indicate the nature of the sugar contained, is carried out as follows : With white wines, to sixty cubic centimetres of the wine are added three cubic centi- metres of the basic acetate of lead solution and the precipitate filtered off on a dry filter. To 31.5 of the filtrate is added 1.5 cubic centimetres of a satu- rated solution of sodium carbonate and the solution again filtered and the polarization tube filled with the filtrate. The dilution of the original wine in this case is 10 : 11. With red wines, sixty cubic centimetres of the wine are treated with six cubic centimetres of the lead solution, and to thirty-three cubic centimetres of the filtrate three cubic centimetres of the saturated sodium carbonate solution added, the solution filtered and polarized. The dilution here is 5:6. This diluted solution is observed in the 220- millimetre tube of the polariscope, and large and accurate instruments are necessary. The free acids (total acid-reacting constituents of the wine) are estimated in ten to twenty cubic centimetres of the wine by means of one-third or one-tenth normal alkali. Any considerable quantity of carbonic acid to be first removed by shaking. The " free acids" to be calculated into and given as tartaric acid (C 4 H 6 O 6 ). The volatile acids are determined by steam distillation and calculated as acetic acid (C 2 H 4 O 2 ). The quantity of non-volatile acids calculated as tartaric is found by sub- tracting the equivalent of the acetic acid in tartaric acid from the free acids previously determined. These three determinations are all that are usually made in wine analyses. If a special qualitative test for free tartaric acid is desired or, in case it be shown to be present in appreciable quantity, a quantitative method for its determination, they can be made by Xessler's method, for details of Avhich the reader is referred to Earth's " Weinanalyse" before mentioned, or to a summary of its methods in the " Journal of the Society of Chemical Indus- try," 1885, p. 553. The tannin may be determined by Neubauer's method with permanganate of potash, or approximately by the following procedure : the free acids in ten cubic centimetres of the wine are neutralized with standard alkali, after which one cubic centimetre of a forty per cent, solution of sodium acetate is added, and finally a ten per cent, solution of ferric chloride, drop by drop, and avoiding excess. One drop of this solution suffices for the precipitation of every .05 per cent, of tannin. Salicylic Acid. To detect this acid, one hundred cubic centimetres of the wine are shaken repeatedly with chloroform, the latter is evaporated, and the aqueous solution of the residue tested with very dilute ferric chloride solu- tion. For the purpose of an approximate quantitative estimation, it is suffi- cient, on the evaporation of the chloroform, to once recrystallize the residue from chloroform and weigh it. One of the most important questions that arises in the examination of 206 FERMENTATION INDUSTRIES. red wines is as to the genuineness of the coloring matter, as both vegetable and artificial dye colors have been used for years to imitate the natural color- ing matter in the manufacture of factitious red wines. Very elaborate schemes for the recognition of foreign coloring matters, including both the vegetable coloring matters like dye- woods and color-yielding berries and the large number of the newer coal-tar colors, have been given by Gautier * and by Chas. Girard,f the director of the Laboratoire Municipal in Paris, to which we can only give references. The coloring matters most generally used to imitate the natural pigment of the grape-skins are fuchsine, coch- ineal, alderberry, hollyhock, and logwood. Dupre tests the coloring matter as follows : Cubes of jelly are prepared by dissolving one part of gelatine in twenty parts of hot water and pouring the solution in moulds to set. These are immersed in the wine under examination for twenty-four hours, then removed, slightly washed, and examined. Pure wine will color the gelatine only very superficially ; the majority of other coloring matters (fuchsine, cochineal, logwood, Brazil-wood, litmus, and indigo) penetrate more readily, passing to the very centre of the cube. A confirmative test can also be made with the dialyzer. The coloring principle of pure wine when sub- jected to dialysis does not paas through the animal membrane to any decided extent, while the color of logwood, Brazil-wood, and cochineal easily dialyzes. If rosaniline colors alone are to be tested for, the procedure of Faliere as improved by Nessler and Barth can be followed. One hundred cubic centi- metres of the wine are shaken in a stoppered jar with thirty cubic centi- metres of ether and five cubic centimetres of strong ammonia, and then twenty cubic centimetres of the ethereal layer removed with a pipette and evaporated in a capsule containing a thread of white wool five centimetres in length. Similar threads-are dyed with known quantities of magenta, and from a comparison of tints the amount of the added coloring matter in the wines is inferred. This test will detect minute quantities of fuchsine or ani- line red. If the same test be carried out without adding ammonia, the acid rosaniline colors and similar dyes will be extracted. The fact that pure wine color is not changed or decolorized by nascent hydrogen (zinc and acid), while most of the aniline dyes are decomposed by it, is also used as a test. D. MANUFACTURE OF DISTILLED LIQUORS, OR ARDENT SPIRITS. This industry differs radically from the two fermentation industries already described, firstly, in that the effort is made to push the fermentation to the fullest possible limit, so that the maximum quantity of alcohol may be produced, and, secondly, in that this product of fermentation is then dis- tilled, and it may be redistilled in order to get a distillate richer in alcohol than the fermentation product itself can be. The end to be attained may be either the production of an alcoholic beverage as the product of distilla- tion or of raw spirit, which takes name from the material used, as " grain spirit," "potato spirit," "corn spirit," etc. From this raw spirit by the processes of rectification are obtained the " rectified spirit" used as the basis of the manufacture of various alcoholic beverages and as a solvent in vari- ous manufacturing processes, and by purification and dehydration the abso- lute ethyl alcohol of the chemist. * Wynter Blyth, Poods, Composition and Analysis, p. 464. | Deuxieme .Rapport du Laboratoire Municipal. RAW MATERIALS. 207 I. Raw Materials. These may he divided into three classes : First, alcoholic liquids, them- selves the product of fermentation, these require only to be submitted to distillation in order to yield the stronger spirit ; second, solid and liquid materials containing some variety of sugar, whether cane-sugar, grape- sugar, or maltose, which are directly or indirectly fermentable; and, third, starch-containing cereals and all materials capable under the influence of diastase or dilute acids of hydrolysis and the production of a fermentable sugar. 1. ALCOHOLIC LIQUIDS ( Wines). The distillation of wines is followed for the production of an alcoholic beverage (brandy) which takes to some degree its flavor and bouquet from the wines used in the distillation. While factitious brandies are largely made from grain or potato spirit, the true product from wine is always regarded as superior. The manufacture of wine brandy has been chiefly carried out in France, and in minor degree in Spain and Portugal. Within recent years California wines have also been used for the manufacture of brandies. The French wines which are used are largely those of the departments Chareiite and Charente- Inferieure, in the southwest of France, and the product is all known as Cognac brandy. White wines are said to yield a superior spirit to that obtained from red wines, and older wines better than newer ones. Alxmt eight and a half hectolitres of wine are needed to produce one hectolitre of brandy. Because of the ravages of the Phylloxera insect, the manufacture of genuine wine Cognac has decreased enormously in France in recent years, while the manufacture of factitious Cognac has correspondingly increased. Thus we find it officially stated * that the production of alcohol from wine in France had decreased from 530,000 hectolitres in 1875 to 14,678 hectolitres in 1883. The marc of the grapes, as already stated (see p. 202), is also utilized in the manufacture of an inferior grade of brandy, known in France as eau de vie demarc. The lees, or sediment, of the wine-casks are also used in this same way. This brandy is not necessarily sold for consumption, but is used to strengthen the alcoholic percentage of wines in which fermentation is to be arrested. 2. SUGAR-CONTAINING RAW MATERIALS. The most important sugar- yielding materials cultivated on a large scale, it will be remembered, are the sugar-cane and the sugar-beet. The sugar-canes are not used directly for the production of spirits (except in the case of accidental souring), and the " bagasse," although still containing saccharine juice, is too bulky, and hence is at once burned as fuel, but the molasses obtained on so large a scale in the extraction of raw sugar is a most valuable material for the purpose. Throughout both the West Indies and the East Indies enormous quantities of this molasses are fermented and the resultant product distilled for rum. Even the sugar-scums obtained in the defecating and concentrating of the sugar juice are fermented, and produce an inferior grade of rum. With the sugar-beet, both the beet itself and the beet-molasses are util- ized, the former being used in France and the latter in both France and German*'. Sweet fruits, the juice of which is rich in sugar, also serve as raw materials for the spirit industry. Thus peaches, plums, and cherries * Deuxieme Rapport du Luboratoire Municipal, p. 272. 208 FERMENTATION INDUSTRIES. are much used in different countries for the manufacture of fruit brandy, and the fermented juice of the date-palm in the East Indies and of the plantain in the West Indies both serve for the distillation of an alcoholic beverage. 3. STARCH-CONTAINING RAW MATERIALS. This list includes the main sources for the distillation of spirits, as the high percentage of starch in many cereals, ranging from sixty to seventy-seven per cent., the ease with which the starch can be converted into fermentable sugar under the influence of diastase or dilute acids, and the cheapness of these starchy products of nature all combine to make them for most countries the cheapest and best materials for the spirit industry. In the United States, the three cereals used almost exclusively for the manufacture of distilled liquors are corn, rye, and malted barley ; in England, barley, both raw and malted, rye, corn, and rice ; in Germany the potato is almost the only starchy material used. The composition of the several cereals showing their rela- tive percentage of starch was given on p. 162. ...-,. * . n. Processes of Manufacture. 1. PREPARATION OF THE WORT. In England and the United States, where grain spirit is mainly manufactured, the first process is that of sac- charifying the starch of the grain. In the special cases where malted grain alone is used, the mash process somewhat resembles that already described under beer-brewing. Most distillers, however, use mixtures of raw and malted grain, in which the raw largely predominates, being often ten to one or even more, as a very small quantity of diastase can be made to con- vert a large amount of starch into maltose or fermentable sugar. It is stated, moreover, that the yield of spirit is larger when several kinds of grain are mixed than when one kind is used singly. The mixture of raw and malted grain, properly ground, is put into the mash-tub (see Fig. 64, p. 185) with water at 150 F. and agitated. This first mashing requires from one to four hours, the larger the quantity of raw grain used the longer being the time required for mashing. The temperature of the mixture is kept up to about 145 F. by the successive additions of water at a some- what higher temperature (190 to 200 F.). The object of the distiller in this is somewhat different from that of the beer-brewer. He wishes to convert the whole of the starch, if possible, into maltose, which is directly fermentable by the action of yeast, while the dextrine is not, so he must mash at not much over 146, which it will be seen from Fig. 63 (p. 179) is the limit above which the maltose production begins to decrease. When the gelatinization of the starch is complete, the temperature of the mash may go slightly higher. By keeping within this limit of temperature, a minimum of diastase from the small admixture of malt will gradually change not only the starch, but bring about a hydration of the residual dextrine, converting it into maltose. When the wort has acquired its maxi- mum density, as found by the saccharometer, it is drawn off, and fresh water at about 190 F. is run upon the residue in the mash-tub and allowed to infuse with it for one or two hours. This second wort is then added to the first. A third weak wort is often obtained, and used to infuse new lots of grain. The mash is then cooled down promptly to the temperature required for fermentation so that the acetous fermentation may not set in. It is stated that in this method of direct mashing ten per cent, of the PROCESSES OF MANUFACTURE. 209 starch escapes decomposition, even although the grain may be taken finely ground. Hence a preliminary warming with water to which a little green malt is sometimes added, followed by heating with w r ater under a pressure of several atmospheres, now often precedes the addition of the main quan- tity of the malt, which is to complete the conversion of the starch and dex- trine into maltose. In this way the loss may be reduced from ten to five per cent. In Germany potatoes constitute the chief raw material for the spirit manufacture. They contain from eighteen to twenty per cent, of starch only, however, while the cereals contain over sixty per cent. The amount of the malt needed for the saccharification of the starch can therefore be cor- respondingly reduced. Instead of mashing the ground, rasped, or chipped potatoes in open mash-tubs as was formerly done, they are now first steamed under a pressure of two to three atmospheres, whereby the starch-contain- ing cells are thoroughly ruptured and the starch put in condition to be easily acted upon by the diastase. Among the forms of apparatus based upon this principle may be mentioned those of Hollefreund, Bohm, Henze, and Ellenberger. In that of Henze, which has been largely adopted, the potatoes, after steaming under a pressure of several atmospheres, are so dis- integrated that on opening a valve in the bottom of the vessel the pulp is forced out through a grating in a thin stream. This is cooled, mixed with the requisite quantity of malt, and started to mashing. In the Hollefreund and in the Bohm apparatus, the steaming, disintegrating, and mashing all take place in the same closed vessel, the malt being added after the dis- integrated mass has been properly cooled down. Green malt is found to work better in this case than air malt, and produces more alcohol. 2. FERMENTATION OF THE WORT, OR SACCHARINE LIQUID. In the case of mashing, as described above, either with grain or with potatoes, the wort must first be cooled down before adding the yeast and starting the fermentation. The yeast used is a surface yeast, and either fresh brewer's yeast or compressed yeast (previously softened in warm water) may be used. The procedure is now somewhat different, according as we have a grain- mash or a potato-mash to deal with. In the former case, using a thin wort drained from the exhausted grain, it has been found that the best results are obtained when the temperature during fermentation rises to about 33 or 34 C. (92 to 94 F.), as shown in Fig. 63 (see p. 179) ; in the latter case, where the entire mash, solid matter and all, is fermented, the fermenta- tion begins at a much lower temperature, and the heat evolved in the fer- mentation of such a concentrated wort ultimately carries the temperature to the same maximum. In the English plan, considerable lactic acid forms because of the higher temperature, and this is, of course, at the expense of the alcohol formation, while in the German plan, because of the low initial temperature of the fermentation, comparatively little lactic acid is produced, and when the higher temperatures are reached the mixture already contains so much alcohol that the lactic acid ferment grows with considerable difficulty. For one thousand litres of grain-mash, eight to ten litres of brewers yeast or one-half kilo, of compressed yeast are used ; for one hundred litres of potato-mash, one to two litres of brewer's yeast or three-fourths to one kilo, of compressed yeast are needed. The fermentation is sometime divided into several stages : the prelimi- nary fermentation, in which the yeast-cells grow without much alcohol formation ; the main fermentation, in which the maltose is fermented ; and 14 210 FERMENTATION INDUSTRIES. the q/ter-fermentation, in which the dextrine is gradually changed into mal- tose and this into alcohol. The time of fermentation varies from three to nine days, but it is carried on until the density of the liquid ceases to lessen or attenuate, which is determined by the saccharometer. The coefficient of purity of a fermentation is a term used to designate what percentage of the available starchy material in a substance has actually undergone the pure alcoholic fermentation. Thus, the reaction C 6 H 10 O 5 -f- H 2 O 2C 2 H 6 O -f- 2CO 2 demands from one kilogramme of starch a percentage of alcohol equal to 71.7 litres, and such a yield from one kilogramme of fermented material would indicate a purity coefficient of one hundred per cent. A percentage yield equal to sixty litres of alcohol from one kilo, of material would give a purity coefficient of 83.7 per cent. In France, the juice from inferior beets instead of being worked for the extraction of sugar is often fermented and distilled. The juice is extracted from the beet either by rasping and pressure or by slicing and maceration, the former method yielding the better spirit. The juice is made slightly acid with sulphuric acid to prevent any viscous fermentation, and a small quantity of brewer's yeast is added. The fermentation of acidulated beet juice sets in speedily and a thick mass of scum forms on the surface of the liquor, which is frequently got rid of by adding fresh quantities of the juice to that already fermenting. The temperature of the fermentation is from 20 to 22 C., and the process is usually complete in twenty-four to thirty- six hours. In still another process, known as " Leplay's method," the sugar is fermented in the beet-slices themselves, which are put in bags in the fer- menting-vats, and then the slices, charged with the alcohol produced, are distilled with the aid of steam until exhausted of spirit. The use of the molasses obtained in the extraction of the raw sugar, whether from the sugar-beet or the sugar-cane, is, however, much more common. In France and Germany, where the beet-sugar molasses is pro- duced in large quantities, the molasses originally marking 40 to 48 Beaume is diluted to 8 or 10 Beaume, and sulphuric acid of 66 is added to the amount of 1.5 per cent, of the molasses taken. This neutralizes the bases of the beet-molasses and inverts the cane-sugar present, bringing it into fermentable form. Brewer's yeast is then added, and the fermentation proceeds rapidly. The temperature ranges from 22 C., that usually chosen in France, where more dilute solutions are fermented, to 25 to 30 C. in Germany, where the concentration is usually as much as 1 2 B. Two hundred- weight of molasses at 42 B. will furnish about six gallons of pure spirit. In the West Indies, notably in Jamaica, the cane-sugar molasses is similarly utilized, but the procedure is somewhat different. In this case the addition of yeast is unnecessary, as the nitrogenous matters present suffice to start spontaneous fermentation. The best rum is that gotten from the molasses alone ; a second grade is obtained from the skimmings and " sweet- waters" which accumulate in the extraction of the sugar. To these is added some " dunder" (fermented wash, deprived by distillation of its alcohol and much concentrated by boiling), which acts as the ferment and starts the action. Molasses is then added in the proportion of six gallons to every hundred gallons of the fermenting liquid and the action allowed to go to completion. One hundred gallons of this mixture when distilled should yield twenty-five gallons of " low wines" or one gallon of proof rum for each gallon of molasses employed. PROCESSES OF MANUFACTURE. 211 3. DISTILLATION OF THE FERMENTED MASH, OR ALCOHOLIC LIQUID. Upon the construction of apparatus for the distilling from the fermented mash of the alcohol which it contains much skill and ingenuity have been displayed, and some of the later forms of stills and rectifying apparatus employed in large distilleries are wonderfully adapted for obtain- ing in a continuous operation the purest and strongest alcohol from the crude fermentation products. We may distinguish some five main classes of distilling apparatus, of which the minor varieties are too numerous to be specially enumerated. These classes are : first, simple stills with worm condenser heated by direct firing ; second, simple stills with closed " wash- warmer" ; third, stills with rectifying " wash-warmer" ; fourth, stills with " wash- warmer," rectifying and dephlegmator apparatus for intermittent working ; and, fifth, similar forms of construction for continuous working. The first and simplest of these classes hardly needs any special description. The stills are usually of copper, flat-bottomed, and often of great size, es- pecially in Irish and Scotch whiskey distilleries. It is obvious that their use involves a great waste of fuel. Therefore one of the earliest devices for economizing the heat of distillation consisted in interposing between the still and the refrigerating apparatus a " wash-warmer," or vessel filled with the liquid ready for distillation. Through this vessel the pipe conveying the hot vapors to the refrigerator coil passed, and the vapors partly condensing there heated up the wash, which then went into the still quite hot. Dorn's appa- ratus, still somewhat used in smaller establishments in Germany, accom- plished the same thing, and effected a partial rectification of the distillate by having interposed between the still and the refrigerator a vessel divided horizontally into two compartments by a diaphragm of copper. The upper and larger compartment served as a wash-warmer, and through it the tube conveying the vapors from the still passed into the lower compartment, where at first the distillate condensed. As the wash becomes warmed up this dis- tillate gives off alcoholic vapors, which then pass on and are condensed in the worm, while the watery portion is allowed to flow back into the still by a side-connection. It is obvious that this rectifying action can be increased by the introduction of two or more such vessels between the still and the final condenser, and so a distillate much richer in alcohol be obtained. Another principle was now brought into play in effecting a fractional condensation, that of dephlegmation, or chilling the vapor coming off by contact with metallic diaphragms so that a portion of it, and of course the most watery, is condensed and separated while the richly alcoholic vapor passes on into the rectifier or condenser. Three types of these most elab- orate apparatus may be briefly referred to : the Pistorius apparatus, used in Germany for the thick potato-mashes of that country, which is intermittent, " the Coffey still, used in England and Scotland for the thinner worts from grain, and the column apparatus, first introduced by Savalle and improved by later inventors, which is used in France for distilling wines and in Ger- many to follow up the work of the Pistorius or similar apparatus. Both the Coffey still and the column apparatus are continuous in action. In the Pistorius apparatus, two boilers and a wash-warmer are used for the fresh mash, and are connected so that the vapors from the first boiler pass into the second boiler, heating it up and in time driving vapor from it, which then passes around the wash-warmer and goes through several dephlegma- tors placed one above the other. In these the watery alcohol is continually being condensed and running back to the second boiler, while the uncon- 212 FERMENTATION INDUSTRIES. densed vapor which escapes from the top dephlegmator goes finally to the refrigerating apparatus. The Pistorius apparatus has been improved upon by Gall, Schwartz, and Siemens. The Coifey still, illustrated in Fig. 67, consists of two columns placed side by side, made of wood and lined with copper. The analyzer, A, is divided into twelve small compartments by four horizontal plates of copper, a, perforated with numerous holes and furnished with valves opening upwards. Dropping-pipes, b b, are also attached to each plate, the upper end of the pipe being an inch or two above the plate and the lower end dipping into a shallow pan, c, placed on the lower plate. The second column or rectifier, B, receives the spirituous vapors passing from the column A through the pipe g. This column is also divided into compartments like A, but there are fifteen instead of twelve. The ten lower diaphragms, /, are pierced with small holes and furnished with drop-pipes, while the upper five have only one large opening sur- rounded by a ring to prevent the finished spirit from returning. Between each of these compartments passes a bend of a long zigzag pipe, n n', one end of which is attached to the pump m, whilst the other end discharges the contents of the pipe into the top of the column J., as indicated by the arrow. The following is the working of the apparatus. In the first place, the fer- mented liquor or wash is pumped up by the pump m until the zigzag pipe is filled and the wort flows over the compartments a a a. Steam is then admitted into the compartments of the analyzer by the pipe d and heats the wash, which is deprived of all its alcohol by the time it reaches the bottom of the cylinder and flows off by e/as spent wash. The strong spirituous vapor passes through g to the rectifier, and at last through the worm c of the refrigerator into the receiver. The Coffey still is recognized as the best and most economical device for preparing a highly-concentrated spirit in a single operation. It is specially adapted for preparing from grain-mashes what is called " silent spirit," which is almost entirely destitute of flavor, and of a strength ranging from fifty-five to seventy over proof. It is not so well adapted for the distillation of malt whiskey as fire-heated stills, because the peculiar flavor of the whiskey depends upon the retention by the alcoholic distillate of the volatile oils produced in the mash, and the Coffey still separates the alcohol from these as well as other impurities. The forms of apparatus used in France for the distillation of wines are illustrated in that of Cellier-Blumenthal as improved by Derosne, shown in Fig. 68. The alcoholic vapors from A pass into B, and thence into the rectifying column (7, which contains a series of perforated metal cups over which wine from the wine-warmer, E, is trickling. The vapors thus enriched go through the upper rectifying column, D, and thence to the wine-warmer, E y which serves as a first condenser, and then to the cold condenser, JP, and so to the collecting vessel. After the operation is well under way the supply of wine can be introduced from H through G, k, and E, while the de-alco- holized liquid can be run off from the lower side of A. Another form of still very largely used in France and Belgium, especially for thin mashes like molasses and beet-mash, is that of Savalle, illustrated in Fig. 69. It is a continuous-working apparatus. B is the still proper heated by steam-pipes, A is the rectifying column, C is for catching froth, D is a warm tube condenser and E the cold condenser. The elements which form the condensing and rectifying parts of the column A are shown in Figs. 70 and 71. The vapors rising pass through the holes of the per- forated plates, on which rests a layer of condensed liquid which can only PROCESSES OF MANUFACTURE. 213 FIG. 67. f f 1 _J . IS " ifW 1- it=-i 1= - 214 FERMENTATION INDUSTRIES. drain down through d into the cup c placed below it. From these cups it overflows upon the perforated plate and is again drained off by the next connecting tube, d. The rising vapors are therefore washed by the liquid upon each perforated plate. FIG. 68. 4. RECTIFYING AND PURIFYING OF THE DISTILLED SPIRIT. The products from the preliminary distillation from the fermented grain- or potato-mash are not at first sufficiently strong, but must be strengthened by rectifying. In England, the spirits obtained by the first distillation from grain-mash are generally called low wines, and have a specific gravity of PROCESSES OF MANUFACTURE. 215 FIG. 69. FIG. 70. FIG. 71. 216 FERMENTATION INDUSTRIES. about .975. By rectifying, or doubling, a crude milky spirit, abounding in oil, at first comes over, followed by clear spirit, which is then caught sepa- rately. When the alcoholic strength of the distilled liquid has considerably diminished, the remaining weak spirit that distils over, called faints, is caught separately and mixed with the low wines preparatory to another FIG. 72. distillation. The rectifying is most rapidly and effectually done in the sev- eral forms of column apparatus, the best of which will yield a very pure alcohol in one or two operations. An improved Savalle rectifying column as used generally in French and Belgian distilleries is shown in Fig. 72. It consists of a still, A, heated by closed steam-coils, a rectifying column, B, two tubular condensers, C and D, PRODUCTS. 217 from the upper of which any condensed vapors flow back into the rectifying column as " low wines," while the lower condenser takes the more volatile product and passes it on as high-grade alcohol to the receiving-vessel, F. The purifying of raw spirit, notably that from grain and potatoes, from what is called fusel oil (propyl, isobutyl, and amyl alcohols) is also a matter of great importance if the spirit is to be used as the basis of any manufac- tured liquors. This fusel oil sticks persistently to the alcoholic distillates, and alcohol rectified until it reaches a strength of ninety-five or ninety-six per cent, by volume contains fusel oil. Some acetaldehyde also remains dis- solved in the alcohol, giving the raw spirit a bitter taste. Various reme- dies have been proposed of a chemical nature, such as a treatment of the raw spirit with oxidizing agents like chromic acid and ozone, but they have accomplished little as yet. The method most generally in use is to dilute the alcohol with water until it is about fifty per cent, strength, by which means the fusel oil separates out insoluble in the dilute spirit, and then to filter through wood charcoal. This process seems to be quite successful in removing the higher alcohols. The wood charcoal can be revivified by heating to redness in closed retorts. Another method which is now being experimented upon on a large scale, known as the Bang and Ruifin process, is to shake up the diluted spirit with petroleum oils, which have the power of absorbing the fusel oil and so withdrawing it from the dilute alcohol. 5. MANUFACTURE OF ALCOHOLIC BEVERAGES FROM RECTIFIED SPIRIT. Much of the rectified spirit, from whatever source derived, is used in connection with the" manufacture of wines for fortifying them and in arresting fermentation at any desired stage. The so-called " silent spirit" made in England by the use of the Coffey still from grain-wort is largely utilized in the manufacture of factitious brandies and wines, and the same thing applies to the spirit manufactured in France from beet-roots and beet- root molasses, where it is made to supply the deficiencies in the wine and Cognac production. The composition of many of these factitious or imita- tion liquors will be spoken of in the next section in enumerating the products of this industry. HI. Products. 1. RECTIFIED AND PROOF SPIRIT. " Rectified spirit of wine" is the name given to the most concentrated alcohol producible by ordinary distil- lation. The British Pharmacopoeia describes rectified spirit as containing eighty-four per cent, by weight of real alcohol and having a specific gravity of .838. The United States Pharmacopeia under the name "alcohol" simply calls for a spirit containing ninety-one per cent, of real alcohol and having a specific gravity of .820. The " spirit" of the German Pharma- copoeia has a specific gravity of .830 to .834, and hence corresponds more nearly to the British " rectified spirit." " Proof spirit" is a term in constant use in England for the purposes of excise, and its strength was defined by act of Parliament to be such that at 51 F. (10 C.) thirteen volumes shall weigh the same as twelve volumes of distilled water. The " proof spirit" so made will have a specific gravity of .91984 at 15.5 C. (60 F.) and contain, according to Fownes, 49.24 per cent, by weight of alcohol and 50.76 per cent, of water. Spirits weaker than proof are described as U. P. (under proof), stronger than proof as O. P. (over proof) ; thus, a spirit of fifty U. P. means fifty water and fifty proof spirit, while fifty O. P. means that the alcohol is of such strength that 218 FERMENTATION INDUSTRIES. to every one hundred of the spirit fifty of water would have to be added to reduce it to proof strength. Tables are in use which give for alcohol of a given specific gravity at 15.5 C. (60 F.) the corresponding percentage by weight, percentage by volume, and percentage of proof spirit contained. (See Wynter Blyth, Foods, Composition and Analysis, p. 371.) 2. ALCOHOLIC BEVERAGES MADE BY DIRECT DISTILLATION OF THE FERMENTATION PRODUCTS. Arrack. Any alcoholic liquor is called "arrack" in the East, but arrack proper is a liquor distilled either from toddy, the fermented juice of the cocoa-nut palm, or from malted rice. The arrack from Goa and Columbo is considered the best, and is made from toddy alone. This latter is gotten by the incision of the palm, and is col- lected in pots hung to the tree under the cuts. It is then fermented and distilled. In preparing the other variety, as carried out in Batavia and Jamaica, the rice is covered with water and allowed to germinate, dried at a temperature of 59 F., which arrests germination, and then a wort is made from the malted rice in the same manner as from malted grain, which is afterwards distilled. The commonest pariah arrack of India is generally narcotic, very intoxicating, and unwholesome. It is prepared from coarse jaggery sugar, spoilt toddy, refuse rice, etc., and rendered more intoxicating by the addition of hemp leaves, poppy-heads, juice of stramonium, and sim- ilar deleterious substances. Brandy in its purest form (Cognac) is the direct product of the distilla- tion of French wines. Its peculiar flavor and aroma are due to the presence of ethyl pelargonate (cenanthic ether). The better qualities of Cognac are distilled from white wines, the inferior varieties from the dark-red Spanish and Portuguese wines or from the marc or refuse of the wine-press, and called eau de vie de marc. A great deal is also entirely factitious, being mix- tures of grain spirit and water to which different coloring and aromatic substances have been added. When first distilled, brandy, like other spirit- uous liquors, is colorless, when it is known as white brandy, and continues so if kept in glass- or stone-ware, but if stored in oak casks, as is usually the case, it gradually acquires a yellowish tint from the wood, and it is then termed pale brandy. The still deeper color which it frequently possesses is given it by the addition of caramel-color, which was originally designed to simulate the appearance of an old brandy long stored in casks. The color- ing matter is also sometimes prepared from catechu and similar astringent and aromatic substances. Numerous recipes for factitious brandies are furnished for the use of rectifiers in making up imitations of Cognac. Two such recipes are given : No. 1. Powdered catechu, 100 grammes; sassafras-wood, 10 grammes; balsam of tolu, 10 grammes ; vanilla, 5 grammes ; essence of bitter almonds, 1 gramme ; well-flavored alcohol (at 85), 1 litre. No. 2. Malt spirit (17 U. P.), 100 gallons; nitrous ether, 2 quarts; ground cassia-buds, 4 ounces ; bitter almond meal, 5 ounces ; sliced orris- root, 6 ounces ; cloves in powder, 1 ounce ; capsicum, 1 J ounces ; good vinegar, 3 gallons ; brandy-coloring, 3 pints ; powdered catechu, 2 pounds ; full-flavored Jamaica rum, 2 gallons. Mix in an empty Cognac-cask and macerate for a fortnight, with occasional stirring. Produces 106 gallons at 21 or 22 U. P. Kirschwasser is a spirituous liquor obtained in the Black Forest and in Switzerland by the distillation of cherries. These are picked free from the PRODUCTS. 219 stalks and only the sound fruit taken. They are crushed for the extraction of the juice, and a portion of the cherry-stones are then separately crushed so as to bruise the kernels and returned to the juice. These bruised kernels impart the almond flavor to the product and give to it a small quantity of prussic acid (.15 gramme per litre in good kirsch and more in inferior kinds). After fermentation the liquor is drawn off and distilled by steam. The kirsch is colorless, of agreeable odor and flavor, which improves by keeping, and equal in strength to the strongest spirit. Rum is a spirit obtained in the West Indies, notably in Jamaica, Mar- tinique, and Guadeloupe, from the molasses of the sugar-cane by fermenta- tion and distillation. The process of fermentation of the molasses as carried out in Jamaica has already been described. When new, rum is white and transparent, and has when freshly distilled an unpleasant odor, due to oils contained. These are got rid of by treatment with charcoal and lime. It owes its characteristic flavor to butyric ether, which compound is also pre- pared artificially on a large scale, and as rum essence is used with " silent spirit" to make a factitious rum. Rum is always colored artificially with caramel-color. Whiskey is the spirit obtained from the fermented wort of corn, rye, and barley, either raw or malted. In Scotland and Ireland, malted barley, pure or mixed with other grain, is chiefly used ; in the preparation of the Bour- bon whiskey of Kentucky partially-malted corn and rye are taken, while for the Monongahela whiskey of Western Pennsylvania only rye (with ten per cent, of malt) is used. The difference between the Irish and the Scotch whiskeys lies mainly in the fact that the former is distilled in the common or so-called pot-stills, which brings over together with the spirit a variety of flavoring and other ingredients from the grain, while in Scotland the Coffey still is used, the product of which is a spirit deprived of essential oils. The Irish " poteen" whiskey has a smoky flavor, due to the use of peat fires in preparing the malt. This flavor is imitated by the addition of one or two drops of crea- sote to the gallon of spirits. 3. ALCOHOLIC BEVERAGES MADE FROM GRAIN SPIRIT BY DISTILLA- TION UNDER SPECIAL CONDITIONS. Gin is common grain spirit distilled and aromatized with juniper-berries, either when the "low wines" are con- centrated or later, using full-strength spirit. The proportion employed is variable, depending upon the nature of the spirit ; usually one kilogramme of berries is enough to flavor one hectolitre of raw grain spirit. The finest gin, known as " Hollands," is made in the distilleries of Schiedam, whence also the name " Schiedam Schnapps." Strassburg turpentine, oil of fennel, coriander and cardamom seeds are frequently substituted either wholly or in part for the juniper-berries, particularly in the English-made gin. The quality and healthfulness of the gin depends largely upon the purity of ths spirit used in the distillation, whether raw or rectified. It is obvious that many factitious brandies belong also in this class, being made by distillation of mixtures of which grain spirit is the basis and not by distillation of wine. These have already been described. 4. LIQUEURS AND CORDIALS. Liqueurs is the name now given to such spirituous drinks as are obtained by mixing various aromatic substances, such as anise, absinthe, essence of orange-peel, etc., with brandy or alcohol. Most are obtained by steeping in pure brandy or spirit different fruits or aromatic herbs and submitting the resulting liquid to distillation. They 220 FERMENTATION INDUSTRIES. are then colored, and are usually sweetened with sugar. The best known of them, absinthe, contains a characteristic ingredient, oil of wormwood, to which its deleterious effects on the nervous system are supposed to be due. At the same time the amount of total essential oils held dissolved in the strongly alcoholic liquid are such that when diluted with water the solution becomes milky and turbid. Among the liqueurs may be enumerated Absinthe (consumed chiefly in Paris), Anisette (made in the south of France), Chartreuse (made by the monks of the Grande Chartreuse Monastery near Grenoble), Curaqoa (originally made in Holland of Curafoa oranges), Maraschino (made in Italy of Dal- matian cherries), Ratafia (made in France from a great variety of fruits), and Usquebaugh (a strong cordial made in Ireland. It furnishes the name from which the word whiskey is derived). The composition of the several alcoholic liquors enumerated cannot be given in great detail, as their differences depend so largely upon the flavor- ing and aromatic ethers and essential oils, which are present in very minute quantities. Their general differences in alcoholic strength and the extract and ash of several are, however, given on the authority of Konig : * 1 Alcohol Alcohol Alcohol Alcohol by by by by volume. weight. volume. weight. Russian Dobry wutky 62.0 54.2 Gin 47.8 40.3 Scotch whiskey . . . 50.3 42.8 Ordinary German schnapps 45.0 37.9 Irish whiskey . . . 49.9 423 Rum . 49.7 42.2 English whiskey . . 49.4 41.9 French Cognac brandy . . 55.0 47.3 American whiskey . . 60.0 52.2 And in one hundred cubic centimetres of the following : Specific gravity. Alcohol by volume. Alcohol by weight. Extract Ash. Arrack 0.9158 60.5 52.7 0.082 0.024 Cognac 0.8987 69.5 61.7 0.645 0.009 Rum 0.9378 51.4 34.7 1.260 0.059 The composition of some of the well-known liqueurs is also given on the same authority : f Specific gravity. Alcohol by volume. Alcohol by weight. Extract. Cane- sugar. Other ex- tractions. Ash. Absinthe 0.9116 58.93 0.18J 0.32 Bonekamp of Maag bitters Benedictine bitters . . . Ginger .... . . 0.9426 1.0709 1.0481 50.0 52.0 47 5 42.5 44.4 40.2 2.05 36.00 27.79 32.57 25.92 3.43 1.87 0.106 0.043 0.141 Creme de men the .... Anisette of Bordeaux . . Cura9oa . . . * 1.0447 1.0847 1.0300 48.0 42.0 55.0 40.7 -85.2 47.3 28.28 34.82 2860 27.63 34.44 28.50 0.65 0.38 0.10 0.068 0.040 0.040 Kiimmel liqueur .... Peppermint liqueur . . . Swedish punch 1.0830 1.1429 1.1030 33.9 34.5 26.3 28.0 28.6 21.6 32.02 48.25 36.61 31.18 47.35 0.84 0.90 0.058 0.068 * Konig, Nah rungs- und Genussmittel, vol. ii. p. 469. f Ibid., p. 470. J Oil of wormwood. ANALYTICAL TESTS AND METHODS. 221 5. SIDE-PRODUCTS. The distiller's residues (Schlempe, vinasse) form a side-product of considerable value as a cattle food because of its composi- tion. It is especially rich in protein matter, fat, and non-nitrogenous ex- tractive, or carbohydrates. The residues from the beet- and cane-molasses distillation, moreover, yield an ash very rich in potash salts, so that they constitute, especially in France, a very important source of potashes. The composition of several of these distillery residues are given in the moist state on the authority of Konig : * Nitro- Non-nitro- Water. Fat. genous genous Cellulose. Ash. matter. extract. Rye-mash residues (ten analyses) 93.48 022 1 40 405 052 0.33 Potato-mash residues (six analyses) .... 95.10 0.17 1.17 2.17 0.92 0.47 Molasses residues . . . 91.86 2.04 4.56 1.54 Two complete analyses of distillery residues dried by centrifugating and heating in kilns are given on the authority of Rosenbaum :f Maize. Water 11.62 Ash 6.50 Crude proteid matter . 21.44 Crude fibre 10.54 Non-nitrogenous extractives 38.96 Crude fat 11.44 100.00 Potatoes. 7.83 16.40 23.08 8.60 40.54 3.55 100.00 Of these constituents the following were assimilable as food : Albuminoids 17.20 18.50 Carbohydrates 37.40 39.40 Fat 9.10 2.85 IV. Analytical Tests and Methods. The most important determination in this class of beverages is the alcoholic strength. In the case of rectified or proof spirit, a simple specific gravity determination is all that is necessary, and then the percentage strength can be found from the alcohol tables that have been prepared. The determination should be made at 15.5 C. (60 F.), or if at another temperature, a correction in the reading must be made. By multiplying the number of degrees above or below 15 by .4 and adding the product to the percentage given by the table when the temperature is lower than 15, or deducting it when the temperature is above, we get a correct result. In freshly-distilled and colorless whiskeys and brandies, in which the amount of extract is trifling, the alcoholic percentage can also be determined with sufficient accuracy by the specific gravity method. In such liquors as con- tain more extractive matter, like rum and the liqueurs and cordials, the * Konig, Nahrungs- und Genussmittel, vol. ii. p. 468. f Jahresber. der Chem. Technol., 1887, p. 1058. 222 FERMENTATION INDUSTRIES. alcohol must first be distilled off, and then made up to original volume with distilled water, as described on p. 203. A process of estimating the alcohol by oxidizing it into acetic acid and determining this by volumetric soda solution has also been recommended by Dupr6, but it can only be applied to a pure alcoholic distillate, and has no advantage over the specific gravity determination made on the same dis- tillate. It is obvious that the Geissler vaporimeter and the several forms of ebullioscope (see p. 203) can be applied with rectified or proof spirit, but, as said before, they are not capable of the greatest accuracy. The detection and determination of fusel oil, which is a persistent im- purity in potato and grain spirit, is one of the most important tests to be made. To detect it, the greater part of the alcohol is distilled off at as low a temperature as possible, the residual liquid mixed with an equal amount of ether and well shaken. The ethereal layer is then separated and allowed to evaporate spontaneously, when amyl alcohol, if present, will be recognized in the residue by its smell and chemical characters. Petro- leum-ether may be advantageously substituted for the ether in this test. Marquardt dilutes forty cubic centimetres of the spirit with sufficient water to bring the density to about .980 and then agitates the liquid with fifteen cubic centimetres of pure chloroform. The chloroform is allowed to settle, separated, and, after shaking with an equal measure of water, is allowed to evaporate spontaneously. The residue is treated with a little water and one or two drops of sulphuric acid, and sufficient solution of potassium permanganate is then added to cause the mixture to remain red after standing for twenty-four hours in a closed tube. Shortly after adding the permanganate the odor of valeric aldehyde will be observable, but after standing only the odor of valeric acid is distinguishable. This can be recognized even when the original residue is almost odorless and the smell is not masked by the presence of essential oils, etc. Marquardt has devised a more elaborate modification of the test to serve for the quantitative deter- mination of the fusel oil present. For the detailed description the reader is referred to Allen, 2d ed., vol. i. p. 121. Caramel (burnt sugar) is used for coloring and flavoring spirits, and is left as a brown residue on evaporating the spirit on the water-bath. This residue is distinguished by its bitter taste, and if further heated it carbonizes and smells of burnt sugar. Tannin is often present in brandy and whiskey, being chiefly extracted from the casks used in storing. Sometimes, as in factitious brandies, it is purposely added in the form of tincture of oak-bark. It may be detected by the darkening produced on adding ferric chloride to the spirit, and any reaction thus obtained may be confirmed by boiling off the alcohol from another portion of the spirit and adding solution of gelatine to the residual liquid, when a precipitate will be produced if tannin be present. E. BREAD-MAKING. Bread-making as ordinarily conducted is to be classed as one of the fer- mentation industries, as the swelling of the dough which must precede the baking is generally accomplished by the aid of the alcoholic fermentation brought about by the addition of " leaven" or yeast. For every kilogramme of bread, on the average, 2.5 grammes of alcohol and 2.7 grammes of car- bon dioxide gas are produced. Both are lost in the baking, but the carbon EAW MATERIALS. 223 dioxide gas when first generated is caught in the thick and viscid dough and causes it to swell up and become spongy in structure. This not only gives to the bread when baked a porous and cellular structure, but allows the chemical changes to take place throughout its entire substance, whereby.it is made more readily digestible. As the only effective result of the alcoholic fermentation is performed by the carbon dioxide, of course the addition of chemical mixtures liber- ating carbon dioxide gas in the dough may be made to obviate the necessity of using leaven or yeast, and similarly aerated breads may be made by simply forcing carbon dioxide under pressure into the dough. A few varieties of bread are made from dough, baked without any aera- tion either natural or artificial, such as hard crackers, the unleavened bread of the Jews, the Scotch oat-cake, and the corn-cake of the Southern States. These exceptions are of relatively minor importance, and by far the largest amount of bread is prepared by the aid of a fermentation process. I. Raw Materials. 1. FLOUR. This may be from either wheat, rye, barley, oats, maize, or Indian corn, and rice, although wheat flour is used in far the largest amount. The average composition of the several cereals has already been given. (See page 162.) Wheat flour contains the following substances : starch, dex- trine, cellulose, sugar, albumen, gliadin, or gluten, mucin, fibrin, cerealin, fat, mineral matters, and water. The first four are carbohydrates, or non-nitro- genous substances, and they form nearly three-fourths of the entire weight of the flour. The nitrogenous matter consists of at least five principles, three of which, gluten (or gliadin), mucin (or mucedin), and fibrin, constitute the bulk of the material known as crude gluten, which is the substance left when flour is kneaded with water and afterwards washed to remove the starch and any soluble substance. The remaining two nitrogenous princi- ples, albumen and cerealin, are soluble in water, and are carried away with the starch in the process of washing. Crude gluten possesses a peculiar ad- hesiveness, arising from the presence of gliadin, which is a highly tenacious body, and which is not present in the same form in other cereal flours. It is this adhesive property which gliadin imparts to gluten that renders wheaten flour so well adapted for bread-making purposes. The vegetable albumen mentioned above as soluble in cold water is ac- companied also by small amounts of legumin, or vegetable casein, which is also soluble in water. The cerealin is a soluble nitrogenized ferment occur- ring especially in the husk or bran of wheat and other cereals. It has a powerful fermentative action on starch, rapidly converting it into dextrine and other soluble bodies. The presence of cerealin in bran renders " whole meal" unsuitable for making bread by fermentation with yeast, though it can be used with baking-powders, and " aerated bread" can be made from it. The cerealin acts like malt extract, causing a too rapid conversion of the starch into dextrine and sugar, and hence, although the bran is rich in nitro- genous food constituents and salts like phosphates, it is ordinarily separated from the^ flour. The difference in the composition of the several parts of the wheat-grain' is seen in the following table given by Church :* * A. H. Church, Pocds, etc., South Kensington Hand-book, pp. C3 and 04. 224 FERMENTATION INDUSTRIES. FINE WHITE FLOUR. COARSE WHEA.T BRAN. In 100 parts. In 1 pound. In 100 parts. In 1 pound. Water 13.0 10.5 74.3 0.8 0.7 0.7 2 ounces 35 grains. 1 ' 297 11 ' 388 ' 57 ' 49 < 49 14.0 15.0 44.0 4.0 17.0 6.0 2 ounces 105 grains. 2 175 7 17 280 ' 2 316 ' 422 Fibrin, etc Starch, etc Fat Cellulose Mineral matter Of course, milling processes have to be specially adapted to the separa- tion of these quite different parts of the wheat-grain, the white flour free from bran being sought. By the old-fashioned " low-milling" process, or grinding between stones placed very close together and bolting, it was impos- sible to obtain a flour entirely free from contamination. The advance to " high-milling" with stones far apart, allowing the middlings which were produced to be purified before grinding to flour, was a step which made it possible to make from winter wheat an excellent and pure flour. When, however, spring wheat with its hard and brittle outer coats became important commercially, it was necessary to resort to the roller methods of milling, which, in conjunction with peculiar purifying machinery, would furnish a flour free from all undesirable impurities. This latter process has now almost universally replaced the other in the newer mills. While most of the other cereals before mentioned may be found occa- sionally in admixture with wheat flour, very few are used alone as substi- tutes for it. Rye flour is probably the only one. It makes a dark-colored, heavy and sourish bread, which, however, keeps moist a long time. It is much used in Germany and Northern Europe under the name of " black bread." A more palatable bread may be made from a mixture of two parts wheat flour and one part rye flour. This latter flour contains a slightly larger amount of fat and of mineral matter than wheat flour. It is never so white as wheat flour and the gluten has very little adhesive character. Ritthausen states that the gluten of rye flour consists chiefly of mucin (mucedin) and vegetable casein, and that gliadin is absent entirely. 2. YEAST, OR FERMENT. The yeast is at present almost always added, either as brewer's yeast or compressed yeast. In former times (and to a considerable extent still in France) wheat bread was made by the use of leaven, which consists of a portion of dough left over from a previous baking, charged with the ferment and in part changed by its action. This leaven is originally gotten by allowing flour and water to start into spontaneous fermentation, the nitrogenous matters becoming soluble and attacking the starch and sugar. The leaven tends, however, to continue its decomposition and to pass from the alcoholic into the lactic fermentation. Hence, if the leaven is in the proper stage of decomposition, it will induce the alcoholic fermentation and generate carbon dioxide gas, raising the dough ; if it be, however, in a more advanced state of decomposition, lactic fermentation will be induced and the bread will not raise, but become heavy and sour. In domestic practice, to avoid this latter result, salseratus (bicarbonate of potash or soda) is added to the dough. This neutralizes the lactic acid as fast as formed, and at the same time liberates carbon dioxide gas to inflate RAW MATERIALS. 225 the dough. An excess of this salt, however, makes the bread alkaline to the taste and yellow in color. The black rye bread of Germany is also made with the aid of a leaven known as " sour dough." In this both the alcoholic and the lactic fermen- tations are in progress, the latter, however, preponderating. Four parts of such sour dough are used for one hundred parts of flour. The brewer's yeast for bread-raising purposes must be a fresh and vig- orous yeast-growth, as its value here depends largely upon the energy of the fermentation set up and the amount of gas given off. Its appearance and characters have been described before. (See p. 177.) Unless of the best quality, compressed yeast is to be preferred because of its reliability. The manufacture of this latter is carried out chiefly in connection with the spirit distilleries. At the time when the fermentation is most energetic, the yeast is skimmed off the surface and conveyed by wooden shoots to steam sieves, by Avhich the husks are eliminated, the strained liquid passing on to the settling cisterns. When settled the surface liquid is drained off and sent for distil- ling purposes, and the yeasty sediment mixed with starch and put into the filter-presses, which squeeze out all the liquid, leaving a dough-like paste, which, when sufficiently dry, is packed into bags and packets and is ready for distribution. Yeast from its peculiar slimy nature cannot be pressed well, hence the addition of starch, which permits the removal of more of the liquid from the yeast. Absolutely pure yeasts do not keep so well as the same yeasts with an addition of from five to ten per cent, of starch. In high-class yeasts the quantity added is about five or six per cent. ; it is often added in quantity beyond this as an adulterant. A good sample of compressed yeast has the following characteristics : It should be only very slightly moist, not sloppy to the touch ; the color should be a creamy white ; when broken it should show a fine fracture ; when placed upon the tongue it should melt readily in the mouth ; it should have an odor of apples, not like that of cheese ; neither should it have an acid taste or odor. Any cheesy odor shows that the yeast is stale and that incipient decomposition has set in. 3. BAKING-POWDERS. To obviate the necessity of using yeast and waiting until the dough should rise sufficiently, under the influence of fer- mentation, it was early sought to supply the necessary carbon dioxide to the dough by chemical reactions. The earliest proposal was that of Liebig to use sodium bicarbonate and hydrochloric acid, which should evolve car- bon dioxide and leave sodium chloride (common salt) in the dough. Next was proposed sodium bicarbonate and tartaric acid, or acid potassium tar- trate (cream of tartar). More generally satisfactory than either of these was acid calcium phosphate (either alone or with acid magnesium phos- phate), which with bicarbonate of soda formed Horsford's baking-powder. More objectionable was the introduction of alum with the sodium bicarbon- ate. Most of these baking-powder mixtures, then, have starch or flour added as " filling," and in amount varying from twenty to sixty per cent. Sesquicarbonate of ammonia is also used in many of the mixtures, re- placing part of the bicarbonate of soda. Self-raising flours have these baking-powders already added to the flour in such proportions as will insure a spongy dough upon the simple addition of water and kneading into loaves. 15 226 FERMENTATION INDUSTRIES. IE. Processes of Manufacture. 1. THE MIXING OF THE DOUGH AND ITS FERMENTATION. The mixing of the flour with water is not only for the purpose of bringing into solution the dextrine, the sugar, and the soluble albuminoids, and of allowing these latter as peptones to act upon the insoluble constituents of the flour, such as the gluten, but also to penetrate and soften the starchy material. The yeast may be added directly along with the water to some of the flour to prepare a " sponge," from which the whole batch of dough is after- wards made, or a " ferment" may be made from the yeast with potatoes, which then is used to prepare the " sponge." In the latter case, potatoes are boiled and mashed with water into a moderately thin liquor, to which the yeast is added, and the fermentation is allowed to proceed for some time. In either case, whether the yeast is used direct or a potato ferment is first made, it is worked up with a portion of the flour into a slack dough, which constitutes the sponge, and is set to rise in a warm place. When the sponge has risen sufficiently the remainder of the flour is worked in with sufficient water to which some salt has been added, and the dough is made, kneaded, allowed to stand again to rise, and then prepared for baking. The use of potato ferment is based upon the belief that the yeast-cells are strengthened by the soluble nitrogenous matter of the potato, which acts as a yeast stimulant and enables a smaller quantity of yeast to hydrolyze a larger amount of starch. The yeast-cells then act very rapidly upon the glucose so produced and develop the alcoholic fermentation. The albumi- noids of the flour are also softened and partially peptonized, and these changed albuminoids in turn assist in the hydrolysis of the starch. 2. BAKING. For baking, the oven should have a temperature of 400 to 450 F. (200 to 230 C.). Before putting the loaves in, they are often wetted on the surface so as to assist in the prompt formation of a crust that shall prevent the dough from expanding too rapidly. The heat expands the gases throughout the loaf and so swells it and vaporizes a portion of the moisture. The action of the heat and steam soon converts the starch on the surface of the loaf into dextrine and maltose, and these at the high tempera- ture are slightly caramelized, thus giving the crust its brownish color. At the temperature of the interior of the loaf (212 F. or slightly above) the starch-cells will have burst, the coagulable albuminoids will have been coagu- lated, and their diastatic power entirely destroyed. Steam is often injected into the oven during the baking. The effect is to produce a glazed surface on the outside of the crust. It not only dex- trinizes and glazes the crust, but keeps the interior of the loaf moist by pre- venting too rapid evaporation. Of course, in perfectly tight ovens the steam resulting from the evaporation of the moisture of the bread is kept in, and soon acts in the same manner though in a lesser degree. One hundred kilogrammes of flour will yield, according to its quality, from one hundred and twenty-five to one hundred and thirty-five kilos, of bread. 3. USE OF CHEMICALS FOREIGN TO THE BREAD. Both alum and sulphate of copper (and notably the former) have been used in baking bread from inferior or unsound flours in order to improve the appearance of the bread. This they do by preventing or lessening the breaking up of the gluten and starch during fermentation, and so cause a loaf made from a bad PRODUCTS. 227 flour to be larger, less sodden, and whiter, giving it the appearance of having been made from better flour. As these chemicals are injurious to health, and as their sole purpose is to allow of deception as to the character of the flour used in bread-baking, they ought to be prohibited by law. Liebig suggested the use of lime-water as a means of retarding too rapid decomposition of the starch during the fermentation of bread-making. The bread made with the proper amount of lime-water is said by Jago* to be more spongy in texture, pleasant in taste, and quite free from sourness. In the bread the lime exists as calcium carbonate, but in such quantities as to be perfectly harmless. The use of lime-water in bread-making is said to be practised extensively by Glasgow bakers. HI. Products. 1. BREAD. The nature of the change which the flour undergoes in the bread-baking process has already been indicated in part. The composition of the finished bread can now be noted. A loaf of wheaten bread consists of two parts, the crumb and the crust, which differ somewhat in both physical and chemical character. The crumb is white in color, more or less vesicular in structure, soft when fresh, and of agreeable taste and sweet odor ; the crust is harder, more easily broken, of a chestnut-brown color, and nearly destitute of all porous character, is sweeter in taste, because of the greater change of the starch into dextrin and maltose. The chemical differences between the crumb and crust of wheat bread are shown in several of the analyses given by Von Bibra.f CALCULATED FOE ANHYDROUS BREAD. Water origi- nally con- tained in the bread. Nitro- genous material. Dextrin and soluble starch. Sugar. Fat. Starch. "Wheaten bread, Niirnberg, crumb Wheaten bread, Nurnberg, crust . Eye bread, Nurnberg, crumb . . Rye bread, Nurnberg, crust . . . "Wheaten bread from Madrid . . Wheaten bread from years 1816 and 1817 11.296 10.967 17.096 14.838 8.064 8.541 7.354 11.296 13.296 6.387 9.741 10.903 14.975 16.092 15.413 18.275 4.763 10.192 14.531 4.363 12.209 5.497 4.653 28.269 4.175 4.149 2.613 4.835 1.470 2.184 4.953 2.145 7.035 4.420 2.846 6.345 1.683 0.715 1.064 0.564 1.173 4.233 0.824 1.360 0.566 10.948 0.807 67.871 68.077 63.814 60.842 84.530 79.083 68.929 81.372 66.100 83.130 71.812 53.676 40.600 13.000 46.440 12.449 15.000 11.666 9.160 11.420 14.000 11.780 8.660 18.333 Pumpernickel from Westphalia (contained some bran) .... Wheaten Zweiback, Hamburg . . Rye Zweiback, Bremen Barley bread from Lower Bavaria Oaten bread from Bavaria (per- fectly free from adulteration) . Fine rye bread from Dalecaria (containing bran) The differences between wheat bread made by the usual fermentation process and wheat bread aerated by carbon dioxide under pressure (Daug- lish system) are shown also in the following analyses by Dr. Bell : J * Chemistry of Wheat, Flour, and Bread, etc., 1886, p. 326. f Stohmann and Kerl, Arigewand. Chem., 4th ed., p. 215. j Analyses and Adulteration of Foods, p. 131. 228 FERMENTATION INDUSTRIES. CONSTITUENTS OP THE BREAD EEDUCED TO DRY STATE. AERATED BREAD. HOME-MADE BREAD. Tin loaf. Cob loaf (Paris bread). Tin loaf. Cob loaf (Paris bread). Crumb. Crust. Crumb. Crust. Crumb. Crust. Crumb. Crust. Starch, dextrine, cellulose, etc. Maltose 78.93 640 10.30 1.96 0.18 2.23 78.96 5.61 11.28 1.75 0.16 2.24 82.75 4.66 8.58 1.80 13 2.08 82.82 3.94 9.09 1.85 0.17 2.13 78.12 6.87 11.65 1.74 0.22 1.40 77.62 6.68 11.17 2.00 1.22 1.31 82.05 4.85 10.59 1.28 0.15 1.08 83.42 4.11 8.68 2.37 0.39 1.03 N itrogenous matter, insolu- ble in alcohol Nitrogenous matter, soluble in alcohol Pat Inorganic matter or ash . . . Percentage of moisture in bread when new 44.09 19.19 41.52 16.48 42.02 22.92 41.98 20.02 2. CRACKERS AND HARD BISCUIT are made from a dough composed of flour and water, with the addition in special cases of a great variety of sweetening and flavoring ingredients, such as milk, eggs, sugar, butter or lard, spices, and flavoring essences. The dough prepared in large masses is passed between rollers, and from the sheet of dough so obtained by other machines are cut out the various forms desired. Sheets or trays of these dough-forms pass by automatic machinery into and through long ovens at a regulated rate of speed, which can be so controlled as to give them exactly the requisite exposure to the heat needed for baking. IV. Analytical Tests and Methods. 1. FOR THE FLOUR. The moisture is determined by drying five grammes of the flour in a water-oven until constant weight is obtained. The starch is estimated from the amount of glucose which is produced from it by the action of dilute acid. Two grammes of the flour are boiled in a flask with inverted condenser for several hours with some twenty cubic centimetres of sulphuric acid suitably diluted. When the conversion of the starch is completed the solution is neutralized with soda, made up to definite volume with water, and the glucose determined with Fehling's solution either gravimetrically or volumetrically, as described under glucose. (See p. 152.) After deduction of the sugar found in a previous test to be con- tained in the sample, the difference is the amount produced from the starch, together with a small quantity from the dextrine and traces of fibre. One hundred parts of glucose correspond to ninety of the starch. To determine the cellulose, a weighed quantity of the flour is boiled with rather dilute sulphuric acid for ten minutes to dissolve the starch. A large quantity of water is then added, and the undissolved part allowed to settle. The residue is thrown upon a filter, well washed with boiling water, and then digested with dilute potash solution to dissolve the albuminous matter. It is then washed upon a tared filter, dried, and weighed. It is now incinerated and the ash determined. This subtracted from the weight of material on the tared filter gives the cellulose or fibre. To determine the sugar, ten grammes of the flour or powdered grain are ANALYTICAL TESTS AND METHODS. 229 repeatedly digested in alcohol of seventy per cent, and the nitrate made up to a bulk of three hundred cubic centimetres. This solution is first tested directly for glucose, but generally with negative results. A known portion of the filtrate is then boiled for four minutes with five cubic centimetres of normal sulphuric acid, neutralized with soda and tested with Fehling's solu- tion, and the sugar present reckoned as cane is calculated from the result. The total nitrogenous compounds, and the portions soluble or insoluble in alcohol, are generally determined. Sometimes the portions of the nitro- genous compounds soluble or insoluble in water are determined instead. In the latter case Wanklyn's ammonia process (see p. 190) is the most con- venient. Generally, however, the distinction made is into those album!-, noids soluble and those insoluble in alcohol. For this determination ten grammes of the flour are completely exhausted with eighty per cent, alcohol at a temperature of 140 F. (60 C.) and an aliquot portion of the total filtrate evaporated to dryness and weighed. A known quantity of this residue is then analyzed for nitrogen by the Dumas process with copper oxide, and the nitrogen so obtained multiplied by 6.3 gives the albuminoids. The flour left after treatment with alcohol is dried, and a weighed portion analyzed for nitrogen and similarly calculated for albuminoids (albumen and fibrin). For another process for these albuminoid determinations by Graham, see Allen, " Commercial Organic Analysis," 2d ed., vol. i. p. 366. The gluten is best determined as recommended by Wanklyn and Cooper.* Ten grammes of the flour are mixed on a porcelain plate with four cubic centimetres of water so as to form a compact dough. This is placed in a conical test-glass or measure, fifty cubic centimetres of water added, and the dough manipulated with a spatula so as to free it from starch. The water is decanted off, a fresh quan- tity added, and the kneading con- FIG. 73. tinued until the water remains col- orless. The gluten mass is then removed, kneaded in a little ether, and spread out in a thin layer on a platinum dish, where it is dried by the aid of a water-oven until the weight is constant. The crude gluten contains ash equal to about .3 per cent, on the flour and fat equivalent to 1.00 of the flour. An examination of the crude gluten as to its power of distending under the influence of heat is often made as a means of judging of the value of a flour for bread-making. This is done by the aid of the aleurometer of Boland, shown in Fig. 73. Some thirty grammes of the flour are kneaded as just de- scribed, and seven grammes of the freshly-separated crude gluten obtained is placed in the inner vessel as shown at a b. In the mean time, while the gluten is* being prepared, the tube D is heated by means of an oil-bath until 150 100 * Bread Analysis, London, 1886, p. 43. 230 FERMENTATION INDUSTRIES. the thermometer T, which is at first sunk in the tube D, registers 150 C. The thermometer is then withdrawn and the aleurometer JE, containing the gluten, put in its place. The spirit-lamp under the oil-bath is allowed to burn for ten minutes longer and then extinguished. The piston G is grad- uated so that when pushed down it registers 25. When the gluten swells and fills the space from a b to c d it touches the bottom of the piston and is at 25. If it continues to swell the reading may be 30 or 35, as shown on the scale when the piston is pushed up. If the gluten does not indicate at least 25 on the aleurometer it may be considered unfit for bread-making. A similar instrument, termed an aleuroscope, has been invented by Sellnick. To determine the fat of the flour, four grammes are dried and repeatedly digested with ether until exhausted. The filtrates are evaporated in a tared vessel and weighed. To determine the ash, ten grammes of the flour are incinerated in a platinum capsule to a white ash, which is then weighed. Among the adulterations of flour, besides the admixture of other starchy material of lesser value, which must be looked for with the micro- scope (see starches, p. 161), the most frequently occurring is alum. For the detection of this, one of the best known tests is based upon the property of alumina of forming a violet- or lavender-colored lake with the coloring matter of logwood. Ten grammes of the flour should be mixed in a wide beaker with ten cubic centimetres of water, one cubic centimetre of the logwood tincture (five grammes of logwood-chips digested with one hundred cubic centimetres of strong alcohol) and an equal measure of a saturated aqueous solution of ammonium carbonate are then added, and the whole mixed together thoroughly. If the flour is pure, a pinkish color, gradually fading to a dirty brown, is obtained ; whereas if alum be present, the pink is changed to a lavender or actual blue. As a precaution, it is desirable to set the mixture aside for a few hours or to warm the paste in the water- oven for an hour or two and note whether the blue color remains. Or to separate any alum from the flour before applying the test, the flour is shaken up with chloroform in a stoppered glass cylinder provided with a stopcock below. After shaking the flour rises to the surface, while any for- eign mineral matter settles at the bottom, and may be run off with a little of the liquid. The mineral matter is warmed and the chloroform gotten rid of by the aid of a current of air. It can then be examined. Any alum in it will of course be soluble in water, and can be shown by the usual tests. Methods for the quantitative determination of alum found as an adulterant in flour have been proposed by Dupre and Bell and by Wanklyn, for an account of which the reader is referred to Bell's work on the " Analyses and Adulteration of Foods." 2. FOR BREAD. The methods just described under flour are almost all equally applicable to the baked bread. To test bread for adulteration from alum a slightly different procedure is to be followed. To about a wine- glassful of water in a porcelain capsule five cubic centimetres of freshly- prepared tincture of logwood and the same quantity of the carbonate of ammonia solution are added. A piece of the crumb of the bread, say about ten grammes, is then soaked therein for about five minutes, after which the liquid is poured away and the bread is dried at a gentle heat. If alum be present the bread will acquire a lavender color or more or less approaching dark blue, according to the quantity of the alum which has been added ; whereas if the color be a dirty brown, the bread may be regarded as pure. RAW MATERIALS. 231 F. THE MANUFACTURE OF VINEGAR. Under the general heading of fermentation mention was made of the acetic fermentation, which frequently follows the alcoholic fermentation. It is produced, it is true, by other species of ferments, but largely upon mate- rials susceptible to the alcoholic fermentation or already changed by it into alcohol-containing products. The close association in nature of these two changes is readily understood when the chemical relationship of alcohol and acetic acid is looked at. The latter is the simple oxidation product of the former, and the processes for developing the alcoholic change in any sugary liquid, such as a beer-wort or a grape-must, have to be controlled carefully that they do not allow of this supplementary change whereby the alcohol goes over into acetic acid. The conditions under which the acetic fermenta- tion sets in may be summarized as follows : 1. A liquid weak in alcohol, containing not more than twelve per cent, by weight of this compound. 2. Abundant access of air. 3. A temperature of from 20 to 35 C. (68 to 95 F.). 4. Acetic ferments (Mycoderma aceti, etc.), together with the food neces- sary for these organisms. Under this heading of acetic ferments Nageli distinguishes, besides the Mycoderma aceti, the Mycoderma cerevisice and Mycoderma vini, although the latter of these is said by De Seynes to arrest the growth of the acetic ferment proper. Hansen also mentions a second ferment as found at times in beer along with the Mycoderma, or, as it is often termed now, Bacterium aceti, to which he gives the name Bacterium Pasteurianum. The acetic ferment, as before stated (see p. 176), develops not by the budding process characteristic of the yeast ferment, but by splitting or fissure of the elongated cell. When these germs, which originally drop from the air, like the yeast-cells, into the fermenting or sugary liquids, find a liquid specially suited for their growth, as, for example, a mixture of wine and vinegar, they develop rapidly over the surface of the liquid, where they have the necessary oxygen supply, and form a gelatinous skin, which thickens and falls to the bottom of the vessel because of its increasing weight. An- other skin forms at once again, and this in turn is replaced by a third, and so on until the liquid is completely exhausted of assimilable material. This skin, called the " mother of vinegar," consists of a multitude of these minute fissure ferments. I. Raw Materials. Only such materials will be considered here as give rise to a vinegar by the normal acetic fermentation. The manufacture of acetic acid and tech- nically important acetates will be spoken of later under pyroligneous acid as derived from the destructive distillation of wood. The materials referred to as furnishing vinegar under the influence of the acetic fermentation are, first, wine ; second, spirits ; third, malt- wort or beer ; fourth, fermented fruit juices other than wine ; and, fifth, sugar-beets. The wines used are both red and white wines, and are such as are of in- ferior vintages, and considered unfit for drinking as wine. Such wines are gathered together from all sections and are made into vinegar largely in France at Orleans and at Paris. The wines do not exceed ten per cent. 232 FERMENTATION INDUSTRIES. alcoholic strength. Wines about a year old are the best for vinegar-making, as the new wines are prone to undergo putrid or ropy fermentation, and older wines do not contain sufficient extractive matter. The spirits used are chiefly the potato brandy of Germany and whiskey in this country, the vinegar in either case being made by the " quick vin- egar" process. These spirits, when used for vinegar-making, are so diluted with water and vinegar already formed that the alcoholic strength ranges between three and ten per cent. The matt-wort used for vinegar-making is exactly like that prepared for grain spirit manufacture, unmalted grain and malt being used admixed, and the alcoholic fermentation being pushed so as to produce the maximum amount of alcohol from the converted starch of the grain. When the alco- holic fermentation is completed it is allowed to stand for some days in the fining-vats, where all dead yeast and cloudiness subside, and it is then made to pass through a filter-bed of wood-chips into the acetifier. The unmalted grain used in the preparation of the wort must be thoroughly dried in a kiln previous to crushing in order that many of the glutinous and albumi- noid matters may be destroyed. These would otherwise interfere with the keeping qualities of the vinegar. Sour ale or beer is said not to yield good vinegar, but a product very liable to undergo putrid fermentation, a very disagreeable smell being imparted to the vinegar in consequence. Cider from apples and Perry from pears are about the only fruit juices besides wine fermented for the production of vinegar. Cider from good, sweet, and ripe apples serves for the manufacture of cider vinegar in this country. The cider is the product of a spontaneous alcoholic fermentation of the apple juice, and the vinegar formation is merely a continuation of this spontaneous change. Perry vinegar is made to some extent in Eng- land, and a vinegar from crab-apples in Wales. Sugar-beets are used somewhat in France for vinegar-making. The beets are rasped to a fine pulp and pressed. The juice is diluted with water and boiled. After cooling, yeast is added and the alcoholic fermentation developed, and this product mixed with vinegar and treated as the other alcoholic liquids before mentioned for the development of the acetic fermen- tation. Artificial glucose, cane-sugar, and molasses have also been used in Eng- land for the production of vinegars which are used to adulterate malt vinegar. n. Processes of Manufacture. 1. THE ORLEANS PROCESS. This is the process by which wine vinegar is made in France and Germany, and is the oldest in practical use of the several methods now employed. The wine which is to be acetified is allowed to stand for a time over wine-lees, and then clarified by being passed through vats containing beech-shavings. The oaken acetifying vessels, holding from fifty to one hundred gallons, and known as " mother-casks," are first steamed out and then soured with boiling vinegar, which is made to fill one-third of the cask. The wine is now added in instalments of ten litres every eight days until the cask has become more than half-full, when one-third of its contents are siphoned off into storage-vats and the periodical addition of wine continued as before. The " mother-casks," or acetifiers, can be used in this way continuously for years until the sediment of yeast, argols, and impurities makes it necessary to give them a thorough cleaning. The viii- PROCESSES OF MANUFACTURE. 233 egar obtained in this way has a very agreeable aroma, that made from white wines being most esteemed. When the wines employed in the Orleans process are too weak it often happens that the vinegar is ropy and wanting in transparency. In such case it must undergo the firing process. The progress of the acetification is judged of by plunging in a rod and examin- ing the froth upon it when withdrawn. This should be white and copious. The temperature that is found to answer best is between 24 and 26.6 C. (75 and 80 F.) Hengstenberg has proposed a modification of the Orleans process, whereby a series of the " mother-casks" are connected together at the base by short pieces of glass tubing. After the acetification of the first addition of wine in each cask the new wine is added only to the first cask, into which it runs slowly, while from the last cask of the series, by means of a siphon- tube fixed in the side, the excess flows off as finished vinegar. The increase of yield by this modification is, however, only slight. 2. THE QUICK-VINEGAR PROCESS. This process was first introduced by Schutzenbach in 1823, and has been considerably improved since. It is used exclusively in the case of spirit vinegar in Germany and in this country, and, with slight modifications, in England for malt vinegar. The vinegar-formers are upright casks from six to twelve feet in height and three to five feet in diam- eter. About a foot above FlG - the true bottom of the cask it has a false bottom perforated like a sieve. Upon this beech-wood shavings are heaped, ex- tending nearly to the top of the cask. Between the true and false bot- toms and just under the latter a series of holes is bored in the cask in a direction slanting down- ward and extending around the entire cask. The beech-shavings are first boiled in water and dried. They are then soured or soaked in warm vinegar for twenty-four hours, filled into place and covered by a wooden disk perforated by fine holes in which pack- thread is loosely filled. This disk also is perfo- rated by four larger glass tubes open at both ends, which serve as air-vents. The cask is then closed on top by a wooden cover with a single hole in the centre, through which the alcoholic liquid is to be poured and from which air may escape. The entire arrangement may be understood from Fig. 74. During the oxidation of the 234 FERMENTATION INDUSTRIES. FIG. 75. alcoholic liquid considerable heat is developed, and a current of air is thus made to enter through the circle of holes under the false bottom and rise through the wet shavings, escaping through the opening at the top. The diluted spirits or mixture to be acetified are poured into the top of each vat, and as they flow off, by the aid of a siphon arrangement from the base they are introduced into the top of the second vat. If not over four per cent, of alcohol were contained in the original liquid, that drawn off from the second vat will be converted into good vinegar. The temperature of the vinegar-forming casks should be about 35 C. (95 F.). Above this there is too much loss of alcohol and aldehyde by evaporation ; below it, the oxidation goes too slowly. If the minute organisms known as " vinegar eels" show themselves, hot vinegar is poured in on top until it shows a temperature of 50 C. (122 F.) on running off, which kills them. Whiskey, brandy, and grain spirit properly diluted are all acetified by the aid of this quick-vinegar process. To these diluted spirits a small amount of malt infusion is generally added to furnish nutritive matter for the development of the acetic ferment, which in this process as in the pre- ceding is the agency whereby the atmospheric oxidation becomes effective in changing alcohol into acetic acid. 3. MANUFACTURE OF MALT VINEGAR. This is effected by a process much resembling the quick-vinegar process. The acetifiers are, however, much larger, holding from eight thousand to ten thousand gallons. Their construction is shown in Fig. 75. Bundles of birch-twigs, B, are sup- ported upon a perforated bottom, from which the liquid trickles in fine streams. The malt-wort fed in be- low is warmed by a closed steam- coil of block-tin, and pumped to the top of the casks, where it is sparged, or sprinkled, in fine streams over the birch-twigs, and the process re- peated until the vinegar shows the requisite strength. These birch- twigs have been previously freed from all juice and coloring matter by repeated boiling with water, and are soured before starting the spar- ging. The entire process of making malt vinegar requires about two months. The temperature at the beginning of the process is about 43 C. (110 F.), and later is kept at 38 C. (100 F.). 4. THE MANUFACTURE OF CIDER VINEGAR. As before stated, this is largely a spontaneous fermentation. The fresh cider is allowed to fer- ment in barrels having the bung-hole open, which are exposed to the sun or placed in a warm cellar. The acetification is often made a progressive change by adding fresh quantities of cider to the barrel every few weeks ; the addition of " mother of vinegar" also is made to accelerate the change. 5. PASTEUR'S PROCESS FOR VINEGAR-MAKING BY DIRECT USE OF THE VINEGAR FUNGUS. Pasteur takes an aqueous liquid containing two per cent, of alcohol and one per cent, of vinegar and small amounts of phos- phates of potassium, magnesium, and lime, and in this propagates the acetic ferment (Mycoderma acdi). The plant soon spreads out and covers the PRODUCTS. 235 whole surface of the liquid, at the same time acetifying the alcohol. When one-half of the alcohol has been changed small quantities of wine or alcohol mixed with beer are added daily until the acetification slackens, when the vinegar is drawn off and the " mother of vinegar" collected, washed, and used again with a freshly-prepared mixture. When wine or beer are used, the addition of the phosphate salts as food for the plant is unnecessary, but when pure alcohol is used they are needed. Vinegar prepared by this process is said to possess the agreeable aroma of wine vinegar. _ IE. Products. Wine Vinegar varies in color from light yellowish to red, according as it has been derived from white or red wines, that from the former being the most highly esteemed. The vinegar from red wines, however, can be decol- orized by filtration through purified bone-black. Skimmed milk is also used for the same purpose. When thoroughly agitated with the vinegar the casein coagulates and carries down with it the greater part of the coloring matter of the vinegar, besides clarifying it. It is not used, however, so much as the filtration through charcoal. Wine vinegar has a specific gravity 1.014 to 1.022, and contains from six to nine per cent, (rarely twelve) of absolute acetic acid. When freshly made, it contains traces of alcohol and aldehyde. The amount of acid potassium tartrate (tartar) contained in wine vinegar averages .25 per cent. - Its presence is peculiar to this variety of vinegar. Matt and Seer Vinegars have a higher specific gravity (1.021 to 1.025), and contain dissolved dextrin, maltose, soluble albuminoids, and similar con- stituents of the malt extract. This kind of vinegar on evaporation leaves a glutinous residue only sparingly soluble in alcohol. It contains from three to six per cent, of acetic acid. Spirit Vinegar is colorless as produced, but is frequently colored with caramel-color to imitate the appearance of wine or cider vinegar. It con- tains from three to eight per cent, of acetic acid, although the so-called " vinegar essence" (double vinegar) may contain as much as fourteen per cent. Older Vinegar is yellowish-brown, has an odor of apples, a density of 1.013 to 1.015, and contains from three and a half to six per cent, of acetic acid. It is distinguished from the other varieties by yielding on evaporation a mucilaginous extract smelling and tasting of baked apples and containing malic acid, which replaces the tartaric acid of the wine vinegar. The differ- ences between cider vinegar and whiskey vinegar as manufactured in this country are shown in the accompanying analyses by Battershall :* Cider vinegar. Whiskey vinegar. Specific gravity 1.0168 1.0107 Specific gravity of the distillate from neutralfzed sample .... 0.9985 0.9973 Acetic acid 4.66 7.36 Total solids 2.70 0.15 Total ash 0.20 0.038 Potassa and phosphoric acid in ash . Considerable. None. Heated with Fehling's solution . . Copious reduction. No reduction. Treated with basic lead acetate . . Flocculent precipitate. No precipitate. Glucese, or Sugar, Vinegar, prepared from different saccharine and amylaceous materials by conversion with dilute acid, followed by fermenta- * Food Adulteration and Detection, New York, 1887, p. 230. 236 FERMENTATION INDUSTRIES. tion and acetification, contains dextrose, dextrin, and often calcium sulphate (from commercial glucose). It is said to be employed in France and Eng- land for adulterating wine or malt vinegars. Factitious Vinegars are often made from pyroligneous acid flavored with acetic ether and colored with caramel-color. Such a product differs from malt vinegar in containing no phosphates, and from wine or cider vinegar in the absence of tartaric or malic acids respectively. IV. Analytical Tests and Methods-. The determination of the acetic acid is usually done by titration with standard alkali, using phenolphthalem as indicator. In the presence of free sulphuric acid, it is necessary to distil a measured quantity of the sam- ple almost to dryness and titrate the distillate, it being assumed that eighty per cent, of the total acetic acid present passes over. The determination of the extract or solid residue in vinegar is executed in the same manner as described under beer or wine. The test for sulphuric acid is an important one. In England, the manu- facturers were allowed by law to add one part of sulphuric acid by volume to one thousand of vinegar in order to protect weak vinegar from the putrid fermentation. This addition is not necessary in good vinegar and is not generally followed at present. Still, it mav. be present, and is to be looked for in all vinegars. The usual test with basic chloride is inoperative here, as sulphates may be present in the vinegar from the water used, etc. Heh- ner's test for free mineral acids (sulphuric and hydrochloric), now regarded as satisfactory in this case, is based on the fact that acetates and most other salts of organic acids are decomposed by ignition into carbonates, having an alkaline reaction to litmus, while sulphates and chlorides of the light metals are unchanged on ignition and possess a neutral reaction. To de- termine the amount of free mineral acid it is sufficient therefore to care- fully neutralize the vinegar with standard solution of soda before evapora- tion to dryness (the same process serving for a determination of the total free acid), ignite the residue, and titrate the aqueous solution of the ash with standard acid. If the free acid originally present were wholly organic, the ash will contain an equivalent amount of alkaline carbonate, which will re- quire an amount of standard acid for its neutralization exactly equivalent to the amount of standard alkali originally added to the vinegar. Any defi- ciency in the amount of standard acid required for neutralization is due to the free mineral acid originally present in the vinegar. The tartaric acid, a normal constituent of wine vinegar, may be tested for by evaporating to dryness and treating the extract with alcohol, which dissolves nearly everything but the tartar or acid potassium tartrate. On pouring off the alcohol and dissolving this in a little hot water its nature can be easily shown by the usual tests for tartaric acid. Caramel is recognized by extracting the solid residue with alcohol and evaporating the solution to dryness ; in its presence the residue now obtained will possess a decidedly dark color and a bitter taste. Metallic impurities, such as lead, copper, and zinc, are at times to be found arising from the use of metallic vessels for storing the vinegar. Arsenic has also been found as an impurity through the use of impure sul- phuric or hydrochloric acid. They are all detected by the usual qualitative tests. BIBLIOGRAPHY AND STATISTICS. 237 V. Bibliography and Statistics. BIBLIOGRAPHY. ON FERMENTATION AND ITS INDUSTRIES IN GENERAL. 1874. Nahrungs- und Genussmittel, etc., C. E. Thiel, Braunschweig. 1876. Food and its Adulterations, Hassall, London. On Fermentation, P. Schutzenberger, London. 1879. Studies on Fermentation, M. Pasteur, translated by Faulkner and Kobb, London. Lehrbuch der Gahrungs-Chemie, A. Mayer, 3te Auf., Heidelberg. Theorie der Gahrung, C. von Nageli, Miinchen. 1880. Gahrungs-Chemie fur Praktiker,"j. Bersch, Berlin. 1882. Chevallier's Dictionnaire des Alterations, etc., 6me ed., Baudrimont, Paris. Nahrungs, Genussmittel und Getriinke, K. Palm, St. Petersburg. Untersuchungen iiber niedere Pilze, Nageli, Miinchen. 1883. The Brewer, Distiller, and Wine Manufacturer, J. Gardner, Philadelphia. 1884. Falsifications des Matieres alimentaires, Laboratoire Municipal, 2e Rapport, Paris. 1887. United States Department of Agriculture, Bulletin No. 13, Part iii. (Fermented Alcoholic Beverages), C. A. Crampton, Washington. 1889. Die Praxis des Nahrungsmittel-Chemikers, F. Eisner, 4te Auf., Leipzig. Untersuchungen aus der Praxis der Gahrungs-Industrie, E. Ch. Hansen, Ite Heft, Miinchen. Des Fermentations, E. Bourguelot, Paris. Chemie der menschlichen Nahrungsmittel, J. Konig, Ste Auf., Berlin. 1890. Die Micro-organismen der Gahrungs-Industrie, A. Jorgensen, 2te Auf., Berlin. ON MALTING AND BREWING AND THEIR PRODUCTS. 1865. Die Bierbrauerei, Branntweinbrennerei und Liqueurfabrikation, F. J. Otto, Braun- schweig. 1866. Practical Treatise on Brewing, Wm. Black, London. 1876. Etudes sur la Biere, ses Maladies, etc., M. Pasteur, Paris. Die Bierbrauerei und Malzextract-Fabrikation, H. Rudinger, Leipzig. 1877. Hops: their Cultivation, Commerce, and Uses, P. L. Simmonds, London. 1878. Die Chemie des Bieres, Reischauer und Griessmayer, Augsburg. Lehrbuch der Bierbraurei, C. Lintner, Braunschweig. " Das Bier und seine Verfalschungen, R. Stierlein, Bern. 1881. Die Bereitung und Behandling des Maizes, F. J. Wolff. Malting and Brewing, Jas. Steele, London and New York. 1882. Preparation of Malt and Fabrication of Beer, Thaussing, edited by Schwarz and Bauer, Philadelphia and London. 1884. Handbuch der Bierbrauerei, L. von Wagner, 6te Auf., 2 Bde., Braunschweig. 1885. Laboratory Text-Book for Brewers, L. Briant, London. Systematic Book of Practical Brewing, E. R. Southby, 2d ed., London. 1886. Die Malz-Fabrikation, K. Weber. 1887. Praktisches Hand- und Hilfsbuch fiir Bierbrauer, Pelz und Habich, Braunschweig. 1888. The Theory and Practice of Modern Brewing, F. Faulkner, 2d ed., London. 1890. Grundriss der Chemie fiir Brauer und Malzer, T. Langer, 2te Auf. 1891. Handbuch der Bierbrauerei, E. Ehrich, 5te Auf., Halle. ON WINES. 1860. History and Description of Modern Wines, C. Redding, London. 1865. Der Weinbau und die Weinbereitungskunde, F. Mohr, Braunschweig. Die Bereitung des Weines, C. J. N. Balling, Prag. 1872. Treatise on the Origin, Nature, and Varieties of Wine, Thudichum and Dupre, London. 1873. Etudes sur le Vin, ses Maladies, etc., M. Pasteur, 2me ed., Paris. 1874. Traite du Travail des Vins, Maumene, 2me ed., Paris. 1877. Die Weinbereitung und die Weinchemie, E. Roth, 2 Theile. 1878. Die Behandlung des Weines, J. Nessler, 3te Auf., Stuttgart. Die Weinbereitung, H. Dahlen, Braunschweig. Der Wein und sein Wesen, J. Bersch, Vienna. 1879. Die*Bereitung des Schaumweines, etc., A. von Regner, Vienna. Ueber die Chemie des Weines, C. Neubauer, Wiesbaden. Manuel pratique d' Analyse chimique des Vins, etc., 3me ed., E. Robinet, Paris. 1881. Handbuch des Weinbaues, etc., A. von Babo, 2 Bde. 238 FERMENTATION INDUSTRIES. 1884. Die "Weinanalyse, Max Bartb, Leipzig. Anleitung zur chemischen Analyse des Weines, Eug. Borgmann, Wiesbaden. La Sophistication des Vins, A. Gautier, 3me ed., Paris. 1888. Die Pi-axis der Weinbereitung, J. Bartsch. 1889. Manuel de 1'analyse des Vins, E. Barillot, Paris. ON SPIRITS AND DISTILLED LIQUORS. 1868. Guide theorique et pratique du Fabricant d'Alcools, etc., N. Basset, 3 vols., Paris. 1872. The Chemical Testing of Wines and Spirits, J. J. Griffin, London. 1875. Chemical Examination of Alcoholic Liquors, A. B. Prescott, New York. 1876. Die Branntweinbrennerei, C. Stammer, Braunschweig. 1879. Handbuch der Spiritus-Fabrikation, M. Maercker, 3te Auf., Berlin. Treatise on the Manufacture of Alcoholic Liquors, P. Duplais, trans, by M. McKennie, Philadelphia. 1881. Die Liqueur-Fabrication, A. Gaber, 3te Auf., Leipzig. 1882. Traite de la Fabrikation des Liqueurs et de la Distillation, P. Duplais, 4me ed., Paris. 1885. Practical Treatise on the Distillation, etc., of Alcohol, Wm. T. Brannt, Philadel- phia. 1886. Die Fabrikation von Rum, Arrak, Cognac, etc., A. Gaber, Leipzig. 1889. Ueber Branntwein, seine Darstellung, etc., Eugen Sell, Berlin. 1890. The Practical Distiller, L. Monzert. Ueber Cognac, Rum und Arrak, etc., Dr. Eugen Sell, Berlin. ON MANUFACTURE OF VINEGAR. 1860. The Manufacture of Vinegar, Chas. M. Wetherill, Philadelphia. 1867. Die Essig, Zucker und Starkefabrikation, F. J. Otto, Braunschweig. 1868. Etudes sur le Vinaigre, M. Pasteur, Paris. 1871. Manufacture of Vinegar, H. Dussauce, Philadelphia and London. 1876. Lehrbuch der Essigfabrikation, P. Bronner, Braunschweig. 1877. Die Essigfabrikation, J. C. Leuchs, 7te Auf. 1881. Die Essigfabrikation, J. Bersch, Vienna. 1885. Acetic Acid and Vinegar, John Gardner, Philadelphia. 1890. Vinegar: a Treatise on the Manufacture of Vinegar, etc., Wm. T. Brannt, Phila- delphia. ON FLOUR AND BREAD. 1871. Die Getreidearten und das Brod, Von Bibra, Niirnberg. 1878. Das Brodbacken, K. Birnbaum, Braunschweig. 1880. The Chemistry of Bread-Making (Lectures before Society of Arts), Chas. Graham, London. 1881. Bread Analysis, Wanklyn and Cooper, London. 1886. United States Department of Agriculture, Bulletins Nos. 1, 4, 9 (American Cere- als), C. Richardson, Washington. The Chemistry of Wheat, Flour, and Bread, W. Jago, Brighton. 1889. Handbuch der Presshefe-Fabrikation, Otto Durst, Berlin. United States Department of Agriculture, Bulletin No. 13, Part v. (Baking- Powders), C. A. Crampton, Washington. 1890. Presshefe, Kunsthefe und Backpulver/A. Wilfert, 2te Auf., Vienna. STATISTICS. I. CONSUMPTION OF MALT LIQUORS, WINES, AND SPIRITS IN THE UNITED STATES. Malt liquors of Imported malt T t , u 1innnrs domestic manufacture. liquors. Total malt ll( l uors - Gallons. Gallons. Gallons. 1885 ........... 594,063,095 2,068,771 596,131,866 1886 ........... 640,746,288 2.221,432 642,967,720 1887 ........... 715,446,038 2,302,816 717,748, 1 854 1888 ........... 765,086,789 2,500,267 767,587,056 Imported wines. Total wines. Gallons. Gallons. Gallons. 1885 ........... 17,404,698 4,495,759 21,900,457 1886 ........... 17,366,393 4,700,827 22,067,220 1887 ........... 27,706,771 4,618,290 32,325,061 1888" ........... 31,680,523 4,654,545 36,335,068 BIBLIOGRAPHY AND STATISTICS. 239 Domestic spirits. Imported spirits. Total spirits. Gallons. Gallons. Gallons. 1885 69,158,025 1,442,067 70,600,092 1886 70,851,355 1,410,259 72,261,614 1887 69,597,036 1,467,697 71,064,733 1888 74,201,386 1,643,966 75,845,353 Total liquors of all kinds. Gallons. 688,632,415 737,296,554 821,138,648 879,767,476 II. PRODUCTION OF FERMENTED LIQUORS IN THE UNITED STATES IN BARRELS OF THIRTY-ONE GALLONS. Barrels. 1885 19,185,953 1886 20,710,933 1887 23,121,526 j Barrels. 1888 24,680,219 1889 25,119,853 Production of Distilled Spirits in the United States in Gallons. Gallons. 1885 76,405,074 1886 81,849,260 1887 79,433,446 Gallons. 1888 71,688,188 1889 91,133,550 Quantities of Grain of all Kinds and Molasses Fermented and Distilled for Spirit. 1888 1889 Malt. Bushels. 1,602,586 2,242,214 Wheat. Bushels. 87,277 48,279 Barley. Bushels. 24,701 21,589 Rye. Bushels. 2,410,381 3,259,917 Corn. Bushels. 11,887,027 15,319,862 Oats. Bushels. 44,232 23,632 Mill-feed. Bushels. 1888 66,254 1889 73,589 Total grain fermented. Bushels. 16,122,509 20,990,924 Molasses fermented. Gallons. 2,519,494 1,951,104 III. a. PRODUCTION AND USE OF BEER IN GERMANY AND LUXEMBURG. 1884-85 42,373,686 1885-86 41,857,098 1886-87 45,068 030 1887-88 47,094,377 1888-89 47,696,195 Amount produced. Import. Export. Hectolitres. Hectolitres. Hectolitres. 112,430 1,200,090 111,319 1,249,697 135,164 1,070,993 142,422 1,064,236 165,939 947,128 Total consumed. Per capita. Hectolitres. 41,286,026 40,718,720 44,132,201 46,172,563 46,915,006 Litres. 90 88 94.6 98 97 III. b. PRODUCTION .OF BEER IN GREAT BRITAIN AND IRELAND. Production of beer in Great Britain and Ireland for 1889 was 49,726,000 hectolitres. The production for the three years 188789 has been, in barrels : 1887. Barrels. England and Wales . 26,323,760 Scotland 1 638,950 Ireland 2,439,589 30,402,299 1888. Barrels. 24,641,759 1,450,453 2,325,567 28,417,779 1889. Barrels. 24,595,090 1.369,628 2,275,177 28,239,895 IT. a. WINE PRODUCTION OF THE WORLD, VINTAGE OF 1888. Gallons. Algeria 72,072,788 Australia (1884) .... 1,902,024 Austria 92459,500 Cape Colony (1884) . . . 4,490,890 France 662,548,344 Germany . , 80,000,000 Greece 46,493,920 Hungary 184,919,000 Italy 798,242,489 Gallons. Portugal 132,085,000 Koumania 18.491,900 Kussia 92,459,500 Servia 52,834,000 Spain 607,591,000 Switzerland 29,058,700 Turkey and Cyprus . . . 68,684,200 United States 32,000,000 240 FERMENTATION INDUSTRIES. IV. 6. WINE PRODUCTION OF THE WORLD, VINTAGE OF 1890. Area under cultivation. Wine produced. Hectares. Hectolitres. France 1,900,000 30,000,000 Algeria 120,000 2,500 000 Italy 1,800,000 28,000,000 Spain 1,750,000 25,000,000 Austria-Hungary 600,000 10,000,000 Koumania 150,000 5,000,000 Germany 100,000 4,500,000 Portugal 200,000 4,000,000 Turkey and Cyprus 100,000 3,500,000 Kussia 150,000 1,500,000 Greece 75,000 1,500,000 United States 45,000 1,500,000 Chili and La Plata 30,000 1,000,000 (Allgemeine Weinzeitung, 1890, p. 313.) V. COMPARATIVE TABLE OF THE CONSUMPTION PER CAPITA OF SPIRITS, WINES, AND MALT LIQUORS IN DIFFERENT COUNTRIES. 1. Distilled Spirits. Great Britain (1887) 36,202,191 gallons = 0.98 gallon per capita. France (1888) 46,667,057 = 1.24 gallons ' Germany (1887) 40,719,950 = 1.09 " Denmark (1886) 8,377,496 = 4.23 Sweden (1886) 11,646,725 = 2.47 " Canada (1887) 3,201,445 = 0.84 gallon United States (1887) 71,064,733 == 1.18 gallons 2.- Wines. Great Britain (1887) 14,142,885 gallons = 0.38 gallon per capita. France (1886) 1,022,017,692 " =26.74 gallons " " Germany (no data). Canada (1887) 475,790 = 0.10 gallon " " United States (1887) 32,325,061 = 0.54 " " " 3. Malt Liquors. United Kingdom (1887) . . . 1,218,881,016 gallons = 32.88 gallons per capita. France (no data). Germany (1887) 1,165,835,044 " =24.99 " " Canada (1887) 15,118,898 " = 3.60 " United States (1887) 717,748,854 =11.96 " CHAPTER VII. MILK INDUSTRIES. I. Raw Materials. MILK is the fluid secreted by the females of the mammalia for the nourishment of their young, and is therefore a food specially adapted for the needs of the animal organism at this stage, furnishing all the nutrients required and furnishing them in the proper proportion. As will be seen from its analysis, it occupies an intermediate position between the cereal and the strictly animal foods, approximating, of course, more nearly the latter, but showing in one important constituent, milk-sugar, its relation- ship to the former. Milk is a secretion of the mammary glands, in which it is produced proximately by certain processes of diffusion from the blood and immedi- ately by the breaking down of the gland-cells themselves, so that milk is described as cell-material liquefied. The milk of all mammalia is essen- tially the same in its constituents, although these vary somewhat in their relative proportions. The essential constituents of milk are water, fat, casein, albumen, milk- sugar, and salts. The relative proportion of these constituents in the milk of different animals may be seen from the following table of analyses from Wynter Blyth : * Fat. Casein. Albu- men. Milk- sugar. Ash. Total solids. Water. Human milk 2.90 2.40 0.57 5.87 0.16 1200 88.00 Cow's milk 3.50 3.98 0.77 4.00 0.17 13.13 86.87 Camel's milk 2.90 / - 3. 1 * 84 5.66 0.66 13.06 86.94 Goat's milk 420 3.00 , ' 062 400 0.56 12.46 87.54 Ass's milk 1 02 1.09 70 550 042 8-83 91.17 Mare's milk 2 50 2.19 042 5 50 50 11.20 8880 Sheep's milk . .... 5.30 6 10 1 00 420 1 00 17-73 82 27 In taking up milk as a raw material for industrial utilization, we shall refer to cow's milk exclusively unless otherwise specified. The fat exists in the milk in the form of minute globules suspended in a thin liquid, forming for the time a perfect emulsion with the aqueous solu- tion of the other constituents. The fat is essentially an intimate mixture of the glycerides of the fatty acids, palmitic, stearic, and oleic, not soluble in water, and of the glycerides of certain soluble volatile fatty acids, such as butyriq, caprpic, caprylic, and capric. The casein of milk exists apparently in the fresh milk as a soluble com- * Foods, Composition and Analysis, 1882, pp. 214, etc. 16 UKI7BRSIT7 242 MILK INDUSTRIES. pound of albumen and calcium phosphate, which by the action of rennet (a ferment from the calf's stomach) is converted into the insoluble one known as casein. The casein precipitated by rennet contains five to eight per cent, of ash, consisting almost entirely of calcium phosphate. If, however, this calcium phosphate compound of albumen is decomposed by mineral acids or acetic acid, the casein precipitated contains only traces of ash. Lactic acid gives the same result, so that the casein coagulated by the souring of the milk shows less ash than that precipitated by rennet from sweet milk. On the other hand, carbon dioxide will act like rennet. The soluble com- pound existing in the fresh milk is considered to be that, of the tricalcium phosphate with albumen, while the insoluble one precipitated by rennet is the acid calcium phosphate with albumen. Pure casein is a perfectly white brittle crumbling substance, insoluble in water, but soluble in very dilute acids or very dilute alkalies. In the action of rennet and acids upon casein a portion is apparently altered into what are called peptones (lacto-protein or lacto-peptone) and remains dissolved in the whey of the milk. The albu- men (or soluble nitrogenous matter) of milk seems to be analogous to the albumen of blood. It may be obtained by precipitation with basic acetate of lead or by dialysis as a yellowish flaky mass. The proportion of albumen in milk is always, according to Wynter Blyth, about one-fifth of the casein. Two additional nitrogenous compounds have been found by Blyth to exist in small amounts in milk, to which the names galaetine and laeto-chrome have been given. Milk-sugar, which is an important and characteristic constituent of the milk, is obtained from the serum, or " whey." After the separation of the curd has been eifected by the addition of rennet the whey is evaporated on the water-bath, and yields the milk-sugar in hard crystals. These when purified by animal charcoal and recrystallized show the composition C^H^OH -f- H 2 O. It is easily distinguished from other sugars of the same formula. It is converted by boiling with dilute acids into dextrose and galactose, which latter has one-fifth less copper-reducing power than dex- trose. It undergoes the lactic fermentation readily but the alcoholic with some difficulty. The ash of milk consists essentially ol the phosphates and chlorides of potassium, sodium, calcium, and magnesium, the salts that are specially needed for the growth of the bone-material in the young nourished by the milk. Cow's milk is a white or yellowish-white liquid, nearly opaque, except in very thin layers, when it has a bluish opalescent appearance, and a specific gravity of from 1.029 to 1.039. It has a mild sweetish taste and a slight but characteristic odor, stronger when still warm from the cow. Upon allowing milk to remain at rest for some time it undergoes two changes : First, a yellowish-white layer forms on the surface known as " cream," due to the rising of the specifically lighter fat-globules from the body of the liquid where they were held back in emulsion with the aqueous liquid ; and, second, the aqueous liquid after a time undergoes further separation into a thick coagulum or " curd" of casein and a thinner liquid or " whey," holding the sugar of milk, any lactic acid formed from it, and the salts in solution. Both of the changes are of the greatest importance, as upon them are based the great milk industries, butter-making and cheese-making respectively. The rising of the cream is largely dependent ordinarily upon two condi- tions : First, the temperature, a low temperature being favorable to the PROCESSES OF MANUFACTURE. 243 separation ; and, second, complete freedom from agitation. These conditions are not, however, indispensable, as will be seen later (see p. 245) in speaking of the use of centrifugals for the separation of cream. The rising of the cream is generally allowed to be an entirely spontaneous change on the part of the milk and the first one which it undergoes, but in some creameries a little sour milk (containing lactic acid) is added to the fresh milk, when first put in the cream-rising pans, so that the curdling of the casein may facilitate the escape of the fat-globules and the rising of the cream. In such a case what remains on removal of the cream is not ordi- nary skimmed milk, but a sour curdled milk. The second change men- tioned, that of curdling, is really preceded by a change of some of the milk-sugar into lactic acid (due to lactic fermentation, which sets in very ' quickly in hot weather or if the milk has not been kept in clean vessels). This souring of the milk may be retarded by the addition of a little car- bonate of soda or boric acid. The lactic acid as soon as liberated decom- poses the soluble casein compound, before referred to (see p. 242), and the casein is thrown out or coagulated as "curd." The separation of the curd is aided by heat. The liquor in which this coagulated casein floats, the serum of milk, or " whey," contains about one-fourth of the nitrogenous matter of the milk, all of its sugar, and most of its mineral matter. The whey is " sour whey" in case lactic acid has formed as the antecedent of the coagulation, or " sweet whey" in case the casein is thrown out by the action of rennet without the formation of lactic acid. The composition of the several parts into which the milk is divided by these changes is thus given by Fleischmann : Water. Fat. Casein. Albumen. Milk-sugar. Ash. ^iVhole milk 87.60 3.98 3.02 0.40 4.30 0.70 Cream 77.30 15.45 3.20 0.20 3.15 0.70 Skim-milk 90.34 1.00 2.87 0.45 4.63 0.71 Butter 14.89 82.02 1.97 0.28 0.28 0.56 Buttermilk 91.00 0.80 3.50 0.20 3.80 0.70 Curd 59.30 6.43 24.22 3.53 5.01 1.51 "Whey 94.00 0.35 0.40 0.40 4.55 0.60 And the relative yield of these several constituents from one hundred parts of milk is thus given by the same author : 100 parts of sweet milk will yield (by natural cream-raising or by centrifugal cream-separating) 20 parts of cream, which (churned into butter) will yield 79.70 parts of skimmed milk, which 0.30 parts (coagulated by rennet or acids) loss, will yield 3.56 parts butter. 16.30 parts buttermilk. 0.14 7.93 parts curd. 71.45 parts whey. 0.32 loss. 0.30 loss. Processes of Manufacture. 1. MANUFACTURE OF CONDENSED AND PRESERVED MILK. Con- densed milk is milk from which a large portion of the water originally present has been driven oif, increasing, of course, in a proportionate degree the percentage of the other constituents. This condensed product may or may not have cane-sugar added to it as a preservative. That to be pre- 244 MILK INDUSTRIES. served with cane-sugar is made much more concentrated, and is that which is manufactured for export and preservation in sealed tin cans. In its preparation, the milk is first heated to 65.6 to 80 C. (150 to 175 F.) by placing the cans containing the milk in hot water, and is then strained and conveyed to the evaporating vessels, which are usually vacuum-pans. Re- fined sugar is added during the boiling to the amount of one to one and a half pounds for every quart of the condensed milk produced. The product is drawn off into cans, cooled to about 70 F., and then weighed into tins, which are at once soldered down. Condensed milk free from cane-sugar is only concentrated to about one- half the degree attained in the other product, and is then cooled and filled into stone or glass flasks provided with ordinary air-tight stoppers. It will remain fresh for from one to two weeks, and requires only to be diluted with its own bulk of water in order to yield the counterpart of the original milk. Preserved milk is either prepared by Appert's process, which consists in boiling the milk to destroy ferments and keeping it then in hermetically- sealed vessels, or by Scherff's improved process, whereby the milk is filled into glass bottles which are stopped with corks previously steamed and then fastened in by clamps, and then heated in closed boilers under a pressure of from two to four atmospheres to about 120 C. The bottles are then taken out of the pressure-vessel and cooled down, with the corks covered with flannel soaked in paraffine, so that as they cool the air entering through the pores of the corks shall be filtered. When cooled down, the cork, which has been drawn into the neck of the bottle considerably, is covered with a layer of paraffine. This kind of preserved milk is used largely in Germany for invalids and children. 2. OF BUTTER. The first operation in this connection is the separation as completely as possible of .the cream from the rest of the milk. This is generally a spontaneous process, it is true, but its completeness is dependent largely upon the conditions before referred to. There are various ways in which the raising of the cream is allowed to take place. We may mention the Holstein process, in which the fresh milk is at once set to raise cream in wide shallow pans at a temperature of 12 to 15 C. (53.6 to 59 F.), the Dutch process, in which it is first rapidly cooled down in large vessels immersed in cold water to about 15 C. (59 F.) and then transferred to the shallow pans for the raising of the cream, and the Schwartz process, largely used in Northern Europe, which differs from the Dutch process chiefly in using much deeper pans at a lower temperature, 4.4 to 10 C. (40 to 50 F.). Very similar to this last mentioned are the Hardin and the Cooley methods, which also use deep cream-raising pans. In the former of these, ice and not ice-water is used to effect the cooling, the pans being exposed to the influence of air cooled by ice, the claim being made that the cream is obtained in more solid condition. In the Cooley method, used largely in this country, the water not only surrounds the can outside as high as the milk inside, but is made to rise an inch or two above the lid, so that the can is completely submerged and all contamination from external sources prevented. The processes which use shallow pans give a larger yield of cream but take a longer time (thirty-six to forty-eight hours as against eighteen to twenty-four for those using deep pans). Within the last ten years the principle of the centrifugal has been applied to the separation of the cream PROCESSES OF MANUFACTURE. 245 FIG. 76 from the milk, and this has proven itself so successful that in most large creameries it is now utilized. The milk is placed in a horizontal rotating vessel driven at a high rate of speed, which causes the heavier milk fluid to gravitate towards the circumference of the vessel, whilst the cream re- mains nearer the centre and rises towards the upper part of the rotating bowl, whence it is removed by a conveniently-placed aperture on the side of the vessel. An exit is also provided for the gradual removal of the skimmed milk, thus making room for fresh milk to be added to the ap- paratus and allowing the process to be carried on continuously. Figs. 76 and 77 show the Laval cream separator in general view and in section. The fresh milk is ad- mitted through a funnel, the tube of which is prolonged so as to deliver the milk near the bottom of the revolving drum. The skim-milk flows out through an opening, , and the cream through a higher opening, the relative position of which can be changed by an adjustable screw above. The cream obtained by these centrifugal separators seems FIG. 77. to be freer from mechanically-enclosed casein than that gotten in any of the old separation processes, as is seen in the appended cream analyses by Bell,* where samples 2 and 6 were separated by the centrifugal separator : Water. Fat. Milk- sugar. Casein. Ash. 1. Raw cream 5402 39 40 1 85 3.76 57 2. Raw cream 60 66 33 60 2 43 2 90 041 3. Raw cream 67 93 2444 2 96 404 63 4. Raw cream 5807 35 67 2 20 3 55 51 ft. Raw cream 63 07 30 74 2 61 3 04 54 6. Thick^ cream 37 62 58 77 1 46 1 83 32 7. Devonshire clotted cream 33 76 59 79 1 01 4 97 47 * Analysis and Adulteration of Food, p. 35. 246 MILK INDUSTRIES. The composition of the skimmed milk of course varies according to the extent to which the cream has been removed. The following analyses by Voelcker represent its average composition as obtained in the ordinary way and as obtained by the Laval separator : Water. Butter- fat. Casein. Milk- sugar. Ash. Ordinary skimmed milk .... .... 89 25 1 12 3 69 5 17 78 Skimmed milk by Laval separator 90.82 0.31 3 31 4 77 79 The coalescence of the fat-globules separated in the cream layer is now to be effected to form the compact butter. This is almost universally accomplished by mechanical agitation in the process called churning. The churns may be of very diverse construction, either for hand or power. The cream may be taken as " sweet cream" freshly separated in the centrif- ugal or raised from deep pans where the skim-milk is still sweet, or it may be " sour cream," which has stood longer and has separated slowly in shal- low pans. The sour cream is more easily churned, but the butter will con- tain more casein, while sweet cream yields a butter with pleasanter taste and better keeping qualities because containing less casein. The tempera- ture most favorable for churning is about 15.5 C. (60 F.). Sometimes cream is heated to a much higher temperature first, and then cooled down to 60 F. before being churned. Butter thus made keeps well. Butter has almost invariably some salt added to it even when for im- mediate consumption ; the quantity in this case need not be large (five-tenths to two per cent.), but when it is to be packed for preservation or for export considerably more is added, so that it is known as " salt butter." Export butter has also a small addition of sugar, and sometimes saltpetre, added, as well as salt, to preserve it. Genuine butter will always have a yellowish color, which, however, becomes deeper in summer when the cows have an abundance of fresh pasture. Most butter manufacturers now add a little vegetable coloring matter like annato, carrot-color, or saffron, to give the butter this desired yellow tint in winter, when the butter would otherwise be very much lighter in color. All butter will in time become rancid and take a strong disagreeable odor. This is due to the gradual spontaneous decomposition of the butyric ether under the influence of air and light whereby free butyric acid is liberated. The composition of butter will be more fully spoken of later on in dis- cussing the products of these industries. 3. OF ARTIFICIAL BUTTER UButterine, Oleomargarine). The manu- facture of substitutes for normal dairy butter began with the experiments of the Frenchman Mege-Mouries in 1870. He found that carefully- washed beef-suet furnished a basis for the manufacture of an excellent substitute for natural butter. The thoroughly-washed and finely-chopped suet was rendered in a steam-heated tank, taking for one thousand parts of fat, three hundred parts of water, one part of carbonate of potash, and two stomachs of pigs or sheep. The temperature of the mixture was raised to 45 C. After two hours, under the influence of the pepsin in the stomachs, the membranes are dissolved and the fat melted and risen to the top of the mixture. After adding a little salt, the melted fat is drawn off, PROCESSES OF MANUFACTURE. 247 stood to cool so as to allow the stearin and palmitin to crystalline out, and then pressed in bags in a hydraulic press. Forty to fifty per cent, of solid stearin remains, while fifty to sixty per cent, of fluid oleopalmitin (so-called " oleomargarine") is pressed out. Mege then mixed the " oleo oil" with ten per cent, of its weight of milk and a little butter-color and churned it. The fat-cutting process of M^ge-Mouries is shown in Fig. 78 FIG. 78. and the churning of the "oleo oil" in Fig. 79. The product was then worked, salted, and constituted the " oleomargarine," or butter substitute. Various improvements have been made in the process of Mege, and it has been found that leaf-lard can be worked in the same way as beef-suet, and will yield an oleopalmitin suitable for churning up into a butter substitute. The processes now followed are given substantially as described by Mr. Phil. D. Armour in his testimony before a committee of Congress : * " The fat is taken from the cattle in the process of slaughtering, and after thorough washing is placed in clean water and surrounded with ice, where it is allowed to remain until all animal heat has been removed. It is then cut into small pieces by machinery and cooked at a temperature of about 150 F. (65.6 C.) until the fat in liquid form has separated from the fibrin or tissue, then settled until it is perfectly clear. Then it is drawn into graining-vats and allowed to stand for a day, when it is ready for the presses. The pressing extracts the stearin, leaving a product commercially known as ' oleo oil/ which when churned with cream or milk, or both, and with usually a pro- portion o*f creamery butter, the whole being properly salted, gives the new * Department of Agriculture, Bulletin No. 13, Part i. p. 16. 248 MILK INDUSTRIES. food product, oleomargarine. In making butterine we use ' neutral lard,' which is made from selected leaf-lard in a very similar manner to oleo oil, excepting that no stearin is extracted. This neutral lard is cured in salt brine for forty-eight to seventy hours at an ice-water temperature. It is FIG. 79. then taken and with the desired proportion of oleo oil and fine butter is churned with cream and milk, producing an article which when properly salted and packed is ready for the market. " In both cases coloring matter is used, which is the same as that used by dairymen to color their butter. At certain seasons of the year viz., in cold weather a small quantity of sesame oil or salad oil made from cotton- seed oil is used to soften the texture of the product." It will be seen that in this process a higher temperature is used in render- ing the fat than was used originally by M6ge. *He obtained about fifty per cent, of oleo oil. The manufacturers now obtain sixty-two per cent, or more. The oleo oil from beef-suet and the neutral lard from leaf-lard are frequently mixed, the proportions varying according to the destination of the product ; a warm climate calling for more " oleo," a cold one for more " neutral." In ordinary practice about forty-eight gallons of milk are used for churning with the oil per two thousand pounds of product. Plain oleo- margarine is the cheapest product made. By adding to the material in the agitator or churn more or less pure butter what is known as butterine is produced, two grades of which are commonly sold, viz., " creamery but- terine," containing more, and " dairy butterine," containing less, butter. Large quantities of oleo oil are now manufactured and exported as such from the United States to Europe, notably to Holland, where it is made up into oleomargarine butter. There are said to be seventy manufactories of this kind in Holland which work up oleo oil from all parts of the world. 4. CHEESE-MAKIXG. The manufacture of cheese depends upon the PROCESSES OF MANUFACTURE. 249 property possessed by casein of being curdled by acids or ferments. In the case of sour milk, the milk-sugar has developed by the lactic fermentation some lactic acid, and this, as before stated, promptly throws out the casein in the insoluble form. In the case of sweet milk we usually accomplish the curdling of the casein not by the use of an acid, but with a ferment con- tained in the preparation called rennet. This is prepared from the fourth stomach of the calf by first cleansing the stomach, cutting and drying it, and then leaving some brine in contact with its lining membrane for a few days. The salt liquid will thus acquire very active properties, so that a small quantity will curdle a large quantity of milk. We would have then, according as one or the other method is followed, a sour-milk cheese or a sweet-milk cheese. The former have a very minor value commercially, being made mainly for immediate domestic consumption. The latter class include all the more valuable commercial varieties. Of these we may distinguish fat, half-fat (or medium), and lean cheeses, or as they are also designated to indicate their origin, cream cheeses, whole milk cheeses, and skim-milk cheeses. As these last names indicate, the material may differ. We may have, moreover, all gradations or mixtures of cream, whole milk, and skim- milk used for the various grades manufactured. In cheese-making from sweet milk, the milk, Avhether whole, mixed with cream, or skimmed, is heated to about 30 C. (86 F.) and the rennet added. It curdles usually in from thirty to forty minutes. After the curd has formed and been cut, or " broken down," the heat is raised to 98 F. (36 C.) to insure the souring of the whey and its more complete separation from the curd. Or the curd produced at not over 86 F. (30 C.) is after being cut collected in a heap, covered with a cloth to preserve the heat, and allowed to stand an hour to develop the acidity which serves to harden the curd and promote its separation from the whey. The curd is now cut up, worked to free it from the whey, salted and pressed. After it has acquired sufficient coherence (which requires from twelve to fourteen hours) it is taken from the press and placed in the curing-room to " ripen." This ripening process is essentially a fermentative one, and during its progress the curd loses its insipidity and acquires the characteristic taste and flavor of cheese. In this process of ripening, the milk-sugar remaining in the cheese be- comes transformed partly into lactic acid and partly into alcohol and carbon dioxide. In some varieties the carbon dioxide swells up (" huffs") the cheese- mass and gives it the porous character so noticeable in the ripened cheese. Fresh cheese has an acid reaction, but this diminishes more and more in the ripening, as the casein is gradually altered, soluble albuminoids, pep- tone-like bodies, and organic bases like leucine, tyrosine, and amines being formed. Some cheeses, especially the cream cheeses, are not pressed, but come on the market as soft cheeses. In these the curdling by rennet has also been effected at a lower temperature than in the case of the hard cheeses. Cheese has also been manufactured extensively in this country from skimmed milk to which oleomargarine or " oleo oil" has been added so as to give the finished product the character of a whole-milk cheese. This product is now quite supplanted, however, by the " lard cheese," which, ac- cording to Caldwell,* was made in 1882 at over twenty factories in the State of New York.' In this process an emulsion of lard is made by bringing * Second Annual Report New York State Board of Health, p. 529. 250 MILK INDUSTRIES. together in a "disintegrator" lard and skimmed milk both previously heated to 140 F. in steam-jacketed tanks; the "disintegrator" consists of a cyl- inder revolving within a cylindrical shell : the surface of the cylinder is covered with fine serrated projections, each one of which is a tooth with a sharp point ; as this cylinder revolves rapidly within its shell the mixture of melted lard and hot skimmed milk is forced up into the narrow inter- space ; and the lard becomes very finely divided and most intimately mixed, or " emulsionized," with the milk. This emulsion consists of from two to three parts of milk to one of lard. In making the cheese, a quantity of this emulsion, containing about eighty pounds of lard, is added to six thou- sand pounds of skimmed milk and about six hundred pounds of butter- milk in the cheese-vat, and the lard that does not remain incorporated with the milk or curd, usually about ten pounds, is carefully skimmed off. These quantities of the materials yield from five hundred to six hundred pounds of cheese containing about seventy pounds of lard, or about fourteen per cent. About one-half of the fat removed as cream in the skimming of the milk is thus replaced by lard. It is claimed that no alkali or antiseptic is used, and that only the best kettle-rendered lard can be employed, because of the injurious effect of any inferior article on the quality of the cheese, and that before even this lard is used it is deodorized by blowing steam under eighty pounds pressure through it for an hour. According to many witnesses the imitation is excellent, for experts have l)een unable to pick out lard cheeses from a lot of these and full-cream cheeses of good quality together. m. Products. 1. CONDENSED AND PRESERVED MILK. The distinction between con- densed milk prepared with the addition of cane-sugar and that prepared without sugar has already been referred to in speaking of the manufacture of this class of products. The first of these classes forms a white or yellow- ish-white product of about the consistency of honey and ranging in specific gravity from 1.25 to 1.41. It should be completely soluble in from four to five times its bulk of water without separation of any flooculent residue, and then possess the taste of perfectly fresh sweetened milk. The second class of condensed milk preparations, those without addition of cane-sugar, are not boiled down to the same degree and remain perfectly liquid, and are put up therefore in glass bottles instead of being sealed in cans. Analyses of both classes are given on the authority of Battershall.* Condensed Milk with Addition of Sugar. BRAND. Water. Fat. Cane- and milk-sugar. Casein. Salts. Alderney . 30.05 10.08 46.01 12.04 1.82 Anglo-Swiss (American) .... Anglo-Swiss (English) .... Anglo-Swiss (Swiss) 29.46 27.80 25.51 8.11 8.24 8.51 50.41 51.07 53.27 10.22 10.80 10.71 1.80 2.09 2.00 Eagle . 27.30 6.60 44.47 10.77 1.86 29.44 9.27 49.26 10.11 1.92 * Food Adulteration and its Detection, p. 53. PRODUCTS. Condensed Milk ivithout Cane-sugar. 251 BRAND. Water. Fat. Milk-sugar. Casein. Salts. American 52.07 15.06 16.97 14.26 2.80 New York . . 56.71 14.13 13.98 13.18 2.00 Granulated Milk Company . . Ea"le . 55.43 56.01 13.16 14.02 14.84 14.06 14.04 13.90 2.53 2.01 2. BUTTER AND BUTTER SURSTITUTES. Commercial butter is more or less granular, and the more perfect the granular condition the higher is its quality considered. Special effort has been made in the case of oleo- margarine or butterine to imitate this granulation, as the artificial product does not naturally tend to show such appearance. A good butter when fresh has a pleasant fragrant odor and agreeable taste, but the flavor, like the color, varies with the food of the cow, certain plants, like garlic, giving a quite pronounced flavor to both milk and butter. At ordinary temperatures but- ter is easily cut or moulded, and it readily melts to a transparent, light- colored oil. It always contains, according to the thoroughness with which it has been kneaded and washed, more or less casein, which is very liable to undergo decomposition, and hence the necessity for the addition of larger or smaller amounts of salt, which acts as a preservative. When the butter-fat is freed from curd and water by melting the butter and drawing off the oily layer it may be kept for a long time without change. This butter-fat is made up, as was stated in speaking of the fat of milk, of the glycerides of oleic, palmitic, and stearic acids (the so-called insoluble acids) and the glycerides of butyric, caproic, caprylic, and capric acids (the so-called soluble acids). The proportion in which they exist in butter-fat varies within very slight limits only, so that five to six per cent, may be called the average percentage of the soluble acids, and eighty-eight per cent, the average percentage of the insoluble acids present in butter-fat. This gives a very important means of distinguishing between a natural butter and oleomargarine or natural butter adulterated with the imitations. In such butter the glycerides of the soluble acids (butyric, etc.) are either wanting entirely or, if a little cream was used in the churning with " oleo oil" present, in very much smaller amount than the normal. This distinction will be evi- dent from the analyses of normal butter and oleomargarine butters, given on the authority of Dr. Bell.* Genuine Suiter, showing Range of Variation in Composition of the Fat. Water. Salt Curd. Butter- fat. Specific gravity at 100 F. Percentage of fixed acids in fat. Percentage of soluble acids as butyric. Melting point, Fahren- heit. 1. . 7.55 1.03 1.15 90.27 913.89 85.56 7.41 85 F. 2. . 11.71 3.60 0.95 83.74 911.45 88.24 5.41 90 F. 3. . 11.42 1.29 1.12 86.17 910.47 88.53 4.84 90 F. 4. . 1255 0.89 0.74 85.82 910.20 89.00 4.57 90 F. 5. . 14.62 1.48 1.88 82.02 910.70 89.00 4.50 91 F. * Analysis and Adulteration of Foods, pp. 68 and 70. 252 MILK INDUSTRIES. Analyses of Oleomargarine Butter or Butterine. Specific Percentage .Percentage Melting Water. Salt. Curd. Fat. gravity at of fixed of soluble point, Fah- 100 F. acids. acids. renheit. 14.30 3.81 0.48 81.41 903.84 94.34 82 F. 11.21 1.70 1.73 85.36 902.34 94.83 0.66 78 F. 12.33 4.00 1.09 82.58 903.15 95.04 0.47 79 F. 5.32 1.09 0.67 92.92 903.79 96.29 0.23 81 F. 13.21 3.99 1.07 81.73 901.36 95.60 0.16 78 F. The best grades of artificial butter do not differ in appearance from ordinary butter. To induce the proper granulation of the oleomargarine, it is chilled thoroughly with fragments of ice immediately after it is taken from the churn and before kneading or salting it. In color, consistence, and taste it may be made to imitate the natural butter so as to deceive most persons. A distinction, it is said, however, can always be noted in the taste when it is melted upon hot boiled potatoes, to which it imparts a peculiar taste recognizable as distinct from that of a true butter. 3. CHEESE. The general classification of the cheeses has been given in speaking of the methods of manufacture, and the distinction between the fat and lean cheeses, between cream cheese, whole-milk and skimmed-milk cheeses given. The terms hard and soft cheeses are applied according as the curd has or has not been pressed in the process of manufacturing. Most of the names which have been attached to the different varieties of cheese are those of localities. We will indicate the character of a few of these. Neufchatel cheese is a Swiss cream cheese. Limburger cheese is a soft fat cheese. Fromage de Brie is a soft French cheese rapidly ripening and devel- oping ammoniacal compounds. Camembert cheese is also a cream cheese. Roquefort cheese is a cheese made from the milk of the ewe. Grtiyere cheese is a peculiarly flavored Swiss cheese. Cheddar cheese is a hard cheese made with whole milk. Single and double Gloucester are made, the first from a mixture of skimmed and entire milk, and the second from the entire milk. Parmesan cheese is a very dry cheese, with a large amount of casein and only a moderate percentage of fat. Eidam cheese is a Dutch cheese, also relatively dry, and covered with red coloring. In illustration of the chemical composition of these different varieties of cheese we will append three tables, the first of analyses from miscellane- ous sources, and the second and third from Bell,* giving a fuller study of the composition of the cheeses and showing the difference between the fat normally belonging to the cheese and the fat added in the shape of lard or " oleo oil" in adulterated cheeses. * Analysis and Adulteration of Foods, pp. 79 and 82. PRODUCTS. 253 Water. Fat. Casein. Non-nitro- genous and loss. Ash. Neufchatel (Fleischmann) 34.50 41.90 13.00 7.00 3.60 Emmenthaler (Fleischmann) 36.10 29.50 28.00 3.30 3.10 Limburger (Fleischmann) 35.70 34.20 24.20 3.00 2.90 Brie (Wvnter Blyth) 51.87 24.83 18.30 5.00 Camembert (Wynter Blyth) 51.30 21.50 19.00 3.50 4.70 Parmesan (Wynter Blyth) 27.56 15.95 44.08 6.69 5.72 100 PARTS CONTAIN Proportion of fat in 100 parts of dry cheese. Proportion of fat in 100 parts of casein and fat. Salt percentage in cheese. PERCENTAGE COMPOSITION OF THE FAT. | 4 Casein. Free acid as lactic. a < S2 5 3 S CO Insoluble acid. Stilton 23.57 28.63 31.55 32.26 31.85 35.60 33.66 37.11 35.75 41.30 39.13 38.24 35.93 34.38 34.34 31.57 30.69 30.68 28.35 22.78 32.55 29.64 28.83 27.16 27.88 28.16 30.67 26.93 31.10 28.25 1.24 6.27 1.32 1.35 0.45 0.27 0.86 0.31 0.57 3.51 3.49 3.42 4.88 4.58 4.22 4.71 4.42 4.49 7.10 51.19 53.57 52.49 50.75 49.02 46.26 48.78 48.78 44.12 38.80 52.50 54.12 53.34 54.24 53.08 50.49 47.02 50.84 45.24 42.41 0.67 0.72 0.82 3.04 2.11 1.43 0.81 1.69 1.28 4.45 4.42 4.26 4.81 4.91 4.40 4.55 4.41 5.55 6.68 5.84 88.% 89.06 88.49 88.70 89.18 88.75 88.97 87.76 86.89 87.58 American (red) American (pale) Roquefort . . . Gorgonzola . . Cheddar (medi um) Gruyere Cheshire Single Gloucester Dutch (Eidam) . . Analyses of Oleomargarine and Lard Cheeses. 100 PARTS CONTAIN 100 PARTS OF FAT CONTAIN Water. Fat. Casein and free acids. Ash. Per cent, of salt. Insol- uble acids. Soluble acids. Melting point of fat. Oleomargarine cheese . . Lard cheese 30.95 31.30 28.80 24.66 36.27 38.87 3.98 5.17 1.14 1.55 92.43 92.88 2.16 1.55 77 F. (25 C.). 92 F. (33.3 C.). 4. KOUMISS. Koumiss is an alcoholic drink made by the fermentation of milk. As made by the fermentation of mare's milk it has long been a favorite beverage with the Tartars and other Asiatic tribes. Cow's milk has been used chiefly in making it in both Europe and America. Mare's milk is the more suitable for fermentation because of the larger percentage of milk-sugar which it contains. The fermentation is started by mixing fresh milk with some already soured. Both the lactic and the alcohol fermentations are set up, with the production of lactic acid, alcohol, and carbonic acid gas. Some of the albu- minoids* are also changed into peptones. The composition of the koumiss as prepared from both mare's and cow's milk is shown in the accompanying analyses from various sources : MILK INDUSTRIES. 6 Lj IM . * u-d a -s "3 A -"2 o 5 a a =? 11 O S3 jA & s h-i < fi < g-a < Koumiss from mare's milk (Fleischmann) 91.53 1.25 1.01 1.91 1.27 1.85 0.88 0.29 Koumiss from cow's milk (Fleischmann) 88.93 3.11 0.79 2.03 0.85 2.65 1.03 0.44 Koumiss from mare's milk (Konig) . . . 92.47 1.24 0.91 1.97 1.26 1.84 0.95 Koumiss from mare's milk (London, 1884) 91.87 0.79 1.04 1.91 1.19 2.86 Koumiss from cow's milk (Wiley) .... 89.32 4.38 0.47 2.56 2.08 0.76 0.83 5. WHEY. The aqueous liquid remaining after the separation of the butter-fat and the casein, or curd, is termed the whey. Its more important constituent is milk-sugar, which in sour whey has been changed in part into lactic acid. It also contains soluble nitrogenous constituents, such as milk, albumen, and peptonized casein. On account of these constituents it is an easily digestible preparation and one assisting digestion. Hence the use of the " whey treatment" in medical practice for dyspeptics and those suffering from enfeebled digestion. The chief importance, however, of the whey is for the extraction of the milk-sugar, which is largely carried out in Switzer- land. For this purpose the whey is concentrated and drained free from separated albumen ; from the concentrated liquid the milk-sugar then crys- tallizes in clusters of hard crystals. These are purified by filtration through bone-black and recrystallized. From two hundred litres of milk originally taken about four kilogrammes of pure milk-sugar are obtained. Other products of minor and local importance only are " whey butter," " whey alcohol," from which latter " whey champagne" is made, and " whey vin- egar." The analysis of the average whey has already been given. (See p. 243.) IV. Analytical Tests and Methods. 1. FOR MILK. The specific gravity of milk is an indication of value, as it varies according to the content of fat, being higher for a skimmed milk than for a whole milk. However, when the cream has been removed, the spe- cific gravity may be reduced to that of normal milk by the addition of water, and then the specific gravity determination taken alone would be fallacious. Hence the detection of the adulteration of milk by addition of water cannot be made with entire accuracy by the lactometer or specific gravity hydrometer in use. The lactometer officially used by milk inspectors in New York and other States indicates specific gravities between 1.000 (the specific gravity of water) and 1.038. A specific gravity of 1.021 (taken as the minimum density of genuine milk) is also marked 100, while the specific gravity of water (1.000) is called 0. Hence if the lactometer read 70, the sample is supposed to contain seventy per cent, pure milk and thirty per cent, water. The average lactometric strength of about twenty thousand samples of milk examined by the New York State Dairy Commissioner in the year 1884 was 110, equivalent to a specific gravity of 1.0319. Another form of lactometer used abroad is the Quevenne-Miiller instrument, which is graduated in absolute specific gravity readings between the limits 1.014 and 1.042, and then the limits of pure milk (1.029 to 1.034) indicated, and degrees of dilution with water also indicated as the specific gravity sinks below this. The degree of adulteration of skimmed milk is also indicated on the instrument in the same way. The total solids form an important element in the examination of milk. ANALYTICAL TESTS AND METHODS. 255 In some States the minimum percentage of total solids allowed in a milk is stated by law. (In Massachusetts thirteen per cent. ; in New York and New Jersey twelve per cent.) To determine the water and total solids, five grams of milk are placed in an accurately weighed flat-bottomed platinum capsule and dried, first on the water-bath and afterwards at 105 C., until constant weight is obtained. Ritthausen proposed coagulating the milk with a few cubic centimetres of absolute alcohol before beginning the drying, but this is said to be unnecessary. To determine the ash, ignite the residue of the total solids just obtained, first over a small flame and finally at a dull red heat. Cover the dish, cool in the desiccator, and weigh. The fat determination may be determined roughly by the " cremorneter" of Chevallier, which is a graduated jar in which a sample of fresh milk is stood for from twenty-four to thirty-six hours and then the height of the separated cream layer read oif. Remembering, however, that all the fat-globules are never likely to rise and form together in the cream layer, more accurate methods are seen to be necessary. A volumetric method of much greater accuracy is that of the lactobutyrometer of Marchand as improved by Tollens and Schmidt. In this the measured milk sample, to which a few drops of sodium or ammonium hydrate has been added, is agi- tated with ether, and then alcohol added, and the agitation repeated. On standing the graduated tube in warm water the ethereal layer of fat sepa- rates out on top the alcoholic ether, and can be read oif and the percentage calculated from tables prepared. An improved form of the lactobutyrome- ter has been described by Caldwell* and the accuracy of the method es- tablished. Another volumetric method based upon the same principle, but more complicated in its details, is that of Soxhlet. In this, the milk made alkaline by caustic potash is shaken with ether, and the ethereal solution of the fat rising to the top of the mixture is separated and its specific gravity determined. Liebermann has also described a third volumetric method, and more recently f Morse, Piggot, and Burton have described what seems to be the most accurate of these methods for the determination of the fat of milk volu metrically. Their method consists in the dehydration of the milk by means of anhydrous copper sulphate ; the extraction of the fat by means of low boiling petroleum-ether ; the saponification of the butter by means of an excess of a standard solution of potassium hydroxide in alcohol ; and the determination of the excess of alkali by means of a solution of hydro- chloric acid. More generally relied upon for absolute accuracy are the gravimetric methods, of which Adams's is generally followed. In this a coil of white blotting-paper (or thick filtering-paper) previously purified with ether and dried is made to soak up the milk to be analyzed from a weighed beaker or pipette. The paper coil is then dried in a hot-air oven and placed in a Soxhlet (see p. 73) or similar fat-extraction apparatus connected with an inverted condenser and the fat extracted by ether or petroleum-ether. The albuminoids are estimated by evaporating a weighed portion of milk to dryness and making a combustion of the residue with soda-lime or by the Kjeldahl method of conversion into ammonia compounds and distil- lation from an alkaline solution. Professor A. R. Leeds | prefers to deter- * Amer. Chem. Journ., vii. p. 243. f Ibid., ix. pp. 108 and 222. J Transactions of the College of Physicians, Philadelphia, 1884, p. 263. 256 MILK INDUSTRIES. mine the albuminoids jointly with the fat by the precipitation with cupric sulphate after the method of Ritthausen as modified by Gerber. The estimation of the milk-sugar by the polariscope is rendered difficult by the presence in milk of various albuminoids, all of which turn the plane of polarization to the left, and the ordinary means of removing these albu- minoids by a solution of basic acetate of lead is far from being perfect. Pro- fessor Wiley* after extensive experiments upon this has adopted a method of optical analysis, using acid mercuric nitrate to precipitate the albuminoids. He takes the specific rotatory power of milk-sugar as (a) D = 52.5. For de- tails of his procedure the reader is referred to his publication. Milk-sugar may also be determined either volumetrically or gravimetrically with the aid of Fehling's solution. (See p. 152.) In this case, it is also necessary to remove the albuminoids first, and this is done by Ritthausen's method of precipitation with copper sulphate, all excess of this reagent being removed with caustic potash solution. In calculating the results it will be remem- bered that the copper reducing power of milk-sugar is 70.5 as compared with dextrose at 100. The sugar is probably most accurately determined by extraction from the fat-free residue with weak boiling alcohol, filtering the alcoholic fluid, and evaporating to dryness. This leaves the sugar with some mineral mat- ter. On burning and determining this matter as ash the amount of sugar can be gotten. 2. FOR BUTTER. The water in butter is determined by drying five grammes of the butter in a platinum dish at a temperature of 100 C. (212 F.) or slightly higher. The melted butter is stirred from time to time to facilitate the escape of the moisture. The water will have been given off in three to four hours, and it has been found that longer heating sometimes causes the melted fat to gain in weight. To determine the salt, the dried butter just obtained is treated with warm ether or petroleum spirit, and the contents of the platinum dish poured on a weighed filter and washed with ether until all fat is removed. The resi- due and filter are dried and weighed. The salt is then dissolved out by warm water, and the chlorides in the solution estimated volumetrically by tritration with decinormal silver nitrate, using a few drops of potassium chromate as indicator. The difference between the weight of salt ascer- tained and the total weight of curd and salt on the weighed filter is regarded as the amount of the casein, or curd, present. If after washing out the salt the residue on the weighed filter be dried and then weighed, the amount of casein so obtained is a little less than that gotten by difference. This is partly due to the small amount of milk-sugar washed out along with the salt and undetermined, and partly to the slight solvent action of warm water on some of the curd. The percentage of fat may be obtained by evaporating the ether filtrate from the previous determination of salt and curd, but the butter-fat is liable to increase in weight by this treatment, and therefore the fat is usually got- ten by difference after determining the water, casein, salt, and milk-sugar. The adulteration of butter and the manufacture on a large scale of butter substitutes makes an examination of the butter-fat one of great importance. This examination may be both qualitative and quantitative. The butter- fat is gotten for examination by melting a sample of butter and, after allow- * Department of Agriculture, Bulletin No. 13, Part i. p. 113. ANALYTICAL TESTS AND METHODS. 257 ing the water and curd to settle, pouring the clear fat on to a dry warm ribbed filter and collecting the filtrate. The specific gravity of the butter-fat may be taken, as first suggested by Bell, in a specific gravity bottle at a temperature of 100 F. (37.7 C.), or, as suggested by Estcourt and endorsed by Allen, with the aid of the Westphal balance (see p. 74) at a temperature of 99 to 100 C. (210 to 212 F.). Bell found by his method that the specific gravity of true but- ter-fat varied from 909.4 to 914 (water 1000), while butterine showed a specific gravity of 901.4 to 903.8. Allen gives the limit for pure butter- fat tested at 99 C. as 867 to 870, while butterine at the same temperature was 858.5 to 862.5. The melting point of the butter-fat is also generally noted. Bell pro- posed determining the melting point by first suddenly cooling some melted butter-fat by floating the capsule containing it upon ice-water, and then taking a fragment of the congealed butter upon the loop of a platinum wire. This is then introduced close to the bulb of a thermometer in a beaker of water which is being heated from without. As the water becomes warmed the globule melts and the thermometer is read 06. An improvement on the method insuring greater accuracy is recorded in Bulletin of the Depart- ment of Agriculture, No. 19, p. 72. The melting point of butter usually ranges between 29.5 C. and 33 C. (85 to 90 F.), while the melting point of butterine is stated to be between 25.5 C. and 28 C. (77.9 to 82.4 F.). The quantitative examination of the supposed butter-fat may be made by several methods, viz., the determination of the saponification equivalent by Koettstorfer's method,* the determination of the percentage of insoluble fatty acids present as glycerides by Hehner's method, f and the determination of the volatile fat acids after distillation by Reichert's method.! To these most generally received methods may also be added the method of Hiibl of iodine saturation as determining the character of fatty acids, and the method of Morse and Burton, which combines the Koettstorfer and the Hehner processes, and determines the saponification equivalent of the soluble and the insoluble fat acids separately. The term " saponification equivalent" is used to indicate the number of grammes of an oil saponified by one equivalent in grammes of an alkali. Thus, tributyrin (the glyceride of butyric acid) has a saponification equiva- lent of 100.67, while tristearine (the glyceride of stearic acid) has a saponi- fication equivalent of 296.67. Butter-fat, it will be remembered, is a mix- ture of the several glycerides of the lower or volatile fatty acids and the higher or non-volatile fatty acids. Its saponification equivalent ranges from 241 to 253, the average being 247 ; butterine has a saponification equivalent ranging from 277 to 294, the average being 285.5. In Hehner's method, the weighed quantity of the fat is saponified by alcoholic potash, the soap solu- tion evaporated down, taken up with w r ater, and the fatty acids set free by an excess of hydrochloric acid. They are now brought upon a weighed filter, washed with boiling water until no longer acid, and then chilled into a cake by immersing the filter in cold water. The filter is then transferred to a weighed beaker-glass and the contents dried at 100 C. until constant in weight. The soluble fat acids can also be determined in this process by * Allen, Commercial Organic Analysis, 2d ed., vol. ii. p. 40. t Bell, Analysis and Adulteration of Foods, Part ii. p. 56. J Allen, Commercial Organic Analysis, 2d ed., vol. ii. p. 45. 17 258 MILK INDUSTRIES. collecting the washings which were obtained with boiling water and making them up to one hundred cubic centimetres and then carefully titrating an aliquot portion with decinormal soda solution. This will give the amount of soluble fat acids plus the excess of standard hydrochloric acid used orig- inally in liberating the fat acids. The amount of this excess can be ascer- tained by carrying through a blank experiment with alcoholic potash and hydrochloric acid, but without the fat. In the analysis of butter-fat the sum of the insoluble fatty acids and of the soluble fatty acids calculated as butyric acid should always amount to fully ninety-four per cent, of the fat taken. The soluble fatty acids calculated as butyric acid should amount to at least five per cent., any notably smaller proportion being due to adultera- tion. As an average, eighty-eight per cent, of insoluble and five and a half per cent, of soluble acids should be obtained. While the true percentage of the volatile fatty acids cannot be easily obtained, the amount of alkali needed to neutralize them after distillation can be determined by Reichert's process. According to this, as improved by Meissl, five grammes of the fused and filtered fat are placed in a flask of about two hundred cubic centimetres contents with about two grammes solid caustic potash and fifty cubic centimetres of seventy per cent, alcohol, saponified on the water-bath and evaporated down until all alcohol is driven off. The thick soap-mass remaining is now dissolved in one hundred cubic centimetres of water, forty cubic centimetres of dilute sulphuric acid added, and, after adding a few fragments of pumice-stone, distilled with the aid of a Liebig condenser. About one hundred and ten cubic centimetres of dis- tillate are collected, which requires about an hour. Filter and collect one hundred cubic centimetres in a graduated flask. Add phenol-phthalein as an indicator, and titrate with decinormal alkali. Increase the result by one- tenth, and reckon the result upon five grammes of the substance. It is found that two and a half grammes of butter-fat, examined by Reichert's method, require about thirteen cubic centimetres of the decinormal alkali, while butterine requires only one cubic centimetre. As the difference be- tween these is twelve cubic centimetres, it may be calculated that there is 8.5 per cent, real butter-fat present in a mixture for every cubic centi- metre of alkali required over the one cubic centimetre required for ordinary butterine. Hiibl's method is founded on the fact that the three series of fatty acids (acetic, acrylic, and tetrolic) unite in different proportions with the halogens, like chlorine, bromine, and iodine, to form addition products. The number of grammes of iodine absorbed is calculated to one hundred grammes of fat, and this is Hiibl's " iodine number." Thus genuine butter has an iodine number from 30.5 to 43.0, while oleomargarine has from 50.9 to 54.9. Morse and Burton * saponify the combined fatty acids, liberate the free acids, wash out the soluble portion of the mixture, and then saponify again the soluble and the insoluble acids separately. They thus combine the Koettstorfer and the Hehner processes and get a greater certainty as to the character of the fat mixture. Thus they find that with butter 86.57 per cent, of potassium hydrate is required to neutralize the insoluble acids and 13.17 per cent, to neutralize the soluble acids, while with oleomargarine 95.40 per cent, of potassium hydrate is required for the insoluble acids and 4.57 per cent, for the soluble acids. * Amer. Chem. Journ., x. p. 322. BIBLIOGRAPHY AND STATISTICS. 259 Perkins* has devised a similar process, which goes further and distils off the volatile fatty acids from the soluble portion washed out of the fatty acid mixture, thus combining the features of the Reichert process with those of the other two. The chief coloring matter added to butter are the vegetable dyes annato, carotin, fustic, turmeric, marigold, and saffron, the coal-tar dyes Victoria and Marti us yellow, and sometimes chrome-yellow (chromate of lead). The following short scheme of testing will show the nature of the butter- color in most cases : Dissolve the supposed artificially-colored butter in alcohol and add, a. Nitric acid : greenish coloration, saffron. b. Sugar solution and hydrochloric acid : red coloration, saffron. c. Ammonia : brownish coloration, turmeric. d. Silver nitrate : blackish coloration, marigold. e. Evaporate the alcoholic solution to dryness and add concentrated sul- phuric acid : greenish-blue coloration, annato ; blue coloration, saffron. f. Hydrochloric acid : decolorization, with formation of yellowish crys- talline precipitate, Victoria or Martins yellow. g. Separation of a heavy and insoluble yellow powder : chrome-yellow. 3. FOR CHEESE. The methods employed in cheese analysis are in most respects the same as those employed in the examination of butter. The fat is best extracted with light petroleum-ether, as common ether dissolves the free lactic acid as well as the fat. The remaining solids not fat can then be dried and weighed. The fat should be examined by Koettstorfer's saponi- fication equivalent method, as the oleomargarine and lard cheeses may be detected in this way. Genuine cheese-fat, according to Muter, f should not consume less than two hundred and twenty milligrammes of potassium hydrate for each gramme used. If the cheese should give unfavorable indications with Koettstorfer's test, then the soluble and insoluble fatty acids are determined in the fat according to Hehner. The percentage of insoluble fat acids in genuine cheese, according to Muter, averages 88.5, while in oleomargarine cheeses it is from 90.5 to 92 per cent. The acidity, calculated as lactic acid, may be determined by treating the residue from the fat determination with water and titrating the washings with decinormal soda solution. The washed residue then is the non-fatty solids. The ash is determined by ignition of the dried cheese before extraction of the fat. V. Bibliography and Statistics. BIBLIOGEAPHY. 1871. Die Milch, Martiny, Danzig. 1875. Das Molkereiwesen, W. Fleischmann, Braunschweig. 187H. Dictionary of Hygiene, with Detection of Adulterations, A. W. Blyth, London. 1878. Butter, its Analysis and Detection, Angell & Hehner, 2d ed., London. Illustrirtes Lexikon der Verfalschungen der Nahrungsmittel, H. Kluncke, Leip- zig- Die Fabrikation der Kunstbutter, Sparbutter, etc., Lang, Leipzig. 1879. Instruction sur 1'Essai et 1'Analyse du Lait, Bouchardat et Quevenne, 3me ed., Paris. 1881. Th Analysis and Adulteration of Foods, James Bell, London. * Zeitsch. fur Anal. Chem., xix. p. 237. f Analyst, vol. x. p. 3. 260 MILK INDUSTRIES. 1882. Food, Sources, Constituents, and Uses, A. H. Church, London. Foods, their Composition and Analysis, A. W. Blyth, London. Chevallier's Dictionnaire des Alterations et Falsifications, 6me ed., Baudrimont, Paris. The Analysis of Milk, Condensed Milk, etc., N. Gerber, New York. Die Milchwirthschaft, Kirchner, Berlin. 1884. Falsifications des Matieres alirnentaires, Lahoratoire Municipal, Paris. 1885. Fabrikation von Kunstbutter, V. Lang, 2te Auf., Leipzig. 1886. Ueber Kunstbutter, ihre Herstellung, etc., Eugen Sell, Berlin. Milk Analysis, J. Alfred Wanklyn, 2d ed., London. Die Analyse der Milch, E. Pfeiffer, 2d ed., Wiesbaden. 1887. Food Adulteration and its Detection, J. P. Battershall, New York. United States Department of Agriculture, Bulletin No. 13, Part i. (Dairy Products), H. W. Wiley, Washington. United States Department of Agriculture, Bulletin No. 16, Methods of Analysis of Dairy Products, etc , C. Richardson, Washington. Le Lait, Etudes chimiques et Microbiologiques, Duclaux, Paris. Illustrirtes Lexikon der Verfalschungen, etc., Dammer, Leipzig. 1888. United States Department of Agriculture, Bulletin No. 19, (Analysis of Dairy Products), C. Richardson, Washington. 1889. Chemieder Menschlichen Nahrungs- und Genussmittel, J. Konig, 3te Auf., Berlin. La Margarine et le Beurre artificiel, Girard et Brevans, Paris. 1891. Die Untersuchung landwirthschaftlich wichtiger Stoffe, J. Konig, Berlin. STATISTICS. In the absence of any governmental control of the milk industries no statistics of production representing the entire country can be given except for oleomargarine. For butter and cheese consumption accurate figures can be given for the amount handled at the port of New York, and from that estimates can be made with some approximation to the truth for the country generally. The following figures and estimates for the last five years are given on the authority of H. R. Chambers, statistician for the New York Mercantile Exchange. The New York market is figured to have fed during the last five years an average of one million seven hundred and fifty thousand people yearly. The receipts and exports at that port were in packages of fifty pounds each. RECEIPTS. EXPORTS. Butter. Cheese. Butter. Cheese. 1890 1,890,949 1,987,217 373,982 1,496,798 1889 2,044,448 1,931,015 398,819 1,500,930 1888 1,697,909 1,993,462 140,993 1,516,614 1887 1,678,660 1,994,857 188,541 1,450,590 1886 1,648,220 1,943,260 233,552 1,575,268 The average receipt yearly, less the average yearly export, will give the average consumption (approximately) of one million seven hundred and fifty thousand people. 1,785,000 266,000 = 1,519,000 packages of fifty pounds each for one million seven hundred and fifty thousand people, or forty-three and one-third pounds for each person, a year as the consumption of butter. In rural districts the consumption is much greater and the waste is greater, so that an average would bring the personal consumption easily to fifty pounds each, which may be reckoned on the population of the country. Very little under- or over-production seems to exist, if we estimate the great steadiness of price during this period. The exportation of dairy products from the United States for the last three years has been as follows : BIBLIOGRAPHY AND STATISTICS. 261 1888. 1889. 1890. Butter (pounds) 10,455,651 15,504,978 29,748,042 Valued at $1,884,908 $2,568,765 $4,187,489 Cheese (pounds) 88,068,458 84,999,828 95,376,053 Valued at $8,736,304 $7,889,671 $8,591,042 Oleomargarine butter (pounds) 1,729.327 2,192,047 2,535,926 Valued at $212,634 $250,605 $297,264 Oleo oil (pounds) 30,141,595 28,102,534 68,218,098 Valued at $3,230,123 $2,664,492 $6,476,258 The production of oleomargarine in the United States for the years end- ing June 30, 1888 and 1889, is given as follows : June 30, 1888. June 30, 1889. Pounds 34,325,527 35,664,526 The greater quantity of the " oleo oil" exported from the United States goes to Holland, where it is converted into oleomargarine. The English importation of oleomargarine (or " margarine," as it is officially known there) for the years 1886-1888 was as follows : Total imported Imported from Holland Re-exported Cwt. 886.573 2,958,300 833,957 I 2,767,599 17,549 48,533 1887. Cwt. 1,273.095 1,172,074 22,180 1888. Cwt. 3,869,948 3,546,591 53,482 1,138,174 1,043,401 20,457 3,263.826 2,951,522 50,614 Jourii. Soc. Chem. Ind., 1889, p. 834. 262 VEGETABLE TEXTILE FIBRES. CHAPTER VIII. VEGETABLE TEXTILE FIBRES. General Characters. ALL the fibres which have been found of technical value for manufacturing purposes may be divided into the two great classes, vegetable fibres and ani- mal fibres, the few found in the mineral kingdom among fibrous minerals being of relatively slight importance in textile manufacturing. Moreover, the distinction is not merely, as the name chosen would indicate, one of origin, but fundamental structural and chemical differences also exist and make themselves evident upon the slightest examination. The vegetable fibres are exclusively cell-growths of relatively simple structure, which dur- ing their life form integral parts of the plant organisms, while the animal fibres may be either a hardened secretion like silk or a more complicated cell-growth like wool, distinguished by its scale-like surface. Thus the vegetable fibres are without exception some form of cellulose (C 6 H 10 O 5 ) n in more or less pure condition or an alteration product of the same, while the animal fibres are composed of protein matter, and hence are nitrogenous. The radical character of their chemical difference just referred to will be more thoroughly appreciated when we note the action of reagents upon the two classes respectively. The vegetable fibres are not dissolved or weakened by alkalies even at a boiling temperature, while the animal fibres are speedily disintegrated, with eventual liberation of ammonia from the nitrogenous material ; while, on the other hand, sulphuric or hydrochloric acid rapidly causes a disintegration of the vegetable fibres by their action upon the cellulose, and nitric acid either oxidizes the cellulose or gives rise to nitrated derivatives, while the animal fibres are only slightly affected even when the acids are concentrated. These reactions will be referred to more fully in speaking of the analytical tests used for distinguishing the fibres in mixed goods. (See p. 301.) The several vegetable fibres may be classified according to botanical or morphological character into three groups : (1) Seed-hairs (filaments com- posed of individual cells) ; (2) bast fibres (filaments or fibre-bundles made up of individual fibre-cells aggregated together) ; and (3) fibro-vascular bundles. Sometimes the term bast fibres is made to include both the second and third classes as just given. Chemically, all vegetable fibres are composed of cellulose. However, it has long been known that it is frequently more or less contaminated with altered products, which have been known as lignin, ligno-cellulose, adipo- cellulose, etc. The recent researches of Messrs. Cross and Bevan have given us a clear understanding of the nature of the lignin and the altera- tion products of cellulose. The combination of cellulose and lignin, to which they apply the name of bastose, may make up the whole bundle of fibres, as in jute, or may be merely a covering upon the unaltered cellulose. GENERAL CHARACTERS OF VEGETABLE FIBRES. 263 By distinguishing between the cellulose and the bastose and mixtures of the two we may establish a chemical classification of the vegetable fibres. We are enabled to do this by the aid of the solutions of iodine (potassium iodine solution saturated with free iodine) and sulphuric acid (concentrated glycer- ine and strong sulphuric acid), which were first proposed by Vetillart.* Pure cellulose when tested with the iodine and sulphuric acid solutions, one after the other, will give a pure blue color, while bastose shows under these conditions a yellow coloration. A complete classification, taking both botani- cal and chemical characters into account, is the following, which is that of Cross and Bevan's f with some additions : Blue reaction with iodine - and sulphuric acid. Yellow reaction with iodine . and sulphuric acid. A. Seed-hairs. Cotton. B. Dicotyledonous bast fibres. Linen. Hemp. China-grass. Ramie. Nettle. Sunn fibre. Hibiscus. Jute. I Monocotolydonous fibres cor- respondfng to bast fibres. Straw. Pineapple. Esparto. Alfa. New Zealand flax. Aloe. Yucca. Manila hemp. Coir. 1. COTTON FIBRE. The cotton, as already noted, is a seed-hair and envelops the seeds, which are at first enclosed in a capsule. With the ripen- ing of the plant this capsule bursts and the contents spread out widely, con- stituting the cotton-boll, which is easily picked. The separation of the fibre from the enclosed seed is afterwards accomplished by the mechanical operation called " ginning," in which it is torn from the seed, so that while one end of an individual fibre is always closed the other is irregularly broken. The genus Gossypium, to which all cotton-plants are referred, includes several well-marked varieties, the most important of which are G. Barbe- dense, or " sea-island cotton," grown off the coast of Georgia, South Caro- lina, and Florida, which yields the longest and strongest fibre or the finest " staple ;" the G. kirsutum, or upland cotton, grown inland in Georgia, Ala- bama, Louisiana, and Mississippi, which yields a shorter staple ; the G. her- baceum, grown in Egypt, Asia Minor, and India ; the G. arboreum, grown in India and Egypt; the G. religiosum, grown in China and India and yielding the so-called u nankin" cotton of brown-yellow color ; and the G. "Peruvianum, yielding the long-stapled Brazilian and Peruvian cotton. The structure of the cotton fibre is very characteristic. It presents a flattened and collapsed tube slightly twisted in spiral form, with compara- tively thick walls and a small central opening. This structure is illustrated in Figs. 80 and 81, in the first of which the fibre is magnified thirty times and in the second of which it is magnified two hundred times. The first illustration shows the spiral twist of the fibres distinctly, but the collapsed character of the tube only slightly ; this latter feature, however, is shown very distinctly in the second illustration. This flattening is not seen in the unripe fibre, which is a tube filled with liquid protoplasmic matter, but in the ripening of the plant this liquid dries up and the walls of the tube * Vetillart, Etudes sur les Fibres, Paris, 1876. f Text-book of Paper-Making, p. 46. 264 VEGETABLE TEXTILE FIBRES. collapse and flatten out. The adhesion of the fibre to the seed also becomes less, so that the ripe cotton is easily separated in the ginning process. In some species (as in G. Barbadense) this separation of hair from the seed is so perfect that the seed shows after the ginning a lustrous black appearance, whence the name locally applied of " black-seed cotton" as distinguished from the upland variety, known as " green-seed cotton." Fia. 80. FIG. 81. The fibre mus't be picked when mature or it becomes " over-ripe" and deteriorates. The length of the " staple," or fibre, varies considerably with the different varieties of the cotton, the long-stapled sea-island cotton grown on the shores of Georgia and Florida attaining a length of nearly two inches (five centimetres), while the short native cotton of India scarcely exceeds three-quarters of an inch (eighteen millimetres) in length.* Chemically, the cotton fibre contains about ninety-one per cent, of pure cellulose, seven per cent, of moisture, and small amounts of fat, nitrogen- ous material, and cuticular substance. An ammoniacal solution of copper oxide causes the cellulose material of the fibre to soften and swell up, whereby the cuticle, which is not softened, takes the appearance of yellow- ish constricting rings binding the swollen cellulose at regular intervals. Prolonged action of the reagent dissolves the cellulose. When bleached by boiling with sodium carbonate or hydrate, the cuticle is decomposed and the fibre yields easily a very pure form of cellulose. 2. FLAX. The flax-plant, Linum usitatissimum, yields the best known and probably the most valuable of the bast fibres as well as other products, like the linseed oil and linseed cake. (See p. 47.) It is not grown for both fibre and seed together, however, as when the fibre is desired in best condition the plant is gathered before it is fully matured, while if the plant is allowed to ripen fully for production of seed, the fibre obtained is more stiff and coarse. The plant is grown through a wide range of climate, although that grown in the tropics, as in India, is chiefly used for seed, the fibre being of little value, while that grown in colder countries, as in the Russian East Sea provinces, yields the best fibre. When the plant is cultivated for the production of fibre, it is either sowed more thickly or, as in Holland and * Bowman, Structure of the Cotton Fibre, p. 19. GENERAL CHARACTERS OF VEGETABLE FIBRES. 265 Belgium, forced to grow up through a net-work of brushwood, thus yield- ing a more slender plant with a longer and finer fibre, known as lin rame. The plant is not cut, but is always carefully pulled up by the roots, and the freshly pulled-up flax is at once submitted to the process of seeding, or " rippling," which is to remove the leaves and seed capsules. This is usually done by hand, drawing the bundles of the flax through upright metallic combs, or " ripples," the prongs of which easily catch the seed capsules, so that three or four drawings suffice to clean the stems or flax straws. This straw r , as it is termed, contains in a dried condition seventy-three or eighty per cent, of its weight of woody matter and encrusting material and twenty to twenty-seven per cent, of bast fibre. The distinction between the several parts of the stem in the flax and similar plants yielding bast fibres is shown in Fig. 82 by both transverse and longitudinal cross-sections, where 1 represents the pith, 2 the woody tissue, 3 the cambium or partially lignified tissue, 4 the bast fibre, and 5 the crust or rind. To free these several parts of the stem from each other so as to obtain in a FIG. 82. clean state the bast fibre is the object of the ,y^??^^ 3 s i 24 process of " retting." This is done either by natural means, as in the case of dew retting and cold-water retting, or by the help of an artificial process, as in warm-water retting and chemical retting. The dew ret- ting, applied most largely in Russia, consists in leaving the flax thinly spread exposed to dew and rain, air and light, for eight or ten weeks, when, by the fermentation of the pectose matter of the rind, the bast fibre is thor- oughly loosened. In cold-water retting either running or stagnant water may be used, the former being used in Belgium and the latter in Ireland. The bundles of flax are placed in crates and submerged, when actual fermenta- tion ensues. The water must be soft water, and care must be taken, especially in the stagnant-water method, to prevent undue heat- ing up during the fermentation. The \varm-water retting requires a tem- perature of 30 to 35 C., and can be carried to completion in fifty to sixty hours, yielding an excellent product. The chemical process consists in the use of dilute sulphuric acid or hydrochloric acid, which allow of the com- pletion of the process in a few days. - After the retting process the flax is well washed and dried, and is then submitted to the mechanical processes of " breaking," " scutching," and " hackling" to thoroughly free the fibre from the woody layer and draw out the fibre-bundles into filaments. The flax fibre as seen under the microscope seems to be a long straight and transparent tube with thick walls and a minute central canal. Fig. 83 show r s these characters of the flax fibre. Characteristic transverse markings also are shown, which may be nodal divisions or slight breaks or wrinkles produced by bending. Longitudinal fissures also show after vigorous rub- bing. The linen fibre when cleansed has a blonde or even white color, a fine silky lustre, and great strength. It is less pliant and elastic than cotton but is a better conductor of heat, and hence seems colder than cotton. Chemi- cally it is, like cotton, a pure cellulose, but when swollen by the action of amuioniacal cupric oxide solution does not show the same uniform series of 266 VEGETABLE TEXTILE FIBRES. constricting bands of cuticle. Linen is in many respects more readily dis- integrated than cotton, especially under the influence of caustic alkalies, calcium hydrate, and strong oxidizing agents like chlorine and hypochlorites. 3. HEMP. The fibre known by this name is the product of the Can- nabis sativa, which is grown for textile purposes chiefly in Russia and Italy, while the seed is grown in India. It is a bast fibre similar to that of the flax-plant, but coarser, stronger, of deeper color and less lustre. Fig. 84 shows the microscopical characters of the hemp fibre. Its cultivation is very FIG. 84. FIG. 83. Flax Hemp ( similar to that already described under flax, and differs according as the fibre or the seed are sought. The freshly-plucked hemp loses sixty per cent, of its weight in drying, and from the air-dried hemp straw twenty per cent, of bast fibre is obtained in the case of the male plant and twenty-two per cent, in the case of the female plant. It is used chiefly for ropes and cord- age, and the fabric woven from it, known as canvas, is used in sail-making. Much of the finer fibre, however, is combined with linen fibre in weaving other goods. The iodine and sulphuric acid test shows that the hem]) fibre is not composed of pure cellulose, but is a mixture of cellulose and bastose. 4. JUTE is the bast fibre of two species of the genus Corchorus, and is grown chiefly in India and Ceylon. The fibre is separated from the plant by methods similar to those employed with flax and hemp, the process of cold retting in stagnant water being followed generally. The bast fibres attain a length of 2.5 metres or even more, are of a yellowish-white color, and have a fine lustre. It is seen under the microscope to consist of bundles of stiff lustrous cylinders with walls of very irregular thickness. These characters of the jute are shown in Fig. 85. Chemically, jute differs from the bast fibres GENERAL CHARACTERS OF VEGETABLE FIBRES. 267 FIG. Jute, Corchorus capsularis (*f hitherto mentioned in that it contains no free cellulose, but consists of the chemical compound of cellulose with lignin, to which Cross and Bevan, who investigated it, gave the name of bas- tose. It gives, treated with iodine and sulphuric acid, a deep brown color. Moreover, the bastose acts with basic dye colors, like the aniline dyes, as if it had been mordanted with tannin, and can therefore be dyed directly without previous treatment. It is much more easily affected by the action of acids and alkalies than flax or hemp. The influence of air and moisture will also rot the jute fibre. It cannot be bleached safely with chloride of lime because of the readiness with which the fibre is oxi- dized, but it may be bleached with a weak solution of sodium hypochlo- rite or by the successive action of po- tassium permanganate and sulphur- ous acid. It may be considered as showing more resemblance to the animal fibres in lustre and appear- ance than any of the other vegetable fibres, and is therefore frequently mixed with wool, mohair, and silk in certain classes of goods. Among the fibres of lesser importance which serve as substitutes for hemp and jute are Manila hemp. Sunn hemp, and Sisal hemp. The first of these is a tropical fibre, obtained on the Philippine Islands from the leaves of the wild plantain. The fibre is obtained by cutting open the leaf-stalks, which are from six to nine feet in length, and then scraping them free from pulpy matter. It furnishes a very superior rope-making fibre because of its combined lightness and strength, and the finer grades are used for woven goods. The color is yellowish or white, and the white variety has a fine silky lustre. It is shown in Fig. 86. The Sunn hemp is grown in India, and furnishes a fibre of light-yellowish color and re- sembles jute, although less lus- trous. It is well adapted for cordage and netting. Sisal hemp (or henequen) is derived from the fleshy leaves of a species FIG. 86. Maniia hemp ( 268 VEGETABLE TEXTILE FIBRES. FIG. 87. of agave grown in Yucatan, British Honduras, and the West Indies and Bahamas. It is used largely in the United States as a substitute for jute in the manufacture of bagging and for cordage, being stronger and lighter than jute. Ramie fibre (China-grass). The bast fibre from two varieties of Boehm- eria nivea, known in India as Rhea, in the Malay Archipelago as Ramie, and to Europeans as China-grass, has in recent years attracted very favor- able attention from all interested in textile industries. It seems to thrive best in the tropics and requires a great deal of moisture. The bast fibre cannot be removed from the woody stems by the retting process used for flax and hemp, as the intercellular substance is so easily decomposed that the water retting rapidly resolves the fibre into a magma of separated cells. The fibre must be removed from the woody stem while the plants are in the green state, as when dried even for several hours' exposure to the sun the fibre becomes difficult to remove from the woody portion. The length of the cells makes it possible to cut the ramie fibre into short lengths and to treat the cleansed fibre like cotton rather than like a long bast fibre. Hence the name " cottonized" ramie which has been applied to that ex- ported from China. With improved methods it is found possible to cleanse it in full lengths, and the fibre is worked like flax rather than with cotton- spinning machinery. The machines for breaking and decorticating the ramie are numerous, but few if any are entirely satisfactory. The properly-prepared fibre is of fine silky lustre, soft, and extraordi- narily strong. It is undoubtedly the most perfect of all the vege- table fibres, and will play a great part in the industries of the fu- ture, especially as the plant, being a perennial, can be grown con- tinuously for years, spreading of itself very rapidly and yielding several crops yearly. Its culti- vation has been begun success- fully in Louisiana and Missis- sippi, and it can probably be extended through the Southern States and Mexico, where it has also been tried. The iodine and sulphuric acid test shows the ramie fibre to be composed of a pure cellulose, which swells easily and china-grass (i?). voluminously when treated with ammoniacal solution of cupric oxide. The appearance of the China-grass is shown in Fig. 87. Nettle Fibre. The bast fibres of the common nettle ( Urtica dioica) were at one time prior to the development of the cotton industry used extensively in spinning and weaving on the Continent of Europe, the cloth made being known as grass-cloth, the name now given to the product of the Cliina- grass, or ramie. The fibre when cleansed is soft, of good length and strength, and quite lustrous and white. The bast fibres of the linden ( T'dia Europcea) GENERAL CHARACTERS OF VEGETABLE FIBRES. 269 and of the paper-mulberry-tree (Broussonetia papyri/era) are also used, the former for the manufacture of mats in Russia and the latter by the paper- makers of China and Japan. New Zealand Flax is a fibre obtained from the leaves of Phormium tenax, which acquires a length of one to two metres. The fibre as prepared by hand-scraping, the method of the native Maoris, is soft, white, and of silky lustre ; as prepared by machinery it is distinctly inferior in character. Its chief value is for rope-making and for coarse textiles. The rope made from this fibre is, however, weakened when wet by sea-water, and therefore must be kept well oiled. Pineapple Fibre. The leaves of the several varieties of Bromelia yield a fine, nearly colorless, fibre, which is worked, especially in Brazil, for the manufacture of the so-called " silk-grass." Esparto. This is a grass, cultivated especially in North Africa and Spain, where ropes and cordage are made from it. Its chief use, however, is in connection with paper-making. (See p. 271.) Cocoa-nut Fibre ( Coir}. The coarse fibrous covering of the nut of the coco palm is largely used for brooms, brushes, matting, and coarse carpet- ing. The fibre is coarse, stiiF, very elastic, round, and smooth like hair. It also has great tenacity, and is well adapted for cordage. The classification of the vegetable fibres just enumerated has already been made upon the basis of the iodine and sulphuric acid reaction accord- ing to Vetillart. Two groups were thus established, the one composed essentially of unaltered cellulose and the other of lignified cellulose bastose. Other reactions for these two classes of materials are given in the accom- panying table from O. Witt :* Reagent. Cellulose. Bastose (compound of cellulose with lignin). Iodine and sulphuric acid. Sulphate of aniline with free sulphuric acid. Basic aniline dyes. Weak oxidizing agents. Ammoniacal cupric oxide. Produces blue color. Indifferent. Indifferent. Indifferent. Immediate solution. Produces a yellow or brown color. Colors deep yellow. Produces fast colors. Rapid disintegration. Swelling up, blue color, and slow solution. To distinguish the several more important vegetable fibres from each other when admixed, a number of chemical and physical tests have been proposed in addition to the microscopical study of the structural differences already mentioned under the individual fibres. Thus, according to Kindt's test, the presence of cotton fibre in linen goods can be distinguished, after first removing the size or dressing by thorough boiling with distilled water and drying again, by dipping them from one-half to two minutes, according to the texture of the goods, in concentrated sulphuric acid. They are then well washed with water, rubbed, dipped for a moment in ammonia-water, and dried. The cotton fibre is either dissolved or gelatinized and removed by the rubbing, while the linen fibre remains unchanged or but slightly attacked. By counting the flax fibres remaining for a given superficial area the relative proportion of cotton admixture can be determined. * Chem. Technologic der Gespinnstfasern, p. 111. 270 VEGETABLE TEXTILE FIBRES. The different effect of strong caustic potash solution upon cotton and linen fibres is also taken as decisive at times, although the difference is not so marked. Both kinds of fibres shrink in size, the cotton fibres remain whitish or grayish yellow, while the linen fibres are colored deep yellow or orange. A very characteristic test is that given by Boettger. A piece of the mixed goods frayed out in three sides is first dipped in a one per cent, solution of fuchsine, then taken out, washed in running water until this runs off clear, and dipped in ammonia-water for from one to three minutes. The cotton fibre is quickly decolorized, while the linen fibre remains bright rose-red in color. A test easily applied and satisfactory is the oil test, but it is only applicable to white goods which are free from size. The well-dried sample is dipped into olive oil, and then well pressed. The linen fibres become translucent from the capillary action upon the oil, while the cotton fibres remain white and dull in appearance. An alcoholic cochineal solution (one part of powdered dyestuff digested with twenty parts of alcohol of .847 specific gravity for twenty-four hours) is also recommended by Bolley. Cotton fibres take a clear red color in this solution, while linen fibres are colored violet. A special test to distinguish the fibre of the Phormium tenax (New Zea- land flax) from linen or hemp is given by Vincent. It is in the use of concentrated nitric acid, which colors the New Zealand flax distinctly red, but does not change the other fibres mentioned. (For tests to distinguish the vegetable fibres as a class from the animal fibres, see p. 262.) The use of the microscope, however, is much the most reliable means of distinguishing the several fibres when occurring in admixtures, as the struct- ural character are sufficiently distinct to allow of easy recognition to those possessed of some practice. INDUSTRIES BASED UPON THE UTILIZATION OF VEGETABLE FIBRES. The great utilization of these fibres is of course in the manufacture of textile fabrics of all grades. Having described the fibres which constitute the raw materials of these industries, we shall pass the mechanical side of their treatment and shall note the chemical processes of bleaching, dyeing, and color-printing in a later section of the work (see p. 447), after the preparation of natural and artificial dye-colors has been described. Other industries based upon utilization of some one or more of the vegetable fibres are Paper-making, Pyroxylin and Gun-cotton, Collodion, Celluloid, and similar products. A. PAPER-MAKING. I. Raw Materials. 1. RAGS. The first in order of use for paper-making and still the most important raw materials for the finer grades of paper are linen and cotton rags. As the cellulose of these rags has already undergone a process of purifying from the coloring and incrusting matter with which it was first associated in nature in its preparation for manufacture into textile fabrics, it is well adapted for use in paper-making, the basis of which is also a cellulose fibre. Of course, the rags may be of all grades of cleanliness. They may be cuttings obtained in the course of manufacture of garments, RAW MATERIALS. 271 and being unworn may be relatively clean, or they may be fragments of cast-off wearing apparel gathered from waste-heaps and reeking with filth. Indeed, so great is the demand for paper-making stock that rags are gath- ered from Japan, Egypt, and all parts of the world, and the bales generally require careful disinfection before they can be used. They may contain sizing and China clay and other loading; materials, or they may be colored with various dyes and metallic salts." Rags considered as paper-making stock must therefore be assorted, and for trade purposes they are divided into a large number of grades or classes distinguished by different letters. Linen rags are distinctly superior for paper-making to cotton rags, as they make a stronger and more durable paper. 2. ESPARTO. This grass, mentioned under the vegetable fibres (see p. 269), is of great importance as a paper-making material, particularly in England. The Spanish variety, according to Hugo Muller, contains 48.25 per cent, and the African variety 45.80 per cent, of cellulose, but the yield of bleached fibre obtained in practice probably does not much exceed forty per cent. .The fibre is tough and it makes an excellent paper, whether used singly or in admixture with other materials. 3. STRAW. As a material for admixing with other fibres, straw-pulp is largely used. The varieties of straw so utilized are oat, wheat, rye, and barley. Of these, rye is the most suitable on account of its yielding the largest amount of fibre, and next in value is wheat. The amount of cellu- lose in winter rye is given by Hugo Muller as 47.69 per cent, and in win- ter w T heat as 46.60 per cent., but probably not more than thirty-five per cent, is actually obtained as pulp, much being lost in the treatment on account of the loose aggregation of the cellular tissue. Straw contains more silica than Esparto, and hence requires more soda in the after-treatment to free the cellulose and adapt it for use. 4. JUTE. The " butts" or " cuttings" rejected by the textile manufac- turer are largely used in the manufacture of the common grades of paper. It possesses a large percentage of cellulose (63.76 per cent, in the best fibre and 60.89 per cent, in the " butts"), but it cannot be economically bleached to a white color. 5. MANILA HEMP. This is very like jute in its adaptability for cheap and colored papers, and as the fibre is a lignified cellulose it requires consid- erable boiling with soda to prepare it for use. 6. WOOD FIBRE. Two varieties of pulp for paper-making may be obtained from wood, viz., mechanically and chemically prepared pulp. Of these, the mechanical wood-pulp obtained by shredding the wood serves for the inferior grades of paper only as its fibres are too short and do not " felt" or interlace sufficiently. It can therefore be used only as a filling material. Moreover, the resin present resists strongly the action of bleaching agents, and the paper becomes yellowish after a time. On the other hand, what is termed chemical wood-pulp has met with great favor as a very pure and easily obtainable form of cellulose. Two main processes for its production are now in use, the caustic soda process and the bisulphite process. In the former, the wood chopped up and crushed is boiled under pressure with caustic soda. This is either done in cylindrical boilers at pressures varying from four atmospheres (sixty pounds), as first used by Watt and Burgess, to fourteen atmospheres (two hundred and ten pounds), as used by Sinclair, or by Ungerer's graduated method in a series of nine connected vessels, using low pressures and partly saturated lyes upon the 272 VEGETABLE TEXTILE FIBRES. fresh wood and increasing the pressure and using fresher lyes upon the partly-converted wood. Somewhat more than fifty per cent, of the soda used is recovered again from the washings. The alkali process is, however, being gradually displaced by the bisulphite process. As first proposed by Mitscherlich, acid calcium sulphite was used. The temperature is brought gradually to 118 C., which is not exceeded, the pressure being from two to three atmospheres. In Ekman's process acid magnesium sulphite is used, and a pressure of from five and a half to six atmospheres is attained. Still another process is that of Franke, which uses bisulphite of lime again. Cross and Bevan explain the efficacy of the bisulphite processes by saying, " The chief agency is the hydrolytic action of sulphurous acid, aided by the conditions of high temperature and pressure ; and the subsidiary agencies are, (1) the prevention of oxidation ; (2) the removal from the sphere of action of the soluble products of resolution in combination with the sulphite as a double compound, for it is to the class of aldehydes that we have shown that the non-cellulosic constituents of wood belong ; and (3) the removal of a portion of the constituents in combination with the base, i.e., with expul- sion of sulphurous acid." The several bisulphite processes, as compared with the ones mentioned previously, yield a larger amount of pure fibre ; they preserve its original strength, which is not done when caustic soda acts upon the loosened fibre under pressure, and there is a greater economy of chemicals. 7. PAPER-MULBERRY. In China and Japan, where the paper-makers excel the best European workmen in the making of some delicate but strong papers, the material chiefly used is the inner bark of the paper-mulberry- tree (Eroussonetia papyri/era^ the leaves of which can be used in feeding silk-worms. The strength of this paper is due to the fact that in making the pulp the long bast-cells are not broken and torn as in European pulp- ing-machines, but merely softened and separated by beating. In taking up the pulp in the mould the cells are made to lie in one direction, and the paper may be strengthened by taking one or more dips in which the cells are made to lie in other directions. Some gum is added to make the cells of the pulp adhere. IE. Processes of Treatment. 1. MECHANICAL PREPARATION OF THE PAPER-MAKING MATERIAL. This differs, of course, according as the raw material is composed of rags, Esparto, straw, or other cellulose-containing substance. With rags, a pre- liminary sorting always takes place, more or less complete according to the make-up of the bales. Numerous commercial designations are in use for these different grades so obtained. We need only speak of white linen, blue or gray linen, white cotton, colored linen or cotton, sacking, half wool, etc. They are then cut into coarse fragments by hand, being passed rapidly over broad knives fixed at a set angle in tables, and all buttons and hard substances removed. A thorough dusting or " thrashing" is now necessary to remove the dust and detachable dirt. This is effected in large wooden boxes with revolving arms. A more thorough cutting now ensues with the aid of revolving knives, followed in most cases by a final and thorough dusting, so as to eliminate as much dirt as possible and save in the amount of boiling necessary as the next operation. With Esparto a mechanical sorting or " picking" is also the first opera- tion. The grass is spread out on tables and the weeds, root-ends, etc., care- fully removed, as these would be difficult to boil and bleach and would give PROCESSES OF TREATMENT. 273 rise to dark-colored specks in the finished paper known as "sheave." Machines for this cleansing of the Esparto are also used quite largely. The preparation of mechanical and chemical wood-pulp has already been referred to. 2. BOILING. The boiling of the rags with caustic soda, caustic lime, or a mixture of soda ash and lime, which is the next operation, is designed to free them from grease, dirt, and coloring matter. This may be done either in rotating spherical or cylindrical boilers or in the so-called " vomit- ing" boilers described later. The boilers are often large enough to take two tons of rags at a charge. The amount of alkali usually ranges from five to ten per cent, on the weight of the rags. Soda is preferred by many paper-makers to lime on account of the greater solubility of the compounds it forms, although both are in general use. The time of boiling varies from two to six hours, according to the quality of the rags, the alkali employed, and the pressure. The use of high pressures is to be avoided as far as pos- sible, as it may result in fixing the dirt and coloring matter instead of dis- solving them. A pressure of from three to four atmospheres is commonly employed. After the pressure has been allowed to fall, the liquor collected at the bottom of the boiler is drawn off and water run in to give the rags a slight preliminary washing. The charge is then drawn off. In the case of Esparto, the " vomiting" boiler or other form of appara- tus for keeping up a continuous circulation of the liquor is used. A form of boiler in which this circulation is kept up by the use of a steam injector is shown in Fig. 88. The grass is put in through the man-hole C and rests upon the false bottom . Circulation is set up by the steam from the pipe D passing through the injector E and drawing the liquor through the small pipe r. In order that this circulation may proceed uniformly, it is neces- sary that the steam shall enter at a pressure one atmosphere higher than the pressure existing in the boiler. A manometer, M, shows the pressure, and a safety-valve, T 7 , allows of the adjustment of the necessary conditions. The contents of the boiler are discharged through s at the end of the oper- ation. The boiling takes from four to six hours. The quantity of soda necessary depends upon the nature of the grass, Spanish requiring less than African, and the pressure employed varies from five to forty-five pounds per square inch. 3. WASHING. This operation, which must be a thorough one, takes place in a washer or " breaker." The name " hollander" is very generally given to this machine as well as to the similar one in which the beating or mixing is done. The hollander is an oval iron tub, from ten to twenty feet long, four to six broad, and about three feet high, divided for two- thirds or more of its length by an upright partition known as the " mid- feather." The details of its construction may be seen from Figs. 89 and 90. The roll A carries upon its circumference a number of steel knives and revolves on one side of the " mid-feather," or longitudinal division Q Q (Fig. 90). The floor on this side is raised in a way as to bring the pulp well under the roll, as shown by the line J O K (Fig. 89). Imme- diately under the roll is the " bed-plate," shown at 0, and provided with knives similar to those in the roll A, but set with their edges in the op- posite direction. The distance between the roll and the bed-plate can be varied at will by means of the hand-wheel h and the mechanism shown at k and i (Fig. 90). After passing between the roll and the bed-plate, the pulp flows down the " back-fall" K K, and finds its way around to the 18 274 VEGETABLE TEXTILE FIBRES. other side of the mid-feather. On the inclined part of the floor and im- mediately in front of the bed-plate a small depression is made at E, covered with an iron grating, for the purpose of catching buttons, small pieces of stone, and other foreign substances that may have found their way into the rags or other paper stock. The dirty water from the rags is removed by the " drum- washers" R R. The ends of the drums are of wood, and the circum- ference is covered with fine copper or brass wire-cloth. The wash-water passes through the wire-cloth into the compartment shown in R, and passing towards the narrower end of the inner conical tub, flows out through the side of the drum into a trough placed to receive it. In washing the rags in this machine, the tub is partly filled with water, the rags from the boiler dumped in, and the operation begun. The action of the roll thoroughly mixes pulp and water and sweeps the rags up the incline and over the back-fall K. The dirty water then passes away through the drum-washer, the supply of pure water being so regulated as to keep the level constant. When the water begins to run off clear the PROCESSES OF TREATMENT. 275 supply is stopped, the washer still being kept in action. As the level falls, the drum is lowered by means of the handle h. When sufficiently drained, the pulp is discharged through the valves C C in the bottom of FIG. 89. the washer. It is now ready to be bleached. This may be done in the washer itself or in separate engines called " potchers." If done in the washer, a solution of bleaching-powder is run in after the withdrawal of the wash-water and the action of the roll con- tinued. Esparto is generally washed in exactly the same way as that just described for rags, but in some mills the grass is washed in a series of connected lixivia- ting tanks like those used in al- kali-works. Pure water flows in at one end, passes through fresh lots of grass in succession, and issues at the farther end highly charged with the soluble products of the grass. The washed and broken pulp now goes by the name of " half-stuff." 4. BLEACHING. This is done with the aid of chlorine or a solution of calcium or sodium hypochlorite. The use of chlo- rine gas, once largely practised, has been almost entirely super- seded by the hypochlorite solu- tions, as chlorine is liable to form difficultly removable compounds, and it also tends to attack and weaken the fibre of the pulp. When chlorine is used, 2.5 to 5 kilos, of salt are taken as needed for 100 kilos, of " halfl-stuff." The solution of calcium hypo- chlorite must be used perfectly clear and free from undissolved hydrate or carbonate. A solution of 6 Twaddle, which contains about half a pound of bleaching- powder to the gallon, is com- monly used. An addition of hy- drochloric or sulphuric acid to the bleaching-liquor is sometimes made, but this must be done with care so as not to liberate chlorine instead of hypochlorous acid. This danger from 276 VEGETABLE TEXTILE FIBRES. FIG. 90. PROCESSES OF TREATMENT. 277 free chlorine is greater when highly lignified fibres, such as wood or jute, are used. The bleaching is often effected by combining a preliminary treat- ment in the " potcher" or washer with a subsequent prolonged steeping in tanks. A process has been recently proposed by Professor Lunge involving the use of acetic acid. The quantity required is very small, as during the process of bleaching it becomes regenerated. Any free lime in the solution is first nearly neutralized with a cheaper acid, such as hydrochloric or sul- phuric acid, followed by the addition of the acetic acid. The process is said by Cross and Bevan to give excellent results with high-class material, such as the best cotton and linen rags, but is not to be recommended for materials like straw or Esparto. A process invented by Thompson is also said to be very effective for the bleaching of rags. It consists in saturating the material with a weak solu- tion of bleaching-powder and then exposing them to the action of carbonic acid gas. The bleaching action is thus made very rapid and effective. One of the most recent innovations in bleaching is the application of electricity in this connection. The only process that has yet attracted much attention is that of M. Hermite. It is thus described by Cross and Bevan :* " This process is based upon the electrolysis of a solution of magnesium chloride, this salt having been found to give the most economical results. The solution, at a strength of about 2.5 per cent, of the anhydrous salt (MgCl 2 ), is electrolyzed until it contains the equivalent of about three grammes of chlorine per litre. This solution is then run into the ' potcher 5 con- taining the pulp to be bleached ; a continuous stream is then kept up, the excess being removed by means of a drum-washer. This excess, which, after being in contact with the pulp in the engine, is more or less deprived of its bleaching properties, is then returned to the electroly zing- vat, where it is again brought up to normal strength. The electrolyzed solution has been found to possess very remarkable properties which have considerable bearing upon the economy of the process. If a solution be taken of equal oxidizing efficiency with one of calcium hypochlorite, as indicated by the arsenious acid test, it is found that the former possesses greater bleaching efficiency than the latter in the proportion of five to three. Moreover, the bleaching is much more rapid and the loss of weight which the substances undergo is less for equal degrees of whiteness obtained." Further details of this process will be found in the article by Cross and Bevan in the "Journal of the Society of Chemical Industry," for April, 1887. The removal of any excess of chlorine or bleaching-liquor must now be looked to. This is done either by careful washing or by the use of an " antichlor." The first method has the advantage of not only removing the bleach but also of the chloride of calcium which has been formed from it. It, however, takes some time and consumes a large amount of water. Much more general is the use of an " antichlor." The commonest of these is sodium thiosulphate (or hyposulphite, as it is commonly called). This is ordinarily decomposed according to the reaction 2(Ca(ClO) 2 ) -f- Na 2 S 2 O 3 -f- H 2 O = 2CaSO4+2HCl + 2NaCl, but when the solutions are very dilute, sodium tetrathionate, Na 2 S 4 O 6 , and caustic soda and lime are formed. For the first equation two hundred and forty-eight parts of commercial thiosul- phate a,re required to neutralize four hundred and nine parts of bleaching- powder of thirty-five per cent, available chlorine strength. The various * Text-book of Paper-Making, p. 115. 278 VEGETABLE TEXTILE FIBRES. sulphites are also in use as antichlors, sodium sulphite being the most' im- portant. A cheap antichlor is also made by boiling together lime and sulphur, the resultant calcium sulphide solution containing a mixture of calcium thiosulphate and calcium pentasulphide. This last-mentioned preparation is, however, objectionable on account of the free sulphur formed, as this affects the pulp injuriously. Whatever antichlor is used, an excess should be avoided, as it may act upon the color or size added sub- sequently. The antichlor should therefore be added in successive small portions, and any hypochlorite solution still remaining be tested for from time to time with iodide of starch paper, which will be turned blue as long as hypochlorite remains. 5. BEATING. The bleached pulp, or " half-stuff," is not yet in condi- tion for making an even paper, as the fibre has not been sufficiently disinte- grated. This is now effected in the beating-engine, which is a hollander very similar to the breaker already illustrated, except that the roll carries more knives and it is usually let down much nearer the bed-plate. The half-stuff is furnished in successive portions to the beater previously par- tially filled with water, each successive portion being allowed to mix thor- oughly with the water before another lot is added. This is continued until the mass is so thick that it will only just turn round under the action of the roll. The operation of beating is designed to be a more complete breaking or tearing apart of the fibres rather than a cutting, as this latter result would interfere with the felting of the fibres so necessary in paper-making. Cotton and linen rags naturally take longer than most other paper-making material, taking often as much as ten hours ; wood-pulp requires to be very gently and slowly beaten, so that it requires some six hours ; while Esparto is sufficiently disintegrated in from two to four hours. In making the finer grades of paper, the roller bars or kniv.es instead of being made of steel are made of bronze, so that contamination with oxide of iron is avoided. Beaters of a totally different form of construction are also largely in use. Thus, in the Jordan beater the roll is in the shape of a truncated cone, fitted with knives and revolving in an iron box of corresponding shape, and also fitted with knives set at an angle. In the Kingsland en- gine and the Gould engine a circular plate furnished with knives revolves against one or more stationary plates similarly fitted, somewhat after the manner of millstones. The half-stuff is even more thoroughly disintegrated in these beaters than in the ordinary forms. 6. LOADING, SIZING, COLORING, ETC. Except in the very finest papers, some mineral-loading material is incorporated with pulp when in the beater. This is, of course, in the main for cheapening purposes, but also serves the useful purpose of filling the pores of the paper and enabling it to take a better surface in the subsequent operations of calendering. Such loading materials are China clay, or kaolin, sulphate of lime, or " pearl hardening," barium sulphate, precipitated chalk, bauxite, precipitated mag- nesia, and magnesium silicate, or " agalite." The amount added varies from two to three per cent, to twenty per cent., or in rare cases even more. All papers except blotting-papers have also to be sized. This is for the purpose of filling the pores with some material that will, to some degree at least, resist the action of water. Thus, all writing-papers, and in general printing-papers also, are sized to prevent the ink applied to them from run- ning. This is done either by what is termed " engine-sizing" that is, in the beating-engine itself or by " tub-sizing," when the paper as it goes PROCESSES OF TREATMENT. 279 through the Fourdrinier machine (see below) passes through a tub of gela- tine size and takes a layer of the same on either surface. In " engine-sizing" a rosin soap is first added to the pulp in the beater, and when this is thoroughly incorporated a solution of alum is run in, form- ing, as it has been generally supposed, a resinate of alumina, which is water resistant when dried. Wurster * claims to have shown, however, that the sizing in this case is not due to the formation of a resinate of alumina but to a separation of free resin, and in this result he has been supported by Conradin.f With the resin soap is also added some starch, and the quantity of mixed rosin and starch is usually from three to four pounds to the one hundred pounds of pulp. The pulp although bleached is rarely white enough to produce a clear white paper, and the yellowish tint requires to be neutralized by the addition of small quantities of blue and pink coloring material. Ultramarine, smalt, and aniline-blue are used for the first color, and either cochineal, Brazil- wood, or aniline-red for the second. The paper may be colored through- out any desired color by using rags previously dyed, or by adding to the bleached pulp in the beater the necessary dyes or pigments. 7. MANUFACTURE OF PAPER FROM THE PULP. We have to con- sider here two diiferent products, viz., hand-made paper and machine- made paper. The former is made by taking in the mould upon the "deckel," or wire-cloth frame, just sufficient of the prepared pulp diluted with water to make a sheet of paper. As the water drains through the wire-cloth and leaves the fibres spread out upon the surface, the felting operation is assisted by shaking the frame gently from side to side. The mould with the sheet of paper is then turned over, and the sheet thus transferred from the wire to a piece of felt. When a number of sheets have been thus prepared, they are piled up with alternate sheets of felt and the whole subjected to strong pressure to expel, water. They are then sized if required by dipping them into a solution of gelatine, again pressed, and hung up to dry. When dry they are calendered or pressed between hot metal rolls. Machine-made paper is made on what is universally known as the Fourdrinier machine, of which an improved form, as manufactured by the Pusey and Jones Company, of Wilmington, Delaware, is shown in Fig. 91. We cannot here describe the various mechanical details of this machine, but may summarize by saying that it consists of an endless mould of wire-cloth on to which the prepared pulp flows from the " stuff-chest" through a " regu- lating-box" and over the " sand-table" and the " screen." From the deckel wire it now passes through a series of rolls, at first covered with felt and later of smooth heated metal known as the " dandy-roll," the " couch-rolls," the " press-rolls," the " drying cylinders," and, finally, the " calenders." The action of the machine is a continuous one, and the speed of the Fourdrinier is from sixty to two hundred and forty feet per minute, the latter for cheap newspaper, the former for the best paper requiring the most care. What is known as "tub-sizing" is applied to many machine-made papers in the course of their passage through the Fourdrinier. A filtered solution of gelatine is used to which about twenty per cent, of its weight of alum has been added. A certain quantity of soap is also often added, a white, soap free from resin being used. Instead of the Fourdrinier, what are turned cylinder-machines are also * Wagner's Jahresbericht, 1878, p. 1155. f Ibid., 1879, p. 1106. 280 VEGETABLE TEXTILE FIBRES. I PRODUCTS. 281 in use, in which a large drum or cylinder covered with wire-cloth revolves in the vat containing the pulp. As it revolves the fibres attach themselves to the wire and the water is sucked through the meshes by a partial vacuum within. The sheet of paper thus formed is taken on to an endless felt pass- ing over a couch-roll, which revolves in contact with the hollow drum, and thence passes to a large drying cylinder heated by steam. Paper made on such a machine is weaker, however, than that made on the Fourdrinier, because it has not been found possible to give the shaking motion to the cylinder necessary to produce the felting of the fibres. HI. Products. The products are almost without number, and vary not only in different countries, but even locally from time to time as different milk change their production. We will therefore attempt only a general classification of the main varieties. 1. BLOTTING- AND TISSUE-PAPER. These are unsized papers. Blot- ting-paper is a mass of loosely-felted fibres, which, however, is free from any loading or filling material, and therefore is capable of easily and quickly taking up water or other liquids. It may be white, gray, or colored to any shade by the addition of the proper dyes. Tissue-papers, which as the name indicates are the thinnest of all papers, are made from very strong fibres, such as that of hemp-bagging and cotton canvas, and on machines somewhat different from the ordinary Fourdrinier. 2. WRAPPING-PAPERS. These are partially-sized papers of coarse materials, such as straw, jute, Manila hemp, common rags, etc. They may show the natural color of the materials or may be colored, as in the case of the blue wrapping-paper commonly used for packing sugar. A more strongly sized and calendered wrapping-paper is made for use with linens and other textile goods. 3. PRINTING-PAPERS. These are white papers, generally with filling and sizing material, although some special grades are given a smooth sur- face by calendering instead of sizing. The cheaper grades for newspaper use are frequently largely adulterated with filling material, and mechanical wood-pulp is also largely used in their manufacture. 4. WRITING-PAPERS. These are thoroughly-sized papers, for which the best materials are generally used, linen rags alone being taken for the finer grades. 5. CARDBOARD, PASTEBOARD, AND PAPIER-MACHE. Pasteboard may be made by pressing a number of sheets of freshly-formed unsized paper in powerful presses, or cementing them together by the use of glue or other cementing material, and then pressing the mass so formed. Cardboard is made direct upon machines adapted for heavy layers of pulp and pressed and calendered like similar grades of ordinary paper. Papier-mache is made chiefly from old paper by boiling to a pulp with water, pressing, mix- ing with glue or starch paste, and then pressing in moulds previously oiled. After drying, the articles are soaked with linseed oil and then dried at higher temperature. 6. SIDE-PRODUCTS. Recovered, Soda. The alkaline liquors in which rags, Esparto, and other paper-making material have been boiled were at one time run off as waste products. This is no longer done in properly- conducted mills, as the alkali used can be recovered in the form of carbon- 282 VEGETABLE TEXTILE FIBRES. ate by evaporation of the waste-liquor and ignition of the residues, and this carbonate can then be causticized and fitted for renewed use. The soda during the process of boiling with the paper-making materials takes up a large amount of non-cellulose fibre constituents, such as resin, coloring mat- ter, and silica. These on evaporation and ignition become either carbonate or silicate. It will not be possible for us here to describe the forms of evaporators in use for this soda recovery. One of the best-known evapora- tors is that of Porion, used largely in England and on the Continent. For a description of this and other forms, see Cross and Bevan's "Text-book of Paper-Making/' p. 182. The Yaryan multiple-effect evaporator (see p. 125) is also being introduced for concentration of the spent liquors. The recovered soda consists essentially of carbonate of soda, together with a certain amount of silicate of soda if the liquor had been obtained by boiling straw or Esparto. The causticizing is done in the usual way with caustic lime and the clear alkali decanted from the separated calcium car- bonate, which is then thoroughly washed. IV. Analytical Tests and Methods. 1. DETERMINATION OF THE NATURE OF THE FIBRE. This may be done in part, if not wholly, by either of two methods, viz., by the aid of the microscope or by the use of chemical tests for individual fibres. The fibre is always torn or cut and often somewhat attacked. By some practice, however, it is possible to distinguish between cotton and linen or to identify both in admixture. Wood and straw can also be identified. In making these tests, it is best to take strips of the paper in question and boil them in succession with alcoholic potash solution, with water, with two per cent, hydrochloric acid, and then again with water. If they are now shaken up with a little warm water, we obtain a fine magma of fibres, which when mixed with an equal volume of glycerine is well adapted for examination under the microscope. The distinctive characters of some of the chief paper-making materials as seen under the microscope may be thus summa- rized, according to Cross and Bevan : * Cotton, flat, ribbon-like fibres, fre- quently twisted upon themselves. The ends generally appear laminated. Linen, cylindrical fibres, similar to the typical bast fibre. The ends are frequently drawn out into numerous fibrillse. Esparto, the pulp consists of a complex of bast fibres and epidermal cells. The most characteristic feature of Esparto pulp is the presence of a number of fine hairs which line the inner surface of the leaf, some of which still remain after the boiling and washing processes. The presence of these hairs may be taken as conclu- sive evidence of the presence of Esparto. Straw, this closely resembles Esparto-pulp in microscopical features, except that the hairs are absent. On the other hand, a number of flat oval cells are always present in paper made from straw. Chemical wood-pidp, flat ribbon-like fibres, showing unbroken ends. The presence of pitted vessels is eminently characteristic of pulp prepared from pine- wood. Mechanical wood-pulp may be recog- nized by the peculiar configuration of the torn ends of the fibres and from the fact that the fibres are rarely separated, but generally more or less ag- glomerated. The pitted vessels of pine-wood also show, and usually more distinctly than in chemical wood-pulp. * Text-book of Paper-Making, p. 199. ANALYTICAL TESTS AND METHODS. 283 The chemical reagent most useful in testing paper-pulp is aniline sul- phate. With most of the fibres which consist of cellulose simply it gives no reaction. Straw, Esparto, and mechanical wood-pulp can, however, be identified by its means. Thus, where paper containing straw or Esparto is treated for some time with a boiling one per cent, solution of aniline sulphate, a pink color is produced. Esparto gives the reaction with greater intensity than straw. Mechanical wood-pulp treated with this solution develops even in the cold a deep-yellow color. According to Bolley,* the moistening of paper containing mechanical wood-pulp with nitric acid will give the same result, and a naphthylamine salt produces a deeper orange color. Accord- ing to Wiesener, phloroglucin is also a delicate reagent for wood fibre in paper. A drop of dilute solution of phloroglucin put upon the paper and this followed by moistening with hydrochloric acid develops an intensely red color. Fuchsine also colors wood fibre red, but has no effect upon paper from linen fibre alone. M. Wurster in " Journ. de Pharm. et Chemie" has extended Wiesener's observation on phloroglucin to a number of the phenols, finding them as a class to serve as reagents for distinguishing between wood-pulp and other cellulose. The results are : Reagent Wood-pulp. Orcin ................... Dark red. No color Resorcin . . ............... Deep green. Violet. Pyrogallol ................. Blue-green. Violet. Phenol .................. Yellow-green. Violet. Phloroglucin ............... Blue-violet. No color According to Godeffroy and Coulon, mechanical wood-pulp from pine- wood possesses the property, after it has been extracted with water, alcohol, and ether, of reducing gold solutions on boiling. This property is not pos- sessed by wood-pulp prepared by the caustic soda or sulphite processes, after similar extraction with solvents, nor by the pulp prepared from linen or cotton fibres. This property depends upon the fact that in mechanical wood-pulp ligno-cellulose remains, and to this composition is due the re- ducing power upon gold solutions. This ligno-cellulose is destroyed in the preparation of chemical wood-pulp, and docs not exist at all in the linen or cotton fibre. It has been found that on the average one hundred parts of mechanical wood-pulp, extracted with solvents and dried at 100 C., will reduce fourteen thousand two hundred and eighty-five grammes of gold. It is thus made possible by weighing the reduced gold to estimate the amount of mechanical wood entering into the composition of the paper. For details of the analytical method based upon this gold reaction, see Bolley's " Hand- buch der Technisch-Chem. Untersuchungen," 6te Auf., p. 1007. 2. DETERMINATION OF THE NATURE OF LOADING MATERIALS. The total amount of the mineral-loading material is determined by igniting a weighed quantity of the paper until the ash is white or grayish and then accurately weighing this. The ash from a paper containing the China clay is insoluble in boiling dilute hydrochloric acid ; that from paper containing cal- cium sulphate is soluble, and deposits on standing needle-shaped crystals of gypsum easily recognizable by chemical tests. 3. PETERMINATION AS TO NATURE OF THE SIZING MATERIALS. The iodine test serves to indicate the use of starch in the size, as it produces * Handbuch der Technisch-Chem. Untersuchungen, Gte Auf., p. 1006. 284 VEGETABLE TEXTILE FIBRES. the well-known blue color. Extraction of the paper with alcohol contain- ing a few drops of acetic acid serves to show the resin used in the size. The alcohol, after cooling, is poured into four or five times its bulk of water, when the resin separates, producing cloudiness or turbidity. Or, after ex- traction, the alcohol is evaporated, leaving the resin capable of being identi- fied by its properties. Notable quantities of alumina in the ash also point to the use of resinate of alumina as sizing material. According to Wurster, if between two sheets of paper which have been sized with resin is pressed paper moistened with tetramethylparaphenylen-diamine solution, a bluish- violet color is produced, while paper free from resin is not aifected. Boil- ing of the paper sample with distilled water, filtering, and adding a few drops of tannic acid solution will serve to show the presence of gelatine sizing. If present, a white curdy precipitate is formed on the addition of the tannic acid. 4. DETERMINATION OF THE NATURE OF THE COLORING MATERIAL. In deciding as to the presence of coloring matter, we must bear in mind the reactions of the commoner pigments used. Ultramarine is destroyed and decolorized on addition of acids ; Prussian blue is decolorized by heat- ing with alkalies ; indigo is decomposed by heating with chlorine or nitric acid ; smalt withstands the action of both acids and alkalies and remains in the ash as a blue glass ; the aniline colors are capable of extraction with alcohol as solvent. B. GUN-COTTON, PYROXYLINE, COLLODION, AND CELLULOID. I. Raw Materials. The basis of these preparations is the class of nitrates formed from cellu- lose by the action of nitric acid, either taken singly or admixed with strong sulphuric acid, or as developed by the action of sulphuric acid upon a nitrate. Using the doubled formula C 12 H 20 O 10 , we may note the following five stages of nitration : Hexanitrate, C 12 H 14 O 4 (NO 3 ) 6 (trinitro-cellulose, C 6 H 7 (NO 2 ) 3 O 5 , of other writers), is the true gun-cotton. It is formed by the action of a mixture of the strongest nitric acid (specific gravity 1.52) with two or three parts of concentrated sulphuric acid, in which the cotton is immersed for twenty- four hours at a temperature not exceeding 10 C. (56 F.). The hexa- nitrate so prepared is insoluble in alcohol, ether, or a mixture of both, in glacial acetic acid or in methyl alcohol. Acetone dissolves it very slowly. According to Eder, the mixtures of nitre and sulphuric acid do not give this nitrate. Pentanitrate, C 12 H 15 O 5 (NO 3 ) 5 . It is difficult, if not impossible, to pre- pare this nitrate in a state of purity by the direct action of the acid upon cellulose. The best method (that of Eder) is to dissolve gun-cotton (hexa- nitrate) in nitric acid at about 80 to 90 C. (176 to 194 F.) and then precipitate as pentanitrate by concentrated sulphuric acid after cooling to C. ; after mixing with a larger volume of water and washing the precipitate with water and then with alcohol, it is dissolved in ether-alcohol and again precipitated with water, when it is obtained pure. This nitrate is insoluble in alcohol, but dissolves readily in ether-alcohol and slightly in acetic acid. Strong potash solution converts this nitrate into the dinitrate, C 12 H 18 O 8 (NO 3 ) 2 . The tetraniirate and trinitrate (collodion pyroxyline) are generally formed together when cellulose is treated with a more dilute nitric acid and at a PROCESSES OF MANUFACTURE. 285 higher temperature and for a much shorter time (thirteen to twenty minutes) than in the formation of the hexanitrate. It is not possible to separate them, as they are soluble to the same extent in ether-alcohol, acetic ether, acetic acid, or wood-spirit. On treatment with concentrated nitric and sul- phuric acids, both the tri- and tet ran it rates are converted into pentanitrate and hexanitrate. Potash and ammonia convert them into dinitrate. The dinitrate, C 12 H 18 O 8 (NO 3 ) 2 , always results as the final product of the action of alkalies on the other nitrates, and also from the action of hot, somewhat dilute nitric acid upon cellulose. The dinitrate is very soluble in ether-alcohol, acetic ether, and in absolute alcohol. The chief raw material for the manufacture of these nitrates at present is the waste from cotton-spinning, which has already been freed from the impurities of the raw cotton. It is first picked clean by hand from admix- ture with foreign matter and then torn and opened up by machinery so as to fit it for easy action of the nitrating acids. It is then treated for a few minutes with boiling potash solution, thoroughly washed, and dried by steam. For the manufacture of celluloid a specially prepared and per- fectly pure tissue-paper is now used, which is torn into shreds by machinery preparatory to the nitrating. n. Processes of Manufacture. 1. GUN-COTTON. The following is the procedure at Waltham Abbey, where gun-cotton is made for the English government under Sir F. Abel's improved method. A mixture of fifty-five parts of nitric acid (1.516 specific gravity) and one hundred and sixty-five parts of sulphuric acid (1.842 specific gravity) is taken for one part of cotton. The nitrating mixture is placed in cast-iron vessels, cooled from without by flowing water, and the cotton immersed. It may either remain in these until ready for washing, or may after a brief immersion be transferred to smaller stone-ware vessels, similarly cooled, in which it then remains for twenty-four hours, for the double purpose of completing the nitration, so that the product shall con- tain a maximum of the highest, or hexanitrate, and of allowing the contents of the jar to cool down perfectly. The nitrated cotton is then centrifugated, stirred up thoroughly with cold water, again centrifugated, and then washed systematically with warm water to which some soda has been added. The gun-cotton so obtained may either be used in the loose form or, when de- signed for manufacture into cartridges, is beaten in a hollander after the manner of paper-pulp, and then washed and pressed in the desired forms. The gun-cotton when finished is usually preserved in a moist state, and dried only when needed for use. It, however, does not require to be sharply dried, as with fifteen to twenty per cent, of moisture it can be made to develop its full explosive powers. 2. PYROXYLINS AND COLLODION. Pyroxyline of various grades of solubility can be prepared according to the strength of acids used and length of immersion given the cotton. In general, the nitric acid taken is less con- centrated than that used for making gun-cotton, and a somewhat higher temperature is employed. Potassium or sodium nitrate is also used along with the sulphuric acid as the nitrating mixture, as the presence of nitrous acid in the nitric acid generated is considered as playing some part in the result. A mixture of twenty parts pulverized potassium nitrate with thirty-one parts of sulphuric acid of 1.835 specific gravity is given as a suit- 286 VEGETABLE TEXTILE FIBRES. able pyroxyline mixture. After the nitre has entirely dissolved in the sul- phuric acid and the mixture has fallen in temperature somewhat below 50 C. the cotton is put in, stirred around thoroughly, and then the vessel left covered for twenty-four hours at a temperature of from 28 to 30 C. The pyroxyline is then washed with cold water until it shows no acid re- action, and finally with boiling water to remove the last traces of potassium sulphate. A similar mixture, using sodium nitrate, is thirty-three parts of sulphuric acid of 1.80 specific gravity, seventeen parts of sodium nitrate, and one-half part cotton. A special grade of pyroxyline for the manufacture of collodion, put upon the market by the Schering factory in Berlin, is made by immersing cotton for fifteen minutes in a mixture of equal volumes of sulphuric acid of 1.845 specific gravity and nitric acid of 1.40 specific gravity, taken at a temperature of 80 C. The pyroxyline made from tissue-paper for the celluloid manufacturers MS made by taking fifty cubic centimetres of nitric acid of 1.47 specific gravity, one hundred cubic centimetres nitric acidfof 1.36 specific gravity, and one hundred cubic centimetres of sulphuric acifl of 1.84 specific gravity. In this mixture eighteen 'grammes of the finely^hredded tissue-paper are immersed at a temperature of 55 C. for one^hour. The paper gains about forty per cent, in weight in the nitratmn. The proportions of ether and alcohol used in dissolving pyroxyline to make collodion solutions vary very greatly. The United States Pharmaco- poeia prescribes for four parts of pyroxyline seventy parts of stronger ether and twenty-six parts of alcohol ; the British Pharmacopoeia takes for one ounce of pyroxyline thirty-six fluidounces of ether and twelve fluidounces of rectified spirit ; the German Pharmacopoeia takes one part of pyroxyline to twenty-one parts of ether and three parts of alcohol. 3. CELLULOID. The conversion of pyroxyline into celluloid is accom- plished by effecting a thorough incorporation with the former of a certain amount of camphor. This may, however, be done in a number of ways, several of which have been carried out in practice. First, it is possible to effect it by heat alone, without the use of any solvent for either the camphor or the pyroxyline. The camphor at the temperature of its fusion becomes a sufficient solvent for the pyroxyline to effect complete physical admixture. This process is essentially that used in this country. The weighed amount of camphor is added to the pyroxyline while the latter is still in a partially moist condition, some alcohol sprinkled upon the mixture to aid in the com- minution of the camphor, and the materials carefully ground together in closed drums. The mixture may now be put through heated rolls to effect the melting of the camphor and cause it to penetrate and take up the pyroxy- line in every part of the mass. It is then put through a heated masticating machine to complete the admixing and make the mass of uniform composi- tion throughout. Coloring matter is added when desired to the materials before the camphor takes up the pyroxyline, so that it may be thoroughly distributed or dissolved as the case may be. A solution of camphor in either ethyl or methyl alcohol has also been used as the means of converting the pyroxyline into celluloid. This may be either with the aid of heat or, if sufficient of the solvent be us3d, it may be carried out at ordinary temperatures. A solution of camphor in ether has also been used in the celluloid fac- tory of Magnus & Co. in Berlin. For fifty parts of pyroxyline is taken PRODUCTS. 287 twenty-five parts of camphor dissolved in one hundred parts of ether to which five parts of alcohol have been added. The mixture is covered up and stirred from time to time. A gelatinous and glutinous mass results, which must be rolled between calender rolls until it acquires plastic charac- ters. The process is distinctly more dangerous than the others mentioned, as the ether is all allowed to evaporate, and it does not yield anything better in the way of product. IE. Products. 1. GUN-COTTON. The explosive variety of gun-cotton, whether in the form of loose fibre or as compressed cartridge or paper sheets, cannot be readily told by outward characteristics from untreated cotton. Microscopi- cally it has not changed. It is on close examination seen to be not quite so white, a slight yellowish tint being recognizable ; it is slightly rougher to the touch, and crinkles slightly when pressed ; when rubbed it is easily electrified and sticks to the fingers. When lighted it burns quickly with- out smouldering or leaving any residue. When heated slowly it begins to decompose with evolution of acid fumes, and above 130 C. it explodes. It is therefore necessary to exercise great care in the drying of it, and espe- cially if all traces of acid have not been removed. It is much safer when wet than dry, although it is possible to explode it by concussion when it still contains from fifteen to twenty per cent, of water. Gun-cotton is insoluble in water, alcohol, ether, chloroform, and acetic acid, in dilute acids and alkalies. It is somewhat soluble in acetone and wood-spirit. Gun-cotton is chiefly used in submarine mines and blasting and for naval torpedoes. The combination of it with nitre-glycerine, known as blasting gelatine, has been referred to under another section. (See p. 72.) 2. PYROXYLINE. This in most physical characters resembles perfectly the explosive gun-cotton. The most important difference is the ready solu- bility of this variety of cellulose nitrate in a mixture of alcohol and ether, in which the true gun-cotton is insoluble. The ordinary pyroxyline is, moreover, only slightly explosive. When dissolved in the strength noted before (see preceding page) we obtain, 3. COLLODION. This is a colorless liquid, which rapidly evaporates on exposure to the air, leaving a transparent film of tetranitrate, or tetra- and trinitrate mixed, insoluble in water and alcohol. It is used as a dressing for wounds under the name of " liquid adhesive plaster," and very largely in photography as a means of covering tne photographic plates with a transparent film which shall hold finely divided and distributed the sensi- tive silver salt. 4. PYROXYLINE VARNISHES. In recent years a very important class of metal varnishes or lacquers have been introduced under trade-names, such as Zapon varnish, etc., in which pyroxyline is the basis. This is dis- solved in either methyl alcohol, acetone, methyl and amyl acetates, or mix- tures of these. Petroleum-naphtha is also added to these solvents to facili- tate the drying. These varnishes are of special value for fine metal-work in brass or bronze, as they leave a perfectly transparent and flexible film of pyroxyline, which protects the metal and will not crack or peel when properlv*applied. 5. CELLULOID. This valuable product of the action of camphor upon pyroxyline is prepared under a great variety of forms, both transparent and 288 VEGETABLE TEXTILE FIBRES. opaque, colored uniformly, or mottled and striated in imitation of ivory, coral, amber, tortoise-shell, agate, and other substances. It cannot be caused to explode by heat, friction, or percussion. When brought in contact with flame it burns like paper, and continues to smoulder after the flame is ex- tinguished, the camphor being distilled off* with production of thick smoke, while the nitro-cellulose undergoes incomplete combustion. Celluloid dissolves in warm, moderately concentrated sulphuric acid, but is carbonized by the strong acid. It is readily soluble in glacial acetic acid, and on diluting the solution with water both camphor and pyroxyline are reprecipitated. It is rapidly soluble in warm, moderately concentrated nitric acid (four volumes of fuming acid to three of water), and is also dissolved with ease by a hot concentrated solution of caustic soda. Ether dissolves out the camphor from celluloid, and wood-spirit behaves similarly. Ether- alcohol (3:1) dissolves both the nitro-cellulose and camphor, leaving the coloring and inert matters as a residue. The density of celluloid ranges from 1.310 to 1.393. When heated to 125 0., it becomes plastic and can be moulded into any desired shapes. Separate pieces can also be welded together by simple pressure when at this temperature. The celluloid is easily cemented to wood, leather, etc., by the use of collodion or a solution of shellac and camphor in alcohol. IV. Analytical Tests and Methods. Pure hexanitrate of cellulose will keep indefinitely, but the presence of free acid, of lower nitrates, or of fatty and waxy matters render it more or less unstable, and therefore unsafe. The most important determinations to make are the examination for free acid and for lower nitrates, and the valua- tion by means of the estimation of NO 2 liberated from any sample. 1. EXAMINATION FOR FREE ACID. This may be detected by treating twenty grammes' weight of the gun-cotton with fifty cubic centimetres of cold water. After twelve hours the water may be pressed out, filtered, and twenty-five cubic centimetres titrated with decinormal caustic alkali. With the remainder of the liquid the nature of the acid, whether sulphuric or nitric, may be ascertained by the usual tests. 2. EXAMINATION FOR LOWER NITRATES. These may be detected if present by treating five grammes of the sample, previously dried at 100 C., with one hundred cubic centimetres of a mixture of three parts of ether and one of alcohol. The mixture is shaken frequently during twelve hours, and then rapidly filtered through loosely-packed glass-wool, the filtrate evapo- rated at a gentle heat, and the residue weighed. 3. EXAMINATION FOR UNALTERED CELLULOSE. This may be esti- mated by treating the gun-cotton left undissolved by the ether-alcohol with acetic ether, which dissolves the hexanitrate and leaves the unchanged cot- ton. An alternative plan is to prepare a solution of sodium stannite by- adding caustic soda to a solution of stannous chloride until the precipi- tate at first formed is just redissolved. This solution when boiled with gun-cotton dissolves the cellulose nitrates without affecting the unchanged cellulose. 4. VALUATION BY DETERMINATION OF NO 2 . The nitrogen peroxide contained in gun-cotton and similar nitrated products is frequently deter- mined by the aid of the reaction of sulphuric acid and mercury upon the nitrates as carried out in a Lunge's nitrometer. This is a burette provided BIBLIOGRAPHY AND STATISTICS. 289 at the one end with stopcock and funnel-tube and narrowed at the other end, which is connected by a stout piece of rubber tubing with a simple gradu- ated burette-tube. The burette with the stopcock is filled with mercury through the rubber connection with the other tube and the stopcock closed. .35 gramme of gun-cotton, dissolved in five cubic centimetres of concen- trated sulphuric acid, are then put into the funnel-tube, and by opening the stopcock and lowering slightly the connecting burette are drawn into the stoppered tube, washed out of the funnel with a little additional pure sul- phuric acid, and the stopcock closed. The tube is then shaken vigorously until the reaction is complete and the volume of gas no longer increases. It is then allowed to attain constant temperature and the volume read oif with correction for temperature and pressure. Allen (Commercial Organic Anal- ysis, 2d ed., vol. i. p. 328) recommends that the volume be compared with that yielded by a standard sample or a nitre solution. V. Bibliography and Statistics. BIBLIOGKAPHY. 1862. Die chemische Technologie der Spinnfasern, P. Bolley, Braunschweig. 1864. Fibrous Substances, Indigenous and Exotic, S. C. Swab, London. 1867. Einleitung in die technische Microscopic, J. Wiesner. 1873. Die Gespinnstfasern, R. Schlesinger, Zurich. Die Rohstoffe der Pflanzenreiches, J. Wiesner, Vienna. Die Pflanzenfasern, Hugo Miiller, Leipzig. 1874. Etude sur le Travail des Lins, A. Renouard, Paris. 1876. Etudes sur les Fibres vegetales textiles, M. Vetillard, Paris. 1877. Die Pflanzenfasern, Hugo Miiller (and Hofmann's Entwickelung der Chem. Ind.), Braunschweig. Die Fabrikation des Papiers, L. Miiller, Berlin. 1880. Das Celluloid, F. Bockmann, Vienna. 1881. Matieres premieres organiques, G. Pennetier, Paris. Practical Treatise on the Manufacture of Paper, C. Hofmann, Philadelphia. Die Gewinnung der Gespinnstfasern, H. Richard, Braunschweig. 1882. Structure of the Cotton Fibre, F. Bowman, Manchester. The Manufacture of Paper, Charles T. Davis, Philadelphia. Chevallier's Dictionnaire des Falsifications, Baudrimont, Paris. " Etude sur les Textiles tropicaux, A. Renouard, Lille. 1884. Ueber pflanzliche Faserstoffe, F. von Hohnel, Vienna. Ramie, Rhea, Chinagras und Nesselfaser, Bouche und Grothe, Berlin. Cotton-Spinning, R. Marsden, London. 1885. The Dyeing of Textile Fabrics, J. J. Hummel, London. 1886. Handbuch der Papierfabrikation, S. Mierzinski, Vienna. 1887. Report on Indian Fibres and Fibrous Substances, Cross and Bevan, London. Die microskopische Untersuchung des Papiers, J. Wiesner, Leipzig. Die Fabrikation des Papiers, Egbert Hoyer, Braunschweig. Microscopie der Faserstoffe, F. von Hohnel, Vienna. 1888. A Text-Book on Paper-Making, Cross and Bevan, London. Die chemische Technologie der Gespinnstfasern, Otto Witt, Braunschweig. 1890. Report on Flax, Hemp, Ramie, etc., United States Department of Agriculture, Washington, D.C. The Cotton Fibre, its Structure, etc., Hugh Monie, Jr., Manchester. The Art of Paper-Making, Alex. Watt, London. STATISTICS. 4 Cotton. The cotton crop of the United States, the average weight per bale, and the aggregate gross weight of the crop for the last ten years have been as follows : 19 290 VEGETABLE TEXTILE FIBRES. Bales. 1880-81 6,589,329 1881-82 5,435,845 1882-83 6,992,234 1883-84 6,714,052 1884-85 5,699,021 1885-86 5,550,215 1886-87 6,613,623 1887-88 7,017,707 1888-89 6,935,082 1889-90 7,311,322 Weight per bale. 485.88 475.67 490.62 482.86 481.21 485.40 486.02 485.35 495.79 492.52 Aggregate weight in pounds. 3,201,546,730 2,585,686,378 3,430,546,794 2,759,047,941 2,727,967,317 3,179,456,091 3,165,745,081 3,406,068,167 3,437,408,499 3,600,972,311 The exportations of unmanufactured cotton from the United States for the last three years have been : 1888. 1889. 1890. Bales 4,664,924 4,872,060 5,020,913 Pounds 2,264,120,826 2,384,816,669 2,471,799,853 The exportations of cotton from India for the past three seasons are stated to have been as follows: For 1887-88, 5,374,542 hundred-weight; for 1888-89, 5,331,536 hundred-weight; for 1889-90, 6,325,898 hundred- weight, of which England takes about one-third. The European importa- tions of cotton for 1 889-90 are estimated to have been as follows : Bales. Pounds per bale. Total in pounds. American 4,800,000 X 470 = 2,256,000,000 East Indian 1,640,000 X 396 = 649,000,000 Egyptian 420,000 X 679 = 285,180,000 Smyrna, etc 40,000 X 350 = 14,000,000 Brazil, West Indies 250,000 x 185 = 46,250,000 7,150,000 X 454J = 3,250,870,000 Flax. The area under flax cultivation and gross produce of various European countries, according to a report made to the Irish Flax Supply Association in 1878, was: Acreage. Austria 253,323 Belgium 140,901 Denmark .... 17,686 Egypt 15,000 France 194,571 Germany .... 530,642 Great Britain . . . 7,481 Greece .... 957 Tons. 34,009 29,580 2,211 1,875 Holland . . . Hungary . . . Ireland . . . . Italy 42,368 74,621 1,333 119 Kussia . . . . Sweden . . . . Acreage. 48,027 19,903 123,362 201,023 1,928,568 37,500 Tons. 9,536 2,488 22,159 221,791 241,071 4,688 3,518,944 488,849 These figures have been largely increased in the last twelve years. Ac- cording to a United States consular report from Odessa (United States Con- sular Reports, March, 1891, p. 365), the total area sown in Europe with flax amounted to 5,700,000 acres, of which Russia alone had 3,700,000 acres. The total quantity of flax fibre produced in Europe is there given as follows : Pounds. Kussia 900,000,000 Autro-Hungary .... 104,400,000 Germany 97,200,000 France 79,200,000 Ireland 46,800,000 Belgium . . . . , Italy All other countries Pounds. 43,200,000 43,200,000 36,000,000 1,350,000,000 BIBLIOGRAPHY AND STATISTICS. 291 Importations of Vegetable Fibres. The importations of unmanufactured vegetable fibres into the United States during the last three years have been as follows : 1888. 1889. 1890. Flax (tons) 5,691 7,896 8,048 Valued at $1,802,089 $2,070,729 $2,188,021 Hemp and substitutes (tons) . 47,947 55,835 36,591 Valued at $6,934,837 $9,433,774 $7,341,956 Jute (tons) 115,163 88,655 90,399 Valued at $3,377,369 $2,853,664 $3,249,926 Sisal-grass, etc. (tons) .... 36,401 38,542 58,858 Valued at $5,430,894 $6,110,308 $7,064,184 Paper-making Materials. The importations of paper stock for the last three years have amounted in value, according to the United States Bureau of Statistics, to : 1888. 1889. 1890. Rags other than woollen . . . $2,033,022 $2,552,851 $2,530,611 All other stock 3,429,234 3,372,196 2,730,837 Total $5,462,256 $5,925,047 $5,261,448 The exportation of mechanical wood-pulp from Norway rose in 1889 to 200,000 tons from 100,000 tons in 1885, while that of chemical pulp was estimated at 35,000 tons against 24,000 tons in 1888. The aggregate value of the pulp exported in 1889 was estimated at $3,210,000. (United States Consular Reports, November, 1890.) The English importations of paper- making materials during the last few years have been as follows : 1888. 1889. 1890. Linen rags (tons) 41,404 42,470 34,889 Valued at 470,883 426,614 304,306 Esparto, etc. (tons) 247,936 215,723 217,048 Valued at 1,265,815 1,083,518 1,045,742 Wood-pulp (tons) 110,040 121,534 137,837 Valued at 677,866 688,571 766,742 According to " Bradstreet's" for November 29, 1890, the American out- put of wood-pulp has more than trebled within the past ten years. There are now 210 factories engaged in its manufacture 183 producing it by the me- chanical process, 15 by the soda, and 12 by the sulphite methods. For the nine months ending September 30, 1890, the imports of wood-pulp amounted in value to $1,182,193; for the same period of the preceding year it was but $497,404, or about two-fifths as large. 292 TEXTILE FIBRES OF ANIMAL ORIGIN. CHAPTER IX. TEXTILE FIBRES OF ANIMAL ORIGIN. As before stated, the only animal fibres that have acquired technical importance are the wool fibre and silk. These will now be considered. I. Raw Materials. A. WOOL. Wool is undoubtedly a variety of hair, found in greater or less quantity on almost all mammals, on a few of which, as the domestic sheep, it forms the principal covering of the body. It is probable that while both hair and wool occur together in wild sheep, domestication has gradually caused the rank hairy fibres to disappear and the soft under-wool to develop until the fleece of wool becomes a thick and complete covering. From ordinary hair the wool is distinguished by two important properties : First, while hair is almost smooth on the surface, the wool fibre is covered by minute overlapping scales arranged like roof-tiles. While these scales are so minute as not to be discernible to the eye, they can be felt if a woollen fibre is drawn between the fingers in the direction opposite to that in which the scales are set. FIG. 92. Secondly, while a hair is per- fectly straight, the woollen fibre is finely crimped or curled, so that it becomes longer when drawn out and shortens again when the strain is removed. The spring due to this curled structure gives woollen fabrics notable elasticity. Owing to the overlapping scale-like struc- ture and the crimped condition of the fibre, wool has also the power of felting, or becoming matted into a compact cloth under the fulling process with- out the necessity of weaving. These structural characters of the wool fibre are shown in Fig. 92. Sheep's wool varies from the long straight coarse hair of certain varieties of the English sheep's wool ( 3 f). sheep (Leicester, Lincolnshire, etc.) to the comparatively short wavy fine soft wool of the Spanish and Saxon Electoral sheep. According to the average length of the fibres or staples two principal classes of wool are established, the long-stapled (eighteen to twenty-three centimetres) and KAW MATERIALS. 293 the short-stapled wools (two and five-tenths to four centimetres). The former class have hitherto been combed and then spun into worsted yarn, while the latter have been carded and spun, yielding woollen yarns. These processes will be referred to again later. (See p. 300.) In general the long straight wools, like Lincoln and Leicester wools, possess a silky lustre, and are known as lustre wools, while the Merino, Colonial, etc., which are shorter and curly, are known as non-lustre wools. The worth of any grade of wool is determined by noting such proper- ties as softness, fineness, length of staple, waviness, lustre, strength, elas- ticity, flexibility, color, and the facility with which it can be dyed. Wool is very hygroscopic. In warm dry weather it may contain eight to twelve per cent, moisture, but if kept for a time in a damp atmosphere it may take up thirty to fifty per cent. This becomes an important item in the sale of wool, and hence in France and Germany the percentage of moisture con- tained in wool to be sold must be officially determined in " wool-condition- ing" establishments. (See silk-conditioning, p. 299.) The legal amount of moisture allowed on the Continent is 18.25 per cent. The best kind of wool is colorless, but inferior grades are often yellow- ish, and sometimes even brown or black in color. , The chemical composition of the wool fibre is, as already noted (see p. 262), nitrogenous, but we must at the same time distinguish between the true fibre and the encrusting matters. These latter, independent of me- chanically adhering impurities or "dirt," are of twofold character, the "wool-fat" (soluble in ether) and the "wool-perspiration" (soluble in water). These two are frequently included together under the name of the " yolk" or " suint" of the wool. The true wool fibre, when cleansed from these, has approximately the following composition : Carbon, 49.25 per cent. ; hydrogen, 7.57 per cent.; oxygen, 23.66 per cent.; nitrogen, 15.86 per cent. ; sulphur, 3.66 per cent. The presence of sulphur is very distinctive of wool and serves to distinguish it from silk, the other nitrogenous fibre. It can be removed in large part, but not without weakening the fibre and destroying its lustre, etc. Wool-fat is a mixture of a solid alcoholic body, cholesterine, together with isocholesterine and the compounds of these bodies with several of the fatty acids. These free higher alcohols are soluble in boiling ethyl alcohol, while the compounds they form with the fatty acids are insoluble in alcohol but soluble in ether. Wool-perspiration has been shown to consist essentially of the potassium salts of oleic and stearic acids, possibly other fixed fatty acids, also potas- sium salts of volatile acids, like acetic and valerianic acid, and small quan- tities of chlorides, phosphates, and sulphates. The wash-water of raw or greasy wool, it will be seen, therefore, would contain large amounts of potash salts, and when evaporated and ignited would yield an abundant product of potassium carbonate. This utilization of the wool wash-water as carried out at present in France and Belgium yields over one million kilos, of potassium carbonate. Another utilization of this yolk of wool is to submit it to dry distillation, when it yields a residue which is an ex- tremely intimate mixture of carbonate of potash and nitrogenous carbon, of great value for the manufacture of yellow prussiate of potash. Wool is decomposed by heat at 130 C., ammoniacal vapors are given off, and at 140 to 150 C. sulphur compounds are also present in the vapors. When ignited by a flame, wool emits the disagreeable odor of 294 TEXTILE FIBRES OF ANIMAL ORIGIN. burnt feathers and leaves a porous caked residue. Ammoniacal solution of cupric hydrate has no action upon wool in the cold, but dissolves it when hot. Dilute solutions of hydrochloric and sulphuric acids have little in- fluence whether hot or cold. This fact is availed of in separating cotton from wool in the process of " carbonizing" mixed cotton and woollen goods. The dilute sulphuric acid used attacks and disintegrates the cotton. They are then dried in closed chambers at 110 C., after which the disorganized cotton can be beaten out, while the wool remains but slightly altered. Nitric acid does not attack the wool seriously, but gives it a yellow color, hence sometimes used as a " stripping" agent for dyed woollen goods in case of re-dying. Sulphurous acid is the most satisfactory bleaching agent for woollens, as it removes the natural yellow tint of the ordinary wool. Caustic alkalies act rapidly and injuriously upon wool. Alkaline carbonates and soap have little or no injurious action if not too concentrated and if the temperature is not above 50 C. Chlorine and hypochlorites act injuri- ously upon wool and cannot be used for bleaching. A very slight action of chlorine, on the other hand, causes wool to assume a yellowish tint and gives it an increased affinity for many coloring matters. Closely related to sheep's wool are a few varieties of animal hair, which are also utilized in some degree as textile fibres in similar classes of goods. Mohair is the product of the Angora goat of Asia Minor and Cape Col- ony, South Africa. It is a long silky hair, which is very soft and lustrous. Cashmere consists of the soft under-wool which grows in winter on the Cashmere goat. It furnishes the material for the costly Cashmere shawls of native manufacture, but is not exported at all as fibre. Alpaca, Vicuna, Llama, and Guanaco are the names of four closely- related species of South American goats found on the western slopes of the Andes, which yield valuable hair-like fibres. Of these, the alpaca is exported in largest amount to Europe and the United States. It is a long silky fibre somewhat intermediate be- tween true wool and hair and possessing a strong lustre. It is both white and of various colors. It is shown in Fig. 93. CameVs Hair is somewhat used in Africa, Asia Minor, and the Caucasus, and latterly in Europe, for the manufacture of woven goods, which are made from the unbleached hair. B. SILK. The silk fibre is, morphologi- cally, the simplest and at the same time, because of its properties, the most perfect of the textile fibres. It differs frorn all other fibres in that it is found in nature as a continuous fine thread, so that the process of spinning is superfluous in its case. In place of this we have the reeling process, whereby several of the natural threads are united into one thicker and stronger thread. Silk is the product of the silk-worm (om- byx mori) and is simply the fibre which the worm spins around itself for protection when entering the pupa or chrysalis state. From the eggs laid by the animal in the moth or butterfly state develops the cater- FIG. 93. Alpaca goat's hair (*f ). RAW MATERIALS. 295 pillar or silk-worm. The eggs are yellowish in color at first, changing to OTUV when dry. They are very light in weight, some thirteen hundred and fifty together weighing one gramme. For the development of the cater- pillar from them a certain amount of warmth and moisture is necessary, the temperature being raised in the incubation chamber during ten or twelve days from 18 to 25 C. The young worms are at once removed to larger chambers, where are lath frame-works strung across with threads and sheets of paper. The animals are placed upon these, and fed regularly during thirty to thirty-three days, till indeed they begin to spin. They are hera fed upon mulberry leaves (M&rus alba], and during this period increase enormously in size, becoming at length about eight to ten centimetres long and about five grammes in weight. To allow of this increase in size it casts its skin some four times during this period (at intervals of from four to six days). When about the thirtieth day of its growth has been reached it ceases to take food and shows a decided restlessness. It is then placed on birch-twigs, and soon begins to spin. This spinning of the cocoon, or oval-shaped house in which the worm is to undergo the chrysalis state before emerging as the butterfly, in- volves the secretion of the fibre FIG. 95. so much prized as silk. The silk substance is secreted by two glands, one on either side of the body of the caterpillar. The substance from these two glands unites in a capillary canal situated in the head of the animal, whence issues the silk as a double fibre only FIG. 94. Silk fibre ( 3 5). rarely separated, cemented throughout by the sericin, or silk-glue. The microscopical appearance of the silk fibre is shown in Fig. 94. This fibre 296 TEXTILE FIBRES OF ANIMAL ORIGIN. which goes to form the cocoon varies in length from three hundred and fifty to twelve hundred and fifty metres, and with a diameter of about .018 millimetre in diameter. The interlacing layers of the silk cocoon are at first loose, but become finer and denser towards the interior, while the inner- most layer which immediately surrounds the animal forms a thin parch- ment-like skin. The several stages of cocoon-spinning are shown in Fig. 95. The cocoons of the female are pure oval in shape, while those of the male are distinctly contracted in the centre. They are white or yellowish, and usually about three centimetres long and one and one-half to two centi- metres thick. Some seven or eight days are allowed for the completion of the cocoon-spinning, and they are then gathered. A sufficient number of both males and females are taken for breeding purposes, and the rest put aside to be reeled for silk. Those chosen for breeding are kept for some twenty days at a temperature of from 19 to 20 C., when the silk-moth which has formed in the interior from the pupa emits a peculiar saliva, which softens the sericin, or silk-glue, at one end of the cocoon and enables the animal to push its way out to daylight. The females within forty hours after their appearance lay their eggs, some four hundred in number, and shortly after die. The eggs are slowly dried, and stored in glass bottles in a dry dark place till the following spring. The cocoons put aside for the reeling of silk must be taken in hand promptly and the chrysalis contained in them killed, in order to prevent the development of the silk-moth and the injury to the cocoon by its pushing its way out. This is done either by heating them for several hours in an oven at 60 to 70 C., or more quickly by steam heat. One hundred grammes of eggs produce under favorable conditions from ninety thousand to one hundred and seventeen thousand cocoons, weighing one hundred and fifty to two hundred kilos., and these yield twelve to sixteen kilos, of reeled silk. The silk fibre consists to the extent of rather more than half its weight of fibroin, C^H^^Og, a nitrogenous principle. Covering this is the silk- glue, or sericin, CuH^NjOg. Whether this latter exists in the glands of the silk- worm along with the fibroin, as maintained by Duseigneur-Kleber, or is produced exclusively by atmospheric change from the fibroin as asserted by Bolley, is still in debate. This sericin, however, is easily dissolved off from the fibroin by warm soap- water and other alkaline liquids. This " boiled-off " liquid plays an important part in silk-dyeing operations. (See p. 466.) The most important physical properties of the silk fibre are its lustre, strength, and avidity for moisture. The regu- lation of the amount of moisture contained in raw silk as offered for sale, or " silk-conditioning," will be spoken of under the process of treatment. (See p. 298.) Besides the true silk, the product of Bombyx mori, we have several so-called " wild silks," the most important of which is the Tussur silk, the product of the larva of the moth Anthercea mylitta, found in India. The cocoons are much larger than those of the true silk-worm, egg- shaped, and of a silvery drab color. They are also attached to the twigs of the food trees by a thread-like prolongation of the cocoon. The cocoon is very firm and hard, and the silk is of a drab color. It is used for the buff-colored Indian silks, and latterly largely in the manufacture of silk plush. Other wild silks are the Eria silk of India, the Muff a silk of Assam, the Atlas or Fagura silk of China, and the Yama-mai silk of Japan. PROCESSES OF MANUFACTURE. 297 n. Processes of Manufacture. It will be beyond the province of this work to take up the manufacture of woollen and silk goods from the mechanical side. Hence we shall only notice the preliminary processes of chemical treatment which the fibres undergo to prepare them for manufacture into goods, and then take up the several classes of manufactured textiles again in speaking of bleaching and dyeing of goods. A. WOOL. 1. Wool-scouring. The condition of the raw wool when first obtained from the back of the sheep has already been referred to. The fibre is covered with both natural and artificial impurities (yolk, dirt, etc.) to such an extent that mordanting and dyeing would be almost impossible. These are therefore to be removed by the process of scouring. It will be remembered, too, that the yolk was stated to be made up of the wool-fat (soluble in alcohol) and the wool-perspiration (soluble in water). Both of these have to be removed in the completed scouring operation. The full operation then must include three stages, viz., steeping, or washing with water (desuhiiage) ; cleansing or scouring proper with weak alkaline solu- tions (degraissage) ; rinsing or final washing with water (rinqage). The first operation may be omitted if the wool has been washed by the wool- grower. This is true, for instance, with Australian wools, while, on the other hand, most South American wools come into commerce unwashed and very rich in yolk. The washing of these wools is largely carried on in France and Belgium, and, as has been stated (see p. 293), is made to yield large amounts of potassium carbonate by evaporating and igniting the wash- waters. The wool is systematically washed in tepid water (about 45 C.) in a series of tanks arranged so that the water passes from one to the other until completely saturated, when it is evaporated. According to M. Chan- delon, one thousand kilos, of raw wool may furnish three hundred and thirteen litres of yolk solution of specific gravity 1.25 (50 Tw.), having a value of fifteen shillings and sixpence, while the cost of extraction does not exceed two shillings and sixpence. The scouring and washing processes for loose wool are usually carried out in the well-known rake scour ing-machines, consisting of a large cast- iron trough provided with an ingenious system of forks or rakes whereby the wool is gradually passed forward by the to-and-fro digging motion of the rakes. Two or three such scouring-machines are placed in series, so that the first may take the bulk of the impurities, the second complete the scouring, and the third effect a thorough washing in a stream of fresh water. The scouring liquid which has been longest in use is stale urine (hint), which is effective because of the ammonium carbonate it contains. It is now largely supplanted by ammonia, sodium carbonate, soaps, etc. The most injurious effects arise from the use of water containing lime or mag- nesia, because of the formation of the insoluble lime or magnesia compounds upon the fibre. In recent years volatile solvents, like fusel oil, ether, petro- leum-naphtha, carbon disulphide, have also been introduced for scouring purposes, although not generally in favor on account of the expense and risk attending their use. They must be followed at all events by a washing with water, as, -while they dissolve fatty matters, they do not take up the oleates, etc., of the wool-perspiration. Woollen yarns and woollen cloth are also scoured to free them from the 298 TEXTILE FIBRES OF ANIMAL ORIGIN. oil which has either purposely or by accident been put upon them in the spinning and weaving operations. The scouring of " union" goods that is, materials with cotton warp and woollen weft is a more difficult opera- tion on account of the differences in elasticity, hygroscopic character, etc., of the cotton and the wool fibre. It includes the operations of crabbing, steam- ing, and scouring. 2. Bleaching of Wool. Wool is generally bleached either as yarn or cloth. The bleaching agent in general use is sulphur dioxide. It may of course be applied either as gas or as sulphurous acid solution, the former method being generally followed, and the yarn or cloth suspended on poles in closed chambers, called sulphur-stoves, which can be charged with the gas. In liquid bleaching with sulphurous acid, a solution of sodium bisul- phite is generally used, which is either mixed with an equivalent amount of hydrochloric acid or, what is better, the goods are passed through one solu- tion after the other in separate baths. The bleaching of sulphur dioxide differs essentially from that effected by chlorine and hypochlorites in that it is not due to oxidation, but to reduction or possibly to the formation of color- less compounds with the natural yellow color of the wool. At all events, it is not permanent in character, and the yellow color gradually returns on ex- posure to atmospheric influences and repeated washings in alkaline solutions. The best liquid bleaching agent is hydrogen dioxide. The woollen mate- rial is steeped for several hours in a dilute and slightly alkaline solution of the commercial H 2 O 2 and then well washed, first with water acidified with sulphuric acid and afterwards with pure water. B. SILK. 1 . Reeling o/Silk.-^The unwinding of the long silk fibre from the cocoon and bringing it into condition for weaving is to be accomplished in the reeling process. The cocoons are thrown into a basin of warm water to soften the silk-glue and allow of the fibres being separated. From four to eighteen fibres, according to the quality, are taken, and two threads formed by passing the fibres together through two perforated agate guides. After being crossed or twisted together at a given point they are again separated and passed through a second pair of guides, thence through the distrib- uting guides on to the reel. The temporary twisting or crossing causes the agglutination of the individual fibres of each thread. In order to form long threads a frequent adding on the fibre of a new cocoon is necessary. Care must be taken, also, that the thread remain as nearly as possible of uni- form thickness, so that as the inner fine fibres of several cocoons come through the guides another cocoon is added to the number used for the thread. One cocoon gives .16 to .20 or at most .25 gramme of raw silk. The loss through removal of the external floss varies from eighteen to thirty per cent., according to the cocoons and the care bestowed by the worker. Before this raw silk can be used for weaving two of the threads are " thrown" together and slightly twisted. 2. Silk-conditioning. Raw silk kept in a humid atmosphere is capable of absorbing thirty per cent, of its weight of moisture without this being at all perceptible. It therefore becomes a matter of great importance for the buyer to know what weight of normal silk there is in any given lot. To ascertain this with accuracy, there have been established in a number of the European centres of silk industry conditioning establishments. The operation is carried out by means of the apparatus shown in Fig. 96, where a number of hanks of silk are shown in the drying chamber. A test hank of silk is taken from the bale, and having been suspended from the one arm PROCESSES OF MANUFACTURE. 299 FIG. 96. of an accurate balance its initial weight is gotten. It is then dried in a cur- rent of air at 110 C. until constant weight is again obtained. The arrange- ment of the drying chamber is shown in the illustration. To the final weight ob- tained for the dry silk eleven per cent, is added, and the result taken as a normal silk weight. The average loss of weight in this conditioning process is about twelve per cent. 3. Silk-scouring. By the scouring of silk the silk-glue is removed to a greater or less extent and the fibre is rendered lustrous and soft and able to take the dye-color. According to the amount of silk-glue removed in this operation the product is called boiled-off silk, souple silk, or tcru. In the first case, the loss of silk-glue amounts to twenty-five to thirty per cent, of the weight of the raw silk ; in the second, to eight to twelve per cent. ; and in the third to three to four per cent, of the original weight of the silk. In preparing the first variety two operations are neces- sary, stripping or ungumming (degom- mage) and boiling off. The hanks of raw silk are suspended by wooden rods in a rectangular trough lined with copper and worked by hand in a thirty to thirty-five per cent, soap solution heated to 90 to 95 C. When the water is very hard it must be corrected or softened previously. Frequently two soap-baths are used one after the other as the first one becomes charged with the silk- glue. The silk at first swells up and becomes glutinous, but as the glue dissolves off it becomes soft and silky. The waste soapy and glutinous liquid obtained is called "boiled-off" liquor, and is a useful addition to the dye-bath in dyeing with coal-tar colors. (See p. 466.) For the pur- pose of removing the last portions of the silk-glue, it is now washed in water at 60 C., to which some soap and carbonate of soda have been added, then put in coarse hempen bags called " pockets" and boiled for half an hour to three hours, according to quality, in open copper vessels with a so- lution of ten to fifteen per cent, of soap. It is then rinsed with a weak tepid solution of sodium carbonate, and finally washed in cold water. Silk intended to remain white or to be dyed pale colors is then at once bleached while moist with gaseous sulphur dioxide for some six hours. The bleach- ing operation may be repeated from two to three times, according to the quality of the silk. Souple silk is that which has been prepared for dyeing w r ith a loss of not more than eight per cent, of its weight. It is, however, not so strong as boiled-off silk, and is used only for tram. Its preparation always in- cludes two operations, and if the silk is to be dyed light colors, 'two addi- tional operations have to be carried out. The raw silk is first " softened/' and the small quantity of fatty matter present removed (degraissage) by 300 TEXTILE FIBRES OF ANIMAL ORIGIN. working it from one to two hours in a ten per cent, soap solution at 25 to 35 C. It is then " bleached" by immersion for ten to fifteen minutes in a dilute solution of aqua regia (five parts hydrochloric acid to one part nitric), or as a substitute for this nitrated sulphuric acid (nitrosyl-sul- phate). This is followed by " stoving," or treatment with sulphur dioxide, and then, without removing the sulphurous acid, by the treatment of sou- pling (ussouplissaye] proper. This consists in working the silk for about an hour and a half at 90 to 100 C. in water containing three to four grammes cream of tartar to the litre. This treatment makes the silk softer and causes it to swell up and become more absorbent. It is then finally washed in tepid water. ficru silk is raw silk which has been washed with hot water, with or without soap, bleached with sulphur, and again washed. It is only used for a base for other silk fabrics like velvet or dyed in blacks. ITJ. Products. A. WOOL. We have already alluded to the distinction between worsted and woollen yarns. Formerly all long-stapled wools were combed, that is, the fibres were brought as nearly as possible parallel to one another and were then spun into what was known as worsted yarn, used in hosiery and in the manufacture of fabrics which did not undergo fulling. All short- stapled wools, on the other hand, were carded and spun much as cotton is spun, and the yarns so obtained were the only ones capable of being used in making milled or fulled cloths, in which the felting property of wool is availed of to thicken the cloth after weaving and in which by teasels the nap of the cloth is raised so as to present a uniform surface. All kinds of wool, therefore, were formerly divided into combing and carding or cloth- ing wools. Machines have been invented latterly, however, capable of combing wools having as short a staple as one inch, and, on the other hand, wools with a staple as much as five inches long may be used in making milled cloth. So the distinction between the several wools is no longer as absolute as it once was. Among the chief kinds of worsted fabrics are serges and merinos and mixed goods of wool and mohair, alpaca, and camel's hair. Hosiery and carpets also belong here, although the best of these latter are made on a ground of strong linen or hemp. The principal varieties of woollen cloth are broadcloths, the finest variety of woollen cloth, cashmeres, a fine thin twilled fabric, tweeds, fabrics of looser texture than broadcloth and less highly milled, doeskin, a strong twilled cloth, blankets, flannels, etc. Shoddy is a material made from fragments of cast-off woollen clothing torn into fibres and re-spun into yarn. It is looser in texture than mungo, which is made from remains of finer fragments, such as old dress-coats, tailor's clippings, etc. A third grade of recovered wool, sometimes called extract wool, is ob- tained from union goods (mixed woollen and cotton goods) by the process of carbonizing the vegetable fibre and then beating it out. The carbonizing is done with dilute sulphuric acid, with aluminum chloride, or with gaseous hydrochloric acid. The last process is said to give the best results. B. SILK. The raw-silk threads obtained in the reeling process are not sufficiently strong for use in the loom, so several must be united. This may be done in different ways. By the union of two or more single threads, ANALYTICAL TESTS AND METHODS. 301 separately twisted in the same direction, which are then doubled and retwisted in the opposite direction, is obtained organzine. The best grades of silk are also taken for the organzine, which is to form the warp in silk- weaving. The product of the union of two or more simple untwisted threads which are then doubled and singly twisted is tram, which forms the weft in weaving. Waste silk is that which proceeds from perforated and double cocoons and such as are soiled in steaming or in any other way. This waste silk is washed, boiled with soap, and dried. When carded and spun like cotton it yields the so-called flurt-silk. Satins are tissues so woven that almost the only threads appearing on the right side of the tissue are weft threads, which present a uniform glossy surface. Velvets are tissues in which the outer surface presents to view a short soft pile, made by passing the warp threads over fine wires, which are after- wards drawn out. The loops then remaining are either left as they are, in which case the tissue is called pile-velvet, or cut to form cut-velvet. This fabric is now largely imitated in cotton and mixed tissues. IV. Analytical Tests and Methods. 1. GENERAL DISTINCTIONS BETWEEN VEGETABLE AND ANIMAL FIBRES. A general scheme for distinguishing between the several classes of fibres has been proposed by R. Schlesinger in his " Leitfaden fur die mikroskopische und mikrochemische Analyse der technisch verwendeten Rohstoffe der Textil-Industrie." It is in outline as follows : TREAT WITH CAUSTIC SODA. The fibre does not dissolve in ten per cent, caustic soda solution, and in burning, which takes place readily, does not develop any burnt horn odor. Vegetable fibres. The fibre dissolves in concen- trated caustic soda, and when treated with ammo- niacal cupric oxide shows scales upon its surface. Animal hairs or wool. The fibre does not dissolve in cold ten per cent, caustic soda, but dissolves per- fectly in concentrated sul- phuric acid ; shows neither scales nor medullary sub- stance. Silks. The vegetable fibres are then to be studied by the aid of the iodine and dilute sul- phuric acid reaction, and the several groups already noted in the classification on p. 263 are established. The animal hairs are to be distinguished best by the microscopical characters and measurements. The several varieties of silk are also to be distinguished by a comparison of the diame- ters of the fibre as measured under the microscope. Several of the simpler differences between the vegetable and the animal fibres as groups have already been alluded to in classifying the fibres. (See j). 262.) Other special tests are as follows : 1. Millon's reagent (mercurous and mercuric nitrate) colors the animal fibres red, but not the vegetable fibres. 2. T^iebermann gives the following test : Prepare a fuchsine solution, add potash solution drop by drop until it is decolorized, filter, and dip in the sample of goods. Wool or silk fibres are colored red, cotton remains colorless. 302 TEXTILE FIBRES OF ANIMAL ORIGIN. 3. Ammoniacal cupric oxide solution dissolves cotton as well as silk. While cotton, however, is precipitated by certain salts as well as by sugar and gum, silk is only precipitable by acids. 4. As wool always contains sulphur, a sodium plumbate solution (made by boiling red lead with caustic soda solution and filtering) is at once black- ened on contact with wool. This test may be interfered with in the presence of sulphur-treated silk. 5. Wool and silk may be distinguished by the use of hot hydrochloric / acid. Silk dissolves easily in this, while wool merely swells up but does not dissolve. 6. According to Hohnel, wild silks behave differently from true silks with chromic acid. If a cold saturated solution of chromic acid be diluted with an equal bulk of water and then boiled for one minute with the sample of silk, the true silk 'dissolves up, Avhile the wild silk remains unattacked even after two to three minutes' boiling. Wool behaves like true silk in this. A. Remont gives a process for determining wool, silk, and cotton when mixed in the same fabric. Four pieces of about two grammes' weight each are taken ; three of these are boiled for a quarter of an hour in two hun- dred cubic centimetres of three per cent, hydrochloric acid, which is renewed if the liquid becomes strongly colored, and the samples are then well washed. The dressing is thus removed and the coloring matter in the case of the cotton, but only slightly in the case of wool and silk ; the weighting of the silk with iron salts is also completely removed by the hydrochloric acid if the weighting does not exceed twenty-five per cent, of the weight of the silk, leaving the fibres chestnut-brown in color. Two of the samples thus treated are dipped for one to two minutes into a boiling solution of basic chloride of zinc of specific gravity 1.69 ; then thrown into water and washed first with acidified water and then with pure water. This removes the silk. The basic chloride of zinc solution is prepared by heating one thousand parts of zinc chloride, forty parts of zinc oxide, and eight hun- dred and fifty parts of water. One of the two samples freed from silk is then boiled gently for a quarter of an hour with sixty to eighty cubic centimetres of caustic soda solution of specific gravity 1.02. This is best done with inverted condenser, so that an injurious concentration of the soda solution is avoided. Wash gently with- out too much rubbing and the wool is removed. All four samples are now washed for a quarter of an hour with distilled water, pressed out, dried in the air, and weighed. The first will weigh as before, two grammes or nearly, a slight difference of a few milligrammes being neglected ; the difference in weight between the first and second samples gives the dressing ; that between the second and third gives the silk ; that between the third and fourth the wool present, and the weight of the fourth sample the vegetable fibre present. This is slightly attacked by the soda solution, and in the case of cotton it is usual to reckon five per cent, as the loss from this cause. V. Bibliography and Statistics. BIBLIOGRAPHY. 1862. Die chemische Technologie der Spinnfasern, P. Bolley, Braunschweig. 1866. Das Woll-haar des Schafes, etc., W. von Nathusius-Konigsborn, Berlin. 1867. Einleitung in die technische Microscopic, J. Wiesner. 1869. Darstellung der Baues und der Eigenschaften der Merinowolle, M. Settegast, Berlin. BIBLIOGRAPHY AND STATISTICS. 303 1873. Die Gespinnstfasern, 11. Schlesinger, Zurich. 1874. Die Wollgarnfarberei, Kichter und Braun. 1878. Le Conditionnement de la Sole, J. Persoz, Paris. 1880. The Woollen Thread: its Nature, Structure, etc.,C. Vickerman, Huddersfield. 1881. Die Gewinnung der Gespinnstfasern, H. Kichard, Braunschweig. Matieres premieres organiques, Pennetier, Paris. The Wild Silks of India, Th. Wardle, London. 1882. Chevallier's Dictionnaire des Falsfications, 4me ed., Baudrimont, Paris. 1885. The Dyeing of Textile Fabrics, J. J. Hummel, London. The Structure of the Wool Fibre, F. H. Bowman, Manchester. L'Art de la Sole, N. Eondot, Paris. 1886. The Catalogue of the Silk-Culture Court, Indian Exhibition, Th. "Wardle, London. 1887. Microscopic der Faserstoffe, F. von Hohnel, Vienna. 1888. Chemische Techuologie der Gespinnstfasern, Otto Witt, Braunschweig. Wool Manufacture, K. Beaumont, London. 1890. Les Industries de la Soie, Sericulture, etc., E. Pariset, Lyons. STATISTICS. Wool. The following figures show both the production, importation, and home consumption of wool for the United States for the last ten years : Production. Imports. Total produc- tion and imports. Home onsumption. Percentage imported. Pounds. Pounds. Pounds. Pounds. 1880-81 . 240,000,000 55,964,236 295,964,236 290,385,247 18.09 1881-82 . 272.000,000 67,861,744 339,861,744 335,913,729 20.00 1882-83 . 290,000,000 70,575,478 360,575,478 356,500,961 19.07 1883-84 . 300,000,000 78,350,651 378,350,651 396,035,558 20.08 1884-85 . 308,000,000 70,596,170 378,596,170 375,392,825 18.08 1885-86 . 302,000,000 129,084,958 431,084,958 422,412,452 30.06 1886-87 . 285,000,000 114,038,030 399,038,030 392,051 ,998 29.01 1887-88 . 269,000,000 113,558,753 382,558,753 378,176,858 30.00 1888-89 . 265,000,000 126,487,929 391,487,729 388,083,059 31.75 1889-90 . 265,000.000 105,431,281 370,431,281 366,911,773 28.73 The number of sheep in the United States, as reported by the Depart- ment of Agriculture, reached its highest figure in 1884, when the figure reported was 50,626,626. In 1888 it was 43,544,755 ; in 1889, 42,599,- 079 ; and in 1890, 44,336,072. The following statistics of the Australian wool export are given in the United States Consular Reports of June, 1890 : 1888-89. Bales. Victoria 336,702 New South Wales 422,863 Queensland 87,763 South Australia 118,656 West Australia 21,170 Tasmania 19,536 New Zealand 207,023 1889-90. Bales. 400,459 443,820 85,206 143,215 24,337 19,251 210,265 1,215,712 1,326,643 The value of the clip in 1889-90 is placed at 21,253,188, or $103,- 428,639. The number of sheep in all the Australian colonies in 1890 is estimated at 100,000,000. 304 TEXTILE FIBRES OF ANIMAL ORIGIN. The annual wool production of Russia is estimated at 10,000,000 poods (160,700 tons), approximately six pounds of wool per sheep. Silk. The statistics for the production of raw silk throughout the world are thus given in the United States Consular Reports of June, 1890 : 1884. 1885. 1886. 1887. 1888. Western Europe : France Kilos. 483,000 Kilos. 535,000 Kilos. 677,000 Kilos. 717,000 Kilos. 798,000 Italy 2,810,000 2,457,000 3,188,000 3,476,000 3,566,000 Spain 85,000 56,000 52,000 78,000 83,000 Austro-Hungary . Eastern Europe : Anatolia .... Salonica, Volo, and Adrianople . . . Syria 142,000 185,000 95,000 230,000 168,000 172,000 100,000 256,000 217,000 206,000 125,000 233,000 264,000 188,000 135,000 340,000 307,000 170,000 120,000 231,000 Greece 20,000 20,000 20,000 20,000 18,000 Caucasus 20,000 75,000 93,000 55,000 50,000 Shipments from Shanghai 2,695 000 2,631,000 2,387,000 2,459,000 2,256,000 Canton 774,000 715,000 1,357,000 1,411,000 695,000 Yokohama .... Calcutta . . . . . 1,346,000 861,000 1,372,000 760,000 1,478,000 781,000 2,217,000 791,000 2,400,000 1,011,000 Total 9,926,000 9,317,000 10,814,000 12,151,000 11,705,000 EAW MATERIALS. 305 CHAPTER X. ANIMAL TISSUES AND THEIR PRODUCTS. A. LEATHER INDUSTRY. I. Raw Materials. 1. ANIMAL, HIDES AND SKINS. The moist animal skin undergoes decomposition very rapidly ; if dried becomes stiff and horny, or if boiled with water is changed into soluble glue. The object of tanning is to bring the animal skin into such a condition that decomposition is arrested, and after drying it no longer forms a stiff horny mass, but an opaque tissue in- soluble in water, distinctly fibrous and pliable. The product known as leather has properties which at once distinguish it from the untanned hide, such as greater or less impermeability to water and toughness and strength. Nevertheless, the best authorities on the subject believe that in the main tanning is a physical rather than a chemical process, and that the function of the tanning material is chiefly to penetrate the pores of the skin and envelop the individual fibres so that in drying they are prevented from ad- hering and so stiffening the whole mass. The power of the skins to fix tanning materials upon the surface of its fibres varies considerably accord- ing to the nature of the material used, and in many grades of leather is undoubtedly supplemented by a chemical combination of the FlQ - 97 - coriin of the skin with the tannin. To understand the nature of the change wrought by tanning in the animal hide, it is necessary first to refer briefly to its anatomical structure. Fig. 97 shows a section of ox-hide cut parallel with the hair, mag- nified about fifty diameters. It consists essentially of three layers : the epidermis, which is itself made up of two layers, the outer horny layer or cuticle A, a dead layer which is con- tinually wearing off and being renewed, and the inner mucous layer B, the rete Malpighi, a watery cellular layer, which rests upon the true skin and is continually renewing the outer layer ; the derma or cormm, the true skin, C, which alone is the leather- making tissue ; and the fatty under tissue, shown in the illustration at D, in 20 306 ANIMAL TISSUES AND THEIR PRODUCTS. which the perspiratory and sebaceous glands are embedded. Both the epi- dermis and the under tissue are removed in the preparatory processes of tanning, so that the corium alone remains to combine with the tanning materials to form leather. The hair of the animal is enclosed in hair- sheaths, which pass down through the epidermis and rest upon the corium, from which in life the hair-glands draw their nourishment. The corium, or true leather-forming layer, is composed of bundles of inter- lacing fibres, between which is found an albuminoid substance, coriin, which as the skin dries cements the fibres together and stiffens the hide. This is insoluble in water but soluble in lime-water, and hence removed in large part by the process of liming to which the hides are sub- mitted. The animal skins which are utilized in the manufacture of leather are, first, those of the ox, cow, buffalo, horse, etc. These are known as hides, or if from younger animals of the same kind as kips. Second, those of the calf, sheep, goat, deer, etc. These are known as skins. For special pur- poses the skins of crocodiles, alligators, porpoises, and seals are also made into leather. The hides may come to the tannery according to the source whence ob- tained either as fresh or green hides, that is, direct from the slaughter- houses, as wet salted, as dry salted, and as dried hides. In addition to the domestic production, which is very large in consequence of the great cattle- raising industry West and Southwest, great numbers of hides are imported into the United States from the Argentine Republic and the River Plate in South America. England imports from India, the Cape of Good Hope, and Australia as well as from South America. 2. TANNIN-CONTAINING MATERIALS. The conversion of the hides into leather is usually accomplished by the action of an extract or infusion of tannin or tannic acid. This powerful astringent acid is very widely dis- tributed in nature, being found in barks, roots, leaves, seed-pods, flowers, and fruits, and in excrescences on trees. More accurately speaking, we find a number of varieties of tannic acid in these different vegetable sources, of which some are more valuable for tanning than others. As a class they are readily soluble in water, amorphous, of slight acid reaction, and astrin- gent taste. They yield with iron salts bluish-black or greenish precipitates, throw gelatine and albumen out of solution, and change hides into leather. In tanning it is not necessary to extract the acid in a pure state, but in- fusions are made from the powdered barks as needed, or concentrated ex- tracts prepared for this purpose are used. We will note briefly the more important tannin-containing materials used at the present time in leather manufactures. Oak-bark. The common English oak (Quercus Robur\ which includes the two varieties Q. pedunoulata and Q. sessiliftora, is one of the most im- portant materials. It contains from twelve to fifteen per cent, of tannic acid and produces an excellent quality of leather. Other varieties in use are Quercus coed/era (or kermes-oak), of which the bark, known as coppice- oak, is yellowish-brown in hue and very rich in tannin ; Quercus suber (or cork-oak) and Quercus Ilex (or evergreen-oak), both of which are grown in Algiers, Italy, Spain, and the South of France. In the United States the most important varieties of oak are Quercus prinus or castanea (chestnut- oak) ; Quercus rubra (common red-oak) ; Quercus alba (or white-oak). The tannin of the several varieties of oak is known as quercitannic acid. RAW MATERIALS. 307 According to the researches of Etti,* the main constituents of the oak-bark are quereitannic acid with the formula C 17 H 16 O 9 ; its first anhydride, phlo- baphene, C^H^O^ ; its second anhydride, C^H^Ojg ; its third anhydride, Oser's oak-red, C 34 H 26 O 15 ; and its fourth anhydride, Lowe's oak-red, C 34 H 24 O 14 . Of these, the quereitannic acid and the phlobaphene are specially concerned in the tanning process. Hemlock-bark. The bark of the hemlock (Abies Canadensis} of Canada and the United States contains nearly fourteen per cent, of tannin. This is extensively used, either jointly with oak-bark (union tanned leather) or as a substitute for it, in the manufacture of sole-leather. It is said to produce a harder leather than oak-bark, but less pliable and more pervious to water. A solid extract from the hemlock- bark containing from twenty-five to thirty-five per cent, of a deep red tannin is prepared in large quantities for export. The production of this solid extract is said to be at present con- siderably over ten thousand tons per annum. Liquid extracts with fifty per cent, of solid matter are also largely sold. Pine-bark is much used in Austria, Bavaria, and Southern Germany. It contains from seven to ten per cent, of tannin and considerable resinous extractive matter. It does not yield so good a leather as oak-bark. Closely related and somewhat used are the barks of the White Spruce, the Larch, and the Fir. Willow-bark. Several species of the willow, notably Salix arenaria and 8. caprcea, are used in Russia and Denmark for the tanning of lighter skins, for the manufacture of glove leather and the so-called Russia leather. It is stated that the yearly consumption of willow-bark in Russia at present is some six and a half million kilos, against two and a half million kilos, of all other tanning barks. The percentage of tannin in the willow is usually given at from three to five per cent., although Eitner f found over twelve per cent, in several species. Chestnut-wood. The wood of the chestnut ( Castanea vescd) contains from eight to ten per cent, of a tannin which closely resembles gallotannic acid. The extract, containing from fourteen to twenty per cent, of tannin, is used largely to modify the color produced by hemlock extract and for tanning and dyeing. Horsechestnut-bark.The bark of the horsechestnut (jEsculus hippocas- tanum) is also said to be used for the manufacture of an extract under the sim- ple name of " chestnut extract," but such manufacture in the United States is very doubtful. Catechu (or Catch) is the name given the dried extract from Acacia Cate- chu, cultivated in India and Burmah, and containing forty-five to fifty-five per cent, of a special variety of tannic acid (catechu or mimotannic). The extract is evaporated until a semi-solid dark-brown product is obtained. This is exported in mats, bags, and boxes to European atod American markets. Gambier or Gambit- (Pale Catechu) is the dried extract from the leaves of Uncaria Gambier and U. acida. It contains thirty-six to forty per cent, of a brown tannin which rapidly penetrates leather and tends to swell it, but taken alone produces a soft, porous tannage ; it is largely used in conjunction with other materials for tanning both light and heavy leathers. It is exported from Singapore, in pressed blocks and cubes. The catechutannic acid of cutch * Wagner's Chemical Technology, 13th ed., p. 1051. f- V. Hohnel, Die Gerberinde, p. 90. 308 ANIMAL TISSUES AND THEIR PRODUCTS. and gambier differs from gallotannic acid in giving a grayish-green precip- itate with ferric salt and no reaction with ferrous salts ; by giving a dense precipitate with cupric sulphate and none with tartar emetic. They also contain catechin, which is said to be an anhydride of catechutannic acid. Kino is an extract somewhat resembling cutch, and is the dried juice from a variety of plants. Thus, the East Indian kino is obtained from Pterocarpus marsupium, the Bengal kino from Butea frondosa, the African from Pterocarpus erinaceum, and the Australian from the several species of Eucalyptus. It ordinarily forms small angular fragments of black lustrous appearance, brittle, and crumbling to brown-red powder. It contains thirty to forty per cent, of a tannin (kinotannic acid) analogous to catechutannic acid, together with phlobaphene. Sumach consists of the powdered leaves, peduncles, and young branches of Rhus coriaria, Rhus cotinus, and other species of Rhus. Thus, Sicilian sumach, the most esteemed variety, is from R. coriaria ; Spanish sumach is from several species of Rhus, and comes in three varieties, Malaga, Molina, Valladolid ; Tyrolean sumach from R. cotinuj ; French from Coriaria myr- tifolia; American from R. glabra, R. Canadense, and R. copallina. The leaves are collected while the shrub is in full foliage and cured by dry- ing in the sun. They are then ground under millstones and the product baled. The sumach contains from sixteen to twenty-four per cent, of a tannin which seems to be identical with gallotannic acid. The American variety contains usually six to eight per cent, more than the European, but also contains more of a dark coloring matter, which renders it inferior to the Sicilian sumach for white leathers. Myrobalans (or Myrabolans). The fruit of several species of Termi- nalia found in Hindostan, Ceylon, Burmah, etc. Myrobalans varies in size from that of a small hazel-nut to that of the nutmeg. The tannin occurs in the pulp which surrounds the kernel. It is generally used in combina- tion with other tanning materials to modify the objectionable color which some of the latter impart to the leather. By itself it produces a soft and porous tannage. Valonia is the commercial name for the acorn cups of several species of oak, Quercus cegilops and Quercus macrolepis, coming from Asia Minor, Roumelia, and Greece. They are of a bright-drab color, and contain twenty-five to thirty-five per cent, of a tannin somewhat resembling that of oak-bark, but giving a browner color and heavier bloom. It is generally used in admixture with oak-bark, myrobalans, or mimosa-bark, because of itself it produces too brittle a leather. Mimosa-bark (Wattle). The bark of numerous species of Acacia (A. decurrens and A. dealbata} from Australia and Tasmania, contains from twenty-four to thirty per cent, of mimotannic acid. The bark comes into commerce chopped or ground and also in the form*of an extract. It makes a red leather and is generally used in admixture. Divi-divi. The seed-pods of Ccesalpinia Coriaria, a small tree found in the neighborhood of Maracaibo, South America. The pods are about three inches long, brownish in color, and generally bent by drying into the shape of the letter S. It contains thirty to fifty per cent, of a peculiar tannin somewhat similar to that of valonia, but is liable to fermentation. Quebracho. This is the name applied to several South American trees possessing hard wood. They are Aspidospermq Quebracho (Quebracho bianco), Loxopterygium Lorentzii ( Quebracho Colorado). The wood and bark PKOCESSES OF MANUFACTURE. 309 of the latter contain from fifteen to twenty-three per cent, of a bright red tannin. Both the wood and the extract are used in tanning. Nutgalls is the term applied to the excrescences on plants produced by the punctures of insects for the purpose of depositing their eggs. The principal commercial kinds are oak-galls (or Aleppo galls) and Chinese galls. The first of these are the product of the female of an insect called Cynips, which pierces the buds on the young branches of the Quercus in- fedoria and other species of oak. In the centre of the gall thus produced the larva is hatched and undergoes its transformation, boring its way out as a winged insect in five to six months. If the galls are gathered while the insect is in the larval state they are known as " blue" or " green" galls ; if the insect has cut its way out they are known as " white" galls, and are of inferior character and less astringent. The best oak-galls contain from sixty to seventy per cent, of gallotannic acid. The Chinese gallnuts are the product from the Rhus semialata, the leaves of which are punctured by an insect, the Aphis Chinensis. The nuts are of irregular shape but are very rich in tannin, containing about seventy per cent. Knoppern are galls from immature acorns of several species of oak largely used for tanning in Austria. They contain from twenty-eight to thirty-five per cent, of tannin. IE. Processes of Manufacture. Leather may be manufactured from hides or skins by a number of methods, which may be summarized, however, under three heads, viz., tanning by the use of tannin-containing barks or extracts ; tanning by the aid of alum and other chemical salts, frequently called " tawing ;" and the manufacture of soft leather by treatment of the skins with oils. We will note first the methods involving the use of tannin-containing materials, and these again differ somewhat according to the grade of leather to be made and the character of the hides or skins used. A. MANUFACTURE OF SOLE-LEATHER. 1. Softening and Cleansing the Hides. This process differs according as the hides are taken in the fresh or green state or are salted or dried. For fresh hides, a washing with pure water to cleanse them from dirt and blood is all that is necessary to pre- pare them for the next or " swelling" process. For salted hides, a soak- ing in fresh w y ater for from two to three days is necessary, while for hard dried hides a longer treatment is necessary, first in water which has been repeatedly used for softening and afterwards in fresh water. This involves often a slight putrefaction of the coagulated albumen of the dry hide. To control this and prevent injury to the corium of the hide a weak salt solution (five per cent.) is often used in this prolonged softening. " Stocking" or kneading the hides with heavy rolls or breaking weights is also needed for heavy hides which have been dried. 2. Dehairing and Swelling. These operations are carried out together. As the swelling proceeds the cells in which the roots of the hair are embedded are softened, so that the hair is easily removed by mechanical means. The horny epidermis is similarly softened, so that it can be removed by the same means. The svVelling may be effected by several different methods : (1) by sweating ; (2) by treatment with acid tan-liquor ; (3) by liming ; (4) by treat- ment with sulphides of sodium and calcium, etc. The sweating process now 310 ANIMAL TISSUES AND THEIR PRODUCTS. in use is the so-called " cold sweating" method, and consists in hanging the hides in a moist chamber kept at a uniform ^temperature of 60 to 70 F. (15 to 21 C.), so that an incipient putrefaction ensues which attacks the soft parts of the epidermis and root-sheaths before materially injuring the corium or leather-forming material. This method is that generally followed for sole-leather in this country and on the Continent of Europe, while in England liming is more generally adopted. The swelling with acid tan- liquor depends upon the action of the acids which are present in considerable quantity in old tan-liquors and their effect upon the connective tissue. The swelling and unhairing by lime always adopted for small skins is also used for sole-leather hides in England. A view of the lime-pits and skins in process of softening by lime as carried out in morocco tanneries is shown in Fig. 98. The action of the lime upon the hide is in part a solvent one. The hair-sheaths are loosened and dissolved and the hardened epidermis swells up and softens, so that both come away more or less completely with the hair when scraped. The intercellular substance, or coriin, as before stated, is also soluble in the lime-water, and as this is removed the fibrous nature of the leather-forming skin becomes more evident. The hides are generally put into several lime-pits in succession, in the first of which is old liquor with the weakest alkaline reaction because of its partial satura- tion with organic material, and in the last the liquor is the freshest and strongest in alkaline reaction. The hides require to be turned and changed in position during this liming process as well as removed from one pit to the other. The swelling and unhairing by the use of alkaline sulphides largely used upon the Continent of Europe consists in taking a solution of sodium sulphide (made from alkali-waste by Schaffner and Helbig's process) and bringing it to a thin pasty condition with lime. This is then spread upon .the hair side of the hides and they are packed together for five to twenty hours, when the loosened hair and sulphide paste is washed off and the hides left in water a time longer to " plump" or swell. Another process uses the sulphide in solution only. The hair having been loosened by one or the other of the means just described, it is to be removed by mechanical means. This is usually done on the " beam," a sloping frame of wood or metal with a blunt two-handled knife, which pushes the hair downward and away from the workman. After the unhairing, the loose flesh and fat, the latter some- what saponified by the lime, are next removed from the inner side of the hide by a sharp-edged knife. Hand " fleshing" is in many cases superseded by machine treatment, as the hide must not only be scraped but worked to force out the fat which remains in the loose tissue, as this would impede tanning. The hides after the fleshing are trimmed, and the inferior ends and edges are cut off with a sharp knife. They have still to be freed from the traces of lime which they have absorbed during the lime treatment before they can be put in the tan-liquors. This used to be done for sole- leathers, as it is still done for calf- and goat-skins, by means of " bate," or dung of animals, mixed with water, but that is now almost entirely replaced by the use of dilute acids which shall combine with the lime, \vhen the lime salts so formed are to be washed out. Dilute sulphuric, phosphoric, and hydrochloric acids have been used (the latter being best because its lime salt is soluble), as well as the acid tan-liquors containing gallic, acetic, and lactic acids. The organic acids are considered to be safer for the hide than the inorganic. 3. Tanning. The bark or other tanning material must be crushed and PEOCESSES OF MANUFACTURE. 311 FIG. 98. 312 ANIMAL TISSUES AND THEIR PRODUCTS. then ground to a state sufficiently fine to allow of the extraction of the tannic acid, and yet not so fine as to cause it to cake together in clayey masses. This is accomplished in bark-mills and disintegrators of various kinds, which need not be specially described here. The tan-house into which the cleansed and prepared hides or " butts" now come is provided with rows of pits running in parallel lines, which are to contain the butts during their treatment with the tan-liquor. The butts in most cases are first suspended in weak tanning infusions before they go into the first, or " handler/' pits. The object of this is to insure the uniform absorption of tannin by the skins before subjecting them to the rough usage of " handling," which in the early stages of the process is liable to cause injury to the delicate struct- ure of the skin. During this suspension the skins should be in continuous agitation to cause the tannin to be taken up evenly. Both the suspension and the agitation are accomplished generally by mechanical means. From the suspenders the butts are transferred to the " handlers," where they are laid flat in the liquor. They are here treated with weak infusion of bark, commencing at about 15 to 20 by the barkometer (see p. 319), and are handled twice a day during the first two or three days. This may be done by taking them out, turning them over, and returning them to the same pit, or more generally by running them, fastened together, from one handler- pit into another. The treatment of the butts in the handlers generally occu- pies about six to eight weeks, by which time the coloring matter of the bark and the tannin should have " struck" through about one-third of the sub- stance of the skin. Many of the butts will have become covered, more- over, with a peculiar " bloom" (ellagic acid) insoluble in water. They are now removed to the " layers," in which they receive the treatment of bark and " ooze," or tan-liquor, in progressive stages until the tanning is complete. Here the butts are stratified with ground oak-bark or valonia, which is spread between each butt to the depth of about one inch, and a thicker layer finally on top. The pit is then filled up with ooze, which varies in strength from about 35 barkometer at the beginning to 70 at the end of the treatment. For heavy tannages six to eight layers are required, the duration of each ranging from ten days at the beginning to a month in the later stages. Each time the butts are raised they should be mopped on the grain to remove dirt and loose bloom. With the use of strong prepared extracts, especially with the aid of heat, the tanning process can be carried out in much shorter time than that just indicated, but the leather produced though hard is deficient in toughness and is liable to crack on bending sharply. 4. Finishing. The butts after coming from the last layer are well brushed, washed in a clear liquor, and then thrown over a horse to drain before going to the drying-shed. They are then frequently oiled lightly on the grain so as to prevent too rapid drying out and hung on poles in the drying-loft. When about half dry, they are heaped upon the floor in piles and covered to sweat a little, which facilitates the operation of " striking," which next follows. The " striking," which may be done by hand with a two-handled tool with triangular blunt edges or by machinery, is chiefly for the purpose of removing the deposit called bloom, although it somewhat flattens and stretches the leather. After a little further drying the butt is laid upon a flat bed of wood or metal and is rolled either by heavy hand-rollers or by the aid of machinery. The leather is then sometimes colored on the grain PROCESSES OF MANUFACTURE. 313 i = E | ^ & o S 1 of * a 1 P 1 G *' i 3 * IN 3 H 1 ff * a r 1 1'^ o | ^ f i' ~ 1 ff | ^ ? e If w | II J 1 |J o A ^ 3* *- M Hj4 S- ~S.' ^' S- 2 3 S" 1 IJ " ^ H '- o gg- 5 1 g | g Z tw"KjfSfB | g, 1* Z ^2. *-3jii-' > 'te'^^ J Qj^ 1 H-l ^ & ^ ^1' P ? T* ^ 2 ' g Z 1 g-1 S| b | * *'-; w a 5, W M S M. G B CB o SIDE-PRODUCTS: > HIDES READY FOR and rolled, and fin i D SOLE-LEATHER Si S!" f 2 i s f i NHAIRED HIDES rom rough ends. OFTENED HIDES the beam. g. o* s. PROCESS ^ C 5 ^ fc* 3 s je tJ* ^rl f f 1 f f ' g-oo ^ CD a. 5j S- 2. 55 ii Is. I 1 o 5 3 = a -5 S | S pi I 5" &" 3 x p (t ro 3 - r w | S.S Og, 3 2' c e 1 i- r ?3 C S o ff S-ff w 6 g"- g & J o 5 >^ p p p 5 * 5 g & _R ^ V "- " S 00 3 o p 1 P g 5 ffi ^ &! 1 f 1 p S " i 3 S w s p (B 1 p a 3. I 3 & g 5" a p s I 314 ANIMAL TISSUES AND THEIR PRODUCTS. with a mixture of yellow ochre, with size and oil to give a gloss, and then brushed again, well rolled, and dried off gradually in a room slightly warmed by steam. The main outlines of sole-leather tanning are summa- rized on the accompanying diagram. B. UPPER AND HAENESS LEATHERS. For upper and harness leathers the hides of cows and smaller oxen are chosen. Fresh hides are, moreover, much better adapted for this class of leathers than dry salted or dry "flint" hides, as the utmost toughness and strength rather than hardness or weight are to be secured. The hides are cleansed, limed, and unhaired very much as already described for sole-leather. They are then " bated" in a bate of hen manure or treated with sour bran-liquor to completely remove the lime from the pores of the skin. The remaining portions of hair-sheaths and fat-glands are at the same time so loosened that they are easily worked out by a blunt knife on the beam. This final cleansing process is called " scud- ding." The action of the " bate" is considered by the best authorities to be a fermentative one, and the weak organic acids produced neutralize and remove the lime and at the same time soften the hide by dissolving out the coriin and probably also portions of the gelatinous fibre. " Stocking" is also used to assist in the softening and cleansing. These lighter tannages are also carried out very largely by the aid of gambier in combination with bark, valonia, mimosa, and myrobalans. The tanning liquors are often used at temperatures of from 110 to 140 F. (43 to 60 C.). The finish- ing of these light liquors requires much care in order to give them the proper softness and strength. They are alternately worked with a stretch- ing-iron, or " sleeker," and rubbed with oil or with a mixture of degras and tallow. C. MOROCCO LEATHER. This is generally made from goat-skins, although a cheaper variety is made from sheep-skins. The skins are soft- ened and then unhaired by lime, to which a small quantity of arsenic sul- phide is often added, whereby calcium sulphydrate and sulpharsenite are produced, which assist in softening the hair-sheaths and in giving the grain a higher gloss. A view of the unhairing machines and washing drums of a morocco tannery is given in Fig. 99. They are then bated with a mixture of dog's dung and water, known as the " pure." This is often followed by a treatment with bran to aid in removing the lime from the skins. A " scudding" or scraping with a blunt two-handled knife on both the grain and flesh sides then ensues to remove the last portions of lime salts and albuminoid matters. The tanning is done chiefly with sumach and gambier, either in revolving paddle " tumblers," as shown in Fig. 100, or according to the English method, by sewing up the skins into bags partially filled, with the sumach-liquor and then distended by air and floated in a large ves- sel of the same liquor. The bags are turned over constantly, and after- wards piled up in heaps. The sumach solution is thus forced through the pores of the skin, and the tanning is rapidly effected. The tanned skins are thoroughly washed and "struck," or scraped and rubbed, until smooth. After thorough drying they are again struck until thoroughly soft and smooth. D. MINERAL TANNING OR " TAWING." Skins may be converted into a substance resembling leather, although in fact essentially different from it, by the action of alum and salt. There has been no chemical combination, however, analogous to that formed by the gelatine and tannic acid in the ordinaiy tanning processes, as the gelatine, alum, and salt can be again separated by treatment with water. PROCESSES OF MANUFACTURE. FIG. 99. 315 316 ANIMAL TISSUES AND THEIR PRODUCTS. The process of tawing is applied to goat, kid, sheep, and other small skins. The preliminary operations of steeping, breaking, liming, unhairing, and fleshing, steeping in bran-water and working on the beam, are essen- tially the same as have been described already. The skins with the pores cleared of lime and sufficiently opened are then put into a kind of wooden drum or " tumbler" such as are used for washing skins and for treating morocco leather skins with sumach solution. For every two hundred skins some twelve pounds of alum and two and a half pounds of salt with twelve gallons of water are used. FIG. 100. The action is continued for a short time only, about five minutes. They are then put into an emulsion of yolk of eggs with flour and water, and tramped and worked in this until it has been thoroughly absorbed. The skins are now hung upon poles to dry, after which they are stretched and softened by drawing them to and fro upon the " stake," a blunt steel blade set in upright position. E. CHAMOIS AND OIL-TANNED LEATHER. The skins tanned in this way are sheep- and calf-skins, and formerly chamois- and deer-skins. The flesh splints of sheep-skins are now generally employed for ordinary wash- leather. If heavy hides are taken, the grain side of the skin is shaved so that the oil can penetrate easily. The skins receive a thorough liming, so that the coriin is thoroughly removed from between the fibres, making them very soft. A bran-drench follows to remove the lime, and they are worked on the beam. The surplus water having been removed by pressing, while still moist they are oiled with fish, seal, or whale oil (to which some five per cent, of carbolic acid is often added). After being stocked for two to three hours, shaken out, and hung up for one-half of an hour to an hour to partially dry, they are again oiled and stocked, and this process is repeated until the skins lose their original smell of limed hide and acquire a peculiar mustard-like odor. The later dryings are frequently conducted in a heated room, and when the oiling is complete the skins are piled up, and the oxida- tion of the oil which has already commenced during the fulling and drying is PRODUCTS. 317 completed by a sort of a fermentation, in which the skins heat considerably. This heating must be controlled so that the leather is not injured, and if necessary the pile of skins is turned. When the oxidation is complete the skins are of the yellow chamois leather color. To remove the surplus oil, the skins are again oiled, then thrown into hot water and wrung out. The semi-solid fat obtained this way is the degras so much prized for curry- ing purposes. Or the whole of the uncombined oil is removed by washing with soda or potash lye and then set free by neutralizing with sulphuric acid. The oil so obtained forms the " sod oil" of commerce. About half of the oil employed is retained by the skin, and cannot be removed even by boiling with alkalies. No gelatine is obtained by boiling with water, to which the chamoised skin is much more resistant than ordinary leather. The skins intended for gloves, etc., are bleached like linen, by sprinkling and exposure to the sun or with weak solution of potassium permanganate followed by sulphurous acid. m. Products. 1. SOLE-LEATHER. This is the heaviest and firmest variety of leather produced. It is made from the heaviest and thickest hides, and is valued for its fine grain and toughness. It retains the whole thickness of the hide, and no part is split off, so that it is not weakened by the loss of the flesh side. The tanning process is protracted until the whole hide is of uniform color throughout and shows the completed action of the tannin upon the interior of the hide. 2. UPPER AND HARNESS LEATHERS. These are made from lighter hides, and are tanned for strength and flexibility rather than for weight, and are finished with care to give it perfect pliability. It may be shaved or split leather. The black color and finish are put on upper leather by coating it with a mixture of lamp-black, linseed oil, and fish oil, to which tallow and wax and a little soap have been added. This is brushed on, allowed to dry, and then thoroughly rubbed in and the skin sized with a glue size. 3. MOROCCO LEATHER. The true morocco leathers are manufactured from goat-skins. A cheaper grade, known as French morocco, is produced from sheep-skins. As they are to be dyed on one side only, two of the skins are fixed face to face with the flesh side inward, so that the dye acts upon one side of each skin only. After dyeing the skins are rinsed and drained, saturated with linseed oil to prevent too rapid drying, and then curried by repeated oiling or waxing and rubbing with a glass " slicker." 4. ENAMELLED OR PATENT LEATHERS. These are leathers finished with a water-proof and bright varnished surface similar to lacquered wood- work. 'The name "enamelled" is generally applied when the leathers are finished with a roughened or grained surface, and " patent," or "japanned," when the finish is smooth. Thin and split hide are used. The skins after drying are prepared with a mixture of linseed oil and white lead and heated in closets to 160 F. (71 C.) or higher, then coated with a varnish of spirits of turpentine, linseed oil, thick copal varnish, and asphaltum, and heated again in closets or " stoves," as they are termed. This varnishing and heating are alternated, while the surface is meanwhile rubbed smooth with pumice, until the desired thickness is acquired. 5. RUSSIA LEATHER. This variety is peculiar in its characteristic odor 318 ANIMAL TISSUES AND THEIR PRODUCTS. and ability to withstand dampness without any tendency to mould, both of which qualities it owes to the currying with the empyreumatic oil of birch- bark. In Russia the skins are tanned with willow-bark, but the imitation Russia leather made largely in Germany and England is tanned in the ordi- nary way with oak-bark. The birch-bark oil is rubbed into the flesh side of the tanned skins with cloths, care being taken not to apply so much as to cause it to pass through and stain the grain side of the leather. The red color is given by dyeing with Brazil-wood or red saunders, and the diamond- shaped marking by rolling with grooved rollers. 6. CHAMOIS LEATHER is a soft felt-like leather originally prepared from the skin of the chamois goat, but now made from other goat-skins and from the " flesh-splits" of sheep-skins. In these leathers the grain has practically been removed by scraping or " prizing" before the oil is applied, so that it is uniformly porous and soft throughout. They acquire a yellow color and a peculiar odor, although they are often bleached whiter by subsequent treat- ment. (See preceding page.) The combination of oil with the hide makes chamois leather very resistant to water and allows it to be washed without any change of nature. 7. WHITE-TANNED OR " TAWED" LEATHER. Skins to be tanned with the hair on, as sheep-skin rugs, etc., are always alum-tanned, as well as light calf kid and glove leather. The glove leather obtained in this process has softness and considerable strength but is not thoroughly water-resistant, although the treatment with egg-yolk and flour-paste which follows the alum treatment tends to give them somewhat of this character. 8. CROWN LEATHER. This is a variety which is intermediate between oil-tanned and tawed leather, being stronger than the first and more water- resistant than the latter. The hides are first tawed with the alum and salt mixture, then washed to partially dissolve out the tawing materials, and now spread upon a table and the flesh side covered with a mixture of fat, ox-brain, barley-flour, and milk. They are then put into a revolving tum- bler and rotated for a time, and again rubbed with the fat mixture and ro- tated if necessary. The leather readily becomes mouldy, but seems to be strong and specially adapted for belting. 9. PARCHMENT AND VELLUM. The first of these is prepared from the skins of sheep and goats and the second from the skins of calves. The skins are washed, limed, unhaired, and fleshed, again well washed, and then stretched either upon hoops or upon a square wooden frame called the herse. On these the skin while wet and soft is stretched thoroughly. It is then scraped again free from the fleshy matters, the flesh side dusted over with sifted chalk or slaked lime and rubbed in all directions with a flat piece of pumice-stone. The grain side is also scraped with a blunt tool and rubbed with pumice. The skin is then allowed to dry on the frame in the shade, care being taken to avoid sunshine or frost. Very fine vellums are prepared with the finest pumice-stone. 10. DEGRAS. Among the side-products of the leather industry is one which is quite valuable for after-use. Degras, originally obtained only as a side-product of the chamois-leather manufacture, is now also made spe- cially on a large scale. The purest degras is essentially an emulsion of oxidized fish oil produced by soluble albuminoids. That which is squeezed out of the skins after the completion of the fermentation and heating, which makes the last stage of the chamois-leather manufacture (see preceding page), is the finest grade of degras. That which is recovered by the aid of caustic ANALYTICAL TESTS AND METHODS. 319 alkalies and after-liberation with sulphuric acid is the second grade (sod oil). The great demand for degras for currying purposes has led to the manufac- ture of it as a special industry. The skins used for this purpose are treated exactly as in the normal chamois-leather manufacture, but are used over and over until no longer capable of taking up the oil. An artificial de"gras has also been made from oleic acid, fat, and a little lime soap to which some tannic acid had been added. IV. Analytical Tests and Methods. 1. QUALITATIVE TESTS FOR THE SEVERAL TANNING MATERIALS. H. R. Procter * has constructed the following table (see p. 320) showing the reactions of the several tanning materials. 2. DETERMINATION OF STRENGTH OF TANNING INFUSIONS. This is most rapidly and conveniently done in practice by the use of the specific gravity hydrometer. A special form of hydrometer constructed for tan- ner's use is known as a " barkometer." The zero point of the scale is taken by sinking the instrument in distilled water at 60 F., and the 10, 20, 30, etc., marks gotten by plunging the instrument in ten, twenty, and thirty per cent, infusions of bark respectively. The intermediate degrees are then obtained by subdivision of the spaces as taken above. It is of course affected by the presence of other substances than tannin in the solution, and hence its indications are only comparable when taken on fresh or par- tially-used liquors, and not on old or spent liquors loaded with impurities. 3. QUANTITATIVE ESTIMATION OF TANNIN. Of the numerous pro- cesses that have been described for this purpose, the only one generally accepted as capable of sufficient accuracy is Lowenthal's permanganate method. This depends upon the oxidation of the tannin, etc., by permanga- nate of potash in acid solution in the presence of indigo, which serves as in- dicator, as its oxidation shows the end of the reaction. As solutions of com- mercial tanning materials contain other oxidizable matters besides tannins, it is necessary to separate these and titrate a second time in order to ascer- tain the volume of permanganate actually required by the tannin present. This separation may be effected by digestion with hide-raspings, or more conveniently by a solution of gelatine. In practice, a mixed solution of gelatine and common salt is used to which a small quantity of sulphuric or hydrochloric acid is added. Procter has also improved the process by adding kaolin, after the gelatine and salt have removed the tannin, for the purpose of facilitating filtration. The special precautions and details of the process as generally practised and as modified by the Commission of German Technical Chemists are given in Allen, f The results are always stated in terms of crystallized oxalic acid to which the tannin is equivalent in reducing power upon the permanganate solution, and are gotten by the aid of the proportion c:(a 6) : : 63 :x, in which c represents the volume of permanganate needed for ten cubic centimetres of decinormal oxalic acid, a and b the volume of permanganate needed for the tanning infusion before and after precipitation of the tannin. Another method of a different kind is that of Simand and Weiss, a used in the Austrian Experimental Station for Leather Industry, * Text-book of Tanning, pp. 112 and 113. f Allen, Commercial Organic Analysis, 2d ed., vol. iii. Part i. pp. 109-116. 320 ANIMAL TISSUES AND THEIR PRODUCTS. Gallotanni acid one per cen ^2 i PI ?> S.3---ft a S is'ft o*,5ft3fto*-3o*-E 55 pa OS 55 !S 55 pa i . I . i . 5 ft sl-Slaliy&d si ** * ft Gambi (Cuba. 1 . 1 * b S S^5 c5o5S8o 55 55 Q 55 l 3. s. 0. - . ' SSS ~.S.S~- 00 W 00 55 P5 Mimos bark. OS ..2' 71 E^ rt S a So pa ' Lei C^'o g< -T=Sg fc I o-O p: '""pl S 2 c S 1 I - o o 5 MM az QJ .1 p *^ 5 s l3l||||^ S Site 3 o)e5T3 v2vw.2 H 9Xb en*-* iSfll'3||9gl3 _6>-g-ft3Ift = S <.!>< i-J fldgl = o a 5 -:' 3 'io J Oj - ANALYTICAL TESTS AND METHODS. 321 which depends upon the absorption of tannin by hide-powder. An extract of the tannin-containing material of definite strength having been prepared,* an aliquot portion of the clear filtered solution is evaporated to dry ness in a platinum dish until constant weight is obtained, ignited, and the weight of ash obtained and deducted. A second definite portion (some two hun- dred cubic centimetres) of the same solution is digested with hide-powder, using the rapid filtration apparatus devised by Procter, f and from the fil- trate an aliquot portion evaporated as before, and the ash determined and deducted. The difference between the first and second weights of ash-free extract gives the tannin of the material used. 4. DETERMINATION OF ACIDITY OF TAN-LIQUORS. A method for the determination of volatile and non-volatile organic acids and the sul- phuric acid present in acid tan-liquors has been given by Kohnstein and Simand.| One hundred cubic centimetres of the tanning liquor is taken and eighty cubic centimetres distilled off, the residue diluted and again dis- tilled with steam. The acidity of the distillate is determined, and the result is the volatile organic acids reckoned in terms of acetic acid. To determine the non-volatile organic acids, eighty cubic centimetres of the tanning in- fusion is treated with three to four grammes of freshly-ignited magnesium oxide and the mixture left for some hours with frequent agitation, when the filtered liquid will be nearly colorless and perfectly free from tannin. The magnesia in solution is determined in an aliquot part of the filtered solu- tion, and will be equivalent to the total free acids of the liquor exclusive of the tannic acid. Another portion of the filtrate is evaporated to dryness, the residue gently ignited, moistened with carbonic acid water, and dried. It is then boiled with distilled water and the solution filtered. The carbon- ate of magnesia remaining insoluble represents the total organic acids, and can be more accurately determined by converting the magnesia into pyrophos- phate and weighing. If these total organic acids be calculated in terms of acetic acid, and the previously found volatile acids, reckoned as acetic, be de- ducted, the difference represents the non-volatile organic acids. The magnesia remaining in the filtrate from the carbonate of magnesia is combined as sul- phate, and when determined gives the sulphuric acid of the original liquors. B. GLUE AND GELATINE MANUFACTURE. Glue is a decomposition product of many nitrogenous animal tissues. These lose on heating with water (analogous to starch-granules) their or- ganized structure, swell up, and gradually go into solution. The solutions, even when very dilute, gelatinize on cooling, forming a jelly, which dries to a horny translucent mass. This mass is glue or gelatine, as the finer grades are termed. It dissolves in hot water to a liquid possessing notable cementing power. Neither the original solution obtained from the nitro- genous tissues nor the jelly formed from it on cooling have any cementing power. This is only acquired when the jelly has dried to the hard mass known as the glue. Two proximate principles seem to be present as char- acteristic in all preparations of glue : glutin, obtained chiefly from the hide and larger bones, and chondrin, from the young bones while yet in the soft state and the cartilage of the ribs, and joints. Of these, the former much t * Horn, Chem. technische Analyse Organischer Stoffe, Wien, 1890, p. 236. j- Allen, Commercial Organic Analysis. 2d ed., vol. iii. Part i. p. 119. j Dingier, Polytech. Journ., 256, pp. 38 and 64. 21 322 ANIMAL TISSUES AND THEIR PRODUCTS. exceeds the latter in adhesive power, and is therefore sought to be obtained predominantly in the glue manufacture. I. Raw Materials. 1. HIDES AND LEATHER. The corium of the animal hides (see p. 305) is the most important glue-yielding material to be had. Neither the epidermis nor the underlying fat-tissue contribute to the glue production, but have rather an injurious effect when present. What is known as " glue- stock" is made up of the trimmings from the ox, sheep, and calf-skins, the refuse of the beam-house, and scraps of parchment which have been soft- ened and unhaired by liming and are in condition for immediate boiling. Of still greater value are the so-called calves' heads, which after liming and drying form a special article of commerce. The amount of glue obtainable from these various materials varies from fifteen to sixty per cent. Accord- ing to Fleck,* the scraps from the alum-tawing process yield forty-five per cent., those from the ox-hides thirty per cent., hare- and rabbit-skins and parchment trimmings fifty to sixty per cent., foot and tail pieces of oxen fif- teen to eighteen per cent., other scraps from the tanneries, such as ear-laps of sheep and cows, sheep's feet, etc., thirty-eight to forty-two per cent. Scraps of bark-tanned leather, such as shoemaker's and saddler's trimmings, are also available after a special treatment for the removal of the tannin. (See p. 324.) 2. BONES. The bones contain on an average nearly one-third (32.2 per cent.) of their weight of organic constituents, extracted by boiling and con- verted into glue, which, however, is inferior in adhesive power to that pre- pared from animal skins. The soft bones of the head, shoulders, ribs, legs, and breast, and especially deer's horns and the bony core of the horns of horned cattle, yield a larger quantity of glue than the hard thigh-bones and the thick parts of the vertebra, which are principally composed of calcium phosphate and require a more prolonged treatment to extract the glue-making constituents. 3. FISH-BLADDER. The inner skin of the air-bladders of the several varieties of sturgeon and cod furnishes a very pure glue substance, which on account of its purity is preferably used for culinary and medicinal pur- poses, and is known as " isinglass." It is inferior in adhesive power to hide-glue, but on account of its freedom from color, taste, and odor, and its almost perfect solubility in hot water, commands a higher price. It is used for food preparations, for clarifying wine, beer, and other liquids. The chief production of isinglass is from the sturgeon in Russia, on the borders of the Caspian and the Black Sea. 4. VEGETABLE GLUE. Certain species of algse (Plocaria tenax and others) found in Chinese and Japanese waters when cleansed and boiled yield a product known under the several names of " Chinese isinglass" and " agar-agar." Of similar character is no doubt the " algin" recently ob- tained from Scotch algse by E. C. C. Stanford, f n. Processes of Manufacture. 1. MANUFACTURE OF GLUE FROM HIDES. The hide trimmings and offal, if in the fresh state, must first of all be well limed, that is, treated * Die Fabrikation Chemischer Producte, etc., p. 60. t Soc. Chem. Ind. Jour., 1884, p. 297. PROCESSES OF MANUFACTURE. 323 with milk of lime in pits for a period varying from ten to forty days, ac- cording to the character and source of the hides, the lime being frequently renewed. The lime softens and swells the hide-tissue, saponifies the fats, and dissolves in large part the coriin, blood, and flesh-particles which do not form glue. The glue-stock is then thoroughly washed free from the lime, lime salts, and dirt, usually by putting it in nets or wicker baskets which are suspended in running water. The liming also serves to preserve the glue-stock in case it is not to be immediately worked up. After wash- ing it is spread out to dry. The lime scum from the pits is often utilized in fertilizer manufacture. Caustic soda has also been used instead of milk of lime for this treatment. A short treatment with chloride of lime im- mediately after taking the stock out of the lime-pits has also been found to give the glue a bright color and excellent adhesive power. In recent years sulphurous acid has been used with advantage to cleanse and prepare the glue-stock, as it bleaches and at the same time swells the hide, at least as well as can be done by the lime. The boiling and conversion of the glue-stock into solution may be effected by heating with water or with steam. The older method was to place the glue-stock in large kettles, but supported upon a false bottom of perforated metal, and adding water to heat it by direct fire. When the whole quantity of water necessary to convert the hides, etc., into glue solu- tion is used at once, the drawback is encountered that the gluten which first goes into solution becomes altered by the prolonged heating and loses its adhesive power. This can be obviated somewhat by using successive smaller portions of water and drawing them off as they become saturated, but the last portions extracted are then darkened in color. The use of steam, either from closed pipes or direct steam from perforated pipes, greatly improves the extraction, shortening the time required and improving the quality of the product. A form of boiler for this glue manufactured by the aid of steam as devised by Dr. B. Terne is given in Fig. 101. Direct high-press- ure steam blown into closed vessels has been found to be quite effective in rapidly melting down the glue-stock and producing a concentrated solution. The use of vacuum-pans and the extraction by steam under reduced pressure and at lower temperatures has also been found very satisfactory in giving a good product in which the adhesive qualities of the gluten are in no way impaired. The solution must be freed from any melted fat and lime soaps by skimming and from suspended impurities by settling, by filtering through linen bags, or clarifying by the use of bone-black. The addition of alum as sometimes practised has an injurious effect upon the adhesive power of the product. The residue of the glue-stock left unextracted is pressed out, dried, and sold as a fertilizer containing about four per cent, of nitrogen. The clarified glue solution is poured into shallow wooden moulds some six inches in depth, in which as it cools it gelatinizes to a brownish- yellow jelly containing eighty to ninety per cent, of water. The block of jelly -is then turned out upon a smooth table previously moistened to pre- vent adherence and sawed by horizontal wires into thin slabs, which are again cut by vertical wires into strips of the proper width. The drying of the jelly is one of the most troublesome parts of the whole process, as it must take place rapidly so that the glue-making ma- terial may not spoil, as it is very prone to do while in the jelly form, and, on the other hand, the heat should not exceed 20 C. (68 PA It may take place with this limitation of temperature in the open air, if the air is not 324 ANIMAL TISSUES AND THEIR PRODUCTS. FIG. too moist or too dry, both of which conditions are unfavorable. It is now generally effected in drying-rooms in which a current of warm dry air at the right temperature is made to circulate. As the surface of the cakes after drying is generally rough and dull, it is improved in appearance by moistening with warm water, brushing with a soft brush, and again drying. 2. MANUFACTURE OF GLUE FROM LEATHER-WASTE. Be- fore attempting to boil the leather- waste to glue, the removal of all traces of tannic acid be- comes absolutely necessary, since the retention of the smallest quantity prevents the animal tissue from dissolving in water. The waste must therefore be com- minuted as thoroughly as pos- sible to facilitate the complete removal of the tannic acid. This is done frequently in the "bol- lander" used for paper-pulp, and the washed and ground leather- waste then heated in a pressure- boiler under a pressure of two at- mospheres with fifteen per cent. of its weight of slaked lime. After thorough washing the residue is ready for use as glue-stock. 3. MANUFACTURE OF GLUE OR GELATINE FROM BONES. Two methods have been followed for the extraction of gelatine, as the product is generally called in this case, from bones. The bones are either boiled under pressure, or they are treated with hydrochloric acid to remove the calcium phosphate and afterwards boiled for the extraction of the gelatine. The bones in either case are with advantage deprived of their fat first, which is done either by heating them with water and steam in boiler-shaped vessels, when the fat rises and can be skimmed off from the water, or in closed vessels with volatile solvents like petroleum-benzine and carbon di- sulphide. The older process of extracting the gelatine by boiling the powdered bones with water under pressure decomposes a portion of the valuable material, and is now generally replaced by the method of treat- ment with hydrochloric acid for the removal of the calcium phosphate. The crushed bones are placed in wooden vats with dilute hydrochloric acid of specific gravity 1.05 (forty litres of acid to ten kilos, of bones) and allowed to remain for several days. They are then placed in lime-water for a time, well washed, and boiled eight to ten hours with a large excess of water, or converted more rapidly into gelatine solution by the aid of steam. The resulting solution is filtered through cloth, bleached by sulphurous oxide, and poured into forms to gelatinize. The manufacture of bone gelatine is frequently combined with the fertilizer manufacture, as the cal- cium phosphate extracted by the hydrochloric acid treatment contains from PRODUCTS. 325 eighteen to twenty per cent, of phosphoric acid. The newer method of ex- tracting the fat by volatile solvents yields five to six per cent, of fat with- out injury to the gelatine of the bones, while the older method of boiling out the fat yields from three to four per cent, only and tends to lessen the yield of gelatine. 4. MANUFACTURE OF FISH GELATINE. The swimming-bladders of the fish are taken and thoroughly washed in water from all fatty and bloody particles. They are then removed and cut longitudinally into sheets, which are exposed to the sun and air to dry, with the outer face turned down, upon the boards of linden or bass-wood. The inner face of the bladders is pure isinglass, which when partially dried can with care be removed from the outer muscular layer. The isinglass layer, possessing a silvery white lustre, is taken either in sheets, rings, or horseshoe-shaped strips, etc., bleached with sulphurous acid, and then thoroughly dried. A product distinct from isinglass and kno\vn as fish glue is prepared by boiling the skin and muscular tissue of fish, and more resembles ordinary hide glue in its adhesive properties, but is offensive in odor. It is prepared from the scales and skins of large fish like the carp by acting on them with hydrochloric acid as upon bones and then extracting with water. HI. Products. 1. HIDE GLUE is the variety which shows most strongly the adhesive property, and hence is that manufactured for joiner's and carpenter's use. Its color may vary considerably without any impairing of its adhesive power. It is rarely perfectly colorless or transparent. A gray to amber or brown-yellow color and translucent or partially opaque appearance is more usual. It should be clear, dry, and hard, and possess a glassy fracture. It should swell up but not dissolve in cold water, but dissolve in water at 62.5 C. (144.5 F.). Inorganic substances (such as white lead) are inten- tionally introduced into some varieties, such as the Russian glue, without injury to their adhesive power. The variety known as " Cologne glue" is manufactured from scrap hide, which after liming is carefully bleached in a chloride of lime bath and then thoroughly washed. " Russian glue," as stated, contains some inorganic admixture. It is of a dirty-white color, and contains from four to eight per cent, of white lead, chalk, zinc-white, or barytes. " Size glue" and " Parchment glue" are both skin glues prepared with special care. 2. BONE GLUE (OR BONE GELATINE). Bones yield a product of less adhesive power than the glue of skins and tendons, but when carefully worked the product is clearer and is free from offensive odor. It is there- fore much used for culinary purposes and for medicinal applications, and for fining or clarifying beer, wine, and other liquids it has largely superseded isinglass. The gelatine thus used must, however, be absolutely tasteless and free from odor. Bone gelatine is now made use of very largely in the manufacture of gelatine capsules, etc., for medicinal uses, of court-plaster for applying to wounds, and of gelatine emulsions with bromide and chloride of silver for coating the photographic dry plates. Mixed with glycerine it makes an elastic mass used for printer's rolls, for hectographs, etc. 326 ANIMAL TISSUES AND THEIR PRODUCTS. " Patent Glue" is a very pure variety of bone glue of deep dark-brown color. It is very glossy and swells up very much in water. 3. ISINGLASS (OR FISH GELATINE). This is the finest and best of ani- mal glues. The best isinglass should be pure white, nearly transparent, dry and horny in texture, and free from smell. It dissolves in water at from 35 to 50 C. (95 to 122 F.) without any residue, and in cooling should produce an almost colorless jelly. The commercial varieties of isinglass are the Russian (the best coming from Astrachan), North American (or New York), East Indian, Hudson's Bay, Brazilian, and German (or Hamburg). 4. LIQUID GLUE. By the action of nitric or acetic acid upon a solu- tion of glue its power to gelatinize may be completely arrested while its adhesive power is not at all interfered with. Thus, if one kilo, of glue is dissolved in one litre of water and .2 kilo, of nitric acid of 36 B. be added, after the escape of the nitrous fumes we have a solution that will not gela- tinize on cooling, although it has the full adhesive power of the glue. Four parts of transparent gelatine, four parts of strong vinegar, one part of alcohol, and a small amount of alum will also yield an excellent liquid glue. IV. Analytical Tests and Methods. The nature of glue makes it rather a question of physical and mechani- cal tests as to quality of a given sample than of chemical tests. 1. ABSORPTION OF WATER. Thus the relative amount of water that a given sample will take up when laid in cold water is regarded as a moder- ately fair criterion of its quality. A weighed sample is laid for twenty-four hours in cold water (not exceeding 12 C. (53.4 F.) in temperature), and at the expiration of that time the excess of water having been poured off, the jelly is weighed. Very good varieties (white gelatine prepared from bones) will take up thirteen times the quantity of water in gelatinizing, second quality glue ten times, and inferior grades only about six times the amount of water. At the same time the consistency of the jelly formed must also be taken into consideration. A firm jelly produced by the absorption of a large quantity of water indicates a glue of the best quality. Two observations are of value in this connection : first, glue twice dis- solved and again dried is capable of drying out more thoroughly and of showing water-assimilating properties on redissolving more fully than glue obtained by a single drying ; and, second, that hide glue on taking up smaller quantities of water becomes very soft and more difficult to weigh accurately than bone glue, which, with larger amounts of absorbed water, still forms a firm jelly. This difference in behavior alone is capable of giving an indication of the source of the glue. 2. INORGANIC IMPURITIES. The presence of inorganic salts, as in the case of Russian glue, can be determined by the use of the appropriate reagents, and the amount also quantitatively determined. 3. ADULTERATION OP ISINGLASS WITH GLUE. Isinglass is sometimes adulterated by rolling up sheets of gelatine (bone gelatine) between the lay- ers of true isinglass and drying them in this condition. Redwood and Letheby have observed that the ash of pure isinglass does not exceed .9 per cent, while glue contains from two to four per cent, of ash. An adulterated sample of isinglass gave Letheby 1.5 per cent, of ash. On heating with water, true isinglass gives only a peculiar fish or algse BIBLIOGRAPHY AND STATISTICS, 327 odor, while the adulterated isinglass gave a strong glue-like odor at once recognizable. V. Bibliography and Statistics. BIBLIOGKAPHY. ON LEATHER. 1865. Tanning, Currying, and Leather-Dressing, F. Dussauce, Philadelphia. 1867. Cuirs et Peaux ; Tannage, Corroyage et Megisserie, H. Villain, Paris. 1869. Die Gerberinde, J. G. Neubrand, Frankfort. 1872. Fabrication et Commerce des Cuirs et Peaux, C. Vincent, Paris. 1873. Die Rohstoft'e des Pflanzenreiches, J. Wiesner, Leipzig. 1874. Die Leder und Kaoutchouc Industrie, O. F. Deissinger, Braunschweig. 1875. Herstellung des Leders in ihren chemischen Vorgangen, J. C. H. Lietzmann, Berlin. 1876. Leather Manufacture, J. S. Schultz, New York. 1877. Die Weissgerberei, etc., F. Wiener, Leipzig. Leder-Industrie-Bericht uber die Austellung in Philadelphia, W. Eitner, Vienna. 1880. Classification de 300 Matieres tannantes, K. J. Bernardin, Gand. Die Gerberinden, F. K. von Hohnel, Berlin. The Culture of Sumach, Department of Agriculture, Special Report 26, W. Mc- Murtrie, Washington. 1881. Matieres premieres organiques, Geo. Pennetier, Paris. 1882. Die Grundzuge der Lederbereitung, Chr. Heinzerling, Braunschweig. 1885. Bericht der Commission der Gerbstoffbestimmung, etc., C. Councler, Cassel. The Manufacture of Leather, C. T. Davis, Philadelphia. Text-book of Tanning, H. R. Procter, London and New York. 1888. Abriss der chemischen Technologie, Chr. Heinzerling, Berlin. 1889. Handbuch der technisch-chemischen Untersuchungen, 6te Auf., Bolley, Leipzig. Hand-book of Commercial Geography, Geo. Chisholm, London and New York. Traite pratique de la Fabrication des Cuirs, etc., A. M. Villon, Paris. 1890. Lehrbuch der technischen Chemie, H. Ost, Berlin. Practical Hand-book of Leather Manufacture, Alex. Watts, 2d ed., London. Die Lohgerberei, F. Wiener, 2te Auf., Leipzig. 1891. Leather Manufacture, J. W. Stevens, London. ON GLUE AND GELATINE. 1871. Die Leimfabrikation, C. Hagen, Berlin. 1878. Die Fabrikation chemischer Producte aus thierischen Abfallen, H. Fleck, Braun- schweig. 1879. Die Leim und Gelatine Fabrikation, 2te Auf., F. Davidowsky, Vienna. 1884. Die Verwerthung der Knochen auf chem. Wege, W. Friedberg, Vienna. Glue and Gelatine, Davidowsky, translated by H. Brannt, Philadelphia. STATISTICS. 1. IMPORTATION OF TANNING MATERIALS INTO THE UNITED STATES. 1888. 1889. 1890. Catechu (or cutch), pounds 12,286,470 10,855,151 f Gambier, pounds 24,733,164 23.213,647 \ Catechu (or cutch), values $660,742 $581,596 J Gambier, values $1,079,678 $1,025,985 \ Sumach and sumach extract, pounds . 16,336,308 14,304,797 16,397,213 Sumach and sumach extract, values . $362,887 $292,572 $302,375 2. IMPORTATIONS OF TANNING MATERIALS INTO GREAT BRITAIN. 1888. 1889. 1890. Cutch and gambier, tons 28,135 25,107 27,445 Cutch and gambler, values 704,731 678,548 717,820 Valonia, tons 32,047 31,361 25,272 Valonia, values 457,634 454,405 501,669 328 ANIMAL TISSUES AND THEIR PRODUCTS. 3. IMPORTATIONS OF TANNING MATERIALS INTO GERMANY. 1888. 1889. 1890. Tons. Tons. Tons. Bark (piece and ground) 97,000 99,450 105,441 Gallnuts, valonia, etc 7,791 10,507 6,799 Catechu 6,874 7,287 7,350 Quebracho-bark 16,608 19,302 21,760 Sumach 5,916 7,124 7,519 Tanning extracts 7,186 8,531 7,718 4. UNITED STATES IMPORTATIONS OF RAW HIDES AND SKINS. 1888. 1889. Goat-skins, value $6,369,411 $7,668,472 All others, value $17,569,928 $17,459,278 1890. $9,106,082 $12,776,004 United States Importations of Tanned Skins. 1888. 1889. 1890. Calf-skins, values $1,363,081 $1,172,080 $1,195,271 Morocco skins, values $3,450,571 $3,416,935 $3,644,695 Upper leathers, values $2,088,512 $1,542,986 United States Exportations of Leather. 1888. 1889. 1890. Sole-leather, pounds 28,712,673 35,558,945 39,595,219 Sole-leather, values $4,959,363 $5,890,509 $6,420,134 5. ENGLISH IMPORTATIONS OF HIDES. 1888. 1889. 1890. Hides, dry, hundredweight 585,254 575,158 455,098 Hides, dry, values 1,648,358 1,573,132 1,191,240 Hides, wet, hundredweight 576,176 647,250 584,948 Hides, wet, values 1,353,663 1,500,455 1,323,176 English Exportations of Leather. 1888. 1889. 1890. Leather, unwrought, hundredweight . 159,138 143,140 153,110 Leather, unwrought, values 1,393,880 1,313,681 1, -388,024 6. IMPORTATION OF GLUE INTO THE UNITED STATES. 1888. 1889. 1890. Glue, pounds 5,282,248 5,059,492 .... Glue, values $483,422 $452,567 .... 7. GERMAN EXPORTATIONS OF GLUE AND GELATINE. 1889. 1889. 1890. Glue and gelatine, tons .... 3,888 3,705 3,960 Glue and gelatine, values . . . 4,317,000 marks 4,172,000 marks . . . EAW MATERIALS. 329 CHAPTER XI. INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. DESTRUCTIVE distillation has been defined as " the decomposition of a substance in a close vessel in such a manner as to obtain liquid products." It must be observed here that the word product is used to indicate some- thing not originally present in the substance distilled. A body may be obtained in the liquid distillate which has merely been driven over by heat and which already existed in the original material in physical or mechani- cal admixture. Such a body is, to speak exactly, an educt and not a product. The substances which are submitted to destructive distillation are in the main solids, as most classes of liquids are capable when heated with care of volatilization without decomposition, although such liquids as fatty oils, glycerine, etc., are decomposed if distilled under normal atmospheric press- ure. (The cracking of petroleum is another illustration of destructive dis- tillation of a liquid purposely brought about.) With solids, on the other hand, it is the exception rather than the rule to find one capable of melting and vaporizing unchanged in composition \vhen distilled under normal atmospheric pressure. The same solid, moreover, if of at all complex molec- ular composition, may decompose quite differently and yield different sets of products according to the conditions which govern the distillation. The most important of these modifying conditions is that of temperature. " Low temperature" distillation and " high temperature" distillation as practised upon the same material (wood or coal, for example) may yield quite differ- ent results. The physical condition or mechanical subdivision of the sub- stance also has an influence, although a subordinate one, upon the nature of the products. Solids, upon the destructive distillation of which important industries are founded, are wood, coal, shales, bones, and animal refuse. The distillation of shale has already been considered in connection with the mineral oil industry. (See p. 26.) The other industries will now be noted in succession. A. DESTRUCTIVE DISTILLATION OF WOOD. I. Raw Materials. 1. COMPOSITION OP WOOD. The wood which is to be destructively distilled is composed, we may say in general terms, of woody fibre and plant-juice or sap, which is an aqueous solution of the substances, both nitrogenous and non-nitrogenous, which serve as the food for the living plant. The woody fibre is made up primarily of cellulose, which is in part changed into " lignin," as the incrusting substance is called. In percentage composition this latter substance differs from the pure cellulose in contain- ing more carbon and less oxygen and hydrogen. The amount of incrusting material varies, being more abundant in hard and heavy varieties than in light and soft kinds, and wood which contains it in the largest proportion 330 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. gives the most acid and naphtha on distillation. The amount of water present in wood also varies not only according to the season of the year, but also quite widely in different woods cut at the same season. Thus, the following table of Schiibler and Hartig shows the percentage of water of different trees taken at the period of minimum amount : Per cent, of water. Beech 18.6 Willow 26.0 Maple 27.0 Elder 28.3 Ash 28.7 Birch 30.8 White hawthorn 32.3 Oak 34.7 White fir. . 37.1 Per cent, of water. Horsechestnut 38.2 Pine 39.7 Alder 41.6 Elm 44.5 Lime 47.1 Lombardy poplar 48.2 Larch . ". 48.6 White poplar 50.6 Black poplar ... ... 51.8 2. EFFECT OF HEAT UPON WOOD. The effect of heat upon wood in the absence of air is a matter which is to be carefully noted as throwing light upon the results obtained in destructive distillation. It of course dif- fers radically from the result of heating with free contact of air. Violette found that when wood was carefully and slowly heated no decomposition occurred under 150 C., water only being given off; between 150 and 160 C. the loss was two per cent, of the weight of the water-free wood ; between 160 and 170 C., 5.5 per cent. ; between 170 and 180 C., 11.4 per cent., and so on until at 280 C. 63.8 per cent, of volatile prod- ucts had been driven off and 36.2 per cent, only of the water-free wood remained in the retort. The products given off in this period of heating between 150 and 280 are the valuable liquid products known as pyrolig- neous acid (acetic acid and its homologues), wood-naphtha or methyl alcohol, methyl acetate, acetone, furfurol, the mixture of phenols known collectively as " wood-creosote," and other bodies of empyreumatic and tarry odor. These bodies differ, as will be seen later in very important respects, from coal-tar products. Above 280 C., the decomposition proceeds somewhat differently, hydrocarbons, both gaseous and liquid, being formed. The ad- ditional percentage of loss by weight between 280 and 350 C. is only 6.5 per cent, of the water-free wood, but it makes from eighty to ninety volumes of gas. The decomposition continues from 350 to 430 C., when the total loss by weight amounts to eighty-one per cent, of the water- free wood. The products obtained within these limits of temperature are largely solid hydrocarbons like paraffin and high temperature products like benzene and toluene, naphthalene, phenol and cresol. From 430 to 1500 C. the additional loss of weight is only 1.7 per cent. We may sum up these results by saying that three periods may be distinguished broadly for this decomposition of wood by heat: first, from 150 to 280 C., the period of watery acid products ; second, from 280 to 350 C., the period of gaseous products ; and, third, from 350 to 430 C., the period of liquid and solid hydrocarbons. Violette found also great difference in the re- sults according as the temperature was slowly raised or as the wood was rapidly brought up to a higher heat. Thus, one hundred parts by weight of wood slowly heated so that the temperature of 432 C. was only reached after six hours left 18.87 parts of charcoal, while one hundred parts of the same wood put into a retort previously heated to 432 C. left only 8.96 parts by weight of charcoal. PROCESSES OF MANUFACTURE. 331 n. Processes of Manufacture. 1. DISTILLATION OF THE WOOD. The primitive method of distilling wood devised by the charcoal-burners, in which the wood was piled up in large heaps covered in by clay and turf so as to form a circular dome-shaped mound, is still followed in some heavily-wooded districts. Of course the charcoal is the only product sought in this case, and the gaseous and liquid products of the distillation are allowed to escape. In Russia and Sweaen the charcoal-burning in mounds is now frequently combined with the col- lection of the tar, which as it condenses is made to flow through inclined troughs, and is drawn off from below. In this way the valuable birch-bark tar (see p. 318) and kienoel (Russian turpentine oil) are obtained. For a proper collection of all the products of the destructive distillation of wood, however, it is essential that the distillation be carried out in retorts provided with proper condensation apparatus. These retorts may be either set in horizontal or vertical position, and may be either fixed or capable of re- moval for emptying and re-charging. It is found convenient in large works where it is desirable to carry on the distillation continuously to have a series of retorts connected with one and the same condensation apparatus and FIG. 102. heated by the same flues. Such an arrangement of retorts is shown in Fig. 102. This arrangement allows of the removal and re-charging of a single retort without interrupting the working of the others. The heating should be conducted slowly at first so that the maximum yield of the low tem- perature products, acetic acid and methyl alcohol, may be obtained, then 332 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. increased until the gas comes off freely, and at the end of this stage of the decomposition again strengthened to drive over the high temperature products characteristic of the last period of distillation. As the maximum temperature needed is beyond the record of the mercury thermometer, a pyrometer can be used or a small bar of metallic antimony which melts at 432 C. taken as indicator. Superheated steam has also been used as a means of accurately controlling the application of heat in the distillation, and it is said that the majority of European works manufacturing charcoal for gunpowder purposes use this method of distillation. The liquid which runs off from the condenser is at first wax-yellow in color, but becomes dark-colored, reddish-brown, and eventually nearly black and quite turbid. When allowed to stand at rest it soon separates in two sharply distinct layers, the lower one of a thick tar, dark or perfectly black in color, and the upper one, which is much the larger in amount, is the crude pyro- ligneous acid and is reddish-yellow or reddish-brown in color. A light film of oil often covers, in part at least, this watery layer and represents the benzene hydrocarbons produced. We have already noted the fact that the yield of liquid products was aifected greatly by the temperature used for distillation. Different varieties of wood also vary somewhat in the results obtained, even when distilled under the same conditions of tempera- ture. This is illustrated in the following few examples : * Charcoal. Tar. Crude pyro- ligneous acid. Containing actual acid. Gases. Red beech / slowl y heated .... h \rapidly heated . . . T>. i f slowly heated . 26.7 21.9 29.2 5.9 4.9 5.5 45.8 39.5 45 6 5.2 3.9 5 6 21.7 33.8 19 7 t rapidly heated 21.5 3.2 39.7 4 4 35 6 f\ i ( slowly heated . 34.7 3.7 44 5 4 1 172 Oak-< .y, i- x j (. rapidlv heated 27.7 3.2 420 3 4 27 T>. ( slowly heated . 30.3 4 4 41 2 7 24 4 \ rapidly heated .... 242 9 8 42 2 4 24 1 Beech-wood and foliage trees in general yield distinctly more acid than coniferous trees, but the latter yield more tar of terebinthinate character. The figures given above, it must be remembered, however, were gotten in experi- ments with small portions. In practice, working with larger quantities, the yield of several of the products is notably larger. The yield of wood-spirit, or methyl alcohol, varies from five-tenths to one per cent, of the weight of the dry wood. The emptying of the retorts, if done as intended while the charcoal is yet glowing, involves the use of air-tight pits into which the charcoal can be emptied from the retorts and immediately covered with moist charcoal- powder to prevent loss by combustion. A form of apparatus for distilling the sawdust so abundantly produced in wood-working processes has been de- vised by Halliday, of Salford, England, and is said to work satisfactorily in practice. It is shown in Fig. 103. It consists of a horizontally placed cylindrical retort, A, within which revolves an endless screw, B. The saw- dust is regularly fed in through the vertical pipe C, and falling upon the * Ost, Lehrbuch der technische Chemie, p. 294. PROCESSES OF MANUFACTURE. 333 screw is kept moving at a uniform speed along the entire length of the heated retort. At the farther end the vapors and gaseous products of the distillation escape through an ascending pipe, K, leading to the condenser, while the powdered charcoal drops through the pipe D into water, where it is at once quenched. A general view of the products of the distillation of wood and their subsequent treatment is given in the accompanying diagram taken from Post.* 2. TREATMENT AND PURIFICATION OF THE CRUDE WOOD-VINEGAR. The brown aqueous solution poured off from the tarry layer (see above) has a strong empyreumatic odor, and contains, besides the acetic acid, methyl alcohol, acetone, and homologous ketones, allyl alcohol, homologues of acetic FIG. 103. acid (such as formic, propionic, butyric, and valerianic acids), methyl acetate, acetate of ammonia and of methylamine, aldehyde, furfurol, phenols, and other empyreumatic and tarry bodies. It is not used in its crude condition except in the preparation of the crude pyrolignite of iron (iron-liquor} or in limited amount for impregnating wood. The first step towards purification is to separate the wood-naphtha (the fraction containing the methyl alcohol acetone and methyl acetate) from the wood-vinegar (crude acetic acid), which is done by distillation. Two procedures are possible here. Either to neu- tralize *the crude pyroligneous acid with milk of lime and then distil off the volatile constituents only, using an iron still, or to distil the crude pyro- * Post, Chern. Technologic, p. 78. 334 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. H Q O O fc O H 2 H W H P 2 O s D Q O OH "ol si a H r-S- 1 i ? 1 25 - :i. > = -g? J i- i _ ftO j 3 3 g si s ' s * II 5' 4B HO a "S 2* 33 ga > o- i 8 ri J u ft ^ ft O w 43 0) 1 e ft I S ^ - 1 ^ O W -2 UM A ke im < 2 o S as M a, M B- BH m ou n A JJ-^. oftSo . . = a^ M ^^s-s-SS- i o .5 i M _^>.-S^ 8cj o - 5-G5 M O o3 -H o cc " o O -r^ C _ PROCESSES OF MANUFACTURE. 335 ligneous acid from a copper still without neutralizing with lime. In the former case, while the wood-naphtha distils off the tarry impurities of the crude pyroligneous acid remain with the lime salt in the still, and on evap- oration a dark mass is obtained known as " brown acetate of lime." In the latter case, after catching the wood-naphtha distillate, the receiver is changed and the crude acetic acid is also collected freed to a considerable extent from tarry matter, so that on neutralizing with milk of lime and evaporating the product is a lighter salt known as " gray acetate of lime." The latter process is now more generally in use. The solution of the cal- cium acetate is evaporated in iron pans ; the phenols and tarry products which volatilized with the acetic acid separate largely as scum and may be skimmed off, so that the residue of the evaporation is much purer than the product of the other method mentioned above. If the brown acetate of lime has been obtained and is to be further worked for acetic acid, it is found necessary to roast it at a temperature not exceeding 250 C. so as to drive off as much of the tarry impurity as pos- sible without decomposing any of the acetate. If, on the other hand, the gray acetate is taken, it is distilled from copper retorts with concentrated aqueous hydrochloric acid, taking care to avoid an excess. The acetic acid distils over between 100 and 120 C., is clear in color and has only a slight empyreumatic odor. Its specific gravity usually ranges from 1.058 to 1.061, and it contains about fifty per cent, of pure acetic acid. If some water is added with the hydrochloric acid so that the distilled acetic acid is more dilute it tends to give a purer product, as the liberated acetic acid can- not decompose any of the calcium chloride before coming over. A good proportion is said to be one hundred parts of acetate of lime, ninety tc ninety-five of hydrochloric acid of 1.160 specific gravity, and twenty-five parts of water. The acetic acid so obtained has, as was just stated, a slight empyreumatic odor. It may be freed from this by distilling with two to three per cent, of potassium bichromate. A trace of empyreumatic odor is also removable by filtration through freshly-ignited wood charcoal. The distillation with hydrochloric acid is much to be preferred to the older method with sulphuric acid, whereby gypsum was formed instead of the freely soluble chloride of calcium, and the sulphuric acid was frequently reduced by the organic impurities of the crude acetate with the formation of sulphurous acid, which is an impurity difficultly removable from the acetic acid. The brown acetate of lime usually contains about sixty-eight to sixty- nine per cent, of pure acetate, while the gray acetate contains from eighty- five to eighty-six per cent, of true acetate. In recent years it has been found practicable to prepare pure acetic acid from the crude pyroligneous acid by making the sodium salt instead of the lime salt. The sodium salt allows of purifying by recrystallization, and can also be fused without decomposition, two positive advantages over the lime salt. Glacial acetic acid is always made by distilling the anhydrous and fused sodium acetate with concentrated sulphuric acid. 3. PURIFICATION OF THE CRUDE WOOD-SPIRIT. The wood-spirit forms the first fraction when the crude pyroligneous acid is distilled, and amounts to perhaps one-sixth of the latter in bulk. It is usual to collect, however, until the hydrometer reading of the distillate, which begins at about .900, has risen to 1.000 or a little beyond. This distillate forms a greenish-yellow liquid of unpleasant odor and contains many impurities 336 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. besides the acetone and methyl acetate, the chief substances which are pres- ent with the methyl alcohol. Milk of lime is first added and allowed to stand with the liquid for several hours. The mixture heats up quite dis- tinctly as the lime combines with any free acid and begins to decompose the methyl acetate and other ethereal compounds of acetic acid, small quantities of ammonia often being given off. It is then distilled by connecting it with a column rectifying apparatus. (See p. 211.) The distillate thus obtained, of about .816 specific gravity, is colorless at first but gradually darkens in color, and if diluted with water becomes milky from separated oily hydro- carbons and ketones. It is therefore diluted down with water to about .935 specific gravity and allowed to stand until this oily impurity rises to the top in a distinct layer. The diluted spirit is again distilled over lime once or twice with a rectifying column and so brought to ninety -eight or ninety-nine per cent, strength. The acetone impurity, however, is not removed by any of these rectifications, as the boiling-point of acetone (56.4 C.) and methyl alcohol (55.1 C.) do not allow of their separation in this way. To re- move the acetone a number of methods have been proposed. The methyl alcohol may be converted into the solid chloride of calcium compound, or the oxalate of methyl and the acetone having been removed by careful heat- ing, the methyl compound is decomposed by water or alkali. Or the methyl alcohol is distilled over chloride of lime, which reacts with the acetone to form chloroform. Or after adding iodine and then caustic alkali until the solution is again decolorized, the methyl alcohol is distilled off from the iodoform produced from the acetone. The passing in of chlorine in order to convert the acetone into high boiling chloracetones, which are then sepa- rated from the methyl alcohol by distillation, has also been proposed. 4. TREATMENT OF THE WOOD-TAR. The tar which has separated from the crude pyroligneous acid by settling, and that which has risen and been skimmed off in the neutralizing of the acid, are united and submitted to dis- tillation in horizontally-placed iron retorts, which are set at a slight inclina- tion. At first acid-water comes over, then light oils, and finally heavy oils until no more will distil. The pitchy residue is run out while hot, so that it does not adhere to the walls of the retort. The relative amounts of the several fractions from the tar depend upon the nature of the wood used in the original distillation and upon the way that distillation has been carried out. Hard woods usually give a tar which, according to Vincent, when redistilled yields as follows : Aqueous distillate (wood-spirit and pyroligneous acid) . . 10 to 20 per cent. Lighter oily distillate (specific eravity .966 to .977) . . . 10 to 15 " " Heavy oily distillate (specific gravity 1.014 to 1.021) ... 16 " Pitch .... 50 to 65 " " The oily distillates are washed with weak soda to remove adhering acid and then carefully rectified, when the oils coming over under 150 C. are collected for solvent and varnish-making purposes, those between 150 and 250 C. collected as creosote oils, and those above 250 C. used for burning oils. The creosote oil, which is the most valuable part, is thoroughly agitated with strong caustic soda solution, the aqueous layer drawn off, mixed with sulphuric acid, and allowed to stand for a time at rest, when the creosote oil separates out. This is best driven off by steam distillation and again rectified finally from glass retorts. PRODUCTS. 337 Stockholm tar, so largely used in ship-building, is the product of a rude distillation of the resinous wood of the pine. North Carolina pine-tar is also the product of a distillation of the pine. The billets of pine-wood are piled in heaps like a charcoal-burner's mound, though not so large, covered in with clay and turf, and lighted from the top. The resin or tar distils downward and runs off through inclined troughs previously fixed for it. It is obvious that the composition of both the Stockholm and the North Carolina tar differs notably from that of wood-tar distilled in retorts from hard woods. This composition will be referred to later. EL Products. 1. PYROLIGNEOUS ACID AND PRODUCTS THEREFROM. The crude acid as obtained in the distillation is a clear liquid of reddish-brown color and strong acid taste, with a peculiar penetrating odor described as empyreu- matic, and now known to be due largely to the furfurol it contains. It possesses a specific gravity of from 1.018 to 1.030 and contains from four to seven per cent, of real acetic acid. Pyrolignite of iron (iron or black liquor) is a solution of ferrous acetate with some ferric acetate, prepared by acting upon scrap-iron with crude pyroligneous acid. It forms a deep- black liquid, and is concentrated by boiling to 1.120 specific gravity, when it contains about ten per cent, of iron. It is extensively used by calico- printers. Brown and gray acetate of lime have been already referred to. Other technically important acetates are lead acetate (sugar of lead), used in the preparation of the alum mordants and the lead pigments ; copper acetate, the basic salt of which is known as " verdigris ;" aluminum acetate, the solution of which is used in calico-printing under the name of " red liquor." Pure acetic acid is a colorless acid liquid with pungent smell and taste. It crystallizes when chilled in large transparent tablets, melting at 16.7 C., whence the name "glacial acetic acid." Its specific gravity at 15 C. is 1.0553, and it boils under normal pressure at 119 C. 2. METHYL, ALCOHOL, AND WOOD-SPIRIT. As before stated, crude wood-spirit is a complex liquid and contains many impurities. The per- centage of real methyl alcohol may rise to ninety-five per cent., but more generally ranges from seventy-five to ninety per cent. Some impure wood- naphthas go much lower, however, than this. A large percentage of acetone does not interfere with its use as a solvent for resins and for var- nish-making, but does interfere with its use in the aniline-color industry, where a very pure methyl alcohol is needed for the manufacture of dimethyl aniline. The methods of freeing methyl alcohol from the two chief im- purities, methyl acetate and acetone, have already been referred to. Pure methyl alcohol has a purely spiritous odor, a specific gravity of .7995 at 15 C., and boils at 55.1 C. It is miscible in all proportions with water, ordinary alcohol, and ether. 3. ACETONE. This substance is of interest as always produced in the distillation of wood, and hence present in the crude wood-spirit. The acetates also yield it as the chief product when submitted to dry distillation. At present it is made on a large scale by distilling the gray acetate of lime in iron stills provided with mechanical agitation at a temperature of about 290 C. When purified, it is a colorless liquid of peculiar ethereal odor and burning taste, and like methyl alcohol is miscible in all proportions with ether, alcohol, and water. It is an excellent solvent for resins, gums, 22 338 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. camphor, fats, and pyroxylin, or gun-cotton. It does not form a compound with dry calcium chloride, and can thus be separated from methyl alcohol when in admixture with this latter. Chlorine and iodine in the presence of an alkali react with acetone to form chloroform and iodoform. 4. CREOSOTE. Wood-tar creosote is a strongly refracting liquid, which is colorless when freshly distilled but gradually acquires a yellow or brown color. It has a smoky aromatic odor, which is very persistent and is quite distinct from that of carbolic acid. It has a specific gravity ranging from 1.030 to 1.080, and boils between 205 and 220 C. It is a powerful antiseptic, and is largely used to preserve meats, etc. It differs from coal- tar creosote in containing relatively little common phenol (carbolic acid) and relatively large amounts of higher phenols, such as phlorol, C 8 H 9 .OH, guaiacol, C 7 H 7 O.OH, and creosol, C 8 H 9 O.OH. 5. PARAFFINE. This mixture of solid hydrocarbons, as already said, occurs in the higher boiling distillate gotten from wood. It is of interest to recall that paraffine was first discovered by Reichenbach in beech-wood tar. At present, however, the extraction of paraffine from wood-tar is not to be thought of because of the cheapness of its production from petroleum and bituminous shales. It has been already described under the chapter on Petroleum. (See p. 30.) 6. CHARCOAL. We have already shown in the table of results of slow and rapid distillation of wood (see p. 332) that the relative amount of char- coal depends upon the manner of heating, being larger with gradual appli- cation of heat and smaller with rapid heating. The properties and chemical composition of the charcoal are similarly dependent upon the temperature to which the wood is heated. Wood is stated to become brown at 220 C., at 280 C. it becomes a deep brownish-black and begins to be friable, and at 310 C. forms an easily friable black mass taking fire easily. That prepared at higher temperatures is harder and less readily ignited, and it eventually becomes graphitic and rings with a metallic sound when struck. The accom- panying table from Violette shows the gradual change in the composition of charcoal prepared at different temperatures from the same kind of wood (buckthorn) : Heated to Carbon, per cent. Hydrogen, per cent. Oxygen, nitro- gen, and loss. Ash, per cent. Dry wood 150 C. 47.51 6.12 46.29 0.08 Charred wood 260 C. 67 85 5.04 26.49 0.56 Red charcoal 280 C. 72.64 4.70 22.10 0.57 Brown charcoal .... 320 C. 73.57 4.83 21.09 0.52 Dull black charcoal . . . 340 0. 75.20 4.41 19.96 0.48 Lustrous black charcoal . 432 C. 81.64 1.96 15.25 1.16 Extreme white heat . . 1500 C. 96.52 0.62 0.94 1.95 IV. Analytical Tests and Methods. 1. ASSAY OF PYROLJGNEOUS ACID AND CRUDE ACETATES. The crude pyroligneous acid, as before stated, contains from four to seven per cent, of real acetic acid. Its strength may be ascertained by titration with standard alkali, using phenol-phthalein as an indicator. If the liquid is too dark to allow of the end reaction being readily seen, it can be diluted sufficiently, as the reaction will still be sufficiently delicate. In the absence ANALYTICAL TESTS AND METHODS. 339 of sulphates in the sample, the acetic acid can be determined by adding excess of pure precipitated barium carbonate to the solution, filtering, and determining the barium in the filtrate by the aid of sulphuric acid. As the pyroligneous acid is largely converted into calcium acetate in the process of purifying, the analysis of the brown or gray acetate of lime as a common commercial product becomes of some importance. This commercial acetate may contain from sixty-five to eighty per cent, of true acetate of lime, with carbonate of lime, so-called " tar-lime," and empyreumatic matter as chief impurities. The acetic acid determination may be made by different methods, but the most accurate according to the experience of the author is the distillation method, as suggested by Stillwell and Gladding. One gramme of the sample of acetate of lime is placed in a small distillation bulb or flask with a long neck, a little distilled water added, and then a solution of five grammes of glacial phosphoric acid dissolved in ten cubic centimetres of water. The flask is then heated to distil off the acetic acid, care being taken to avoid spurting and mechanical carrying over of any of the phosphoric acid. When the contents have nearly gone to dryness, some twenty-five cubic centimetres of distilled water are introduced and the distillation re- peated. If this is done some three or four times, the distillate will be found to be free from acid reaction. The combined distillate is then brought to definite volume and titrated with decinormal soda solution, using phenol- phthalein as indicator. 2. DETERMINATION OF METHYL ALCOHOL IN COMMERCIAL WOOD- SPIRIT. But one method, and that not capable of the most accurate working, is at present available. Five cubic centimetres of the sample of wood-spirit are allowed to drop slowly upon fifteen grammes of phosphorous di-iodide placed in a small flask of some thirty cubic centimetres capacity. This is con- nected with an inverted condenser and cooled externally while the reaction takes place. Five cubic centimetres of a solution of one part iodine in one part of hydrogen iodide of 1.7 specific gravity is then added and the mixture gently digested for a quarter of an hour, when the condenser having been turned downward the iodide of methyl formed is distilled off. It is col- lected in a graduated tube divided into one-tenth cubic centimetres, washed with some fifteen cubic centimetres of water with vigorous agitation, allowed to settle, and the volume read off. Five cubic centimetres of pure and perfectly dry methyl alcohol should give 7.45 cubic centimetres of iodide of methyl. 3. DETERMINATION OF THE ACETONE IN COMMERCIAL WOOD-SPIRIT. This may be done by either the Kraemer and Grodzki gravimetric method or the Messinger volumetric method, both of which depend upon its quanti- tative conversion in the presence of iodine and caustic alkali into iodoform. In the former case, one cubic centimetre of the sample of wood-spirit is mixed with ten cubic centimetres of a double normal solution of caustic soda (eighty grammes to the litre), and to the mixture, after thorough agita- tion, is added five cubic centimetres of a solution containing two hundred and fifty- four grammes of iodine and three hundred and thirty-two grammes of potassium iodide to the litre. The iodoform which separates on agitation is dissolved by the addition of ten cubic centimetres of ether free from alcohol. An aliquot portion of the ethereal layer is then pipetted off into a tared watch-crystal, and the iodoform remaining after evaporation is weighed. Three hundred and ninety-four parts of iodoform correspond to fifty-eight parts of acetone. More accurate is the Messinger volumetric process. In this, twenty cubic centimetres (or thirty cubic centimetres in 340 INDUSTEIES BASED UPON DESTRUCTIVE DISTILLATION. samples rich in acetone) of normal potash solution and one or two cubic centimetres of the wood-spirit in question are shaken together in a stop- pered 250-cubic-centimetre flask and a known quantity (twenty or thirty cubic centimetres) of a one-fifth normal iodine solution added. The mixture is shaken until the supernatant liquid clears perfectly on momentary stand- ing, hydrochloric acid of 1.025 specific gravity is added in amount equal to the potash solution before used, and excess of decinormal sodium thio- sulphate run in. Starch paste is then added, and the excess of sodium thiosulphate titrated with one-fifth normal iodine solution. If r be the volume in cubic centimetres of the iodine solution required to combine with the acetone, and n the volume in cubic centimetres of the methyl alcohol taken, then the quantity of acetone by weight in one hundred cubic centime- , ,, , . r X .193345 tres 01 the sample is equal to n 4. QUALITATIVE TESTS FOR WOOD-TAR CREOSOTE. Allen * enumer- ates the following tests as characteristic of wood-tar creosote or as sufficing to distinguish it from coal-tar creosote : (1) An alcoholic solution of wood- creosote should not give any coloration whatever (neither blue nor reddish) with baryta-water ; (2) wood-tar creosote is practically insoluble in strong ammonia ; (3) wood-tar creosote is also distinguished from the coal-tar acids by its reaction with an ethereal solution of nitrocellulose. Shaken with half its measure of collodion solution carbolic acid coagulates the gun-cotton to a transparent jelly. Creosote does not precipitate the nitrocellulose from collodion but mixes perfectly with the ethereal solution ; (4) wood-tar creo- sote is sharply distinguished from the coal-tar acids by its insolubility in absolute glycerine (specific gravity 1.26), whether one, two, or three times its volume of that liquid be employed. B. DESTRUCTIVE DISTILLATION OF COAL. N . I. Raw Materials. Probably the most important industry involving the destructive distilla- tion of coal is the manufacture of illuminating gas. The classes of coals em- ployed for the purpose are confined to those varieties which are bituminous in their nature, yielding when distilled volatile hydrocarbons in varying quan- tity. The uncombined or " fixed carbon," with the mineral constituents originally present in the coal, remaining after the distillation comprise coke. Bituminous Coals have the property, not possessed by the anthracites, of softening and apparently fusing when subjected to a temperature below that at which combustion would take place. This fusion indicates the com- mencement of destructive distillation, when both solid, liquid, and gaseous carbon compounds are formed. Bituminous coal is essentially a coking coal, and as such is, to a very great extent, employed in the coking regions of Western Pennsylvania. It is black or grayish-black in color, of a resinous lustre, and somewhat friable, being easily broken into cubical fragments of more or less regularity ; upon ignition it burns with a yellow flame. When it is heated to bright redness in retorts or ovens, free from the access of air, the volatile matter, before mentioned, carbon compounds of hydrogen and of oxygen, with water, pass off. Coals having a large percentage of hydro- gen will yield more volatile substances at the temperature of distillation * Commercial Organic Analysis, 2d ed., vol. ii. p. 568. RAW MATERIALS. 341 and less carbonaceous residue than others which may contain less hydrogen and more carbon, approaching anthracite in composition. Coking and Non-coking Coals are quite similar in chemical composition ; the coking varieties contain less volatile matter, however, than the non- coking ; the latter do not possess the property of fusing to a compact " coky" mass, but retain their original form, and yield a coke which has no commercial value unless it is obtained from large pieces of the coal. Cannel Coal is much more compact than gas or coking coals, duller in appearance, possessing a grayish-black to brown color, and burning with a clean candle-like flame. It does not soil the hands, and is not readily frac- tured. It is capable of taking a high polish, and can be cut or turned into articles for use or ornamentation. Cannel coal occurs in large quantities in West Virginia, and near Glasgow, Scotland, in Lancashire, England, and at other localities. Destructively distilled, it yields a larger amount of volatile matter and ash, with much less coke, than the bituminous coals. Brown Coal, or Lignite, appears to occupy an intermediate position be- tween the bituminous coals and wood. It retains the ligneous structure of the material from which it is formed, hence the name Lignite. The vege- table remains in a great many cases are quite distinct. The color varies from yellowish-brown in the earthy, to black in the more compact, coal-like varieties. The percentage of carbon contained is low, fifty to eighty per cent., though rarely exceeding seventy per cent., while the hydrogen is from 4 to 6.85 per cent. Oxygen and nitrogen are present in variable quan- tities from 7.59 to 36.1 per cent. The ash in good qualities is low, in earthy specimens is high, in many cases exceeding fifty per cent. Lignite does not yield coke. Aside from being utilized as fuel in the several local- ities where it is found, for both domestic and industrial purposes, it has been distilled for volatile constituents in Saxony. Peat, or Turf, occurring in large areas in Ireland and in some parts of Europe, consists of the decayed remains of certain forms of plants. It has been, according to Mills, destructively distilled for tarry products, the in- dustry, however, being no longer profitable. The following tables, taken from the Reports of the Second Geological Survey of Pennsylvania, show the analyses of some of the more important varieties of American gas coals, coking coals, and non-coking, or block coals. /. Gas Coals. WESTMORELAND COAL COMPANY. PENNSYLVANIA GAS COAL COMPANY. South Side Mine. Foster Mine. Larrimer, No. 2. Irwin, No. 1. Irwin. No. 2. Sewickley. Water at 225 . . Volatile matter . Fixed carbon. . Sulphur .... Ash 1.410 37.655 54.439 0.636 5.860 1.310 37.100 55.004 0.636 5.950 1.560 39.185 54.352 0.643 4.260 1.780 35.360 59.290 0.680 2.890 1.280 38.105 54.383 0.792 5.440 1.490 37.153 58.193 '0.658 2.506 Total .... 100.000 100.000 100.000 100.000 100.000 100.000 Coke, per cent. . Fuel ratio . . . 60935 1:1.47 McCreath. 61.590 1:1.48 McCreath. 59.255 1:1.38 McCreath. 62.860 1 : 1.67 McCreath. 60.615 1 : 1.42 McCreath. 61.357 1:1.56 McCreath. 342 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. //. Coking Coals. Connells- ville, Frick & Co. Bennington, Cambria Iron Company. Broad Top, Barnet. Broad Top, Kelley. Cumber- land. Huntingdon County, Alloway Colliery. Moisture .... Volatile matter . Fixed carbon . Sulphur .... Ash 1.260 30.107 59.616 0.784 8233 1.400 27.225 61.843 2.602 6930 16.00 74.65 1.85 750 19.68 71.12 1.70 7 50 1.10 15.30 73.28 1.23 908 0.250 14.510 77.042 1.338 6 860 Total. . . . 100.000 100.000 100.00 100.00 100.00 100.000 Coke, per cent. . Fuel ratio . . . 68.63 1 : 1.98 McCreath. 71.375 1:2.27 McCreath. 81.00 T.T.Morrell. 71.00 T. T. Morrell. 83.59 1 : 4.78 McCreath. 85.24 1:5.30 McCreath. III. Non-coking Coals (Block Coat). Mercer County, Pa., Sharon Coal. Youngstown. Ohio. Mercer County, Pa. Straitsville, Ohio. Brazil, Ind. Moisture .... Volatile matter . . Fixed carbon . . Sulphur 3.79 35.30 53.875 0675 3.60 32.58 62.66 (085) 3.80 25.49 68.03 1 04 36'.50 55.60 96 4o!l5 57.20 75 Ash 6 36 1 16 1 70 6 94 1 90 Total .... 100.000 100.00 100.06 100.00 100.00 Coke, per cent. . . 60.91 McCreath. Wormley. Jno. Fulton. 61.00 Wormley. 58.00 Prof. Cox. Effects of High or Low Temperature in the Distillation of Coal. Coal when distilled at a low temperature yields products of a very different nature from those obtained if the temperature employed had been high. On this subject Professor Edmund T. Mills, of Glasgow, in his little man- ual on " Destructive Distillation" (3d ed., p. 9), states that " at a very high temperature the products from coal and shales are carbon and carbonized gases of low illuminating power, with but little liquid distillate ; at a low temperature there is much liquid product and gas of high illuminating power. The greatest amount of liquid product of low boiling-point is found in American and Russian petroleums, which have probably been produced by the long-continued application of a very gentle natural heat. " When coal is slowly heated (as must be to a great extent the case when it is broken fine, or when a large retort is used), its oxygen is chiefly con- verted into water ; when rapidly heated, the oxygen is expelled as carbonic oxides." To show the verification of these principles in practice, the results of high and low temperature distillation upon three different coals may be quoted from the same authority : RAW MATERIALS. 343 Yield of Gas, Oil, etc., from Shales and Coals at High and Low Heats. GOOD SUALIS. BOGHEAD COAL. GAS COAL. High heats. Low heats. High heats. Low heats. High heats. Low heats. 4ti 3 1 =3 -3 ' ~~ 03 1" Coke Coke or c Speci coa ' Gas 13.65 3.65 11.04 0.99 2.82 2.54 6.47 17.65 37.32 2.43 20.65 0.18 0.80 4.83 3.23 50.29 20.49 3.09 17.08 0.29 4.15 6.49 7.24 26.45 Ammonia-water . . Tar or oil Sulphur Water at 212 .... f Fixed carbon . . . < Sulphur 32.15 4.16 1.05 62.64 26.66 10.81 62.53 61.38 9.01 0.06 29.55 58.35 12.40 29.25 45.10 45.00 0.34 9.56 40.18 49.93 '9.89' (_ Ash (dry) per ton of shale oaf 67.85 73.34 38.62 41.65 54.90 59.82 100.00 100.00 100.00 100.00 100.00 100.00 1,520 Ibs. l.f 1,642.2 Ibs. 18 865 Ibs. LJ 934 Ibs. 24 1,230 Ibs. 1.5 1,340 Ibs. 96 ic gravity of shale or NOTE. The low heat results were gotten by distilling the sample in a two-inch iron tube in a gas- furnace. Lunge (Coal-Tar and Ammonia, 2d ed., p. 17) states that "The quan- tity, and to a much greater extent the quality, of the tar are influenced by the temperature at which the decomposition of the case is carried on. Low temperatures, with nine thousand cubic feet of gas per ton of coal, will yield, with some coals, sixteen gallons of tar ; whilst at high temperatures the yield will be but nine gallons, with about eleven thousand cubic feet of gas, from the same coal."* If the temperature being a comparatively low one, mostly such hydrocarbons are formed as belong to a paraffin (methane) series, having the general formula C n H 2n + 2 , along with the olefins, C n H 2n . The lower members of this series are liquid, and, furnished in the pure state, are lighting and lubricating oils ; the higher ones are solid and form commercial paraffine. They are always accompanied by oxygenized deriva- tives of the benzene series (phenols) ; but of these the more complicated ones predominate, in some of which methyl occurs in the benzene nucleus, in others replacing the hydrogen of hydroxyl, e.g., cresol, C 6 H 4 (CH 3 )(OH) ; guaiacol, C 6 H 4 (OH)(OCH 3 ) ; creosol, C 6 H 3 (CH 3 )(OH)(OCH 3 ), etc. Liquid products prevail ; and among the watery ones acetic acid (which is again a compound of the fatty series) is paramount. Of course also permanent gases are always given off, though in comparatively small quantity. If, on the other hand, the coal has been decomposed at a very high temperature, the molecules are grouped quite differently. Whilst the olefins and members of the acetylene series still occur more or less, the hydrocarbons of the paraffin series disappear almost entirely; and from them are formed on the one hand compounds much richer in carbon, on the other hand more hydrogenized bodies. The latter always occur in the gas- eous state ; hence the gas so produced contains methane, or marsh-gas,' CH 4 , and free from hydrogen as principal constituents, and is very much increased in quantity. The carbon ttms s'et free is partly cbposited in the retorts themselves, arid then occurs in a very compact grajmitoidal form ; another * . * Davis, Journ. Soc. Chem. Ind., 1886, p. 5. 344 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. portion of the free carbon occurs in a state of extremely fine division in the tar, and forms a constituent of the pitch or coke remaining behind from tar-distilling ; another portion contributes to the formation of compounds richer in carbon, belonging to the " aromatic" series, all of which are de- rived from benzene, C 6 H 6 . At the same time the action of heat effects further molecular " condensations," usually with separation of hydrogen, by which process compounds of a higher molecular weight are formed, as naphthalene, anthracene, phenanthrene, chrysene, etc. The never absent oxygen must also in this case cause the formation of phenols ; but here phenol proper, or carbolic acid, C 6 H 5 (OH), predominates, whilst cresol and the other homologues are diminished in quantity, and the dioxy-benzenes, as well as their methylated derivatives, disappear altogether. The above will be better illustrated by the statement (from Stohmann-Kerl's " Chemie," 3d ed., vi. p. 1162) that Zwickau glance coal yielded the following quite different products, according to whether it was put into a cold retort and gradually brought to a red heat (a), or distilled quickly from a very hot retort (6) : a. b. Coke 60.0 50.0 Water 10.7 7.7 Tar 12.0 10.0 Gas and loss 17.1 32.1 The tar from (a) consisted of photogen, paraffine oil, lubricating oil, paraffine, and creosote ; that from (6), of benzene, toluene, naphthalene, an- thracene (together with heavy oils corresponding to the paraffine and lubri- cating oil), and much creosote. The annexed diagram, constructed by S. B. Boulton, and published in the Society of Chem. Ind. Journal, 1885, p. 471, represents the whole pro- cess of the destructive distillation of coal, including the subsequent treat- ment of the main fractions, and exhibits in their proper order the various products obtained therefrom. n. Processes of Treatment. 1 . GAS-EETOET DISTILLATIONS OF COAL. The distillation of coal as carried out in retorts differs from distillations of other substances mainly in the apparatus employed and in the nature of the substances to be recovered. For gas purposes, retorts, wherein the decomposition of the coal used takes place, are made use of, which were originally constructed of cast iron, about one inch in thickness, twelve to fifteen inches in width, and about seven feet in length, closed at the rear end, and provided at the front or mouth with a heavy shoulder or rim supplied with studs to which is attached a cast-iron extension, technically termed the " neck," which carries on its upper side a flange to which is secured upright pipes serving to lead the gases generated away from the retort. The front of the neck is provided with a screw- clamp to retain the lid or cap of the retort in position. Iron retorts are destroyed with great rapidity ; the destruction being caused by the heat of combustion of the fuel used, the sulphur in the gas coal (an impurity always present in more or less quantity), which acts, forming sulphide of iron, and the carbon, which, as a carbide of iron, graphitic in appearance, forms layers within the retort from one to two inches in thickness. The oxygen of the air also has a very deleterious influence, especially upon retorts when heated to redness. PROCESSES OF TREATMENT. 345 In later years fire-clay retorts have been substituted for those made of cast iron, for the reason that they are more durable. These retorts are made of a mixture of clay and sand, and are furnished to the gas-works in several shapes, the semi-cylindrical being the one most generally employed. The sizes vary, six to nine feet in length, fifteen to twenty inches in width, and from ten to fifteen inches in height being the average, and take a charge of one hundred and fifty to two hundred pounds of coal. Retorts have been made up to nineteen feet in length, being charged from both ends. The retorts, varying in number from five to seven, or even nine and more, are mounted in brick furnaces of special construction, in such a manner that the gases of combustion of the coal will pass around and over the retorts and out through a main flue leading to the chimney. The fuel employed can be either coal, coke, or a mixture of both. Gas as a means of firing has been used for the purpose, the method being based upon the well-known regenerative system of Sir William Siemens. The retorts are charged by hand, care being taken to evenly distribute the coal over the sole, or bottom, and to close it quickly. Various attempts have been made to perform this laborious work with mechanical means, but at present no entirely satisfactory substitute has been found. The products of distillation pass from the retorts proper through the neck, and upward through cast-iron stand-pipes, which are provided with <70ose-neck outlets, dipping below the surface of water in what is termed the hydraulic main. It is in this part of the process that the main bulk of the tar is ob- tained, together with the ammonia-liquor. The hydraulic main is provided with an overflow-pipe through which all the tarry matters pass. This overflow-pipe leads to the tar- well, wherein the liquid products collect. The gas having been freed from the tarry matters, etc., contained, passes from the hydraulic main with a considerably elevated temperature, carrying in a vaporized state hydrocarbons that would separate as its temperature is lowered. It is necessarily very important to remove these volatile and con- densable products, which is effected by causing the gas to pass through a series of pipes, which reduces its temperature very close to that of the atmos- phere. The older form of condenser was a series of pipes completely cov- ered with water, similar to the worms as at present employed in connection with spirit and other distillations. This arrangement was replaced, however, by the forms now universally employed, and known as the atmospheric condensers, consisting of vertical pipes connected in pairs near the top by straight or curved pieces ; the lower end of the upright pipes being con- nected to a box or trough containing water, divided by partitions, causing the gas to pass up and down alternately, as shown in Figs. 104 and 105. Tarry matters and more ammoniacal liquor are again obtained, which finds its way to the tar- well. The gas after circulating through the condensers still contains impuri- ties, which are removed by passing it through an apparatus known as the scrubber, consisting essentially of cylindrical wrought-iron towers filled with coke, over and through which trickles a light flow of water, or better, weak ammoniacal liquor ; the gas passing upward, meets this downward flow of liquid, and to it gives up the hydrogen sulphide contained, with the forma- tion of ammonium sulphide, etc. Tarry matters again are separated, and in time cause the coke to become somewhat clogged. This apparent draw- back has led to the introduction of perforated iron plates in place of the 346 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. FIG. 104. coke, or, what has also proved equally efficient, wooden lattice screens. Anderson's rotating scrubber consists of brushes, which while rotating dip into a trough of ammoniacal liquor, and thereby perform functions similar to the means above mentioned. Another form of scrubber consists of a tower containing cast-iron plates provided with perforations, through which ammoniacal liquor passes in its down- ward course, meeting the gas. The liquid is contin- uously pumped to the top, when it again passes down, coming in contact with fresh gas. This is repeated until the liquor has taken up sufficient am- monia to make it available to the ammonia sulphate manufacturer. From the scrubber the gas passes on to the purifiers, where the hydrogen sulphide still remaining, carbon-disulphide vapor, and the carbonic acid are removed. The purifiers ordinarily used con- sist of a large shallow box, constructed of cast iron in sections, and bolted together, or of wrought-iron plates, provided with a cover, the edge of which dips in water contained in a channel provided at the top of the box, acting as a seal and preventing the escape of gas at that point, as shown in Fig. 106. The purifying agent generally employed is slaked lime, which is spread upon wood screens, within the box, from four to six in number, one above the other, and supported by ledges. Hydrogen sulphide and carbon dioxide are absorbed by the lime, while compounds of cyanogen are at the same time decomposed. Four purifiers are generally used, three being in service, while the fourth is reserved charged with fresh lime. Gas enters the one containing the oldest lime, and when it is noticed that lead-acetate paper is discolored by some of the gas acting upon it, it is known that the purifying material is saturated ; this purifier is discontinued, and the freshly-charged one placed in service. In this manner they are con- tinually rotated. Ferric hydrate (hydrated ferric oxide) is also largely employed in gas puri- fication, Laming process. Gas charged with hydrogen sulphide coming in contact with the above causes a reduction to ferrous sulphide, at the same FIG. 105. time some sulphur is deposited, with the formation of water. This process does not absorb the carbon dioxide from the gas ; for this purpose lime is mixed with the ferric hydrate, together with some cinders or sawdust, in order that the whole may be porous, and resist as little as possible the pas- sage of the gas. When the purifying action has ceased, simply exposing PROCESSES OF TREATMENT. 347 the inert mixture to the action of the air for a while restores its properties, until after repeated use it becomes so charged with separated sulphur that it is no longer available. The introduction of free oxygen into the gas, previous to it entering the purifiers, has been found to lengthen the time during which the oxide of iron can remain without being changed, thereby saving much handling. Ti It FIG. 106. has also improved the illuminating power of the gas. (Journ. Soc. Chem. Ind., vol. viii. pp. 84 and 694.) From the purifiers the gas passes through the meter of the works, where the volume is registered, then on to the gas-holders, where it is stored and from which it is distributed. The following table illustrates the composition of illuminating gas taken from various stages of manufacture : Entering the air-con- denser. Entering the scrubber. Entering the Lami tig's purifier. Entering the lime- purifier. Entering the gas- holder. 37.97 37.97 37.97 37.97 37.97 Marsh-o'as ... 39.78 38.81 38.48 40.29 39.37 Carbonic oxide 7.21 7.15 7.11 3.93 3.97 Heavy hydrocarbons 4.19 4.66 4.46 4.66 4.29 Nitrogen 4.81 4.99 6.89 7.86 9.99 Oxygen 0.31 0.47 0.15 0.48 0.61 Carbon dioxide 3.72 3.87 3.39 3.33 0.41 Hydrogen sulphide 1.06 1.47 0.56 0.36 Ammonia 0.95 0.54 2. COKE-OVEN DISTILLATION OF COAL. The burning of coke in pits, " meilers," or mounds, represents the first rough and wasteful method of converting bituminous coal into coke ; involving, at the same time, the total loss of all the volatile matter of the coal. It allows, however, of the smothering the finished coke with fine dust, instead of requiring it to be quenched with water, as in other methods. The so-called " bee-hive" ovens allow of the volatilizing of a much greater amount of sulphur in the coal, and give a decidedly increased yield of coke over the pit-burning method. 348 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. The charge can be run through, too, in less than half the time. Some air is admitted in both cases, with consequent loss of coke, and no attempt is made to save the residuals in either case. The distillation of coal in ovens differs materially from the older methods of production in piles or kilns in that the inflammable gases given off are to some extent utilized. The AppoWs oven consists of a series of vertical retorts built, generally, in two rows, enclosed by brick walls. Each retort is surrounded by air- spaces which are in communication one with the other, and with the inside of each retort. It is within this air-space that combustion of the gases gener- ated by the decomposition of the coal occurs ; air having been permitted to enter through openings for the purpose. The bottom of each retort is provided with a large door, which is opened to permit the charge of finished coke to fall into a pit built for the purpose. The Coppers oven is mainly employed in the coking of finely-divided coal. The shape of each chamber is long, slightly tapering, to facilitate the re- moval of the coke, narrow, and of a height equal to about three times the width. The gaseous products pass from the oven through vertical flues, built in the walls dividing the ovens, which open into horizontal flues under each chamber, thereby thoroughly distributing the heat. The waste gases are either led under steam-boilers, or are allowed to pass directly to the open air. The Simon-Carve' s oven, illustrated in Fig. 107, is similar in construction to the Coppee oven, but provision is made for the recovery and utilization of the by-products. Mr. Henry Simon, C.E., in an address before the British Iron and Steel Institute (Journ. Iron and' Steel Inst, No. 1, 1880), states : " According to our system, the coal is rapidly carbonized by subjecting a comparatively thin layer of it to a high temperature in a closed and retort- like vessel, and, whilst in the bee-hive ovens the volatile products are burned inside, we burn them around and outside of this retort-like vessel, and only after they are deprived of the tar and ammoniacal liquor. Each oven is in the form of a long, high, narrow chamber of brick-work, and a number of these are built side by side, with partition-walls between them sufficiently thick to contain horizontal flues. Flues are also formed under the floor of each oven, and at one end of these is a small fireplace, consist- ing of a fire-grate and ash-pit, with suitable door, the fire-door having fitted above it a nozzle, through which gas produced from the coking is admitted to form a flame over some fuel burning on the grate. Only a very trifling amount of such fuel, consisting exclusively of the small refuse coke, is used here, its function being really more that of igniting the gas than that of giving off heat. These grates are not charged with fuel more than twice in each twenty-four hours when in regular work. The products of combustion pass from the fireplace along a flue under the oven floor to the end farthest from the fire. They return along another flue under the floor to the fire end ; they then ascend by a flue in the partition- wall to the uppermost of several horizontal flues formed therein, and descend in a zig- zag direction along these flues, finally passing into a horizontal channel leading to a chimney. The oven in consequence is evenly heated at the bottom and sides, and the coal contained is rapidly and completely coked. No air enters the chambers, the only openings being for the escape of the volatile products. The improved ovens are fed with coal by openings in the roof, over which coal-trucks are run on rails ; and the coal is evenly PROCESSES OF TREATMENT. FIG. 107. 349 350 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. distributed by rakes introduced at end openings, provided with doors faced with refractory material, which doors are closed and kept tightly luted while the oven is in operation. The feed-holes in the roof are also provided with covers. Through the middle of the roof rises a gas-pipe provided with a hydraulic valve, which closes the passage by a lip projecting down from it into an annular cavity surrounding its seating, in which it is im- mersed in a quantity of tar and ammoniacal liquor, lodged there during previous distillations. The volatile products of the coal distillation rise by the gas-pipe, and are led through a range of pipes kept cool by external wetting, so that the tar and ammoniacal liquor become condensed and sepa- rated from the combustible gas." The gas, after having been freed from the tar, etc., is led through scrubbers and other apparatus, as mentioned under " Retort Distillation of Coal," and is then consumed in the fireplaces under the ovens. When the charge of coal has been converted to coke, it is removed from the ovens by means of a piston worked by an engine traversing rails in front of the battery. The yield of coke has been stated to be frt>m seventy-five to seventy-seven per cent, of the coal. During a run of two hundred and fifteen days, the yield of residuals averaged 27.70 gallons of ammoniacal liquors per ton of coal carbonized, and 6.12 gallons of tar per ton of coal carbonized. The Jameson oven, structurally considered, is but a simple modification of the common bee-hive oven, and is made by introducing channels in the floor of the oven radiating from the centre. These channels are covered with perforated tiles, and are, from the centre of the oven (where the chan- nels are lowest), connected by means of pipes which lead to an exhausting apparatus, and also for the discharge of the products of distillation. In this process the products are removed as soon as they are formed, being drawn down by means of the suction applied through the mass of cooler coal than that from which they were generated. Considerable difference exists between the tars obtained from the Simon- Carve's and the Jameson coking processes. The first-mentioned tar has a specific gravity of 1.106, and closely resembles, chemically, the tars pro- duced in the illuminating (retort) gas process, both being obtained at a high temperature. The Simon-Carve's tar is rich in naphthalene and anthracene, but low in naphtha, benzene, phenols, etc. The Jameson tar is a low tem- perature tar, with a specific gravity varying from .960 to .994, and contain- ing no benzene, but trifling amounts of toluene and xylene, while a consid- erable proportion of phenoloid bodies are found, containing, at the most, a very small quantity of carbolic acid.* 3. FRACTIONAL SEPARATION OF CRUDE COAL-TAR. Following gas retort distillation, in point of technical importance is certainly the distilla- tion of the coal-tar obtained from the former processes and the separation therefrom of certain constituents which have a wide application in several industries. The same general mechanical arrangement, though somewhat simplified, is employed, consisting of a still, a condenser, and a receiver. The still should be constructed entirely of wrought iron, and can be either horizontal or vertical. Horizontal stills are, according to Lunge, far less economical than the vertical. Fig. 108 is a vertical section of a tar-still showing the construction and fittings. The heat from the fire on the grate 6 * Consult Journ. Soc. Chcm. Ind., 1883, p. 495, for tables of analyses of Simon-Carve's and Jameson tars. PROCESSES OF TREATMENT. 351 is prevented from impinging against the concave bottom of the still by means of the arch g y but passes through the openings h in the circular wall k into vertical flues i, from which it enters the annular space I and through flues in the front of the still to the upper space n, finally entering the flue p, which leads to the chimney. The supply-pipe r is for feeding the still, the pipe s is an overflow, and serves to indicate when the tank is full. The cock a is for drawing off the pitch. The still-head t is for conducting the vapors, and FIG. 108. is connected with the condenser. The system of pipes xyz indicated is for conducting superheated steam into the still for finishing the distillation ; the pipes conforming to the shape of the bottom, are provided with a number of jets for a more equal distribution of the steam. The remaining attach- ments require no further mention. The condenser consists of a coil of pipe immersed in water contained in an iron tank. In England, the pipe used is from six to nine feet in length, and from four to six inches in diameter ; the total length for one still is 352 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. calculated at from one hundred and forty to two hundred feet. In Ger- many, preference is given to worms of iron (or lead, in which case the pipe from the still must be continued below the surface of the water in the con- denser and join the worm there, in order to obviate the possibility of it being melted), made of two-inch pipe, and mounted in circular tanks pro- vided with a steam-pipe for heating the water, and also with a small pipe connected with the worm for blowing in steam whenever it is necessary to clean it. Connected with the condenser, and located at a safe distance from the still, is the receiver, which can be of any convenient shape, and of such a size as to contain the whole of one fraction ; or a number can be employed, each acting as a store-tank and receiver. For the receivers to contain the volatile fractions, tight-closing covers must be supplied to guard against evaporation and fire, and the one containing the first fraction to have means for separating the oily from the watery layer. The receivers for the oils which deposit crystalline matter to be so arranged that they can be easily cleaned. "Coal-tar (Allen, Commercial Organic Analysis, vol. ii. p. 352), as obtained as a by-product in the manufacture of illuminating gas, is a black viscid fluid of a characteristic and disagreeable odor. The specific gravity ranges from 1.10 to 1.20, being usually between 1.12 and 1.15. " Coal-tar is a product of extremely complex composition, and contains many bodies ; the exact nature of which are still unknown, though it has been the subject of numerous researches. . " As coal-tar is always more or less mixed with ammoniacal liquor, the constituents of the latter liquid are present in addition to those of the tar proper, and the constituents of the illuminating gas itself are also present in a state of solution. " The first treatment of coal-tar on a large scale consists in distilling it in iron retorts and collecting the distillate in three or four fractions. The temperatures at which the receivers are changed vary considerably with the practice of different works, and hence the products are far from being strictly parallel." The annexed table indicates the three most important methods of frac- tionation : A. B. C. Product. Distilling- point C. Product. Distill ing- point C. Product. Distilling- pointC. Crude naphtha, or light oils . Heavy oils, dead oils, or creo- sote oils . . . to 170 170 to 270 flVinvp 970 First runnings, or first light oils .... Second light oils Carbolic oils . to 110 110 to 210 210 to 240 240 to 270 Light naphtha Light oils . . . Carbolic oils . Creosote oils . Anthracene oils Pitch to 110 110 to 170 170 to 225 225 to 270 270 to 360 Pitch A nthracene oils above 270 Pitch The principal constituents of coal-tar are separated, one from the other, by means of fractional distillation, a process depending upon the fact that, if a mixture of liquids, each having a different boiling-point, be heated, PROCESSES OF TREATMENT. 353 the one having the lowest will pass over first, and if the temperature is not increased beyond that point at which the distillation of this fraction takes place, no other constituent will come over ; if the temperature be gradually increased the others will follow in the order of their boiling-points. In cases where the boiling-points are close, and even in others where they are widely diifering, the action of one substance upon another often prevents exact separations. The hot stills (from the previous working) are charged with fresh tar, all the openings are then closed, and the fire carefully watched in order that no undue rise in temperature, and consequent boiling over of the contents, may take place. Gases, ammonia-liquor, and light oils distil over at 170, the whole being designated "first runnings." This fraction is collected and allowed to stand, when the watery portion separates more or less com- pletely from the oils, which are redistilled, yielding ammonia boiling under 70, crude benzol at 140, which is subsequently purified with sulphuric acid and distilled, naphtha, 140 to 170, treated as the benzol, yielding " solvent naphtha." This whole fraction has a specific gravity nearly equal to that of water. The second fraction " middle oil," or " carbolic oil" distils over from 170 to 230, and contains the impure phenols or carbolic acid and naphthalene. It is crystallized and pressed ; the mother-liquor is agitated with caustic soda in an iron tank, the alkaline liquor (carbolate of soda) decomposed with sulphuric acid separating crude carbolic acid, which is distilled and crystallized, yielding liquid and pure carbolic acid in crystals. The unchanged oil from the soda treatment is returned to the second frac- tion for re-working. The press-cake from the first treatment of this frac- tion is purified with sulphuric acid, distilled, and yields naphthalene. The third fraction constitutes the heavy or dead oil, so called from the fact that the specific gravity is greater than water, and boils from 230 to 270, occupying a position between middle oil and the anthracene fraction. It is subjected to no further treatment, but is employed chiefly for preserving timber, varnish manufacture, burning for lamp-black, etc. The fourth frac- tion, or anthracene oil, boiling over 270, constitutes the green oil or green grease, from which, upon subsequent treatment, the commercial anthracene is obtained. This fraction is allowed to stand for some time, in order to cool and to separate the crystallizable substances, when the mass is drained from the excess of oil and pressed. The press-cake is crude anthracene, which is dissolved in naphtha and known as fifty per cent, anthracene. The mother-liquor from the first pressing with the drainings are redistilled, crys- tallized and pressed, yielding crude anthracene, treated as above, and an- thracene oil. The residue in the still constitutes pitch, which is withdrawn and employed for making pavements, varnishes, etc. The annexed diagram from Ost's " Lehrbuch der Technischen Chemie" graphically represents the preceding outline of the tar distillation process. 4. TREATMENT OF AMMONIACAL, LIQUOR. The ammoniacal liquor of the gas-works is that which passes out continuously from the scrubbers and other parts of the process, and is the chief source of nearly all the ammonia of commerce. According to Lunge, ordinary gas-liquor contains the follow- ing : (a) Volatile at ordinary temperatures. & Ammonium carbonates (mono-, sesqui-, and bi-). Ammonium sulphide (NH 4 ) 2 S. Ammonium hydrosulphide, NH 4 .HS. 354 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. g < w -3 s>! H c -o r t*r .2 5 S'H 52 * HO w 2ft 311 H "* oj |1 8 " 2 - mixing the residual gas with air, and passing the mixture Nitrogen (N). j over palladium sponge. V. Bibliography and Statistics. BIBLIOGRAPHY. 1862. Das Beleuchtungswesen, Bolley und Wiedemann, 2 Theile, Braunschweig. Handbuch der Fabrikation mineraliseher Oele, etc., Dr. Th. Oppler, Berlin. 1863. Handbuch fur Holz- und Torfgas Beleuchtung, W. Reissig, Miinchen. 1867. Chimie Industrielle, A. Payen, 6me ed., Paris. 1870. Das Naphthalin und seine Derivate, M. Ballo, Braunschweig. 1873. Traite des Derives de la Houille, Girard et De Laire, Paris. 1877. Gasometrische Methoden, Robert Bunsen, 2te Auf., Braunschweig. 1879. Handbuch, der Steinkohlengas Beleuchtung, 2 Bde., 3te Auf., N. H. Schilling, Munchen. 1880. Das Anthracen und seine Derivate, G. Auerbach, 2te Auf., Braunschweig. Das Holz und seine Destillations-Producte, Dr. G. Thenius, Vienna. 24 370 INDUSTRIES BASED UPON DESTRUCTIVE DISTILLATION. 1883. Die Verwerthung des Holzes auf Chemischen Wege, J. Bersch, Vienna. Die Meiler- und Retorten-Verkohlung, Dr. G. Thenius, Vienna. 1886. Destructive Distillation, Edmund J. Mills, 3d ed., London. Die Chemie des Steinkohlentheers, 2te Auf, G. Schultz, 2 Bde., Braunschweig. 1887. Coal-tar and Ammonia, 2d ed., G. Lunge, London. Die technische Verwerthung des Steinkohlentheers, G. Thenius, Vienna. Die chemische Technologic der Brennstott'e, F. Fischer, Braunschweig. 1889. Ammoniak and Ammomak Praeparate, K. Arnold, Berlin. Traitement des Eaux Ammoniac-ales, etc., Weill-Goetz et Desor, Paris. 1890. Ammonia and Ammonia Compounds, Arnold, translated by Colman, London. Gas Analytische Methoden, Dr. W. Hempel, 2te Auf., Braunschweig. A Practical Treatise on the Manufacture of Coal-Gas, W. Richards, London. Dictionary of Applied Chemistry, T. E. Thorpe, 3 vols., London. L'Ammoniaque dans 1'Industrie, C. Tellier, Paris. 1891. Fabrikation der Leuchtgase, G. Thenius, Leipzig. STATISTICS. 1. OF COAL CARBONIZED IN GAS-MAKING. Lunge (Coal-Tar and Am- monia, 2d ed., pp. 12 and 13) gives several estimates of the amount of coal distilled for gas-making in Great Britain and Ireland, varying from nine million to twelve million tons per annum. The annual distillation for the same purpose in Germany is given at two million tons. For the United States, no estimates of the coal used in gas-making can be found. 2. OF COAL CARBONIZED IN COKE-OVENS. According to "Mineral Resources of the United States" for 1888, the quantity of coke produced in the United States for that year was 8,540,030 short tons, distributed as follows : Pennsylvania, 6,545,779 tons ; West Virginia, 531,762 tons ; Ala- bama, 508,511 tons; Tennessee, 385,693 tons; Colorado, 179,682 tons; Virginia, 149,199 tons; all other States, 239,404 tons. This total product was worth $12,445,963 at the coke-ovens, and required for carbonization 12,945,350 tons of coal. 3. OF COAL-TAR PRODUCTION. Gallois* gives the following as the production of gas-tar in some of the principal European countries for the year 1883 : Number of gas-works. Coal-tar produced. Great Britain 452 450,000 tons. Germany 481 85,000 " France 601 75,000 " Belgium 50,000 " Holland 15,000 " Total 675,000 " Other estimates of the production of coal-tar in Great Britain and Ire- land as quoted by Lunge vary from 450,000 tons to 750,000 tons. That of Mr. Wilton, of the Beckton Tar-works, putting the quantity of tar dis- tilled in 1885 at 120,000,000 gallons, averaging twelve pounds, or about 643,000 tons, would seem to be near the mean of these estimates. The same author, f from information gathered by himself, puts the pro- duction of coal-tar for 1886 in Holland at 20,000 to 22,000 tons, in Bel- gium at about 30,000 tons, and in the United States at 120,000 tons, of which some 60,000 tons are distilled, 37,000 tons are employed for manu- facturing roofing-paper, roof-coating, etc., and some 23,000 tons are used up in the raw state. 4. OF COAL-TAR DISTILLATION PRODUCTS. The estimate of Mr. * Lunge, Coal-Tar and Ammonia, 2d ed., p. 13. f Ibid., 'p. 15. BIBLIOGRAPHY AND STATISTICS. 371 Wilton of the coal-tar production of the United Kingdom for 1885 above quoted includes the following additional details : s Ammoniacal liquor from tar alone . 3,600,000 gallons = 1200 tons of sulphate. Carbolic acid (crude) 600,000 " Creosote oil 21,600,000 " Of this, there was liquid creosote . 10,800,000 " Of this, there were creosote salts (crude naphthalene, etc.) . . . 56,620 tons. Corresponding to pure naphtha- lene 25,310 " Green oil 20,400,000 gallons. Benzol and toluol 1,500,000 " Solvent naphtha 620,000 " Anthracene (pure) 3,420 tons. Pitch 396,000 " The production of benzol and toluol in Great Britain is also given by Schultz (Chemie des Steinkohlentheers, 2te Auf., i. p. 68) as follows : From gas-tar, 7,880 000 litres (2,080,320 gallons) ; from coke-tar, 1,150,000 litres (303,600 gallons). 5. PRODUCTION OF SULPHATE OF AMMONIA. The production for Great Britain and Ireland much exceeds that of all other countries combined. For the last five years it has been :* 1886. Tons. 1887. Tons. 1888. Tons. 1889. Tons. 1890. Tons. Production England, Scotland, and Ireland 106,500 113,700 122,800 132,000 140,000 Deliveries and exports Germany, Denmark, Sweden, Russia, etc. Deliveries and exports France, Spain, and Italy 34,000 16,000 33,000 21,000 32,000 19,000 32,000 18,000 31,000 17,000 Deliveries and exports Belgium and Holland 19,000 16,000 18,000 20,000 23,000 Deliveries and exports America and colonies 10,000 11,500 14,000 17,000 19000 Home consumption, for agricul- tural and chemical purposes . . Stocks at works 25,500 2,000 30,400 1,800 31,300 8,500 40,000 5,000 44,000 6,000 Total 106,500 113,700 122,800 132,000 140 000 Lunge states (Coal-Tar and Ammonia, 2d ed., p. 667) that Germany produces about 10,000 tons of sulphate of ammonia per annum, France produces about 12,500 tons, Holland and Belgium about 3,000 tons, and the United States about 11,000 tons per annum. * Soc. of Chem. Ind. Journ., 1891, p. 78. 372 THE ARTIFICIAL COLORING MATTERS. CHAPTER XII. THE ARTIFICIAL, COLORING MATTERS. I. Raw Materials. 1. HYDROCARBONS. Benzene Series. In the manufacture of the arti- ficial coloring matters, the hydrocarbons which find application as raw materials are limited mainly to benzene, naphthalene, and anthracene, their homologues and derivatives ; of which, probably, benzene is the most im- portant. The benzene series is as follows : Boiling-point. Specific gravity. Benzene, C 6 H 6 80.4 C. .884 at 15 C. Toluene, C 6 H 5 .CH 3 110.3 C. .872 " 15 C. f o-Xylene 142-143 C. Xylene, C 6 H 4 .(CH 3 ) 2 4 m-Xylene 139 8 C. .866 " 16 C. (. j9-Xylene . 136-137 C. .862 " 19.5 C. Pseudocumene, \ rTT , pn , f 169.8 C. .853 " 20 C. Mesitylene, / >v 6 n rW n ^ \ 164.5 C. .869" 9.8 C. Durene, C 6 H 2 .(CH 3 ) 4 . (Fuses at 79-80 C.) 189-191 C. . . . . - Pentamethylbenzene, C 6 H.(CH 3 ) 5 . (Fuses at 53 C.) . 230 C. Hexamethylbenzene, C 6 (CH 3 ) 6 . (Fuses at 164 C.) . . 264 C. Of which only the first three are employed to any extent. Benzene has been described in a previous chapter (see Tar Distillation), but for the manufacture of colors an explanation is necessary ; the name benzene, chemically speaking, does not refer to the light fractions obtained from petroleum, but applies solely to the substance distilled from coal-tar; boiling at 80.4 to 81 C., having a specific gravity of .899 at 0, with the definite composition C 6 H 6 . The term benzol, on the other hand, is not given to a definite compound, but to a mixture of benzene with variable quantities of toluene and xylene, with other homologues of the same series. The quantity of these homologous bodies contained have an influence upon the use to which the aniline oil obtained (by subsequent treatment of the benzol) can be put. The pure benzene, free from the high boiling homologues, is successively converted through several processes to dimethylaniline, which is the base of the valuable methyl-violets. For the fuchsine process, benzol, seventy-five per cent, of which distils between 80 and 100 C. (containing toluene), is em- ployed, producing aniline, seventy-five per cent, of which distils between 180 and 190 C. High-boiling benzol, 115 to 120 C., yields aniline, which is the starting-point for the production of the beautiful series of xylidine scarlets ; the introduction, however, of pure xylene has served to displace the above. Allen states (Commercial Organic Analysis, 2d ed., vol. ii. p. 489), " Ninety per cent, benzol is a product of which ninety per cent, by volume distils before the thermometer rises above 100 C. A good sample should not begin to distil under 80 C., and should not yield more than twenty to thirty per cent, at 85, or much more than ninety per cent, at KAW MATERIALS. 373 100 C. It should wholly distil below 120 C. An excessive distillate e.g., thirty-five to forty per cent, at 85 C. indicates a larger proportion of carbon bisulphide or light hydrocarbons than is desirable. " The actual percentage composition of a ninety per cent, benzol of good quality is about seventy of benzene, twenty-four of toluene, including a little xylene, and four to six of carbon bisulphide and light hydrocarbons. The proportion of real benzene may fall as low as sixty or rise as high as seventy-five per cent. Ninety per cent, benzol should be colorless and free from opalescence." "Fifty per cent, benzol, often called 50/90 benzol, is a product of which fifty per cent, by volume distils over at a temperature not exceeding 100 C., and forty per cent, more below 120. It should wholly distil below 130." " Thirty per cent, benzol is a product of which thirty per cent, distils below 100, about sixty per cent, more passing over between 100 and 120. It consists chiefly of toluene and xylene, with small proportions of benzene, cumene, etc." The following table from Schultz (Steinkohlentheers) indicates the gen- eral properties of the three commercial benzols above described when sub- jected to distillation : Thirty per cent. Fifty per cent. Ninety per cent. To 80 o o 25 90 2 4 70 95 12 26 83 100 30 50 90 105 42 62 94 110 70 71 97 115 82 82 98 < 120 90 90 99 The theoretical quantities of commercially applicable products from benzol are : For 100 parts, 157.6 parts nitrobenzol. " " 119.2 " aniline. " " " 215.3 " dinitrobenzol. " " " 155.1 " dimethylaniline. " " " 191.0 " diethylaniline. Toluene, or Methylbenzene, C 6 H 5 .CH 3 , is obtained by careful distillation of coal-tar benzols, and can be obtained from the balsam of tolu and other sources. It is quite similar in its properties to benzene ; fluid at ordinary temperatures, and when pure boils between 111 and 112 C. Specific gravity .882. It is employed for the production of nitrotoluene, toluidine, benzylchloride, benzalchloride, and benzaldehyde, the base of a valuable series of green colors. The theoretical yield of commercial products from toluene are as follows : For 100 parts, 148.9 parts nitrotoluene. i " " " 116.3 " toluidine. " " " 115.3 " benzaldehyde. Xylene, or Dimethylbenzene, C 6 H 4 .(CH 3 ) 2 , exists under similar conditions 374 THE ARTIFICIAL COLORING MATTERS. to toluene, and is found in coal-tar. There are three xylenes, the ortho-, meta-, and para-, the second being most abundantly obtained. Owing to the slight difference between their respective boiling-points, a commercial separation by distillation is practically impossible. The annexed table gives the nature and behavior of the three isomeric hydrocarbons mentioned. Ortho-xylene. Meta-xylene. Para-xyiene. Melting point Fluid. Fluid. 15 C Boiling-point 141 to 142 C. 139 C. 137.5 to 138 C Specific gravity .... .8668 at 19 C. .8621 at 19 5 C ,-j f Dilute nitric acid 0) If x ^ Permanganate . ^ [ Chromic acid . . Sulphuric acid (66 Be.) Sulphuric acid (fuming) Melting point of the sul- phochloride .... o-Toluic acid, melting point 102 C. Phthalic acid. Decomposed. Sulphonic acid. Sulphonic acid. 52 C. m-Toluic acid, melt- ing point 160 C. \ Isophthalic acid. Two sulphonic acids. Two sulphonic acids. (a) 34 C (b) liquid jo-Toluic acid, melting point 178 C. Terephthalic acid No change. Sulphonic acid. 26 C Melting point of the sul- phamide 144 C. (a) 137 C , (b) 96 C 148 C From Schultz, " Steinkohlentheers." Naphthalene Series. Naphthalene, C 10 H 8 , as a raw material, enters largely into the production of the extensive series of azo-coloring matters, and for such use it is converted into intermediary products, of which the alpha- and beta-naphthols are the most familiar. The occurrence, proper- ties, and production of naphthalene are referred to on page 360. Methyl-naphthalene, C 10 H 7 CH 3 . Two isomers exist in coal-tar, and can be separated from that fraction of the distillate, boiling from 220 to 270 ; at ordinary temperatures, is a liquid boiling between 240 and 242. Specific gravity 1.0287 at 11.5. Dimethyl-naphthalene, C 10 H 6 (CH 3 ) 2 , is found in the fraction from tar, boiling between 262 and 264, melting at 118. Ethyl-naphthalene, C^H^. Two isomers, - and /?-, are known. a-Ethyl- naphthalene, produced from a-brom-naphthalene and ethyl-bromide, and dis- tilled in vacuum, boils from 257 to 259.5 C. /?-Ethyl-naphthalene, from ,3-brorn-naphthalene, ethyl-bromide, and sodium. Boils at 250 to 251 C. Phenyl-naphthalene, C 10 H 7 .C 6 H 5 . Obtained by heating a mixture of brom- benzene and naphthalene with crushed pumice-stone in a combustion-tube. Diphenyl and isonaphthyl are at the same time formed. The product is fractionated, and the distillate passing over above 250 is purified by boil- ing slowly with petroleum-ether, and the residue is similarly treated with dry alcohol. The phenyl-naphthalene passes into solution, from which it is crystallized and sublimed in plates, possessing a lustrous white color, with a faint blue fluorescent appearance, having the odor of oranges, and melting at 101 to 102 C. Anthracene Series. Anthracene, C U H 10 , reference to which has been made in the previous chapter, is employed for the production of alizarine and allied bodies, the successful introduction of which caused a revolution in the processes of dyeing, and made useless for the time great areas of land RAW MATERIALS. 375 which were devoted to the culture of madder. Anthracene, as it occurs in commerce, is rarely pure, being made up of a very large number of hydro- carbons, several of which have not been investigated. The following may be mentioned : Methyl-anthracene, C^H^, closely resembles anthracene. It differs from that body in having a methyl group substituted for an H atom of one of the benzene rings. It occurs in coal-tar in small quantity, and owing to the high boiling-point, over 360 C., it is found in the anthracene. Crys- tallizes in pale-yellow leaflets, melting at 199 to 200. Phenyl-anthracene, C2QH 14 , is formed when phenyl-anthranol or coeru- lei'n is heated with zinc-dust. Slightly soluble in hot alcohol, ether, ben- zene, carbon bisulphide, and chloroform, and upon cooling, crystallizes from the above solvents in yellow plates, melting at 152 to 153 C. The solutions have a blue fluorescence. Fluorene, or Diphenylen-methane, C 13 H 10 , is found in coal-tar, and can be obtained by passing diphenylmethane through a combustion-tube heated to redness ; it can also be obtained by distilling diphenyleneketone over heated zinc-dust, or by heating the same substance with hydroiodic acid and phos- phorus from 150 to 160. Very soluble in hot alcohol, less in the cold; crystallizes in colorless plates having a violet fluorescence. Melts at 113 C., boils at 295 C. Phenanthrene, C 14 H 10 . This hydrocarbon is isomeric with anthracene, is found with it, and forms a large part of, the last fraction of coal-tar. Com- pared with anthracene, the melting point is considerably lower, while the boiling-points are somewhat closer. It is much more soluble in alcohol, by which means a separation is effected ; the low melting point materially assisting. Crystallizes in colorless, shining plates, melting at 100 and boil- ing at 340, insoluble in water, but soluble in fifty parts of alcohol in the cold, and in ten parts on boiling ; easily soluble in ether and benzene. It imparts a blue fluorescence when dissolved. When oxidized, phenanthren- quinone is formed. Technically, but little use is made of it, being chiefly employed in the oil-baths for alkali melts, heating autoclaves, subliming phthalic anhydride, etc. fluoranthene, C 15 H 10 , occurs in the highest boiling tar fractions ; crystal- lizes in needles; melts at 109. Pseudophenanthrene, Ci 6 H 12 , is found in crude anthracene, and crystal- lizes in large glistening plates, which melt at 115. Pyrene, C 16 H 10 , Retene, C, 8 H 18 , Chrysene, C 18 H 12 , and Picene, C^H^, are bodies which occur in the highest fractions with fluoranthene, and cannot be classed as raw materials, no technical importance being attached to them. 2. HALOGEN DERIVATIVES. From Benzene. The following table of the halogen derivatives of benzene indicates those whose constitution is known. They are produced by the action of the halogens upon the hy- drocarbons directly, or through the action of the halogen compounds of phosphorus upon phenols and aromatic alcohols. Two classes are produced, substitution and addition compounds. The former occurs under ordinary conditions, while the latter are formed when the reaction takes place in direct sunlight. Of the two, the substitution products are the more stable, the addition products being easily decomposed. The following table gives the formulas of the several halogen deriva- tives of benzene and the boiling-points of the more important of the several isomeric compounds : 376 THE ARTIFICIAL COLORING MATTERS. Halogen substitution products of benzene. C 6 H 6 C 6 H 5 C 6 H 4 C 6 H 3 C 6 H 2 CH C 6 'ci " C1 2 C1 3 Cl ci 5 eq 81 133 179 213 246 276 332 Br Br 2 Br, Br Br 5 Br fl 154 224 276 329 219 278 219 I 185 277 285 172 208 246 173 218 254 From Toluene. (1) Benzyl-chloride (Chlorbenzyl), C 6 H 5 .CH 2 .C1, results from the action of hydrochloric acid upon benzyl alcohol (C 6 H 5 .CH 2 .OH), or by acting on boiling toluene with chlorine, this method being the one most generally used ; the product is washed with water containing a little alkali, when it is freed from impurities by distillation. It is a colorless fluid, specific gravity 1.113, boils at 179, insoluble in water, but soluble in alco- hol and ether, and possesses an exceedingly penetrating odor, acting upon the eyes and mucous membrane of the nose. Technically, it finds consid- erable application in the color industry. (2) Benzol-chloride (Benzidene Dichloride), C 6 H 5 .CH.C1 2 . Formed when chlorine acts upon boiling benzyl-chloride, or when phosphorus penta-chloride acts upon benzaldehyde. It is a colorless liquid, having ordinarily but little odor, but upon the application of heat gives off a vapor producing effects similar to the preceding. Boils at 206 to 207 ; specific gravity at 16 1.295. (3) Benzo-trichloride, C 6 H 5 .C.C1 3 , is obtained by acting with chlorine upon boiling toluene until no further increase in weight takes place, when it is washed in water containing alkali, dried, and distilled in a vacuum. Boils at 213 to 214; specific gravity 1.38 at 14. It has a penetrating odor, and is highly refractive. Bromine Derivatives of Xylene. These are obtained when bromine is allowed to act upon the hydrocarbon or its isomers, or upon brominated compounds of the same, with or without the presence of iodine. They find no application industrially. Halogen Derivatives of Naphthalene. (1) Naphthalene Dichloride, C 10 H 8 C1 2 , is a liquid, easily decomposed ; produced as an addition compound by the action of chlorine gas upon naphthalene. (2) Naphthalene Tetrachloride, C 10 H 8 .'C1 4 . This substance is manufac- tured in large quantities by passing chlorine gas through the melted hydro- carbon in a suitable apparatus, or by grinding the naphthalene to a paste with water and intimately kneading therein sodium or potassium chlorate, moulding into balls, and drying, after which they are immersed in concen- trated hydrochloric acid. It crystallizes from chloroform in large rhom- bohedra, melting at 182, and when boiled with nitric acid is converted into phthalic acid, which is the chief product obtained from it. (3) a-Brom-naphthalene, Ci H 7 .Br. Formed by the direct bromination of the hydrocarbon, or by the substitution of bromine for the amido group in brom-a-naphthylamine. It is a liquid, boiling at 277 ; specific gravity 1.503 at 12. Insoluble in water, soluble in alcohol and ether. (4) 13-Naphthyl-chloride, C 10 H 7 .CH 2 C1, is formed when chlorine acts upon /5-methyl-naphthalene at a temperature of 240 to 250. Melts at 47, boils at 168. RAW MATERIALS. 377 (5) p-Naphthyl-bromide, C 10 H 7 .CH 2 Br. Formed when the vapor of bromine with CO 2 gas is brought in contact with /3-methyl-naphthalene, heated to 240. Crystallizes from alcohol in white plates, which melt at 56. Anthracene Derivatives. (1) Monochlor-anthracene, C 14 H 9 .C1. When dichlor-anthracene is heated hydrochloric acid is evolved, having the mono- chlor derivative. Soluble in alcohol, ether, carbon bisulphide, and benzene. Crystallizes in yellow needles, melting at 103. (2) DicMor-anthracene, C U H 8 .C1 2 , is produced when anthracene is al- lowed to remain in contact with chlorine, or when the monochlor derivative is- similarly treated, being maintained at a temperature of 100. Freely soluble in benzene, but not readily in alcohol or ether. Forms beautiful yellow lustrous needles, which melt at 209. Treated with sulphuric acid at a low temperature, dichlor-anthracene-sulphonic acid occurs in solution ; this, when heated, yields sulphurous acid, hydrochloric acid, and the an- thraquinone-disulphonic acid, which is the immediate base of the artificial alizarine. (3) Dibrom-anthracene, C u H 8 Br 2 . Upon agitating bromine with a so- lution of anthracene in carbon bisulphide this derivative is formed. Diffi- cultly soluble in alcohol, ether, and benzene ; hot toluene or xylene answer best.* Crystallizes in gold-yellow needles, melting at 221, and subliming without decomposition. 3. NITRO- DERIVATIVES. By the action of nitric acid upon the hydro- carbons nitro- derivatives are obtained, and one of the most important of these nitrobenzene is manufactured in very large quantities for use in the color industry. (1) Nitrobenzene, C 6 H 5 .NO 2 , was discovered by Mitscherlich, who ob- tained it by heating benzene or benzoic acid with fuming nitric acid. It was first brought into trade, bearing the name " oil of mirbane" (artificial oil of bitter almonds), by Collas, and in 1847 a patent for its manufacture from coal-tar was granted to Mansfield. It is obtained by adding a cooled mixture of concentrated sulphuric and nitric acid (150 : 100) to the hydro- carbon and agitating, taking care that the temperature does not go above 50 C. After the addition of the acid is complete, heat is applied, and it is again agitated. The oily layer is removed, washed with dilute alkali, dried, and distilled. Nitrobenzene, when pure, is a pale-yellow fluid, strongly re- fractive, having the odor of bitter almonds, and a sweet, though burning, taste. Specific gravity 1.208 at 15 ; boils at 206 to 207, and when the temperature is reduced it crystallizes in large needles, which melt at +3. Nearly insoluble in water, though with alcohol, ether, and benzene it is readily soluble. It is exceedingly stable, and even at a boiling temperature it is not acted upon by either bromine or chlorine. It is poisonous, and, according to Roscoe and Schorlemmer (vol. iii. pt. iii.), " especially when the vapor is inhaled ; it produces a burning sensation in the mouth, nausea and giddiness, also cyanosis of the lips and face, and in serious cases, which frequently end fatally, symptoms of a general depression." (2) Dinitrobenzene, C 6 H 4 (NO 2 ) 2 . Three isomers of this derivative exist, being obtained when benzene is nitrated with the concentrated acids, as in the preceding case, but instead of being cooled is boiled for a short time, when the product is washed with water, pressed, dissolved in alcohol, from which the meta-nitro body crystallizes, followed upon standing by the para- nitro compound. Upon distilling the alcohol remaining in the mother- 378 THE ARTIFICIAL COLORING MATTERS. liquors from the para- compound a further yield of the meta- body is ob- tained, finally the ortho-dinitrobenzene, which occurs in small quantity, crystallizes, and is purified by treatment with acetic acid, from which it is deposited in needles, having a melting point of 117.9. The para- com- pound occurs in monoclinic needles, melting at 172, and subliming. The meta- compound finds technical application in the production of chrysoidine and Bismark brown, and is manufactured on a large scale by adding a mixture of one hundred kilos, nitric acid (specific gravity 1.38) and one hundred and fifty-six kilos, sulphuric acid (specific gravity 1.84) to one hundred kilos, of benzene. When the reaction is over, a separation of the acids (which can be used again) from the product occurs ; commercially, the product is washed with warm and cold water, further purification being unnecessary. It crystallizes in needles or rhombic tables, which melt at 89.8, boiling at 297. Difficultly soluble in warm water, easily in ether and alcohol. Nitrotoluene. (1) Nitrotoluene, C 6 H 4 (NO 2 )CH 3 , occurs in three isomers. The ortho- derivative is a liquid boiling at 223, and at 23.5 has a specific gravity of 1.162. Does not become solid at 20. The meta- derivative melts at 16, boils at 230 to 231. Specific gravity at 22 1.168. Para- nitrotoluene, melting point 54, distilling unchanged at 236, occurs in colorless prisms. Nitrotoluene, consisting more or less of a mixture of the above, is manufactured in large quantities and in the same manner as for nitrobenzene. Ten parts of toluene are mixed, and continually agitated with eleven parts of nitric acid (specific gravity 1.22) and one part sul- phuric acid (specific gravity 1.33). The product is treated with water, and afterwards with caustic alkali ; distilled to remove uncombined toluene, and finally distilled with superheated steam. When fractionated, that part pass- ing over at 230 yields, when purified, para-nitrotoluene, and is employed in the production of toluidine, tolidine, and fuchsine. The fraction between 222 and 223 is nearly all ortho-nitrotoluene. (2) Dinitrotoluenes, C 6 H 3 (NO 2 ) 2 .CH 3 . - or ordinary dinitrotoluene is produced when toluene is added to a mixture of fuming nitric and sul- phuric acids and boiled ; ortho-nitrotoluene is employed for the manufac- ture also. Crystallizes in needles, which melt at 70.5 ; insoluble in water, little soluble in alcohol, ether, or carbon bisulphide. /3-dinitrotoluene, isomeric with the above, is produced under similar conditions ; or it can be made by replacing the amido group of dinitroparatoluidine with hydrogen. Crystallizes in golden-yellow needles; melting point 61.5. Trinitrotoluene, C 6 H 2 .(NO 2 ) 3 CH 3 . Produced by the action of nitric and sulphuric acids upon toluene, or dinotrotoluene, and heating for several days. a-Trinitrotoluene is soluble in alcohol, crystallizing from it in beau- tiful needles, which melt at 82. ^-Trinitrotoluene crystallizes from acetone in transparent prisms, which melt at 112, while from alcohol it forms plates or flat white needles. ^-Trinitrotoluene is deposited from acetone in small hexagonal crystals, melting at 104. Mononitronaphthalene, C 10 H 7 .NO 2 . Two isomers exist ; the - compound is produced when ten parts naphthalene, eight parts nitric acid (specific gravity 1.4), and ten parts sulphuric acid (specific gravity 1.84) are combined in a nitrobenzene apparatus. The naphthalene is added in small portions and continually stirred. The product is washed with water, and freed from acid by treatment with alkali. Insoluble in water, easily in benzene, carbon bisulphide, ether, and alcohol. Crystallizing in yellow needles, melting at RAW MATERIALS. 379 61, boiling at 304. The /9- compound is produced when r-nitronaph- thylamine is melted with nitrate of potassa. Soluble in alcohol, ether, or glacial acetic acid. Crystallizes in yellow needles ; melts at 79. a-Dinitronaphthalene, C 10 H 6 (NO 2 ) 2 , obtained in a similar manner to the above. Difficultly soluble in cold, easily in warm, benzol. From glacial acetic acid it crystallizes in needles, melting at 217. /3-Dinitronaphthalene, isomeric with the above, crystallizes in rhombic plates, melting at 170. 4. AMINE DERIVATIVES. The amine derivatives of benzene, toluene, and xylene can be regarded as forming one of the most important groups of raw materials from which are obtained the basic coloring matters, all of which contain nitrogen. The structure of the amines can readily be seen if we em- ploy ammonia, NH 3 , as the type ; in this case there are three atoms of hydro- gen. If one of these be replaced by an organic radical a primary amine is produced ; if two, or all three are replaced, a secondary or tertiary amine respectively is formed. Aniline, or Amido-benzene, C 6 H 5 .NH 2 . This substance was discovered by Unverdorben in 1826, who noticed its property of combining with acids to form salts. Runge, subsequently, experimenting upon coal-tar, found a volatile substance which, when treated with a solution of bleaching-powder, produced a blue coloration, giving rise to the name kyanol. It was he who noticed that when a drop of the " nitrate of kyanol" was brought in contact with dried cupric chloride, a black spot was formed. Fritsche, later, exam- ined the distillation products of indigo, and found a body to which he gave the name aniline. Aniline was formerly obtained in large quantities by re- ducing the nitrobenzene with iron filings or scrapings and acetic acid, but now it is wholly produced with hydrochloric acid. The following reaction showing the change that occurs : (Nitrobenzene.) C 6 H 5 .NO 2 + 3Fe + 6HC1 = (Aniline.) C 6 H 5 .NH 2 + 3FeCl 2 + 2H 2 O. The quantity of acid represented by the above equation is more than sufficient for the purpose, from the fact that ferrous chloride (FeCl 2 ), a reducing agent itself, will act in the reduction of a further quantity of nitrobenzene : C 6 H 5 .N0 2 + 6FeCl 2 + 6HC1 = C 6 H 5 .NH 2 + 3Fe 2 Cl 6 +H 2 O. Aniline is a liquid, fluid at ordinary temperatures, but when frozen melts at 8 ; boils at 182 when pure ; specific gravity 1.036 ; colorless w r hen freshly distilled, but becomes reddish-brown upon exposure to light and air ; impurities hasten discoloration. Soluble in alcohol, ether, and benzene in all proportions ; in water it is soluble to a slight extent, one hundred parts of water dissolving three parts aniline, while it, in turn, dissolves water to the extent of five per cent. Aniline forms a series of well-crystallized salts, among which are the hydrochloride, C 6 H 7 .N.C1H, known as " aniline salt," largely employed in the production of black upon cotton ; and the sulphate, (C 6 H 7 N) 2 H 2 SO 4 , of considerable importance. Toluidine, or Amido-toluene, C 6 H 4 (CH 3 )NH 2 , occurs in three isomers, according to the extent to which the nitration of the toluene was originally 380 THE ARTIFICIAL COLORING MATTERS. carried to. Qtho-toluidine is produced by the reduction of ortho-nitro-toluene, by the same means as was applied in the case of aniline. It is a fluid, color- less at first, but becoming brown upon exposure. Specific gravity 1.000 at 16, boiling point 197 ; soluble to a slight extent in water (2 : 100) and in alcohol. Meta-toluidine, occurring similarly to the preceding, is a liquid. Specific gravity .998, boiling at 197, little soluble in water, but freely in alcohol and ether. Para-toluidine is obtained in the form of large colorless leaflets, crystal- lizing from alcohol. Specific gravity 1.0017, melting point 45, and boil- ing at 198 ; slightly soluble in water, readily in alcohol and ether. Com- mercial toluidine consists chiefly of a mixture of the ortho- and para- bodies, and containing very little aniline ; it is of considerable importance in the color industry. Xylidine, or Amido-xylene, C 6 H 3 (CH 3 ) 2 .NH 2 , homologous with aniline and toluidine, is produced from xylene, as aniline is from benzene, nitration followed by reduction. Six isomers are obtainable, but the xylidine indus- trially employed consists of a mixture of five. At ordinary temperature it is a liquid, specific gravity .9184 at 25, boiling-point 212. From this de- rivative the beautiful series of xylidine scarlets are produced. Naphthy famine, C 10 H 7 .NH 2 . Two isomers exist. For a-Naphthylamine, naphthalene is converted into the nitro- derivative as has been described, and equal parts of this body and water are heated to 80, incorporated with an equal part of iron filings, and reduced with hydrochloric acid. The product is distilled with lime, and finally rectified by further distillation. Nearly insoluble in water, soluble in alcohol and ether; crystallizes in colorless needles or prisms, which melt at 50 and boil at 300. Upon contact with the air it acquires a red color, and oxidizing agents cause a blue precipitate to form in solutions of its salts. It finds extensive application in the prep- aration of several colors of importance. /9-Naphthylamine is produced when gaseous ammonia combines with /S-naphthol in the fused state ; commercially it is obtained by the action of ammonio-chloride of calcium, or ammonio- chloride of zinc, upon the same body, assisted by heat, and the subsequent separation of by-products. It occurs in white or pearly leaflets, odorless, difficultly soluble in cold, freely in hot, water, and in alcohol and ether. Melting point 112, boiling at 294. Unlike the a-naphthylamine, it is not acted upon by oxidizing agents. 5. PHENOL DERIVATIVES. Phenol, C 6 H 5 OH. The occurrence of this body has been mentioned under tar products, page 359. It crystallizes in needles, which have the well-known odor of " carbolic acid." Specific gravity 1.08, and melting at 37.5, boiling at 132 to 133 ; soluble in water (1 : 15) and readily in alkalies, alcohol, and ether. It finds extensive application in the color and other industries, large quantities being consumed in the manu- facture of picric acid. Resorcin, or Dioxy-benzene, C 6 H 4 (OH) 2 , is obtained from benzene by fusing the sodium sulphonate of the latter with caustic soda. (See page 387.) Occurs in sweetish, colorless crystals, which, however, eventually become dark colored, melting point 110, boiling-point, 271; readily soluble in water, alcohol, and ether. Specific gravity 1.28. Pyrogattol, or Trioxy-benzene, C 6 H 3 (OH) 3 , is readily obtained from gallic or tannic acid when the same are heated to 210 to 220. It can be obtained from benzene, but the above method is more generally adopted. Processes RAW MATERIALS. 381 for its manufacture are detailed on page 388. Pyrogallol occurs in white leaflets, which melt at 115 and boil at 210 ; soluble in water, alcohol, and ether. Naphthols, C 10 H 7 .OH. The two derivatives of naphthalene, a- and /9-naphthol, find extensive application in the manufacture of artificial color- ing matters. They are prepared from the two isomeric naphthalene sul- phonic acids, a and /?, which are discussed under Processes, page 388. a-Naphthol occurs as lustrous needles, which melt at 94, boil at 278 to 280; specific gravity 1.224; sparingly soluble in hot, insoluble in cold, water ; soluble in alcohol, ether, benzene, and in solution of caustic alka- lies. /9-Naphthol occurs in leaflets, melting at 122, boiling from 285 to 290 ; solubility same as for the preceding. Allen (Commercial Organic Analysis, 2d ed., vol. ii. p. 511) gives the following table of the distinguish- ing characteristics of the two naphthols : a-Naphthol. ^-Naphthol. Crystallizes in small monoclinic needles. Melting point 94 ; boils at 278 to 280. Faint odor, resembling phenol. j Almost odorless. Crystallizes in rhombic laminae. Melting point 122 ; boils at 285 to 290. Volatilizes readily with vapor of water. Aqueous solution becomes dark violet. changing to reddish-brown on adding solution of bleaching-powder. Aqueous solution becomes red, and then violet, on adding ferric chloride. Scarcely volatile with vapor of water. Aqueous solution colored pale yellow by solution of bleaching-powder. Aqueous solution becomes pale green on adding ferric chloride. 6. SULPHO- ACIDS. This group constitutes an interesting and techni- cally valuable series of bodies, which are obtained by the action of concen- trated sulphuric acid upon the hydrocarbons, or upon coloring matters already formed. (1) Benzene-sulphonic Add, C 6 H 5 .SO 3 H, is readily obtained by heating two parts benzene with three parts sulphuric acid to 100 C., diluting with water, saturating with carbonate of lead, and decomposing with sulphuric acid to liberate the sulphonic acid. The acid is soluble in water and alcohol, and crystallizes in small plates. (2) Benzene-disulphonic Acid, C 6 H 4 (SO 3 H) 2 , is produced \vhen benzene is heated with fuming sulphuric acid to 275. Employed in the production of resorcin. (3) Toluene-sulphonic Acid, C 6 H 4 (CH 3 )SO 3 H. No importance. (4) Naphthalene-sutphonic Acids, C 10 H 7 .SO 3 H. Two isomeric bodies are obtained when naphthalene is submitted to the action of sulphuric acid. At temperatures ranging from 80 to 100 the a-derivative is largely ob- tained, and at temperatures from 160 to 170 the /?-derivative is produced. Their separation is based upon the different degrees of solubility of the lead salts upon concentrating their aqueous solutions, a-naphthalene sul- phonic acid being soluble in twenty-seven parts water, while the ?- acid requires one hundred and fifteen parts. (5) ^.nthracene-sulphonic Acid, C U H 9 .SO 3 H, is produced similarly to the above, or 'by the reduction of sodium anthraquinone-sulphonate with zinc-dust and ammonia. Phenol-sulphonic Acid, C 6 H 4 (OH)CO 3 H. Three isomers are known, 382 THE ARTIFICIAL COLORING MATTERS. two, the ortho- and para-, being produced by the direct action of sulphuric acid upon phenol, while the meta- compound must be produced by other means. The ortho- acid is largely obtained when one part of phenol is slowly mixed with one part of sulphuric acid, care being taken to keep the temperature from rising. The para- acid will be obtained if the mixture be heated to 100. These bodies are much employed as antiseptics under various names; the para- compound, also, in the production of picric acid. Naphthol-sulphonic Adds. The two naphthols are easily converted into mono-sulphonic acids upon being heated to 100 C. with concentrated sul- phuric acid ; disulphonic acids being produced if the temperature reaches 110 C. fi-naphthol-sulphonic acid, C 10 H 6 .SO 3 H.OH. One hundred parts of /3-naphthol are added to two hundred parts of sulphuric acid (specific gravity 1.84) and carefully heated to 50 or 60, when two acids result, ordinary P-naphthol-sulphonic acid (known also as " Schqjfer's acid" or u acid S") and ft-naphthol-a-sulphonic acid ("Bayer's acid," or "acid J5"). When converted into their sodium salts they can be separated by treatment with alcohol, in which menstruum the latter acid is more soluble than the former. They are extensively used for the production of the crocei'n scarlets ; and upon nitration yield other colors of importance. If the mixed acid and naphthol is heated to about 20 C. Bayer's acid will be formed, while the employment of a temperature about 90 will cause the formation, as the chief product, of Schaffer's acid. Disulphonic Acids of @-Naphthol, C 10 H 5 (SO 3 H) 2 OH, are obtained when the naphthol is subjected to a temperature of 100 to 110 with three times its weight of sulphuric acid (specific gravity 1.84). Upon dilution milk of lime is added, the precipitated calcium sulphate filtered off, carbonate of soda added, and the whole evaporated to dryness, and lixiviated with alcohol, when " salt G" (yellow shade) is dissolved from " salt R" (red shade). Ordinarily, after the addition of the carbonate of soda, the solution is used without further treatment. Anthraquinone-sulphonic Acid, C 6 H 4 (CO) 2 C 6 H 3 .SO 3 H, is formed when anthraquinone is treated with fuming sulphuric acid to 1 60 C. The unal- tered anthraquinone is separated, the solution neutralized with soda, when the white soda salt settles out. The free acid occurs in yellow plates, solu- ble in water and in alcohol. When fused with either caustic soda or pot- ash alizarin is obtained (when the anthraquinone disulphonic acid is used, either by itself or in the melt, purpurin is produced along with alizarin) ; anthraquinone-sulphonic acid being employed directly for the production of this most valuable coloring matter. Naphthylamine-sulphonic Acids are prepared from naphthylamine by treatment with sulphuric acid and the application of heat. Several deriva- tives are produced, which, however, find limited application, mainly in some patented specialties. Toluidine-sulphonic Acid, C 6 H 3 .CH 3 .NH 2 .SO 3 H. Prepared similarly to the above. Technically, at present, of but little importance. 7. PYRIDINE AND QUINOLJNE BASES. Pyridine, C 5 H 5 N, is regarded as a benzene nucleus (C 6 H 6 ), with one of the CH groups replaced by an atom of nitrogen. It is obtained when bone oil or other nitrogen-contain- ing organic bodies are distilled. It possesses a pungent odor, is liquid, boils at 116.7, and is soluble in water; specific gravity .986. A large number of the pyridine derivatives bear a relationship to the alkaloids. RAW MATERIALS. 383 Quinoline (Chinoline), C 9 H 7 N, diifers from pyridine in that naphthalene is the base, C 10 H 8 , one nitrogen atom replacing, as before, one of the CH groups. Quinoline is readily prepared by carefully heating in a flask one hundred and twenty grammes glycerine, thirty-eight grammes aniline, twenty-four grammes nitrobenzene (oxidizing agent), with one hundred grammes concentrated sulphuric acid ; when the reaction is over, boil for two or three hours, dilute with water, and remove the unchanged nitroben- zene with steam, saturate with caustic alkali, distil, add sulphuric acid and sodium nitrite (NaNO 2 ) to destroy any aniline present, make alkaline, and again distil. Quinoline is a colorless fluid, having a penetrating odor, highly refractive, becoming brown upon exposure to the air ; boils at 238 ; specific gravity 1.094 at 20. Quinaldine (a-Methyl-quinoline), C 9 H 6 (CH 3 )N. Obtained by the action of hydrochloric acid upon paraldehyde and aniline, for several hours, with the aid of heat. It has a faint odor, is fluid, and boils at 238 to 239. Technically employed, mainly for the production of " quinoline yellow," cyanine blue, quinoline red, etc. Acridine, C 13 H 9 N. Anthracene is the base from which this derivative is obtained by a substitution of a nitrogen atom for one of the CH groups, as in the previous instances many derivatives of the above bodies exist, which have considerable interest, but no technical importance is attached to them as raw materials. 8. DIAZO- COMPOUNDS. These form the most extensive, and probably the most thoroughly investigated of the several groups of coal-tar colors. They are produced where nitrous acid (obtained from starch and nitric acid) is allowed to act upon the primary amines of the aromatic series, in which case the following change is noted, assuming aniline nitrate to be acted upon : C 6 H 5 NH 2 .HNO 3 + HO.NO = C 6 H 5 N=N.NO 3 + 2H 2 O. (Diazo-benzene nitrate.) Aniline hydrochloride, treated in the same manner, will yield diazo-benzene chloride : C 6 H 5 .NH 2 .HC1 + HO.NO = C 6 H 5 N=N.C1 + 2H 2 O. The diazo- compounds .differ from those of the azo- group in that one of the bonds of the diatomic nitrogen group N = N is satisfied with an hydro- carbon radicle, while in the latter it is saturated with an atom of oxygen, nitrogen, bromine, chlorine, etc., or with an acid or basic group. The annexed list of diazo- bodies illustrates the above : C 6 H 5 N = NCI Diazo-benzene chloride. (C 6 H-.N = ]Sr) 2 SO 4 " " sulphate. C 6 H 5 N = N.Br " " bromide. C 6 H 5 N = N.NH.C 6 H 5 Diazo-amido-benzene. The azo- compounds have the two nitrogen atoms ( N = N ) united, each to a hydrocarbon group ; mixed azo- compounds result if these hydro- carbon groups are not identical. (1) Diazo-benzene Chloride, C 6 H 5 .N 2 C1, is formed when nitrite of soda (NaNO 2 ) is added to a solution of aniline chloride in the presence of an excess of 'hydrochloric acid, the solution being kept cool by means of ice. The product finds application in the manufacture of aniline yellow and other colors. 384 THE ARTIFICIAL COLORING MATTERS. Diazo-amido Compounds result from the action of salts of the diazo- derivatives upon the primary and secondary amines. Diazo-amido-benzene, C 6 H 5 .N 2 .NH.C 6 H 5 , occurs when nitrous acid is passed through a solution of aniline in alcohol ; or by adding a solution of sodium nitrite to a mixture of aniline hydrochloride and aniline. Crystal- lizes in golden-yellow prisms or scales, insoluble in water, easily in ether, benzene, and alcohol ; melting point 91, exploding at a higher temperature. (2) Diazo-benzene-sulphonic Acid, C 6 H 4 .N 2 .SO 3 (the anhydride of the sulphonic acid of diazo-benzene). Sulphanilic acid, C 6 H 4 NH 2 .SO 3 H, is dis- solved in water, and sodium nitrite added, when the whole is poured into dilute sulphuric acid, which causes a precipitation of the crystals. 9. AROMATIC ACIDS AND ALDEHYDES. The aromatic acids form a class of bodies of considerable importance, derived from benzenes by sub- stituting the carboxyl group CO.OH for hydrogen. The simplest of the series is Benzoic Acid (Benzene-carboxylic Acid), C 6 H 5 .CO.OH, which, be- sides finding extensive application in medicine, is also used in the color manufacture. It can be prepared by a number of methods, chiefly by the sublimation of gum benzoin ; by treating the urine of herbivorous animals with hydrochloric acid, which causes the hippuric acid to break up, yield- ing the acid and glycocine; and from benzyl-chloride after boiling with nitric acid. It crystallizes in needles or scales, lustrous, and odorless when pure. Specific gravity 1.291, melting at 121, and boiling at 249 ; solu- ble in alcohol, ether, benzene, etc., sparingly in water. PUhalic acid (Benzene-dicarboxylic Acid), C 6 H 4 .(CO.OH) 2 . Three iso- mers of the above are known, but only the ortho- acid will be considered. It is obtained from naphthalene tetrachloride by heating with nitric acid. It can also be obtained by heating naphthalene direct in the presence of nitric acid, but this process is not much employed. It occurs in rhombic crystals, specific gravity 1.585, and melting at 213 ; upon being heated, it is liable to split up into water and the anhydride ; soluble in hot water, alcohol, and ether. When a phenol is heated with the phthalic anhydride phthalems result ; of these, the resorcin and pyrogallol-phthale'ins are the most important, being the basis of the eosins and gallei'ns and ccerulei'ns. Gallic Acid (Trihydroxybenzoic Acid], C 6 H 2 (OH) 3 .CO.OH. This acid occurs in several vegetable substances, chiefly gailnuts, sumach, tea, etc. It is ordinarily prepared by heating gallo-tannic acid with dilute mineral acid, or by allowing crushed galls to remain exposed in a moistened state to the action of the atmosphere for some time, when a fermentation takes place, after which boiling with water removes the gallic acid. It yields needle-shaped crystals, sometimes white, but mostly light brown in color. Specific gravity 1.70. When heated to 220 it decomposes, forming pyro- gattol (Trihydroxybenzene, C 6 H 3 (OH) 3 ) and CO 2 . Gallic acid is the chief source of pyrogallol, reference to the application of which has been made under phthalic acid. Benzaldehyde (Benzoic Aldehyde], C 6 H 5 .CO.H. This body, also known as " Bitter Almond Oil," is a colorless liquid, possessing an agreeable odor, and high refracting power. Specific gravity 1.063, boiling at 180, diffi- cultly soluble in water (1:300), easily in alcohol and ether. Several methods are employed for the production of this substance ; for industrial purposes, benzyl-chloride is boiled with nitrate of copper and water, half of the contents are distilled, when the oily layer is separated from the dis- tillate and purified. Mercuric oxide has been used instead of the copper salt. PROCESSES OF MANUFACTURE. 385 It finds extensive application in the color industry, also for the production of cinnamic and benzoic acid, and several derivatives of value. 10. KETONES AND DERIVATIVES, ANTHRAQUINONE. The ketones are closely related to the aldehydes, as will be seen from their structure, CH 3 CO H, Aldehyde, CH 3 CO CH 3 , Dimethyl-ketone (acetone). The CO group carbonyl is possessed by both classes, but in the alde- hydes is united, on the one hand to an alcohol radical, and on the other to an atom of hydrogen. The ketones, however, are distinguished by having two alcohol radicals (alkyls) linked by the CO group. Benzophenone, C 6 H 5 .CO.C 6 H 5 , is a ketone of the benzene series, and can be obtained by distilling calcium benzoate, or by heating benzoyl chloride with aluminum chloride and benzene. It occurs in crystals having an aromatic odor, and which melt at 48 to 49, subliming at 300. Insolu- ble in water, soluble in alcohol and ether. It is of some importance, to- gether with the amido- and oxy- derivatives, in the manufacture of certain colors. Acetophenone (Phenyl-methyl-ketone), C 6 H 5 .CO.CH 3 . This is a mixed ketone, and contains two residues of different hydrocarbons united to the carbonyl group. Acetophenone can be obtained by distilling a mixture of the benzoate and acetate of calcium. It occurs in crystalline plates, melting at 14 to 15, and boils at 198. CO Anthraquinone, C 6 H 4 C 6 H 4 . This substance is of the utmost im- portance in the manufacture of alizarine. It can be obtained by several pro- cesses, the simplest of which is probably the distillation of calcium phthalate, or by oxidizing anthracene (C 10 H 8 ) with bichromate of potash and sulphuric acid. Anthraquinone is very stable, oxidizing agents having but little effect upon it. When heated it sublimes, yielding yellowish rhombic crystals. Specific gravity 1.425, melting point 273; insoluble in water, but some- what in alcohol and ether. Upon fusion with caustic alkalies it yields benzoic acid. For use in the alizarine process, it must first be converted into the sulphonic acid, and this fused with caustic alkali, dissolved in water, and the coloring matter precipitated by a mineral acid, and sublimed. (See Processes of Manufacture, p. 389.) IE. Processes of Manufacture. 1. OF NITROBENZENE AND ANILINE. The commercial production of nitrobenzene is carried out essentially in the following manner, although the details may vary in the different works. Sulphuric acid, 66 Be., and nitric acid, 42 Be. (= seventy per cent. HNO 3 ), are mixed together, in the pro- portion of fifteen parts by weight of the former to ten parts of the latter, in a lead-lined wooden tank (preferably situated above the nitrating appa- ratus) and allowed to become cold. Three hundred pounds of this " nitrat- ing acid" are run into the nitrating apparatus, either by gravity or by pressure, when the benzene is allowed to flow in in a slow, steady stream. During the admission of the benzene the temperature, which should be maintained between 80 C. and 90 C., is regulated by means of water kept at ^bout 50 C. circulating around the vessel, or stopping the inflow, should the temperature give indication of rising, thereby producing the di- nitro- derivative. About one hundred pounds of benzene are used, although this quantity is subject to change, according to quality. After the nitration 25 386 THE ARTIFICIAL COLORING MATTERS. is finished, the contents of the vessel are emptied slowly into large tanks, the acid layer being drawn off first, and the nitric acid recovered therefrom, and the nitrobenzene, insoluble in the acid, coming last, is immediately poured into a tank containing water, and washed, followed by a wash with caustic alkali, and finally agitated with water. The quantities by weight of the two acids to effectually nitrate either benzene, toluene, or xylene, is shown below : 100 kilos, benzene 120 kilos, nitric acid. 100 " toluene 105 " " " 100 " xylene 90 " " " 180 kilos, sulphuric acid. 175 " " " 150 " " " FIG. 114 Or, of a standard mixture of one hundred kilos, nitric acid and one hundred and fifty kilos, sulphuric acid, there will be required for the effectual nitration of one hun- dred kilos, of the above tabu- lated hydrocarbons three hun^- dred, two hundred and sixty, and two hundred and twenty- five kilos, respectively. The form of nitrating apparatus in use is usually cylindrical, with a flat or round bottom. Fig. 114 illustrates the latter form. The cover is provided with several openings : / is for general charging ; e is for the gas exit, while pro- vision is made for the intro- duction of the thermometer, and for carrying the agitator shaft. The opening for with- drawing the charge is at g. The best plan in arranging the plant is to provide for the acid mixing and nitrating on one floor, on the floor be- low the washing, and, if de- sirable, a steam still employed to separate the benzene which has not been acted on by the acids, and which is always found dissolved in the nitro- benzene. On the lowest floor, the alkali and final water- wash. If all the- operations are performed on one level, a "monte-jus" should be used for the transportation of liquids. Aniline (" Aniline Oil" of commerce). Aniline is obtained by the treat- ment of nitrobenzene with iron filings or scrapings and hydrochloric acid. The apparatus employed are generally of two kinds, vertical and horizontal, PROCESSES OF MANUFACTURE. 387 FIG. 115, the method of working being in each case the same. In the former, the agitator is attached to an upright hollpw shaft, so constructed as to provide for the admission of steam to the bottom of the vessel. The cover supports the gearing, and gooseneck for leading the vapors to the condenser, etc. The horizontal form is shown in Fig. 115 ; the construction provides for agitators attached to a horizontal re- volving shaft passing through boxes in the heads. Steam enters through the pipes underneath. A steady supply of fine iron is maintained by means of the mechanical feed on the cover. The operation is conducted by adding some of the iron filings with water, followed by the acid and nitrobenzene ; steam is turned on, and the agitators set in motion, at once the reaction begins, and a mixture of nitrobenzene, aniline, and water appears in the condenser, which is continually returned to the main body in the apparatus ; after the reac- tion has commenced and the distillate comes over regularly, the iron can be fed steadily, or at uniform intervals. If all the iron is added at once, serious loss is occasioned by a reduction of aniline to benzene and ammonia. For a charge of six hundred kilos, of nitrobenzene, about seven hundred kilos, of iron filings will be required and sixty kilos, of 21 Be. hydrochloric acid. The solubility of the distillate in hydrochloric acid is noted, until a point is reached when no nitrobenzene separates in an unaltered condition. Formerly it was the general practice to add lime to the tank, and distil off the aniline by means of steam ; now the contents are emptied into large tanks containing water and allowed to subside for a day or more, when the lower layer, consisting of aniline, is drawn off and pumped into a large iron still mounted over an open fire and rectified. One hundred parts nitrobenzene will yield about seventy-five parts of aniline if the process is carefully attended. Ordinarily, the yield will be seventy-one to seventy-four parts. 2. OF PHENOLS, NAPHTHOLS, ETC. Phenol. See Chapter XI., " Coal- tar Distillation," p. 359. Resorcin is manufactured commercially from the soda salt of benzene- disulphonic acid, by fusing with caustic soda and subsequent extraction with ether. One hundred kilos, of fuming sulphuric acid are contained in a large cast-iron vessel provided with means for agitating the contents, and into it is gradually allowed to flow twenty-eight kilos, of benzene ; the whole is maintained at a moderate temperature for several hours, and finally raised to about 270 C. to 275 C., after which the contents are transferred to a large volume of water and boiled. Lime is added, the precipitated sul- phate removed, and the soluble lime salt decomposed by the addition of the requisite quantity of carbonate of soda ; carbonate of lime is precipitated, filtered, and the precipitate freed from the excess of solution in the filter- press. This solution is evaporated to dryness in iron pans. For the re- sorcin melt, sixty kilos, of the above salt and one hundred and fifty kilos. 388 THE ARTIFICIAL COLORING MATTERS. of 76 caustic soda are fused together for about eight hours at a temperature near 270 ; when fusion is finished the melt is cooled, leached out with boil- ing water, and boiled with hydrochloric acid for some time, when the heat is withdrawn, and the solution allowed to become cold, and subjected to the action of ether or benzene in an extraction apparatus, which removes the re- sorcin. The benzene is distilled off and recovered, while the crude resorcin remaining is dried at about 210. Pure resorcin is obtained from the above by distillation. Pyrogallol. Several processes are employed for the production of this substance, all being based upon the use of an aqueous extract of gallnuts or of gallic acid. One process is carried out by heating a glycerine solu- tion of gallic acid to about 200 C., diluting with an equal volume of water, and extracting therefrom the pyrogallol with ether, which is evaporated off and recovered. Another process is to heat one part of gallic acid and two parts water in a closed vessel to 200 to 210 0. for half an hour, cooled, and heated with bone-black, the solution filtered, and evaporated to the crystallizing-point. The crystals are further purified by being distilled in a vacuum. Alpha- and Beta-Naphthols. a-Naphthol is manufactured on a large scale in the same general manner as resorcin. a-Naphthalene-sulphonic acid is first prepared by heating naphthalene with fuming sulphuric acid to 90 C., diluting with water, and completely neutralizing with milk of lime, filtering from the magma of sulphate which is passed through a filter-press, the solution of the soluble lime salt decomposed with carbonate of soda, filtered and pressed again, and the solutions finally evaporated to crystallization, when, on cool- ing, the /5-naphthalene-sulphonate separates out and is removed. The a- salt is fused with caustic soda, when the corresponding naphthol is obtained. 0-Naphthol, of much more commercial importance than the preceding, is manufactured similarly. The naphthalene-sulphonic acid is made as above, but at a temperature of 200 C., in order to obtain a large yield of the ft- de- rivative. This is converted into the soda salt, dried, and one part by weight fused with two parts of caustic soda, dissolved in the smallest quantity of water at a temperature of 270 to 300 C. ; when the reaction is over, the melt is treated with water, the /J-naphthol separated by the addition of hy drochloric acid, filtered, dried, melted, and poured into cylindrical moulds. 3. OF AROMATIC ACIDS AND PHTHALEINS. Benzole Acid can be man- ufactured on a large scale by several processes, of which the outlines of the two following are probably the most important. From benzyl-chloride, one part of which is heated to boiling with three parts of nitric acid (35 B6.) and two parts of water in a retort carrying an inverted condenser ; the boil- ing being continued until all odor of benzaldehyde has ceased, and upon withdrawing a sample and allowing it to cool it forms a crystalline mass. From hippuric acid. For this purpose large quantities of the urine of cattle are taken, to which milk of lime in excess is added, and the whole evapo- rated down to small bulk (about one-tenth the original volume), hydrochloric acid is added, filtered through animal charcoal, boiled, and allowed to become cold, when crude hippuric acid crystallizes out ; this is removed, boiled with hydrochloric acid, yielding glycocoll and benzoic acid. Phthalic Add and Phthalic Anhydride. The process for their manu- facture is as follows. Naphthalene is converted into the tetrachloride de- rivative by means of chlorine gas acting upon it in the fused state, or by grinding naphthalene with an alkaline chlorate and sufficient moisture to PROCESSES OF MANUFACTURE. 389 cause the mass to cohere, when it is dried in small lumps, which are im- mersed in concentrated hydrochloric acid, when the tetrachloride separates as a sticky mass, afterwards becoming hard. This is taken and acted upon by concentrated nitric acid, heated till the solution is complete and the excess of nitric acid has been distilled off, when, upon cooling, the phthalic acid separates out in crystals. The anhydride is obtained by acting upon phthalic acid, heated to about 200 C., with carbon dioxide and subliming. Phthaleins. When phthalic acid or its anhydride acts upon phenols a class of bodies termed " phthalei'ns" are formed with elimination of water. Phenolphthale'in is manufactured by heating the anhydride, phenol, and sul- phuric acid for ten to twelve hours at 120 C. ; the sulphuric acid acts only as a dehydrating agent. The melt is boiled with water, the residue dis- solved in caustic soda, and the phthalem is precipitated upon the addi- tion of an acid. Resorcin-phthalein, or Fluorescein, is obtained by heating three parts of phthalic anhydride with about four parts of resorcin until the fusion yields no more vapors, and becomes solid at a temperature not exceeding 210 C. The melt is dissolved in dilute caustic soda, with an addition of phosphate of soda and chloride of calcium to remove impurities. The fluorescem is precipitated from the solution by the addition of dilute hydrochloric acid. 4. OF ANTHRAQUINONES, ETC. Anthracene in a finely-divided state is suspended in water by agitation, and oxidized by means of potassium bichromate and sulphuric acid at a boiling temperature ; allowed to cool, and the anthraquinone is collected on filter-frames, washed with water and dried, and for further purification is treated with concentrated sulphuric acid, and heated to 110 to 120 C., when the dark mass obtained is treated with steam, which causes a dilution, followed by a gradual separation of the anthraquinone in crystals. These are washed with hot water, and after- wards with hot dilute soda to remove organic acids. The yield is about fifty to fifty-five per cent, of the weight of the anthracene used. Anthraquinone-monosulphonic Acid. (See p. 382.) This is manufac- tured by heating one hundred kilos, anthraquinone with one hundred kilos, fuming sulphuric acid (containing forty-five to fifty per cent, anhydride) to 160 0. in an enamelled cast-iron vessel mounted in an oil-bath. By vary- ing either the quantity of sulphuric acid or the temperature the alpha- or beta-disulphonic acid will result. The separation of the two latter from the mono-sulphonic acid is effected by converting the sulphonic acids into lead salts, decomposing these with carbonate of soda, and acting upon the resulting soda salts with dilute sulphuric acid, which has but a slight solvent action upon the mono-sulphonic acid. Alizarin. The alizarin process is carried on in large iron vessels or autoclaves, mounted as shown in Fig. 116. To the central shaft D agita- tors are attached, so that the charge may be constantly mixed. F is a thermometer, and the openings in the top to the right are for introducing the charge, and the small one on the left for admitting steam and water. The process is commenced by melting two hundred and fifty to three hun- dred parts of caustic soda in a small quantity of water, and then adding twelve to fifteen parts of chlorate of potash and one hundred parts of the sodium anthraquinone-sulphonate, when the vessel is closed and the agitator put in motion,, the whole being kept at a temperature of 180 C. for two days, when it is allowed to cool, dissolved in a large quantity of water, and the alizarin precipitated by the addition of hydrochloric acid. The alizarin 390 THE ARTIFICIAL COLORING MATTERS. is washed to free it from soda salts, passed through filter-presses, and is ready to be either dried and ground, or ground in glycerine to a paste. Neutralizing the soda solution with sulphurous acid instead of with hydro- chloric acid enables a recovery of the caustic soda. The yield from one hundred kilos, anthraquinone is one hundred and five to one hundred and ten kilos, alizarine (Schultz). Several processes are employed, varying mainly in the duration of the melt and in the proportion of materials used. Instead of soda, lime is employed, in which case a " lake" is formed. FIG. 116. 5. OF QUIXOLIXE (CHIXOLIXE) AXD ACRIDIXE. Quinoline is pro- duced from nitrobenzene and aniline. Twenty-four grammes of the for- mer and thirty-eight grammes of the latter, with one hundred and twenty grammes of glycerine, are placed in a flask (provided with a return con- denser) containing one hundred grammes of concentrated sulphuric acid ; when the reaction is over, the contents are boiled for some time, diluted, and the unconsumed nitrobenzene is distilled off; an excess of alkali is added to the solution, and the quinoline distilled off with a current of steam. It can also be obtained from crude quinoline from coal-tar with phthalic an- hydride and zinc chloride. Acridine is found along with crude anthracene, from which it is separated by treatment with dilute sulphuric acid, precipi- tating with chromate of potash, recry stall i zing, precipitating by ammonia, dissolving in hot water, from which it separates in crystals on cooling. 6. SULPHOXATING. This general process consists in dissolving the compound to be changed in fuming sulphuric acid, whereby one or more H atoms are replaced by HSO 3 groups, producing mono-, di-, or trisul- phonic acids. Examples of this process are given under Resorcin (see p. PRODUCTS. 391 387), the Naphthols (see p. 388), and will be frequently referred to in classifying the artificial dye-colors. 7. DIAZOTIZING. By the action of nitrous acid upon primary aromatic amines a diazo- compound is formed, as in the following reaction : C 6 H 5 .N ! H 2 H : NO 3 =C 6 H 5 .N = N.NO 3 + 2H 2 O. H-N; o 2 Hl These diazo- compounds are susceptible of a great variety of reactions whereby other groups or atoms of elements may be substituted. Thus, by the aid of the diazotizing reaction it is possible to replace a NO 2 or a NH 2 group by OH, H, Cl, Br, I, CN, etc. It is therefore of the greatest im- portance in synthetic organic chemistry. The process is carried out in one of two general ways : (a) by conduct- ing a current of nitrous acid gas through a solution of the substance to be diazotized, the nitrous acid in this case being most conveniently obtained by acting upon starch with concentrated nitric acid in a suitable generator, or (6) by diazotizing in a bath together with the nitrous acid-yielding substance (nitrite of soda generally). In this case the gas is evolved by adding an acid, usually sulphuric, to the solution. Diazotizing is always conducted at a low temperature. IE. Products. It would be impossible in the space of this chapter to do more than give a classification of the artificial dye-colors and enumerate a few of the more important under each group. The number of distinct products has already run far into the thousands, and the trade-names by which many are exclu- sively known frequently bear so little relation to the chemical names that it would be idle for us to attempt to cover the ground in any other way than by a simple outlining at present. But before taking up this classification it will be well to examine what general principles, if any, underlie the pro- duction of a dye-color. O. N. Witt* has proposed a theory which explains in a very simple way this color formation in the aromatic series. He names a series of radicals or groups which by their entrance alone or with others change a colorless hydrocarbon into a colored compound. These radicals, which he calls " chromophor" groups, are only capable of producing the " chromogens/' or parent substances of dye-colors, which chromogens, how- ever, are at once changed into dye-colors of distinct basic or acid character when a salt-forming group enters. Thus, from two molecules of benzene by the entrance of the chromphor group N N is formed azo-benzene, an orange-colored chromogen, but not capable of dyeing silk or wool. Wheri the NH 2 group enters there results, however, amido-azo-benzene, a real dyestuff. Or from benzene by the entrance of the chromophor group NO 2 is formed the chromogen trinitro-benzene, which by the entrance of the salt- forming group OH becomes trinitro-phenol (or picric acid), a yellow dye- color. Witt indicates some eleven of these chromophor groups, to which we shall refer under the appropriate heads in our classification. Of salt-form- ing groups which change the chromogens to dyestutfs, two are specially to be noted, the amido group NH 2 , which imparts a basic character to the dye- * Berichte derChem. Ges., ix. p. 522. 392 THE ARTIFICIAL COLORING MATTERS. color, and the hydroxyl group OH, which gives the dye-color an acid char- acter. Almost all dye-colors are changed to colorless compounds by the action of reducing agents. The nitro- compounds are changed into the corresponding amido- derivatives, the azo- compounds into hydrazo- or even amido- compounds, while more complex dye-colors are changed by careful reduction into bodies richer in hydrogen, which are known as " leuco" compounds. From these " leuco" compounds the corresponding dye-colors are then formed more or less easily by oxidation. In some cases atmos- pheric oxidation alone suffices, as with indigo, in others more energetic oxidizing agents, such as lead peroxide, are needed. Again, the study of dye-colors soon shows that they possess different characters with reference to the ease with which they may be fastened upon the fibre to be dyed or the kind of mordant needed to effect such fastening upon the fibre. We therefore distinguish between basic, acid, and indiffer- ent or neutral dyestuffs. Basic dyes like magenta fasten upon the animal fibre at once, and upon the vegetable fibres after treatment with tannic acid and similar acid mordants. They are used in the form of their salts. The acid dyes are frequently sparingly soluble, and are either brought into soluble condition by forming alkaline salts and sul phonic derivatives, which are then used for dyeing, or they are used with fibres previously mordanted with metallic hydrates or salts, as in the case of alizarin. In the latter case, however, the color acid forms a variety of different colored compounds (lakes) with the different bases. To the third class (indifferent or neutral bodies) belongs indigo-blue and some other substances. The classification which is now generally accepted is that based in the main upon Witt's chromophor groups, and we will simply note a few illus- trative compounds under each group. 1. ANILINE OR AMINE DYE-COLORS. (a) TRIPHENYL-METHANE DYES. Benzaldehyde Green (or Malachite Green), known also under a variety of other names, is made by the action of benzaldehyde upon dimethyl-aniline. The commercial dye is the oxalate or zinc chloride double salt. Ethyl Green (or Solid Green) is the corresponding derivative from di- ethyl-aniline. Acid Green (or Helvetia Green) is the sodium salt of the monosulphonic acid of the benzaldehyde green. Magenta (Aniline Red, or Fuchsine) is a mixture of the chlorhydrates of para rosaniline and rosaniline, and is obtained by oxidizing aniline oil with arsenic acid or nitrobenzene. ' A large number of side-products are obtained in the manufacture of magenta, and have been used under the names of cerise, cardinal, amaranth, chrysaniline, phosphine, maroon, mauvaniline, etc. Acid Magenta (Fuchsine S) is the sodium or ammonium salt of para- rosaniline and rosaniline trisulphonic acids, and is prepared by sulphonating the ordinary magenta. Aniline Blue (spirit soluble Blue) is a salt of triphenylated para-rosani- line, and is made by the action of a large excess of aniline upon rosaniline. If magenta is used instead of rosaniline a reddish-blue is obtained. Diphenylamine Blue (spirit soluble) is probably the chlorhydrate of tri- phenylated para-rosaniline, and is made, as the name indicates, from di- phenylamine, which is heated with oxalic acid to 120 to 130 C. Alkali Blue (Nicholson's Blue, Soluble Blue) is the sodium salt of the mono- sulphonic acid of a spirit soluble blue, and is made by sulphonating the latter PRODUCTS. 393 Water Blue (Cotton Blue) consists of salts of triphenyl-rosaniline tri- sulphonic acid with small amounts of the corresponding disulphonic salts. Ho/mann's Violets consist of salts of the ethyl and methyl derivatives of rosaniline and para-rosaniline, and are made by the action of methyl or ethyl chloride or iodide upon magenta in the presence of caustic soda. It is of historic interest, but has been replaced almost completely by methyl violet. Methyl Violet is a salt of pentamethyl para-rosaniline, and is produced by the direct oxidation of the purest dimethyl-aniline with copper chloride. Methyl Green. This dye is formed by the action of methyl chloride upon methyl violet. The commercial dye is the zinc double chloride. Auramine may be mentioned here, but is probably a representative of the diphenyl- methane group. It is an important yellow dye, and is pre- pared by the action of phosgene gas, COC1 2 , upon dimethyl-aniline and heat- ing the product with sal ammoniac and zinc chloride to from 150 to 160 C. (6) AZINES (EURHODINES AND SAFRANINES). Chromophor group =N N=. Neutral Red (Toluylen Red) is a basic dye-color prepared by the action of nitroso-dimethyl-aniline upon ?n-toluylen-diamine. It is used with cotton after mordanting with tannic acid and tartar emetic. Safranine (Aniline Rose) is prepared by the oxidation of amidoazoto- luene and toluidine, or of p-toluylen-diamine, ortho-toluidine, and aniline. The commercial salt is the chlorhydrate of the safranine base. Naphthalene Red (Magdala Red) is the compound in the naphthalene series corresponding to the preceding. It is obtained by fusing the chlor- hydrate of a-naphthylen-diamine, a-naphthylamine, and amidoazonaphtha- lene. It forms a dark-brown powder, soluble in alcohol with strong red fluorescence. It is used largely in silk-dyeing and for velvet because of its fine color and fluorescence. Mauvein (Perkin's Violet) is of historic interest mainly as the first ani- line color. It was obtained by "W. H. Perkin in 1856 by the oxidation with sulphuric acid and bichromate of potash of a mixture of aniline and tolui- dine. (c) INDULINES AND NIGROSINE. Induline, spirit soluble (Coupler's Blue, Guernsey Blue, etc.), is prepared by heating amidoazobenzene with aniline to 160 C. Induline, water soluble (Indigo substitute), is the sodium salt of the di- sulphonate of the preceding, and is extensively used for silk and wool. Nigrosine (Coupler's Gray) is prepared by heating nitrophenol with ani- line and aniline chlorhydrate. The alcohol soluble compound is the simple salt of the base, while the sodium sulphonate forms the water soluble com- pound. (d) ANILINE BLACK. For the preparation of aniline black, aniline chlorhydrate is very carefully oxidized. The dyestuif is not prepared for dyeing or printing, but is fixed on the fibre by an oxidation process which develops it gradually. It is a very fast black. Quite-a variety of oxid- izing agents may be used. Potassium chlorate and copper sulphate are frequently used in admixture, and vanadate of ammonia is also of especial serviceableness in connection with the chlorate. Electrolysis of a concen- trated splution of an aniline salt will also produce aniline black. 2. PHENOL DYE-COLORS. (a) NITRO- AND NITROSO- DERIVATIVES. Picric Add (Trinitrophenol) is made by nitrating carbolic acid direct with strong nitric acid, or, better, by 394 THE ARTIFICIAL, COLORING MATTERS. acting upon phenol-sulphonic acid with strong nitric acid. Forms light- yellow leaflets or scales, and extensively used as a dye for silk and wool. Phenyl Brown (Phenicieune) is a mixture of potassium or ammonium compounds of two isomeric diuitrophenols and some resinous products. It is obtained by the direct nitration of phenol. It is used for wool and silk and in dyeing leather. Victoria Yellow is a mixture of the alkali salts of dinitro-ortho-cresol and dinitro-para-cresol. Naphthol Yellow (Martins Yellow, Manchester Yellow, etc.) is the so- dium, potassium, or calcium salt of dinitro-a-naphthol, and is prepared by the nitration of a-naphthol either directly, or after conversion into the mono- sulphonic acid. Naphthol Yellow S is a sulphonate of the preceding, and is made by nitrating the a-naphthol-trisulphonic acid. . The color is faster than picric acid or the simple naphthol yellow. Aurantia is the ammonium salt of hexa-nitro-diphenylamine, and is made by the nitration of diphenylamine. It was formerly used for wool and silk, but is now used only for leather coloring. .;/ Naphthol Green is obtained by oxidizing nitroso-/3-naphthol monosul- phonate of soda with iron salts. The basic soda is the commercial dye, and is used for wool chiefly. Resorcin Blue. By the action of nitrous acid upon resorcin is pro- duced diazoresorcin, which by the action of. concentrated sulphuric acid is changed into diazoresorufin. This yields a hexabrom- derivative, the am- monium salt of which is the commercial dye. It is used for dyeing silk and wool a blue color, which has a red fluorescence, especially by artificial light. By combining with yellow dyes it yields a fluorescent olive color. (6) ROSOLIC ACIDS. Rosolic Add and Aurin (Pararosolic Acid) may be prepared from rosaniline and pararosaniline respectively by treatment with sodium nitrite and after boiling in the presence of sulphuric acid. These two coloring matters are no longer of commercial importance. Yellow Corallin is prepared by heating pure phenol with concentrated 'sulphuric acid and oxalic acid for some hours until the evolution of gas nearly ceases. The crude product of the reaction obtained by pouring the melted mass into water is changed into the commercial dye by dissolving it in caustic soda solution and evaporation to dryness. Red Corallin (Paeonin) is obtained by the action of ammonia under pressure upon the yellow corallin, and represents an intermediate product between aurin and para-rosaniline. (c) PHTHALEINS. Phenol-phthal'ein is not used as a dyestuff, but as an indicator in alkalimetry. Fluorescein (Resorcin Phthalein) is made by heating molecular propor- tions of resorcin and phthalic anhydride to 195 to 200. Fluorescein is not used as such for dyeing, but is converted into the eosins. The sodium salt of the fluorescein comes into commerce under the name of uranine. Eosins. The several halogen substitution derivatives of fluorescein form the class of dyes known as eosins. Thus, the potassium or sodium salt of tetrabrom-fluorescein is the eosin yellow shade, while the correspond- ing salts of tetraiodo-fluorescein constitute eosin blue shade. Methyl and Ethyl Eosin (Primrose) are the methyl and ethyl ethers of tetrabrom- fluorescein. Aureosin is a chlorinated fluorescein. Rubeosin is prepared from this latter by the action of nitric acid. Erythrosin is the potassium PRODUCTS. 395 salt of di-iodo-fluorescein. Rose Bengale is the sodium salt of tetraiodo- dichlor-fluorescein. Phloxin is the potassium salt of tetrabromdichlor- fluorescein, and Cyanosine is the potassium salt of the methyl ether of phloxin. Rhodamine is the phthalein of diethyl-meta-amidophenol. Wool and silk especially are dyed with the eosins, and cotton after mordanting with various metallic salts. Gallein is the phthalein of pyrogallol, and is prepared by an analogous method to that described under fluorescein. It is very little used in dyeing, but serves for the preparation of Ccerulein. This dye is obtained by heating gallein with twenty times its weight of strong sulphuric acid. Forms a dark amorphous mass, which dissolves in alkalies with a beautiful green color. Ccerulein forms a color- less compound with sodium bisulphite, which is known as Ccerul'ein S, and is much used in dyeing, as it is easily decomposed by steaming. (d) INDOPHENOLS AND LAUTH'S DYES. Indophenol (a-Naphthol Blue) is prepared by oxidizing dimethyl-paraphenylene-diamine and a-naphthol with bichromate of potash and acetic acid. Indophenol may be reduced by glucose and caustic soda to a leuco- compound known as Indophenol while, which is also sold commercially. When cotton goods are printed with leuco- indophenol, the blue color may then be developed in dilute bichromate of potash solution. Methylene blue is prepared from dimethyl-aniline by the treatment of this first with sodium nitrite and then hydrogen sulphide after acidifying with hydrochloric acid. The commercial salt is a zinc double chloride of the sulphur base, called tetramethyl-thionin. Ethylene blue is a salt of the corresponding tetra-ethyl base. Gallocyanin is obtained by the action of nitrosodimethyl-aniline upon gallic acid. It is gray paste, insoluble in water, but soluble in alcohol with bluish-violet color. 3. Azo DYE-COLORS. Chromophor group, N = N" . A. MONOAZO DYES. (a) Amidoazo Dyes. Aniline Yellow (Amidoazo- benzene Hydrochloride) is no longer used as a dye, as it is volatile with steam and not at all fast. Chrysoidine (Diamidoazobenzene Hydrochloride) is obtained by ad- mixing solutions of diazobenzene hydrochloride and ra-phenylene-diamine. Forms reddish-brown crystals. Phenylene Brown (Bismarck Brown, or Vesuvine) is triamido-azoben- zene hydrochloride. Forms a brown powder soluble in water. (6) Amidoazosulphonic Acids. Acid Yellow (Fast Yellow) is the sodium salt of the disulphonic acid of aniline yellow (amidoazobenzene). It is used largely in dyeing compound shades. Dimethyl-aniline Orange (Helianthin) is the ammonia salt of dimethyl- aniline azobenzene-sulphonic acid. Dyes silk and wool a fiery orange. It is also used as an indicator in alkalinity, as the light-yellow color of the solution is immediately turned red by the addition of a drop of hydro- chloric acid. Diphenylamine Orange (Tropseolin GO, Orange IV) is formed by the action of diazobenzene-sulphonic acid upon diphenylamine. Dyes a very fine golden yellow upon silk or wool. Metanil Yellow is the sodium salt of phenylamidoazobenzene-m-sul- phonic acid. Forms a yellow soluble powder. (c) Oxyazo Dyes. Soudan G (Aniline-azoresorcin) is a brown powder 396 THE ARTIFICIAL COLORING MATTERS. hardly soluble in water, soluble in alcohol. It is used for coloring spirit varnishes, oils, etc. Soudan Brown (Pigment Brown) is made by the action of hydrochloride of a-diazonaphthalene upon a-naphthol. It is used for coloring varnishes, soaps. Carmine-naphte is an isomeric compound formed from /?-diazonaph- thalene and /?-naphthol. Forms a red-brown powder, soluble in sulphuric acid with fuchsine-red color. Azarin is an ammonium bisulphite compound of the dye resulting from the action of diazodichlorphenol and /3-naphthol. When the azarin-paste is used in cotton-printing and steamed, the sulphite combination is broken up and a brilliant red color remains. (d) Oxyazosulphonic Acids. Orocein Orange (Ponceau 4GB) is pre- pared from hydrochloride of diazobenzene and /?-naphthol-monosulphonic acid. It is a fiery-red powder, dyeing a reddish orange on wool. Orange G is the sodium salt of diazobenzene-/3-naphthol-disulphonic acid. It dyes an orange-yellow shade. Cochineal Scarlet 2R results from the action of diazotoluene upon a-naph- thol-monosulphonic acid. It forms a cinnabar-red dye-color. Azococcin 2R results from the action of hydrochloride of diazoxylene upon a-naphthol-sulphonic acid. It forms a red-brown powder, difficultly soluble in water. It is used in silk dyeing. Wool Scarlet R results from the action of hydrochloride of diazoxylene upon a-naphthol-disul phonic acid. It forms a brown-red powder, soluble in water with yellowish-red color. Ponceau 2R (Xylidine Eed) results from the action of hydrochloride of diazo-m-xylene upon /J-naphthol-disulphonic acid. It forms a red powder, easily soluble. It has been used in large quantities as a substitute for coch- ineal. Ponceau 3R (Cumidine Red) results from the action of hydrochloride of diazo-m-cumene upon /9-naphthol-disulphonic acid. It is used as the pre- ceding, but gives redder shades. Anisol Red and Phenetol Red are formed by the action of anisidine and amido-phenetol respectively upon /5-naphthol-disulphonic acid. Fast Red B (Bordeaux B) is formed by the action of hydrochloride of diazonaphthalene upon /3-naphthol-disulphonic acid. a-Naphthol Orange (Tropseolin OOO, No. 1) is the sodium salt of ^>-sul- phanilic-acid-azo-a-naphthol. Forms orange-yellow scales, tolerably solu- ble in water. It dyes silk and wool a reddish orange. p-Naphthol Orange (Tropseolin OOO, No. 2, Mandarin) results from the action of p-diazobenzene-sulphonic acid upon ^>-naphthol in alkaline solu- tion. It forms an orange-red soluble powder, and is used largely for wool- dyeing. Fast Red A (Rocelline, Cerasine, etc.) is prepared by uniting a-diazo- uaphthalene-sulphonic acid acid with /9-naphthol. It forms a brown-red powder, more soluble in hot than in cold water. It is used largely as a substitute for barwood and orseille. Azorubin S (Fast Red C, Carmoisin) is the sodium salt of the disul- phonic acid of naphthalene-azo-a-naphthol. It forms a reddish-brown soluble powder. Brilliant Ponceau 4R (Cochineal Red A) and Fast Red D (Amaranth) are both sodium salts of trisulphonic acids of naphthalene-azo-/3-naphthol, PRODUCTS. 397 isomeric with each other. The former is a scarlet-red easily soluble powder, the latter a reddish -brown powder. B. DISAZO DYES. (a) Disazo Dyes from Azo Dye-colors (Primary Disazo Dyes). Resorcin Brown is the sodium salt of a sulphonic acid of resorcin- disazo-xylene-benzene. Forms a brown soluble powder. Fast Brown results from the action of two molecules of a-diazo-naph- thalene-sulphonic acid upon one molecule of resorcin. Acid Brown G is formed by the action of hydrochloride of diazo-ben- zene upon chrysoidin-sulphonic acid. Dyes wool brown in acid solution. (6) Disazo Dyes from Amido-azo Dyes (Secondary Disazo Dyes). Cloth Red G (Azococcin 7B) results from the action of diazoazo-benzene upon a-naphthol-sulphonic acid. Forms a brown powder not readily soluble in water. Used in wool-dyeing, either alone or in connection with logwood, fustic, etc. Brilliant Orocein (Cotton Scarlet) results from the action of hydro- chloride of diazoazo-benzene upon /5-naphthol-disulphonic acid. Forms a reddish soluble powder. Biebrich Scarlet (Ponceau B). It is the sodium salt of amido-azo-ben- zene-disulphonic-aeid-azo-/?-naphthol. Forms a brown-red fairly soluble powder. Dyes wool and silk in acid-bath a red color like cochineal. Crocein Scarlet 3B (Ponceau 4KB) results from the action of diazoazo- benzene-mono-sulphonic acid upon /3-naphthol-mono-sulphonic acid. Forms a red-brown powder dissolving with scarlet-red color. Used in wool- and silk-dyeing. Naphthol Black is the sodium salt of the tetrasulphonic acid of naphtha- lene-disazo-naphthalene-,9-naphthol. Forms a violet-black powder. Used exclusively in wool-dyeing. Wool Black is the sodium salt of the disul phonic acid of a benzene- disazo-benzene-p-tolyl-,?-naphthylamine. It forms a bluish-black soluble powder. Dyes a deep blue-black color and is quite stable. Fast Violet is the sodium salt of the disulphonic acid of a naphthalene- disazo-benzene-y9-naphthol. Forms a dark-brown soluble pow r der. Used in wool-dyeing. (c) Disazo Dyes from Diamido Compounds (Congo Group, or Benzidine Dyes). These dyes are distinguished from all other coal-tar dyes by the readiness with which vegetable fibres may be dyed with them without pre- vious mordanting, so that they are equally applicable to vegetable or animal fibres, and can be used with goods of mixed fibre. They are often called substantive cotton dyes. Their affinity for the fibres indeed goes so far that they can be used like mordants to facilitate the fastening of other coal-tar dyes upon the vegetable fibres. Nor need the dyeing with these coloring matters precede the use of the other dyes, but they may be used at once in admixture with the benzidine dyes. Chrysamin is obtained by the action of tetrazo-diphenyl chloride upon salicylate of soda. It forms a yellow powder, sparingly soluble in cold water, but soluble on boiling. Used in cotton-dyeing and for mixed cotton and woollen goods. Congo Red is the sodium salt of diphenyl-p-disazo-naphthionic acid. Forms a^ reddish-brown powder, soluble in water with fine red color. This solution is so sensitive to acids that a single drop of very dilute sulphuric acid suffices to convert the whole of the liquid to a beautiful blue. It is therefore a valuable indicator in volumetric analysis. 398 THE ARTIFICIAL COLORING MATTERS. Benzopurpurin is formed by the action of tetrazo-ditolyl chloride upon naphthylamine sulphonate of soda. It is a dark-red powder, dissolving easily in water. The scarlet obtained from this dye is not changed by dilute acid as is that from Congo red. Azo Blue is formed by the action of tetrazo-ditolyl chloride upon /9-naph- thol-sulphonate of potash. It is a dark-blue powder, dissolving easily in water. It is fast to acids but not to light. Supplementary to the Azo Dyes. Tartrazin is formed by the action of two molecules of phenyl-hydrazin-p-sulphonic acid upon one molecule of dioxytartaric acid. Orange-yellow powder, easily soluble in water. It is a valuable woollen dye, very fast to light and fulling. Primuline and Ingrain Colors. Primuline is mentioned here because of its ready convertibility into azo colors (ingrain colors). It is the sodium salt of the sulpho- acid of a sulphated amido- compound, and is formed by the action of sulphur upon _p-toluidine. The primuline base is a yellow powder, very soluble in hot water, and dyes unmordanted cotton direct from a neutral or alkaline bath. Its great importance, however, lies in the fact that as the sulpho- acid of a primary amine it can be diazotized (see p. 391), and then is capable of combining with the whole range of phenols and amines to form azo colors. These operations can be readily carried out upon the fibre, whence the colors so obtained have been called ingrain colors. This diazotizing and developing with the phenol or amine may be effected upon the silk, wool, or cotton fibre previously dyed with the primuline base. In this way yellows, oranges, purples, reds, scarlets, maroons, and browns are produced. 4. QUINOLINE AND ACRIDINE DYES. Quinoline Yellow is the sodium salt of quinoline-phthalon-sulphonic acid. It forms a yellow powder, soluble in water or alcohol with yellow color. Used for wool- and silk- dyeing. Flavaniline is obtained by heating acetanilid with anhydrous zinc chlo- ride for several hours to 250 C. The commercial salt is the hydrochloride of the base so obtained. Was formerly used for wool- and silk-dyeing, and for cotton after mordanting with tannin and tartar emetic. Cyanine (Quinoline Blue) is prepared by treating a mixture of quino- line and lepidine with amyl iodide. It forms a fine blue color, but unstable to light. It is not of importance in textile coloring, but is used in the manu- facture of orthochromatic photographic dry plates. Phosphine (Chrysaniline) is, as was before noted (see p. 392), a by-prod- uct in the manufacture of magenta, but is probably diamido-phenyl-acridine. The phosphine of commerce is the nitrate or chlorhydrate of the base chrys- aniline. Used at present chiefly in silk-dyeing. 5. ARTIFICIAL INDIGO. Artificial indigo is not manufactured and sold as such, but what is known as " propiolic paste," which is a moist paste con- taining a definite percentage (usually twenty-five per cent.) of o-nitrophenyl- propiol ic acid prepared from synthetic cinnamie acid. Professor Baeyer found that this o-nitrophenyl-propiolic acid wlien in alkaline solution is readily changed by reducing agents, like grape-sugar, milk-sugar, sulphides, sulphy- drates, and especially by xanthogenate, into indigo-blue. The reducing agents act already in the cold in either aqueous or alcoholic solutions. This " propiolic paste" was used for a time in calico-printing, being printed on the goods along with the reducing agent, but the decomposition of the xan- thogenate of soda develops mercaptan, the unpleasant odor of which adheres PRODUCTS. 399 very persistently to the goods, and the blue color is slightly gray in shade. It has therefore been given up for the present. A more recent synthesis of indigo from phenylglycocoll by Professor Heumann has not as yet been developed on a commercial scale. 6. ANTHRACENE DYE-COLORS. Alizarin. This term may be applied commercially to the pure dioxyanthraquinone found in the madder-root and made artificially from the anthraquinone-monosulphonic acid, or to the two trioxyanthraquinones obtained from the anthraquinone-disulphonic acid, and known more accurately as anthrapurpurin and flavopurpurin. The first or true alizarin is the blue shade alizarin. This is a yellow powder coming into commerce as a ten per cent, or twenty per cent, paste. When dried and sublimed it forms splendid orange-red crystals, melting at 280 C. It is insoluble in water and sparingly soluble only in cold alcohol. Sulphuric acid dissolves it, and on diluting the alizarin is precipitated again unchanged. It acts as a weak acid, and forms alizarates with the alkalies and metallic hydrates. Anthrapurpurin (Isopurpurin), as before stated, is a trioxyanthraqui- none, but is generally produced along with the preceding compound in the manufacture of commercial alizarin, as both the monosulphonic and the disulphonic acids are obtained in sulphonating anthraquinone. Anthra- purpurin is obtained in the purest state by melting pure /5-anthraquinone- disulphonic acid with caustic soda and chlorate of potash. It melts at 360 C. Flavopurpurin is obtained also in the manufacture of commercial aliz- arin, and can be prepared as sole product by melting a-anthraquinone- disulphonic acid with caustic soda and chlorate of potash. Forms orange- colored needles, melting at over 300 C. A mixture of anthrapurpuriu and flavopurpurin with little alizarin constitutes the commercial yellow shade alizarin. Purpurin is also a trioxyanthaquinone, but differs in its molecular for- mula from both anthrapurpurin and flavopurpurin, and is therefore one of three isomers. It is not a constituent of commercial artificial alizarin, but is found accompanying true alizarin in the madder-root. It forms red needles, beginning to sublime at 150 C. and melting at 253 C. It is soluble in boiling water with dark-red color. Alizarin Orange (Nitroalizarin) is formed from alizarin by the action of nitrous acid, or by the action of nitric acid of 42 B. upon alizarin sus- pended in glacial acetic acid. It forms a yellow paste of twenty per cent. dry material. Aluminum salts form an orange color, chromium salts a brown-red shade. Used with silk, wool, and cotton. Alizarin Blue is a dioxyanthraquinone-quinoline, and is made by heating /5- nitroalizarin with glycerine and sulphuric acid to 90 C. Dark-blue powder, almost insoluble in water. Hence is used either by reduction with zinc-dust, grape-sugar, or similar reducing agent and subsequent atmos- pheric oxidation, as in indigo-dyeing, or by forming a soluble compound with alkaline bisulphites, designated as Alizarin Blue S. This latter is much faster to light than the original color. Anthracene Brown (Anthragallol). It is formed by heating benzoic and gallic acids with concentrated sulphuric acid, or by heating pyrogallol with phthalic* anhydride or zinc chloride. It comes into commerce as a dark- brown paste, and yields very fast shades. 7. MISCELLANEOUS COLORS. Galloflavin is formed by the atmospheric 400 THE ARTIFICIAL COLORING MATTERS. oxidation of gallic acid in alkaline solution. Forms a dirty-yellow paste, insoluble in water or hydrochloric acid. Wool mordanted with chromium salts takes a color resembling that obtained from fustic. Canarin (Persulphocyanogen) is a color obtained by the oxidation of potassium sulphocyanate. It is an orange-yellow powder, insoluble in water and alcohol. It is used for cotton-dyeing and for producing com- pound shades with basic aniline dyes. Oachou de Laval. This name is given to the alkali salts of very com- plicated compound mercaptan acids. The shades obtained vary from gray to brown, and can be used to form compound colors with artificial dye- stuffs and with dye-wood extracts. IV. Analytical Tests and Methods. In this section it is not the intention to exhaust the subject of the chemical examination of coal-tar colors, but to briefly indicate the more important and characteristic tests. The complete chemical analysis of the artificial organic dyes is very seldom resorted to, the analyst usually determining the identity of the coloring matter by means of the tabular schemes which have been published from time to time as new products have appeared on the market, and estimating the moisture of the sample and such foreign substances as the sulphates of soda, and of magnesia, salt, sugar, starch, and dextrine, sand, etc. Of considerable value in connection with the above is a dyed sample of cloth or yarn, which, although not strictly a chemical test, is one of equal importance, especially for the information of the immediate user of the dye. The recognition of dyes, either by themselves or on the fibre, is often desirable, but this requires considerable care and judgment, from the fact that a very large number are simply mixtures, some with as many as five separate dyes ; in such cases the task is almost hopeless. These mix- tures are sometimes made at the color manufactory, and again by the local agent ; in the latter case, usually to supply some particular shade called for, and generally without any regard to the chemical nature of the constituents ; this indiscriminate mixing accounts in a measure for the streakiness and uneven effects noticed in dyeing piece goods and yarn with such colors, which cannot always be detected by dyeing the small test samples in the laboratory. Fastness to Light is determined by exposing one-half of a dyed skein or piece of dyed cloth to the action of direct sunlight for a definite time, say thirty days or longer. Fastness to Soap. A piece of dyed cloth or yarn is worked in a neutral soap lather, washed, dried, and compared with the original. Comparative Dye-trials. For this purpose vessels of glass, porcelain, or tinned copper are most convenient, the latter is the best suited, and if means can be had to provide heating by steam, it leaves nothing to be de- sired. When several comparative dyeings are to be made at one time of the same class of samples, one equal temperature is necessary. For Wool and Silk. In either case it is best to use a vessel containing about one litre. From twenty to twenty-five grammes of wool (yarn or fabric) and about five to ten grammes of silk answer well for the tests. The quantity of dye used varies, although two standards, representing one per cent, and five per cent, of the weight of the wool or silk, answer, as they give two shades which are convenient for estimating the dyeing value of ANALYTICAL TESTS AND METHODS. 401 the sample. To make the test, the color is weighed out carefully, washed into the dye-bath containing water, and brought to the boil, into which the material, previously wetted out, is immersed and kept moving about for a definite time, say twenty to thirty minutes, or until the bath is exhausted of color, when it is withdrawn, washed, dried, and the shade compared with a swatch of the same weight, treated under exactly the same conditions as to temperature, time, etc. To determine the relative dyeing values of color samples, two solutions of equal value are made of equal (known) weights of the dyes, and two dyeings are made as above, only adding the dye solution to the bath as fast as it is taken up by the fabric ; a point will be reached when no more color will be taken up, when the addition must stop, the difference in the volume of the solution remaining, from their original volume, gives the amount used in each test ; and as the strength was known, the relative amounts absorbed by the fabric can be calculated. The above applies equally to silk. No general rule can be given which will embrace the application of the colors to fibres in testing, reference must be had to the various classes of dyes and methods in Chapter XIV. For Cotton. Few colors are directly applicable to this fibre without previously mordanting it with suitable substances which will cause the color to remain. In the laboratory, a quantity of cotton is taken (yarn or piece), boiled well in water, and immersed in a five per cent, solution of tannin for about twelve hours, when it is removed and boiled in a bath con- taining two and a half per cent, of tartar emetic for thirty to forty-five minutes, washed, dried, and kept for use. (Other mordants e.g., tin, iron, alumina, etc. are used according to the kind of work done in the estab- lishment.) In the matter of printed goods, swatches of cotton cloth, mor- danted on one piece with several bases, are made by the printer, and these are then passed through one solution of color, and the effect can be conveni- ently noticed. For Woollen Yarn Printing. Pastes are made up of the color in vary- ing strengths with starch or flour, and with such assistants as may be re- quired, such as oxalic or tartaric acids, stannous chloride, etc., in the fol- lowing manner : Five grammes of color are taken and mixed with a little \vater containing dextrine or glycerine, and this is made up to five hundred cubic centimetres with a paste of flour (one pound per gallon). Twenty or thirty strands of yarn about a metre long are taken, held at one end, and the color-paste rubbed well in for a space of about six inches with a glass rod or spatula ; one-tenth of the color-paste is emptied out, and the remain- ing is diluted again to five hundred cubic centimetres, and this is then applied to the yarn, leaving a space of an inch or so from the first. The diluting operation is continued so that the printings on the yarn will repre- sent color in the proportion of 1, .9, .8, .7, etc., giving a range of shades of one color. The yarn so printed is then steamed for about twenty to thirty minutes under pressure, or longer without pressure, washed, and dried. This method is of much value in matching and valuing shades in tapestry carpets. By Colorimetry. This method involves the use of two graduated glass tubes, closed at one end, each of the same diameter, thickness, and length. The standard sample of dye being weighed and dissolved in water, is poured into one tube, while an equal weight of the sample to be tested is poured into the other, and by holding the tubes to the light the depth of color is 26 402 THE ARTIFICIAL COLORING MATTERS. seen. If one is darker in shade than the other, it is diluted until the shades are equal, when, by knowing the number of cubic centimetres of water added to equalize the tint, the relative strength of the dyes can be ascertained. Mixtures of Dyes can be detected by sprinkling some of the powder on the surface of distilled water, and noticing the color of the streaks formed as the particles subside, or by dissolving the dye in a little alcohol and water con- tained in a small evaporating dish or beaker, and immersing therein the end of a strip of white blotting-paper, when, in the case of mixtures, several dif- ferently-colored bands are seen on the paper, owing to the fact that the con- stituents of the mixture do not always possess the same degree of capillarity. These bands can be cut off and separately tested by proper reagents according to the scheme for identification of dyes following. Fractional dyeing has also furnished information of value ; usually wool or silk being employed. Identification of Goal-tar Dyes. Weingartner's comprehensive tables, which follow, affords means of determining the group to which a sample of dye under examination belongs. The dyes are divided conveniently into two divisions, basic and acid coloring matters, and the latter into soluble and insoluble in water. I. The Dye is Soluble in Water. Add a few drops of a solution of tannin* to a solution of the dye, and note the formation of a precipitate, after heating. A. Precipitation takes Place. The color is basic. A small quantity of the original color is dissolved in water, and reduced with hydrochloric acid and zinc-dust, rapidly filtered, and neutralized with sodium acetate ; small strips of filter-paper are immersed in the solution, and exposed to oxidize. THE ORIGINA^ COLOR REAPPEARS ON THE PAPER. The original color does not reappear. Reds. Oranges and yellows. Greens. Blues. Violets. FUCHSINE, PHOSPHINE, MALACHITE METHYLENE METHYL VIOLET. CHRYSOIDINE. MAGENTA, CHRYSANI- GREEN. VIC- BLUE. With Sulphuric acid Color, orange. ROSEINE. LINE. With TORIA GREEN. sulphuric causes a yel- In sulphuric With sul- sulphuric acid, With sulphuric acid, green. lowish-brown acid, dis- phuric add, reddish-yel- acid, yellow, Caustic soda coloration; on solves to a Drown. low precipi- on diluting causes vio- dilution brownish- NEUTRAL RED. tate. Green with water, let-black changes to yellcw solu- With sul- fluorescence. green. Ammo- precipitate. green and vio- tion. phuric acid, Caustic soda, nia causes NEW BLUE. let-blue. VESUVINE. green. With light-yellow gray or red With caustic NEUTRAL VIO- Color, brown, caustic soda solution, yel- precipitate. Soluble in precipitate. BRILLIANT soda, blue- black pre- LET. Sulphuric acid causes upon silk, orange. In low-brown ether with GREEN. With cipitate. bright violet sulphuric precipitate. green fluores- sulphuric acid. MUSCARINE. color ; on dilu- add, soluble SAKRANINE. cence. same as above, Caustic soda tion changes to a pale With sul- FLAVANILINE. color reap- causes to blue. liquid. phuric acid. With sulphuric pears slowly. brownish- MAUVEINE. AURAMINE. green. Caus- tic soda, acid, dirty yel- low precipi- Ammonia, lit- tle or no pre- red precipi- tate. With Sulphuric acid causes gray Color, yellow. With alkalies, brownish- tate. Soluble cipitate. tannin. color; on dilu- white pre- red precipi- in ether with METHYL GREEN, indigo-blue tion changes cipitate. tate. blue fluores- PARIS GREEN. precipitate. to light blue On warming cence. With sulphuric and violet-red. with ful- acid, same as AMETHYST. phuric add. above, color Sulphuric acid solution de- not reappear- gives green colorized ing on dilu- color; blue on VICTORIA tion. Ammonia, dilution. BLUE. Color. solution de- blue. In sul- composed, no phuric acid, precipitate. brownish- red, changes to bluish- green. * Twenty-five parts of tannin, twenty-five parts of acetate of soda, and two hundred and fifty parts of water. ANALYTICAL TESTS AND METHODS. 403 .B. JVb Precipitation takes Place. The color is acid. O O JS *0 & w o*^j^o c* a ^ -^ *^ P i o o o S ^ -^ o"3s "* P * Q-P^ Q H 3 re, o" 2 t? re o' - ^ p 3" O^ r* P 3! "^ O 2 B (] r* *^ o' H 3" S* T "^ C" 1 9fi 6 a ^^ftr^h^t O O 2 ^* ^ * a O OQ ! S. B ^ 3- re re B . ^ 5 B S 2 9*5 "' S. 2 S'^ 2 f ! n*m re I'^^V Its.* 13> S-e_ rlSs 11 1 ' 2.s !!"'' $*&? -la *$ z *g SJ >n S"s >fl 'f ' T * re ^ K Q O5 a "2 Z *"* ^ ie O Oa *OfD S" S 2 2c *?* ^ ( ! ^ p; X * . re jo^c: ST 3* > ^ (D *"* ^* o S P ^D^*-c*5" W *"o ^ f B ?^W ' Us ^^?a P ' S 'i'--2. S-j 3 3 5-S Sf c *o ! ET. ~ O 0* as >n 5! | g|l |S-| || |2 r 2 -i f-Ilg ? re 3Q * o '^ .B * * * i !T ' "~a- ^ j J< ? o o_ | i SS *S Pi "^ Hal i if/^g B 1^ ss -. i o i ao c ^' > > ^^ 5-a S j Q h-. w ^ ^ dQKxawO ^^wS DQjt^ Sv*^*^ ^^o** * ft O tW ^ P^tfl lltll 3 II? II || llti = * "1 H |= 1 III ti pi IJ; r' S G I^>,CB E > S 5 c re a 3 n 1 5'S^'^-^o g'O 2 ' ui ^^ jj St. S 2. re o^? llftla 5's ^S as a a -l ^ FsV?' pSSTfs I'g ^s 3 ~*l rg ra < y r remains lored. hloric acid, .EDUCE WITH j S w x! flip III ^Ifl IP- H O 3| DROCH aa> ^fts* EL*!'^ l-ire'i* g 3 > SQ if S |?||? ^a |P'P ^fi.!' 2 Ho TO O H V 3 3 S < S H 3- 2 o ^' 2 p* El ^ i ?i' r . ft 2 <^ <^ "" oS Q > ^ Oft s^*o *"--r^ ' 3 Ji* o a 2 O ! ^tlaS K M-^ iH ^ 1 ts o tjj ^ 03 0* - S ||p iifl f!t=li |I| i E^Ea 3 n i B 09 a 1 o |||| ||.S ' " "ig2 P. w l B O ~< B 3 P |-|s:p |s> Ssllg i:! 5 ' o _,|2, ^i| 3 i H 2 2e M^SO c*"^^ ^ 3 ? si* * ^a <-^H're "" g-, = ? c"i * 2 2, 2. rv, 3* i re^> ^ 2O- P^re" 1 n a o" "" ?"5"-2 i * H ^J in. Qfii 11 ^ III rS.S> S-M re f 1 ar on t ? a re ^S" 1 3- re WWO *B f5 X ^S 1 Hr 1 ^!?; g;>H^ H H cw is 1 a a i SJOO- ZOp-.-^-Og-^iO'^P'K^^jOo^'^re re r* e. -I BS^ISB:5K:2 o i^2O:-' :i '5 r 'S'> 3 |s ? i 5 E 1 i ^ ^K2- S r5^ "^r""-^ S* S- J^ B 2 X55*^v^^ r ^ V*l ~ v ^ rj ^ ^ -5 O *1 .<* C i ' "l c re o* > * o ff "l i X "l ^ *| o 2 "* 's ' *O en 01 ^ S P^w^S"^ Kp- "|3 K - "l fc (} " |l|*ij| iii Jll Jf ^ilffl S.a .1 o ^ re " a 2 3 re 1 a""| O? " IHII^g ii ii| 5 2. Su.y'E > Ii s| OT3 2 3 "-i H * , ^*- S C" -' s, 2 (K g" 3 B 2 3 S' c ^ o > * ! (9 fi 01 2* fpjfl p lllj 1 ?l 'S ^ n o c 3 .. S""^ If 404 THE ARTIFICIAL COLORING MATTERS. II. The Dye is Insoluble in Water. Treat with a five per cent, solution of caustic soda. III |||l||||i S >>.H o '> M aj ft 5 e * 03 .3 ,j c 5 . "- 1 ,J 2 2 "2 ~ 2 S ~ = a -i 5i g a a ? "5 s x5 -5 * II* "o J o "o i> 3 js -iA 50 Iff ^55| ^|| 3 --> *C 4) i*^ > ^ . ,' . 5- sj S l S !s' g .g Z 1" a -~ fc. OS PJ 4> o ^ S 3 S"S"c^ <"S'^S 3 OC9 9 g> % U33 h|*PK .2 5 a, o 3 -a i aJ'O _O P..3 a S ? 3* Xo a "o 1 *= o a |a aj ri "o v M 2 i "a P Sg| 2|| Q s J3 = 2 a '!= H i^ ~ S<5 ft < ^ > ^3 o z ft " * s >> u i iJ i S o fi Z a l-il M 1 ^~ id o s J si fi" be" , jjS =13"^ s^'C-S a 2 ^* O 3 H 3 e ^ cc eg K S s.SJ ~ o 3 CG a 55O O"^ 3 "ii u - S a 1 i Z .2 3 fti-S X|5l^1 OB|?^ _0 m" 3 "3 e 2.C'-' M'S^*.^ 3 "S o = t*'5i _ o W 1o'i S 1 a> f.a2 5> ]| < |1| H -l ^l|| a "C *S ^U33iJ^fQQ ^ ^ ^^Stj p 5 M Ss ^-1 js S d^l-^'&ES'S alls ii'l~|| liSslill ^ uc>0 ^J- 09, II 2 o -^y i a aj g - ~ 6 6 ^"3 6 s-a *i 1 -I -si f,.S? -%> | g d s filtered, and small slips of ill on, and expose* nal color does n eappear. If sl^ | go e^- 2 6g| -w- 265 ' la 1S^ ^ | S| ll| 5 &| *J " -03 Z 2^ .2 y-^S gl -12 1$ S 5 s z| "I s Ijl > >j 5 C of 3 = -.S'O < 3 i o> "o 53 M N ^ Tjf *c o 0) i rti ** .E 15 C3 &* **! b*W -C *- 5 ^ - 5 "-* p! |!1 |i 1 Jlf 1111 ills !H M M If'S Oft e^ ^ 4^ 8^ . S tn 12 a ^. eo o3 So^ H gla o cl ^ .. 2j o S r~5 5 u "o ^ ^2 M~ 8 " SB o"* *lj5. _ z'"o - ". S - ^'~ ^! a '^ ? w 2* .55 ^ v S ^bc^ 1 ^ ^ (ill |J| sil l! Ill 111 ~8a3 |5ft o o y o ANALYTICAL TESTS AND METHODS. 405 Chemical Analysis of Dyes. Ultimate analysis is not within the scope of this work. Proximate analysis is constantly resorted to, and embraces the determination of the moisture, mineral matter, salts, starches, etc. Determination of Moisture. One to three grammes of the coloring matter are weighed in a shallow porcelain or platinum dish, and exposed to a temperature of 100 to 105 C. in an air-bath, allowed to cool in a desic- cator, and weighed again, the difference is moisture. Insoluble Matter. The dried residue from the above is dissolved in water, warmed to facilitate solution if necessary, and filtered through a small tared filter, washed until no color remains, dried, cooled in a desic- cator, and weighed. If dextrine is present, it will be noticed in this test by its odor. Sodium Chloride (Common Salt). This is usually determined by nitrate of silver, but as many dyes contain chlorine in the molecule, the addition of this reagent directly to the solution is inadmissible. Salt can be esti- mated indirectly by calculating from the amount of chlorine found in the ash left upon igniting some of the dye by dissolving in water, filtering to re- move any insoluble matter, acidulating with a few drops of nitric acid, and adding nitrate of silver to complete precipitation. Then boil for a few minutes, and filter, wash well with warm water, dry on the filter, remove the pre- cipitate carefully, and ignite the filter separately, when cool add one or two drops of nitric acid and a drop of hydrochloric acid, ignite again, and add the main bulk of the precipitate, and ignite until the edges begin to fuse, cool in a desiccator, and weigh the chloride of silver, from which can be calculated the percentage of salt. Allen states that chlorine so found probably existed originally in the dye as common salt. Another method, which does not answer in every case, is to acidulate an aqueous solution of a known weight of the dye with sulphuric acid, agitate with several changes of ether until all the color has been taken up from the aqueous solution in which the salt remains, separated by a tap-funnel, when it can be precipi- tated and estimated as usual. Sulphate of Sodium (Glauber's Salt) in the anhydrous condition is an admirable adulterant for light-colored dyes. By adding a hot solution of barium chloride to an acidulated (hydrochloric acid) solution of a dye which is sulphonated, and contains an admixed sulphate, a precipitate of barium sulphate and barium sulphonate will be formed, this is filtered and well washed with water, and treated with a solution of ammonium carbonate, the sulphonate will be converted into barium carbonate by decomposition ; upon adding dilute hydrochloric acid, the carbonate dissolves while the sul- phate will remain unchanged, wash with warm water, dry, detach from the filter, ignite, and weigh. Sulphate of Magnesia (Epsom Salt). This body is to a considerable ex- tent employee! as an adulterant, and as magnesium is never a chemical con- stituent of tar-dyes, its presence in the ash is conclusive. The estimation is carried out by igniting the dye, dissolving in dilute hydrochloric acid, filtering if necessary, adding ammonium chloride and a slight excess of ammonium hydrate, and finally a solution of sodium ammonium phosphate, stirring, care being taken to prevent the glass rod used from rubbing the sides of the beaker, and allowing to stand overnight, filter, wash, dry, ignite, and weigh as magnesium pyrophosphate. Carbonates. Indication of presence by effervescing upon addition of a dilute acid. Estimated by use of one of the forms of carbonic acid apparatus. 406 THE ARTIFICIAL COLORING MATTERS. Dextrine. This substance is estimated by weighing one or two grammes of the dye in a small tared beaker, provided with a glass rod. The dye is dissolved in a little water, and absolute alcohol added, when the dextrine will be thrown down, and adheres closely to the glass. The contents are emptied, and the glass rinsed two or three times with alcohol, dried, and weighed. Starch. The presence of this substance must not be taken as an adulter- ant in every case it is found ; owing to its peculiar properties it acts as a drier or absorber of moistness, and hence prevents the caking of the dye. By dissolving a quantity of the dye in water, and allowing the solution to stand in a conical glass for a while, any starch present will subside, the clear liquid is poured off, and the residue repeatedly washed with distilled water and alcohol until no color remains, it can then be examined with the micro- scope ; a drop is placed on a slide with a drop of water, the cover-glass put on, and a drop or two of iodine solution placed on the edge, and allowed to displace the water by the aid of a piece of filter-paper opposite the iodine, will, if starch is present, develop the characteristic reaction, blue. Sugar. Estimated as for dextrine; the alcohol used should be satu- rated with sugar. Sugar can be estimated in dyes by precipitating the col- oring matter with basic acetate of lead, and proceeding as for raw sugar with the polariscope (see page 150), or by inverting and estimating with Fehling's solution (page 152). Sand and Iron Filings are gross adulterations occasionally met with in dyes from unprincipled dealers. Their presence would have been noticed under the insoluble matter determination. Iron filings can be easily deter- mined with a magnet. A careful microscopic examination of ground and crystallized dyes will throw much light on their preparation ; bronze-powder and sugar crystals have been thus found. Paste-dyes, etc., are best estimated by evaporating a weighed quantity to absolute dryness in a small glass mortar, grind thoroughly, add water, and filter through a tared filter, wash with water, dry, and weigh. If this is not done, trouble will be met ; paste-dyes not filtering well if simply diluted with water. The Examination of Dyed Fibres can well be accomplished by the aid of the following table, which is adapted from those of Hummell,* of R. Lepetit,f and of Lehne and Rusterholz,J and embraces a majority of the more important coloring matters which have found application. The re- agents employed are hydrochloric acid (HC1), concentrated, 21 Beaume, and dilute, one part of acid 21 B. and three parts water; sulphuric acid (HgSO.,), concentrated, 66 B., and dilute, one part of acid 66 B. and five parts of water; nitric acid (HNO 3 ), concentrated, specific gravity 1.40, dilute one part of the strong acid and two parts of water ; caustic soda solu- tion (NaOH), concentrated, 38 B., and dilute, one part of the strong solu- tion and ten parts of water ; ammonia, specific gravity .960 ; alcohol ninety-six per cent. ; stannous chloride, tin salt (Sn01 2 + 2H 2 O), and con- centrated hydrochloric acid equal parts ; acetate of ammonia solution, by neutralizing ammonia with pure acetic acid and bringing exactly to 5 B. * Hummell, The Dyeing of Textile Fabrics, London, 1885. f K. Lepetit, Journ. Soc. Chem. Ind., vol. viii. p. 773 (from Zeits. f. angew. Chem., 1888, 535). J Furber-zeitung, 1891, Hefte 11, 13, etc. ANALYTICAL TESTS AND METHODS. 407 The initials or names in parentheses following the names of the dye-colors are those of the manufacturers who furnish the particular dyestutf, and will be readily understood by those accustomed to handle these wares. A separate column has not been made for nitric acid, but where its action is distinctive it is noted under the head of remarks. Method of Procedure. For the testing with concentrated acids and caustic alkalies small watch-crystals are most advantageously used. These are then placed upon white paper in order to be able to observe carefully the changes of color. The concentrated acid^are most conveniently dropped from small dropping tubes or pipettes, so that they can be added drop by drop until the fibre is completely covered. After addition of the acids four to five minutes are allowed, and the action is then noted. The watch- crystals are then heated carefully by using a very small flame or placing them upon a steam-coil, but the liquids upon the watch-crystals should not be allowed to boil. After waiting a few minutes and allowing them to cool, water is added to the contents of the watch-crystals. All the other reactions of the tables are carried out in test-tubes. The fibre is placed in the test-tube, covered with the reagent, and allowed to stand for several minutes, then treated without quite bringing the liquids to the boiling-point, when the action is carefully noted. Finally the liquids are boiled for a short time. The solution is then poured off and caustic alkali or acid, as the case may be, is added, and any change carefully noted. After the tests with concentrated hydrochloric or sulphuric acids the fibres are well washed with water in order to observe whether the original color is thereby restored. 408 THE ARTIFICIAL COLORING MATTERS. 1 o 11 1 it fit i = g.| gi 1 C ~ 'ZZ ~Z _c ^ ^ wS -2 i O fc. O J^t^-f^f^ r4 . c % Q > ^ ** G - -C C ^ /-!>-* S *^ .2 ^ "O '.3'3> <_""" a; K > & "S 8 > g r3 .5^ a'' S ^ " cj5 r J= g i * si to J] cifc Jffi |f| .|| IllS.! ^l^* 3 -2 O> ,a 12 9 S B |?1 |a|^ Ijipl ^ "'St'o o> ^-C > -S-SSl |2 >p o,o^-t* ^ p ^ 1^ C ^ S 'O ^*,G *Q ^ 5 T o oC? ^S.-aJ-g^^gS'-js;; e^JS^I&aSjsll SxiSl. ?ljl || SJ5J s! M |J-B -c| S=g^5 S %X -!S O PQ B3 < O --g* 5 lli*= i' ? i 03 33 , o S* ^T^ *o 01 g g ^ c _j A j3 _o o a ^0 < S W -S t5 9 o o"o S 2" I ^ "3 3 pq ^ "o x o O W o z c^ H 13 *o ' ' "O a H 1 K S If III j|| | ** iii^w T3 + X^ k M S ^.5 h^ 31*I^ "3 a O S = .S CSg-ogJ gg-2 ^_s OQ "3 o ^ **.Q ^\ pQ |*^ *g Q "^ .^ bC O cc o 6 E S PH oT g EH 1 H 8 aJ c g J^" 1 05 9 O "* ""a s -'S 2 ^ O 1^3 J5 5*" ^ M ^ O o g ^ c 3 K- a> be P^ 2 a "(5 'C r-' j ^ g K 'O'o o o u a O al Z c S c i| 1-1 1 &, M > z 55 1 d | . -i (B 2||||" I || 5 3,- =-| a - 5 ^ 8 K *'8* 1 85* - c! !l--='o K 3i2-2 ^if.2 c O 5 * * 2 S -S 1 >-l'^ ^ li'^-d 5 ^2*^2 S-c" 1 1 (4 ^ S- C^^^'So^'^ANsD.^' * ? ^ c c ^ S O H H S ". 5 *> ?/-^J? >, = ' E -'3 O ^- J= '^ a S *? i* 2? 3-S - o" 0) ^ c c cw p" 1 ?^ S a, S^'^-^ii 3 ' -^ C " "^ _o c ^ "^ E-; cw 5 S fa c ^ 'S 1 14 ;c_o e -151 3 a) a-|; p^ 4)5 a> ^8 ^ ^ ^? 83 ^ w'o .e CM O C 5 K ill M" 5 tu | _-5Sgo> 1 gfjfl ^^'T: oa S'o 5^ g S_s o 50 1 S 5 o sSSoW E Q 5 o "3 i tfi S S . 2 5~ 1C la S | 5-^ tf b *r O Ed S5 1. ^ fll ^ ^ 1 51 u' 1 ! . 2 - ^ OJ O ' 0) *-*.* 55 sf r o 8 ?-c^ o a ^-S^S -C _l*H Q 11 1 8 I A NO 3 gives a dark-blue spot changes to brown with blue border. itrous acid, fibre black black-violet with ammonl icric acid, fibre brown. NO 3 , brown-violet spot, peering on washing. itrous acid, fibre dark washed with ammonia tu genta-red. itric acid, blackish-blui original color restored monia. itrous acid, fibre reddish- ammonia does not restor nal color, but turns th brownish-purple and th tion bluish-red, icric acid fibre bluish-blac itric acid gives at first a da spot, which changes to yellow with a greenish-bl der. itrous acid, fibre violet turns violet-red on the a of ammonia, icric acid, fibre brownish-: itrous acid, fibre reddish- unchanged by ammonia, icric acid, brown spot. as K 04 S fc X "A fcK Z, PH 'A fe 6 f 9 g 3 S c i d 8 .2 1 d 5 d li 3 o . o ; 2 ||-o i i| t> . 08 1 Ss ^ 8 o x C o "ZI O K-O o o *3 H Z, OS SQ 3 H 55 Ss - g gd , , C S L. o *- fl*^ 'Z O^3 N " > oT o o 03 fc. oj aj c j^ :? O o S =3 *> 3 B o v "t- K C> 9j o . |J8| S Stl 8 3 ^-c s-S= . o * > X 1-2 "s 'C . o Ql *O 11 111 |||| 3 5 3 II ill si jJ|J lilt! 11 ^^ ^J E E 2 fa E E E Q d aj ^ as .0 5"* - a. c* d ' Hi _s "C _ _o _o 3 e =. ^ G .^ & -rZ S ^5 ^ 32"- i 3 ^ ^ 'g J< 08 08 08 gj; 2 2 g 2-a * | S s"S"S o ^0 jQ 2i OB*O fa fa 55 E . 5 . . o CO 7 o _3 Fs * tfg*a 'O ^j w O <-> ^ 3 * Q. 5 5? 5 B d CJ H *j"3 *o "22s j C < J3 ^3 y S. a a a oj _0 5 ^ 3 c 8. 2 o'S'H o = ~ c^ 1 . s "5* 3~ 2 3 o a l = " c e|.j S 2| S'a ! -^ -^i S 2 2 2 llll g 3=^o 3 5 'S, x>3 S S 5^ i^J A o E 12 fa E 3 E to S5 E | -!A - .n i* 3aJ 1 ,11 o_3 '3 *s c o S | s | a ^53 52 sj 3'2'S^ *5 B 2.1^1 CJ^ 3 *^ =1^5 s d * s a ^00- s"? 2J '-i u _ 3 3^|s OJ "" 11 *-> o3 os o - a oj"!f e Si2 iifl c 2 * Jill I! ll 2 s * 53 g oj jlUe ijijsfi 2|o E 1 " E* " " E" E E w " 2 S |^ Jj i^ *||s S2 C 09 3lV! g BC-g S"o5 0^ ao .M , 3 aj 1| *lll Si- M S 1*1 3 C S'g S li'ji 2^1^ tls-i ^3 = 8 sgss 3g2o dj S U b5s *>-n S c " C 3) a = 8| 35 4S 2 ea^-o c =3 o3-o .; S || S-r-3 p| 111 SS^|2 ii||i tC^-g.0 *B**9 3:5 "5 ^"3 ": S 8 MJJ 0> . --OJ u ts'C gg - S ~ k^tCA " - ^ ^cs oJ^Sfl = .22o E p~ - 3 fa E Q Q Q" S o d M a K d 1 7T i^" | U oa o w H Eg 1 a H -^* OS _ a 1 1-3 ^r O W ^ M pfl " ^ "^ B < 3J 2^ 5j ca rn ^ ii 0.0 >* S *"! >t 2 ? > O M ^ ^ ' o*P pa i 5n MM 2 5 H So PQ m 0^ 8" 8 3 Q Q 5"^ 410 THE ARTIFICIAL COLORING MATTERS. ~2 t'5 ~ o* M O as X i i - II 1 lf|H ||| S 1 O is 2 cf 5 ~~ 3 --- <^H .^ ^ T5 P^* O '*" oj & ^ - ^ a e ";"= _. g o -g^ ^ a: -o .. "c? 1 .Sf g Remarks. Hot water containi NH 4 OH extracts a from soluble eosins. Nitrous acid, fibre brown-red with amr Picric acid, fibre browi 1 To detect in presence tract in boiling alco] J3 be*" "*" jj'S^-S? ?S Jj ** J^ c"^ SS- 1 - ajS-^sg '^".5 S-oSgic^t|t^l|c = SI'S '^ S-a- .2= = a gf Bs8f Sf8a!3fl!e coH "^ <; Nitric acid, violet spol on washing. Fast to soap, light, a ordinary dyeing strei 'Er c 'i _i. 'tH 1 Bleaching- powder bles Boiled with a solutior and cooling, gives ai orescent solution. " ' 1^ c M ^J J4"g u.2 ll lip O >> "s s y a || r _o t; g K.'"* St ft . |s If s " xi " c S'S'S *; 111 .S S Q = i> O i^ 3 O*^ t^*^ r _f^'C>C gj^ oj*^ jf; r zr ^ CO HI ^5 5-3 3 S . p, o .2 1 o ^ J 3 S/o c I S fa S ^__ 53" # fa S i* 4> ^> | 8 P* >tC p d d O O j- ^ i^. O ~ C .2 a H. S, ^O 'c - o"S *T?* K? *c 5 Q C CO X o 'E S bo OS rf a 00 03 ^ y ^ 4) bfi i'S Cp "^ ^1 "c > " 2-3 5"S r o | = S 03 X g a ?.fi S ^ i _^ ,M~ ;: Lo ^5 * ^ ^ '"^ > K- 5^ ^ O d o w = *5 *~ r* ^ ^4 M ^ o CO M . 3.B SpQ .S .i 8 S _* o ^^"3 -III S. 4) O o> s^ 2 5'5 ; S3 A S ilili ill! j fa B 0) E ' "E fa A ^ || IF ||.S _o 6 - O 3 ~ 3_b^O 4>i3f2 S r: ~ "aJ , "o o'g >.. ^ "o . c ? o o O) i S| c ||I| 's^.ss'p 11 1 * i 2 X! 11 |||| ||||l 4>-O s "z z n fa Q fa fa" 1 fa fa X 1 S fc M ? j K d *g B O a! a . o * N ~ M . C< H^ W M ' 2 < 5? 3 d bi 3? |8d /. w 5 i > o wg j *> JS P4B ^ S ^CQ a o ^ w M ^ Bli O s ft I a~" 4| S~ K S O PH fi~ c Q I ANALYTICAL TESTS AND METHODS. 411 tit C LH >> (^ OJ *~^ ^ 1 2 5 3 03 3 ft ^ . O 1 5 . 5 Q,S 2 I i J o I M O * IT 8 ft S, -3 ^J^ a S- i o ^ h !>. I X o 5c >^3 OT ga a t-> *f 5 5?2 S-c 2" It o .a ^ f o - rL 03 60 ^'rt > ^ !~ 8 "3 o -2 o 3 o-o O 3! = M 08 - . '! '3 tH 'S S -jO| ' C o t fl\ & o eifl xs _>. "3 o tt _o x: B S^TS a) "" .a .2 "O .5 o ^ -^ bb T3 O "3 "c e o tJ "S ^"^ ^ M a> s 3} O ^.' e ~ -S ^*? 0) ^ S .2 "Si's .2 *^* ? 3 2 O"3 e " >> N bo .N O ~ N :5 & a c 2s o 'E = OS'S N g - 01 5 > - 3 3 oa o "O "ca'E ,o> -o ..>, ^^o-o j2 5 "3 3'C 2 -.-a o 8.5 .a .2 S i|.a i 1* Ills t. i'3 4> 5 a> 3.2_0.2 1 a> CTJ 55 .N^J J;^ 3e z Q Q fe o s CO < fa E OH , 3 "O Q^ "3 a T3 ig t. g i>> ^ o ^s u "3,2 > "32 o X .'S> tf ft S 1 ^> ^ ^? ft S . .2 ^ *2 -? 2 ^ * i a * e ft ^ ^_C "3 . i j i5 g . > ? z^ 3 o s S'w'5 o ^ "O ."u "* t. r t> w " 60 s jj 5 S ~ 5 >i OS J 4> t -'~ 3 .3 3 --'o "d PH ajTS^ 4>_O < * ^-o"6o r> 3 k I'i^JI 'S 2a S-oSll 3 S S S S ^.2 8*s 8 ^ OJ = o "a! .22 gift O '*" K~ E E h OH CO CO fa 611 a' - 00 H a O> .3 7? rf4 niic as precedin ibre black, changes to gree lute, no action : concentrated, color extracted. > action. ibre decolorized solution colorle ibre black-viol solution violet. ibre magenta-r solution red-v let. _ ibrebrownish-n solution red. 5 E Q E K M ^ E fa E Fibre brick-red, so- lution colorless; color restored after washing. Concentrated, fibre blue. Nearly decolorized on boiling; much color extracted. Fibre not changed on boiling, solu- tion bluish-red. Fibre nearly decol- orized, solution colorless; on dilu- tion original color restored. Concentrated, fibre dark yellow. Dilute, fibre pale yellow, concen- trated, fibre red- dish-brown, solu- tion pink, yellow on dilution. Fibre red. Concentrated, fibre blackish-violet, solution scarcely colored. (S Dilute, fibre lighter, concentrated, fibre blackish-blue, solution violet. It s Es ^ ^"^ 3 g o ,, S3 CQ H H 5 ^o Ij ** .ti -J'C Qj'O >" y z H 2fa y *O Bod 55 ^5 ^3 z E Si? _E 7? uco ^*23 E . H . H . > CO CO >, ^ ^* >> o 1? h BO <. a CJ I- a^"' 412 THE ARTIFICIAL COLORING MATTERS. > " K 5 g i-e o i n S %a 8 .5 O *- C d a.2a -1 ii.t ?S tco 2 1 1 k-S S """o .G ^^ > ^ c .o ^ c 5 '? 2 *" o s ~ *> s 5 'o'os os^ ,__ p tf oT32 S * ~"S ^5"O 4> **" e D SStis W^K S'S'I^- 2.1 5 lilll S HI sN.c * |g3| 11 it i'"j ; i EK" 5^ 2 1 MiB CO. "o M S j g ^ t,-d c (H 1 i_ d d d 1 < _o o .2 1 II ^> X Id *1 11 l| 0) o 5 u 'S o> h _ "c-d O 4) f! o _o o 2 o ^g 1 5 fc M > 2" 5 CO * S 'C > > . t O C ^ 1 S => H O B fe^o . 3 -0 t* o.gS.5 6C.O a>"3r.Q a> Is'SlH oi.2 S'K o S = S 1 _o 1 g q gj g-"g 55 B03fl 2'^ g 1 S Is? < 5 1 E ** 1 i 3 3 XS E E o a ^^ s ? s S S K c ** I |ll ibre deep red. i 81 5 1 o ibre paler anc yellower. ibre becomes orange, solu- tion yellow. ibre dark red- brown, solu- tion scarcely .fif i||||g Ofli^-M ojs-'O^'Ou 3 E-g as c =5 g o 5^5 >^ ^-aSa-N-s washing, ibre orange, solution or- ange-yellow. K E fe E & fe t* h E m m ^5 & bi SP A . S > A If 2 % j c ^3 *5 gS c c 1 "8 1 S .2 "S 9 i *Q "S ^ <5 1 S I 1 8 | g . J 1 2 % s- S A be . N CJ *JJ QJ M< M* K a> a S | * 1 C S ,o_o _0 > o g 3 QJ !c J O) Q S o 5 a> 3 s E | .2P 1 g'o) 5 ^ O fc" U 03 .O.O'O 55 1 S a> CO CQ OJ Q E E 03 | ^ o 5 ' -_&2 i O a 34 sg T3 S 5-^ c "s V*B 09 . a o *-* O 4) r- ^ S?*-^ C Q oJ > W2 GQ . *" ^*3 w 'r* ~-3 c? l!'. t^'d ^ o H N a> 51 1 . lulsh-red a> S "5. "'S s li -2 P,. Ifl 4) N P3 J? E 4> .5 o ^ 'S si2 4) C C ^Eg C 2 3.0 M III o reacti 01 B5 < !'3 g S.5^2 "3 o >> o> a fe 5-3 Q E E R E 55 E K o . u I S 1 E v t |d u (N CO <4 Si H >< -r .^ 3 u S ji5 ^ '^ o s H E U O < ANGE NO. 6 K a z OSPHINE. :RIC ACID n i IMUI.INE OW. w fe . Z CO 3 . j RTRAZINF B. A. S. F 3 < x IS M S *-' 5 ft! ^ ^3 -j ^^ ^ ' ' S3 2 O O O fi OH ft, 2 H ANALYTICAL TESTS AND METHODS. 413 JL a > S 8 'S ft a w 03 ^*O to i O > ! c x s o a 5 ". g a_ 33 iJ, to 1 I'l 1* I 1 aS "Si 3 *j - a O 00 bo ^ h 5 S 1 ** rr^ 2J *""' a & ^ a ^ ^2 4> 5 S OJ *^ *^ *-S pO X 2 -35 "3 * , "O "O *O " *O 53 *O 'O 53 . | a| S 1 111 . &3 | 1 fill 111 "C "u _> IJgJ If 1 1 Z Z"" 1 Z Z Z z St z S z d "O-i. 1 5 CO a' a a a i* a ^* a' *3 o 5 1 _o .2 i So *5 1 S"L 1 a = 2 a 2 2 2 2 g 0) t. j; o< 3 3 *< o >>o t> 3^: Z Z o o "3 Z Z o "o-Q u o -3^2 Z O Z 03 i a i c ig J2 t- OJ ^ [xC^Og t fl .'O a _i . -3 i? . 3T3 J/T3 M - ajq i> so a> M i j ~ N a v ** B M 5'S.S^ 5 8J33 IIjiliiMfi |5||1||1 lf|l s s s S E z 2 a a 3 3 S a a ?' s s 1 . 1 1 11 1 o o a t3 "2 u - -r o s s - o3 O =*j^ 2 2 "^ 2 2 o O. 2 o 2.5 2 ^ o o a> ^ 5 a o ^ Z Z Q Z Q fa Z . . ^ O ^ p !p I rfil 1 . |-J .|||| o "S S aj S O -os aD^ 3 a 2 > i o'S o M ^73 QJ 3 313 4> bD ta ^ 2 2 ^-53 a> o) o> ^ ^j N cj _r_z; ^j .S gjii * 5 00 O i&ij 3Sb 53S '32 O.5 5 S z b. a E E S S 1 ft ^ 3 "g - IS > 4C ,2 - ''- : 5P fill if is ll| S S"a3 4J-5 a S ^"-^ g *"3 J*5 5 ~-^ ^ 53 a . U- a. a . -c 2 3 * ' o 5 s"o -C4.5P ~3 Stcs a i o ^ SO ^ ^I V- _" _ ^aoo" ^"x.n ^P -.0*7? aS o ^ ."-" ; "So s ~ a ^ 43 -'S -''S ^^"3 ^ a = ^. - O ZH CJ 3 J a> 3 ^j oj -a o N .SP " ^ ^*5 ^'O"" 4*3 ^oj^^3 5 a .G^ ? S"? ?* 5'" 1 5 '5S ^s'oij'c _aii5 53 > o t- oo.2 S 5 S"" E 5 ' S. S .* ^S^^e-sii s . 3 ..3 1| |l d '||ls 3. I 1*1 || || Sjflg! si^slii^-gj*! 11 i Si^ Hie . |l l I jilt's a* g'g p^ 3 3 "S .5 g'E 3 ^S"' jj l^ilfllf t, EC "> * bc'^"^ e-Szi'O 5~ ill ill flllll S o C a a -^ O^ - ^ ^ t- ^ t- 01 't N 5S * bo Jc _c ^ p-S be S a> Remarks. _O I ' I s Heated with olive oil, purp extracted. Induline NN is not chan bleaching-powder. Nitric acid gives a dark green spot. Nitric acid, green spot. Bleaching-powder change green, and finally decolor On cotton it is faster than ir lines, resisting action oi light, and weak bleachi: der. HCI vapors change color of a chocolate-brown. Destroy color bv boiling wi wash, and add NaOH : th rin on the fibre isdissolv purple color. Picric acid, fibre black. Dilute acetic acid, fibre blut V 3 XJ o fe .0^ . ? . 1 9 E ^ ^5*S c ^5 X Q3 C +j fs| .2.2 i i si eg **< B SaB8.fi sii =| o o fc W CO fc S5 d . || o> O K d i 1 is t-5 N O "* *1g ^ o P 2i "3 to * o ^ ll c CO Q $ xS Q W aJ Q fa 1* E 1 .5- . | ^"3^ . ijl q III O f^ .1 s . e S "~ CO B 1 -1^ 55 "0 o S "3 C. CC w 03 > fi^sra Xi'>'5 So ^-5 o rS^'-S ^^ X!^ p,(. fa iz; co ^ 55 fa ^ - ^ g ^ 6 4 Sa ^ a 4 5 S a I re dark r ilution pi i |8 - It! Igl 0)7; a)- 3 ^ o t- T5 3 -o'-g S 00 o 8 3"H OtB O jBsM "S^'? ~ o Xi C E !?; E E fa E > o> f3 bb oi C Sd bp 2 3 B Jlx: ^ S 3 SiS cu >3 ,3 i * 9 ~ a> "* 1 F-2 * Ss 1 03 ^* O> 3 = _ Ilc'l * Sg K 5" *"- "* cS S Z0 fl 5 ' g, S ^ = -3 5 | ft Q *Q a 5 x^ bo -7 ,H "c *" "^ W bC fa OS CO CO E E CO E c - .2 V a;"^ S "? 3 "3 3 fSs a s bo 5 > 2 "25 -2 58 S *-^ >5 * 'S a 5 H || Of f-g-a || 1 If l||| 2 -28 siii |B^|BI ||| |s| || ff ||| fa E E fa fa" E S g W ti ** d -P H D m H * X o Z J . s S2 < 0) I 1 5 S < SJ? z "* a Q s - H - W ~ >, "3 * 5 5 S ANALYTICAL TESTS AND METHODS. 415 is 111 'is 3 T* *]?. g. c - i few u C * 8'SggJ M 1 ^ or: 9 * g " ^4 2 3 4> 2 ^ aS^ 'C J *J (^ Sy 2 * J <" a .5 j;ss. 3 -2 ^"s^ 3 C'-c * "S* 3 "o o" ' s "= '5 =3 2 "o" 2" *'o sS** ^ as a< o bo 1 w-I * g 2 3.0 83 ""s t" *'5 _0 ||| 1 llfl B = I'll 3 2 g* 1 g '" S 2 ""g" 73 ^ i S 3 ^5 d _o o i 2 . o .S x^-o 2 3 i o i 1 S 33 1 2 I a E| 2 a> K t-t _o 2 03 3 S 'a'o g 2 'S-S o "o o o .ti-^ a; o o "o fl- |J 2; o ^ Jz; iJ K Z CO 52 x^ 5 i" 5 ^ A Q ^^_^ 0) i 8 . aj-O o o> "i's 11 ill 2^o||. Pl!ll 2 bc"5 ^ . ^ >*'-2 A g oS J> M " S 4* 0.2 B S5^ "-i| 30 Sa-" S o .0.2 XI ' ^ *cc O ^ G O tc *2 i z "c: -^. H HN O oj cc Q^*".2 '^ai'OO ^ QQ A fa fa S S 02 fa < fa fa 3 6 li o S _L 1 .0-2 1 _o in ^ 5ir^ *3 .2 S iis* _0 ~ 0- .i S 03 >v^ 'C "'P s^, c S V III! if 1 c a) S. fe * E J= H O 1-3 3 P. q S i ! Jfjij fa 5 fa fa S t> Jz; E co~* fa _o 44 3J3 .2 *ls si tn'g'S^ ^ o . 2 Sfc-S B 33 a I 1 llfr 1 ?'g" s s -* o> o> |1| 2! 1 ei| 2-slll 2| Hill g| gug^ .O.Q c. >:c & O x ^ *^ G* ^ ? ,G "o ^C SQ ^3 O *Q >> 2 'O !3 M fa fa fa fa fa < z fa fa >va bb d bb .1^ b bb , ^" "5 2 2 C O .5 .S Ifo'e gc S v ilfel 1 2^ 3 -5 Q) O gill ?| If || o. a ~^'-5 R|8 C 03 >T3 p. M S 5 --' O Q> P. P. S o ol "S c ^1 .2^3 =j -c "S 3 Oj 5^ 0) a> 3 | o> t. a> 2.2 *j,,E g J3'o2 5 _o"3 g o3 sc"? g j' - .3 a fa "fa * fa d CO fa 7. fa 03 o3 44 , o ,2 BQ . S 3 e ^_3 g c M t- A JS ^ ^ - 44 h^ _c: fc- C3 ^ " o _o3 n 8 O^ < . *^ ^ *^ <- . '" -^ 03 0^ r* 4) ' A ^ ^ 'S QI /. ~ 2 d g S j ' D' s o-H"ii ^"3 ^JT3 S 8 >, o j= 3 "5 S 3 *"5 c^> ij'^3 o S '" c -'i3 = ^"l ^E 1 '^ gag Si," - - !C - ^js. S*.-J f o 2 2 A o] o S s'll sS^ pillllel lllli|llgll|ll Uliijl Sa 2 ^21 Jo I 2- 05 %,o fa p Q fa fa ' 5 fa fa fa * -2 Ed J H ^ S rn 2 Jr ^ z A* 1 S E > 1 o S5 OS'T M Z " 1 H > f ,J m H o 3 H S 3 i It Kg 1 fa f o H S S D S 5 pq fa" !? 416 THE ARTIFICIAL COLORING MATTERS. a 5 a S 8. '5 = 4 2 s o x" 2 |o | ^ 1 s S'ol e * o A 4> O ^ 2 JO 4 as S O It sil |1 >> B E I M aJ ./3 "0 S lii is I 3 i be ^ J3 "0 .2 ^O *O at be ! c g w *S o> iJc 2^ O^3 aj .X s .2 'i .-"o K |3SP 3s PQ !Z;EH "C s "K z 13 "3 3 B' 1 S!-d 1 8 B a _o 1 III - i 1 I 8- o * e a .^ia 3 O "" 0) II ! |||p_ ||| .2 H _o o ? o a as -a S Ifl 'o o g o g s bc^ lei "5 CO o u.0 pOS he's; B '3^' Q S J-a ,S JS N 53 fa fa fa M 8 1 1 G _o p 1 | u 1 o A fc 55 3 ai 5^ _fl a 3 il i s c - 14 ^ '-3 ' ' a> c ^ r~ *'" a5 B g> "3 B ^, oj'oi c bi h g iF O o O _ n 2 i ~ 4) 5 B g 5 s 02-3 M"O JS'es c9 J2" S o o'?.5'? E 53 fa fa z bi bb bib 1 . ~ a> 0) a _3 | 1 1 ft IB O 8 Q. n a S B=B SB v C> *^5 1) 10 2,823,962 1888. 7,340 48,310 28,135 Cochineal, hundredweight ... Valued at Cutch and gambier, tons . . .'. Valued at .......... 704,731 Indigo, hundredweight ..... 78,188 Valued at .......... 1,703,682 Madder, hundredweight ..... 15,034 Valued at ..... ..... 19,292 1889. 8,095 50,297 25,107 678,548 90,483 1,783,256 14,199 17,139 1890. 7,808 51,067 27,445 717,820 81,844 1,521,369 11,373 15,545 The German importations of dye-woods, etc., for the same period have been : Madder Quercitron Logwood Fustic ..... Brazil-wood, etc Cochineal Catechu and gambier Indigo Orseille and perseo Dye-wood extracts 1888. Met. cent. 5,077 9,332 521,245 70,313 66,325 1,119 68,739 15,772 7,335 50,923 1889. Met. cent. 3,821 10,249 508,104 66,909 83,086 904 72,867 19,350 3,974 45,491 1890. Met. cent. 2,495 14,263 528,806 65,162 69,162 772 73,500 20,076 8,809 46,855 BLEACHING. 447 CHAPTER XIV. BLEACHING, DYEING, AND TEXTILE PRINTING. PRELIMINARY. Prior to the operation of bleaching, except in cases where delicate shades are required, it is always necessary to thoroughly cleanse the fibre or fabric of grease and dirt. For cotton, which is generally handled as hanks, warps, and pieces, it is sufficient to boil it in a dilute solution of caustic soda or soda ash, followed by a good 'rinsing ; it may, in some in- stances, be boiled in plain water, wrung out, and bleached or dyed ; ordi- narily, however, a boiling for two to three hours in a bath of eight to ten per cent, of crystallized soda and one to two per cent, of soap, calculated to the weight of the cotton, yields good result. Wool is always thoroughly scoured both before and after it is manufactured into yarn. The soap solu- tion generally employed contains from four to five ounces to the gallon of water, accompanied usually with a carbonated alkali (potash or ammonia) in about the following proportion : ten per cent, of soda and two per cent, of soap. The temperature of the bath being about 40 to 50 C. (See p. 297.) For silk (see p. 299) the scouring-bath contains about twenty-five to thirty pounds of Castile, Marseilles, or other neutral soap for each hundred pounds of silk, and a temperature at or near the boiling-point is taken for about two hours, turning the silk occasionally. For some colors a second scouring can be employed to advantage, only one-half the quantity of soap being used as in the first bath. It is the practice to use the baths several times, care be- ing taken to enrich them with fresh soap. Further information in regard to the general treatment of the above fibres, the recovery of products, etc., is given in Chapter IX. p. 292. A. BLEACHING. This highly-important operation results in a more or less complete destruction of the natural coloring matter which is found in all fibres of industrial importance. Owing to the somewhat powerful action of most of the agents employed for the purpose, it will appear that unless care and discretion are applied to their use on the part of the bleacher, something more than a destruction of the coloring matter w r ill occur, a probable partial destruction of the fibre. The operation has been known since the earliest times ; the white linens of the Egyptians and Phrenicians were much esteemed by the nations trading with them. Pliny refers to the use of plant-ashes, used, possibly, on account of the alkalies in them. For many years the Dutch appear to have monopolized the industry and trade in Europe. In the early part of the eighteenth century immense fields were given up wholly to bleaching in the United Kingdom the process as carried out required several months, consisting of a successive treatment of the cloth or fabric in alkaline solution termed " bucking" and washing, then exposing, while damp, and spread out on the grass to the sunlight for a few weeks (Grafting), immersing in sour milk, washing again, and finally exposing on the grass. These several operations being repeated until the required degree of whiteness is obtained. Great improvements in the above 448 BLEACHING, DYEING, AND TEXTILE PRINTING. FIG. 123. tedious process resulted when the use of sulphuric acid was substi- tuted for the sour milk, and chlo- rine gas replaced the lengthy field exposure, this latter being due to M. Berthollet ; but the general use of this substance was not estab- lished until the manufacture of the now familiar " chloride of lime" or " bleach." Since then many other bleaching agents, notably, hydro- gen peroxide, have appeared, but whether they will ever displace the above is an uncertainty. 1. Cotton in the raw or unmanu- factured state is rarely, if ever, bleached ; as yarn, however, it is continually. The hanks, which have been previously scoured, are boiled in a solution of chloride of lime (chemick) from one to two hours, washed well in water, and passed through dilute sulphuric acid (1 Tw.) for about half an hour, and finally well washed. These operations can be easily con- ducted in the ordinary wooden tubs of the dye-house in places where much yarn does not have to be bleached, otherwise special arrange- ments should be provided. Cotton warps are similarly treated, the ap- paratus employed being a contin- uous (warp) dyeing-machine. Cot- ton fabrics require much care and skill, especially those intended for domestic use in the bleached condi- tion, and also those which are to be afterwards dyed or printed with deli- cate shades. The method of bleach- ing, which has reached a high state of perfection, is the so-called " mad- der-bleach," from the fact that it is employed on all piece goods to be printed with alizarin. The process detailed and illustrated below must not be accepted as the exact method followed in every establishment, it being remembered that nearly every bleacher has his own modifi- cations which he introduces, but all yield the same result. The opera- BLEACHING. 449 tion of stamping or sewing on designating marks ; sewing the pieces together and singeing, a removal of the nap or down from the cloth by means of a gas flame or curved hot plate (" singeing-plate"), need not be detailed here ; reference may be had to special works on textile manufacture. Fig. 123 is a plan of part of a bleach-house for cotton cloth. The goods being received, they are passed through the first washing-machine, on the left of the figure ; this operation has for its object the removal of loose dirt, grease, added to the fabric during weaving, and other matters; usually the goods are stacked overnight in order to allow an incipient fer- mentation to take place, when they are passed several times through the lime-wash (milk of lime) in order to become thoroughly impregnated with about five per cent, of lime, this being accomplished by means of rollers immersed in and below the surface of the lime-bath and a pair of squeezing or " nipping rollers." Following the liming operation is the boiling (" bowking") in kiers ; these are strong, wrought-iron cylindrical vessels, provided with a series of pipes, and in some cases with injectors, which enable the liquids contained in them to circulate completely through the cloth, which is previously intro- duced in the form of a rope. Fig. 124 is a vertical section of a single FIG. 124. injector-kier, and one well adapted for working at low pressures. Reference being had to the figure, the vessel being filled with the fabric, which is well laid in, the liquid is admitted, gradually finding its way to the false bottom, 29 450 BLEACHING, DYEING, AND TEXTILE PRINTING. through which it passes to the injector at a, where it meets a steam current, which forces it upward through the large pipe, finally being admitted to the kier again through the valve 6, repeatedly following the circuit. Barlow's high-pressure kiers are usually worked in pairs, and the liquid is forced from one to the other by the aid of steam. This kier has a central perforated tube, through which the liquid passes to come in contact with the cloth. Several other forms of kiers are in use, even open kettles acting as such, the object being the same in each case. The length of time the cloth remains in the kier varies considerably, in some establishments, where a high-pressure is used (forty to fifty pounds per square inch), less time is required, five to six hours being deemed suf- ficient ; again, where a low-pressure is used (eight to twelve pounds) the goods are allowed to remain in from ten to twelve hours. From this boil- ing the pieces are washed in water, and passed through dilute hydrochloric acid (specific gravity 1.01 =2 Tw.), the bath being technically termed a " sour." The pieces are slowly worked until the lime is completely dis- solved, when the goods are thoroughly washed, or until every trace of acid is removed, when a boiling with soap and soda follows in kiers exactly as in the boiling previously mentioned. For each hundred pounds of cloth a resin soap is used, made with five to six pounds of soda ash and one to two pounds of resin ; the soda is dissolved in two gallons of water, the resin added, and the whole boiled for several hours ; for each pound of cloth to be acted upon one gallon of water is used. The time required for this boil is nearly the same as in the previous boiling. When the resin soap solu- tion is run off, the goods are boiled for three or four hours with a one per cent, solution of soda, to remove the soap and any unconverted resin re- maining, followed immediately by a wash. At this stage of the process occurs the real whitening, or bleaching, of the goods, the so-called " chem- icking," requiring much care, and is performed with a solution made by dissolving chloride of lime, allowing to settle and become clear, the super- natant liquor alone being used. The strength of the solution, varying from i Tw. to 2 Tw. (specific gravity 1.001 to 1.01), being used cold, or but slightly warmed, in the latter case penetrating the cloth better. Repeated passage of the goods through a weak solution is preferable to a shorter time in a strong solution, the danger from injury to the pieces being less. The next operation may be (not always) a wash, and then a souring in dilute (specific gravity 1.01) sulphuric acid, termed a white sour, after which the goods are allowed to remain for some time in a heap, but not long enough to become dry, as a tendering of the cloth will result ; this is fol- lowed with a final wash to remove every trace of acid, passed through squeezing rollers, and over revolving cans heated by steam, to dry. The length of time required in the above process varies ; if the goods are to receive a fine clear bleach, or are to receive delicate shades in dyeing and printing, four or five days may be necessary, but in the event of the goods being intended for full shades, half that time will answer. Mather- Thompson's Process. This is one of the newer processes, and is admirably suited for warps and piece-goods. The goods are sewed together, or tied, in the case of warps, subjected to the action of hot caustic alkali, washed, and transferred to wagons, the sides of which are of iron lattice- work (cages), and pushed into a horizontal kier, and for five hours acted upon by a solution of caustic soda (2 to 4 Tw. = specific gravity 1.01 to 1.02) delivered in a spray and at a pressure of four to five pounds. With- BLEACHING. 451 out removing the goods from the kier they are washed with hot water, removed, and rinsed with cold water, completing the scouring. The bleaching is carried out in a continuous apparatus through the following stages : 1. Rinsing with warm water. 2. First chemick bath (chloride of lime solution, 1 Tw. = specific gravity 1.005). 3. Passage through atmosphere of carbonic acid gas. 4. Washing with cold water. 5. Worked through a one per cent, soda solution at 175 F. 6. Second washing. 7. Second chemick (chloride of lime solution .5 Tw.). 8. Second passage through carbonic acid gas. 9. Third wash. 10. Through one per cent, hydrochloric acid, or through one per cent, of a mixture of hydrochloric and sulphuric acid (2:1). 11. Final wash. In this process the real bleaching is effected by the hypochlorous acid liberated by the action of the carbonic acid gas upon the calcium hypo- chlorite. Lunges Bleaching Process differs but slightly from others using chloride of lime, except that he increases the bleaching action by the use of a small quantity of some organic acid, preferably acetic. Chloride of lime in contact with acetic acid forms calcium acetate, with evolution of free hypo- chlorous acid ; this gives up oxygen during the bleaching, leaving hydro- chloric acid, which acts on the calcium acetate, forming calcium chloride and regenerating the acetic acid. The hydrochloric acid never being in the free state cannot act on the fibre ; acetic acid has no action, even at the high temperature or pressure used in bleaching. Hermite Process for Electrolytic Bleaching. This process is probably one of the most successful yet brought forward, embodying the use of elec- tricity, effecting the bleaching by the decomposition of a four to five per cent, solution of chloride of calcium (not " chloride of lime," or " bleaching- powder"), of magnesium, or of aluminum. The chloride is decomposed, the chlorine uniting at the positive pole with the oxygen of the water, which is simultaneously decomposed, and the metallic base (with the hydrogen of the water) at the negative pole. It has not been met with very great approval from bleachers, from the fact that it is not fully developed to the degree of efficiency desired. 2. Linen. This fibre is much more subject to the destructive action of bleaching agents than cotton, in consequence of which the same process is not applicable, and also on account of the greater amount of impurities present, chiefly pectic acid. For yarns the trade distinguishes three im- portant grades of bleaching, half, three-guartei^s, and full white, to obtain which several operations are necessary : 1. Boiling for three or four hours in a ten per cent, solution of soda ash, or in a six per cent, solution of caustic soda. Wash, rinse, and pass through squeezing rollers. 2. Pass through a .4 Be. solution of chloride of lime, and work or reel one hour, and wash. 3. Transfer to dilute sulphuric acid for one hour (one part acid to two hundred parts water). 452 BLEACHING, DYEING, AND TEXTILE PRINTING. 4. Boil again in a kier with two per cent, caustic soda. 5. Repeat the passage through chloride of lime and wash. 6. Final treatment with sulphuric acid as in No. 3. The above will produce a half-bleach, and by repeating the three final operations a full white will be obtained. Reeling is a term particularly appli- cable to linen-bleaching, owing to the way the yarn is handled, the result being that the carbonic acid in the air acts upon and decomposes the chloride of lime, setting free hypochlorous acid, similarly to the use of the gas in the Mather-Thompson process. Linen doth, notwithstanding many trials, still requires much longer time to successfully bleach than yarn. It is quite possible to bleach the cloth in a comparatively short time, but the strength of the fibre would be weakened. The following outline of the general pro- cess indicates the successive stages : 1. Liming. Boil with eight to ten per cent, for fourteen hours and wash. 2. Allow to remain in dilute hydrochloric acid (specific gravity 1.012) for four to six hours and wash. 3. Boil with resin soap (two pounds caustic soda and two pounds resin) for ten hours, followed immediately by a boiling for six to eight hours with one pound caustic soda. 4. " Grass." Expose on the fields for a week or more. 5. " Chemick." Pass through chloride of lime solution of J Tw. for about five hours and wash. 6. "Sour." Steep in dilute sulphuric acid 1 Tw. for two to three hours and wash. 7. Boil for four to five hours with .5 to .75 per cent, of caustic soda, wash, and 8. Expose again for four to five days in the fields. 9. Second chemick. Same as No. 5, only Tw. for five hours. 10. If necessary, rub with a soft soap between " rubbing-boards" * to remove brown spots. 11. Expose again on the grass as before. The frequent exposure of the goods on the grass to the combined action of moisture, air, and light necessarily dispenses with a certain amount of the chloride of lime, besides allowing of a less energetic action. 3. Jute. A good white on this fibre is difficult to obtain. Prior to bleaching, jute is scoured with a five per cent, solution of sodium silicate (soluble glass) at 70 C., washed, and bleached with a solution of sodium hypochlorite containing about one per cent, of available chlorine, made by decomposing bleach ing-powder with carbonate of soda, settling, and using the clear liquid. -The goods are thoroughly washed, and treated in a dilute bath of hydrochloric acid ( to 1 Tw.) and washed, or they can be further acted on by sulphurous acid by immersing in a bath of sodium bisulphite for two to three hours, and dry. Jute can also be bleached by being worked in a solution containing one per cent, permanganate potash (calcu- lated to the weight of its material) and exposing to the air until it becomes brown, when it is immersed in a solution of sulphurous acid and washed. 4. Wool. For yarns, etc., the best known method of bleaching is "stov- ing" that is, an exposure of the damp goods to the vapors of burning sul- * " Rubbing boards'' are two fluted pieces horizontally placed, the upper of which is moved in an opposite direction to the course of the cloth. BLEACHING. 453 phur, confined, usually, in a frame building ; in the centre of the floor is mounted an iron pot in which the sulphur, in rolls, is ignited, by means of a piece of iron heated to redness and dropped in. From six to eight per cent, of sulphur is consumed, and the time required is about eight hours, but for carpet yarns and goods of a similar grade twelve hours may be neces- sary. The yarn is removed and well washed, the water containing, pos- sibly, a little carbonate of soda to neutralize any sulphurous acid remaining. For piece-goods the same process is applicable, but it requires arrange- ments for passing the fabric over rollers inside the sulphur-house at a uni- form rate. Piece-goods can also be bleached according to two somewhat lengthy processes, embodying the sulphuring in chambers, detailed in San- sone's " Dyeing," vol. i. p. 123. The process based upon the action of hydrogen peroxide is destined to become the most valuable for wool. Recent attempts in this country to re- duce the price of this article having met with partial success, it has thus been brought more prominently to notice. No metal should be exposed in the wooden vats in which the bleaching is performed, and care should be taken to see that no sediment is in the water-supply pipe, all such taking up oxygen from the reagent and thus weakening it. A " six-volume" solution of hydro- gen peroxide is made up in the vat, and this is carefully neutralized with silicate of soda which has been previously diluted with warm water ; the yarn or goods is immersed and kept below the surface of the liquid by means of a wooden lattice frame. The temperature must not be above the normal. In a few hours the color of the wool will have changed to a white or nearly so, and by keeping it in, a " wool white" will be obtained, when the material is lifted, and allowed to drain back into the vat, when the liquid is brought up to the original six-volume strength with fresh peroxide. The bath can be kept in use for six months. After draining, wash in water containing a trace of sulphuric acid, finally with water alone. 5. Silk. The preliminary operations for treating this substance have already been mentioned. Ordinarily, silk is treated in a similar manner to wool, being hung on poles in an atmosphere of sulphurous acid for several hours (four to six), taken down and washed ; or the silk can be worked in a bath of bisulphite of soda, followed by a weak alkaline wash and a final rinse. Aqua regia (hydrochloric acid and nitric acid, 5 : 1) of 3 to 4 Tw., and at 70 Fahr., is much used for small lots ; the silk being constantly worked for about twenty minutes when the bleaching is finished. For very fine tints, the silk is entered into a soap-bath heated from 85 to 105 Fahr., wrung out, and hung in the sulphur-house for ten or twelve hours, washed in warm and cold water, and dried. Tussah silk is always bleached with hydrogen peroxide, being immersed, as in the case of wool, for several hours, or even days. When the necessary degree of whiteness is obtained, the silk is rinsed and dried. Sansone men- tions immersing the silk in strong peroxide, wringing out the excess, and steaming in a closed vessel. This method has yielded good results. B. BLEACHING AGENTS AND ASSISTANTS. Chloride of Lime (" Bleach- ing Powder"), the most important agent for bleaching purposes, is produced in immense quantities by acting on dry slaked lime with chlorine. It occurs in commerce as a white powder possessing a characteristic odor resembling that of ciilorine, and if exposed rapidly absorbs moisture. The real strength depends upon the amount of available chlorine obtainable, ranging between twenty-two and thirty-five per cent. Solutions of the {' 454 BLEACHING, DYEING, AND TEXTILE PRINTING. fanciful names are met with in the trade varying in strength from five to eight per cent. " Chlbr-ozone" is a product considerably used, and is essen- tially a solution of sodium hypochlorite. Permanganate of Potash (K 2 Mn 2 O 8 ), although not strictly a bleaching agent, is mentioned on account of its very high oxidizing properties. It is manufactured from manganese dioxide by heating with chlorate of potassium and caustic potash, leaching out the mass, filtering, and evaporating to crystallization. It finds some application in connection with the manufacture of imitation furs, being employed to discharge the body color from the tips of the fibres to produce whites. Hydrogen Peroxide (H 2 O 2 ) is a colorless, odorless liquid obtained by the action of hydrofluoric acid upon barium peroxide in a lead-lined tank. The operation is conducted at as low a temperature as possible, and with continuous stirring ; in about twelve hours the reaction is over, and the supernatant liquid drawn oif and preserved. The residue, barium fluoride, is decomposed with sulphuric acid, and the hydrofluoric acid recovered. It is customary to refer to the strength of hydrogen peroxide as being of so many volume capacity, six, ten, etc. ; this means that one volume of the peroxide will yield six, ten, etc., volumes of oxygen gas. Soda Ash (Na^Og). This is the commercial anhydrous carbonate of soda, used principally in scouring. It is generally contaminated with vary- ing percentages of caustic soda, sodium chloride, sulphate, etc. Its value depends on the amount of Na 2 O contained. Soda Crystals (Na 2 CO 3 .10H 2 O) is a much purer and more expensive carbonate; it contains no caustic soda, which renders it well suited to scouring. Caustic Soda (NaOH). It comes in trade in iron drums solidly filled or in a coarse powder. It is obtained by treating carbonate of soda with milk of lime, whereby the carbonate is decomposed with formation of calcium carbonate, when the clear liquid is drawn off and evaporated down to the solidifying point. Carbonate of Potash (K 2 CO 3 ) is not used in the dye and bleach works to the same extent as soda, although for silk- and wool-scouring it leaves the yarns, etc., with a better " feel," and when used in soaps, it does not cause colors to run or "bleed" to the same extent as soda. Its value depends upon the percentage of carbonate. Acids. The mineral acids are used in bleaching chiefly to neutralize alkalies, or to cause a disengagement of hypochlorous acid in the so-called "sours," and reference to their production is unnecessary. Hydrochloric Acid of commerce (also called Spirit of Salt, or Muriatic Acid) is yellow in color, due to impurities. The general strength is 21 B6. (specific gravity 1.17). Nitric Acid, used in conjunction with the above for silk-bleaching, and largely in the preparation of some mordants, is bought with a gravity of 17.7 Be. (specific gravity 1.140). Sulphuric Acid (H 2 SO 4 ) is obtained by the burning of sulphur and conducting the gas into lead chambers, in con- tact with nitrous vapors and steam. It is a heavy, oily-looking liquid, and when pure is colorless. It is ordinarily sold at 66 B6. (specific gravity 1 .84). Soaps. The soaps employed in bleaching, etc., embrace Tallow, Rosin, and Olive Oil (for silks), although others are used, but mainly for special purposes. Reference to them has been made in the chapter on Oils and Fats. (See p. 59.) In most large establishments soap-boiling appliances are in use. MORDANTS. 455 C. MORDANTS EMPLOYED IN DYEING AND PRINTING. The process of mordanting is of the utmost importance, having for its object the pre- cipitation of some substance upon the fibre which has an affinity for, and will effect a more or less complete fixation of, the coloring matter used for the dyeing. The nature of the mordanting substance used depends upon the character of the fibre, the kind of dye, and upon the effect sought ; some shades require the use of several. Under ordinary circumstances wool is simply boiled in a solution of a metallic salt, for example, bichro- mate of potash (" chrome"), in the presence of a small quantity of some acid, in this case, preferably, sulphuric. Wool so treated is said to be chromed, and is in a condition fit to receive a black when dyed with log- wood decoction. Silk is mordanted similarly, lower temperatures, however, being employed. If silk and wool are immersed for a time in a solution of a metallic salt, an absorption will take place, when the fibre can be washed in water, during which operation a deposition of a basic oxide will occur. Cotton, unlike wool or silk, has but little natural affinity for the majority of coloring matters, and of necessity must be specially prepared. It is well known that cotton has a strong tendency to combine with tannic acid, and this is made use of by steeping cotton in a solution of sumach ex- tract, catechu, or other tannin-yielding material ; if it is afterwards washed and worked in a bath of some soluble metallic salt, an insoluble compound will be formed, which then has the property of uniting with the dye. It is not always necessary to prepare the cotton with tannin, an immersion in the mordant, followed by an oxidation or ageing, being deemed sufficient. Substantive Dyeing is where the coloring matter is taken up from its solution by the fibre without the assistance of any agent. Wool and silk are dyed with the coal-tar dyes in this manner, using some sulphate of soda and sulphuric acid in the case of the former, and with a soap-bath and a little acetic acid in the case of the latter. Cotton, when dyed with the benzidine colors, also comes under this head ; it is possible a colored com- pound of cellulose and the base of the dye is formed. The use of salts in dyeing the above is merely to prevent a too rapid absorption of the dye by the fibre, thereby obviating uneven shades. Adjective Dyeing necessitates the intervention of mordants, as above ex- plained. Albumen, however, does not cause the formation of an insoluble precipitate on the fibre, but causes the cotton fibre to behave towards the dye in a manner similar to wool. Many coloring matters already fixed on cotton have the valuable property of serving as mordants for other dyes, a property much employed in the production of compound shades. The following list of mordants embrace only those of prominence and in general use ; exact methods for their manufacture will be found in the works of Hummel, Sansone, Herzfeld, and others. (a) Mordants of Mineral Origin. Tin Mordants. These are first in im- portance to the dyer and printer. They are used in two states of oxidation, stannous and stannic. The former salts have a great affinity for oxygen, a property of considerable value as a discharge for other colors. Their solutions are colorless or nearly so, except those prepared with nitric acid, which are yel- lowish, due, possibly, to an incomplete oxidation of the tin. The most promi- nent tin compound is Stannous Chloride, when crystallized, " tin crystals," or as a, liquid known as " single muriate of tin," or " double muriate of tin," ac- cording to the gravity. The crystals are obtained by dissolving feathered tin in commercial hydrochloric acid and evaporating ; good samples contain about 456 BLEACHING, DYEING, AND TEXTILE PRINTING. fifty per cent, of metal. The impurities are iron (from the acid used), lead (from the crude metal, and from the table-tops on which the crystals are drained), and sometimes copper. The " muriates" are nothing more than the mother-liquor from the crystals, diluted for " single" to 60 Tw. (specific gravity 1.3 = about thirty-eight per cent. SnCl 2 .2H 2 O) and for "double" to 120 Tw. (specific gravity 1.6= about sixty-one per cent. SnCl 2 .2H 2 O). The above are chiefly used in connection with the natural coloring matters. Tin Spirits, owing to the advent of the tar-colors, are much less used than formerly. Their composition was exceedingly variable, consisting usually of stannous chloride, with or without additions of sulphuric, oxalic, tartaric, and nitric acids, and they bore such names as Amaranth Spirit, Yellow Spirit, Finishing Spirit, etc. " Stannous Nitrate" (nitrate of tin) is essen- tially a solution of tin in nitric acid, the chemical composition of which is doubtful. " Tin spirits" is a collective name for a long list of stannic com- pounds, made, usually by the dyer, from hydrochloric and nitric acids, sodium and ammonium chlorides, etc. Their use is gradually going out. Stannate of Soda, or Preparing Salt, is used in cotton- and woollen-printing ; its value depends upon the amount of stannic oxide contained. Alumina Mordants. Sulphate of Aluminum, also known as Patent Alum, does not find much application in the dye-house, but is considerably em- ployed in the preparation of other alumina compounds which are, being much more economical than potash or ammonia alum. It is obtained from the mineral bauxite, and from cryolite. The brand manufactured for paper-makers is the purest, containing but little or no iron. Potash Alum contains 10.83 per cent, alumina, and occurs in large, well-defined crystals. Ammonia Alum contains 11.9 per cent. Alums ought to be bought already ground. Their application to cotton is by precipitation with alkaline car- bonates or ammonia, or with sulphated oil ; to wool generally with cream of tartar, and to silk by immersion overnight in the solution, followed by a washing, which causes the formation of a basic salt. Aluminum Acetate, or " Red Liquor," so called from the original use to which it was put, dyeing reds, is obtained by the double decomposition of aluminum sulphate and calcium or lead acetate in the proper proportions, and using the supernatant liquid. Professors Liechti and Suida, and Kochlin have conducted elab- orate researches into the action of the aluminum compounds as mordants, and their results have thrown much light upon the whole subject of mor- danting. Sulpho-acetate of Alumina is obtained when an insufficient quan- tity of the acetate (lead or calcium) is added to decompose the alumina salt, and this forms the red liquor of trade. Ordinarily, the solutions have a dark-brown color and are characterized by a strong pyroligneous odor. The cotton-dyer and printer, especially the latter, make considerable use of this mordant, for reference to which, see p. 469. The remaining alumina com- pounds viz., chloride, nitrate, hyposulphite, oxalate, etc. are but little used, chiefly in calico-printing for alizarin shades. Iron Mordants. Like tin, iron is employed in two states of oxidation, ferrous and ferric. Ferrous Sulphate (FeSO 4 .7H 2 O), Copperas, or Green Vitriol, occurs as a by-product from several chemical processes, and is much used in cotton-dyeing, and in the preparation of iron mordants. Acetate of Iron, also called Pyrolignite of Iron and Black-iron Liquor, is manufac- tured similarly to the acetate of alumina, or by dissolving scrap-iron in crude acetic acid. It is applied in the same general manner, and to the same fibres, as the alumina compound. The remaining iron mordants are the MORDANTS. 457 Nitrates and the Nitro-sulphates. The former are obtained by dissolving scrap-iron in nitric acid to the proper degree of saturation, and the latter, by treating copperas with nitric acid ; as an iron mordant for black on silks this latter is probably the best, from the fact that the iron exists in both states of oxidization. Chromium Mordants comprise among the most important Bichromate of Potash and Bichromate of Soda, both being products obtained from chromite. The former is well crystallized, the latter is quite deliquescent, frequently becoming fluid ; in price it is cheaper than the potash salt, and yields the same results. It is a valuable wool mordant, and is also much used as an oxidiz- ing agent. Chrome Alum (Potassium Chromium Sulphate) is a residue from the manufacture of alizarin, and is employed as the basis for producing many of the chromium mordants. Chromium Acetate is obtained by double decom- position of lead acetate and chromium sulphate, and in commerce it is found of about 30 Tw. (specific gravity 1.15). It is used in printing. Other com- pounds used are the nitrate, chloride, sulphate-acetate, nitrate-acetate, etc. Copper Mordants are well represented by the sulphate (blue-stone) and the nitrate. Sulphate of Copper is used in dyeing blacks, mostly in con- junction with other mordants, and, owing to its cheapness, is used for the production of nearly all the copper compounds. Nitrate of Copper is easily prepared by dissolving scrap-copper, not brass (as free from lead and solder as possible), in nitric acid, and diluting to 1.4 specific gravity. In cold weather good crystals are obtained, but they absorb moisture very rapidly. The sulphide and acetate find little application except in special cases. Antimony Mordants. Tartar Emetic (Antimony Potassium Tartrate) is the best known of this group, and is much used for fixing tannin in cotton- dyeing. Oxymuriate of Antimony is another form, used for the same pur- pose. It is sold as a concentrated solution, made by dissolving metallic antimony in a mixture of hydrochloric and nitric acids and diluting very cautiously to 80 Tw. (specific gravity 1.4). Of late, double fluorides of antimony and potassium, and of sodium have been brought on the market as substitutes for tartar emetic. They are well crystallized, easily soluble, and cheaper. The mode of application is the same as for other antimony salts. Other mordants besides those above mentioned are used, but not as ex- tensively, and enough has been said to indicate their general nature ; under the operations of dyeing the special uses to which they are applied will be mentioned. (6) Mordants of Organic Origin. Tannin (Tannic Acid) is now pro- duced in large quantities of exceptional purity for use in the arts, and offers to the dyer a convenient mordant in place of many tannin-yielding sub- stances, which, however, still hold their position on account of other prop- erties. Tannin is much used by the cotton-dyer, and is applied generally in two ways : first, by steeping, and, second, by padding. For silk, tannin is extensively used in the production of blacks, and also for weighting. Catechu, or Cutch (see p. 427), is used in a similar manner to tannin, for the production of browns, drabs, blacks, and other shades, in combination with bichromate of potash, copper, iron, etc. Catechu is bought in mats weighing about one hundred and fifty pounds, and also as " cutch extract," or " prepared cutch," made by dissolving the crude cutch, straining from sticks, stone, etc., and evaporating to about 51 Tw. It is used for wool and for silk. Sumach (Shumach) is used in the dye-house in the ground state, and as an extract, which is, in some instances, grossly adulterated. 458 BLEACHING, DYEING, AND TEXTILE PRINTING. Nutgalls, rich in tannin, find extensive application both in dyeing and printing, especially when light shades are to be fixed. They occur whole, " crushed," and as an extract, which comes usually of two qualities. My- robalans, kino, divi-divi, etc., are also employed. D. DYEING AND PRINTING. 1. Dyeing. The apparatus used by the dyer consists of vats, kettles, cisterns, etc., and are ordinarily constructed of wood, although they may be also of metal, and even stone. Their capacity, in case of woollen yarn, is such that they can conveniently accommodate a hundred pounds of material, although the sizes vary according to circum- stances. Wooden kettles are heated by a copper steam-coil inside and on the bottom, and are provided with a water-supply pipe, and a lifting plug- valve for emptying. Metal kettles are preferably heated with steam by a coil or double bottom. Open fires are used in England and Europe to some extent, but in the United States very rarely, if at all. The shapes of the vat or kettle vary with the material to be dyed. For cotton, wool, and silk yarns they are mostly rectangular, and of varying depth, for loose material, mostly circular ; in the case of indigo- vats for yarns, they are wine-pipes stood on end ; this gives a great depth of liquid with a mini- mum of exposure. In hand-dyeing, the yarn is hung, and worked on sticks laid across the top of the kettles ; piece-goods are worked by means of a movable winch, sliding as occasion requires from one end of the kettle to the other, taking care to guard against twisting the fabric. Loose material is either dyed as such in circular tubs, or else is tied up in bags ; and warps are passed over a series of rollers immersed in the dye-liquor, and then between squeezing or nipping rollers. Of primary importance in successful dyeing is a regular supply of pure water, and in the absence of this, various means must be resorted to to purify the water at hand, which may be contaminated with sewage, which may not render it unfit for use, or else it may contain lime or magnesia, usually as bicarbonates, which are soluble, or it may have sulphates or chlorides. Iron (when present it is as a bicarbonate) is very objectionable, and, for some operations, prevents the use of the water. Water which has flowed through limestone regions will invariably be hard from the lime dis- solved, and that which flows or is pumped from granitic regions will be soft, due to the absence of lime, etc. In the event of water having suspended matter, this can be easily removed by suitable filtration, but if other impuri- ties are present, chemical purification should be resorted to. A hard water is one which has bicarbonate of lime or magnesia dissolved, this solution being really a dissolving of carbonate of lime in carbonic acid contained in the water ; besides the above, it may contain in solution sulphates of lime or magnesia. A water containing no sulphates, if boiled, would lose its hard- ness by the bicarbonate splitting off into carbonic acid gas and carbonate of lime or magnesia, which would be precipitated (temporary hardness) ; if sul- phates were present, the boiling would have no effect on them (permanent hardness). A soft water is one containing no such impurities. Chemical Purification for water embraces several processes, notably Dr. Clark's : decomposing the bicarbonate with a clear solution of calcium hydrate, by this means the excess of carbon dioxide is combined with the lime added, which is precipitated and removed by settling. Only the tem- porary hardness is removed. The Porter-Clark' process is similar to the above, with the exception that the precipitates are removed by the water being passed through a filter-press. Caustic Soda is also used as a purifying DYEING. 459 agent, which removes both the temporary and permanent hardness. The water will then be slightly alkaline. Solution of Coal-tar Colors requires a little care, because if imperfectly done the yarn or fabric will be spotted or striped : effects exceedingly diffi- cult to remove. The colors are dissolved readily in warm water ; some may require almost a boiling temperature, while others are injured when highly heated. They ought never be over a direct fire. In all cases it is well to strain them through felt. Cotton-dyeing. Two operations are necessary, mordanting and dyeing, except in indigo-dyeing, where no mordant is required, and in the applica- tion of the benzidine and primuline colors. In the case of raw stock, the operations are conducted in large circular or rectangular vats, heated as previously described, and provided with the necessary inlets and outlets for water, the outlet being covered with a gauze screen in order to keep the loose material from stopping it up. The material is " poled" or worked by long-handled rakes or by mechanical means. The washing can be done in a similar apparatus, or in one similar to a wool-scouring machine. For yarns, besides the open kettles mentioned on the preceding page, many mechanical devices are in use, and are well suited where large quantities of material are to be worked to one shade, but in cases where different shades are to be produced, hand-dyeing cannot be excelled. For warps, the apparatus re- ferred to on p. 448 is used ; it can be made with two or more kettles, so that the warp can pass through two or more different solutions. This arrange- ment is admirable for mordanting, dyeing, and washing, or in the event of using the primuline colors, requiring rapid treatment. The several baths can be maintained at different temperatures. Yarns and warps are washed in the same or similar apparatus to those in which they are dyed. Cloth-dyeing Machinery. The vats are either iron frames and wood or all wood, in some places small enough to stand on the floor of the dye- house, in others they must be sunk below that level, in all cases surmounted with a hand or power winch for working the pieces. Drying is accom- plished by wringing out the yarn, centrifugating, and hanging on wooden sticks in a " dry-room," or in the case of piece-goods, squeezing through rollers, centrifugating, and carefully arranging on sticks as above. Raw stock is dried by squeezing, and spreading on wire gauze over steam-pipes, or by passing through an automatic drying-machine. Application of the Natural Coloring Matters. Indigo. This dye is always applied in the cold, and by any of the several " vats" now known, among which the lime and copperas may be mentioned. This vat, or series (usually ten), is made up in various proportions, the amount of ground indigo ranging from thirty to thirty-eight pounds, copperas, fifty to eighty- five, lime, eighty to ninety. The vats being filled with water, the lime is added, followed by the ground indigo and the copperas, raking the whole up occasionally until the indigo has been reduced, which is known by the olive-colored appearance of the liquid. A good working vat is known by peculiar blue streaks or veins which appear when it is raked. The dyeing is performed by dipping the wetted yarns in the oldest- (weakest) vat, then squeezed out, placed aside to oxidize, and passed through the next, and so on until the proper depth of shade is reached, the whole operation being con- ducted systematically. The lime which is precipitated on the yarn is re- moved by means of a weak acid and washing. Piece-goods are dyed in a similar solution by fastening the material to a large frame, which is dipped 460 BLEACHING, DYEING, AND TEXTILE PRINTING. and re-dipped until the proper shade is obtained, or, in case of warps, also by passing over immersed rollers in a large vat, and finally over rollers exposed to the atmosphere ; this is particularly suited for light shades. Zinc-powder is much used in indigo-dyeing, supplanting copperas ; for forty pounds of indigo about twenty pounds of zinc-dust are used. This vat is more economical than the preceding. Other vats are also employed, viz., hydrosulphite, German soda vat, urine, etc., but those detailed in- dicate sufficiently the character of the operation. Logwood. This dye-wood is used in the form of liquid or solid extracts, and as chips, and mainly for the production of blacks. The cotton is mor- danted in a cold solution of acetate or nitrate of iron, squeezed, and the iron precipitated on the fibre by passing through a solution of carbonate of soda, and boiled in the logwood-bath ; or the cotton is allowed to steep in a solution of tannin (sumach, galls, etc.) for several hours, then worked in dilute iron solutions as above, this produces a tannate of iron, followed by a passage through weak lime-water, and dye in a separate kettle. Ace- tate of alumina can be used with the iron, somewhat modifying the shade. A " chrome black" can be obtained by dyeing in a single bath of bichromate of potash, hydrochloric acid, and logwood ; many modifications of this pro- cess are known. Gray shades can be obtained by first working in logwood, and afterwards in the copperas or bichromate of potash baths. Of the red dye-woods little need be said, as their practical utility in dye- ing is on the decrease ; their coloring matters are fixed in the usual manner with tin, alumina, or iron mordants. Of the yellows, Quercitron Bark and Turmeric are the most important ; the former, used chiefly as an extract, is available for the production of greens, etc., in combination with other col- oring matters. Turmeric is applied directly to the cotton by working in a plain bath, the color having a natural affinity, although it is not very fast. Application of the Artificial Coloring Matter to Cotton.* In this section only the individual colors will be referred to, any attempt to discuss the production of shades by compounding would be beyond the scope of this publication. Fuchsine is dyed upon tannin-prepared cotton, or upon cotton that has been worked in small quantities at a time in a bath of ten per cent, of neutral soap or Turkey-red oil, followed by an immersion in a warm bath of two hundred and fifty gallons water and one gallon acetate of alumina (9 Tw.). Work half an hour, wash, pass through a soap-bath for fifteen minutes, wash, squeeze, and dye. The color is added in successive portions until the required shade is obtained. Safranine is dyed upon a tannin mordant, or the tanned material is worked in a 3 Tw. bath of stannous chloride for an hour, washed, and passed through a two per cent, soap solution, and dyed at 140 F. Methyl and allied Violets can be dyed upon tannin as above, or pass the un tanned cotton through a one per cent, olive-oil-bath, squeeze, and dye at 100 F., or with the assistance of acetate of tin, or with alum and soda. The basic greens, including Victoria Green, Methyl Green, Brilliant Green, etc., are easily dyed upon cotton in the ordinary manner with a little (.5 per cent.) acetic acid. The Eosins, with Phloxin, etc., are dyed in several ways : first, by pass- ing the cotton through a two per cent, soap-bath, followed by an immer- * Reference has been made in the preparation of this and subsequent sections on its applications to several of the published trade circulars issued by the coal-tar color manufac- turers, and also to information from private sources. DYEING. 461 sioii for two hours in two to three per cent, acetate of lead, washing well, and dyeing, cold, with a little acetic acid ; or, second, by working in a dye- bath with eight to ten per cent, sulphate of soda, or the cotton can be worked in 5 Tw. bath of stannate of soda for an hour, worked for thirty minutes in a ten per cent, alum solution, rinsed, and dyed cold. Rhodamin- is dyed on acetate of alumina exactly as for fuchsine. Brilliant, Cotton, and Soluble Blues, The cotton is tanned and dyed with five per cent, alum and one per cent, soda ; or the tanned cotton can be worked in a 3 Tw. stan- nous-chloride bath for an hour, rinsed, and dyed at 150 F. If light shades are to be produced, work the cotton in a five per cent, soap-bath for an hour, squeeze, and work in a three per cent, tannin-bath, wring out, and dye with the assistance of tartaric acid and alum. Victoria Blue. Cotton is mordanted with tannin ; dye with one per cent, acetate of alumina. Methylene Blue. This is an exceedingly valuable color to the cotton-dyer, as with it he can produce indigo shades. The cotton is mordanted with twenty-five per cent, sumach at 160 F. Give several turns, and allow to steep ten hours, wring out, and work for twenty minutes in two and one- half per cent, tartar emetic, wash, and dye in a bath prepared with acetic acid (three per cent.) at 75 F., gradually raising the temperature to 160 F. Crocein Scarlets are dyed on cotton by working the untanned yarn in stannate of soda, wring, and pass for half an hour through sulphate of alumina, rinse, and dye. Cotton can also be dyed by passing first through stannic chloride, and then through acetate of alumina. Dye cold, or dye direct, with sulphate of alumina. Auramin, of considerable value, is dyed in the same manner as methylene blue. Bismark Brown and Chrysddine. Dye same as safranine; temperature 100 F. Induline and Nigrosine. Dye in same manner as for the cotton blues. Paraphenylene Blue is dyed upon tin or antimony, and tannin. The shades produced are very dark, and extremely fast ; treated with bichromate of potash, the shade closely imi- tates, and is faster than, indigo. The substantive colors of the Congo and parallel groups are exceedingly valuable, for the reason that they are easily dyed upon unmordanted cotton, and that they are of exceptional fastness. The several Congos, Benzo- and Delta-purpurin, and Rosazarin, are dyed with two and one-half per cent, soap and ten per cent, sulphate of soda, or phosphate of soda, boil for one hour. * Hessian Purple is dyed at a boil for half an hour with ten per cent, common salt, followed by a passage through dilute soda. Chrysamin is dyed with ten per cent, sulphate of soda and two and one-half per cent, soap at a boil. Hessian Yellow is dyed with ten per cent, of salt and a little Turkey-red oil. Brilliant Yellow and Chryso- phenin are dyed with ten per cent, salt and two per cent, oxalic acid, work half an hour, squeeze, rinse, and dry. Azo Blue, and Benzoazimine, Helio- trope, etc., are dyed with ten per cent, sulphate or phosphate of soda and two and one-half pounds of soap, let stand, and skim the surface, add the dye, boil, and put in the yarn, and work for an hour, boiling, rinse the yarn, and dry at as low a temperature as possible. Indigo shades from Benzoazimine are obtained as above, but for every one hundred parts of color add three parts Chrysamin. All the benzidine dyes act as mordants for a very large number of other colors, no other fixing agent being required. Aniline Black. This color is produced directly upon the fibre during the dyeing by means of aniline oil in the presence of oxidizing agents ; to obtain good results it is necessary that the oil used should be as pure as pos- sible. Two methods are in general use, warm (Grawitz patent) and the cold. 462 BLEACHING, DYEING, AND TEXTILE PRINTING. In the former method, two thousand four hundred litres of water, thirty-two kilos, hydrochloric acid, sixteen kilos, bichromate of potash, and eight kilos, aniline oil are taken. The acid and aniline are each diluted with water and carefully mixed, the solution thus obtained being added to the main volume of water. The bichromate of potash is previously dissolved and added after the aniline. Immerse the cotton, and work for three-quarters of an hour in the cold, and then gradually raise the temperature to 60 or 70 C. In the cold method take eighteen kilos, hydrochloric acid, eight to ten kilos, ani- line oil, twenty kilos, sulphuric acid, 66 Be"., fourteen to twenty kilos, bichromate of potash, and ten kilos.- copperas. This bath is made up similarly to the previous one, with the exception that much less water is used, in order that the operation may be conducted in as concentrated a bath as possible. The yarn is worked in one-half of the materials for an hour or so, after which the remainder is added, and the operation carried on for about one and a half hours longer, followed by a washing, and a boiling in a soap solution. In either case, the cotton after dyeing is sub- jected to a further oxidization with bichromate of potash, copperas, and sulphuric acid, this having a tendency to prevent greening. Chlorate of soda is used considerably as an oxidizing agent in the dye-bath. Vana- dium chloride, or vanadate of ammonia, has been recommended to be used with a chlorate in place of bichromate of potash ; the proportion of the vanadium salt being to the displaced bichromate as 1 : 4000. Another method is to produce the aniline black in powder form, purify it, liberate the base, which is dissolved in sulphuric acid, poured into water, and the precipitate formed thereby dissolved in caustic soda. This is reduced as in the case of indigo, and dyed in a similar manner. Alizarin-dyeing, Turkey-red Process. J. J. Hummel, in his " Dyeing of Textile Fabrics," 1886, p. 427 et seq., details the emulsion process, which need not be described here. It may be stated, however, that beautiful re- sults have been obtained from its use; the yarn passes through fourteen operations, as follows : boiling in soda and drying, worked in an emulsion of oil, dung, and carbonate of soda ; passed through the previous process twice again ; worked four times in carbonate of soda, steeped in water, and in carbonate of soda, sumached, mordanted with alumina, dyed with aliza- rin (ten per cent.), sumach, and bloody cleared with carbonate of soda, final clearing with soap and tin crystals. To finish the dyeing requires about three weeks, but a real Turkey-red is produced. Except for some grades of goods, it is doubtful whether such a lengthy process w r ould be profit- able. The following scheme of a process represents the type of a reasonably short one ; it is well to remember that it can be modified to a considerable extent without altering its product. It is used in several establishments essentially as given. Boil the cotton for two hours in a 1.04 specific gravity solution of caustic soda, wash well in water, dry, and work in seven to ten per cent, solution of Turkey-red oil, squeeze, dry at about 115 to 120 F., steam in a chest, mordant with acetate of alumina (red liquor) at 80 Tw., and dry as before ; work for an hour in a hot bath of five pounds of dung and eight to ten pounds of chalk, followed by a good wash, and pass to the dye-bath, made up of eight per cent, of alizarin, two per cent. Turkey-red oil, and about one per cent, of ground sumach, or equivalent in pure extract. Enter cold, and slowly increase the temperature to and maintain it at 160 F. for over half an hour. Dry, and steam in DYEING. 463 the chest as above. The final operation is a soaping with carbonate of soda and stannous chloride as in the above emulsion process. An almost unlimited number of processes could be given, but it is hardly necessary, the principle remaining the same in every case. For full informa- tion reference is made to Hummel, above mentioned, Sansone, " Dyeing," vol. i., 1888, and others. The apparatus used for alizarin-dyeing is not special, with the exception of the machines for " padding," the material to be dyed with the oils and for working in the liquors ; the most important is the steam-chest, which is essentially a large cylindrical wrought-iron drum with cast ends, one of which is provided with a well-closing door. The chest, or steamer, is provided with a steam-supply pipe, gauge, and safety-valve. The yarn or cloth is hung on sticks supported on rods inside, or, as shown in Fig. 125, mounted on iron carriages. Some chests are so built that the FIG. 125. yarn contained can be turned while closed and with the steam pressure on, which seldom exceeds four or five pounds. Ingrain Red, a color obtained from primuline or polychromine, is fpr some purposes a perfect substitute for Turkey-red, being fast to light, soap, and acids. Primuline is dissolved in warm water, common salt or sulphate of soda added, and the yarn worked in the bath until a good full yellow is obtained, when the material is washed, and immersed in a cold solution of nitrite of soda slightly acidulated with either hydrochloric or sulphuric acid, this causes a diazotizing of the yellow color, with the production of an unstable orange shade ; the yarn is lifted out, washed rapidly, and at once dipped in a warm solution of P-naphihol in caustic soda, when a deep- red color is developed. The yarn is worked for a while, and afterwards well washed in water. If phenol or resorcin is substituted for the /5-naph- thol, a fast yellow and orange color, respectively, will be obtained. The diazotized yarn is very sensitive to the light, if it is not in a reasonable time developed, no color will be obtained ; this fact is at the present time experimented upon with a view to its possible use in photography. Linen. The uses to which fabrics made of this fibre are put demand colors that shall be fast to washing, light, and air ; this requirement being satisfied by alizarin and indigo. The coal-tar colors, as a rule, are not applied, although they can be by treating the fibre in the same manner as cotton. Jute-, owing to its peculiar chemical structure, does not require any mordanting ; all basic colors can be applied by simply boiling in a neutral bath. Some scarlets and a few of the acid colors are fixed with the assist- 464 BLEACHING, DYEING, AND TEXTILE PRINTING. ance of a little acetic acid in the dye-bath, sometimes with a little sulphuric acid and alum. Wool-dyeing. Raw wool is dyed in the same manner as raw cotton, in open kettles, or in machines made for the purpose. Woollen yarn and cloth are similar in their manipulation to cotton, the apparatus being in both cases nearly the same. Dyeing-machines for carpet yarns are coming slowly into use, several forms being capable of handling a large quantity in comparison with hand labor. Some classes of goods, i.e., plushes, have cotton backs, these being previously dyed in the hank and warp and then woven, the face, or pile, is afterwards dyed the proper shade, care being taken to select such colors as will have no modifying effect upon the cotton color. For this purpose cotton dyed with aniline black, indigo, or alizarin are best suited. Natural Coloring Matters applied to Wool. Indigo, as extract, is easily applied, and is extensively employed in the production of light and dark shades by simply boiling the wool in a bath made up with the color, sulphuric acid, and sulphate of soda. If other coloring matters are to be used in con- nection with the above for the production of compound shades, a neutral ex- tract had better be used, and the dyeing done without the above acid. Wool is dyed in a vat, where exceptionally fast and full shades are demanded, espe- cially for army cloth. Loose wool is dyed in the so-called fermentation-vat. The wool being kept below the surface of the liquor, worked about by means of long rakes for a sufficient time, and taken out and put in large cord bags, or placed upon rope screens to drain and oxidize. It is finally dipped in very dilute acid to remove soluble impurities, well washed, and dried. Woollen yarn is worked in vats exactly as in the case of cotton. Cloth is worked in the vat below the surface of the liquid, by means of poles with hooks. The best indigo-dyed cloth is that made from wool which has been previ- ously dyed in the raw state, dyed in the wool. Logwood. This dyestuff is the real base of the blacks upon wool, the most generally followed method being with bichromate of potash as a mor- dant. Boil the wool in a bath of three per cent, bichromate and one per cent, sulphuric acid for an hour, lift out, rinse, and boil in a bath (made with a decoction of about forty per cent, chipped logwood) for an hour, lift the wool, and add a little extract of fustic, continue the boiling for a half- hour. This will yield a rich black. Various modifications are practised, depending upon the exact shade desired. For cheap work " one-dip blacks" are used, these consist chiefly of a mixture of logwood and a mineral mor- dant, iron or copper. Wool can be mordanted with copperas, copper, and cream of tartar, etc., followed by dyeing in the logwood, or it can be worked in the logwood first, followed by a " development" in a bath of ferrous sul- phate of iron and copper. Logwood Blue, for some kinds of work, is an excellent substitute for indigo, full shades being obtained by direct dyeing, or by dyeing upon a light indigo bottom. Hummel gives the following method : Mordant the wool for one to one and a half hours at 100 C. with four per cent, of aluminum sulphate, four to five per cent, of cream of tartar; wash well, and dye in a separate bath for one to one and a half hours at 100 C., with fifteen to thirty per cent, of logwood and two to three per cent, of chalk. The addition of a little alizarin or tin crystals to the bath at the termination of the dyeing will cause the appearance of " bloom," peculiar to indigo. The red woods are fast losing ground, although before the introduction of DYEING. 465 the artificial scarlets and cardinals they were much used. Madder, likewise, has been superseded by artificial alizarin. Wool was mordanted for browns with bichromate of potash as for logwood ; for reds, mordant with alum, or sulphate of alumina, with cream of tartar (argols), and boil. Tin crystals and tartar produce a reddish-yellow. These colors were not brilliant, but the value of them depended upon their fastness. The use of Cochineal is mainly for the scarlets obtained therefrom. The wool is mordanted with tin crys- tals and cream of tartar, washed, and dyed in a bath with five to ten per cent, of cochineal (ground) for an hour. Another method is to boil the unmordanted wool in a bath of cochineal, tin crystals, and potassium oxalate for an hour. For scarlets with a bluish cast (crimsons") the wool is mordanted with aluminum sulphate and cream of tartar, or the wool can be mordanted in a bath containing tin crystals, tartar, and aluminum sulphate, followed by the dyeing in a separate bath. Copper, or iron, as a mordant will produce dark shades, and as impurities in the dye-baths will have a sad- dening effect upon the color obtained. Fustic is largely used in wool-dye- ing, chiefly, however, in combination with other colors, i.e., indigo extract to produce greens, olives, sages, etc., and always upon mordanted wool, using tin crystals, sulphate of alumina, bichromate of potash, iron, and copper. Quercitron Bark is used for the same purpose as fustic and under the same conditions. Flavin, a production of the latter, is used in the same manner, its chief advantage is that it is much more concentrated. Archil (Orchil] as "extract," liquor, or paste is extensively used in the dyeing of carpet yarns ; it is applied by simply boiling the yarn in a bath with the color, sulphuric acid, and sulphate of soda. It is exceedingly difficult to remove from yarn once dyed with it ; a process which will economically accomplish this is much sought after by manufacturers. Application of the Coal-tar Colors. As a general rule, it may be stated that nearly all the soluble artificial colors can be dyed upon wool without any special treatment, by boiling in a bath with ten per cent, of sulphate of soda and two to four per cent, of sulphuric acid. A few exceptions may be given : Alkali Blue (Nicholson's Blue). The color is dissolved in car- bonate of soda, poured into the dye-bath, the wool entered, and the tem- perature raised to the boil, keep boiling for a while, lift, rinse well, and immerse in a bath of very dilute sulphuric acid, when the color will be at once developed. The Violets (Hofmann's, etc.) are dyed neutral, or with a little soap. Methyl Green is applied to wool with borax, after having been previously mordanted with hyposulphite of soda and hydrochloric acid. Auramine is dyed neutral. The Indulines are dyed neutral, fol- lowed by a boil in dilute sulphuric acid. Gallein and Ccerulein are dyed upon wool mordanted with bichromate of potash and a trace of sulphuric acid. The application of Alizarin to wool is exactly as for madder, the general mordant being sulphate of alumina and tartar for reds ; tin crystals and tartar for orange ; bichromate of potash and sulphuric acid for red- browns; iron and tartar yield violet; and copper, shades of brown. The addition of a little lime to the dye-bath is necessary in case none is naturally present in the water. Nitro-alizarin (Alizarin Orange) produces with several metallic mor- dants, applied as above, a range of shades, which have not reached commer- cial importance.- Alizarin Blue is dyed upon a chromium mordant, and yields a durable blue, of some value, for wool, the price of the dye is against it. 30 466 BLEACHING, DYEING, AND TEXTILE PRINTING. The mineral colors are dyed upon fibres through the decomposition of metallic salts, for example, to dye Prussian Blue, the wool is worked in a bath of red prussiate of potash and sulphuric acid, and gradually brought to a boil, squeezed, rinsed, and dried. Silk-dyeing. Silk has a great affinity for the coal-tar colors, with which it can be dyed without any mordant, although it is customary to employ a soap-bath (boiled-oif liquor) with or without the addition of a weak acid, usually acetic. If soap is not used the colors will appear streaky or spotted. For ribbons, fancy dress goods, plushes, etc., the above colors are solely employed, with the possible exception now and then of recourse to some natural coloring matter, the use of the latter being almost restricted to logwood for blacks and modified shades, including browns. Silk is dyed in skeins or hanks, warps, or pieces, this latter including plushes. The machinery is of the simplest kind, embracing the kettles, with and without winches, washing-machines, etc., and need not be especially described. Silk is not dyed with indigo (vat process), but indigo shades are obtained by using indigo-carmine. Black is obtained by several processes. Work the silk in acetate of iron and wash, then in a warm soap solution, followed by an immersion in ferrocyanide of potash, washed, and worked again in the iron-bath, rinsed well, and steeped in a solution of catechu or gambir for ten or twelve hours and washed. This preliminary process is necessary in order to insure a good result if systematically carried out and not forced. The material is dyed in a logwood decoction containing soap. A method giving excellent results, and which is considerably used, is as follows : Wash the goods, and pass through a bath of nitrosulphate of iron, wash, and then through a solution of carbonate of soda. These two operations are repeated several times, each time causing the precipita- tion of more iron upon the fibre, and consequently " weighting" the silk. Work for some time in a bath of ferroprussiate of potash and then in a bath of catechu, followed with a little " muriate of tin" or tin crystals, wash, and transfer to the logwood-bath, which may contain a little extract of fustic to modify the shade required, then to a soap-bath. Every locality is not suited to black silk-dyeing on account of impurities in the water, careful purification of which is a special requisite. Seal plushes are dyed, first in a dye-bath in the ordinary manner, a dark-brown shade, followed by the application of a black, blue-black, or other color, in the form of a paste thickened with starch, gum, or other medium. The application of this being done on a machine provided with revolving brushes, and so regu- lated that only the tip or face of the piece of goods is coated. One impor- tant feature in plushes of this character, and also in other kinds of silk goods which have been heavily iron-mordanted, is that the natural lustre of the fibre is somewhat destroyed ; this is supplied by means of a paste mixture of vegetable oils made into a paste with starch or other substance, applied as in the case of the tip, and steamed in an apparatus similar to that used for alizarin red (p. 463). The oil, usually a definite amount, is absorbed by the silk fibre under the influence of steam, imparting a per- manent lustre. The goods, when removed from the steamer, are washed to remove the starch, excess of oil, etc., when they are ready for other opera- tions. The weighting of silk is accomplished by the use of iron, as explained above. This, however, is only suitable for dark shades ; for light shades, tin in combination with soap is used. TEXTILE PRINTING. 467 A class of fabrics similar to plush, but with the pile of two or even three colors, much used for carriage-robes, etc., and dyed to imitate the skins of animals, are prepared in the following manner : The material (cotton- black and silk pile, the former previously dyed a fast color) is dyed, say a brown, in the ordinary manner ; upon the fibre is then applied a dis- charge made of stannous chloride solution and permanganate of potash. This is so controlled that only one-Half of the fibre is acted upon. When the effect is produced the excess is washed off, rinsed, dried, and, if neces- sary, a tip is applied, which only dyes the very face of the pile. In this manner three colors are obtained on each thread of the face. After treat- ing as above, the whole may be dyed a very light shade, thereby producing modified effects. The artificial coloring matters are applied to silk as previously stated. Nicholson's Blue (Alkali Blue) is applied as directed for wool, and seldom for the production of mixed shades. Picric Acid is much used for compounding, especially for greens, faster colors can be obtained by using naphthol yellow and indigo-carmine. The Eosins yield beautiful colors, and are applied in a soap-bath followed by a brightening in dilute acid. The Azo dyes are applied with a neutral soap-bath. The use of Alizarin with silk is only in cases where fastness is of more importance than brilliant shades. Alizarin Black is being much used in dyeing mohair goods (astrachans), and is applied in the ordinary manner. E. PRINTING TEXTILE FABRICS. A brief outline of the more impor- tant " styles" in use is all that will be attempted in this section, from the fact that the subject is too extensive to enter into the details satisfactorily. The processes in general are conveniently divided into two main groups, differing in the manner of applying the colors, namely, Direct Printed Colors, Dyed Colors. Direct Printing is done by mixing the desired color with the proper fixing agents and applying directly to the fabric by means of blocks en- graved with the design, or in a machine provided with a cylinder upon which the design is likewise engraved ; for each color to be applied a sepa- rate cylinder is needed. From the above it is obvious that the color so applied will appear only on those portions of the fabric brought in contact with the design. Dyed Colors are obtained by printing different mordants upon the cloth, as above, and fixing as fpr ordinary cloth, and then dyeing the whole, or, by printing upon the cloth resists, substances which will prevent the dye from becoming fixed at those places so printed, or, again, by dyeing the whole piece first, and then producing patterns or designs by means of sub- stances which will destroy the ground-color whenever brought in contact ; these substances are called discharges. This broad definition is deemed suf- ficient for the purpose intended ; the principle of each style will be apparent upon following the methods hereafter given. The operations conducted in a print-works embraces as a preliminary bleaching, the details of which are referred to on p. 448. Then the prep- aration of the colors, which is always done in copper pans mounted in such a manner that they can be emptied easily, and that their contents can be boiled by steam, and cooled by water, facilities for this being done by means of steam and water trunnions connecting with the double bottom of each pan. From five to eight pans are supplied in a " battery," although it is often convenient to have one or more pans separately mounted, and 468 BLEACHING, DYEING, AND TEXTILE PRINTING. FIG. 126. without steam taps. The agitation of the contents is performed either by means of wooden paddles or, preferably, by mechanical agitation, which can be raised clear above the top of the pan, and without interfering with the working of the others. As the majority of colors used are made with either starch or flour for thickening, it is necessary, to insure good results, that they are strained or filtered ; for this purpose it is well to have wooden frames made, over which is tacked brass or copper wire cloth (iron is inadmissible). The most important piece of apparatus is the printing- machine, an idea of the construction and operation of which may be had from Fig. 126. A is a cylindrical " bowl" or drum, covered with several thicknesses of felt cloth, c, around this drum, and passing over a smaller one, B, is an endless band, d (full width of the machine), over this band, and acting as a guide to the fabric to be printed, is another band, c, which serves to keep d clean, being, in fact, a piece of cloth, yet to be bleached and printed ; the piece being printed is indicated by/. The means for applying the color are shown in the figure below the large drum, viz., the printing rollers or engraved cylinders h l} h 2 , A 8 , which are fed with color through coming in con- tact with the wooden rollers n^ n 2 , n 3 , which dip in the color contained in the troughs k l} k 2 , k s . Pressing against each of the rollers, A, is shown a small strip of metal, r, technically termed the "doctor," the purpose of which is to remove the excess of color from the face of the printing-rollers before they come in contact with the cloth. These " doctors" are best made of bronze or gun-metal, or some of the newer aluminum-copper alloys, capable of better resisting weak acid. Before the cloth is printed upon it passes over a " lint doctor," the office of which is to remove any loose hair or fibres from the cloth. Printing-machines are built with any number of color boxes and rollers up to twelve or fourteen, each being for a separate color. Sansone mentions one for use with twenty colors. Great nicety is required in adjusting the machines in working to have no overlapping of colors or mordants, perfect " registration" being sought. For drying the printed goods revolving cylinders, or "cans" of large diameter, are used, or the goods are passed over heated plates, in no case allowing the printed face to come in contact with any part of the apparatus. Steaming follows to fix the colors. The apparatus being a steamer, as shown on p. 463, or one constructed of brick and iron, acting continuously, thereby turning out much more work than the former. The dyeing- and washing-machines are similar to those already described. Mordants, Resists, Discharges, etc. All the various substances used in printing must be applied in the form of pastes, the consistency of which TEXTILE PRINTING. 469 must be such that whenever applied they will not run or spread, which impairs the sharpness of outline of the printed pattern. For the purpose the color- mixer has recourse to the starches and gums, the most important of which are corn, wheat starch, and flour, usually made up into ten per cent, pastes. The gums include gum arable, dextrine (British gum), and tragacanth. The first is used in several degrees of consistency, from a fifty to a one hun- dred and fifty per cent, solution, dextrine the same, and the last in a ten per cent, paste. The proportions are by no means uniform, but they represent the average strengths used in the color house. Blood albumen is considerably used, large quantities being manufactured cheaply in Chicago and other Western localities. The mordants used embrace the acetates of alumina of various strengths, basic sulphate, and others of less importance. The acetates and nitrates of iron are the most prominent salts of this element, and of chromium there may be mentioned the acetates and nitrates ; others, including salts of tin, calcium, manganese, are also used. Owing to the great number of recipes published for preparing mordants, and of the diffi- culty in selecting those which may be called representative, only a few will be given of the more important. Acetate of Alumina, or " Red Liquor" (Crookes). Water 45 gallons. 46 gallons. Alum 100 pounds. 200 pounds. Acetate of lead 100 " 200 " Soda crystals 10 " 10 " Or the same result can be had by substituting acetate of calcium for the lead salt. In either case the alumina salt is dissolved in about half the quantity of water, and the acetate in the remainder, when the two solu- tions are mixed and allowed to settle, the precipitated lime or lead sul- phate being removed. The addition of soda is to neutralize any free acetic acid. Acetate of Iron, or " Black Iron Liquor," can be obtained either by double decomposition as above, or by dissolving scrap-iron or precipitated oxide of iron in crude acetic acid. In the former method sulphate of iron and acetate of lead are used as follows : Water, forty pounds, sulphate of iron, twenty-four pounds, acetate of lead, twenty-four pounds. Dissolve each separately, mix, and filter. The oxide of iron above mentioned is ob- tained by precipitating a solution of copperas with ammonia or soda, filter- ing and washing, and dissolving the moist precipitate in ordinary acetic acid to make a twenty-five per cent, solution. In the event of using soda, much longer washing is required. Nitrate of Iron is made as above. Copperas and nitrate of lead being used for the decompositions in equal proportions. Nitrates made by direct solution are obtained by several methods, the best being nitric acid nearly saturated with scrap-iron and diluted to about 80 Tw. Others may con- tain hydrochloric acid, with or without the addition of copperas. Acetate of Chromium is similarly prepared with chrome alum and acetate of lead, or by precipitating chrome alum with an alkali, and dissolving the washed precipitate in acetic acid, or in nitric acid if the nitrate is wanted. This latter mordant can be made by using lead nitrate and chrome alum. The principal styles of printing tissues are given in the following scheme, condensed from a tabular view given in Sansone's excellent work on " Cotton-Printing." 470 BLEACHING, DYEING, AND TEXTILE PRINTING. PRINTED (DIRECT) COLORS. 1. Steam or Extract Styles, (a) Coal-tar Colors. Alizarin, Basic Aniline Colors, Acid Colors. (6) Dyewood Extracts (natural organic coloring matters). Logwood, Quercitron Bark, Sapan and other lied Woods, Catechu, Annatto, Cochineal. (c) Steam Mineral Colors. 2. Pigment Styles (fixed by albumen). 3. Oxidation Colors. 4. Direct Indigo-printing (alkaline styles). DYED COLORS. 5. Alizarin Dyed Styles. 6. Turkey-red Styles. 7. Indigo Styles. 8. Manganese Bronze Styles. 1. Steam Styles. Here the colors and proper mordants are mixed, and applied to the fabric in one operation, followed by air drying and steaming, or by immediate steaming, drying, and again steaming, the object in each case being to fix and develop the colors. Several conditions are to be noted in this style, chiefly the humidity of the steam, temperature, pressure, and the duration of the steaming, in order that the same shades may be again obtained with the same colors. Before being printed the cloth is passed through a solution of stannate of soda, also called " preparing salt," and then through sulphuric acid (1.005 to 1.015 specific gravity), washed, and dried. The colors best suited are the basic, that is, those which form in- soluble lakes with tannin in combination with a metal, and the general method of applying the same is given in the following extract from San- sone (" Printing"), p. 208 : " A color is formed consisting of thickening, the solution of coloring matter, and acetic acid. The acetic acid is added in the preparation of the color in order to prevent the tannic acid from com- bining with the dyestuff; in other words, the acetic acid keeps both the coloring matter and the tannin in solution in the thickened color, and pre- vents their combining with each other ; but when the color is printed and the cloth is dried and steamed, the acetic acid is expelled, and the coloring matter and the tannin then go into combination to form the insoluble col- ored lake. This lake, however, not being sufficiently fast to stand by itself, a metallic mordant is necessary to give additional fastness to the colors ; for this reason the cloth, after printing, dyeing, and steaming, is passed into a solution containing tartar emetic." The antimony of which at once unites with the " tannate" of the color already on the fabric, thereby producing a more insoluble body. The steaming operation must be conducted with such a volume of steam that the acetic acid volatilized can be carried away, or else the colors may be injured. Of the colors employed may be men- tioned the Fuchsines, Methyl Violets and Greens, Bismarck Brown, Naph- thylene Blue, etc. Alizarin, without exception, is the most important coloring matter used in cotton-printing, for which purpose the goods are previously treated with alizarin oil and dried. With alizarin in printing, as in dyeing, the color obtained depends upon the selection of the mordant, which can, however, be a mixture ; for reds, alumina, with or without tin ; purples, iron ; browns, with either ferricyanide of potassium or acetate of iron, and acetate of TEXTILE PRINTING. 471 alumina, or with chromium mordants. When the fabrics have been printed they are steamed for one or two hours, and passed through a heated chalk- bath, washed, and soaped. The following indicate the methods of preparing several colors : Red. (Standard.) Alizarin paste (fifteen per cent.) 6 pounds. Starch paste 2 gallons. Acetate of alumina (11 Be.) 1J pints. Acetate of lime (15 Be.) 1 pint. Nitrate of alumina (13 Be.) f " Purple. (Standard.) Alizarin 2 pounds. Starch paste 1 gallon. Acetate of iron (13 Be.) 1 quart. Acetate of lime (13 Be.) 1 pint. Acetic acid 1 " Brown. (Standard.) Alizarin (fifteen per cent.) 4 pounds. Starch paste 1 gallon. Nitro-acetate of chromium (25 Be.) 'A pounds. Acetate of lime (13 Be.) |- pound. Since the introduction of the alizarin greens and violets, their use in con- nection with chromium in cotton-printing has been most rapid. Dye-woods, with the exception of logwood, have been nearly superseded by the tar colors. The method of applying the color is nearly the same as for other steam colors, viz., print, dry in the air, steam, and wash, and. is made up with chromium as the mordant, and an oxidizing agent, with or without the presence of another coloring matter to modify the shade. The following recipes illustrate the color as made for blacks : Steam Logwood Black. (Sansone.) Water 1 gallon. Acetic acid (6 Tw.) 1 Logwood extract (30 Tw.) 1 Quercitron bark extract (30 Tw.) 2 pounds. Starch- 5 Dextrine 2.5 " Olive oil 5 " Chlorate of potash or soda .75 pound. Boil, stir, until cold, then add Acetate of chromium (20 Tw.) 1 gallon. Steam Logwood Black. (Sansone.) Starch 6 pounds. Flour 6 Acetic acid (6 Tw.) 2.5 gallons. Logwood extract (20 Tw.) 3.5 Acetate of iron (15 Tw.) 3.5 " Olive oil 1-5 pounds. Of the other natural coloring matters there may be mentioned Cochineal, applied with tin or alumina ; Sapan, in the same manner, and Quercitron Bark, with alumina or chromium. Catechu, much used for browns, may be applied with acetate of chromium or with logwood and fuchsine. The Mineral Colors are to some extent made use of, their application depending upon the principle of double decomposition upon its fibre when subjected to steaming. The following examples will make the principle clear : Yellows are obtained by the decomposition of nitrate of lead and a 472 BLEACHING, DYEING, AND TEXTILE FEINTING. soluble chromate, the insoluble chromate of lead (" chrome yellow") being formed. Another shade is obtained by decomposing a soluble cadmium salt with thiosulphate of soda, when sulphide of cadmium is precipitated. For Blues, both prussiates of potash are used. Brown is obtained by means of chloride of manganese and bichromate of potash. 2. Pigment Styles. For this style effects are produced by means of in- soluble color lakes and the mineral colors, which are fixed upon the cloth by steaming, the action of which coagulates the albumen with which the colors are invariably mixed for printing. The colors are generally supplied to the color-mixer in a dry condition, and include Ultramarine of various .qualities, Vermilion (sulphide of mercury), the Chromates of Lead and Barium, Cadmium Yellow (cadmium sulphide), Chrome Green (oxide of chromium), the Ochres, yellow and red, and Lamp-black. A familiar ex- ample of this style is seen in cheap flags and decorative muslins. 3. Oxidation Colors. The most important of this class is Aniline Slack, and will be briefly outlined as follows : Aniline oil is made into a paste with a chlorate (soda generally) and a metallic salt, with the proper amount of starch paste. This is printed upon the fabric, "aged" for forty-eight hours, or passed through a "steam ager," then passed through a warm bath of bichromate of potash, washed well, and finally worked through a soap-bath. The metallic salt mentioned acts as a carrier of oxygen, and for the purpose vanadate of ammonium, sulphide of copper, bichromate of potash, etc., are used. For the preparation of the color paste the following methods are given : 1. Water 1 gallon. Aniline salt 2 pounds. Aniline oil . . 2 " Starch 2 " Dextrine pound. The past,e is made first with the starch and dextrine, then the aniline is added. 2. Chlorate of soda (8 Be.) 1 gallon. Starch 2 pounds. Dextrine pound. Chloride of ammonium | u These are made separately, but when wanted are mixed, and two pounds of sulphide of copper paste are added, and the whole well mixed and strained. (Crookes.) The use of vanadium is shown by the following method (Sansone, " Printing," p. 275) : Water 1 gallon. Starch 1J pounds. Dextrine J " Boil, cool down to 120 F., then add Aniline oil 1J " previously neutralized with Hydrochloric acid (32 Tw.) 1 " Stir until cold, then add a cold solution of Chlorate of soda pound. Boiling water 1 " Before printing add further Vanadium solution " Print, dry not too hard, age two days, then pass through two per cent, solution of bichro- mate of potash at 160 F., wash and soap. The vanadium solution is made with vanadate of ammonia, hydrochloric acid, glycerine, and water, and contains about .15 gramme per litre. TEXTILE FEINTING. 473 FIG. 127. Other colors are produced by oxidation, namely, Brown (with phenylen diamine, Sansone), by simply printing with a chlorate, drying, and steaming, Yellow, Grays, Olives, Blues, etc. To obtain white patterns on goods printed with aniline black, a " resist" or " reserve" is first applied of the desired pattern, consisting of white arsenic as the base, with caustic soda, and the proper thickening. For discharging the aniline black after it is printed, permanganate of potash is used ; the goods are afterwards passed through a solution of oxalic acid. 4. Indigo-printing. Indigo is printed upon cotton fabrics in two ways, one of which is known as the " Glucose," and the other the " Reduced Indigo" Process. The former is carried out as follows : Indigo is finely ground, and made into a paste with water, to which is added caustic soda ; this is now kept in a closed vessel in order to prevent as much as possible the absorption of carbonic oxide from the atmosphere. When used in printing, it is thickened with dextrine and starch ; the following table (from Sansone, "Cotton-Printing," p. 284) showing the proportions used for several shades : Dark blue. Medium blue. Light blue. Light calcined starch 3 parts. 3 parts. 3 parts. Indian corn starch H " H " 1J " Water 3| " 3 " 3| " Caustic soda lye (70 Tw.) 16 " 28 " 40 " Indigo paste 30 " 18 " 6 " The cloth, before being printed upon, is worked through a twenty-five per cent, solution of glucose and dried. After printing, the cloth must be again dried and passed through an atmosphere of wet steam, in an apparatus shown in Fig. 127, to effect the reduction of the indigo which now takes place. The cloth is now washed in water, being repeatedly, during the washing, exposed to the air, when the reduced indigo is ox- idized and its real color appears. The reason for rapidly steaming is to act upon the caustic alkali while it is still in that state, as if it should become carbonated through delay little reduction will take place. This method is employed in printing indigo upon alizarin-dyed goods and in other combinations with resists, etc. The " Reduced Indigo Process" is based upon the fact that indigo, when finely ground and mixed with lime and thiosulphate of soda in suitable thick- ening agents, is reduced, if with this reduced indigo paste, patterns are printed upon cotton fabrics, and then exposed to the air, the indigo is oxidized with a regeneration of the blue color. The pieces are then washed and dried. 5. Dyed Alizarin. This process differs from all those previously men- tioned in that' the colors are produced by first printing upon the fabric the thickened mordants suited to alizarin, ageing, during which the mordants so printed are decomposed and more firmly fixed upon the cloth, dunging, 474 BLEACHING, DYEING, AND TEXTILE FEINTING. an operation which removes the thickening no longer needed, followed by a washing, and then dyeing with alizarin, and, finally, brightening. The mordants used for Reds are generally made with acetate of alumina, thick- ened with starch or flour, and dextrine, while by the addition of tin to such a mixture blue shades will be obtained. For Purples or Violets, acetate of iron is used diluted with paste, if used strong, blacks can be produced. Browns are obtained with catechu and copper acetates. Mixtures of the acetates of iron and alumina yield varying shades of Chocolate. Follow- ing the printing operation, the fabric is allowed to dry, when it is aged by being caused to pass through the continuous steamer; here the acetates are decomposed, basic salts remaining fixed upon the cloth. Formerly the operation was conducted in large rooms, and often required a week to finish ; now long chambers provided with a series of rollers, and with requisite means for steam control, are used ; it must be remarked that colors obtained upon cloth rapidly aged do not compare in fastness with those ob- tained upon cloth slowly aged. Dunging is merely a transmission of the aged cloth through solutions of phosphate, arseniate, or silicate of soda, these chemicals having displaced the somewhat offensive cow-dung in the operations of precipitating the mordant upon the fibre, and also to remove the thickening and excess of mordant, after which the cloth is well washed and then dyed. The dye-bath is made up with alizarin, alizarin oil, tannin, etc., in a similar manner to that described under Dyeing (p. 462), after which the cloth washed, worked in alizarin oil, dried, and steamed, then washed and soaped. In case reds have been dyed, and it is desirable to reduce their tone, " cutting" is resorted to after the soaping, by means of a solution of stannic chloride. Resists are substances printed upon the fabric which will prevent the fix- ation of color at those places, and are of two kinds, chemical and mechanical ; the former are composed chiefly of citric acid, while the latter are made up of some inert substances, such as pipe-clay, beeswax, etc. Discharges are sub- stances printed upon goods, the whole of which had been mordanted, the object being to remove the mordant from such places where whites are to appear, consequently when the piece is dyed only where the mordant is intact will the cloth be colored ; these discharges are made principally with citric acid. 6. Turkey-red Styles. This process is simply printing upon cloth which has been previously dyed Turkey-red (see p. 462) by means of discharges, which may or may not be made so as to yield colored patterns. The base is citric or tartaric acid, thickened with a suitable paste, and if for colors, containing a salt of lead, if for a yellow discharge, or ferro-prussiate of potash, for a blue discharge, or iron and logwood, for a black discharge. After printing on the discharges, the goods are passed through a bath of bleaching-powder, well washed, and then, if lead has been printed on, passed through a bath of bichromate of potash, when chrome yellow will be produced. If the prussiate of potash has been printed, a blue color will be developed. Green is obtained by mixing both discharges first. 7. Indigo Styles are similar to the above ; resists are printed on the cloth, which is then dyed in the vat in the ordinary manner, when, upon a removal of the resist by suitable means, white patterns are had upon a blue ground. By the system of discharges various colors may be put on by means of lead and other metallic salts. Vermilion is applied directly with albumen. For a discharge which has to be afterwards dyed red with alizarin, bromide of manganese and an aluminum salt are used. BIBLIOGRAPHY. 475 8. Manganese Bronze Style, or Bistre Style. This process has for its ob- ject the production of hydrated peroxide of manganese upon the fibre, and the subsequent printing of colors by means of discharges. The goods are worked in a solution of manganous chloride, dried, and worked in soda lye, washed, and passed through a solution of chloride of lime until a brown color is produced. Wash, dry, and the goods are ready for printing. A discharge for white is made with muriate of tin (120 Tw.) ; for blue, yellow prussiate of potash with an organic acid ; for yellow, a lead salt, developed with bichromate of potash. Green and black as in the previous style. Woollen- and Silk-printing. Wool, either as yarn or fabric, is generally printed with the tar colors, and according to the steam style previously de- scribed. The goods are dried after printing, steamed for one hour, and well washed. Silk is printed in the same style after being prepared by suitable agents, such as tin with or without an acid. Previous to being printed both silk and wool must be entirely free from grease. Bibliography. 1864. Dictionary of Calico-Printing and Dyeing, C. O'Neill, London. 1873. Die Farbstoffe und ihre Anwendung, P. Schutzenberger, Berlin. 1874. Die Prufung der Zeugfarben, W. Stein. Hand-book of Dyeing and Calico-Printing, W. Crookes, London. Anilin-Farberei, A. Beckers, 5te Auf., von M. Reimann, Berlin. 1875. Die Colorie der Baumwolle, C. Romen, Berlin. Manual of Dyeing and Dyeing Receipts, Napier, London. 1876. Dyeing and Calico-Printing, Grace Calvert, Manchester. Cantor Lectures on Wool-Dyeing, G. Jarmain, London. 1877. Traite de la Teinture des Soies, M. Moyret, Lyons. Die Seidenfarberei, Werner Schmid. Die cheraische Bearbeitung der Schafwolle, V. Joclet, Vienna. 1878. Le Conditionnement de la Soie, Jules Persoz, Paris. Handbuch der Bleichkunst. Victor Joclet, Vienna. Calico-Printing, Bleaching, and Dyeing, C. O'Neill, London. The American Dyer, by Gibson, Boston. 1879. Die Woll- und Seidendruckerei, Victor Joclet, Vienna. Handbuch der Seidenfarberei, Philip David. Bleicherei, Farberei und Appretur, C. Romen, Berlin. 1880. A System of Chemistry applied to Dyeing, Jas. Napier, Philadelphia. 1881. The Art of Dyeing, Cleaning, and Scouring, Thos. Love, 2d ed., Philadelphia. 1882. Die Technologic der Gespinnstfasern, 2 Bde., H. Grothe, Berlin. The English Dyer, David Smith, Manchester. Die Wascherei, Bleicherei und Farberei von Wollengarnen, R. Sachse, Leipzig. , Manual of Colors and Dye-wares, J. W. Slater, London. Dyeing and Tissue-Printing, W. Crookes, London. 1883. La Teinture du Coton, A. Renard, Paris. 1884. Bleaching, Dyeing, and Calico-Printing, J. Gardner, London. Bleaching, Dyeing, and Calico-Printing, F. J. Bird, London. Die Bleicherei, Druckerei, Farberei, etc., der baumwollenen Gewebe, G. Stein, Braunschweig. Die praktische Anwendung der Theerfarben in der Industrie, E. J. Hodl, Vienna. 1885. The Dyeing of Textile Fabrics, J. J. Hummel, London. Die Beizen, ihre Darstellung, etc., H. Wolff, Vienna. Die Gesammte Indigo-Kupenblau Farberei, etc., E. Rudolf. 1886. Praktische Anleitung zur Bleicherei, etc., von Jutestoffen, R. Ernst. Die Appretur-Mittel und ihre Anwendung, F. Polleyn, Vienna. 1887. Teinture et Apprets des Tissus de Coton, L. Lefebre, Paris. The Printing of Cotton Fabrics, A. Sansone, Manchester. 1888. Dyeing, A. Sansone, 2 vols., Manchester. Praktische Handbuch der Zeugdrucks, E. Lauber. 1889. Das Farben und Bleichen von Baumwolle, Wolle, Seide, Jute, etc., J. Herzfeld, Berlin. Handbuch der Farberei, Dr. A. Ganswindt, Weimar. 1891. Traite de la Teinture et de PImpression, lere partie, J. Depierre, Miilhausen. APPENDIX. I. The Metric System. THE French metric system is based upon the idea of employing, as the unit of all measures, whether of length, capacity, or weight, a uniform un- changeable standard, adopted from nature, the multiples and subdivisions of which should follow in decimal progression. To obtain such a standard, the length of one-fourth part of the terrestrial meridian, extending from the equator to the pole, was ascertained. The ten-millionth part of this arc was chosen as the unit of measures of length, and was denominated metre. The cube of the tenth part of the metre was taken as the unit of measures of capacity, and denominated litre. The weight of distilled water, at its greatest density, which this cube is capable of containing, was called kilo- gramme, of which the thousandth part was adopted as the unit of weight, under the name of gramme. The multiples of these measures, proceeding in a decimal progression, are distinguished by employing the prefixes, deca, hecto, Idlo, and myria, taken from the Greek numerals; and the sub- divisions, following the same order, by deci, centi, milli, from the Latin numerals. Since the introduction of this system it has been adopted by the principal nations of Europe, excepting Great Britain, and in many of them its use is compulsory. It is in general use in France, Germany, Aus- tria, Italy, Spain, Norway, Sweden, Netherlands, Switzerland, Greece, and British India. It was legalized in Great Britain in 1864, and in the United States by an act of Congress in 1866. The metre, or unit of length, at 32, = 39.370432 inches. The litre, or unit of capacity, = 33.816 fluidounces. U. S. The gramme, or unit of weight, = 15.43,234874 Troy grains. Upon this basis the following tables have been constructed : MEASURES OF LENGTH. English inches. Millimetre (mm.) == .03937 Centimetre (cm.) ' = .39370 Decimetre (dm.) = 3.93704 Metre (m.) = 39.37043 English inches. Decametre (Dm.) = 393.70432 Hectometre (Hm.) = 3937.04320 Kilometre (Km.) = 39370.43200 Myriametre (Mm.) = 393704.32000 477 478 Millilitre (ml.) Centilitre (cl.) Decilitre (dl.) Litre (1.) APPENDIX. MEASURES OF CAPACITY. English cubic inches. .061028 .610280 6.102800 61.028000 Decalitre (Dl.) Hectolitre ( HI.) Kilolitre (Kl.) Myrialitre (Ml.) English cubic inches. 610.280000 6102.800000 61028.000000 610280.000000 MEASURES OF WEIGHT. Milligramme (mg.) = Centigramme (eg.) = Decigramme (dg.) = Gramme (gm.) = Troy grains. .0154 .1543 1.5432 15.4323 Decagramme (Dg.) = Hectogramme (Hg.) = Kilogramme (Kg.) = Myriagramme (Mg.) = Troy grains. 154.3234 1543.2348 15432.3487 154323.4874 Value of Avoirdupois Weights and Imperial Measures, in Metric Weights and Measures, as stated in the British Pharmacopoeia. Avoirdupois weights. 1 pound = 1 ounce = 1 grain = Metric weights. 453.5925 grammes. 28.3495 " 0.0648 " Imperial measures. 1 gallon 1 pint 1 fluidounce 1 fluidrachm 1 minim Metric measures. 4.543487 litres. 0.567936 " 0.028396 " 0.003549 " 0.000059 " n. Tables for Determination of Temperature. RELATIONS BETWEEN THERMOMETERS. In Fahrenheit's thermometer, the freezing-point of water is placed at 32, and the boiling-point at 212, and the number of intervening degrees is 180. The Centigrade or Celsius's thermometer, which is now recognized in the U. S. Pharmacopoeia and has been adopted generally by scientists, marks the freezing-point zero, and the boiling-point 100. From the above statement, it is evident that 180 degrees of Fahrenheit are equal to 100 of the Centigrade, or one degree of the first is equal to | of a degree of the second. It is easy, therefore, to convert the degrees of one into the equivalent number of degrees of the other ; but in ascertaining the corresponding points upon the different scales, it is necessary to take into consideration their different modes of graduation. Thus, as the zero of Fahrenheit is 32 below the point at which that of the Centigrade is placed, this number must be taken into account in the calculation. 1 . If any degree on the Centigrade scale, either above or below zero, be multiplied by 1.8, the result will, in either case, be the number of degrees above or below 32, or the freezing-point of Fahrenheit. 2. The number of degrees between any point of Fahrenheit's scale and 32, if divided by 1.8, will give the corresponding point on the Centigrade. APPENDIX. 479 THERMOMETRIC EQUIVALENTS. ACCORDING TO THE CENTIGRADE AND FAHRENHEIT SCALES. c. F. C. F. C F. C" 1 F. C. F. 39.4 39 17.2 1 5 41 27.2 81 49.4 121 39 38.2 17 1.4 5.5 42 27.7 82 50 122 38.8 38 16.6 2 6 42.8 28 82.4 50.5 123 38.3 37 16.1 3 6.1 43 28.3 83 51 123.8 -38 36.4 16 3.2 6.6 44 28.8 84 51.1 124 37.7 36 15.5 4 7 44.6 29 84.2 51.6 125 37.2 35 15 5 7.2 45 29.4 85 52 125.6 37 34.6 14.4 6 7.7 46 30 86 52.2 126 36.6 34 14 6.8 8 46.4 30.5 87 52.7 127 36.1 33 13.8 7 8.3 47 31 87.8 53 127.4 36 -32.8 13.3 8 8.8 48 31.1 88 53.3 128 35.5 32 13 8.6 9. 48.2 31.6 89 53.8 129 35 31 12.7 9 9.4 49 32 89.6 54 129.2 34.4 -30 12.2 10 10 50 32.2 90 54.4 130 34 29.2 12 10.4 10.5 51 32.7 91 55 131 33.8 29 11.6 11 11 51.8 33 91.4 55.5 132 33.3 28 11.1 12 11.1 52 33.3 92 56 132.8 33 27.4 11 12.2 11.6 53 33.8 93 56.1 133 32.7 27 10.5 13 12 53.6 34 93.2 56.6 134 32.2 26 10 14 12.2 54 34.4 94 57 134.6 32 25.6 9.4 15 12.7 55 35 95 57.2 135 31.6 25 9 15.8 13 55.4 35.5 96 57.7 136 31.1 24 8.8 16 13.3 56 36 96.8 58 136.4 31 23.8 8.3 17 13.8 57 36.1 97 58.3 137 30.5 23 8 17.6 14 57.2 36.6 98 58.8 138 30 22 7.7 18 14.4 58 37 98.6 59 138.2 29.4 21 7.2 19 15 59 37.2 99 59.4 ' 139 29 20.2 7 19.4 15.5 60 37.7 100 60 140 28.8 20 6.6 20 16 60.8 38 100.4 60.5 141 28.3 19 6.1 21 16.1 61 38.3 101 61 141.8 28 18.4 6 21.2 16.6 62 38.8 102 61.1 142 27.7 18 5.5 22 17 62.6 39 102.2 61.6 143 27.2 17 5 23 17.2 63 39.4 103 62 143.6 27 16.6 4.4 24 17.7 64 40 104 62.2 144 26.6 16 4 24.8 18 64.4 40.5 105 62.7 145 26.1 15 3.8 25 18.3 65 41 105.8 63 145.4 26 14.8 3.3 26 18.8 66 41.1 106 63.3 146 25.5 14 3 26.6 19 66.2 41.6 107 63.8 147 25 13 2.7 27 19.4 67 42 107.6 64 147.2 24 .4 12 2.2 28 20 68 42.2 108 64.4 148 24 11.2 2 28.4 20.5 69 42.7 109 65 149 23.8 11 1.6 29 21 69.8 43 109.4 65.5 150 23.3 10 1.1 30 21.1 70 43.3 110 66 150.8 23 9.4 1 30.2 21.6 71 43.8 111 66.1 151 22.7 9 0.5 31 22 71.6 44 111.2 66.6 152 22.2 8 32 22.2 72 44.4 112 67 152.6 22 7.6 0.5 33 22.7 73 45 113 67.2 153 21.6 7 1 33.8 23 73.4 45.5 114 67.7 154 21.1 6 1.1 34 23.3 74 46 114.8 68 154.4 21 5.8 1.6 35 23.8 75 46.1 115 68.3 155 20.5 5 2 35.6 24 75.2 46.6 116 68.8 156 20 4 2.2 36 24.4 76 47 116.6 69 156.2 19.4 3 2.7 37 25 77 47.2 117 69.4 157 19 -2.2 3 37.4 25.5 78 47.7 118 70 158 18.8 , 2 3.3 38 26 78.8 48 118.4 70.5 159 18.3* 1 3.8 39 26.1 79 48.3 119 71 159.8 18 0.4 4. 39.2 26.6 80 48.8 120 71.1 160 17.7 4.4 40 27 80.6 49 120.2 71.6 161 480 APPENDIX. Thermometric Equivalents. Cont i n ued. c. P. C. F. C. F. C. F. C. F. 72 161.6 95.5 204 118.8 246 142.2 288 166 330.8 72.2 162 96 204.8 119 246.2 142.7 289 166.1 331 72.7 163 96.1 205 119.4 247 143 289.4 166.6 332 73 163.4 96.6 206 120 248 143.3 290 167 332.6 73.3 164 97 206.6 120.5 249 143.8 291 167.2 333 73.8 165 97.2 207 121 249.8 144 291.2 167.7 334 74 165.2 97.7 208 121.1 250 144.4 292 168 334.4 74.4 166 98 208.4 121.6 251 145 293 168.3 335 75 167 98.3 209 122 251.6 145.5 294 168.8 336 75.5 168 98.8 210 122.2 252 146 294.8 169 336.2 76 168.8 99 210.2 122.7 253 146.1 295 169.4 337 76.1 169 99.4 211 123 253.4 146.6 296 170 338 76.6 170 100 212 123.3 254 147 296.6 170.5 339 77 170.6 100.5 213 123.8 255 147.2 297 171 339.8 77.2 171 101 213.8 124 255.2 147.7 298 171.1 340 77.7 172 101.1 214 124.4 256 148 298.4 171.6 341 78 172.4 101.6 215 125 257 148.3 299 172 341.6 78.3 173 102 215.6 125.5 258 148.8 300 172.2 342 78.8 174 102.2 216 126 258.8 149 300.2 172.7 343 79 174.2 102.7 217 126.1 259 149.4 301 173 343.4 79.4 175 103 217.4 126.6 260 150 302 173.3 344 80 176 103.3 218 127 260.6 150.5 303 173.8 345 80.5 177 103.8 219 127.2 261 151 303.8 174 345.2 81 177.8 104 219.2 127.7 262 151.1 304 174.4 346 81.1 178 104.4 220 128 262.4 151.6 305 175 347 81.6 179 105 221 128.3 263 152 305.6 175.5 348 82 179.6 105.5 222 128.8 264 152.2 306 176 348.8 82.2 180 106 222.8 129 264.2 152.7 307 176.1 349 82.7 181 106.1 223 129.4 265 153 307.4 176.6 350 83 181.4 106.6 224 130 266 153.3 308 177 350.6 83.3 182 107 224.6 130.5 267 153.8 309 177.2 351 83.8 183 107.2 225 131 267.8 154 309.2 177.7 352 84 183.2 107.7 226 131.1 268 154.4 310 178 352.4 84.4 184 108 226.4 131.6 269 155 311 178.3 353 85 185 108.3 227 132 269.6 155.5 312 178.8 354 85.5 186 108.8 228 132.2 270 156 312.8 179 354.2 86 186.8 109 228.2 132.7 271 156.1 313 179.4 355 86.1 187 109.4 229 133 271.4 156.6 314 180 356 86.6 188 110 230 133.3 272 157 314.6 180.5 357 87 188.6 110.5 231 133.8 273 157.2 315 181 357.8 87.2 189 111 231.8 134 273.2 157.7 316 181.1 358 87.7 190 111.1 232 134.4 274 158 316.4 181.6 359 88 190.4 111.6 233 135 275 158.3 317 182 359.6 88.3 191 112 233.6 135.5 276 158.8 318 182.2 360 88.8 192 112.2 234 136 276.8 159 318.2 182.7 361 89 192.2 112.7 235 136.1 277 159.4 319 183 361.4 89.4 193 113 235.4 136.6 278 160 320 183.3 362 90 194 113.3 236 137 278.6 160.5 321 183.8 363 90.5 195 113.8 237 137.2 279 161 321.8 184 363.2 91 195.8 114 237.2 137.7 280 161.1 322 184.4 364 91.1 196 114.4 238 138 280.4 161.6 323 185 365 91.6 197 115 239 138.3 281 162 323.6 185.5 366 92 197.6 115.5 240 138.8 282 162.2 324 186 366.8 92.2 198 116 240.8 139 282.2 162.7 325 186.1 367 92.7 199 116.1 241 139.4 283 163 325.4 186.6 368 93 199.4 116.6 242 140 284 163.3 326 187 368.6 93.3 200 117 242.6 140.5 285 163.8 327 187.2 369 93.8 201 117.2 243 141 285.8 164 327.2 187.7 370 94 201.2 117.7 244 141.1 286 164.4 ,328 188 370.4 94.4 202 118 244.4 141.6 287 165 329 188.3 371 95 203 118.3 245 142 287.6 165.5 330 188.8 372 APPENDIX. Tliemnometric Equivalents. Continued. 481 c. P. C. F. C. F. C. P. C. F. 189 372.2 211.6 413 233.8 453 256.1 493 278.3 533 189.4 373 212 413.6 234 453.2 256.6 494 278.8 534 190 374 212.2 414 234.4 454 257 494.6 279 534.2 190.5 375 212.7 415 235 455 257.2 495 279.4 535 191 375.8 213 415.4 235.5 456 257.7 496 280 536 191.1 376 213.3 416 236 456.8 258 496.4 280.5 537 191.6 377 213.8 417 236.1 457 258.3 497 281 537.8 192 377.6 214 417.2 236.6 458 258.8 498 281.1 538 192.2 378 214.4 418 237 458.6 259 498.2 281.6 539 192.7 379 215 419 237.2 459 259.4 499 282 539.6 193 379.4 215.5 420 237.7 460 260 500 282.2 540 193.3 380 216 420.8 238 460.4 260.5 501 282.7 541 193.8 381 216.1 421 238.3 461 261 501.8 283 541.4 194 381.2 216.6 422 238.8 462 261.1 502 283.3 542 194.4 382 217 4226 239 462.2 261.6 503 283.8 543 195 383 217.2 423 239.4 463 262 503.6 284 5432 195.5 384 217.7 424 240 464 262.2 504 284.4 544 196 384.8 218 424.4 240.5 465 262.7 505 285 545 196.1 385 218.3 425 241 465.8 263 505.4 285.5 546 196.6 386 218.8 426 241.1 466 263.3 506 286 546.8 197 386.6 219 426.2 241.6 467 263.8 507 286.1 547 197.2 387 219.4 427 242 467.6 264 507.2 286.6 548 197.7 388 220 428 242.2 468 264.4 508 287 548.6 198 388.4 220.5 429 242.7 469 265 509 287.2 549 198.3 389 221 429.8 243 469.4 265.5 510 287.7 550 198.8 390 221.1 430 243.3 470 266 510.8 288 550.4 199 390.2 221.6 431 243.8 471 266.1 511 288.3 551 199.4 391 222 431.6 244 471.2 266.6 512 288.8 552 200 392 222.2 432 2444 472 267 512.6 289 552.2 200.5 393 222.7 433 245 473 267.2 513 289.4 553 201 393.8 223 433.4 j 245.5 474 267.7 614 290 554 201.1 394 223.3 434 246 474.8 268 514.4 290.5 555 201.6 395 223.8 435 246.1 475 268.3 515 291 555.8 202 395.6 224 435.2 246.6 476 268.8 516 291.1 556 202.2 396 224.4 436 247 476.6 269 516.2 291.6 557 202.7 397 225 437 247.2 477 269.4 517 292 557.6 203 397.4 225.5 438 247.7 478 270 518 292.2 558 203.3 398 226 438.8 248 478.4 270.5 519 292.7 559 203.8 399 226.1 439 248.3 479 271 519.8 293 559.4 204 399.2 226.6 440 248.8 480 271.1 520 293.3 560 204.4 400 227 440.6 249 480.2 271.6 521 293.8 561 205 401 227.2 441 249.4 481 272 521.6 294 561.2 205.5 402 227.7 442 250 482 272.2 522 294.4 562 206 402.8 228 442.4 250.5 483 272.7 523 295 663 206.1 403 228.3 443 251 483.8 273 523.4 295.5 564 206.6 404 228.8 444 251.1 484 273.3 524 296 564.8 207 404.6 229 444.2 251.6 485 273.8 525 296.1 565 207.2 405 229.4 445 252 485.6 274 525.2 296.6 566 207.7 406 230 446 252.2 486 274.4 526 297 566.6 208 406.4 230.5 447 252.7 487 275 527 297.2 567 208.3 407 231 447.8 253 487.4 275.5 528 297.7 568 208.8 408 231.1 448 253.3 488 276 528.8 298 568.4 209 408.2 231.6 449 253.8 489 276.1 529 298.3 569 209.4 409 232 449.6 254 489.2 276.6 530 298.8 570 210 410 232.2 450 254.4 490 277 530.6 299 570.2 210.5 411 232.7 451 255 491 277.2 531 299.4 571 211 411.8 233 451.4 255.5 492 277.7 532 300 572 211.1 412 233.3 452 256 492.8 278 532.4 31 482 APPENDIX. m. Specific Gravity Tables. 1. Beaum&s Scale for Liquids Lighter than Water. The following table is calculated for a temperature of 17.5 C. (63.5 F.), and 'is based on the formulas = specific gravity and B.+130 J specific gravity 130 = B. Degree Baum6. Specific gravity. Degree Baume. Specific gravity. Degree r.iimnt''. Specific gravity. Degree Baume. Specific gravity. 10 1.0000 33 0.8588 56 0.7526 79 0.6698 11 0.9929 34 0.8536 57 0.7486 80 0.6666 12 0.9859 35 0.8484 58 0.7446 81 0.6635 13 0.9790 36 0.8433 59 0.7407 82 0.6604 14 0.9722 37 0.8383 60 0.7368 83 0.6573 15 0.9655 38 0.8333 61 0.7329 84 0.6542 16 0.9589 39 0.8284 62 0.7290 85 0.6511 17 0.9523 40 0.8235 63 0.7253 86 0.6482 18 0.9459 41 0.8187 64 0.7216 87 0.6452 19 0.9395 42 0.8139 66 0.7179 88 0.6422 20 0.9333 43 0.8092 66 0.7142 89 0.6393 21 0.9271 44 0.8045 67 0.7106 90 0.6363 22 0.9210 45 0.8000 68 0.7070 91 0.6335 . 23 0.9150 46 0.7954 69 0.7035 92 0.6306 24 0.9090 47 0.7909 70 0.7000 93 0.6278 25 0.9032 48 0.7865 71 0.6965 94 0.6250 26 0.8974 49 0.7821 72 0.6931 95 0.6222 27 0.8917 60 0.7777 73 0.6896 96 0.6195 28 0.8860 51 0.7734 74 0.6863 97 0.6167 29 0.8805 52 0.7692 75 0.6829 98 0.6140 30 0.8750 53 0.7650 76 0.6796 99 0.6113 31 0.8695 54 0.7608 77 0.6763 100 0.607 32 0.8641 55 0.7567 78 0.6731 The coefficient of expansion of petroleum oils for increase or decrease of 1 C. in temperature has been determined for both Russian and American oils. For the latter the following figures have been given (Iron Age, xxxviii. No. 7) : Specific gravity at 15 C. (59 F.). Coefficient of expansion for 1 C. Under 0.700 0.00090 0.700 to 0.750 ... 0.00085 0.750 to 0.800 O.OOOSO 0.800 to 0.815 0.00070 Over 0.815 . 0.00065 As stated in the text (p. 33), it is customary in practice to take as the coefficient of expansion 0.004 for every 10 F. (0.00072 for 1 C.). APPENDIX. 483 2. Baume and Beck's Scales for Liquids Heavier* than Water. u> 1 Baume , 17.5 C. Rational Baume scale, 12.5 C. Beck, 12.5 C. Q Baume, 17.5 C. Rational Baume scale, 12.5 C. Beck, 12.5 C. Sp. gr. Sp. gr. Sp. gr. Sp. gr. Sp. gr. Sp. gr. 1.0000 1.0000 1.0000 37 1.3370 1.3447 1.2782 1 1.0068 1.0069 1.0059 38 1.3494 1.3574 1.2879 2 1.0138 1.0140 1.0119 39 1.3619 1.3703 1.2977 3 1.0208 1.0212 1.0180 40 1.3746 1.3834 1.3077 4 1.0280 1.0285 1.0241 41 1.3876 1.3968 1.3178 5 1.0353 1.0358 1.0303 42 1.4009 1.4105 1.3281 6 1.0426 1.0434 1.0366 43 1.4143 1.4244 1.3386 7 1.0501 1.0509 1.0429 44 1.4281 1.4386 1.3492 8 1.0576 1.0587 1.0494 45 1.4421 1.4531 1.3600 9 1.0653 1.0665 1.0559 46 1.4564 1.4678 1.3710 10 1.0731 1.0745 1.0625 47 1.4710 1.4828 1.3821 11 1.0810 1.0825 1.0692 48 1.4860 1.4984 1.3934 12 1.0890 1.0907 1.0759 49 1.5012 1.5141 1.4050 13 1.0972 1.0990 1.0828 50 1.5167 1.5301 1.3167 14 1.1054 1.1074 1.0897 51 1.5325 1.5466 1.4286 15 1.1138 1.1160 1.0968 52 1.5487 1.5633 1.4407 16 1.1224 1.1247 1.1031 53 1.5652 1.5804 1.4530 17 1.1310 1.1335 1.1119 54 1.5820 1.5978 1.4655 18 1.1398 1.1425 1.1184 55 1.5993 1.6158 1.4783 19 1.1487 1.1516 1.1258 56 1.6169 1.6342 1.4912 20 1.1578 1.1608 1.1333 57 1.6349 1.6529 1.5044 21 1.1670 1.1702 1.1409 58 1.6533 1.6720 1.5179 22 1.1763 1.1798 1.1486 59 1.6721 1.6916 1.5315 23 1.1858 1.1896 1.1565 60 1.6914 1.7116 1 5434 24 1.1955 1.1994 1.1644 61 1.7111 1.7322 1.5596 25 1.2053 1.2095 1.1724 62 1.7313 1.7532 1.6741 26 1.2153 1.2198 1.1806 63 1.7520 1.7748 1.5888 27 1.2254 1.2301 1.1888 64 1.7731 1.7960 1.6038 28 1.2357 1.2407 1.1972 65 1.7948 1.8195 1.6190 29 1.2462 1.2515 1.2057 66 1.8171 1.8428 1.6346 30 1.2569 1.2624 1.2143 67 1.8398 1.839 1.6505 31 1.2677 1.2736 1.2230 68 1.8632 1.864 1.6667 32 1.2788 1.2849 1.2319 69 1.8871 1.885 1.6832 33 1.2901 1.2965 1.2409 70 1.9117 1.909 1.7000 34 1.3015 1.3082 1.2500 71 1.9370 1.935 1.7272 35 1.3131 1.3202 1.2593 72 1.9629 1.960 1.7347 36 1.3250 1.3324 1.2687 What is known as the " Rational" Baum6 scale is calculated by taking water at the temperature chosen at B. and sulphuric acid of 1.842 specific gravity at 66 B. and using the formula - =d. (See ATI*TO '" ' 7t Lunge's " Sulphuric Acid and Alkali," vol. i. p. 20.) 484 APPENDIX. 3. Twaddle's Scale for Liquids Heavier than Water. .0 oti B tf >> ri .r? ge o >, >. .4 o S.2 c > 1 > a i > SS a. bo OQ Twaddle. oJ 1 8 g '? O 03 |6 DO Twaddle. Baume. o '> 5 v 2 Oita 02 1.000 44 26.0 1.220 88 44.1 1.440 131 57.1 1.655 1 0.7 1.005 45 26.4 1.225 89 44.4 1.445 132 57.4 1.660 2 1.4 1.010 46 26.9 1.230 90 44.8 1.450 133 57.7 1.665 3 2.1 1.015 47 27.4 1.235 91 45.1 1.455 134 57.9 1.670 4 2.7 1.020 48 27.9 1.240 92 45.4 1.460 135 58.2 1.675 6 3.4 1.025 49 28.4 1.245 93 45.8 1.465 136 58.4 1.680 6 4.1 1.030 50 28.8 1.250 94 46.1 1.470 137 58.7 1.685 7 4.7 1.035 51 29.3 1.255 95 46.4 1.475 138 58.9 1.690 8 5.4 1.040 52 29.7 1.260 96 46.8 1.480 139 59.2 1.695 9 6.0 1.045 53 30.2 1.265 97 47.1 1.485 140 59.5 1.700 10 6.7 1.050 54 30.6 1.270 98 47.4 1.490 141 59.7 1.705 11 7.4 1.055 55 31.1 1.275 99 47.8 1.495 142 60.0 1.710 12 8.0 1.060 56 31.5 1.280 100 48.1 1.500 143 60.2 1.715 13 8.7 1.065 57 32.0 1.285 101 48.4 1.505 144 60.4 1.720 14 9.4 1.070 58 32.4 1.290 102 48.7 1.510 145 606 1.725 15 10.0 1.075 59 32.8 1.295 103 49.0 1.515 146 60.9 1.730 16 10.6 1.080 60 33.3 1.300 104 49.4 1.520 147 61.1 1.735 17 11.2 1.085 61 33.7 1.305 105 49.7 1.525 148 61.4 1.740 18 11.9 1.090 62 34.2 1.310 106 50.0 1.530 149 61.6 1.745 19 12.4 1.095 63 34.6 1.315 107 50.3 1.535 150 61 8 1.750 20 13.0 1.100 64 35.0 1.320 108 50.6 1.540 151 62.1 1.755 21 13.6 1.105 65 35.4 1.325 109 50.9 1.545 152 62.3 1.760 22 14.2 1.110 66 35.8 1.330 110 51.2 1.550 153 62.5 1.765 23 14.9 1.115 67 36.2 1.335 111 51.5 1.555 154 62.8 1.770 24 15.4 1.120 68 36.6 1.340 112 51.8 1.560 155 63.0 1.775 25 16.0 1.125 69 37.0 1.345 113 52.1 1.565 156 63.2 1.780 26 16.5 1.130 70 37.4 1350 114 52.4 1.570 157 63.5 1.785 27 17.1 1.135 71 37.8 1.355 115 52.7 1.575 158 63.7 1.790 28 17.7 1.140 72 38.2 1.360 116 53.0 1.580 159 64.0 1.795 29 18.3 1.145 73 38.6 1.365 117 53.3 1.585 160 64.2 1.800 30 18.8 1.150 74 39.0 1.370 118 53.6 1.590 161 64.4 1.805 31 19.3 1.155 75 39.4 1.375 119 53.9 1.595 162 64.6 1.810 32 19.8 1.160 76 39.8 1.380 120 54.1 1.600 163 64.8 1.815 33 20.3 1.165 77 40.1 1.385 121 54.4 1.605 164 65.0 1.820 34 20.9 1.170 78 40.5 1.390 122 54.7 1.610 165 65.2 1.825 35 21.4 1.175 79 40.8 1.395 123 55.0 1.615 166 65.5 1.830 36 22.0 1.180 80 41.2 1.400 124 55.2 1.620 167 65.7 1.835 37 22.5 1.185 81 41.6 1.405 125 55.5 1.625 168 65.9 1.840 38 23.0 1.190 82 42.0 1.410 126 55.8 1.630 169 66.1 1.845 39 23.5 1.195 83 42.3 1.415 127 56.0 1.635 170 66.3 1.850 40 24.0 1.200 84 42.7 1.420 128 56.3 1.640 171 66.5 1.855 41 24.5 1.205 85 43.1 1.425 129 56.6 1.645 172 66.7 1.860 42 25.0 1.210 86 43.4 1.430 130 56.9 1.650 173 67.0 1.865 43 25.5 1.215 87 43.8 1.435 486 APPENDIX. 5. Comparison of Gay-Lussac Scale with Absolute Specific Gravity Figures. Degree. Specific gravity, Gay-Lussac. Degree. Specific gravity, Gay-Lussac. Degree. Specific gravity, Gay-Lussac. Degree. Specific gravity, Gay-Lussac. 50 2.0000 76 1.3158 102 0.9804 127 0.7874 51 1.9608 77 1.2987 103 0.9709 128 0.7813 52 1.9231 78 1.2821 104 0.9615 129 0.7752 53 1.8868 79 1.2658 105 0.9524 130 0.7692 54 1.8519 80 1.2500 106 0.9434 131 0.7634 55 1.8182 81 1.2346 107 0.9346 132 0.7576 66 1.7857 82 1.2195 108 0.9259 133 0.7519 57 1.7544 83 1.2048 109 0.9174 134 0.7463 58 1.7241 84 1.1905 110 0.9091 135 0.7408 59 1.6949 85 1.1765 111 0.9009 136 0.7353 60 1.6667 86 1.1628 112 0.8929 137 0.7299 61 1.6393 87 1.1494 113 0.8850 138 0.7246 62 1.6129 88 1.1364 114 0.8772 139 0.7194 63 1.5873 89 1.1236 115 0.8696 140 0.7143 04 1.6625 90 1.1111 116 0.8621 141 0.7092 65 1.5385 91 1.0989 117 0.8547 142 0.7042 66 1.5152 92 1.0870 118 0.8475 143 0.6993 67 1.4925 93 1.0753 119 0.8403 144 0.6944 68 1.4706 94 1.0638 120 0.8333 145 0.6897 69 1.4493 95 1.0526 121 0.8264 146 0.6850 70 1.4286 96 1.0417 122 0.8197 147 0.6803 71 1.4085 97 1.0309 123 0.8130 148 0.6757 72 1.3889 98 1.0204 124 0.8065 149 0.6711 73 1.3699 99 1.0101 125 0.8000 150 0.6667 74 1.3514 100 1.0000 126 0.7937 75 1.3333 101 0.9901 APPENDIX. 487 6. Comparison between Specific Gravity Figures, Degree Baume and Degree Brix (as used for su'gar solutions). Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. |I Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. -o 81 Id Q Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. aJ si g fl ! 0.0 1.00000 0.00 5.0 1.01970 2.84 10.0 1.04014 5.67 0.1 1.00038 0.06 5.1 1.02010 2.89 10.1 1.04055 5.72 0.2 1.0007" 0.11 5.2 1.02051 2.95 10.2 1.04097 5.78 0.3 1.00116 0.17 6.3 1.02091 3.01 10.3 1.04139 5.83 04 100155 0.23 5.4 1.02131 3.06 10.4 1.04180 5.89 0.5 1.00193 0.28 ' 5.5 1.02171 3.12 10.5 1.04222 5.95 0.6 1.00232 0.34 6.6 1.02211 3.18 10.6 1.04264 6.00 0.7 1.00271 0.40 6.7 1.02252 3.23 10.7 1.04306 6.06 08 1.00310 0.45 5.8 1.02292 3.29 10.8 1.04348 6.12 0.9 1.00349 0.51 5.9 1.02333 3.35 10.9 1.04390 6.17 1.0 1.00388 0.57 6.0 1.02373 3.40 11.0 1.04431 6.23 1.1 1.00427 0.63 6.1 1.02413 3.46 11.1 1.04473 6.29 1.2 1.00466 0.68 6.2 1.02454 3.52 11.2 1.04515 6.34 1.3 1.00505 0.74 6.3 1.02494 3.57 11.3 1.04557 6.40 1.4 1.00544 0.80 6.4 1.02535 3.63 11.4 1.04599 6.46 1.5 1.00583 0.85 6.6 1.02575 3.69 11.5 1.04641 6.51 1.6 1.00622 0.91 6.6 1.02616 3.74 11.6 1.04683 6.57 1.7 1.00662 0.97 6.7 1.02657 380 11.7 1.04726 6.62 1.8 1.00701 1.02 6.8 1.02697 3.86 11.8 1.04768 6.68 1.9 1.00740 1.08 6.9 1.02738 3.91 11.9 1.04810 6.74 2.0 1.00779 1.14 7.0 1.02779 3.97 12.0 1.04852 6.79 2.1 1.00818 1.19 7.1 1.02819 4.03 12.1 1.04894 6.85 2.2 1.00858 1.25 7.2 1.02860 4.08 12.2 1.04937 6.91 2.3 1.00897 1.31 7.3 1.02901 4.14 12.3 1.04979 6.96 2.4 1.00936 1.36 7.4 1.02942 4.20 VIA 1.05021 7.02 2.5 1.00976 1.42 7.5 1.02983 4.25 12.5 1.05064 7.08 2.6 1.01015 1.48 7.6 1.03024 4.31 12.6 1.05106 7.13 2.7 1.01055 1.63 7.7 1.03064 437 12.7 1.05149 7.19 2.8 1.01094 1.59 7.8 1.03105 4.42 12.8 1.05191 7.24 2.9 1.01134 1.65 7.9 1.03146 4.48 12.9 1.05233 7.30 8.0 1.01173 1.70 8.0 1.03187 4.53 13.0 1.05276 7.36 3.1 1.01213 1.76 8.1 1.03228 4.59 13.1 1.05318 7.41 3.2 1.01252 1.82 8.2 1.03270 4.65 13.2 1.05361 7.47 3.3 1.01292 1.87 8.3 1.03311 4.70 13.3 1.05404 7.53 3.4 1.01332 1.93 8.4 1.03352 4.76 13.4 1.05446 7.58 3.6 1.01371 1.99 8.5 1.03393 4.82 13.5 1.05489 7.64 3.6 1.01411 2.04 8.6 1.03434 4.87 13.6 1.05532 7.69 8.7 1.01451 2.10 8.7 1.03475 4.93 13.7 1.05574 7.75 3.8 1.01491 2.16 8.8 1.03517 4.99 13.8 1.05617 7.81 3.9 1.01531 2.21 8.9 1.03558 5.04 13.9 1.05660 7.86 4.0 1.01570 2.27 9.0 1.03599 5.10 14.0 1 05703 7.92 4.1 1.01610 2.33 9.1 1.03640 5.16 14.1 1.05746 7.98 4.2 1.01650 2.38 9.2 1.03682 6.21 14.2 1.05789 8.03 4.3 1.01690 2.44 9.3 1.03723 5.27 14.3 1.05831 8.09 4.4 1.01730 250 9.4 1.03765 5.33 14.4 1.05874 8.14 4.5 1.01770 2.55 9.6 1.03806 5.38 14.5 1.05917 8.20 4.6 1.01810 2.61 9.6 1.03848 5.44 14.6 1.05960 8.26 4.7 * 1.01850 2.67 9.7 1.03889 5.50 14.7 1.06003 8.31 4.8 1.01890 2.72 9.8 1.03931 5.55 14.8 1 06047 8.37 4.9 1.01930 2.78 9.9 1.03972 561 14.9 1 06090 8.43 488 APPENDIX. Comparison between Specific Gravity Figures, Degree Baume and Degree Brix. Continued. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. & |J Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. d ! V 3 P P Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Baum6. 15.0 1.06133 8.48 20.0 1.08329 11.29 25.0 1.10607 14.08 15.1 1.06176 8.54 20.1 1.08374 11.34 25.1 1.10653 14.13 15.2 1.06219 8.59 20.2 1.08419 11.40 25.2 1.10700 14.19 15.3 1.06262 8.65 20.3 1.08464 11.45 25.3 1.10746 14.24 15.4 1.06306 8.71 20.4 1.08509 11.51 25.4 1.10793 14.30 15.5 1.06349 8.76 20.5 1.08553 11 57 25.5 1.10839 14.35 15.6 1.06392 8.82 20.6 1.08599 11.62 25.6 1.10886 14.41 15.7 1.06436 8.88 20.7 1.08643 11.68 25.7 1.10932 14.47 15.8 1.06479 8.93 20.8 1.08688 11.73 25.8 1.10979 14.52 15.9 1.06522 8.99 20.9 1.08733 11.79 25.9 1.11026 14.68 16.0 1.06566 9.04 21.0 1.08778 11.85 26.0 1.11072 14.63 16.1 1.06609 9.10 21.1 1.08824 11.90 26.1 1.11119 14.69 16.2 1.06653 9.16 21.2 1.08869 11.96 26.2 1.11166 14.74 16.3 1.06696 9.21 21.3 1.08914 12.01 26.3 1.11213 14.80 16.4 1.06740 9.27 21.4 1.08959 12.07 26.4 1.11259 14.85 16.5 1.06783 9.33 21.5 1.09004 12.13 26.5 1.11306 14.91 16.6 1.06827 9.38 21.6 1.09049 12.18 26.6 1.11353 14.97 16.7 1.06871 9.44 21.7 1.09095 12.24 26.7 1.11400 15.02 16.8 1.06914 9.49 21.8 1.09140 12.29 26.8 1.11447 15.08 16.9 1.06958 9.55 21.9 1.09185 12.35 26.9 1.11494 16.13 17.0 1.07002 9.61 22.0 1.09231 12.40 27.0 1.11541 15.19 17.1 1.07046 9.66 22.1 1.09276 12.46 27.1 1.11588 15.24 17.2 1.07090 9.72 22.2 1.09321 12.52 27.2 1.11635 15.30 17.3 1.07133 9.77 22.3 1.09367 12.57 27.3 1.11682 15.35 17.4 1.07177 9.83 22.4 1.09412 12.63 27.4 1.11729 15.41 17.5 1.07221 9.89 22.5 1.09458 12.68 27.5 1.11776 15.46 17.6 1.07265 9.94 22.6 1.09503 12.74 27.6 1.11824 15.52 17.7 1.07309 10.00 22.7 1.09549 12.80 27.7 1.11871 15.58 17.8 1.07358 10.06 22.8 1.09595 12.85 27.8 1.11918 15.63 17.9 1.07397 10.11 22.9 1.09640 12.91 27.9 1.11965 15.69 18.0 1.07441 10.17 23.0 1.09686 12.96 28.0 1.12013 16.74 18.1 1.07485 10.22 23.1 1.09732 13.02 28.1 1.12060 15.80 18.2 1.07530 10.28 23.2 1.09777 13.07 28.2 1.12107 15.85 18.3 1.07574 10.33 23.3 1.09823 13.13 28.3 1.12155 15.91 18.4 1.07618 10.39 23.4 1.09869 13.19 28.4 1.12202 15.96 18.5 1 07662 10.45 23.5 1.09915 13.24 28.5 1.12250 16.02 18.6 1.07706 10.50 23.6 1.09961 13.30 28.6 1.12297 16.07 18.7 1.07751 10.56 23.7 1.10007 13.35 28.7 1.12345 16.13 18.8 1.07795 10.62 23.8 1.10053 13.41 28.8 1.12393 16.18 18.9 1.07839 10.67 23.9 1.10099 1.3.46 28.9 1.12440 16.24 19.0 1.07884 10.73 24.0 1.10145 13.52 29.0 1.12488 16.30 19.1 1.07928 10.78 24.1 1.10191 13.58 29.1 1.12536 16.35 19.2 1.07973 10.84 24.2 1.10237 13.63 29.2 1.12583 16.41 19.3 1.08017 10.90 24.3 1.10283 13.69 29.3 1.12631 16.46 19.4 1.08062 10.95 24.4 1.10329 13.74 29.4 1.12679 16.52 19.5 1.08106 11.01 24.5 1.10375 13.80 29.5 1.12727 16.57 19.6 1.08151 11.06 24.6 1.10421 13.85 29.6 1.12775 16.63 19.7 1 08196 11.12 24.7 1.10468 13.91 29.7 1.12823 16.68 19.8 1.08240 11.18 24.8 1.10514 13.96 29.8 1.12871 16.74 19.9 1.0?285 11.27 24.9 1.10560 14.02 29.9 1.12919 16.79 APPENDIX. 489 Comparison between Specific Gravity Figures, Degree Baume and Degree Brix. Continued. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. 0,9 Q Percentage of sugar ac- cording to Bulling or degree Brix. Specific gravity. <3 oS 3 fcCflQ BW Q Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. -5 a) 9 ifl 30.0 1.12967 16.85 35.0 1.15411 19.60 40.0 1.17943 22.33 30.1 1.13015 16.90 35.1 1.15461 19.66 40.1 1.17995 22.38 30.2 1.13063 16.96 35.2 1.15511 19.71 40.2 1.18046 22.44 30.3 1.13111 17.01 35.3 1.15561 19.76 40.3 1.18098 22.49 30.4 1.13159 17.07 35.4 1.15611 19.82 40.4 1.18150 22.55 30.5 1.13207 17.12 35.5 1.15661 19.87 40.5 1.18201 22.60 30.6 1.13255 17.18 35.6 1.15710 19.93 40.6 1.18253 22.66 30.7 1.13304 17.23 35.7 1.15760 19.98 40.7 1.18305 22.71 30.8 1.13352 17.29 35.8 1.15810 20.04 40.8 1.18357 22.77 30.9 1.13400 17.35 35.9 1.15861 20.09 40.9 1.18408 22.82 31.0 1.13449 17.40 36.0 1.15911 20.15 41.0 1.18460 22.87 31.1 1.13497 17.46 36.1 1.15961 20.20 41.1 1.18512 22.93 31.2 1.13545 17.51 36.2 1.16011 20.26 41.2 1.18564 22.98 31.3 1.13594 17.57 36.3 1.16061 20.31 41.3 1.18616 23.04 31.4 1.13642 17.62 36.4 1.16111 20.37 41.4 1.18668 23.09 31.5 1.13691 17.68 36.5 1.16162 20.42 41.5 1.18720 23.15 31.6 1.13740 17.73 36.6 1.16212 20.48 41.6 1.18772 23.20 31.7 1.13788 17.79 36.7 1.16262 20.53 41.7 1.18824 23.25 31.8 1.13837 17.84 36.8 1.16313 20.59 41.8 1.18887 23.31 31.9 1.13885 17.90 36.9 1.16363 20.64 41.9 1.18929 23.36 32.0 1.13934 17.95 37.0 1.16413 20.70 42.0 1.18981 23.42 32.1 1.13983 18.01 37.1 1.16464 20.75 42.1 1.19033 23.47 32.2 1.14032 18.06 37.2 1.16514 20.80 42.2 1.19086 23.52 32.3 1.14081 18.12 37.3 1.16565 20.86 42.3 1.19138 23.58 32.4 1.14129 18.17 37.4 1.16616 20.91 42.4 1.19190 23.63 32.5 1.14178 18.23 37.5 1.16666 20.97 42.5 1.19243 23.69 32.6 1.14227 18.28 37.6 1.16717 21.02 42.6 1.19295 23.74 32.7 1.14276 18.34 37.7 1.16768 21.08 42.7 1.19348 23.79 32.8 1.14325 18.39 37.8 1.16818 21.13 42.8 1.19400 23.85 32.9 1.14374 18.45 37.9 1.16869 21.19 42.9 1.19453 23.90 33.0 1.14423 18.50 38.0 1.16920 21.24 43.0 1.19505 23.96 33.1 1.14472 18.56 38.1 1.16971 21.30 43.1 1.19558 24.01 33.2 1.14521 18.61 38.2 1.17022 21.35 43.2 1.19611 24.07 33.3 1.14570 18.67 38.3 1.17072 21.40 43.3 1.19663 24.12 33.4 1.14620 18.72 38.4 1.17122 21.46 43.4 1.19716 24.17 33.5 1.14669 18.78 38.5 1.17174 21.51 43.5 1.19769 24.23 33.6 1.14718 18.83 38.6 1.17225 21.57 43.6 1.19822 24.28 33.7 1.14767 18.89 38.7 1.17276 21.62 43.7 1.19875 24.34 33.8 1.14817 18.94 38.8 1.17327 21.68 43.8 1.19927 24.39 33.9 1.14866 19.00 38.9 1.17379 21.73 43.9 1.19980 24.44 34.0 1.14915 19.05 39.0 1.17430 21.79 44.0 1.20033 24.50 34.1 1.14965 19.11 39.1 1.17481 21.84 44.1 1.20086 24.55 34.2 1.15014 19.16 39.2 1.17532 21.90 44.2 1.20139 24.61 34.3 1.15064 19.22 39.3 1.17583 21.95 44.3 1.20192 24.66 34.4 1.15113 19.27 39.4 1.17635 22.00 44.4 1.20245 24.71 34.5 1.15163 19.33 39.5 1.17686 22.06 44.5 1.20299 24.77 34.6 1.15213 19.38 39.6 1.17737 22.11 44.6 1.20352 24.82 34.7 1.15262 19.44 39.7 1.17789 22.17 44.7 1.20405 24.88 34.8 1.15312 19.49 39.8 1.17840 22.22 44.8 1.20458 24.93 34.9 1.15362 19.55 39.9 1.17892 22.28 44.9 1.20512 24.98 490 APPENDIX. Comparison between Specific Gravity Figures, Degree Baume and Degree Brix. Continued. Percentage of sugar ac- cording to Balling or degree Brix Specific gravity. ol si r Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Baume. Percentage of sugar ac- cording to Balling or degree Brix Specific gravity. CJ *s Z% w ft 45.0 1.20565 25.04 50.0 1.23278 27.72 55.0 1.26086 30.37 45.1 1.20618 25.09 50.1 1.23334 27.77 55.1 1.26143 30.42 45.2 1.20672 25.14 50.2 1.23389 27.82 55.2 1.26200 30.47 45.3 1.20725 25.20 50.3 1.23444 27.88 55.3 1.26257 30.53 45.4 1.20779 25.25 50.4 1.23499 27.93 55.4 1.26314 30.58 45.5 1.20832 25.31 50.5 1.23555 27.98 55.5 1.26372 30.63 45.6 1.20886 25.36 50.6 1.23610 28.04 55.6 1.26429 30.68 45.7 1.20939 25.41 50.7 1.23666 28.09 55.7 1.26486 30.74 45.8 1.20993 25.47 50.8 1.23721 28.14 55.8 1.26544 30.79 45.9 1.21046 25.52 50.9 1.23777 28.20 55.9 1.26601 30.84 46.0 1.21100 25.57 51.0 1.23832 28.25 56.0 1.26658 30.89 46.1 1.21154 25.63 51.1 1.23888 28.30 56.1 1.26716 30.95 46.2 1.21208 25.68 51.2 1.23943 28.36 56.2 1.26773 31.00 46.3 1.21261 25.74 51.3 1.23999 28.41 56.3 1.26831 31.05 46.4 1.21315 25.79 51.4 1.24055 28.46 56.4 1.26889 31.10 46.5 1.21369 25.84 51.5 1.24111 28.51 56.5 1.26946 31.16 46.6 1.21423 25.90 51.6 1.24166 28.57 56.6 1.27004 31.21 46.7 1.21477 25.95 51.7 1.24222 28.62 56.7 1.27062 31.26 46.8 1.21531 26.00 51.8 1.24278 28.67 56.8 1.27120 31.31 46.9 1.21585 26.06 61.9 1.24334 28.73 56.9 1.27177 31.37 47.0 1.21639 26.11 52.0 1.24390 28.78 57.0 1.27235 31.42 47.1 1.21693 26.17 52.1 1.24446 28.83 57.1 1.27293 31.47 47.2 1.21747 26.22 52.2 1.24502 28.89 57.2 1.27361 31.52 47.3 1.21802 26.27 52.3 1.24558 28.94 57.3 1.27409 31.58 47.4 1.21856 26.33 52.4 1.24614 28.99 57.4 1.27467 31.63 47.5 1.21910 26.38 52.5 1.24670 29.05 57.5 1.27525 31.68 47.6 1.21964 26.43 52.6 1.24726 29.10 57.6 1.27583 31.73 47.7 1.22019 26.49 52.7 1.24782 29.15 57.7 1.27641 31.79 47.8 1.22073 26.54 52.8 1.24839 29.20 57.8 1.27699 31.84 47.9 1.22127 26.59 52.9 1.24895 29.26 57.9 1.27758 31.89 48.0 1.22182 26.65 53.0 1.24951 29.31 58.0 1.27816 31.94 48.1 1.22236 26.70 63.1 1.25008 29.36 58.1 1.27874 32.00 48.2 1.22291 26.75 53.2 1.25064 29.42 58.2 1.27932 32.05 48.3 1.22345 26.81 53.3 1.25120 29.47 58.3 1.27991 32.10 48.4 1.22400 26.86 53.4 1.25177 29.52 58.4 1.28049 32.15 48.5 1.22455 26.92 53.5 1.25233 29.57 58.5 1.28107 32.20 48.6 1.22509 26.97 53.6 1.25290 29.63 58.6 1.28166 32.26 48.7 1.22564 27.02 53.7 1.25347 29.68 58.7 1.28224 32.31 48.8 1.22619 27.08 53.8 1.25403 29.73 58.8 1.28283 32.36 48.9 1.22673 27.13 53.9 1.25460 29.79 58.9 1.28342 32.41 49.0 1.22728 27.18 54.0 1.25517 29.84 59.0 1.28400 32.42 49.1 1.22783 27.24 54.1 1.25573 29.89 59.1 1.28459 32.52 49.2 1.22838 27.29 54.2 1.25630 29.94 59.2 1.28518 32.57 49.3 1.22893 27.34 54.3 1.25687 30.00 59.3 1.28576 32.62 49.4 1.22948 27.40 54.4 1.25744 30.05 59.4 1.28635 32.67 49.5 1.23003 27.45 54.5 1.25801 30.10 59.5 1.28694 32.73 49.6 1.23058 27.50 54.6 1.25857 30.16 59.6 1.28753 32.78 49.7 1.23113 27.56 54.7 1.25914 30.21 59.7 1.28812 32.83 49.8 1.23168 27.61 54.8 1.25971 30.26 59.8 1.28871 32.88 49.9 1.23223 27.66 54.9 1.26028 30.31 59.9 1.28930 32.93 APPENDIX. 491 Comparison between Specific Gravity Figures, Degree Baume and Degree Brix. Continued. Percentage of sugar ac- cording to Balling or degree Brlx. Specific gravity. o I 2 3 ft Percentage of sugar ac- cording to Balling or degree Brix Specific gravity. o .1 l ? ft Percentage of sugar ac- cording to Balling or degree Brix Specific gravity. o 1 j# 60.0 1.28989 32.99 65.0 1.31989 35.57 700 1.35088 38.12 60.1 1.29048 33.04 65.1 1.32050 35.63 70.1 1.35155 38.18 60.2 1.29107 33.09 65.2 1.32111 35.68 70.2 1.35214 38.23 60.3 1.29166 33.14 65.3 1.32172 35.73 70.3 1.35277 38.28 60.4 1.29225 33.20 65.4 1.32233 35.78 70.4 1.35340 38.33 60.5 1.29284 33.25 65.5 1.32294 35.83 70.5 1.35403 38.38 60.6 1.29343 33.30 65.6 1.32355 35.88 70.6 1.35466 38.43 60.7 1.29403 33.35 65.7 1.32417 35.93 70.7 1.35530 38.48 60.8 1.29462 33.40 65.8 1.32478 35.98 70.8 1.35593 38.53 60.9 1.29521 33.46 65.9 1.32539 36.04 70.9 1.35656 38.58 61.0 1.29581 33.51 66.0 1.32601 36.09 71.0 1.35720 38.63 61.1 1.29646 33.56 66.1 1.32662 36.14 71.1 1.35783 38.68 61.2 1.29700 33.61 66.2 1.32724 36.19 71.2 1.35847 38.73 61.3 1.29759 33.66 66.3 1.32785 36.24 71.3 1.35910 38.78 61.4 1.29819 33.71 66.4 1.32847 36.29 71.4 1.35974 38.83 61.5 1.29878 33.77 66.5 1.32908 36.34 71.5 1.36037 38.88 61.6 1.29938 33.82 66.6 1.32970 36.39 71.6 '1.36101 38.93 61.7 1.29998 33.87 66.7 1.33031 36.45 71.7 1.36164 38.98 61.8 1.30057 33.92 66.8 1.33093 36.50 71.8 1.36228 39.03 61.9 1.30117 33.97 66.9 1.33155 36.65 71,9 1.36292 39.08 62.0 1.30177 34.03 67.0 1.33217 36.60 72.0 1.36355 39.13 62.1 1.30237 34.08 67.1 1.33278 36.65 72.1 1.36419 39.19 62.2 1.30297 34.13 67.2 1.33340 36.70 72.2 1.36483 39.24 62.3 1.30356 34.18 67.3 1.33402 36.75 72.3 1.36547 39.29 62.4 1.30416 34.23 67.4 1.33464 36.80 72.4 1.36611 39.34 62.5 1.30476 34.28 67.5 1.33526 36.85 72.5 1.36675 39.39 62.6 1.30536 34.34 67.6 1.33588 36.90 72.6 1.36739 39.44 62.7 1.30596 34.39 67.7 1.33650 36.96 72.7 1.36803 39.49 62.8 1.30657 34.44 67.8 1.33712 37.01 72.8 1.36867 39.54 62.9 1.30717 34.49 67.9 1.33774 37.06 72.9 1.36931 39.59 63.0 1.30777 34.54 68.0 1.33836 37.11 73.0 1.36995 39.64 63.1 1.30837 34.59 68.1 1.33899 37.16 73.1 1.37059 39.69 63.2 1.30897 34.65 68.2 1.33961 37.21 73.2 1.37124 39.74 63.3 1.30958 34.70 68.3 1.34023 37.26 73.3 1.37188 39.79 63.4 1.31018 34.75 68.4 1.34085 37.31 73.4 1.37252 39.84 63.5 1.31078 34.80 68.5 1.34148 37.36 73.5 1.37317 39.89 63.6 1.31139 34.85 68.6 1.34210 37.41 73.6 1.37381 39.94 63.7 1.31199 34.90 68.7 1.34273 37.47 73.7 1.37446 39.99 63.8 1.31260 34.96 68.8 1.34335 37.52 73.8 1.37510 40.04 63.9 1.31320 35.01 68.9 1.34398 37.57 73.9 1.37575 40.09 64.0 1.31381 35.06 69.0 1.34460 37.62 74.0 1.37639 40.14 64.1 1.31442 35.11 69.1 1.34523 37.67 74.1 1.37704 40.19 64.2 1.31502 35.16 69.2 1.34525 37.72 74.2 1.37768 40.24 64.3 1.31563 35.21 69.3 1.34648 37.77 74.3 1.37833 40.29 64.4 1.31624 35.27 69.4 1.34711 37.82 74.4 1.37898 40.34 64.5 1.31684 35.32 69.5 1.34774 37.87 74.5 1.37962 40.39 64.6 1.31745 35.37 69.6 1.34836 37.92 74.6 1.38027 40.44 64.7 1.31806 35.42 69.7 1.34899 37.97 74.7 1.38092 40.49 64.8 1.31867 35.47 69.8 1.34962 38.02 74.8 1.38157 40.54 64.9 1.31928 35.52 69.9 1.35025 38.07 74.9 1.38222 40.59 492 APPENDIX. Comparison between Specific Gh'avity Figures, Degree Baume and Degree Brix. Continued. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Baum6. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. .1 o & **W Q Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. a> 0>S 2g STpq Q 75.0 1.38287 40.64 80.0 1.41586 43.11 85.0 1.44986 45.54 75.1 1.38352 40.69 80.1 1.41653 43.61 85.1 1.45055 45.59 75.2 1.38417 40.74 80.2 1.41720 43.21 85.2 1.45124 45.64 75.3 1.38482 40.79 80.3 1.41787 43.26 85.3 1.45193 45.69 75.4 1.38547 40.84 80.4 1.41854 43.31 85.4 1.45262 45.74 75.5 1.38612 40.89 80.5 1.41921 43.36 85.5 1.45331 45.78 75.6 1.38677 40.94 80.6 1.41989 43.41 85.6 1.45401 45.83 75.7 1.38743 40.99 80.7 1.42056 43.45 85-7 1.45470 45.88 75.8 1.38808 41.04 80.8 1.42123 43.50 85.8 1.45539 45.93 75.9 1.38873 41.09 80.9 1.42190 43.55 85.9 1.45609 45.98 76.0 1.38939 41.14 81.0 1.42258 43.60 86.0 1.45678 46.02 76.1 1.39004 41.19 81.1 1.42325 43.65 86.1 1.45748 46.07 76.2 1.39070 41.24 81.2 1.42393 43.70 86.2 1.45817 46.12 76.3 1.39135 41.29 81.3 1.42460 43.75 86.3 1.45887 46.17 76.4 1.39201 41.33 81.4 1.42528 43.80 86.4 1.45956 46.22 76.5 1.39266 41.38 81.5 1.42595 43.85 86.5 1.46026 46.26 76.6 1.39332 41.43 81.6 1,42663 43.89 86.6 1.46095 46.31 76.7 1.39397 41.48 81.7 1.42731 43.94 86.7 1.46165 46.36 76.8 1.39463 41.53 81.8 1.42798 43.99 86.8 1.46235 46.41 76.9 1.39529 41.58 81.9 1.42866 44.04 86.9 1.46304 46.46 77.0 1.39595 41.63 82.0 1.42934 44.09 87.0 1.46374 46.50 77.1 1.39660 41.68 82.1 1.43002 44.14 87.1 1.46444 46.56 77.2 1.39726 41.73 82.2 1.43070 44.19 87.2 1.46514 46.60 77.3 1.39792 41.78 82.3 1.43137 44.24 87.3 1.46584 46.65 77.4 1.39858 41.83 82.4 1.43205 44.28 87.4 1.46654 46.69 77.5 1.39924 41.88 82.5 1.43273 44.33 87.5 1.46724 46.74 77.6 1.39990 41.93 82.6 1.43341 44.38 87.6 1.46794 46.79 77.7 1.40056 41.98 82.7 1.43409 44.43 87.7 1.46864 46.84 77.8 1.40122 42.03 82.8 1.43478 44.48 87-8 1.46934 46.88 77.9 1.40188 42.08 82.9 1.43546 44.53 87.9 1.47004 46.93 78.0 1.40254 42.13 83.0 1.43614 44.58 88.0 1.47074 46.98 78.1 1.40321 42.18 83.1 1.43682 44.62 88.1 1.47145 47.03 78.2 1.40387 42.23 83.2 1.43750 44.67 88.2 1.47215 47.08 78.3 1.40453 42.28 83.3 1.43819 44.72 88.3 1.47285 47.12 78.4 1.40520 42.32 83.4 1.43887 44.77 88.4 1.47356 47.17 78.5 1.40586 42.37 83.5 1.43955 44.82 88.5 1.47426 47.22 78.6 1.40652 42.42 83.6 1.44024 44.87 88.6 1.47496 47.27 78.7 1.40719 42.47 83.7 1.44092 44.91 88.7 1.47567 47.31 78.8 1.40785 42.52 83.8 1.44161 44.96 88.8 1.47637 47.36 78.9 1.40852 42.57 83.9 1.44229 45.01 88.9 1.47708 47.41 79.0 1.40918 42.62 84.0 1.44298 45.06 89.0 1.47778 47.46 79.1 1.40985 42.67 84.1 1.44367 45.11 89.1 1.47849 47.50 79.2 1.41052 42.72 84.2 1.44435 45.16 89.2 1.47920 47.55 79.3 1.41118 42.77 84.3 1.44504 45.21 89.3 1.47991 47.60 79.4 1.41185 42.82 84.4 1.44573 46.25 89.4 1.48061 47.65 79.5 1.41252 42.87 84.5 1.44641 45.30 89.5 1.48132 47.69 79.6 1.41318 42.92 84.6 1.44710 45.35 89.6 1.48203 47.74 79.7 1.41385 42.96 84.7 1.44779 45.40 89.7 1.48274 47.79 79.8 1.41452 43.01 84.8 1.44848 45.45 89.8 1.48345 47.83 79.9 1.41519 43.06 84.9 1.44917 45.49 89.9 1.48416 47.88 APPENDIX. 493 Comparison between Specific Gravity Figures, Degree Baume and Degree Brix. Continued. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. cJ ll p Q Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Baum<5. Percentage of sugar ac- cording to Balling or degree Brix. Specific gravity. Degree Bum<5. 90.0 1.48486 47.93 94.0 1.51359 49.81 98.0 1.54290 51.65 90.1 1.48558 47.98 94.1 1.51431 49.85 98.1 1.54365 51.70 90.2 1.48629 48.02 94.2 1.51504 49.90 98.2 1.54440 51.74 90.3 1.48700 48.07 94.3 1.51577 49.94 98.3 1.54515 51.79 90.4 1.48771 48.12 94.4 1.51649 49.99 98.4 1.54590 51.83 90.5 1.48842 48.17 94.5 1.51722 50.04 98.5 1.54665 51.88 90.6 1.48913 48.21 94.6 1.51795 50.08 98.6 1.54740 51.92 90.7 1.48985 48.26 94.7 1.51868 50.13 98.7 1.54815 51.97 90.8 1.49056 48.31 94.8 1.51941 50.18 98.8 1.54890 52.01 90.9 1.49127 48.35 94.9 1.52014 50.22 98.9 1.54965 52.06 91.0 1.49199 48.40 95.0 1.52087 50.27 99.0 1.55040 52.11 91.1 1.49270 48.45 95.1 1.52159 50.32 99.1 1.55115 52.15 91.2 1.49342 48.50 95.2 1.52232 50.36 99.2 1.55189 52.20 91.3 1.49413 48.54 95.3 1.52304 50.41 99.3 1.55264 52.24 91.4 1.49485 48.59 95.4 1.52376 50.45 99.4 1.55338 52.29 91.5 1.49556 48.64 95.5 1.52449 50.50 99.5 1.55413 52.33 91.6 1.49628 48.68 95.6 1.52521 50.55 99.6 1.55487 52.38 91.7 1.49700 48.73 95.7 1.52593 50.59 99.7 1.55562 52.42 91.8 1.49771 48.78 95.8 1.52G65 50.64 99.8 1.55636 52.47 91.9 1.49843 48.82 95.9 1.52738 50.69 99.9 1.55711 52.51 92.0 1.49915 48.87 96.0 1.52810 50.73 100.0 1.55785 52.56 92.1 1.49987 48.92 96.1 1.52884 50.78 92.2 1.50058 48.96 ' 96.2 1.52958 50.82 92.3 1.50130 49.01 96.3 1.53032 50.87 92.4 1.50202 49.06 96.4 1.53106 50.92 92.5 1.50274 49.11 96.5 1.53180 50.96 92.6 1.50346 49.15 96.6 1.53254 51.01 92.7 1.50419 49.20 96.7 1.53328 51.05 92.8 1.50491 49.25 96.8 1.53402 61.10 92.9 1.50563 49.29 96.9 1.53476 51.15 93.0 1.50633 49.34 97.0 1.53550 51.19 93.1 1.50707 49.39 97.1 1.53624 51.24 93.2 1.50779 49.43 97.2 1.53698 51.28 93.3 1.50852 49.48 97.3 1.53772 51.33 93.4 1.50924 49.53 97.4 1.53846 51.38 93.5 1.50996 49.57 97.5 1.53920 51.42 93.6 1.51069 49.62 97.6 1.53994 51.47 93.7 1.51141 49.67 97.7 1.54068 51.51 93.8 1.51214 49.71 97.8 1.54142 51.56 93.9 1.51286 49.76 97.9 1.54216 51.60 494 APPENDIX. IV. Alcohol Tables. Percentage of Alcohol by Weight and by Volume from the Specific Gravity (at 15.5 G), by Otto Hehner. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. 1.0000 0.00 0.00 0.9999 0.05 0.07 0.9949 2.89 3.62 0.9899 5.94 7.40 8 0.11 0.13 8 2.94 3.69 8 6.00 7.48 7 0.16 0.20 7 3.00 3.76 7 6.07 7.57 6 0.21 0.26 6 3.06 3.83 6 6.14 7.66 5 0.26 0.33 5 3.12 3.90 5 6.21 7.74 4 0.32 0.40 4 3.18 3.98 4 6.28 7.83 3 0.37 0.46 3 3.24 4.05 3 6.36 7.92 2 0.42 0.53 2 3.29 4.12 2 6.43 8.01 1 0.47 0.60 1 3.35 4.20 1 6.50 8.10 0.53 0.66 3.41 4.27 6.57 8.18 0.9989 0.58 0.73 0.9939 3.47 4.34 0.9889 6.64 8.27 8 0.63 0.79 8 3.53 4.42 8 6.71 8.36 7 0.68 0.86 7 3.59 4.49 7 6.78 8.45 6 0.74 0.93 6 3.65 4.56 6 6.86 8.54 5 0.79 0.99 5 3.71 4.63 5 6.93 8.63 4 0.84 1.06 4 3.76 4.71 4 7.00 8.72 3 0.89 1.13 3 3.82 4.78 3 7.07 8.80 2 0.95 1.19 2 3.88 4.85 2 7.13 8.88 1 1.00 1.26 1 3.94 4.93 1 7.20 8.96 1.06 1.34 4.00 5.00 7.27 9.04 0.9979 1.12 1.42 0.9929 4.06 5.08 0.9879 7.33 9.13 8 1.19 1.49 8 4.12 5.16 8 7.40 9.21 7 1.25 1.57 7 4.19 5.24 7 7.47 9.29 6 1.31 1.65 6 4.25 5.32 6 7.53 9.37 5 1.37 1.73 5 4.31 5.39 5 7.60 9.45 4 1.44 1.81 4 4.37 5.47 4 7.67 9.54 3 1.50 1.88 3 4.44 5.55 3 7.73 9.62 2 1.56 1.96 2 4.50 5.63 2 7.80 9.70 1 1.62 2.04 1 4.56 5.71 1 7.87 9.78 1.69 2.12 4.62 5.78 7.93 9.86 0.9969 1.75 2.20 0.9919 4.69 5.86 0.9869 8.00 9.95 8 1.81 2.27 8 4.75 5.94 8 8.07 10.03 7 1.87 2.35 7 4.81 6.02 7 8.14 10.12 6 1.94 2.43 6 4.87 6.10 6 8.21 10.21 6 2.00 2.51 5 4.94 6.17 5 8.29 10.30 4 2.06 2.58 4 5.00 6.24 4 8.36 10.38 3 2.11 2.62 3 5.06 6.32 3 8.43 10.47 2 2.17 2.72 2 5.12 6.40 2 8.50 10.56 1 2.22 2.79 1 5.19 6.48 1 8.57 10.65 2.28 2.86 5.25 6.55 8.64 10.73 0.9959 2.33 2.93 0.9909 5.31 6.63 0.9859 8.71 10.82 8 2.39 3.00 8 5.37 6.71 8 8.79 10.91 7 2.44 3.07 7 5.44 6.78 7 8.86 11.00 6 2.50 3.14 6 5.50 6.86 6 8.93 11.08 5 2.56 3.21 5 5.56 6.94 5 9.00 11.17 4 2.61 3.28 4 5.62 7.01 4 9.07 11.26 3 2.67 3.35 3 5.69 7.09 3 9.14 11.86 2 2.72 3.42 2 5.75 7.17 2 9.21 11.44 1 2.78 3.49 1 5.81 7.25 1 9.29 11.52 , 2.83 3.55 5.87 7.32 9.36 11.61 APPENDIX. 495 Percentage of Alcohol by Weight and by Volume from the Specific Gravity (at 15.5 C), by Otto Helmet: Continued. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age ol absolute alcohol by volume. 0.9849 9.43 11.70 0.9799 13.23 16.33 0.9749 17.33 21.29 8 9.50 11.79 8 13.31 16.43 8 17.42 21.39 7 9.57 11.87 7 13.38 16.52 7 17.50 21.49 6 9.64 11.96 6 13.46 16.61 6 17.58 21.59 5 9.71 12.05 5 13.54 16.70 5 17.67 21.69 4 9.79 12.13 4 13.62 16.80 4 17.75 21.79 3 9.86 12.22 3 13.69 16.89 3 17.83 21.89 2 9.93 12.31 2 13.77 16.98 2 17.92 21.99 1 10.00 12.40 1 13.85 17.08 1 18.00 22.09 10.08 12.49 13.92 17.17 18.08 22.18 0.9839 10.15 12.58 0.9789 14.00 17.26 0.9739 18.15 22.27 8 10.23 12.68 8 14.09 17.37 8 18.23 22.36 7 10.31 12.77 7 14.18 17.48 7 18.31 22.46 6 10.38 12.87 6 14.27 17.59 6 18.38 22.65 5 10.46 12.96 5 14.36 17.70 5 18.46 22.64 4 10.54 13.05 4 14.45 17.81 4 18.54 22.73 3 10.62 13.15 3 14.55 17.92 3 18.62 22.82 2 10.69 1:5.24 2 14.64 18.03 2 18.69 22.92 1 10.77 13.34 1 14.73 18.14 1 18.77 23.01 10.85 13.43 14.82 18.25 18.85 23.10 0.9829 10.92 13.52 0.9779 14.90 18.36 0.9729 18.92 23.19 8 11.00 13.62 8 15.00 18.48 8 19.00 23.28 7 11.08 13.71 7 15.08 18.58 7 19.08 23.38 6 11.15 13.81 6 15.17 18.68 6 19.17 23.48 5 11.23 13.90 5 15.25 18.78 5 19.25 23.o8 4 11.31 13.99 4 15.33 18.88 4 19.33 23.68 3 11.38 14.09 8 15.42 18.98 3 19.42 23.78 2 11.46 14.18 2 15.50 19.08 2 19.50 23.88 1 11.54 14.27 1 15.58 19.18 1 19.58 23.98 11.62 14.37 15.67 19.28 19.67 24.08 0.9819 11.69 14.46 0.9769 15.75 19.39 0.9719 19.75 24.18 8 11.77 14.56 8 15.83 19.49 8 19.83 24.28 7 11.85 14.65 7 15.92 19.59 7 19.92 24.38 6 11.92 14.74 6 16.00 19.68 6 20.00 24.48 5 12.00 14.84 5 16.08 19.78 5 20.08 24.58 4 12.08 14.93 4 16.15 19.87 4 20.17 24.68 3 12.15 15.02 3 16.23 19.96 3 20.25 24.78 2 12.23 15.12 2 16.31 20.06 2 20.33 24.88 1 12.31 15.21 1 16.38 20.15 1 20.42 24.98 12.38 15.30 16.46 20.24 20.50 25.07 0.9809 12.46 15.40 0.9759 16.54 20.33 0.9709 20.58 25.17 8 12.54 15.49 8 16.62 20.43 8 20.67 25.27 7 12.62 15.58 7 16.69 20.52 7 20.75 25.37 6 12.69 15.68 6 16.77 20.61 6 20.83 25.47 5 12.77 15.77 5 16.85 20.71 5 20.92 25.57 4 12.85 15.86 4 16.92 20.80 4 21.00 25.67 3 12.92 15.96 3 17.00 20.89 3 21.08 25.76 2' 13.00 16.05 2 17.08 /0.99 2 21.15 25.86 1 13.08 16.15 1 17.17 21.09 1 21.23 25.95 13.15 16.24 17.25 21.19 21.31 26.04 496 APPENDIX. Percentage of Alcohol by Weight and by Volume from the Sjiecific Gravity (at 15.5 C.\ by Otto Hehner. Continued. Specific gravity at 15.5 C. Percen t- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- \ age of absolute alcohol by volume. 0.9699 21.38 26.13 0.9649 25.21 30.65 0.9599 28.62 34.61 8 21.46 26.22 8 25.29 30.73 8 28.69 34.69 7 21.54 26.31 7 25.36 30.82 7 28.75 34.76 6 21.62 26.40 6 25.43 30.90 6 28.81 34.83 5 21.69 26.49 5 25.50 30.98 5 28.87 34.90 4 21.77 26.58 4 25.57 31.07 4 28.94 34.97 3 21.85 26.67 3 25.64 31.15 3 29.00 35.05 2 21.92 26.77 2 25.71 31.23 2 29.07 35.12 1 22.00 26.86 1 25.79 31.32 1 29.13 35.20 22.08 26.95 25.86 31.40 29.20 35.28 0.9689 22.15 27.04 0.9639 25.93 31.48 0.9589 29.27 35.35 8 22.23 27.13 8 26.00 31.57 8 29.33 35.43 7 22.31 27.22 7 26.07 31.65 7 29.40 35.51 6 22.38 27.31 6 26.13 31.72 6 29.47 35.58 5 22.46 27.40 5 26.20 31.80 5 29.53 35.66 4 22.54 27.49 4 26.27 31.88 4 29.60 35.74 3 22.62 27.59 3 26.33 31.96 3 29.67 35.81 2 22.69 27.68 2 26.40 32.03 2 29.73 35.89 1 22.77 27.77 1 26.47 32.11 1 29.80 35.97 22.85 27.86 26.53 32.19 29.87 36.04 0.9679 22.92 27.95 0.9629 26.60 32.27 0.9579 29.93 36.12 8 23.00 28.04 8 26.67 32.34 8 30.00 36.20 7 23.08 28.13 7 26.73 32.42 7 30.06 36.26 6 23.15 28.22 6 26.80 32.50 6 30.11 36.32 5 23.23 28.31 5 26.87 32.58 5 30.17 36.39 4 23.31 28.41 4 26.93 32.65 4 30.22 36.45 3 23.38 28.50 3 27.00 32.73 3 30.28 36.51 2 23.46 28.59 2 27.07 32.81 2 30.33 36.57 1 23.54 28.68 1 27.14 32.90 1 30.39 36.64 23.62 28.77 27.21 32.98 30.44 36.70 0.9669 23.69 28.86 0.9619 27.29 33.06 0.9569 30.50 36.76 8 23.77 28.95 8 27.36 33.15 8 30.56 36.83 7 23.85 29.04 7 27.43 33.23 7 30.61 36.89 6 23.92 29.13 6 27.50 33.31 6 30.67 36.95 5 24.00 29.22 5 27.57 33.39 5 30.72 37.02 4 24.08 29.31 4 27.64 33.48 4 30.78 37.08 3 24.15 29.40 3 27.71 33.56 3 30.83 37.14 2 24.23 29.49 2 27.79 33.64 2 30.89 37.20 1 24.31 29.58 1 27.86 33.73 1 30.94 37.27 24.38 29.67 27.93 33.81 31.00 37.34 0.9659 24.46 29.76 0.9609 28.00 33.89 0.9559 31.06 37.41 8 24.54 29.8(5 8 28.06 33.97 8 31.12 37.48 7 24.62 29.95 7 28.12 34.04 7 31.19 37.55 6 24.69 30.04 6 28.19 34.11 6 31.25 37.62 5 24.77 30.13 6 28.25 34.18 5 31.31 37.69 4 24.85 30.22 4 28.31 34.25 4 31.37 37.76 3 24.92 30.31 3 28.37 34.33 3 31.44 37.83 2 25.00 30.40 2 28.44 34.40 2 31.50 37.90 1 25.07 30.48 1 28.50 34.47 1 31.56 37.97 25.14 30.57 28.56 34.54 31.62 38.04 APPENDIX. 497 Percentage of Alcohol by Weight and by Volume from the Specific Gravity (at 15.5 C.), by Otto Hehner. Continued. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by Tolume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. 0.9549 31.69 38.11 0.9499 34.57 41.37 0.9449 37.17 44.24 8 31.75 38.18 8 34.62 41.42 8 37.22 44.30 7 31.81 38.25 7 34.67 41.48 7 37.28 44.36 6 31.87 38.33 6 34.71 41.53 6 37.33 44.43 5 31.94 38.40 5 34.76 41.58 5 37.39 44.49 4 32.00 38.47 4 34.81 41.63 4 37.44 44.55 3 32.06 38.53 3 34.86 41.69 3 37.50 44.61 2 32.12 38.60 2 34.90 41.74 2 37.56 44.67 1 32.19 38.68 1 34.95 41.79 1 37.61 44.73 32.25 38.75 35.00 41.84 37.67 44.79 0.9539 32.31 38.82 0.9489 35.05 41.90 0.9439 37.72 44.86 8 32.37 38.89 8 35.10 41.95 8 37.78 44.92 7 32.44 38.96 7 35.15 42.01 7 37.83 44.98 6 32.50 39.04 6 35.20 42.06 6 37.89 45.04 5 32.56 39.11 5 35.25 42.12 5 37.94 45.10 4 32.62 39.18 4 35.30 42.17 4 38.00 45.16 3 32.69 39.25 3 35.35 42.23 3 38.06 45.22 2 32.75 39.32 2 35.40 42.29 2 38.11 45.28 1 32.81 39.40 1 35.45 42.34 1 38.17 45.34 32.87 39.47 35.50 42.40 38.22 45.41 0.9529 32.94 39.54 0.9479 35.55 42.45 0.9429 38.28 45.47 8 33.00 39.61 8 35.60 42.51 8 38.33 45.53 7 33.06 39.68 7 35.65 42.56 7 38.39 45.59 6 33.12 39.74 6 35.70 42.62 6 38.44 45.65 5 33.18 39.81 5 35.75 42.67 5 38.50 45.71 4 33.24 39.87 4 35.80 42.73 4 38.56 45.77 3 33.29 39.94 3 35.85 42.78 3 38.61 45.83 2 33.35 40.01 2 35.90 42.84 2 38.67 45.89 1 33.41 40.07 1 35.95 42.89 1 38.72 45.95 33.47 40.14 36.00 42.95 38.78 46.02 0.9519 33.53 40.20 0.94G9 36.06 43.01 0.9419 38.83 46.08 8 33.59 40.27 8 36.11 43.07 8 38.89 46.14 7 33.65 40.34 7 36.17 43.13 7 38.94 46.20 6 33.71 40.40 6 36.22 43.19 6 39.00 46.26 5 33.76 40.47 5 36.28 43.26 5 39.05 46.32 4 33.82 40.53 4 36.33 43.32 4 39.10 46.37 3 33.88 40.60 3 36.39 43.38 3 39.15 46.42 2 33.94 40.67 2 36.44 43.44 2 39.20 46.48 1 34.00 40.74 1 36.50 43.50 1 39.25 46.53 34.05 40.79 36.56 43.56 39.30 46.59 0.9509 34.10 40.84 0.9459 36.61 43.63 0.9409 39.35 46.64 8 34.14 40.90 8 36.67 43.69 8 39.40 46.70 7 34.19 40.95 7 36.72 43.75 7 39.45 46.75 6 34.24 41.00 6 36.78 43.81 6 39.50 46.80 5 34.29 41.05 5 36.83 43.87 6 39.55 46.86 4 34.33 41.11 4 36.89 43.93 4 39.60 46.91 3 34.38 41.16 3 36.94 44.00 3 39.65 46.97 2 34.43 , 41.21 2 37.00 44.06 2 39.70 47.02 1 34.48 41.26 1 37.06 44.12 1 39.75 47.08 34.52 41.32 37.11 44.18 39.80 47.13 32 498 APPENDIX. Percentage of Alcohol by Weight and by Volume from the Specific Gravity (at 15.5 C.\ by Otto Hehner. Continued. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. 0.9399 39.85 47.18 0.9349 42.33 49.86 0.9299 44.68 52.34 8 39.90 47.24 8 42.38 49.91 8 44.73 52.39 7 3995 47.29 7 42.43 49.96 7 44.77 52.44 6 40.00 47.35 6 42:48 50.01 6 44.82 52.48 5 40.05 47.40 5 42.52 50.06 5 44.86 52.53 4 40.10 47.45 4 42.57 50.11 4 44.91 52.58 3 40.15 47.51 3 42.62 50.16 3 44.96 52.63 2 40.20 47.56 2 42.67 50.21 2 45.00 52.68 1 40.25 47.62 1 42.71 50.26 1 45.05 52.72 40.30 47.67 42.76 50.31 45.09 52.77 0.9389 40.35 47.72 0.9339 42.81 50.37 0.9280 45.55 53.24 8 40.40 47.78 8 42.86 50.42 70 46.00 53.72 7 40.45 47.83 7 42.90 50.47 60 46.46 54.19 6 40.50 47.89 6 42.95 50.52 50 46.91 54.66 5 40.55 47.94 5 43.00 50.57 40 47.36 55.13 4 40.60 47.99 4 43.05 50.62 30 47.82 55.60 3 40.65 48.05 3 43.10 50.67 20 48.27 56.07 2 40.70 48.10 2 43.14 50.72 10 48.73 56.54 1 40.75 48.16 1 43.19 50.77 00 49.16 56.98 40.80 48.21 43.24 50.82 0.9379 40.85 48.26 0.9329 43.29 50.87 0.9190 49.64 57.45 8 40.90 48.32 8 43.33 50.92 80 50.09 57.92 7 40.95 48.37 7 43.39 50.97 70 50.52 58.36 6 41.00 48.43 6 43.43 51.02 60 50.96 58.80 5 41.05 48.48 5 43.48 51.07 50 51.38 59.22 4 41.10 48.54 4 43.52 51.12 40 51.79 59.63 3 41.15 48.59 3 43.57 51.17 30 52.23 60.07 2 41.20 48.64 2 43.62 51.22 20 52.58 60.52 1 41.25 48.70 1 43.67 51.27 10 53.13 60.97 41.30 48.75 43.71 51.32 00 53.57 61.40 0.9369 41.35 48.80 0.9319 43.76 51.38 0.9090 54.00 61.84 8 41.40 48.86 8 43.81 51.43 80 54.48 62.31 7 41.45 48.91 7 43.86 51.48 70 54.95 62.79 6 41.50 48.97 6 43.90 51.53 60 55.41 63.24 5 41.55 49.02 5 43.95 51.58 50 55.86 63.69 4 41.60 49.07 4 44.00 51.63 40 56.32 64.14 3 41.65 49.13 3 44.05 51.68 30 56.77 64.58 2 41.70 49.18 2 44.09 51.72 20 57.21 65.01 1 41.75 49.23 1 44.14 51.77 10 57.63 65.41 41.80 49.29 44.18 61.82 00 58.05 65.81 0.9359 41.85 49.34 0.9309 44.23 51.87 0.8990 58.50 66.25 8 41.90 49.40 8 44.27 51.91 80 58.95 66.69 7 41.95 49.45 7 44.32 51.96 70 59.39 67.11 6 42.00 49.50 6 44.36 52.01 60 59.83 67.53 5 42.05 49.55 5 44.41 52.06 50 60.26 67.93 4 42.10 49.61 4 44.46 52.10 40 60.67 68.33 3 42.14 49.66 3 44.50 52.15 30 61.08 68.72 2 42.19 49.71 2 44.55 52.20 20 61.50 69.11 1 42.24 49.76 1 44.59 52.25 10 61.92 69.50 42.29 49.81 44.64 52.29 00 62.36 69.92 APPENDIX. 499 Percentage of Alcohol by Weight and by Volume from the Specific Gravity (at 15.5 C.), by Otto Ifehner. Continued. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at . 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. Specific gravity at 15.5 C. Percent- age of absolute alcohol by weight. Percent- age of absolute alcohol by volume. 0.8890 62.82 70.35 40 77.71 83.60 0.8190 91.36 94.26 80 63.26 70.77 30 78.12 83.94 80 91.71 94.51 70 63.70 71.17 20 78.52 84.27 70 92.07 94.76 60 64.13 71.58 10 78.92 84.60 60 92.44 95.03 50 64.57 71.98 00 79.32 84.93 50 92.81 95.29 40 65.00 72.38 40 93.18 95.55 30 65.42 72.77 0.8490 79.72 85.26 30 93.55 95.82 20 65.83 73.15 80 80.13 85.59 20 93.92 96.08 10 66.26 73.54 70 80.54 85.94 10 94.28 96.32 00 66.70 73.93 60 80.96 86.28 00 94.62 96.55 50 81.36 86.61 0.8790 67.13 74.33 40 81.76 86.93 0.8090 94.97 96.78 80 67.54 74.70 30 82.15 87.24 80 95.32 97.02 70 67.96 75.08 20 82.54 87.55 70 95.68 97.27 60 68.38 75.45 10 82.92 87.85 60 96.03 97.51 60 68.79 75.83 00 83.31 88.16 50 96.37 97.73 40 69.21 76.20 40 96.70 97.94 30 69.63 76.57 0.8390 83.69 88.46 30 97.03 98.16 20 70.04 76.94 80 84.08 88.76 20 97.37 98.37 10 70.44 77.29 70 84.48 89.08 10 97.70 98.59 00 70.84 77.64 60 84.88 89.39 00 98.03 98.80 50 85.27 89.70 0.8690 71.25 78.00 40 85.65 89.99 0.7990 98.34 98.98 80 71.67 78.36 30 86.04 90.29 80 98.66 99.16 70 72.09 78.73 20 86.42 90.58 70 98.97 99.35 60 72.52 79.12 10 86.81 90.88 60 99.29 99.55 50 72.96 79.50 00 87.19 91.17 60 99.61 99.75 40 73.38 79.86 40 99.94 99.96 30 73.79 80.22 0.8290 87.58 91.46 20 74.23 80.60 80 87.96 91.75 0.7939 99.97 99.98 10 74.68 81.00 70 88.36 92.05 Absolute Alcohol. 00 75.14 81.40 60 88.76 92.36 0.7938 100.00 100.00 50 89.16 92.66 0.8590 75.59 81.80 40 89.54 92.94 80 76.04 82.19 30 89.92 93.23 70 76.46 82.54 20 90.29 93.49 60 76.88 82.90 10 90.64 93.75 60 77.29 83.25 00 91.00 94.00 INDEX. A. a-Brom-naphthalene, 376. Acetate of iron, 456. of lead, 337. of lime, brown, 335. gray, 335. Acetates, crude, analysis of, 338. Acetic acid, 330. glacial, 335, 337. in vinegar, determination of, 236. process for, 335. Acetone, 330, 337. determination of, in wood-spirit, 339. use in varnish, 98. Acetophenone, 385. Acid, acetic, 330. glacial, 335, 337. process for, 335. benzoic, 384. carbolic, 359. gallic, 384. hydrochloric, 454. nitric, 454. palmitic, 64. phthalic, 384. picric, 393. pyroligneous, 330. analysis of, 338. products of, 337. sludge, 23. stearic, 62. sulphuric, 454. Acidity of tan-liquors, 321. Acids, action of, upon starch, 163. amidoazo-sulphonic, 395. aromatic, and aldehydes, 384. manufacture of, 388. free, estimation of, in wines, 205. naphthalene sul phonic, 381. non-volatile, estimation of, in wines, 205. oxyazosulphonic, 396. rosolic, 394. sulpho-, 381. volatile, estimation of, in wines, 205. Acridine, 383. dyes, 398. manufacture of, 390. a-Dinitronaphthalene, 379. Adulterations of caoutchouc, 110. Aerated bread, 223. Agalite, 278. Agar-agar, 322. Albertite, 26. Albert mineral, 16. Albumen, blood, 469. Albuminoids, estimation of, in milk, 255. Alcohol, 217. in beer, determination of, 191. in essential oils, detection of, 106. in wines, determination of, 203. methyl, 330, 337. determination of, in wood-spirit, 339. use in varnish, 98. tables. See Appendix. Alcoholic beverages, 217. fermentation, conditions of, 179. See Fermentation. liquid, distillation of, 211. liquids, 207. liquors, composition of, 220. strength of liquors, determination of, 221. Aldehydes, aromatic, 90. aromatic acids and, 384. benzoic, 384. Ale, 187. Aleurometer, Boland, 229. Aleuroscope, 230. Alizarin, 363, 399. blue, 399, 465. colors of, in printing, 470. dyeing, 462. manufacture of, 389. orange, 399. Alkali blue, 392. Almond oil, 47. Alpaca fibre, 294. microscopic appearance of, 294. Alumina, acetate of, 469. mordants, 456. sulpho-acetate of, 456. Aluminum acetate, 337, 456. sulphate of, 456. Amber, 91, 97. American and Russian oils, viscosity table, 30. Amidoazo dyes, 395. sulphonic acids, 395. Amido-benzene, 379. toluene, 379. xylene, 380. Amine derivatives, 379. dye-colors, 392. Ammonia, 353. alum, 456. liquor, valuation of, 368. salts of, 355. still, 355. 501 502 INDEX. Ammoniacal liquor, treatment of, 353. Ammonium sulphate, 355, 356. Analysis of artificial dyes, 405, 406. of beer, 190. of bone-black, 156. of butter, 256. of cheese, 259. of commercial glucose, 173. of crude acetates, 338. of dextrine, 173. of dynamite, 82. of glucose, 173. of glycerine, 81. of malt, 188. of maltose, 173. of molasses and syrups, 154. of natural gas. See Rluminating Gas. gases, table of, 14. of nitro-cellulose, 288. of nitro-glycerine, 81. of oils and fats, methods for, 72. of oleomargarine butter, 252. of petroleum, 32. of pyroligneous acid, 338. of raw sugar, 153. of soaps, 78. table of, 70. of starch, 171. of sugar-beets and juices, 165. of sugar-canes, 113. and juices, 155. of sugar-scums, press-cakes, etc., 157. of tanning materials, 319. Analytical tests and methods, sugar, 149. of essential oils, 106. a-N"aphthol orange, 396. Anatomical structure of hides, 305. Aniline, 379. black, 393,461. printing of, 472. blue, 392. dye-colors, 392. manufacture of, 385. oil, 357, 386. salt, 379. yellow, 395. Animal hair, varieties of, 294. oils, fats, and waxes, 48. Anime, 91, 97. Anisol red, 396. Ahnatto, 423. adulterants of, 440. Anthracene, 353, 362, 374. brown, 399. derivatives, 377. dyes, 399. in tar and pitch, 367. oil, 353, 361. series, 374. sulphonic-acids, 381. tests of, 367. Anthracite coal, 340. Anthragallol, 399. Anthrapurpurin, 399. Anthraquinone, 363, 385. monosulphonic acid, manufacture of, 389. sulphonic acid, 382. Anthraquinones, manufacture of, 389. Antichlor, 277. Antimony mordants, 457. oxymuriate of, 457. Apparatus for determining flashing point of petroleum, 34. Appert's process for preserved milk, 244. Appolt's oven, 348. Arabic, gum, 91. Archil. See Orseille. Ardent spirits, 206. Argol, 194, 202. Armour, P. D., testimony of. See Artificial Butter. Armstrong, test of temperature, 108. Aromatic acids and aldehydes, 384. manufacture of, 388. aldehydes, 90. Arrack, 218. Arrow-root, varieties of, 161. Artificial butter, 246. manufacture, 66. coloring matters, 372. bibliography of, 417. statistics of, 417,418. dyes, tests of, 400. indigo, 398. vaseline, 32. Ash, of flour, determination of, 230. of wines, determination of, 204. Asphalt, 16, 97, 363. Cuban, 16. pavements, 26. Trinidad, 26. Asphalts, treatment of, 26. Assouplissage. See Silk-bleaching. Astatki, 22. Atlas powder, composition of, 72. Auramine, 393. Aurantia, 394. Azarin, 396. Azines, 393. Azo blue, 398. dye-colors, 395. dyes, supplementary, 398. Azococcin 2K, 396. Azorubin S, 396. B. Bagasse, 118. Bag-filters, 128, 130. Baking, 226. Baking-powders, 225. Balance, Westphal, 74. Balata, 94. Balsams, 91. Barkometer, use of, 319. Barlow's kiers, 450. Barwood, 419. Bases, pyridine and quinoline, 382. Bastards. See Raw Sugars. Bast fibres, 262. Bastose, 262. Bate liquor, 314. Battery, diffusion, 133. Baume and Beck's scales, comparison of, 483. INDEX. 503 Baume and Brix, and specific gravity de- grees, comparison of, 487, 493. Rational, and Twaddle scales, compari- son of, 485. Baume's scale, liquid lighter than water, 482. Beating. See Paper-making. Becchi's test for cotton-seed oil, 78. Beck's scale, Baume and, comparison of, 483. Bee-hive ovens, 347. Beer, acidity of, 192. adulterations of, 192. analysis of, 190. ferment, 177. preservation of, 187. worts, specific gravity of, 190. Beers, composition of, 188. Beeswax, 49. Beet-root molasses, 139. Beet-sugar, diagram of working, 136. production of, 130. statistics of, 160. Ben oil, 47. Benzal-chloride, 376. Benzaldehyde. 385. green, 392. Benzene, 23, 330, 372. amido, 379. deodorization of, 23. deodorized, 29. distillate, 22. disulphonic acid, 381. halogen derivatives of, 375. series, 372. shale oil, 31. still, 358. sulphonic acid, 381. Benzidene dichloride, 376. dyes, 397. Benzoic acid, 384. aldehyde, 384. Benzol, 364, 372. crude, 353. fifty percent., 357, 373. ninety per cent., 357, 372. thirty per cent., 373. Benzols, property of, 373. Benzophenone, 385. Benzopurpurin, 398. Benzo-trichloride, 376. Benzyl-chloride, 376. /3-Naphthol-disulphonic acids, 382. orange. 396. /3-Naphthyl-bromide, 377. chloride, 376. Berries, Persian, 423. Beverages, alcoholic, manufacture of, 217. Bibliography, animal fibres, 302, 303. artificial coloring matter, 417. bleaching, dyeing, and textile printing, 475. destructive distillation, 369, 370. essential oils and resins, 110. fat* and fa^ty oils, 82. fermentation industries, 237. gelatine, 827. glue, 327. Bibliography, leather. 327. malting and brewing, 237. milk industries, 259. natural coloring matters, 445. petroleum and mineral oil, 42. starch, etc., 175. sugar, 159. vegetable fibres, 289. wines, 237. Biebrich scarlet, 397. Biscuit, hard, 228. Bismarck brown, 395. Bistre style. See Textile Printing. Bitumen, 16. Bitumens, asphalts, and bituminous shales, products of, 31. Bituminous shales and shale oil statistics, 45. treatment of, 26. coals, 340. Black, aniline, 393, 461. bread, 224. iron liquor, 456. japan, 103. lamp-, 29. naphthol, 397. seed cotton, 264. wool, 397. Blanket-scum, 122. Blasting gelatine, 72. See Gun-cotton. Bleach, madder, 448. Bleached lac. See Lac. Bleaching agents, 453. jute, 452. linen, 451. Lunge's process, 451. Mather-Thompson's process, 450. See Paper-making, 275. silk, 300, 453. sugar, 122. textile, 447. wool, 298, 452. Block parafBne, 25. Bloom, 30. Blotting-paper, 281. Blue, aniline, 392. alizarin, 399. alkali, 392. azo, 398. Boiley's. See Saxony Blue. diphenylamine, 392. dyes, natural, 424. dyestuffs, products of, 436. ethylene, 395. methylene, 395. Nicholson's, 392. oil, 25. resorcin, 394. water, 393. Blum, Griineberg and, ammonia still, 355. Bock-beer, 188. Boghead coal, 26. Boiled-off silk, 296, 299. Boiled oil, 69. Boiley's blue. See Saxony Blue. Boiling of sugar juice, 120. point of petroleum. See Fire-test. See Paper-making. 504 INDEX. Bone-black, analysis of, 156. exhausted, 148. filters, 122, 130. revivification of, 143. washer, Klusemann, 143. Bone fat, 49. glue, 325. Bones, 322. Brandies, factitious, 207. Brandy, 207, 218. pale, 218. white, 218. Brazil-wood, 419. Bread, adulterations of, 230. aerated. 223. black, 224. making, 222. process of manufacture, 226. table of composition of, 227, 228. tests of, 230. varieties of, 223. yield of, to flour, 226. Brilliant crocein, 397. Ponceau 4R, 396. Briquettes, 363. British gum, 170. Brix, Baume, and specific gravity degrees, comparison of, 487, 493. Bromine, absorption of, by resin, 109. by turpentine, 108. and iodine, absorption of, by fats and oils, 75, 76, 77. Brown, alizarin, 471. anthracene, 399. coal, 341. dyes, natural, 427. products of, 439. fast, 397. G, acid, 397. phenyl, 394. phenylene, 395. resorcin, 397. Soudan, 396. Bucking. See Bleaching. Bullock's blood, defecating raw sugar with, 128. Burmese lacquer, 94. Burning naphtha, 357. oil, 29. grades of, 29, 30. springs, 13. Butter, 244, 251. analyses of, 251. analysis of, 256. artificial, 246. manufacture of, 66 cacao. 47. coloring matter of, 259. fat, 48. substitutes, 251. Butterine, 246. Button-lac. See Lac. C. Cacao butter, 47. Cachou de laval, 400. Calorisator. See Beet-sugar Production. Camel's hair, 294. Camphor, 91. statistics of, 111. Cam- wood, 419. Canadian oil, treatment of, 24. Canadol, 29. Canarin, 400. Candle manufacture, 62. Candles, 71, 88. Cane-shredder, 118. Cane-sugar, determination of, 151. diagram of production, 121. industry, 113. production of, 117. statistics of, 159. , syrups, molasses and, 146. Canna arrow-root, 161. Can n el coal, 341. Caoutchouc, 93. and gutta-percha, processes of treat- ment, 99. tests of, 110. Caramel, detection of, 222. in vinegar, 236. See Sugar-coloring. Carbohydrates, un fermentable, 171. Carbolic acid, 359. varieties of, 359. oil, 353. Carbon, fixed, 340. Carbonate of lime, use of, in sugar diffu- sion, 120. Carbonates, estimation of, in dyes, 405. Cardboard, 281. Carmine. See Cochineal Preparations. naphte, 396. preparation of. 432. Carnauba wax, 48, 87. Cashmere, 294. Cassonade. See Raw Sugars. Castor oil, 46. "Catch-alls." See Yarynn Evaporator. Catechu, 307, 427, 439, 457. extract, valuation of, 442. Cedrenes, 90. Celluloid, 270, 284, 287. manufacture of, 286. Cellulose in flour, determination of, 228. stages of nitration, 284, 285. Centrifugals for sugar, 125. Ceresine, 25, 31. uses of, 31. white, 26. yellow, 26. Chamois leather, 316, 318. Champagne wines, 200. Champagnes. See Effervescing Wines, Chapapote, 16. Charcoal, 331, 338. Cheese, 252. analyses of, 253. analysis of, 259. classes of, 249. making, 248. ripening of, 249. varieties of, 252. Cheese-box stills, 20. Chomic blue. See Saxony Blue. INDEX. 505 Chemical characters of oils and fats, 49. determination of cane-sugar, 151. retting. See Flax. wood-pulp, microscopic feature of, 282. Chestnut-wood, 307. Chewing-gums, 31. China-grass, 268. microscopical appearance of, 268. Chinese green. See Lokao. wax, 49, 87. Chinoline. See Quinoline. Chloride of lime. 453. Chlorophyll, 426'. Chrome-alum, 457. Chromium mordants, 457. Chromogens, 391. Chromophor groups, 391. Chrysamin, 397. Chrysene, 375. Chrysoidine, 395. Cider, 232. vinegar, 235, manufacture of, 234. Cingalese and Indian lacquer, 94. Clayed sugars. See Raw Sugars. Cloth red G, 397. woollen, scouring of, 297. Coal, anthracite, 340. bituminous, 340. Boghead, 26. brown, 341. cannel, 341. coke-oven distillation of, 347. gas-retort distillation of, 344. Coals, coking, 341. effects of temperature upon, 342. non-coking, 341. Coal-tar colors, solution of, 459. diagram of treatment, 354. dyes, identification of, 402, 404. production, statistics of, 370. products of, 356. statistics of, 370. separation of crude, 350. Cochineal, 422. ammoniacal, preparation of, 432. carmine, 435. preparations, 435. scarlet 2R, 396. valuation of, 442. Cocoa-nut fibre, 269. oil. 47, 83. Cod-liver oil, 49, 86. Ccerulein, 395. Cognac, 218. imitations of, 218. Coir fibre, 269. Coke-oven distillation of coal, 347. ovens, varieties of, 348, 350. Coke, petroleum, 25. Coking-coal, statistics of, 370. Coking-coals. 341. table of, '342. Cold test, determining of, in lubricating oils, 37. Cold-water retting. See Flax. Collodion, 270, 284, 287. Collodion, manufacture of, 285. Cologne- water, 95. Colophony resin, 92. Colorimetric tests of petroleum, 41. Colorimetry, 401. Coloring matters, artificial, 372. in wines, 206. of butter, 259. natural, application of, 459. bibliography of, 445. nature of, for paper, 284. paper, 278. sugar, manufacture of, 168 Color-mixing, thickenings used in, 469. Color-pans, 467. Colors, mineral, application of, in textile printing, 471. miscellaneous, 399. used in varnishes, 98. Colza oil, 47. Compressed yeast, characteristics of, 225. Compression test of paraffins, 40. Concentration of raw sugars, 127. Concrete. See Raw Sugar. Concretor, Fryer, 127. Condensation, fractional, 211. Condensed milk, 250. analyses of, 250. manufacture of, 243. Conditioning silk, 298. Congealing point of paraffine. See Melting Point. Congo group dyes, 397. red, 397. Continuous distillation of petroleum, 22. Copal, 91, 97. Coppee's oven, 348. Copper acetate, 337. mordants, 457. nitrate of, 457. sulphate of, 457. wall (sugar-boiling), 122. Copperas, 456. Corallin, red, 394. yellow, 394. Cordials, 219. Corn spirit, 206. starch, manufacture of, 163. Cotton, application of artificial colors to, 460, 461. black seed, 264. bleaching, 448. dyeing, 459. fibre, 263. ginning, 263. green seed, 264. microscopic appearance of, 263. features of, 282. sea-island, 263. statistics of, 289, 290. Cottonized ramie, 268. Cotton-seed, diagram of utilization of, 69. oil, 46, 84. Beech i's test for, 78. Cow's milk, 242. Crackers. 228. Cracking. See Crude Petroleum. Cream, 242. 506 INDEX. Cream, analysis of, 245. of tartar, 202. separator, 245. Creamometer, use of, 255. Creosote, 338. oil, 336, 360. oils, tests of, 366. wood, 330. wood-tar, tests of, 3-JO. Cresol, 330. Crocein, brilliant, 397. orange, 396. scarlet 3B, 397. Crofting. See Bleaching. Crown leather, 318. Crude benzol, 353. paraffine, 16. petroleum, 14. process, 18. table of distillation of, 18. Cuban asphalt, 16. Cudbear, 435. See Orseille. Cuisinier, Dubrunfaut and, process for mal- tose, 167. Curcuma arrow-root, 161. Curd, 242. Cutch, 457. Cyanine, 398. Cylinder oil, 30. filtered, 25. Cymogene, 23, 29. D. Dammar, 92, 97. varnish, 98. Danforth's oil, 29. Dead oil, 353. Defecation of sugar juice, 120. Defibrator, 118. Degraissage. See Silk-scouring. See Wool-scouring. Degras, 318. Dehairing of hides. See Leather. Demerara crystals. See Raw Sugars. Dental rubber. See Vulcanite. Deodorization of benzene, 23. Deodorized benzene, 29. Destructive distillation, 329. bibliography of, 369, 370. Desuintage. See Wool-scouring. Determination of invert sugar and glucose, 152. of sucrose, 149. Dew retting (see Flax), 265. Dextrine, 162, 163, 170. analysis of, 173. estimation of, in dyes, 406. manufacture of, 168. Dextrose, 163. Diagram of composition of sugar-beet, 115. of petroleum distillation, 19. of production of cane-sugar, 121. of tanning process, 313. of treatment of coal-tar, 354. of utilization of a fat, 58. of cotton-seed, 69. Diagram of wood-tar treatment, 334. of working beet-sugar, 136. Diastase, 176. Diazo-amido benzene, 384. compounds, 384. benzene chloride, 383. sulphonic acids, 384. compounds, 383. Diazotizing, process of, 391. Dibrom-anthracene, 377. Dichlor-arithracene, 377. Diffusion battery, 133. working of, 134. of sugar-beets, Robert's method, 131. process for sugar-beet, 119. Dimethyl-aniline orange, 395. benzene (see Xylene). naphthalene, 374. Dinitrobenzene, 377. Dinitrotoluenes, 378. Dioxy-benzene, 380. Diphenylamine blue, 392. orange, 395. Diphenylen-methane, 375. Direct printing, 467. Disazo dyes, 397. Discharges, 467, 468. Diseases of wines, treatment of, 195. Distillation, destructive, 329. of coal, gas-retort, 344. of essential oils, 89. of petroleum, continuous, 22. of resins for varnish, 97. of wood, 331. Distilled liquors, classes of, 207. manufacture of, 206, 208. spirit, rectification of, 214. spirits, fermentation of wort, 209. preparation of wort, 208. Distiller's side-products, 221. Divi-divi, 308. Dog's dung, use of, in tanning, 314. Double-effects. See Vacuum-pan. Drum-washers, 274. Drying oils, 60. Dry wine, 199. Dualine, 72. Dubrunfaut and Cuisinier, process for mal- tose, 167. Duchassing's maceration process. See Sugar. Durgen system. See Starch. Dye-colors, arnine and aniline, 392. azo, 395. natural, 419. phenol, 393. Dyed alizarin, 473. colors, 467, 470. fibres, examination of, 406, 416. Dyeing, 458. adjective, 455. alizarin, 462. apparatus used in, 458. jute, 463. linen, 463. silk, 466. substantive, 4'"5. textile, 447. wool, 464. INDEX. Dyes, nmidoazo, 395. analysis of, 405, 406. artificial, tests of, 400. disazo, 397. mixtures of, 402. monoazo, 395. oxyazo, 395. Dye-trials, comparative, 400, 401. Dye-wood extracts, manufacture of, 429. test of, 439. Dye-woods, curing of, 427. cutting of, 427. red, dyeing with, 460. statistics of, 446. tests of, 439. use of, in textile printing, 471. Dynamite, 72. analysis of, 82. gelatine, 72. nitro-glycerine and, 67. E. Earth-wax, 16. Ecru silk, 299. Eels, vinegar, 234. Effervescing wines, 197. Electric-light carbons from natural gas car- bon, 29. from petroleum coke, 25. Electrolytic bleaching, 451. Elution process for molasses of Scheibler- Seyferth, 140. Emulsine, 176. Enamelled leather, 317. Enfleurage, 31, 95. Engine-sizing, 278. Eosins, 394. Erdoel, 14. Erythrosin. See Eosins. Esparto, 269. microscopic features of, 282. use in paper-making, 271. Essential oils, distillation of, 89. and resins, products of, 102. detection of alcohol in, 106. of fixed oils in, 106. iodine absorption of, 108. statistics of, 111. turpentine in, 107. Ether, petroleum-, 29. Ethereal salts, 90. Ethylene blue, 395. Ethyl green, 392. Ethyl-naphthalene, 374. Eurhodines and safranines, 393. Exhausted bone black, 148. Extract, safflower, 434. in vinegar, determination of, 236. in wines, determination of, 204. Extraction of oils and fats, 51. Extractor, dye-wood, 430. Soxhlet, 73. Thorn, 73. Extracts, Brazil-wood, 434. dye-wood, manufacture of, 429. odoriferous, 95. F. Farinose. See Starch. Fast brown, 397. red A, 396. B, 396. D, 396. yellow, 395. Fat, bone, 49. butter, 48. estimation of, in butter, 256. in flour, determination of, 230. in milk, 255. wool-, 293. Fats and fatty oils, bibliography of, 82. industry of, 46. statistics of, 82. and oils, raw materials, 46. animal, 48. saponification of, 55, 57. Fatty oils, analysis of, 78, 79. Fehling's solution, 152. Feldmann's ammonia apparatus, 355. Fermentation, coefficient of purity, 210. industries, 176. bibliography of, 237. statistics of, 238, 340. of the wort, 186. stages of (wort), 186. varieties of, 176. Fermentations, alcoholic, conditions of, 179. Ferments, acetic, 231. organized, 176. soluble, 176. Ferrous sulphate, 456. Fibres animal, 292. bibliography of, 302, -303. statistics of/303, 304. and vegetable, distinctions between, 301. determination of mixed, 302. of the nature of, 282. dyed, examination of, 406-416. special tests for, 301. vegetable, classification of, 262, 263. bibliography of, 289. textile, 262. wool, length of, 292. Fibroin, 296. Fibro- vascular bundles, 262. Fifty per cent, benzol, 357, 373. Filled soaps, 61. Filtered cylinder oil, 25. oils, 25. Filters, bag, 128-130. bone-black, 122. Fire-test of petroleum, determination of, 33. First light oil, 356. molasses, 138. runnings, 353. Fish-bladder, 322. gelatine, 326. manufacture of, 325. oil, 86. Fixed carbon, 340. oils in essential oils, detection of, 106. 508 INDEX. Flashing point, apparatus for determining, 34. of petroleum. See Fire-test. Flavaniline, 398. Flavine, preparation of, 433. See Quercitron. Flavopurpurin, 399 Flax, 264. microscopic appearance of, 265. New Zealand, 269. statistics of, 290. Flour, adulterants of, 230. and bread, bibliography of, 238. self-raising, 225. sources of, 223. tests of, 228. Fluoranthrene, 375. Fluorene, 375. Fluoreseein, 394. Flurt-silk, 301. Fourdrinier machine, 279. Fryer concretor, 127. Fuchsine. See Magenta. Fuel gas from natural gas, 28. Furfurol, 330. Fusel oil, determination of, 222. Fustic extracts, 435. old, 422. young, 423. G. Galician ozokerite, 25, 31 Gallein, 395. Gallic acid, 384. Gallipoli oil, 69. Gallisin, 171. Gallization (wines), 197. Gallocyanin, 395. Galls (see Nutgalls), 309. Gambir, 307. Gas coal, statistics of, 370. coals, table of, 341. fuels, table of effects of different, 28. illuminating, 28. analysis of, 368. composition of, 347. liquor, composition of, 353. making, use of paraffine oil in, 32. natural, 13. purifying, Laming's process, 346. retorts, 344. Gasolene, 23, 29. Gay-Lussac scale, and absolute specific gravity figures, comparison of, 486. Gelatine, bibliography of, 327. blasting, 72. dynamite, 72. fish, manufacture of, 325. manufacture, 321. Giant powder, 72. Gin, 219. Glauber's salt, estimation of, in dyes, 405. Glucose, analysis of, 173. and grape-sugar, 169. manufacture of, 165. inassi'-. See Glucose. vinegar, 235. Glue, 325. analysis of, 326. bibliography of, 327. industry, statistics of, 328. liquid, 326. manufacture, 321. of, from bones, 324. of, from leather waste, 324. raw materials, 322. process of manufacture, 322. vegetable, 322. Gluten in flour, determination of, 229. Glycerine, 88. analysis of, 81. and nitro-glycerine, 71, 72. determination in wines, 204. manufacture, 66. soap, 71. Golden syrup. See Molasses. Gossypium (see Cotton Fibre), 263. Grade of wool, determination of, 293. Grades of burning oil, 29, 30. of molasses, 138. Grain, malting of, 181. spirit, 206. Granulose. See Starch. Grape. See Wine Manufacture. Grape-sugar, Behr's process, 167. glucose and, 169. manufacture of, 165. Green, acid, 392. benzaldehyde, 392. dyes, natural, 426. ethyl, 392. methyl, 393. naphthol, 394. seed cotton, 264. syrup. See Molasses. vitriol, 456. Griineberg and Blum, ammonia still, 355. Guanaco fibre, 294. Guarancine, preparation of, 432. Gum arable, 91. British, 170. resins, 91. Gums, chewing-, 31. Gun-cotton, 280, 284, 287. manufacture of. 285. Gutta-percha, 93, 105. and caoutchouc, statistics of, 111. caoutchouc and. processes, 99. tests of, 110. products, India-rubber and, 105. scrap, use of, 102. treatment of, 101. vulcanization of, 94. H. Haematein. See Indigo Substitute. Hair, animal, varieties of, 294. distinction from wool, 292. Half-stuff, 275. Hand fleshing. See Leather Manufacture. Hard biscuit, 228. rubber. See Vulcanite. soap, 59. Harness leather, 314, 317. INDEX. 509 Headlight oil, 30. Heavy oil, 360. Hehner's alcohol table, 494, 499. Helianthin. 395. Hemlock-bark, 307. Hemp, 266. Manila, microscopic appearance of, 267. use in paper-making, 271. microscopic appearance of, 206. Hempel's gas apparatus, 368. Hemp-seed oil, 46, 85. Henderson's process for shales, 26. Hermite process for bleaching, 277, 451. Herzfeld's process for maltose, 168. Hide glue, 325. Hides, 306. anatomical structure of, 305. dehairing of. See Leather. fresh, 306. green, 306. manufacture of glue from, 322, 324. varieties of, 306. High-milling process, 224. Hofmann's violets, 393. Hollands. See Gin. Hops, 180. analysis of, 181. Horsechestnut-bark, 307. Hiibner process for shale oil, 28. Huile tournante, 69. Hydrated soap, 59. Hydraulic main, 345. Hydrocarbons, illuminating, 16. Hydrogen peroxide, 454. bleaching oils with, 55. use of, in bleaching, 453. use of, in wool-bleaching, 298. I. Illuminating gas, 28. analysis of, 368 from natural gas, 17. hydrocarbons, 16. oil, treatment of, 23. Imitation wines, 198. Indian corn, Jebb process for starch from, 164. India-rubber. See Caoutchouc. and gutta-percha products, 105. Indigo, 424, 459. artificial, 398. assay of, 443, 445. carmine, 436. preparation of, 433. commercial, 436. printing, 473. purple, 434, 437. soluble, 433 statistics of, 445. styles. See Textile Printing. substitute, 438. See Indulines. Indophenols, 395. Indulines, 393. , Industry of fats and fatty oils, 46. Ingrain colors, 398. red, 463. Ink, lithographic, 98. Inks, colored printing, 99. printing, 98, 104. Insect wax. See Chinese Wax. Invention of vacuum-pan, 124. Invertin, 176. Invert sugar and glucose, determination of, 152. Iodine absorption by essential oils, 108. action upon starch, 162. Iron, acetate of, 469. filings, estimation of, in dyes, 406. liquor, 333. black, 337. mordants, 456. nitrate of, 457, 469. pyrolignite of, 337. sulphate of, 456. Isinglass, 326. adulterated with glue, 326. Chinese, 322 J- Jaggery. See Raw Sugars. Jameson oven, 350. Japan, use of, 104. wax, 48, 87. Japanese and Chinese lacquer, 94. Japanning. See Japans. Japans, 103. Jebb process. See Starch. Juice- warmers. See Beet-sugar Production. Jute, 266. bleaching, 452. dyeing, 463. microscopic appearance of, 266, 267. use in paper-making, 271. Kauri. See Laminar. Kermes, 422. Kerosene, 29. Ketones, 385. Kienoel, 331. Kino, 308, 427. Kips. See Hides. Kirschwasser, 218. Klusemann bone-black washer, 143, 144. Knoppern, 309. Koumiss, 253. L. Lac, 92. dye, 422. Lacquer, Burmese, 94. Cingalese and Indian, 94. Japanese and Chinese, 94. Lager-beer. 187. Lamp-black, 29. from natural gas, 17. Landbeck, salicylic acid test for turpentine in essential oils, 107. Lard and lard oil, 48, 86. cheese, 249. Lauth's dyes, indophenols and, 395. Lead, acetate of, 337. sugar of, 337. 510 INDEX. Leather, bibliography of, 327. chamois, 316, 318. crown, 318. enamelled, 317. harness, 314. industry, 305. statistics of, 327, 328. manufacture of, 309. morocco, 314, 317. oil-tanned, 316. patent, 317. products, 317. Russia, 317. sole, 317. "tawed," 318. white-tanned, 318. Leaven, 224. Leeds's scheme for analysis of soaps, 78-80. Lees, wine, 202. Leguminous starches, 161. Light, fastness of dyes to, 400. Lignin, 291, 329. Lignite, 341. use of, in clarifying sugar juices, 122. Lillie evaporator, 125. Lima oil, 15. treatment of, 24. Lima-wood, 419. Lime, acetates of, 337. brown acetate of, 335. carbonate of, use of, in sugar diffusion, 120. gray acetate of, 335. or strontia methods for molasses, pro- cesses based on, 140. purifiers for gas, 346. use of, in sugar diffusion, 120. Lincrusta. See Oil-cloth. Linen bleaching, 451. dyeing, 463. microscopic features of, 282. Linoleum. See Oil-cloth. oil-cloth and, 104. Linseed oil, 47, 85. caoutchouc, 105. varnishes, 95, 102. Liqueurs, 219. Liquid glue, 326. Liquids, alcoholic, 207. Liquors, distilled, manufacture of, 206. Lithofracteur, 72. Lithographic ink, 98. Litmus, 426, 438. Llama hair, 294. Loading materials, nature of, for paper, 283. for paper, 278. sizing, and coloring paper, 278. Logwood', 425, 460. black, steam, 471. extract, valuation of, 441. extracts, 438. wool-dyeing with, 464. Lokao, 426. Low-milling process, 224. Low wines, 219. Lubricating oils, 30. determination of cold test of, 37. neutral, 30 Lubricating oils, viscosity of, 38. value of oils, 38. Lunge's bleaching process, 451. Lustre wools, 293. M. Maceration process, Duchassing's. See Sugar. Machinery, cloth-dyeing, 459. Madder, 420. bleach, 448. flowersj preparation of, 432. preparations, 434. Magenta, 392. acid, 302. Magnesia, sulphate of, estimation in dyes, 405. Malt, 179. air-dried, 183. analysis of, 188. and beer vinegars, 235. kiln-dried, 183. liquors, industries connected with, 179. vinegar, manufacture of, 234. wort, 232. Malting and brewing, bibliography of, 237. of the grain, 181. Maltose. 163, 170. analysis of, 173. Herzfeld's process, 168. manufacture of, 167. Manganese bronze style. See Textile Print" ing. Manganous borate, use as drier in varnish, 103. Manila hemp, 267. Manufacture of dextrine, 168. of glycerine, 66. of oil-cloth, 99. of perfumes, 94. of printer's ink, 98. of varnishes, 95. Maple-sugar, 114. Maranta, 161. Marc of grapes. See Wine Manufacture. Martin's process, for wheat starch, 165. Mash, fermented, distillation of, 211. Masse -cuite, 122, 125, 137. Mastic, 92. varnish, 98. Masut, 22. Mather-Thompson's bleaching process, 450. Mauvein, 393. McKay and Critchlow process, 17, 29. Mechanical wood-pulp, microscopic feature of, 282. Mege-Mouries. See Butter, Artificial. Meilers. See Coke-oven Distillation. Melada. See Raw Sugars. Melis, 146. Melting point of butter, 257. determination of, in paraffino, 39. of fats, 75. of paraffine, 30. Menhaden oil, 49. INDEX. 511 Metals in vinegar, 236. Metanil yellow, 395. Meta-toluidine, 380. Methyl acetate, 330. alcohol, 330, 337. determination of, in wood-spirit, 339. anthracene, 375. benzene. See Toluene. green, 393. naphthalene, 374. violet, 393. Methylene blue, 395 Metric system, 477, 478. Middle oil, 353, 359. Milk analysis, 241, 254, 2E6. constituents of, 241. cows, 242. industries, 241. bibliography of, 259. statistics of, 260. specific gravity of, 254. sugar, 242. estimation of, 256. treatment of whey for, 254. tests of, 254. yield of products of, 243. Millon's reagent, 301. Mills, oil-seed, 52. sugar-, 117. Mimosa-bark, 308. Mineral acids in vinegar, 236. Albert, 16. colors, 466. colza oil, 30. oil, petroleum and, bibliography, 42. sperm, 30. tanning, 314. Miscellaneous colors, 399. Mixed fibres, determination of, 302. wines, 198. Mixing-syrup, 147. Mohair, 294. Moisture in flour, determination of, 228. Molasses, beet-root, 139. grades of, 138. processes, lime and strontia method, 140. residues. See Vinasse. Scheibler process for, 141, 142. Steffen process, 140. and syrups, analysis of, 154. table of grades of, 147. working up of, 138. Monoazo dyes, 395. Monochlor-anthracene, 377. Mononitronaphthalene, 378. Mordants, 455, 468. Morocco leather, 314, 317. Mother-casks, 232. Mother of vinegar, 231. Mould growths. See Fermentation. sugar, 130. Muscovado sugar, 122. See Raw Sugars. Must fermentation, 194. See Wine Manufacture. Myrobalans, 308, 458. Myrosine, 176. Myrtle wax, 48. N. Naphtha, 14, 23, 29, 353. burning, 357. shale, 31. solvent, 353, 357. wood, 330, 333. Naphthalene, 330, 359, 360, 374. assay of, 366. dichloride, 376. halogen derivatives of, 376. red, 393. series, 374. sulphonic acids, 381, 382. tetrachloride, 376. Naphthenes, 15, 16. Naphthol black, 397. green, 394. sulphonic acids, 382. yellows, 394. Naphthols, 381. manufacture of, 388. Naphthylamine, 380. sulphonic acids, 382. Natal arrow-root, 161. Natural bitumens, treatment of, 26. blue dyes, 424. brown dyes, 427. dye-colors, 419. gas, 13. analysis of. See Illuminating Gas. fuel gas from, 28. illuminating gas from, 17. lamp-black from, 17. process, 16 statistics, 42. green dyes, 426. paramne, 28. varnishes, 94, 102. vaseline, 32. Neat's-foot oil, 48. Nettle fibre, 268. Neutral lard, 248. lubricating oils, 30. oils, 30. Nicholson's blue, 392. Nigrosine, 393. Ninety per cent, benzol, 357, 372. Nitro-alizarin, 399, 465. Nitrobenzene, 377. manufacture of, 385. Nitro- and nitroso- derivatives, 393. derivatives, 377. Nitrogenous compounds, in flour, determi- nation of, 229. Nitro-glycerine, 71, 72. analysis of, 81. and dynamite, 67. Nitroso- derivatives, nitro- and, 393. Nitrotoluene, 378. Non-coking coals, 341. table of, 342. Non-lustre wools, 293. Nutgalls, 309, 45S. 512 INDEX. O. Oak-bark, 306. Odoriferous extracts, 95. Oil, almond, 47. aniline, 357, 386. anthracene, 353, 361. ben, 47. birch-bark, use of, in tanning, 318. blue, 25. boiled, 69. burning, 29. cake, 86. meal, 86. table of composition of, 68. Canadian, treatment of, 24. castor, 46. cloth and linoleum, 104. manufacture of, 99. cocoa-nut, 47. cod-liver, 49. colza, 47, 84. cotton-seed, 46-84. creosote, 336, 360. cylinder, 30. Danforth's, 29. dead, 353. filtered, 25. first light, 356. Gallipoli, 69. headlight, 30. heavy, 360. hernp seed, 46. lard, 48. Lima, 15. treatment of, 24. linseed, 47. menhaden, 49. middle. 359. neat's-foot, 48. olive, 47. palm, 48, 83. paraffine, 25, 32. poppy-seed, 47. rape, 47. red, 61. reduced, 18, 30. rosin, 104. seed mill, 52. sesame, 84. shark, 49. Sherwood, 29. solar, 31. sperm. 49. spindle, 30. stills, 20. sunned, 12. tallow, 48. train, 49. vaseline, 32. whale, 49. Oils, American and Russian, table of viscos- ity, 30. and fats, analysis of, 72. bromine and iodine absorption of, 75, 76, 77. characteristics of, 49. composition of, 50. Oils and fats, extraction of, 51. saponincation equivalent of, 75. animal, 48. creosote, tests of, 366. essential, and resins, 89. processes, 94. classes of, 90. extraction by solvent*, 89. tests of, 106.' fats, and waxes, products of, 68. fish, 86. lubricating, 30. value of, 38. neutral, 30. vegetable, 46. Old fustic, 422. Olefines, 16. Oleomargarine, 66, 246. Oleometer, 73. Oleo oil, 247. use in cheese, 249. Oleo-resins, 91. Olive oil, 47, 83. Orange IV., 395. alizarin, 399. a-naphthol, 396. /3-naphthol, 396. crocein, 396. dimethyl-aniline, 395. diphenylamine, 395. G, 396. Organized ferments, 176. Orleans process for vinegar, 232. Orseille, 421. adulterations of, 440. extract, tests of, 439. preparations, 434. Osmogene. See Beet-root Molasses. Osmose process for beet-root molasses, 139. O'Sullivan and Valentine's process. See Maltose. Oxidation colors, 472. Oxyazo dyes, 396. Oxyazosulphonic acids, 396. Ozokerine, pomade, 32. Ozokerite and natural paraffines, products of, 31. statistics, 45. Galician, 25, 31. P. Pale brandy, 218. cutch. See Gamblr. Palmitic acid, 64. Palm oil, 48. Papaine, 176. Paper, machine-made, 279. manufacture of, from the pulp, 279. mulberry, 272. testing, 283. Paper-making, 270. material, preparation of, 272. materials, statistics of, 290. Papier-mache, 281. Parafline, 30, 338, 340. block, 25. compression test of, 48. INDEX. 513 Paraffinc, congealing point of. See Melting Point. crude, 16. determination of melting point, 39. hardness and melting point of, 30. oil, 25, 32. uses of, in gas-making, 32. solubility of^ 31. uses of, 31. Paraffins, natural and ozokerite, products of, 31. Paraffinum liquidum, 32. solidum, 32. Para-toluidine, 380. Parchment, 318. Parke's process of vulcanization, 100. Pasteboard, 281. Pasteurizing, 187, 196. Pasteur's process for vinegar, 234. Patent alum, 456. fuel, 363. leather, 317. Peach- wood, 419. Pearl hardening, 278. Peat, 341. Pepsin, 176. Perfumes, 102. manufacture of, 94. Perry, 232. Persian berries, 423. extracts of, 436. Perspiration, wool, 293. Petiotization (wines), 197. Petrolatum, 25, 32. ' Petroleum and mineral oil, 13. bibliography, 42. analysis of, 32. coke, 25. colorimetric tests of, 41. continuous distillation of, 22. crude, process, 18. distillation, diagram of, 19. ether, 29. fire-test determination of, 33. products, 29. tests of, 33. refining, 19. specific gravity, determination of, 33. spirit, use in varnish, 98. statistics, 43, 44. sulphur in, 15. Pharmaceutical soap, table of analysis of, 71. Phenanthrene, 375. Phenetol red, 396. Phenol, 330, 359, 380. derivatives, 380. dye-colors, 393. phthalein, 394. sulphonic acids, 381. Phenols, tests for, 365. Phenyl-anthracene, 375. brown, 394. naphthalene, 374. Phenylene brown, 395. Phloxin.- See Eosins. Phosphine, 398. Phosphotage, 196. Photogene, 31. Phthalein, manufacture of, 389. Phthaleins, 394. manufacture of, 388. Phthalic acid, 384. anhydride, manufacture of, 388. Phylloxera, 198. Physical characters of oils and fats, 49. Picene, 375. Picric acid, 393. Pigment style, 472. Pineapple fibre, 269. Pine-bark, 307. tar, 337. Pitch, 353, 363, 368. anthracene in, 367. coal-tar, uses of, 363. Plastering wines, 196. Plush, 466. Polariscope, 149, 150. Polychromine, 463. Pomade ozokerine, 32. Pomades, 95. Ponceau 2R, 396. 3R, 396. 4R, brilliant, 396. Poppv-seed oil, 47. Porter, 187. Potash alum, 456. bichromate of, 457. carbonate of, 454. permanganate of, 454. Potato spirit, 206. starch, 161. manufacture of, 1G5. Poteen, 219. Preparation of the wort, 183. Prepared catechu, 439. Preparing salt, 456. Preserved milk, 244, 250. Press-cakes, scums, and saturation (sugar), 148. Primuline, 463. colors, 398. Printed colors, 470. Printer's ink, manufacture of, 98. use of soap in, 98. Printing, 457. direct, 467. inks, 104. machine, textile, 468. papers, 281. silk, 475. style of textile, 470. textile, 467. woollen, 475. Processes, essential oils and resins, 94. of manufacture of starch, 163. of treatment, caoutchouc and gutta- percha, 99. sugar-cane, 117. Production of cane-sugar, diagram of, 121. of sugar from the sugar-beet, 130, 138. Products of bitumens, asphalts, and bitu- minous shales, 21. of essential oils and resins, 102. of manufacture, sugar, 145. oils, fats, and waxes, 68. petroleum, 29. 33 514 INDEX. Products of starch, 169. Proof spirit, 217. Proof-stick. See Vacuum-pan. Pseudophenanthrene, 375. Purifiers for coal gas, use of, 346. Purple, alizarin, 471. Purpurin, 399. Pyrene, 375. Pyridine bases, 382. Pyrogallol, 380. manufacture of, 388. Pyroligneous acid, 330. analysis of, 338. products of, 337. Pyrolignite of iron, 456. Pyronaphtha, 30. Pyroxylin, 270. Pyroxyline, 284, 287. manufacture of, 285. varnishes, 287. Q Quebracho, 308. Quercitron, 423. bark, 460. extracts, 436. dyeing, value of, 440. Quick vinegar process, 232, 233. Quinaldine, 383. Quinoline, 383. and acridine, manufacture of, 390. bases, 382. dyes, 398. yellow, 398. R. Raffinade. See Refined Sugars. Rags. See Paper-making. Raisin wine, composition of, 198, 199. Ramie, cottonized, 268. fibre, 268. Rape oil, 47, 84. Raw materials, distilled spirits, 207. essential oils and resins, 89. fats and oils, 46. natural gas, 13. petroleum, 13. sugar, concentration of, 127. defecating with bullock's blood, 128. sugars, 117., 145. composition of, 145, 146. refining, value of, 154. Recovered soda, 281. Rectified spirit, 206, 217. Rectifying distilled spirit, 214. Red, A, fast, 396. alizarin, 471. anisol, 396. B, fast, 396. Congo, 397. corallin, 394. D, fast, 396. dyestuffs products of, 434. G, cloth, 397. liquor, 337, 456. naphthalene, 393. Red oil, 61. phenetol, 396. Reduced indigo process, 473. oil, 18, 30. oils, use of, as lubricants, 25. Red wines, coloring matter in, 206. Refined molasses, 147. sugars, 146. wax, 25. Refining value of raw sugar, 154. Rendrock, 72. Resin acids, 91. Resins, 91. bromine, absorption by, 109. essential oils and, 89. processes, 94. for varnish, distillation of, 97. saponification, equivalent of, 109. statistics of, 111. tests of, 108. Resists, 467, 468, 474. Resorcin, 380. blue, 394. brown, 397. Resorcine, manufacture of, 387. Retene, 375. Retorts for coal distillation, 344. Retting process, flax, 265. Revivification of bone-black, 143. Rhigolene, 23. Rhodamine. See Eosins. Rice starch group, 161. Ricinus communis. See Castor Oil. Rin9age. See Wool-scouring. Roofing materials, 26. Rose Ben gale. See Eosins. Rosin, 90 1 , 92. colophony, 92. grease, 104. oil, 104. Rosolic acids, 394. Rubber, India-. See Caoutchouc. scrap, use of, 101. vulcanization of, 100. Rubeosin. See Eosins. Rum, 219. Russia leather, 317. S. Saccharine liquid (spirits), 208. Saccharomyces, 176, 177. cerevisiae, 177, 179. ellipsoideus, 177, 179. Pastorianus, 177, 179. Safflower, 421. preparations, 434. Safranine, 393. Sago starch group, 161. Salicylic acid in wines, estimation of, 205. Salt butter, 246. common, estimation of, in dyes, 405. estimation of, in butter. 256. Salts, ethereal, 90. Sand, estimation of, in dyes, 406. Sandal-wood, 419. Sandarach varnish, 98. Sapan-wood, 419. INDEX. 515 Saponiflcation of fats, 55, 57. equivalent, of fats and oils, 75. of resins, 109. Satins, 301. Savalle's rectifying column, 216. "Save-all." See Vacuum-pan. Sawdust, apparatus for distilling, 332. Saxony blue, 437. Scarlet Biebrich, 397. B, wool, 396. 2K, cochineal, 396. 3B, crocein, 397. Scheibler, molasses process, 141, 142. Scheibler-Seyferth elution process for mo- lasses, 140. Scheelization (wines), 197. .Schenk-beer, 187. Schiedam schnapps. See Gin. Schizomycetes, 176. Schyzophycetes, 176. Scouring silk, 299. textile, 447. wool, 297. Scrap gutta-percha, use of, 102. rubber, use of, 101. Scrubber, use of, in gas purification, 345. Scums and saturation press-cakei (sugar), 148. Sealing-wax, 104. Second molasses, 138, 139. Seed hairs, 267. Seed-lac, 92. Sericin, 296. Sesame oil, 84. Shale, naphtha, 31. oil benzene, 31. Hiibner process for, 28. Shales, Henderson's process for, 26. Young and Beilby's process for, 26, 27. Shark oil, 49. Sheep's wool, 292. Shellac. See Lac. varnish, 98. Sherwood oil, 29. Shoddy, 300. Side-products, distiller's, 221. Silent spirit. 217. Silk, 294, 298, 304. artificial colors applied to, 467. bleaching, 300, 453. boiled-off, 299. conditioning, 296, 298. ecru, 299. microscopic appearance of, 295. printing, 475. products of, 300. reeling, 298. scouring, 299. souple, 299. Tussur, 296. weighting of, 466. Silks, wild, 296. Simon-Carve's oven, 348. Sirop cristal. See Glucose. Sisal hemp, 267.' Sizing materials, nature of, for paper, 283. paper, 278. Skins, animal, 305. Skins. See Hides. Sludge acid, 23. Soap analysis, Leed's scheme for, 80. fastness of dyes to, 400. hard, 59. hydrated, 59. making, 57-62. soft, 59. toilet, 71. transparent, 71. Soaps, 70, 87. filled, 61. glycerine, 71. pharmaceutical, table of analyses of, 71. table of analyses of, 70. used in bleaching, 454. Soda ash, 454. bichromate of, 457. crystals, 454. Sod-oil, 317. Soft soap, 59. Solar oil, 31. Sole-leather, 317. manufacture of, 309. Solid fats, melting point of, 76. Solubility of parafline, 31. Soluble ferments, 176. Solution, Fehling's, 152. Solvent naphtha, 353, 357. Sorghum plant, 114. Soudan brown, 396. G, 395. Souple silk, 299. Sour cream, 246. dough, 225. whey, 243. Soxhlet extractor, 73. Specific gravity, absolute, and Gay-Lussac scales, comparison of, 486. Baume, and Brix degrees, com- parison of, 487, 493. of petroleum, determination of, 33. tables. See Appendix. Sperm oil, 49, 86. Spermaceti, 49, 86. Spindle oil, 30. Spirit, proof, 217. rectified, 206, 217. varnishes, 98, 103. vinegar, 235, Spirits, ardent, 206. bibliography of, 238. Sprengel tube, 74. Stannate of soda, 456. Stannous chloride, 455. Starch, 161. action of acids upon. 163. iodine upon, 162. analysis of, 171. etc., bibliography of, 175. composition of, 162. estimation of, in dyes, 406. in flour, determination of, 228. paste, 162. processes of manufacture, 163. products from, 169. See Manufacture of Distilled Liquors. statistics of, 176. 516 INDEX. Starches, leguminous, 161. Statistics of animal fibres, 303, 304. of artificial coloring matters, 417, 418. of beet-sugar, 160. bituminous shales and shale oil, 45. cane-sugar, 159. of destructive distillation, 370, 371. of dye-woods, 446. of essential oils and resins, 111. of glue industry, 328. of indigo, 445. of leather industry, 327, 328. of natural gas, 42. of oils and fats, 82. ozokerite and natural paraffine, 45. petroleum, 43, 44. of starch, 175. of sugar consumption, 160. of the milk industries, 260, 261. Steam style. See Textile Printing. Stearic acid, manufacture of, 62. Steffen molasses process, 140, 141. Stick-lac. See Lac. Stills, cheese-box, 20. Coffey, 211, 355. oil, 20. Pistorius, 211. Savalle, 212. vacuum, 21. Stockholm tar, 337. Stout, 187. Straw, microscopic feature of, 282. use in paper-making, 271. Strike-pan, sugar, 122. St. Vincent arrow-root, 161. Substitutes, butter, 251. Sucrose, determination of, 149. Sugar, 113. analytical tests and methods, 149. beet, diffusion process for, 119. general view of composition, 115. Robert's method of diffusion, 131. beets, 113,232. and juices, analysis of, 165. bibliography, 159. bleaching, 122. canes, analysis of, 113. and juices, analysis of, 155. centrifugals, 125. coloring, manufacture of, 168. concentration of, with vacuum-pans, 122. consumption, statistics of, 160. cured, 125. estimation of, in dyes, 406. grape-, manufacture of, 165. in flour, determination of, 228. in wines, determination of, 204. juice, boiling of, 120. defecated, 120. juices, clarifying with lignite, 122. loaf, 130. maple, 114. mills, 117. muscovado, 122. of lead, 337. production of, from sugar-beets, 130. scums, etc., analysis of, 157. Sugar. See Manufacture. Distilled Liquors, 208. side-products from, 147. solutions, specific gravity, table for, 487, 493. sources of, 113. vinegar, 235. yield of, 126. from sorghum, 114. Sugars, raw, analysis of, 163. refined, 146. Suint, 293. Sulphate of ammonia, 355, 356. statistics of, 371. Sulpho- acids, 381. Sulphonating, process of, 390. Sulphur in wool, 293. in petroleum, 15. Sumach, 308, 457. Sunn hemp, 267. Sunned oils, 18. Sweating process. See Leather Manufacture. Sweet cream, 246. water, 130. whey, 243. wine, 198, 199. Swelling. See Leather Manufacture. Swenson, Prof., use of carbonate of lime in sugar diffusion, 120. Syrups, molasses and, analysis of, 154. and cane-sugar, 146. T. Table of American wines, 201, 202. of analyses of condensed milk, 250. of milk, 241. of natural gases, 14. of oleomargarine butter, 252. of pharmaceutical soaps, 71. of soaps, 70. of classification of vegetable fibres, 269. of commercial indigoes, 445, of comparative effects of different gas fuels, 28. of composition of bread, 227, 228. of oil-cakes, 68. of raw sugars, 146. of wheat grain, 224. of effervescing wines, 201. of French wines, 200. of grades of molasses, 147. of illuminating gas, 347. of isomeric xylenes, 374. of natural and unfortified wines, 200. of sweet and fortified wines, 201. of tanning materials, 320. of thermometric equivalents, 479, 481. Tables of analyses of butter, 251. of cheese, 253. of composition of alcoholic liquors, 220. Tallow, 87. and tallow oil, 48. Tan-liquors, acidity of, 321. Tannin, detection of, in liquors, 222. estimation of, 319. use of, in dyeing, 457. in wines, estimation of, 205. INDEX. 517 Tanning infusions, strength of, 319. materials, 306. analysis of, 319. table of, 320. mineral, 314. process of, 310, 312. Tar, anthracene in, 367. birch-bark, 331. coal, fractionation of, 352. constituents, tests for, 364. -lime, 338. still, description of, 350. Stockholm, 337. valuation of, 363, 364. wood, diagram of treatment, 334. treatment of, 336. Tars from coke processes, varieties of, 350. Tartar, crude. See Wine Manufacture. emetic, 457. Tawing. See Mineral Tanning. Temperature, effects of, upon coal, 342. Terpenes, 90. Tests of caoutchouc and gutta-percha, 110. of essential oils and resins, 106. of resins, 108. of varnishes, 110. Textile fabrics, printing of, 467. fibres, vegetable, 262. Thermometers, relations between, 478. Thermometric equivalents, table of, 479, 481. Thick mash process. See Malt Industries. Third molasses, 139. Thirty per cent, benzol, 373. Thorn extractor, 73. Thurston's oil-tester, 38, 39. Timber, preservation of, 361. Tin crystals, 455. mordants, 454. spirits, 456. Tissue-paper, 281. Toilet soaps, 71. Toluene, 330, 372, 373. amido-, 379. halogen derivatives of, 376. sulphonic acid, 381. Toluidine, 379. sulphonic acid, 382. Total solids in milk, 254. Tout les mois, 161. Train oil, 49. Transparent soaps, 71. Treacle, 147. Treatment of asphalts, 26. of bituminous shales, 26. of Canadian oil, 24. of gutta-percha, 101. of illuminating oil, 23. of Lima oil, 24. of natural bitumens, 26. Trinidad asphalt, 26. Trinitrotoluene, 378. Trioxy-benzene, 380. Triphenyl-methane dyes, 392. Triple-effect. See Vacuum-pan. Tropseolin OO, 395. True resins. 91. Trypsine, 176. Tub-sizing, 278. Turf, 341. Turkey-red dyeing, 462. oil (see Huile Tournante), 69. styles. See Textile Printing. Turmeric, 424, 460. Turpentine, bromine absorption by, 108. in essential oils, 107. examination of, 108. oil of, 90. adulterants of, 107. varnishes, 98, 103. varieties of, 90. Tussur silk, bleaching of, 296, 453. Twaddle and Rational Baume scale, com- parison of, 485. Twaddle's scale with specific gravity, 484. U. Unfermentable carbohydrates, 171. Unguentum paramni, 32. Unhairing of hides, 310. Upper leather, 317. Usquebaugh. See Liqueurs. Utilization of cotton-seed, diagram of, 69. V. Vacuum-pan, 123, 124. dye-wood, 431. pans, "use of, for concentrating sugar, 122. stills, 21. Valentin, O'Sullivan and. See Maltose. Valonia, 308. Varieties of cheese, 252. Varnishes, 102. colored, 98. linseed oil, 95, 102. manufacture of, 95. natural, 94, 102. pyroxyline, 287. spirit, 98, 103. tests of, 110. turpentine oil, 98, 103. Vaseline, 25, 32. artificial, 32. natural, 32. oil, 32. Vats, indigo, 460. Vegetable fibre, statistics of, 289, 290. fibres, bibliography of, 289. table of classification of, 269. tests of, 270. glue, 322. growths. See Fermentation. oils, fats and waxes, 46. Vellum. See Parchment. Velvets, 301. Verdigris, 337. Victoria yellow, 394. Vicuna fibre, 294. Vinasse, 148. Vin de raisin sec, 198. Vinegar, acids in, 236. bibliography of, 238. cider, 234. 518 INDEX. Vinegar, eels, 234. essence, 235. malt, manufacture of, 234. manufacture of, 231. mother of, 231. Pasteur's process, 234. process of manufacture, 232. raw materials of, 231. tests of, 236. Vinegars, factitious, 236. malt and beer, 235. Violet, fast, 397. methyl, 393. Violets, Hofmann's, 393. Virgin oil, 53. Viscosity, determination of, in lubricating oils, 38. table of American and Kussian oils, 30. Vulcanite, 101. Vulcanization of gutta-percha, 94. of rubber, 100. W. Walrath. See Spermaceti. Warm water retting, 265. "Washing. See Paper-making. Waste silk, 301. Water blue, 393. estimation of, in butter, 256. purification of, 458. See Malt Industries. Watt and Burgess Process. See Wood Fibre. Wax, bees, 49. carnauba, 48. Chinese, 49. insect. See Chinese Wax. Japan, 48. myrtle, 48. refined, 25. sealing-, 104. yellow, 25. Waxes, animal, 48. Weiss-beer, 187, 188. Weld, 423. Westphal balance, 74. Wetzel pan, 127. Whale oil, 49. Wheat-grain, table of composition of, 224. starch group, 161. Martius process, 165. Whey, 242, 254. Whiskey, 219. White brandy, 218. ceresine, 26. wines, 207. Wild silks, 296. yeast, 177. Wiley, Prof., use of lime in sugar diffusion, 120. Willow bark, 307. Wine, analysis of, 203. ferment, 177. manufacture, 192. side-products of, 202. specific gravity of, 203. vinegar, 235. volatile constituents of, 199. Wines, 207. ash determination of, 204. bibliography of, 237. classification of, 199. determination of alcohol in, 203. of extract in, 204. of sugar in, 204. diseases of, treatment, 195. effervescing, 197. estimation of free acids in, 205. of non-volatile acids in, 205. of salicylic acid in, 205. of tannin in, 205. of volatile acids in, 205. fortified, mixed, and imitation, 198. glycerine determination in, 204. white, 207. Woad, 425. Wood, Brazil-, 419. composition of, 329. creosote, 330. destructive distillation of, 329. distillation of, 331. retorts for, 331. distilling, primitive method of, 331. effect of heat upon, 330. fibre, use in paper-making, 271. naphtha, 330, 333. pulp, chemical, microscopic features of, 282. See Paper-making. mechanical, microscopic features of, 282. See Paper-making. spirit, 337. crude, purification of, 335. determination of acetone in, 339. tar, diagram of treatment, 334. treatment of, 336. vinegar, 333. Wool, 292, 297, 303. black, 397. bleaching, 298, 452. coal-tar colors applied to, 465. coloring matters applied to, 464. composition of, 293. conditioning, 293. dyeing, 464. fat, 293. microscopic structure of, 292. perspiration, 293. products of, 300. scarlet K, 396. scouring, 297. Woollen cloth printing, 475. scouring of, 297. yarns, scouring of, 297. Wools, carded, 300. combed, 300. Working up of molasses, 138. Wort, fermentation of, 186. (distilled liquors), 209. See Manufacture of Distilled Spirits. preparation of the, 183. See Manufacture of Distilled Liquors. Wrapping-papers, 281. Writing-papers, 281. INDEX. 519 X. Xylene, 372, 373. amido-, 380. bromine derivatives of, 376. Xylenes, isomeric, 374. Xylidine, 380. Y. Yarns, woollen, scouring of, 297. Yaryan evaporator, 125. Yeast, or ferment. See Bread-making. plants. See Fermentation. Yellow, acid, 395. aniline, 395. ceresine, 26. Yellow corallin, 394. dyes, natural, 422. dyestuffs, products of, 435. fast, 395. metanil, 395. naphthol, 394. S, naphthol, 394. quinoline, 398. Victoria, 394. wax, 25. Yield of sugar, 126. Young and Beilby's process forshales, 26, 27. fustic, 423. Z. Zinc-powder, use of, in dyeing, 460. THE END. PRINTED BY J. B. LIPPINCOTT COMPANY, PHILADELPHIA. THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW AN INITIAL FINE OF 25 CENTS WILL BE ASSESSED FOR FAILURE TO RETURN THIS BOOK ON THE DATE DUE. THE PENALTY WILL INCREASE TO SO CENTS ON THE FOURTH DAY AND TO $1.OO ON THE SEVENTH DAY OVERDUE. T^~ HFC 11 1939 LD 21-5m-6,'37