None
Lithium Citrate.— As usually prepared, this a white powder, but it may be obtained in crystals with 4 mol. of water. The salt is generally stated to be deliquescent, but this is an error. It should be soluble without residue in 25 parts of cold water. The pure salt, after being rendered anhydrous by drying at 115°, on ignition leaves 52.9% of lithium carbonate. The residue should be treated with ammonium carbonate, and again ignited very gently, as it is liable to lose carbonic acid. A higher ash than the above indi- cates impurity or adulteration by (probably) sodium citrate ^ which leaves 61.5% on ignition, i grm. of anhydrous lithium citrate leaves on ignition a residue which should neutralise at least 14 c.c. of normal hydrochloric acid. The same amount of sodium citrate (after ignition) would only neutralise 11.25 ^.c. of acid. If the re- sultant solution be evaporated to dryness, lithium chloride may be dissolved out of the residue by a mixture of equal volumes of alcohol and ether, while any potassium or sodium chloride will remain undissolved. Much of the commercial lithium citrate contains lithium carbonate. This gives it an alkaline reaction and increases its ash and saturating capacity. Excess of citric acid gives the salt an acid reaction and re- duces the percentage of ash and saturating power. Hence these im- purities can be distinguished from sodium citrate, which raises the ash and diminishes the saturating power of the sample. Potassium salts may be detected by adding tartaric acid to the con- centrated solution of the sample and stirring, when a white crystalline precipitate of acid potassium tartrate will be produced. Insoluble matters, such as powdered petalite or lepidolite, will be 566 ACID DERIVATIVES OF ALCOHOLS. left undissolved on dissolving the sample in hot water, and calcium compounds may be estimated in the solution by adding ammonium oxalate. Calcium Citr&te. — This is a white substance, veiy sparingly soluble in cold, and still less in hot water. It is produced, in an impure state, by the citric acid manufacturer by boiling the juice with calcium car- bonate, and is ofiered in the market as a convenient source of citric acid. The product consists essentially of citrate mixed with other salts of calcium, and excess of lime or calcium carbonate. In Sicily, dolomitic lime is sometimes used for neutralising the juice, in which case magnesium salts will be present. It is particularly liable to decompose if the percentage of moisture is considerable (more than lo or 12%), and therefore some samples contain scarcely any real citrate. For the analytical examination of commercial calcium citrate it is sufficient to estimate the citric acid and the excess of carbonate or lime. For the latter purpose, 5 grm. of the sample should be dissolved in a known quantity of weak standard hydrochloric acid kept gently boiling, and, when the solution is quite cold, the amount of acid neutralised is ascertained by titration with standard alkali in the usual manner. Each c.c. of normal acid neutralised by the sample cor- responds to 0.050 grm. of calcium carbonate in the portion taken. To estimate the organic acids, 2 grm. of the sample should be ignited, the ash boiled with standard acid, the liquid liltered and titrated with alkali. The acid neutralised by the ash is due to the calcium carbonate existing as such in the sample, plus that produced by the ignition of the citrate and other organic salts. By subtracting the neutralisation due lo the former, the equivalent of the organic acids is found; i c.c of normal add neutralised being equivalent to 0.070 grm. of monohy- drated citric add. This method gives all the organic adds as dlric acid, a result which is misleading in decomposed dtrate. In such samples, the real citric add should be estimated by dissolving a known weight in hydrochloric add, exactly neutralising with sodium hydroxide and treating the precipitated caldum citrate as described on page 562. Magnesium citrate and citrate prepared with dolomitic lime can be correctly analysed by the titration method; but if precipitation be de- sired, the sample must be decomposed by boiling with sodium c bonate, the magnesium carbonate filtered off, the filtrate neutralised with hydrochloric acid, and precipitated with calcium chloride. Ferric citrate, may be obtained by dissolving ferric hydroxide CTTKATES. 567 in citric acid and evaporating the solution in thin layers. It is thus obtained in transparent garnet-red scales, which are permanent in the air. It is insoluble in alcohol, but dissolves slowly in water to form a solution of a faintly ferruginous taste, not precipitated by ammonium hydroxide, but yielding ferric hydroxide on boiling with sodium hydroxide. After drying at 100^, the scales should leave from 29 to 3C3% of residue on ignition. Iron ammonium citrate may be made by dissolving precipitated ferric hydroxide in a solution of citric acid and adding ammonia. It occurs in thin, transparent, deep red scales, slightly sweetish and astringent. When heated with potassium hydroxide its solution evolves ammonium hydroxide and deposits ferric hydroxide. The alkaline liquid filtered from the precipitate should not give any crys- talline precipitate or streaks of potassium hydrogen tartrate, when acidulated with acetic acid and vigorously stirred. Ferric ammonium citrate is readily soluble in water, forming a faintly acid solution, but is almost insoluble in 95% alcohol. APPENDIX. The detection of lead is materially influenced by the presence of iron. Freshly precipitated ferric hydroxide will, by adsorption, cany down lead hydroxide. The procedure under such conditions has been recently investigated by J. M. Wilkie {J.Soc. Chem. Ind., 1909, 28, 637) who finds that the usual method of preventing precipitation of iron by adding potassium cyanide succeeds only when the iron is in the ferrous state. As a result of many experiments, Wilkie gives a special process. He uses sodium sulphide as the final precipitant, but W. A. Davis prefers freshly-made colourless ammonium sulphide, prepared by diluting 2 c.c. of 0.880 ammonia to 10 c.c. and saturating with well-washed hydrogen sulphide. Standard lead solutions may be conveniendy made from a strong solution of pure lead (5 grm. in nitric acid, evaporated to remove all but a small amount of the add and made up to 1000 c.c. This strong solution keeps fairly well. For use portions of it are diluted 100 times and applied in the usual manner for colour comparisons. Tartaric Acid, — Dissolve 10 grm. of the acid in about 25 c.c. of hot water, cool, add 2 c.c. of N/io sodium thiosulphate, heat to incipient boiling, cool, add i c.c. of 10 per cent, potassium cyanide and then ammonia (0.880) in small portions until the solution smeUs faindy of the reagent. Boil until the liquid is colourless, pour into a tall cylinder, make up to 100 c.c, and add 2 drops of freshly-prepared colourless ammonium sulphide. The tint developed is compared with tints produced by solutions made from absolutely lead-free acid to which known amounts of lead have been added, so as to give comparisons at say 5 parts per 1,000,000, 10 per 1,000,000, etc. Cream of tartar should be tested by dissolving 10 grm. of the sample in hydrochloric acid, adding sodium thiosulphate and proceeding as above directed. Owing to the wide distribution of lead, care must be taken that all the reagents are free from it. 568 ASSAY OF FORMALDEHYDE SOLUTIONS. 569 Assay of Formaldehyde Solutions, — E. Elvove {Anter. J, Pharm,, 191 1, 83, 455) has investigated the methods usually employed for estimating formaldehyde and finds the cyanide method the most trustworthy. He gives the following description of the procedure: Transfer 0.5 c.c. of the sample to a 150 c.c. Erlenmeyer flask and ascertain the exact weight. Add immediately 100 c.c. of a solution of potassium cyanide as nearly as possible N/io, the exact strength of which is known. Mix well and add the solution to a mixture of 40 c.c N/io silver nitrate and 10 c.c. dilute (10%) nitric acid in a 200 c.c measuring flask. Rinse the Erlenmeyer flask, add the rinsings to the mixture, and make up to 200 c.c. Shake well, collect 100 c.c. through a dry filter and titrate the excess of silver with N/ 10 thiocyanate solution, using ferric alum as an indicator. Multiply the number of cubic centimeters of thiocyanate solution used by 2 and subtract the product from 40; the remainder will be the equivalent of uncom- bined cyanide in cubic centimeters of the silver nitrate solution. Subtract this from the corresponding equivalent of the total cyanide, multiply by 0.3 and divide this product by the weight of the sample. The quotient will represent the percentage by weight of formaldehyde present. Note to Page 313. — In the German beet-root sugar industry instead of the Raffinose formula given on page 313, the formula 0.5124 P-L 0.8390 due to Herzfeld is used (see Friihling, Anleitung Unters. Zuckerind,, 7th Ed., 191 1, page 109). The letters have the same significance as those in the formula on page 313, which is official in the United States {Bulletin 107, Bureau of Cliem., U. S. Dept, Agric, 1907). The PS formula R= remains the same as before. 1.852 Note to Page 328. — Mr. A. E. Johnson points out, in a private com- munication, that the table on page 328 due to Allen and reprinted from the last Edition, in view of corrected atomic weights (191 2), etc., is more correctly replaced by that which follows: 570 ASSAY OF FORMALDEHYDE SOLUTIONS. ^'"»«^»i (after inversion) ^""«HJ"+"«« ^anhydrous) CijHjjOii Cooper.*... 0.5676 ■ 0.5393 ! 0.7621 ' 0.7340 j 0.91^5 Cuprous oxide 0.5042 0.4790 0.6769 0.6431 j 0.8132 Cupric oxide o-4S35 0.4308 0.6088 0.5784 1 o.73i<4 Note to Page 362. — ^The value of K 3.93 given as 61.9 by Brown and Heron has been corrected to K absolute = 62.24 by Brown, Morris and Millar (Trans, , 1897, page 100). This paper should be consulted for the table of reducing powers of different weights of maltose under their standard conditions. INDEX. Absorption spectra, 33 Acacia, gum, 440 Acetal, 268 dimethyl, 268 Acetaldehvde, 264 Acetate 01 iron, 511 lime,. 507 Acetates, 488, 506 Acetic acid, 488 assay of, 490 glacial, 494 nomologues of, 514 Acetic aldehyde, 264 ether, 236 Acetone, 104 in urine, ic6, 108 in wood spirit, 100 Acid mercuric iodide, 368 nitrate, 368 Acids, vegetable, 485 Adracantnin, 444 Agar-agar, 437 Alcohol, no absolute, no denatured, 113 detection of, 114 estimation of, 115 in essences, 129, 130 in fusel oil, 130 in tinctures, 129, 130 methyl compounds in, 95 specific gravity of, 115 ethyl, no methyl, 85 Alcohols, 85 Aldehyde, 253 acetic, 264 acrylic, 235 formic, 256 resin, 254 trichlor-, 268 valeric, 252 Aldehydes, 253 Ale, 149 AUylene dichloride, 273 Alum in bread, 459 — in flour, 457 Alumina cream, 309 Aluminum acetate, 5x0 Amyl acetate, 249 alcohol, 130 nitrate, 252 nitrite, 250 Amylan, 406 Amylin, 427 A. O. A. C, 28s Appendix, 568 Arabic acid, 440 gum, 440 Arabin, 444 Arabinose, 287, 400 Argol, 542 Arrowroot, 417 Arsenic, detection of, 63 estimation of, 146 Artifical fruit flavors, 235 Ash, estimation of, 71 Attenuation, 151 Balling's hydrometer, 291 Bamboo fibre, 481 Barley, 142, 463 sugar, 339 Bananas, 463 Barfoed's reagent, 333 Basic lead acetate, 308 Bassorin, 444 Bate's saccharometer, 291 Baum^'s hydrometer, 15 Beer, 149 bitters in, 161 carbon dioxide in, 157 extract in, 156 preservatives in, 163 stability of, 164 Beer-wort, orginal gravity of, 151 maltose and dextrin on, 141 Beet products, 359 root, composition of, 360 juice, 359 molasses, 357 sugar, 360 Benedict's reagent, 395 Bergamot juice, 559 571 572 INDEX. Bi-rotation, 315 Bitters in beer, 161 Black liquor, 511 Boiling point, 17 Brandy, 200 Bread, 418 Breakfast foods, 464 Brewing sugar, 379 British gum, 427 Brix hydrometer, 291 Bromine in organic substances, 62 Bromoform, 281 Butyl alcohol, 187 chloral, 273 Butyrate, 523 Butyric acid, 521 chloral, 273 Citric acid, detection of, 487, 555 estimation of, 555 liquors, 558 Claret, 186 Cleyet's formula, 313 Cologne spirit, 112 Colonial spirit, 88 Columbian spirit, 88 Compound ethers, 231 Confectionery sugar, 358 Copper acetate, 513 Cotton fibre, 481 Cream of tartar, 543 Croton chloral, 273 Crude fibre, estimation of, 70 Cutocellulose, 434 Cutose, 434 Calcium acetate, 507 citrate, 566 tartrate, 548 Candy, 338, 358 Cane products, 359 Cane sugar, 288, 301, 313, 338 detection of, 341 estimation of, 342 inversion of, 290 Caramel in wine, 179 Carbinol, 85 Carbohydrates, 285 Carbon dioxide in beer, 157 Cartier's hydrometer, 15 Cellulose, 406, 429 : estimation of, 437 purification of, 435 Cereals, 450 composition of, 450 mineral matters in, 456 proteins in, 412 Chloral, 269 alcoholate, 269 butyl, 273 detection of, 271 estimation of, 271 formamide, 274 hydrate, 269 meta-, 268 Chlorethylene, 248 Chlorine in organic substance, 62 Chloroform, 274 commercial, 276 detection of, 274 estimation of, 274 methylated, 276 spirit of, 280 Cider, 187 Citrates, 555, 565 Citric acid, 555 Denatxjued alcohol, 113 Dephlegmators, 21 Dextrin, 427 apparent, 141 in beer, 150 Dextro-glucose, 287 Dextrose, 287, 301, 372 estimation, 325 Diastase, preparation of, 421 Diastatic power of malt, 136 Dichlormethane, 281 Dimethylacetal, 268 Disaccharides, 286 Dispersion, 22 Distillation, 18 fractional, 18 Dutch liquid, 248 Ebullioscope, 127 Erythrodextrin, 428 Esparto fibre, 481 Essences, alcohol in, 130 artificial, 235 Esters, 231 in spirits, 195 in wood naphtha, loi Ether, 227 acetic, 236 commercial, 228 methylated, 231 methyl, 231 nitrous, 241 spirit of, 241 spirit of, 231 Ethers, compound, 231 Ethyl acetate, 236 alcohol, no bromide, 248 carbamate, 248 INDEX. 573 Ethyl chloride, 247 chlorinated, 248 dithiocarbonates, 240 ether, 227 nitrite, 241 oxide, 227 sulphate, 239 sulphuric acid, 240 thiocarbonates, 240 Ilthylene dichloride, 277 Ethylidene chloride, 248 Extract in beer, 157 in wine, 168 malt, 145 Fehling*s solution, 318 Fermentation, acetic, 488 alcoholic, 223, 298 Fibre, crude, 70 Fibres, vegetable, 418 Finish, methylated, 114 Flax fibre, 481 Flour, 453 gluten in, 455 Fluorescence, 40 Formaldehyde, 256 methyl alcohol in, 93 Formalin, 257 Formates, 520 Formic acid, 519 Fractional distillation, 18 Fruit essences, 235 Furfural, 196 Fusel oil, 187 alcohol in, 130 in spirits, 188 • Galactose, 287, 376 Gin, 203 Gliadin, 455 Gloy, 429 Glucose, 287, 372 laevo-, 287, 373 syrup, 377 Glucoside, 391 Glucuronic aldehyde, 399 acid. 399 Gluten, 455 Glutenin, 455 Glycerol in wine, 160 Glycogen, 406 Grain, raw, 144 Grape sugar, 377 Grits, 144 Gum acacia, 440 arabic, 440 tragacanth, 444 Gums, 406, 438 Hemp fibre, 481 Hexamethylene-amine, 263 Higher alcohols, 187 High wines, 112 Honey, 384 Hop resin, 161 substitutes, 161 Hydrochloric ether, 247 Hydrometers, 7 Hydrolysis, 296 Immiscible solvents, 79 Inversion, 296 Invertase, 314 Invert sugar, 289, 329, 375, 385 Iodine in organic substances, 62 Iodoform, 282 Iron acetate, 511 liquor, 511 Isobutyl alcohol, 194 Isobutyric acid, 523 Isomaltose, 379 Isovaleric acid, 524 Jute fibre, 433 KjELDAHL- Arnold method, 62 Gunning method, 59 Knapp's solution, 337 Koettstorfer method, 232 Lactose, 288, 301, 365 Laeonlose, 401 Lsvulose, 287, 301 Lead in citric acid, 557, 568 in tartaric acid, 549, 568 Lees, 542, 546 Lemon juice, 559 Lignin, 433 Lignocellulose, 433 Lime juice, 559 Linen fibre, 481 Lintner value, 136 Liow wines, 495 Maize, 462, 463 Malates, 534 Malic acid, 533 Malt, 133 diastatic value of, 136 extract, 145 574 INDEX. Malt, liquors, 133, 149 substitutes, 143 sugar, 141, 361 wort, 13s, 140 Maltose, 288, 301, 361 apparent, 141 Manila hemp fibre, 481 Mannose, 287 Maple sugar, 388 syrup, 388 Massacuites, 344 Melibiose, 288 Melting point, 16 Mercuric iodide solution, 368 nitrate solution, 368 Mesotartaric acid, 533 Metals in organic substances, 63, 75 Metachloral, 268 Methaldehyde, 250 Methyl alcohol, 8$ carbinol, no ether, 231 Methylated chloroform, 277 ether, 231 finish, 114 spirit, 95, 104 Milk sugar, 288, 301, 365 Moisture, estimation of, 64 Molasses, 344, 355 Monochromatic, 43 Monosaccharides, 286, 372 Mucic acid, 376 Mucocellulose, 434 Mucilages, 434 Mutarotation, 315 Nitre, spirit of, 242 Nitrogen, estimation of, 58 Nitroethane, 243 Nitropentane, 252 Nitrous ether, 241 spirit of, 242 Oats, 463 CEnolin, 181 Optical properties, 22 Orange juice, 401 Original gravity of worts, 151 Ovens, drying, 66, 69 Oxalates, 528 Oxalic acid, 527 Oxycellulose, 531 Paper, 465 fibres, 474 testing, 466 Paraform, 256 Paraldehyde, 267 Parchment paper, 431 Pavy's solution, 331 Pectates, 434 Pectic acids, 434 Pectocellulose, 434 Pectose, 434 Pentoses, 400 Pentyl acetate, 249 alcohol, 187 Perry, 125 Pith, 429 Plants, proximate analysis of, 445 Polarimeters, 41 Polarisation, 41, 310 Polysaccharids, 286, 405 Porter, 149 Potable spirits, 187 Potato spirit, 187 Potatoes, assay of, 426 Pot-still whisky, 202 Preservatives in beer, 163 in wine, 175 Proof spirit. III vinegar, 496 Propionic acid, 522 Propyl alcohol, 187 Proteins in cereals, 452 Proximate analysis of plants, 445 Pyridine in wood spirit, loa Pyrolignite of iron, 511 (M lead, 512 of lime, 507 Pulp, paper, 418 Quassia in beer, 161 Racemic acid, 53<^ 541 Raffinose, 288 Raw grain, 144 sugar, 351 Rectified spirit, in Red liquor, 510 Refractometers, 22 Rhamnose, 403 Rice, 454 Rochelle salt, 552 Rum, 203 Rye, 463 Sagcharimetry, 305 Saccharin, 164, 175 Saccharine solutions, 289 Saccharometry, 291 Saccharum, 375 Sachsse's solution, 337 Salicylic acid in beer, 163 in wine, 175 INDEX. 575 Saponification, 933 Schweitzer^s reagent, 430 Seidlitz powders, 553 Silent spirit, iia Solidifying points. Solvents, action of, 76 immiscible, 79 Sorbose, 287 Soxhlet's solution, 318 Specific gravity, 4 rotatory power, 44 Spectra absorption, $^ Spectrograph, $$ Spectroscope, 33 Spectrometer, 33 Spirit, cologne, 112 indication, 153 of nitre, 241 of nitrous ether, 241 of wine, 1 1 1 methylated, 95, 104, 246 proof, III rectified, 1 1 1 silent, 112 Spirits, potable, 187 aldehydes in, 197 esters in, 195 tannin in, 199 Sprengel's tube, 6 Spruce fibre, 481 Stability of beers, 164 Starch, 405 commercial, 425 detection of, 418 estimation of, 420 microscopy of, 408 soluble, 136 sugar, 354, 378 Straw fibre, 481 Subliming point, 16 Succinates, 532 Succinic acid, 531 Sucrates, 340 Sucrose, 288, 313, 338 Sugar, beet, 359 brewing, 375 cane, 359 commercial, 343 grape, 377 in urine, 393 inversion of, 296 invert, 289, 329, 375, 385 malt, 288, 301, 361 maple, 388 milk, 288, 301, 365 of lead, 512 Sugar-beet, composition of, 349, 356, 359 Sugar-cane, composition of, 349, 356, 359 Sugar-candy, 358 Sugar-confectionery, 358 Sugars, 285 classification of, 285 table of, 287, 288 Sulphates in wine, 174 Sulphites in wine, 174 Sulphovinic acid, 239 Sweet spirit of nitre, 241 Syrup, glucose, 377 maple, 388 sugar, 355 Szombathy's tube, 17 Tartar, 542 cream of, 543 emetic, 553 Tartaric acid, 536 in wine, 177 liquors, 540 Tartrates, 537, 551 Thermostats, 29, 55 Tin in molasses, 348 in sugar, 348 Tinctures, alcohol in, 95, 129 Tragacanth, 444 Tragacanthin, 444 Treacle, 355 Trehalose, 288 Trichloracetic acid, 272 Trichloraldehyde, 268 Trichlormethane, 274 Tunacin, 429 Turanose, 288 Twaddeirs hydrometer, 7 Ultimate analysis, 57 Urine, acetone in, 106, 108 sugar in, 393 Valeral, 252 Valeraldehyde, 252 Valerianic acid, 524 Valeric acid, 524 aldehyde, 252 Vapor densities, 16 Vegetable acids, 485 fibres, 481 mucilages, 434 Verdigris, 512 Vinasse, 85 Vinegar, 495 aromatic, 501 beer, 491 cider, 497 glucose, 498 malt, 498 576 INDEX. Vinegar, spirit, 4< wine, 496 wood, 491 Vinous fermentatioi Wheat, 453 Whisky, 201 Wine, 165 acid in, 169 boric acid in, 176^ colouring matters extract of, 168 tluorides in, 176 glycerol in, 166 saccharin in, 175 salicylic acid in, 170 spirit of. III sulphates in, 174 sulphites in, 174 sugar in, 1 70 298 177 Wine, tannin in, 175 tartaric acid in, 169 volatile acids in, 169 Wines, high, 112 low, 495 Wood naphtha, 99 pulp, 480 spirit, 85, 99 vinegar, 491 Xanthates, 240 Xanthic acid, 240 Xylose, 287, 400 Yeast, 205 compressed, 219 Zinc in organic substances, 75 LANE MEDICAL LIBRARY Til avoid fine, Ihis book should be returned o. >r before tlie date lasi stamped below. )CT 21 i-i 'IIAR27 19; 4 0271 Allen. A.H. A425 Allen's cotnmercial 1912 organic analysis. 