:.:;Y.iffii.;-,'s|;-:„';.:;-;' ,.*«w'S.'?'l!vi',vi{r'j:;'';,'"i!,'','i'1 - 18 k?***** iJiii^nvSg^" SB ^^fe^rr-vl- {-'.■■;■■■-.'- 'v.v '•gi&r.f.a; v.v;-:-'v ■:;■'■" '•v-,.:.v. "•»#»•» Jt'l t ■ :',.,,., ■/'*••■• •*^■•^^^'^^:;^^r/^^•,^-^■■.•;•.." 5^/.Y•*yyJ^i/."•,'■">*"u*'"'^'• * - !&*^-y^s»«CK:. ':rj;-J.:. ■'■■ ' ■■.(jj.^t.Mti-n..^^.^.. ..-/. .-/-TX.-.:;;;?^.::. : ".•;■£:.v ";.^w. ADULTERATIONS VARIOUS SUBSTANCES MEDICINE AND THE ARTS WITH THE MEANS OF DETECTING THEM: INTENDED AS A MANUAL FOR THE PHYSICIAN, THE APOTHECARY, AND THE ARTISAN. BY LEWIS C. BECK, M.D. PROFESSOR OF CHEMISTRY IN RUTGERS COLLEGE, NEW JERSEY, AND IN THE ALBANY MEDICAL COLLEGE ; HONORARY MEMBER OF THE MEDICAL SOCIETY OF THE STATE OF NEW YORK, ETC, NEW-YORK: ^^U^^ SAMUEL S. AND WILLIAM WOOD, NO. 261 PEARL STREET. 1S46. **»%*\ %Vv^\ Entered, according to Act of Congress, in the year 1846, by LEWIS C. BECK, M.D. in the Clerk's Office of the District Court for the Southern District of New York. E. O. JENKINS, PRINTER, 114 Nassau street. *%*-• PREFACE. The design of this work is to exhibit the adulterations of various substances, being principally such as are used in Medicine and the Arts, and to describe the processes by which they may be detected. The authorities upon which I have chiefly depended are, a Manual published several years since under the title of the Domestic Che- mist ; a treatise Des Falsifications des Substances Alimentaires, &c. par J. Gamier et C. Harel; the United States Dispensatory, by Pro- fessors Wood and Bache ; Pereira's Materia Medica; Neligan's Me- dicines, their Uses, &c.; Ure's Dictionary of Arts, &c.; Parnell's Applied Chemistry; H. Hose's Manual of Analytical Chemistry, and Fresenius on Qualitative Chemical Analysis. "Various scientific periodicals have also been consulted; but these it is unnecessary to enumerate, as due credit is given for every important fact which has been obtained from them. The processes for the detection of the adulterations noticed in this volume, are usually quite simple, and may be easily followed even by the tyro in chemistry. In a few cases, however, they are more difficult, and some knowledge of the details of the science and some experience in the business of testing will be necessary. I have en- deavoured especially to render the descriptions of such processes as plain and as free from technicalities as possible. IV PREFACE. It should be distinctly stated, that directions for the accurate quan- titative analysis of the substances here described do not fall within the scope of this work. All that is proposed to be determined is the nature of their adulterations, and in some cases an approximation to the proportions in which these exist. As a means towards the accomplishment of the object in view, I have also given the charac- teristics of most of the bodies in their state of entire purity. Besides the names employed as the basis of the alphabetical ar- rangement which has been adopted, others have been added as sy- nonyms. Thus of the medicinal articles, the names used in the Pharmacopoeia of the United States (indicated by the letters U. S.) have in all cases been given. To obviate the difficulty which might otherwise arise on this account, a very copious index has been pre- pared. It is believed that no one who may use this volume as a book of reference will consider this an unnecessary addition. In the appendix will be found full descriptions of the various chemical operations noticed in the body of the work, directions for the preparation of reagents, and several tables exhibiting the beha- viour of some reagents with the more important substances. The materials for the first two divisions have been chiefly drawn from the work of Fresenius already referred to; while the tables have been compiled from Will's Outlines of Qualitative Analysis. If it is deemed important to guard against the bodily injury and pecuniary loss which must often arise from the employment of adulterated substances, the utility of a work of this kind will be readily admitted. Whether the author has been successsful in his attempt to prepare such a manual as seems to be required, is now submitted to the decision of those for whom it is especially in- tended. Rutgers College, N. J., September, 1846. CONTENTS. Acetic Acid, . . 13 Atropine, Aconitine, 18 Balsam of Copaiba, . Alcohol, . . , 19 Balsam of Peru, Aloes, .... 23 Balsam of Tolu, Alum, .... 24 Barium, Chloride of, Amber, .... 25 Nitrate of, . Ammonia, 25 Beer, . Acetate of, 26 Benzoic Acid, . Muriate of, 26 Benzoin, . . . . Nitrate of, 27 Bismuth,. . . . Sesquicarbonate of, 27 Subnitrate of, . Spirit of, . 28 Bleaching Powder, . Ammoniac, 28 Boracic Acid, . Anime\ .... 29 Bromine,. Aniseed, .... 30 Burgundy Pitch, Annotto, .... 30 Cacao and Chocolate, Antimony, 31 Cajeput Oil, . Oxysulphuret of, 32 Calcium, Chloride of, Sesquioxide of, 34 Camphor, Sesquisulphuret of, 35 Canella Alba, . Antimony and Potassa, Canna Starch, . Tartrate of, 35 Cantharides, Antimonial Wine, . 37 Caraway Seeds, Arrow-root, 37 Cardamon Seeds, Arsenic, .... 38 Carmine, . . . . Yellow sulphuret of, 39 Castor, . Arsenious Acid, 39 Castor Oil, Assafcetida, 40 Catechu, . . . . VI CONTENTS. Cayenne Pepper, Charcoal, 62 62 Gum Arabic, . Gunpowder, . 93 94 Animal, 63 Hog's Lard, 94 Cider, . . • • 64 Honey, . 95 Cinnamon, 65 Hops, . 96 Citric Acid, 66 Hydrocyanic Acid, . 96 Cloves, . . • • 68 Hyoscyamine, . 98 Coal Gas, 68 Indigo, .... 98 Cobalt, . 69 Iodine..... 99 Oxide of, 69 Tincture of, . 100 Cocculuslndicus, 69 Ipecacuanha, . 100 Cochineal, 70 Iron, .... 101 Coffee, . 71 Black Oxide of, 102 Colchicum, 73 Carbonate of, . 102 Colocynth, 74 Lactate of, 103 Colcothar, 74 Perchloride of, . 103 Colomba Root,. 75 Protiodide of, . 104 Common Salt, . 76 Sulphate of, 104 Confectionary, 78 Red Oxide of, . 105 Conium, . 80 Iron and Potassa, Tartrate of, 107 Copper, . 81 Jalap, .... 107 Acetate of, . 81 Kino, .... 108 Ammoniacal sulpl late Lampblack, 109 of, . 82 Lead, .... 109 Diacetate of, 82 Acetate of, 110 Sulphate of, . . 83 Carbonate of, . 111 Creasote,. . 83 Chromate of, . 112 Croton Oil, . 84 Iodide of, 113 Cubebs, . . 85 Protoxide of, . 114 Dragon's Blood, . 86 Red Oxide of, . 114 Ergot, . 86 Lime, . 115 Gall-Nuts, . 87 Carbonate of, . 117 Gamboge, . 88 Liquorice, 118 Gentian, . . 89 Logwood, 119 Gold, . 89 Lycopodium, . 119 Chloride of, . 91 Madder, .... 120 Iodide of, . 91 Magnesia, Calcined, . 121 Graphite, 91 Carbonate of, . 122 Guaiac, . . 92 Sulphate of, 124 CONTENTS. Vir Manganese, Peroxide of, 126 Phosphorus, 163 Manna, . 128 Platinum, 164 Mercury, 129 Pomegranate Bark, . 165 Bicyanide of, 130 Potassa, Acetate of, 165 Black Sulphuret of, 130 Bicarbonate of, 166 Perchlorideof, 131 Binoxalate of, 166 Periodide of, 131 Bitartrate of, . 167 Peroxide of, . 132 Carbonate of, . 168 Protochloride of, 133 Chlorate of, 171 Protoxide of, . 135 Chromate of, 172 RedSulphuretof , 136 Nitrate of, 172 White Precipitate Sulphate of, . 175 of,. . 137 Tartrate of, 175 Milk, . . 138 Potassa and Soda, Tartrate Morphine, 141 of, . , . 176 Acetate of, . 141 Potassium, Bromide of, . 177 Muriate of, 142 Chloride of, 177 Sulphate of, 142 Cyanide of, . 178 Muriatic Acid, . 143 Ferrocyanide < )f, 179 Mushrooms, . 144 Iodide of, . 180 Musk, . 145 Protoxide of, 182 Mustard, . 146 Prussian Blue,. . 183 Myrrh, . 147 Purple of Cassius, . . 184 Naphtha, 148 Quassia, . . . 185 Nitric Acid, 148 Quinine or Quinia, . 185 Nitrogen, Protoxide of, 149 Disulphate of, 185 Nitromuriatic Acid, . 150 Red Saunders, . 188 Nitrous or Hyponitrous Rhubarb,. 189 Ether, . 150 Roses, Otto or Attar of, 192 Nutmeg and Mace, . 152 Safflower, . 192 Oils, Essential or Volatile 153 Saffron, . . 193 Olive Oil, 155 Sago, 194 Opium, . 157 Salep, 195 Oxalic Acid, 158 Salicin, . 196 Palm Oil, 159 Sarsaparilla, 196 Pepper, Black, 159 Scammony, 198 Peruvian Bark, 160 Scheele's Green, 199 Phloridzin, 162 Schweinfurt Green, . 200 Phosphoric Acid, 162 Sealing Wax, . 200 CONTENTS. Selenium, 200 Sulphur, Precipitated, 233 Senna, 201 Iodide of, . 233 Silver, 203 Sulphuric Acid, 233 Chloride of, 204 Sulphuric Ether, 237 Cyanide of, 205 Spirit of, . 238 Nitrate of, 205 Tallow, . 238 Soap, 207 Tamarinds, 239 Soda, Acetate of, 210 Tapioca, . 240 Biborate of, 211 Tartaric Acid, . 241 Bicarbonate of, 212 Tea, . . . . 242 Carbonate of, (Com- Thenard's Blue, 248 mercial,) 212 Tin, . 248 Carbonate of, (pure,) 214 Bisulphuret of, . 250 Hypochlorite of, 215 Titanic Acid, . 251 Hyposulphite of, 215 Turmeric, 251 Nitrate of, 216 Ultramarine, 252 Phosphate of, . 216 Uva-ursi, 252 Sulphate of, . 217 Venice Turpentine, . 253 Soda Water, . 218 Veratrine, 253 Sodium, Iodide of, . 219 Water, . . . . 254 Protoxide of, 219 Wax, . . . . 255 Spermaceti, 219 Wheat Flour, . 256 Starch, .... 220 Wine, . . . . 262 Storax, .... 222 Zinc, . . . . 266 Strontium, Chloride of, 223 Acetate of, 267 Strychnine, 224 Carbonate of, . 268 Succinic Acid, . 225 Chloride of, 268 Sugar, .... 226 Oxide of, . 269 Sulphur, . 231 Sulphate of, 270 ADDITIONS. Opium, .... 273 Potassium, Cyanide of, . 274 Iodide of, . 275 Quinoidine, . . . 275 Arsemous Acid, . 271 Iodine, . 271 Muriatic Acid, , • 271 Oils, Fat or Fixed, . . 272 CONTENTS. APPENDIX. IX -OPERATIONS AND INSTRUMENTS EMPLOYED IN QUAL- ITATIVE ANALYSIS. Reduction of Soli is to pow- Edulcoration, . . 284 der, . . 279 Evaporation, . . 284 Solution, . . 279 Distillation, . 285 Crystallization, . 280 Sublimation, . . 285 Precipitation, . • 281 Ignition, . . 286 Filtration, . 283 Testing, . . 286 Decantation, . 283 II.--PREPARATION OF TESTS OR REAGENTS. Definitions,.........287 A.--REAGENTS IN THE HUMID WAY. 1.--GENERAL REAGENTS. a. Reagents principally used as Simple Solvents. 1. Water, . . . 290 ) 2. Alcohol, b. Reagents principally used as Chemical Solvents. 3. Muriatic Acid, . . 291 4. Nitric Acid, . . 292 5. Nitromuriatic Acid, . 292 6. Acetic Acid, 7. Muriate of Ammonia, 291 293 293 c. Reagents which serve especially to separate, or otherwise to charac- terize groups of substances. 8. Litmus, . . .294 9. Turmeric, . . . 294 10. Sulphuric Acid, . . 295 11. Sulphuretted Hydrogen, 295 12. Hydrosulphuret of Am- monia, . . . 296 13. Sulphuret of Potassium, 297 14. Potassa, ... 297 15. Carbonate of Potassa, 298 16. Ammonia, . . . 299 17. Carbonale of Ammonia, 299 18. Chloride of Barium, . 300 19. Nitrate of Baryta, . 301 20. Chloride of Calcium, . 301 21. Nitrate of Silver, . 302 X CONTENTS. 2.--SPECIAL REAGENTS. a. Reagents which serve especially for the detection of various bases- 22. Sulphate of Potassa, . 23. Phosphate of Soda, . 24. Chromate of Potassa, 25. Ferrocyanide of Potas- sium, 26. Ferricyanide of Potas- sium, 27. Oxalic Acid, 28. Oxalate of Ammonia, . 302 303 303 304 304 304 305 29. Tartaric Acid, . . 305 30. Bitartrate of Potassa, . 306 31. Piotochloride of Tin, . 306 32. Chloride of Gold, . 306 33. Chloride of Platinum, 307 34. Zinc, . . . .308 35. Iron, . . .308 36. Copper, . . .308 b. Reagents which are particularly applied to the detection of various ACIDS. 37. Acetate of Potassa, . 38. Caustic Lime, 39. Sulphate of Lime, 40. Protosulphate of Iron, 41. Acetate of Lead, 42. Sulphate of Copper, . 43. Ammonio-nitrate of Sil- ver, .... 308 309 309 309 310 310 310 44. Sulphurous Acid, . 311 45. Chlorine, . . .311 46. Solution of Indigo, . 311 47. Starch Paste, . . 312 48. Tincture of Iodine, . 312 B.--REAGENTS IN THE DRY WAY. 51. Nitrate of Potassa, 49. Charcoal, . . .312 50. Cyanide of Potassium, 313 314 III.--TABLES EXHIBITING THE BEHAVIOUR OF SOME REAGENTS WITH THE MORE IMPORTANT METALS, METALLIC OXIDES AND ACIDS. Table i.—Behaviour of solutions of the metals with sulphuretted hydrogen and hydrosulphuret of ammonia,........317, 318 CONTENTS. Table ii.—Behaviour of the more important acids, on heating their salts with sulphuric acid, . . 319 Table hi.—Behaviour of the more important acids, with chloride of barium, .... 320 Table iv.—Behaviour of the more important acids, with nitrate of silver, . . . , 321 Table v.—Behaviour of certain acids, with chloride of calcium,...... 322 ERRATA. Page 24, 7th line from top, for " Cabilline" read " Caballine." Page 94, 14th line from top, for " eprovette," read " c^n-ouvette." Page 98,1st line from top, for hyocyamine or hyocyamia," read "hy - oscyamine or hyoscyamia."—2d and 9th line from top, for " hyocyamine," read "hyoscyamine." Page 151, 1st line from top, for "uEthcri," read " JEtheris." Page 158,15th line from bottom, for " Rumea acetosa," read "Rumex acetosa." ADULTERATIONS OF ARTICLES USED IN MEDICINE AND THE ARTS- ACACIA.—See GUM ARABIC. ACETIC ACID. Acidum Acelicum, U. S. Pure acetic acid has a specific gravity of 1.063, compared with distilled water at 1.000. It has a pungent and very characteristic odour, and a caustic taste ; it dissolves cam- phor and the essential oils, reddens litmus powerfully, and combines with bases ; it forms blisters on the skin like a mineral acid. Acetic acid is the basis of the article known under the name of distilled vinegar, and of the vinegar of commerce in all its varieties. These several articles are often adulterated with various substances. Acetic acid and distilled vinegar should be perfectly colourless, and should evaporate when heated in a watch glass without leaving any residue. They must, when diluted with water, give no precipitate with chloride of ba- rium, or we may suspect the presence of sulphuric acid. If when neutralized with ammonia and tested with a solu- tion of chloride of barium, they give a white precipitate 2 14 ACETIC ACID. which dissolves in dilute muriatic acid, they contain sul- phurous acid. If they give a precipitate with a solution of nitrate of silver, they contain muriatic acid. The presence of nitric acid may be suspected if, when a portion of sul- phuric acid is added to the suspected liquid, a crystal of protosulphate of iron gives a deep brown tint to the sur- rounding liquid, and if the solution of indigo is discoloured on being heated with the acid. If when heated with a slight excess of ammonia, a blue solution is produced, it is an evidence of the presence of copper ; but if brown-red flocks separate on such addition, the acid holds iron in solu- tion. If liquid sulphuretted hydrogen causes a precipitate, it is due to the presence of a metal. Six parts of pure acetic acid should saturate about ten parts of pure crystallized bicarbonate of potassa. And by a reference to this standard the proportion of pure acid in dis- tilled and common vinegar may be accurately determined. There are various kinds of vinegar in commerce, such as wine vinegar, vinegar of wood, cider vinegar and beer vin- egar. Wine vinegar is prepared by the fermentation of white wine, and is usually colourless. Vinegar of wood is obtained by the distillation of wood, and was formerly an important article of commerce. It is said to be now chief- ly used for the purpose of increasing the strength of wine vinegar. Cider vinegar is obtained from the fermentation of the juice of the apple, and is largely used in this country. Beer vinegar is but little used for domestic purposes. Its chief consumption is in the arts. Vinegar is often adulterated with the stronger acids, as the sulphuric, the muriatic and the nitric ; also with some of the vegetable acids, as the tartaric and oxalic acids. Acrid substances are moreover sometimes added to give a factitious pungency to the vinegar, and, through careless- ACETIC ACID. 15 ness in the manufacture, it may contain certain metallic salts. As most of these varieties of vinegar naturally contain minute proportions of certain salts which affect the reagents employed in the detection of the adulterants, the processes are more complicated than those which are applicable to acetic acid. Vinegar being largely employed in domestic economy and the arts, it will be useful to present these pro- cesses in detail. They are principally drawn from the work of Gamier and Harel, Des Falsifications des Substances Ali- mentaires. Detection of Sulphuric Acid.—Take a known quantity of the suspected vinegar, a pint for example, put it into a por- celain capsule and[evaporate it by a gentle heat to one-eighth its volume. Add to the concentrated liquid, when cool, five or six times its volume of spirit of wine, and stir the liquid with a glass rod. The alcohol will dissolve the acid, and cause the precipitation of the salts which it held in so- lution. Filter the alcoholic liquor and wash the insoluble matter which remains on the filter with alcohol. To the clear filtered solution diluted with water, add chloride of barium in excess. If any sulphuric acid is present a white precipitate will be formed which is insoluble in nitric acid. There is said to be a kind of vinegar in France which gives an abundant precipitate with chloride of barium, but which, however, does not contain free sulphuric acid. It is a mixture of wine vinegar with a vinegar prepared from the syrup of fecula, and from the eaux de bac. This vinegar treated with alcohol does not yield free sulphuric acid ; the precipitate caused by the chloride of barium, before the addi- tion of alcohol, is due to the presence of sulphate of lime. Detection of Muriatic Acid.—As the purest vinegar often contains a certain quantity of chlorides, as well as sulphates, 16 ACETIC ACID. the presence of free muriatic acid is determined as follows A known quantity of the suspected vinegar, say a pint, is in- troduced into a tubulated retort, to which an adopter and re- ceiver are attached. The liquid is then distilled to near dry- ness, and it passes into the receiver, which must be kept cool. The distilled liquid is treated with a solution of nitrate of silver, which causes no precipitate when the vinegar has not been mixed with muriatic acid, but produces a more or less abundant one when this acid has been added to it. Detection of Nitric Acid.—The adulteration of vinegar by nitric acid is of rare occurrence. We can determine its pre- sence in vinegar by carbonate of potassa. When the suspect- ed liquor is saturated with the salt and evaporated to dryness we obtain a saline mass, which, if it contains nitrate of potas- sa, will burn with scintillations when thrown upon burning charcoal. This mass, also, when mixed with copper filings, and treated with sulphuric acid, will cause the disengage- ment of reddish vapors of nitrous acid, if a nitrate is contained in it. Another process for the detection of nitric acid in vinegar has been recently proposed. Put into a capsule some drops of the suspected vinegar, and into the liquid introduce a few scrapings or cuttings of the barrel of a writing quill. If upon the application of heat the organic matter acquires a yellow colour, it is certain that the vinegar contains nitric acid. Detection of Tartaric Acid.—Vinegar is sometimes adul- terated with water acidulated with tartaric acid. One part of crystallized tartaric acid in twenty-four parts of water, gives a liquor which has the same specific gravity as good vinegar. This solution is often sold in France under the name of Verjuice. For the purpose of detecting the presence of tartaric acid evaporate a portion of the suspected vinegar to about ACETIC ACID. 17 three-fourths of its volume, and when cool, filter the solution and add solution of acetate of potassa. If tartaric acid is mixed with the vinegar, crystals of cream of tartar are slowly formed, the quantity of which is increased by agitation. No such precipitate is obtained if the vinegar is pure. The presence of tartaric acid in vinegar can also be deter- mined by saturating the suspected liquor with potassa. Upon adding to the saturated liquid a solution of chloride of barium, or chloride of calcium, if the vinegar contains tartaric acid, we obtain a precipitate of tartrate of lime, or tartrate of bary- ta, which is not the case when pure vinegar saturated with potassa is employed. Detection of Oxalic Acid.—The adulteration of vinegar with oxalic acid is, probably, quite rare, although it is men- tioned by some authors. It may be easily detected by satu- rating the suspected vinegar with ammonia, and then adding to the saturated liquor a solution of a soluble salt of lime, when, if the vinegar is adulterated with oxalic acid, there will be an abundant precipitate of oxalate of lime. To dis- tinguish between oxalic and tartaric acids, lime water may be used, which instantly gives a precipitate with the former, but not with the latter, unless added until alkaline reaction is produced. Detection of Acrid Substances.—These are sometimes added for the purpose of increasing the pungency of the vinegar. They can generally be detected by their peculiar taste, and by the irritation which they occasion when taken into the mouth, or applied to the lips. They may also be detected by evaporating the vinegar at a gentle heat to the form of an extract: this extract of vinegar, to which pepper, pellitory, &c, has been added, has an acrid, piquant and caustic taste, which is not possessed by the extract pro- duced by pure vinegar. 2* 18 ACONITINE. Detection of Metallic Salts.—Vinegar sometimes contains salts of copper, lead and zinc. The presence of these salts is due to the employment in its manufacture of instruments made of copper, lead and brass, and to the use of metallic faucets. The following are the tests :— The yellow ferrocyanide of potassium gives a white preci- pitate with the salts of zinc, and a reddish-brown precipitate with the salts of copper. The iodide of potassium gives a yellow precipitate with the salts of lead. Sulphuretted hydrogen causes with the salts of lead and of copper a precipitate of a brown or black color. Chromate of potassa gives a fine yellow precipitate with a salt of lead. ACONITINE, or ACONITIA. Aconilum, U. S. The active principle of the Monkshood, Aconitum Napelius L., a plant found in the mountainous parts of Europe and extensively cultivated in gardens. It is extracted from the leaves and root of the plant, and usually occurs in the form of a colourless and somewhat vitreous mass. It has a sharp and bitter taste and an alkaline reaction. It is soluble in alcohol, ether and the acids, and when heated on platinum foil it is speedily and entirely dissipated. It is one of the most deadly poisons, although in minute doses used medicinally. According to Pereira a spurious aconitine is found in the shops. It is imported from France and bears the stamps and label of a celebrated French chemical firm. Its colour is grayish yellow. It is inert or nearly so, is not completely soluble in alcohol or ether, and when burnt on platinum foil leaves a calcareous residue.—(Elements of Materia Me- dica.) ALCOHOL. 19 ADEPS.—See HOG'S LARD. ALCOHOL. Alcohol, U. S. A limpid, colourless liquid, having a penetrating odour and burning taste. The lightest that can be obtained by simple distillation has a specific gravity of 0.825, but by the inter- vention of substances that strongly attract water, it has been brought to the specific gravity of 0.790, at 60° F. In that state it boils at 168° F., and does not become solid even in the most intense cold. The spirituous products which are obtained from ferment- ed liquors by the ordinary processes of distillation have re- ceived various names. Thus, brandy is obtained from wine ; rum, from molasses or the juice of the sugar-cane ; whiskey, from barley, rye and potatoes ; gin, from beer and fermented cereals, with the addition of juniper-berries ; ar- rack, from fermented rice, &c. The intoxicating properties of all these liquors depend upon the proportion of pure al- cohol which they contain. As alcohol is specifically lighter than water, all the pro- cesses for determining its proportion in mixtures of alcohol and water, have for their object some mode of ascertaining the specific gravity of these mixtures. For this purpose a convenient instrument has been devised by Gay Lussac, call- ed the Centesimal Alcoomeler. The scale of this instru- ment is divided into 100 equal parts ; of which 0 corresponds to pure water and 100 to absolute alcohol, at a certain tem- perature ; so that when it is introduced at this temperature into a liquor containing equal volumes of water and of absolute alcohol, it will sink to the line of 50°. Thus also in every other case the proportion of absolute alcohol and water will be indicated by the degree which corresponds to the level 20 ALCOHOL. of the liquid under examination. Suppose, for example, a pipe containing 126 gallons filled with brandy, in which the alcoometer stands at 55°, at 59° F., (15° Cent., the tempera- ture assumed as the standard by Gay Lussac, and this tem- perature being attained either by warming the sample with the hand or cooling it by plunging the vessel which contains it in well water,) the pipe will contain 69.3 gallons of ab- solute alcohol. For, 100 : 55 :: 126 : 69.3. As the specific gravity of absolute alcohol is well known, and tables have been constructed showing the specific grav- ities of various mixtures of alcohol and water at a common temperature, the proportion of alcohol in any mixture may also be determined by a thousand grain bottle, an instrument constantly employed in the analysis of mineral waters. The following table shows the density of absolute alcohol and of mixtures of alcohol and water at 59° F. Alcohol Densities Alcohol Densities in 100 parts. of the liquor. in 100 parts. of the liquor. 100 0. 7947 60 0 9141 95 0. 8168 55 0.9248 90 0. 83-16 50 0. 9348 85 0. 8502 45 0. 9440 80 0.8643 40 0.9523 75 0. 8779 35 0. 9595 70 0. 8907 30 0. 9636 65 0. 9027 The brandy of commerce has a brownish yellow colour which it acquires by being kept in hogsheads of oak. This kind of liquor always contains an extractive principle and tannic acid, to which it owes the property of being blacken- ed when a few drops of a solution of persulphate of iron are added to it. In France, the retailers often sell, under the name of brandy, alcohol diluted with water, and coloured with a little caramel. This liquor differs from genuine brandy in its taste, and in not changing its colour upon the addition of per- sulphate of iron. ALCOHOL. 21 Brandy often contains a small quantity of copper, derived from the distillatory apparatus, dissolved by the acid con- tained in the liquor. The presence of this metal in the state of a salt, can be detected by solution of ammonia, and by a clean plate of iron. After decolourizing the brandy by animal charcoal, ammonia gives to the liquor, if it contains copper, a fine blue colour, which sometimes, however, ap- pears only at the end of several hours. A piece of iron properly cleansed and put in contact with such a liquid, is covered with a coating of metallic copper. M. Chevallier has found copper in many specimens of brandy, and is said to have in his possession a nail taken from a pipe of that liquor which was so charged with copper that it appeared to be made of this metal.—(Gamier and Harel.) Brandy sometimes contains lead. This metal, which is found in the form of a salt, is derived either from the solder or from the capital of the still. It has also been recently ascertained that a solution of acetate of lead is sometimes added to this liquor to facilitate its clarification. The presence of this metal can be detected by evaporating the liquor to one half its volume in a porcelain capsule, and then adding to separate portions of it a solution of sulphate of soda and of sulphuretted hydrogen. The first of these causes a white precipitate of sulphate of lead : the second a black precipitate of the sulphuret of lead. To determine whether acetate of lead has been added, the liquor should be evaporated nearly to dryness, when if that salt is present, the addition of sulphuric acid will liberate acetic acid which may be recognized by its odour. Acrid substances are sometimes added to brandy and weak alcohol. This fraud can be easily detected by evap- orating a portion of the liquor to dryness, when the acrimo- ny is at once perceptible to the taste. Dr. Ure states that various frauds are practiced in the introduction of alcohol into Great Britain on account of its 22 ALCOHOL. high price there, and the high duty imposed upon it. Some- times it is introduced under the mask of oil of turpentine, from which it can be sufficiently freed by rectification for the purpose of the gin manufacturer. Sometimes it is dis- guised with wood naphtha, wood vinegar, or with coal naphtha. From wood vinegar and coal naphtha it may be separated by distillation on account of the difference be- tween the boiling points of the two liquids. Coal naphtha does not combine with water as alcohol does. When the object is to discover whether wood spirit con- tains alcohol, we may proceed as follows: Add to the suspected liquid a little nitric acid, of specific gravity 1.45. If alcohol is present, in even small proportion, an efferves- cence will ensue from the evolution of etherized nitrous gas, with its characteristic etherous smell. Pure wood spirit when mixed with nitric acid, becomes of a ruby tint, but remains tranquil. Alcohol continues colourless, but en- ters into violent ebullition, and is nearly all dissipated in fumes. The mixture of wood spirit with alcohol may also be detected by the addition of caustic potassa, a little of which, in powder, causes wood spirit to become speedily yellow and brown, while it gives no tint to alcohol. Ac- cording to Dr. Ure, in this way one per cent, of wood spirit may be discovered in any sample of spirits of wine. The alcohol distilled from damaged grain sometimes con- tains a peculiar volatile body, which, when the spirit is in a hot state, irritates the eyes and nose. It has nearly the same smell as alcoholic solution of cyanogen. Such spirits intoxicate more strongly than pure spirit of the same strength, and excite in many persons even a temporary frenzy. Dr. Ure says he separated it in cold weather at some of the great distilleries in Scotland, and then found it to be a volatile fatty matter, of a very fetid odour. At the end of a few months, it spontaneously decomposes in the spirits and leaves them in a less nauseous and noxious state. ALOES. 23 The greater part of the oil may be separated by largely diluting the spirits with water and distilling at a moderate temperature.—(Dictionary of Arts, §c.) ALOES. Aloe, U. S. The substance, known in commerce under the name of aloes, is the extract of several species of Aloe, as A. spicata L., A. socolrina D. C, A. vulgaris D. C, and A. arborescens D. C. The Socotrine is made in the various islands in the Straits of Babelmandel, but being originally brought from Socotra, one name is given to the whole. The A. spicata is extensively cultivated at the Cape of Good Hope, and such large quantities of it are ex- ported that it is said to have nearly driven the Socotrine from market, (BurneWs Outlines of Botany.) Aloes is also obtained from Barbadoes, where it is made from several different species : it is in general a less pure and sightly drug than either the Socotrine or the Cape. Socotrine aloes has a brilliant reddish brown colour, is usually translucent, has a smooth conchoidal fracture, an aromatic, agreeable odour, and an intensely bitter and nauseous taste. It affords a gold- en yellow powder. It is almost entirely soluble in boiling water and in common alcohol. As usually obtained, it is of a darker colour, more opaque, and has a more disagreeable taste and odour. It is sometimes adulterated by being mixed with common resin, a fraud which can be detected by the insolubility of such aloes in boiling water. Cape Aloes, when freshly broken, has a dark olive or greenish colour, approaching to black; it has an almost glassy fracture, and is translucent at the edges. The powder is of a fine greenish yellow colour; its odour is strong and disagree- able, but not nauseous. In cold weather it is brittle, and easily reduced to powder, but in very hot weather it is apt 24 ALUM. to become soft and tenaceous. The superiority of this vari- ety is said to be entirely owing to the care observed in the evaporation, and in avoiding the intermixture of earth, stones and other impurities. Barbadoes Aloes.—This is supposed to be more active than the Socotrine aloes, and is hence used by farriers; it is on this account called Cabilline aloes. It is usually of a darker colour, and is more opaque than the Socotrine aloes; it has also a tougher consistence, and a more disagreeable odour. It leaves a considerable residue when acted on by boiling water and alcohol, by which means it can be distin- guished from the other kind which dissolves almost entirely in these menstrua. ALUM. Alumen, U. S. The term alum is now applied to several different kinds of salts. The most common of these are the sulphate of alumina and potassa, sulphate of alumina and soda, and sulphate of alumina and ammonia. These may be distin- guished from each other by exposing portions of them to the action of a blow-pipe. Soda alum produces a rich yel- low flame ; potash alum a weak violet flame ; ammonia alum a transient green flame, and an odour of ammonia. Common alum (the sulphate of alumina and potassa) usu- ally crystallizes in regular octahedrons frequently with trun- cated edges and angles, and sometimes in cubes. It has an astringent and sweetish acid taste, and an acid reaction on vegetable blues. By exposure to the air it effloresces slightly, and when heated it undergoes watery fusion, swells up, and is converted into a white spongy mass called burnt alum. It dissolves in eighteen parts of cold, and less than its own weight of boiling, water. Alum should be colourless, and completely soluble in wa- ter, which proves the absence of earthy matter. Solution AMMONIA. of potassa or soda should form a colourless precipitate of hy- drate of alumina, soluble in an excess of the alkali. If the alum is mixed with sulphate of iron, which is sometimes the case, the precipitate formed by the addition of potassa or soda, is not entirely soluble in excess of the alkali; and the portion which remains undissolved is either of a red brown colour, or becomes so by exposure to the air. The presence of iron greatly injures alum for some purposes. AMBER. Succinum, U. S. This resin is of various shades of yellow or brown, transparent or translucent, with a specific gravity of 1.06 to 1.07. When heated it swells and burns, exhal- ing a white smoke of a pungent odour, but it does not run into drops. It is by these tests that amber may be dis- tinguished from copal and other resins with which it is some- times mixed. When pure, sixteen ounces of amber yield about half an ounce of succinic acid, three ounces of oil, and ten ounces of torrefied resin, fit for amber varnish. AMMONIA. Ammonice Liquor, U. S. The pure liquor, or solution, of ammonia, is a perfectly colourless liquid, and has a specific gravity of 0.93. It must have a pure ammoniacal odour, and when evaporated upon a watch glass must not leave the slightest residue. It ought not to be troubled by the addition of lime water, otherwise it contains carbonate of ammonia. When super- saturated with nitric acid, it should give no precipitate with chloride of barium, otherwise it contains sulphuric acid. If this solution gives a precipitate with nitrate of silver, it probably contains sal ammoniac ; if with oxalic acid, lime ; and if it is coloured by sulphuretted hydrogen, it contains some metal. 3 25 AMMONIA. It is difficult to obtain a solution of ammonia quite free from carbonic acid, and the presence of that substance in small quantity presents no difficulty for pharmaceutical uses. For certain chemical purposes it requires to be as pure as possible. It should be kept in bottles, accurately closed with glass stoppers. AMMONIA, ACETATE OF, (SOLUTION.) Liquor Ammonia Acetatis, U. S. This is a solution obtained by the addition of sesquicar- bonate of ammonia to distilled vinegar, until there is only a very slight excess of acid. When pure, the liquid is colour- less, and should leave no residue on the application of heat. Upon the addition of strong sulphuric acid it evolves vapours of acetic acid, and if potassa or lime be mixed with it, ammo- nia is given out when gently heated. This solution may contain muriatic acid, sulphuric acid, or some metal. Nitrate of silver will give a white precipi- tate if the first is present; chloride of barium will give a white precipitate, insoluble in nitric acid, if it contains sul- phuric acid. The discolouration produced by sulphuretted hydrogen will indicate the presence of a metal. If chloride of barium gives a white precipitate, soluble in an acid, or if acetate of lead produces a white precipitate, also soluble in nitric acid, it is due to the presence of carbonic acid. AMMONIA, MURIATE OF. Murias Ammonia, U. S.— Sal Ammoniac. This substance generally occurs in the form of hard, colourless and translucent cakes, having a somewhat fibrous structure. It has a sharp taste, is soluble in about three parts of water at 60°, and in an equal weight at 212°. It is also soluble in alcohol. Exposed to a heat below that of ignition, it sublimes without fusion or decom- AMMONIA. 27 position, and condenses on cool surfaces. When rubbed with quicklime it gives out the odour of ammonia. The impurities generally found in muriate of ammonia are sulphate of ammonia, sulphate of soda, chloride of sodium, and occasionally the oxides of lead, iron and copper. If it sublimes without residue, while its solution gives with chloride of barium a white precipitate insoluble in nitric acid, it contains sulphate of ammonia. If it leaves a residue upon being subjected to heat, it may contain sulphate of soda, or chloride of sodium. These substances are often found in unpurified sal ammoniac, to the amount often per cent. The presence of metals may be determined by the change of colour produced in a solution of the sal ammoniac by sulphuretted hydrogen, or hydrosulphuret of ammonia. AMMONIA, NITRATE OF. This is the salt employed in the preparation of the prot- oxide of nitrogen. It sometimes is met with in the form of six-sided crystals terminated by six-sided pyramids, in which state it is deliquescent and frequently contains an excess of acid. Sometimes the crystals are thin and fibrous, and sometimes, in consequence of the evaporation being carried farther, it forms a compact and shapeless mass. It is soluble in twice its weight of water at 60°; has an acid and bitter taste ; undergoes watery fusion when exposed to heat. It is liable to be contaminated with muriate of am- monia and the gas obtained from it is sometimes mixed with the vapour of nitrous acid. (See Nitrogen, Protoxide of.) AMMONIA, OXALATE OF.—See APPENDIX. AMMONIA, SESQUICARBONATE OF. Ammonia Carbonas, U. S.—Smelling Salts. This salt usually occurs in white, very hard, masses, of a fibrous crystalline structure, which effloresce and fall to pieces in the air. It has a strong ammoniacal odour, 28 AMMONIAC. which, however, must not be disagreeable and empyreu- matic. Pure carbonate of ammonia yields a colourless solution in water, and completely evaporates when heated in a platinum spoon. After supersaturation with nitric acid, it must not be precipitated by solution of chloride of barium, nor by solu- tion of nitrate of silver, nor by sulphuretted hydrogen. Carbonate of ammonia is often employed by bakers in the preparation of bread. That which is prepared from the liquor produced in gas-works is unfit for this purpose, as it has a disagreeable odour, from which it is difficult to free it. AMMONIA, SPIRIT OF. Ammonia Spiritus, U. S. This is a solution of ammonia, or more commonly of car- bonate of ammonia, in rectified spirit diluted with water. It is entirely unfit for most chemical uses, although it may be substituted for the solution of ammonia in pharmacy. In its pure form it is obtained by distillation. It is sometimes imitated by dissolving sal ammoniac, pot- assa and empyreumatic oil in water, without submitting the solution to the process of distillation. The two compounds may be distinguished from each other, by evaporation in a platinum spoon. The pure spirit of ammonia will leave scarcely any residue, while the other will leave a residue of chloride of potassium. Spirit of ammonia is said usually to contain a little hydrocyanic acid. This may be deter- mined by neutralizing the liquid with muriatic acid and adding a solution of sulphate of iron. If hydrocyanic acid is present a blue precipitate will be formed. AMMONIAC. Ammoniacmn, U. S. This gum resin is an exudation from a plant which grows in Persia called by Mr. Don, Dorema Armeniacum. The ANIME. 29 plant is about seven feet high, and sometimes seven or eight inches in circumference near the root. The exudation is in the form of a milky juice which concretes on the stem and when it becomes solid is collected by the inhabitants for exportation.—(BurneWs Outlines of Botany.) .£L, ' - Ammoniac occurs in market either in small tears cluster- ed together, yellowish on the outside and whitish within, with numerous whitish tears, or in brownish lumps. It has a peculiar odour, not unlike that of assafoetida, and a bit- terish, somewhat acrid taste. The specific gravity is 1.207. When heated it softens, becomes adhesive, but does not melt. It burns with a white flame, and emits during com- bustion a strong resinous, slightly alliaceous odour. It forms a white emulsion with water, is soluble in vinegar, and par- tially so in alcohol, ether, and solutions of the alkalies. It contains many impurities, as seeds, fragments of vegetables, and earthy matters. Some of these can be detected by their want of miscibility in water and solubility in vinegar. ANIMAL CHARCOAL.—-See CHARCOAL. ANIME. A resin of a pale brown yellow colour, transparent and brittle. It is the produce of several species of Hymenaa, especially H. Courbaril L. and H. Martiana, trees which grow in various parts of South America. It occurs in pieces of various sizes, and sometimes filled with insects of different kinds belonging to living species. According to Dr. Ure it contains about one-fifth of one per cent, of a vol- atile oil which gives it an agreeable odour. Alcohol does not dissolve the genuine anime, nor does caoutchoucine; but a mixture of the two in equal parts softens it into a tremulous jelly, though it will not produce a liquid solution. When reduced to this state the insects may De picked out without injury to their most delicate parts. Specific grav- ity from 1.054 to 1.057. Exposed to heat in a Florence 3* 30 ANNOTTO. flask it softens, and by careful management, may be brought into liquid fusion without discolouration. It then exhales a few white vapours, of an ambrosial odour, which being con- densed in water, and the liquid being tested, is found to be succinic acid.—(lire's Dictionary of Arts, %c.) ANISEED. Anisum, U. S. The seed of the Pimpinella anisum L., a native of the Island of Scio and Egypt, but largely cultivated in Spain and various parts of Germany. It is ovate-oblong, gibbous convex, anteriorly flatfish, and has a greyish-green colour, and a warm and sweetish taste. It must be free from mustiness, and when rubbed between the hands should give out its peculiar aromatic odour. The heavier the seed is, the more oil it contains. It is said that the small, compact, Spanish seed is preferable to the lighter and larger kind else- where grown. ANNOTTO, or ARNOTTO. This well-known dye is prepared from the red pulpy matter that surrounds the seeds of the Bixa orellana L. a tree of tropical America. It occurs in the form of a some- what dry and hard paste, brown without and red within. It is imported in cakes of two or three pounds weight, wrapped up in leaves of large reeds, packed in casks. This drug is extensively used by the Spaniards to heighten the fla- vour, and impart a rich colour, to their soups and chocolates, and is employed in England and Holland to give a fine red colour to cheese. It is also used as a dye for silks. Occa- sionally it is mixed with red lead, or at least a mixture of red lead and other substances has been employed as a sub- stitute for annotto in the colouring of cheese. This danger- ous substitution, arising probably from ignorance of the na- ANTIMONY. 31 ture of red lead, can be detected by dissolving the suspected substance in nitric acid and adding liquid sulphuretted hy- drogen to the solution. If lead is present, a black precipi- tate of sulphuret of lead will be produced. ANTIMONY. A brittle metal, of a silvery white colour, scaly texture, and possessing considerable lustre. It fuses at about 800° F. and is volatile at a white heat. When placed on ignited charcoal, under a current of oxygen gas, it burns with great brilliancy, giving off an oxide in the form of a dense yellow smoke. Commercial antimony almost always contains arsenic, the presence of which can be detected by the garlic smell emitted by such an alloy when heated by the blow-pipe; or the presence of arsenic may be detected by dissolving the mixed metals in nitromuriatic acid, and then passing through the solution a current of sulphuretted hydro- gen. The orange-red precipitate of sulphuret of antimony is first deposited, and afterwards the bright yellow precipi- tate of sulphuret of arsenic. The current of sulphuretted hydrogen gas is to be continued until the solution is com- pletely saturated, and the solution is to be afterwards heated to cause the entire precipitation of the sulphurets. The solution is now filtered, and the mixed sulphurets are to be defra°rated with carbonate of soda and nitre in a crucible, the mass treated with water, filtered, and afterwards treated with nitric acid, to decompose the basic alkaline antimoniates which the filtrate contains in solution to a small extent. By this means almost all the antimony is obtained as an insolu- ble, and all the arsenic as a soluble, compound. Water digested upon the mixture, filtered, and then tested with ni- trate of silver, will give the brown-red precipitate character- istic of arsenic acid. If the solution is slightly acidulated with muriatic acid, sulphuretted hydrogen will produce a bright yellow precipitate, especially if heat be applied. From 32 ANTIMONY. this precipitate metallic arsenic may be obtained, by mixing it with equal parts of cyanide of potassium and carbonate of soda, and subjecting the mixture to a strong heat in a test tube. In a case of poisoning, by arsenic, several precautions are necessary in consequence of the organic substances mixed with it, which may here be omitted. Minute directions for obviating the difficulties which such investigations present, will be found in almost all the recent chemical treatises. I would refer the inquirer, especially, to Fresenius's Work on Chemical Analysis. Antimony is frequently contaminated with iron, copper and lead. These may be detected by dissolving the metal in nitro-muriatic acid, precipitating the oxichloride by the addition of water, and then treating the clear and filtered solution with carbonate of potassa. The precipitate may contain iron, copper, lead and antimony. Treat it with nitric acid, which will dissolve all except the antimony. The ad- dition of sulphuric acid will give a white precipitate of sul- phate of lead. Liquid sulphuretted hydrogen will give a black or brown precipitate of sulphuret of copper ; and ex- cess of ammonia will cause the separation of brown-red flocks of peroxide of iron. ANTIMONY, OXYSULPHURET OF. Anlimonii Oxysulphuretum, L. Under this name are included certain products obtained by subjecting the native sulphuret of antimony to the ac- tion of heat and acids, and concerning the precise nature of which chemists are not agreed. These are Glass of Anti- mony, Saffron of Antimony and Liver of Antimony. Kermes Mineral and Golden Sulphuret of Antimony are analogous compounds. They are all objectionable for medicinal use in consequence of the variable proportions of sulphuret and oxide of antimony which they contain. ANTIMONY. 33 As the native sulphuret is the substance from which these preparations are obtained, they may all contain a mi- nute quantity of arsenic. The presence of this metal may be detected by the process already described. Professor Brande states that in the glass of antimony brought into England for pharmaceutical purposes from Germany and Holland, there is usually a portion of silicious earth, and that it is sometimes adulterated with oxide of lead. This fraud is detected by dissolving the finely-powdered glass in muriatic acid. Silica, or brick-dust, with which it may be also be mixed, will remain unacted on. If it contains oxide of lead, the filtered solution, when diluted with water, will give a white precipitate on the addition of sulphate of soda. If a blue precipitate is produced in a solution of this, or of any of the above compounds upon the addition of ferrocyanide of potassium, the presence of iron is indicated. Organic substances may be detected by the empyreumatic odour which is given out when the compound is subjected to heat in a glass tube. If sulphate of potassa is mixed with it, solution of chloride of barium, added to the diluted mu- riatic solution of the compound, will cause a white precipi- tate, insoluble in nitric acid. Recently the oxysulphuret of antimony has been found to be largely adulterated with sulphate of lime, in conse- quence of boiling the sulphuret of antimony with lime in- stead of a solution of potassa. On the addition of sulphuric acid, the oxysulphuret of antimony is precipitated with about thirty per cent, of sulphate of lime. The latter sub- stance may be detected by boiling the suspected oxysulphu- ret in water, and testing portions of the filtered solution with chloride of barium and oxalate of ammonia. If sul- phate of lime is present, white precipitates will be pro- duced by the addition of these tests.—(The Chemist, Febru- ary, 1S46.) 34 ANTIMONY. ANTIMONY, SESQUIOXIDE OF. Antimonii Oxidum, E. This substance, used for the preparation of Tartar Emetic, may be obtained by adding to an acid and boiling solution of antimony in muriatic acid, carbonate of soda in excess, washing the precipitate with cold water until it ceases to redden litmus paper and then drying it over a va- pour bath. It is a powder of a dirty white colour, which fuses at a red heat and forms on cooling an opaque crystal- line mass. It is volatile and may be sublimed in close ves- sels by a strong heat. The presence of arsenic, sometimes found in this as well as in other antimonial preparations, may be proved by boil- ing the suspected powder in water slightly acidulated with muriatic acid. The filtered solution is then to be tested with ammonia-nitrate of silver, ammonia-sulphate of cop- per, and sulphuretted hydrogen. If arsenic is mixed with the oxide of antimony, the first test will give a light yellow precipitate, the second a green, and the last a bright yellow one. The solution may also be evaporated, and the powder mixed with powdered charcoal put into a glass test tube, and subjected to the heat of a spirit lamp. If arsenic is present the garlic odour will be given out, and a brilliant metallic sublimate produced in a cool part of the tube, which by heat and air is again converted into arsenious acid. The mixture of iron with the oxide of antimony may be detected by dissolving the powder in muriatic acid, precipi- tating it by the addition of water, and then adding solution of ferrocyanide of potassium to the clear liquor. A blue precipitate will be formed, either immediately or after a short exposure to the air, if any iron is present. If the oxide of antimony is mixed with silica, it will not be entire- ly soluble in muriatic acid. ANTIMONY AND POTASSA. 35 ANTIMONY, SESQUISULPHURET OF. Antimonii Sulphuretum, U. S.—Crude Antimony. This compound of antimony, which occurs native, is found in the form of masses having a brilliant lead grey, or steel grey colour, and a radiated or fibrous crystalline structure. It is said to be rarely free from sulphuret of arsenic, which is the source of that metal found in the various antimonial preparations. It also frequently contains sulphuret of iron. The presence of these substances may be detected by the processes already described. Dr. Ure recommends the fusion of the sulphuret of an- timony with three-fourths of its wreight of cyanide of potas- sium in a porcelain crucible over a spirit lamp, when a reg- ulus of antimony is obtained. The metal may then be easily tested for arsenic, since none of this volatile substance can have been lost, owing to the low temperature employed. —(Dictionary of Arts, &;c.) The sesquisulphuret of antimony should always be pur- chased in mass, as its properties cannot be well judged of when it is in powder. ANTIMONY AND POTASSA, TARTRATE OF. Antimonii el Potassa Tartras, U. S.— Tartar Emetic. This salt occurs in rhombic octahedrons, with many secondary planes, which, on being pulverized, produce a white powder. It is transparent at first, but by expo- sure it loses water, and becomes opaque. It is soluble in about fourteen or fifteen parts of cold, and two of hot, water; insoluble in alcohol. When heated in a porcelain or glass capsule the salt is charred, owing to the presence of tartaric acid, and sulphuretted hydrogen passed through a solution of it causes an orange-red precipitate, from which metallic antimony can be obtained. It should be kept in the 36 ANTIMONY AND POTASSA. state of powder, to prevent loss of weight from the escape of water, and to ensure uniformity in the strength of its doses. Tartar emetic frequently contains tartrate of lime, tartrate of iron, tartrate of potassa, and bitartrate of potassa. The latter is particularly liable to be found in the tartar emetic manufactured according to the process recommended by Mr. Phillips. Arsenic is also occasionally found in it as in the other antimonial preparations, the presence of which can be determined as already described. If tartar emetic does not dissolve in fifteen parts of cold water, it may contain tartrate of lime or bitartrate of potassa. Dissolve this residuum in hot water, and test the solution with sulphuretted hydrogen, to ascertain whether any me- tallic salts are present. According to Mr. Hennell, however, 4he antimonial salt may contain 10 per cent, of bitartrate of potassa, and yet the whole will dissolve in the proper quantity (about 15 parts) of water. In order to detect any uncombined bitartrate, he adds a few drops of a solution of carbonate of soda to a boil- ing solution of the antimonial salt, and if the precipitate formed be not dissolved, he concludes that there is no bitar- trate of potassa present.—(Pereira's Elements of Materia Medica.) The solution of tartar emetic in water must be perfectly colourless, and exhibit no tint of yellow, otherwise it con- tains iron. The presence of this metal may also be detected by the blue precipitate which is formed on the addition of a solution of ferrocyanide of potassium, a few drops of sul- phuric acid being previously added. If the solution gives a white precipitate with nitrate of silver, it contains muri- atic acid. If it gives with a solution of chloride of barium, a precipitate insoluble in nitric acid, it contains sulphuric acid. When tested with sulphuretted hydrogen or hydro- sulphuret of ammonia, it must give a pure orange-coloured, and never any black, precipitate. ARROW-ROOT. 37 When tartar emetic dissolves in less than fifteen parts of water it probably contains neutral tartrate of potassa. It should always, if possible, be bought in crystals. ANTIMONIAL WINE. Antimonii Vinum, U. S. This should be recently prepared, because all solutions of tartar emetic are very liable to undergo spontaneous de- composition. It ought to be clear and without deposit. If it has undergone decomposition, it will contain no antimo- ny ; which may be proved by passing through a portion of it, diluted with water, a current of|sulphuretted hydrogen, or by adding to it some hydrosulphuret of ammonia. The presence of antimony is proved by the orange coloured pre- cipitate which is produced upon the application of this test. ARGENTUM.—See SILVER. ARROW-ROOT. Maranta, U. S. A farinaceous substance obtained from the root of the Maranta arundinacea L., a plant growing in the West In- dies. When pure it is in the form of a light white powder, or small pulverulent masses, having a firm feel if pressed be- tween the fingers, and entirely destitute of taste or smell. It is a kind of starch, but is much more nutritious and di- gestible than that from wheat or potatoes; it differs also in physical properties. It is exported from most of the West India Islands in tin cases, and in barrels and boxes. A cheap imitation of arrow-root is manufactured from po- tatoe starch. This fraud can be detected by the micro- scope. Arrow-root consists of regular ovoid particles of nearly equal size, while potatoe starch consists of particles 4 38 ARSENIC. of an irregular ovoid or truncated form, very irregular in their dimensions. The particles of arrow-root are also much smaller and free from the streaks and furrows seen in pota- toe starch by a good microscope. Dilute nitric acid, tritu- rated in a mortar with potatoe starch, forms immediately a transparent, very viscid paste or jelly. Flour starch exhib- its a similar appearance. Arrow-root, however, forms an opaque paste, and takes a much longer time to become vis- cid. Arrow-root, moreover, is destitute of that fetid, un- wholesome oil, extractable by alcohol from potatoe starch. Perhaps the best tests of the purity of arrow-root, are its white colour and the entire absence of taste or smell. The " East Indian arrow-root" is obtained from the tuber of the narrow-leaved turmeric Curcuma angustifolia Roxb., brought from Calcutta, Para, Maranham and Sierra Leone. Two kinds are met with in commerce, the white and the pale buff-coloured. The first is a fine white powder, readily distinguishable, both by the eye and touch, from West In- dian arrow-root. In appearance it somewhat resembles a finely-powdered salt (as bicarbonate of soda or Rochelle salt.) The pale, buff-coloured East Indian arrow-root is in the form of powder or pulverulent masses, mixed with husks, woody fibre and other impurities. Both kinds pre- sent the same appearance under the microscope.—(Par- nelPs Applied Chemistry.) The fecula known as the Brazilian arrow-root, is obtain- ed from the tuberous root of the Jatropha Manihot L.; and the " Portland arrow-root " is derived from the Arum macu- latum L.—(Ibid.) ARSENIC. This is a very brittle metal, having a strong metallic lus- tre, a steel-grey colour, and a crystalline structure. At 356° F. it volatilizes without being fused, and in close ves- sels may be collected unchanged. When thrown upon hot ARSENIOUS ACID. 39 coals it burns with a blue flame and a white smoke, and a strong smell of garlic is perceived. As usually met with in the shops it has a dull grey colour, owing to partial oxi- dation at the surface. In this state it is often known by the name of fly powder, and is also sometimes sold as cobalt. The purity of arsenic may be determined by its volatility. If put into a tube of hard glass closed at one end and sub- jected to a heat below redness, the arsenic, if pure, will be entirely volatilized. Cobalt and iron, with which it may sometimes be mixed, will remain unaffected by the heat. Antimony requires a white heat for its conversion into va- pour. In all the experiments upon arsenic or its compounds the operator should be careful not to inhale any of the fumes which may be given out. ARSENIC, YELLOW SULPHURET OF. Orpiment. This compound has a rich yellow colour, is insoluble in acids, but soluble in pure alkalies, yielding colourless solu- tions. It is the colouring principle of the pigment called King^s Yellow. A compound is sometimes sold under this name which is nothing more than arsenious acid combined with a little sulphur. It is quite soluble in water, which is not the case with the properly prepared orpiment. Al- though poisonous, the real sulphuret of arsenic is less viru- lent than arsenious acid, and hence this sophistication may sometimes be productive of very injurious effects. The Realgar, or red sulphuret of arsenic, is sometimes imitated by a mixture of arsenious acid, sulphur and charcoal. ARSENIOUS ACID. Acidum Arseniosum, U. S.— White Oxide of Arsenic. A transparent and colourless substance, having a vitreous fracture, which gradually becomes milk-white and opaque. 40 ASSAFCETIDA. Its specific gravity is from 3.698 to 3.738. It sublimes at 380° F., without softening or fusing; and when the operation is conducted slowly in a glass tube, transparent octahedral crystals are obtained, having an adamantine lustre. It is sparingly soluble in water, and more so in hot, than in cold ; reddens vegetable blue colours. Most commonly arsenious acid occurs in the shops in the form of a white powder, and it is often mixed with chalk and sulphate of lime. Pure arsenious acid, when heated in an iron spoon, volatilizes without residue. If it contains chalk or sulphate of lime they remain behind. The adul- terated arsenious acid can never be safely employed in med- icine, as its preparations are of uncertain strength and can- not be relied on. It should, if possible, be purchased in the massive form. ASSAFCETIDA. Assafcetida, U. S. This is a gum resin, the produce of the Ferula assafcetida L., a native of Persia. The best kind is found, in commerce, in large lumps, composed of irregular agglutinated masses, which have a tough consistence, and a very mottled ap- pearance, in consequence of the presence of drops or tears of a white, red and brown tint, all mixed together. It has a very fetid, alliaceous odour, and a bitter, acrid taste. By long keeping it becomes more hard and brittle, and the in- tensity of its taste and smell is diminished. An inferior kind, sometimes met with, is full of sand, and has a very fetid smell; it is said to be composed of garlic, sagapenum, tur- pentine, and a small proportion of real assafcetida. It is very brittle, and gives a large residue when treated with spirit of wine, whereas good assafcetida leaves but about the fifth part of its weight of insoluble residue. BALSAM OF COPAIBA. 41 ATROPINE or ATROPIA. Belladona, U. S. This is the active principle of the Atropa Belladona L. When perfectly pure, it is in the form of white, transparent prisms, having a silky lustre. It is inodorous, soluble in absolute alcohol and in sulphuric ether, both of which take up more when hot than when cold. Water, at the common temperature, dissolves about 1.500 of its weight. This solu- tion has an unpleasant bitterness, and when applied to the eye dilates the pupil, quickly and durably. By simple contact with water and air, at the ordinary temperature, atropine loses its crystalline property; and the crystals already formed disappear. The liquor which results assumes a yellow co- lour, and leaves an uncrystallizable residue, soluble in all proportions in water. The atropine thus changed has a nauseous narcotic odour ; it is equally poisonous as before, and when combined with an acid, and the solution treated with animal charcoal, the alkalies precipitate solid and crys- tallizable atropine. The aqueous solution of atropine gives an abundant white precipitate, with the infusion of gall- nuts. It gives a citron yellow precipitate with chloride of gold, and an Isabella yellow with the solution of chloride of platinum. According to Dumas, the solution of chloride of gold, slightly acid, is characteristic in its action upon a solu- tion of atropine. The citron yellow precipitate, at the end of a certain time, assumes a crystalline structure, and con- sists of a compound of hydrochlorate of atropine and chlo- ride of gold.—(Chimie appliquee aux Arts.) BALSAM OF COPAIBA. Copaiba, U. S. This is the produce of several species of Copaifera, the chief supplies being drawn from the C. Langsdorfii Desf. 4* 42 BALSAM OF COPAIBA. and the C. Jaquini Desf.; the former of which is a native of Brazil, and the latter of the West Indies. The best kind is said to be that which comes from Brazil. It is a clear, trans- parent liquid, of a pale yellow colour, of the consistence of olive oil, having a peculiar odour, and a hot, bitterish, nau- seous taste. Its specific gravity is from 0.950 to 1,000. It is insoluble in water, but entirely soluble in absolute alco- hol, ether, and the fixed and volatile oils. Balsam of copaiba is often adulterated with castor oil, and the following tests have been proposed for the detection of its presence. 1st. By agitating the balsam with a solution of caustic soda, and setting it aside to repose ; the balsam will at length float, clear, on the top, and leave a soapy, thick magna of the oil below. 2d. When the balsam is boiled with water, in a thin film, for some hours, it will become a brittle resin on cooling, but it will remain viscid, if mixed with castor oil. 3d. If a drop of the balsam on white paper be held over a lamp, at a proper distance, its volatile oil will evaporate and leave the brittle resin without causing a stain around, which the oil will produce. 4th. If the balsam be triturated with a little common magnesia alba, it will form a transparent so- lution, if it be pure; but will form a white liniment, if it contain castor oil. When balsam of copaiba is adulterated with oil of turpentine, the fraud is detected by the smell, on heating the mixture. It must be confessed, however, that these tests sometimes fail to detect the impurities of copaiba. In proof of the adulterations which were practiced with balsam of copaiba, in England, when its price was high, Dr. Paris refers to a curious trial, which took place " be- tween the owner of certain premises that were burnt down, and the governors of the Sun Fire Office, in consequence of the latter refusing to indemnify the proprietor for his loss, because the fire had been occasioned by the making of bal- sam of'copaiba.—(BurnelVs Outlines of Botany.) ? ' BALSAM OF PERU AND OF TOLU. 43 BALSAM OF PERU AND BALSAM OF TOLU. Myroxylon, U. S.—Balsamum Peruvianum, L. and Bal- samum Tolutanum, L. These are resins obtained from the Myroxylon peruiferum and M. toluifera Kunth. (Myrospermum peruiferum, D. C. and M. toluiferum Rich.), trees of the warmer regions of South America, by making incisions into the bark. The re- sinous secretions which flow out are received in vessels of various kinds, in which they harden by exposure to the air. These balsams are so similar that, in commerce, they are frequently confounded. The ordinary Balsam of Peru, which is liquid, and of a dark colour, is produced by boil- ing the small twigs of the M. peruiferum in water, and skim- ming off the supernatant balsam. Its taste is pungent, acrid and bitter. It should dissolve in rectified alcohol, and leave a very slight pulverulent residue. It is sometimes adulter- ated with a fixed oil, and sometimes with alcohol. The presence of the former can be detected by processes similar to those described under the preceding article. If mixed with spirit of wine, the liquid, when shaken with some wa- ter in a graduated glass tube, becomes milky, and after it has settled, and the oil and water have separated, the oil is found to have diminished in bulk, and the water to have in- creased. The loss of bulk of the oil indicates the extent of the adulteration. Balsam of Tolu, when first imported, has a soft, tenacious consistence, but by age it becomes hard and brittle, like re- sin. It is of a reddish yellow colour, and has a fragrant odour. When pure, it is entirely dissolved by alcohol, and the es- sential oils. Boiling water extracts the benzoic and cinna- mic acids which it contains. 44 BARYTA, NITRATE OF. BARIUM, CHLORIDE OF. Barii Chloridum, U. S. This salt crystallizes in the form of white, flat, four-sided tables, bevelled at the edges. It has a disagreeable, and slight- ly bitter taste, and undergoes little or no change in ordinary states of the air. When heated, the crystals decrepitate, lose their water of crystallization, and at a red heat, fuse. 100 parts of water dissolve about 43 of these crystals, at 60° F., and 78, at 222° F., which is the boiling point of the saturated solution. If nitrate of silver be added to a solution of the chloride of barium, it gives a white precipitate insolu- ble in nitric acid, but soluble in ammonia; all the soluble sulphates give with it a white precipitate of sulphate of ba- ryta, insoluble in nitric acid Alcohol, impregnated with this salt, burns with a yellow flame. Pure chloride of barium must not affect vegetable colours, nor ought its solution to be altered by ammonia, which proves the absence of alumina, and oxide of iron; nor by sulphuretted hydrogen, nor by hydrosulphuret of ammonia, which shows that it contains neither lead nor copper. Pure sulphuric acid must precipitate every fixed particle from it, so that the filtered liquid leaves not the slightest residue when evaporated on platinum foil. If it contains lime or strontia, the filtered liquid will give a white precipitate, with carbonate of soda: in the former case more abundant than in the latter, from the greater solubility of the sulphate of lime. If any considerable portion of strontia is present, the alco- holic solution will burn with a red flame. BARYTA, NITRATE OF. This salt crystallizes in transparent octahedrons, which are not altered by exposure to the air. It is soluble in 12 times its weight of water at 60° F., and in three or four of BEER. 45 boiling water ; insoluble in alcohol. At a bright red heat, it decrepitates, is decomposed, and yields pure baryta. The tests of its purity are the same as those of chloride of barium. Nitrate of silver must not render its solution turbid. BEER. This liquor has been subject to various adulterations, having for their object to economise the hops, by substitut- ing for them cheaper vegetable matters, to give to the must a bitter taste, as the wood of box, the root of gentian and leaves of menyanthes ; and, in England, it is said they em- ploy, for the same purpose, a most deadly poison, viz. : strychnine. As a very minute proportion of this]alkali gives an excessively bitter taste to a great quantity of liquid, the beer thus adulterated does not immediately produce serious disorders in the animal economy, but the constant use of such a drink must, at length, injuriously affect the health. When beer is sour it is the practise to correct the acidity by the addition of chalk, potassa, magnesia, &c. In some cases also, this liquor contains the oxides of copper and of lead, derived from the vessels in which it has been manufactured or kept. * Beer of good quality should present the following char- acters, viz. : 1. It should be transparent, and not flocculent; its taste should be slightly bitter, acid and alcoholic. 2. It should contain a sufficient quantity of carbonic acid to produce a brisk effervescence when it is drawn. 3. It should redden litmus paper; but when it acts strongly upon this colour, and when it produces no froth on being drawn, it is a proof that the acetous fermentation has set in, and its taste is disagreeable. 4. Oxalate of ammonia, acetate of lead, and nitrate of baryta should produce only slight precipitates. 46 BENZOIC ACID. 5. Chloride of platinum ought scarcely to trouble it, be- cause it contains only a small quantity of salts with a base of potassa. Various narcotic plants are said to be added to beer, to increase its effect upon the animal economy. Among these are, Ledum paluslre, Asarum Europeum, Veratrum nigrum, Papaver somniferum, Eyoscyamus niger, Salvia sclarea, &c. These produce a high degree of excitement, which is soon followed by indirect atony. The hop belongs, in some measure, also to this class ; and the same is- true of the Loli- um temulentum. Beer is also sometimes adulterated with grains of paradise, Spanish pepper, coriander, nut-galls, juice of liquorice, treacle, and tobacco leaves. Unfortunately we are not yet in possession of the means of accurately detecting these adulterations and slow poisons. We are not without hope, however, that some process may hereafter be devised. To stop the fermentation of beer, a plate of tin is some- times introduced into the liquor ; an acetate and carbonate of tin are thus formed, which render the beer very dan- gerous. It is said that salt is added to beer for the purpose of in- creasing the thirst of the consumers. This substance can be detected by nitrate of silver, which causes a precipitate of chloride of silver insoluble in water and in nitric acid, and which becomes black when exposed to the sun. —(Gamier and Harel, Des Falsifications des Substances Aliment aires.) BENZOIC ACID. Acidum Benzoicum, U. S.—Flowers of Benzoin. This acid is obtained by sublimation from gum benzoin, a resinous exudation from the Styrax Benzoin, Dry and., a native of Sumatra and Borneo. It occurs in white aci- BENZOIN. 47 cular crystals, of a satiny appearance. When pure it is in- odorous ; it has a hot, sweetish, and very peculiar taste, and reddens litmus. It dissolves in 25 parts of boiling water, but requires 200 of cold water for its solution. It is soluble in twice its weight of alcohol, and this solution when evapo- rated gives the acid pure and in prismatic crystals. At 248° F. it fuses, and at 293° F. should volatilize without residue, otherwise it contains some impurity. The vapours are very irritating, and cough provoking. The solution of benzoic acid in water should give no precipitate with a so- lution of chloride of barium'or it contains sulphuric'acid, nor with solution of oxalate of ammonia, otherwise it contains lime. The benzoic acid obtained by simple sublimation from gum benzoin often has a very strong odour and an acrid taste, owing to the presence of an oily and volatile substance. This fact should not be overlooked in the employment of benzoic acid for medicinal purposes.—(Dumas, Chimie ap- pliquee aux Arts.) BENZOIN. Benzoinum, U. S. This is the resin from which benzoic acid is procured. It is brought to market in large masses of an amygdaloidal or motley appearance ; its colour is pale brown with white spots. It is brittle, has a resinous aspect and fracture, and becomes very fragrant when warmed. Its specific gravity is from 1.063 to 1.092. When heated it exhales pungent fumes, which consist chiefly of benzoic acid. It is wholly soluble in alcohol except the impurities, and is precipitated from the solution by water. An article is sometimes met with, which is indistinctly mottled, has a dark colour, and abounds in impurities. 48 BISMUTH. BISMUTH. Bismuthum, U. S. A metal having a white colour resembling antimony, but with a reddish tint. It is very brittle and may be easily re- duced to powder; specific gravity, 9.83. At 480° F. it undergoes fusion ; at a strong heat it volatilizes, may be distilled in close vessels, and is thus obtained in crystalline lamina?. Commercial bismuth often contains an admixture of lead, iron, arsenic, &c. Dissolve the suspected metal in nitric acid, add a considerable quantity of water to throw down the subnitrate, and to the filtered solution add some dilute sulphuric acid. If lead is present, a white precipitate of sulphate of lead will be produced. The presence of iron may be shown by the red brown precipitate produced in this solution upon the addition of ammonia ; and of copper, by the blue colour which it assumes when supersaturated with this alkali. Arsenic, when mixed with bismuth, may be detected by the following process. To the filtered solution obtained after the affusion of the nitrate of bismuth with water, add excess of ammonia, and afterwards hydrosulphuret of am- monia in sufficient quantity, and digest with a gentle heat. If arsenic is present, the sulphuret thus formed will be dis- solved by the ammonia, and may be separated by filtration. The filtered solution is then acidulated by muriatic acid, and digested at a gentle heat until it no longer smells of sulphur- etted hydrogen ; the dissolved sulphuret of arsenic then falls down in the form of a bright yellow precipitate. From this, metallic arsenic may be obtained by the process de- scribed under the article Antimony. Bismuth sometimes contains a little silver, and hence the nitrate becomes grey or dingy coloured on exposure to the BISMUTH, SUBNITRATE OF. 49 light. This can be further determined by adding a little muriatic acid to the solution of bismuth in nitric acid, when, if silver is present, a white curdy precipitate will be formed^ which, by exposure to light, becomes of a dark colour. BISMUTH, SUBNITRATE or TRINITRATE OF. Bismuthi Subnilras, U. S.—Pearl White. This is a pure white tasteless powder obtained by dis- solving metallic bismuth in dilute nitric acid, then throwing the solution into a large quantity of water, washing the precipitate which subsides, and drying it at a gentle heat. At a red-heat this powder fuses into a brown liquid, and it forms, on cooling, a yellow vitreous mass. The subnitrate of bismuth is often mixed with chalk and white lead. To detect these substances, dissolve the pow- der in nitric acid, and add sulphuric acid. If carbonate of lead is present a white precipitate of sulphate of lead will be produced. To another portion of the solution, previously treated with acetic acid and diluted with water, add hydro- sulphuret of ammonia as long as any precipitation takes place. Separate the clear part by filtration, and test it by oxalate of ammonia. If a white precipitate is formed it is owing to the presence of lime. Arsenic and silver, sometimes found in metallic bismuth, rarely occur in the subnitrate if properly prepared. The nitrate of silver resulting from the action of nitric acid, is soluble in water, while the arseniate of bismuth is entirely soluble in water and in nitric acid, and will, of course, re- main behind when the solution of bismuth is thrown into water. When the nitrate of silver is present, however, it causes the pearl white to blacken when used as a cos- metic. To avoid this disagreeable result, Dumas recom- mends the addition of some drops of muriatic acid to the solution of nitrate of bismuth, which should then be decanted before it is decomposed by water, 5 50 BLEACHING POWDER. BLEACHING POWDER. Calx Chlorinata, U. S.—Chloride of Lime—Hypochlorite of Lime. A dry, white powder, which smells faintly of chlorine, and has a strong taste. It dissolves partially in water, the solution possessing strong bleaching powers, and being gradually decomposed by exposure to the atmosphere. The dry powder is decomposed by heat, evolving first chlorine, and afterwards pure oxygen gas, while chloride of calcium remains. A convenient process for estimating the value of this pow- der consists in ascertaining the bleaching power of the liquid produced by its solution in water. A blue liquor is prepared by dissolving indigo in concentrated sulphuric acid, and di- luting the solution with 1,000 parts of water: A portion of the chloride of lime, to be estimated, is weighed and mixed with water. A given quantity of the clear solution which it produces is mixed with as much of the blue liquor as it can deprive of colour. The value of a given quantity of the blue liquor is previously determined by an experiment made with a good specimen of bleaching powder, and all subse- quent experiments are compared with this standard. This test has been objected to on account of the change which indigo undergoes by keeping; and another has been proposed, in which protosulphate of iron is employed, and which depends upon the fact, that protoxide of iron is con- verted into peroxide by the agency of chlorine, through the decomposition of water. To carry out this test, 78 grains of green sulphate of iron are dissolved in about two ounces of water, and acidulated by a few drops of sulphuric or muriatic acid ; this quantity will require for peroxi- dation, exactly ten grains of chlorine. Fifty grains of the bleaching powder to be examined are next rubbed up with BORACIC ACID. 51 a little tepid water, and the whole transferred to the alkali- meter, (see the article, Potassa,) which is then filled up to O with water, after which the contents are well mixed by agitation. The liquid is next gradually poured into the solution of iron, with constant stirring, until the latter has become peroxidized, which may be known by a drop ceas- ing to give a deep blue precipitate with red ferricyanide of potassium. The number of grain-measures of the chloride solution employed may then be read off, and since these must contain ten grains of serviceable chlorine, the quantity of the latter in the 50 grains may be easily reckoned. Thus, suppose 72 such measures have been taken, then— Measures Grs. Chlorine Measures Grs. Chlorine 72 : 10 : : 100 : 13.89 The bleaching powder therefore contains 27.78 per cent. of chlorine.—(Graham's Elements of Chemistry.) The most common impurities in bleaching powder.are carbonate of lime, hydrate of lime, water and sand. It is not necessary, however, to point out the modes in which the presence of these substances can be detected, as the most certain test of the real value of the powder is to deter- mine by one or other of the above processes the proportion of chlorine which it contains. BORACIC ACID. Homberg^s Sedative Salt. This substance, which is found native in the hot springs of Lipari, and in those of Tasso, in the Florentine territory, usually occurs in the form of small, white, pearly scales, without smell and nearly tasteless. It is soluble in about thirty parts of cold, and three of boiling, water ; the latter solution deposits it in pearly scales as it cools. It is also soluble in alcohol, to the flame of which it communicates a yellowish-green colour. The aqueous solution reddens lit- 52 BURGUNDY PITCH. mus paper, but it tinges turmeric paper brown. Its purity can in o-eneral be determined by a close attention to the above characters. BORAX.—See SODA, BIBORATE OF. BROMINE. Brominium, U. S. A dark brownish-red liquid, of a hyacinthine tint, in thin strata. It has a disagreeable odour, somewhat resembling that of chlorine, and a powerful taste. It is very volatile, so that when a few drops of it are thrown into a bottle, beau- tiful red vapours soon fill the vessel. It stains the skin of a yellow colour, is soluble to a small extent in water, more so in alcohol, and still more so in ether. When mixed with a solution of starch, it produces an orange-yellow colour. Bromine has recently been introduced into use in the Daguerreotype process ; it has also been recommended as a medicinal article. Its purity can be judged of by the above characters, but especially by its colour, odour and volatility. BURGUNDY PITCH. Pix Abietis, U. S. This is the concreted juice of various species of Finns, (Abies, D. C.,) found in Europe and Asia, as P. Abies L., and P. Picea L. It is solid, brittle, opaque, of a brownish-yel- low colour, and gives an agreeable odour when burned. It softens and becomes adhesive at the temperature of the body. Burgundy pitch is generally mixed with impurities, which render it necessary to melt and strain it before being used. A factitious article is made by melting together pitch, resin and turpentine, and agitating the mixture with water. Its odour is different from that of the genuine article.—( U. S. Dispensatory.) CACAO AND CHOCOLATE. 53 CACAO AND CHOCOLATE. The seeds of the Theobroma Cacao, L., a native of South America, are known by the name of Cacao. They are of a reddish brown colour, somewhat brilliant, very brittle, rich, unctuous, and agreeably bitter. They must not be mouldy, nor white, nor have a rancid or insipid taste. Small, very dark coloured, and very bitter or styptic nuts should be re- jected. Chocolate. Cacao, when prepared, by being dried and powdered, and then mixed with annotto and certain spices, forms the deli- cious and nourishing food called Chocolate. " The facility with which it can be conveyed and prepared, when wanted to be eaten, makes chocolate a most valuable and favorite food for travellers. Humboldt says that it is chocolate and maize flour that have rendered accessible to man the stu- pendous table lands of the Andes, and enabled him to pene- trate the vast uninhabited forests of central America." Chocolate is now extensively manufactured in Europe and America, and there are probably few articles that are more largely adulterated. Wheat flour, the flour of pota- toes, of beans, rice and peas, fat, the yolk of eggs, almonds, gum, soap, &c, are some of the substances employed for this purpose. The most common adulteration of chocolate, however, consists in mixing it with fecula slightly torrefied. This fraud may be detected by treating the chocolate with forty or fifty times its weight of water, causing the water to boil and treating the filtered liquor with the alcoholic tincture of iodine. A yellowish brown colour is the result when the decoction is one of chocolate without fecula, whereas if the chocolate contains fecula it will give a blue colour more or less intense. 5* 54 CACAO AND CHOCOLATE. Sometimes the butter of cacao is removed from the choc- olate by pressure and heat, and its place supplied by tallow, oil of sweet almonds, or by almonds themselves. Chocolate, thus adulterated, soon becomes rancid, by which the fraud may be detected. Some specimens of chocolate have been found to contain, in addition to less injurious articles, sulphuret of mercury, sulphuret of mercury associated with the red oxide of mer- cury, the same sulphuret with the oxide of lead or minium and red ochre. These articles seem to be employed for the purpose of giving the chocolate a fine red colour which dif- fers from that of the natural chocolate and of increasing its weight. One mode of detecting their presence consists in rasping the chocolate, and treating it with cold water in sufficient quantity, taking care to agitate the liquid con- stantly. The adulterated chocolate gives a very abundant deposit which is of a brick red colour ; this deposit is scarce- ly observable, is longer in forming, and is of a dull fawn colour, in the pure chocolate. It is stated by Cadet that chocolate contains iron and lime in notable quantity, the latter derived probably from the stones which are employed in grinding the cacao.— (Gamier and Hard, Des Falsifications des Substances All- mentaires.) Dr. Ure states that some chocolate made at Deptford,for the use of the British Navy, and which had produced sick- ness and in a few cases even death, was upon examination found to consist of gritty grains, from very imperfect tritu- ration or milling. These grains were quite immiscible witb water, and contained many sharp spiculae of the cacao-bean husks, and when swallowed, they were calculated to form mechanically irritating lodgements in the villous coats of the stomach and bowels. From the insoluble condition of the chocolate, moreover, it could be of little use as an arti- cle of food, or as a demulcent substitute for milk, and three- CALCIUM, CHLORIDE OF. 55 fourths of it were on this account, an ineffective article of diet; or were wasted.—(Dictionary of Arts, 8$c, Suppl) CAJEPUT OIL. Cajeputi, L. This oil is obtained by the distillation of the leaves of the Melaleuca Leucadendron L.,a. tree which grows in the Mo- lucca Islands. It is very limpid, lighter than water, of a strong smell resembling camphor, and a pungent taste like cardamon. It often has a green colour from the copper flasks in which it is sent to market. When rectified it be- comes colourless. Dr. Burnett states that during the pre- valence of the cholera in London there was a great demand for this article on account of its reputed virtue in that dis- ease. In consequence of this its price became exorbitantly advanced, and in an inverse ratio its quality diminished. Much that was sold under the name of cajeput oil did not contain even a drop of the veritable drug.—(Outlines of Botany.) J > 7 -' "- CALCIUM, CHLORIDE OF. Calcii Chloridum, L. It commonly forms a white mass, but can be procured in large transparent crystals. It deliquesces very rapidly in the air and easily dissolves both in water and in alcohol. It gives a white precipitate on the addition of a solution of oxalic acid or oxalate of ammonia, and also causes a white precipitate, insoluble in nitric acid, but soluble in ammonia, by solution of nitrate of silver. Its solution must be colour- less and perfectly neutral. It must give no precipitate with pure caustic ammonia, otherwise it contains magnesia. A reddish precipitate with this reagent indicates iron ; a white one alumina. It should not evolve ammonia when mixed 56 CANELLA ALBA. r with potassa or hydrate of lime, nor give a precipitate with chloride of barium. CAMPHOR. Camphora, U. S. An inflammable substance closely resembling the essen- tial oils. There are two kinds of camphor : that of Japan or common camphor, obtained from the Laurus camphora L.; and that of Borneo, Borneo camphor, the produce of the Dryobalanops aromatica, Gaertner.—(D. Camphora, Cole- brooke.) The latter is said to be so highly prized by the Japanese, that it is not found in the markets of Europe. It occurs in small crystalline fragments, and its odour is distinctly alliaceous. The common camphor, in its ordina- ry state, is in white, translucent, semi-crystalline masses, which are tough, but easily pulverized when moistened with alcohol. Its specific gravity is from 0.985° to 0.997. It fuses at 347° F., and boils at about 400° F. In close vessels it may be sublimed unchanged. It readily takes fire and burns with a brilliant flame, giving out much smoke, and leaving no residue. It is insoluble in water, but freely soluble in alcohol. The best tests of its purity, are its complete solubility in alcohol, and its combustion without residue. CANELLA ALBA. Canella, U. S. This is the bark of the Canella alba, Murr., (Winlerana Canella L.,) a native of the Caribbean Islands, and of the warmer parts of South America. It is imported in long quill-like pieces, of a yellowish grey colour, has an agreea- ble aromatic odour, resembling that of cloves or coriander, and a warm, pungent and somewhat bitter taste. It gives a yellow powder, and its virtues are partially extracted by water, and entirely by alcohol. CANTHA.RIDES. 57 Canella is sometimes confounded with Winter's bark, from which it differs both in sensible properties and in composi- tion. CANNA STARCH. This is a variety of starch recently introduced into the markets of Europe and America. It is known in France by the name of Tous les Mois. It is said to be prepared in the Island of St. Kitts, from the root of the Carina coccinea. This variety of starch is in the form of a light, beautifully white powder, having a shining appearance, unlike the com- mon forms of that substance. Its granules are said to be larger than those of any other variety, are ovate or oblong, with numerous regular, unequally distant rings, and a circu- lar hilum situated at the smaller extremity. It has the chemical properties of starch, and forms a stiff nutritious jelly with boiling water.—( U. S. Dispensatory.) CANTHARIDES. Canlharis, U. S.—Blister Beetle, or Spanish Fly. This is an insect, the Canlharis Vesicatoria, Letreille, found in the southern and temperate parts of Europe, and in the west of Asia. It is from six to ten lines in length, by two or three in breadth, and of a beautiful shining golden green colour. The head is large, and heart-shaped, bearing two thread-like, black, jointed feelers ; the thorax short and quadrilateral; the wing-sheaths long and flexible, covering brownish membranous wings. In the dry state, Spanish flies have a burning, acrid and urinous taste. Their powder is of a greyish brown colour, interspersed with shining parti- cles. If kept perfectly dry, in a well closed vessel, they re- tain their activity for a long time ; but if exposed to damp air, they quickly undergo putrefaction, especially if in pow- der. They are liable, however, to the attack of mites, which greatly impairs their vesicating properties. 58 CARDAMON SEEDS. Spanish flies are sometimes mixed with other insects, either purposely, or through carelessness. A careful in- spection will generally detect this adulteration. Pereira states that powdered flies are sometimes adulterated with eu- phorbium. Cantharides should never be purchased in pow- der, as in this state they are more liable to injury, as well as more easily adulterated. CAPSICUM.— See CAYENNE PEPPER. CARAWAY SEEDS. Carum, U. S. These are the seeds of the Carum Carui L., found in all parts of Europe. Those which are the growth of England are said to be the best, at least by the English authors. The seeds are ovate-oblong, and striated; odour, aromatic ; taste, warm and grateful. The Dutch seeds are sometimes musty and insipid. CARBONIC ACID WATER. Aqua Acidi Carbonici, U. S. This is water charged with several times its bulk of car- bonic acid, and the only point to be determined is the purity of the water employed. The large excess of carbonic acid renders various substances soluble which will be precipitated on allowing the gas to escape. CARDAMON SEEDS. Cardamomum, U. S. These are the seeds of the Alpinia Cardamomum Roxb., a native of Malabar. They are angular, irregular, rough, of a brown colour, and easily reduced to powder. They have a fragrant odour, a warm and highly aromatic taste. These properties are extracted by water, and by alcohol, but more readily by the latter. CARMINE. 59 Cardamon seeds are imported in their pods, and three va- rieties of these are found in British commerce : 1. the shorts, from three to six lines long, from two to three broad, browner and more coarsely ribbed, and more highly esteemed than the other varieties ; 2. the long-longs, from seven lines to an inch in length, by two or three lines in breadth, elongated, and somewhat acuminate ; and 3. short-longs, which differ from the second variety in being somewhat shorter and less pointed.—(Pereira's Materia Medica.) The seeds are best preserved in their capsules, and should be powdered only when wanted for immediate use. CARMINE. Carmine, according to Pelletier and Caventou, is a triple compound of the colouring substance, and an animal matter contained in cochineal, combined with an acid added to effect the precipitation. There are several kinds in market, dis- tinguished by numbers and possessed of a corresponding value. This difference depends either upon the proportion of alumina added in the precipitation, or of a certain quantity of vermillion put in to dilute the colour. In the first case, the shade is paler; in the second, it has not the same lustre. These adulterations may be detected by the employment of water of ammonia in which carmine is soluble ; the foreign matter remains untouched, and its amount may be deter- mined by drying the residue. Sometimes carmine is adul- terated with red lead. This may be detected by digesting it in nitric acid, diluting the solution, and causing a stream of sulphuretted hydrogen to pass through it, when, if lead is present, a black precipitate of sulphuret of lead will be formed. When adulterated with starch, as it sometimes is, solution of ammonia enables us to detect the fraud, in con- sequence of the solubility of pure carmine in that alkali. The presence of the starch may be afterwards determined by tincture of iodine. 60 CASTOR OIL. CASTOR. Castoreum, L. This is the name given to a secretion of the Castor fiber L., or beaver, an amphibious quadruped, inhabiting the northern parts of Europe, Asia and America. It is con- tained in pear-shaped sacks or bags placed near the genital organs. It has a bitter taste, a reddish colour, and a pow- erfully fetid smell; but when dried, it becomes inodorous. The castor bags, as they usually occur, are joined in pairs. Sometimes a portion of the castoreum is extracted and re- placed by lead, clay, gums and other foreign matters. This fraud may be easily detected, even when it exists in a small degree, by the absence of the membranous partition in the interior of the bags, as well as by the altered smell and taste. This drug is distinguishedvaccording to its source, into the Canadian or American and the Russian castors. The for- mer is considered the most valuable, but our market is supplied chiefly by the latter. It is said that the Canadian castor, treated with distilled water and ammonia, affords an orange precipitate, while the matter thrown down from the Russian is white. CASTOR OIL. Oleum Ricini, U. S. This is the produce of the seeds of the Ricinus Communis L., a native of the East Indies ; but which is extensively cultivated in Europe and America. It has a pale yellow colour, and a slightly nauseous odour and taste. That which is cold drawn by pressure is less acrid and purgative than the West India castor oil, formerly preferred for medical use, and which was often pressed with heat and even boiled CATECHU. 61 out of the seeds. Specific gravity at 55° F. 0.969. It con- geals at about 0°. Exposed to air it gradually becomes rancid, thick, and at length congeals. It dissolves com- pletely in alcohol of the specific gravity of 0.820. If it forms a milky mixture, or if any portion remains undis- solved, it is probably adulterated with some of the more common oils. Castor oil which has become rancid, is ex- cessively acrid, and should not be used medicinally. It is then poisonous, even though taken in small quantities. —(Dumas, Chimie appliquee aux Arts.) CATECHU. Catechu, U. S.—Terra Japonica—Cutch. An extract made from the wood of the Acacia Catechu Willd., a native of the East Indies ; of the Uncaria Gambir Roxb., a native of many of the islands of the Indian Archi- pelago ; and other species. It is prepared by boiling the chips of the interior of the trunk in water, until the de- coction is sufficiently concentrated to become on cooling a tough extract; it is then divided into small masses and slowly dried by exposure to the air. Several varieties of catechu occur in commerce, but those most commonly met with in the druggists' shops, are the pale catechu and the brown catechu. The former is ob- tained from the Uncaria Gambir. It occurs in cubes whose faces are about an inch square; it has a yellowish brown colour, but paler internally ; it is without odour, but has an astringent taste, becoming feebly sweetish. The brown catechu is the produce of the Acacia catechu. It occurs in irregular masses of a chocolate brown colour, very friable, with an astringent bitter taste. When of good quality, catechu is almost entirely soluble in alcohol, but it often contains earthy matters which resist solution. The best test of the value of any variety is to de- 6 Q2 CHARCOAL. termine the amount of tannin which it contains. Probably the best process for this purpose is to add solution of gelatin to a solution of the catechu in water. The tannogelatin which results, when dried, at 212° F., consists of about 54 tannin and 46 gelatin. CAYENNE PEPPER. Capsicum, U. S. The powder known by this name is the produce of seve- ral species of Capsicum, as C. annuum L., C. baccatum L., $c. It has a more or less bright red colour, a pungent, aromatic odour, and a very biting, hot and aromatic taste. It is often mixed with variable proportions of common salt. The salt may be separated by dissolving the pepper in water, filtering, and slowly evaporating the filtered solution at a moderate heat. Or its presence and proportion may be determined by adding to a filtered solution of a weighed portion of the pepper, a solution of nitrate of silver as long as it causes a precipitate, arid then filtering, washing, drying and weighing the precipitated chloride of silver. Cayenne pepper is sometimes adulterated with coloured saw-dust. It is also often mixed with red lead, to prevent it losing its colour on exposure to light. The latter im- purity can be detected by solution in nitric acid, and pre- cipitation of the black sulphuret of lead by a stream of sulphuretted hydrogen, or by the formation of a white pre- cipitate of sulphate of lead upon the addition of sulphate of soda to the clear solution in nitric acid. CERA FLAVA.—See WAX. CHARCOAL. Carbo Ligni, U. S. An article of prime importance as a fuel, prepared by burying in sand, or in earth, pieces of wood, and burn- CHARCOAL, ANIMAL. g3 ing them with a limited supply of atmospheric air. The process is often very carelessly conducted, and the conse- quence is a great reduction in the value of the charcoal. The different kinds of wood furnish variable quantities of charcoal. That which is obtained from the hard woods is most highly esteemed. Its value may, therefore, be deter- mined by ascertaining its density. When used in the laboratory, or in pharmacy, charcoal should be recently prepared. If it cannot be had fresh made, it must be heated to redness under sand in a crucible, in or- der to drive out the moisture and gases which it has absorb- ed and condensed. If charcoal powder is ever employed as a dentrifice, it should also be recently prepared, powdered with the utmost despatch in a hot metallic mortar, and speedily introduced into a phial, which should be well corked, and even sealed. When this powder is used, it ought to be exposed to the air as short a time as possible. What is sold in boxes is totally useless for the purpose of correcting foetor, the only object for which charcoal should ever be employed as a dentrifice. CHARCOAL, ANIMAL. Carbo Animalis, U. S.—Ivory Black. This is obtained by the carbonization of animal substances, such as muscle, horns, or hoofs. When pure, it is a dark, brownish black powder, having a peculiar lustre. It should not be acted on by muriatic acid. If the charcoal contains carbonate of lime, it will effervesce upon the addition of this acid, and the clear solution will give a white precipitate with carbonate of ammonia. If phosphate of lime is present, it will also be dissolved by muriatic acid, and yield a preci- pitate upon the addition of ammonia. This will explain the reason why when purified animal charcoal is required, the bone black is to be washed with muriatic acid, continued as 64 CIDER. long as the washings give a white precipitate with ammonia. It should then be washed with pure water until the liquid does not change the colour of litmus. According to the Edinburgh College, purified animal charcoal, when incine- rated with its own volume of red oxide of mercury, is dissi- pated, leaving only a scanty ash. The charcoal obtained by charring bones, and known in commerce by the name of Ivory black, is mixed with the phosphate and carbonate of lime. For decolourizing ope- rations the presence of these bodies does no injury. It is said, however, that when the charcoal has been too much or too little calcined, it is much less active than when the calcination has been just carried to the point at which all the animal matter is destroyed. CIDER. There are various substances which are added to cider to heighten its colour, and to make it appear stronger than it really is ; such as the flowers of the false poppy, elder-ber- ries, cochineal, &c. The addition of these substances is seldom attended with any injurious consequences, and their presence can, to a certain extent, be determined by the modes pointed out under the article Wine. Brandy is sometimes added to cider, for the purpose of giving it more strength. This may be recognized by the odour and taste which brandy communicates to the liquid. It has been thought that cider mixed with brandy could be easily distinguished from that which does not contain it, by the property which it possesses of giving out its alcohol at the gentle heat of the water bath, while the natural cider loses its alcohol only when it is raised to the boiling point. But this test is of no value, inasmuch as the alcohol can be separated from ordinary cider by heating it in a water-bath to 150° or 160° F. Lime, chalk or ashes are sometimes added to cider, to CINNAMON. 65 heighten the colour, and to saturate the acetic acid which is always formed when the cider has been for some time on draught. The presence of lime may be detected by the ad- dition of oxalate of ammonia, which, although it occasions a slight disturbance in pure cider, on account of a minute quantity of calcareous salts which it contains, does not pro- duce that abundant precipitate which is caused by this reagent when the lime has been added for the purpose of saturating the acetic acid. The presence of potassa may be shown by the employment of the chloride of platinum, which occasions an abundant precipitate. As cider in its natural state con- tains only a very minute proportion of potassa salts, it is scarcely troubled by the addition of this test. Various preparations of lead, such as white lead, litharge, &c, are employed to saturate the excess of acetic acid, and to correct the disagreeable taste of cider. A portion of lead is also sometimes derived from the presses and troughs em- ployed in the manufacture. In some countries this practice has been followed to a great extent. The presence of lead in any of its forms of combination can be detected by the process indicated under the article Wine. CINCHONA.—See QUININE. CINNAMON. Cinnamomum, U. S. The cinnamons and cassias of commerce are the bark of various species of Laurus L., ( Cinnamomum Nees,) of which the most esteemed is the inner bark of the Laurus Cinna- momum L., a native of Ceylon, but which is also cultivated in the Cape de Verds, Brazil, the West India Islands, &c. The best cinnamon is in long cylindrical bundles composed of numerous quills, the larger enclosing the smaller. These quills are of a light brownish yellow colour, almost as thin as paper, smooth, somewhat pliable, have a fragrant odour, 6* 66 CITRIC ACID. and a warm, aromatic, sweetish and slighty astringent taste. It is said to be often adulterated with cassia bark, or with cinnamon bark, from which the essential oil has been sepa- rated by distillation. The goodness of cinnamon can be judged of by the above characters, and especially by its taste. The inferior kinds are browner, thicker, less splintery, and have a less agreeable flavour. Under the name of Cassia various inferior kinds of cin- namon are found in market. These varieties are usually in single tubes, much thicker, rougher and denser than the Ceylon cinnamon. They have also a darker colour, a strong- er, more pungent and astringent, but less pleasant taste. It is said, also, that by infusion cassia imparts a yellow colour to alcohol, whereas cinnamon produces a much fainter coloured solution. The genuine Oil of Cinnamon is exceedingly hot, sweet and aromatic, but its flavour, when diluted, is very rich and agreeable, and very different from that of oil of cassia, which is sometimes substituted for it, and with which it is occa- sionally adulterated. It sinks in water. CITRIC ACID. Acidum Citricum, U. S. This acid is contained in large quantity in the juice of the lime and lemon, Citrus Medica L. It occurs in large and transparent crystals, the primary form of which is a right rhombic prism, if the process of evaporation has been con- ducted slowly; but if the solution is evaporated at 212° F., the form is different, and two atoms of water are removed. In the former state, it is soluble in an equal weight of cold, and about half its weight of boiling, water. The solution is strongly acid, and becomes mouldy by keeping. When added in excess to lime water, no precipitate is produced. CITRIC ACID. 67 It does not yield a crystalline precipitate when added in ex- cess to a solution of carbonate of potassa. It forms with barytic water a white precipitate of citrate of baryta, and with solution of acetate of lead a white precipitate of citrate of lead, soluble in ammonia. Citric acid is liable to be adulterated with tartaric acid; and very often tartaric acid is substituted in bulk for citric acid. Large crystals of oxalic acid also have been occasionally found among the crystals of citric acid. To detect the pre- sence of tartaric acid, dissolve the suspected citric acid in a small quantity of water, and add to the solution some po- tassa, which will occasion a white crystalline precipitate of cream of tartar. Excess of lime water also when added to the solution of suspected citric acid, will cause a precipitate, in the cold, if tartaric acid is present. This precipitate is readily soluble in cold potassa, the solution forming a gela- tinous precipitate on boiling, which disappears again on cool- ing. To detect oxalic acid, add to a similar solution of the suspected citric acid a solution of sulphate of lime; if any oxalic acid is present, a white precipitate of oxalate of lime will be formed. If the presence of lime is suspected in the citric acid, dis- solve the acid in water, neutralize the solution with ammo- nia, and add a solution of oxalate of ammonia ; if lime be present, it will produce a white precipitate of oxalate of lime. Crystallized citric acid is sometimes found to attract the moisture of the atmosphere. This may be owing to its con- taining a portion of sulphuric acid. To determine this fact, dissolve the citric acid in water, and add to the solution a few drops of a solution of chloride of barium. If this causes a white precipitate, insoluble in muriatic acid on being gently heated, it is due to the presence of sulphuric acid. 68 COAL GAS. CLOVES. Caryophyllus, U. S. The unexpanded flower buds of the Caryophyllus aromat- icus L., a tree which is a native of the Moluccas, and of other islands in the Chinese Sea, but which is cultivated in India, China, Persia, Arabia, &c. They have a strong aromatic and peculiar odour, an acrid and pungent taste. They re- semble a small nail with a toothed head ; colour deep brown. At one time the fraud was common of extracting part of the oil from the cloves, and then sending them into market with various quantities of the uninjured spice. The cloves which have been subjected to distillation are lighter than those which are good, shrivelled, of a paler colour, and give out no oil when compressed by the finger nail. Cloves are re- markable for their power of absorbing moisture, and cunning traders put the bulk of spice, when any quantity is ordered, near a vessel of water, and as they are sold by weight, a very considerable addition is made surreptitiously to the ac- tual quantity of the spice. The clove tree, when growing, absorbs moisture most greedily, both from the soil and at- mosphere ; even to such an extent, that it is said no herbage is found beneath its shade.—(Burnett's Outlines of Botany.) COAL GAS. This gas when first made contains a great number of other substances in small quantities. Several of these are sepa- rated by the lime water employed in the process. If the odour of sulphuretted hydrogen is observed, it may be infer- red that the quantity of lime is insufficient for the purifica- tion of the gas. Naphtha vapour, which exists in a very mi- nute quantity, is the principal cause of the peculiar odour of coal gas, and the sulphuret of carbon, causes it to blacken COCCULUS INDICUS. 69 lead and silver, and gives sulphurous acid when burned. The specific gravity of the purified gas varies from 0.450 to 0.700. The relative value of a specimen of coal gas, as compared with any other substance employed for a similar purpose, may be determined by comparing the illuminating power, and the cost of each per hour. COBALT. This metal is difficultly reduced from its ores, and has not been hitherto employed in the arts. The metal often sold by that name in the shops is arsenic, which may be proved by throwing a small fragment of it on hot coals, when the garlic odour will be instantly perceived. COBALT, OXIDE OF. This oxide, in its pure form, is of an ash grey colour. It is soluble in acids, and when recently precipitated almost entirely soluble in excess of ammonia. The Zaffre of com- merce is prepared by calcining the ores of cobalt, by which the sulphur and arsenic are volatilized, and an impure oxide of cobalt remains, which is mixed with about twice its weight of finely-powdered flints. Smalt and Azure Blue are made by fusing zaffre with glass. A blue glass is thus formed, which, while hot, is dropped into water, and after- wards reduced to a very fine powder. The oxide of cobalt is sometimes contaminated with iron, copper, arsenic, antimony and bismuth. COCCULUS INDICUS. The drug known by this name consists of the fruit of the Cocculus suberosus D. C, (Menispermum GocculusL.) a large tree which grows upon the coasts of Malabar, Ceylon, &c. It is very poisonous, and is often employed to destroy ver- min, and to intoxicate or poison fish. It is largely imported 70 COCHINEAL. both into England and into the United States, and is said to be used to adulterate fermented liquors, and to increase the intoxicating property of beer. The fruit is about the size of a large pea, dark brown and wrinkled, within which is a bivalved, one-celled shell; the kernel is white and oily, and does not completely fill the shell. It is without odour, but has an intensely bitter taste. Its narcotic and poisonous properties are due to a vegeto-alkaline principle, which has been called Picrotoxine. As met with in commerce, the kernel of the Cocculus In- dicus is often completely dried up, so as to leave the shell nearly if not quite empty. The Edinburgh College directs " that the kernels should fill at least two-thirds of the fruit." COCHINEAL. Cocci, U. S. The article known in commerce by the name of Cochineal, is the dried body of an insect, the female of the Coccus Cacti L., found in Mexico. The fine cochineal, when well dried and preserved, should have a grey colour, bordering on purple. It is wrinkled with parallel furrows across its back, which are intersected in the middle by a longitudinal one ; hence when viewed by a magnifier, especially after being swollen by soaking for a little while in water, it is easily distinguished from the fac- titious, smooth, glistening, black grains, of no value, called East India Cochineal, with which, according to Dr. Ure, it is often shamefully adulterated by certain London merchants. The genuine cochineal has the shape of an egg bisected through its long axis, or of a tortoise, being rounded like a shield upon the back, flat upon the belly, and without wings. The principal sorts of cochineal are the silvery, being of an ash-grey colour, aud the black; the latter being most highly esteemed. COFFEE. 7j Dr. Ure states that the adulteration of cochineal has for many years been practiced upon a prodigious scale by a mer- cantile house in London. The genuine article is moistened with gum water, agitated in a box or leather bag, first with sulphate of baryta in fine powder, afterwards with bone or ivory black, to give it the appearance of black cochineal, and then dried. The specific gravity of genuine cochineal is 1.25 ; that of the cochineal loaded with the barytic sul- phate 1.35.—(Dictionary of Arts, $c.) If this adulterated cochineal is macerated in warm water, the powder separates and falls to the bottom of the vessel. Cochineal is some- times also manufactured by mixing dust and refuse of cochi- neal with water and mucilage into a paste, which is after- wards granulated to the size of the dried insect. This sort of cochineal falls to pieces when put into water, which is not the case with the real cochineal. As the value of cochineal depends upon its colouring power, one of the most exact methods of determining it is that re- commended by Robiquet: Take a certain weight of cochi- neal, of good quality, and the same weight of the cochineal which is to be tried. Boil each in an equal quantity of water, and put an equal quantity of each solution into two little graduated glass tubes. Add to each, a little at a time, a solution of chlorine gas in water, until the two red liquors are rendered yellow. The different quantity of chlorine liquor required for the bleaching of each cochineal liquor, serves to point out the relative strength or colouring power of the two liquors ; that which requires the most chlorine to bleach it being, of course, the one which contains the most colour. Cochineal should be kept in a dry place. COFFEE. It is well known that coffee, when sold in powder, is adulterated with various torrefied substances ; such as the 72 COFFEE. roots of the chicory, of the beet, the carrot, and with peas, beans, rye, &c. Most commonly, however, torrefied chico- ry is preferred, and a powder is sold in France by the name of Chicory coffee and Mocha coffee. It is quite easy to determine by the taste whether chicory has been mixed with coffee. But there are other modes of detecting this adulteration. In rolling between the index finger and the thumb a mixture of coffee and chicory, after having moistened it, we obtain a small ball; pure coffee remains in powder. Or we fill a glass with water, and throw into it some ground coffee. The coffee is pure when nothing falls to the bottom, for the chicory immediately ab- sorbs, the water, falls to the bottom of the vessel and gives the liquid a yellow colour. This test depends upon the fact that the two substances absorb water in different pe- riods of time, the coffee being less permeable on account of the oil which it contains. Ground and burnt coffee is also adulterated with burnt rye. This mixture can be detected by passing the infusion of the coffee through animal charcoal to deprive it of its colour and then adding to the filtered solution the tincture of iodine. A blue colour will appear if rye is present, from the action of the starch which it contains. Adulteration of Chicory.—It is now ascertained that in France, even chicory, the price of which is so low, is adul- terated with articles still cheaper. Among these may be enumerated roasted bread, roasted barley, animal charcoal which has been used in sugar refineries, and the dregs of coffee. The two former may be detected by adding to the filtered and clarified decoction, some tincture of iodine, which will produce a blue precipitate, while no such change will follow if the chicory is pure. The powder of chicory, moreover, when thrown into water instantly falls to the bottom, which is not the case with the mixed powder. Animal charcoal exhibits black brilliant points, and renders COLCHICUM. 73 the mixture inodorous. Upon adding to it repeated por- tions of boiling water and pouring off from time to time the light matters held in suspension, the black powder remains at the bottom and after calcination its weight may be deter- mined. The presence of coffee-grounds may be detected by drying the mixture and then throwing it into a glass of water ; the coffee-grounds remain on the surface of the wa- ter for a certain length of time. COLCHICUM. Colchici Radix, U. S. This is the bulb or cormus of the Colchicum Autumnale L., sometimes called Meadow Saffron, a native of the tem- perate parts of Europe. In its recent state it resembles the bulb of a tulip. It is covered externally with a brown mem- branous coat; internally it is solid, white and fleshy. In the shops it usually occurs in dried, transverse, circular slices, about the eighth or tenth of an inch in thickness, with a notch at one part of the circumference. These pieces have a white surface, are inodorous, but have a bitter, hotand acrid taste. The active properties of the Colchicurri are supposed to be due to a peculiar principle which has been called Colchi- cine, and which seems to be entirely extracted by wine and vinegar. Dr. A. T. Thomson states that the milky juice of the fresh bulb produces a beautiful cerulean blue colour if rubbed with the alcoholic solution of guaiac ; and that the same effect is obtained by substituting for the juice an acetic solution of the dried bulb. He considers the appearance of this colour, when the slices are rubbed with a little distilled vinegar and tincture of guaiac, as a proof that the drug is good° and has been well dried. A very deep or large notch in the circumference of the slices is considered by the same author an unfavourable sign, as it indicates that the bulb has been somewhat exhausted in the nourishment of the offset. The decoction yields a deep blue precipitate with tincture 7 74 COLCOTHAR. of iodine, white precipitates with the acetates of lead, nitrate of protoxide of mercury, and nitrate of silver, and a slight precipitate with tincture of galls.—(U. S. Dispensatory.) COLOCYNTH. Colocynthis, U. S.—Bitter Cucumber. This is the fruit of the Cucumis Colocynthis L.,%. native of several parts of Asia and Africa, and cultivated in Greece and Spain. The peeled fruit, which is the part used in medicine, is globular, has a spongy appearance, a white col- our, a tough consistence, and an extremely bitter taste. When it is of a greyish or brownish colour, it is of inferior quality. The compound extract of Colocynth, which is a highly valued preparation of this article, is often adulterated by the use of impure scammony. The substances thus introduced are principally chalk and starch. The former may be de- tected by the effervesence of the compound extract in dilute muriatic acid, and the white precipitate caused in this muriat- ic solution on the addition of oxalate of ammonia. If the filtered decoction, slightly acidified, becomes blue or pur- plish on the addition of tincture of iodine, we may infer the presence of some starchy substance. COLCOTHAR. An old name for the red oxide of iron. It is a brown red powder, which is obtained in its purest state by calcining dried sulphate of iron in a furnace till all the acid is ex- pelled, levigating, elutriating and drying the residue. It is much used forgiving the finishing lustre to instruments made of steel, &c. Much of the Colcothar in market is made from the copperas and alum sediments, and is greatly inferior to that prepared according to the former mode.—(See Iron.) COLOMBA ROOT. 75 COLOMBA ROOT. Colomba, U. S. The root of the Cocculus palmatus D. C. (Menisper- mum palmatum Lam.), a native of Southern Africa. It is generally found in the shops in dried cylindrical slices, which have a thick yellow bark covered with an olive-coloured skin, and a browner-and spongy central portion. It is usu- ally much worm eaten, and for use those pieces should be selected which are the least so. It ought to have a bright colour. It is sometimes mixed with slices of bryony root, Bryonia dioica, a most dangerous adulteration, consisting in the substitution of a drastic purgative for a grateful tonic? The fraud probably originated in a belief which once pre- vailed that colomba was the root of the Bryonia cpigaa W. which is said to resemble it in its properties.—(Burnett's Outlines of Botany.) ° . i Colomba, when moistened and touched with tincture of iodine, should become blackish in consequence of the pres- ence of starch. False colomba presents no change of col- our when treated in this manner. Pure colomba gives no colour to sulphuric ether ; false colomba gives it a fine yel- low. The root of the American columba, Frasera Walleri Mich., is said to have been sold in some parts of Europe for the genuine, and perhaps the same thing has been done in this country. According to M. Stolze of Halle, it ap- pears that while the tincture of columba remains unaffected by the sulphate or sesquichloride of iron and gives a dirty grey precipitate with tincture of galls, the tincture of fra- sera acquires a dark green with the former reagent, and is not affected by the latter. 76 COMMON SALT. COMMON SALT. In France where there is a high duty upon this important article, there are numerous adulterations of it which are never practiced in this country. Among these may be men- tioned the moistening of the salt to increase its weight, the addition of saltpetre, the soda of varech, sulphate of soda, plaster of Paris, alum and earthy matters. In this country the impurities which are found in salt arise chiefly from carelessness in its manufacture. Some of these I shall briefly notice. The presence of water.—Several specimens of Onondaga salt which I have examined were moist, and were found to contain from 5 to 12 per cent, of water. This is not owing to the fraudulent addition of a certain quantity of water, but to the want of attention in the drainage of the salt after it has been removed from the kettles in which the manufacture has been conducted. The Onondaga brine contains, in addition to common salt, notable proportions of the chlorides of calcium and magnesium. These being much more soluble than chloride of sodium must be re- moved by long drainage and by washing with saturated brine. If mixed with the salt their deliquescent property will cause the absorption of moisture from the air and thus the whole mass will become moist and increase considerably in its weight. I have repeatedly urged this subject upon the attention of the manufacturers of salt in Onondaga county as one of the greatest importance. It is through a want of attention to the removal of these deliquescent chlorides, that much of the prejudice which has been excited against this salt is to be ascribed. There is less excuse for this because the objection may be obviated and the perfect purity of the salt secured, so far at least as these substances are concerned, 4 COMMON SALT. 77 by the simple mode of washing the product, while in the process of drainage, by a saturated brine. By this means these soluble chlorides will be dissolved, while the common salt suffers but a trilling loss ; and the whole amount which has been removed may again be recovered by the evapora- tion of the brine employed in this washing. The presence of the deliquescing chlorides may some- times be detected by the bitter taste which they give to the salt. This fact can also be determined by weighing a cer- tain quantity of salt that has been dried in a sand bath at a moderate heat, and then ascertaining the increase of weight which takes place by exposing it to the air for twelve or fif- teen hours. The larger the proportion of these earthy chlo- rides the greater will be the increase in weight. Carbonate and Sulphate of Lime.—These substances are sometimes added to common salt for fraudulent purposes- It is said that in France plaster of Paris is reduced to a fine powder, and has been offered for sale under the name of " a powder to mix with salt.'''—(Gamier and Hard.) Plaster gives salt a very white appearance, and is often on this account added to table salt. This practice is, I think, pursued to some extent at the salt works in Western New York. Sulphate of lime is, moreover, one of the constituents of all the western brines ; and the almost uni- versal employment of lime at these works to promote the precipitation of the sparingly soluble substances, introduces into the salt a greater or less proportion of carbonate of lime, depending upon the care which has been exercised in the removal of the lime. The presence and amount of carbonate of lime can be determined by dissolving a known quantity of the salt in water, with the aid of heat, throwing the solution upon a filter, and washing the insoluble residue with a sufficient quantity of water to ensure the solution of the sulphate of 78 CONFECTIONARY. lime. The carbonate of lime will remain on the filter, and may be separated from silica or other insoluble matters by dilute muriatic acid and subsequent filtration. The pre- sence of the carbonate is proved by the effervescence caused by the muriatic acid and by the white precipitate produced by the saturation of the clear muriatic solution with ammo- nia and the subsequent addition of oxalate of ammonia. If sulphate of lime is mixed with the salt, chloride of ba- rium added to a portion of the solution filtered from the carbonate of lime, will give a white precipitate of sulphate of baryta ; while oxalate of ammonia, added to another por- tion of the same solution, will cause a white precipitate of the oxalate of lime. By dividing such a solution into equal parts, and carefully washing, drying, igniting and weighing the precipitates, the proportion of sulphate of lime may be determined, if the absence of any other sulphate has been previously ascertained. CONFECTIONARY. The various articles of confectionary are sometimes col- oured with poisonous mineral or organic substances. Theie frauds are the more dangerous because the great consump- tion of confectionary is by children and young persons. Among the colouring matters thus employed, may be men- tioned chrome yellow, gamboge, Scheele's green, Schwein- furt green, minium and vermillion. Detection of Injurious Colouring Matters.—All the above preparations are insoluble in water, except gamboge which is partly soluble ; and they can be separated by putting a certain quantity of the confectionary into cold water, by which the sugar and the various extractive matters forming the basis of the confectionary will be dissolved, while the insoluble colouring matters will remain at the bottom of the vessel. They may then be separated by decantation or CONFECTIONARY. 79 otherwise, washed repeatedly with pure water, and dried in a small capsule at a gentle heat. Chrome yellow, or chromate of lead, may be detected as follows: Calcined with a little soda upon charcoal, a globule of metallic lead is obtained. When boiled with a solution of carbonate of potassa, it is decomposed with the formation of chromate of potassa. This solution has a lemon yellow colour, and being saturated with nitric acid becomes orange, and causes red precipi- tates in solutions of nitrate of silver and of mercury, and a yellow one in a solution of acetate of lead. Gamboge is distinguished by the yellow emulsion which is formed in the water containing the dissolved confection- ary of which it forms a part. For the purpose of separat- ing it the confectionary should be treated with rectified alcohol. Water added to the alcoholic solution, causes the precipitation of the resinous part of this gum. The portion held in solution by the water is changed to a red colour by the addition of a few drops of solution of ammonia. Scheele's green and Schweinfurt green, the former of which is an arsenite of copper, and the latter a compound of an acetate and an arsenite of copper, can be detected by the garlic odour which they exhale when thrown upon hot coals, and by the sublimate of metallic arsenic which is formed when they are mixed with black flux and subjected to heat in a glass tube. Minium is converted into a brown-coloured powder by the action of nitric ac.id, and when calcined in contact with carbon, yields a globule of metallic lead. Vermillion is not acted on by nitric acid, but when thrown upon red-hot char- coal burns with a bluish flame, and gives out the odour of sulphur. When calcined in a small tube with iron filings it is reduced to metallic mercury. Besides these colouring materials, other substances are 80 CONIUM. mixed with confectionary, which, although not poisonous are indigestible. Thus sugar plums almost always contain sulphate and carbonate of lime; and pastry cooks often add alum to certain kinds of bon-bons to increase the lightness of the paste. The papers which are used as envelopes of confectionary are also sometimes coloured with the poisonous substances above mentioned. Children often put these papers into their mouths, and accidents have been known to occur in this manner.—(See Gamier and Hard.) CONIUM. Conii Folia, U. S.—Hemlock. The leaves of the Conium Maculatum L., which inhabits various parts of Europe, Asia and America. They are large and tripinnate ; leafets lanceolate, pinnatifid, with acute and often cut segments. In the fresh state they have a glaucous green colour, and have the characteristic odour of the plant. They have a nauseous, bitter taste. By drying they lose much of their odour, and acquire a dull greyish green col- our. The active principle of the leaves and fruit is a vegcto- alkali, which has been called Coneine, or Conia. It is a colourless, oily liquid, which has a peculiar penetrating and disagreeable odour, an intensely acrid taste, and is a most active poison. Other umbelliferous plants, which bear a general resem- blance to the conium, are frequently confounded with it, and their leaves are often sold for those of the true plant. The only mode of discrimination is afforded by a close atten- tion to the botanical characters of this species. Chemically all parts of the conium are known by the peculiar odour of coneine which is evolved on trituration with caustic potas- sa.—(Neligan, Medicines, their Uses, <5fc.) COPPER, ACETATE OF. 81 COPAIBA,—See BALSAM OF COPAIBA. COPPER. Cuprum, U. S. This well-known metal is distinguished from all others, except titanium, by its red colour. It is malleable and duc- tile, has a specific gravity of 8.89, is less fusible than silver and more so than gold. The commercial copper is seldom free from iron, which can be detected by dissolving it in muriatic acid and adding to the solution a sufficient quantity of ammonia to dissolve the copper, which will give a deep blue solution, when the iron will be thrown down in the form of brownish red flocks. Perfectly pure copper may be ob- tained by dissolving the copper of commerce in muriatic acid ; the solution is diluted and a plate of iron immersed, upon which the copper is precipitated. After washing it in dilute sulphuric acid to separate a little iron that adheres to it, it may be fused into a button. Copper almost always contains lead, and it is stated by Dumas that one-thousandth part of this metal affects the te- nacity of copper, and renders it unfit for the manufacture of wire. To ascertain its presence dissolve the metal in nitric acid, and add dilute sulphuric acid to the solution. If any lead is present a white precipitate is formed, which is solu- ble in a solution of potassa, and is inst antly blackened by being moistened with the hydrosulphuret of ammonia.— ( Chimie appliquee auxArts.) COPPER, ACETATE OF. Crystallized Verdigris—Distilled Verdigris. This salt is prepared by dissolving common verdigris in acetic acid ; the solution is put into pans and allowed slowly to crystallize, generally upon twigs or pieces of string sus- 82 COPPER, DIACETATE OF. pended in it. It is in the form of oblique rhombic prisms, of a rich bluish green colour, soluble in five parts of water. It is frequently adulterated with sulphate of copper, which can be detected in the manner described under Diacetate of Copper. COPPER, AMMONIACAL SULPHATE OF. Cuprum Ammoniatum, U. S. This is in the form pf a deep blue crystalline powder or dark blue crystals. It is soluble in one and a half parts of cold water, and insoluble in alcohol. When exposed for a long time to air it loses ammonia and crumbles down into a green powder, (a mixture of sulphate of ammonia and car- bonate of copper.) It is then insoluble in water. If it leaves a brown powder when dissolved in nitric acid, it contains oxide of iron. COPPER, DIACETATE or SUBACETATE OF. Cupri Subacetatis} U. S.—Common Verdigris. This substance is procured by the action of acetic acid, obtained from the refuse of grapes, upon copper. It is usu- ally a mixture of acetate and subacetate of copper in varia- ble proportions, and is often adulterated with foreign bodies, as pieces of copper, grape stalks, &c. The proportion of the latter can be ascertained by dissolving the verdigris in water and filtering the liquid through paper. To the filtered solution add a solution of chloride of barium. If this pro- duces an abundant precipitate, soluble in muriatic acid, the verdigris contains tartrate of copper ; if the precipitate is insoluble in this acid, we infer the presence of sulphate of copper. Chalk, which is also used as an adulterant of this substance, is insoluble in water, but dissolves, with efferves- cence, in dilute muriatic acid ; and the solution give a white precipitate with oxalate of ammonia. CREASOTE. 83 COPPER, SULPHATE OF. Cupri Sulphas, U, S.—Blue Vitriol. A salt occurring in rhomboidal crystals of a fine blue co- lour, having a styptic metallic taste and an acid reaction. It effloresces slightly on exposure to the air, and becomes cov- ered with a greenish white powder. It is soluble in about four parts of water at 60° F., and in two parts of boiling wa- ter. The solution should remain clear on exposure to the air. If it deposites a precipitate, it may be finely divided copper owing to the mixture of protosulphate of copper, or it may be peroxide of iron, or a basic salt of the peroxide of iron. To determine which, dissolve the precipitate in mu- riatic acid, and add excess of ammonia. Upon allowing the mixture to remain exposed to the air a blue solution will be produced by oxide of copper, and a brown red precipitate by oxide of iron. If the blue vitriol dissolves without residue it may still contain a salt of iron. Add ammonia to the so- lution in excess when a beautiful blue transparent solution will be formed. If a reddish brown insoluble precipitate appears, it proves the presence of a considerable proportion of iron. If zinc is suspected to be present, it may be de- tected by the following process. Acidulate the solution with sulphuric acid, and precipitate the whole of the copper by sulphuretted hydrogen gas ; filter the solution from the pre- cipitate ; make it boil, and while it is boiling add a solution of carbonate of potassa. If a white precipitate is produced, let it cool, then filter, wash and dry it. If this precipitate becomes yellow when heated and white when cold, the pre- sence of zinc is demonstrated. CREASOTE. An oily colourless liquid, with a penetrating, disagreeable odour, similar to that of smoked beef. Its taste is burning and caustic, its specific gravity about 1.037 at 68° F. It 84 CROTON OIL. boils at 397° F., and is not congealed at a temperature of 16.6° F.; it burns with a smoky flame ; combines with ace- tic acid, water, alcohol, ether, and with the alkalies ; it also coagulates albumen. Creasote, when pure, is perfectly colourless; but that which is sold in the shops often has a brownish tinge. This may be owing to the presence of oil of tar, capnomor, and other impurities. They may be detected by mixing sepa- rate portions of the suspected liquid with acetic acid and solu- tion of caustic potassa. Pure creasote is completely soluble in these liquids, while the adulterated article is not. Fixed oils are also discovered by a stain on paper which is not dis- charged by heat. If the creasote is very light it may.be adulterated with alcohol. This may be separated by care- ful distillation, the alcohol coming over first and distinguish- able by its burning with a clear instead of a. smoky flame. CROCUS.—See SAFFRON. CROTON OIL. Tiglii Oleum, U. S. This oil is obtained from the seeds of the Croton Tiglium L., a native of the Molucca Islands and of Cochin China. It has a yellowish or brownish colour, a consistence like that of nut oil, a very disagreeable odour, and an extremely acrid taste. It is soluble in sulphuric ether, and partly so in alcohol. As this is a very active medicine, a drop or two producing the most violent purgative effects, adulterations may cause more serious consequences than in less powerful articles. If a sample which has been adulterated with cer- tain fixed oils, of which a dose may be several drops, is fol- lowed by a pure oil, the most alarming results may be pro- duced. The following test of the purity of Croton oil is given by the Edinburgh College. " When agitated with itsownvol- CUBEBS. 85 ume of pure alcohol and gently heated, it separates on stand- ing, without having undergone any apparent diminution." But this does not accord with the researches of Dr. Nimmo, who states that croton oil consists of two portions, one acrid and purgative, amounting to forty-five per cent., soluble in cold alcohol, the other a mild oleaginous substance like olive oil, soluble in ether and oil of turpentine, but very slightly soluble in hot alcohol, by which it is deposited when the liquor cools. CUBEBS. Cubeba, U. S. The dried unripe berries of the Piper Cubeba L., a na- tive of Java and Prince of Wales' Island. They are about the size of black pepper, wrinkled on the surface, brownish externally, and containing a single loose seed, which is white and oleaginous within. They are furnished with a stalk two or three lines in length ; have an agreeable aro- matic odour; and a warm, bitterish, camphorous taste. The powder is of a dark colour and of an oily aspect. Be- sides other ingredients, they contain volatile oils, and a pe- culiar principle called Cubebin, which closely resembles piperin but is said to differ from it in composition. Cubebs gradually deteriorate by age; and in the state of powder become rapidly weaker, in consequence of the es- cape of their active volatile ingredient. They should al- ways be kept whole, and pulverized at the time they are pre- scribed. The powder is said to be sometimes adulterated with that of pimento, and it is also stated that the berries of the Uvaria ceylanica L. are sometimes used under the name of cubebs. They are, however, wholly different from the genuine drug, and may be distinguished by their containing four seeds in each berry, while the latter has but one.—( U. S. Dispensatory.) 8 86 ERGOT. DRAGON'S BLOOD. This is a resinous substance, which is brought from the East Indies, Africa and South America, as the produce of several trees, viz. : the Draccena Draco L., the Pterocarpus santalinusL., Pterocarpus Draco L., and the Calamus Dra- co Willd. It occurs in commerce sometimes in small balls of the size of a pigeon's egg, sometimes in rods like the fin- ger, and sometimes in irregular cakes. Its colour, in lump, is dark brown red, in powder, bright red ; it is friable, and has a shining fracture. Specific gravity 1.196. It is insolu- ble in water, but readily soluble in alcohol, ether and the oils, with the exception of a slight woody residue. When thrown upon burning coals, it disengages an aromatic odour. False Dragon's Blood consists of different resins coloured with red sandal, colcothar, Armenian bole and pure dragon's blood. It has not the shining red fracture of true dragon's blood ; its powder has a dull colour ; it disengages a dis- agreeable odour when thrown on burning coals ; it dissolves in alcohol, but leaves a considerable residue. ERGOT. Ergota, U. S.— Spurred Rye. This is a fungus, which is sometimes found upon rye, and other grains and grasses. It consists of grains varying from a few lines to an inch or an inch and a half in length, and from half a line to four lines in breadth. It is cylindrical, or obscurely triangular, curved like the spur of a cock, furrowed or striated on two sides. Colour, exter- nally, purplish brown or black; internally, whitish. It is inodorous, except when in large quantity, and has a mawk- ish and somewhat acrid taste. It is inflammable, and burns with a clear yellowish white flame. Ergot, although in most cases poisonous, is sometimes GALL-NUTS. 87 used for medicinal purposes. It is liable to adulteration and deterioration. Some specimens, procured for analysis by a celebrated chemist, were found to be only plaster of Paris casts, coloured in imitation of the ergot. The active princi- ple of the fungus resides in the outer covering, and if heavy rains fall at the time when this is soft and moist, it will be washed away, and the hardened nucleus will be entirely inert. But if the weather is fine during the maturation of the fungus, the ergot will be in its highest state of activity.— (Burnett.) Ergot is also sometimes attacked by a worm, which consumes the interior of the fungus, and impairs its medicinal properties. In a state of powder it is more liable to deteriorate than when kept entire. Pereira thinks ergot ought not to be used that has been kept for more than two years. The above facts will probably, in a great measure at least, account for the difference of opinion which prevails in regard to the physiological effects of this article. For further par- ticulars on this subject, see "Observations on Ergot, by Professor J. B. Beck."—(Transactions IV. Y State Medical Society, 1842.) ETHER.—See NITROUS ETHER and SULPHURIC ETHER. GALL-NUTS. Galla, U. S. These are excrescences found upon the leaves and leaf- stalks of a small shrubby species of oak, the Quercus infec- toria Oliv., found in all parts of Asia Minor, especially in the neighborhood of Smyrna and Aleppo. They are the result of the puncture of a small insect called Diplolepis galla tinctoria, made to deposit its eggs ; round which the juice of the tree exudes and dries in concentric portions. When the insect gets fully formed, it eats through the nut, and flies off. There are two qualities of Levant galls. The gg GAMBOGE. first are heavy, compact, imperforated, the insect having not been sufficiently advanced to eat its way through the shell. They are prickly on the surface, have a blackish or bluish green hue, and are about the size of a musket ball. These are called black, blue or Aleppo galls. The second are light, spongy, pierced with one or more holes, are smooth on the surface, have a greyish or reddish yellow colour, generally larger than the first. They are called white galls. Another kind of an inferior quality, which is smaller, irregular in shape, and of a brownish colour, comes from Calabria, Illyria, Dalmatia, &c, being found on the Quercus C err is L. GAMBOGE. Gambogia, U. S. A gum resin obtained from a plant which inhabits Siam, and which is supposed to be a species of Hebradendron,an& nearly allied to the II. Gambogiodes Graham, from which the Ceylon gamboge is procured. The Siam gamboge,£ which is the commercial article, occurs in hollow or solid cylinders known by the name of pipe gamboge, and in ir- regularly shaped masses, forming the cake or lump gamboge. The pipe gamboge is of a rich reddish yellow colour, gene- rally greenish and dusty externally ; inodorous, tasteless at first, but soon producing a sensation of acridity in the throat. It has a smooth, shining, conchoidal fracture. The lump gamboge has a duller colour than the former variety, and is of inferior purity. Some parcels of gamboge are said to be adulterated with starch, and to contain lignin. The former may be detected by the greenish colour produced in the cooled decoction on the addition of the tincture of iodine ; and the presence of the latter may be known by the fracture not being smooth and conchoidal.—(Neligan's Medicines, their Uses, fyc.) GOLD. 89 Gamboge is sometimes employed to colour confectionary, but this practice is highly reprehensible. (See Confec- tionary.) GENTIAN. Genliana, U. S. The root of the Gentiana lutea L., a native of the moun- tains in the middle parts of Europe. It is in cylindrical, rough and twisted pieces, varying in length and breadth, wrinkled annularly and longitudinally. The larger pieces are split lengthwise. The colour of the epidermis is brown- ish yellow. Internally the root has a bright yellow colour, and a spongy texture. It has a faint aromatic odour, and an intensely bitter taste. Its active "properties are due to a crystallizable principle which has been called Gentianine. The roots of the other species of Gentian are often mixed with those of G. lutea, an adulteration of little importance, as they possess nearly analogous properties. The untoward symptoms which have sometimes been observed to follow the administration of what was supposed to be true gentian, have been proved to be owing to the Veratrum album L., or white hellebore, which grows in the same districts and has sor.13 slight resemblance to it, having been collected by mis- take.—(Burnett's Outlines of Botany.) The roots of the belladona and the monkshood are said also to be sometimes mixed with gentian. All these, how- ever, want the intense bitter taste,, and the bright yellow colour internally, of the latter root. GOLD. One of the best tests of the purity of this metal is its spe- cific gravity, which is from 19.40 to 19.65. It is very soft and flexible when pure, is less fusible than silver, and is so- luble in nitromuriatic acid. On adding protosulphate of iron to this solution, the gold is wholly precipitated as a 8* 90 GOLD. brown or brownish yellow powder, quite destitute of the metallic lustre, which, however, appears when the powder is rubbed. The presence of copper and silver may be de- termined by boiling the granulated metal in concentrated sulphuric acid, which dissolves both the silver and the cop- per, leaving the gold nearly pure, in the form of a black powder. The solution is then placed in a leaden vessel containing metallic copper ; this is gradually dissolved, and the silver is precipitated in a pure metallic state. The pres- ence of copper may be previously determined, if necessary, by the addition of ammonia, with which it forms a blue so- lution. Or after the precipitation of the silver, the whole sulphate of copper may be obtained by evaporating the solu- tion. The only common metal with which gold can be cpntam- inated, without reducing the specific gravity, is platinum, but this is not likely to be used in consequence of the change of colour which it produces. Even a twentieth part of plati- num greatly deteriorates the colour of gold. An alloy of four of platinum and one of gold, nearly resembles platinum in colour ; the gold colour does not predominate till it forms eight-ninths of the alloy. A mode of counterfeiting gold coin which has recently been somewhat practiced, is to prepare an alloy of the pro- per specific gravity by the introduction of a sufficient quan- tity of platinum, and then to cover the coin with a coating of gold, by the electrotype process. Such a fraud can be detected only by filing through the coating, or by subjecting the coin to heat. The infusibility of the platinum will dis- tinguish from most other metals. To separate it from gold, dissolve the alloy in nitromuriatic acid, the platinum may be thrown down by muriate of ammonia ; afterwards the gold may be precipitated by the protosulphate of iron. GRAPHITE. 91 GOLD, CHLORIDE OF. It occurs in small crystalline needles, of an orange red colour. It has a styptic, disagreeable taste, is soluble in al- cohol, ether and water, forming a solution of a beautiful yel- low colour. Chloride of silver is insoluble, and will there- fore remain unacted on when the chloride of gold is dissolved in water. The real value of a sample may be ascertained by the application of heat, when the chlorine will be driven off, and metallic gold remain in the crucible. The solution of chloride of gold must give a brown precipitate upon the addition of protosulphate of ijfou, and a purple precipitate with the protochloride of tin. GOLD, IODIDE OF. A yellowish brown powder insoluble in cold water, and very sparingly soluble in hot, easily decomposed by heat, and by the liquid alkalies. When heated in a crucible, it evolves iodine vapour, and leaves metallic gold. In this way the purity of this costly substance may be determined. GOLD AND TIN, OXIDE OF.—See PURPLE OF CASSIUS. GRAPHITE. Black Lead.—Plumbago. A mineral of a lead grey colour, a metallic lustre, soft to the touch, and staining the fingers with a lead grey colour. It is employed for counteracting friction between rubbing surfaces of wood or metal, for making crucibles and portable furnaces, and for giving a gloss to the surface of cast iron. The Graphite brought into market from the northern part of New York is largely mixed with magnetic iron ore, which can be proved by passing a magnet through the powder. The magnetic oxide will adhere to the poles of the magnet. 92 GUAIAC. The excuse offered for this adulteration is, that without this addition to the graphite, it cannot be reduced to powder in the mill. GUAIAC. Guaiaci Resina, U. S. This is the concrete juice of the Guaiacum officinale L., a large tree growing in the West Indies, and in the warmer parts of the neighbouring continent. It occurs in pieces of a deep greenish brown or dark olive colour on the external surface, reddish brown internally. It has a feeble but fra- grant odour, a taste which at first is scarcely perceptible, but after a short time becomes acrid. It is brittle, and when broken, presents a shining, glassy surface. The powder is at first of a light grey colour, but becomes green on exposure to light. Its specific gravity varies from 1.20 to 1.23. When pure, it is wholly dissolved by alcohol, giving a deep brown tincture which is decomposed by water, and affords blue, green and brown precipitates with the mineral acids. Guaiac is sometimes adulterated with the resin of the pine, a fraud which may be detected by the terebinate odour given out when such guaiac is thrown upon burning coals, as well as by its partial solubility in hot oil of turpentine. It is said also to be adulterated with amber. Paper moistened with a tincture of guaiac, if exposed to the fumes of nitric acid, speedily becomes blue, affording an excellent test of this drug.—( U. S. Dispensatory.) The wood of the Guaiacum ( Guaiaci Lignum U. S.) may be detected, according to Schwacke, by pouring a few drops of solution of perchloride of mercury over some shavings of the wood in a test tube, and slightly warming it over a spirit lamp ; a bluish green colour is immediately produced with all the genuine samples.—(The Chemist, March, 1846.) GTJM ARABIC. 93 GUM ARABIC. Acacia, U. S. This substance may be procured from upwards of forty species of Acacia, but the gum Arabic of commerce is prin- cipally obtained from the A. Arabica Willd., A. vera Willd., A. gummifera Willd., natives of the banks of the Nile, and of Arabia. It occurs in commerce in the form of small pieces, rounded upon one side, and hollow upon the other. It is transparent, without smell, brittle, easy to pulverize, colourless, or with a yellowish or brownish tint. Its specific gravity is 1.355. Gum Senegal, which is the produce of the Acacia Senegal Willd., is usually in larger masses, of a darker colour, and more clammy and tenacious than gum Arabic. Its specific gravity is 1.436. The gum of the cherry and plum tree, which is often mixed with the pre- ceding, is generally in irregular pieces, strongly coloured, and much less brittle than gum Arabic. When put into water, it dissolves but partially, whereas gum Arabic and gum Senegal are completely soluble. Gum Arabic is often sold in powder, when it is usually adulterated with starch, or wheat flour. Sulphate of lime or gypsum has also been found in large quantity in this pow- dered gum. Shake a little of the gum with some cold water in a glass tube. The gum dissolves, and the starch, flour and sulphate of lime, if present, fall to the bottom. Boil the gum in water, add a little nitric acid, and when cold, a few drops of a solution of iodide of potassium. The formation of a blue colour indicates the presence of starch or flour. Mix a little of the suspected gum with a few drops of water to a dough, fix this on the end of a platinum wire, and calcine it in the flame of the blow-pipe. If it does not burn quite away, but leaves a substance which shines very brightly 94 HOG'S LARD. when the blow-pipe flame is directed on it, and which is in- soluble in water, the gum probably contains sulphate of lime. At all events, the incombustible substance is not gum. GUNPOWDER. The strength and goodness of gunpowder may be judged of in various ways. 1st. By the colour and feel. 2d. By ascertaining whether it is well granulated, or whether the grains have been broken. For this purpose pass the dry hand into a vessel of the gunpowder : if the granulation is perfect the hand will not be blackened. 3d. Fire a small pinch of the gunpowder upon a piece of white paper or card: if good there will be but a slight residue. 4th. But'the most certain mode of determining the strength of gunpow- der is by measuring the actual projectile force by the epro- vette, and by the distance to which a given weight of it will project a ball of the same weight under circumstances ex- actly similar. On this subject see Ure's Dictionary of Arts, fyc. HOG'S LARD. Adeps, U. S. Lard, when pure, is white, a little granular, of a soft con- sistence, and almost destitute of taste and odour. It is in- soluble in water, partially soluble in alcohol, more so in ether and the volatile oils. It melts at about 85° F. into a clear transparent liquid, but if water is present this liquid is whitish or milky. When melted it readily unites with wax and resins. It is often adulterated with other fats, which give it a dark colour and a disagreeable odour. By exposure to the air it absorbs oxygen and becomes rancid ; on this account it should be kept in well-closed vessels. In this rancid state, lard reddens litmus, is irritating to the skin, and some- times acts injuriously on substances mixed with it. HONEY. 95 The presence of salt also renders lard unfit for pharma- ceutical uses. For its removal it is recommended that the lard be melted with twice its weight of boiling water, the mixture agitated, and the lard again separated when cold. In consequence of the introduction of lard for burning in lamps its consumption has greatly increased. Rancid lard, if in other respects pure, answers sufficiently well for this purpose. But an article is sometimes offered for sale as burning lard, which is largely mixed with refuse resin, oil, or other fats, or perhaps with the cheaper kinds of flour, and which is totally unfit for use. When burned in an iron spoon it sputters and leaves a large coaly residue ; in the lamp a thick black crust is soon formed on the wick, and in an hour or two the flame is extinguished. HONEY. Mel, U. S. This article, when pure and fresh, is fluid, but on being kept it gradually forms a crystalline deposit, and is at length converted into a soft granular mass. Its colour is somewhat variable, being white, yellowish, or with a slight brownish tinge. The odour differs with that of the flowers from which it was collected. It is soluble in cold water. Honey is sometimes adulterated with sand, potatoe starch, wheat or bean flour, to increase its weight and to give it whiteness. In the former case the solution of the honey in water will detect the fraud. If honey, which is mixed with flour or starch, is exposed to heat, it at first is rendered liquid, but as it cools it solidifies and becomes tenacious. The fraud, however, may be more certainly detected by the tinc- ture of iodine. The following process maybe employed : Dissolve two or three drachms of the suspected honey in about three ounces of boiling water, allow the solution to cool, throw it into a glass, and add two or three drops of the 96 HYDROCYANIC ACID. tincture of iodine. If the honey is pure, the liquid remains very limpid and scarcely changes its colour ; if, on the other hand, it contains flour or starch, it will be instantly troubled, take a deep blue tint, and after a few minutes cause a blue precipitate. In France, the most common adulterant of honey is said to be starch sugar. For some directions in regard to the detection of this substance the reader is referred to the arti- cle Sugar. HOPS. Humulus, U. S. The dried strobiles of the Humulus Lupulus L., a native of Europe and America, and extensively cultivated in vari- ous countries. They occur in the form of thin papery scales, of a greenish yellow colour, sprinkled with a yellow pow- der which has been called Lupulin. They have a strong'and somewhat fragrant odour, and an aromatic, bitter and slightly astringent taste. Hops are said to be sometimes bleached by exposure to the fumes of burning sulphur. In this case they smell of sulphurous acid and are worthless. The best way to judge of their goodness is to rub them between the hands; we can then determine whether "they have the characteristic odour, and the proper quantity of yellow powder. HYDRARGYRUM.-See MERCURY. HYDROCYANIC ACID. Acidum Hydrocyanicum, U. S.—Prussic acid. Various processes are given for the preparation of this acid in the dilute form in which it is employed for medicinal purposes. It is of great consequence that the strength of the preparation should be uniform, and the rules which are HYDROCYANIC ACID. 97 given for this purpose should be followed with great exact- ness. It should also be recollected that the acid loses strength by being kept. Fatal accidents have occurred from prescriptions with old acid, found after experience to act favourably, being made up with a fresh stock of acid, even though this was exactly of the standard strength. In this case, as in some others, the danger actually arose from too weak an acid having been at first employed. Diluted hydrocyanic acid should be perfectly colourless, and entirely vaporizable by heat. It should give no precip- itate with sulphuretted hydrogen or it contains some metal- lic matter. If it strongly reddens litmus it must contain some other acid. The presence of sulphuric acid,can be detected by the white precipitate, insoluble in nitric acid, pro- duced by the addition of nitrate of baryta or chloride of ba- rium. Muriatic acid is detected by nitrate of silver, which forms a white precipitate insoluble in boiling nitric acid, while the cyanide of silver is soluble in nitric acid at a boil- ing heat. The presence of either of these acids is only objectionable on account of the difficulty in determining the strength of the hydrocyanic acid ; while on the other hand, it is said to confer the advantage of rendering, the hydrocy- anic acid much less liable to decomposition. Medicinal hydrocyanic acid is sometimes replaced by con- centrated water of bitter almonds. This adulteration can be detected by placing a little of the suspected acid in a phial and afterwards subjecting it to the heat of a sand bath. Hold a piece of blue litmus paper over the mouth of the phial. In proportion as the acid tested is gently heated, the hydro- cyanic acid is disengaged and reddens the test paper. This effect is not produced when the liquid operated on consists only of the water of bitter almonds.—(The Chemist, Nov., 1844.) One hundred grains treated with nitrate of silver should precipitate ten grains of cyanide of silver. Nitrate of baryta should cause no precipitate if the acid is pure. 9 98 INDIGO. HYOCYAMINE, ok HYOCYAMIA. Hyocyamine is the active principle of the Hyoscyamus niger L. When pure, it crystallizes in transparent, colour- less needles, having a silky lustre. It is inodorous, slightly soluble in water, more so than atropine. Taste bitter and disagreeable, like that of tobacco. It is very poisonous, and the smallest quantity applied to the eye causes a dila- tation of the pupil which continues for a very long time. The aqueous solution of hyocyamine mixed with the tinc- ture of iodine assumes the colour of kermes. It gives a yellowish white precipitate with chloride of gold, and none with that of platinum. By these reagents it can be dis- tinguished from atropine. The leaves of the Hyoscyamus niger, sometimes em- ployed medicinally, are ovate-oblong, amplexicaul, sinuated, of a greenish yellow colour when dry, and have a fetid, narcotic odour, and a bitter, nauseous taste. They lose much of their activity by keeping, and should therefore be gathered every year. The admixture of other leaves may be readily detected by an attention to the above characters. INDIA INK.—See LAMPBLACK. INDIGO. This highly important colouring material is the produce of various species oilndigofera, especially the I. tinctoria L., I. Anil L., and I. argentea L. It is also obtained from the Nerium tinctorium Roxb., Isatis tinctoria L. and Polygonum, tinctorium Ait. It generally occurs in commerce in the form of square cakes or cubical masses of a deep blue col- our, passing into violet purple. On being rubbed by a smooth hard body it acquires the lustre and hue of copper. It is without odour, but has a somewhat metallic taste. IODINE. 99 Its density seems to be influenced by its freedom from for- eign impurities, as well as by the peculiar mode of manu- facture which has been adopted. It is insoluble in water, in cold alcohol and in ether ; it is partially soluble in boil- ing alcohol and oils, which deposit it again on cooling. Samples of this drug vary greatly in the proportion of pure indigo which they contain. According to Dr. Ure, the range is from about twenty-eight to seventy-five per cent. Several test processes have been proposed. One of these consists in the use of chlorine water. A known quantity of finely-powdered indigo is to be added little by little to a definite volume of chlorine water, till its colour ceases to be destroyed. A standard of comparison must have been previously fixed by a trial with a sample of indigo of known purity. Another mode suggested by Dr. Ure, as susceptible of great precision, is to convert 10 or 100 grains of indigo finely powdered into its deoxidized state, as in the blue vat, by the proper quantity of slaked lime and solution of green sulphate of iron ; then to preci- pitate the indigo,.collect and weigh it. The indigo should be ground upon a muller along with the quick-lime, the levigated mixture should be diluted with water, and added to the solution of the copperas. But this exact analytical process requires much nicety in the operator.—(Diction- ary of Arts, S^c.) IODINE. lodinum, U. S. A soft and friable solid, of a bluish black colour, and a metallic lustre. It produces a yellow stain upon the skin ; evaporates slowly in the air at ordinary temperatures, and rapidly if heat is applied, producing violet vapours. It is very sparingly soluble in water, but readily so in alcohol or ether, and forms a blue compound with starch. The bottles of iodine usually contain less of that substance 10Q IPECACUANHA. than the quantity marked upon the labels, a fraud which has recently been extensively practiced. The presence of slate, coal or graphite, with which it is sometimes mixed, may be detected by their remaining behind when the iodine is volatilized, and by their insolubility in alcohol. Some specimens of iodine exhibit the appearance of a humid mass instead of dry scales : they have been found to con- tain 20 or 25 per cent, of water. In this moist state it is unfit for making pharmaceutic preparations of fixed and uniform strength. The fraud may be detected by compressing the iodine between folds of blotting paper. The Edinburgh College directs that such moist iodine, before being used, should be dried by being placed in a shallow basin of earthenware in a small con- fined space of air, with ten or twelve times its weight of fresh burnt lime, till it scarcely adheres to the inside of a dry bottle. IODINE, TINCTURE OF. Tinctura Iodini, U. S. This is made by dissolving one ounce of iodine in sixteen ounces of rectified spirit. When kept for any length of time its strength varies, owing to the separation of a por- tion of the iodine in a crystalline form ; it also undergoes change by exposure to the light. The iodine combines with a portion of the hydrogen of the spirit and forms hydriodic acid, which reacting upon the spirit gives rise to a little hydriodic ether. As an internal remedy it is there- fore unsafe unless very recently prepared. IPECACUANHA. Ipecacuanha, U. S. The root of the Cephaelis Ipecacuanha Rich., an herba- ceous plant which is a native of Brazil. It is in pieces of IRON. 101 three or four inches in length, about the thickness of a goose quill, irregularly twisted, and marked with numerous small, but deep, circular rings ; internally it exhibits a small white woody fibre, from which the thick greyish brown bark is detached with difficulty. The bark has a brittle and resinous fracture, a faint nauseous odour, and a bitter, somewhat acrid taste. Its active properties reside in a peculiar principle called Emetine or Emelina, which is very soluble in alcohol, but sparingly so in water. Ipecacuanha, when in the form of powder, is liable to be mixed with other roots, the presence of which it is not easy to detect. When adulterated with tartar emetic, as is said to be the case with what are called Ipecacuanha lozenges and other reputed preparations of this root, and which may produce serious accidents, the fact may be ea- sily ascertained by the following process : Dissolve the suspected preparation in water slightly heated, filter, and treat the clear solution with sulphuretted hydrogen. If any tartar emetic is present an orange red precipitate of sul- phuret of antimony will be produced. IRON. Ferrum, U. S. This metal, when in a state of purity, has a bluish white colour, is susceptible of a high polish, is malleable and duc- tile, and more tenacious than any other. It is attracted by the magnet, but when perfectly pure, does not retain magnetism. Specific gravity 7.78. In the form of filings it is sometimes employed medicinally. They are liable to contain copper, a fact which may be determined by shaking them with solution of ammonia in a small open bottle. If copper is present, a blue colour will after a time be com- municated to the ammonia. If mixed with sand the iron filings may be separated by the magnet. They should be kept in a clean, dry, and well-closed bottle. 102 IRON, LACTATE OF. IRON, BLACK OXIDE OF. Ferri Oxidum Nigrum, E.—Martial Ethiops. To obtain this oxide, the scales collected round the anvils of smiths are washed, dried and purified from dross, by the employment of a magnet. These are then reduced to pow- der, and the finer parts separated by suspension in water. It is easily soluble in muriatic acid, and its recent solution gives green precipitates with the alkalies, which, on expo- sure to the air, become red. If it becomes blue when mixed with an excess of ammonia, it contains copper; and if its so- lution in muriatic acid is attended with effervescence, it con- tains metallic iron. IRON, CARBONATE OF. Ferri Subcarbonas, U. S. This salt is formed by the addition of carbonate of soda to a solution of protosulphate of iron. The greenish white precipitate should be washed, and preserved in a moist state in a close vessel. On being exposed to the air, it evolves carbonic acid, and is converted into the reddish brown hydrated peroxide. This is the common form of most of the samples called carbonate of iron in the shops. The pure carbonate is white or greenish white, and completely taste- less ; but it is exceedingly difficult to prevent its decompo- sition. Its colour and the effervescence caused by acids will be sufficient tests of this substance. After solution, the presence of iron may be exhibited by adding an excess of ammonia, when the characteristic precipitate will be formed. IRON, FERROCYANIDE OF.—See PRUSSIAN BLUE. IRON, LACTATE OF. This salt, when pure, occurs in white crystalline plates, which undergo little change upon exposure to the air. It is IRON, PERCHLORIDE OF. 103 soluble in forty parts of boiling water. It has a mild ferru- ginous taste, and an acid reaction. The aqueous solution becomes yellow by exposure to the air, in consequence of the peroxidation of the iron. This salt is adulterated by effloresced sulphate of iron, starch and lactine. The first of these substances may be detected by the addition of chloride of barium to the solu- tion of the suspected salt. Lactate of baryta is soluble, but the sulphate of baryta is insoluble. The presence of starch may be detected by the blue colour produced by the tincture of iodine. Lactine is soluble in about six parts of cold water, whereas lactate of iron requires about forty parts of boiling water for its solution. Lactate of iron should only be purchased when in the form of white crystalline plates. If it occurs as a yellowish or greenish white powder, it is impure. IRON, PERCHLORIDE or SESQUICHLORIDE OF. This is employed in medicine, in the form of a solution in alcohol, under the name of Tincture of Chloride of Iron. It has a brownish yellow colour, and a very austere and styp- tic taste. The solution should be clear, should give a brown red precipitate upon the addition of alkalies, and have a spe- cific gravity of about 0.992. A fluid ounce when decomposed by potassa, should give nearly 30 grains of sesquioxide of iron. For the purposes of chemical analysis the perchloride of iron must not contain acid in excess : a portion of it must, therefore, when stirred with a small rod dipped in ammonia, yield a precipitate which is not re-dissolved on shaking the vessel. Red ferricyanide of potassium must not give a blue tinge to its solution. 104 IRON, SULPHATE OF. IRON, PROTIODIDE OF. Ferri Iodidum, U. S. This compound is prepared by digesting iodine with water and iron wire, or iron filings, the latter being excess. It may be obtained in a grey crystalline mass by evaporating the solution to dryness out of contact of air. The application of heat is apt to expel the iodine and leave sesquioxide of iron. It is soluble in water and in alcohol. If recently prepared, the solution in water has a pale green colour ; but if it has been prepared for some time, it contains some sesquioxide of iron, and is not entirely soluble. The aqueous solution is liable to spontaneous decomposition, and assumes an orange red colour, free iodine being generated, and sesquioxide of iron deposited. This change may be prevented by adding some sugar to the solution. IRON, SULPHATE OF. Ferri Sulphas, U. S.—Green Vitriol—Copperas. This salt occurs in the form of oblique rhombic prisms, which are transparent and of a pale green colour. It has a strong, styptic, inky taste, is soluble in one and a half parts of cold, and in one-fourth its weight of boiling, water. On being exposed to moist air, it becomes of a rusty red colour from the absorption of oxygen, whence the French term couperose, corrupted into copperas, has been applied to it. When the sulphate of iron has something of an emerald colour, it is impure. The presence of copper or zinc may be accurately determined as follows : Dissolve the salt in water and boil it with a small quantity of nitric acid, until it becomes clear, adding more nitric acid if it becomes neces- sary. Precipitate the oxide of iron by an excess of ammo- nia. If much copper is present, the liquid will then be blue. IRON, RED OXIDE OF. 105 Neutralize the ammonia by sulphuric aci'd, and add a solu- tion of the yellow ferrocyanide of potassium. If this pro- duces a red precipitate, it indicates the presence of copper; if it produces a white precipitate, it indicates the presence of zinc. Some specimens of commercial copperas have recently been found to contain arsenic. The presence of this metal may be detected by dissolving a portion of the salt in water, with the aid of heat, precipitating the oxide of iron by ex- cess of ammonia, filtering the solution, and after adding mu- riatic acid, so as to be slightly in excess, passing a stream of sulphuretted hydrogen through the solution. If a yellow precipitate is produced, which, upon being mixed with cya- nide of potassium and heated in a glass tube, gives a metal- lic sublimate, the presence of arsenic may be inferred. Copperas is frequently mixed with sulphate of the sesqui- oxide. This may be known by the yellowish green colour of the crystals, and by the blue colour produced on the ad- dition of ferrocyanide of potassium. IRON, RED OXIDE or SESQUIOXIDE OF. Ferri Sesquioxidum, L.—Ferri Subcarbonas, U. S.—Cro- cus Mar lis—Colcothar. A reddish brown, tasteless, insoluble powder, obtained by subjecting the sulphate of iron to a very high temperature, and also by decomposing a solution of iron in nitromuriatic acid by an alkali, washing and drying the precipitate. Sesquioxide of iron is not attracted by the magnet, should not deliquesce on exposure, nor give an acid reaction. It should be entirely soluble in muriatic acid without effer- vescence, and should give a red brown precipitate with the alkalies. If it contains copper, which is sometimes the case, when it is procured by the decomposition of green vitriol, its muriatic solution will deposit this metal upon a 106 IRON, RED OXIDE OF. clean plate of iron. After the sesquioxide has been thrown down from the muriatic solution by ammonia, the superna- tant liquor should give no indications of containing any other metal in solution ; and chloride of barium ought not to occasion any precipitate. Orfila obtained traces of arse- nic in the red oxide of commerce, by boiling this substance for five hours with pure sulphuric acid, and placing the so- lution in Marsh's apparatus. The preparation known under the name of the hydrated peroxide or hydrated sesquioxide of iron, is the red oxide combined with water. The U. S. Pharmacopoeia recom- mends the following mode of preparation, which is here in- troduced in consequence of its important use as an antidote to the poisonous effects of arsenious acid: " Take of sul- phate of iron four ounces ; Sulphuric acid three fluid drachms and a half; Nitric acid six fluid drachms or a suffident quantity; Water two pints. Dissolve the sulphate of iron in the water, and having added the sulphuric acid, boil the solution ; then add the nitric acid in small portions, boiling the liquid for a minute or two after each addition, until the acid ceases to produce a dark colour. Filter the liquid and allow it to cool, and add solution of ammonia in excess, stirring the mixture briskly. Wash the precipitate with water until the washings cease to yield a precipitate with chloride of barium, and keep it in close bottles with water sufficient to cover it." It is of great consequence that this preparation, when it is intended to be used as an antidote for arsenic, should be kept in a moist state. As obtained above it contains a little ammonia, which is thought to as- sist its antidotal powers. When ignited it becomes anhy- drous, and it is then totally inefficient as an antidote. It should, if possible, be recently prepared. JALAP. 107 IRON AND POTASSA, TARTRATE OF. Ferri et Potassa Tartras, U. S. An olive brown inodorous powder, with a styptic, inky taste. It is mildly alkaline, slightly deliquescent, dissolves in about four times its weight of water, and slightly in alco- hol. Tincture of galls causes a dark coloured precipitate, but ferrocyanide of potassium does not produce a blue colour with it, unless a few drops of acid be added. It is not de- composed by potassa or soda at ordinary temperatures. Tar- taric acid causes the formation of crystals of cream of tartar. Heated out of contact of air it yields charcoal, carbonate of potassa and protoxide of iron. In commerce we frequently meet with an imperfectly pre- pared compound, in which none or only part of the sesqui- oxide of iron is in chemical combination with bitartrate of potassa. In this state it is only partially soluble in water, and the solution strikes a blue colour with the ferrocyanide of potassium, and throws down a reddish brown precipitate with solution of potassa.—(Pereira). It sometimes also con- tains metallic iron, the presence of which can be detected by the magnet. Carbonate of potassa has, moreover, been found in many specimens of this salt; they are very deli- quescent, and effervesce with dilute acids. JALAP. Jalapa, U. S. The root of the Ipomaa purga Wenderoth. (I. Jalapa Nuttall), a native of Mexico. It is tuberous, of an oval shape and varying from the size of a nut to that of an orange, generally incised more or less deeply in different di- rections. The tubers are covered with a thin brown wrinkled cuticle. Internally they are of a yellowish grey colour, marked with deep brown concentric zones. The flat pieces are merely transverse slices of the entire tubers. The frac- ture is resinous ; odour faint and disagreeable ; taste nau- seous. The active principle, which is a resin, is soluble in alcohol. Jalap was at one time mixed with slices of Bryony root, but the white coloured intense bitterness of the spurious root rendered the fraud easy of detection. On the Continent many forms of spurious or counterfeit Jalaps are met with, mixed with the true root; they may, for the most part, be distinguished by being very rugose, of a reddish or rose col- our internally, not compact, with a faint odour, and almost insipid.—(Neligan.) Jalap is also liable to the attack of insects, and thus becomes what is called worm-eaten. But in such cases the starch only is consumed, and there is more resin in proportion to the weight. Worm-eaten jalap, there- fore, is well adapted for the preparation of extract. r Jalap resin may be distinguished from scammony resin by its not forming an emulsion when triturated with milk. Its insolubility in oil of turpentine is a means of detecting the intermixture of some other resins. KINO. Kino, U. S. "~ This is the concreted or evaporated juice of the Pterocar- pus erinaceus Lamarck, a native of Senegal; and of other undetermined plants. As it usually occurs, it is in the form of small angular fragments, scarcely larger than a pea, opaque, glistening and of a reddish black color. They are brittle, when chewed stick to the teeth, and give the saliva a red- dish black colour. They are without odour, have an in- tensely astringent taste, are partially soluble in water, and more largely so in alcohol. Kino is often mixed with other astringent substances of LEAD. log inferior value. These, however, all want the reddish black colour and glistening fracture which are so characteristic of kino. LAMPBLACK. This is a form of carbon obtained chiefly by turpentine manufacturers from refuse resin, which is burned in a fur- nace so constructed that the dense smoke arising from it may pass into chambers hung with sacking, where the soot is deposited, and swept off from time to time and put up in papers for sale. But this article is often quite impure, con- taining in addition to carbon, some resinous and bituminous matters and several saline substances, together with some ulmine. These impurities may be removed by digestion in alcohol, washing in solution of potassa, then with muriatic acid, and finally with water ; after which it is to be dried. The lampblack from camphor furnishes the basis of the best India ink, on which account it always has the odour of that substance. Most of the India ink, however, is made from oil-lampblack, occasionally disguised, as to smell, with musk or a little camphor black. The binding substance is gelatine made from parchment or ass' skin. Sometimes common glue is employed, which gives the ink when in use, especially in warm weather, a very offensive odour. LEAD. This well-known metal is of a bluish white colour, and has considerable malleability and ductility. Its specific gravity is about 11.40. It melts at 612° F. ; and when ex- posed to a red heat with free access of air it smokes and sublimes, giving off a grey oxide which collects on sur- rounding bodies. The lead of commerce generally contains copper and iron, and sometimes zinc and traces of silver. Dissolve it in ni- tric acid, dilute the solution and add diluted sulphuric acid. 10 110 LEAD, ACETATE OF. The lead will thus be thrown down in the form of a sul- phate, insoluble in acids. Filter, and add to the clear solu- tion, some solution of ammonia. If a blue colour results, it is owing to the presence of copper. A red brown precip- itate indicates iron. To detect silver, if in notable propor- tion, dilute the nitric solution and then add some muriatic acid. Chlorides of iron, copper and lead are dissolved, (the latter, however, requiring for this purpose a large quantity of water,) while chloride of silver is insoluble in water or dilute acids, but is soluble in ammonia. On exposure to the air its white colour is changed to a violet. LEAD, ACETATE OF. Plumbi Acetas, U. S.—Sugar of Lead. This salt, when pure, crystallizes in long six-sided pris- matic crystals. It has a taste at first sweet and then astrin- gent ; effloresces when exposed to the air, and is partially converted into a carbonate. It should therefore be preserved in well-closed bottles. It is soluble in both water and alco- hol. When heated with sulphuric acid, the vapour of ace- tic acid is disengaged, and when treated with liquid sulphu- retted hydrogen the lead is thrown down in the form of a black sulphuret. Acetate of lead is sometimes adulterated with carbonate of lead, acetate of lime and acetate of iron. The presence of the former may be detected by its want of solubility in water. To determine whether it contains the other ace- tates throw down the whole of the lead by sulphuretted hy- drogen. To the filtered liquor add ammonia. If any iron is present a red brown precipitate will be formed. If the acetate contains lime, oxalate of ammonia will cause a white precipitate in the clear solution. LEAD, CARBONATE OF. Ill LEAD, CARBONATE OF. Plumbi Carbonas, U. S.— White Lead—Cerusse. Carbonate of lead, when pure, is usually in the form of a heavy white powder, insoluble in water. Its specific gravi- ty varies from 6.40 to 6.75. It entirely dissolves, with ef- fervescence, in dilute nitric acid. By exposure to heat it becomes yellow, and with charcoal it is reduced to the me- tallic state. It is immediately discoloured and ultimately blackened by sulphuretted hydrogen, and is one of the most delicate tests for the presence of that gas. The commercial carbonate of lead is often largely adul- terated with chalk, sulphate of lead and sulphate of baryta. It almost always, moreover, contains a portion of oxide of lead. The following processes may be employed for ascer- taining the presence and proportions of these adulterants. Detection of Sulphates.—Mix a weighed portion of the suspected white lead in a Florence flask with dilute nitric acid, adding the white lead or the acid gradually, to render the effervescence moderate. Boil the mixture over a lamp for a few minutes. If the white lead dissolves entirely, it is free from sulphates. If it leaves a precipitate, let the solu- tion settle, filter it, and wash the precipitate on the filter till the liquor which runs through it gives no precipitate with sulphate of soda. Weigh the precipitate after it has been dried, and boil it in a glass flask with a solution of caustic po- tassa. If it dissolves entirely it is sulphate of lead. If it leaves a residue, this will be sulphate of baryta. Fil- ter the solution and add a little sulphuretted hydrogen. If it contains lead a black precipitate will be produced. When sulphate of baryta alone is present, the solution of potassa leaves a residue, and the filtered liquor affords no black pre- cipitate when treated with sulphuretted hydrogen. Sulphate 112 LEAD, CHROMATE OF. of lead is said also to be soluble in oxalate of ammo- nia. • Sulphate of lime maybe detected in white lead by boiling a portion of the suspected powder in a large quantity of dis- tilled water. If sulphate of lime is present the filtered solu- tion will give a white precipitate upon the addition of oxa- late of ammonia, as the sulphate is sparingly soluble in water. Detection of Chalk.—To detect the presence of this sub- stance dissolve a little of the suspected white lead in dilute nitric acid. After filtration to separate the insoluble sul- phates, dilute the clear solution with water and subject it to the action of a stream of sulphuretted hydrogen, which must be continued as long as any black precipitate is produced. Throw this upon a filter, neutralize the clear solution with ammonia, and add oxalate of ammonia. If any chalk was mixed with the white lead it will be thrown down as a white precipitate of oxalate of lime. The proportion may be de- termined by calcining this precipitate and weighing it. On the other hand, the proportion of lead may be deduced by converting the sulphuret of lead into sulphate of lead, by treating it with strong nitric acid carefully added, and subse- quent ignition and weighing. Common white lead is also usually mixed with a very minute quantity of lampblack or indigo, the object of which is to give it a bluish tint more agreeable to the eye than the yellowish colour which it naturally possesses. The white lead of Holland is said to be coloured by galena. LEAD, CHROMATE OF. Chrome Yellow. A fine yellow powder, insoluble in water, but soluble in nitric acid and in solution of potassa. Upon being heated its colour is deepened, and it fuses at a red heat. If the LEAD, IODIDE OF. 113 heat be continued, it is converted into oxide of lead and oxide of chromium. In consequence of the beautiful yellow colour of this compound, its adulteration is very easily accomplished. The substances most commonly found in it are, carbonate of lime, carbonate of lead, sulphate of lime, sulphate of lead, and starch. If carbonates are present a few drops of nitric acid will cause an effervescence. Calcine some of the suspected powder with a quarter of its weight of char- coal in a crucible for an hour. Pound the calcined mix- ture, and boil it in a flask in a mixture of water and muri- atic acid. If it gives out the odour of sulphuretted hydrogen it indicates the presence of a sulphate. Filter the liquor and throw down the oxide of chromium by ammonia. Again filter and add to the clear liquor oxalate of ammonia, which if lime is present will give a white precipitate. If it produces a smoke and gives out the odour of burning vege- table matter, it denotes the presence of starch; or boil a portion of the chromate in water and test the liquor for starch by tincture of iodine. A more accurate method of analysis, however, is the fol- lowing : Boil a weighed portion of the chrome yellow with a mixture of muriatic acid and alcohol. The chloride of chromium thus formed dissolves in the muriatic acid, while the chloride of lead is precipitated. The solution is then filtered and the precipitate washed with spirit of wine, and afterwards dried and weighed. 100 grains of pure chro- mate of lead should yield about 85 of chloride of lead. According to Dumas a small quantity of sulphate of lime increases the brilliancy of the chromate of lead. LEAD, IODIDE OF. Plumbi lodidum, L. A beautiful yellow powder, very sparingly soluble in cold water, but readily soluble in boiling water, from which it 10* 114 LEAD, PROTOXIDE OF. usually separates, as the solution cools, in the form of golden yellow brilliant small scales. It is soluble in acetic acid and alcohol. When subjected to heat it first forms a yel- low vapour, and afterwards a violet vapour, owing to the decomposition of the iodide. The remaining lead may be dissolved in nitric acid and tested in the usual way. Iodide of lead may be distinguished from the chromate, by the complete solubility of the former in boiling water, and by the different effect of heat. The Edinburgh College gives the following tests of its purity: " Bright yellow ; five grains are entirely soluble with the aid of ebullition in a fluid ounce of pyroligneous acid diluted with one and a half ounces of water ; and golden crystals are abundantly deposited on cooling." LEAD, PROTOXIDE OF. Plumbi Oxidum Semivitreum, U. S.—Litharge. This is found in commerce in the form of small, thin, transparent scales, which are commonly produced by the artificial oxidation of lead in the treatment of argentiferous lead ores. It generally contains more or less red lead, and hence its variations in colour; and also carbonic acid, espe- cially when it has been exposed to the air. It morever sometimes contains the oxides of iron and copper. The best solvents for litharge are the nitric and acetic acids. When it does not entirely dissolve in these reagents it is impure. The mixture of sand or brick dust may thus be easily detected by their want of solubility. To deter- mine the presence of copper and iron proceed as follows : Dissolve the litharge in pure nitric acid, filter the solution from the insoluble matter, if any, and precipitate the lead by adding sulphuric acid. Separate the precipitate by fil- tration, wash, and mix the solution with solution of ammo- nia. If the litharge contains copper, the ammoniacal solu- LIME. 115 tion will assume a blue colour. If it contains iron a brown red precipitate will be produced. The proportion of oxide of lead in a given quantity of litharge may be ascertained by subjecting to heat the precipitate obtained by the addition of sulphuric acid to the nitric solution, in order to expel the excess of sulphuric acid. The sulphate is then to be weighed. 100 parts of pure litharge should give about 136 parts of sulphate of lead. LEAD, RED OXIDE OF. Plumbi Oxidum Rubrum, U. S.—Minium or Red Lead. This is a powder of a brick red colour. When gently heated it turns black, but again becomes red on cooling. By a strong heat it is converted into protoxide of lead, with the disengagement of oxygen gas. When put into nitric or acetic acid it is partly converted into protoxide which dis- solves in the acid, and partly into brown oxide which re- mains undissolved. If red lead is adulterated, as is often the case, with brick dust, the latter is best detected by treating the ignited oxide with diluted nitric acid ; the brick dust then remains undissolved. To detect oxides of iron and copper, which are sometimes mixed with minium, add sulphuric acid to the nitric solution ; sulphate of lead will be thrown down. Filter, and add ammonia : a blue solu- tion proves the presence of copper; a brown red precipi- tate, of iron. The minium obtained from lead which con- tains either copper or iron cannot with advantage be employed in the manufacture of flint glass, for pottery glazes or for house painting. LEMON JUICE.—See CITRIC ACID. LIME. Calx, U. S. When pure, this is a white or light grey brittle solid, hav- ing an acrid and caustic taste : it changes vegetable blues to 116 LIME. green. Its specific gravity is 2.30. It is very difficult of fusion, but remarkably promotes the fusion of other bodies, and hence is a cheap and powerful flux. When moistened with water it becomes hot, smokes strongly, and falls to a fine powder, the bulk of which is much greater than that of the lime employed. Pure lime is obtained by exposing Iceland spar and some other kinds of pure carbonate of lime to a red heat. When common limestone is employed for this purpose,^ it often contains silica, alumina, and oxide of iron. Dissolve the sample in dilute muriatic acid : if the filtered solution gives a precipitate with potassa it contains alumina, or oxide of iron, or both. Excess of the alkali dissolves the alumina and leaves the oxide of iron. The silica will remain undis- solved, and may be separated by filtration. If the calcina- tion has not been properly conducted, the lime will effer- vesce when treated with a dilute acid ; and in this case also, the specimen does not slake upon the addition of water. Lime being largely employed as a manure and for the man- ufacture of mortar, it often becomes important to determine the relative value of various samples. In such investiga- tions the points to be particularly attended to are, as above indicated, the proportion of carbonic acid, which is some- times considerable through carelessness in the calcination or in the keeping of the lime, and the proportions of silica, alumina and oxide of iron, which it may contain. After having ascertained the presence of carbonic acid by the ac- tion of dilute muriatic acid, subject a weighed portion, say 100 grains, to a white heat in a porcelain or platinum cruci- ble, for half an hour. The loss of weight will indicate the amount of water and carbonic acid. Treat the residue with dilute muriatic acid, the whole being introduced into a glass flask, which is to be gently heated in a sand-bath. Filter the solution and carefully wash the precipitate, dry, heat to redness and weigh. To the filtered solution add ammonia LIME, CARBONATE OF. 117 until the acid is completely saturated, then quickly filter, wash, dry, heat and weigh the precipitate. This will be either alumina, oxide of iron, or a mixture of both, and when its weight is added to that of the portion undissolved by muriatic acid, the total amount of earthy matters and of oxide of iron will be determined. Lime water, which is prepared by mixing hydrate of lime with water and agitating the mixture, has a harsh, acrid taste, and changes vegetable blues to green. It has a strong attraction for carbonic acid, and forms with it an in- soluble carbonate ; hence lime water should be kept in well- stopped bottles which should be full, or in bottles contain- ing an excess of lime. LIME, CARBONATE OF. Creta, L.—Marmor, U. S. This is an abundant native product, and occurs in the form of marble, chalk, &c. The Creta Preparata of the Phar- macopoeias is obtained by rubbing chalk in a sufficient quan- tity of water until it is reduced to a very fine powder, and then after a short interval pouring off the supernatant liquid into another vessel that the powder may subside. The wa- ter is then drawn off by a syphon and the powder dried and kept for use. This preparation is white, tasteless, almost insoluble in water, and when heated to redness in a current of air, loses its carbonic acid and leaves quicklime. It should be perfectly soluble with effervescence in dilute muriatic acid. In this solution ammonia should produce no precipitate, otherwise it contains alumina or oxide of iron; nor should sulphate of lime throw down anything, by which the absence of baryta and strontia is proved. 118 LIQUORICE. LIME, HYPOCHLORITE OF.—See BLEACHING POWDER LIQUORICE. Glycyrrhiza, U. S. The article called Liquorice is obtained by evaporating to dryness a decoction of the root of various species of Glycyr- rhiza, as G. echinata L., G. lepidota Nutt., and G. glabra L. It is imported from Spain and Sicily in round sticks of five or six inches in length and about an inch in thickness. Its fracture is smooth and brilliant, its internal colour deep black, and its taste sweet and agreeable. When the sticks are packed up in boxes, previous to exportation, they are stratified with dry bay leaves, to hinder their adhesion to each other. But notwithstanding this precaution, they generally lose their cylindrical form and conglomerate into masses. An inferior kind of liquorice is found in market, made by mixing a solution of the genuine liquorice with some cheap kind of gum and adding lampblack or other black colouring matter and evaporating the solution until it acquires the pro- per consistence to be rolled into cylinders. These sticks are packed up in boxes with strata of bay leaves like the genu- ine liquorice imported from Spain. The real liquorice should dissolve in water without leaving any residue, and by this character, some of the impurities contained in the adulterated article may be detected. Its chief consumption is by the brewers. It has been ascertained that its sweetness depends upon a peculiar form of sugar which has been called Gly- cyrrhizin. The Refined Liquorice is prepared as follows. Take one pound of Spanish liquorice, half a pound of gum Arabic, and enough water to dissolve the mixture; strain the solution through muslin ; evaporate it gently till it forms a soft ex- LYC0P0D1UM. 119 tract; roll it into cylinders of the size of a quill; cut these into lengths and polish by rubbing them together in a box. An inferior kind is prepared by dissolving Spanish liquorice with an equal weight of carpenter's glue. If this kind is heated in a glass tube or before the blow-pipe, it gives out the odour of ammonia. Another variety of refined liquorice is made by mixing a solution of Spanish liquorice with starch. It is found in commerce in little sticks, which are perfectly cylindrical, and very flexible ; its fracture is dull and granular, and sometimes exhibits minute white points, which no doubt result from an imperfect mixture of the component parts of the compound. It divides between the teeth into small lumps, and does not possess the tenacity of the pure liquorice. Treated with cold water, it dissolves but partially, and immediately deposites a dirty white pow- der, possessing the well-known properties of starch.— (Do- mestic Chemist.) LOGWOOD. Hazmatoxylon, U. S. The wood of the Hcematoxylon Campechianum L., a na- tive of Campeachy in Central America, and now naturalized in Jamaica. It is imported in billets about three feet long, the bark and alburnum of which are chipped off. It is hard, compact, heavy, of a deep red colour, a weak, agreeable odour, and an astringent taste. It yields its active principles both to water and alcohol; the solutions are of a fine purple colour, which is changed to violet by the alkalies. Various red coloured woods are substituted for logwood, from which they may be readily distinguished by not pos- sessing the same agreeable odour.—(Neligan.) LYCOPODIUM. This is the pollen or seed of the Lycopodium Clavatum L., which is collected in large quantities, and is sometimes j20 MADDER. known by the name of Vegetable Sulphur. On account of the utter impalpability of the powder, when set fire to, it is at once consumed, and it is hence employed in theatres to imi- tate a sudden flash of lightning. It is sometimes mixed with talc or with starch. To detect these substances make a paste of the lycopodium with water, and then mix it with a large quantity of water: the lycopodium will swim and the talc sink. Boil the lycopodium in water, and test the liquor by tincture of iodine. If a blue colour is produced, it indi- cates the presence of starch. MACE.—See NUTMEG. MADDER. Rubia, U. S. The roots of the Rubia tinctorum L., and R. peregrina L., natives of the Levant and South of Europe ; and extensive- ly cultivated in various countries. They are imported whole or in the form of powder. In the former case they are long, cylindrical fibres, from the size of a writing quill to that of the little finger, branched, and externally of a deep reddish brown colour. They have a feeble odour, and a bitterish astringent taste. According to Runge, madder contains five distinct colouring principles ; madder red, madder purple, madder orange, madder yellow and madder brown. A form of madder containing more colouring matter than the natural root is now met with in commerce, under the name of Garancine. This article is said to be prepared by digesting powdered madder in cold oil of vitriol, which de- stroys most of the constituents of the root, but leaves the red colouring matter unaltered.—(Parnell's Applied Chem- istry.) It appears that madder differs in the presence or absence of carbonate of lime, depending upon the difference in the soil upon which the plant is reared. Avignon madder indi- ■#r MAGNESIA, CALCINED. 121 cates the presence of carbonate of lime in it, by effervescing with dilute acids, while Alsace madder does not. A know- ledge of this difference is said to be of great importance in the employment of this article as a dye.—(See Ure's Diet. of Arts, fyc.) MAGNESIA, CALCINED. Magnesia, U. S. A white, insipid, friable powder, of an earthy appearance, which slightly greens the blue of violets and reddens tur- meric. Specific gravity 2.30. It is almost infusible and very sparingly soluble in water. It often contains carbonate of magnesia, owing to the imperfect manner in which the calcination has been conducted. To ascertain this fact throw a small quantity of the magnesia into a glass, and cover it with pure water. Then add a small quantity of very dilute muriatic or sulphuric acid. If effervescence is occasioned by the addition of the acid, carbonate of magnesia or of lime is present. The addition of some water previous to that of the acid should not be omitted, as the extrication of air involved between the particles gives the appearance of effervescence which may be mistaken for that arising from carbonic acid. Strong acid, also, when added to magnesia causes such an elevation of temperature as to produce a kind of efferves- cence. To determine whether the effervescence upon the addition of dilute acid, with the precautions above mentioned, is due to carbonate of lime or carbonate of magnesia, pro- ceed as follows : Dissolve a portion of the powder in muri- atic acid, with the aid of gentle heat. Filter the solution and then neutralize it with ammonia, and if the quantity of acid is not considerable, add some solution of muriate of ammonia. Then add solution of oxalate of ammonia, which if lime is present will cause a white precipitate, while the magnesia is held in solution by the muriate of ammonia, an excess of which must be ensured as above directed. Ano- 11 •** 122 MAGNESIA, CARBONATE OF. ther mode of determining the presence of lime when mixed with magnesia is to supersaturate the muriatic solution with ammonia, and then to add a sufficient quantity of muriate of ammonia. The addition of carbonate of ammonia to this so- lution causes the precipitate of the lime, while the magnesia remains in the filtered liquor and may afterwards be thrown down by phosphate of soda. The presence of a sulphate, a soluble carbonate, silica and alumina, may be determined by the processes indicated in the next article. The Heavy Calcined Magnesia is preferred for medical pur- poses. It is made by calcining the carbonate of magnesia, previously made into a firm paste with water, dried in an oven and pressed down in the crucible. This kind is less soluble in acid, less liable to condense carbonic acid, andis said to be identical with Henry's Calcined Magnesia. MAGNESIA, CARBONATE OF. Magnesia Carbonas, U. S. Two kinds of carbonate of magnesia are kept in the shops, the light and the heavy ; the difference depending upon the process employed in their manufacture. Both varieties are nearly tasteless, have a feeble alkaline reaction on test paper, and are nearly insoluble in water, but readily dissolve in carbonic acid water. They effervesce on being treated with dilute mineral acids, and are thus distinguished from calcined magnesia. Carbonate of magnesia may contain carbonate of lime, either fraudulently added, or from a want of care in the preparation of the magnesian compounds. The presence of this sub- stance may be determined by the process described under the preceding article. It also sometimes contains soluble alkaline salts. Boil a portion of the suspected substance for a quarter of an hour in ten parts of water and filter the so- lution. The clear liquor should have no taste, be without MAGNESIA, CARBONATE OF. 123 action on turmeric paper, otherwise it contains alkali; and should give no precipitate with a solution of nitrate of silver, otherwise it contains muriatic acid ; or of chloride of barium, otherwise it contains sulphuric acid. The minute quantity of carbonate of magnesia dissolved by the water will scarcely affect the two latter tests. Detection of Alumina.—Magnesia sometimes contains alumina, the presence of which may be detected as follows : Saturate a small quantity of diluted sulphuric acid with the suspected magnesia, filter the solution, condense to a small bulk by evaporation, and add a solution of potassa, either caustic or carbonated, taking care that the acid is in slight excess. If alumina is present, a crystalline precipitate of alum will, at the end of an hour, be produced. Or dissolve the magnesia in muriatic acid, filter the solution, and super- saturate it with ammonia. If alumina is present a white voluminous precipitate will be formed, the separation of which, from magnesia, may be ensured by the addition of a quantity of muriate of ammonia. Magnesia is almost entirely soluble in muriate of ammonia, but alumina is insoluble in it. Detection of Silica.—If silica is contained in either the calcined or carbonated magnesia, its presence can be de- tected as follows: Dissolve a quantity of the suspected magnesia in diluted muriatic acid, and evaporate the mixture without previous filtration to perfect dryness, in a wedge- wood ware basin, applying the heat of a lamp or of a charcoal fire, and stirring the mixture with a glass rod when it gets thick. After it has cooled thoroughly moisten it with strong muriatic acid, allow it to repose for half an hour, and then dilute it with water and filter it. The in- soluble powder, if any, is silica. 124 MAGNESIA, SULPHATE OF. MAGNESIA, SULPHATE OF. Magnesia Sulphas, U. S.—Epsom Salt. This salt crystallizes in small quadrangular prisms, which effloresce slightly in dry air, and also in larger crystals which are six-sided prisms terminated by six-sided summits. The crystals are soluble in an equal weight of water at 60°, and in three-fourths of their weight of boiling water. They have a bitter and disagreeable taste. This salt sometimes contains chloride of magnesium, when it becomes moist on exposure to the air. It is also frequent- ly contaminated with lime on account of the mode employed in its manufacture. Sulphate of soda, moreover, has been substituted for sulphate of magnesia ; and, through care- lessness, oxalic acid has been repeatedly mistaken for it, and fatal accidents have thus occurred. Detection of Chlorides.—The presence of a chloride in sulphate of magnesia may be detected by dissolving a portion of the suspected salt in water, and then adding to the clear solution a solution of sulphate of silver. If a white curdy precipitate is formed, which is insoluble in nitric acid, it indicates the presence of muriatic acid, its chlorine com- bining with the silver, forming a chloride of silver. The proportion of this adulterant maybe determined by filtering the solution, washing, drying and weighing the precipitate. Detection of Lime.—To detect lime, dissolve the salt in water as before, add muriate of ammonia in sufficient quan- tity to hold the magnesia in solution, and then render it alka- line, by adding ammonia. If this causes a precipitate, add muriatic acid to re-dissolve it, and again make the solution alkaline by ammonia. When the solution is alkaline and clear, test it with oxalic acid or oxalate of ammonia. If lime is present, a white precipitate of oxalate of lime is produced. MAGNESIA, SULPHATE OF. 125 Detection of Sulphate of Soda.—To distinguish between sulphate of soda and sulphate of magnesia, dissolve the salt in water, and add to the solution a small portion of a solution of carbonate of potassa. If the salt contains soda, the solution remains clear; if it contains magnesia, an abundant white precipitate is produced. If sulphate of soda and sulphate of magnesia are mixed, they may be separated, and the proportion of each de- termined, although not with absolute accuracy, by the following process : Dissolve the mixed sulphates in water, and add so much acetate of baryta, that all the sulphuric acid is precipitated as sulphate of baryta. The mixture is warmed ; the solution of sulphate of baryta separated by filtration ; the filtered solution evaporated to dryness; the dry mass ignited in a platinum capsule. By this means the acetates are converted into carbonates. Hot water is poured over the mass after ignition, the carbonate of soda dissolves, while the carbonates of baryta and magnesia re- main undissolved. The solution is filtered and the insoluble matter edulcorated with hot water, but the washing must not be long continued. The alkaline solution is evapo- rated to dryness, and the dry mass is ignited, converted into a sulphate by the addition of sulphuric acid, ignited and weighed. The carbonates of baryta and magnesia, which remained undissolved in water, are dissolved in muriatic acid ; the baryta precipitated by sulphuric acid ; the so- lution is filtered from the sulphate of baryta and evapo- rated to dryness ; the dry mass so obtained, which consists entirely of sulphate of magnesia, is ignited and weighed. If only sulphate of soda and sulphate of magnesia are con- tained in the salt under examination, the weight of the two must a--------two parts water. Acid of sp. gr. 1.632--------one---------------three parts water. SULPHURIC ETHER. JEther Sulphuricus, U. S. A transparent, limpid liquid, of a hot pungent taste and fragrant odour. Its specific gravity in its purest form is from 0.716 to 0.730, but the ether of the shops is seldom less, and often more than 0.750, owing to the presence of alco- hol. It is very volatile, a few drops poured on the hand in- stantly evaporating with the production of cold: it boils at about 98°. It should burn with a brighter flame than alco- hol, give but little smoke, and leave no residue. By exposure to air and light, as in vessels which are fre- quently opened, ether gradually absorbs oxygen, and thus a portion of acetic acid is generated. The presence of this acid is not at first apparent, because it forms acetic ether, but it gives the ether a peculiar odour, and in time it be- comes acid to tests. A more common adulteration is the mixture of a large proportion of alcohol. I have recently examined several specimens put up in bottles and labelled " best sulphuric ether," which did not contain ten per cent. of real ether, and which were wholly worthless for the pur- poses of the laboratory. When pure ether is shaken with an equal volume of water, its bulk is not diminished more than about one-tenth, but in proportion as it is mixed with alcohol will the bulk of the suspected ether be diminished by this treatment. The method given by the Edinburgh College for detecting and measuring any alcohol which may be contained in ether is to agitate it in a minim measure, with half its volume of a concentrated solution of chloride 238 TALLOW. of calcium. This will remove the alcohol, and the reduc- tion of the volume of the ether when it rises to the surface will indicate its amount. Heavy oil of wine may be de- tected by the ether becoming milky upon being mixed with water. Should sulphuric acid be present, from carelessness in the manufacture, when the ether is mixed with water and treated with a solution of chloride of barium, it will cause a white precipitate, insoluble in nitric acid. These impurities may be removed by shaking the ether in a close vessel, with about twice its bulk of water, pouring off the ether, adding to it a sufficient quantity of well burnt lime and distilling the mixture. The first third that distils over is pure ether. SULPHURIC ETHER, SPIRIT OF. Spiritus JEtheris Sulphurici, E. This is a mixture of one measure of sulphuric ether and two measures of rectified spirit. Its density should be about 0.809. When pure, it does not affect litmus paper, or render water turbid. When agitated with twice its volume of a concentrated solution of chloride of calcium twenty-eight per cent, of ether separates by rest. It pos- sesses the advantage over sulphuric ether for medicinal pur- poses in being miscible with water in all proportions.— (Pereira's Materia Medica.) TALLOW. This is the concrete fat of oxen, deer and large quadru- peds, in general, melted and separated from the fibrous matter with which it is at first accompanied. It consists chiefly of stearine, with a little oleine, and is firm, brittle, and has a peculiar heavy odour. It soon becomes rancid on exposure to the air. As met with in commerce, it usu- TAMARINDS. 239 ally has a yellow tinge; but when pure, it is white and nearly insipid. It is divided into two principal varieties, according to its purity and consistence, viz., candle and soap tallow; and these are subdivided into other classes, according to the colour of the tallow, and to the place from whence it is obtained. Its quality depends in some degree on the animal from which it is procured ; but more prob- ably, on the care observed in its preparation.—(Parndl's Applied Chemistry.) The purity of tallow can, in general, be judged of by its colour and consistence, by its burning with a clear white light, and by its leaving little or no residue when subjected to heat. TAMARINDS. Tamarindus, U. S. The fruit of the Tamarindus Indica L., an East Indian tree, and of the T. Occidentalis Gart., a native of the West Indies. As imported, they are of a reddish yellow, or red- dish brown colour, of the consistence of candied honey, being composed of the pulp, the seeds and numerous vege- table fibres. They have a slightly vinous odour, and an agreeable acid taste. They contain sugar, citric, tartaric and malic acids, to which their refreshing properties are to be ascribed. The oriental tamarinds are more pulpy than the occidental ones. They also have a darker colour, and being preserved without sugar, are more acid and better adapted for medicinal purposes than the West Indian fruit, which is preserved by the addition of a considerable quantity of sugar. Tamarinds frequently contain an appreciable quantity of copper which is derived from the vessels in which the pulp has been evaporated. The presence of this metal may be 240 TAPIOCA. detected by the reddish coloured coat which is formed upon a bright piece of iron when plunged into the tamarinds. Sulphuric acid is also sometimes added to the] fruit when it has not been well preserved, or too long kept, to give it an acid taste. This is readily ascertained by the white pre- cipitate, insoluble in nitric acid, which the filtered decoction of tamarinds gives with the chloride of barium. Tamarinds are sometimes imitated by a mixture of black prunes with tartaric acid, or tartrate of potassa ; but this fraud can be detected on account of the absence of the smooth, hard, quadrangular seeds which form part of the genuine fruit. TAPIOCA. Tapioca, U. S. This is obtained from the tubers of the Jatropa Manihot L., a native of South America, and is one of the purest forms of starch met with in commerce. It occurs in irregu- lar, hard, granular masses, from its having been dried on hot plates with agitation. It is white, inodorous and taste- less, slightly soluble in cold water, and the solution strikes a blue colour with iodine, which shows the rupture of some of the starch granules in the preparation of this substance. Most of the granules, however, remain uninjured, and when examined by the microscope are found to be spherical, of nearly equal size, and smaller than those of arrow-root, or the average of wheat starch. A factitious tapioca occurs in the shops, consisting of very small, smooth spherical grains, probably prepared from po- tatoe starch. It passes under the name of Pearl Tapioca, and may be distinguished from the genuiue, by the char- acters of Potatoe starch, given in the article Starch. TARTARIC ACID. 241 TARTARIC ACID. Acidum Tartaricum, U. S. This acid, when pure, occurs in transparent, colourless crystals, the primary form of which is a rhombic prism. But it is often found in the form of a mass resembling the lumps of fine salt. It has a very sour taste, reddens litmus powerfully ; is soluble in one and a half parts of cold, and in less of hot, water ; also soluble in alcohol. The solution is very sour, and causes with solutions of caustic lime, baryta and strontia, white precipitates soluble in an excess of the acid. If it be added in excess to a concentrated solution of a potassa salt, small granular crystals of bitartrate of po- tassa are deposited. Tartaric acid is adulterated with various substances; as, sulphuric acid, malic acid, lime and potassa. Detection of Sulphuric Acid and Lime.—To a solution of the suspected tartaric acid add chloride of barium; if sulphuric acid is present, a white precipitate will be pro- duced, which is insoluble in nitric acid. If, when neutra- lized by ammonia, it gives a precipitate with oxalic acid it indicates the presence of lime. Detection of Malic Acid.—Malic acid causes the tartaric acid to become moist on exposure to the air. It may be detected by the following process : Neutralize a solution of the suspected tartaric acid with ammonia, and then add solution of chloride of calcium. Tartrate of lime will be precipitated while the malate of lime, if any is present, will beheld in solution. Filter, and add alcohol to the clear solution; the malate of lime will be thrown down in the form of a white powder. If the tartaric acid contains sul- phuric acid, sulphate of lime will be thrown by the same 21 242 TEA. process. But the two salts can be distinguished by the dif- ferent effects produced by heat. Malate of lime is fusible into a gummy mass in a boiling solution, and if it is sub- jected to a higher heat it is decomposed with the usual re- sults of the distillation of a vegetable salt. Sulphate of lime does not suffer decomposition even at a very high tem- perature. Detection of Potassa.—If potassa is mixed with tartaric acid, it is probably in the form of the bitartrate. The pres- ence of this salt may be suspected when the tartaric acid does not dissolve in one and a half parts of water, and when the saline residue is rendered entirely soluble by the ad- dition of solution of potassa. TEA. This important article is the leaf of an evergreen shrub, the Thea Chinensis Sims, a native of China and Japan, and extensively cultivated in both countries, but especially in the former. Linnaeus supposed that there were two distinct species from which tea was derived, viz.: T. Bohea and T. viridis, and this view is adopted by Lindley; but De Can- dolle and Sprengel consider these merely as varieties. Ac- cording to Lindley, the leaves of the T. viridis are acuminate and emarginate at the apex, while those of the T. Bohea are smaller, flatter, darker green, finely serrate and terminating in a point, but not at all acuminate or emarginate. The numerous varieties of tea which exist in commerce may all be arranged under the two divisions of green and black. The former of these is characterized by a dark green colour, an aromatic odour, and an astringent, agreeably bit- ter taste. The latter has a dark brown colour, sometimes inclined to black, a fainter odour and a less pungent taste. The active principle of tea is Thein, a white, crystalline sub- TEA. 243 stance, fyhich may be easily obtained, after the separation of the tannic acid and colouring matter, by the process of sub- limation. It has been found to be identical with Caffein, procured from coffee, and the opinion has been advanced by Liebig and adopted by several other chemists, that it con- tains essential principles of nutrition which exceed in im- portance its stimulating properties. If this is correct, tea and coffee are to be ranked, in every respect, among the most desirable articles of general use. The frauds in tea seem to have kept pace with the increase in its consumption. These consist principally in the substi- tution of the leaves of other plants for those of the genuine tea plant, and in the employment of various substances to give a desirable colour to inferior qualities of tea. Substitution of other Leaves.—According to Dr. Burnett, the leaves of the sloe, Primus spinosa L., are dried in Eng- land, as a kind of tea, and mixed in large proportion with China tea. From the result of a parliamentary investigation, it appears that upwards of four millions of pounds of facti- tious tea are, on an average, annually made in that country, and used to mix with that imported from China. An attempt was made to legalize the practice by taking out a patent for the preparation of" British leaf" as a substitute for tea, but it was soon ascertained that this article was not sold at re- tail and used as such, but was purchased by fraudulent grocers to adulterate the genuine article.—(Outlines of Bota- ny.) The manufacture was then suppressed, and subsequently upwards of forty-five hogsheads of leaves, in different stages of preparation, were condemned and burned. There can be no doubt that this adulteration is still largely, although clan- destinely, practised. It appears that the manufacture of factitious tea is exten- sively carried on by the Chinese themselves. Dr. Royle 244 TEA. states that " the Chinese in the neighborhood of Canton are able to prepare a tea which can be coloured and made up to imitate various qualities of green tea, and large quantities are thus yearly made up." And Dr. Dickson informs us that " the Chinese annually dry many millions of pounds of leaves of different plants, to mingle with the genuine, as those of the ash, plum, &c."—(Penny Cyclopadia, art. Thea.) The mixture of other leaves with those of the tea plant may sometimes be detected by the difference in their botan- ical characters. For the purpose of examination, the leaves should be macerated in water and then spread out and pressed between papers until they are perfectly dry. The leaves of the tea plant are oblong or lanceolate, acutely pointed, ser- rate, except at the base, smooth on both sides, green and shining, marked with one rib and many transverse veins. The leaves of the sloe are much broader in proportion to their length than those of tea; they have a rounder form, and an obtuse instead of an acute point; their surface, more- over, is more uneven, and their texture less delicate. The spurious leaves employed by the Chinese, are sometimes so cut up as to render it impossible to ascertain the plant to which they belong. In the adulteration of a peculiar kind of tea, called Ankoi, the most common are said to have been a thick, soft, dark green, very smooth leaf, and a palish, hairy leaf, with the veins strongly marked.. The former can be detected only by inspecting the leaves after infusion, as it imparts no bad smell to the lea, and it is hardly percep'ti- ble even to the taste ; the latter is readily discovered by its giving to the tea a " faint and odd " smell as well as taste. —(Davis' " Chinese.") Employment of Colouring Materials.—The other class of frauds which are practised with tea, consist in the use of various colouring materials, to give other leaves the appear- TEA. 245 ance of those of the tea plant, and to increase the value of the inferior kinds of tea. Mr. R. Warrington, after examining a great number of samples, concludes that all the green teas imported into England are faced or covered superficially with a powder consisting of either Prussian blue and sulphate of lime or gypsum, with occasionally a yellow or orange-coloured ve- getable substance ; or of sulphate of lime previously stained with Prussian blue ; or of Prussian blue, the orange-coloured substance, with sulphate of lime and a material supposed to be kaolin. These facings or coverings occurred in what are called the glazed, while sulphate of lime alone was found in the unglazed, varieties. With a little care, he says, " the whole of the powder with which the tea was covered could be easily removed, by simply agitating the samples briskly for a few seconds in a phial with distilled water, and then throwing the whole on a lawn filter, in order to strain the liquid, with the suspended matter, from the leaves as rapidly as possible." The presence of Prussian blue was shown by adding a drop of caustic potassa to a little of the sediment, when the green hue was instantly converted to a bright red- dish brown, the original blue appearance being again restored by the subsequent addition of a little sulphuric acid. By subjecting another portion to a red heat, the whole of the vegetable° matter and the Prussian blue were destroyed, and a white powder, with a slight shade of brown, obtained. This was dissolved in dilute muriatic acid, and when tested with solution of chloride of barium, gave indications of sul- phuric acid; it was then evaporated to dryness, and again acted upon by very dilute muriatic acid ; a trace of silica re- mained undissolved. Solution of ammonia being added, threw down a little alumina and oxide of iron, and the am- moniacal solution treated with oxalic acid, gave a precipitate of oxalate of lime. The white powder left after the calcina- 21* 246 TEA. lion of the coloured substance, and boiling the residue in distilled water, was supposed to be kaolin or powdered agalmatolite, the figure stone of the Chinese.—( Warrington, in Bond. Edin. fy Dub. Phil. Mag. $c. xxiv. 507.) Mr. Davis, in his interesting work, above quoted, states some facts in regard to the adulteration of tea, which en- tirely confirm the results of the investigations of Warrington and others. Thus young hyson, until spoiled by the large demand of the Americans, is said to have been a delicate and genuine leaf. But as it could not be fairly produced in any large quantities, the call for it on the part of the Ameri- cans was answered by cutting up and sifting other green teas through seives of a certain size. The coarsest black tea leaves were also cut up and then coloured with a pre- paration resembling the hue of green teas. " But this was nothing in comparison with the effrontery which the Chi- nese displayed in carrying on an extensive manufactory of green teas from damaged black leaves, at a village or suburb called Honan." In one of these "laboratories of factitious hyson" which Mr. Davis visited, large quantities of black tea which had been damaged in consequence of the floods of the preceding autumn, were drying in baskets with seive bottoms, placed over pans of charcoal. The dried leaves were afterwards transferred in small portions to cast iron pans and mixed with a small quantity of turmeric in powder which gave the leaves a yellow or orange tinge ; they were afterwards stirred with a mixture of Prussian blue and gyp- sum which had a light blue colour. The coarse leaves were then picked out by hand and the rest passed in succes- sion through seives of different degrees of fineness. The first sifting produced what was sold as Hyson Skin, and the last by the name of Young Hyson. Mr. Davis further states it as a well-ascertained and unde- niable fact, that the Chinese themselves do not consume TEA. 247 those kinds of green tea which are prepared for exportation. Those which are most esteemed by them are made from the green tea plant, and have a yellower, and as it were a more natural, hue than the bluish green that distinguishes the teas which they send away. Much was formerly said about the employment of some of the salts of copper for the colouring of teas, but this seems to be rarely, if ever, resorted to. Their presence, however, can easily be detected by agitating a small quan- tity of the suspected tea in water for some minutes and then adding to it a solution of ammonia or of ferrocyanide of po- tassium. A salt of copper will produce with the former, a fine blue liquid, and with the latter, a reddish brown pre- cipitate. The presence of logwood, sometimes used for colouring tea, may be ascertained by rubbing the suspected article upon paper, after it has been moistened. A bluish black stain will be produced ; and when such adulterated tea is thrown into water, it gives a tint of the same colour, which is reddened-by the addition of a few drops of sulphuric acid. Pure tea forms a liquid of an amber colour, which is not reddened by this acid. It has been stated in an English journal that some of the London tea merchants have introduced a new species of fraud, which consists in obtaining from the large hotels the spent tea leaves, drying and rolling them, under the influ- ence of a gentle heat, by a process similar to that practised in China with the fresh leaves. The leaves thus deprived of their thein, before being mixed with those of genuine tea, are coloured with Prussian blue and other substances to bring them to the tint of the peculiar variety which it is in- tended to imitate. We are also informed that a quantity of tea, damaged in consequence of the shipwreck of a vessel, was washed in order to remove the sea salt, and afterwards 248 TIN. faced with a powder composed of indigo, chromate of lead, and talc. In this condition the article was exposed for sale? and a considerable quantity of it fell into the hands of the French police.—(Gamier £f Hard.) THENARD'S BLUE. Cobalt Blue. This is a beautiful blue pigment obtained by the decom- position of nitrate of cobalt by phosphate of soda, and the mixture of the washed 'precipitate which results, with a certain quantity of alumina. It sometimes has a greenish tint which is owing to the presence of a little phosphuretof cobalt or of oxide of iron. TIN. Stannum, U. S. A well-known metal having a white colour and a lustre resembling silver. It is soft and inelastic, and when bent backwards and forwards emits a peculiar crackling noise. At 442° F. it fuses, and if at the same time it is exposed to the air, its surface tarnishes, and a grey powder is formed. Its specific gravity when pure, is 7.29, but when alloyed with other metals it is usually higher. Tin is sometimes adulterated with lead, copper, iron and arsenic. Boil the suspected metal in pure nitric acid, until it is entirely converted into the peroxide of tin. Wash this powder with water, filter the solution and test it with sul- phuric acid. If lead is present a white precipitate will re- sult. The solution filtered from the sulphate of lead may next be tested for copper and iron, which are also some- times mixed with tin. Add solution of ammonia to the fil- tered solution. If copper is present a blue transparent TIN. 249 liquid will be formed, but reddish brown insoluble flocks will indicate the presence of iron. Minute quantities of arsenic have also been occasionally found in specimens of tin. A process for the detection of the former metal, and its separation from the latter, will be found in the article Sul- phuric Acid. Dr. Ure's mode of testing the quality of tin is as follows: " Dissolve a certain weight of it with heat in muriatic acid ; should it contain arsenic, brown black flocks will be sepa- rated during the solution, and arseniuretted hydrogen will be disengaged, which, on being burned at a jet, will deposit the usual grey film of metallic arsenic upon a white saucer held a little way above the flame. Other metals present in tin, are to be sought for by treating the above solution with nitric acid of the specific gravity of 1.16, first in the cold, and at last with heat and a small excess of acid. When the action is over, the supernatant liquid is to be decanted off the peroxidized tin, which is to be washed with very dilute nitric acid, and both liquors are to be evaporated to dissipate the acid excess. If on the addition of water to the concentrat- ed liquor, a white powder falls, it is a proof that the tin con- tains bismuth; if on adding sulphate of ammonia, a white precipitate appears, the tin contains lead ; water of ammo- nia added to supersaturation, will occasion reddish brown flocks, if iron is present; and on evaporating the superna- tant liquid to dryness, the copper will be obtained."— (Dic- tionary of Arts, fyc.) The Malacca and the Banca tin and the English grain tin are said to be the purest kinds found in commerce, while block tin and the metal obtained from Germany are usually adulterated. A preparation called Powder of Tin, is sometimes made for pharmaceutical use, by shaking the melted metal in a wooden box rubbed with chalk on the inside; tin filings 250 TIN, BISULPHURET OF. have also a place in some pharmacopoeias. These prepara- tions, however, are said to be dangerous in consequence of the slight oxidation of the metal. Pewter filings are sometimes substituted for tin filings in commerce ; and Christison says that lead powder is not un- frequently sold for powder of tin. These adulterations may be detected by acting upon the specimens with nitric acid, and then treating the solution with sulphuric acid as above described. TIN, BISULPHURET OF. Aurum Musivum.—Bronze Powder. This is a compound of a golden yellow colour, consisting of brilliant scales which are very friable and adhere to the fingers. It is insoluble in the acids, except in nitromuriatic acid. When mixed with twice its weight of nitre and heat- ed to redness, it is decomposed with a violent explosion. It is soluble also in a solution of the alkaline sulphurets. In a solution of caustic potassa, with the aid of heat, it dis- solves slowly and assumes a greenish colour. The best bronze powder is brought from Holland and Germany. It should not be confounded with the hydrated bisulphuret of tin, which is obtained by the humid process, and has very different properties. The latter has a pale yellow colour, and when decomposed by heat gives rise to water, sulphurous acid and sulphur, and leaves a residue consisting of bisulphuret of tin, probably mixed with the protosulphuret or the peroxide of that metal. It dissolves easily in solution of potassa, from which it is again precipi- tated by acids. It is also readily soluble in boiling muriatic acid, with the disengagement of sulphuretted hydrogen. TURMERIC. 251 TITANIC ACID. When pure, this substance is white, but it acquires a yel- lowish tint at a high temperature, which it again loses on becoming cold. It seems, however, to give this tint to cer- tain porcellaneous mixtures, as it is used in the manufacture of artificial teeth. After exposure to a red heat it is not attacked by any acid except the hydrofluoric ; but it is ren- dered soluble by ignition with an alkaline carbonate. Its solution gives a bulky red precipitate with infusion of galls, which is very characteristic. It often contains a small por- tion of iron which injures its colour. TURMERIC. Curcuma, U. S. The root of the Curcuma Long a £., a native of the East Indies, and cultivated in various parts of Southern Asia. There are two varieties, the long and the round. The former occurs in short, roundish, somewhat curved pieces, about the thickness of the little finger, reddish yellow ex- ternally, reddish brown within; the latter, more rare, is round, oval, or ovate, about two inches long, and marked externally with numerous annular wrinkles. The taste of turmeric is warm and somewhat aromatic. It tinges the saliva yellow, and gives an orange yellow powder. The colouring principle, which has been named Cur cumin, may be obtained by digesting the alcoholic extract of the root in ether. Turmeric is one of the ingredients of Curry powder, and is used as a yellow dye. It is also employed in chemistry as a test for the alkalies and alkaline earths, which change its fine yellow colour to a red brown By this means tur- meric can be distinguished from other roots which it re- sembles. 252 UVA-URSI. TURNBULL'S BLUE—.See PRUSSIAN BLUE. ULTRAMARINE. The real ultramarine is a beautiful blue pigment obtained from the Lapis Lazuli, a mineral found in Persia, China, Siberia, and Bucharia. It works well with oil, and does not change by time. It is now made artificially, and the manufactured ultramarine is little, if at all, inferior to that obtained from the native mineral. The high price of this article has led to its adulteration. The genuine ultramarine, when subjected to a high heat, fuses into a white, transparent, or opaque glass. With nitric and muriatic acids it forms a jelly, with the evolution of sulphuretted hydrogen. When diffused through water the colour of ultramarine is discharged by a current of gaseous chlorine. No substance which can be mixed with, or substituted for, the true ultramarine, exhibits these prop- erties. UVA-URSI. Uva-Ursi, U. S.—Bearberry. The leaves of the Arctostaphylos Uva-ursi Sprengel, a native of the Northern parts of Europe, Asia, and America. As they occur for medicinal use, they are dark green, shininp-, convex above, concave and reticulated on the under surface ; they have an astringent, somewhat bitter taste, and when powdered they give out an odour something like that of hay. The leaves of the red whortleberry, Vaccinium Vilis-idoza L., and of the common box, Buxus sempervirens L., are often mixed with, or substituted for, those of the uva-ursi. The former are readily distinguished by their being dotted on the under surface, and minutely toothed at the edges; the latter are detected by their want of astringency VERATRINE. 253 VENICE TURPENTINE. This is obtained from the Larix Europaza D. C, by openings in the trunks of the trees. It is a thick and con- sistent fluid, flowing with difficulty, usually cloudy, but sometimes transparent, having a yellow or greenish-yellow colour, a peculiar odour, and an acrid bitter taste. It is dis- tinguished from common turpentine by its having little or no tendency to concrete. Venice turpentine is said to be no longer imported into England or this country. A factitious article, which has taken its place, and is known by its name, is prepared by mixing oil of turpentine with black rosin. VERATRINE. Veratria, U. S. A vegeto-alkali obtained from the seeds of the Veralrum Sabadilla Relz., and the roots of Veralrum album L., or white hellebore ; and from the Colchicum autumnale L., or meadow saffron. In a state of purity it is white, incrystal- lizable, friable, inodorous, of a very acrid taste, but without bitterness. It is nearly insoluble in water, but is soluble in alcohol and ether. When treated with strong sulphuric acid, it assumes an intense red colour, and with nitric acid it forms a yellow solution. A minute quantity of it excites violent sneezing, and a few grains produce death. In its impure form, veratrine has the appearance of a re- sin. As it occurs in commerce it often contains a consider- able proportion of lime, or magnesia, sometimes employed in its manufacture ; and as they improve the appearance of the alkali and prevent it from becoming resinous by drying, they are purposely left in admixture. This may be ascer- tained by heating a portion of the veratrine in a platinum 22 254 WATER. spoon. If it is pure it will all sublime ; lime or magnesia will be left behind, if mixed with the veratrine. To purify veratrine from these^ubstances, dissolve it in alcohol, add- ing a small quantity of sulphuric acid, filter, precipitate with ammonia, and distill over the alcohol. WATER. The purest water that can be found, as a natural product, is produced by freshly fallen snow, or by receiving rain in clean vessels at a distance from houses. But this water is not absolutely pure, for it contains a portion of air or gas, as can be proved by placing a tumbler of it under the receiver of the air-pump, and exhausting the air. Water that has once fallen, on the ground, becomes im- pregnated with a greater or less proportion of saline and earthy matters. The presence of these substances interfere greatly with the purity of the water, as can be proved by its not dissolving soap. A few tests will, in general, deter- mine the nature of the impurities found in water. Thus, so- lution of chloride of barium will cause a white precipitate if carbonic or sulphuric acid is present. Should the precipi- tate be insoluble in muriatic acid, it indicates the presence of sulphuric aeid. If a white precipitate results from the addition of a solution of nitrate of silver, it is due to chlorine ; and if oxalate of ammonia causes a white precipitate, it is owing to lime. A small fragment of a gall-nut, suspended in the water, will, after twelve or twenty-four hours, be sur- rounded with a bluish cloud, if only the smallest proportion of iron is present. The purification of water, for the purposes of analysis and pharmacy, can be effected by the process of distillation, which consists in subjecting the water to heat in a retort, to which a receiver is attached ; the latter being kept cold by ice or snow, or by being immersed in cold water. The first portions are to be rejected, as they may contain some gaseous matter, and the process must be stopped when about three-fourths of the water are carried over. The distilled water thus obtained, should be kept in clean and well-stopped bottles. WAX. Cera Flava and Cera Alba, U. S. In its common form, wax has a bright, pale yellow colour ; is insipid to the taste, with a slight odour of honey. It is solid at ordinary temperatures, and somewhat brittle and granular, but may easily be cut with a knife and moulded between the fingers. It is insoluble in water, cold alcohol and ether ; but when assisted by heat is soluble in the fixed oils, forming a compound of variable consistence, which is the basis of cerates and ointments. When wax is prepared it is melted at a gentle heat, with a small quantity of water, and then poured into moulds to give it a certain form. As the wax cools, it deposites a variety of impurities, which are cut from the bottom of the cake with a knife. In purchasing wax, the cake should be broken, in order to ascertain whether these impurities have been removed. The substances generally employed to adulterate wax, are, resin, tallow, earth, pea meal, potatoe starch and a mixture of oil and litharge. Earth and pea meal may be suspected when the cake is very brittle and the colour inclines more to grey than to bright pale yellow ; these substances may be separated by re-melting and straining the wax. The pre- sence of resin may be suspected when the fracture appears smooth and shining, instead of being granular ; and it maybe detected by putting small pieces of the wax into cold alco- hol, which will readily dissolve the resinous part, but will not act on the w?ax. Tallow is discovered by the greater softness and unctuosity of the cake, and by the disagreeable 256 WHEAT FLOUR. suffocating odour which it exhales on being melted. Potatoe starch is detected by digesting the suspected wax in spirit of turpentine, at a gentle heat. The wax dissolves entirely in this liquid, but the starch remains behind. Wax which contains starch has generally a dull yellow colour, and is much heavier than wax of a good quality. White wax is sometimes adulterated with carbonate of lead, white tallow and spermaceti. The presence of the former may be ascertained by melting the wax in water, when the salt falls to the bottom of the vessel ; or by moist- ening the adulterated wax with liquid sulphuretted hydro- gen, which turns it black. Tallow is detected by the dull white colour, and the opacity which it communicates to the wax. The mixture of spermaceti and white wax is softer and more opaque than pure wax, and the surface of the cake exhibits a peculiar mottled appearance. It is also more easily fusible than pure wax.—(Domestic Chemist.) WHEAT FLOUR. " This well-known substance is the flour of the seeds of the Triticum vulgare Vill., of which there are several varieties extensively cultivated in various parts of the world. It is white, inodorous, and nearly insipid." Its chief constituents are starch, saccharine matter, gum, and a nitrogenous prin- ciple, commonly called gluten, but which has been ascer- tained to be a compound of vegetable fibrin and albumen. It is now generally admitted that the nutritive properties of wheat flour depend chiefly upon the gluten, and hence the value of different samples may be determined by ascertain- ing the proportion of this substance which they contain. . The adulterations of wheat flour and of the bread manu- factured from it, consist in the mixture of cheaper and less nutritious substances, as rye and bean flour, potatoe starch, &c.; and in the addition of various saline bodies to facilitate WHEAT FLOUR. 257 the process of manufacture, and to enable the baker to use inferior, and even damaged, kinds. Proportion of Gluten in Wheat Flour.—As the nutritive powers of sound flour and also of bread,are proportional to the quantity of gluten which they contain,it is of great importance to determine this point. For this purpose various processes have been proposed. One of these consists in digesting in a water-bath, at the temperature of 167° F., 1,000 grains of flour (or bread), with 1,000 grains of bruised barley- malt, in 5,000 grains, or in a little more than half a pint, of water. When this mixture ceases to take a blue colour from iodine, (that is, when all the starch is converted into soluble dextrine,) the gluten left unchanged may be col- lected on a filter cloth, washed, dried at a heat of 212° F., and weighed. The colour, texture, and taste of the gluten ought also to be examined, in forming a judgment of good flour or bread.—( Ure's Dictionary of Arts, fyc. Suppl.) Another test for ascertaining the proportion of gluten in a given quantity of flour, has been proposed by M. Boland, and is as follows : Weigh exactly 1,000 grains of the flour to be examined and put it into a capsule. Into a cup formed of the flour pour about 400 grains of water, stir with a spoon or spatula, until the whole of the water is absorbed and a plastic and consistent mass obtained. It is then kneaded between the fingers for two or three minutes, and afterward left for fifteen minutes ;in summer, and about an hour in winter, that the hydration may be com- pleted. A metallic sieve is then immersed in cold water and the paste is plunged repeatedly, for an instant at a time, into the water of the sieve, constantly kneading it, slowly at first, and afterwards more rapidly. By a little practice, the water, the greater part of the starch, and the soluble matters may be removed, while the adhering par- ticles of gluten remain in the hand in the form of an elastic 22* 258 WHEAT FLOUR. mass. The sieve is then raised, and any shreds of gluten which may have escaped are united to the mass. The washing of the whole is completed by kneading it strongly for ten minutes under a stream of cold water. The gluten thus obtained is subjected to strong pressure, then wiped dry and weighed ; it is afterwards put into an oven, where it is quickly dried, and before it changes colour is taken out and weighed a second time. We thus determine the pro- portions of moist and dry gluten which serve as a check upon each other. By this test the addition of from ten to fifteen per cent, of starch can be determined, as it reduces in the same ratio the proportion of gluten. In following out these processes it should be recollected that the proportion of gluten depends as much upon the state of humidity or dryness of the flour, as upon its quality. Thus, although the best samples of flour contain from eleven to seventeen per cent, of dry gluten, the amount of water may be so large as even in these to reduce the proportion of the nutritive constituents to that of the inferior kinds. The proportion of water in flour varies from six to twenty- five per cent.; a range which must greatly influence the results of the tests for gluten. The effect of moisture upon flour is very injurious. It occasions an alteration of the gluten which renders it unfit to produce good bread, and it favours the formation of sporules of different kinds of mushrooms which are after- Wards developed in the bread. Dumas states that the flour of the wheat of 1841 suffered great injury in this way during the summer of 1842. In spoiled flour, such as is said to be often used by the English bakers, and probably also by those of the United States, the gluten disappears altogether, and is replaced by ammoniacal salts. In this case quicklime separates am- monia from the flour without heat ; in flour slightly damaged, or ground from damaged wheat, the gluten pre- WHEAT FLOUR. 259 sent is deprived of its elasticity, and is softer than in the natural state. On this account the gluten test of M. Boland is valuable. It consists in putting some gluten into the bottom of a copper tube, and in subjecting this tube in an oven, or in oil, to the temperature of 284° F. The length to which the cylinder of gluten expands is propor- tional to, and indicates, its quality. For details, see Dumas, Chimie Appliquee aux Arts, vi. 425. Detection of Potatoe Starch.—This is said to be a com- mon adulterant of flour and bread in France, although it is seldom employed in England or the United States. When introduced after grinding the flour, the presence of potatoe starch can usually be detected by the microscope, on ac- count of the peculiar ovoid shape and large size of its par- ticles. The proportion of this adulterant cannot be very accurately determined. The process of M. Boland, which is an improvement upon that of Gay Lussac, affords only an approximation to a correct result, (see Dumas.) The test of the proportion of gluten, above described, will serve as an indirect method of determining the amount of starch that may have been mixed with the flour. Detection of Sulphate of Copper.—In Belgium and the northern part of France this substance has been, singularly enough, long used in the manufacture of bread. The bakers are said to derive many advantages from its employment. It enables them to use flour of an inferior quality, and to increase the weight of the bread by the addition of a larger quantity of water. It also lightens the labour of preparing the bread and renders the process of panification more speedy. The proportion of the sulphate of copper thus employed is sometimes very small, being not more than two or three grains to a loaf weighing about two pounds and a half. But 260 WHEAT FLOUR. M. Kulmann has justly observed, that there can be no safety whatever to the public when such a practice is per- mitted, because ignorance and avarice are always apt to in- crease the quantity of the poisonous substance. In analyses made by him and his colleagues, portions of bread were several times found so impregnated with this salt that they had acquired a blue colour, and presented occasionally even small crystals of the sulphate. The presence of sulphate of copper may often be de- tected by acting, on the poisoned bread with distilled water and testing the water with the solution of ferrocyanide of potassium, when the reddish brown precipitate character- istic of copper will appear even if the quantity is quite small. Should the proportion of the sulphate be still more minute, it may be detected by the following process : In- cinerate in a porcelain capsule about half a pound of the suspected bread, reduce the product of the incineration to a very fine powder and treat it with two or three drachms of nitric acid. The mixture is subjected to heat until nearly the whole of the free acid is evaporated, and the residue boiled in two or three ounces of distilled water. The whole is then thrown upon a filter, and to the filtered liquor there are added a small excess of solution of ammo- nia, and some drops of a solution of subcarbonate of am- monia. After being allowed to cool, the copious preci- pitate which is formed is separated by a filter, and the al- kaline liquor is boiled to expel the excess of ammonia, and is reduced to about a fourth of its volume. This liquor, being slightly acidulated by a few drops of nitric acid, is divided into two portions ; to the one is added ferrocyanide of potassium, and to the other, sulphuretted hydrogen, or hydrosulphuret of ammonia. If the least portion of sulphate of copper is present, it is rendered evident by the formation, after some hours, of a reddish precipitate with the first test, and of a less voluminous WHEAT FLOUR. 261 brown precipitate with the last. It is said that so small a proportion of sulphate of copper as one to 70,000 parts of bread can be detected by this process. According to Dumas, a few drops of a solution of ferro- cyanide of potassium thrown upon bread, produce a rose colour at the end of a few minutes, when there is present only one part of sulphate of copper to 9,000 parts of bread. Detection of Alum.—The employment of this salt in the fabrication of bread, appears to have been practised from a remote period. It increases the whiteness of bread, and en- ables the bakers to use inferior kinds of flour. The quantity employed varies greatly, being from one in 964 to one in 127 parts of flour, or from one in 1,077 to one in 143 parts of bread. The presence of this salt may be detected as follows : Incinerate about half a pound of the bread, treat the residue with nitric acid, evaporate the mixture to dryness, and add distilled water, as in the process for detecting sulphate of copper. Filter, divide the clear liquor into two portions, and to the one 'add solution of chloride of barium, and to the other a few drops of solution of ammonia. If alum is present, the former will give a dense white precipitate, and the latter a light precipitate, which is redissolved by a small quantity of caustic potassa. Alkaline Carbonates—Several authors have asserted that carbonate of ammonia may be advantageously employed for making bread light and increasing its whiteness. The property which this salt has of being converted into vapour and even of being decomposed into carbonic acid and am- monia by the action of heat, seems to justify this assertion. The carbonates of potassa and soda seem also to have been used, probably for the purpose of preserving for a long- er time the moisture of the bread, or of increasing its light- ness by the disengagement of carbonic acid. 262 WINE. Numerous other substances have sometimes been mixed with flour 4.0 increase the whiteness and weight of the bread, such as chalk, pipe-clay and plaster of Paris. As they answer no purpose unless they are added in consider- able quantity, their presence can in general be determined by the incineration of the bread and by the comparison of the weight of the residue with that obtained from the same quantity of unadulterated bread. If nitric acid be added, chalk may be detected by its effervescence, while the plaster will be dissolved. The calcareous matter may be rendered evident in the solution by neutralization with ammonia, and the subsequent addition of oxalic acid. WINE. Vinum, U. S. Wine is a transparent liquid, of a yellowish, reddish yel- low, or deep red colour. It consists principally of water and alcohol; but a great number of other substances are also found in it, as, sugar, fecula, gluten, extractive, colouring matter, tannic acid, bitartrate of potassa, tartrate of lime, vol- atile oil,cenanthic ether, &c. It is upon the volatile oil that the peculiar taste and odour of wine, called the bouquet, is supposed to depend. The proportions of the ingredients vary greatly in the different kinds of wine. Tannic acid and colouring matter are in larger quantity in the red wines than in the white, while the alcohol ranges from nine or ten to twenty-five per cent. Numerous frauds are practised with wine, and it is to be regretted that chemistry does not yet furnish the means of detecting them all with certainty. The most common of these are the mixture of wines of different vintages, and the addition of water, of brandy, of colouring matters, and of various saline substances. WINE. 263 Colouring Matters.—The colour of red wines is due to the skins of the red raisins, with which the musf is fermented. These wines also derive from this source the tannic acid to which they owe their astringent taste and their change from a red to a brownish black colour, upon the addition of a soluble persalt of iron. Among the substances said to be used for the purpose of giving a red colour to wines, are logwood, Brazil-wood, beet root, and the fruit of the elder and of the sloe. The process most to be relied on for determining their presence is that of Nees d'Esenbeck. It consists in dissolving one part of alum in eleven parts of distilled water, and one part of carbonate of potassa in eight, parts of water. The sus- pected wine is mixed with an equal volume of the solution of alum, which renders its colour more brilliant; to this mixture the alkaline solution is then added, little by little, taking care not to decompose all the alum. The alumina is precipitated with the colouring matter of the wine in the form of a lake, which, both before and after the addition of the potassa, assumes tints which vary with the nature of the colouring matter. In pure wine the solution of alum pro- duces a lake of a dirty grey colour, which an excess of the alkali partly dissolves, leaving the residue of an ash grey colour. If the wTine has been coloured by any of the sub- stances above mentioned, the precipitate left, after follow- ing out this process, is some shade of blue, violet, or rose. Detection of Carbonates.—The carbonates of lime, potassa and soda are sometimes employed to neutralize the acidity of certain wines. The first of these may be detected by evaporating a portion of the wine to about one-eighth its volume and adding to the residue twice its volume of alco- hol of sp. gr. 0.921. By this means the sulphate and tar- trate of lime, which naturally exist in the wine, are precipi- tated, and the acetate of lime dissolved. The solution is 26,4 W1NE- then filtered, and carefully evaporated to dryness. The fil- tered solution of this residue in water gives an abundant white precipitate with oxalate of ammonia, and evolves the odour of vinegar when decomposed by sulphuric acid. Carbonate of potassa is sometimes added to wine for the purpose of stopping the fermentation and of saturating the acetic acid which it may contain in excess. In this case acetate of potassa will exist in the wine. To determine the presence of this salt, evaporate a portion of the wine to a syrupy consistence and agitate the residue for some minutes with a small quantity of alcohol of the sp. gr. of about 0.842; upon the application of heat the acetate of potassa will be dissolved. The liquid after filtration is divided into two parts : the one is treated with a solution of the chloride of platinum, which gives with potassa a yellowish precipi- tate ; the other is evaporated to dryness and the residue moistened with strong sulphuric acid,'which liberates acetic acid, known by its peculiar odour. It should be stated that pure wine always contains acetate of potassa, but the quan- tity is so minute that these tests produce with it scarcely perceptible results. When wine, is saturated with carbonate of soda, the tests employed for acetate of potassa give only negative results. In this case, the residue of the evaporation should be treated with alcohol of the sp. gr. of 0.920, which dissolves the acetate of soda. This solution is then evaporated, the resi- due dissolved in water, the solution filtered and slowly evap- orated. If acetate of soda is present, crystals will be formed which have a sharp and slightly bitter taste, and are decom- posed by strong sulphuric acid. Detection of Lead.—The addition of white lead or li- tharge to sour wines, to neutralize their acidity and to ren- der them sweet, was formerly often practised, but is now rarely resorted to. The presence of lead in wine may be WINE. 265 detected as follows : Evaporate a 'portion of the suspected liquor to dryness in a Berlin ware capsule, collect the dry residue and heat it to redness. Triturate the coaly mass with twice its weight of nitrate of potassa, and throw the mixture, a little at a time, into a small porcelain crucible heated to redness. The nitrate of potassa causes the com- bustion of the charcoal, and a fused mass, which contains the lead, remains. If the matter retains a deep brown colour, the ignition may be repeated with another portion of the nitrate. The residue is then treated with water acid- ulated with nitric acid until it is completely dissolved. This solution is then filtered, and if it contains a salt of lead it will grum . . sulphuretum ru brum . . Hydrargyrum.....129 ammoniatum. 137 Hydrochloric acid .... 143 Hydrocyanic acid .... 96 Hymenaea Courbaril ... 29 martiana ... 29 Hyoscyamia......98 Hyoscyamine.....98 Hyoscyamus niger .... 98 Hypochlorite of lime ... 50 Hyponitrous ether .... 150 I. 9fifi mq India myrrh .... 147 Indigofera .... 98 Indigofera Anil . . 98 argentea 98 tinctoria 98 Indigo...... Q8 solution of . . 311 99 271 tincture of . . 100 312 Iodinum..... 99 ion lozenges . 101 107 101 ,308 black oxide of. . 102 carbonate of . . 102 hydrated sesquioxidi ;of 106 102 perchloride of. . 103 protiodide of . 1U4 protoxide of . 104 protosulphate of . 309 red oxide of . . 105 sesquichloride of 103 sesquioxide of . 105 sulphate of . . 104 328 l^DEX. Iron and Potassa, tartrate of 107 Isatis tinctoria.....93 Ivory black......63 Lycopodium clavatum 119 119 J. Jalap .... Jalapa. . . . Jatropa Manihot . 107 . 107 38, 240 K. Kelp........212 Kermes mineral .... 32 King's yellow.....39 Kino........108 L.. Labarraque's disinfecting li quid . . . Lac sulphuris . Lactometers. . Lactoscopes . . Lampblack . . Lapis calaminaris Lapis lazuli . . Larix Europaea. Laurus Camphora Cinnamomum Lead . . . acetate of carbonate of chromate of iodide of . protoxide of red oxide of Lead powder . Lemon juice Lime . . . . carbonate of caustic chloride of hypochlorite sulphate of Lime water . . Liquor ammoniae acetatis Liquorice Litharge . . Litmus . . Liver of antimony Logwood . . • Lolium temulentum Lupulin .... of 110, 50, 215 233 138 138 109 268 252 253 56 05 109 310 111 112 113 114 115 250 115 115 117 309 50 118 309 117 26 118 114 294 32 119 4G 90 Mace . ..... oil of..... Madder...... Magnesia..... calcined carbonate of heavy calcined Henry's calcined sulphate of Magnesiae carbonas . . sulphas . . Manganese, peroxide of Manganesii binoxidum . Manna...... flake..... Mannite.....■ Maple sugar .... Maranta...... Maranta arundinacea . . Marmor...... Martial Ethiops . . . Meadow saffron . . . Mel....... Melaleuca Leucadendron Menispermum Cocculus palmatum Menstruum..... Mercury..... bicyanide of. black sulphuret cyanuret of . perchloride of periodide of . peroxide of . protochloride of protoxide of red oxide of red sulphuret of . white precipitate of Metroxylon Sagus.... Milk....... . Minium . . •..... Mocha coffee..... Monkshood ..... Morphia.....! . Morphiae hydrochloras . . sulphas .... of 132 152 153 120 121 121 122 122 122 121 122 124 120 120 128 129 129 230 37 37 117 102 73 95 55 69 75 280 129 130 130 130 131 131 132 133 135 , 135 136 137 194 138 115 72 18 141 142 112 INDEX. 329 Morphine.....141^ 157 acetate of . . . 141 muriate of . . . 142 sulphate of . . 142 Moschus.......145 ] moschiferus . . 145 Mother water.....281 I Muriatic acid . . . 143, 271 Mushrooms......144 ! Musk........145 Mustard ......146 Myristica......152 moschata . . . 152 tomentosa . . 152 Myroxylon......43 Peruiferum . . 43 Toluifera . . 43 Myrrh.......147 Myrrha.......147 . 157 Nerium tinctorium . . 98 Neutralization . . . . 280 . 172 cubic . • . . . 216 . 148 Nitrogen, protoxide of . 149 Nitromuriatic acid . 150 Nitrous ether . . . . 150 . 152 butter of . . . 153 153,225 o. Oil, cod.......272 linseed......272 olive . • . . .155,272 of cinnamon .... 66 of poppies.....272 of sweet almonds . . 272 of vitriol.....233 tallow......272 whale......272 Oils, essential.....153 fat or fixed . . . 153,272 volatile.....153 Olea Europaea.....155 Oleine.......272 28* Oleometer Oleum olivae ricini rosae Olive oil . . Opium . . Smyrna Turkey Orchis mascula Ornus Europaea Orpiment- ; . Oxalic acid . . Oxalis Acetosella 273 155 60 192 155 157, 273 157 157 195 129 39 153 158 P. Palm oil.......159 Papaver somniferum . . . 157 Pearl sago......195 Pearl white......49 Pepper, black . . . . • 159 white.....159 Peruvian bark.....160 Pewter filings.....250 Phosphoric acid . . . . 162 Phosphorus......163 Phloridzin......162 Phlorizin......102 Physeter macrocephalus . 219 Picraena excelsa .... 185 Picrotoxine ...... 70 Pimpinella anisum ... 30 Pinus Abies......52 Picea ..... 52 Piper Cubeba.....85 nigrum ..... 159 Piperine.......160 Pitaya bark......161 Piton bark......161 Pix abietis......52 Platinum, chloride of . . 307 Plumbago......91 Plumbi acetas.....110 carbonas . . . . Ill iodidum .... 113 oxidum rubrum . . 115 oxidum semivitreum 114 Polygonum tinctorium . • 98 Pomegranate bark .... 103 Poppy oil......155 Portland arrow-root ... 38 Potash.......108 330 INDEX. Potash, prussiate of . . . 179 red prussiate of , . 304 yellow prussiate of . 301 Potassa.......182 of acetate of . , bicarbonate of bichromate of binoxalate of bitartrate of carbonate of caustic . . chlorate of chromate of fusa . . . hydriodate of muriate of. nitrate of . solution of. sulphate of tartras . . tartrate of . Potassa and soda, tartrate Potassae acetas '. . . bicarbonas bitartras . . chloras . . nitras . . . sulphas . . Potassae et sodae, tartras Potassii bromidum cyanuretum . ferrocyanuretum iodidum . Potassium, bromide of chloride of cyanide of 178,274,313 cyanuret of . . 178 ferricyanide of . 304 ferrocyanide of 179,304 iodide of . . 180,275 protoxide of . . 182 sulphuret of . . 297 Potatoe sago.....195 Powder of tin.....249 Precipitant . . . . . 282 Precipitate......282 Precipitation.....281 Prunus spinosa.....243 Prussian blue.....183 Prussicacid .....96 Pterocarpus Draco ... 86 Pterocarpus erinaceus . . 108 Pterocarpus santalinus . 86, 188 163,308 . 106 . 172 . 166 167,306 108,298 182,297 • 171 172, 303 . 182 . 180 . 177 172,314 . 183 175,302 . 175 . 175 176 165 100 167 171 172 175 176 177 178 179 180 177 177 Punica Granatum .... 165 Purple of Cassius .... 184 Pyrolusite......120 <*• Qualitative analysis, instru- ments of.....279 operations of 279 Quassia.......185 Quassia excelsa .... 185 Quercus Cerris . infectoria Quicksilver . . , Quinia.....160, Quinia? sulphas Quinine.....160, disulphate of subsulphate of sulphate of Quinoidine . . . R. 87 129 185 185 185 185 185 185 275 Reagents, definition oi 287 preparation of 287 39 115 Red precipitate 132 Red saunders . . 183 189 compactum 189 palmatum . 1S9 Rhaponticum 1S9 undulatum . 189 Rhubarb .... 189 Chinese . 189 East Indian 189 European . 190 Krimea 191 Russian 189 Turkey 189 Ricinus communis 60 176 Rock oil ... 148 . 231 Rosa damascena 192 192 192 Roses, otto or attar of 192 Rouge ..... 193 120 INDEX. 331 Rubia peregrina tinctorum Rum . . . • Rumex Acetosa 120 120 19 158 s. Saccharum......226 officinarum . . 226 Safflower........ 192 Saffron.......19r 32 . 194 . 195 . 194 26, 293 . 195 . 196 of antimony Sago .... meal. . . S.igus Rumphii . Sal ammoniac . Salep . . • • Salicin . • Salix alba......190 Salt of sorrel.....160 Salt of tartar.....170 Saltpetre.......I72 Sandal wood.....188 Santalin ...... 188 Santalum......188 Sarsaparilla......196 false .... 197 Saturation......280 Scammonium.....198 Scammony......I98 Scheele's green .... 199 Schweinfurt green . . . 200 Sealing wax......200 Selenium......200 Senna........2°1 Silver.......• 203 ammonio-nitrate of . 310 Soap, tincture of . . yellow or rosin . Soda, acetate of . . biborate of . . bicarbonate of. carbonate of caustic . . . chloride of . . hydrate of . . hypochlorite of hyposulphite of nitrate of . . phosphate of . sulphate of . . Soda alum......24 Soda ash......170,212 Soda water......218 Sodae acetas . . . . • • 210 chloride of cyanide of nitrate of Sinapis . . . Sinapis alba nigra 204 , . 205 205, 302 , . 146 . . 146 . . 146 , . 208 . 209 . 210 . 211 . 212 212,214 . . 219 , . 215 , . 219 , . 215 , . 215 . . 210 .210,303 . . 217 212 211 214 212 215 216 217 219 219 279 Smalt........69 Smelling salts.....^ Smilaxmedica.....19° officinalis . . . • 19« Sarsaparilla . . • 19° syphilitica . . • lfi Smyrna opium.....JJJ SoaP ■ . •.......210 officinal.....~ soft.......Mb bicarbonas .... boras...... carbonas..... carbonas impura . ' chlorinatae liquor phosphas ... sulphas .... Sodium, iodide of . . . protoxide of . . Solids, reduction to powder Soluble tartar.....I75 Solution.......279 Solvent . . • • • • 280 Spanish fly......57 Specific gravity bottle . Spelter...... Spermaceti..... Spiritus aetheris nitrici . Spiritus aetheris sulphurici Spurred rye..... Stannum...... Starch.......220 common ...» 221 potatoe.....221 Starch paste.....312 Starch sugar ..... j*> Storax.......222 common . . • • **A liquid.....223 Strontium, chloride of . . 223 Strychnia......; Strychnine . . ._ . Strychnos nux vomica Styrax ...... Styrax Benzoin . . 20 260 219 151 238 86 248 224 224 222 4G 332 INDEX. Styrax officinale Sublimation . . Sublimed sulphur Succinic acid , Succinum . . Sugar .... cane . . maple . . purified . starch unpurified white . Sugar of grapes Sugar of lead Sulphur . . . iodide of milk of praecipitatum precipitated vegetable . Sulphuretted hydrogen Sulphuric acid . Sulphuric ether spirit of Sulphuris iodidum Sweet spirit of nitre T. . 222 . 285 231,232 . 225 . 25 . 226 . 226 . 230 . 226 . 227 » 226 . 226 . 227 . 110 . 231 . 233 . 233 . 233 . 233 . 120 . 295 . 233 . 237 . 238 . 233 . 151 Tallow.......238 Tamarinds......239 Tamarindus .....239 Indica .... 239 orientals . . . 239 Tapioca.......240 pearl.....240 Tartar emetic .... 34, 35 soluble.....175 Tartaric acid,.....241 Tea........242 Terra Japonica.....61 Tephrosia Apolinea . . . 201 Testing.......286 Tests, definition of . . . 287 preparation of . . . 287 Thea JBohea......242 chinensis.....242 viridis......242 Thein........242 Thenard's blue.....248 Theobroma cacao .... 53 Thousand grain bottle . . 20 Tiglii oleum.....84 Tin...... . . 24S bisulphuret of . . . 250 powder of.....249 protochloride of . . . 306 Tin filings ..:... 249 Tinctura iodini . . • . 100 Tincture of chloride of iron 103 Titanic acid .....251 Tous les mois .... 57, 221 Triticum vulgare .... 256 Turmeric.....251,894 Turnbull's blue .... 184 Turpentine, Venice . . . 253 Tutty........270 U. Ultramarine • . Uncaria catechu Gambir Uvaria Ceylanica Uva-ursi . . . V. Vaccinium Vifis-idaea Venice turpentine Veratria . . . Veratrine . . . Veratrum album . Sabadilla Verdigris, crystallized common distilled Verjuice .... Vermilion . . , Vinegar . . Vinum ... Vitriol, blue oil of . 252 01 61 85 252 252 253 253 253 253 253 81 82 81 16 136 13 262 83 295 w. Wad........ 126 Water......-254,290 distilled.....254 Wax........255 Wheat flour......256 Whiskey ....... 19 White lead . . . . . " m Wine........262 Wine vinegar.....13 INDEX. 333 Winterana Canella Wood vinegar . . Z. Zaffre .... Zinc • . . • acetate of . butter of carbonate of . 69 266, 308 . 207 . 268 . 208 Zinc, chloride of flowers of . oxide of. . sulphate of. Zinci acetas . . carbonas . chloridum oxidum sulphas Zincum . • . 263 266, 269 269 270 267 268 268 269 270 265 NATIONAL LIBRARY OF MEDICINE NLM QDTflflbbE 3 |llf$ I ?TH,f*,»i*'*wMt«lWWi U^)«.t>I.Vi« cr*::- ."£iV* ■ - • • . i ».!r ^'r^'^wwTwWitii.iiSifli NLM009886623