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SOLUTION OF POTASSIUM ARSENITE.

107

Acid.

335.14) with a very small amount of antimony trioxide. A reddish-brown, amorphous powder; odorless and tasteless. Made by boiling antimonous sulphide with solution of soda, and adding sulphuric acid to the hot solution.

This process consists of two steps. First, the formation of sodium antimonite by the action of sodium hydrate on antimonous sulphide :

Sb,Sg + 6NaHO = Na Sbo, + Na SbS; + 3H,0. Antimonous Sodium

Sodium Sodium Sulph- Water. Sulphide. Hydrate. Antimonite. Antimonite.

Second, decomposition of sodium antimonite and sodium sulph-antimonite by sulphuric acid :

2Na SbO2 + 3H,SO, 3Na, SO + Sb.02 + 3H,0. Sodium

Sulphuric Sodium Antimonous Water. Antimonite.

Acid.

Sulphate. Oxide. And

2NazSbsz + 3H2SO, 3Na, SO + Sb S2 + 3H,S. Sodium

Sulphuric Sodium Antimonous HydrosulphuSulph-antimonite.

Sulphate. Sulphide. ric Acid. PILULÆ ANTIMONII COMPOSITÆ, U. S.-Compound Pills of Antimony. (Plummer's Pills.)-Each contains one-half grain sulphurated antimony, one-half grain calomel, and one grain guaiac. (See Pilulæ, Part II.)

PULVIS ANTIMONIALIS, U. S.-Antimonial Powder. (James' Powder.)—33 Gm. antimonous oxide ; 67 Gm. precipitated calcium phosphate. (See Pulveres, Part II..)

VINUM ANTIMONII, U. S.-Wine of Antimony.—4 Gm. tartar emetic; 65 C.c. distilled water ; 150 C.c. alcohol; stronger white wine to make 1000 C.c. (See Vina, Part II.)

ARSENIC. As; 74.9. ACIDUM ARSENOSUM, U. S.-Arsenous Acid. As,Oz; 197.68. (Arsenic Trioxide. White Arsenic.)—A heavy, white solid, occurring either as an opaque powder, or in transparent or semi-transparent masses, which usually have a striated appearance; odorless ; tasteless ; faintly acid reaction. Prepared by roasting arsenical ores, and resubliming the sublimate. “ An anhydride, not a true acid.” The oxide (As,O3) becomes an acid (H,AsOy) when added to water :

As2O3 + 3H,0 2H1,AsOg.

Arsenous Oxide. Water. Arsenous Acid. LIQUOR ACIDI ARSENOSI, U. S.-Solution of Arsenous Acid. (Liquor Arsenici Chloridi, Pharm. 1870.)—A solution of arsenious acid in diluted hydrochloric acid. 10 Gm. arsenic ; 50 C.c. diluted HCI; distilled water to 1000 C.c. No chemical reaction takes place.

LIQUOR POTASSII ARSENITIS, U. S.-Solution of Potassium Arsenite. (Fowler's Solution.)--10 Gm. arsenous acid; 20 Gm. KHCO3; 30 C.c. tr. lavender comp. ; 'distilled water to 1000 C.c.:

2KHCO3 + As,O3 + H2O 2KH,AsO2 + 2C02. Acid Potassium Arsenous Water. Potassium

Carbon
Carbonate Oxide

Arsenite When arsenous oxide is boiled with KHCO, in concentrated solution, potassium arsenite is produced, and CO, evolved. The quantity of water

Dioxide.

directed in the formula, however, is sufficient to dissolve the salts, so that a solution can be effected without any chemical change.

SODII ARSENAS, U. S.-Arsenate of Sodium. Na,HASO, 71,0; 311.9.-Made by fusing arsenous acid with sodium nitrate and carbonate.

LIQUOR SODII ARSENATIS, U. S. (See Liquores, Part II.)

ARSENI IODIDUM, U. S.-Arsenic Iodide. Asig; 454.49. (Arsenici Iodidum, Pharm. 1870.) — Glossy, orange-red, crystalline masses, or shining, orange-red, crystalline scales, gradually losing iodine when exposed to the air ; iodine-like odor ; iodine-like. taste ; neutral reaction. Made by fusing i p. of arsenic and 5 p. of iodine together.

LIQUOR ARSENI ET HYDRARGYRI IODIDI, U. S.Solution of Arsenic and Mercuric Iodide. (Liquor Arsenici et Hydrargyri lodidi, Pharm. 1870. Donovan's Solution.) — Solution should be light straw-color ; if darker, free iodine is probably present. (See Liquores, Part II.)

BISMUTH. Bi; 208.9. BISMUTHI CITRAS, U. S.-Bismuth Citrate. BiC H,07; 397.44.-A white, amorphous powder, permanent in the air ; odorless and tasteless. Prepared by boiling bismuth subnitrate with citric acid and water, and adding distilled water to the clear solution. The reaction is as follows :

BIONO.H,0 + H,CH,O, = BiC H,O+ HNO, + 2H,0. Bismuth Subnitrate. Citric Acid Bismuth Citrate. Nitric Acid. Water.

BISMUTHI ET AMMONII CITRAS, U. S.-Bismuth and Ammonium Citrate.--Small, shining, pearly or translucent scales, becoming opaque on exposure to air ; slightly acidulous and metallic taste; neutral or faintly alkaline reaction. Made by dissolving bismuth citrate in water of ammonia, evaporating the solution, and scaling.

BISMUTHI SUBCARBONAS, U. S.—Bismu Subcarbo ate. (BIO),CO,.H,0; 530.-A white, or pale yellowish-white powder, permanent in the air; odorless and tasteless. Made by dissolving bismuth in nitric acid, purifying, and precipitating by adding solution of sodium carbonate.

The most injurious impurity in bismuth is arsenic. In the official formula, directions are carefully made to leave out the arsenic. “The bismuth is first dissolved in nitric acid, a portion of which oxidizes the metal, with evolution of nitrous vapors, while another portion combines with the oxide produced, to form a bismuth nitrate. At the same time the arsenic is also oxidized at the expense of the nitric acid, and unites with a portion of the oxidized metal, so as to produce bismuth arsenate. Both of these salts, therefore, are contained in the solution, which is very concentrated. Both have the property, when their solution is diluted with water, of separating into two salts—one an insoluble subsalt, which is deposited, and the other a soluble acid salt, which is held in solution. But the arsenate is more disposed to the change than the nitrate, and requires for the purpose a smaller amount of water of dilution. The subarsenate is

GOLD AND PLATINUM.

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slowly deposited in twenty-four hours, and is then separated by filtration. The addition of a large quantity of distilled water precipitates the bismuth subnitrate, the ammonia being added to separate it more thoroughly by combining with the nitric acid. The precipitate thus freed from arsenic is now redissolved in nitric acid, partially diluted, and added to solution of sodium carbonate; by double decomposition bismuth subcarbonate and soaium nitrate are thus produced.”--(Remington.)

BISMUTHI SUBNITRAS, U. S.--Bismuth Subnitrate. BioNO3. H,0; 306.—A heavy, white powder, permanent in the air; odorless; almost tasteless; slightly acid reaction. Prepared by dissolving bis muth in nitric acid, purifying and adding the solution, in nitric acid, to water. The reactions are as follows :

Bi, + 8HNO, (Bi3NO3)2 + 4H,0 + 2NO. Bismuth. Nitric

Bismuth

Water. Nitrogen
Acid.
Nitrate.

Monoxide.
then
5(BizNO3) + 8H,0 = 4BIONO,H,0 + BizNO, + 8HNO3.
Water.

Nitric
Nitrate.
Subnitrate.

Acid. “ The separation of the arsenic is accomplished by first preparing the carbonate, by adding the solution of bismuth to a solution of sodium carbonate in excess, whereby most of the arsenic is retained in the solution, probably as sodium arsenate, while the insoluble carbonate is precipitated. This is dissolved, with the aid of beat, in nitric acid, so as to make a very concentrated solution of the nitrate, to which, when cold, just so much water is added as to begin to produce a permanent turbidness. The object of this is to allow any arsenic that may still be present to be deposited, which happens for reasons explained above. (See Subcarbonate.) The deposited matter having been precipitated, only the pure nitrate remains in solution, which is made to yield the subnitrate by a large dilution with water, and still more completely, by the addition of ammonia.”—(Remington.)

Bismuth

Bismuth

Bismuth
Nitrate.

GOLD AND PLATINUM.

Au; 196.7. Pt; 194.3. AURI ET SODII CHLORIDUM, U. S.-Gold and Sodium Chloride.—An orange-yellow powder, slightly deliquescent in damp air; odorless; saline, metallic taste; slightly acid reaction. A mixture com posed of equal parts of dry chloride of gold (AuClz) and chloride of sodiur (NaCl). Made by dissolving gold in nitrohydrochloric acid, evaporating to dryness, weighing, and dissolving in eight times its weight of distilled water. Pure decrepitated common salt, equal in weight to the dry chloride, is then added, previously dissolved in four parts of water. The mixture is then evaporated to dryness, with constant stirring.

TEST-SOLUTION OF PLATINIC CHLORIDE.-I p. chloride ; 20 p. distilled water.

PART IV.

THE PREPARATIONS OF THE ORGANIC

MATERIA MEDICA. What is Organic Chemistry? The science of the carbon compounds.

The following pages treat of both official and non-official organic substances, and the former may be distinguished from the latter by the letters U. S. following the official names.

THE CELLULOSE GROUP.

CELLULOSE. C.H1005. What is cellulose ? The woody fibre of plants, forming the skeleton for the vegetable tissues.

What is lignin ? “ The substances which are found adhering to the cellulin skeleton of plants and vegetable tissues.”

Describe pure cellulose. It is seen in the pure condition in raw cotton, the hairs of the seed of the cotton plant, and in many vegetable products. It is white, translucent, unalterable in the air; sp. gr. 1.5; insoluble in all the usual solvents, but soluble in ammoniacal solution of oxide of copper ; converted into dextrin by treating with strong sulphuric or phosphoric acid, and, further, converted into glucose if the mixture be diluted with water and heated.

What is parchment-paper ? Cellulose, in the form of unsized paper, after treatment with a mixture consisting of 2 p. H2SO4, sp. gr., 1.840, and I p. H,O, by measure, cooled to 15o C. (59° F.), and washing in dilute NH,HD.

For what is parchment-paper used in pharmacy? As a septum for dialysis.

What important principle in pharmacy is owing to the insolubility of cellulose in ordinary solvents ? As cellulose forms the bulk of inert matter in plants, and is insoluble in ordinary solvents, active prin: ciples soluble in such solvents can be readily separated from it.

When used for the purpose of separating the active principles ir, plants from the inert cellulose, what are solvents called ? Menstrua.

GOSSYPIUM PURIFICATUM, U.S.-Purified Cotton* (Gos sypium, Pharm. 1880. Absorbent Cotton.)—The hairs of the seeds of Gossypium herbaceum, freed from adhering impurities, and deprived of fatty matter. Cotton is freed from the trace of fatty matters always existing in raw cotton, by boiling it in a weak alkaline solution, rinsing it in a weak solution of chlorinated lime, to whiten it, dipping it in a very dilute solution of HCl, washing with cold water, drying, and carding. The loss is about 10 per cent.

* Purified cotton wool is cellulose in one of its purest forms.

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Products Resulting from the Decomposition of Cellulose. CLASS 1.–PRODUCTS MADE BY DECOMPOSING CELLULOSE OR LIGNIN BY

THE ACTION OF ACIDS OR ALKALIES. PYROXYLINUM,U.S.–Pyroxylin. (Soluble Gun-Cotton. Colloxylin.)- A very inflammable, slightly explosive substance, resembling cotton, formed by acting on cotton i Gm. with nitric acid 14 C.c., and sulphuric acid 22 Č.c., for ten hours, or until a portion taken out is found soluble in a mixture consisting of 1 p. Alcohol, 3 p. Ether (by volume), after which it is washed and dried.

What is Pyroxylinum chemically ? Di-nitro-cellulin. CcHo(2N02)05.

Explain its formation. It belongs to a series of closely related nitrocompounds of cellulin, formed by the action of nitric acid on this substance, in which the nitric acid radical replaces the hydroxyl of the cellulose formula. This may be shown by taking the double formula for cellulose C1,H2, 10 and the displacement of the HO, thus :6HNO, + CH20010

C2H4O (NO3)6 + 6H,O. Nitric Acid.

Cellulose. Cellulose-hexanitrate. Water. 5HNO3 +

C2H2010 C2H1505(NO3)5 + 5H,O. Nitric Acid.

Cellulose. Cellulose-pentanitrate. Water. 4HNO3 + C2H20010

C2H1606(NO3)4 + 41,0. Nitric Acid.

Cellulose. Cellulose-tetranitrate. Water. 3HNO3 +

C2H,70,(NO3)2 + 2010

3H,0. Nitric Acid. Cellulose. Cellulose-trinitrate. Water. 2HNO3 C2H20010

C12H1803(NO3)2 + 2H,0. Nitric Acid. Cellulose. Cellulose-dinitrate.

Water The soluble pyroxylin used in preparing collodion is a varying mixture of the di- tri- tetra- and pentanitrates. The hexanitrate is the true explosive gun-cotton, and is insoluble in ether, alcohol and water.

Celluloid.A substance made from pyroxylin, camphor and coloring matter heated together and powerfully pressed into appropriate moulds.

Pyroxylin was once extensively employed by photographers for producing the basis of the sensitized film upon which impressions are made. It is now replaced to a great extent by gelatin.

Pharmaceutically pyroxylin is used in collodion. (See Collodia, Part II.)

ACIDUM OXALICUM.–Oxalic Acid. H,C,0,2H,0; 125.7.Small, colorless, prismatic crystals; odorless, and with a very sour taste. Made by acting on cellulin, sugar, or starch, with nitric acid; but prepared on a commercial scale by heating sawdust with a mixture of two molecules caustic soda and one molecule potassa. The gray mass resulting is washed with Na, CO3, whereby the potash is removed as carbonate, and the less soluble sodium oxalate remains. This is converted into calcium oxalate by milk of lime, and then decomposed with H,SO,, and purified by recrystallization. Products Resulting from the Destructive Distillation of

Cellulose and Lignin. What occurs when wood is distilled in close vessels without air ? Several solid, liquid, and gaseous products are formed, of which the principal ones are the following :

SOLID.—Charcoal, inorganic salts, etc. LIQUIDS.-I. Aqueous liquid,

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