Page images
PDF
EPUB

phosphate, obtained by treating calcium phosphate with sulphuric acid, with charcoal.

[merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small]

The process is conducted in a retort. Carbon, at a high temperature, takes oxygen from the phosphoric acid, and becomes carbonic acid. Phosphorus and carbonic oxide distill over, and the former is condensed in water, while the latter escapes.

Red Phosphorus.-A non-luminous, non-poisonous, red amorphous powder, consisting of phosphorus in one of its allotropic forms, prepared by allowing phosphorus to remain in an atmosphere of carbon dioxide for several days, at a temperature ranging from 215° to 250° C. (419°-482° F.). By heating it to 280° C. (536° F.) it is converted into ordinary phosphorus.

The three oxides formed by phosphorus are: Phosphoric Oxide, PO; Phosphorous Oxide, PO; and Hypophosphorous Oxide (?), PO".

The three corresponding acids are: Orthophosphoric Acid (tribasic acid), H3PO4; Pyrophosphoric Acid, HP2O,; and Metaphosphoric Acid, HPO.. These acids are prepared as follows; Orthophosphoric Acid-by dissolving PO in boiling water (P2O5 + 3H2O 2H,PO). Pyrophosphoric Acid-by heating orthophosphoric acid to 213° C. (4150 F.). Metaphosphoric Acid-by igniting orthophosphoric acid.

Orthophosphoric acid may also be made by acting on P with HNO3. Metaphosophoric acid may also be prepared by dissolving P2O, in cold

water.

The official Acidum Phosphoricum is the orthophosphoric acid.

There are two other phosphoric acids; Phosphorous Acid H,PO, (dibasic, containing one H atom not replaceable by a metal); and Hypophosphorous Acid, H,PO, (monobasic, containing two H atoms not replaceable by a metal). These acids cannot be produced directly from their corresponding oxides, Phosphorous Oxide (P2O2), and Hypophosphorous Oxide, P2O.

Official preparations of Phosphorus: Oleum Phosphoratum, Pilula Phosphori, and Spiritus Phosphori.

CARBON, BORON, AND SILICON.

C; 11.97. B; 10.9. Si; 28.3.

CARBON. C; 11.97.

Carbon is a constituent of all organic substances, and found in nature in the forms of coal, plumbago, diamond, etc.

The two oxides of carbon and their corresponding acids are, carbon dioxide, CO,, and carbonic acid, H,CO, (CO2 + H2O = H2CO3), carbon monoxide, CO, which is of little interest in pharmacy.

Carbon Dioxide. -A colorless, odorless gas, with slightly acid taste, heavier than the air, incombustible and a non-supporter of combustion. Water absorbs its own volume of it at ordinary temperature and pressure, and many times its volume under cold and pressure.

[blocks in formation]

Aqua Acidi Carbonici or "Soda Water." A solution of Carbon dioxide in water made under pressure, and dispensed under the well-known name, "Soda Water." It was formerly official.

CARBO ANIMALIS, U. S.-Animal Charcoal. Bone Black, or Ivory Black.-Dull black, granular fragments, or a dull-black powder, odorless and nearly tasteless, prepared by subjecting bones to a red heat in close vessels.

Preparation.-Bones consist of calcium phosphate and carbonate with animal matter. In the destructive distillation, which is conducted in iron cylinders without access of air, the N and H of the animal matter unite to form NH,, which distills over, leaving most of the C behind with the calcium salts.

Bone Spirit and Bone Oil.-The ammoniacal liquor and dark tarry liquid that distill over are known as bone spirit and bone oil, respectively. CARBO ANIMALIS PURIFICATUS, U. S.—Purified Animal Charcoal.-Animal charcoal purified from calcium salts by HCl.

CARBO LIGNI, U. S.-Charcoal.-Prepared by burning wood out of contact with the air, whereby its volatile portions, hydrogen, oxygen, water, etc., are dissipated, carbon, mixed with mineral salts, being left.

BORON. B; 10.9.

Boron exists in three allotropic forms, amorphous, crystalline, and graphitoidal (same as carbon).

The result of its combination with O and H is Boric (Boracic) Acid, HyBOg.

ACIDUM BORICUM, U. S.-Boric Acid. Boracic Acid. H,BO, = 61.78.—Is obtained in the lagoons in Tuscany; in California lakes, etc., in the forms of boric acid and borate of sodium (borax). Boric acid is made by decomposing borax with HCl :

[blocks in formation]

Acidum Boricum occurs in the form of transparent, colorless, six-sided plates, slightly unctuous to the touch, permanent in the air. Odorless; cooling, bitterish taste, feebly acid in solution.

SILICON. Si; 28.3.

Silicon exists in three allotropic forms, amorphous, crystalline, and graphitoidal.

It is found in combination with Al, Mg, and Ca, in pumice, meerschaum, asbestos, etc., and as an anhydride (silica) in sand, flint, quartz,

etc.

SILICA. SIO,.-Silicic Anhydride. Is obtained in a pure condi. tion by treating the official solution of silicate of sodium with HCl :

[blocks in formation]

LIQUOR SODII SILICATIS, U. S.—(Na,SiO3). Soluble Glass. -A semi-transparent, almost colorless, or yellowish, or pale greenish-yellow, viscid liquid, sp. gr. 1.3 or 1.4. Odorless; sharp, saline, and alkaline taste; alkaline reaction. Made by fusing I p. fine sand (silica) with 2 p. dried sodium carbonate, and dissolving the product. Used in surgery to prepare mechanical dressings.

POTASSIUM, SODIUM, LITHIUM, AND
AMMONIUM.

K; 39.03 Na: 23 Li; 7.01 NH4; 18.01.

Alkaline Metals and their Characteristics.-The alkaline metals are Potassium, Sodium, and Lithium. They are characterized, I, by their silvery-white appearance; 2, softness; 3, powerful affinity for oxygen; 4, lightness, being lighter than water, on which they float and take fire spontaneously, owing to their power of decomposing that fluid. They are all univalent.

The metals may be obtained by exposing their carbonates, mixed with charcoal, to an intense heat, carbon monoxide being liberated, and the vaporized metals condensed in appropriate receivers.

Ammonium is a compound radical, consisting of NH4, but, owing to its many analogies with the alkali metals, classed with them.

Characteristics of Alkalies.-I. They combine with acids to form salts. 2. They restore the color of reddened litmus, turn vegetable blues to green, and yellow to brown. 3. Their taste is characteristic and, if concentrated, caustic.

POTASSIUM.

Sources of Potassium Salts.-Formerly, wood ashes; now, the principal source is an impure chloride from the Stassfurt mines, in Germany. Lye, Potash, and Pearlash.-When wood is burned to ashes, the salts of potassium contained therein are converted into carbonates. Wood ashes are placed in a conical wooden vessel, termed a leach, and water allowed to percolate through, which becomes impregnated with the potassium carbonate contained in the ashes, and the solution is called le. By evaporating lye to dryness in an iron pot, a solid remains, consisting principally of impure carbonate, which is called potash. Potash, calcined on the hearth of a reverberatory furnace, loses its water and becomes white. It is then known as pearlash, and is an impure carbonate of potassium.

POTASSA, U. S.-Potassa. Potassium Hydrate, Potassium Hydroxide, Caustic Potash. KHO; 55.99.-A white, hard, and dry solid, generally in form of pencils; very deliquescent; odorless or having a faint odor of lye; very acrid and caustic taste; strongly alkaline reaction. Prepared from wood ashes by lixiviating, evaporating, purifying, redissolving, treating with lime, evaporating, fusing, and casting into moulds.

[blocks in formation]

POTASSIUM BICHROMATE.

75

POTASSA CUM CALCE, U. S.-Potassa with Lime.-A grayish-white powder, deliquescent, strongly alkaline, made by mixing together equal parts well-dried potassa and lime.

LIQUOR POTASSÆ, U. S.- Solution of Potassa.-An aqueous solution of hydrate of potassium, containing about 5 per cent. of the hydrate; clear and colorless; odorless; with very acrid and caustic taste; strongly alkaline reaction. Made by decomposing potassium bicarbonate through the action of calcium hydrate and heat, or by dissolving the hydrate in water.

POTASSA SULPHURATA, U. S.-Sulphurated Potassa. Liver of Sulphur.-An indefinite chemical compound, occurring in irregular pieces, of a liver-brown color when freshly prepared, turning gradually to greenish-yellow or brownish-yellow, with a faint, disagreeable odor, and bitter, alkaline, repulsive taste; alkaline reaction. Made by melting potassa and sulphur together in a crucible, pouring the liquid on a slab, and cooling. 3K,CO + 4S2 = 2K,S ̧ + K2S2O3 + 3CO2.

POTASSII ACETAS, U. S.-Potassium Acetate. KC,H2O2; 97.89.-White, foliaceous, satiny, crystalline masses, or a white, granular powder; very deliquescent; odorless; warming, mildly pungent, and saline taste; neutral or faintly alkaline reaction. Made by decomposing potassium bicarbonate with acetic acid, filtering and evaporating, carefully avoiding contact with iron.

[blocks in formation]

POTASSII BICARBONAS, U. S.-Potassium Bicarbonate. KHCO3; 99.88.—Colorless, transparent, monoclinic prisms, permanent in dry air; odorless; saline and slightly alkaline taste; feebly alkaline reaction. Made by passing carbon dioxide into a solution of carbonate, evaporating, and crystallizing.

[ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

POTASSII BICHROMAS, U. S.-Potassium Bichromate. K1Cr207; 293.78.-Large, orange-red, transparent, four-sided tabular prisms; permanent in the air; odorless; bitter, disagreeable, metallic taste; acid reaction; made by treating potassium chromate, prepared from chrome iron ore, with sulphuric acid, evaporating, and crystallizing

The ore is heated with potassium carbonate and chalk in contact with air, and the following reaction takes place :

[blocks in formation]

2(K,Cro) + H2SO, K,Cr2O, + K2SO, + H2O.

POTASSII BITARTRAS, U. S.—Potassium Bitartrate. KHCH4O6; 187.67. Cream of Tartar.-Colorless, or slightly opaque, rhombic crystals, or a white, somewhat gritty powder; permanent in the air; odorless; pleasant, acidulous taste; acid reaction. Made by purifying argol, the sediment deposited in wine casks during fermentation.

KBr;

POTASSII BROMIDUM, U. S.-Potassium Bromide. 118.79.-Colorless, translucent, cubical crystals; permanent in dry air; generally appearing in commerce in white, opaque, or semi-transparent crystals, having a faint alkaline reaction; odorless, pungent, saline taste; neutral reaction. Made by treating solution of potassa with bromine and charcoal.

The rationale of the process is as follows: Bromine added to solution potassa forms bromide and bromate. The solution is evaporated to dryness, and heated with charcoal, which deoxidizes the bromate, CO escaping.

[blocks in formation]

2K Br + 6CO Potassium Carbon Bromide. Monoxide.

POTASSII CARBONAS, U. S.-Potassium Carbonate. K,CO,; 137.91. Sal Tartar.-A white, crystalline or granular powder, very deliquescent at 13° C. (55.4° F.); odorless; strongly alkaline taste; alkaline reaction. Made by purifying pearlash, by dissolving it in cold water, filtering, evaporating, and granulating.

POTASSII CHLORAS, U. S.-Potassium Chlorate. KCIO,; 122.28.-Colorless, monoclinic prisms or plates, or a white powder of a pearly lustre, permanent in the air; odorless; cooling, saline taste, neutral reaction. Made by reacting on potassium chloride with calcium hypochlorite.

The rationale of the process is as follows: When solution of calcium hypochlorite is boiled, it is decomposed into calcium chlorate and chloride; and when calcium chlorate is heated with potassium chloride, double decomposition forms potassium chlorate and calcium chloride.

[blocks in formation]
[ocr errors]

POTASSII CITRAS, U. S.-Potassium Citrate. K,CH,O,. 1 323.59.-A white, granular powder, deliquescent on exposure to air; odorless; slightly cooling, faintly alkaline taste; neutral or faintly alkaline reaction. Made by decomposing potassium bicarbonate with citric acid, filtering, evaporating, and granulating.

[blocks in formation]

POTASSII CITRAS EFFERVESCENS, U. S.-Effervescent Potassium Citrate.-Citric Acid 63 Gm.; Potassium Bicarb. 90 Gm.; Sugar 47 Gm. Powder ingredients separately and mix in warm mortar

« PreviousContinue »