2. If albumen be added to metaphosphoric acid, or to a solution of a metaphosphate containing acetic acid, a white precipitate is produced. No precipitate occurs if it be added to pyrophosphoric acid or orthophosphoric acid. 3. Official test-solution of magnesium (see Tests) produces with phosphoric acid or a solution of a phosphate a precipitate of ammoniomagnesium phosphate. 4. If solution of ammonium molybdate in diluted nitric acid be added in excess to phosphoric acid or to a solution of a phosphate in nitric acid, and heat applied, a yellow precipitate of ammonium phosphomolybdate will be produced. 5. If a solution of barium chloride be added to a neutral solution of a phosphate, a white precipitate of barium phosphate is produced, which is soluble in acids. Tests for Hypophosphites. 1. When heated, they evolve spontaneously inflammable hydrogen phosphide. 2. An acid solution of potassium permanganate is decolorized. 3. From solution of mercuric chloride, mercury is precipitated upon the addition of a solution of a hypophosphite. A translucent, nearly colorless solid, of a waxy lustre, having, at the ordinary temperature, about the consistence of beeswax. By long keeping, the surface becomes red, and occasionally black. It melts at 44° C. (111.2° F.). Sp. gr. 1.830 at 10° C. (50° F.). TESTS FOR IDENTITY. When exposed to the air, it emits white fumes, which are luminous in the dark, and have an odor somewhat resembling that of garlic. On longer exposure to air, it takes fire spontaneously. SOLUBILITY. Other Solvents. Distinctive and dis- Insoluble. Soluble in 350 parts of absolute al agreeable odor; IMPURITIES. Arsenic. Sulphur. cohol at 15° C. (59° F.), in 240 parts of boiling absolute alcohol, in 80 parts of absolute ether, in about 50 parts of any fatty oil, and very soluble in chloroform or carbon disulphide, the latter yielding a solution which must be handled with the greatest care to prevent danger from fire. TESTS FOR IMPURITIES. Add 3 Gm. of Phosphorus to 15 C.c. of nitric acid diluted with 15 C.c. of distilled water in a flask having the capacity of 50 C.c., and digest the mixture at a gentle heat on a water-bath, until the Phosphorus is dissolved. Transfer the solution to a capsule, and evaporate it until no more nitrous vapors are given off, and then dilute the solution to 30 C.c. with distilled water. Heat 20 C.c. of the diluted solution to about 70° C. (158° F.) for half an hour, passing hydrogen sulphide through it during the half hour's heating, and then until the liquid has become cold. If the liquid be now allowed to stand at rest during twenty-four hours, not more than a very small quantity of lemon-yellow precipitate should be visible (limit of arsenic). On adding barium chloride T.S. to the remainder of the liquid, not more than a slight opalescence should be produced (limit of sulphur). Uses.-Phosphorus is administered internally, in doses of of a grain (0.0006 Gm.), as a nervous stimulant. In large doses it is poisonous. Its value in this connection depends upon its being administered in a free state. The oxide of phosphorus, phosphoric acid, does not have the same action: hence all pharmaceutical preparations of phosphorus must be protected from ox dation. (See Pilula Phosphori.) Introduce a sufficient quantity of Expressed Oil of Almond into a flask, heat it on a sand-bath to 250° C. (482° F.), and keep it at that temperature for fifteen minutes. Then allow it to cool, and filter it. Put 90 Gm. [old form 7 fl. dr.] of the filtered Oil together with the Phosphorus, previously well dried by filtering paper, into a dry, tared bottle capable of holding about 120 C.c. [old form 2 fl. oz.], insert the stopper, and heat the bottle in a water-bath until the Phosphorus melts. Then agitate it until the Phosphorus is dissolved, allow it to cool, add enough Ether to make the mixture weigh 100 Gm. [or measure, old form, 1 fl. oz.], and agitate it again. Lastly, transfer the solution to small glass-stoppered vials, which should be completely filled and kept in a cool and dark place. The object of this preparation is to administer phosphorus in minute doses, dissolved in a bland oil. When fresh, it is a clear and colorless or slightly colored oil, not phosphorescent in the dark, and having the odor and taste of phosphorus quite distinctly. The object of heating the oil is to expel air and traces of water, which would aid in oxidizing the phosphorus. The ether not only assists in the preservation of the finished preparation, but is of use in rendering the oil less disagreeable to the taste. It may be administered in the form of an emulsion, preferably the official almond emulsion, and flavored with oil of bitter almond, or in capsules: each minim contains about of a grain of phosphorus. The dose of the U. S. solution is from three to five minims. (0.18 to 0.3 C.c.). QUESTIONS ON CHAPTER XXXV. SULPHUR AND PHOSPHORUS. Give the symbol and atomic weight of sulphur. In what forms is sulphur official? What gas is formed by it in combination with hydrogen? What are sulphides? What are salts, called sulpho-salts by Berzelius? What combination does sulphur form with oxygen? What do these oxides form by their union with water? Give their formulas in symbols. What is hyposulphurous acid? Is there an oxide corresponding to this acid? What is thiosulphuric acid? What acids are known as the thionic series of acids? What are the salts which sulphurous acid forms with bases called, and what those which are similarly produced from sulphuric acid? Which are more important salts, sulphates or sulphites? What are the tests for sulphites and sulphurous acid? For sulphates and sulphuric acid? What is sublimed sulphur? What are its physical properties? How is it used medicinally, and what is the dose? How is washed sulphur prepared? What is the use of adding ammonia in washing it? At what temperature does it melt? How may impurities of free acid be detected? Of arsenous sulphide? Of arsenous acid? Why is washed sulphur preferred for medicinal purposes? What is the dose? In what official preparations is it used? How is precipitated sulphur prepared? Explain the reaction that takes place between lime and sulphur in the above process. What would be the result if sulphuric acid were used instead of hydrochloric acid to precipitate the sulphur? What is the popular name of this preparation? How may the following impurities be detected?-viz. free acid; calcium sulphate; alkalies, alkaline earths, or sulphide; arsenous sulphide; arsenous acid. For what uses is precipitated sulphur preferable to other forms of sulphur? What is the dose? How is sulphur iodide prepared? What is it called chemically? Is it a definite chemical compound? How may it be tested? What is its use? Carbon disulphide-Give formula in symbols and molecular weight. How is it prepared, and how may it be purified? What are its physical properties? What is its specific gravity? How may the following impurities be detected?—viz.: sulphurous acid; sulphur; hydrogen sulphide. For what is it used? Is it ever used internally? Phosphorus-Give symbol and atomic weight. What is phosphorus, and how is it prepared? How is acid calcium phosphate obtained? Explain the reaction which takes place in its formation. How is red phosphorus, or amorphous phosphorus, obtained? What oxides does phosphorus form with oxygen? Give their formulas in symbols. What three acids correspond to phosphoric oxide? What is its formula in symbols? How is pyrophosphoric acid obtained? Give its formula in symbols. How is metaphosphoric acid obtained? Give its formula in symbols. Can phosphorous acid be formed directly from phosphorous oxide? What is the character of its basicity? Can hypophosphorous acid be obtained directly from hypophosphorous oxide? What is the character of its basicity? What are the tests for phosphates and phosphoric acid? What are the tests for hypophosphites? What is the specific gravity of phosphorus? What is its melting-point? How may impurities be detected?—Sulphur; arsenic. What is its medicinal action, and what is the dose? Upon what does its value depend? Does phosphoric acid have the same action? Give the formula for phosphorated oil. What is the object of this preparation? What is the dose? CHAPTER XXXVI. CARBON, BORON, AND SILICON. C; 11.97. B; 10.9. Si; 28.3. THESE three elements present some analogies, and, although the number of pharmaceutical preparations made from them is not great, they are of considerable interest. Official Preparations of Carbon, Boron, and Silicon. Carbo Animalis.-Prepared by burning bones out of contact with air. Carbonei Disulphidum.-See preparations of sulphur. Acidum Boricum.-Made by purifying the natural product. Sodii Boras.-See preparations of soda. Liquor Sodii Silicatis.-Made by fusing silica with dried sodium carbonate and dissolving the product. Carbon. C; 11.97. Carbon is a very widely diffused element. It is a constituent of all organic substances, and is found in nature in the form of the diamond, graphite, plumbago, coal, etc. Two compounds with oxygen are known,-carbon dioxide, CO, and carbon monoxide, CO. Carbon dioxide, CO2, is a colorless, odorless gas, with a slightly acid taste, heavier than ordinary air. It is not combustible, and not a supporter of combustion; indeed, it is used extensively in fire-extinguishers and other contrivances to extinguish flame. Water is capable of absorbing its own volume of carbon dioxide, but many times its volume under pressure. This solution was formerly officinal, under the name of Aqua Acidi Carbonici, or carbonic acid water, the well-known "soda water." Carbonic acid, H,CO,, is produced when carbon dioxide is brought in contact with water. The salts known as carbonates are widely diffused in nature, and many chemical processes are based upon the decomposition of carbonates by strong acids. Carbonic acid, although present everywhere, is one of the weakest acids known. |