The dispensatory of the United States of America / by George B. Wood and Franklin Bache.

Date:
1865
Catalogue details

Licence: Public Domain Mark

Credit: The dispensatory of the United States of America / by George B. Wood and Franklin Bache. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    acid; and, with an excess of ammonia, should cause only a slight turbidness, proving the almost total absence of earthy salts. Should the presence of arsenic be ascertained by the tests for that metal, it may be separated by boiling with muriatic acid, so as to convert the arsenic into its very volatile chloride, which would escape with the vapours of the muriatic acid. Medical Uses. Glacial phosphoric acid is seldom if ever used medicinally in reference to its influence on the system, though probably capable of producing all the effects for which the officinal diluted acid is employed. It was introduced into the Materia Medica of our Pharmacopoeia as affording a convenient method of preparing the medicinal acid. It may also be used in prescriptions with the insoluble phosphates to render them soluble iu the liquors of the stomach, and thereby favour their entrance into the circulation. Thirty-eight and a half grains, dissolved in a fluidounce of water, form a solution about equal in strength to the officinal U. S. diluted acid. Off. Pre]). Acidum Phosphoricum Dilutum, U. S. B. ACIDUM SULPHURICUM. U.S., Br, Sulphuric Acid. Sulphuric acid, of the specific gravity 1843. U. S. Monohydrated Sulphuric Acid, HO,S03. Sp.gr. 1846. Br. Oil of vitriol, Vitriolic acid; Acide sulfurique, Fr.; Vitriolol, Schwefelsiiure, Germ.; Acido solfoiico, Ital.; Acido sult'urico, Span. Sulphuric acid is placed in the Materia Medica list of the U. S. Pharmaco- poeia, as an article to be obtained from the wholesale manufacturer. Provision, however, is made that it shall be free from all odorous substances, and all me- tallic and other non-volatile impurities. The British Pharmacopoeia admits only the purified acid in its Materia Medica, giving a process for its preparation from the commercial acid, which is placed in the Appendix of that work, with the name of Sulphuric Acid of Commerce, or Oil of Vitriol, as one of the arti- cles employed iu the preparation of medicines. Preparation. Sulphuric acid is obtained by burning sulphur, mixed with one- eighth of its weight of nitre, over a stratum of water contained in a chamber lined with sheet-lead. If the sulphur were burned by itself, the product would be sulphurous acid, which contains only two-thirds as much oxygen as sulphuric acid. The object of the nitre is to furnish, by its decomposition, the requisite additional quantity of oxygen. To understand the process, it is necessary to bear iu mind that nitric acid contains five, sulphuric acid three, sulphurous acid two, nitric oxide two, nitrous acid three, and hyponitric acid four equivalents of oxygen, combined with one eq. of their several radicals. One eq. of sulphur decomposes one eq. of nitric acid of the nitre, and becomes one eq. of sulphuric acid, which combines with the potassa of the nitre to form sulphate of potassa. In the mean time, the nitric acid, by furnishing three eqs. of oxygen to form the sulphuric acid, is converted into one eq. of nitric oxide, which is evolved. This gas, by combining with two eqs. of the oxygen of the air, immediately be- comes hyponitric acid vapour, which diffuses itself throughout the leaden cham- ber. While these changes are taking place, the remainder of the sulphur is un- dergoing combustion, and filling the chamber with sulphurous acid gas. One eq. of hyponitric acid vapour, and one eq. of sulphurous acid gas, being thus inter- mingled in the chamber, react on each other, by the aid of moisture, so as to form a crystalline compound, consisting of one eq. of sulphuric acid and one eq. of nitrous acid, united with a portion of water. This compound falls into the water of the chamber, and is instantly decomposed. The sulphuric acid dissolves in the water, and the nitrous acid, resolved, at the moment of its extrication, into