The American homoeopathic pharmacopoeia / compiled and published by Boericke & Tafel.

Date:
1882
Catalogue details

Licence: Public Domain Mark

Credit: The American homoeopathic pharmacopoeia / compiled and published by Boericke & Tafel. 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.)

    48/562
    ter has undergone putrefaction. It is found in the juice of many plants, and in small quantities in rain and snow-water. It is prepared for medicinal and technical purposes by decomposing the nitrate of so- dium or of potassium by sulphuric acid. Preparation of Nitiic Acid.—The usual practice, adopted in the laboratory for obtaining nitric acid, is to add to nitrate of potas- sium in coarse poAvder, contained in a retort, an equal weight of strong sulphuric acid, poured in by means of a tube or funnel, so as not to soil the neck. The materials should not occupy more than two-thirds of the capacity of the retort. A receiver being adapted, heat is ap- plied by means of a spirit-lamp, the naked fire, or a sand-bath, moder- ately at first, but afterwards more strongly when the materials begin to thicken, in order to bring the whole into a state of perfect fusion. Red vapors will at first arise, and afterwards disappear in the course of the distillation. Towards its close they will be reproduced, and their reappearance will indicate that the process is completed. Nitric Acid. (sp. gr. 1.42.) Quadrihydrated Nitric Acid. —This is the acid now officinal in both the U. S. and Br. Pharmaco- poeias. To satisfy the tests, it must be colorless and entirely volatiliza- ble by heat; must dissolve copper with the disengagement of red va- pours; and, when diluted with at least six times its bulk of distilled water, must not be precipitated by hydrosulphuric acid, nitrate of sil- ver, or chloride of barium. Acid of the density of 1.42 is the most stable of the hydrated compounds of nitric acid, and boils at 250° F. When either stronger or weaker than this, it distils over at a lower temperature; and, by losing more acid than water in the first case, and more water than acid in the second, constantly approaches to the sp. gr. 1.42, when its boiling point becomes stationary. These facts in re- lation to quadrihydrated nitric acid were first observed by Dalton, and have since been confirmed by Mr. Arthur Smith, of London. This acid consists of one eq. of dry acid and four of water (4 HO, N02); but as only one of the eq. of water is basic, the other three being consti- tutional, the true formula is HO, N05 + 3 HO. Ninety grains by weight of it, mixed with half an ounce of distilled water, require, for neutralization, 1000 grain-measures of the volumetric solution of soda. —(Br.) General Properties.—Nitric acid, so called from nitre, i- a liquid, extremely sour and corrosive. When perfectly pure it is colorless. The concentrated acid, when exposed to the air, emits white fumes, possessing a disagreeable odor. By the action of light it undergoes a slight decomposition, and becomes yellow. It acts powerfully on ani- mal matter, causing its decomposition. On the living fibre it operates as a strong caustic. It stains the skin and most animal substances of an indelible yellow color. When mixed with muriatic acid, mutual decomposition takes place, and a liquid is formed capable of dissolving gold, called nitromuriatic acid or aqua regia. Tests.—The most common impurities in nitric acid are sulphuric acid and chlorine; the former derived from the acid used in the pro- cess for obtaining it, the latter from common salt, which is not an un-