Contractions. - Nitr. Ac. Ni.-x.
Present name. - Hydric Nitrate. Hno3.
Nitric Acid. For. name: German, Salpetersaure.
Prepared from Nitrate of Potash or Nitrate of Soda by distillation with Sulphuric Acid and water. It may be obtained from the manufacturing chemists of the strength ordered by the British Pharmacopoeia, which contains 70 per cent. of the pure acid, but must answer the following
Characters and Tests. - A colourless liquid, sp. gr. 1.42, emitting powerfully acrid fumes. Evaporated to dryness, it leaves no residue; poured over copper filings, dense red vapours are immediately formed; but if the acid be mixed with an equal volume of water and then added to the copper, it gives off a colourless gas, which becomes orange-red when mixed with air. Diluted with six times its volume of distilled water, it gives no precipitate with Chloride of Barium or Nitrate of Silver; 90 grains by weight mixed with half an ounce of distilled water require 1,000 grain measures of the volumetric solution of Soda for neutralization.
Preparation. - 1 fluid drachm diluted with' distilled water until it measures 10 fluid drachms will make the lx dilution. Distilled water must be used for 1, distilled water to which 5 per cent. of rectified spirit has been added up to 3, and dilute alcohol for 4, after which rectified spirit may be employed.
Reference to Horn. Proving. - Chr. Kr., vol. iv.
Proper forms for dispensing. - Below 4, watery Solution only. 4, dilute Tincture. 5 and upwards, Tincture, Pilules, or Globules.