Contractions. - Mur. Ac. Mu.-x.

Present name. - Hydrochloric Acid. Hc1. For. name: German, Salzsaure.

The process for preparing this should be that recommended in the British Pharmacopoeia of 1867.

Take of

Chloride of Sodium, dried .

48 ounces;

Sulphuric Acid . . .

44 fluid ounces;

Water . . . .

36 fluid ounces;

Distilled Water . . .

50 fluid ounces.

Pour the Sulphuric Acid slowly into 32 ounces of the water, and when the mixture has cooled add it to the Chloride of Sodium previously introduced into a flask having the capacity of at least one gallon. Connect the flask by corks and a bent glass tube with a three-necked wash-bottle, furnished with a safety tube, and containing the remaining 4 ounces of the water; then, applying heat to the flask, conduct the disengaged gas through the wash-bottle into a second bottle containing the distilled water, by means of a bent tube dipping about half an inch below the surface, and let the process be continued until the product measures 66 ounces, or the liquid has acquired a specific gravity of 1.16. The bottle containing the distilled water must be kept cool during the whole operation.

Characters and Tests. - Colourless, strongly acid, emitting white vapours having a very pungent odour. Evaporated to dryness, it leaves no residue; it gives a curdy white precipitate with Nitrate of Silver, soluble in excess of Ammonia, insoluble in Nitric Acid. 114.8 grains by weight, mixed with half an ounce of distilled water, require for neutralization 1,000 grain measures of the volumetric solution of Soda. When diluted with four times its volume of distilled water it gives no precipitate with Chloride of Barium or Sulphuretted Hydrogen; no red colour with Sulphocyanide of Potassium, and does not tarnish bright copper foil when boiled in it If half a fluid drachm of the acid mixed with 2 fluid drachms of distilled water be put into a test-tube with a few pieces of granulated zinc, and while the effervescence continues, a slip of bibulous paper moistened with a solution of Acetate of Lead be suspended in the upper part of the tube for a few minutes, the paper will not become discoloured.

Preparation. - As this solution contains 31.8 per cent. of the pure acid, 1 1/2 fluid drachm mixed with 4 fluid drachms of distilled water will make the lx dilution. In diluting, distilled water only should be used up to 1, distilled water to which 5 per cent. of rectified spirit has been added up to 3, then dilute alcohol for 4, and after that rectified spirit.

Reference to Hom. Proving. - Chr. Kr., vol. iv.

Proper forms for dispensing. - Below 4, watery Solution only. 4, dilute Tincture. 5 and upwards, Tincture, Pilules, or Globules.