Contractions. - Phos. Ac. Ph.-x.
Present name. - Hydric Phosphate. H3Po4.
Phosphoric Acid. For. name: German, Phosphorsaure.
Hahnemann directs this to be prepared by the action of Sulphuric Acid on calcined bones. It can be better prepared by burning Phosphorus in oxygen and diluting the product to sp. gr. 1.055.
Characters and Tests. - A colourless liquid, having a sour taste and strongly acid reaction. Specific gravity 1.055. It gives a canary-yellow precipitate with Ammonio-Nitrate of Silver, which is soluble in Ammonia and in diluted Nitric Acid. Evaporated, it leaves a residue which melts at a low red heat, and upon cooling exhibits a glassy appearance. It is not precipitated by Sulphuretted Hydrogen, Chloride of Barium, Nitrate of Silver with excess of Nitric Acid, or solution of Albumen. When mixed with an equal volume of pure Sulphuric Acid and introduced into a solution of Sulphate of Iron, it does not communicate a dark colour. Mixed with an equal volume of solution of Perchloride of Mercury and heated, no precipitate is formed.
Preparation. - The solution recommended above forms our lx preparation.
The 1 dilution should be made with distilled water, the 3X and 2 with distilled water to which 5 per cent. of rectified spirit has been added, the 5X with dilute alcohol, the 3 and following with rectified spirit.
Reference to Horn. Proving. - Chr. Kr., vol. v.
Proper forms for dispensing. - lx to 2, watery Solution only. 5X, dilute Tincture. 3 and upwards, Tincture, Pilules, or Globules.