Obtained from the ashes of marine plants, or produced by chemical decomposition with chloride of sodium.

Characters. - In transparent, colourless, laminar crystals, of a rhombic shape, efflorescent, with a harsh alkaline taste and strong alkaline reaction.

Reactions. - By heat it undergoes aqueous fusion, and then dries up, losing 63 per cent. of its weight.

20 grains Carbonate of Sodium neutralise

9.7 grains Citric Acid. 10 1/2 grains Tartaric Acid.

Dose. - 5 to 30 grains.

Preparations

B.P.

Dose.

Sodii Carbonas Exsiccata. Dried carbonate of sodium (used for pills)......................................................................................................................

3-10 grs.

Uses. - It is not much used as a remedy. Its chief use is in the preparation of other sodium salts. A dilute solution of it may be used as a wash to the skin to remove itching. In cases of anaemia it may be combined with ferri sulphas exsiccata, 4 grains of each, in pill.