An aqueous solution of hydrate of sodium (NaHO; 40) containing about 3 per cent. of the hydrate, U.S.P. (4.1 per cent. B.P.).

Characters. - Like those of liquor potassae (p. 607), but it is not precipitated by tartaric acid nor by perchloride of platinum.

Uses. - Is used in preparing ferric oxide and in other pharmaceutical processes, as it is cheaper than solution of potash. Internally it may act on the blood, rendering it and the secretions more alkaline, but it will not alter nutrition in the way that potassium salts do.