Caustic Soda. Hydrate of Soda. NaO, HO. Made by boiling down a solution of Soda to a fluid of an oily consistence, which is to be poured on a clean silver or iron plate, and allowed to solidify. It is then broken in pieces, and should be preserved in a green glass stoppered bottle.

Med. Prop. and Action. Caustic and escharotic. It is used in the same manner, and applicable to the same cases as Potash. It is, however, less deliquescent, and therefore more manageable, although probably not so powerful, as Potassa Caustica.¶ Liquor SodAe possesses similar medicinal properties to Liquor PotassAe. It is antacid, and acts as a direct sedative to the stomach. There seems, however, to be good evidence that, whilst the preparations of Potash affect the secretion of the kidneys, those of soda influence that of the liver. ** Hence, in the treatment of certain forms of Dyspepsia connected with biliary derangement, the Liq. Sodas or the Carbonates of Soda may be advantageously substituted for the analogous preparations of Potash.

* Mat. Med., p. 182.

Med.-Chir. Rev., Nov. xliv. p. 511.

Lancet, May 1S35.

§ Journ. de Pharm., t. x. p. 543.

|| Journ. de Chir. Med., t. i. p. 45. ¶ Garrod. Ess Mat. Med., p. 118. ** Garrod, Med. Times and Gaz., April 9.

Offic. Prep. Liquor SodAe (prepared by decomposing Carbonate of Soda dissolved in water with slaked lime. Carbonate of Lime is precipitated, and Soda remains in solution. Sp. gr. 1.047). Dose, x. - fl. drm. j., freely diluted.