Characters. - In colourless transparent prisms.

Preparation. - By fusing arsenious acid with nitrate and carbonate of sodium. The As2O3 is oxidised by the nitrate to As2O5, which combines with the sodium to form arseniate.

Solubility. - It is soluble in water.

Reactions. - The solution in water is alkaline, giving white precipitates with chloride of barium, chloride of calcium, and sulphate of zinc, and a brick-red precipitate with nitrate of silver (arseniate), all of which are soluble in nitric acid.

Dose.- 1/16 to 1/8 gr.; of the dried salt, 1/24 to 1/12 gr.

Preparations. b. and u.s.p.

liquor Sodii Arseniatis. 4 1/2 grains dried in 1 fl. oz. of water, or 1 in 100. B. and U.S.P.

Dose. - 5 to 10 minims.

Action. - It acts like other preparations of arsenic, but does not irritate the stomach so much, and may be given in larger doses. In frogs it produces, like arsenious acid, paralysis of the brain and spinal cord, but is much less powerful (Ringer and Murrell).

Uses. - It may be used in the same diseases as arsenious acid. It is perhaps one of the best remedies for neuralgia which we have.