Properties.—A heavy solid, occurring either as an opaque, white powder, or in irregular masses of two varieties; the one amorphous, transparent and colorless, like glass; the other crystalline, opaque, and white, resembling porcelain. Frequently the same piece has an opaque, white outer crust enclosing the glassy variety. Contact with moist air gradually changes the glassy into the white opaque variety. Both are odorless and tasteless. The glassy variety dissolves slowly in thirty parts of water; the porcelain-like in eighty parts of water. Arcenous acid is sparingly soluble in alcohol, but soluble in glycerin, hydrochloric acid and solutions of the alkali hydrates and carbonates. When heated to 424°, arcenous acid is completely volatilized without melting.
Incompatibles.—Lime water, salts of iron and magnesia.
Dose.—Horses, 1 to 5 grs.; cattle, 2 to 8 grs.; sheep and pigs, 1 to 2 grs.; dogs, 1⁄30 to 1⁄10 gr.
LIQUOR POTASSII ARSENITIS—SOLUTION OF POTASSIUM ARSENITE (Fowler’s Solution)
Derivation.—Arcenous acid, potassium bicarbonate, compound tincture of lavender and distilled water. Strength one part of arcenous acid in 100.
Dose.—Horses, 2 drs. to 1 oz.; cattle, 1⁄2 to 11⁄2 ozs.; sheep and pigs, 10 to 40 ms.; dogs, 2 to 5 ms. Average dose for horse is 1⁄2 oz. usually given three times daily in drinking water or bran mash.
LIQUOR ACIDI ARSENOSI—SOLUTION OF ARCENOUS ACID
Derivation.—Arcenous acid, diluted hydrochloric acid, and distilled water. Strength one part arcenous acid in 100.
Dose.—Same as liquor potassii arsenitis.