Origin.—Sodium sulphate effloresces on the soil in various parts of Europe. It also exists in solution in many mineral springs in the United States. Sodium sulphate is also produced artificially in several chemical operations.

Properties.—Sodium sulphate is in large, colorless, transparent, monoclinic prisms, or granular crystals; odorless, and having a bitter, saline taste. It effloresces rapidly in the air, and finally loses all its water of crystalization. Soluble in three parts of water at the temperature of 59° F., insoluble in alcohol, soluble in glycerine.

Actions.—Saline cathartic, cholagogue, hepatic stimulant, slightly diuretic and febrifuge. When the effects of a hepatic stimulant is required it should be given in small repeated doses.

Uses.—It is advantageously used as a cathartic in congestion of the liver, in small repeated doses, also useful in dropsical conditions, influenza, especially where the liver is involved; tetanus and febrile diseases, where the bowels are apt to be constipated. Give two to four ounces in a bucket of water. It is successfully used in itching skin diseases in full doses combined with bicarbonate of soda two to four ounces.

Doses.—As a cathartic, well diluted in water at about 59° F.; horses, 16 to 24 ounces; cattle, 1 to 2 pounds; sheep and pigs, 2 to 4 ounces. Where repetition is necessary the dose should be reduced one-eighth of the above. Best results are obtained when administered with capsicum or ginger, as it prevents griping and assists its action.