(Glauber's Salt.)

Origin. - The residue left in the manufacture of hydrochloric acid from salt is neutralized with sodium carbonate.

Description and Properties. - arge, colorless, transparent, monoclinic prisms or granular crystals; odorless, and having a bitter, saline taste. The salt effloresces rapidly in the air, and finally loses all its water of crystallization. Soluble in 2.8 parts of water and in glycerin; insoluble in alcohol.

Dose. - 1-8 drams (4.0-32.0 Gm.) [15 grains (1 Gm.), U. S. P.].

Physiological Action and Therapeutics of the Salines. - These preparations greatly augment the amount of fluid in the intestinal canal. This increase of fluid is not a secretion, but a result of the high osmotic equivalent of the salts, which tends to draw the body-fluids into the intestines, while hindering to a certain extent absorption of fluid from the intestines. The purgative influence is really due to the mechanical action of the fluid in the intestines.

Save the sulphate and phosphate of sodium, the salines have little effect upon the biliary secretions.

The sodium salts are more efficient than the potassium salts as purgatives, owing to their higher osmotic equivalents.

Purgation by the salines is painless, and occurs usually in from two to three hours after administration, there being ordinarily two or three watery evacuations.

In cases of habitual constipation, particularly that associated with the gouty diathesis, there are no better purgatives than the salts of sodium or mineral waters containing them, such as Carlsbad, Marienbad, Hunyadi Janos, Apenta, etc.

For children there is no better purgative than sodium phosphate, especially where the stools show a deficiency of bile. In duodenal catarrh excellent results are obtained by this drug; also in chronic rheumatism, and to retard the formation of biliary calcidi.

Concentrated saline purgatives are efficient remedies for the removal of dropsical and pleuritic effusions.

Magnesium sulphate, combined with dilute sulphuric acid, is the most efficient treatment in cases of chronic lead-poisoning.

Rochelle salt and Seidlitz powder are pleasant and useful purgatives in cases of biliousness, migraine, etc. Solution of magnesium citrate is used for the same purpose, but, while very palatable and acceptable to the stomach, is not always reliable, besides being apt to occasion slight griping.

Administration. - The salines should be taken dissolved in as concentrated a solution as possible, and ordinarily should be administered in the morning, when the stomach is empty.