Glauber, JOHANN RUDOLPH, a German alchemist and physician, was born at Karlstadt, in Franconia, in 1603 or 1604, and died at Amsterdam in 1668. No details regarding his life are known, except that he resided at Vienna, Salzburg, Frankfurt-on-the-Main, and Cologne, from whence in 1648 he removed probably to Amsterdam. Although a believer in the philosopher's stone and in the clixir vitæ, he contributed very materially to the progress of chemistry. In 1648 he discovered hydrochloric acid whilst experimenting with oil of vitriol and common salt; he was probably the first to procure nitric acid; and his name has been transmitted in Glauber's Salt, which he likewise discovered. His treatises were published at Amsterdam in 7 vols., 1661; and an English translation was printed by Packe at London in 1689.
GLAUBER'S SALT is the popular name of the neutral sulphate of soda whose chemical composition is represented by the formula . It occurs in long four-sided translucent prisms, terminated by dihedral summits, and containing ten atoms of water. On exposure to the air, the crystals lose all their water, and become resolved into a white powder. When heated they readily melt in their water of crystallisation; and, if the heat is sufficiently continued, the whole of the water is expelled, and the anhydrous salt remains. Glauber's salt has a cooling, bitter, and saltish taste; it is readily soluble in water; its solubility (in the ordinary crystalline form) increasing up to 92°, when it appears to undergo a molecular change, and to be converted into the anhydrous salt, which at this temperature is less soluble than the hydrated compound, and separates in minute crystals. Glauber's salt is a constituent of many mineral waters (as at Carlsbad and Cheltenham), and is found also as an efflorescence about saline lakes in some parts of the United States; and it occurs in small quantity in the blood and other animal fluids.
The anhydrous salt is prepared in enormous quantity from common salt and oil of vitriol, with the view of being afterwards converted into carbonate of soda (see SODA). For medical use a purer form is required. The salt which remains after the distillation of hydrochloric acid—this salt being sulphate of soda contaminated with free sulphuric acid—is dissolved in water, to which is added powdered white marble (carbonate of lime), to neutralise the free acid, and to precipitate it as an insoluble sulphate; the solution is boiled down till a pellicle appears, is strained, and set aside to crystallise.
It is used as a common purgative, and is especially applicable in fevers and inflammatory affections, when it is necessary to evacuate the bowels without increasing or exciting febrile disturbance. The usual dose is from half an ounce to an ounce; but if it is previously dried, so as to expel the water of crystallisation, it becomes doubly efficient as a purgative. It is now much less frequently used in domestic medicine than formerly, having given place to milder aperients.