So called from its discoverer or inventor. Glauber's salt, sal mirabilis, admirabilis, sal catharticum Glauberi, natron vitriolatum. The Dau-phiny salt is a natural production of this kind, obtained from an earth in the province of Dauphiny in France; but that in general use, and which receives the name of Glauber, its author, is artificial; consisting of a vitriolic acid with the mineral alkali. See Chemistry.

The salt which remains after the distillation of the muriatic acid is directed to be exposed to a strong fire, in an open vessel, to separate the remaining acid, to be boiled in distilled water, strained, and crystallized. Ph. Lond. 1788. In cold weather it will shoot in forty-eight hours, and in warmer weather in about twice the time.

The fineness and largeness of the crystals greatly depend on the quantity of acid. The Edinburgh college directs one part of the oil of vitriol to two parts of sea salt for obtaining the spirit of salt, and the residuum is as nearly of a due degree of acidity as can be ascertained by a general rule.

Mr. Fergus, of Piccadilly, London, says, that from two pounds and half of kelp, and nearly two ounces of the oil of vitriol, he obtained half a pound or more of Glauber's salt. He takes calcined kelp lb i. powders, and dissolves it in a glazed earthen pan with boiling water lb ij. filters the clear liquor into a similar vessel, adding gradually, when hot, as much oil of vitriol, diluted with somewhat more than an equal part of water as is necessary to saturate it. It is then filtered, evaporated to a pellicle, and crystallized.

The sal catharticum amarum is nearly of the same quality with the natron vitriolatum, and often substituted for it. But its basis, instead of the alkali, is magnesia, which is detected by adding an alkali in solution to the sal catharticum, from whence the magnesia is separated. The salts do not, however, differ in their medical properties.

The true natron vitriolatum is apt to lose so much of its water of crystallization as to become opake, and fall into a white powder. It is applied externally in a cataplasm, by dissolving an ounce of the vitriolated natron in half a pint of water, and reducing it to a proper consistence by crumb of bread. It is applied in those inflammations of the eye where the secretions are deficient; the form is attributed to Dr. Kirkland.

In small doses, plentifully diluted with water, it is laxative and diuretic; in larger ones, cathartic. For the latter purpose it is given from Glauberi Sal 3908 ss. to ij. and, if diluted in water, from one pint to two should be employed, and in that case the dose of the salt may be diminished. It then answers every purpose of the Epsom and similar waters; cools and checks the circulation so much, that Dr. Alston thinks it specific in active haemorrhages. Gangrenes are sometimes washed with a solution of it in vinegar. It has been supposed, when too freely taken, to attenuate the blood, and produce dropsies. It may perhaps debilitate, by injuring the digestive organs; but can produce little permanent mischief. See Lewis's Materia Medica, Glauber, Boyle, Becher, and Stahl.