JOHANN

RUDOLF

See also:

• JOHANN RUDOLF GLAUBER (1604-1668)

GLAUBER (1604-1668)  , German chemist, was born at Karlstadt, Bavaria, in 1604 and died at Amsterdam in 1668 . Little more is known of his life than that he resided successively in Vienna, Salzburg, Frankfurt and Cologne before settling in Holland, where he made his living chiefly by the sale of secret chemical and medicinal preparations . Though his writings abound in universal solvents and other devices of the alchemists, he made some real contributions to chemical know-ledge . Thus he clearly described the preparation of hydrochloricacid by the action of oil of vitriol on common salt, the manifold virtues of sodium sulphate—sal mirabile, Glauber's salt—formed in the process being one of the chief themes of his Miraculum mundi; and he noticed that nitric acid was formed when nitre was substituted for the common salt . Further he prepared a large number of substances, including the chlorides and other salts of lead, tin, iron, zinc, copper, antimony and arsenic, and he even noted some of the phenomena of double decomposition . He was always anxious to turn his knowledge to practical account, whether in preparing medicines, or in furthering industrial arts such as dyeing, or in increasing the fertility of the soil by artificial manures . One of his most notable works was his Teutschlands Wohlfarth in which he urged that the natural resources of Germany should be developed for the profit of the country and gave various instances of how this might be done . His treatises, about 30 in number, were collected and published at Frankfort in 1658-1659, at Amsterdam in 1661, and, in an English translation by Packe, at London in 1689 . GLAUBER'S SALT, decahydrated sodium sulphate, Na2SO4,10H2O . It is said by J . Kunkel to have been known as an arcanum or secret medicine to the electoral house of Saxony in the middle of the 16th century, but it was first described by J . R .

Glauber (De natura salium, 1658), who prepared it by the action of oil of vitriol or sulphuric acid on common salt, and, ascribing to it many medicinal virtues, termed it sal mirabile Glauberi . As the

mineral thenardite or mirabilite, which crystallizes in the rhombic system, it occurs in many parts of the world, as in Spain, the western states of North America and the Russian Caucasus; in the last-named region, about 25 M . E. of Tiflis, there is a thick bed of the pure salt about 5 ft. below the surface, and at Balalpashinsk there are lakes or ponds the waters of which are an almost pure solution . The substance is the active principle of many mineral waters, e.g . Fredericks-hall; it occurs in sea-water and it is a constant constituent of the blood . In combination with calcium sulphate, it constitutes the mineral glauberite or brongniartite, Na2SO4•CaSO4, which assumes forms belonging to the monoclinic system and occurs in Spain and Austria . It has a bitter, saline, but not acrid taste . At ordinary temperatures it crystallizes from aqueous solutions in large colourless monoclinic prisms, which effloresce in dry air, and at 35° C. melt in their water of crystallization . At roe they lose all their water, and on further heating fuse at 843° . Its maximum solubility in water is at 340; above that temperature it ceases to exist in the solution as a decahydrate, but changes to the anhydrous salt, the solubility of which decreases with rise of temperature . Glauber's salt readily forms supersaturated solutions, in which crystallization takes place suddenly when a crystal of the salt is thrown in; the same effect is obtained by exposure to the air or by touching the solution with a glass rod . In medicine it is employed as an aperient, and is one of the safest and most innocuous known .

For

children it may be mixed with common salt and the two be used with the food without the child being conscious of any difference . Its simulation of the taste of common salt also renders it suitable for administration to insane patients and others who refuse to take any drug . If, however, its presence is recognized sodium phosphate may be substituted .