BORAX

Tills salt is found native in some of the lakes of Thibet and Persia, and is imported from India under the name of lineal, which after purification forms the refined borax of commerce. Of late years borax has been obtained by combining native boracic acid with soda. Borax forms hexaedral prisms, slightly efflorescent, and requiring 20 of cold and 6 of boiling water for solution. When heated, water of crystallization is driven off, and the residuary salt fuses into what is called gla of borax. Crystallized borax consists of 68 boracic acid + 32 soda + 90 water. It has upon some tests an alkaline reaction, and has hence been called sub-borate of soda. Borax is chiefly used by workers in metals as a flux: it is also employed in medicine. [s. 168]