BORAX 



According to Wittstein, the commercial boracic acid is composed as follows : 



Sulphate of manganese . .a trace 



iron . . 0-365 



alumina . . . 0-320 



lime . . 1-018 



magnesia . . . 2-632 



ammonia . . . 8'508 



soda . . 0-917 



potash . . . 0-369 



Sal ammoniac . . . 0-298 



Silica (in solution) . . 1-200 



Sulphuric acid (with the boracic) . 1-322 



Crystallisable boracic acid . . . 76-494 



Water ........... . . 6-557 



100-000 



To obtain puro boracic acid, the crude commercial product should be converted into 

 borax by saturating its solution' with' carbonate" of soda, and a hot solution of this 

 borax be then decomposed by addition of oil 'of vitriol, when sulphate of soda is 

 formed, and boracic "acid 'set free. 'Pure' boracic acid crystallises in pearly, white, 

 greasy scales, sparingly soluble in cold water; but -dissolving 1 in three times their 

 weight of boiling water, and forming a solution possessing but feebly acid properties. 

 It is more soluble in alcohol, and the solution burns with a characteristic green flame. 

 This flame examined by the spectroscope presents a peculiar system of green bands. 

 At a moderate temperature boracic acid loses part of its water of crystallisation, and 

 forms a compound known as metaboric acid. By further heating, the remainder of 

 the water is expelled, and the anhydrous oxide (BO 3 ) left. This anhydride is readily 

 fusible to a transparent glass of specific gravity 1 '83. Many of the borates are also 

 eminently fusible, and hence their value as fluxes. At a higher temperature, boracic 

 anhydride volatilises. 



Boracic acid was formerly called Hombcrg's sedative salt, but is not now officinal. 

 It is sometimes used by the druggist to increase the solubility of cream of tartar. 



BORACXTE. See BORACIC ACID. 



EQUATE OF XiZIVXi:. See BoHAcic ACID. 



BORATE or SODA. See BORAX. 



BORATES. Salts of boracic acid. See ' Watts's Dictionary of Chemistry.' 



BORAX. (Borax, Fr. ; Borar, Ger.) Supposed to be the chryeocolla of Pliny, 

 In the seventh century, Geber mentions borax ; and it was described by Geoffrey and 

 by Baron in the early part of the eighteenth century. Borax is a compound of 

 boracic acid and soda (biborate of soda), found native in Thibet, in China, in Persia, 

 the island of Ceylon, California, and in South America ; it has also been found in. 

 small quantities in Saxony. The crude product from the former locality was imported 

 into Europe under the name of tincal. Tincal was originally brought from a salt 

 lake in Thibet ; tho borax was dug in masses from the edges and shallow parts of the 

 lake ; and in the course of a short time the holes thus made were again filled. The 

 imported tincal was purified from some adhering fatty matter by a process kept a 

 long time secret by the Venetians and the Dutch, and which consisted chiefly in 

 boiling the substance, in water with a little quicklime. 



Attention has been directed within the last few years to some extraordinary de- 

 posits of borax in Borax Lake, California. This lake is a small body of water, form- 

 ing a narrow arm on the eastern side of Clear Lake, from which it is separated by a 

 low ridge of loose volcanic materials. It is situated about 65 miles N. W. of Suisan 

 Bay, and about 36 miles from the Pacific coast. Borax Lake was first described in 

 1856, by Dr. Veatch, who detected tho presence of borax in the water, and some 

 months afterwards a large bed of crystals of borax was discovered at the bottom. 

 Some of these crystals are microscopic, but others are unusually large, some of tho 

 faces measuring from 2 to 3 inches across. They form a layer of variable thickness, 

 intermixed with blue mud at the bottom of tho lake, from which they are collected 

 during the dry season. A sample of water from the lake, collected in September 

 J863, and analysed by Mr. G. E. Moore, contained 240T56 grains of solid matter per 

 gallon, of which about one-half was chloride of sodium, one-fourth carbonate of soda, 

 and the rest chiefly borax. Indeed, the water contained per gallon 281*48 grains of 

 anhydrous biborate of soda, equivalent to 535'08 grains of crystallised borax. 

 Samples collected from a coffer-dam sunk in the middle of the lake were even richer. 

 The borate of soda has also been found at Potcei, in Peru ; and it has been discovered 



