BORAX. 107 



used even in uncivilized countries, as among the Pacific 

 Islands. It is better to have a large receiving basin foi 

 the salt water, which shall detain the mechanical impurities 

 of the water. 



Martinsitv is a compound of 91 per cent, of chlorid of sodium and 

 f sulphate of magnesia. It is from the salines of Stassfurth. 



borax. — Borate of Soda. 



Monoclinic. In right rhomboidal prisms, (see fig. 11, 

 page 26) ; M : T = 106 35'. Cleavage parallel with M per- 

 fect. The crystals are white and transparent with a glassy 

 luster. H=2 — 2*5. Gr= 1*716. Taste sweetish-alkaline. 



Composition : soda 16*25, boracic acid 36*58, water 

 47*17. Swells up to many times its bulk and becomes 

 opaque white before the blowpipe, and finally fuses to a 

 glassy globule. 



Obs. Borax was originally brought from a salt lake in 

 Thibet, where it is dug in considerable masses from the 

 edges and shallow parts of the lakes. The holes thus made 

 in a short time become filled again with borax. The crude 

 borax was formerly sent to Europe under the name oftincal, 

 and there purified for the arts. It has also been found in 

 Peru and Ceylon. It has of late been extensively made 

 from the boracic acid of the Tuscan lagoons by the reaction 

 of this acid on carbonate of soda. 



Uses. Borax is used as a flux not only by the mineralo- 

 gist in blowpipe experiments, but extensively in metallurgi- 

 cal operations, in the process of soldering, and in the manu 

 facture of gems. 



Boracic acid. Occurs in small scales, white or yellowish. Feel 

 smooth and unctuous. Taste acidulous and a little saline and bitter. 

 G=l - 48. Composition, boracic acid 5638, water 4362. Fuses easily 

 in the flame of a candle, tinging the flame at first green. 



Found at the crater of Vulcano, and also at Sasso in Italy, whence it 

 was called Sassolin. The hot vapors of the lagoons of Tuscany afford 

 it in large quantities. The vapors are made to pass through water, 

 which condenses them ; and the water is then evaporated by the steam 

 of the springs, and boracic acid obtained in large crystalline flakes. It 



What are some of the characters of borax ? What is its composition 1 

 What are its effects before the blowpipe 1 What is it used for 1 Where 

 was it originally obtained? How is it procured in Tuscany 1 What 

 is boracic acid 1 What is said of the boracic acid lagoons of Tuscany 1 



