446 COMPOUND SALTS, CONTAINING 



without any of the sourness which distinguishes 

 that salt. When exposed to a moderate heat on 

 the sand bath, it gradually becomes solid, with- 

 out exhibiting any tendency to crystallization or 

 losing any of its transparency. Its colour be- 

 comes slightly yellow, and it bears some resem- 

 blance to nut oil prepared for printers' ink, and 

 the process continued till the oil becomes solid. 

 When the compound salt is weighed in this state, 

 it is found precisely equal to the weight of the 

 two salts employed to form it. Consequently, 

 each salt retains its water of crystallization. By 

 exposure to the air it slowly deliquesces. The 

 constituents are 



1 atom biborate of soda 10 



2 atoms bitartrate of potash 22-5 

 12 atoms water 13-5 



46 



Soda sni- 4. Soda-sulphate of lime. This is the name 

 Hme. which designates the substance known to 

 mineralogists by the name of Glauberite, and 

 found originally embedded in rock salt, about 

 ten leagues south of Madrid, at Vela Rubia, 

 and more lately, in the blue salt of Ischel in 

 Upper Austria. It is crystallized in oblique 

 rhombic prisms, and is composed of 



