270 SALTS 



Borax, 6. Borax. This well known salt has been long 



in the hands of chemists, and subjected to many 

 analytical experiments ; but our processes for 

 separating the boracic acid from the soda are so 

 imperfect, that it was not till after perusing Mr. 

 Arfwedson's new process for analyzing the bo- 

 rates, that I was able to perform a satisfactory 

 analysis. I have shown in a preceding part of 

 this work, that borax is, in reality, a biborate of 

 soda, composed of 



2 atoms boracic acid . 6 

 1 atom soda . . 4 



8 atoms water . . 9 



19 



Phosphate, 7. Phosphate of soda. This salt, which is the 

 best known of all the phosphates, is much more 

 soluble in hot than in cold water ; and, there- 

 fore, is easily obtained in regular crystals. The 

 primary form of the crystal is an oblique prism 

 with a rhombic base. The inclinations of the 

 faces of the prism to each other are, according to 

 Mitcherlich's measurement, 67 <50', and 112 10'. 

 It effloresces very speedily when exposed to the 

 air ; and, on that account, the water of crystal- 

 lization is not easily determined. The taste of 

 this salt is saline, and not strong. It melts rea- 

 dily when heated ; and even the anhydrous salt 

 easily fuses in a red heat. 



