438 COMPOUND SALTS 



formed by M. Mitcherlich, by saturating the bi- 

 phosphate of potash with carbonate of soda, and 

 crystallizing the solution. The primary form of 

 the crystal is an oblique prism with a rhombic 

 base. The inclination of the faces of the prism 

 is, according to Mitcherlich's measurement, 78 

 40'. The constituents of the salt from Mitcher- 

 lich's experiments, seem to be the following : 



1 atom phosphate of potash 9'5 



1 atom phosphate of soda 7-5 



15 atoms water 16-875 



33-875 



The quantity of water found by Mitcherlich, 

 somewhat exceeded 15 atoms : for it was ] 7-272, 

 which exceeds 15 atoms by about one-third of 

 an atom. 



13. Potash-arseniate of soda. This salt was 



scniate of 



soda- formed by Mitcherlich in the same way as the 

 preceding ; the form of its crystals is the same 

 also. Its constituents, according to Mitcher- 

 lich's analysis, are as follows : 



1 atom arseniate of potash 13-75 



' 1 atom arseniate of soda 11-75 



18 atoms water 20-25 



I <) 



Potash ox- 14. Potash-oxalate of copper. This salt was 



alate of 

 copper. 



* Ann. do Chim. et dc Phys. XIX. 396. 



