PLATS XLIX. 



Fig. 



Fig- 



Fig. 313. 



Fig. 



Fie'. 315. 





FIST. 



Double salt of sulphate of zinc and sulphate of ma4r,es:.i crystallized at different temperatures, from 75 to 170. The 

 varied effects depend upon the loss of varying proportions of water of crystallization, p. 2t5 

 After Ivlr. Thomas. Mic. Journ., April, 1866. 



[To fr - LVIII. 



