OF ZI\( . 



hitherto been mistaken for a triple salt, but it 

 contains no potash. Its constituents are 



1 atom tartaric acid . . 8*25 



1 atom protoxide of manganese 4-5 

 2 atoms water . . . 2-2.5 



1.1 



All the salts of manganese included in the pre- 

 ceding list contain water of crystallization. The 

 smallest quantity of water is 2 atoms and the 

 greatest 10 atoms. The carbonate, phosphate, 

 and tartrate contain 2 atoms the oxalate con- 

 tains 3 the acetate 4 the sulphate 5 the ni- 

 trate 7 and the arseniate 10 atoms. 



14. SALTS OF ZIXC. 



1. Sulphate of zinc. This salt crystallizes in 

 right rhombic prisms, frequently the prisms are 

 terminated by four-sided pyramids. The figure 

 of the crystals is modified a good deal by the 

 excess of acid allowed to remain in the liquid 

 from which the crystals are to be separated. I 

 have never been able to obtain this salt, though 

 ever so frequently crystallized, in a state in 

 which it did not redden vegetable blues. 



The analyses of two varieties have been de- 

 tailed in the first section of the first chapter of 

 this work ; I shall merely give the results in this 

 place. 



VOL. II. / 



