28 



WRITINGS OF JAMES SMITHSON. 



The test of this hypothesis, is in the quantities of the re- 

 mote elements which analysis would obtain from a calamine 

 thus composed. 



The following tahle will show how very insignificantly the 

 calamine compounded by the theory, would differ in this 

 respect from the calamine of nature. 



1000 parts of the compound salt of carbonate and hydrate 

 of zinc consist of 



Carbonate of zinc 400 =- 



Hydrate of zinc = 600 - 



Carbonic , nA 



J 4UU 



acid = = 



Calx of 

 zinc 



400X2 



C f =J50X8 



Ice - - = 



= - - 716f 



Great as is the agreement between the quantities of the 

 last column and those obtained by the analysis of the 

 Bleyberg calamine, it would be yet more perfect, probably, 

 had there been, in this instance, no sources of fallacy but 

 those attached to chemical operations, such as errors of 

 weighing, waste, &c., but the differences which exist are 

 owing, in some measure at least, to -the admixture of car- 

 bonate of lime and carbonate of lead, in the calamine 

 analysed, and also to some portion of water, which is un- 

 doubtedly contained, in the state of moisture, in so porous 

 and bibulous a body. 



It has also appeared, in the experiments on the Mendip 

 Hill calamine, that acids indicate a greater quantity of car- 

 bonic acid than fire does, by yf^. If we make this deduc- 

 tion for dissolved water, it reduces the quantity of carbonic 

 acid in the Bleyberg calamine, to 0.1321. 



If we assume this quantity of carbonic acid as the datum 

 to calculate, on this system, the composition of the calamine 

 from Bleyberg, we shall obtain the following results : 



