WRITINGS OF JAMES SMITHSON. 25 



The saline solution afforded on crystallization, only vitriol 

 of zinc. 



These crystals therefore consist of 



Quartz - - - - 0.250 



Calx of zinc - - - 0.683 



Water - - - - 0.044 



0.977 

 Loss - - - . 0.023 



1.000. 



The water is most probably not an essential element of 

 this calamine, or in it in the state of, what is improperly 

 called, water of crystallization, but rather exists in the crys- 

 tals in fluid drops interposed between their plates, as it often 

 is in crystals of nitre, of quartz, &c. Its small quantity, 

 and the crystals not falling to powder on its expulsion, but 

 retaining almost perfectly their original solidity, and spath- 

 fiSQ appearance in the places of fracture, and, above all, 

 preserving their electrical quality wholly unimpaired, which 

 would hardly be the case after the loss of a real element of 

 their constitution, seem to warrant this opinion. 



If the water is only accidental in this calamine, its com- 

 position, from the above experiments, will be 



Quartz - - - - 0.261 



Calx of zinc . - . 0.739 



1.000. 



I have found this species of calamine amongst the pro- 

 ductions of Derbyshire, in small brown crystals, deposited, 

 together with the foregoing small crystals of carbonate of 

 zinc, on crystals of carbonate of lime. Their form seems, 

 as far as their minuteness and compression together would 

 allow of judging, nearly or quite the same as that of those 

 from Regbania ; and the least atom of them immediately 

 evinces its nature, on being heated, by the strong electricity 

 it acquires. On their solution in acids, they leave quartz. 



