so 



Jt is found in 

 Perby/hire. 



CHEMICAL ANALYSIS OF SOME CALAMtNES, 



The water is raoft probably not an eflTential element of this 

 calamine, or in it in the ftate of, what is improperly called, 

 water of cryftallization, but rather exifts in the cryftals in fluid 

 drops interpofed between their plates, as it often is in cryftals 

 of nitre, of quartz, &c. Its fmall quantity, and the cryftals not 

 falling to powder on its expulfion, but retaining almoft per- 

 fe6lly their original folidity, and fpathofe appearance in the 

 places of frafture, and, above all, preferving their eledrical 

 quality wholly unimpaired, which would hardly be the cafe 

 after the lofs of a real element of their conftitution, feem to 

 warrant this opinion. 



If the water is oivly accidental in this calamine, its compofi- 

 tion, from the above experiments, will be. 



Quartz ----- 0.261 

 Calx of zinc - - . 0.739 



1.000 



I have found this fpecies of calamine amongft the produc- 

 tions of Derbyfhire, in fmall brown cryftals, depofited, to- 

 gether with the foregoing fmall cryftals of carbonate of zinc, 

 on cryftals of carbonate of lime. Their form feems, a'^ far as 

 their minutenefs and compreflion together would allow of 

 judging, nearly or quite the fame as that of thofe from Reg- 

 bania ; and the leaft atom of them immediately evinces its 

 nature, on being heated, by the ftrong eledricity it acquires. 

 On their folution in acids, they leave quartz. 



OBSERVATIONS. 



Chemlftry is yet fo new a fcience, what we know of it bears 

 fo fmall a proportion to what we are ignorant of, our know- 

 ledge in every department of it is fo incomplete, fo broken, 

 confifting fo entirely of ifolated points thinly fcattered like 

 lucid fpecks on a vaft field of darknefs, that no refearches can 

 be undertaken without producing fome facls, leading to fome 

 confcquences, which extend beyond the boundaries of their im- 

 mediate objedl. 

 Component ] . The foregoing experiments throw light on the proportions 



SfVinc. ^^ ^^"^ '" which its elements exift in vitriol of zinc. 23.0 grs. of the 

 Mendip Hill calamine, produced 29.8 grs. of arid vitriol of 

 zinc. Thefe 23.0 grs. of calamine contained 14-.9 grs. of 



ealji 



