1 92 Elements of Mineralogy, 



SPECIES IX. 

 Vitriol of Copper. 



Its colour is blue, which degenerates into 

 a mixture of blue and rufiy yellow after it 

 has been long expofed to the air ; it requires 

 about four times its weight of water to dif- 

 folve it in the temperature of 60. Its fpecific 

 gravity is about 2,23 ; if a piece of clean po- 

 lifhed iron be dipped into the folution of this 

 fait, it will almoft immediately be covered with 

 a cupreous coat, this together with the deep blue 

 colour ariiing from mixing it with a volatile 

 alkali, diicovers its bafis, as its uniform mix- 

 ture with other vitriolic falts does its acid, 



i oo Parts of vitriol of copper contain 30 of 

 real acid, 27 of copper, and 43 of water. 

 80 Parts of good iron precipitate 100 of cop- 

 per, from a folution, that does not contain a 

 notable excefs of acid. 



This fait rarely occurs cryftalized, but is 

 often found naturally diflblved in water, in 

 Hungary, Sweden and Ireland: from this 

 water blue vitriol is generally prepared. Mr. 

 Cronjled fays it is feldom free from iron and 

 zinc ; it is alfo occalionally extracted from 

 fulphurated copper ores after torrefadion. 



Scblutt. 



