50 
Dr. Thomson’s Analysis ^ ^c. 
riment I dissolved almost all the copper without touching the 
iron. Yet it deserves attention, that 77,4 and 19.5, the weight 
of carbonate of copper and oxide of iron found by the pre- 
ceding analysis, correspond with three integrant particles of 
carbonate of copper, and one integrant particle of peroxide 
of iron. 
We were previously acquainted with two other native spe- 
cies of this salt, namely, malachite and blue carbonate or copper 
azure. But both of these are hydrous carbonates containing 
water as a constituent, and if any confidence be put in the 
analyses of Klaproth, whose precision is sufficiently known, 
malachite contains twice as much water as the blue carbonate. 
Blue carbonate is a compound of one integrant particle of 
water, and one integrant particle of carbonate of copper, while 
malachite contains two particles of water. Our ore is an anhy- 
drous carbonate of copper. When heated to redness, it loses its 
carbonic acid, but undergoes no further change. Some speci- 
mens lost about half a grain more than their carbonic acid. 
This I ascribed to the water in the malachite, with which the 
ore was occasionally mixed. 
