390 
Book II. 
Division II. 
SALTS. 
saturated with carbonic acid, is capable of dissolving 
alumina ; but this combination is destroyed by simple 
exposure to the air. Carbonat of alumina, then, can 
not exist in a dry state. What had been considered 
formerly as a dry carbonat is a triple compound of 
alumina, carbonic acid, and the alkali employed in pre 
cipitating the aluminaf. 
Sp. 11. Carbonat of Zirconia. 
THIS salt was formed by Vauquelin by precipitating 
zirconia from its solution in acids by alkaline carbo 
nats. It is a tasteless white powder, composed of 
44. 5 acid and water 
55.5 zirconia 
100.0 
When heated the carbonic acid is driven off. 
This salt is soluble in the three alkaline carbonats, 
and seems to form with them triple salts. 
GENUS XII. ARSENIATS. 
THE existence of this genus of salts was first disco 
vered by Macquer; but their nature and composition 
was first pointed out by Scheele in his Dissertation 
on Arsenic, published in 1775. Since the researches 
of these two illustrious chemists, scarcely any addition 
has been made to our knowledge of the arseniats, if we 
except a few observations on some of these salts by Pel 
letier. 
They may be distinguished by the following pro 
perty : 
* Jour. de Pbys. lii. 28.