89 
TUNCSTIC. 
Reg. 
The affinities of this oxide, as far as they have been 
ascertained, are as follows * : 
Alhnites. 
Lime, 
Barytes, 
Strontian, 
Magnesia, 
Potass, 
Soda, 
Ammonia, 
Glucina, 
Alumina, 
Zirconia. 
SECT. XIV. 
OF MOLYBDIC ACID. 
MOLYEDIC ACID, which is a compound of molybde- Dixcoverz. 
num and oxygen, was discovered by Scheele in 1778. 
It is commonly procured from molybdena, or sulphuret 
of molybdenum, by distilling off from it nitric acid re 
peatedly, till both the sulphur and metal are acidified ; 
which is known by the conversion of the whole into a 
white mass. Hot water carries off the sulphuric acid, 
and leaves the molybdic in a state of purity. 
Molybdic acid, thus prepared, is a white powder, of Properties. 
a sharp metallic taste, and a specific gravity of 3.4. 
When heated in a close vessal, it melts and crystallizes ; 
* Luyarts.