70 URANIUM, ANTIMONY, CHROMIUM, &c. 



I atom tungstic acid . 18-75 

 1 atom soda , . 4 



6 atoms water . . 6*75 



29-50 



The salt, while on the sand bath, lost 5-86 grains 

 of weight, so that the quantity which remained 

 was less than an atom. 



5. From Berzelius' experiments, related at the 

 beginning of this section, there is reason to con- 

 clude, that tungstic acid contains 3 atoms of 

 ox yg en > anc ^ brown oxide of tungsten 2 atoms ; 

 consequently, the atomic weight of tungsten 

 must be 15*75, and that of brown oxide 17'75. 



6. From my experiments on the tungstate of 

 ammonia, compared with the analysis of it by 

 Berzelius, I have little doubt that its constituents 

 are 



2 atoms tungstic acid 



1 atom ammonia 



2 atoms water 



41-875 



The quantity of the most soluble tungstate of 

 ammonia in my possession was too small to admit 

 of an accurate analysis, but it certainly contained 

 a smaller proportion of acid than the least solu- 

 ble tungstate. Probably, therefore, it is a 

 compound of 1 atom acid and 1 atom ammo- 



