22 URANIUM, ANTIMONY, CHROMIUM, &c. 



character of pure sulphate of potash. Thus it 

 appears, that 51 grains of the crystallized com- 

 pound salt contain exactly 11 grains of sulphate 

 of potash. 



(4.) I did not attempt to determine the weight 

 of the peroxide of uranium. As it was precipi- 

 tated it contained a quantity of ammonia united 

 to it. By exposure to a heat, very nearly but 

 not quite so high as a red heat, I drove off most 

 of the ammonia, if not the whole of it ; by which 

 the peroxide was deprived of its yellow colour, 

 and assumed a fine red with a shade of brown ; 

 and 31 '8 grains, by this treatment, were reduced 

 to 28 grains. Hence, I consider the yellow pre- 

 cipitate as a compound of 



1 atom peroxide of uranium 

 1 atom ammonia 

 1 atom water 



31-8125 



The matter driven off consisted partly of am- 

 monia and partly of water ; but it would have 

 been difficult to have determined the proportions 

 of each. 



(5.) From the above analysis, which was made 

 with the most scrupulous care, it follows, that 

 51 grains of the crystallized compound salt 

 of uranium contained the following constitu- 

 ents: 



