URANIUM. 15 



the oxygen driven off when the peroxide of 

 uranium was converted into protoxide. Now, 

 1-186 : 0-0294 : : 100 : 2-4-789. It appears from 

 this experiment that 100 protoxide + 2-4789 = 

 102-4789 peroxide. 



The mean of these two experiments gives us 

 peroxide of uranium composed of 



Protoxide of uranium 100 



Oxygen . . . 2-4437 



Now, if the protoxide of uranium be a compound 

 of 26 uranium + 1 oxygen, it is obvious that 100 

 parts of it must contain 96-2963 uranium and 

 3-7037 oxygen ; and peroxide of uranium must 

 be a compound of 



Uranium 96-2963 or 100 



Oxygen 6-1474 - 6-3839 



102-4437 



The proportion of oxygen in the peroxide of 

 uranium, found by the analysis of this salt, ex- 

 ceeds considerably that obtained from the ana- 

 lysis of uraniate of lead. Though it does not 

 amount to two atoms, it exceeds li atom, being 

 very nearly If atom. 



(3.) M. Arfwedson analyzed the potash sul- 

 phate of uranium in the following manner : 2-172 

 parts of the anhydrous salt were dissolved in 

 water, and precipitated by muriate of barytes. 

 The sulphate of barytes obtained weighed 1-814 



