UllANIUM. 17 



This would give us peroxide of uranium com- 

 posed of 



Uranium 54-8734 or 100 

 Oxygen 3-4316 - 6-254 



58-3050 



But this canon of Berzelius is correct only 

 when the basis is a protoxide, and when the 

 salt is neutral, or a compound of 1 atom sulphu- 

 ric acid and 1 atom base ; for sulphuric acid is 

 capable of combining with bases in various pro- 

 portions. Sometimes 1 atom of the base unites 

 with 2 atoms of sulphuric acid. Bisulphate of 

 potash is a salt of this kind. In it the potash, 

 combined with a 100 parts of the acid, contains 

 only 10 parts of oxygen instead of 20. Some- 

 times li atom of sulphuric acid combines with 

 1 atom of base ; such combinations I distinguish 

 by the name of ses quisulphr.tes. The sesquisul- 

 phate of potash (did it exist) would be a com- 

 pound of such a nature, that the oxygen in the 

 potash, combined with 100 sulphuric acid, would 

 contain only 15 parts of oxygen. 



As peroxide of uranium contains certainly 

 more than 1 atom of oxygen, the canon of Ber- 

 zelius cannot apply to it. As the triple salt, ana- 

 lyzed by Arfwedson, reddens vegetable blues 

 even after having been fused, there is a pre- 

 sumption that it contains more than 1 atom of 

 sulphuric acid united with 1 atom of peroxide of 



VOL. II. B 



