10 URANIUM, ANTIMONY, CHROMIUM, & C . 



protoxide, with the following proportion of oxy- 

 gen : 



By first experiment, with 3-66812 



By second experiment, with 3-67231 



Mean . . . 3-670215 



He made two other experiments, the reverse of 

 the preceding. A quantity of metallic uranium 

 was exposed to a red heat in an open vessel : by 

 this means it was converted into protoxide, and 

 the increase of weight was determined. These 

 experiments were as follows : 



(1.) 0-636 uranium absorbed, 0-0235 oxygen. 

 (2.) 1-006 0-0375 



According to these experiments, 100 uranium, 

 when converted into protoxide, combines with 



By first experiment . 3-69497 oxygen 



By second experiment . 3-72763 



Mean . . . 3-71130 

 Mean of first set 3 -6702 1 5 



Mean of the whole . 3-690757 



This last mean, being the result of four careful 

 experiments made in different ways, maybe con- 

 sidered to come as near the truth as can be ex- 

 pected by that mode of experimenting. Let us 

 see the atomic weight of uranium which results 



