38 



A FEW CHEMICAL CHANGES 



360 cc. of hydrogen peroxide, of the 

 strength mentioned above, were placed in 

 the bottle just described, a'nd put in the 

 dark without being under the action of 

 radium. The volume of gas enclosed over 

 the liquid was 350 cc. The variations in 

 pressure as observed by the pressure gauge 

 were recorded for three hundred hours. 

 After correcting this pressure for the varia- 

 tions due to changes of temperature and 

 pressure, it was found that the pressure of 

 the enclosed gas had not varied, showing 

 that the peroxide had not suffered any 

 decomposition during the time it was under observation. 



Next an experiment was carried out, similar to that just 

 described, except that the surface of the peroxide was bom- 

 barded by radium radiations. The increase in pressure was 

 recorded from time to time, and the results obtained are 

 tabulated in the following table : 



TABLE I. 



20 scale divisions = 25 mm. 



