Manchester Me)Hozrs, Vol. liii. (1909), No. 7. 



7 



deposited directly on quartz and platinum and docs not 

 point to any direct action of the acid. 



Effect of an Electric Field on Radium C. 



It is well known that when radium A is produced from 

 the emanation under normal conditions it is charged with 

 positive electricity. It thus happens that, when a nega- 

 tively charged conductor is exposed to the emanation, 

 nearly all the radium A produced is driven to the con- 

 ductor, where it is deposited. It seemed of interest to 

 find out whether radium C is similarly charged after its 

 production from radium B. 



Now we have seen that the volatilisation point of radium 

 A is at 900° C, and the volatilisation point of radium B 

 is lower. Since the volatilisation point of radium C is 

 about 1,200° C, it would be impossible for either radium 

 A or radium B to be deposited on a rod whose tempera- 

 ture was above 900° C, whereas radium C might, under 

 suitable conditions, be deposited on the rod. In order to 

 test whether radium C is charged at the moment of its 



