320 



Profs. J. A. Fleming and J. Dewar. 



The copper ball proved to be ferromagnetic, owing, no doubt, to 

 traces of iron. We constructed a curve by which its susceptibility 

 in various fields could be deduced from the above observations, but 

 the only reason we employed it was because it seemed desirable to 

 determine the absolute susceptibility of the liquid oxygen with bodies 

 as far as possible different in susceptibility. Hence we selected 

 silver, bismuth, and the above slightly ferromagnetic copper ball for 

 the purpose. 



The Magnetic Susceptibility of various Glass Sails partly filled with 



Mercury. 



We have, then, the following data for the glass balls : 



As a further check on the method we employed the above deter- 

 minations of the susceptibilities of the silver and glass ball, No. 3, 

 to obtain the value of the susceptibility of distilled water. The 

 measurements were as follows : 





