Id UNIVERSITY OF MISSOURI BULLETIN 



have been catalogued at sight; others only after very pro- 

 longed work. The number that still remains is small com- 

 pared to the immense number that have been classified. 



Of greater interest to all physicists should be the ques- 

 tion : Are these fundamental concepts and principles, these 

 notions of matter, force, and energy, the most fundamental 

 that we can find? At no time in the history of physics has 

 so much attention been directed towards this question as at 

 present. Through these experiments on the relation of matter 

 to the ether and of electricity to matter, there now seem to 

 be opening up experimental methods that will throw much 

 light on this profound problem. Our future success in classi- 

 fying all facts seems to depend on our success in dealing with 

 this last question. 



