Continuity 13 



whether it can in any sense depend on the 

 motion or the position of an observer: 

 all these things in some form or other are 

 discussed. 



The Conservation of Matter also, that 

 mainmast of nineteenth century chem- 

 istry, and the existence of the Ether of 

 Space, that sheet-anchor of nineteenth 

 century physics, do they not sometimes 

 seem to be going by the board? 



Professor Schuster, in his Indian lec- 

 tures, commented on the modern receptive 

 attitude as follows: 



The state of plasticity and flux a healthy 

 state, in my opinion, in which scientific thought 

 of the present day adapts itself to almost any 

 novelty, is illustrated by the complacency with 

 which the most cherished tenets of our fathers 

 are being abandoned. Though it was never an 

 article of orthodox faith that chemical elements 

 were immutable and would not some day be 

 resolved into simpler constituents, yet the con- 

 servation of mass seemed to lie at the very 

 foundation of creation. But nowadays the 

 student finds little to disturb him, perhaps too 

 little, in the idea that mass changes with 

 velocity; and he does not always realise the 



