234 SCIENCE AND METHOD. 



This I have already explained in Book III., Chap. I., 

 Sec. 4. The details of the laws of the emission of 

 light by dark bodies are perfectly explained by this 

 hypothesis. (5.) Lastly, when the cathode rays strike 

 the anticathode, the negative electrons constituting 

 these rays, which are animated with very great velo- 

 cities, are suddenly stopped. In consequence of the 

 acceleration they thus undergo, they produce undula- 

 tions in the ether. This, according to certain 

 physicists, is the origin of the Rontgen rays, which are 

 nothing else than light rays of very short wave length. 



