On the Reflection of Cathode Rays. 

 FIG. 2. 



379 



it was found that the gold leaves invariably diverged with a negative 

 charge. The divergence of the leaves was increased by connecting A 

 to earth, and when a horse-shoe magnet was held so as to deflect the 

 paracathodic rays, and prevent them from entering the Faraday cylinder, 

 the closing together of the leaves showed that the cylinder no longer 

 received any charge at all. 



These experiments appear to show conclusively both that para- 

 cathodic rays are deflected magnetically in the same way as cathode 

 rays, and also that they behave similarly to the latter in conveying a 

 negative charge. In addition they cause green fluorescence of the glass 

 upon which they fall, and as the writer has already shown,* they also 

 generate Eontgen rays where they impinge upon a solid body. 



Paracathodic rays appear therefore to be simply reflected cathode 

 rays. 



The Mechanical Force Exerted by Reflected Cathode Rays. 



These reflected cathode rays appear however to be relatively of very 

 feeble intensity. The amount of Rontgen rays that they generate 

 where they strike the glass is very small ; while, so far as the writer 

 has been able to ascertain, they exert no appreciable mechanical force 

 on the most delicately arranged radiometer mill wheels. 



At one time it seemed possible that reflected cathode rays might be 

 the cause of the inverse rotation of mill wheels placed just outside of 



* ' Koy. Soc. Proc./ vol. 63, 1898, pp. 436437. 



