68 ",V RAYS 



precautions, and the constancy of the results 

 is an absolute guarantee of their worth. 



From my communication of May n, 1903, 

 and from what precedes, it is clear that, from 

 the beginning of my researches on " N " rays, 

 I had succeeded in recording their action on the 

 spark by an objective method. 



On a New Species of "N" Rays (February 29, 



1904). 



Observations made during a very complex 

 experiment, which I owe to Dr. Th. Guidloz, 

 led me to suspect the existence of a variety of 

 " N " rays, which, instead of increasing, on the 

 contrary, diminished the glow of a feeble lumi- 

 nous source. I undertook to search for rays of 

 this type amongst those emitted by a Nernst 

 lamp. While previously studying the spec- 

 trum of this emission, produced by an aluminium 

 prism, I had not met with such radiations. I 

 consequently thought that there were reasons 

 for studying anew, and still more minutely, the 

 feebly deviated part of the spectrum, On 



