66 " N " RA YS 



incurring any risk of the points touching by 

 any chance vibration, which would make it 

 disappear intermittently. By a methodical pro- 

 cess of trial and error, which sometimes de- 

 mands much time and patience, one succeeds 

 in getting a spark both regular and very feeble ; 

 it is then sensitive to the action of " N " rays. 

 If one directs on it a pencil of these radiations, 

 proceeding from any source, one sees the patch 

 on the ground glass increase in size and glow ; 

 at the same time its central part becomes more 

 luminous, appearing wrapped in a kind of nimbus. 

 One can then proceed with the photographic 

 experiment. I made about forty such ex- 

 periments, employing in turn, as sources of 

 " N " rays, a Nernst lamp, compressed wood, 

 hardened steel, Rupert's drops, etc. I have 

 varied the experiments in different ways 

 for example, by changing the side of the screen 

 CD, by using a zinc screen transparent to " 'N " 

 rays, etc. Several eminent physicists, who 

 have been good enough to visit my laboratory, 

 have witnessed them. Of these forty experi- 

 ments, one was unsuccessful : the rays were 

 produced by a Nernst lamp, and instead of 



