NEW SPECIES OF LIGHT n 



conditions, by the use of Newton's arrange- 

 ment for obtaining a pure spectrum. 



From all that precedes, the fact results that 

 the rays which I have thus studied are not 

 Rontgen rays, since these undergo neither 

 refraction nor reflection. In fact, the little 

 spark reveals a new species of radiations 

 emitted by the focus tube, which traverse 

 aluminium, black paper, wood, etc. These are 

 plane-polarized from the moment of their 

 emission, are susceptible of rotatory and 

 elliptic polarization, are refracted, reflected, 

 diffused, but produce neither fluorescence nor 

 photographic action. 



I had expected to find that amongst these 

 rays some existed whose refractive index for 

 quartz is about 2 ; but probably quite a 

 spectrum of such rays exists, for in the refraction 

 experiments with a prism, the deviated pencil 

 appears to cover a broad angle. The study of 

 this dispersion remains to be pursued, as well 

 as that of the wave-lengths of the rays. 



By progressively diminishing the intensity 

 of the current actuating the induction-coil, one 

 still gets these new rays, even when the tube 



