PROPERTY OF EMITTING " N" RAYS 53 



state of molecular strain is transitory, as is also 

 the emission of " N " rays. 



Torsion produces effects analogous to 

 compression. 



On the Dispersion of "A 7 "" Rays and on their 

 Wave-length (January 18, 1904). 



To study the dispersion and the wave- 

 lengths of " N " rays, I used methods quite 

 similar to those employed for light. In order to 

 avoid complications which might have resulted 

 from the storing-up of " N " rays, I used ex- 

 clusively prisms and lenses of aluminium, a 

 substance which does not absorb their rays. 



The following is the method employed to 

 study dispersion. The rays are produced by a 

 Nernst lamp, enclosed in a lantern of sheet-iron, 

 pierced with an opening, which is shut by 

 aluminium foil ; the rays from the lamp which 

 pass through this opening are sifted by a deal 

 board 2 cms. thick, a second sheet of aluminium, 

 and two leaves of black paper, so as to eliminate 



