38 "N n RAYS 



recently observed that the Auer burner can be 

 advantageously replaced by the Nernst lamp, 

 without a glass, this lamp giving more intense 

 " N " rays. With a 2OO-watt lamp, the pheno- 

 mena are marked enough to be, in my belief, 

 easily visible to any one at the first trial. 



On the Storing-up of "N" rays by Certain 

 Bodies (November 9, 1903). 



In the course of my researches on " N w 

 rays, I had occasion to note a very remarkable 

 fact. The " N " rays were produced by an 

 Auer burner enclosed in a lantern, and after 

 passing through one of the sides of the lantern, 

 formed by a sheet of aluminium, were concen- 

 trated by a quartz lens upon phosphorescent 

 calcium sulphide. 1 The Auer burner having 



1 This sulphide was tightly packed into a slit cut into a 



sheet of cardboard o'8 mm. thick ; the width of the slit was 0*5 



nd its length 15 mm. After exposure to sunlight, a small, 



luminous source is thus obtained, which is very sensitive to 



" N " rays. 



