NEW ACTION PRODUCED BY " N" RAVS 31 



its electric resistance. The current flowing 

 through the wire is produced by five accumula- 

 tors ; with the aid of high-resistance rheostats, 

 the intensity is adjusted to make the platinum 

 wire a dull red. The wire is stretched between 

 two massive brass pliers, *A and B, which are 

 connected to the terminals of a capillary electro- 

 meter ; on one of the connecting wires an 

 adjustable electromotive force is inserted, 

 obtained by shunting a portion of the circuit 

 of an auxiliary battery. This electromotive force 

 is regulated so that the electrometer is at zero. 

 Every variation in resistance of the platinum 

 wire produces a deviation of the electrometer. 

 Now, with " N " rays playing on the wire, no 

 deviation of the meniscus was observed. The 

 interposition of a lead or wet-paper screen 

 remained without effect on the electrometer, 

 though the wire underwent the usual varia- 

 tions in brightness. This certainly proves that 

 " N " rays do not raise its temperature. I, 

 moreover, assured myself that the method was 

 sufficiently sensitive by the following experi- 

 ments ; by means of a wire rheostat, an assis- 

 tant varied the resistance of a circuit containing 



