202 Prof. Town send on the Conductivity produced in 



of conductivity arising from the large secondary effect due 

 to the brass. ]n Section 9, an account is given of the 

 effect produced by reversing the electromotive force between 

 the plates. 



Fig. 2. — Pressure 41 3 mm. 



240 320 400 480 



Volts per centimetre. 



640 



720 



Three seis of observations were made at each pressure 

 for distances of '5, 1, and 2 centimetres between the plates. 

 The curves corresponding to these distances are marked *5, 1, 



