178 



Industrial Applications of Electrons 



[June 8, 



small, we see that unless n is exceedingly small, the grid potential 

 ought to be a very small fraction of the anode potential. Another 

 method of obtaining great sensitiveness is to work with gas at a 



much higher pressure, when the current is due chiefly to conization. 

 In this case I find that in the most sensitive state — 



8c 



_L 



1-8 



8e 



Q 



where c is the current, 8 c the change in c due to the change 8 e in 

 the grid potential, and Q the conising potential of the gas. The 

 use of these higher pressures is subject to the disadvantage that 

 owing to the action of the luminous gas in the tube, the life of the 

 filament is short. 



[J. J. T.] 



