184 



of iVl, and P according fo I he metfiod discussed above, which is 

 likewise expressed in the figures. In this it should be taken into 



Fig. 6. 



account that this maximum slightly differs with respect to the 

 tension at which unelastic collisions lake place, viz. the amount 

 equal to the small counter-potential (here 0,2 Volt). It maj also be 

 mentioned that the measured stream in these experiments was about 



Fig. 7. 



thirty times the flow of electrons issuing from D, so that in this 

 way an accurate measurement of the ionization potential is possible, 

 even with an ordinary millivoltmeter. 



