Mr Oiuen, On the Magnetic Deflexion, etc. 



508 



It will be seen from the curve that the current is practically 

 saturated by a potential under 40 volts. 



We have already seen that e/ra is given by 2V/a 2 H 2 . There- 

 fore for any given value of a H 2 /V= constant. Before investi- 



Diagram II. 



2 50 



100 



io ±o 6o 80 



Potential on Wire. 



IOO no 

 volts 



gating the discharge at high temperatures a series of observations 

 was made at a temperature of 795° C. to see if this law was at 

 all obeyed. The results obtained are given in Table III. 



The curves given in this diagram will enable us to see if the 

 law H 2 /V— constant is obeyed. We shall, as before, take as the 

 critical values of H those which stop 60°/ o of the discharge. 

 These values are got from the curves and are given in the follow- 

 ing table together with the corresponding values of e/m. 



Table IV. 



Mean value of — = 1*41 x 10 7 

 m 



