Emanation and Active Deposit produced by it. 377 



positively charged active deposit particles, and assume D = «P, 

 where a is some function of the pressure p. 

 We have then 



or if 



'' ( j=y, 



then D s/ v e -^Xv* 



For the pressure corresponding to the maximum cathodic 

 deposit 



^=0 



dp ' 



and this gives 



1 Ay 1 1 1 . Ai n ,_v 



According to Kennedy's results, we have also the relation 



px—c, (4) 



and combining equations (3) and (4) we have 



Idy 1 1 £_ Ai_ ft 

 ydp + 2p~2piV A,~ U; 



log #p*= -~^+Ci where a=c\J -*■ . 

 From this ypi = e -a^+c^ 



= A 2 e~ a!p *> where A 2 =^% 



Now from the form of the function constituting the right- 

 hand member of this equation we see that y vanishes both 

 for very high and for very low values of p. It follows then 



