[mclennan-keys] 



ELECTRICAL CONDUCTIVITY 



55 



One set of readings from a number taken with this appar- 

 atus is given in Talkie VI, and curves drawn from them are shewn 

 in Figs. 8 and 9. In both diagrams the values of y are taken as 

 ordinates but the values of v are taken as abscissse in Fig. 8 and the 

 values of v^ in Figs. 9. 



TABLE VII. 



Mobility of positive ion^k. Mobility of negative ion ka 



Pressure^llG • 1 atmospheres. 



Positive ion. 

 k, = P k,= 

 0-005294 , 0-06152 



Negative ion. 



K2 Xli.2 



0-000G217 , 0-07224 



Ratio k2/ki=l-18 



Kovarik's Results for pressures up to 75 atmospheres 

 Pk,=l-346. Pk2=l-89. 



From the numbers given in Table VI and from the curves in 

 Figs. 8 and 9, it will be seen that for potentials up to about 800 

 volts, the relation between y and V^ is practically a linear one, and 



HOC ^ i-^ 



100 200 300 '^OO 500 



€00 



800 



900 \/ol*» 



Figure 8 



that the mol^ility of the negative ion is about 18% greater than that 

 of the positive. This would go to show that one is warranted 

 in applying the Rutherford-Child relation to the present experiments. 

 But the absolute values of the mobilities which have been deduced 



