386 



Prof. C. Shear d on the 



from a maximum value of 800 x 10~ 10 ampere to 8xl0 -ll> 

 ampere in seven minutes ; the positive current increased 

 with time from a value of 1*7 x 10 -10 ampere to 12*2 X TO -10 

 ampere after 45-60 minutes' heating. These experiments, in 

 toto, show conclusively that there is an emission of ions from 

 the salt, and that there are negative as well as positive ions. 



Ihe Ionization Effects from the Distillates. 



Various distillates collected on the cool inner electrode 

 were re-run at the same temperature and pressure as the 

 original sample of salt. The first distillate from the original 

 salt at a pressure of 2 cm. and a temperature of 465° C.,. 

 showed a negative ionization falling oft' with time from a 

 maximum value of 260 x 10~ 10 ampere in a manner analogous 

 to curve 2, fig. 6. The positive current-time relations, 

 however, differed considerably from those shown in curve 1, 

 fig. 6. Three distinct current maxima were exhibited after 

 20, 40-45, and 80-90 minutes' heating; this third maximum, 

 the greatest of the three, had a value of 22 x 10 ~ 10 ampere 

 in comparison with 5*8 x 10 -10 ampere shown by the original 

 salt. The positive ionization curve for the second distillate 

 is given in curve 1, fig. 7, and is practically the duplicate of 



Fio-. 7. 



fco So 



that given by the first distillate. The negative current 

 (curve 2, fig. 7) had an initial maximum value of 3*2 x 10" 10 

 ampere. These curves show that the ratio 



Maximum Negative Emission, Original Salt _^ . . 



Maximum Negative Emission, Second Distillate G * 



and that 



Maximum Positive Emission, Original Salt 



Maximum Positive Emission, Second Distillate 



= 0-33. 



