Ionization produced by Heated Salts. 



387 



Two grams of cadmium iodide were originally used, and 

 750 mgms. of the second distillate were recovered and used 

 as described above. Ten distillates from this original sample 

 of salt were re-tested ; alternations of greater negative or 

 positive emission occurred. The power which the distillates 

 had of producing negative ionization was in no wise com- 

 parable to that of the original salt ; on the other hand, the 

 positive ionization was considerably greater in certain of 

 the distillates. 



The results showing the maximum values of the positive 

 and negative currents at a temperature of 465° C. and a 

 pressure of 0'8 cm. are given in Table VI. 



Table VI. 

 P = 0'8 cm. Hg. T = 465°C. 1 div. = lx lO" 10 ampere. 



Substance. 



Maximum 

 Negative. 



Maximum 

 Positive. 



Original Cdl, 



800-0 



0-9 



92-0 



1-2 



54-2 



10-5 

 30-0 



3-2 

 16-6 



5-1 



1st distillate 



2nd distillate 



3rd distillate 



4th distillate 





These figures show that the ratio of 



Maximum Negative Emission, Original Salt 

 Maximum Negative Emission, Eirsfc Distillate 



and that the 



900 (roughly), 



Maximum Positive Emission, Original Salt 

 Maximum Positive Emission, Eirst Distillate 



= 0-34. 



No explanation can, as yet, be offered why these distillates 

 exhibit such alternations in their powers of negative and 

 positive emission. No visible differences existed in the 

 colour or general appearance of the distillates and the original 

 salt. It seemed possible that the presence or absence of 

 moisture might account in part for the marked dissimilarities 

 in the ionization from the distillates. To this end the sixth 

 and seventh distillates in the experiments at 2 cm. pressure 

 were, in turn, treated with about a gram of water, and the 

 negative and positive current-time relations determined. 



