288 



Scientific Proceedings, Royal Dublin Society. 



point near 120 volts, indicating an ion of mobility about "009. For the 

 larger spark distances this ion is present in small quantities only. Thus 

 when the spark is 3 nuns, from the quartz tube, the largest ion is about 

 16 per cent, of the total ; at 2 mms. 40 per cent. : at 1 mm. 61 per cent. The 

 data from which the curves were drawn are given in the following tables : — 



Table foe Curves 2. 



Similar behaviour of (+) and (-) Ions. 



Our experiments showed that no difference existed between positive and 

 negative numbers ; or, in other words, that the nuclei attached themselves 

 indifferently to positive or negative small ions. 



A current-voltage curve was plotted, using positive and negative voltages 

 alternately. A preliminary test had shown that when the first terminal Tj 

 was earthed, and the uranium removed, no ions (due to the spark), either 

 positive or negative, reached the second terminal Tj. The following table 

 gives the numbers observed : — 



