482 Dr. S. Brodetsky and Dr. B. Hodgson on the 



of the cathode with normal cathode-fall. This suggests, 

 therefore, that there is a close relationship between disin- 

 tegration and absorption. Further support is lent to this 



Experiments with Normal Cathode-Fall, 

 Copper Electrodes. 



Gas used. 



Current 

 sti*ength. 



Coulombs. 



Maximum J 



Minimum 







pressure. 



pressure. 



Air 



•0080 

 •0030 



120 

 11 



2*79 mm. 



2-38 



2*76 mm. 

 2-365 







•0030 



9 



1-10 



106 





•0030 



108 



2-81 



2-77 





•0025 



86 



2-84 



2-80 





•0020 



48 



2-91 



2-80 





•0040 



36 



2-50 



2-47 





•0050 



114 



2-80 



2-75 





•0020 



32 



1-03 



101 





•0050 



21 



•85 



•83 





•0070 



38 



•55 



•54 



Oxvsfen 



•0030 



115 



2-67 



2'34 



VA J6 v ' 



•0040 



29 



•72 



•66 



Hydrogen 



•0020 



25 



1-83 



1-66 





•0020 



50 



1-71 



1-52 







18 



1-39 



1-38 





•0030 



5 



2-78 



2-70 



Carbon dioxide . 



•0025 



14 



•922 



•900 evoln. 





•0025 



45 



113 



1*01 evoln. 



view by the results obtained by Hodgson 4 , who found that 

 absorption always accompanied disintegration. 



On the other hand, if chemical action were the cause of 

 absorption, it would be reasonable to expect absorption to 

 take place both with the normal and with the abnormal 

 discharge. The absence of absorption in the former case is 

 at once explained on the disintegration-absorption theory 

 of Soddy and Mackenzie 9 . With normal discharge there is 

 no disintegration, and consequently the walls of the vessel 

 do not attain the high potential reached when they are 

 bombarded by the charged particles emitted from the cathode 

 in the case of the abnormal discharge. Further, when 

 disintegration occurs, absorption is perhaps stimulated by 

 the electrolysis of the glass of the vacuum-tube (see par. 9) . 



7. Experiments with Abnormal Cathode Glow. — In experi- 

 ments with abnormal cathode glow, it was found that the 

 rate of absorption varied with the cathode-fall, which was 

 measured by using a fine point kept always just in the 

 negative glow. In air and oxygen the rate increased as the 



4 See par. 1, note 4. 9 See par. 1, note 9. 



