﻿of Ions made by a, /3, 7, and X Rays. 



295 



8 volts respectively between gauze and plate. A polonium 

 film of greater strength was used in these experiments, the 

 tubes now used being "5 cm. high and *15 cm. in diameter. 

 Both the polonium films were purchased from Dr. Sthamer, 

 ot" Hamburg. 



In order to test whether the leaks were affected by a drift 

 of ions into the chamber, the two curves E and F, corre- 

 sponding to 8 and 320 volts respectively, were plotted from 

 readings taken with the protecting gauze h. It will be seen 

 that the curves are of the same shape as D and B. 



Curves G and H were plotted from readings taken with a 

 different apparatus, but constructed on the same lines. The 

 distance of plate from gauze was 4 mms., and the potential- 

 differences used were 10 and 500 volts respectively. 



I append the readings from which these curves have been 

 plotted, and also the lack of saturation corresponding to 

 different distances of polonium from gauze. 



Distance 

 from gauze. 



Leak for 

 500 volts 



Leak for 

 10 volts 



Lack of 

 saturation. 





per cm. 



per cm. 





"7 cm. 



489 



395 



192 p. cent. 



10 



518 



408 



21-2 



1-3 



558 



425 



238 



1-6 



592 



442 



253 



1-9 



635 



469 



261 



22 



692 



494 



28-6 



2-4 



737 



520 



294 



2-6 



787 



552 



299 



2-8 



863 



571 



33-8 



30 



903 



592 



344 



31 



887 



585 





32 



800 



532 





33 



637 



436 





3-5 



245 



183 





36 



110 



79 





3-7 



28 



24 





3-8 



5 



5 





41 



5 







It will be seen that the lack of saturation increases with 

 distance from gauze. 



General recombination could scarcely have affected any of 

 the observations made. The greatest leak observed was about 

 120 scale-divisions per second. This leak was received on an 

 area of 20 cm. 2 The capacity of the system was about 130 

 E.S.Us. From this Ave obtain that about ^-J-^ of the number of 

 ions received on the plate were lost by general recombination. 



The increase of lack of saturation with decrease of velocity 

 of the ionizing a. particles is probably due to the velocity o£ 



