﻿328 Prof. Barkla and Mr. Simons on Ionization 



Table IV. 



Ionization-charnber 3-5 cm. long, with Al window and end. 

 liadiation : the fluorescent X-radiation from Ag (series K). 

 [Ionization was by the primary and all secondary rays except 

 Br X-radiation (series K).] 



Relative 



Partial 



Observed 

 Ionization 

 in mixture. 



Ionization 



Ionization 

 due to air 

 in mixture 

 (air ends to 

 chamber). 



Additional 



Ionization 



weights of 



C 2 H s Br & 



air. 



pressures of 



C. 2 H 5 Br & 



air in cm. of 



corrected 

 for 



absorption. 



Ionization 



due to 

 C.,H 5 13r. 



due to 

 C 2 H 5 Br 

 -7- partial 





mercury. 





* 





pressure. 



100 



76 



1-0 



10 



1-c 









0-85 99-15 



0-18 75-82 



1-39 



1-39 



1-c 



•39 



22 



1-64 98-36 



034 75-66 



1-68 



1-68 



1-c 



•68 



2-0 



2-84 97-16 



060 75-40 



2-20 



220 



•99(l-c) 



1-21 



2-0 



3-60 96-40 



0-75 75-25 



2-72 



2-72 



•99(1 -c) 



1-74 



[2-3] 



45 95-5 



0-94 75-06 



312 



3-13 



•99(1 -c) 



2-15 



2-3 



8-8 91-2 



1-9 74-1 



5-13 



5-16 



•98(l-c) 



4-2 



2-2 



16-5 83-5 



40 72-0 



8-95 



904 



•95(1 -e) 



8-15 



2-0 



29-7 70-3 



7-65 68-35 



16-0 



16-3 



•91(1 -c) 



15-5 



2-0 



39-7 60-3 



1135 64-65 



22-9 



23-5 



-86(1 -c) 



22-7 



20 



480 520 



15-0 610 



29-0 



30-0 



•81 (1-c) 



29-4 



2-0 



Columns 1, 2, 3, and 4 give quantities similar to those in 

 Table III., the absorption in this case being given by 

 \= -001 35 p v + -00001 Pa . 



Column 5 gives the ionization in air of the mixture if 

 there had been no gain of corpuscles from the ends. The 

 ionization due to the end effect is represented by " c." 



Column 6 gives the ionization due to the presence of 

 C 2 H 5 Br with the air. The values were obtained by taking 

 from the total ionization (column 4), the ionization in air 

 by X-rays (column 5) and the ionization x due to net gain 

 of corpuscular radiation from the ends. The quantity x 

 diminishes with an increase in the quantity of ethyl bromide 

 present, becoming negative for large quantities of ethyl 

 bromide. The quantity " c " was obtained from Sadler's 

 experiments* and x computed from these and a knowledge 

 of ionization in the mixtures. Great inaccuracies in these 

 values would, however, produce very small errors in column 6, 

 so the method of their determination need not be given. 



In order to study the relation for very small quantities of 



the vapour of ethyl bromide, about J c.c. of the liquid was 



introduced into the gas-chamber, and air was forced in to 



bring the pressure to 2 atmospheres. The mixture was then 



* Phil. Man-. March 1910. 



