Rontgen Radiation from Vapours. 



453 



electroscope suffered a certain deflexion, was noticed. The 

 .carbon dioxide cylinder was replaced by a hydrogen "kip/' 

 and hydrogen saturated at the same temperature was passed 

 under similar conditions through the box, and the deflexion 

 of the chamber electroscope, while the standardize]' under- 

 went the same deflexion, was noticed. The results are 

 shown : — 



Intensities of Radiations in the two cases. 

 Temperature of saturation = 3°*5 C. 



Deflexion 



of standardizing 



electrosrope. 



Deflexion of 



chamber electroscope 



with carbon dioxide as 



saturated gas. 



Deflexion of 



chamber electroscope 



with hydrogen as 



saturated gas. 



50 

 50 

 50 

 50 



38-0 

 37-8 

 38-2 

 38-0 



38-6 

 38-4 

 38-0 

 38-4 



Mean values 



38-0 



384 



Amount of secondary radiation with H 2 as gas saturated with C 2 II 5 Br 



Amount of secondary radiation with C0 2 as gas saturated with C 2 H 5 Br 



This slight difference in the intensities is of the order of 

 magnitude which would result from the excess of absorption 

 in the heavier carbon dioxide gas. 



Knowing the vapour pressure at 3°*5 C, some relative idea 

 of the magnitude of the difference can be deduced. For, 

 assuming that the absorption of the/3 particles varies directly 

 as the absorbing mass, we get : — ■ 



;= 1*08, 



Case I. 



Amount of corpuscular radiation absorbed by ethyl bromide 



•83. 



Amouut of corpuscular radiation absorbed by C0 o 



Cas^ IT. 



Amount of corpuscular radiation absorbed by ethyl bromide _ -, ^o 

 Amount of corpuscular radiation absorbed by H 2 



Thus if the expelled electrons do by bombarding the bromine 

 atom make it emit its characteristic radiation, the above 

 calculations show that there must be a most noticeable 

 difference in the intensities of radiation in the two cases. 



