on the Ionization produced in Gases by Rontgen Rays. 197 



the temperature of the air does not affect the amount of ionization 

 produced in it if the density of the air does not change. It 



Table I. — Air. 



may be just mentioned here that these results are confirmed by 

 some experiments which have not yet been published, and which 

 were made with a different apparatus which was not air-tight 

 where the air was allowed to expand freely. In that case when 

 the proper correction was made for the change in density of the air 

 the same result was obtained as in the present instance. 



Experiments have also been made on carbon dioxide gas, and 

 they give exactly the same results as tbose obtained for air. One 

 of the series obtained is given in Table II. 



Table II. — Carbon Dioxide. 



The results show clearly that carbon dioxide acts in exactly the 

 same way as air does in regard to the effect which the temperature 



