246 



Sir J. J. Thomson : Further 



due to the hydrogen atom and molecule. The curve shows, 

 on the other hand, that the number of hydrogen particles is 

 only a small fraction of the number of CO particles. The 

 extraordinary sensitiveness of the photographic plate for the 

 hydrogen atom, in comparison with its sensitiveness to other 

 atoms and molecules, is well brought out by this curve. 



Fiff. 23. 



TV 



H, 



CO CO co 2 



Ca.rkon Monoxide, 320 Volts. 



Another instance of the same effect is that when the 

 discharge-tube is filled with mixtures of hydrogen and 

 oxygen, the proportions of gases in the mixture may be 

 altered within wide limits without producing any sensible 

 effect on the relative brightness of the hydrogen and 

 oxygen lines on the photograph. With the Faraday 

 cylinder method, however, the magnitude of the effects 

 found for the hydrogen and oxygen particles were roughly 

 proportional to the amounts of these gases in the mixture. 

 Examples for mixtures when the proportions by volume of 

 the mixture were (1) 1 of H and 2 of 0, and (2) 2 of H 

 and 1 of 0, are shown in figs. 24 and 25. 



It will be noticed that in the mixture of hydrogen with two 

 parts of oxygen, the number of charged oxygen molecules is 

 greater than the number of charged atoms; while in the case 

 of the mixture of two volumes of hydrogen to one of oxygen, 

 the number of charged oxygen atoms appears to be greater 

 than the number of charged oxygen molecules. This may 



