252 Mr. J. J. Thomson on the 



Now if M be the number of hydrogen or chlorine atoms 

 in the vessel where the combination takes place, since m and 

 p are small compared with n and q respectively, we may put 

 n = q = ^M., and equation (11) becomes 



Now of the quantities involved in this equation, we know 

 v, M, ti, t 2 , so that it will enable us to find t 2 2 /tiT 3 ; but 

 equation (9) will give us ht^/t^r^; hence we can find t % . 

 We require two more equations to enable us to determine 

 all the tf's and t's. Let a and j3 be the specific gravities of 

 normal hydrogen and chlorine respectively; then the specific 

 gravities of the hydrogen and chlorine in the vessel where 

 combination takes place, are respectively 



1+™' i + £' 



but 



m ' =Ti {* + 3 =Tl {" + 2r l }' 



/=Ts {" + =T3 {" + l}' 



since, as before, n=^ = |M; thus the specific gravity of the 

 hydrogen in the vessel 



that of the chlorine 



/9 



1 + M 



and the specific gravity of the mixture 



"'t« + i[«(. + S)]* +,+ i[»(- + S]* } - 



By observing the specific gravity of the mixture when the 

 pressure is made to vary, i. e. when M is made to vary, we 

 shall get equations sufficient to determine t x and t 3 , and then 

 by equation (12) we can find t 2 , so that in this way all the 

 *'s and t's could be determined. 



