180 Rev. P. J. Kirkby on Union of Hydrogen and Oxygen 



the results of similar experiments made with the hydrogen 

 and oxygen obtained by the electrolysis of barium hydrate. 



Table VIII. D = l cm. 



p. 



Ap. 



C. 



I 

 AQ. 



4-0 



•6 



3-13 



•313 



3-4 



•58 



315 



•315 



2-8 



•58 



33 



•33 



2-22 



•6 



3-36 



•336 



1-63 



•59 



32 



•32 



1-2 



•26 



30 



•151 



Ap 

 AQ 



1-92 

 1-84 

 1-75 

 T77 

 1-85 

 1-73 



X. 



420 

 418 

 408 

 402 

 414 

 428 



X 

 pj> 



Ap 



p.AQ.V 



106 



•48 



124 



•55 



145 



•62 



181 



*8 



254 



113 



356 



1-45 



It follows that the equation 



Ap 



pDAQ 



='© 



is approximately true for the range of pressures dealt with, 

 and that the functional relation is independent of the elec- 

 trodes. 



Moreover, the curve determined by all these observations 

 does not differ sensibly from the right line 



pDAQ 



A 3X 



10 + 800^0* 



Thus the results of all the experiments recorded in the 

 tables can be approximately represented by 



Ap pD 

 AQ = 10 + 



3X 



800 



(1) 



With regard to X the potential-difference of the plates, it 

 never seems to undergo any great variation. The limits, of 

 X for all the experiments recorded above lie between 370 

 and 500 volts. The variation of X in the tables scarcely 

 exceeds 15 per cent, of its mean. It might, therefore, be 

 doubted whether it is necessary to introduce X at all, in 

 order to coordinate these experiments. The tables show that, 

 in the great majority of cases, X differs by only about 5 per 

 cent, from 400 volts. It might, therefore, be replaced by 

 that constant value without dislocating, to any great exteut, 

 more than a very few of the points which have been plotted 

 in fig. 3. 



Nevertheless, the necessity of introducing X was shown 



