366 



Mr Townsend, Electrical Properties of [Nov. 22, 



into the atmosphere of the room through F. As the charged gas 



entered P, the conducting cylinder Q being connected to the 



quadrant, the deflection on the electrometer scale registers the 

 total charge that enters P. 



When a sufficient charge had entered P, the tube T was closed 

 and the sulphuric acid in the manometer U rose rapidly and 

 showed a maximum difference of pressure between the atmosphere 

 inside and outside P of about 3 centimetres of acid. As the 

 blowing into E was continued the sulphuric acid in U began to fall 

 gradually and in a few minutes the difference of pressure was 

 reduced to one or two millimetres, which showed that practically 

 all the hydrogen had diffused out. 



The question was then decided by observing what charge 

 could be blown out of P by blowing through T, and it was found 

 that a large fraction of the original charge could be thus removed 

 from inside P. The charge which is thus blown out does not 

 represent quite all the electricity left in the atmosphere in P 

 after the hydrogen had diffused out as about 10 per cent, got 

 discharged in bubbling through the sulphuric acid before escaping 

 through v. 



The numbers obtained in three experiments which were per- 

 formed in the above manner are given in the following table : — 

 n 1 is the charge (in divisions of the scale) put into P, t x the time 

 in minutes required to admit the charge, \ the maximum height 

 in centimetres that the sulphuric acid rises in U after the tube T 

 is closed, t 2 the time that elapsed while the manometer fell from 

 k x to h. 2 , and n 2 the charge that was blown out of P. 



The current through the electrolyte was in each case 14 

 amperes. 



In the last experiment the charge on the gas was reduced by 

 passing it through a tube of phosphorus pentoxide before it 

 enters T. 



We thus see that the carriers of the electricity in the charged 

 hydrogen can with ease be transferred to an atmosphere of any 



