368 Mr Townsend, Electrical Properties of [Nov. 22, 



(25) The electric state of the gases was examined by leading 

 them into an insulated inductor, connected to one pair of quad- 

 rants of an electrometer. The other pair of quadrants, the case 

 of the electrometer, and the screen inside which the inductor was 

 placed, were connected to earth. 



The hydrogen was bubbled through a strong solution of 

 caustic potash and the chlorine through water, before entering the 

 inductor. 



(26) The charge carried by the hydrogen evolved from a 

 hydrochloric acid electrolyte varies in a very peculiar manner. 

 When new carbon electrodes are used and the current turned on, 

 the electrometer shows that the gas, at first, has a positive charge, 

 but although the current is kept constant, this charge diminishes 

 gradually and after some minutes becomes negative, it soon 

 reaches its maximum negative value and the charge then remains 

 constant, except for a small variation due to temperature. When 

 the electrolyte is cooled, and the same current again sent through 

 the acid, the hydrogen begins to come off with a negative 

 charge. 



(27) The chlorine, which has been evolved from the positive 

 electrode, will be seen to have dissolved' in the acid not only round 

 the positive electrode, but also round the negative, before the 

 change of sign is observed in the hydrogen. If now this acid be 

 removed from Q, and the electrodes well washed, and a fresh 

 quantity of acid used, it will be found that the electrometer will 

 indicate charges on the hydrogen, exactly similar to those at first 

 observed except that the positive charges are not so large. 



After washing the electrodes a second time, and experiment- 

 ing again with a fresh quantity of acid, the same effect will be 

 observed without any further diminution in the positive charges. 



The number of divisions of the scale obtained in an experi- 

 ment of this kind are :— 



{1st minute 14 divisions positive, 

 2nd „ 11 

 3rd „ 5 



after a few minutes the hydrogen came off with a negative charge, 

 corresponding to 5 divisions per minute. The current through 

 the electrolyte being 10 amperes, and the value of divisions on 

 the electrometer scale in absolute units of quantity, being obtained 

 by multiplying them by "003. 



When the chlorine was similarly examined it was found to 

 have a small negative charge, corresponding to 4 divisions of the 



