132 Dr. G. Gore on the Reality of 



strength as before, and none of it appeared to pass through 

 the liquid ; but notwithstanding no cooling influence by 

 evolution of hydrogen now operated, there was no visible 

 movement of the index or expansion of air in the bottle. 

 This experiment of passing the current alternately through 

 the liquid and through the bottle was repeated a number of 

 times, and the same results respectively obtained. With 

 nitric acid diluted in the same proportion, instead of the 

 sulphuric acid, the effects were similar but a little more con- 

 spicuous, probably because the resistance was greater, and a 

 portion of the hydrogen was oxidized. 



As when the current passed through the liquid, certain 

 amounts of heat must have been absorbed by the liberation of 

 hydrogen, and by that substance assuming the gaseous state, 

 each result ensuing at the surface of the bottle, and notwith- 

 standing these cooling influences, the temperature of the bottle 

 rose, an amount of heat more than sufficient to compensate for 

 these losses must have been produced by the current. What 

 was the source of this heat ? Was it due to ordinary conduc- 

 tion-resistance in the mass of the electrodes or liquid, or to 

 some action at the surface of the bottle ? As the index did not 

 suddenly advance when the current w r as passed through the 

 bottle only, the heat was not due to ordinary conduction- 

 resistance of that vessel; and whatever the amount of heat 

 produced by such resistance was, it must have been very 

 small in comparison with that which produced the expansion. 

 As the expansion was sudden, it could not have been due to 

 resistance of any kind at the anode. And as the temperature 

 of the bottle rose suddenly and fell quickly, and the mass and 

 specific heat of the liquid were each considerable, it could not 

 have been produced by heat of conduction-resistance of the 

 liquid. The sudden expansion was therefore probably due to 

 some influence, other than that ot chemical change, acting at 

 the surfaces of mutual contact of the liquid and bottle. 



The influence of difference of liquid with currents of equal 

 strength was also tried, the electrolytes consisting of (1st) a 

 mixture of one volume of strong sulphuric acid and ten of 

 water, and (2nd) of ordinary concentrated nitric acid for the 

 purpose of preventing the evolution of free hydrogen. The 

 current was from six Grove's cells in single series, and its 

 strength in each case was =*454 ampere ; it was stopped in 

 each instance after a few seconds (whilst the expansion was 

 increasing, though at a diminished rate), in order to exclude 

 as much as possible the influence of heat of conduction- 

 resistance of the liquid. The anode of sheet platinum was 

 used in each case. 



