56 
MR. GROVE ON THE EFFECT OF 
temperature of the water at the commencement of the experiment was 60 ° Fahr. 
In four minutes the water surrounding the hydrogen had risen to 94°, and became 
stationary there, while that surrounding the air had only reached 87°; in ten minutes 
tlie water surrounding the hydrogen had sank to 92°'5, while that surrounding the 
air had risen to 93°, which was the highest temperature it reached ; thus the respective 
maxima were 94° and 93°; but considering the greater time which the water sur- 
rounding the air required to attain its maximum temperature, and that being during 
this time at a temperature above that of the surrounding atmosphere, it must have 
lost something of its acquired heat, we may fairly consider the maxima to be the 
same, and that the difference of effect in the two gases had reference solely to the 
time occupied in the transference of the heat. In a second experiment the results 
were similar, the maximum being in this experiment 92‘5 in hydrogen, and 91 
in air^'. 
As far as ordinary ignition is concerned, hydrogen has been shown by the expe- 
riments of Leslie and Daw to produce a more rapid cooling effect than air; and 
the above experiment having shown that* it does not alter or convert into any other 
force the actual amount of heat given off, my next step was to inquire whether this 
rapidity of cooling effect of the hydrogen would account for the effects observed with 
voltaic ignition. Although the two classes of effects were apparently very different, 
it might be that the improved power of conduction arising from the rapid cooling 
effect of the hydrogen might, by enabling the current to pass more readily, carry off 
the force in the form of electricity, which if the wire offered more resistance (as it 
would when more highly ignited) would be developed in the form of heat. By em- 
ploying the same medium, but impeding the circulation of the heated currents in one 
case, while their circulation was free in the other, some light might be expected to be 
thrown on the inverse relation of the conducting power to the heat developed. The 
following experiment was therefore tried. 
In the apparatus represented in fig. 1, tube A was uncorked, so as to allow free 
passage for the water, while tube B was filled up with fine sand soaked with water, 
and then corked at both ends ; the current was passed and the following was the 
result. In the vessel containing tube A, the thermometer rose in five minutes from 
52° to 60°, and in that containing tube B from 52° to 60° also ; during a second five 
minutes, the thermometer rose in the vessel containing A from 60° to 67°, and in the 
vessel containing B from 60° to 67° also. 
I tried another analogous experiment : a coil of platinum wire was placed in a very 
narrow glass tube one-sixth of an inch diameter ; this was hermetically sealed at one 
end, and the other drawn into a very narrow aperture, little more than sufficient to 
allow the platinum wire to pass, and filled with water (it was necessary to leave a 
small aperture to prevent the bursting of the tube by the expansion of the heated 
water) ; in the other vessel a similar coil of platinutn wire was placed, but without 
* Iron wire produces a similar effect to platinum wire in the voltaic experiments. 
