72 Prof. Liveing, On the Influence of [Feb. 14, 
quantity of acid is so small as to be not nearly equivalent to 
the amount of peroxide in the solution. 
I have made no special mention of the action of those com- 
pounds which, like silver oxide, themselves undergo decomposition 
while they induce the decomposition of the peroxide. In all these 
cases there is energy enough rendered available by the decom- 
position of the peroxide to bring about the other decomposition. 
It becomes now a question of interest whether the measured 
variations in the surface energies of water and aqueous solutions 
are quantities comparable in magnitude with the work which this 
theory requires to be done by them. I know of no measure- 
ments of the changes of surface energy of water produced by 
the solution in the water of any gases except hydrochloric acid, 
but Quincke has measured the surface tensions of pure water 
and of a solution of sodium hyposulphite, and though we cannot 
assume that the difference between them gives any indication 
of the difference of surface tension of water and solutions in any 
other case, it will serve to give us an indication of the order of 
magnitude which we may expect such differences to shew. 
Now Quincke’s measures give a ditference of surface energy per 
square centimetre for water and solution of hyposulphite amount- 
ing to 3°5 milligrammes. This will produce an increase of pressure 
upon a bubble of oxygen in the liquid of about 3°38 x 10° of an 
atmosphere per square centimetre. The work done by this on a 
bubble containing 1 cc. of oxygen would be about equal to that of 
a pressure of one atmosphere on a square centimetre working 
through 3°38 x 10° cm. Now the volume of oxygen under a 
pressure of one atmosphere absorbed by 1 cc. of water at 10°C. is 
0:0325 cc.; and if we assume that the radius of molecular action 
which gives rise to capillary effects is z54>5 of a millimetre, the 
volume of oxygen absorbed by a film of water of that thickness 
extending over one square cm. will be only 3:25 x 10“ ce. 
The work which would have to be done in order to compress n 
times as much oxygen originally at atmospheric pressure into that 
space, with an isothermal arrangement, would be equal to the 
pressure of one atmosphere on one square cm. acting through 
n log n x 3°25 x 107 cm. 
Now the work above found for the change of surface energy of 
water, due to the solution of hyposulphite in it, is nearly equal to 
this when n log n= 10, which gives a value for n between 5 and 6. 
This is as much as to say that the change of superficial energy of 
water in contact with air when hyposulphite is dissolved in it is 
capable of doing the work requisite to make the superficial film 
take up 5 or 6 times as much oxygen per unit of volume as the 
bulk of the water absorbs. 
I think this shews that I am dealing with quantities which are 
