66 Prof. Liveing, On the Influence of [Feb. 14, 
February 14, 1887. 
Mr TROTTER, PRESIDENT, IN THE CHAIR. 
The following Communications were made to the Society. 
(1) On the Influence of Capillary Action in some Chemical 
Decompositions. By G. D. Liveine, M.A. 
There are numerous cases in which chemical action is pro- 
moted by means which are believed to be purely mechanical, but 
where the precise nature of the mechanical action is quite 
undefined, or only vaguely indicated by some analogy which is 
not clearly made out. Such cases are the rapid decomposition of 
hydrogen peroxide and hydrogen persulphide in the presence of 
many substances in fine powder, and of potassium chlorate in the 
presence of manganese black oxide, and many actions called 
katalytic. The action in some of these cases may, I think and 
shall try to shew, be referred to the same causes as those which 
produce the common effects of capillarity. 
There is no doubt that solids condense on their surfaces films 
of air and other gases in which they may be immersed; and if 
we accept Laplace’s theory of capillarity it seems impossible to 
escape the conclusion that the molecular attractions which pro- 
duce surface tension must act upon, and condense, the molecules 
of gases in contact with the surfaces. Indeed the surface tension 
at the common boundary of two fluids depends on the nature of 
both fluids, even when one of them is a gas and can hardly be 
said to have any surface tension of its own. The condensation 
upon hygroscopic bodies of aqueous vapour from the atmosphere 
at temperatures above the dew point is recognised to be the result 
