704 Proceedings of Royal Society of Edinburgh. [sess. 
the total energy and 16 times the electricity. I am confirmed in 
supposing the above to be their difference in size by the angle of 
crystallisation of ice, viz., 60°. (See p. 62, “ Constitution of 
Matter and Ether.”) 
31. We will now consider the origin of the current in the 
battery, which we will suppose to be a zinc-copper-sulphuric acid 
one. The acid first of all acts by induction both on the zinc and 
copper in the manner already pointed out (see par. 28), tending 
to send a current in both directions ; both the copper and zinc tend 
to unite with the negative ions of the acid, which, by their 
contact with the plates, give up a quantity of electricity to the 
latter ; this electricity tends to fill up the collapse at the junctions 
of the molecules and atoms of both the zinc and copper, but as, 
presumably, the collapse at the copper bonds is considerably 
greater, the filling up of the latter does not proceed further than 
would be sufficient to fill up a bond of zinc, and to detach it. In 
fact, the electricity in this case would act as water would which it 
was desirable to raise to a certain height, but which would not 
rise beyond half if a sufficiently wide opening were made in the 
pipe at that height — the electricity always expending itself in 
the direction of least resistance. In the process of union of the 
negative ions with the zinc the electricity which would be set free 
by the collapse at the bonds of the new molecule would be 
sufficient to detach the hydrogen, which would be attracted to the 
copper plate with a positive charge, the copper itself being 
negative owing to its electricity escaping to, and doing work on, 
the zinc through the connecting wire. In short, the energy of 
the union of zinc and sulphion being greater than that of hydrogen 
and sulphion, the former overbalances the latter, so to speak, and 
the surplus energy produced by the new union comes away as a 
“ current of electricity.” 
32. We now come to electrolysis, and the first thing which 
seems to require explanation is why the current cannot be con- 
ducted without decomposition of the electrolyte. The solution of 
this enigma is not altogether on the surface, but yet it is 
thoroughly mechanical, and very simple, according to this theory 
All electrolytes are compounds ; and according to this theory all 
compounds are made up of atoms of different sizes and masses, 
