el 
ON ELECTROLYSIS. 763 
Consequences of an atomic theory of electricity. Possible electrostatic 
saturation. 
The fact that atoms in electrolytes have a constant charge which 
is the same for every kind of atom, or at least can only be multiplied by 
an integer, is so striking, that one is constrained to think whether elec- 
tricity is something necessarily associated with atoms of matter, whether 
all electrical actions are simple electrostatics among the atomic charges, 
and whether no quantity of electricity smaller than an atomic charge can 
exist. 
The notion is repugnant, but it just wants considering; though I 
should hardly have ventured to suggest it but for the support Helmholtz 
has given to the view as at least a possible one (see above). 
The first difficulty which meets us is the serious one that, since air and 
gases are not electrolytes, nothing is known about the atomic charges of 
their molecules. 
On the atomic theory, however, the unit of electricity is about 10-", 
and nothing smaller is possible; so we must provisionally use this as 
applicable even to air atoms; for it is hardly reasonable to suppose that 
the aqueous vapour, or other true compound, present is essential to elec- 
trostatic actions. 
Consider a centimetre cube of air at pressure p dynes per sq. cm.; the 
number of atoms init is _?.. ” or say 10" p- 
10° 800 
The number in each face of the cube is 10-° n? p 4, or 101° p 4, 
The available quantity of electricity of either kind on a face of the- 
cube, when every molecule is fully polarised, is therefore 
Fi 3 
1, eae = is electrostatic units. 
This is therefore the maximum possible density to which an air con- 
denser could be charged, on the atomic theory. 
If p is a millionth of an atmosphere, this gives 400 volts per centi- 
metre as the maximum possible. 
If p is 1 atmosphere, it gives 4,000,000 volts per centimetre. 
A liquid condenser would have 400,000,000 volts per centimetre as its. 
maximum charge. 
It is to be understood that this calculation has nothing to do with the 
dielectric strength of the medium. It is not considered whether the 
medium can stand this stress or not; all that is reckoned is the maximum 
that can possibly be produced, on the atomic hypothesis. 
If every dielectric refuses to stand anything like so much, it is diffi- 
cult to test the hypothesis; but if the maximum possible were to come 
out something comparable with what a substance under certain conditions 
can stand, then it may be possible to try the experiment and to discover 
some evidence of the existence of an upper limit to the charge a condenser, 
made of that substance, is able to receive. 
One effect naturally suggests itself. If the maximum possible charge 
is insufficient to burst a given kind of condenser then that condenser 
cannot be burst—it will behave as if infinitely strong. 
Now if what I have said has any sense (an improbable assumption) 
the law of variation of maximum charge with pressure, in a gas, is as p?. 
