478 Dr. Faraday on the Chemical and Contact 
sumes also that the particles, being by their mutual action 
rendered plus and minus, can, whilst under this inductive ac- 
tion, discharge to particles of like matter with themselves and 
so produce a current. 
2068. This is in no respect consistent with known actions. 
If in relation to chemical phenomena we take two substances, 
as oxygen and hydrogen, we may conceive that two particles, 
one of each, being placed together and heat applied, they induce 
contrary states in their opposed surfaces, according, perhaps, 
to the view of Berzelius (1739.), and that these states beco- 
ming more and more exalted end at last in a mutual discharge 
of the forces, the particles being ultimately found combined, 
and unable to repeat the effect. Whilst they are under in- 
duction and before the final action comes on, they cannot 
spontaneously lose that state; but by removing the cause of 
the increased inductive effect, namely the heat, the effect itself 
can be lowered to its first condition. If the acting particles 
are involved in the constitution of an electrolyte, then they 
can produce current force (921. 924.) proportionate to the 
amount of chemical force consumed (868.). 
2069. But the contact theory, which is obliged, according 
to the facts, to admit that the acting particles are not changed 
(1802. 2067.) (for otherwise it would be the chemical theory), 
is constrained to admit also, that the force which is able to 
make two particles assume a certain state in respect to each 
other, is unable to make them refazn that state; and so it vir- 
tually denies the great principle in natural philosophy, that cause 
and effect are equal (2071.). Ifa particle of platinum by con- 
tact with a particle of zinc willingly gives of its own electricity 
to the zinc, because this by its presence tends to make the pla- 
tinum assume a negative state, why should the particle of pla- 
tinum take electricity from any other particle of platinum be- 
hind it, since that would only tend to destroy the very state 
which the zinc has just forced it into? Such is not the case in 
common induction; (and Marianini admits that the effect of 
contact may takeplace through air and measurable distances*}) 
for there a ball rendered negative by induction, will not take 
electricity from surrounding bodies, however thoroughly we 
may uninsulate it; and if we force electricity into it, it will, 
as it were, be spurned back ayain with a power equivalent to 
that of the inducing body. 
2070. Or if it be supposed rather, that the zinc particle, by 
its inductive action, tends to make the platinum particle posi- 
tive, and the latter, being in connection with the earth by other 
platinum particles, calls upon them for electricity, and so ac- 
quires a positive state; why should it discharge that state to 
* Memorie della Societd Italiana im Modena, 1837, xxi. 232, 233, &c. 
