264 Faraday's Researches

contact theory, balanced (848). Then fig. 68 may represent
the circle of platinum, lead, and solution of sulphuret, which
does produce a current, and, as I have assumed, with a resulting
force of ii .—$=>. This in a few minutes becomes quiescent,
i.e. the current ceases, and fig. 69 may represent this new case
according to the contact theory. Now is it at all likely[that

+

platinum-

Fig. 68.

by the intervention of sulphuret of lead at the contact c, fig. 68,
and the production of two contacts d and e, fig. 69, such an
enormous change of the contact force suffering alteration
should be made as from 10 to 21? the intervention of the
same sulphuret either at a or b (822, 828) being able to do
nothing of the kind, for the sum of the force of the two new
contacts is in that case exactly equal to the force of the contact
which they replace, as is proved by such interposition making
no change in the effects of the circle (855, 828). If therefore the
intervention of this body between lead and platinum at a, or

~——-—\--------;-----:-------1-------------. I

pot.

platinum,
Fig. 69.

between solution of sulphuret of potassium and platinum at b
(fig. 68) causes no change, these cases including its contact with
both lead and the solution of sulphuret, is it at all probable
that its intervention between these two bodies at c should
make a difference equal to double the amount of force previously
existing, or indeed any difference at all ?

878. Such an alteration as this in the sum assigned as the
amount of the forces belonging to the sulphuret of lead by
virtue of its two places of contact, is equivalent I think to say-
ing that it partakes of the anomalous character already supposeditional reasons