Note

207

It seems to me that all these Experiments, and an infinite number of
others, analogous to them, sufficiently prove and confirm the Propositions I
have already advanced, namely,

1st: That if two dissimilar metals are applied to wet substances that
communicate with each other, as soon as the circle is completed, by making
these metals themselves also communicate with each other, the Equilibrium
of the Electric fluid is disturbed; the fluid is taken out of its state of quiet,
and drawn into a continued circulation.

2dly: That if in this circuit it meets with nerves, and particularly if
it is obliged to pass through them by a narrow passage, it irritates and sti-
mulates them very strongly, and

3rdly : That from this arise effects corresponding to the proper functions
of those nerves. If they are nerves subservient to muscular motion, that
motion is excited. If they are nerves of sensation, the sensation belonging to
them is produced, as my Experiments upon the Tongue demonstrate.

But indeed, Experiments upon some other sense are still wanted. Here
follow some upon the sight. I apply to the naked ball of the eye a strip of
Tinfoil, and I shut the eyelids upon it, keeping them shut with the finger,
and keeping also the. tinfoil quite close to the ball of the eye; Then grasping
with the hand wetted, a silver Candlestick or Spoon, I bring it into contact
with the strip of Tinfoil hanging from the eye; and immediately there is pro-
duced in my Eye a transitory flash of Light, similar to that which sometimes
takes place when a blow is received on the Eye, or when the nose is blown
with violence. The Experiment succeeds best at a time, and in a place of
darkness; and if the silver spoon is held in the mouth, rather than in the Hand.
But best of all by applying the Tinfoil to one Eye, and the silver plate to the
other Eye; in this manner a flash twice as bright is produced. In order not
to offend the Eye by the immediate contact of the metals, a piece of linen
folded up, and well soaked in cold or warm water, may be interposed. It must
be remarked that with respect to the sensation of the Eye, it is indifferent whe-
ther the silver or the tin be applied to it, that, is, whether the Electric fluid goes
out of it or enters into it; the instantaneous light is the same, always weak,
it neither alters in strength nor in colour; though the taste, as we have already
seen, is altered. Another remarkable difference is that although the taste con-
tinues while the contacts are continued, the flash of light is transitory, and in
order to produce it again, the metals must be separated and brought together
repeatedly. ^[5]

This Experiment also may be made with a chain of persons, and in va-
rious other manners.