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80 FRAGMENTS or SCIENCE.

figure as flowing through the wire when the voltaic circuit
is complete.

I have said that no visible change occurs in the wire
when the current passes through it. Still a change over
and above what you have seen-really does take place. Lay
hold of those Spirals, and you will find them warm. Let
me exalt this warmth so as to render it visible toyou. In
front of the table is a thin platinum wire six feet long. On
sending a current from a battery of fifty pairs of plates
through this wire it glows, as you see, vividly red. I shorten
the wire; more electricity now flows through it, and its
light becomes more intense. It is now bright yellow; and
now it is a dazzling white. This light is so strong that
though the wire is not much thicker. than a bristle, it ap-
pears to those on the nearest benches as thick as a quill;
while to those at a distance it appears as thick as a man’s
finger. This effect, which we call irradiation, is always pro-
duced by a very strong light. It is this same electric cur-
rent that furnished us with the powerful light employed in
one of our first experiments. The lamp then made use of
is provided with these coke rods; and when the electric
current passes between them we obtain a light almost as
brilliant as that of the sun.

And now let us return to the point at which the elec-
tric current was introduced—the point, namely, where the
tearing asunder of the locked atoms of a . chemical com-
pound was spoken of. The agent by which we effect this
is also the electric current; and I hope to make its action
visible to you all. Into this small cell, containing water,
dip two thin wires. By means of a solar microscope and
the powerful light of our electric lamp, a magnified image
of this cell is thrown upon the screen before you. You
see plainly the images of the Wires. And now I send
from a second small battery which rests upon this table an
electric current from wire to wire. Bubbles of gas rise

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