the iodide, and formed a brown spot where the iodine was liberated.
Then he immersed two wires, one of zinc, the other of platinum, each
1/13th of an inch in diameter, to a depth of 5/8ths of an inch in
acidulated water during eight beats of his watch, or 3/20ths of a
second; and found that the needle of his galvanometer swung through
the same arc, and coloured his moistened paper to the same extent,
as thirty turns of his large electrical machine. Twenty-eight turns
of the machine produced an effect distinctly less than that produced
by his two wires. Now, the quantity of water decomposed by the
wires in this experiment totally eluded observation; it was
immeasurably small; and still that amount of decomposition involved
the development of a quantity of electric force which, if applied in
a proper form, would kill a rat, and no man would like to bear it.

In his subsequent researches 'On the absolute Quantity of
Electricity associated with the Particles or Atoms of matter,'
he endeavours to give an idea of the amount of electrical force
involved in the decomposition of a single grain of water. He is
almost afraid to mention it, for he estimates it at 800,000
discharges of his large Leyden battery. This, if concentrated in a
single discharge, would be equal to a very great flash of lightning;
while the chemical action of a single grain of water on four grains
of zinc would yield electricity equal in quantity to a powerful
thunderstorm. Thus his mind rises from the minute to the vast,
expanding involuntarily from the smallest laboratory fact till it
embraces the largest and grandest natural phenomena.[1]

In reality, however, he is at this time only clearing his way,
and he continues laboriously to clear it for some time afterwards.
He is digging the shaft, guided by that instinct towards the mineral