tricity from the battery (363. 364.); and a new part of the zinc wire
having been brought into position with the platina, the comparative
experiments were made.

370. On plunging the zinc and platina wires five eighths of an inch deep
into the acid, and retaining them there for eight beats of the watch,
(after which they were quickly withdrawn,) the needle was deflected, and
continued to advance in the same direction some time after the voltaic
apparatus had been removed from the acid. It attained the five-and-a-half
division, and then returned swinging an equal distance on the other side.
This experiment was repeated many times, and always with the same result.

371. Hence, as an approximation, and judging from _magnetic force_ only at
present (376.), it would appear that two wires, one of platina and one of
zinc, each one eighteenth of an inch in diameter, placed five sixteenths of
an inch apart and immersed to the depth of five eighths of an inch in acid,
consisting of one drop oil of vitriol and four ounces distilled water, at a
temperature about 60 deg., and connected at the other extremities by a copper
wire eighteen feet long and one eighteenth of an inch thick (being the wire
of the galvanometer coils), yield as much electricity in eight beats of my
watch, or in 8/150ths of a minute, as the electrical battery charged by
thirty turns of the large machine, in excellent order (363. 364.).
Notwithstanding this apparently enormous disproportion, the results are
perfectly in harmony with those effects which are known to be produced by
variations in the intensity and quantity of the electric fluid.

372. In order to procure a reference to _chemical action_, the wires were
now retained immersed in the acid to the depth of five eighths of an inch,
and the needle, when stationary, observed; it stood, as nearly as the
unassisted eye could decide, at 5-1/3 division. Hence a permanent
deflection to that extent might be considered as indicating a constant
voltaic current, which in eight beats of my watch (369.) could supply as
much electricity as the electrical battery charged by thirty turns of the
machine.

373. The following arrangements and results are selected from many that
were made and obtained relative to chemical action. A platina wire one
twelfth of an inch in diameter, weighing two hundred and sixty grains, had
the extremity rendered plain, so as to offer a definite surface equal to a
circle of the same diameter