Decomposition by a Single Pole 49

insulated in the air by suspenders of silk, so that the electricity
passed through its entire length: decomposition took place
exactly as in former cases, alkali and acid appearing at the two
extremities in their proper places.

192. Experiments were then made both with sulphate of
soda and iodide of potassium, to ascertain if any diminution of
decomposing effect was produced by such great extension as
those just described of the moist conductor or body under
decomposition; but whether the contact of the decomposing
point connected with the discharging train was made with
turmeric paper touching the prime conductor, or with other
turmeric paper connected with it through the seventy feet of
string, the spot of alkali for an equal number of turns of the
machine had equal intensity of colour. The same results
occurred at the other decomposing wire, whether the salt or the
iodide were used; and it was fully proved that this great ex-
tension' of the distance between the poles produced no effect
whatever on the amount of decomposition, provided the same
quantity of electricity were passed in both cases (113).

193. The negative point of the discharging train, the tur-
meric paper, and the string were then removed; the positive
point was left resting upon the litmus paper, and the latter
touched by a piece of moistened string held in the hand. A
few turns of the machine evolved acid at the positive point as
freely as before.

194. The end of the moistened string, instead of being held
in the hand, was suspended by glass in the air. On working
the machine the electricity proceeded from the conductor
through the wire point to the litmus paper, and thence away
by the intervention of the string to the air, so that there was
(as in the last experiment) but one metallic pole; still acid
was evolved there as freely as in any former case.

195. When any of these experiments were repeated with
electricity from the negative conductor, corresponding effects
were produced whether one or two decomposing wires were
used. The results were always constant, considered in relation
to the direction of the electric current.

196. These experiments were varied so as to include the
action of only one metallic pole, but that not the pole connected
with the machine. Turmeric paper was moistened in solution
of sulphate of soda, placed upon glass, and connected with the
discharging train (28) by a decomposing wire (48); a piece
of wet string was hung from it, the lower extremity of which

De the temperature