y but extreme beauty, when viewed in relation to the
evolution of an electric current and its decomposing powers.

863. A dilute sulphuric acid, made by adding about one part by measure of
oil of vitriol to thirty parts of water, will act energetically upon a
piece of zinc plate in its ordinary and simple state: but, as Mr. Sturgeon
has shown[A], not at all, or scarcely so, if the surface of the metal has
in the first instance been amalgamated; yet the amalgamated zinc will act
powerfully with platina as an electromotor, hydrogen being evolved on the
surface of the latter metal, as the zinc is oxidized and dissolved. The
amalgamation is best effected by sprinkling a few drops of mercury upon the
surface of the zinc, the latter being moistened with the dilute acid, and
rubbing with the fingers or two so as to extend the liquid metal over the
whole of the surface. Any mercury in excess, forming liquid drops upon the
zinc, should be wiped off[B].

[A] Recent Experimental Researches, &c., 1830, p.74, &c.

[B] The experiment may be made with pure zinc, which, as chemists well
know, is but slightly acted upon by dilute sulphuric acid in
comparison with ordinary zinc, which during the action is subject to
an infinity of voltaic actions. See De la Rive on this subject,
Bibliotheque Universelle, 1830, p.391.

864. Two plates of zinc thus amalgamated were dried and accurately weighed;
one, which we will call A, weighed 163.1 grains; the other, to be called B,
weighed 148.3 grains. They were about five inches long, and 0.4 of an inch
wide. An earthenware pneumatic trough was filled with dilute sulphuric
acid, of the strength just described (863.), and a gas jar, also filled
with the acid, inverted in it[A]. A plate of platina of nearly the same
length, but about three times as wide as the zinc plates, was put up into
this jar. The zinc plate A was also introduced into the jar, and brought in
contact with the platina, and at the same moment the plate B was put into
the acid of the trough, but out of contact with other metallic matter.

[A] The acid was left during a night with a small piece of
unamalgamated zinc in it, for the purpose of evolving such air as
might be inclined to separate, and bringing the whole into a constant
state.

865. Strong action immediately occurred in the jar upon the contact of the
zinc and platina plates. Hydrogen gas rose from the platina, and was
collected in the jar, but no hy