they gave to an extensive part of electrical science.

381. I was working with ice, and the solids resulting from the freezing of
solutions, arranged either as barriers across a substance to be decomposed,
or as the actual poles of a voltaic battery, that I might trace and catch
certain elements in their transit, when I was suddenly stopped in my
progress by finding that ice was in such circumstances a non-conductor of
electricity; and that as soon as a thin film of it was interposed, in the
circuit of a very powerful voltaic battery, the transmission of electricity
was prevented, and all decomposition ceased.

382. At first the experiments were made with common ice, during the cold
freezing weather of the latter end of January 1833; but the results were
fallacious, from the imperfection of the arrangements, and the following
more unexceptionable form of experiment was adopted.

383. Tin vessels were formed, five inches deep, one inch and a quarter wide
in one direction, of different widths from three eighths to five eighths of
an inch in the other, and open at one extremity. Into these were fixed by
corks, plates of platina, so that the latter should not touch the tin
cases; and copper wires having previously been soldered to the plate, these
were easily connected, when required, with a voltaic pile. Then distilled
water, previously boiled for three hours, was poured into the vessels, and
frozen by a mixture of salt and snow, so that pure transparent solid ice
intervened between the platina and tin; and finally these metals were
connected with the opposite extremities of the voltaic apparatus, a
galvanometer being at the same time included in the circuit.

384. In the first experiment, the platina pole was three inches and a half
long, and seven eighths of an inch wide; it was wholly immersed in the