Copy 1, Volume 1

Hand-book of chemistry / Translated by Henry Watts.

  • Gmelin, Leopold, 1788-1853
Date:
1848-1872
Catalogue details

Licence: Public Domain Mark

Credit: Hand-book of chemistry / Translated by Henry Watts. Source: Wellcome Collection.

    451/562 (page 427)
    ) Ae —— ws? —— | 3 sz - . « BATTERIES OF ONE METAL AND ONE LIQUID. A27 ing to 24°; the application of a stronger heat produces no perceptible increase of tension. In vacuo, the pile exhibits the same tension as in the air. If the positive pole be connected with the conductor of an elec- trical machine, the negative electricity of the opposite pole sinks to 0; but when the negative pole is connected with the conductor, the tension of the positive pole increases. (Donné.) After the lapse of some time, the tin of the silver paper becomes dull and tarnished (H. Davy), and the pile gradually loses the whole of its power. (Jiiger.) Comp. Zamboni (Gib. 60, 151); Heinrich, Schiibler, Schweigger (Schw. 15, 113, 126, 182); Jager (@ilb. 62, 227); Donné (Ann. Chim. 4 a 42, 71,—abstr. Schw. 58, 81); Rosenchéld (Pogg. 43, 193, and 3. Batteries consisting of one Metal and one Liquid. If square pieces with long tails be cut out of zine or tin-foil, and placed in about thirty watch-glasses filled with water, and arranged near one another, so that a square may lie in one watch-glass and the strip attached to it in the next,—and consequently each watch-glass, excepting the first and last may contain a square and a strip belonging to two dif- ferent pieces of metal,—the arrangement thus produced will be Zamboni’s Pile of two Elements. In such a case, according to Zamboni, the first watch-glass into which the first square dips, or the pole towards which all the squares are directed, is negative,—and the last watch-glass into which the last strip dips, or the pole towards which all the strips are directed, positive. With copper-foil, the opposite arrangement of the poles takes place. [According to this, the piece of zinc or tin of greater surface must be negative towards that of smaller surface, and the contrary with cop- per.| But, according to Erman, the positive pole in the zinc-foil arrange- ment is that towards which the squares are directed, and the negative pole that towards which all the points are directed; the contrary with silver. According to Erman, also, the current continues for two days only at the utmost, and may then be reproduced for a shorter time by the addition of common salt to the water. If pieces of so-called gold-paper (or silver-paper) be formed into a pile, the metallic pole of this pile is positive, the paper pole negative. (Erman.) [Is the surface of the metal which is turned towards the paper less smooth than the outer surface] If eighty zinc plates, 4 square inches in surface, polished on one side and rough on the other, be placed in a wooden trough at the distance of 1 or 2 millimetres from one another, so that they may be separated by thin strata of air, and one pole of this pile be connected with the electro- scope, the other with the ground,-—the electroscope receives a considerable charge. The two surfaces of the zinc, being®of different degrees of smooth- ness, act like two metals, and the film of air supplies the place of a liquid. (Watkins, Pogg. 14, 386.) [This deserves verification. | On filling a number of copper vessels, 1, 2, 3, 4, 5, 6, 7, 8, with dilute sulphuric acid, connecting 1 with 2, 3 with 4, 5 with 6, and 7 with 8, by means of brass wires,—on the other hand, 2 with 3, 4 with 5, and 6 with 7, by means of bundles of thread saturated with salt-water,—and heating only the vessels 1, 3, 5, and 7,—a current is produced, suflicient, when fourteen vessels are used, to decompose water, if the electricity be con- ducted through that liquid by means of brass wires. As the heated ves- sels cool, the current ceases. (Schweigger, WV. Gehl. 9, 704.)