A manual of magnetism : including galvanism, magnetism, electro-magnetism, electro-dynamics, magneto-electricity, and thermo-electricity.

  • Davis, Daniel.
Date:
1847
Catalogue details

Licence: Public Domain Mark

Credit: A manual of magnetism : including galvanism, magnetism, electro-magnetism, electro-dynamics, magneto-electricity, and thermo-electricity. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    of copper and zinc are coiled in concentric spirals, sometimes placed side by side; and they may be divided into a great number of small plates, provided that all the zinc plates are connected together, and all the copper plates together, and then, finally, tnat the experiments are performed in a chaimel of elec- trical communication opened between the one con- geries and the other; for it is immaterial whether one large surface be used, or many small surfaces, electrically connected together. The effect of all these arrangements, by which the metallic surface of a single pair is augmented, is to increase the quantity of the electricity produced. — 2. The extension of the number of the plates consecutively; that is, by con- necting the copper plate of each pair with the zinc plate of the next pair. By this arrangement, the electricity is obliged to traverse a longer or shorter series of pairs; each pair being separated from the adjoining ones by a stratum of imperfectly conduct- ing liquid, or by the walls of an insulating cell. The result is, that the electricity acquires that ad- ditional impulse, which has already been referred to, as intensity. It has greater power to pass through imperfect conductors, or through intervals in the circuit, to give shocks to the animal system, and to decompose chemical compounds; and when the number of consecutive pairs of plates is increased to some thousands, or even hundreds, the electricity developed approaches very near in its character to that produced by the electrical machine ; it manifests similar attractions and repulsions, and in fact the 2