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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    battery over the sulphate of copper battery, for the same amount of zinc dissolved, is equal to the differ- ence of affinity between oxygen for nitrous acid and oxygen for copper. The force of Grove's battery is, therefore, equal to the affinity of oxygen for zinc, minus the affinity of oxygen for nitrous acid. 42. It should also be remembered that the energy of a galvanic arrangement depends, to some extent, upon the difference in the affinity for oxygen of the metals employed, which, in the case of platinum and zinc, is at a maximum. The zinc plates are amal- gamated, and the battery is worked by two fluids; the one within the porous cell and in contact with the platinum being strong nitric acid, and the other, which is in contact with the zinc, being sulphuric acid, diluted with ten or twelve parts of water, as in Smee's, >§> 25. This battery is the most energetic yet known. A Grove's battery, exposing a surface of zinc equal to 20 square inches, was found, by its magnetizing power, to afford a current of greater quantity than a sulphate of copper battery exposing 210 inches of zinc. The intensity of the current in Grove's is also considered three times as great as in the latter, and perhaps four times as great as in Smee's. The same platinum and zinc of a Grove's battery, being used as a Smee's, gave less than a fifth of the current in magnetizing power. Grove's battery is also exceedingly constant. 43. The disadvantages of this battery for common use are, first, the strength of the acids which are em- ployed, making it disagreeable and unsafe to a careless