Essay on the origin, progress, and present state of galvanism. Containing investigations, experimental and speculative, of the principal doctrines offered for the explanation of its phenomena, and a statement of a new hypothesis / [Michael Donovan].

  • Donovan, Michael, -1876
Date:
1816
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Licence: Public Domain Mark

Credit: Essay on the origin, progress, and present state of galvanism. Containing investigations, experimental and speculative, of the principal doctrines offered for the explanation of its phenomena, and a statement of a new hypothesis / [Michael Donovan]. Source: Wellcome Collection.

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    called m question the opinions of the latter philo- sopher* He denied the chemical action of bodies on the fibre, and maintained that these bodies act, not by increasing irritability, but by be- coming new and exceedingly active links of the galvanic chain.* In cases where Humboldt had employed metals, PfafF is no doubt right; but there are cases in which no metals were used, as in the experiment of occasioning contractions in a frog’s legs by immersion into oxymuriatic acid, after they had been rendered insensible to metal- lic irritation by opium. Would PfafF in this case suppose that any galvanic chain was formed, when all the parts were connected and entirely enveloped in good conductors. In the early part of his inquiries, PfafF concluded the galvanic in- fluence to be a fluid sui generis, and not identical with electricity. He afterwards altered his opi- nion, and subscribed to the hypothesis of Volta. Indeed the doctrine of the identity of the two agents was as yet far from being established, and had still many opponents : it seems to have been much more prevalent in England than on the continent. The names of Fourcroy, Vauquelin, and Thenard, are found among those who consi- dered the galvanic influence as a peculiar fluid. Robertson read to the National Institute a me- moir in which be not only denied the identity of the two fluids, but conceived the galvanic to be a * Annul. dc Clam, tome 34, 307,