Experiments and Observations Relative to the Influence Lately Discovered by M. Galvani and Commonly Called Animal Electricity — Story, Setting & Ideas

m, during the whole of the time they were under experiment; and their skins were suffered to remain as entire as possible, since I found their muscles lost their contractile power, in a few hours, and became rigid when exposed, deprived of their skins, to the action of the water.

M. Fontana, in the first volume of his work on Poisons, mentions some facts, which may, to some, appear to give considerable countenance to this explanation. The microscopical eels found in dry and smutty wheat; the seta equina or gordius of Linnaeus; and the wheal polypus, all, when dry, become apparently dead: but again recover motion and life when moistened with water. One of the latter was put, by M. Fontana, upon a bit of glass, and exposed, during a whole summer, to the noon-day sun. It became so dry that it was like a piece of hardened glue. A few drops of water, however, did not fail to restore it to life. Another was, in this way, recovered after a similar exposure of a year and a half. Father Gumillo, a Jesuit, and the Indians of Peru, are quoted by the same author, on the authority of Bonguer, as speaking of ‘a large and venemous snake, which being dead and dried in the open air, or in the smoke of a chimney, has the property of coming again to life, on its being exposed, for some days, to the sun, in a stagnant and corrupted water.’

But it would almost require the credulity of an Indian to credit the testimony of the Jesuit.

Since what I had before written upon this subject went to the press, I have been informed by a friend, that Dr Lind of Windsor has found, that contractions may be excited in a frog by touching it with iron alone. In a frog very recently killed, I have myself, sometimes, excited contractions, by touching its nerves with iron and steel in conjunction. But I can by no means consider this as a satisfactory proof, that contractions may be excited by the contact of one metal alone; since I have never been able to excite contractions with a piece of iron, of the same quality throughout, applied to a frog which had been so long dead as to leave no suspicion that the contractions were occasioned by mechanical irritation. In Dr Valli’s experiment, with scissars of bad steel, upon a frog recently killed, these circumstances do not appear to have been sufficiently attended to.

Phil. Trans. vol. 72. part i. Appen.

------------------------------------------------------------------------

_Has Magnetism any concern in the Phenomena discovered by Galvani?_

In answer to this question I have little to say, as the experiments which it suggested, and which I had an opportunity of making, have been but few.

I have repeatedly excited contractions, both with the natural and the artificial loadstone, but I could never observe any difference between them, and such as were excited by unmagnetised iron, or an ore containing an equal quantity of iron with the natural loadstone.

When the separated leg of a frog was laid upon a plate of iron, and a loadstone was brought in contact both with its nerve and the plate, no contraction was excited. I have often brought frogs, in every state of preparation, as nearly as possible to a very sensible magnetic needle, but no variation in its direction was in any case produced by the contractions of the frogs excited by the metals.

------------------------------------------------------------------------

_What are the relations which subsist between the influence discovered by Galvani, and the muscles, the nervous, and the vascular systems, of animals?_

In proposing to myself a question of this very extensive nature, it will hardly be imputed to me, that I ever entertained, for a moment, the idle expectation of being able completely to solve it. It is prefixed to the following experiments as the most commodious general head under which I could arrange, not only what I had further to say, upon the influence discovered by Galvani, but likewise upon the several physiological subjects, in the examination of which this influence was employed merely as a test.

As I am acquainted with no criterion by which we can assure ourselves of the complete separation of muscular fibres from nerves, without rendering them objects too minute for accurate experiment; it can never be in our power, so far as I am able to judge, to satisfy ourselves, if this new influence can act immediately upon the muscular fibre. A doubt must always remain, whether nerve has not been present; and from this doubt will arise another still more difficult to solve, whether the influence produced or excited by the metals have passed through the nerve to the muscles? or if it have merely acted as a stimulus