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. Footnote 9: 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. Footnote 10: Phil. Trans. vol. 72. part i. Appen. ------------------------------------------------------------------------ SECTION II. _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.