Читать книгу An Account of the Late Improvements in Galvanism - Giovanni Aldini - Страница 14

Certain fluids, applied to the whole surface of the pile, or of animal parts, do not prevent the action of Galvanism.

EXPERIMENT I.

Two years ago, I made various experiments on this subject at Florence, with the celebrated Fontana; and we found that a pile, composed of a hundred plates of zinc and silver, after being immersed some time in common water, still exercised a very strong action. Professor Fontana informs me, in a letter, that he has performed the same experiment several ways, and always with the same success.

EXPERIMENT II.

Being desirous to examine the nature of the element inhabited by the numerous family of fishes, which are also subject to the influence of the Galvanic processes, I filled with sea-water thirty earthen vessels; and having formed a communication between them, by means of heterogeneous arcs, composed of brass and zinc, I obtained a shock, which appeared to me stronger than that obtained with artificial salt water. By establishing an arc with only five of these vessels, the action was very sensible. A pile composed of pieces of pasteboard, moistened with sea-water, and entirely immersed in the same water, gave, when tried, very strong shocks.

EXPERIMENT III.

I was able to prove the action of the Galvanic pile and of metals under water, by the following simple experiment: I placed a plate of zinc at the bottom of a vessel filled with salt water, (Plate II. fig. 6.). A person then brought the spinal marrow of a frog into contact with the surface of the salt water; and another person, absolutely insulated, touched with a silvered copper wire the plate of zinc. Every time that the wire was brought into contact with the zinc, muscular contractions took place. I am well aware, that the advocates for metallic electricity will deduce from the plain statement of this fact, an induction contrary to Galvanism; but my candour, on this occasion, will show how much I am attached to the cause of truth.

EXPERIMENT IV.

Among animal bodies, the torpedo is one of those which produce the most powerful Galvanic action. In the autumn of 1801, I made some experiments on this animal at Genoa, in conjunction with Professor Mojon and his brother, who gave me every assistance in their power. When I touched the torpedo, under water, at the moment when it gave the shock, it contracted itself, and two jets of water proceeded from the two holes in its head. To obtain the shock, it was not necessary to touch two distinct parts of its body: in many cases, the application of the hand to the electric organ was sufficient.