Commentary on the Effect of Electricity on Muscular Motion

Therefore, we erected a long and suitable conductor original: "conductorem"—namely an iron wire—in a higher part of the house, and we insulated it [Fig. 7, Tab. 2]. To this wire, when a storm arose in the sky, we hung either prepared frogs or the prepared legs of warm-blooded animals original: "calidorum animalium," referring to birds or mammals by their nerves, as seen in Fig. 20 and 21, Tab. 4. We also added another conductor—specifically another iron wire—to their feet; this one was very long, so that it reached all the way to the water of the well original: "putei" indicated in the figure.

The result turned out exactly as we had hoped, quite the same as in our experiments with artificial electricity electricity generated by machines like a Leyden jar or friction plate. Whenever the lightning broke out, at that same moment all the muscles fell into violent and multiple contractions. Just as the brightness and light of the lightning usually precede the sound of the thunder, the muscular movements and contractions of those animals preceded the thunderclaps, as if to provide a warning of them.

Indeed, so consistent was this phenomenon that the contractions occurred even when no conductor was added to the muscles, and even when the nerve conductor was not insulated at all. Furthermore, contrary to our expectations and belief, we were able to observe these same results even when the conductor was placed in lower locations [Fig. 8, Tab. 2], especially if the lightning flashes were large, if they broke out from clouds closer to the site of the experiment, or if someone held the iron wire (marked F) in their hands at the moment the lightning struck.

This phenomenon occurred whether the animal was exposed to the open air or, for convenience, had been enclosed in a suitable vessel [Fig. 7] or kept inside a room. It even occurred if the nerve conductor was at some distance from the nerves themselves, particularly with the more violent or closer lightning flashes—just as we said happened with artificial electricity when sparks were either stronger or drawn out closer to the animal.

Finally, one observation worthy of notice was that the entire process during a lightning strike was not completed by a single muscular contraction (as happens with a simple spark), but by several contractions succeeding each other in what seemed like a single moment of time. The number of these contractions seemed to correspond to the number of "crashes" original: "fragorum" that thunder is usually heard to produce.

Now, indeed, such contractions were produced not only by lightning, but they arose almost spontaneously when the sky was stormy and clouds were passing near the elevated nerve conductors. When this happened, the electrometers early instruments for detecting and measuring electric charge also gave significant [indications]...