Another End to Infinity, Found in a Frog's Leg

Hermann von Helmholtz. “Note sur la vitesse de propagation de l'agent nerveux dans les nerfs rachidiens.” Published in Comptes Rendus vol 30, 25 February 1850, pp. 204-6. AND WITH: "Deuxieme Note surla vitesse de propagation de l'agentnerveux", again in .Comptes Rendus, vol 33, 1851 in pp. 262-5. Both are offered in their original weekly format, removed/extracted from a larger bound volume, the first paper with the original wrappers, and the second one without. Very good copies.  $750

This is an interesting chapter in the history of infinity—in this case, closing the boundaries of speed of the neural impulses. As with the speed of light (thought to be infinite or thereabouts into the 17^th century) the speed of “thought' or “pre-thought” was thought to be infinite until this paper by the polymathic von Helmholtz. Von H worked in many different fields and made major contributions across numerous disciplines—he was a very very impressive guy, and evidently a good teacher, and also of fine character (as seen in the 2^nd law business with Mayer). In this paper he was able to determine the speed of the nerve impulse in a frog, using its sciatic nerve and the calf it was connected to, and elegantly finding a speed of between 24-38 metres/sec., and presented in these two papers for the first time in French. The experiment was fairly simple and just remarkable, and presented the speed of the neural impulse at very much not light speed. And so, the infinity of the speed of thought—thought perhaps so because of religious demands—definitely had a bookend.