Page:Popular Science Monthly Volume 11.djvu/242

saw that he, too, was for that world a mirror worthy of love. He was full of religion and full of the holy spirit; and therefore he appears to us solitary and unequaled, master in his art, but lifted above the profane, without disciples, and without right of citizenship anywhere."

That right of citizenship you are now about to confer on him. Your monument will be the link between his genius and the earth. His spirit will brood like a guardian angel over the spot where his rapid journey among men came to its end. Woe to him who, in passing-by, should dare to level an insult at that gentle and pensive figure! He would be punished as all vulgar hearts are punished—by his very vulgarity and his impotence to comprehend the divine. Spinoza, meanwhile, from his granite pedestal shall teach to all the way of happiness he himself had found; and for ages to come the cultivated man who passes along the Pavilioengragt will inwardly say, "It is hence, perhaps, that God has been seen most near!"—Contemporary Review.

 

TRANSMISSION OF EXCITATIONS IN SENSORY NERVES.^[1]

By PAUL BERT.

PHYSIOLOGISTS are as yet by no means agreed whether the nerves which, from their special functions, have been termed motor and sensor nerves, are in their essential properties identical or different; in other words, whether a sensor nerve can transmit excitations whose result is motion, and vice versa. We do not even know whether an excitation produced midway in the length of a nerve is simultaneously propagated in both directions, centrifugally and centripetally. The admirable experiments made by Philipeaux and Vulpian to determine these knotty questions are, as Vulpian was the first to observe, susceptible of a different interpretation from that unanimously put upon them by the world of science.

Such being the state of the case, I thought it advisable to take up again an experiment I had made in 1863,^[2] but which I had neglected to prosecute, in view of the apparently far more conclusive and far more general results obtained by the able experimenters just named. This experiment I have now completed, and strengthened against any objection that might have been raised against it.

If we pinch a sensor nerve at any point of its length, the pain that is felt clearly shows that the excitation is propagated in the centripetal direction; but of a centrifugal propagation we know nothing, for the very simple reason that at the terminal extremity of the nerve

1. Translated from the French by J. Fitzgerald, A.M.
2. "Comptes rendus de la Société de Biologie (1863), p. 179.