self did acknowledge, that he misinterpreted an experiment in his first attempt to prove that which he afterwards did prove through Mr. John Shaw, that the fifth nerve is a nerve of motion as well as of sensation. And we may agree in receiv- ing with doubt, or at least without conviction, as not proved, his views with respect to certain nerves being superadded in the higher classes of animals, for the purposes of respiration.
But, after all these acknowledgments, there re- mains to Bell clearly and unequivocally the merit of having first shown—
That in investigating the functions of the nervous system, we must direct our attention to the roots and not to the trunks of the nerves.
That the nervous trunks conveying motion and sensation, consist of two distinct sets of filaments in the same sheath.
That the filaments for motion form a distinct root from those for sensation, and that the anterior roots are for motion ; leaving it to be inferred that the posterior are for sensation.
That the portio dura is a nerve of motion, and the fifth a nerve both of motion and sensation.
And lastly, of having been the first who, dis- satisfied with the observation and study of the mere form of the various parts of the nervous system, applied the method of experiment to aid him in determining their functions.
In a word, there belongs to Bell the great dis- covery, the greatest in the physiology of the nervous system for twenty centuries, that distinct portions
