Previous to his time, the most confused notions prevailed as to the functions of the nerves, and this branch of study was little more advanced than it had been in the times of Democritus and Anaxagoras three thousand years before. Sir Charles Bell, in the valuable series of papers the publication of which was commenced in 1821, took an entirely original view of the subject, based upon a long series of careful, accurate, and oft-repeated experiments.
Elaborately tracing the development of the nervous system up from the lowest order of animated being, to man - the lord of the animal kingdom, - he displayed it, to use his own words, "as plainly as if it were written in our mother-tongue." His discovery consisted in the fact, that the spinal nerves are double in their function, and arise by double roots from the spinal marrow, - volition being conveyed by that part of the nerves springing from the one root, and sensation by the other. The subject occupied the mind of Sir Charles Bell for a period of forty years, when, in 1840, he laid his last paper before the Royal Society. As in the cases of Harvey and Jenner, when he had lived down the ridicule and opposition with which his views were first received, and their truth came to be recognised, numerous claims for priority in making the discovery were set up at home and abroad. Like them, too, he lost practice by the publication of his papers; and he left it on record that, after every step in his discovery, he was obliged to work harder than ever to preserve his reputation as a practitioner. The great merits of Sir Charles Bell were, however, at length fully recognised; and Cuvier himself, when on his death-bed, finding his face distorted and drawn to one side, pointed out the symptom to his attendants as a proof of the correctness of Sir Charles Bell's theory.
An equally devoted pursuer of the same branch of science was the late Dr. Marshall Hall, whose name posterity will rank with those of Harvey, Hunter, Jenner, and Bell. During the whole course of his long and useful life he was a most careful and minute observer;and no fact, however apparently insignificant, escaped his attention. His important discovery of the diastaltic nervous system, by which his name will long be known amongst scientific men, originated in an exceedingly simple circumstance. When investigating the pneumonic circulation in the Triton, the decapitated object lay upon the table; and on separating the tail and accidentally pricking the external integument, he observed that it moved with energy, and became contorted into various forms. He had not touched a muscle or a muscular nerve; what then was the nature of these movements? The same phenomena had probably been often observed before, but Dr. Hall was the first to apply himself perseveringly to the investigation of their causes; and he exclaimed on the occasion, "I will never rest satisfied until Ihave found all this out, and made it clear." His attention to the subject was almost incessant; and it is estimated that in the course of his life he devoted not less than 25,000 hours to its experimental and chemical investigation. He was at the same time carrying on an extensive private practice, and officiating as lecturer at St. Thomas's Hospital and other Medical Schools. It will scarcely be credited that the paper in which he embodied his discovery was rejected by the Royal Society, and was only accepted after the lapse of seventeen years, when the truth of his views had become acknowledged by scientific men both at home and abroad.
The life of Sir William Herschel affords another remarkable illustration of the force of perseverance in another branch of science. His father was a poor German musician, who brought up his four sons to the same calling. William came over to England to seek his fortune, and he joined the band of the Durham Militia, in which he played the oboe. The regiment was lying at Doncaster, where Dr. Miller first became acquainted with Herschel, having heard him perform a solo on the violin in a surprising manner. The Doctor entered into conversation with the youth, and was so pleased with him, that he urged him to leave the militia and take up his residence at his house for a time. Herschel did so, and while at Doncaster was principally occupied in violin-playing at concerts, availing himself of the advantages of Dr. Miller's library to study at his leisure hours. A new organ having been built for the parish church of Halifax, an organist was advertised for, on which Herschel applied for the office, and was selected. Leading the wandering life of an artist, he was next attracted to Bath, where he played in the Pump-room band, and also officiated as organist in the Octagon chapel. Some recent discoveries in astronomy having arrested his mind, and awakened in him a powerful spirit of curiosity, he sought and obtained from a friend the loan of a two-foot Gregorian telescope. So fascinated was the poor musician by the science, that he even thought of purchasing a telescope, but the price asked by the London optician was so alarming, that he determined to make one. Those who know what a reflecting telescope is, and the skill which is required to prepare the concave metallic speculum which forms the most important part of the apparatus, will be able to form some idea of the difficulty of this undertaking.
