Harvey was as indefatigable a labourer as any we have named. He spent not less than eight long years of investigation and research before he published his views of the circulation of the blood. He repeated and verified his experiments again and again, probably anticipating the opposition he would have to encounter from the profession on making known his discovery. The tract in which he at length announced his views, was a most modest one,—but simple, perspicuous, and conclusive. It was nevertheless received with ridicule, as the utterance of a crack-brained impostor. For some time, he did not make a single convert, and gained nothing but contumely and abuse. He had called in question the revered authority of the ancients; and it was even averred that his views were calculated to subvert the authority of the Scriptures and undermine the very foundations of morality and religion. His little practice fell away, and he was left almost without a friend. This lasted for some years, until the great truth, held fast by Harvey amidst all his adversity, and which had dropped into many thoughtful minds, gradually ripened by further observation, and after a period of about twenty-five years, it became generally recognised as an established scientific truth.

The difficulties encountered by Dr. Jenner in promulgating and establishing his discovery of vaccination as a preventive of small-pox, were even greater than those of Harvey. Many, before him, had witnessed the cow-pox, and had heard of the report current among the milkmaids in Gloucestershire, that whoever had taken that disease was secure against small-pox. It was a trifling, vulgar rumour, supposed to have no significance whatever; and no one had thought it worthy of investigation, until it was accidentally brought under the notice of Jenner. He was a youth, pursuing his studies at Sodbury, when his attention was arrested by the casual observation made by a country girl who came to his master’s shop for advice. The small-pox was mentioned, when the girl said, “I can’t take that disease, for I have had cow-pox.” The observation immediately riveted Jenner’s attention, and he forthwith set about inquiring and making observations on the subject. His professional friends, to whom he mentioned his views as to the prophylactic virtues of cow-pox, laughed at him, and even threatened to expel him from their society, if he persisted in harassing them with the subject. In London he was so fortunate as to study under John Hunter, to whom he communicated his views. The advice of the great anatomist was thoroughly characteristic: “Don’t think, but try; be patient, be accurate.” Jenner’s courage was supported by the advice, which conveyed to him the true art of philosophical investigation. He went back to the country to practise his profession and make observations and experiments, which he continued to pursue for a period of twenty years. His faith in his discovery was so implicit that he vaccinated his own son on three several occasions. At length he published his views in a quarto of about seventy pages, in which he gave the details of twenty-three cases of successful vaccination of individuals, to whom it was found afterwards impossible to communicate the small-pox either by contagion or inoculation. It was in 1798 that this treatise was published; though he had been working out his ideas since the year 1775, when they had begun to assume a definite form.

How was the discovery received? First with indifference, then with active hostility. Jenner proceeded to London to exhibit to the profession the process of vaccination and its results; but not a single medical man could be induced to make trial of it, and after fruitlessly waiting for nearly three months, he returned to his native village. He was even caricatured and abused for his attempt to “bestialize” his species by the introduction into their systems of diseased matter from the cow’s udder. Vaccination was denounced from the pulpit as “diabolical.” It was averred that vaccinated children became “ox-faced,” that abscesses broke out to “indicate sprouting horns,” and that the countenance was gradually “transmuted into the visage of a cow, the voice into the bellowing of bulls.” Vaccination, however, was a truth, and notwithstanding the violence of the opposition, belief in it spread slowly. In one village, where a gentleman tried to introduce the practice, the first persons who permitted themselves to be vaccinated were absolutely pelted and driven into their houses if they appeared out of doors. Two ladies of title—Lady Ducie and the Countess of Berkeley—to their honour be it remembered—had the courage to vaccinate their children; and the prejudices of the day were at once broken through. The medical profession gradually came round, and there were several who even sought to rob Dr. Jenner of the merit of the discovery, when its importance came to be recognised. Jenner’s cause at last triumphed, and he was publicly honoured and rewarded. In his prosperity he was as modest as he had been in his obscurity. He was invited to settle in London, and told that he might command a practice of 10,000l. a year. But his answer was, “No! In the morning of my days I have sought the sequestered and lowly paths of life—the valley, and not the mountain,—and now, in the evening of my days, it is not meet for me to hold myself up as an object for fortune and for fame.” During Jenner’s own life-time the practice of vaccination became adopted all over the civilized world; and when he died, his title as a Benefactor of his kind was recognised far and wide. Cuvier has said, “If vaccine were the only discovery of the epoch, it would serve to render it illustrious for ever; yet it knocked twenty times in vain at the doors of the Academies.”

Not less patient, resolute, and persevering was Sir Charles Bell in the prosecution of his discoveries relating to the nervous system. 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 I have 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. Nevertheless, Herschel succeeded, after long and painful labour, in completing a five-foot reflector, with which he had the gratification of observing the ring and satellites of Saturn. Not satisfied with his triumph, he proceeded to make other instruments in succession, of seven, ten, and even twenty feet. In constructing the seven-foot reflector, he finished no fewer than two hundred specula before he produced one that would bear any power that was applied to it,—a striking instance of the persevering laboriousness of the man. While gauging the heavens with his instruments, he continued patiently to earn his bread by piping to the fashionable frequenters of the Pump-room. So eager was he in his astronomical observations, that he would steal away from the room during an interval of the performance, give a little turn at his telescope, and contentedly return to his oboe. Thus working away, Herschel discovered the Georgium Sidus, the orbit and rate of motion of which he carefully calculated, and sent the result to the Royal Society; when the humble oboe player found himself at once elevated from obscurity to fame. He was shortly after appointed Astronomer Royal, and by the kindness of George III. was placed in a position of honourable competency for life. He bore his honours with the same meekness and humility which had distinguished him in the days of his obscurity. So gentle and patient, and withal so distinguished and successful a follower of science under difficulties, perhaps cannot be found in the entire history of biography.

The career of William Smith, the father of English geology, though perhaps less known, is not less interesting and instructive as an example of patient and laborious effort, and the diligent cultivation of opportunities. He was born in 1769, the son of a yeoman farmer at Churchill, in Oxfordshire. His father dying when he was but a child, he received a very sparing education at the village school, and even that was to a considerable extent interfered with by his wandering and somewhat idle habits as a boy. His mother having married a second time, he was taken in charge by an uncle, also a farmer, by whom he was brought up. Though the uncle was by no means pleased with the boy’s love of wandering about, collecting “poundstones,” “pundips,” and other stony curiosities which lay scattered about the adjoining land, he yet enabled him to purchase a few of the necessary books wherewith to instruct himself in the rudiments of geometry and surveying; for the boy was already destined for the business of a land-surveyor. One of his marked characteristics, even as a youth, was the accuracy and keenness of his observation; and what he once clearly saw he never forgot. He began to draw, attempted to colour, and practised the arts of mensuration and surveying, all without regular instruction; and by his efforts in self-culture, he shortly became so proficient, that he was taken on as assistant to a local surveyor of ability in the neighbourhood. In carrying on his business he was constantly under the necessity of traversing Oxfordshire and the adjoining counties. One of the first things he seriously pondered over, was the position of the various soils and strata that came under his notice on the lands which he surveyed or travelled over; more especially the position of the red earth in regard to the lias and superincumbent rocks. The surveys of numerous collieries which he was called upon to make, gave him further experience; and already, when only twenty-three years of age, he contemplated making a model of the strata of the earth.

While engaged in levelling for a proposed canal in Gloucestershire, the idea of a general law occurred to him relating to the strata of that district. He conceived that the strata lying above the coal were not laid horizontally, but inclined, and in one direction, towards the east; resembling, on a large scale, “the ordinary appearance of superposed slices of bread and butter.” The correctness of this theory he shortly after confirmed by observations of the strata in two parallel valleys, the “red ground,” “lias,” and “freestone” or “oolite,” being found to come down in an eastern direction, and to sink below the level, yielding place to the next in succession. He was shortly enabled to verify the truth of his views on a larger scale, having been appointed to examine personally into the management of canals in England and Wales. During his journeys, which extended from Bath to Newcastle-on-Tyne, returning by Shropshire and Wales, his keen eyes were never idle for a moment. He rapidly noted the aspect and structure of the country through which he passed with his companions, treasuring up his observations for future use. His geologic vision was so acute, that though the road along which he passed from York to Newcastle in the post chaise was from five to fifteen miles distant from the hills of chalk and oolite on the east, he was satisfied as to their nature, by their contours and relative position, and their ranges on the surface in relation to the lias and “red ground” occasionally seen on the road.

The general results of his observation seem to have been these. He noted that the rocky masses of country in the western parts of England generally inclined to the east and south-east; that the red sandstones and marls above the coal measures passed beneath the lias, clay, and limestone, that these again passed beneath the sands, yellow limestones and clays, forming the table-land of the Cotswold Hills, while these in turn passed beneath the great chalk deposits occupying the eastern parts of England. He further observed, that each layer of clay, sand, and limestone held its own peculiar classes of fossils; and pondering much on these things, he at length came to the then unheard-of conclusion, that each distinct deposit of marine animals, in these several strata, indicated a distinct sea-bottom, and that each layer of clay, sand, chalk, and stone, marked a distinct epoch of time in the history of the earth.

This idea took firm possession of his mind, and he could talk and think of nothing else. At canal boards, at sheep-shearings, at county meetings, and at agricultural associations, ‘Strata Smith,’ as he came to be called, was always running over with the subject that possessed him. He had indeed made a great discovery, though he was as yet a man utterly unknown in the scientific world. He proceeded to project a map of the stratification of England; but was for some time deterred from proceeding with it, being fully occupied in carrying out the works of the Somersetshire coal canal, which engaged him for a period of about six years. He continued, nevertheless, to be unremitting in his observation of facts; and he became so expert in apprehending the internal structure of a district and detecting the lie of the strata from its external configuration, that he was often consulted respecting the drainage of extensive tracts of land, in which, guided by his geological knowledge, he proved remarkably successful, and acquired an extensive reputation.