On the cessation of this most fearful of plagues, Dr. Reid, after a short interval, and while he was yearning for active employment, received two offers. The one was to settle in a medical vacancy near his native Bathgate, where he might have secured the quiet, easy, and respectable life of a country doctor, and talked politics with the parish minister, or general gossip with the laird’s family. The other offer was to become a partner in the school of anatomy in Old Surgeons’ Hall, Edinburgh, where the growing crowd of students required an addition to the usual staff of instructors. Here, as demonstrator, his duty would be a revolting one. He would have to wait all day, like a ghoul, in the dissecting-room, amidst mangled human subjects, and expound, from morning till night, the construction of these revolting masses, and trace in them the sources of those various maladies which flesh is heir to. He felt that he must thus dwell among the dead to benefit the living. He knew, also, that in this way alone he could prosecute those anatomical researches in reference to physiology, to which his whole heart was so intensely devoted. On this account, he did not hesitate to accept the office, notwithstanding the horror of his family at the idea of one of their number being a mangler of the dead—a very henchman of the common executioner! From 1833 to 1836, he continued to be the demonstrator of Old Surgeons’ Hall, and his labours in this capacity have elicited the most enthusiastic encomiums from those distinguished successors who were originally his pupils. "He was the most painstaking demonstrator," one of them declares, "I ever knew or heard of. No ‘grinder’ paid by the hour could have displayed more patience, or taken more trouble to make anatomy easy to the meanest capacity. Where he might have contented himself in the discharge of his duty, by a bare demonstration and description of the parts, he seemed to be animated by a sincere purpose of stereotyping his lesson on the memory and understanding of the dullest of his audience. His patience with those who wished to learn had no limit." "We used to crowd round him," another pupil writes, "and ask questions on any point that was not thoroughly understood; but this was very seldom necessary; for such was the order, clearness, and minuteness of his description, that the subject was indeed made easy to the dullest comprehension. That kind of instruction, also, which with him, as with every great anatomist of this country, sought for illustration in those points bearing on surgical or medical practice, was never lost sight of; and I, for one, up to this hour, and I firmly believe on this account, have never forgotten his admirable demonstrations." In this way he was wont, during nine months of each year, to give instructions daily in the dissecting-room from nine in the morning till four in the afternoon; and as some time was necessary for rest after such fatiguing labours, he generally commenced his private studies late in the evening, and continued them till long after midnight, declaring that he always found himself fittest for work when other people were going to their beds. He also attended, on the evenings of the six months of winter, the meetings of the scientific societies in Edinburgh connected with his profession, where the discussions were of such an interesting character as to attract the intellectual of every class, either as members or auditors. At this time, also, he gave the fruits of some of his more diligent investigations in the form of essays read before these societies, which were published in 1835. Two of these were on certain curious structures observed in connection with the veins; a third was on the organization of certain glands in the whale, and some peculiarities in the internal arrangement of the blood-vessels of man during the period of juvenility. But amidst all this heroism of labour and research, we must confess that with Dr. Reid one important subject had been, and still continued to be omitted. On one occasion, a discussion among some of his medical friends who had met in his apartment was carried on, in which a religious question was involved, and Scripture was appealed to as conclusive evidence. But on searching his well-stored library for a Bible to quote chapter and verse, none could at first be found; and it was only after careful rummaging, that at length this most momentous of all volumes was found thrust behind the other books, and covered with dust. He was at present labouring for distinction, and had no time to study it; by and by, when the prize was won, he would again read his Bible, as he had done when he was a boy. It is well that this indifference, lately so common among intellectual men, is now regarded not only as profane, but even unliterary, and in bad taste. It was well, also, for Reid, that that "more convenient season," which so many have expected in vain, was vouchsafed to him at last.

In consequence of the high reputation which Dr. Reid had acquired as the anatomical demonstrator of Old Surgeons’ hall during three years’ attendance, he was unanimously called, by his brethren of Edinburgh, to occupy a more honourable and important office. It was that of lecturer on physiology in the Extra -Academical Medical School, now left vacant by the death of Dr. Fletcher, author of the "Rudiments of Physiology." Into this new sphere he removed with considerable reluctance, for he was diffident of his powers as a lecturer, which were still untried. His perseverance, however, not only overcame his timidity, but enabled him to become as distinguished in the oratorical as he had formerly been in the conversational form of instruction. He now also had more leisure for self-improvement, as his course for the year commenced in November, and terminated with the close of April. In 1838 he was appointed pathologist to the Royal Infirmary of Edinburgh, where his duties consisted in collecting the weekly statistics of the institution, and conducting the postmortem examinations of the patients who had died in the hospital; and in the following year, he was also appointed superintendent of the infirmary. In this last capacity, we are told in the "Monthly Journal of Medical Science," "he carried into his inquiries concerning morbid anatomy and pathology, the same accuracy in observing facts, and the same cautious spirit in drawing inferences from them, that characterized his anatomical and physiological researches. He at once saw the necessity of making his position serviceable to the advancement of medical knowledge, and, struck with the inconsistencies which existed as to the absolute and relative size and weight of the principal organs of the body, he commenced another laborious investigation on this subject. He introduced weighing-machines into the pathological theatre, by means of which the weight of the entire body was first ascertained, and then, respectively, the weights of the different organs." In 1839 Dr. Reid was candidate for the chair of medicine in King’s College, Aberdeen, but was unsuccessful; in the same year he was candidate for the chair of anatomy in Marischal College, and was again unsuccessful. These disappointments, however, he bore with such good humour, as consciousness of desert, and hope of better luck in store, acting upon a naturally cheerful, buoyant spirit, seldom fail to supply. Already he had broken ground, and most successfully, into those discoveries upon the anatomy and physiology of the heart, and especially of the nervous system, upon which he may be said to have established for himself a European reputation; and in the latter department he had produced and read before the British Association an epitome of his "Experimental Investigation into the Functions of the eight pair of nerves, or the glosso-pharyngeal, pneumogastric, and spinal accessory." The light which was dawning upon him in the course of these investigations was soon to be worth more than the distinction that can be conferred by a seat upon the bench of a College Senatus Consultum. All this was soon after attested at a public scientific meeting, in which it was declared, among other just encomiums, that Dr. Reid, by his "original investigations into the physiology of the nervous system, had made the profession acquainted with valuable facts, which had at once enriched the science their discoverer cultivated, and procured for himself an extensive and enviable reputation." Such was the testimony of Professor Alison, one of the most competent of judges upon such a subject.

Having now attained a high reputation in his own favourite walks of science, an appointment soon offered that consoled Dr. Reid for his late mischances. This was the professorship of anatomy in the university of St. Andrews, which was conferred upon him in March, 1841. He had now only reached his thirty-first year; and from what he had already accomplished, combined with his robust, vigorous, healthy constitution, it was hoped that a long life was yet in store for him, as well as an ample field of research and discovery. He commenced in winter the course of lectures that properly belonged to his professorship; but as this class, composed of medical students only, was too limited a sphere, he also delivered a course of lectures on comparative anatomy and general physiology, which all were free to attend gratuitously, whether from town or college. A delighted crowd usually assembled at these prelections, composed not only of professors, ministers, and students from several classes, but also of the citizens of St. Andrews, whose earnest animated attention would of itself have been a rich reward to any public instructor. But even amidst all this, Dr. Reid felt that there was something wanting. St. Andrews was not a medical school of any mark, as most of the county students destined for the healing profession were wont to pass over to the university of Edinburgh. Besides, it was difficult to procure subjects, without which anatomical dissertations are all but useless—for even yet there still lingered among the living of Fifeshire that jealous care of their dead, which was placarded not a hundred years ago over one of their cemeteries, in these ominous words: "Whoever enters this churchyard will be shot." These drawbacks he felt so sensitively that he was impatient for wider action, until 1844, when St. Andrews was converted into a happy home for him, by his marriage with Miss Ann Blyth. Four years followed, in which his researches were chiefly directed to the natural history of the marine animals so plentiful on the Fifeshire coast, and the results of which he communicated in several papers to the "Annals and Magazine of Natural History." In 1848 he made a collection, in one volume, of the essays which he had published in several scientific journals during the course of thirteen years. The work is entitled, "Physiological, Anatomical, and Pathological Researches," and consists of twenty-eight articles. Of the value of these, especially of the six that contain the results of his inquiries into the functions of living organs, it would be impossible to convey an adequate idea, without such a full analysis as would far exceed the plan and limits of our work. We content ourselves with quoting, from a host of congenial critics who reviewed the volume, the opinions of one who was well qualified to estimate its worth. "As a physiologist," says Dr. J. H. Bennett, "he (Dr. Reid) may be considered to have been unsurpassed; not, indeed, because it has fallen to his lot to make those great discoveries or wide generalizations which constitute epochs in the history of the science, but because he possessed such a rare degree of caution and conscientiousness in all his researches, that no kind of investigation, whether literary, anatomical, physiological, or pathological, that could illustrate any particular fact, did he ever allow to be neglected. . . .His volume contains more original matter and sound physiology than will be found in any work that has issued from the British press for many years."