Deciding to study medicine, young Bennett was apprenticed to a Mr. Sedgwick of Maidstone, and for a short time attended St. Bartholomew’s Hospital. A little later, however, he decided to enter at Edinburgh University, and soon showed himself an assiduous student. He made the acquaintance of Edward Forbes, J. H. Balfour, John Reid, and others, who afterwards distinguished themselves, and became one of the Presidents of the Royal Medical Society. In 1837 he took the M.D. degree, being awarded a gold medal, on Syme’s recommendation, for the best surgical report, and being mentioned as worthy of a second medal by Sir Charles Bell.
Bennett next studied for two years in Paris, founding the Parisian Medical Society, of which he was the first president. Other two years he devoted to study in German medical schools. The microscope and the stethoscope became in his hands familiar implements of research, and he already began to give forth the results of his study, contributing to Tweedie’s “Library of Medicine” a large proportion of the second volume dealing with diseases of the nervous system.
Bennett returned to Edinburgh in 1841, and on the 1st October published “Treatise on the Oleum Jecoris Aselli, or Cod-liver Oil, as a Therapeutic Agent in certain Forms of Gout, Rheumatism, and Scrofula, with Cases.” His knowledge of this remedy had been acquired in Germany, where cod-liver oil was being used in the treatment of these diseases. Its use had however long been known among the Scotch fishing folk, and Drs. Kay and Bardsley had many years before prescribed it in the Manchester Infirmary. The publication, however, stagnated, and there was added in 1847 to the remaining copies an appendix of cases benefited by cod-liver oil. By this time its administration was decidedly on the increase, and one firm of druggists in Edinburgh had sold six hundred gallons in the preceding year, as compared with one gallon in 1841. At the same time Dr. C. J. B. Williams was introducing purer forms of the oil in London, as we have already related, and by his writings and practice and study of cases of pulmonary consumption did very much to promote its general use.
In November 1841 Bennett started a course of lectures on histology at Edinburgh, in which he illustrated physiology and pathology by microscopical preparations: he also formed classes for private instruction in microscopical manipulation. At that time minute changes in structure were generally overlooked, and to Bennett belongs the credit of first giving such instruction in a systematic form. He strongly desired to gain the chair of General Pathology at Edinburgh, which was vacant in 1842, but he was unsuccessful.
When he was soon afterwards appointed physician to the Royal Dispensary, Bennett had an opportunity of putting into practice what he had learnt in Germany, by establishing what he called a polyclinical course, his students being taught practically, under the eye of the teacher, to examine and prescribe for patients. It must not be forgotten, however, that Syme had previously introduced a somewhat similar procedure at his Minto House (Surgical) Hospital. As Pathologist to the Royal Infirmary, Bennett had great opportunities of studying morbid specimens, and he got together a large pathological collection. He further gave courses of lectures on pathology.
For many years Bennett took a large part in maintaining the literary activity of the Edinburgh School. Many papers by him appeared in the London and Edinburgh Monthly Journal of Medical Science, of which he subsequently was part and sole proprietor two or three times, being so lucky as to make a profit on each of his transactions.
In 1848 Dr. Bennett was unanimously elected Professor of the Institutes of Medicine (i.e., Physiology) at Edinburgh. In this new work he was soon conspicuous for the practicality of his teaching, and for his continual introduction of matters bearing on pathology and medicine. He made every lecture a complete study, enriching it with all the appliances, material and artistic, that he could command, and embellishing it by finished elocution. He would now and again lay aside his manuscript to comment upon, and frequently to denounce, the opinions of others, by which course he made enemies, for he was not sufficiently measured in his treatment of opponents. Yet it might safely be said that he was not actuated by personal hostility, but only by antagonism of view. Still he was too favourable to his own work, and did not adequately appreciate other men. The general student enjoyed those peculiarities of Dr. Bennett of which he did not himself feel the brunt, but in the clinical class or in the examination hall his unsparing logical acumen tasked the student mind somewhat severely, and he was a generally dreaded examiner.
From the peculiar organisation of Edinburgh work Bennett was expected to be a clinical teacher of medicine as well as a professor of physiology; thus the importance of his work in the infirmary was as great as that in the lecture-room. He was a clinical teacher of the highest order—nothing was suffered to pass unnoticed. All methods of inquiry into the patient’s case were diligently taught to the students, who were led to observe precisely and methodically for themselves. He would test and stimulate his pupils[15] most acutely by disputation, questioning, and argument; and he thus trained a body of men who carry his impress into all their work.
In 1845 Dr. Bennett published a case of “Hypertrophy of the Spleen and Liver,” which is the first recorded case of a disease characterised by a great abundance of white corpuscles in the blood, now known as leucocythæmia. Although Bennett did not at first recognise its true nature, his description and subsequent labours did much to elucidate the disease, and his name must be honourably associated with the subject.
Perhaps, however, the greatest service Bennett rendered to medicine, independently of his promotion of the use of cod-liver oil in phthisis, is his strong protest against the lowering treatment in pneumonia and other inflammatory diseases. On this point the Lancet (October 9, 1875) says: “He reduced the mortality of uncomplicated pneumonia to nil. He demonstrated, not only the dispensableness, but the injuriousness, of the antiphlogistic treatment which had ruled the best minds of the civilised world for ages. Doubtless other physicians were working in the same direction even before Bennett, but he devised a treatment of his own which has given most brilliant results, and he adhered to it and to the pathological views on which it was based so steadily and over so long a series of years as to establish its truth, and so largely revolutionise the practice of medicine in acute diseases.” Dr. Bennett’s later attacks on the mercurial treatment of liver diseases were almost equally strong with that on bleeding and the antiphlogistic methods, but being undertaken late in life did not leave such an impression.