The Cullenian system forms an era in the history of medicine, which, from various causes, may perhaps escape the notice of future inquirers; for the physicians on the continent had scarcely escaped from the trammels of Boerhaave, before the eccentricities of Brown caught their attention; and to him they look for that revolution in the science, which taught that the functions of a living being were to be explained only by the laws of animation. Causes, already hinted at, have obscured the lustre of Dr. Cullen's fame; and it is left to a son to explain why the character of a father must be rescued from oblivion by strangers.
The early years of Dr. Cullen were spent in active life. He had few opportunities for study, but many for observation. Nature had given him an intuitive sagacity, which caught at every fact, and stored it advantageously for future use. Of his chemistry we have had little information; but, during his holding the professorship of chemistry, he gave a private course of pathology. This must be explained. The institutions of medicine comprehend physiology, pathology, hygieine (the doctrine of health), and therapeutics, the general doctrines of remedies. In the university of Edinburgh, at that period, the professor of the institutions confined his attention chiefly, and almost exclusively, to the first branch. The other subjects, therefore, confessedly of importance, were left open to any enterprising teacher. Such, apparently, at that time was our author; for we have many reasons to convince us, that even at this time he aspired to be the founder of a sect. In the pathology he had the best opportunities for laying his foundation; and the additional advantage of illustrating his principles by experience in the clinical lectures, which he gave at this time in the infirmary. We have seen some extracts from these lectures, and find in them the germ of his future system; the embryo, already formed, which required only to be evolved and augmented.
His fame gradually expanded till the year 1763, when an accidental circumstance rendered it more brilliant and extensive. In 1763, Dr. Alston, the professor of materia medica, died in the midst of his course; and Dr. Cullen either offered or was requested to continue it. A common genius would have copied in the moment of exigency, or repeated, with the slight variation which his own opinions suggested, the lectures of his predecessor. Dr. Cullen started at once into a new path, bold, comprehensive, and original. We remember our first opinions of it; and now that thirty-five succeeding years have cooled our ardour, uninterrupted study and practice added to our information, we can decidedly pronounce that his plan has not been excelled; has not publicly been equalled. We take it not from the improved edition of the author himself, but from the outline in the lectures originally delivered.
While our astonishment is excited by this apparently sudden display of talent, of united genius and industry, we must reflect that he had taken his degree; and, at the age of thirty-four, was elected professor of chemistry in Glasgow. This professorship he retained five years, when he was appointed professor of medicine in the same university. Five years after that period he became professor of chemistry at Edinburgh, viz. in 1756; and in 1763 did he continue the course of Dr. Alston. Seventeen years may have been, and probably were, employed in maturing a system which, with all its imperfections, is a splendid monument of genius; and though private practice, convivial hilarity, and the duties of his chemical chair, must have employed many of his hours; yet industry, a habit of early rising; above all, an able, comprehensive mind, which, at once catching the principle, included innumerable consequences, enabled him to retain a vast fund of medical erudition, and to complete those extensive views which seem already to have assumed a consistent form.
In 1765 he approached nearer to his object, by his appointment to the chair of the institutions of medicine, vacant by the death of Dr. Whytt; and, in 1769, the agreement between him and Dr. Gregory, to give alternately courses of the theory and practice of medicine, was carried into effect. These professors, at the same time, agreed to divide the clinical course.
It is not our subject to write the life of Dr. Cullen; but the events detailed are connected with our views of his system, and we have been enabled to add some facts, and correct some dates in the only narrative of his life which has any pretensions to accuracy, viz. that in the Supplement to the Encyclopedia Britannica, from our own knowledge.
The foundation of Dr. Cullen's system is, as we have hinted, considering the human body as a congeries of animated organs, regulated by the laws, not of inanimate matter, but of life, and superintended by an immaterial principle, acting wisely, but necessarily, for the general health; correcting deviations, and supplying defects, not from a knowledge and choice of the means, but by a pre-established relation between the changes produced, and the motions required for the restoration of health. This principle, in its various ramifications, influenced every part of his theory of medicine. The circulation was no longer to be explained by mechanical laws; the. angles at which the branches of the larger arteries divaricated, were shown to have little influence; lentor, viscidity, and acrimony, either acid or alkaline, were proved, if they existed, to have no influence in producing diseases. The whole was resolved into motions, regulated by the living principle, and chiefly influenced by the action or torpor of the extreme arteries.
This total revolution in the science was received by the younger with the stare of admiration, by the elder with doubt, suspicion, and dislike. From the system of Boerhaave there had been hitherto no appeal; and to doubt his theory was to undermine the whole fabric of medicine. Dr. Cullen was certainly considered for a time as a fanciful innovator; but, whatever may have been the deviations from his system even in Brown and Darwin, still it must be considered that each adopted the same great principle, and explained the functions of a living system by the laws of animation.