—So long as this universal scourge of humanity has been the object of clinical study, it has been regarded as contagious; and this not merely by the people, but also by the profoundest minds of the medical profession.
Aristotle is reported to have so considered it, and Morgagni is said to have entertained such fear of its contagion, that he would not perform an autopsy on any one who died of the disease. For ages, the opinions of the profession were based upon clinical observation. At length, however, with advance in pathological knowledge, seekers after truth grew distrustful of mere clinical observation, and this method, with its liability to error, became subjected to the test of another.
Various of the lower animals were inoculated with tuberculous tissues; and though this procedure was likewise liable to error, it was thought to afford the best prospect of ultimately solving the problem. Klencke,