field of pathological anatomy, in which he is generally recognized as the founder of the theory of cellular pathology. The character and value of his work in this field are reviewed by Professor Jacobi, of this city, in his address before the New York College of Physicians and Surgeons. He remarks that, before and about the time when Virchow was preparing to commence his career, medical science in Germany was by no means independent and self-governing. There was no country in Europe in which observation and regard for facts, and facts only, were less esteemed than in Germany. England had enjoyed a predilection for pathological anatomy since John Hunter. France had lived through its most brilliant medical career, and could show a roll of illustrious, sober, and painstaking men, whose successful labors had placed the medical science of that country far above the level of any other. "Meanwhile, German medicine was controlled by what was called philosophy, and mainly by the so-called philosophy of nature. . . . Everything in medicine, not accepted because it was old and traditional, was a matter of speculation a priori only. The bases of speculation were premises construed by reasoning, not founded on facts; by theories not built on experience, far less on experimentation. Both facts and experimentation were claimed by Virchow as the only admissible foundations of scientific medicine, no matter how long it would take to collect them or to establish them. At the same time he was perfectly well aware that the literature of the last two thousand years contained a great many available points; nobody ever was more honest in collecting material or giving credit."
Virchow wrote in the first volume of his "Archiv," in 1847: "We ought not to deceive ourselves or each other in regard to the present condition of medical science. Unmistakably, medical men are sick of the large number of new hypothetical systems which are thrown aside as rubbish, only to be replaced by similar ones. We shall soon perceive that observation and experiments only have a permanent value. Then, not as the outgrowth of personal enthusiasm, but as the result of the labors of many close investigators, pathological physiology will find its sphere. It will prove the fortress of scientific medicine, the outworks of which are pathological anatomy and clinical research."
The cell had been discovered to be the fundamental basis, by Schleiden, of the vegetable, and, by Schwann, of the animal tissues. Virchow, after a series of observations and experiments, became convinced that the cell had the power of propagating and multiplying itself within the individual, and proved that it is the physical body "with which the action of mechanical substance is connected, and within which the latter can retain its functions, which alone justify the name of life. Whatever outside of the cell acts upon it, works a mechanical or chemical change within it, which change is disorder or disease." The external cause may excite a reaction within the cell, when it works as an irritant, or it may go without reaction, when it