Page:A History of the Medical Department of the University of Pennsylvania.djvu/173

 organs is not always reciprocal; why the sympathetic effect is not perpetual, as it ought to be, if the causes of sympathy were mechanical; and why an organ is not affected directly by an irritant cause, in the same way that it is by sympathy from the impression made by this cause upon another organ.”

At the commencement of the present century, when the preceding indefinite propositions were written, the functions of particular nerves and of the different portions of the nervous centres were unknown. The discovery of the motor and sensitive columns of the spinal marrow first lifted the veil which concealed the secret machinery of nervous action, and led to the only philosophical method of experimenting—the study of the nerves separately in their functional relations.

It is to be inferred that Dr. Chapman derived his ideas of sympathy from the writings of Cullen, and of the professors of the French school who have been mentioned, and he adhered to them to the termination of his career, during which revelation upon revelation was made in this line of research. By the investigations of Sir Charles Bell, Magendie, Flourens Müller, Hall, Bernard, Brown-Séquard, and others, sympathy from a mythical condition has assumed a tangible form for the enlightenment and guidance of practitioners of medicine and surgery. The error committed by Dr. Chapman was the rejection of the proof of an introduction into the circulation of medicinal or noxious substances, which has now become irrefragable, and constitutes, in great measure, the foundation of modern medicine.

The second peculiarity of Dr. Chapman’s teaching was the prominent part attributed to the stomach in connection with numerous diseases; indeed, the “fons et origo” of a large number of them. He, however, was not a maintainer of the opinion that gastric derangement was uniformly inflammatory; and in this he differed from Broussais, but he fully recognized the stomach as a ruling power in the maintenance of disease, and in directing the means for its removal. In this particular he 12