direct value to medicine, in the establishing of sound principles of physiology.
In the meantime, however, the practise of medicine labored under great difficulties and was largely a matter of empiricism. Without a knowledge of etiology, without pathological anatomy, that firm foundation for diagnosis, and without a rational therapy it could be nothing else. Mercury, cinchona, cathartics and bleeding were the general methods of treatment. Great and noble men filled the universities-and hospitals; they labored conscientiously, and elaborated systems, and did what they could to relieve human misery, but to the advance of the science of medicine they contributed little or nothing.
Anatomy as a descriptive science dealing with adult structures and their gross appearance had been well established; l)ut it waited for its fullest development upon the methods destined to establish histology and embryology. Experimental physiology, except as Haller and Hunter had influenced it, was an unknown field, soon, however, to be widely explored as the result of the introduction of instruments of precision and analytical methods. Pathology, dependent upon the methods of histology and physiology was marking time, and, in turn, internal medicine awaited the development of pathological anatomy. Surgery, slowly improving technical procedures, likewise marked time until anesthesia and asepsis opened new worlds to it.
The advance in these general subjects it is my intention to follow along the lines of physics, chemistry and biology, as they developed in France, England and Germany. And, if in the course of this presentation I have much to say about the work shops of these sciences, it is because universities, laboratories and hospitals, as. well as societies and journals, represent the visible machinery of nineteenth century research in medicine, and whether we regard them as the cause or the effect of the awakening of 70 years ago, they to-day constitute our hope for the future of medical research.
It is difficult to select a starting point for a systematic survey. Chemistry, however, appears to promise the most direct course, for it was toward the end of the eighteenth century that Lavoisier introduced the modern scientific spirit of exact measurement as applied to chemical phenomena and through it established the great reform responsible for modern chemical knowledge and research. Carbonic acid had already been discovered by Black, hydrogen by Cavendish, nitrogen by Rutherford and ammonia by Priestley; oxygen had been studied by Priestley, Scheele and Lavoisier, so that with Dalton's atomic theorv, Cavendish's analysis of the air and Lavoisier's study of oxidation, definite knowledge of the chemistry of air and water, and of combustion and respiration was at hand for the use of the physiologist and physiological chemist. At about the same time the science of crystallography
