“On a course on the pathological physiology of the circulation,” with demonstration of instruments,specimens,etc.

In general in the teaching of pathology the anatomical alterations produced by disease are dwelt upon, and little attention is devoted to the detailed study of the alterations in function produced by these diseases. A course was arranged during the past year at the Johns Hopkins University to cover this ground and half of the new laboratory of experimental medicine was planned to give facilities for this work.

The aim of the course was to reproduce experimentally such diseased conditions as are seen by the students in the wards of the hospital so that they might be studied with the aid of any or all of the methods at the command of the physiologist and of the pathologist. The study of the anatomical changes which are usually found in such conditions was carried on together with these experiments.

It was planned to attempt the study of only a limited portion of the subject each year, and during the past term the diseases of the circulatory system have occupied the attention of the class. Next year it is intended to study the digestive system in a similar way.

Only those lesions were produced of which experimental study was certain to be of value — thus in the case of the pericardium, while various infections might have been used to give rise to an exudate, the blood-pressure relations, changes in heart-beat, heart-sounds, etc., were studied during the distention of the pericardium with water.

Similarly it was thought sufficient to study mechanical injuries of the heart-valves rather than to attempt their production with the aid of bacteria. Therefore, while the actual lesions were studied in the museum and histologically, the injuries to the valves were produced by cutting the valves with a special blunt hook having a knife edge on the inner side of the curve. The pressure relations were then rendered visible to the students by the curves traced in inks of different colors from cannulas inserted at various points in the circulation.