Abstract

1. A method has been devised by which diffusible constituents may be removed from the blood of a living animal, which does not involve any procedure prejudicial to life.

2. Two animals have made rapid and complete recovery after being subjected to the procedure for two and three hours respectively.

3. The method has been shown to be available for collecting from the blood, under the ordinary conditions of physiological experimentation, substances present only in small amount at one time.

4. Several types of apparatus have been constructed adapted to various purposes, and full details as to methods of construction are given.

5. Experience has been accumulated on the use of hirudin, and the procedure adopted for the economical preparation of solutions of this active principle from leech heads is given in detail.

6. As an organ of elimination of abnormal substances (e.g., poisons), quantitative results obtained with salicylic acid show that the apparatus in its present form compares not preferably with the kidney. The direction of improvement is indicated and experiments in this direction are in progress.

7. Data as to the effect of the procedure on blood pressure are given. It is shown that general oedema in striking degree may result from neglect of certain precautions.

8. Material has been collected in large quantity for the study of the non-proteid amino-bodies present in the blood. The chemical separation of these bodies is in progress and only preliminary results are here given.

9. Directions in which the method may be utilized, both for the study of problems in physiological chemistry, and as a promising therapeutic agent, have been indicated.