III. STUDIES ON HAEMOLYSIS. 1 



THIRD COMMUNICATION. 2 

 By Professor Dr. P. EHRLICH and Dr. J. MORGENROTH. 



BY injecting one animal with the cells of another, we can produce 

 substances in the serum of the first, which have a specific damaging 

 or destructive influence on these cells. This possibility has within 

 a short time extended the theoretical doctrines of immunity in vari- 

 ous directions. First Belfanti and Carbone showed that the serum 

 of animals, after these had been treated with blood-cells of a differ- 

 ent species, acquires a high degree of toxicity for just this species- 

 Shortly afterward, Bordet was able to demonstrate that this toxicity 

 in corpore corresponds to a specific haemolysis in vitro. This was 

 confirmed independently by von Dungeni and Landsteiner by experi. 

 ments published somewhat later, and further by those of our own 

 mentioned in previous communications. The result of the experi- 

 ments is always, that, following the introduction of red blood-cells 

 of one species into the organism of another, a hsernolysin is formed 

 which so injures the blood-cells of the first species that their haemo- 

 globin goes into solution. Bordet also showed that this haemolysis 

 depends on the action of two substances in the haemolytic serum. 



The importance of this subject, due specially to the complete 

 analogy between the hsemolytic and the bacteriolytic processes, 

 led us to a detailed study of the mechanism of these processes. We 

 were able to show that the substance produced by immunization, the 

 immune body, possesses a maximum chemical affinity for the corre- 

 sponding blood-cell. This affinity is due to the presence of a specific 

 combining group in the molecule of the immune body, which fits 

 to a corresponding group in the protoplasm of the erythrocyte. 

 Beside this, the immune body possesses a second combining group 



1 Reprint from the Berliner klin. Wochenschr. 1900, No. 21. 



2 See pages 1 and 11. 



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