VI. ON THE AGGLUTINATION AND DISSOLUTION OF 



RED BLOOD CELLS BY THE SERUM OF ANIMALS 



INJECTED WITH DEFIBRINATED BLOOD.* 



By DR. JULES BORDET. 



In an article published in lS95f we called attention to the 

 following facts: 



First : — The serum of animals which have been vaccinated against 

 the cholera vibrio causes a remarkable phenomenon when mixed 

 with a culture of vibrios suspended in salt solution or bouillon. 

 A very small dose of this serum will cause a loss of motility in the 

 bacteria and will collect them in masses or clumps. If the serum 

 has been freshly obtained and added in a sufficient dose to the 

 emulsion its action on the bacteria is still more extensive. The 

 vibrios that have been clumped are soon transformed into granules 

 identical with those observed by Pfeiffer in the peritoneal cavity of 

 immunized guinea-pigs on injecting a culture, and the same as 

 those produced by Metchnikoff in vitro by mixing an emulsion 

 of vibrios, preventive serum, and peritoneal exudate containing 

 leucocytes. This granular transformation is the visible indication 

 of an extensive destruction of the bacteria. 



Second : — Serum kept for some time or heated to 55 degrees loses 

 its power to produce a granular transformation in vibrios but still 

 clumps them. This clumping always occurs in the presence of 

 preventive serum and may, therefore, be very marked with a serum 

 deprived of its bactericidal activity. 



We may note that Fraenkel and Sobernheim (Hygienische Rund- 

 schau, January, 1894) had already noted that cholera serum heated 

 to 55 degrees or even as high as 60 degrees or 70 degrees C. loses its 

 bactericidal power but retains its preventive power. 



* Sur l'agglutination et dissolution des globules rouges par le serum d'animaux 

 injectes de sang defibrine\ Annales de l'lnstitut Pasteur, 1898, XII, 688. 

 t See p. 8. 



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