228 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Bio-chemical Antagonisms.* — Emmerich and Loew, after referring 

 to the selective action exercised hy some fungi for optically active com- 

 ponents (some preferring the dextro-, others the laevo-) of an optically 

 inactive food-substance, suggest as a new theory of immunity, agglutina- 

 tion and hemolysis, that anti-bodies formed in the blood-serum of 

 animals are simply the optically active opposites of the bodies that 

 stimulated their production, and by combination with them form racemic 

 compounds which are inert physiologically as well as optically. 



Interpretation of Agglutination Reaction Results, f — The many 

 and conflicting opinions held by different observers with regard to 

 the meaning and value of agglutination reactions, led Dr. Goldberg to 

 attempt to determine the time at which the reaction first became appar- 

 ent in severe infections, and also to estimate, from the reaction, the 

 degree of immunity artificially conferred upon an animal, chiefly with 

 reference to infections caused by the B. pyocyaneus and the B. typhosus. 

 In performing the reactions he employed 24-hour-old broth cultiva- 

 tions of these organisms, filtered through Swedish filter-paper, and 

 blood itself diluted with normal saline solution, and examined for 

 half an hour in hanging-drop preparation. As the result of his experi- 

 ments Dr. Goldberg agrees with Chantemesse that the toxins formed 

 by the bacteria are the responsible agents in provoking the formation of 

 agglutinins, and then proceeds to formulate the following conclusions : — 



In fatal infections the agglutinative value remains unaltered. Non- 

 fatal medium-sized doses usually, but not invariably, cause an increase 

 in the agglutinative value of the blood. This agglutinative value under- 

 goes a progressive increase, reaches a maximum, and then gradually 

 subsides to normal. 



The intensity of the reaction forms no criterion of the degree of 

 immunity possessed by the animal from which the blood was obtained, 

 although the increase of agglutinative value is an early indication of 

 successful self-protection on the part of the infected animal. 



Agglutination of Vibrios. :f — Dr. Kohlbrugge criticises the hypo- 

 thesis of Emmerich and Loew (whose experiments he had unsuccessfully 

 attempted to repeat), who assert that the deposit appearing in old 

 bouillon cultivations of the B. pyocyaneus is a true agglutination due to 

 the presence in the medium of enzymes elaborated, by the organism 

 itself, and contends that agglutination should not be inferred simply 

 from the naked-eye appearances, but the existence of the phenomenon 

 should be demonstrated by microscopical examination of hanging-drop 

 specimens. 



He then details his experiments with toxins obtained from two 

 pathogenic water vibrios, iu which broth cultivations were first prepared 

 from the various organisms ; incubated for about 48 hours at 37° C. ; 

 sterilised by heat (70° C. and 100° C. to eliminate the possible action 

 of enzymes), or by first heating and then filtering through a porcelain 

 bougie or centrifugalising ; and then used as media in which to culti- 

 vate several different strains of cholera vibrios, including both virulent 

 aud non-pathogenic varieties. The resulting growth was found in every 



* Centralbl. Bakt., I" Abt., xxx. (1901) pp. 552-5. 

 t Tom. cit., pp. 605-17. J Tom. cit, pp. 639-96. 



