690 SUMMARY OF CURRENT RESEARCHES RELATING TO 



must be divided into two distinct parts according as the fermentation 

 takes place in connection with sodium nitrate or with calcium nitrate, 

 which is the final product of nitrification. 



Negative Chemiotaxis of Leucocytes. * — A. Zilberberg and J. 

 Zeliony record observations as to the negative chemiotaxis of the 

 leucocytes of rabbits when infected with pure cultures of fowl-cholera. 

 They found there was an absence of phagocytosis when virulent cultures 

 were used, and almost none when the microbes were somewhat less 

 virulent. When phagocytosis occurs, it is probably due to the presence 

 of non-virulent bacteria among the virulent ones, for the rabbit leuco- 

 cytes never incorporate virulent fowl-cholera bacteria. The absence of 

 phagocytosis is not due to poisoning of the leucocytes, but to their 

 negative chemiotactic sensibility ; for the same leucocytes preserve their 

 power of ingesting non-virulent microbes even when the animal is in 

 a moribund condition, as was shown by injecting non-virulent bacteria 

 some eight minutes before death. 



*&* 



Agglutinating Substance.f — F. C. Harrison conducted experiments 

 to find out if the agglutinating substance was present only in the 

 external layers of the microbe, and if the phenomenon of agglutination 

 was a kind of coagulation of the substance dissolved or not dissolved 

 in an ambient medium. In order to carry out the condition, it was 

 necessary to dissolve the external layers and yet leave the inner portion 

 of the microbes intact. Three series of experiments are recorded for 

 which immune horse-serum, pyocyanase, and B. typhi were used. The 

 results showed that the agglutinating substance exists entirely in the 

 outer layers of the bacilli, and that the nuclear portion is incapable of 

 giving the reaction, and therefore endorse Nicolle's hypothesis that 

 " agglutination consists in the coagulation and the coalescence of the 

 external layers of the agglutinable microbes under the influence of the 

 agglutinating serum." But in view of the author's experiments, he 

 would insert " dissolved or not dissolved " between the words " external 

 layers." 



Importance of Inorganic Salts and Organic Crystalloids in the 

 Agglutination of Bacteria. + — Dr. E. Friedberger states that agglutina- 

 tion does not occur when the suspension fluids are totally devoid of 

 crystalloid substances. Of these substances the most effective are the 

 inorganic salts, and even these are of different degrees of activity. The 

 rapidity of the occurrence of agglutination in dialysed cultures is 

 dependent on the saline contents of the suspension fluid, and in bac- 

 terial emulsions on the presence of sodium chloride. The action of the 

 salts is not a chemical one. 



Presence of Typhoid Bacilli in Sputum. § — P. Edel examined the 

 sputum of eleven cases of typhoid, and in one which was complicated 

 with pneumonia found on three occasions typhoid bacilli in the expec- 

 toration. 



* Ann. Inst. Pasteur, xv. (1901) pp. 615-30 (1 pi.). 



t Centralbl. Bakt., 1" Abt., xxx. (1901) pp. 115-8. J Tom. cit., pp. 336-47. 

 § Festschr. d. Med., 1901, No. 14. See Centralbl. Bakt., 1" Abt., xxix. (l'.tOl) 

 p. 911. 



