316 



KAN-ICHIRO MORISHIMA 



From these experiments it becomes apparent that the inag- 

 glutinabihty of our sermn strains is not analogous to the similar 

 inagglutinability of the Friedlander bacilU used by Forges in 

 his experiments. At any rate our experiments do not permit 

 us to conclude that the acquired inagglutinability of our strains 

 is due to a capsule or to any analogous substance. 



Acid agglutination 



In 1911 Michaelis (1911) investigated the flocculation of 

 bacteria by acids. His experiments were based upon the fact 

 that serum globulins, casein, the so-called nucleoproteins and 

 other forms of protein could be shown to precipitate at very 

 definite optimum H-ion concentrations. Since Kraus (1897) 

 and Neisser and Friedemann (1904) had claimed that the agglu- 

 tination of bacteria depended upon the precipitation of a protein 

 constituent of their cell bodies, Michaelis believed that for each 

 species of bacteria an optimum H-ion concentration could be 

 found which would agglutinate them. This he indeed demon- 

 strated, and claimed that the typhoid bacillus especially could 

 be shown to agglutinate at a definite H-ion concentration suffi- 

 ciently characteristic to aid in the diagnosis of this organism. 

 A number of investigators have confirmed this. For this reason 

 we carried out the Michaelis technique with our broth and serum 

 strains, to determine whether the H-ion optimum for agglutina- 

 tion had been altered by growth in serum. 



The solutions were made as follows : 



