1909.] HcBrn- agglutinins , etc., in the Blood. 213 



a month later, neither spontaneous nor auto-agglutination was present, and 

 normal serum failed to react with these cells, while when the immune serum 

 and normal red cells were mixed hemolytic agglutination occurred as 

 before. 



Typhoid Fever. — Auto-agglutination was never found to occur. The 

 iso-agglutinius are of great interest. In every instance marked agglutination 

 of red cells occurred when either the immune cells were added to normal 

 serum or normal cells to immune serum. In a certain number of experi- 

 ments both phenomena occurred. The fact that there was absence of 

 agglutination when immune serum was added to normal red cells, although 

 the serum clumped typhoid bacilli, can readily be explained by the absence 

 of any relationship between bacterial and haem-agglutinins. It was 

 especially in these experiments that the hemolytic agglutinins were noted 

 after serum and red cells had been in contact for one hour at 37° C. 



Attempts were made to extract " hypothetical agglutinins " from the red 

 blood corpuscles in those diseases in which a marked reaction took place 

 between the immune red cells and normal serum, but without success. The 

 red cells were powdered in a mortar with finely broken glass, and the 

 mixture centrifuged at high speed. The fluid resulting from this procedure 

 was added to suitable red cells, but in no instance did agglutination occur. 

 Other methods with a similar object in view were found to be ecpaally futile. 



Specific Agglutinins. 



A considerable amount of further work has been completed to emphasise 

 the specificity of the haem-agglutinins. The same technique has been 

 adopted, except that it has been shown that it is unnecessary to incubate the 

 active mixtures of red cells and serum for several hours as on previous 

 occasions. Two or three hours has since proved to be sufficient, while it has 

 been shown that a considerable degree of this special reaction can be 

 removed when the active red cells and serum are mixed well together for two 

 or three minutes, not incubated, but immediately centrifuged, and the 

 resulting fluid tested in the usual manner. It was found that although 

 slight agglutination with the clear fluid and suitable red cells could be 

 demonstrated, yet the greater proportion of it had been removed. 



This experiment will serve to show the effect of a temperature of 37° C. 

 for one and a cprarter hours on the specific agglutinins: 



Immune Serum (Typhoid) + Normal red cells. 

 Extreme degree of agglutination present. 



VOL. lxxxi. — B. 



Q 



