On the Factors Concerned in Agglutination. 417 



moreover, that, although this agglutinative property was lost by heating 

 the ox serum at 56° C, it could be restored by adding a little of the fresh 

 serum (complement) of another animal. They concluded that there exists 

 in ox serum a special substance which resists a temperature' of 56° C, 

 and which may be preserved for many months in the heated serum. This 

 substance, which was presumably of an albuminous or colloidal nature, 

 showed no tendency to unite with normal corpuscles, but was precipitated 

 on the corpuscles charged with the substance sensibilisatrice and alexine. 

 They called this substance Colloide du bceuf. This form of agglutination, 

 which has received the name of conglutination, is attributed by Bordet 

 to the action of three factors on the red corpuscles, namely : (1) the 

 specific antiserum, (2) the ox colloid, (3) a fresh serum or alexine. The 

 heat-resisting substance present in ox serum is called in subsequent papers 

 conglutinin. 



Bordet and Streng (1909) published a series of experiments dealing with 

 the agglutinative properties of ox serum. They declared that the conglutinins 

 were essentially different from the agglutinins. As a point of difference they 

 stated that the conglutinins had no need to be fixed on the cells which they 

 conglutinated. This statement appears to be at variance with the previously- 

 quoted observation that the specific substance of the ox colloid is precipitated 

 on corpuscles duly laden with substance sensibilisatrice and alexine. 



Bordet and Streng also subjected ox serum after it had been heated to 

 56° C. to dialysis. They found that the fraction which remained in solution 

 favoured haemolysis, while the precipitate, if re-dissolved in normal saline, 

 favoured agglutination. 



In another communication Streng (1909) claims considerable success 

 for the conglutination method in the identification and differentiation of 

 bacteria. By the addition of ox serum and complement he obtained marked 

 agglutination of bacteria with a dilution of homologous antiserum, which 

 by itself was too weak to produce any trace of agglutination. Streng also 

 stated that conglutinin could be separated from agglutinin by dialysis. The 

 agglutinin, under these conditions, remained in solution, while the con- 

 glutinin was precipitated with the globulin fraction. 



Barikine (1910) effected a similar separation of agglutinin and conglutinin 

 by saturating ox serum with carbon dioxide. As in the dialysis experiment, 

 the conglutinin was precipitated with the globulin, and the agglutinin 

 remained in solution. Barikine also found that the flocculi of a specific 

 precipitate, formed by the union of antigen and antibody, could be con- 

 glutinated by the addition of fresh serum (complement) and heated ox 

 serum (conglutinin). 



