VELOCITY OF REACTION. HETEROGENEOUS SYSTEMS 1 1/ 



the same order of magnitude (probably equal) in the two 

 instances. The progress of agglutination with time indi- 

 cates that after the agglutinin has been absorbed (in the 

 first five minutes) some change (probably coagulation) 

 takes place slowly within the bacteria, which thereby 

 obtain their agglutinating properties. In the same man- 

 ner, after a haemolysin has been very rapidly taken up 

 by erythrocytes, these are subject to a slow chemical 

 change, which causes them to give up their colouring 

 matter. This circumstance seems rather incompatible 

 with the commonly adopted idea that the agglutination 

 might depend upon some electric charge of the bacteria, 

 due to the absorption of the agglutinin, since the electric 

 charge very likely follows immediately upon the absorp- 

 tion of agglutinin. 



These far-reaching investigations of Madsen and his 

 pupils have also made us familiar with some substances, 

 the action of which increases with sinking temperature, 

 or has a maximum or minimum at a certain temperature. 



H^EMOLYTIC ACTION AT DIFFERENT TEMPERATURES 



