142 LECTURES ON IMMUNITY 



due to some perturbation introduced by the life-processes 

 of the yeast-cells. Euler, however, also observed some 

 complications which require additional experimentation 

 before they can be explained. The velocity of reaction 

 increases more rapidly than the concentration of the en- 

 zyme, and not proportionally to a simple power of it. The 

 quantity decomposed does not increase with the concentra- 

 tion of the sugar, but shows on the contrary a relative 

 decrease, if the concentration of sugar is raised. 



The study of the velocities of reactions in heterogeneous 

 systems indicates that they behave very nearly in the same 

 manner as in homogeneous systems. This observation 

 has often been made concerning the velocity of reactions 

 in heterogeneous systems. 1 It depends upon the circum- 

 stance that by means of the experimental arrangements 

 the diffusion goes on so rapidly that it does not perturb 

 the chemical processes. If capillary tubes are employed, 

 this cannot be said to be the case, and therefore Mett's 

 tubes should not be used for quantitative measurements. 



Even the influence of temperature on these reactions is 

 of the same order of magnitude as for those processes in 

 which different substances react with one another in 

 homogenenous systems. Remarkable is the low value for 

 the haemolysis by means of sodium oleate (/4 = 3800). The 

 agglutination of erythrocytes by means of mercuric chloride 

 and ricin give nearly the same values for //, (17,900 and 

 17,200) and the values for JJL for the two different bacterio- 

 agglutinins are not of very different order (>i= 30,100 

 for coli-agglutinin, p= 37,200 for typhoid-agglutin). Near 

 this value also stands that for haemolysins of bacterial 



1 Cf . Goldschmidt : Zeitschr. / physikal. CAemig,&l, 235 (1899). 



