VELOCITY OF REACTION. HETEROGENEOUS SYSTEMS 141 



The production of alcohol and carbonic acid from glu- 

 cose is, as Buchner showed, not a peculiarity for the living 

 cell, as Pasteur had supposed, but may be performed by 

 dead yeast-cells or an extract from them called zymase. 

 With dead yeast-cells (Herzog) 1 and with zymase (Euler) 2 

 experiments have been carried out, in the latter case the 

 reaction occurs in a homogeneous medium. Euler followed 

 the progress of the reaction by measuring the quantity of 

 carbonic acid developed, or with the polarimeter the 

 destruction of the sugar. The quantity of glucose was 

 20 c.c. of I n. solution. The quantity of zymase used 

 was 3.6 g. in the first, 1.2 g. in the second series. 



PRODUCTION OF ALCOHOL FROM GLUCOSE BY MEANS OF ZYMASE 



Here we find a slow decrease in the values of K and not 

 an increase, in which case the formula of Henri might be 

 applicable. It is therefore probable that the agreement 

 of Henri's formula with the measurements of Aberson is 



1 Herzog: Hoppe-Seylers Zeitschr. 37. 149 (1903). 



2 Euler: Hoppe-Seylers Zeitschr. 44. 53 (1905). 



