Chemistry. — “Catalysis — Part VIL — Temperature Coefficient 
of Physiological processes’. By Dr. Ni Ratan Duar. (Com- 
municated by Prof. Ernst Conen). 
(Communicated at the meeting of May 29, 1920). 
In this article it is proposed to subject to critical examination the 
results obtained with regard to the effect of temperature on physio- 
logical processes. Before proceeding to the consideration of these 
reactions I shall briefly state the results obtained in the case of 
purely chemical reactions and then try to show how far these rela- 
tions are applicable to physiological changes. 
In homogeneous medium the following general results have been 
obtained. 
a. The higher the order of the reaction, the smaller is the coefficient 
of temperature, in other words, unimolecular reactions have higher 
temperature coefficients than polymolecular reactions under identical 
conditions. | 
6. The greater the velocity of a reaction the smaller is the temp- 
erature coefficient. . . 
c. The temperature coefficient of a positively catalysed reaction 
is smaller than that of the uncatalysed reaction and the greater the 
concentration of the catalyst the greater is the fall in the temperature 
coefficient. 
In the case of negative catalysis, a reaction which is catalysed 
(negatively), has a higher temperature coefficient than the uncatal- 
ysed reaction. In this case, the greater the concentration of the 
catalyst the greater is the increase in the temperature coefficient. 
In the case of heterogeneous reactions, the following points have 
been established : 
a. Diffusion is the guiding factor in the velocity of heterogeneous 
reactions. 
6. With heterogeneous catalysts which cause reaction between 
the substance in question to take place with practically infinite 
velocity, the actual rate of reaction will be determined solely with 
which the substance is diffused to the surface of the catalyst. 
c. If the heterogeneous velocity is that of the diffusion process, 
one will always get a unimolecular coefficient for the reaction in 
question, independent of the actual order of the more rapid chem- 
