(760 ) 
Chemistry. — “A few observations on autocatalysis and the trans- 
formation of y-hydroxy-acids, with and without addition of 
other acids, conceived as an ion-reaction.” By Dr. A. W. Visser. 
(Communicated by Prof. H. J. HAMBURGER). 
1. The general equation for catalytic processes as proposed by 
OstTWALD ') is: 
== hk FSE NAS DIB oen 
in which Z4f(w) indicates the changeable catalytic influences. He 
remarks here that he cannot give a general method for drawing 
a conclusion from the observed progress of a definite reaction, as to 
the form of the function f(x). 
Whilst studying the transformations of cane-sugar by invertase and 
of salicin by emulsin?), I have shown, that, by introducing a correct 
measure for the intensity of a catalyzer, the changeable catalytic 
influences which occur here, could be indicated during the whole of 
the progress of the reaction and it appears to me, that the method 
given in my dissertation for determining that change in intensity 
during the progress of the reaction may be called a general method 
for determining the above mentioned function. 
The most simple case imaginable is this, that the change in intensity 
of the catalyzer with the change in concentration of the substance 
acted upon is constant. In that case : 
dt 
"Ene oe 
therefore : 
Ikk, 
In this equation is J—=k, when C—0; therefore 4, is the 
intensity of the catalyzer when all has been converted, whilst 4, 
is the increase in intensity, when the concentration diminishes with 
the unity. 
Schematically this may be represented as follows : 
1) Osrwarp, Lehrbuch der Allgem. Chem. IL, 2, p. 270. 
2) Visser, Dissertatie, Amsterdam 1904. A translation will shortly appear in the 
Zeitschr. f. phys. Chem. 
