° pe ee ete CACATIE [JANvaRY 
proteids and nucleins is another of the problems of physiology which 
will contribute to the main problem, the analysis of the constitution of 
living matter. I believe that the influence of stereochemistry will be 
more or less directly felt in many branches of physiology, in questionsof 
heredity, as well as in the theory of space sensations as E. Mach has” 
- already intimated. a 
In living organisms chemical energy is frequently transformed into 
osmotic energy. WVan’t Hoff’s theory of osmotic pressure permits at 
application of the law of conservation of energy to a class of phenom 
ena to which this law was hitherto inapplicable, namely the phenomena 
of growth, functional adaptation, secretion, absorption and even patho- : 
logical y such ascedema. The physiologists who thought that the - 
blood pressure determined secretion could not understand why secretion 
took place under a higher pressure than the blood pressure. Compara 
tive physiology shows that secretion does not depend upon circulation, ~ 
and the theory of osmotic pressure'indicates that the osmotic pressure 
in the cells is more than twenty times as high as the blood pressure. 
The work of secretion is done by osmotic pressure and not by blood 
pressure. A prominent physiological chemist has become a_vitalist 
because he could not explain why the secretions differ from the blood — 
from which he thinks they are formed. He overlooks among others 
the fact that the protoplasm possesses the quality of semi-permeability, _ 
which means that it allows certain substances to pass through and 
others not. In my opinion the working out of a theory of 
CAR Rr: is one of the main physiological problems of the 
ay. 
The theory of the dissociation of electrolytes is of fundamental 
ar- 
gy will perhaps be best seen in ™ 
n active element of living matter 
ric to its surrounding parts. 
the active part and that the passive | 
are n ig 
eas nae i ine, bositive hydrogen ions of the acid have a ™ 
Sreater velocity of migration than the anions. Hence the former 
