INFLUENCE OF TEMPERATURE ON CHEMICAL REACTION 221 
physiological reactions, 2 would be more approximate value for this 
temperature coefficient than 3. 
It is much to be regretted that for reasons such as have been 
touched upon, the chemist is unable to generalize very far concerning 
temperature and the reaction velocity. Many reactions, and par- 
ticularly those which occur between the compounds of carbon, exhibit 
the phenomena of false equilibria. Indeed, it may be said without 
exaggeration that organic chemistry is the chemistry of metastable 
states. In the study of such reactions, therefore, the final equilibrium 
toward which the system tends is a matter of less moment than the 
relative velocities of change. Particularly do such considerations 
apply to physiological processes, in which successive reactions overlap 
and influence each other in a bewildering complexity of delicate adjust- 
ments, which from the chemist's viewpoint constitute the essential 
objective characteristic of the life process. It is in these processes, 
moreover — which occur within disperse systems incompletely isolated 
from each other and from the environment, where the continuous 
phase, probably attenuated to thin laminae, presents very large surfaces 
of contact — that all phenomena associated with changes in surface 
energy manifest themselves most markedly. In such systems, which 
contain not only colloidal complexes but electrolytes in water solution, 
we must look for the most varied superimposed effects, due not only 
to false equilibria, but to the varied influences of change in acidity, 
basidity and salt concentration upon the distribution of solution con- 
centrations at these surfaces; upon the change in the velocity of 
contact catalysis thus occasioned, or upon that brought about by the 
presence of characteristic enzymes; and upon alteration in the col- 
loidal substances themselves, which bring about concentration changes 
in the continuous phase, and readjustments continuously renewed. 
The picture need not be more completely drawn: no added emphasis 
need be placed upon the extreme complexity of such phenomena, 
which appears perhaps even more striking to the chemist's eye than 
to that of the more accustomed biologist. 
In this brief and fragmentary review many interesting and sig- 
nificant facts, all pertinent to the inquiry, have had to be passed over. 
coefficients he tabulates must accordingly be interpreted as caused by variable in- 
activation of the contact surfaces, and corresponding differences in the highly 
characteristic optima shown by all such reactions. Even in these cases, therefore, 
which might be expected to show the greatest uniformity in the temperature coeffi- 
cients, we observe the predominating influence of superimposed effects. 
