12 
Transactions Texas Academy of Science. 
determining cause is to be found in the external conditions which 
vary according to time 'and place. 
It is not difficult to see that these theories are upholding entities 
as the cause of disease. While a kernal of truth is to be found in 
each, they all fail to realize the continuity of causes in the sense 
of modern exact science. “The true and sufficient cause of any 
effect is always something internal, something that follows from 
the kind and amount of initial energy, and from that quality and 
quantity alone and entirely. * * * It is the absolute thing 
That exists behind all change and remains primordially the same/ 
as Helmholtz expressed it ." 7 Or as the modern physicist would 
put it : potential energy = cause, kinetic energy = effect ; and as a 
liberating impulse will change potential energy into kinetic energy, 
so a liberating impulse will change cause into effect. 
The cloudiness that characterizes many of the theories that have 
sought to explain the phenomena of infectious diseases is largely 
a legacy of Kantism, and is clearly out of place in these days of 
modern science. It is somewhat strange that “ontological toys" 
are still to be found in th$ workshop of some really brilliant inves- 
tigators of natural phenomena. Nevertheless, they are there — 
which explains some explanations that do not explain. 
The parallelism which subsists between the phenomena of fer- 
mentation, infection and immunity suggests the mental route to he 
traveled if an insight into our problem is to be gained ; and for this 
reason it is necessary to first point out a few facts about 
FERMENTATION. 
If the phenomena of matter be defined as periodic functions of 
the atomic and molecular masses which constitute it and the rates 
of motion of these masses, and the chemical unit be viewed as a 
“center through which energy manifests itself," then the theories 
of modern chemistry should supply an explanation of the phe- 
nomena of fermentation. 
The crucial test of every theory which seeks to explain fermenta- 
tion is the satisfactory explanation of the following phenomena : 
Enzymes appear to be capable of disrupting complex chemical 
bodies without undergoing any apparent chemical change them- 
selves — 'that is, they bring about a chemical change in dispropor- 
tionately large quantities of material. When the newly produced 
subtances attain a certain concentration the further action of the 
enzyme is inhibited, but its action is reasserted when the concen- 
tration of the zymolytic products is again lowered. Maximum, 
minimum and optimum temperature and pressure influence these 
