and inorganic, that is
between that which is alive and that which is not alive. So that with
this explanation we do not get at the problem.

Organic change, as such, is frequently found where life does not
exist. There are whole series of processes in chemistry, which by the
proper combination of the elements, produce again their own
conditions, so that thereby a certain body is the creator of a
process. Thus in the manufacture of sulphuric acid by the burning of
sulphur, there is created in this process sulphuric dioxide SO_{2},
and if one add steam and nitric acid thereto, the sulphuric dioxide
takes up the water and the oxygen and becomes H_{2} SO_{4}. Nitric
acid gives off oxygen and becomes nitric oxide, this nitric oxide
simultaneously takes up new oxygen from the atmosphere and is
transformed into a higher oxide of nitrogen and from this acid
sulphuric dioxide is again given off and made by the same process, so
that, theoretically, an infinitely small amount of nitric acid should
be effective to transform an unlimited quantity of sulphuric dioxide,
oxygen and water into sulphuric acid. Change in matter regularly
occurs through the passing of fluids through dead organic and
inorganic membranes as in the artificial cells of Traube. It therefore
appears that there is no progress by the way of organic change for the
quality of organic change which was to explain life must itself be
explained by life. We must therefore seek it elsewhere.

Life is a mode of existence of protoplasm and consists essentially in
the constant renewal of the chemical constituents of this substance.
Protoplasm is here understood in the modern chemical sense and
comprises under this name all substances analogous to the white of an
egg, otherwise called protein substances. The name is not
satisfactory, for the ordinary white of egg plays the least active
role of all transformed substances, since it only serves as mere
nourishment for the yolk, for the self-developing germ. As long
however as so little is known of the chemical constituents of
protoplasm the name is better than any other because more inclusive.

Whenever we discover life we also find it bound up with protoplasm,
and when we find a piece of protoplasm not in solution there we find
also life, without exception. Doubtless the presence of other chemical
constituents is necessary to a living body, to produce the various
differentiations of these elements of life. They are not neces