n shown in too many instances, yet
one could not help feeling that the barrier between the organized and
unorganized worlds was one which the chemist at present saw no chance
of breaking down. True, there were those who professed to foresee that
the day would arrive when the chemist, by a succession of constructive
efforts, might pass beyond albumen, and gather the elements of
lifeless matter into a living structure. Whatever might be said
regarding this from other standpoints, the chemist could only say that
at present no such problem lay within his province.

Protoplasm, with which the simplest manifestations of life are
associated, was not a compound, but a structure built up of compounds.
The chemist might successfully synthesize any of its component
molecules, but he had no more reason to look forward to the synthetic
production of the structure than to imagine that the synthesis of
gallic acid led to the artificial production of gall nuts. Although
there was thus no prospect of effecting a synthesis of organized
material, yet the progress made in our knowledge of the chemistry of
life during the last fifty years had been very great, so much so
indeed that the sciences of physiological and of pathological
chemistry might be said to have entirely arisen within that period.

CHEMISTRY OF VITAL FUNCTIONS.

He would now briefly trace a few of the more important steps which had
marked the recent study of the relations between the vital phenomena
and those of the inorganic world. No portion of the science of
chemistry was of greater interest or greater complexity than that
which, bearing on the vital functions both of plants and of animals,
endeavored to unravel the tangled skein of the chemistry of life, and
to explain the principles according to which our bodies live, and
move, and have their being. If, therefore, in the less complicated
problems with which other portions of our science have to deal, we
found ourselves often far from possessing satisfactory solutions, we
could not be surprised to learn that with regard to the chemistry of
the living body--whether vegetable or animal--in health or disease, we
were still farther from a complete knowledge of phenomena, even those
of fundamental importance.

Liebig asked if we could distinguish, on the one hand, between the
kind of food which goes to create warmth and, on the other, that by
the oxidation of which the motions and mechanical energy of the body
are kep