nt could obtain the carbon for its growth was the
atmospheric carbonic acid. The quantity of carbon which on an average
was removed in the form of wheat and straw from a plot manured only
with mineral matter was 1,000 lb., while on another plot, for which a
nitrogenous manure was employed, 1,500 lb. more carbon was annually
removed, or 2,500 lb. of carbon were removed by this crop annually
without the addition of any carbonaceous manure. So that Liebig's
prevision had received a complete experimental verification.

CHEMICAL PATHOLOGY.

Touching us as human beings even still more closely than the foregoing
was the influence which chemistry had exerted on the science of
pathology, and in no direction had greater progress been made than in
the study of micro-organisms in relation to health and disease. In the
complicated chemical changes to which we gave the names of
fermentation and putrefaction, Pasteur had established the fundamental
principle that these processes were inseparately connected with the
life of certain low forms of organisms. Thus was founded the science
of bacteriology, which in Lister's hands had yielded such splendid
results in the treatment of surgical cases, and in those of Klebs,
Koch, and others, had been the means of detecting the cause of many
diseases both in man and animals, the latest and not the least
important of which was the remarkable series of successful researches
by Pasteur into the nature and mode of cure of that most dreadful of
maladies, hydrophobia. The value of his discovery was greater than
could be estimated by its present utility, for it showed that it might
be possible to avert other diseases besides hydrophobia by the
adoption of a somewhat similar method of investigation and of
treatment.

Here it might seem as if we had outstepped the boundaries of
chemistry, and had to do with phenomena purely vital. But recent
research indicated that this was not the case, and pointed to the
conclusion that the microscopist must again give way to the chemist,
and that it was by chemical rather than biological investigation that
the causes of diseases would be discovered, and the power of removing
them obtained. For we learned that the symptoms of infective diseases
were no more due to the microbes which constituted the infection than
alcoholic intoxication was produced by the yeast cell, but that these
symptoms were due to the presence of definite chemical compounds, the
result of th