The Story of Germ Life | Page 3

middle of the century. It is true that Schwann shrewdly drew
conclusions as to the relation of microscopic organisms to various
processes of fermentation and decay--conclusions which, although not
accepted at the time, have subsequently proved to be correct. It is true
that Fuchs made a careful study of the infection of "blue milk,"
reaching the correct conclusion that the infection was caused by a
microscopic organism which he discovered and carefully studied. It is
true that Henle made a general theory as to the relation of such
organisms to diseases, and pointed out the logically necessary steps in a
demonstration of the causal connection between any organism and a
disease. It is true also that a general theory of the production of ail
kinds of fermentation by living organisms had been advanced. But all
these suggestions made little impression. On the one hand, bacteria
were not recognised as a class of organisms by themselves--were not,
indeed, distinguished from yeasts or other minute animalcuise. Their
variety was not mistrusted and their significance not conceived. As
microscopic organisms, there were no reasons for considering them of
any more importance than any other small animals or plants, and their
extreme minuteness and simplicity made them of little interest to the
microscopist. On the other hand, their causal connection with
fermentative and putrefactive processes was entirely obscured by the
overshadowing weight of the chemist Liebig, who believed that
fermentations and putrefactions were simply chemical processes.
Liebig insisted that all albuminoid bodies were in a state of chemically

unstable equilibrium, and if left to themselves would fall to pieces
without any need of the action of microscopic organisms. The force of
Liebig's authority and the brilliancy of his expositions led to the wide
acceptance of his views and the temporary obscurity of the relation of
microscopic organisms to fermentative and putrefactive processes. The
objections to Liebig's views were hardly noticed, and the force of the
experiments of Schwann was silently ignored. Until the sixth decade of
the century, therefore, these organisms, which have since become the
basis of a new branch of science, had hardly emerged from obscurity. A
few microscopists recognised their existence, just as they did any other
group of small animals or plants, but even yet they failed to look upon
them as forming a distinct group. A growing number of observations
was accumulating, pointing toward a probable causal connection
between fermentative and putrefactive processes and the growth of
microscopic organisms; but these observations were known only to a
few, and were ignored by the majority of scientists.
It was Louis Pasteur who brought bacteria to the front, and it was by
his labours that these organisms were rescued from the obscurity of
scientific publications and made objects of general and crowning
interest. It was Pasteur who first successfully combated the chemical
theory of fermentation by showing that albuminous matter had no
inherent tendency to decomposition. It was Pasteur who first clearly
demonstrated that these little bodies, like all larger animals and plants,
come into existence only by ordinary methods of reproduction, and not
by any spontaneous generation, as had been earlier claimed. It was
Pasteur who first proved that such a common phenomenon as. the
souring of milk was produced by microscopic organisms growing in the
milk. It was Pasteur who first succeeded in demonstrating that certain
species of microscopic organisms are the cause of certain diseases, and
in suggesting successful methods of avoiding them. All these
discoveries were made in rapid succession. Within ten years of the time
that his name began to be heard in this connection by scientists, the
subject had advanced so rapidly that it had become evident that here
was a new subject of importance to the scientific world, if not to the
public at large. The other important discoveries which Pasteur made it
is not our purpose to mention here. His claim to be considered the

founder of bacteriology will be recognised from what has already been
mentioned. It was not that he first discovered the organisms, or first
studied them; it was not that he first suggested their causal connection
with fermentation and disease, but it was because he for the first time
placed the subject upon a firm foundation by proving with rigid
experiment some of the suggestions made by others, and in this way
turned the attention of science to the study of micro-organisms.
After the importance of the subject had been demonstrated by Pasteur,
others turned their attention in the same direction, either for the purpose
of verification or refutation of Pasteur's views. The advance was not
very rapid, however, since bacteriological experimentation proved to be
a subject of extraordinary difficulty. Bacteria were not even yet
recognised as a group of organisms distinct enough to be grouped by
themselves, but were even