HISTORY OF BACTERIOLOGY. 
3 
These experiments had a far-reaching influence 
upon the conception of bacteriology, as may be imag¬ 
ined, and proved beyond question that germs originate 
only from germs. Upon this fact rest all our ideas 
of preventing the spread of disease and the aseptic 
precautions used in surgery. 
The association of micro-organisms with the pro¬ 
duction of disease, conceived long before the organ¬ 
isms were seen, received much 'attention after the 
observations of von Leeuwenhoeck. During the next 
hundred years all sorts and kinds of disease were one 
after another attributed to the growth of germs in 
the body. Von Plenciz ( 1762 ), a physician of 
Vienna, was perhaps the foremost advocate of these 
new ideas of the causation of disease. He believed 
not only that germs gave rise to‘ some diseases, but 
that each disease had its own particular germ which, 
after entering the body, developed and multiplied. 
These theories of von Plenciz were subjected to 
much ridicule, to be sure; but they continued to gain 
adherents nevertheless, and have proven, as we know, 
to be correct. Some years later Henle ( 1840 ) col¬ 
lected and published all the work that had been done 
up to that time, and pointed out that the causal 
relationship of germs to disease could not be proven 
simply by finding germs in the diseased tissues of 
the body, but that they must also be grown and 
studied outside of the body. Experiments to prove 
the doctrines of Henle were lacking chiefly because 
Association 
of germs 
with cause 
of disease 
