CHAPTER I. 
THE HISTORY OF BACTERIOLOGY. 
The history of this science is interesting because 
it tells how the study of bacteria developed from mere 
theories into a science based upon facts. Long before 
anything was known of the existence of germs, ref¬ 
erences could be found in the writings of the ancient 
Greeks discussing the possibility of disease passing 
from one person to another. The agent of infection 
was supposed to originate from the air or moisture. 
With the instruments of ancient times it was inv 
possible to see the minute living particles which we 
now know as germs; in fact, it is doubtful that such 
minute forms were thought of. The seventeenth 
century, however, marked a new era in the making 
of optical instruments. Anthony von Leeuwenhoeck 
in 1675 , a linen draper of Amsterdam in Holland, 
succeeded in perfecting a lens of much greater mag¬ 
nifying power than those hitherto in use. By means 
of this lens he was able to see minute living animal¬ 
cules in saliva, water, and other fluids, that were 
smaller than any seen before. The descriptions of the 
animalcules he saw were very accurate and correspond 
to some of the forms we recognize today. 
The discovery of these minute living organisms 
provoked a great deal of discussion, as may be 
imagined. Perhaps the question most debated was 
1 ( 1 ) 
The dis¬ 
covery of 
germs 
The theory 
of spon¬ 
taneous 
genera¬ 
tion 
