II2 
HOUSEHOLD BACTERIOLOGY 
Method 
of Study 
i. 
h A:-» : 
Bacteria 
Classed 
as Plants 
Founding: 
of the 
Science 
By finding what they grow on and their behavior in 
different soils; what they like best to eat; what tem¬ 
perature is most favorable to reproduction; adding to 
this the knowledge of structure, motion, and form 
which the microscope reveals, and lastly by chemical 
analysis of the substances produced by them during 
growth the species are determined. 
These methods have also made possible the cultiva¬ 
tion of pure cultures which are highly desirable with 
all species of commercial value. A pure yeast makes 
possible a saving of thousands of dollars in the brew¬ 
ing industries alone, and some time, let us hope, the 
housewife may be able to buy pure yeast for her bread¬ 
making. 
It was not until 1850 that these organisms were 
studied as plants. Dr. Waldo Burnett, a young phys¬ 
ician of Boston, suggested this and related theories, 
which since his death have been proved. 
Ten years after, these forms were accepted and 
classified by botanists. 
There were many observers and experimenters in 
the field and about 1881 the science of Bacteriology 
was founded. To Louis Pasteur must be ascribed the 
honor of laying its corner-stone, for he first endeav¬ 
ored to cultivate bacteria and yeasts and tried to make 
pure cultures. Upon the foundation thus laid Robert 
Koch built the germ theory of disease. He culti¬ 
vated certain germs and introducing them into the 
bodies of certain animals was able to produce certain 
diseases. He then suggested the four rules which still 
