BACTERIOLOGICAL INVESTIGATIONS. 
SUMMARIZED BY 
H. A. HARDING. 
While the Bacteriological Department was not created until 1899, 
problems involving the activity of bacteria have been studied from 
the very foundation of the institution. In discussing plant path- 
ology reference is made to the work with pear blight,’ bacteriosis 
of beans? and sweet corn® and soft rot of cabbage* and cauliflower. 
PASTEURIZATION FOR BUTTER MAKING. 
Great interest in the struggle against tuberculosis followed the 
introduction of the tuberculin test about 1890; and about the same 
time difficulties were met with in manufacturing a satisfactory 
grade of butter in the attempts at winter dairying which then began 
to be common. Pasteurization was an agency employed in solving 
both problems; so that much interest in this subject was felt by 
owners of cattle, veterinarians, milk handlers and consumers of 
dairy products. The mingling of the two dissimilar ideas produced 
a confusion which for a time prevented progress in pasteurization 
for butter making and caused severe criticism of pasteurization for 
the city milk trade. 
The butter work demanded a cheap and rapid means of destroy- 
ing the major portion of the germs present, so that those added in 
the form of a starter might have the desired effect. The continu- 
ously-flowing Danish machines had been developed to meet this 
need. 
The city milk trade required the destruction of the disease germs 
with certainty, but at the same time the consumer expected a well- 
marked cream line and objected to any cooked flavor. To avoid 
changes in the physical condition and flavor of the milk it is neces- 


* See page 142. 
*See page 125. 
®* See page 132. 
*See page 126. 
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