1897 THE MICROSCOPE. 23 
Practical and Economic Side of Bacteriology. 
By LE. BH. SAY RE; 
UNIVERSITY OF KANSAS. 
[ Abstract ] 
When it was shown over a century ago, that putres- 
cible liquids could be perserved almost indefinitely by 
first boiling them and then excluding the atmospheric 
air, perhaps little more was expected from this experi- 
ment than its practical application in the preservation of 
foods. In hermetically sealed contrivances these would 
be kept unchanged till wanted, To-day thereis a new 
department of biology based upon it. 
The life history of different species of micro-organisms 
has been studied as minutely as if they were plants from 
the higher orders of the vegetable world. The amount 
of heat required to destroy many of them has become 
accurately known. It is asserted that cholera spirillum 
is destroyed by ten minutes exposure at the temperature 
of 52° C; the typhoid bacillus by 60° C; and from this is 
drawn the practical conclusion that clothing infected 
with any of the above, could be speedily disinfected by 
being immersed in water at 70° C, or above, and then 
would be without danger as far as the disease germs 
were concerned. 
The practical results coming from the study of the 
micro-organisms, as they manifest themselves in the in- 
fectious diseases among domestic animals, have been in- 
creasingly astonishing and gratifying. No infectious 
disease among domestic animals, such as glanders, tuber- 
culosis, swine plague, and hog cholera, is treated to-day 
without first consulting the latest developments from the 
bacteriological laboratory. 
A practical application of bacteriology for economic pur- 
poses was successfully made when bacterial poison was 
cultivated for the purpose of destroying field mice. To 
the farmers of Europe the destruction of these pests was 
