SOURCES OF INFECTION IN THE STABLE. 29 



next to the upper rim of the milk-pail. When the milk- 

 ing began both plates were uncovered at the same time, 

 so that the bacteria gained free access to the gelatine. 

 After a moment both specimens were again covered at the 

 same time. The bacteria were then allowed to develop in 

 the gelatine for twenty-four hours or more, when they 

 formed colonies; and it could be observed with the naked 

 eye that a many times larger number of bacteria fell into 

 the dish placed under the belly of the cow than into the 

 one placed farther away. 



If this experiment is made in a stable filled with cows, 

 the infection arising from the body of the cows will be 

 shown still more plainly, as the cows are then far more in- 

 fected by bacteria than in the free air. It is important in 

 experiments of this kind in the stable to place the dishes 

 at the same height from the floor, as there is a considerable 

 difference between the bacterial contents of the upper and 

 lower layers of the atmosphere in a stable. If the direc- 

 tions given are followed it will be found, as in my experi- 

 ments, that although a goodly number of bacteria will fall 

 into both plates, the sample placed under the udder will 

 contain a much larger number of bacteria than the plate 

 placed a little away from the cow. 



These experiments show the truth of the fact known 

 long ago, but often overlooked, that it is very important to 

 keep the skin of the cows as clean as possible. 



Importance of Proper Bedding. The first point to ob- 

 serve in this regard is to provide the cows with bedding of 

 dry, clean straw. The cows are often left to lie in manure 

 and other filth a condition which nullifies all precautions 

 taken later on. Remnants of manure, etc., may be seen by 

 a microscope in the milk from cows taken fairly good care 



