512 
medium for their growth, and most of the changes that take place in 
milk can be traced directly to such action. 
Neither straining nor clarifying will remove the bacteria from the 
milk, hence the necessity of keeping the dirt out, not straining it out. 
SOURCES OF CONTAMINATION. 
From the act of milking to the final consumption of the milk the 
possibilities of contamination are many and varied in character. 
Everything that comes in direct contact with the milk may be a 
source of trouble, and many things may act indirectly and seriously 
affect the results desired. 
MILKING-. 
The first contamination usually begins with the act of milking. 
If the udder and flanks of the cow are covered with the dirt of the 
yard or stable the process of milking will dislodge a greater or less 
portion of this filth, causing it to fall into the pail. 
The amount of filth that may be on a cow will depend very much 
on the condition of the stable yard, and floor, gutter, and bedding 
in the stables. 
The following illustrations are used to better show conditions which 
are too common the country over. The condition of the cow shown 
in Fig. 1 is not exaggerated. The milker is probably all unconscious 
that he is sowing the seeds of contamination and destruction, which 
may sooner or later cause the death of infants who are unfortunate 
enough to be fed from milk produced under such circumstances. If 
he is aware of this fact he is criminal in purpose and intent, and the 
most stringent penalties should be provided to stop such work. 
Figs. 3, 4, 5, and 6 show exteriors and interiors of barns which will 
contribute to such a fearful condition. 
As to the amount of filth that will get into the milk and the result 
on the product, reports from the Illinois Experiment Station and 
Storrs (Conn.) Experiment Station are here quoted: 
The average weight of dirt which falls from muddy udders during milking is 90 
times as great as that which falls from the same udders after washing, and when udders i 
are slightly soiled it is 32 times as great. (Bulletin Ho. 84, Illinois Experiment 
Station.) 
Wiping the flank and udder of the cow with a damp cloth just before milking is a 
very efficient method for reducing the number of bacteria which falls into the milk 
pail. (Stocking. — Bulletin No. 42, Storrs Experiment Station.) 
An, average of 13 experiments at Storrs station showed the follow- 
ing results: 
Bacteria in milk from un wiped udders per c. c 7, 058 
Bacteria in milk from wiped udders per c. c 716 
Decrease due to wiping 6, 342 - 1 
