52 BUTTER-MAKING. 
results cannot be obtained unless extreme precautions are 
taken. Milk produced under average farm conditions sel- 
dom contains less than 50,000 germs per c.c. shortly after the 
milking. Milk which is produced under filthy conditions, 
and which is several hours old, may contain several millions 
of bacteria per c.c. 
Sources of Bacteria in Milk.—Except in the cow’s udder 
where they are present to only a small extent, bacteria are 
present almost everywhere. They float in the atmosphere 
i 
TS 
Fic. 11—The wrong and the right kind of a milk-pail. a, the ordinary 
type of pail showing sharp angle between sides and bottom; B, the same 
peepery flushed with solder so as to facilitate thorough cleaning. The 
ower figure represents a joint as ordinarily made in tinware. The de- 
pression a affords a place of refuge for bacteria from which they are 
not readily dislodged. This open joint should be filled completely with 
solder. (From Bul. 62, Wis.) 
and adhere to particles of dust. Especially is this so in the 
dusty cow-stable. They are present in all well water to a greater 
or less extent. They are very abundant in streams and rivers. 
They are present in the soil to a depth of several feet, the 
number decreasing with the depth. As these germs are prac- 
tically present everywhere, the source of germs in milk may 
be said to be all around us. The principal sources of germs 
in milk are, however, unclean dairy utensils, unclean cows, 
and unclean surroundings. As these germs multiply chiefly 
by fission, or by one cell dividing into two, it is plain that the 
number of germs will increase very rapidly under favorable 
conditions. Under the most favorable conditions it requires 
