lurk.

In addition to this thorough cleansing with hot water, we should be
careful never to stir up the dust of the barn just before milking. Such
dusty work as pitching hay or stover or arranging bedding should be done
either after or long before milking-time, for more germs fall into the
milk if the air be full of dust.

To further avoid germs the milker should wear clean overalls, should
have clean hands, and, above all, should never wet his hands with milk.
This last habit, in addition to being filthy, lessens the keeping power
of the milk. The milker should also moisten the parts of the cow which
are nearest him, so that dust from the cow's sides may not fall into the
milker's pail. For greater cleanliness and safety many milkmen curry
their cows.

The first few streams from each teat should be thrown away, because the
teat at its mouth is filled with milk which, having been exposed to the
air, is full of germs, and will do much toward souring the other milk in
the pail. Barely a gill will be lost by throwing the first drawings
away, and this of the poorest milk too. The increase in the keeping
quality of the milk will much more than repay the small loss. If these
precautions are taken, the milk will keep several hours or even several
days longer than milk carelessly handled. By taking these steps to
prevent germs from falling into the milk, a can of milk was once kept
sweet for thirty-one days.

The work of the germ in the dairy is not, however, confined to souring
the milk. Certain kinds of germs give to the different sorts of cheeses
their marked flavors and to butter its flavor. If the right germ is
present, cheese or butter gets a proper flavor. Sometimes undesirable
germs gain entrance and give flavors that we do not like. Such germs
produce cheese or butter diseases. "Bitter butter" is one of these
diseases. To keep out all unpleasant meddlers, thoroughly cleanse and
scald every utensil.

EXERCISE

What causes milk to sour? Why do unclean utensils affect the milk?
How should milk be cared for to prevent its souring? Prepare two
samples, one carefully, the other carelessly. Place them side by
side. Which keeps longer? Why?

SECTION LXIII. THE BABCOCK MILK-TESTER

It is not sufficient for a farmer or a dairyman to know how much milk
each of his cows yields. He should also know how rich the milk is in
butter-fat. Wide-awake makers of butter and cheese now buy milk, not by