until eaten by man with
imperfectly cooked meat; after being swallowed, the embryo parasite
passes to the intestine and soon becomes a fully developed tapeworm.

Particular reference at this point should be directed to the evil
effects, which are even still greater than those that come from the
privy, of permitting children and hired helpers to scatter their feces
indiscriminately in corners of the yard, the apple-orchard, or in the
horse-lot; under such circumstances, where hook-worm disease is once
introduced, the soil in the course of a short time becomes thoroughly
permeated with the embryos of this worm, and, as a consequence, all of
the children who play in the infected area barefooted, as is customary in
the country, are sooner or later infected with these parasites. It is
thus seen that soil-pollution from fecal material is a most dangerous
thing, and, particularly in the southern portion of the United States,
deserves the most earnest consideration of everyone. We should see to it
that our children only evacuate their bowels in properly constructed
closets; and it is the duty of the head of every family to provide such a
place for the accommodation of those who are dependent on him.

_Proper Construction of Out-door Privies._--The most practical and
generally satisfactory device heretofore invented for the disposal of
the sewage of communities unprovided with water-works is what is known as
the Rochdale, or dry-closet, system. By this system a privy, at a
distance from the dwelling, is constructed in the ordinary manner, with
the exception that instead of being open at the back it is tightly
closed. In the space beneath the seat receptacles are placed for
receiving the urine and feces. These may consist of pails of wood or
better of galvanized iron; or a single box occupying the whole space. If
wooden receptacles are used, they should be thoroughly coated on the
inside with tar, to prevent both leakage and the soaking of the liquids
into the wood. One such structure, which the writer knows has been wholly
satisfactory has a brick foundation with walls two feet high around the
front and sides, within which rests a shallow tarred box. It ensures
perfect cleanliness.

In any case this space under the seat is tightly closed, being guarded by
doors that open outward, through which the pails or box may be introduced
and removed for emptying.

Each privy contains a box in which is placed either wood ashes or dry
p