into milk.

THE OX makes poor dung and rich urine.

THE HORSE makes rich dung and poor urine.[AB]

NIGHT SOIL.

[What is the most valuable manure accessible to the farmer?

What is the probable value of the night soil yearly lost in the United
States?

Of what does the manure of man consist?]

The _best_ manure within the reach of the farmer is _night soil_, or
human excrement. There has always been a false delicacy about mentioning
this fertilizer, which has caused much waste, and great loss of health,
from the impure and offensive odors which it is allowed to send forth to
taint the air.

The value of the night soil yearly lost in the United States is,
probably, about _fifty millions of dollars_ (50,000,000); an amount
nearly equal to the entire expenses of our National Government. Much of
the ill health of our people is undoubtedly occasioned by neglecting the
proper treatment of night soil.

[Describe this manure as compared with the excrements of other
animals.

Does the use of night soil produce disagreeable properties in plants?]

That which directly affects agriculture, as treated of in this book, is
the value of this substance as a fertilizer. The manure of man consists
(as is the case with that of other animals) of those parts of his food
which are not retained in the increase of his body. If he be _growing_,
his manure is poorer, as in the case of the ox, and it is subject to all
the other modifications named in the early part of this chapter. His
food is usually of a varied character, and is rich in nitrogen, the
phosphates, and other inorganic constituents; consequently, his manure
is made valuable by containing large quantities of these matters. As is
the case with the ox, the _dung_ contains the undigested food, the
secretions (or leakings) of the digestive organs, and the insoluble
parts of the ash of the digested food. The _urine_, in like manner,
contains a large proportion of the nitrogen and the soluble inorganic
parts of the digested food. When we consider how much richer the _food_
of man is than that of horned cattle, we shall see the superior value of
his _excrement_.

Night soil has been used as a manure, for ages, in China, which is,
undoubtedly, one great secret of their success in supporting a dense
population, for so long a time, without impoverishing the soil. It has
been found, in many instances, to increase the productive power of the
natural soil three-fold. That is, if