The vital thing which thus presents itself is the disposal of fecal matter
and other refuse so that the wells, upon which most rural families depend
for their drinking water, may remain pure. To this matter we will first
turn our attention.
Every person who tills the soil is acquainted with the remarkable
transforming power of the superficial layers of the earth upon manure and
excrement. Out of these offensive wastes harmless substances are produced
which are essential to the growth of vegetation. This power, known as
decay, is now generally attributed to very minute organisms (bacteria)
which are found in immense numbers in the superficial layers of the soil,
which diminish in number as we go deeper, and which completely disappear
below a depth of 6 to 12 feet, according to the physical condition of
the soil. Bacteria are more numerous where waste and excrement are most
abundant. When night soil and manure are deposited in excavations or
so-called cesspools in the earth, from which the fluid matter may enter
the ground at some depth below the surface, where the air or certain kinds
of bacteria can penetrate only to a slight extent, the substances, which
under the influence of the air (oxygen) and of bacteria near the surface,
would have decayed, now undergo partial putrefaction with the setting
free of disagreeable gases and odors. The deeper layers of the earth
slowly become saturated with organic matter, which is carried by the
ground-water into the wells or springs near by. There is also some reason
to believe that disease germs live longer in the oxygen-free depths of the
soil than at or near the surface.
The extent to which the filling up of the soil with excrementitious matter
may go on in densely populated cities has been shown by Fodor for the
Hungarian city Budapest. By analyzing the soil at different levels from
the surface to a depth of about 13 feet, he found, over an area comprising
15 acres, about 1,000,000,000 pounds organic matter, equivalent to the
excrement of 100,000 people voided during thirty-seven years.
[Illustration: Fig. 1.--The shallow barnyard well, with privy vault and
manure heaps near by. The water is likely to receive fluid from these at
any time.]
To the surface of the earth we owe thus a purifying influence whose
activity furnishes us vegetation and food on the one hand and preservation
from disease on the other. This purifying power is not possessed by the
deeper layers, and therefore the percolation of organic refuse into them
from deep cesspools is wasteful to agriculture and dangerous to our
storehouse of drinking water.
Even the surface of the soil when overloaded with sewage loses partially
its power of purifying the organic matter. After sufficient rest, such an
overloaded soil regains its original power. The purifying activity of the
soil from a sanitary aspect is the same as that governing fertility from
an agricultural standpoint, hence any further discussion of this subject
is unnecessary.
A hint as to the proper disposition of waste, excrement, etc., is
furnished by what is stated above concerning the purifying capacities of
the earth's surface. Waste, night soil, etc., should be deposited with
proper precautions on or immediately below the surface of the soil, where
it may perform the double function of ridding the household of a nuisance
and of enriching the soil itself. This leads us to a consideration of the
best means of taking care of the household wastes. These are, in general,
of three classes: First, fecal matter; second, kitchen and chamber slops;
and third, miscellaneous rubbish and ashes.