88 
THE MANURE HEAP AND SEWAGE. 
his barnyard manure, and the constant addition of lime thereto 
is certainly to be most thoroughly recommended. In other respects 
this material has exactly the same relations to decomposition and 
reconstructive processes as barnyard manure. 
The portion of sewage which comes from the wash-water of 
the sink or the dairy on the ordinary farm is so small that it may 
commonly be left to care for itself. The amount of solid material 
in such water is slight, and it can be allowed to run out on the soil 
where, generally, it is rapidly absorbed and decomposed without 
OVERFLOW 
SEPTIC TANK 
FIG. 19. Diagram showing the method of applying the septic tank to a farm house. 
any undue pollution. The organic matter undergoes the same type 
of decomposition as that to which all organic bodies are subjected 
under the influence of bacteria, and becomes eventually converted 
into plant food and incorporated into soil. The drainage which 
comes from the large dairy or creamery may be too much to be 
disposed of by such a simple manner. In this case some means 
must be adopted for its disposal. The problem thus presenting 
itself is precisely the same as that presented to the city for disposing 
of its sewage, and the same means are to be used in each case. 
The time is coming, and, in some places, has arrived, when 
it is necessary to find a plan for disposing of the sewage on the ordi- 
nary farm in some other way than by emptying it into a stream. 
