TREATMENT OF FARM SEWAGE 95 
manure, and should be handled in essentially the same manner 
It is always emphatically necessary, however, to remember that 
the contents of the privy vault are far more likely to contain patho- 
genic bacteria than is barnyard manure, and it should, conse- 
quently, be much more carefully handled. That such material 
has been the means of distributing typhoid fever in many cases Is 
surely demonstrated. The bacilli of this disease are voided by the 
patient in the excreta, and are thus sure to find their way into the 
vault, to be subsequently distributed over the fields, where they 
may percolate through the soil and pollute streams and wells. 
The contents of the privy vault should never be left in position 
where it can possibly pollute the water of either brook or well. 
Precaution should also be taken to prevent its distribution around 
the farm by means of soiled boots or tools which have been used in 
handling it. There is much more likelthood of finding pathogenic 
bacteria in kuwman excrement than in that of domestic cattle, and 
the disease germs thus found are far more likely to be injurious to 
human health. Evidently the farmer should exercise much more 
care is disposing of the contents of his privy vault than in the use of 
his barnyard manure, and the constant addition of lime thereto 
is certainly to be most thoroughly recommended. In other re- 
spects this material has exactly the same relations to decomposi- 
tion 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 
any undue pollution. The organic matter undergoes the same 
type of decomposition as that to which all organic bodies are sub- 
jected 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 
