Medical Officers of the Army of India.

119

conditions of soil and climate. The best of earth-disposal systems can only give
satisfactory results under the four conditions of—

         (a) a suitable soil,

         (b) a sufficiency of water for irrigation,

         (c) a suitable climate,

         (d) strict attention to all the details, including subsequent cultivation,
            which cannot always be carried out at the most dangerous time.

     In many places these conditions are not obtainable, and "even where cir-
cumstances are most favourable, the best system (the "shallow trench") is
generally improperly carried out." "There is not enough care or intelligence
given to the supervision of details; I believe there is a good deal of pollution of
air, water and soil, arising from the defective carrying out of the Allahabad
system." (Major Davies.)

     The danger of accumulating organic filth in deep pits, and in overcharg-
ing deep trenches, is an accepted commonplace and needs no emphasis, but
it may well be that under our special meteorological conditions, we have gone too
far to the opposite extreme of surface disposal. But without labouring this point,
the whole question of earth disposal in the neighbourhood of the inhabited site in
this country is open to grave question, in view of the well-accredited results of
recent research, and in view also of the heavy toll we are paying year by year, in
valuable lives lost from bowel diseases in one or other form; and it is unnecessary
to elaborate the thesis that these diseases have the most direct relation to the
presence in the environment of organic filth. The recent contributions to our
knowledge of the question we have stated may be summarised under three
heads, partly eidemiological and partly the result of exac: research.

     In the first place we have the long list of carefully investigated cases on which
the accepted view is based that soil polluted with excreta has directly or indirectly
influenced the outbreak of enteric fever—a leaking cesspool, a defective drain pipe
is held to provide sufficient evidence of the cause of an outbreak in England.*

Summary of evi-
dence as to soil pol-
lution.

     More definitely bearing on our present case is the evidence adduced as re-
gards the causes of the prevalence of the enteric fever in Munich (see Dr. Childs'
striking paper read before the Epidemiological Society, January 21st, 1898), of
which we may quote the conclusions. "(1) The drinking-water has not played
an important part in producing and reducing the typhoid fever epidemics in Mu-
nich; (2) the great prevalence of the disease there was due to the pollution of the
soil (including specific pollution), modified by certain conditions in the soil which
are correlated with the movements of the subsoil water; (3) the gradual reduction
of the typhoid fever was due to the gradual purification of the soil." We have

* See Corfield, Harveian Lectures, "Disease and defective house sanitation."