Village Sanitary Econounj. 
243 
sewage, which would rise by evaporation and load the air with 
that organic dust which Professor Tjndall has shown to exist in 
a quantity quite unappreciated even by those most advanced in 
science. Moreover, the system of sub-irrigation is opposed to the 
practice of the best cultivators, who water the roots of all growing 
vegetation from above and not from below; in proof of this good 
gardeners have long ceased to water plants in pots by means of 
saucers. Should, however, notwithstanding the above objec- 
tions, circumstances favour the adoption of sub-irrigation in 
particular cases, one of the most promising methods of carrying 
it out, of which the writer is aware, is that now being tried at 
some cottages in Essex by Mr. Rogers Field, C.E. Each 
cottage is provided with a small water-tight deposit tank which 
receives the water from the sink ; to this tank is attached a self- 
acting syphon, so arranged that it empties the liquid whenever 
the tank becomes full, but not before, leaving the solid that has 
been deposited behind to be cleared out by hand when a sufficient 
quantity has accumulated. The syphon discharges into the sub- 
irrigation drains, and the flow, being intermittent, is considerable 
when it does occur and is under favourable conditions for forcing 
the sewagi along the pipes and for feeding vegetation. The last 
method of dealing with the refuse of the house which has been 
suggested by the advocates of the dry-earth system, viz. by con- 
ducting it into tanks in which earth is placed for the means of 
deodorising and filtering it, is really only another plan of separating 
a part of the sewage from the whole, and this, for the reasons 
already assigned when referring to the processes of precipitation, 
&c., must be passed over as incomplete and unsatisfactory. 
The general conclusion is, that to effect the sewerage of 
villages one of the following modes of treatment must be 
adopted. 
1. By a system of underground sewers of sufficient capacity 
to remove the whole of the refuse by the agency of water, or-— 
2. By the substitution of dry earth for water as a vehicle for 
the removal of the whole refuse, or — 
3. By confining the use of dry earth to the deodorising and 
removal of excretal matter only, and either discharging the 
remaining refuse by a system of underground sewers, or dealing 
with it by sub-irrigation or surface-absorption. 
As the sewerage of every village must depend upon the 
specialities of the place it would be useless to venture upon any 
estimate of cost. Villages are frequently much scattered, but 
the cost of sewers would not necessarily be great, inasmuch as 
glazed earthenware pipes would be suitable, and the quantity of 
sewage would at most be inconsiderable. When earth is used 
instead of water a system of scavenging must be adopted too, or 
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