438 
Half-a-dozen English Sewage Farms. 
a gradually growing market on the ground for Italian rye-grass 
and for mangel-wurzel, cabbages, and other vegetables, the diffi- 
culties of a sewage-farm, greatest in the marketing department, 
will gradually disappear. And if, by good management, the 
labour-account can be kept within reasonable limits, a profit 
may be ultimately looked for. The experience hitherto has not 
been wholly discouraging. The Doncaster and Leamington farms 
— both of them in private hands — are perhaps the most hopeful 
of the six that have been described. The Cheltenham farm, 
where the profit arises out of the small amount of the annual 
labour-bill, is also instructive. The Tunbridge Wells and Bed- 
ford farms, and in a less degree the Chorley farm, and in a much 
greater degree the Blackburn farm, must Ije taken as a warning 
against excessive expenditure. 
Meanwhile, it may be held as certain that the agricultural 
remedy for the sewage nuisance is alone trustworthy. None of 
the chemical methods having to deal with a putrescible liquid 
can send it from them in a non-putrescible condition. The 
agricultural remedy alone is perfectly efficient. A putrescible 
liquid passing through the aerated soil — and over that incal- 
culable quantity of surface, within it, to which the superficies 
of all its particles amounts — meets with the oxygen of the air 
under circumstances which promote, hasten, and produce the 
chemical transformation which it requires in order to its perfect 
defaecation. Its organic matters are thus oxidised and trans- 
mitted in a condition in which they are no longer capable of 
creating a nuisance. This is the explanation of ordinary agri- 
cultural experience on a sewage farm, to which Dr. Frankland's 
laboratory experiments, conducted with admirable insight into 
the conditions of the problem, have directed him. It is the 
explanation of the perfect efficiency of his method of downward 
intermittent filtration — a sufficient depth of soil and subsoil being 
filled alternately with sewage and with air — which is just an 
intensive form of the ordinary agricultural experience on a well- 
managed sewage-farm. And whether on the extensive or inten- 
sive scale, this, whatever be the expense of it, is the only pro- 
cess capable of dealing efficiently with a liquid in ^which the 
mischievous organic ingredients, filthy as they may be, are, 
nevertheless, in such extremely dilute solution as they are in 
town sewage. From this method alone, moreover, on the exten- 
sive or agricultural scale, is there any hope of extracting a pro- 
duce which will contribute in any sensible degree to the expense 
of the process. Let us hope that this discussion of some of 
the cases in which it has recently been adopted, may lead to a 
more profitable result than has hitherto been achieved. 
