Use of Town Sewage as Manure. 
137 
manures. It will simplify matters if we consider the subject 
under two divisions, namely — 
1, The nature of sewaijc, and the circumstances affecting the 
possibility of economically employing it in agriculture. 
2. The plans proposed, and their prospects of success. 
In order tliat tlie reader may, however, see, as he proceeds, the 
object with whicli different points are brought forward, I would 
simply say, at the risk of somewhat forestalling the result at 
which I hope ultimately to arrive, that all plans for utilising town 
sewage must resolve themselves into two classes : the first, that 
of employing it in the natural state, conveyed by pipes or other- 
wise into the country ; the second, that of obtaining from the 
liquid, by particular methods of manufacture, a more or less dry 
and portable manure for general distribution in the ordinary way. 
With the first of these classes, namely, the plans for employing 
liquid sewage, I do not intend, to any great extent, to meddle at 
the present moment, not because I do not think it of the very 
first importance, — for, indeed, I feel that no other than the liquid 
method can finally satisfy all the necessities of the case, — but 
because the desirableness of this system has been most ably 
advocated by men whose opinions on such subjects are much 
more worthy of attention than my own could be ; and because, 
again, it is my intention, in the present paper, to guard against 
what ought not to be done, rather than to point out what should 
be attempted — to check error, rather than to propound truth. It 
is one thing to say what will not succeed, and another to point to 
courses certain of success. I feel competent to offer an opinion 
on the first ; but I need not be ashamed to own, in common with 
those best informed on the subject, that at present I do not see 
my way very clearly in the other. I am not unaware that there 
are those who consider the collection and utilisation, in the 
liquid form, of town sewage on a great scale not only possible, 
but readily practicable ; and its conveyance from the town would 
not seem to offer insuperable difficulties. But there are always 
two parties to a bargain ; and until the agricultural community 
is prepared to use liquid sewage it is of no avail to offer it. I 
have no doubt that that time will come shortly, but before com- 
prehensive schemes in this direction can be brought to bear, ex- 
aggerated ideas of the value of different processes for the manu- 
facture of a solid manure from sewage must be corrected. This 
it is my present object to attempt, at all events, in part, and for 
these reasons I do not purpose to enter, to any extent, upon the 
various plans for using liquid sewage, especially as all that a 
chemist can contribute to the subject is to suggest the best 
methods of deodorizing and preserving these matters. 
The system of sewerage of a town is designed to remove from 
