1883.] An Unwelcome Truth. 215 
lands of Western Asia, Northern Africa, and Europe on the 
one hand, and those of China and Japan on the other? 
The former group has, as we well know, received for centu- 
ries the manure produced in the farmyard, and has in most 
places become impoverished to a greater or less extent ; but 
in China, where the bulk of the land has been under regu- 
lar cultivation for probably two thousand years at least, 
where there is little or no pasture or meadow land, whether 
natural or artificial, and where the chief manure consists of 
human excreta, the soil under this treatment is said not to 
have become deteriorated or exhausted. Of course no 
analysis of Chinese soils, as they existed from 2000 to 3000 
years ago, are to be procured ; but there is no reason to 
suppose that they were at the outset richer than those of 
the rest of the world. We know that the soil was let alone, 
and we can only therefore infer that their manuring has kept 
up the fertility of the land. 
This brings me to the question of sewage-irrigation. It 
has been admitted, as far as I am aware, by one of the 
arch-advocates of this method of disposing of foecal matters, 
that two-thirds of the combined nitrogen present in the 
sewage may, instead of being retained by the soil, pass out 
in the effluent water. This statement, in the light of the 
experiments of M. Deherain, becomes highly probable. 
Nitrogenous matter dissolved or suspended in a large 
excess of water, and passed through a porous medium, such 
as the soil, can scarcely fail to undergo decomposition, the 
ultimate produdt being nitrates. Hence it will appear that 
sewage irrigation must for ever fail in utilising the whole, or 
even the greater part, of the nitrogen present in human ex- 
creta. In sewage precipitation, on the contrary, much of 
the “ organic nitrogen ” of the Franklandians, or the “ albu- 
menoid ammonia ” of the Wanklynites, forms a combination 
with alumina, and is only gradually rendered soluble in the 
soiL In this manner it is much more likely to minister to 
the wants of a growing crop. 
The double objection to the old method of dealing with 
sewage, i.e., running it into the nearest river, is that it 
wastes manurial matter, and that it renders the water of 
such river what is now called a “ culture solution ” — that is, 
a liquid in which Badteria, of sorts, if once introduced may 
increase and multiply. But the difficulty of dealing with 
this double evil now appears. If we turn the sewage of a 
town, not diredtly into a river, but pass it over an irrigation 
field, the bulk of the combined nitrogen still finds its way 
into the stream and is wasted. From the sanitary point of 
