aste, and the importance of exceedingly
cheap and fertilizing manure in the reclamation of waste lands and the
improvement of soil is a question likely to become of most supreme
importance in this overcrowded island. Indeed, if we are to believe the
social philosophers, the naturally fertile lands of the earth may before
long become insufficient for the needs of the human race; and posterity may
then be largely dependent for their daily bread upon the fertilizing
essences of the stored-up plants of the carboniferous epoch, just as we are
largely dependent on the stored-up sunlight of that period for our light,
our warmth, and our power. They will not then burn crude coal, therefore.
They will carefully distill it--extract its valuable juices--and will
supply for combustion only its carbureted hydrogen and its carbon in some
gaseous or finely divided form.

Gaseous fuel is more manageable in every way than solid fuel, and is far
more easily and reliably conveyed from place to place. Dr. Siemens, you
remember, expected that coal would not even be raised, but turned into gas
in the pits, to rise by its own buoyancy to be burnt on the surface
wherever wanted. And not only will the useful products be first removed and
saved, its sulphur will be removed too; not because it is valuable, but
because its product of combustion is a poisonous nuisance. Depend upon it,
the cities of the future will not allow people to turn sulphurous acid
wholesale into the air, there to oxidize and become oil of vitriol. Even if
it entails a slight strain upon the purse they will, I hope, be wise enough
to prefer it to the more serious strain upon their lungs. We forbid sulphur
as much as possible in our lighting gas, because we find it is deleterious
in our rooms. But what is London but one huge room packed with over four
millions of inhabitants? The air of a city is limited, fearfully limited,
and we allow all this horrible stuff to be belched out of hundreds of
thousands of chimneys all day long.

Get up and see London at four or five in the morning, and compare it with
four or five in the afternoon; the contrast is painful. A city might be
delightful, but you make it loathsome; not only by smoke, indeed, but still
greatly by smoke. When no one is about, then the air is almost pure; have
it well fouled before you rise to enjoy it. Where no one lives, the breeze
of heaven still blows; where human life is thickest, there it is not fit to
live. Is