This analysis shows that if the temperature is allowed to reach a
cherry red, complete decomposition of the illuminating hydrocarbons is
taking place, and a gas of practically no illuminating value results.
The power of regulating the temperature and the body of carbon as a
cracking medium in the Van Steenbergh water gas plant especially fits
it for using this oil, and removes the objections which could have
been urged against the lighter naphthas.

This oil is at present not in the market, but given a demand, it can
be produced in four months, at the latest, in very large quantities,
as the apparatus is very easy and cheap to erect, and the crude
material can be plentifully obtained.

If this oil becomes, as I think it will, an important factor in the
illumination of the future, it will mark as important an era in the
history of our industries as any which the century has seen, as, by
using it, you are giving smoke a commercial value, and this will do
what the Society of Arts and the County Council have failed in--that
is, to give us an improved atmosphere. If I were lecturing on an
imaginary "Hygeia," I should point out that the smoke of London
contains large quantities of these oils, and they, by coating the
drops of mist on which they condense, give the fog that haunts our
streets that peculiar richness which is so irritating and injurious to
the system, and, further, by preventing the water from being again
easily taken up by the air, prolong the duration of the fog. Make this
oil a marketable commodity, and another twenty years will see London
without a chimney; underground shafts will be run alongside the
sewers; into these shafts by means of a down draught all the products
of combustion from our fires will be sucked by local pumping stations,
and the oil condensing in the tubes will serve in turn to illuminate