he
products whose composition and history have just been described the
fuel supply of the future will depend, consists in the question of the
extent and duration of these natural gas and oil reservoirs. If we are
beginning to look forward to a time when our coal supply will have
been worked out, it behooves us to ask whether or not the supply of
natural gas and oil is practically illimitable. The geologist will be
able to give the coming man some degree of comfort on this point, by
informing him that there seems to be no limit to the formation of the
fuel of the future.

Natural gas is being manufactured to-day by nature on a big scale.
Wherever plant material has been entombed in the rock formations, and
wherever its decomposition proceeds, as proceed it must, there natural
gas is being made. So that with the prospect of coal becoming as rare
as the dodo itself, the world, we are told by scientists, may still
regard with complacency the failure of our ordinary carbon supply. The
natural gases and oils of the world will provide the human race with
combustible material for untold ages--such at least is the opinion of
those who are best informed on the subject. For one thing, we are
reminded that gas is found to be the most convenient and most
economical of fuels. Rock gas is being utilized abroad even now in
manufacturing processes. Dr. M'Gee says that even if the natural
supply of rock gas were exhausted to-morrow, manufacturers of glass,
certain grades of iron, and other products would substitute an
artificial gas for the natural product rather than return to coal. He
adds that "enormous waste would thereby be prevented, the gas by which
the air of whole counties in coke-burning regions is contaminated
would be utilized, and the carbon of the dense smoke clouds by which
manufacturing cities are overshadowed would be turned to good
account." So that, as regards the latter point, even Mr. Ruskin with
his horror of the black smoke of to-day and of the disfigurement of
sky and air might become a warm ally of the fuel of the future. The
chemist in his laudation of rock gas and allied products is only
re-echoing, when all is said and done, the modern eulogy pronounced on
ordinary coal gas as a cooking and heating medium.

We are within the mark when we say that the past five years alone have
witnessed a wonderful extension in the use of gas in the kitchen and
elsewhere. It would be singular, indeed, if we should happen to