374 Editorial Comment. 
than a few feet in a mile. All the chief data required for the 
new theory are conspicuously absent. 
Finally Prof. Mendeleef seems to depend largely for the sup- 
port of his theory on the enormous quantities and high pres- 
sure and permanence of the oil and gas supplies. This he 
uses as a powerful argument against the belief in their deriva- 
tion from any organic source, such as the bituminous shales 
of the Secondary or even of the Palaeozoic rocks. This 
abundance indicates, he thinks, an origin in chemical action 
in the primary nucleus of the earth or in the deeper parts of 
the crust. This doctrine would be welcomed by all those 
whose money is in gas and oil and would be indeed joyful 
news to all who have hoped to be delivered from the plague 
of smoke by the advent of natural gas. But we can assure 
Prof. Mendeleef that this last hope will prove fallacious, and 
that how abundant soever may be the present supply, that sup- 
ply is destined to fail, and before very long. The new oil and gas 
region of the Caucasus may not yet show sign of failure, and 
years may pass before such sign appears, but the falling off 
of the spouting and flowing wells which is as constant there 
as elsewhere, and the need for pumping where the yield was 
once spontaneous, are indications that can not be mistaken ; 
and as the great gushers of Pennsylvania have long since 
ceased to flow, so the enormous supplies elsewhere will one 
day follow suit.' Economy is the Avise policy of all engaged 
in the manufacture, in order that the wonderful store of nat- 
ural fuel, liquid and gaseous, may last as long as possible. 
Signs are abundant that the quantity is limited, and that if 
produced now at all the production is far slower than the con- 
sumption. Apprehension is already felt that the great blowers 
of gas at Pittsburg are running down and such announcements 
as the following are not calculated to allay the feeling. 
"That the gas supply in this (Pittsburgh ) district and adjoin- 
ing places has passed its zenith and is now on the wane can no 
longer be satisfactorily denied. The reason usually given was 
that new mains were being laid to the wells or that the size of 
those already down was being enlarged. These changes have 
all been made and still the desired fuel does not pour through 
^ See an article on "The Future of Natural Gas" in the "American 
Geologist for Januar_v, 1888, where this state of things was distinctly 
foretold. 
