point.
7CaCO3 + 7H2S + 7H2O2 " 7(CaSO4.H2O) + C7H14 --
8CaCO3 + 8H2S + 8H2O2 " 8(CaSO4.H2O) + C8H16 189°C.
9CaCO3 + 9H2S + 9H2O2 " 9(CaSO4.H2O) + C9H18 136°C.
10CaCO3 + 10H2S + 10H2O2 " 10(CaSO4.H2O) + C10H20 160°C.
11CaCO3 + 11H2S + 11H2O2 " 11(CaSO4.H2O) + C11H22 180°C.
12CaCO3 + 12H2S + 12H2O2 " 12(CaSO4.H2O) + C12H24 196°C.
13CaCO3 + 13H2S + 13H2O2 " 13(CaSO4.H2O) + C13H26 240°C.
14CaCO3 + 14H2S + 14H2O2 " 14(CaSO4.H2O) + C14H28 247°C.
15CaCO3 + 15H2S + 15H2O2 " 15(CaSO4.H2O) + C15H30 --

It is explained that these effects must have occurred, not at periods
of acute volcanic eruptions, but in conditions which maybe, and have
been, observed at the present time, wherever there are active
solfataras or mud volcanoes at work. Descriptions of the action of
solfataras by the late Sir Richard Burton and by a British consul in
Iceland are quoted, and also a paragraph from Lyall's "Principles of
Geology," in which he remarks of the mud volcanoes at Girgenti
(Sicily) that _carbureted hydrogen_ is discharged from them, sometimes
with great violence, and that they are known to have been casting out
water, mixed with mud and _bitumen_, with the same activity as now for
the last fifteen centuries. Probably at all these solfataras, if the
gases traverse limestone, fresh deposits of oil-bearing strata are
accumulating, and the same volcanic action has been occurring during
many successive geological periods and millions of years; so that it
is difficult to conceive limits to the magnitude of the stores of
petroleum which may be awaiting discovery in the subterranean
depths.[2]

[Footnote 2: Professor J. Le Conte, when presiding recently at the