2CaCO3 + 2H2S + 2H2O2 yield 2(CaSO4.H2O) + C2H4 ethylene (gaseous). 3CaCO3 + 3H2S + 3H2O2 " 3(CaSO4.H2O) + C3H6 4CaCO3 + 4H2S + 4H2O2 " 4(CaSO4.H2O) + C4H8 5CaCO3 + 5H2S + 5H2O2 " 5(CaSO4.H2O) + C5H10 6CaCO3 + 6H2S + 6H2O2 " 6(CaSO4.H2O) + C6H12 Boiling point. 7CaCO3 + 7H2S + 7H2O2 " 7(CaSO4.H2O) + C7H14 -- 8CaCO3 + 8H2S + 8H2O2 " 8(CaSO4.H2O) + C8H16 189 deg.C. 9CaCO3 + 9H2S + 9H2O2 " 9(CaSO4.H2O) + C9H18 136 deg.C. 10CaCO3 + 10H2S + 10H2O2 " 10(CaSO4.H2O) + C10H20 160 deg.C. 11CaCO3 + 11H2S + 11H2O2 " 11(CaSO4.H2O) + C11H22 180 deg.C. 12CaCO3 + 12H2S + 12H2O2 " 12(CaSO4.H2O) + C12H24 196 deg.C. 13CaCO3 + 13H2S + 13H2O2 " 13(CaSO4.H2O) + C13H26 240 deg.C. 14CaCO3 + 14H2S + 14H2O2 " 14(CaSO4.H2O) + C14H28 247 deg.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 International Geological Congress at Washington, mentioned that in the United States extensive lava floods have been observed, covering areas from 10,000 to 100,000 square miles in extent and from 2,000 to 4,000 feet deep. We have similar lava flows and ashes in the North of England, in Scotland, and in Ireland, varying from 3,000 to 6,000 feet in depth. In the Lake District they are nearly 12,000 feet deep. Solfataras are active during the intermediate, or so-called "dormant," periods which occur between acute volcanic eruptions.]