Fig. 60.—Cylinder to show the formation of gas by bacteria. The gauge shows 265 pounds. It went beyond 500 pounds.
Fig. 61.—A burning natural gas well at night. From a photograph colored.
In the fermentation of the polysaccharids—starch and especially cellulose and woody material—large amounts of CH4 occur, particularly when the changes are due to anaërobic bacteria. This phenomenon may be readily observed in sluggish streams, ponds and swamps where vegetable matter accumulates on the bottom. The bubbles of gas which arise when the mass is disturbed explode if a lighted match is applied to them.
The author has conducted a number of experiments to demonstrate this action as follows: Material taken from the bottom
of a pond in the fall after vegetation had died out was packed into a cylinder five feet long and six inches in diameter, water was added to within about 2 inches of the top. After leaving them open for a few days to permit all the dissolved oxygen to be used up by the aërobes, the cylinders were tightly capped and allowed to stand undisturbed. Pressure gauges reading to 500 lbs. were attached ([Fig. 60]). At the end of six months the gauge showed a pressure beyond the limits of the readings on it. Most of the gas was collected and measured 146 liters. An analysis of portions collected when about one-half had been allowed to escape showed the following composition, according to Prof. D. J. Demorest of the Department of Metallurgy:
| CO2 | 18.6 per cent. |
| CH4 | 76.1 per cent. |
| H | 1.0 per cent. |
| N | 4.3 per cent. |
In the author’s opinion natural gas and petroleum have been formed in this way[12] ([Figs. 61] and [62]).
Fig. 62.—A “flowing” oil well.