IGNIS FATUUS n.
A phosphorescent light that appears, in the night, over marshy ground, supposed to be occasioned by the decomposition of animal or vegetable substances, or by some inflammable gas; -- popularly called also Will-with-the-wisp, or Will-o'-the-wisp, and Jack-with-a- lantern, or Jack-o'-lantern.
METHANE n.
A light, colorless, gaseous, inflammable hydrocarbon, CH4; marsh gas. See Marsh gas, under Gas. Methane series (Chem.), a series of saturated hydrocarbons, of which methane is the first member and type, and (because of their general chemical inertness and indifference) called also the paraffin (little affinity) series.…