Swamp Fever

SWAMP FEVER, see Malaria-SWAMP GAS, or methane (CH₄), the simplest hydrocarbon of the paraffin series, is formed during the slow decomposition of plant matter without access to air, as follows: 1) during the decay of cellulose under water, in swamps (hence its name), in standing waters, in ponds; 2) during the decomposition of plant residues in coal deposits, which accounts for the high content of S. g. (up to 97%) in mine gas. S. g. is also formed during dry distillation and heating of hydrogen-containing organic substances, consequently it is a constant component of illuminating gas, both coal gas (contains 33-37% CH₄) and water gas (16% CH₄). S. g. is colorless, odorless, sp. gr. 0.553, and almost insoluble in water. Having a very weak narcotic effect, S. g. even in significant concentrations in air with normal O₂ content causes only mild, rapidly passing intoxication, and its role as an industrial poison in the proper sense is extremely insignificant. But in mines, as a constant and principal component of mine gas, S. g. is one of the most dangerous factors in miners' labor, since 1) when large masses of S. g. accumulate in mine air and displace O₂, there may be danger of suffocation, and 2) S. g. has the ability, when mixed with air in certain proportions, to form a highly explosive fire-damp—the cause of numerous disasters and accidents in mines. For details on the professional-hygienic significance of S. g., see Illuminating gas, Gas production.