getable matter in underground strata. Others think it may be primordial gases that rise up from the mantle. Natural gas was known to the ancients but was considered by them to be a supernatural phenomenon because it appeared as a mysterious fire bursting from the ground.
             Gas is also a fossil fuel. It is a gaseous substance that burns in the air and releases enough heat to be useful as a fuel. It is advantageous if a fuel gas is readily transportable through pipes and is easily liquefied. Oil gas is a type of gas made by applying heat to various petroleum distillates. Its principal use is as a supplement to natural gas during periods of heavy demand. Coal gas may be any of a variety of gases produced by heating coal in the absence of air and driving off the volatile constituents. It is not as high in fuel value as other gases and often contains tars, light oils, ammonia, and hydrogen sulfide. These common fuels are used in industry, transportation, and the home are burned in the air. Scientists research and develop alternatives to gasoline every single day. One possible alternative is methanol, which can be produced from wood, coal, or natural gas. Another possibility is ethanol. Ethanol is an alcohol produced from grain and currently used in some types of US gasoline. A example of this is gasohol. It is a compressed natural gas, which is much less polluting than gasoline and is currently used by a half-million vehicles around the world.
             Petroleum is a fossil fuel thought to have been formed over millions of years from incompletely decayed plant and animal remains buried under thick layers of rock. The widespread burning of petroleum products as fuels has resulted in serious problems of air pollution. Oil spilled from tankers and offshore wells has damaged ocean and coastline environments. The environmentally disruptive effects of oil wells have sometimes led to strong opposition to new drilling, as in wildern...