This reaction is of peculiar importance because it bridges the gulf between the organic and inorganic worlds. It was formerly supposed that the substances found in plants and animals, mostly complex compounds of carbon, hydrogen and oxygen, could only be produced by "vital forces." If this were true it meant that chemistry was limited to the mineral kingdom and to the extraction of such carbon compounds as happened to exist ready formed in the vegetable and animal kingdoms. But fortunately this barrier to human achievement proved purely illusory. The organic field, once man had broken into it, proved easier to work in than the inorganic. But it must be confessed that man is dreadfully clumsy about it yet. He takes a thousand horsepower engine and an electric furnace at several thousand degrees to get carbon into combination with hydrogen while the little green leaf in the sunshine does it quietly without getting hot about it. Evidently man is working as wastefully as when he used a thousand slaves to drag a stone to the pyramid or burned down a house to roast a pig. Not until his laboratory is as cool and calm and comfortable as the forest and the field can the chemist call himself completely successful. But in spite of his clumsiness the chemist is actually making things that he wants and cannot get elsewhere. The calcium carbide that he manufactures from inorganic material serves as the raw material for producing all sorts of organic compounds. The electric furnace was first employed on a large scale by the Cowles Electric Smelting and Aluminum Company at Cleveland in 1885. On the dump were found certain lumps of porous gray stone which, dropped into water, gave off a gas that exploded at touch of a match with a splendid bang and flare. This gas was acetylene, and we can represent the reaction thus: CaC_{2} + 2 H_{2}O --> C_{2}H_{2} + CaO_{2}H_{2} calcium carbide _added_ to water _ gives_ acetylene _and_ slaked lime