Creosote that creosote contained a mixture of creosol and guaiacol. Later investigations by Gorup-Besanez, A.E. Hoffmann, and Siegfried Marasse showed that wood-tar creosote also contained phenols, giving it a feature in common with coal-tar creosote. Historically, coal-tar creosote has been distinguished from what was thought of as creosote proper—the original substance of Reichenbach's discovery—and it has been referred to specifically as "creosote oil". But, because creosote from coal-tar and wood-tar are obtained from a similar process and have some common uses, they have also been placed in the same class of substances, with the terms "creosote" or "creosote oil" referring to
Coal gas flame but the light output could be greatly increased by using a gas mantle. The by-products of coal gas manufacture included coke, coal tar, sulfur and ammonia and these were all useful products. Dyes, medicines such as sulfa drugs, saccharine, and dozens of organic compounds are made from coal tar. Coke is used as a smokeless fuel and for the manufacture of water gas and producer gas. Coal tar was subjected to fractional distillation to recover various products, including Used in the manufacture of sulfuric acid Used in the manufacture of fertilisers Coal gas was initially manufactured by independent companies