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 oil indoor lamps. Coal oil that burned cleanly enough to compete with whale oil as an indoor illuminant was first produced in 1850 on the Union Canal in Scotland by James Young, who patented the process. Production thrived in Scotland, making Young a very wealthy man. In Addiewell, West Lothian, Young built a substantial industrial complex for separating petroleum from various oil shales, including cannel coal. In its time it was one of the largest chemical works in Scotland. Construction began in 1866. Addiewell remained the centre of operations for Young's Paraffin Light and Mineral Oil Co. Ltd., but as local