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
Picoline its unpleasant smell. In 1849, the Scottish chemist Thomas Anderson (1819 – 1874) prepared picoline in pure form, from coal tar and via the pyrolysis of bones. Anderson also named picoline by combining the Latin words "pix" (tar) and "oleum" (oil) because coal tar oil was a source of picoline. By 1870, the German chemist Adolf von Baeyer had synthesized picoline in two ways: by the dry distillation of "acroleïnammoniak" (CH=CH-CH=N-CHOH-CH=CH) and by heating "tribromallyl" (1,2,3-tribromopropane) with ammonia in ethanol. In 1871, the English chemist and physicist James Dewar speculated that picoline was methylpyridine. If the structure of pyridine that