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
Birch tar Birch tar Birch tar or birch pitch is a substance (liquid when heated) derived from the dry distillation of the bark of the birch tree. It is composed of phenols such as guaiacol, cresol, xylenol and creosol. Birch tar was used widely as an adhesive as early as the Middle Paleolithic to early Mesolithic era. Neanderthals produced tar through the dry distillation of birch bark as early as 200,000 years ago. It has also been used as a disinfectant, in leather dressing, and in medicine. 5,000-year-old chewing gum made from birch bark tar, with tooth imprints, has been found in