or birch-pitch is a substance (liquid when heated) derived from the dry distillation
of the wood of the birch
. It is therefore pyroligneous.
Birch-tar was used widely as an adhesive as early as the late Paleolithic or early Mesolithic era. It has also been used as a disinfectant, in leather dressing, and in medicine.
It is compounded of guaiacol, phenols, cresol, xylenol, and creosol.