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.