Resins and pitches were extensively used in ancient Egypt and other cultures as aids to mummification and in some structures. Many different names have been applied to bitumens, asphalts and other mineral products which have led to confusion with vegetable pitches. All these products have been used at one time or another to caulk the hulls of ships.
Vegetable pitches have been variously identified in Egyptian sarcophagi, but doubt has existed over their origin. Often this seems to have been juniper rather than cedar, but certainly cedar pitch was used in Egypt from prehistoric times.
A related product, birch bark tar, according to a paper in Antiquity for September, by E. M. Aveling and C. Heron of the University of Bradford, may have served as a primitive form of chewing gum. Samples of mesolithic date from Scandinavia in the form of tarry masses have been found to carry the impression of human teeth.
This pitch was made by heating birch bark in a vessel with limited supply of air, and other samples of it have been found used to glue a copper axe, arrow heads and arrow flights found with the celebrated ice-man of the Alps. Other fragments from neolithic sites in Southern Germany and Switzerland in the form of tarry bars bear discernible impressions of teeth.
The mesolithic samples from Scandinavia have yielded triterpenoids characteristic of Betula species, but no diterpenoids which would suggest Pinus. The presence of some pollen from Pinus, Corylus and Quercus was attributed to background contamination from the forest environment. It is possible that prior chewing of the samples was practised to soften the pitch to enable it to be used as a sealant or adhesive, or that alternatively a piece was chewed off a long bar of pitch immediately before it was required for these purposes.
No stimulants or possible addictive components could be detected in the bark, so that it is unlikely that there is a parallel with betel, coca or tobacco chewing. However, birch bark has been used for sore throat and blistered lips, and chewing it stimulates salivation and serves to clean teeth and gums.
It is interesting to note that in four of five instances the Scandinavian samples carried the tooth impressions of children or adolescents with an age range of six to 15 years. This corresponds with the time of life when the deciduous milk teeth begin to work loose. Possibly birch bark pitch was used to facilitate the shedding of teeth at this crucial time.