Differences in birch tar composition are explained by adhesive function in the central European Iron Age.

Birch bark tar is the most widely documented adhesive in prehistoric Europe. More recent periods attest to a diversification in terms of the materials used as adhesives and their application. Some studies have shown that conifer resins and beeswax were added to produce compound adhesives.

[Pleural involvement caused by contiguity or metastases in primary malignant bone tumors in children].

Pleural location of primary osseous malignant tumors of children are infrequent. They may be secondary from a distant primary osteosarcoma. It is necessary to investigate them via conventional chest X-ray followed by a CT of the thorax.