Gakushuin Natural Radiocarbon Measurements V

Abstract

This list includes many of the datings done from September 1964 to October 1965. The instruments and techniques used for this work are essentially the same as those used previously (Gakushuin III). Bone samples were dated on the organic materials obtained by the following procedure. After washing with distilled water the powdered bone samples were boiled with 10% H₂SO₄ solution 10 to 40 hours. The extract, a clear solution, was exaporated to almost dryness, and, after concentrated H₂SO₄ was added, heating was continued until most of the organic compounds became insoluble carbonized or polymerized material. The black residue was washed in water and treated as the usual charcoal sample for dating.