| Popis: |
This is a summarized report of experiments about pigments used in ancient Japanese paintings, by the different extents of the penetration of X-rays through them. Materials used in these experiments were: hakudo (clay), gofun (calcium carbonate), aenka (zinc oxide) and empaku (white lead, or basic lead carbonate) for white pigments; ōdo (yellow ochre), seki-ō (orpiment) and mitsudasō (litharge) for yellow pigments; bengara (red ochre), shu (cinnabar) and tan (red lead) for red pigments; iwa-gunjō (azurite) for blue pigment; and iwa-rokushō (malachite) for green pigment. Samples were prepared in six different thicknesses for each material, 0.02mm., 0.04mm., 0.06mm., 0.11mm., 0.17mm., and 0.22mm., respectively. On these samples X-rays were cast in various conditions to make X-ray penetration photographs. The experiments proved that different pigments, even of the same thickness, allowed different degrees of penetration, for the photographs thus taken showed different densities of black. In the white pigments, the degree of penetration proved smaller in the order of clay, calcium carbonate, zinc oxide and white lead. In the yellow pigments, the order was yellow ochre, orpiment and litharge. In the red pigments, it was in the order of red ochre, cinnabar and red lead. Azurite allowed larger degree of penetration than malachite did. These results prove that we can tell an unidentified pigment by means of X-ray penetration photography. |
