絵因果経・紫式部日記絵巻・金棺出現図のX線による鑑識

Given here are some results of our preliminary investigations performed by means of a portable X-ray apparatus. First we investigated the degree of penetration by X-rays through the various pigments used in Japanese paintings before the introduction of Occidental technique during the XIXth century. (Cf. the article by Prof. Nakayama.) We made investigations on emakimono and buddhist paintings (VIIIth-XIIIth centuries), with the collaboration of Dr. Yamasaki, professor of chemistry in the Nagoya University. Among the results of those studies, we shall first deal with the identification of a white pigment used in the “Kako Genzai Inga Kyo” (Illustrated scroll of Inga-kyo Sūtra, VIIIth century). (PI. VIII, Fig. 1, 2 and 3) Heretofore it was generally admitted that this pigment was carbonate of calcium but we recognised it to be white lead. As for the yellow pigment it was proved to be white lead covered with gamboge, instead of yellow ochre as usually: admitted. Such results prove the efficiency of X-ray investigations in the identification of pigments used in paintings too precious to be submitted to chemical examinations. During X-ray investigations on the “Murasaki Shikibu Nikki” (XIIIth century), we discovered that two different white pigments had been used, viz: china clay and white lead. We also realized that a chemical transformation of white lead had produced the violet shades appearing in this scroll, a fact which had never been accounted for before. (Pl. I, II and III) After these investigations on paper scrolls, we went on with Buddhist paintings on silk such as “Shaka Kinkan Shutsugen” (Resurrection of Buddha, end of XIth century). (Pl. IV, V, Fig. 4). In this picture, the silk base damaged in several places had been repaired on many spots. X-ray photographs revealed these repairs (for instance, the places shown by a and b in Pl. IV) which the human eye could not detect. A new X-ray apparatus provided with an anticathodic brass target will certainly give still more important results which will be published currently in this survey.