Studies on Japanese Paper-Making (VII)

Abstract

Mitsumata trees may be cut down any day in autumn when they have shed their leaves. The bark of the trees which are cut down in autumn or March of the following year is called fuyu-kawa or the winter bark, while that of the trees are cut down since April is called haru-kawa, or the spring bark. According to tradition, as a matter of course, the winter bark makes better paper, but the spring bark gives higher retention. The raw mitsumata is steamed, and the bark is stripped and dried. This dried bark is called kuro-kawa, or the black bark. In order to make highh-grade paper, kuro-kawa must be turned into shiro-kawa, or the white bark. According to tradition, paper after boiling the black bark with alkaline solution gives higher retention than that of the white bark. For the purpose of investigating these tradition, analyses were made at the various stages of the process of mitsumata paper-making. Mitsumata-Edgeworthia Papirifera Sieb..-, grown in Kochi-ken. Shizuoka race, was employed in the present study. The results of experiments are shown in Table, 1, 2, 3, 4 and may be summarized as follows : (1) The spring bark gives higher retention than the winter bark at the stage of the stripping off the black bark, while the winter bark gives highe retention than the spring bark at the process of paper-making.(2) It is not a fact that the black bark treated by the soda process gives high er retention than that of the white bark at the process of paper-paking.(3) The quality of mitsumata-paper ;1) Strength and stiffness of boilling the white bark is more than that of the black bark, so the winter bark is more than the spring bark.2) Opacity is the most in the boiling of the black bark of the spring bark.3) Brightness or lustre is the most in the boiling of the winter bark.