and silk surfaces. From chemical analysis it isfound that the memecylon solution is composedmainly of tannic acid, which increases the acidityof dye solution (see Table 4) and enhances theadsorption of laccaic acid on the protein fiber.From slopes of graphs in Figs. 6 and 7, the heat ofdyeing and the entropy of dyeing were calculatedto be 10.3 kcal/mol and 0.02 kcal/mol.K,respectively. It seems that the dyeing with memecy-lon evolves less heat, compared to the dyeingwithout memecylon