Solubilities, of the alkali lignins by soda process, of the thiolignins and of the sulfuric acid lignins from the wood hydrolysed by the strong acid process, in the binary mixtures of water and solvents, e. g. acetone, dimethylsulfoxide, methyl alcohol, are measured at 25 ℃.
Acetone-water, dimetlylsulfoxide-water, as well as ethylalcohol-water binary mixture, showed maximum solubilities at a certain volume ratio. The solubility curve of lignin against the volume ratios of the dimethylsulfoxide-water mixtures is very similar to that of acetone-water mixture, but it has not showed a specially excellent solvent power comparing with with those of the acetone or dioxane.