When Larix Kaempferi Sarg. is seasoned as sap wood sawdust and heart wood sawdust respectively in a long time (6-12 months),
1) galactans and mannans in sawdusts are increased respectively but total celluloses are somewhat decreased and pentosans and lignins are almost unchanged.
2) in sulfite digestion with heart wood sawdust and sap wood sawdust, yields of pulps and total celluloses in the pulps are greatly increased and colors of pulps from heart wood are clearly changed but lignins in the pulps are increased.
3) extracts by organ;c solvents are increased, especially by alcohol benzene (I : I), aceton.
4) cellulose in the pulp from heart wood is easy to change in hydro-cellulose but by seasoning its degree is decreased greatly.
5) polysaccharides (gala ctan and mannan) are greatly dissolved in sulfite liquor at early stages of digestion, but by seasoning their solubilities are decreased in grade respectively.
6) ligains by method of conc. sulfuric acid are not identical between heart wood and sap wood and those differences of lignins are more and more decreased.

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We studied on the manufacture of wet strength paper by mixing water soluble melamine resin solution to sulphite pulp and Edgeworthia papyrifera sieb stuff.
When wet strength Japanese paper is made, wallpaper, filter paper, umbrella paper, bag paper etc whick are difficult to tear in wet stage are produced.
Melamine resin solutions were aged as follows :

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The process of preparation of urea melamine formaldehyde copolycondensates according to Wohnsiedler and others is improper when 70 mol% or more of urea are to be used, the resin colloidal solution coagulates in the case of such high ureacontent to soft white jellies or white insolubles precipitates in a short time. However, we have found that the maximum of urea can be raised to obout 8554, when the resin is produced under more suitable conditions. The resin solution is aged at 50, 4 by weight concentration, and at 70deg;C for 3 hours, using 1 mol of melamine, 5 mols of urea, 13 mols of formaldehyde and 0.7 mol of HC1. In order to preserve the solution for a long time, it must be diluted two times. This resin, when applied in the beater, is capable of imparting the wet strength to paper almost equal to melamine resin. The pH of paper stock is controlled by HC1 or Al₂ (SO₄) ₃. As they do not show an appreciable difference in producing wet strength, the latter is more suitable than the former in mill application. The effect of the resin is more remarkable in the case of unbleached pulp than in the bleached one.The industrial production of the wet strength paper by this resin has been put in practice, and the satisfactory results have generally been obtained.

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Not only the unbleached sulphite pulp often causes the pitch trouble in summer, but the rosin size in bleached sulphite pulp causes the same pitch trouble very suriously.The latter is more severe than the former. The rosin; dark and brittle, showed M.P. 8083deg;C. In these two kinds of rosin contained Ca+Zn and Fe respectively. It is 318deg;C higher than usual Japanese rosin. In the ash of rosin, Ca Zn Fe Si Al were detected mainly. These two kinds of rosin contained Ca+Zn or Fe respecti vely.
By the vacuum distillation of terpentine (from Pinus Thumbergii) the distillate was gained as the standard pale rosin (M.P.73deg;C, ash 0.00%). The impure rosin are made to contain resinate as 0.2% of inorganic oxide, from the standard pale rosin.
The resinate shows M.P. 7880deg;C. By using the size-pitch-determining-appartus which was devised by the author, the rosin was found to cause the severe pitch trouble respectively. From these two points, the two kinds of rosin were thought to contain Ca+Zn or Fe resinated respectively. From the standpoint of pitch trouble, the M.P. of rosin should be 6575deg;C, and yet if the ash content of rosin is the less, the better it will be.

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The purpose of the reseach : To improve the grade of the plants by the chemical analysis of “Kozo” and by the scientific investigation of the soil and earth property and other conditions in which they grow. “Shirokawa and Kurokawa of Kozo” were analysed by standard method.

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