An attempt was made to elucidate the effect of air seasoning on pine heartwood phenols which have intense antipulping activity in, sulfite digestion, and the following results were obtained :
1. Seasoning in the air results in mild decrease in two phenols contents (on pinosylvin and its monomethyl ether).
The benefits derived from seasoning must be also considered from another these aspects than that of decreased pitch formation.
2. On air exposure, two phenols decrease in different ways, respectively.
3. It appears that the most successful diminution of phenolic compounds would be expected on exposure of wood in the finest meal.
4. Considering the time-elapse after wood felling and its seasoning condition, we must determine the content of pine phenols in heartwood.

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The authors have studied the effect of synthetic resin latex coating on the tensile strength (TS) of papers. Two kinds of commercial latices (latex A and B) were used (A is the latex of PVC, T_f=75°C and B the latex of copolymer of VC and vinyliden chloride, T_f=15°C, where Tf is the minimum film-forming temp. of latices, see Report I).
In this study, commercial kraft papers were coated with the latices of various conc . and dried at various temp., and some of the coated papers were cured at 120°C for 5 min. The TS was measured with Schopper type TS tester.
The authors have found the important relations between the TS of coated papers and Tr of the latices used. When the coated papers were dried below T_f of the latices, the TS were increased very little or decreased, in this case, the curing of coated papers increased the TS very much . The authors have explained the results from the rigidity or plasticity of the resin particles in the latices.

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In order to measure the turbidity of the colored solutions, we must know not only the scattering coeffi cient but also the absorption coefficient, for the scattered light from a point in solutions is absorbed within the sample cell. Then we have constructed an instrument as indicated in Fig. 3, which can be used to measure the intensity of the scattered and transmitted light. Using the peculier constants for the instrument k, a, b and c, we can get the ratio X as Eq. (5), which is the scattered light intensity divided by the transmi tted intensity, and when the extinction coefficient is small, it becomes to Eq. (6) approximately. Therefore we can express the scattering intensity of the solution by X, which is measured by reading the intensity of the scattered light when we adjust the incident light intensity to make the transmitted intensity a cons tant value. The limits of the approximations have been discussed and the examples of the measurement have been shown.

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