The purpose of these tests were to decide the most suitable ratio of length to width (L/W) of Clupak paper bag and Normal Japanese kraft paper bag respectively.
In these tests, the paper bags used were all small type of them.
1) In Face & Back drop test, the most suitable ratio of L/W of Normal kraft paper bag was from 1.75 to 2.00 and that of Clupak paper bag was 1.25.
For one of the reasons, it seemed from the state of rupture of the bag dropped that the higher the ratio was the heavier the main impact energy might add to the lengthwise direction of the bag.
From the above assumption, Clupak paper bag was stronger by increasing the ratio because the toughness of M.D. was larger than that of C. D. of the paper, and while Normal kraft paper bag was stronger by decreasing the ratio because the toughness of C.D. was larger than that of M.D. of the paper.
2) Butt drop was not tesied. But, in this case, it was assumed that Clupak paper bag and Normal kraft paper bag would be stronger together by decreasing the ratio of L/W of the bag.
Therefore, the most suitable ratio of L/W of Clupak paper bag might exist in 1 .25 in the case of the both types of drop test.
3) It could be stated from the results of drop test that the rate of the strength of Clupak paper bag to Normal kraft paper bag was 1.82.1 times in the ratio=1.001.25, 1.51 .6 times in the ratio=1.50 and 1.2 times in the ratio=1.752.00.
4) In the most suitable ratio of L/W of each paper bag, the strength of Clupak paper bag to Normal kraft paper bag had 1.41.5 times.
5) Theoretical explanations about these results of the experiments mentioned above are carried out now by testing the decrease rate of the strength properties of paper during dropping the bag.

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Bleached sulfite, bisulfite and sulfate pulps were made from fir and birch wood chips (Table 1), and their papermaking properties were compared, especially on the tearing strength.
Sulfite pulps are easy to swell by beating operation (Fig. 1), and higher in water retention value and accordingly lower in specific scattering coefficient of dried sheet, namely higher in fiber bonded area, compared with sulfate pulp beaten to the equal freeness (Fig. 2). On the other hand, tensile or bursting strengths of sulfate pulp are generally higher than those of sulfite pulps at the equal freeness (Fig. 3 and 4). This is mainly due to that sulfate pulp is higher in strength of a fiber-to-fiber bond than sulfite pulps. The reason is that tensile and bursting strengths of sulfate pulp are considerably higher than those of sulfite pulps at the equal specific scattering coefficient (Fig. 8), in spite of a little difference between their fiber strengths (Fig. 9).
Sulfate pulp is considerably higher in tearing strength than sulfite pulps at the equal freeness (Fig. 3 and 4), in spite of a slight difference in fiber strength and in average fiber length (Fig. 12) between these pulps. On the other hand, in comparison between sulfite and sulfate pulps at the equal specific scattering coefficient, tearing strength of sulfate pulp is higher than that of sulfite pulps in the early stage of beating, but these strengths approach together in the later stage of beating (Fig. 10).
These facts are probably due to the following reasons ;
(1) The higher tearing strength of sulfate pulp than that of sulfite pulp at the beginning of beating is mainly due to the higher strength of fiber bonds in sulfate pulp, because most part of tearing energy is consumed by the deformation of fiber, destruction of fiber-to-fiber bond and the following inter-fiber friction in this stage.
(2) The fact that the tearing strengths of sulfite and sulfate pulps at equal specific scattering coefficient approach together at the later stage of beating, is due to the nearly equal fiber strength of the pulps, because tearing energy is mainly consumed by the cutting of fiber in this stage.
(3) In comparison between sulfite and sulfate pulps at the equal freeness, the former is considerably lower than the latter in tearing strength even at the later stage of beating. This is explained by higher swellability and greater fiber bonded area of dried sheet of sulfite pulp, and accordingly the tearing work is performed mainly on the cutting of fiber, and the deformation and slip of fiber are lesser compared with sulfate pulp at the equal freeness.
In short, it is considered that the difference of papermaking properties between sulfite and sulfate pulps are mainly due to the difference in swellability and strength of a fiber-to-fiber bond between them.
Bisulfite pulp is higher in tearing strength than conventional acid sulfite pulp (Fig. 3. 4 and 10). It is probably due to that the former is poor in swellabilty (Fig. 1 and 2) and higher in strength of a bond than the latter.
Further consideration was made on the difference in tearing strength between fir and birch pulps.

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The standing corps of beech wood were felled every month at the same location. 6 logs were prepared for each month and the resin content was determined immediately in usual method .
The resin contents in beech wood were variable under the reasonal conditions as observed in the case of red pine wood (Pious densiflora Siev. et Zucc.) [cf. Japan TAPPI, 10. 667 (1956)]
1. The resin content tends to decrease in winter at which time the growth of treewas being inhibited and tends to increase in summer at which time the growth of tree was being accelerated . This results suggested the variation of resin content may occur as biological phenomenon in livina wood .
2. The resin content in dissolving pulp which obtained by sulfite process showed the same variation as observed in living w ood.
3. The efTect of seasoning on resin content of material wood and of resulted dissolving puti had also been observed. The resin contents of material wood which does not contain the false heartwood and of sapwood were clearly decreased by the seasoning treatment . However, it was also observed that the seasoning had no effect to decrease the resin content in false heartwood.

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