In alluvial plains along the northern to central part of the Japan Sea Coast of the Main Island, Japan, namely West Tohoku-and Hokuriku Districts, paddy fields of heavyclay soils are widely distributed. Because of the extremely low water permeability ofthe subsoils, these paddy soils are characterized by ill-drainage and poor bearing capacity.Consequently, it is difficult to use large-sized farm machines and to practice crop rotationincluding upland crops, and the productivity of rice is naturally low. In addition, improvement of these low land heavy clay soils to well-drained paddy soils by theoperation of underdrainage is difficult because of their poor water permeability and largewater holding capacity. Techniques of their conversion to upland state and changesof physical properties of the soil in the process of drying were studied. The resultsobtained are summarized.
1. Gley horizon of low water permeability of the ill-drained clayey paddy soils graduallycracked by drainage and subsequent drying, and finally, became to show a highwater permeability.
2. After drainage and subsequent drying, a horizon of high bulk density was formeddirectly below the plow layer. This horizon obstructed the percoration of gravitationalwater as well as the upward movement of capillary water.
3. Conversion of an ill-drained paddy into an upland field was accompanied by anincrease in the macro pores of the plowlayer and aeration was, therefore, improved.Although the holding capacity of available water was reduced in the early stage of theconversion, it gradually increased with the lapse. of time.
4. As for the growth of a crop (corn), growth and yield were poor in the earlystage of the conversion. This was attributed to a violent fluctuations in soil moisturetensions. Afterwards, however, the yields increased according to the improvement ofthe drainage. It took a few years to complete a conversion into the upland field.
5. It was found that a drainage system including mole drain and block drainagewas required for conversion of an ill-drained clayey paddy soil to an upland state. Inorder to accelerate soil drying, growing crops having deeply penetrable root systemand operation of sub-soiling are desirable.
6. Application of rice straw and aluminum chloride increased macro pores and holding capacity of available water, respectively, and these materials improved the soilconsistency.

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Mordenite was synthesized from aqueous clear solutions with composition of sodiumaluminosilicates, at 100°C under atmospheric pressure. The optimum composition ofstarting materials in the synthesis was 10Na₂O·0.1Al₂O₃·34SiO₂·440H₂O. In unseeded systems, the crystallization of mordenite was characterized by a long induction period, and analcime also crystalized as a minor phase. In seeded systems, mordenite was rapidly formed because the seed surface played a role as the nucleation sites. Such rapidcrystallization inhibited the formation of analcime.
The exchange of various cations for sodium in synthetic Na form (Na_6.50 (Al_6.50Si_41.50O₉₆)·25. 50H₂O) was carried out by the reaction at 25°C for 60 hrs. The degree ofexchange varied with depending on ionic radii and charges of entering cations: in generalit was high for univalent cations as compared with divalent and trivalent ones.
The experiments of the adsorption of benzene on the ion exchanged forms wereperformed at 25°C, and their adsorption isotherms corresponded to Langmuir type. Theadsorbed amounts of benzene on the exchanged forms varied with depending on thecation species: they were large for H form and alkali metal ion forms, very small fortransition metal ion forms, and intermediate for alkaline earth metal ion forms. Especially, the adsorbed quantity for the H form was the largest, and the four molecules of C₆H₆ per the unit cell were occluded, which were maximum from the geometrical con-figuration in a mordenite cavity.
The heat of adsorption of benzene and water on H form was about 5.8 and 10.9kcal/mol, respectively, at temperatures ranged from 287 to 320°K.

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An interstratified mineral of muscovite and vermiculite was found as an alteration mineral of muscovite in the crystalline schist at Mikamo-cho, Miyoshi-gun, Tokushima Prefecture. The grain size of this mineral was fairly large. The material used contains a little amount of kaolin mineral as an impurity. The interstratification seems to be produced by a two component stacking of about 50% muscovite layers and about 50% vermiculite-like layers. The d-spacing of the basal reflection treated by EG changes according to osaturating time at following position ; 24. 83Å untreated, 23. 62Å after 0.5hr and 26.94Å after 14 days.

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A mica-smectite interstratified clay mineral was found in the Hiraki mine, Hyogo Prefecture, Japan. Main X-ray diffraction peaks appear at 26.8Å, 12.4Å, 5.09Å, 3.16Å except those of kaolinite and quartz. This diffraction data were plotted on the Sato's diagram calculated theoretically which showed the relation between X-ray diffraction pattern and the ratio of mica smectite composition. This clay is composed of mica (62%) and smectite (38%). Chemical analysis gave SiO₂ 47.25%, Al₂O₃ 35.75%, TiO₂ 0.11%, Fe₂O₃ 0.12%, CaO 1.23%, K₂O 4.91%, Na₂O 0.35% and Ig. loss 11.51%.

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