In order to know the possibility for factory use of Barker-Truog's pH-controlled process, the measurements of the buffer actions with sodium hydroxide and hydrochloric acid solutions were made with Japanese ceramic raw materials.
Exchangeable calcium and magnesium ions and exchange acidity with sodium chloride and ammonium chloride were also determined.
The results are summarized as follows:
(1) Clays were divided into three classes depending on their buffer actions, A and B type clays, which were highly plastic, C type clays, which were feebly plastic. Generally, the working properties of the B type clays could be improved by the treatment with monavalent cations. (2) No relationship was recognized between the base exchange capacity at pH 7 and the plastic properties with the natural clays. (3) Considerable differences were found in the speed of reaction with sodium hydroxide or with hydrochloric acid solutions with the nontreated natural ceramic materials of different origins. (4) With some clays, addition of a small amount of sodium hydroxide caused a marked decrease in the pH value of the clear part of the suspension. Bentonite was this type. (5) Clays having highly exchangeable calcium ions were found to be feebly plastic. (6) The measurements of exchange acidity with NaCl and NH₄Cl suggested some ideas on the process of salvaging scrap bodies.

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In part I of this series physico-chemical studies on the fixation phenomenon of the cations adsorbed on kaolinite caused by drying were carried out and a new theory of the fixation of adsorbed cations, being quite different from any current theories which have been introduced so far by soil scientists, was advanced by the authors.
In the present paper the fixation phenomenon of adsorbed cations such as Li⁺, Na⁺, K⁺ and Ca⁺⁺ on halloysite surface caused by drying was studied. it was confirmed that the mechanism of the fixation for kaolinite may also be applicable to halloysite.

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The purpose of this investigation is to determine the rapid and simple method for estimating the quality of portland cement admixtures.
Five samples of silicious rocks and residue of sulphur smelting were used. The results of chemical analysis of these materials were shown in Table 1. Heating 0.2 gr of specimen suspended 70cc of the saturated solution of lime at 100-120°C for 0.5-5 hrs in an autoclave, rate of lime absorption by the specimen was determined. And it was confirmed that this method is sufficient for routine control.

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All phenomena occurring in a glass tank furnace, i.e., melting the batch, refining and conditioning the molten glass, and other chemical and physical processes are connected inseparably with the convection current of molten glass. It may, therefore, be said that the effort to understand these complicated processes cannot be successful without learning the fundamental characteristics or trends of convection current.
From this view point the authors carried out some series of model experiments using glycerin in place of the molten glass. In a box having a simple rectangular shape the glycerin was heated uniformly from above and cooled through side and bottom walls of the box. Temperature distributions in the fluid were measured with Cu-Constantan thermocopules whose junctions were fixed at twenty points in the vessel, and the flow patterns were observed from the photographic records of the tracks of tracer particles moving in the illuminated area of the liquid. Various factors, for example, heat input from the top surface, arrangement of heaters, viscosity of the fluid, heat transfer coefficient of the wall, and depth of the liquid were changed successively for the purpose of understanding the influence of these factors on the convection current and the temperature distribution. From the results obtained the authors pointed out some important characteristics of the convection current. Some of them are digested as follows:
(1) The change of heat input causes the proportional change of temperature gradients both in vertical and horizontal directions as well as the amount of heat discharged from unit surface area of side and bottom walls, but it has not so much effect on the flow velocity of convection current.
(2) Increase of heat input indicates a tendency to shift upward the circulating current and consequently the fluid near the bottom remains stagnant. These tendencies were also observed when the viscosity of fluid was decreased and when the heaters concentrated at the center of the vessel.
(3) Decreases of the overall heat transfer coefficient of wall, depth of the fluid and increase of viscosity of the fluid result in a reduction in the velocity of convection current. Generally it could be pointed out that the change of the flow velocity is not so large as one would expect at first. This may be regarded as self-controlling effect of the convection current.

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