Na₂O・2SiO₂ガラスは多くのdiscrete ionにより構成されているというモデルの基に, 異なったdiscrete ion中の非架橋酸素間の有効ポテンシャル関数を仮定して (続報で検討する), このガラスの体積温度関係を統計熱力学的に検討する.
その結果, ガラス変態は, 近似関数として使用されているLennard-Jones型ポテンシャル関数の最小値より少し大きな距離で, この関数に比較して急に立上がるようなポテンシャル関数の形によって決定される. 終りに, この理論の観点より実際のガラスの体積温度関係を検討する.

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2CaO・SiO₂-3CaO・B₂O₃系の状態図については, 1936年にFlintにより報告されたものがあり, その系のほぼ中央に化合物5CaO・B₂O₃・SiO₂が存在するとされている.
著者らは, この系について検討を行ない, 5CaO・B₂O₃・SiO₂よりも2CaO・SiO₂に近いところに2CaO・SiO₂と構造的に近似した11CaO・4SiO₂・B₂O₃が存在し, 5CaO・B₂O₃・SiO₂は存在しないことをみとめた. 11CaO・4SiO₂・B₂O₃には高温で安定と思われるところの急冷により生成するものと, 徐冷により生成する低温で安定なものとあり, 前者はa10.65Å, b 55.43Å, c6.89Å, 後者はa31.96Å, b55.20Å, c6.83Åでいずれもα'-2CaO・SiO₂の9倍および3倍格子となる. 低温型はα'-2CaO・SiO₂と連続固溶体は作らず, 1270℃でα-2CaO・SiO₂固溶相に転移する. これはさらに1440℃でα-2CaO・SiO₂相に転移するが, これは純2CaO・SiO₂のα型に相当し, 固溶相ではないと思われる. 11CaO・4SiO₂・B₂O₃と3CaO・B₂O₃系は1270℃以上ではα-2CaO・SiO₂相と3CaO・B₂O₂となる.
α'-2CaO・SiO₂の構造についてはすでに著者らにより報告されているが, 3CaO・B₂O₃については単結晶により解析を行なった結果P31cまたはP31cの空間群をもち, a14.96Å, c11.86Åであることが見いだされた.

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As basic compositions, 15Na₂O⋅85SiO₂ (Na glass) and 25Li₂O⋅75SiO₂ or 30Li₂O⋅70SiO₂ (Li glass) were selected and the effects of addition or substitution of the components such as MgO, CaO, BaO, ZnO, CdO, PbO, Al₂O₃, B₂O₃, TiO₂, ZrO₂, SiO₂, GeO₂ and P₂O₅ on miscibility temperature (T_m), viscosity, texture of phase separated glass etc. were examined.
The addition of small amount of the divalent components lowered T_m of Na glass in the order CaO<BaO<CdO<ZnO<MgO<PbO. But even in the case of CaO the introduction to the amount contained in commercial soda-lime-silica glasses (e. g. sheet glass) prevented the phase separation occurring. Among the polyvalent components, the effects of P₂O₅ and Al₂O₃ on T_m were especially remarkable, the former raised and the latter lowered it. B₂O₃ lowered T_m at first and then raised it with increasing amount of the addition, for viscosity B₂O₃ gave reverse change, though. In the glasses added the components which raised T_m, the interconnected two phase structures were liable to be observed after heat treatment. Similar results were also obtained in Li glass.
It was showed from the plot of T_m of 15Na₂O⋅85SiO₂+2.5RO_x glasses against ionic field strength of added cations that (i) in case of the network modifiers, T_m rose with increasing ionic field strength of added cation, (ii) this was also true for network formers, but (iii) this relation became inverse for intermediates. The possible reason was discussed from the point of the effects of added cations on the compatibility between SiO₂ and Na containing phase.
Moreover it was pointed out that the chemical durability was low in the glass with high T_m.

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Grain growth in vacuum sintering of thermally decomposed alumina from aluminum sulfate was observed.
Two series of specimens, i.e. with and without addition of 0.05wt% MgO were prepared. Specimens were sintered in the temperature range from 1550° to 1700°C and from 15 to 120 min.
The results obtained were as follows:
1) Grain growth of specimens with MgO can be expressed as the following equation:
D-D₀=Ktⁿ
The value of n obtained in this experiment was 0.31. The activation energy for grain growth obtained from Arrhenius plot was 155kcal/mol.
2) For the series of specimens without MgO exaggerated grain growth was observed in firing at 1550°C for more than 30 min and at temperatures above 1600°C for more than 15 min.
3) For specimens in which exaggerated grain growth was occurred locally, any normal grain growth was not confirmed in other part of the observed area.
Large crystals resulted from exaggerated grain growth were estimated to complete their growth in an earlier stage independently.
4) The areas where large crystals appeared first were in accordance with the area of the highest density in green specimens.
5) The critical point for exaggerated grain growth seemed to be that the closed porosity of specimens reached to about 6%.
6) When the specimens with local large crystals were reheated in vacuum after adding a small amount of MgO, the large crystals held their own shape and size, while in the area other than large crystals normal grain growth occurred in the same way as in the specimen containing MgO from the beginning. And these grains were much larger than those of the latter.

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