固体反応の機構は気相または液相反応の機構とは均一性の上で非常に異っていて, 均一反応における通常の理論では説明できないにもかかわらず, 多くは反応の不均一な機構を実証することなしに, これを説明しようとしている. これでは誤ちにおちいる恐れがあり, 固体反応の説明には先ず機構の実証が第一である. この目的の一助として高温電子顕微鏡により二つの固体反応の機構の観察を試みた.
外形で確認できるブルーサイトと酸化第二鉄を電子顕微鏡の視野に共存させ加熱した. 400℃の高真空下で酸化第二鉄は還元されて酸化第一鉄となり結晶成長をおこした. ブルーサイトは同じ条件で外形を保ったまま脱水してペリクレースクリスタライトの集合体となった. 700℃では酸化第一鉄に接するが約1μ以内にあるペリクレースクリスタライトは酸化第一鉄を固溶して格子定数の増大と結晶成長とをおこしたが, それ以上離れたペリクレースクリスタライトではこのような現象がおきなかった.
外形で確認できるブルーサイトとベーマイトを電子顕微鏡の視野に共存させ高真空下の電子衝撃で加熱した. 両水和物は先ず外形を保ったまま脱水して無水酸化物クリスタライトとなったのち, 1500℃の加熱ではAl₂O₃クリスタライトに接するか約3μ以内にあるMgOクリスタライトはAl₂O₃クリスタライト集合体に向って蒸発に似た現象をおこして消滅して行くが, それ以上離れたものにはこの現象が認められなかった. MgOと反応してAl₂O₃はδ-Al₂O₃の電子線回折像が認められた.

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In order to improve the electrical conductivity of zirconia, the systems ZrO₂-MoSi₂ and ZrO₂-SiC up to 40wt% of MoSi₂ and SiC have been studied.
Sintering atmosphere of hydrogen was the best among 3 sorts of atmosphere of combustion gas of city gas, vacuum, and hydrogen. Values for electrical conductivity and energy for conduction of the both systems did not differ markedly from values of stabilized zirconia. The systems ZrO₂-MoSi₂ and ZrO₂-SiC had less advantages in comparison with stabilized zirconia as an oxide heating element.
Zircon was coexisted with MoSi₂ in the samples sintered at 1300°C, 1400°C and 1500°C in H₂ and with SiC in the samples sintered at 1300°C in H₂. ZrC was formed in the mixtures of ZrO₂ and SiC sintered at 1600°C in H₂.
After oxidation in air at 1400°C, appearance of zircon and its growth was recognized in all samples and stabilized zirconia was changed into monoclinic zirconia in the sample sintered at 1600°C in H₂.

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Al³⁺, Fe³⁺, Cr³⁺はたがいに化学的性質が似ており, またその配位数も共に6である. それらの燐酸塩はイオン半径の大きさから, いずれもシリカ等構造体をつくることができ, また実際にAlPO₄は石英型, トリジマイト型, クリストバライト型をとるし, FePO₄は石英型をとることがしられている. このように構造的にきわめて類似したこれら燐酸塩相互の固溶の有無を追究しつぎの結果をえた.
AlPO₄-FePO₄系は無限に固溶するが, [Al³⁺/Fe³⁺]≧3/7ではクリストバライト型, [Al³⁺/Fe³⁺]≦2/8では石英型をとる. Al³⁺=0.55-0.3モルの範囲ではクリストバライト型であるが, 石英型への遷移過程にある.
一方AlPO₄-CrPO₄系は[Al³⁺/Cr³⁺]=8/2に固溶の限界があり, それ以上ではクリストバライト型の結晶であるが, それ以下ではβ-CrPO₄を遊離する.

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To obtain highly refractory mineral wool (glass fiber), authors tried to produce those which crystallize without softening during heating. The wool, the composition of which is within the system CaO⋅Al₂O₃⋅2SiO₂-2MgO⋅2Al₂O₃⋅5SiO₂-CaO⋅TiO₂⋅SiO₂, was easily produced by arc smelting of raw materials and by blowing compressed air to the melt. These samples, however, softened between 700°C and 800°C during heating before the crystallization took place. Surface treatment with various salts, especially such as Cu(NO₃)₂ and AgNO₃, was found to be effective to accelerate the crystallization and decrease the shrinkage during heating (compare Fig. 1 and 2).
By X-ray analysis it was observed that these nitrates decompose to the oxides at relatively lower temperatures and react with the glass fiber at the surface and accelerate the crystallization (Fig. 4, 5, 6 and 7). Microscopic observation showed also the decomposition of the nitrate and the reaction with the glass fiber at the surface. It was observed that the reacted oxides diffused into glass phase and formed dense metallic nuclei (Fig. 3 and 8). The reaction at the surface seemed also to remove Griffith flaw and to decrease the effect of the orientation of crystals by the crystallization from these flaws. Dense core of crystals thus formed around each fiber seemed to support the inner glass which should soften at high temperature by itself.
The shrinkage of the properly salt-treated wool was only within a few per cent at 1000°C.

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D. c. conductivities and dielectric losses in BaO-P₂O₅ glasses having various water contents were measured. Water was assumed to be contained in the form of OH group in the glasses as has been shown in our previous works, and its effects on the electrical properties were discussed in terms of proton diffusion in an electrical field;
(1) Contrary to the usual alkali free glasses, the BaO-P₂O₅ glasses showed a clear dielectric dispersion in very low frequency region. Its correlation with d. c. conductivity was similar to that of dispersion of ionic relaxation loss observed in usual alkali containing glasses. The spectral shape was also nearly identical to that for the alkali containing glasses. These facts suggest that the movement of some ions in BaO-P₂O₅ glasses is responsible for both of d. c. conduction and dielectric relaxation.
(2) D. c. conductivities (σ) and magnitudes of dielectric dispersion (Δ ε), which should be closely related to carrier ion concentration, were roughly proportional to the water content. The findings and the acidic nature of OH bond in polymeric phosphates led us to a conclusion that the carrier ion in BaO-P₂O₅ glasses is a proton.

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