The possibility of introducing ammonium ion into glass with and without electric field has been investigated. As the results, it was shown that the weight reduction of glass treated in ammonium bisulfate bath might mainly be attributed to the replacing reaction (2) and partly to the dehydrating condensation of the proton-glass (3).
Since a small quantity of ammonium which corresponds to 2-7mole% of the removed alkali has been found in the treated glass, it is obvious that the reaction (1) also takes place to some extent accompanying the decomposition of ammonium (1)′. Ammonium in glass is considered to be metastable, as its amount varies with the condition of the experiment.
The glass after the treatment has a network structurer of crack, 10-30μ in size. The forming process and the properties of the treated glass are explained based on this structure. Because of the inferior properties of this glass as porous material, it has been considered that its uses may be limited.
(1) Na⁺(glass)+NH₄⁺(melt)_??_NH₄⁺(glass)+Na⁺(melt)
(1)′ NH₄⁺(glass)→H⁺(glass)+NH₃↑
(2) Na⁺(glass)+H⁺(melt)_??_H⁺(glass)+Na⁺(melt)
(3) Proton-glass dehydration→ Dealkali glass.

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Magnesia whiskers grown via vapor phase reaction were studied by means of X-ray topography, and optical and electron microscopies. The results obtained were as follows:
1) No internal defects were detected by X-ray topography, but contrast changes were found at tips of the whiskers. There contrast changes may be due to the inclusion of impurities which take part in the growth.
2) Triangular closed growth hills were found on {111} surface of a [112] whisker.
3) The surfaces of whiskers having diameters smaller or larger than a few micron were bounded by smooth or heavily stepped faces, respectively. Mechanical properties may be controlled by the surface structure as well as the internal structure.

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熱線法による固体物質の高温熱伝導率の測定には, その耐熱性の問題から, 白金線あるいは白金ロジウム合金線が熱源用抵抗線として多く用いられている.
ところがこれらは他の抵抗用金属線とくらべると, 抵抗の温度係数が大きいので, これに定電圧を印加して熱源とした場合に, 抵抗線の温度上昇による抵抗値の増加が発熱量の減少をきたし, これが熱伝導率の測定結果に誤差をもたらす原因となる.
本研究では, 白金線を熱源とし, 演算回路を用いてその抵抗値が変化しても, 印加電圧と電流の積が常に一定になるように制御することによって熱線からの発熱量を不変にし, また, 熱線への供給電力が一定に制御されていると, 印加電圧は熱線の抵抗値の平方根に比例することから, 熱源温度の変化をこの印加電圧によって検出する装置を試作した.
この装置の精度, 再現性およびばらつきを透明石英ガラスを用いて検定したところ, 次のような結果がえられた.
1) 100℃までの測定値は, Ratcliffeの “most probable value” と2%の誤差内で一致した.
2) 200°-600℃の範囲の測定値は, WrayとConnollyの値の上限に一致した.
3) 測定結果の再現性とばらつきの範囲は, それぞれ4%および7.3%であった.
この装置を用いて, 耐火断熱煉瓦, アルミナ煉瓦, 塩基性煉瓦, 珪石および蝋石煉瓦の1200℃までの熱伝導率を測定した結果, その温度依存性は従来の測定結果とよい一致をみた.
ムライト質, ジルコニアーアルミナ質およびα, β-アルミナ質電鋳煉瓦は, いずれも放物線状の温度依存性を示した.

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The electric resistance of electrolytic solutions is usually measured using an A. C. bridge. Frequency dependence of resistance has been observed, and is considered as caused by electrode reactions at low frequencies up to several kHz. Electric resistance ρ is ususlly proportional to f^-n(n; from 0.5 to 1).
It is reported that resistance of molten alkali silicates, measured with Pt electrodes, depends upon frequency, and that Pt electrodes behave as oxygen electrode. It is also reported that the rate determining step of the electrode reaction is diffusion of O^2- ion, and that the frequency dependence of ρ decreases with increasing activity a and diffusivity D of O^2- ion. It is known that a_o^2- and D_o^2- depend upon the structure of molten oxides, therefore, it is able to discuss the structure of molten oxides on the basis of the relations between frequency dependence and the composition of the melts.
In this study, frequency dependence in molten oxide systems, PbO-B₂O₃ and Na₂O-B₂O₃, was measured, and the structure of molten borates was discussed. The results are the followings.
(1) Electric conductivities above 5kHz showed poor frequency dependence. They increase sharply from 0 to 30mol% PbO or Na₂O, and then slowly with further addition of PbO or Na₂O. Such behavious of conductivity depend upon the structure of borate complex anion.
(2) At about 0.2-5kHz, ρ is proportional to f^-1, and it is considered that the frequency dependence of ρ in borate melts is mainly caused by the oxygen electrode reaction on the Pt electrodes as in silicates.
(3) At the composition range from 0 to 30mol% PbO, or from 0 to 25mol% Na₂O, frequency dependence d ρ/d(1/f), decreases with increasing PbO or Na₂O concentration. It is caused by the dissociation of the borate network structure.
(4) It is considered that the concentration of borate anion in cage structure, containing four-coordinated boron, increases at PbO content from 30 to 50mol%, or Na₂O from 25 to 40mol%. And a_o^2- and/or D_o^2- decrease in this region, then d ρ/d(1/f) increases with increasing PbO or Na₂O content.
(5) For the melts containing more than 50mol% PbO or more than 40mol% Na₂O, borate anion in the chain structure is dominant. The chain anions dissociate into smaller anions such as BO₃^3-, O^2- with increasing PbO or Na₂O content, then frequency dependence of ρ decreases.

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Gas chromatography appears to be particularly suitable for the analysis of gas bubbles in glass.
The paper describes the results obtained by the author in the use of gas chromatography which has a helium ionization detector.
The columns are molecular sieve 5A for the separation of H₂, O₂, N₂ and CO, silica gel for CO₂, and triton X-305 for H₂S and SO₂.
Helium ionization detector is very sensitive, and the minimum detectable quantity of gases are as follows:
H₂ 0.001μl (at n. t. p.)
O₂ 0.001
N₂ 0.001
CO 0.001
CO₂ 0.05
H₂S 0.001
SO₂ 0.003
With this apparatus it is possible to separate and analyse the gases in small bubbles less than 0.5mm in diameter.
The time necessary for one analysis is about 15 minutes.

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Magnesium metaphosphate glass was prepared by melting a mixture of orthophosphoric acid and magnesium phosphate, dibasic, in a Pt-crucible at 1300°-1350°C. The composition of the glass used was determined as MgO 48.2, P₂O₅ 48.2 and H₂O 3.6 in mol% and transformation temperature of the glass was 538°C.
For elucidation of crystallization kinetics of the glass, the growth rate of magnesium metaphosphate crystals deposited in the blown film sample at temperatures 675°-870°C and the amount of the crystals formed in the powdered sample in size from 44 to 74 μ at temperatures 620°-710°C were measured by means of high temperature microscopy and high temperature X-ray diffraction techniques.
1. No induction period was found in all the isothermal crystallization curves. This means that the magnesium metaphosphate crystal precipitates through athermal nucleation.
2. The isothermal crystallization curves were represented by the Kolmogorow-Avrami equation, where both k and m (=n+1 in the J-M-A equation) had unequal two values depending on the degree of crystallization, V.
3. In the range V<0.4, m=1 was obtained. This result shows athermal nucleation and one-dimensional growth occurred. In the range V>0.4, a different value, m=2, was obtained, which is considered to mean thermal nucleation and one-dimensional growth.
4. The activation energy for the crystal growth was found to be ca. 110kcal/mol being comparable with P-O-P bond energy, and the growth rate, G (μ/min), was expressed by the equation: logG=24.5-25.3×10³/T.
5. In the ranges V<0.4 and V>0.4, the activation energies for the crystallization were found to be ca. 110 and 90kcal/mol, respectively. In the former the crystallization preceded substantially through only crystal growth process, and in the latter, through both nucleation and the growth process. The activation energy for the nucleation was estimated to be ca. 70kcal/mol.

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It was found that an indialite-like crystal was precipitated on heat treatment of some glasses of the compositions near 2ZnO⋅2Al₂O₃⋅5SiO₂. The formation and the thermal stability of this phase and some characters of the crystallized glasses containing this phase were examined and the following results were obtained.
1) Zn-indialite (2ZnO⋅2Al₂O₃⋅5SiO₂) was precipitated as a main phase when glasses of the compositions 2.17ZnO⋅2Al₂O₃⋅4.77SiO₂, 2.16ZnO⋅2Al₂O₃⋅5SiO₂, for example, were heated at 870°-1000°C.
2) Zn-indialite was metastable, converting easily to a mixture of gahnite and silica above 1000°C.
3) Long crystals (500μ) were formed at the block surface, perpendicular to it, when glass block was heated.
4) The Zn-indialite precipitated in glasses was hexagonal or pseudohexagonal and in many cases optically uniaxial negative, having unit cell lengths a and c equaling 9.82Å and 9.35Å, respectively.
5) The coefficient of thermal expansion of the Zn-indialite aggregate was 11×10^-7/c, similar to that of indialite.

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Phase separation in the frits of PbO-B₂O₃-SiO₂ system was investigated by the infra-red reflection spectrometry. The shift of the infra-red reflection peak due to Si-O-Si stretching vibration in the region of 900-1300cm^-1 and the shape change of spectrum were discussed.
In the frits of non phase separable composition, the spectrum of the slowly cooled specimen was the same as that of the quenched specimen. Whereas in the frits of phase separable composition, the spectrum of the slowly cooled specimen was different in the peak position and in the shape from that of the quenched one.
The reason why the peak shift and the shape change of spectrum occurred after heat treatment in a certain frit of PbO-B₂O₃-SiO₂ system was attributed to the increase of Si-O-Si bond strength resulted from the separation of the phase rich in silica from a homogeneous phase. The changes of spectrum near 1050cm^-1 and 1150cm^-1 were characteristic of the phase separation in present frits. It was considered that the former is dependent on the increase of Pb content and the latter is on the increase of B content.

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The glass-forming regions in three vanadate systems were determined and some physical properties and the ratio of V⁴⁺ state to total vanadium, i.e. V⁴⁺/V_total, were investigated.
The remarkable features of these glasses are as follows: dark and opaque in color, poor chemical durability, devitrification tendency on heating, large thermal expansion coefficient, low transformation and softening temperatures, large specific gravity, and low Vickers hardness. In the BaO-ZnO-V₂O₅ glass which has stable and wide glass-forming region ranging 33 to 70mol% of V₂O₅, the remarkable nonlinear relations between the compositions and its properties were observed. The chemical analysis of vanadium in these glasses indicated that vanadium in 5+ state was predominant and the value of V⁴⁺/V_total was less than 4 percent.
From the contribution of N. W. M., i.e. K₂O, BaO, and ZnO, to the properties of glasses, it is considered that the character of each N. W. M. in these vanadate glasses is similar to that in the silicate glasses and the coexistence of two kinds of N. W. M. is effective for the stabilization of vanadate glasses.

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(Ba_xSr_1-x)FeO_3-δ系は酸素原子に関して広範囲な非化学量論性 (0≦δ≦0.5) を示すこと, また, それに伴って鉄イオンが混合原子価状態 (Fe³⁺とFe⁴⁺) をとるという点において興味深い. 空気中あるいは高酸素圧雰囲気下で得られた (Ba_xSr_1-x)FeO_3-δ系の固溶体の結晶構造はそのx値とδ値により異なり, δ≦0.30の酸素分率を有する試料は0≦x≦0.8で正方または立方ペロブスカイト型構造をとるのに対し, x=1の試料は六方ペロブスカイト型構造をとった. また, δ値の増加とともに結晶格子の膨脹が見られ, δの値が0.5に近づくと, ペロブスカイト型からブラウンミラーライト型格子への構造変化が認められた. さらに, ペロブスカイト型構造をとるSrFeO_2.89 (立方相) とBaFeO_2.81 (六方相) のFe⁴⁺のisomer shiftは, その結晶の対称の差異に対応して, それぞれ+0.18mm/sec, +0.05mm/secの値をとった.

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Excellent clay raw materials such as the ‘Gaerome’ and ‘Kibushi’ clays lie in the lower part of ‘Shigaraki’ clay stratum overlying basal granite. The ‘Gaerome’ clay contains mainly coarser grains of quartz and weathered feldspar, and the ‘Kibushi’ clay is stained into dark brown by organic matter. The ‘Gaerome’ and ‘Kibushi’ clays mostly contain the kaolinite and are accompanied with hydrated halloysite. Under electron-microcopic observation, we can find that the large flakes of kaoline minerals have curled shape and the small particles appear to be rolled into tube-like forms. The white clay (Shirae) that is weathering product of volcanic ash generally contains the hydrated halloysite of lettuce- or cabbage-like forms, tubular and curled shapes. The clays in the upper part of ‘Shigaraki’ sand-silt stratum have a small quantity of montmorillonite.
The clay stratums of ‘Shigaraki and Iga’ districts were deposited (first), under warm climate condition, on the basement rocks and ‘Shigaraki’ sand-silt stratum and ‘Shigaraki’ mud stratum accumulated on it. The original formation of present geographical features in the ‘Shigaraki’ plateau was constructed by abrupt compression of E-W direction in the middle period of Diluvial epoch. Considering the history of later basal movement and erosion, we can understand the formation of main faults and the variety of clay deposit in ‘Shigaraki’ district.

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Dielectric constants of glasses in the system As-S-Se have been measured in the frequency range 30 to 10⁶Hz at room temperature. It is shown that dielectric constants of the glass samples are almost independent of frequency over the measuring frequency range. Dielectric constants of the glass system As₄₀S_60-xSe_x with 0≤x≤60 at fixed frequency (300kHz) increase linearly with Se content, while those of the glass system As_x(S, Se)_100-x with 10≤x≤45 increase nonlinearly with As content and show a maximum peak at about 40 atomic % As and then decrease with As content.

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