Some physical and chemical properties of glasses in the systems CaO-P₂O₅-SiO₂ and MgO-P₂O₅-SiO₂ have been measured. The glass samples were prepared to have the compositions ranging from 0.7 to 1.7 in mole ratio RO/P₂O₅ (RO=CaO, MgO) and from 0 to 1.1 in mole ratio SiO₂/P₂O₅.
In the composition range with high SiO₂ content, the glass-forming region in the system MgO-P₂O₅-SiO₂ was found to be more extended than that in the system CaO-P₂O₅-SiO₂.
Density and refractive index of these samples decreased with increasing SiO₂ content. The anomalies were found on the physical properties, i.e. density and refractive index, of the glasses in the system MgO-P₂O₅-SiO₂ at a composition corresponding to about 1 in mole ratio MgO/P₂O₅, similar to those of the glasses in the system MgO-P₂O₅ which had been reported by other investigators.
Solubility tests for the silicophosphate glasses with various solvents, especially, acid solvents such as hydrochloric acid and citric acid solutions, resulted in the considerably high solubilities of P₂O₅ component as compared with the solubilities of the corresponding phosphate glasses for the same solvents.
As the forms of the phosphate ions existing in the CaO-P₂O₅-SiO₂ glass whose mole ratio CaO/P₂O₅ is over 1, pyro-, trimeta- and tetrameta-phosphate ions were detected by paper chromatography. It was confirmed that the crystals formed by heat-treatment of these glasses were neither silica nor silicate minerals but condensed phosphates without exception.

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立方晶のメタ珪酸塩であるN₂CS₃, K₂CS₃, および新たに見出された相であるK_xN_1-xC₂S₃ (0.4<x<0.7, 900℃) などについてその結晶学的データを与えた. これらの化合物はいずれも同じメタ珪酸塩である三方晶NC₂S₃と密接な構造的関係を有することが示された.
N₂CS₃はアルミン酸三石灰C₃Aときわめて良く似た結晶データを示し, さらにX線回折, 赤外線吸収スペクトルなどによる検討の結果, 両化合物はほぼ同様な結晶構造を有するものと結論された. この結果はアルミン酸三石灰中のアルミニウム・イオンはすべて4配位であるという実験事実と一致し, かつ支持するものである.

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By the sublimation method, 2H-type SiC whiskers were obtained. From the experimental results and the results from the heating experiments of powdered mixture of high pure silicon and graphite, the thermal stability of the basic polytypes of SiC were discussed. The conclusions are summarized as follows;
1) The β-SiC grow in the whole range of temperature under the condition of high supersaturation.
2) Initial phase appeared from β-SiC with heatings is mainly 6H above 1600°C and mainly 4H or 2H below 1400°C.
3) Each basic polytypes of SiC, 2H, 3C, 4H, and 6H is stable in the range of temperature, below 1400°C, 1400°-1600°C, 1600°-2100°C, and above 2100°C respectively. The 15R-type is unstable form in the whole range of temperature.

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Local changes of compositions of alkali silicate glasses with time of electron bombardment during electron microprobe analysis are observed. The concentration of an element in the probed region varies with time in different ways depending upon the glass composition, the intensity of electron beam and the composition and thickness of conducting coating.
The results are summerized as follows:
(1) Generally, the X-ray intensities of the alkali metals decrease with time in the low-alkali glasses. On the other hand, the X-ray intensities of the alkali metals increase after a short period of decrease in the high-alkali glasses.
(2) The increase of the X-ray intensities of the alkali metals is more rapid for higher beam loadings. Moreover, high beam loadings cause the increase of the X-ray intensities of the alkali metals in the low-alkali glasses.
(3) For the same beam loading, the X-ray intensities change relatively quickly in Na₂O-SiO₂ glass, somewhat slowly in K₂O-SiO₂ glass, and even more slowly in Cs₂O-SiO₂ glass.
(4) The X-ray intensities of the alkali metals of crystallized glasses decrease with time irrespective of their compositions.
(5) In the absence of conducting coating, X-ray intensities of the alkali metals always increase with time.
(6) In alkali-free glasses, X-ray intensity of each element is practically constant with time.
The results suggest that the X-ray intensity changes result predominantly from the migration of the alkali ions. The decrease of the X-ray intensities of the alkali metals is consistent with the model proposed by Lineweaver. The increase of the X-ray intensities of the alkali metals, which is inconsistent with the Lineweaver mechanism, is explained as follows. Vaporization of the glass, which is more severe in the high-alkali glasses and for higher beam loadings, leads to a damage of the conducting coating in the region under the beam. A negative charge builds up on and near the surface and the positive alkali ions are attracted to the surface to neutralize the charge.

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