Firstly, the writers investigated numerous materials effective for the crystallization of mullite by X-ray methods, and found out the following 11 kinds of compounds containing Ca, Li, W, Cd, Mg, Bi, Pb, Mo, B, Mn and Cu, respectively, suitable for mineralizing.
Next, added 0.5-5% of the above mineralizers respectively to kaoline only, to the mixture of kaoline and alumina, and lastly to that of quartz and alumina; and heated at different temperatures 900-1400°C, and investigated the various effects due to the kind and the quantity of the mineralizers. In all cases of the above test, the crystallization temperature of mullite could be lowered by 50-200°C than such cases without mineralizers. Each mineralizer has its respective proper temperature at which it is most efficacious, namely: (a) compounds of Mo and B at relatively lower temperature, (b) that of Cu at comperatively wider range, (c) that of Mn at low temperature but better at higher temperature, (d) that of W at wider range, (e) those of Cu, Li and Mg show the same results as that of Mn as regards temperature, but less efficacious, and (f) those of Cd, Bi and Pb show the least efficacy regardless temperature.

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In the present study, first of all, several sample glasses have been made by replacing one after another the lime contents with cobalt oxide while keeping constant the amounts of alkali and silica contents in alkali-lime-siliea glass. Examination have been given in these glasses with respect to how the chemical properties therein are changed as the amount of cobalt oxide increases and the amount of lime decreases.
The effects on chemical properties have been studied according to the changes in the solubility on water, 20.24% HCl, 2N-sodium carbonate solution, and 2N-sodium hydroxide solution, by employing the powder method.
As a result of experiments it has been found that no marked changes have occurred in the solubility of glasses due to the alterations of both lime and cobalt oxide contents in glass compositions however, in the case where the amount of lime and that of cobalt oxide are equal the solubility thereof has been observed to be slightly greater than in other cases. And it has also been found that the solubility of glasses with respect to hydrochloric acid is always small and not changed, with irrespective to the amounts of lime and cobalt oxide contents in the composition of glasses.

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[in Japanese]

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Feldspar is essential for the ceramic industry, as raw material for various potteries, glazes, Seger cones and so on. The quality of Seger cones, especially, depends on that of feldspar, which varies greatly according to the kind and the quantities of its impurities. Hence, on manufacturing Seger cones of superior quality, it is essential to execute most carefully various preliminary tests, physically and chemically.
We examined firstly various kinds of feldspar, such as orthoclase, anorthoclase, albite, oligoclase, andesine, labradrite and anorthite, by physical and chemical methods, and confirmed mutual close relation between them. Next we prepared the mixtures of orthoclase and albite, and heating at high temperatures, confirmed their eutectic phenomenon: the point is the most important factor on manufacture of Seger cones. Lastly MgO, CaO, borax, PbO, quartz and kaoline are added respectively to orthoclase and albite, and examined various fusing phenomena due to the additions.

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The authors continued the previous studies reported already by one of the present author (S. Nagai and K. Fukai, This Journal, 1934, 42, 339, 471; 1935, 43, 55, and S. Nagai and G. Inoue, This Journal, 1935, 43, 133, 263, 343, 412) on the fine ceramics for electric insulating material “Steatite”, and reported here the results of further executed comparative results. The main points of the present communication are briefly abstracted from the original Japanese paper, as following:
(1) Raw materials were further collected (This Journal, 1934, 42, 340; 1935, 43, 133), i.e., (a) 13 talc samples in Japan Proper, Korea, Manchoukuo and Shantung Peninsula of North China, (b) 8 serpentine samples in Japan Proper and Korea, and (c) 1 Shuganseki sample of bowenite or meerschaum type from Manchoukuo, and these samples were tested on their chemical compositions. The results are shown in the following table 1.
Table 1 Chemical Composition of Raw Materials
From these results, it was seen that all samples obtained in Japan Proper are impure, containing large amounts of alumina, iron oxide or lime, and talc samples (J)-(K) obtained from Korea, Manchoukuo and North China are suitable for the use to the present study.
(2) Powder of Manchurian talc (J), or (M)-(Q) was mixed with various oxide as ZnO, Al₂O₃, PbO, BaO, Cr₂O₃ or TiO₂ in amount of 5, 10 or 15%, moulded to plate (Length: 60mm, Breadth: 30mm and Thickness: 5-6mm) or cylinder (Diameter: 20mm and Hight: 25-30mm) in dry powder press by the pressure 300, 500 or 700kg/cm², burned at 1350°, 1400° or 1450°C for several hours, and then tested comparatively for many physical propperties, e. g., (1) Burning shrinkage and weight-decrease, (2) Bending or compressive strength, (3) Porosity, (4) water absoption, (5) Specific gravity, (6) Thermal expansion and linear expansion coefficient, (7) Stability to boiling water or superheated steam under pressure of 10 atm, (8) Spalling test by quick cooling, etc. From these results, the considerable result was cbtained by adding 5% Al₂O₃, folloved by 10-15% ZnO, 5% BaO, 5% PbO, etc., and the addition of 5% TiO₂ or Cr₂O₃ did not give good result.

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In diesem Bericht beschriebt der Verfasser den zweien Methoden, welchen die T itanhaltigen Massen den hoehwertigen Dielektrizitätskonstant ergibt, (1) durch der Dielektrizitätskonstant der Sinterrutil, oder (2) durch der zusammenwirkenden Dielektrizitätskonstant in den Titanats-Massen.
Die 48-artigen Massen werden mit Ammoniumsphosphat als Mineralisatoren hergestellt. und diesen Massen bei Kegel 10 und Kegel 12 verbrannte.
Für jeden Massen, ihre ε und tan δ bei Hochfrequenz wurden gemessen. Ferner wurde die Einflüsse der Beimengungen und Breunstemperaturen.

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Der Verfasser benützte Windsichtern zur Forschung der Zementfeinheit, denn die Windsichtung ist eine sichere und zuverlässige Messmethod.
So bedürfte es zuerst, die zugrundlegenden Prinzipien in bezug auf dem Verhalten der Zementkörner bei der Windsichtung zu untersuchen.
Die Erforschung würde folgenderweise gefördert, indem verschiedene Arten von Durchmessern der am Ende der Windsichtung steigenden 400 so gennanten grenzenden Körner mittels Mikroskopes genau abgemessen und statistisch untergesucht wurden. Von den grenzenden Körnern 20, 000 Teilchen abgezählt und ihre Masse und spezifische Gewicht abgemessen und so das durchschnittliche Volumen v_m eines Korns wurde gerechnet.
Die Resultate der Forschungen sind folgendes;
(1) Die Zementkörner haben unregelmässige Formen, aber die Volumen der Partikeln, die am Ende der Windsichtung emporsteigen, sind gleich voneinander.
(2) Zwischen 3√v_m und der durchschnittlichen windgeschwindigkeit durch den Querschnitt der Sichtungszylinder, bestcht Goldsteinischen oder Oseenischen Gesetz.

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