The author prepared the following 4 kinds of cement and examined the physical properties of these cements.
Composition of clinkers
In conclusion, the author ascertained that: (1) The burning temperature of clinker decreased and the setting time of cement was retarded as the Cr₂O₃ in the clinker increased. (2) Cr-2 containing 0.5% Cr₂O₃ gave good results than Cr-1, Cr-3 and Cr-4, on the 1:3 hard mortar, 1:3 plastic mortar and 1:2:4 concrete tests. (3) The chromium cement gave good results than the common cement on the tensile and bending strength tests.

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1) On the basis of a series of chemical composition as well as of the thermal dehydration behavior of the Yamagata-bentonite, the author proved a primary substance of bentonite-itself and also figured the microstructure of it. The samples used in the present research were the following 26 sorts:
Group 1. Kaolin, Pyrophillite, Natural and artifical silica gels (5 kinds).
Group 2. Raw bentonite and its related rock (5 kinds).
Group 3. A typical good bentonite and its fractional sediments (7 kinds).
Group 4. A good bentonite and its fractional sediments (9 kinds).
A proviso: group 3 and 4, each of which contains one purified with electrolysis respectively.
2) Arguing against the already known three different conclusions or formulae of Japanese acid-clay, the author showed that the primary substances of acid-clay and of bentonite should be identical.
3) The author showed a typical composition of the Yamagata-bentonite and a standard characteristic thermal dehydration curve of bentonite-itself, and argued that the bentonite-itself is nothing but the so-called montmorillonite. The stated chemical composition is the following: H₂O SiO₂ Al₂O₃ Fe₂O₃ CaO MgO Alk. Per cent 7.83 60.71 21.58 4.03 0.88 3.05 1.97 Mol. ratio 2.05 4.76 1.00 0.12 0.07 0.36 0.10
The dehydration curve is such that it can be cut into three distinct parts, i.e., S-shaped (room temp. -150°C, corresponding to reversible moisture), striaight (150°-550°, to ad-and chemi-sorped moisture by Si₂O₃(OH)₂ layer) and hook-like shaped (550°-1000°, to structural water) part. But, in another words, the curve cnn be taken to correspond to such a pyrophillite-curve as that be cut and replaced its lower half with an equivalent half of typical silica-gel curve.
4) In the end, the author arrived at the conclusion that at least the montmorillonite from the Yamagata-bentonite should certainly be a pile of the leaf-like crystallite of pyrophillite, a pyrophillite such that the outermost layer of Si₂O₃(OH)₂ of it being highly activated on account of some (may be correspond to about 30% of Si₂O₃(OH)₂) discordance in the arrangement of atoms within the Si-lattice layer. Where, say in addition, the activated layer is highly silica-gel-like in character, hence it seems reasonable to think the X-ray diffraction spectra from the layer might be far from distinction.
The structural formula which the author induced is the following one: [Al₂(Si₄O₁₀)(OH)₂)]⋅xSiO₂⋅Aq. or [Al₂(Si₄O₁₀)(OH)₂]⋅Aq.

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The expansion coefficient of the series of alkali-lime-silica glasses in which the increasing lime being substituted by increasing iron oxide were measured. The measurements were carried out by a dilatometer constructed by Dr. Abe. The dilatometer is a differential type with an optical lever, using vitreous silica as the neutral. The optical lever consists of a brass plate with a stabilizing weight and three steel needles, on the points of which it stands, the effective length being about 2.5mm.
The specimen was a rod of glass about 100mm. long and 1.5mm. in diameter. Each end of the rod was drawn into a point and well annealed. It was then supported by a quartz rod in the middle portion of a vertical electric furnace having a steel core. The uniformity of temperature was maintained within 2°C. The specimen was heated to a certain temperature below strain point and the contraction was measured as the temperature was lowered. The mean coefficient of linear expansion of vitreous silica was taken as 5.7×10^-7. Taking that the coefficients of expansion of the glass can be obtained from the Winkelmann and Schotts' formula: 3α=a₁x₁+a₂x₂+a₃x₃+………
the calculated value were obtained from the chemical compositions already published in the X, XII, and XIII report using both English and Turmer's factors, SiO₂ 0.15, Al₂O₃ 0.42, CaO 4.89, K₂O 11.7 and the present author's factors Na₂O 15, Li₂O 20, Fe₂O₃ 1.5, FeO 5.4
Also variations of the calculated and the observed value, and the percentage between them were set out in the following table.
Teble
Using the factors of expansion coefficient stated above, the calculated value of the series FAN-B-2, FCN, FAN-C-3, FAK-C-3, of which composition already published in the XIV report, was practically in accordance with the observed value. From the above experiments it will readily be seen that the expansion factors of Fe₂O₃ is smaller than that of CaO, while that of FeO is much larger that of Fe₂O₃ and a little larger than that of CaO. In conclusion, the value obtained by calculated, using the factors of expansion coefficient here adopted is quite in coincident with that obtained by measurement.

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