An accurate measurement of the abrupt change of magnetic suscepti-bility in metals during melting and allotropic transformation was made. An attempt is also made to explain quantitatively these abrupt changes of susceptibility by applying the theory, which was proposed in the explanation of the change of susceptibility in metals caused by cold working.
As is well known, tin changes the sign of its magnetic susceptibility twice as the temperature rises, that is, at the transformation point and also at the melting point. These interesting phenomena have been satisfactorily explained by the above theory. A good agreement has also been found between the observed change of susceptibility during melting and its theoretical value in the case of copper, silver, gold, aluminium, mercury, sodium, potassium, rubidium and caesium.

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There is a considerable variation in values for the thermal conductivity of pure iron found in literatures, and the selection of the most probably correct one is very difficult. The present investigation was carried out to meet this necessity. By devising a new apparatus suitable for measuring the thermal conductivity of iron and steel, the conductivity of Armco iron at various temperatures between 30° and 700° was determined. The most probable value for the conductivity of pure iron at about 30° was concluded to be 0-174 with a range of 0-172 to 0-175 in cal. per °C, cm, sec. The conductivity at temperatures between 50° and 700° was also given.

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The magnetic and electric properties of the binary and ternary alloys involving iron, silicon and aluminium have been measured, and the relations of these properties to their respective concentrations have also been investigated. Those alloys containing 6_??_11 per cent of Si, 4_??_8 per cent of Al show specially excellent magnetic properties and their representative alloy has been shown to contain 9.62 per cent of Si, 5.38 per cent of Al. Some of its physical constants are as follows : the initial permeability, 35100; the maximum permeability, 117500; the magnetic hysteresis-loss, 28 egrs/cm³ per cycle: the coercive force, 0.022 oersteds; and the specific electric resistance, 81 microhms /cm³ at 20°.

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The equili-brium of the system Cobalt-Silicon is thoroughly investigated by means of thermal, microscopic, X-ray, dilatometric and magnetic analyses, and a new equilibrium diagram is proposed. In this system there exist four compounds, i.e., Co₂Si(ε), CoSi(η), CoSi₂ and Co₃Si(γ); the first three melt without decomposition at 1332°, 1460° and 1336° respectively, while the last one is formed by the following peritectic reaction ;
melt+δ_??_Co₃Si (γ).
The compound Co₂Si changes to δ phase at 1320°: the change is probably an allotropic one. The compound CoSi₂ has a slight thermal change at 1258°, but it is not an'allotropic change. The compounds Co₃Si₂ and CoSi₃, Proposed by K. Lewkonya, do not exist. The α_??_β allotropic transformation point of Cobalt rises with the increasing content of Silicon, and decomposes to P and S by the peritectoid reaction at 755° and 6.5per cent silicon.

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The equilibrium diagram of the Pb-Bi system has been studied by means of thermal (inverserate cooling method) and X-ray analyses, electrical resistance measurement and microscopic examination. By the present investigation it was found that theres exists β solid solution which is formed by a peritectic reaction at 188° and has a hexagonal close packed lattice, besides the primary solid solutions formed by the mutual solubility of the component metals as previous found. The solubility limits of the primary solid solutions differ from those of the previous investi-gations; the solubility of Bi in Pb decreases from 14% at 188° to 13% at 6°, and that of Pb in Bi is about 0.5% at 125° (eutectic temp.) and it is almost same down to 6°.

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