From the results obtained from the sintering and volatilising experiments, the following conclusions may be stated:
(1) Under oxidizing atmosphere the ferro-manganese ores from Kemaman are not melted at 1, 250°C, while under reducing atmosphere, they are melted in heating at that temperature for a while with addition of carbonaceous fuels.
(2) The ores are sintered well in heating at 1, 200°C with or without addition of carbonaceous fuels.
(3) The elimination of lead and zinc by volatilisation and the strength of sintered ores increase according to the increase of anthracite added.
(4) In general lead is easily eliminated by volatilisation, but that of zinc is comparatively difficult.
(5) On roasting at 1, 100°C for 2 hours with addition of 5% anthracite the eliminating rates of lead and zinc run up to 98·7% and 82·5% respectively and then the contents of lead and zinc in the sintered ores are decreased to 0·1%. Pb and 0·4% Zn respectively.
(6) On roasting at 1, 100°C and 1, 200°C respectively with addition of 5% anthracite and 5% BaCO3, the eliminating rates of lead and zinc both run up to 91·0-96·5% and the contents of lead aud zinc are both decreased to 0·1-0·2%,
(7) To eliminate lead and zinc contained in the ferro-manganese ores by volatilisation in practice, the ores should be roased in a long rotary kiln with addition of at least more 5% powdered anthracite or coke, so that the carbonaceous fuels added may be completely burnt until they reach the discharging end of the kiln, where they should be sintered at 1, 200°-1, 250°C under oxidizing atmosphere.

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In the previous paper of his investigations author showed the carbon and oxygen equilibrium in the molten steel fairly expressed by the two conjugated equilibria, FeO(Fe)+CO Fe+CO₂(2) and C(fe)+CO₂=2CO₂ (3) Principal par of thet present paper is the investigation of thetemperature relationship of these equilibria up to 1, 650°C. According to his results of experiments, as far as the gaseous compositions are unchanged, the solubility of carbon in molten Steel in equilibrium with CO and CO₂ mixture, tends to decrease and the contrary is true with oxygen solubility. The relationship of equilibrium constant and temperature also found for equilibrium (2), log K₂=7, 450/T-4·66, and for equilibrium (3), log K₂=-8, 800/T+7·40.

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Part I. The Brittlenss of Steels at Sub-Zero Temperatures:
The brittleness of steels at sub-zero temperatures was investigated as to plain carbon and several alloy steels in their various heat treated conditions. In the test, the Charpy impact test-pieces were dipped in Duwer's vessel being kept at various low temperatures by means of ether and dry ice. The writers'. view on the brittleness is that it is not the characteristic of α-iron itself, but due to the Presence of foreign substance and internal stress in it.
Part II. Rapid Colling Brittleness of Annealed Steel:-
Annealed low carbon steels show an extreme brittleness if they are rapidly cooled from the temporatures close to and under the critical point. The effect is equally observable down to 500° with decreasing magnitude. This brittleness shall hereafter be called as "Rapid Cooling Brittleness of Annealed Steel" In this investigation, various characteristics of the brittleness were shown and made clear the nature of the phenomenon. The brittleness is due to the precipitation hardening of cementite at room temperature.

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The pure white pig iron was melted in a high vaccum furnace which was specially deviced using tungsten wire as heating element, and thermal analysis was carried out. The eutecticreaction in the pure iron-carbon system takes place in two steps which differs as 7-10° This phenomenon well agrees with Ruer and Goerens' result, and the change which takes place at the higher temperature, in cooling is due to the formation of the austenite-graphite eutectic, and that of the lower temperature, to the austenite-cementite eutectic, so called ledeburite. In the specimens subjected to the analysis, two kinds of eutectics above mentioned were well observed under microscope. Therefore, the authors pointed out the correctness of the double diagram of the iron-carbon system. The mechanisms of formation of various forms of graphite, mottled iron and "Umgekehrter Hartguss" were discussed on the basis of the results obtained in the present investigation. By assuming a fact that the degree of dissociation of Fe₃C in molten pig iron decreases as the amounts of some impurities or dissolved gasses increases or the beating temperature rises, the readiness of formation of the graphite eutectic in the pig iron melted in vaccum was well elucidaetd.

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