In the present investigation solubilities of nitrogen under one atmospheric pressure in 10 kinds of elements (Ca, Cu, Cr, Mn, Mo Ni, Si, Ti, V, W, ) and 7 kinds of binary ferrous alloys (Fe-Ni, Fe-Co, Fe-Cr, Fe-Mn, Fe-Al, Fe-Si, Fe-Ti)- are determined. The results obtained are as follows. No solubilities of nitrogen in Ni, Co, Cu and W are observed at temperatures below 1200°, while a great deal of it is absorbed in nitride forming elements, i.e. Cr, Mn, Si, Ti and V. The quantities of nitrogen absorbed decrease as the rise of temperature owing to the decomposition of the nitrides except those at relatively lower temperatures. The solubilities of nitrogen in Fe-Co and Fe-Ni alloys which make continuous series of solid solution decrease as the content of Co or Ni in the alloy increases. In Fe-Cr and Fe-Mn alloys the reverse is the case. In Fe-Al and Fe-Si alloys, rich in Al and Si respectively, N₂ is absorb-ed by them forming definite nitride which has no solubility in iron.

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Zahlreich sind die Untersuchungen fiber die Kathodische Abscheidung des Zinns. Dagegen sind viel seltener Experimente fiber sein anodisches Inlosunggehen angestellt worden. Unter verschiedenartigen Erscheinungen bei seinem anodischen Inlosunggehen, ist seine Passivitat von groBer Bedeutung. Trat die Passivitat einmal ein, wird die Elektrolyse ganz undurchfiihrbar. Auf diesen Tatsachen berucksichtigend, untersuchte ich zuerst die Passivitat der reine Zinnanode in schwefelsauren Zinnsulfatelelotrolyten.
Es gibt verschiedenen Untersuchungmethoden über Passivität. Die von mir verwendete Methods ist wie folgt: Eine bestimmte Spannung wird zwischen beide Elektroden aufgedruckt, Schalter geschlossen, dann der Strom and das Anodenpotential je eines bestimmten Zeitintervall gleichzeitig gemessen. Das Eintreten der Passivitat wird durch plotzlichen Abfall des Stromes, der ein ebenso pldtzlicher Aufsteigen des Anodenpotentiales begleitet, anerkannt. Als Prufungsanode dient ein Ouerschnitt des schmalen Zinndrahtes (1.32mm Dmr.).
Die Ergebnisse sind wie folgt:
1) Die Passivität des Zinns ist von mechanischer Natur.
2) Die Beziehungen zwischen Anfangstromdichte and Passivierungzeit stellt sich eine hyperbolische Funktion dar.
3) Bei konz. Lösungen geschieht die Passivität, im allgemeinen, schwerer als bei diinne.
4) Je kleiner die Säurekonzentration ist, desto edler der Anodenpotential nach dem Passivieren liegt. Die Zinnkonzentration hat ohne bedeutende Beeinflussung über ihn.
Die Messung der Anodenpotential wurde mit einem D. C. -Röhrenvoltmeter durchgeführt, weil die Potentialänderung beim Passivieren so schnell ist, daB der gewöhnliche Kompensationpotentiometer ganz unbrauchbar ist.

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The studies on oxidation and reduction of magnetite was previously reported by the present writer; quite recently he studied also by means of X-rays the orientations of iron oxides with respect to parent substances, when single crystals of iron, FeO and reduced iron glance were oxidized, and the following results were obtained.
When Fe becomes FeO by oxidation, the plane (100) of FeO is parallel to the plane (100) of the Fe and the direction [110] of FeO in this plane is parallel to the direction [100] of Fe. The orientation of the crystals of Fe₃O₄ as produced by oxidation of FeO agrees with that of the parent substance. In the crystals of Fe₃O₄ as produced by reduction of Fe₂O₃, the plane (111) of Fe₃O₄ is parallel to the plane (111) of the Fe₂O₃ and the direction [011] of Fe₃O₄ is parallel to the direction [211] of the Fe₃O₄, as in the case of oxidation.
The present writer summarized these results and proposed mechanisms for the oxidation of iron and the reduction of iron oxides on the basis of the present experimental results.

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In the present paper, the authors examined the mechanical properties of sheets and wires of phosphorbronze, containing up to 1% P and 3-9% Sn, and studied the effects of cold-working and low-temperature annealing on them. It was shown that the most suitable bronze is an alloy of 6% Sn, its phosphor content being not more than 0.6%, preferably, about 0.25%. It was also ascertained that the limit of proportionality and the modulus of elasticity of cold-worked phosphor-bronze are somewhat increased by low-tem-perature annealing. It would be, therefore, better to anneal the spring-products at about 200° after forming. The influence of cold-drawing on the moduli of elasticity and rigidity was also investigated; the definite conclusion with regard to this work will be given in a next paper.

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The distribution of shearing stresses at various parts of a valve spring subjected to compression was examined by means of small mirrors attached to the spring wire. The experimental results at each part of the spring wire agree fairly well to the value obtained from the formula,
F=16WR/πrd³
where, F denotes the shearing stress in the spring wire, W the compressive load applied to the spring, R the radius of the spring, d the diameter of the spring wire, provided that the srping is subjected to a statical load.
Under repeated compression, such as in the valve mechanism of high speed internal combustion engines, it was found that the spring coils vibrate at its natural frequency; it begins to “surge”. This is due to the resonance between the natural frequency of the spring and the frequency of the forced vibration as related to the revolution of the camshaft. How surge affects spring stresses was experimentally studied by means of small mirrors explained above; the total range of repeated stress in the region of about 2 coils from the end of the spring is especially high, amounting to about S times the calculated value from the formula. This is accordant with the fact that fatigue failures actually take place at this portion. Surge is a prolific source of valve spring failure due to the stress conditions and the rapidity of the stress cycle.

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