Page:Experimental researches in chemistry and.djvu/74

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1820]
59
On the Alloys of Steel.

the eighth of an inch in width. The results of several experiments on its composition, which appeared very uniform, gave 94.36 iron + 5.64 carbon. This being broken and rubbed to powder in a mortar, was mixed with pure alumina, and the whole intensely heated in a close crucible for a considerable time. On being removed from the furnace and opened, an alloy was obtained of a white colour, a close granular texture, and very brittle: this, when analysed, gave 6.4 per cent. alumina, and a portion of carbon not accurately estimated. 700 grains of good steel, with 40 of the alumine alloy, were fused together, and formed a very good button, perfectly malleable; this, on being forged into a little bar and the surface polished, gave, on the application of dilute sulphuric acid, the beautiful damask which will presently be noticed as belonging peculiarly to wootz. A second experiment was made with 500 grains of the same steel and 67 of the alumine alloy, and this also proved good; it forged well, and gave the damask. This specimen has all the appreciable characters of the best Bombay wootz.

We have ascertained, by direct experiment, that the wootz, although repeatedly fused, retains the peculiar property of presenting a damask surface, when forged, polished, and acted upon by dilute acid. This appearance is apparently produced by a dissection of the crystals by the acid; for though by the hammering the crystals have been bent about, yet their forms may be readily traced through the curves which the twisting and hammering have produced. From this uniform appearance on the surface of wootz, it is highly probable that the much admired sabres of Damascus are made from this steel; and if this be admitted, there can be little reason to doubt that the damask itself is merely an exhibition of crystallization. That on wootz it cannot be the effect of the mechanical mixture of two substances, as iron and steel, unequally acted upon by acid, is shown by the circumstance of its admitting re-fusion without losing this property. It is certainly true that a damasked surface may be produced by welding together wires of iron and steel; but if these welded specimens are fused, the damask does not again appear. Supposing that the damasked surface is dependent on the development of a crystalline structure, then the superiority of wootz in showing the effect, may fairly be considered as dependent on its power of crystallizing, when solidi-