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bar-iron by a larger quantity of carbon. Now with our western processes steel is produced: 1st, by extracting carbon from the pig-iron (raw-steel); or 2nd, by combining bar-iron with the requisite amount of carbon (cement-steel). It seems, however, that a third method is probable which is not used by us, but is used in Japan. It consists in smelting pig iron and bar-iron together in certain well defined proportions. The borax dissolves many impurities in the slag. It must be said that chemistry has not yet explained the production of steel insufficiently satisfactory manner. Although steel owes its properties in a great measure to the presence of a just proper quantity of carbon, it is pretty sure that small quantities of silicon, nitrogen, aluminium, titanium and perhaps other elements are not without influence on the quality of the steel. Hence steel-manufacture is still a matter of chance and this is proved also by the excellent Kinds of steel manufactured by many oriental nations who have no knowledge of chemistry.
When steel has been cast by the Japanese in the above-mentioned way, and the different objects have got their shape and are sufficiently forged, it is cemented and tempered, in order to convert the soft steel into hard steel. The old armourers of Japan seem to have taken great care in this operation. The most famous armourers were held in high distinction, as has already been shown by Mr. McClatchie in his interesting paper[1]. They kept their method of cementing secret. The Japanese blades are hard and not very elastic, and belong for this reason to the class of cement-steel. An armourer told me that different blade-forgers cemented their swords in different manners, one of which consisted in finally covering the strongly-hammered blades with a liquid mixture of clay, loam, ashes, charcoal-powder and water. After drying this layer, the whole is exposed to a red heat and the glowing blades are cooled very slowly end gradually in warm water. The swords are then ground on a very precious
