the manipulation of cast steel a small quantity of oxide of manganese and charcoal in the form of powder is put into the bottom of covered crucibles, nearly filled with cold broken-up steel bars. In such crucibles only a very small amount of atmospheric air is present, consequently the charcoal at the bottom of the covered crucible is not consumed. But as soon as a very high temperature is attained the carbon present gradually deoxydises the manganese, producing a fluid carburet of that metal, which unites with the steel as soon as the latter is fused. Now, Mr. Mushet proposed a somewhat different method of procedure. In this first patent for improvements in the manufacture of steel he stated that he preferred to use pitch as the carbon element, and having melted it, to put into the fluid pitch an equal weight of oxide of manganese in the form of powder, and to stir them well together. This mixture was to be allowed to cool, after which the brittle mass was to be reduced to a state of powder, and a quantity equal to one-fifth, or to one- tenth, the weight of the converted metal was to be used before, during, or after the conversion. Now, I have found on testing the specific gravity of this fine powder that a cubic foot of it weighs, as near as may be, 62 1/2 lb. (the same as water); hence the minimum charge of one-tenth of the weight of the contents of an ordinary 5-ton converter, or 10 cwt., would have a bulk of 13.9, or nearly 14, bushels -- we may call it 13 bushels -- while the maximum charge would be 26 bushels. Let us see how such an addition would behave if put into a Bessemer converter: a vessel with an interior lining brilliantly red-hot, and containing about 90 to 100 cubic feet of atmospheric air, at a temperature of about 1000 deg. Fahr. Certainly the first shovelful of such a highly-combustible powder thrown into this red-hot chamber filled with heated air would result in a dangerous gas explosion, and the instant rejection of the unreduced manganese powder present in the mixture. How, then, were the 13 bushels, or the 26 bushels, of this explosive powder to be got into the red-hot vessel? For even if it were possible to put in only the smaller quantity of 13 bushels, of this powder, it would form for a few minutes a huge bath of molten pitch, and it would require a very bold man to pour into it 5 tons of molten iron. The whole proposition is so absolutely unpractical that it requires no further comment.

Six days later (September 22nd, 1856), Mr. Mushet applied for another patent, which did not differ from the use of carburet of manganese as patented by Josiah Marshall Heath in 1839, for years used by Sheffield steel manufacturers, and in which patent Mr. Heath claims, fourthly, "the use of carburet of manganese, in any process whereby iron is converted into cast steel," to which I have previously referred. Now, it is obvious that this use of carburet of manganese, even if it could not have been claimed by Heath in his patent of 1839, had -- as I have already stated -- become, by mere publication, common property for a period of no less than sixteen years prior to Mr. Mushet's patent of September, 1856. The only plea that could possibly be advanced to justify Mushet's claim to a long-ago expired patent, which had been extensively used, was that the steel into which this carburet of manganese was to be put had been made by a different process. Now, let us see to what a deadlock all improved manufactures would be reduced if once we admit such a claim. Let us take an example which is strictly analogous. Some fifty or more years ago a great discovery was made by Mr. Pattinson, of Newcastle, who invented a most ingenious mode of extracting metallic silver from ordinary commercial pigs of argentiferous lead. Previous to this, silver had been almost exclusively obtained from silver ore, amalgamated with mercury, and afterwards refined, melted, and cast into ingots. There was no analogy whatever between the old process of extracting silver and that discovered by Mr. Pattinson. It had long previously been found that silver, though a very beautiful metal in appearance, was almost useless, either for the manufacture of utensils or for current coin, on account of its extreme softness; articles made from pure silver being easily bent or misshapen, and coins losing their impression by wear and abrasion. But it was fortunately discovered that an addition of 10 lb. of copper to every 90 lb. of silver, so hardened and strengthened the silver as to render it eminently adapted both for the manufacture of utensils, and also for current coin. This valuable alloy of copper and silver was accepted by all European Governments as a standard alloy to be stamped as "silver," and it has been in universal use for many years, just as steel alloyed with carburet of manganese passes current as steel, the alloy having also been in public use for many years. But the silver obtained from lead pigs by Mr. Pattinson's new process, like that obtained from silver ore, was, of course, too soft to be used in that state. Now, if some speculative patentee had, on the first announcement to the world of Mr. Pattinson's great discovery, rushed to the Patent Office to claim the sole right to put 10 per cent. of copper into silver obtained by Pattinson's process, under the