A few years ago Mr. Mackintosh, of Crossbaskets, in Lanarkshire, took out a patent for converting malleable iron into steel, by subjecting it to a stream of carburetted hydrogen gas, evolved from coal under distillation. The iron is inclosed in a pot or crucible in the furnace, and when arrived at a proper heat, a stream of gas is directed by a pipe into the crucible, which has another aperture to allow that part of the gas to escape which has not been taken up by the metal. The apparatus for conducting this process will of course admit of various modifications. This invention appears to have reason for its basis; for it must be evident that m the process of cementation before described, the carbon must have entered into combination in a gaseous state with the iron: the steel made by it was reported to be excellent. Whether experience has proved it to be an economical process, is a point upon which we are not informed.