CHEMISTRY. 257 



the hammer in this state when cold, it would undoubtedly crumble, but if it 

 is first thoroughly heated, it may be hammered or rolled into bars of genuine 

 fibrous iron. 



The American process which we have spoken of as far in advance of Bes- 

 semer's, was privately brought out some years ago by one of our most 

 eminent chemists, and at the present time is comparatively little known, 

 although it has been employed by several furnaces for a number of years with 

 great success. It consists in adding- to the pig iron placed in the puddling 

 furnace, such a proportion of a pure variety of iron ore (i. e. oxide of iron), 

 that the oxygen of the ore shall exactly suffice for eliminating the carbon of 

 the pig metal as carbonic oxide, or carbonic acid. This proportion, if we 

 remember rightly, is about fifteen parts ore to one hundred of pig metal. The 

 whole is melted up together in the puddling furnace. The oxide at first acts 

 as a flux, but is gradually reduced to pure metal, giving up its oxygen to the 

 carbon of the pig metal. "When the operation is complete, the iron master 

 finds that he has not only obtained a perfectly fibrous iron without loss, but 

 for every one hundred pounds of pig metal put into the furnace, he draws 

 out an average of one hundred and five pounds of fibrous iron. This is a 

 step far in advance of anything that Mr. Bessemer, or any other inventor, has 

 yet attained. With these prefatory remarks, we copy the following state- 

 ment made by Mr. Bessemer at the last meeting of the British Association, 

 as the best familiar explanation of his process : EDITOR. 



"I set out with the assumption that crude iron contains about five per 

 cent, of carbon ; that carbon cannot exist at a white heat in the presence of 

 oxygen without uniting therewith and producing combustion; that such 

 combustion would proceed with a rapidity dependent on the amount of sur- 

 face of carbon exposed ; and, lastly, that the temperature which the metal 

 would acquire would be also dependent on the rapidity with which the 

 oxygen and carbon were made to combine, and consequently that it was only 

 necessaiy to bring the oxygen and carbon together in such a manner that a 

 vast surface should be exposed to their mutual action, in order to produce a 

 temperature hitherto unattainable in our largest furnaces. 



" "With a view of testing practically this theory, I constructed a cylindrical 

 vessel of three feet in diameter and five feet in height, somewhat like an 

 ordinary cupola furnace, the interior of which is lined with fire bricks, and at 

 about two inches from the bottom of it I insert five tuyere pipes, the nozzles 

 of which are formed of well burned fire clay, the orifice of each tuyere being 

 about three- eighths of an inch in diameter; they are so put into the brick 

 lining (from the outer side) as to admit of their removal and renewal in a few 

 minutes when they are w^orn out. At one side of the vessel, about half way 

 up from the bottom, there is a hole made for running in the crude metal, and 

 on the opposite side there is a tap hole stopped with loam, by means of which 

 the iron is run out at the end of the process. In practice this converting 

 vessel may be made of any convenient size, but I prefer that it should not 

 hold less than one, or more than five tons, of fluid iron at each charge. The 

 vessel should be placed so near to the discharge hole of the blast furnace as 

 to allow the iron to flow along a gutter into it ; a small blast cylinder will be 



