268 M. Bretint on Damasked Steel. [Oct. 



quently no separation of distinct compounds can take place on 

 coolino-. " But if the carbon be in slight excess, the whole of 

 the iron will first be converted into steel ; then the free carbon 

 which remains in the crucible will combine in a new proportion 

 with a part of the fused steel already formed, and there will thus 

 be two distinct compounds, pure steel, and carburetted or cast 

 steel. These two compounds, at first indiscriminately mingled 

 together, will tend to separate as soon as the liquid matter is at 

 rest, and crystallization will ensue, during which the molecules 

 of the two compounds will arrange themselves according to 

 their respective affinities and weights. 



" If we dip a blade made of steel thus prepared in acidulated 

 water, a very evident damask will be developed, in which the 

 portions of pure steel will be black, and those of the carburetted 

 will remain white, because the acidulated water does not so 

 readily lay bare the carbon of the carburetted steel as of the 

 pure. 



** It is, therefore, to the irregular division of the carbon by the 

 metal, and the formation of two distinct compounds, that the 

 production of the damasked surface is to be attributed, and it is 

 obvious that the more gradually the mass is cooled, the larger 

 will be the veins of the damask. It is, perhaps, for this reason, 

 that we should avoid fusing the substance in too great a mass, or 

 at least that some limit should be observed in the process ; in 

 support of which opinion 1 may quote Tavernier, who has given 

 in his " Voyage en Perse" some information as to the size of 

 the balls of steel, which, in his day, were used in making the 

 damasked blades. 



" The steel capable of being damasked comes, says he, from 

 the kingdom of Golconda ; it occurs in commerce in masses of 

 the size of a halfpenny loaf; they are cut in two to see if they be 

 of good quality, and each half makes one sword blade. 



" From this account it is evident, that this Golconda steel 

 was in buttons like icootz, and that each button could not have 

 weighed more than five or six pounds. 



" Tavernier adds, that if this steel were tempered by the 

 European processes, it would be as brittle as glass. Hence, as 

 Reaumur observed, it must be very difficult to forge. 



" That philosopher having received some specimens of Indian 

 steel from Cairo found no one in Paris who could forge it ; 

 whereupon he laid the blame on our workmen ; since the inha- 

 bitants of the east know how to work that kind of steel. I will 

 explain presently the proper method of proceeding to ensure 

 success. 



" As carbon has the chief influence not only in producing the 

 damask on steel, but also on its intrinsic qualities, I fear that 

 Messrs. Stodart and Faraday were led into error in their experi- 

 ments (as I, for a long time, was myself), and attributed effects 



