1823.] the Alloys of Steel. 207 



taken from an alloy, the metal of which is soluble in nitric 

 acid ; but if the powder is from an alloy, the metal of which 

 is not soluble in nitric acid, then a black residuum is left 

 not touched by the acid ; and which, when washed and carefully 

 dried, is found, when heated, to be deflagrating ; and with 

 some of the metals, when carefully prepared, strongly ex- 

 plosive. 



The fulminating preparation obtained from the platina alloy, 

 when dissolved in nitromuriatic acid, gave a solution containing 

 much platina, and very little iron. When a little of it was wrap- 

 ped in foil and heated, it exploded with much force, tearing open 

 the foil, and evolving a faint light. When dropped on the sur- 

 face of heated mercury, it exploded readily at 400° of Fahren- 

 heit, but with difficulty at 370°. When its temperature was 

 raised slowly, it did not explode, but was decomposed quietly. 

 When detonated in the bottom of a hot glass tube, much water 

 and fume were given off', and the residuum collected was metal- 

 lic platina with a very little iron and charcoal. We are uncer- 

 tain how far this preparation resembles the fulminating platina of 

 Mr. Edmund Davy. 



In these alloys of steel the differences of specific gravity are 

 not great, and may probably be in part referred to the denser 

 state of the metals from more or less hammering; at the same 

 time it may be observed, that they are nearly in the order of the 

 specific gravities of the respective alloying metals. 



The alloys of steel with gold, tin, copper, and chromium, we 

 have not attempted in the large way. In the laboratory, steel 

 and gold were combined in various proportions ; none of the 

 results were so promising as the alloys already named, nor did 

 either tin or copper, as far as we could judge, at all improve 

 steel. With titanium we failed, owing to the imperfection of 

 crucibles. In one instance, in which the fused button gave a 

 fine damask surface, we were disposed to attribute the appear- 

 ance to the presence of titanium ; but in this we were mistaken ; 

 the fact was, we had unintentionally made wootz. The button, 

 by analysis, gave a little silex and alumine, but not an atom of 

 titanium ; menachanite, in a particular state of preparation, was 

 used : this might possibly contain the earths or their basis, or 

 they may have formed a part of the crucible. 



M. Berthier, who first made the alloy of steel and chromium,* 

 speaks very favourably of it. We have made only two experi- 

 ments : 1600 grains of steel, with 16 of pure chrome, were 

 packed into one of the best crucibles, and placed in an excellent 

 blast furnace : the metals were fused, and kept in that state for 

 some time. The fused button proved good and forged well : 

 although hard, it showed no disposition to crack. The surface 

 being brightened, and slightly acted on by dilute sulphuric acid, 



* Annales de C'hiniie, xvti. 55. 



