78 On the Alloys of Steel. [1822. 



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 explosive. 



The fulminating preparation obtained from the platinum alloy, 

 when dissolved in nitromuriatic acid, gave a solution contain- 

 ing much platinum and very little iron. When a little of it was 

 wrapped in foil and heated, it exploded with much force, tear- 

 ing open the foil, and evolving a faint light. When dropped 

 on the surface of heated mercury, it exploded readily at 400 

 of Fahrenheit, but with difficulty at 370. When its tempera- 

 ture 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 col- 

 lected was metallic platinum with a very little iron and charcoal. 

 We are uncertain how far this preparation resembles the ful- 

 minating platinum 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 imper- 

 fection of crucibles. In one instance, in which the fused but- 

 ton gave a fine damask surface, we were disposed to attribute 

 the appearance 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 alumina, 

 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*, 

 * Annales de Chimie, xvii, 55. 



