Expeyiments on the Alloys of Steel. *361 



at a high temperature. Although this experiment failed in 

 effecting the alloy of steel with silver, there is reason to believe 

 that with some other metals, alloys may be obtained by this 

 process : — the following circumstance favours this suggestion. 

 Wires of platinum and steel, of about equal diameter, were 

 packed together, and, by an expert workman, Avere perfectly 

 united by welding. This was etfected with the same facility 

 as could have been done with steel and iron. On being forged, 

 the surface polished, and the steel slightly acted on by an acid, 

 a very novel and beautiful surface appeared, the steel and pla- 

 tinum forming dai'k and white clouds; if this can be effected 

 with very fine vsires, a damasked surface will be obtained, of 

 exquisite beauty. This experiment, made to ascertain the weld- 

 ing property of platinum, is only named here in consequence 

 of observing that some of the largest of the steel clouds liad 

 much the appearance of being alloyed with a poi'tion of the 

 platinum. A njore correct survey of the surface, by a high 

 magnif3'ing power, went far to confirm this curious fact: some 

 more direct experiments are pioposed to be made on this ap- 

 parent alloy by cementation. 



The alloys of steel with platinum, when both are in a state 

 of fusion, are very perfect, in every proportion that has been 

 tried. Equal parts by weight form a beautiful alloy, which 

 takes a fine polish, and does not tarnish ; the colour is the 

 finest imaginable for a mirror. TJie specific gravity of this 

 beautiful compound is 9"862. 



90 of platinum with 20 of steel, gave also a perfect alloy, 

 which has no disposition to tarnish, the specific gravity 15"88; 

 both these buttons are malleable, but have not yet been applied 

 to any specific purpose. 



10 of j)latinum to 80 of steel, formed an excellent alloy. This 

 was ground, and very highly polished, to be tried as a mirror; 

 a fine damask, however, renders it quite unfit tor that purpose. 



The proportions of platinum that appear to improve steel 

 for edge-histruments, are from 1 to 3 per anit. Experience 

 does not yet enable us to state the exact proporticjn that forms 

 the best possiljle alloy of these metals; I' 5 per cent, will pro- 

 bably be very nearly right. At the tinje of combining 10 of 

 platinum with SO steel, with a view to a mirror, the same pro- 

 portions were tried with nickel and steel ; this too had tlie da- 

 mask, and consecjuently was unfit for its hitention. It is cu- 

 rious to observe the difference between these two alloys, as to 

 susceptibility for oxygen. The jilatinum and steel, alter laying 

 many months, had not a sj)oton its surflice, while that with nickel 

 was covered with rust; they were in every respect left under 

 similar circumstances. This is given as an instance, showing 

 that nickel with steel is much more subject to oxidiition than 

 when combined with iron. 



The 



