72 On the Alloys of Steel. [1822. 



markable for smoothness of surface and beauty of fracture* 

 Our own observation, as well as that of the workmen employed 

 to make from it various articles of cutlery, was, that this alloy, 

 though not so hard as the former, had considerably more 

 toughness : this property will render it valuable for every pur- 

 pose where tenacity, as well as hardness, is required ; neither 

 will the expense of platinum exclude it from a pretty general 

 application in the arts ; its excellence will much more than 

 repay the extra cost. 



The alloys of steel with rhodium have also been made in 

 the large way, and are perhaps the most valuable of all ; but 

 these, however desirable, can never, owing to the scarcity of 

 the metal, be brought into very general use. The compound 

 of steel, iridium, and osmium, made in the large way, is also 

 of great value ; but the same cause, namely the scarcity and 

 difficulty of procuring the metals, will operate against its very 

 general introduction. A sufficient quantity of these metals 

 may, perhaps, be obtained to combine with steel for the pur- 

 pose of making some delicate instruments, and also as an article 

 of luxury, when manufactured into razors. In the meantime, 

 we have been enabled, repeatedly, to make all these alloys 

 (that with palladium excepted) in masses of from 8 to 20 Ibs. 

 each ; with such liberality were we furnished with the metals 

 from the source already named. 



A point of great importance in experiments of this kind 

 was, to ascertain whether the products obtained were exactly 

 such as we wished to produce. For this purpose, a part of 

 each product was analysed, and in some cases the quantity 

 ascertained ; but it was not considered necessary in every case 

 to verify the quantity by analysis, because, in all the experi- 

 ments made in the laboratory, the button produced after fusion 

 was weighed, and if it fell short of the weight of both metals 

 put into the crucible, it was rejected as imperfect, and put 

 aside. When the button gave the weight, and on analysis 

 gave proofs of containing the metal put in to form the alloy, 

 and also, on being forged into a bar and acted on by acids, 

 presented a uniform surface, we considered the evidence of 

 its composition as sufficiently satisfactory. The processes of 

 analysis, though simple, we shall briefly state : the information 

 may be desirable to others who may be engaged on similar 



