202 Messrs. Stodart and Faraday on [March, 



extended not only to the manufacture of cutlery, but also to 

 various descriptions of tools; the trifling addition of price can- 

 not operate against its very general introduction. The silver 

 alloy may be advantageously used for almost every purpose for 

 which good steel is required. 



Our next experiment made in the large way was with steel and 

 platina : 10 lbs. of the same steel, with l-100th part of platina, 

 the latter in the state produced by heating the ammonia muriate 

 in a crucible to redness, was forwarded to our agent, with 

 instructions to treat this in the same way as the last named 

 metals. The whole of this was returned in bars remarkable for 

 smoothness of surface and beauty of fracture. Our own obser- 

 vation, 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 pro- 

 perty will render it valuable for every purpose where tenacity, as 

 well as hardness, is required ; neither will the expense of platina 

 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 diffi- 

 culty 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 purpose of making 

 some delicate instruments, and also as an article of luxury, when 

 manufactured into razors. In the mean time, we have been 

 enabled, repeatedly, to make all these alloys (that with palladium 

 excepted), in masses of from 8 to 20 lbs. each; with such libe- 

 rality 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 quan- 

 tity by analysis, because, in all the experiments 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 an uniform surface, we 

 considered the evidence of its composition as sufficiently satis- 

 factory. The processes of analysis, though simple, we shall 

 briefly state ; the information may be desirable to others who 



