258 Mr . Stodart and Mr. Faraday 
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 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 
solbs. 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 fu- 
sion 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 satisfactory. The processes of 
analysis, though simple, we shall briefly state ; the informa- 
