Hidory of Chemical Discoveries. 309 
The metals which were used w^ere Platimm^ Rhodium^ Gold., 
Sliver, Nickel, Copper and Tin, all of which were alloyed in 
various proportions with both English and Indian Steel. All 
these metals have a sufficiently strong affinity to steel, to make 
them combine. The platlna fuses when in contact with the steel 
at a temperature at which the steel itself is not affected. 
1. Steel and Silver. — “• If steel and silver be kept in fusion to- 
gether for a length of time, an alloy is obtained, which appears 
to be very perfect while the metals are in the fluid state, but on 
solidifying and cooling, globules of pure silver are expressed 
from the mass, and appear on the surface of the button. If an 
alloy of this kind be forged into a bar, and then dissected by 
the action of dilute sulphuric acid, the silver appears, not in 
combination with the steel, but in threads throughout the mass ; 
so that the whole has the appearance of a bundle of fibres of 
silver and steel, as if they had been united by welding. The 
appearance of these silver fibres is very beautiful ; they are 
sometimes |th of an inch in length, and suggested the idea of 
giving mechanical toughness to steel, where a very perfect edge 
may not be required. 
When silver and steel have been very long in a state of per- 
fect fusion, the sides of the crucible, and frequently the top al- 
so, are covered with a fine and beautiful dew of minute globules 
of silver ; this effect can be produced at pleasure. At first we 
were not successful in detecting silver by chemical tests in these 
buttons ; and finding the steel uniformly improved, were dis- 
posed to attribute its excellence to an effect of the silveiV or to a 
quantity too small to be tested. By subsequent experiments we 
were, however, able to detect the silver, even to less than 1 in 
500 .^ 
In making the silver alloys, the proportion first tried was 
1 silver to 160 steel; the resulting buttons were uniformly steel 
and silver in fibres, the silver being likewise given out in globules 
during solidifying, and adhering to the surface of the fused 
button ; some of these when forged gave out more globules of 
silver. In this state of mechanical mixture, the little bars, when 
exposed to a moist atmosphere, evidently produced voltaic ac- 
tion, and to this Ave are disposed to attribute the rapid destruc- 
tion of the r letal by oxidation, no such destructive action taking 
