64 On the Alloijs of Steel. [ 1 820. 



proportions : platinum, rhodium, gold, silver, nickel, copper 

 and tin. 



All the above-named metals appear to have an affinity for 

 steel sufficiently strong to make them combine : alloys of 

 platinum, rhodium, gold and nickel may be obtained when 

 the heat is sufficiently high. This is so remarkable with 

 platinum, that it will fuse when in contact with steel, at a heat 

 at which the steel itself is not affected. 



With respect to the alloy of silver, there are some very 

 curious circumstances attending it. If steel and silver be kept 

 in fusion together 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 sil- 

 ver 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 

 suggest the idea of giving mechanical toughness to steel, where 

 a very perfect edge may not be required. 



At other times, when silver and steel have been very long in 

 a state of perfect fusion, the sides of the crucible, and fre- 

 quently the top also, 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 uni- 

 formly improved, were disposed to attribute its excellence to 

 an effect of the silver, 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 glo- 

 bules 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 



