312 
Hhiory of Chemical Discoveries. 
The valuable properties of the rhodium alloys are hardness, 
with sufficient tenacity to prevent cracking either in forging or 
in hardening. This superior hardness is so remarkable, that in 
tempering a few cutting articles made from the alloy, they required 
to be heated full 30° F. higher than the best wootz, wootz itself 
requiring to be heated full 40^ above the best English cast steel. 
4. Steel with Gold. — Gold forms a good alloy with steel. 
Experience does not yet enable us to speak of its properties. It 
certainly does not promise to be of the same value as the alloys 
of silver, platinum and rhodium. 
Steel with Copper and with Tin. — Steel with 2 per cent. 
of copper, forms an alloy. Steel also alloys with tin. Of the 
value of these we have doubts.” 
Table of Specific Gravities of Alloys.^ <^c., mentioned in the 
preceding Paper. 
Iron, unhammered, . - - - 7.847 
Wootz, unhammered, (Bombay) - - 7.665 
Wootz, tilted, (Bombay) - > « 7.6707 
Wootz, in cake, (Bengal) - - - 7.730 
Wootz, fused and hammered, (Bengal) - 7.787 
Meteoric iron, hammered, « _ - 7.965 
Iron, and 3 per cent, nickel, - - - 7.804 
Iron, and 10 nickel - - - 7.849 
Steel, and 10 per cent, platinum, (mirror) - 8.100 
Steel, and 13 per cent, nickel, (mirror) - 7.684 
Steel, and 1 per cent, gold, hammered, - 7.870 
Steel, and 2 per cent, silver, hammered, - 7.808 
Steel, and 1.5 per cent, platinum, hammered, - 7.732 
Steel, and 1.5 per cent, rhodium, hammered, - 7.795 
Steel, and 3 per cent, nickel, hammered, - 7.750 
Platinum 50, and steel 50, unhammered <- 9 862 
Platinum 90, and steel 20, unhammered -j-, - 15.88 
Platinum hammered and rolled, - - 21.25 
* The calculated mean specific gravity of this alloy is 11.27^3 assuming the 
specific gravity of platinum and steel, as expressed in this Table. 
-f- The calculated mean specific gTavity of this alloy is 16.0766. 
