Kirwan first made its specific heat 0.05 ; Dalton gave it as the same ; Dulong and Petit obtained 0.0298 by the method of cooling. Regnault obtained 0.03244 (12'-98'), with gold ggg fine. Violle worked with gold 1,000 fine, and obtained for o"-~ooo 0.0316. This is stated to remain sensibly constant up to 6oo", and then to increase gradually towards the melting point (I ,035").
At qo', Violle makes its specific heat 0.0345 and at I,OZO~, 0.0352.
It would appear from these figures that the specific heat of gold is more nearly constant, or rather changes less with the temperature than that of any other metal.
INl)IU1\1.
Bunsen has found with the ice calorimeterIo*o574 and 0.0565, mean 0.0570 between o" and 100'.
IRII)IUM.
Regnault
found 0.03672 (17~-98~), but remarks that the metal he used was impure.
Kopp obtained 0.0358 (15'-6o"), with metal of greater purity.
Violle found for it exactly the same value as for platinum, S?% = 0'0317 + o.ooooo6 t
He verified this formula up to 1,400'. Violle further determined the heat in solid iridium just set as 84.2, 85.3 and 83.9 calories, mean 84'5, which, by the above formula, would indicate a maximum fusing point of 1,950". IRON.