42 
PROFESSOR W. A. TILDEN ON THE SPECIFIC HEATS OF METALS AND 
observed in the specific heats of their sulpiiides, in wliich presumably the atoms are 
separated. On the other hand, if the differences are due to molecular difterences or 
to the properties of the metal in mass, somewhat different values for the specific 
heats miglit Ije oljtained. In tlie result it was found that the mean specific heat of 
silver sulphide is less than that of nickel sulj^hide at all temperatures. 
Range of tempei’ature. 
Mean specific heats. 
Nickel sulphide.* 
Silver sulphide.* 
- 180 to + 15 
•0972 
■0568 
15 „ 100 
•1248 
•07.37 
15 „ 324 
• 1.333 
•0903 
When these results are plotted in the same manner and on the same scale as 
shown for the metals in fig. I, the two curves for the sulphides are seen to he very 
similar to those for the metals. See fig. 3. 
* Reonaui.t foniul the mean specific heat of fused NiS to he '1281 and of fused Ago8 -0740 lietween 
0° and loot 
