220 The Relation of Specific Heed to Atomic Weight. [Dec, 8, 



•• The Specific Heats of Metals and the Relation of Specific Heat 

 to Atomic Weight. Part II." By W. A. Tildex, D.Sc, 

 F.B.S. 3 Professor of Chemistry in the Royal College of 

 Science. London. Beceived December 8. — Read December ll r 

 1902. 



(Abstract.) 



The following values have been obtained for the mean specific heats 

 of pure aluminium, nickel, cobalt, silver, and platinum, within the 

 several limits of temperature indicated : — 



Centigrade. 



Aluminium. 



Nickel. 



Cobalt. 



Silver. 



Platinum 



-182 ; to +15° 



-1677 



-083S 



-0822 



0-0519 



-0292 



- 78 „ +15 



-1984 



-0975 



0-0939 



-0550 





+ 15 „ 100 





-1084 



-1030 



-055S 



0-0315 



15 185 



0-21S9 



o-noi 



-1047 



-0561 





15 „ 335 



-2247 











15 „ 350 





0-1186 



0-10S7 



-0576 





15 „ 415 





-1227 









15 „ 435 



-2356 



-1240 



0-1147 



-05S1 



0338 



15 „ 550 





01240 



-1209 







15 „ 630 





0-1246 



-1234 







1000 











0377* 



„ 1177 











0-0388* 



From these results the specific heats at successive temperatures on 

 the absolute scale have been calculated, and it appears that the 

 assumption of a constant atomic heat at absolute zero is untenable. 



The mean specific heat of a sample of nickel steel, containing 36 per 

 cent, of nickel and having remarkably small dilatation, was found to 

 be as follows : — 



Range of temperature 

 - 182 ; to + 15" 

 15 3 „ 100 

 15 ; „ 360 

 15 ; „ 600 



Mean specific heat. 

 0'0917 

 0-1204: 

 0-1215 

 0*1258 



The mean specific heats of the sulphides of nickel and silver were 

 also determined with the object of getting some evidence as to the 

 cause of the difference observed between the two metals in regard to 

 the influence of temperature on their respective specific heats. The 

 following are the values obtained : — 



* Yiolle, 'Comptes Rendus' (1877), vol. S5 ; p. 543: also f Phil. Mag..' [5> 

 vol. 4, p. 318. 



