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PROFESSOR W. A. TILPEN ON THE SPECIFIC HEATS OF METALS, 



but it might be expected to reduce the specific heat rather than raise it, as seems to 

 be the case. In view of the uncertainty of the present state of knowledge, T have 

 made some direct experiments upon the influence of impurities, the results of which 

 are given briefly below. From these experiments it appears that the presence of a 

 non-metal affects the result far more than the presence of a second metal, which 

 produces very little effect upon the specific heat till the quantity of it is large enough 

 to be felt through the difference of atomic weight (see Copper-tin). The influence of 

 a small amount of carbon is proportionately much greater than the effect of a large 

 amount. 



Three samples of electrical iron, for which I am indebted to Messrs. J. SANKEY 

 and SONS, of Bilston, were then examined. Their composition is stated below. The 

 metal was fused in the oxyhydrogen flame, as in all the previous experiments. 



There seems to be no doubt that the presence of non-metallic impurities tends to 

 raise the specific heat of a metal. Iron, however, is a metal which does not afford 

 the best experimental material. 



An attempt to discriminate between two samples of copper wire differing consider- 

 ably in electrical conductivity failed, inasmuch as they gave practically the same 



