2 SCHMITZ, Specific Heats and Volumes of Certain Alloys. 



methods to investigate more completely certain apparently- 

 exceptional cases not dealt with in the present paper. 



The specific volumes as well as the specific heats of 

 the specimens have been determined. As pointed out by 

 Maey,* the non-agreement or agreement of the specific 

 volume with that calculated from the law of mixtures, 

 indicates the existence or non-existence of a chemical 

 compound. 



Analyses of the alloys were kindly undertaken by. 

 Mr. J. Race. Where, as in the work now recorded, alloys 

 are prepared on a small scale, it is in some cases not easy, 

 even if several analyses are made, to obtain satisfactory 

 evidence as to whether or not the specimen is of uniform 

 composition throughout. In such cases the proportions 

 of materials used may represent the average composition 

 better than the results of analysis. In the following pages 

 computed values for specific heat or specific volume are 

 distinguished by letters in brackets as follows : — 



(«) computed from analysis, 



{b) computed from proportions of materials used, 



{c) computed from atomic proportions. 



Most of the alloys examined were prepared from the 

 pure or nearly pure metals.f To ensure more perfect 

 mixing, the first casting was reversed and remelted at 

 least once. The metals were melted and mixed in a 

 fireclay or carbon crucible in a small gas-furnace, with or 

 without an appropriate flux, and cast in a cylindrical iron 

 mould {1% inches internal diameter). The prepared 

 specimen was about one inch in diameter ; it was made as 

 long as the nature of the particular casting would allow. 

 My thanks are due to Mr. F. W. Parrott for his careful 

 attention to the details of this part of the work. 



*Zeitschr. Phys. Chem., IQOI, Vol. 38, pp 292-306. 



tCopper, zinc and tin practically pure. Analysis of aluminium by Mr. 

 Race : copper 0*05, zinc 0'05, lead 0"02, iron 0"02, magnesium o'Oi, silicon 

 0*03, aluminium (by difference) 99"82. 



