8 SCHMITZ, Specific Heats and Volumes of Certain Alloys. 



The last two alloys of the table show differences 

 between the observed and calculated values both of specific 

 heat and specific volume, but this may be due to experi- 

 mental difficulties. The bismuth alloy was prepared by 

 adding lo parts of bismuth to 90 parts of aluminium; after 

 four meltings the product seemed to be homogeneous,* 

 but some of the bismuth had been removed in the 

 successive examinations of the material. Mr. Race in 

 two analyses of turnings from the outside of the specimen 

 found 94'0 and 94"3 per cent of aluminium. It may be 

 observed that, if the specific heat and specific volume are 

 assumed to be normal, they would both correspond with 

 slightly less than 97 per cent, of aluminium. As regards 

 the specimen of commercial aluminium, the analyses and 

 other indications suggested a want of homogeneity. 

 The first analysis gave approximately aluminium 88 per 

 cent, zinc 7 per cent, copper 4 per cent, lead 07 per 

 cent, iron 0*4 per cent. Another analysis, using a 

 relatively large quantity of the material, gave aluminium 

 84'8 per cent. After twice remelting and recasting the 

 specimen, turnings from the upper end (outside) of the 

 new casting gave aluminium 85' i per cent, and turnings 

 from the lower end (centre) gave aluminium 84*0 per cent. 

 The calculated values of the table are on the basis 

 aluminium 85 per cent. The observed specific heat, 

 assumed normal, would correspond approximately with 

 79 per cent, of aluminium ; the observed specific volume, 

 assumed normal, would correspond approximately with 

 81 per cent, of aluminium.-|- 



*According to Tissier Brothers, quoted by J. W. Richards, "Aluminium," 

 second edition, p. 398, alloys containing up to 25 per cent, of bismuth may 

 be made by mixing the metals. 



tA second specimen of commercial aluminium (so called) gave 

 similar results. Analysis made the percentage of aluminium 78, while both 

 the specific heat and the specific volume (assumed normal) corresponded 

 with a percentage 74^. 



