538 
MR. T. J. BAKER OK THE THERMO-CHEMISTRY 
The subjoined Table proves that if any voltaic action occurs in this case it does not 
appreciably affect the course of the reaction, for calculated and observed values differ 
by less than 1 per cent. 
TabliiI III.—Water Ecpiivalent of Calorimeter and Contents = 430 7 grammes. 
Weight of mixture 
of Cu and Zu in 
grammes. 
Percentage of Cu 
in mixture. 
Rise in tempera¬ 
ture ° C. 
Calories evolved 
per gramme. 
■ 
Calories evolved cal¬ 
culated from Tables 
I. and H. 
■502.3 
. 10^2 
■989 
8.50 
851 
•5419 
18^2 
•9925 
789 
791 
■5836 
32 ■ 05 
■ 9365 
690 
687 
■633 
39^95 
■926 
632 
628 
■ 8203 
49 ■ 4 
R068 
561 
558 
ROO 
62^27 
R067 
459 
461 
1-2016 
79^6 
■9305 
334 
332 
Beat of Dissolution of Alloys q/ Copper and Zinc in Ammoninm Ferric Chloride. 
The method of preparation and mode of dealing with the alloys was exactly similar 
to that previously described. 
The quantity of water used to moisten the powdered alloys was so small that its 
effect on the water equivalent of the whole was negligible. 
If we subtract the number of calories evolved Ijy the dissolution of 1 gram of any 
alloy from the number calculated for a mere mixture of the same composition by the 
aid of Tables I. and II., the difference represents the heat of formation of 1 gramme of 
the alloy. 
The seventh column in the following Table gives the numbers so obtained for 
twenty-one different alloys. 
Table IV.—Water Equivalent of Calorimeter and Contents = 430'7 grammes. 
Percentage 
of copper 
in alloy. 
AVeight of 
alloy in 
grammes. 
Rise in 
tempera¬ 
ture °C. 
Calories 
per gramme 
of alloy. 
Mean calories 
per gramme 
of alloy. 
Calories per gramme 
of mixture calcu¬ 
lated from Tables 
I. and H. 
Heat of for¬ 
mation of one 
gramme of 
alloy. 
6^73 
■4286 
■4878 
■863 
■9836 
868 
869 
868 ■ 5 
876^5 
8 
12^0 
■5801 
■5629 
M03 
R073 
820 
821 
820 ■ 5 
837 ■ 5 
17 
18^17 
■6152 
■5894 
R086 
R043 
761 
763 
762 
791 
29 
