DURING METALLIC SUBSTITUTIONS. 
95 
Second Series. — Sulphate of Copper and Zinc. 
The solution of sulphate of copper weighed 100 grms., and contained 0’360 grin, 
oxide of copper. The specific heat of the solution of sulphate of zinc was ascertained 
by experiment to be 0’989. A large excess of zinc (4‘5 grms.) in the state of fine 
filings was taken, in order to complete the action in the shortest possible time. The 
zinc had been carefully distilled, and contained not more than 0’0005 of impurity, 
which was chiefly lead. The glass vessel in which the experiment was performed, 
weighed 50 grms., and the thermal value of the entire apparatus with its contents 
was 106‘3grms. The whole of the copper was precipitated in the course of one 
minute and a half of agitation. 
I. Air ]7°'9. Increment found 2°‘48, corrected 2°‘35. 
II. Air 17°‘8. Increment found 2°’50, corrected 2°'37. 
III. Air 17°’5. Increment found 2°'48, corrected 2°'35. 
In these experiments the glass vessel was not entirely filled with the solution, and 
the correction for the secondary development of heat amounts, it will be observed, 
to 0°‘13. In the two following experiments, a much smaller quantity of air was left 
in the vessel, and the correction was thereby reduced to 0°'05. The solution now 
weighed 130'0 grms., and contained 0‘468 grm. oxide of copper. The thermal equi- 
valent of the whole apparatus was 136'3 grms. 
IV. Air 15°‘5. Increment found 2°'40, corrected 2°’35. 
V. Air 16°‘0. Increment found 2°*42, corrected 2°‘37. 
I. 
869° 
Mean. 
868°. 
II. III. IV. V. 
876° 869° 857° 867° 
Chloride of Copper and Zinc. — The solution contained the same weight of oxide of 
copper, and the zinc solution had the same specific heat as the preceding. The last 
experiment was adjusted in the same manner as the fourth and fifth of the foregoing 
series. 
Increment found 2°'43, corrected 2°‘31. 
Increment found 2°'46, corrected 2°'34. 
Increment found 2°*46, corrected 2°’34. 
Increment found 2°'44, corrected 2°’32. 
Increment found 2°‘40, corrected 2°'35. 
I. Air l7°-2. 
II. Air 17°'0. 
III. Air 17°'6. 
IV. Air 17°-8. 
V. Air 16°T. 
I. II. III. IV. V. Mean. 
854° 865° 865° 858° 857° 860°. 
Acetate of Copper and Zinc. — 100 grms. of a solution of this salt containing 
0‘360 grm. oxide of copper were taken. Specific heat of zinc solution 0’987. Ther- 
mal value of the whole 106‘1 grms. 
I. Air 17°'3. Increment found 2°’49, corrected 2°'37. 
II. Air I7°‘3. Increment found 2°‘50, corrected 2°‘38. 
III. Air 18°'0. Increment found 2°'50, corrected 2° 38. 
I. II. III. 
875° 878° 878° 
Mean. 
