94 
PROFESSOR KOPP ON THE SPECIFIC HEAT OF SOLID BODIES. 
The second series of experiments gave the following results : — 
Temperature of the Air 19°-9-19°*8. 
T. 
r. 
t. 
M. 
X. 
0 
grms. 
80-41 
21-08 
20-06 
26-965 
0-464 
79-64 
21-10 
20-09 
26-965 
0-465 
79-98 
21-12 
20T2 
26-96 
0-458 
80-22 
21T2 
20-12 
26-985 
0-457 
7953 
21-10 
20-12 
26-965 
0-452 
80-52 
21-13 
20-14 
26-96 
0-450 
Mean . 
. 0-458 
The reduced value of glass 3 = 0453 grm., the average of the mean numbers of both 
series of experiments. 
23. In those experiments in which a glass containing a liquid and perhaps a 
solid substance is immersed, while warm, in the water of the calorimeter, it may be 
asked if, when the water has become heated to a certain maximum temperature, the 
contents of the glass have actually cooled to the same temperature. In earlier experi- 
ments made by the method of mixture, it was at once assumed that the temperature 
assumed by the water of the calorimeter after immersing the solid was actually that 
also to which the immersed body sank. Neumann has taken into account that the 
immersed body, when the water shows its maximum temperature, may have a somewhat 
higher temperature *. Avogadro has also taken this into account f, and Regnault has 
also allowed for this circumstance in the case in which the mass, immersed in the water 
of the calorimeter, is a bad conductor of heat J. A correction for this fact is certainly 
inconsiderable and unnecessary if the immersed body conducts heat well, and the range 
of temperature through which it cools in the liquid is great. This interval of tempera- 
ture was in my experiments considerably smaller than in those of Neumann and of 
Regnault ; and as in my experiments the excess of heat of the contents of the glass 
had to pass through its sides to the water of the calorimeter, it might be doubted 
whether, when the temperature of the water was at its maximum, this temperature 
could be considered as that of the contents of the glass. 
I have endeavoured to answer these questions experimentally. A glass, such as was 
used for holding the solid investigated and a liquid, was filled with water, and a per- 
forated cork fitted, by means of which the glass could be handled, and which permitted 
the introduction of a thermometer into the water within the glass. The glass filled 
with water was warmed, and then placed in the calorimeter filled with water ; a thermo- 
meter A, passing through the cork, showed the temperature of the water in the glass ; 
* In the memoirs mentioned in § 4, Pape has also discussed and applied the correction to he made for the 
above circumstance (P oggexdokfe’s •' Annalen,’ vol. cxx. p. 341). 
t Ann. de Chim. et de Phys. [2] vol. lv. p. 90. ■ ± Ibid [2] vol. lxxiii. p. 26. 
