182 THOMSON ON CARNOT'S 



experiments of Delaroche and Berard on the spe- 

 cific heat of gases, by a process approximately 

 equivalent to the calculation of the value of 



/ / V for the temperature 1. There are also, in 

 vdq/dv 



the same work, determinations of the values of /* 

 from observations on the vapors of alcohol and 

 water ; but a table given in M. Clapeyron's paper, 

 of the values of ^ derived from the data supplied 

 by various experiments with reference to the va- 

 pors of ether, alcohol, water, and oil of turpen- 

 tine, at the respective boiling-points of these 

 liquids, affords us the means of comparison through 

 a more extensive range of temperature. In the 

 cases of alcohol and water, these results ought of 

 course to agree with those of Carnot. There are, 

 however, slight discrepancies which must be owing 

 to the uncertainty of the experimental data.* In 

 the opposite table, Carnot's results with reference 

 to air, and Clapeyron's results with reference to 

 the four different liquids, are exhibited, and com- 

 pared with the values of /* which have been given 



* Thus, from Carnot's calculations, we find, in the case 

 of alcohol 4.035, and in the case of water 3.648, instead 

 of 3.963 and 3.658, which are Clapeyron's results in the 

 same cases. 



