ae) 
XLVI. On the Capacity for Heat, or Calorific Power of various 
Liquids. By Bensamin Count Rumrorp*, 
Tae subject is of rather an obscure nature, and it has been so 
little examined, that it will be useful to begin by elucidating it as 
well as I can. 
Let us suppose two cylindrical vessels, with very thick sides, 
made of lead or any other metal, and perfectly equal im size, each 
being capable of containing a pint. 
These two vessels being at the freezing point, we shall pour 
into the one a pound of water at the temperature of 96 F 
(=28!R) being that of the blood, and into the other a pound 
of olive oil at the same temperature. 
Each of these liquids will heat the cold vessel in which it is 
placed, the vessel in its turn will cool the liquid, and both the 
liquid and the vessel will latterly be of the same temperature. 
If water and oil of olives had the same calorific power, a 
pound of water at the temperature of 96° would heat its cold 
vessel precisely as much and not more than a pound of oil would 
heat its vessel, the two vessels being of the same weight, and at 
the same temperature at the commencement of the experiment. 
But experience shews that water heats its vessel much more 
than oil does : consequently the calorific power of water is greater 
than the calorific power of oil of olives, when the quantities 
of these two liquids are estimated by their weight ; and if we de- 
signate the calorific power of water by 1. the calorific power of 
oil of olives will be expressed by a fraction under 1. 
The power with which any given body, solid or liquid, being 
at a given temperature, resists the calorific or frigorific action of 
bodies warmer or colder than itself, is in proportion to its calo- 
rific power; and the greater is this power, the longer it resists 
these actions of surrounding bedies. 
If, under equal surfaces, a pound of water and a pound of oil 
of olives, both at the same temperature (96 F) are placed at 
the same time in a place where the temperature is lower (that 
of freezing for instance) the oil of olives will be cooled much more 
rapidly than the water. 
if it be in a warm place that the two liquids are exposed, the 
oil of olives will still have its temperature most rapidly changed ; 
it will be more heated than the water. 
In two cylindrical glass vessels of equal size and very thin, 
place equal quantities of water and at the same temperature 
(96 F.) 
* This paper was read before the French Institute as a supplement to 
the Count’s Inquiry into the Heat developed by Combustion, Vide Phil. 
Mag, vol. xl, p. 296, and vol, xliii, p. 64, 
A piece 
