On the Capacity for Heat. 213 
A piece of lead weighing a pound, and a piece of copper of 
the same weight, having been cooled in a mixture of pounded 
ice and water, remove them from this cold mixture and plunge 
each of them suddenly into one of the vessels of water. 
The two masses of water will be cooled: but that which con- 
tains the copper most, for the calorific power of copper is greater 
than the calorific power of lead. 
We may also say that the frigorific power of copper is greater 
than the frigorific power otf lead, and in the case in question, 
the expression perhaps will be most suitable. 
It is always the same power : it is that by means of which any 
body resists the action of surrounding bodies, and which tends 
to change its temperature either by increase or diminution. 
Much obscurity has been introduced into the science by vague 
ideas, being attached to the words hof and cold: but it will not 
suit my purpose to enlarge upon this subject at present. 1 have 
already delivered my opinion in a former paper. 
The little heat which I discovered in the condensation of al- 
cohol, having induced me to think that the specific heat of this 
liquid had not been accurately determined, and wishing to know 
it precisely, in order to enable me to finish the calculations which 
were necesssary for elucidating the results of some of my experi- 
ments, I constructed a small and very simple apparatus, by the 
help of which I could easily, and as I presume accurately, deter- 
mine it. ‘ 
This apparatus consists of a small bottle of a particular form — 
constructed of thin leaves of red copper, intended to contain 
the liquid which is to be the subject of the experiment ; and a 
small cylindrical vase, also constructed of thin pieces of red 
copper in which I place water at a certain temperature, Into 
this water I plunge the bottle of copper containing the liquid 
which is the subject of the experiment : this liquid being of a 
different temperature from that of the water in the outer vase. 
As the capacity of the vase for heat, as well as that of the bot- 
tle are known, I determine by a very simple calculation, the ca- 
pacity for heat of the liquid contained in the bottle. This cal- 
culation which is well known, is founded in the changes which 
take place in the temperature of liquids, in the vase and in the 
bottle, by taking an uniform temperature, when the bottle is im- 
mersed in the water contained in the vessel. 
In order that this equality of temperature may be speedily 
brought about, the form of the bottle is such that it has a very 
great surface relative to its small capacity, and in order to ma- 
nage it without touching it, its neck which is small is closed by 
a long cork, which serves as a handle. 
In order to diminish as much as possible the effect of the at- 
O 3 mosphere, 
