66 On the Quantities of Heat developed 
By expressing the mean result of these two experiments in the 
way employed by Mr. Watt and others, I shall say that 1040 
degrees of heat (Fahrenheit) are liberated in the condensation of 
steam, and that consequently this very quantity of heat is em- 
ployed and rendered latent when the water, already at the tem- 
perature of boiling water, is changed into steam. 
The duration of each of these two experiments was from ten 
to eleven minutes, and I had boiled the water some time in the 
matrass (to drive out the air which it contained) before I directed 
the steam from it into the serpentine of the calorimeter. 
As the results of these experiments have beenvvery uniform, 
and as they agree very well with the latter experiments made by 
Mr. Watt with a view to determine the same question, I have not 
thought it necessary to repeat them. 
I have besides been very much occupied with the following 
branch of my inquiries. 
§ Il. Of the Quantity of Heat developed in the Condensation 
of the Vapour of Alcohol. 
As chemists are not agreed as to the state of the elements of 
the water which exist in alcohol, I thought that, by determining 
with precision the quantity of heat which is developed, we should 
be better able to form conjectures as to the state of the water, if 
it be at all times found in this inflammable liquid. 
The results of the experiments which I made with alcohol are 
less regular than those of the experiments made with water, as 
might have been expected ; but they have nevertheless been sufh- 
ciently uniform to establish a fact, which will be regarded without 
doubt as very curious and important. 
As the vapour which is extricated from spirit of wine when 
boiled, varies a little with the intensity of the fire used in boiling 
it, | took care to note the time which was taken in every experi- 
ment, in order to be able to judge, by comparing the quantity 
of vapour condensed, with the time employed to form it, of the 
intensity of the heat employed to boil the liquid. 
In the following table we shall see the details and results of 
five experiments made on the same day (January 21, 1812) with 
alcohol of different degrees of strength. The capacity of the 
calorimeter was always equal to that of 2781 grammes of water, 
and the thermometer employed was that of Fahrenheit. 
TABLE. 
