and in the Condensation of Vapours. 421 



On determining, by calculation, the quantity of water 

 which may be heated one degree^ by the heat developed 

 in the combustion of one pound of this vapour, I took 

 care to keep an account of the difference between the 

 capacity of water for heat and that of alcohol, when I 

 determined how much heat should have been communi- 

 cated to the calorimeter by the alcohol, and produced 

 by the condensation of the steam, by being cooled in the 

 worm. 



In order to prove the state of the elements of the 

 water which exist in the steam of alcohol, it must be 

 shown how much water these elements ought to form. 



We shall select the experiment which was made with 

 alcohol of the specific gravity of 81,763, and which con- 

 tained the least water. The quantity of steam con- 

 densed in this experiment was 56.61 grammes. 



In 100 parts of this alcohol there were 



91.79 parts of pure alcohol of Lowitz, and 

 8.21 parts of water. 



Consequently there were in the 56.61 grammes of 

 alcohol condensed in the calorimeter, 



51.962 grammes of alcohol of Lowitz, and 

 4.648 grammes of water. 



Now, as M. de Saussure has shown that there are 47 

 parts of water in 100 parts of alcohol of Lowitz, there 

 must have been 24.422 grammes of water in the 51.962 

 grammes of alcohol of Lowitz, which were condensed in 

 the calorimeter. 



If to this quantity of water ( = 24.422 grammes) we 

 add the 4.648 grammes which were found mixed with 

 51.962 grammes of alcohol of Lowitz, in order to com- 

 pose the 56.61 grammes of alcohol employed in the 



