190 
Book II. 
COMPOUND COMBUSTIELES. 
tity of water was not known by actual weight, but by 
calculation. 
To this we may add, that Mr Lavoisier was not war 
ranted to conclude from his experiment, that the water 
found in the vessel, which had not been formed by the 
oxygen gas used, had existed in tlie alcohol in the state 
of water : he was intitled to conclude from his data, 
that the ingredients of that water existed in the alcohol 
before combustion ; but not that they were actually 
combined in the state of water, because that combina 
tion might have taken place, and in all probability did 
partly take place, during the combustion. It follows, 
therefore, from Mr Lavoisier's experiments, that alco 
hol, supposing he used it perfectly pure, which is not 
probable, is composed of 
0.5172 parts oxygen 
o.2988 parts carbon 
0.1840 parts hydrogen 
1.0000 
But it gives us no information whatever of the manner 
in which these ingredients are combined. That alcohol 
contains oxygen, has been proved by a very ingenious 
set of experiments performed by Messrs Fourcroy and 
Vauquelin. When equal parts of alcohol and sulphuric 
acid are mixed together, the sulphuric acid suffers no 
change ; but the alcohol is decomposed, being partly 
converted into water and partly into ether. Now it is 
evident that the alcohol could not have been converted 
into water unless it had contained oxygen *. 
When alcohol, in the state of vapour, is made to pass 
* Nicholson's Journal, i. 391.