242 Mr. Hennell on the mutual action of 
In resuming the analysis of oil of wine by ignited oxide 
of copper, I found it necessary to mix it perfectly with the 
greater part of the oxide employed, otherwise, as in the first 
experiment, suphurous acid was formed in consequence of 
the perfect reduction of a portion of oxide, and the action of 
the metal thus reduced upon the sulphuric acid. With this 
precaution several experiments were performed, the results 
of which were very uniform, and as follows : 2.08 grains of 
oil of wine carefully freed from all adhering moisture by 
quicklime, were properly mixed with 200 grains of oxide of 
copper, and subjected with due precautions to a red heat, in 
the apparatus formerly adverted to: the products were 8.8 
cubic inches of carbonic acid gas, and 1 ,54 grains of water, 
and these are equivalent to 0,171 of a grain of hydrogen, and 
1,118 grains of carbon : 100 grains therefore of oil of wine 
would afford 
Hydrogen 8,30 
Carbon - 53,70 
62. 
and the deficiency of 38 grains must be referred to sulphuric 
acid, a conclusion which is verified by the former experiment 
with solution of potassa, in which the proportion of that acid 
is shown to be 37 per cent. We may I think therefore con- 
clude the above estimate to be near the truth, and the results, 
as respects the carbon and hydrogen, approximate nearly to 
the proportional quantities 6 and 1. 
From the above experiment however we can only infer the 
composition of the hydrocarbon, which is combined with and 
neutralises the sulphuric acid, for in all the specimens of oil 
