Memoir on Sulphuric Ether. 179 
these two gases, but has a little carburetted 
hydrogen occasionally mixed with them, 
» When a certain volume of ether vapour is 
completely burnt at one operation, or it is” 
partially burnt at the first, as in (a), (6), (¢) 
and (d), and the combustion finished by a se- 
cond operation, still the same volume of va- 
pour requires the same volume of oxygen 
for its complete combustion, and produces 
the same volume of carbonic acid, And it 
is always found that the carbonic acid con- 
tains 2 of the oxygen: spent, and conse- 
quently the hydrogen engages 4 of the oxy- 
gen tv form water—Hence it appears that 
the_combustible element of ether is olefiant 
gas; but as there is, reason to conclude that 
oxygen is one of the elements of ether, it 
must be combined with hydrogen, so that 
water must be the incombustible element, 
. In order to find what number of atoms of 
water and olefiant gas must be combined, to 
form one of ether, we must have regard to 
the weights of the different elements, which 
combine. Now, from the experiments above 
related, it appears that 1, measure of ether 
vapour (weighing 3.1) requires 6. measures of 
exygen gas (weighing 6,6); but 2 atoms of 
olefiant. gas, weigh 12.8, and. 1 of water 
weighs 8, making together 20.8, which would 
