178 Memoir on Sulphurie Ether. 
sues, and the whole of the vapour is conver- 
ted into carbonic acid, water, and new com- 
bustible gas; a little charcoal is sometimes 
deposited, so as to make the air muddy at the 
instant after explosion; no oxygen is found 
in the residue, ) 
(d@) The combustion of ether vapour may 
be effected by common air as well as by oxy- 
gen gas, only the proportion of vapour to 
air is very small and limited. If the vapour 
exceed 5 per cent,, it will not fire; and if it 
fall short of two per cent., it rarely fires. 
The combustion is attended with the produc- 
tion of new cambustible gas, or otherwise 
complete, according to the greater or less 
proportion of vapour, as is the case with oxy- 
gen gas, 
In respect to the new combustible gas in the 
above paragraph, its nature may be ascer- 
tained by abstractihg the carbonic acid in the 
usual way, and then exploding it with oxy- 
gen. In the paragraph (a), the new gas is 
often nearly pure carburetted hydrogen; but 
in (c) and (d), it is always a mixture of car- 
boniec oxide and hydrogen, in nearly equal 
volumes ; as is proved from its requiring 50 
per cent. of oxygen, and producing 5 Oper 
cent. of carbonic acid. In (6) it is chiefly 
