234 University Geological Survey of Kansas. 
which is noticed in some samples of natural gas, is usually due 
to the presence of these higher hydrocarbons. The amount 
of them which is normally present in the gas from wells is 
very difficult to determine satisfactorily. It is probable that 
only a long series of fractional distillations of the liquefied 
gases will prove conclusively the quantities present. 
OLEFIN HYDROCARBONS. 
The olefin series has as its most important representative in 
natural gas ethylene, or olefiant gas (C2H:). This contains 
85.59 per cent. of carbon and 14.41 per cent. of hydrogen. It 
boils at —103.5° C. It burns with a much more luminous flame 
than the members of the paraffin series. Its presence in a gas 
would serve to increase its luminosity. It is, however, seldom 
found in more than a small fraction of a per cent. in American 
gases. 
The other olefins have little interest as constituents of gas. 
It is possible that slight traces are present in some samples. 
OXIDS OF CARBON. 
Two more compounds of carbon are frequently reported in 
gas analyses: the oxids of carbon, one of which, carbon mon- 
oxid, is a fuel, and the other, carbon dioxid, has no fuel value 
whatever. 
CARBON MONOXID.—Carbon monoxid, CO, a gas which may 
be produced artificially by the partial oxidation of carbon or 
carbon compounds, is colorless, odorless, and easily combus- 
tible, with a boiling-point of —190° C. It is especially to be 
noted for its poisonous qualities. A comparatively small 
amount breathed into the lungs produces death. One part in 
300,000 parts of air produces poisonous effects, and a liter is 
a fatal dose. It is, however, a good fuel, with a heat value of 
344 British thermal units per cubic foot, or 3062 calories per 
cubic meter, and is much used for that purpose in producer- 
gas, water-gas, and blast-furnace gas, in all of which it is the 
chief constituent. In natural gas it occurs only in very small 
quantities and is of little practical importance. 
CARBON DIOXID.—Carbon dioxid, COz, is quite commonly 
found in natural gases, and, indeed, in some, especially 
those from mineral springs, it is the chief component. It has 
been found in Kansas gases in quantities up to two per cent. 
It is much heavier than air, having a specific gravity of 1.5241, 
and is incombustible, being itself a product of the combustion 
