CADY AND MCFARLAND.| Composition of Natural Gas. 279 
error in the calculated results. Both reveal the fact that the 
gas, which is about an average good gas for the Kansas field, is 
of high fuel value. 
IMPORTANCE OF CALORIMETRIC DETERMINATIONS. 
The principal uses to which natural gas is put at present 
are those which involve the heating effect of the gas. This is 
even true in the use of the gas for lighting purposes, since it is 
the heating of a mantle of rare earths which produces inean- 
descence and gives the light. Dilution of the gas with incom- 
bustible substances will, of course, lower the heating value, and 
the gas is not worth so much to the consumer. The presence 
of nitrogen lowers the heating effect in this way. Not only 
does the nitrogen not burn itself, but it decreases the heat 
effect of the other constituents of the gas which really are 
fuels. The amount of heat given up to any surface hotter than 
the surrounding air decreases with the dilution of the gas by 
nitrogen, by an amount which is equal to the weight of the 
nitrogen, times the difference in temperature, times the specific 
heat of nitrogen. This effect becomes of importance in gases 
like the Dexter supply, which contains nearly 83 per cent. of 
nitrogen; Kureka gas, which has 46.4 per cent. nitrogen; the 
gas from Moline, which contains nearly 25 per cent. of nitro- 
gen, and some others of the state which are relatively high in 
nitrogen. These obviously cannot have as high heat value as 
other gases in the state which are lower in nitrogen and corre- 
spondingly high in methane and ethane. 
Natural gas is usually sold by the thousand cubic feet, a fixed 
price being made for this unit. The ordinary user does not 
discriminate between gas of high fuel value and gas of lower 
fuel value. He does not appreciate the fact that in buying a 
gas low in fuel value at the same rate as that paid for the gas 
of high fuel value he is paying a much higher price for the 
amount of heat obtained. It will be easily seen that about 
twice as much of a gas like that from Eureka, which is nearly 
half nitrogen, will be required to produce the same amount of 
heat in a stove that is produced by a gas of high methane con- 
tent, such as the gas from Iola or Chanute, which has only 
about 5 per cent. of nitrogen. This nearly doubles the actual 
cost to the consumer. 
A short calculation will show the difference in the cost of 
heat units to consumers of Eureka gas at 30 cents per thousand 
and to consumers of Iola gas at 25 cents per thousand. 
