66 ECONOMIC GEOLOGY OF AMITY QUADRANGLE, PA. 
COMPOSITION OF NATURAL GAS. 
Chemically, natural gas from the Pennsylvania fields consists chiefly 
of the hydrocarbons of the paraffin series, with nitrogen, traces of 
carbon dioxide, oxygen, hydrogen, and ammonia. The chief con- 
stituent is methane (CH 4 ), the lowest member of the paraffin series of 
hydrocarbons. Methane is one of the products of the destructive dis- 
tillation of coal and consequently constitutes a large proportion of 
ordinary coal gas. It is also produced in association with hydrogen 
when plants decay- at the bottom of rivers and swamps. The name 
"marsh gas" is therefore sometimes applied to it. Methane, when 
pure, is odorless and not poisonous. Its specific gravity is 0.55297. 
One cubic meter weighs 0.7148 kilogram; 1 cubic foot, 312.36 grams. 
Methane requires twice its volume of oxygen, or 10 volumes of air, for 
its complete combustion, and the products are carbon dioxide and 
water vapor. « 
Occasionally a well yields this gas in a nearly pure condition. Gen- 
erally, however, there is quite a proportion of impurities. A number 
of analyses have been made at various times of gas from Pennsylvania 
wells. One of these is from the I Iouston well at Houston, one-third of 
;i mile west of the station, on Plum Run. The well is 1,794 feet deep 
and is drilled nearly through the Gantz sand. The Salt sand and its 
gas were found at 850 feet, but this was cased off. The well may 
therefore be considered as yielding gas from the Gantz sand exclu- 
sively. The gas from the Salt sand is said to burn with a whiter but 
more sooty flame than that from the greater depth. The occurrence 
of ;iii upper, less productive sand, yielding gas of greater illuminating 
power, is said to be a common feature in the gas fields of the State. 
The sample of gas was collected on March 18, 1887. The analysis is 
given below; 
Analysis of gas from the Houston well. 
( )xygen Trace. 
Hydrogen sulphide (H 2 S) 
Parraffins (mostly) (CH4) 8 1. 26 
Nitrogen 15.30 
Carbon dioxide (C0 2 ) 11 
Hydrogen 
Ammonia (NH 3 ) . Trace. 
100 
The paraffins mentioned in this analysis have the following average 
composition: Carbon, 76.68 per cent; Irydrogen, 23.32 per cent. 
The following analysis represents a fair average for Pennsylvania 
natural gas in general and is given here for comparison : 
. 1 1 h rage analysis of natural gas in Pennsylvania and West Virginia.** 
Marsh gas (CH 4 ) 80. 85 ! Hydrogen 0. 10 
Other hydrocarbons 14 Hydrogen sulphide (H 2 S) 
Nil rogen 4. 60 
( ';i rb< »n dioxide (CO.,) 05 
Carbon monoxide (CO) 40 
Oxygen Trace. 
100 
' W hite, I. C, West Virginia Geol. Survey, vol. 1 (a), Oil and gas, 1904, p. 539. 
b Oliphant, F. H., The production of natural gas; extract from Mineral Resources U. S. for 1904, Q. 3 
Geol. Survey, 1905, p, 12, 
