220 RESEARCHES UPOlSr THE CHEMICAL PROPERTIES OF GASES. 



occasions no oxygen could be found. It has only been recognized when the gas had 

 bubbled continuously for many hours or days through the reagent. It cannot be 

 said that oxygen is a constant constituent, although it does unquestionably occur in 

 much of natural gas iii minute traces. 



CARBON DIOXIDE. 



Carbon dioxide is present in all natural gas, as is easily proved by its action 

 upon lime water. 



AMMONIA. . 



In the case of a gas well near Canonsburg, the following result was obtained : 

 Gas was caused to bubble directly from the main at the well through water for sev- 

 eral hours. On applying !N^estler's reagent to the water, a feeble reaction was 

 obtained. Ammonia was not found elsewhere in the trials I have made. 



Mr. S. A. Ford, of the Edgar-Thompson Steel Works, reports a very interesting 

 case where masses of solid ammonium carbonate were blown out from a gas well by 

 the pressure of the gas. 



ISTatural gas appears to consist chiefly of methane, with traces of higher hydro- 

 carbons of the paraffin series. JSTitrogen is probably always present, together with 

 a little carbon dioxide. The absence of free hydrogen, of defines and of carbon 

 monoxide is, I believe, clearly shown in the case of the natural gas I have examined. 



If natural gas as found in the wells of any one gas region is derived from one 

 vast subterranean reservoir, approximate uniformity in composition should be looked 

 for. It is often noticed, however, that gas from adjacent wells possesses a different 

 odor. 



A carbon dioxide determination was made in the case of samples of gas from 

 six wells near Tarentum, Pa. These wells were situated nearly on a straight line 

 less than one mile in length. The samples were all taken within an interval of three 

 hours. 



The determinations were made by a 7 per cent, soda solution in a eudiometer 

 over mercury. 



WELL. CARBON DIOXIDE. WELL, CARBON DIOXIDE. 



No. 1 0.42 per cent. No. 4 1.47 per cent. 



" 2 1.25 " " 5 1.28 



" 3 0.25 " " 6 1.28 



The differences in the pi'oportion of carbon dioxide, a constituent determinable 

 with great precision, would be difficult to explain if the gas flowing from these dif- 

 ferent wells is derived from one subterranean reservoir. 



