236 University Geological Survey of Kansas. 
with the natural gas would introduce a considerable percentage 
of oxygen; consequently, if oxygen is found in any considerable 
quantity suspicion is at once raised that the sample has be- 
come contaminated with air. Therefore a large percentage of 
oxygen reported in an analysis is viewed with suspicion, es- 
pecially if it be accompanied by a correspondingly high amount 
of nitrogen, since this points to contamination of the gas 
sample. : 
HYDROGEN. 
Hydrogen, a very light, highly combustible elementary gas, 
was formerly reported in large quantity in natural gases. In 
all probability this report was, in many cases, based on an in- 
correct interpretation of analytical results and upon faulty 
methods of analysis. The methods which at present seem best 
recommended for its determination show occasionally small 
percentages of hydrogen in the Kansas gases. Some of the 
best authorities on the analysis of natural gas, notably F. C. 
Phillips, whose work on the gases of Pennsylvania is of a very 
high order, are of the opinion that hydrogen is almost never 
a normal constituent of natural gas. Mr. Phillips cites this as 
an argument against the Mendelejeff carbide theory of the 
origin of natural gas." 
When present in a gaseous mixture free hydrogen has a con- 
siderable fuel value.: Its heating power is 293.5 British ther- 
mal units per cubic foot, or 2613 calories per cubic meter. 
Owing to the erroneous reports of hydrogen in early gas an- 
alyses some doubt is cast on calculations of heat value based 
upon these analyses. 
GASES OF THE ARGON GROUP. 
These gases, argon, helium, neon, krypton, xenon, have been 
supposed to be of rather rare occurrence. Their presence in 
air was demonstrated by Rayleigh and Ramsey in the period 
from 1894 to 1898, and they have been shown to be present in 
gases from a number of mineral springs. Their complete lack 
of chemical reactivity and apparent inability to enter into any 
sort of chemical combination has rendered their detection very 
difficult and out of reach of the analyst in the ordinary ways. 
Recent methods of analysis, developed from the work of Dewar 
on the absorbing power of cocoanut charcoal at the tempera- 
ture of liquid air, have greatly facilitated the separation of 
115. Am. Chem. Jour., vol. 16, pp. 406-429. 
