284 University Geological Survey of Kansas. 
weaker sand then the latter will act as a storage reservoir for 
the gas from the stronger, giving it up again with increased de- 
mands upon the well, thereby producing extremely complicated 
variations in the composition of the gas. 
Prof. I. C. White! describes a well which passed through 
three gas-sands, and which was expected to show when closed 
a pressure of 1500 pounds. Instead, the pressure rose to only 
650 pounds, corresponding to about that of one of its higher 
sands. After standing closed for a year the pressure was so 
great as to blow up in several places a two-inch pipe-line into 
which it was turned, so that the pressure must have reached - 
the point first expected, and the low pressure at the start must 
have been due to the storage in the weaker sand. Other similar 
cases are reported by Doctor White (loc. cit.). 
Another source of variation in the composition of natural 
gases is to be looked for in the diffusion phenomena taking place 
during the passage of the gas from remote rocks to the well. 
As is well known, the lighter gases diffuse more rapidly than 
the heavier. Here again, alterations in the flow would change 
the composition somewhat. This point has been discussed by 
Doctor Chance.!” 
It is a matter of considerable importance to a community 
which uses as much natural gas as Kansas does to know 
whether or not the supply from the wells is changing materially 
in composition. We have seen the relation between composi- 
tion and heat value, and since this heat value is the important 
thing to users of the gas any marked change would be of inter- 
est to the user. It is hoped that a complete investigation can be 
made of the Kansas gas-supplies in the future to determine 
whether or not such a variation is taking place. 
THE USES OF NATURAL GAS. 
The use of natural gas as a fuel is of course so familiar that 
there is no need to speak of it at length here. To a chemist, it 
would seem better, since it is a good starting-point for the 
manufacture of various chemical substances, to use it for this 
purpose rather than as a combustible. 
The main constituent of ordinary natural gas is, of course, 
methane (CH,). The chemical substances which may be de- 
rived from this compound by various chemical reactions are 
170. W. Va. Geol. Surv., vol. 1a, 71, 1906. 
171. Proc. Eng. Club, Philadelphia, 5, 369 (1886). 
