92, University Geological Survey of Kansas. 
an impervious cover. It is evident that moisture is the only 
efficient cover for an oil-field.” 
Here, as in many other instances of nature study, we find a 
possible way according to which certain results may have 
been produced. The discovery of such a possibility by no 
means renders it certain that nature used such a method. 
Having discovered the possibility, the question naturally arises: 
Is this possibility probable? | 
ORGANIC THEORY. 
By the term organic theory for the origin of oil and gas 
should be understood a belief that oil and gas originated in 
some way from organic matter by its partial decomposition 
under water, or in the rocks of the earth from which oxygen 
of the air is totally or partially excluded. Expositions of this 
theory have been published in so many places that it need here 
only be referred to in a general way, or outlined very briefly. 
When organic matter, either animal or vegetable, is sub- 
jected to partial decomposition away from oxygen of the air, 
the decomposition is principally along the lines of molecular 
disintegration, complex molecules breaking down resulting in 
the formation of two or more less complex molecules. In gen- 
eral, the molecular structure of plant and animal tissue is very 
complex. Decomposition processes tend to simplify such struc- 
ture by the formation of two or more simpler molecules. These 
decomposition products necessarily are exceedingly varied and 
usually are obtainable in the form of mixtures of such varied 
molecules. Often some of them are the identical hydrocarbons 
constituting oil and gas, each of which, particularly the former, 
is a complicated mixture of various molecules. We have a 
familiar example of such changes in the production of ordinary 
marsh-gas. Leaves of trees and blades of grass falling beneath 
the surface of the water in stagnant pools gradually decom- 
pose. The mud at the bottoms of the pools is made black by 
the carbon set free, and along with other products of partial 
decomposition, one is produced which in part is held in place by 
the mud at the bottom of the pool, and in part rises to the sur- 
face in bubbles, which may be caught for examination if de- 
sired. Everybody is familiar with this condition. In winter, 
when the surface of the pool is covered with ice, the gas thus 
generated is gathered in big bubbles, and people skating on the 
ponds sometimes amuse themselves by drilling holes through 
