194 University Geological Survey of Kansas. 
interesting point in history that such distillations were made 
in large quantities in America and Europe previous to the com- 
mercial utilization of petroleum, and even at the present time 
this industry is carried on in some parts of the world. It is 
true it may be argued that the oil got into these shales by 
rising from below after having been produced according to the 
chemical theory. Probably, however, most observers would 
look upon this as straining a contention beyond reasonable be- 
lief. 
Some of the advocates of the chemical theory for the origin 
of oil and gas argue that the amount of such products now ob- 
tainable, added to the amount which probably has been dissi- 
pated through surface seepages, is entirely too great to have 
originated according to the conditions of the organic theory. 
The writer confesses that at one time such a contention ap- 
peared to him to be a difficulty. A more extended observation, 
however, on the amount of organic matter entombed in the 
stratified rocks and now being embedded in the same as they 
are forming, has entirely removed such a difficulty from his 
mind. Few people realize the vast amount of organic matter 
annually carried down to the ocean by surface drainage. Vege- 
tation covers practically the entire dry land area of the earth 
and has done so throughout all geologic time. Varying cli- 
matic conditions and other influences doubtless have made a 
corresponding variation in the richness of organic materials in 
different rock masses. But when all allowances are made for 
such variations, it remains that the amount of organic matter 
thus entombed is and has been enormously great. And such 
matter need not be confined to vegetation, for our ocean-water 
is teeming with animal life. Speaking broadly, it is well known 
that animals subsist on vegetation, and that the constant addi- 
tion of food matter to the ocean-water for the ocean fauna 
comes from vegetation, as plants are the great agents for chang- 
ing inorganic matter into organic matter. When it is recalled 
how universal the presence of animal life is throughout ocean- 
water, and that such animals must live largely on organic mat- 
ter, some conception of the enormous amount of organic mat- 
ter carried to the ocean may be obtained. These ocean animals 
die, and portions of their tissues are consumed by other ani- 
mals. But in the aggregate vast proportions subside and be- 
come engulfed in the silt which ultimately becomes rock. If 
this is true at the present time, likewise it has been true 
