48 The Amerlc dn Geologist January, 1905 
ioientist familiar with the question from a geological as 
well as the chemical side can be found to support this 
theory. 
The almost universal association of bitumen with ani- 
mal and vegetable remains has led to the assumption of 
svich material as the source from which it has been derived. 
For many years the adherents of these two theories main- 
tained mutually exclusive positions, but wider investigation 
of the natural deposits seems to indicate on the one hand 
that bitumen has been formed from both of these sources 
and deeper investigations into the nature of animal and 
vegetable tissue have shown them to be very closely analo- 
gous. Hence a fusion of these two views has taken place 
in what is known as the theory of organic origin. 
\'arious experiments have been made in the labora- 
tory or factory with the idea of obtaining support for these 
theories or in the hope that a cheap method of manufac- 
turing petroleum might be discovered. About the middle 
of the century Warren made a soap out of fish oil by heat- 
ing it with lime in a manner entirely analogous to the way 
iu which fat is boiled with potas'h or soda lye in making or- 
dinary soap. By distilling this soap under pressure he ob- 
tained an oil containing the same kinds of bodies as are 
found in Pennsylvania petroleum. Later Engler distilled 
the fish oil itself and obtained a "light distillate" that could 
not be differentiated from a similar "light fraction" from 
natural oils. Some of this product was actually sold on the 
market. From linseed oil similarly treated Sadtler obtained 
a mixture of hydrocarbons which, on distillation, gave a 
light oil similar to Pennsylvania oil and left behind a 
vaseline residue containing paraflfine. Further Day pre- 
pared asphalt-like material by distilling wood chips, herring 
or a mixture of both and "cracking" the distillate at high 
temperatures. Thus it is apparent that the results of ex- 
perimentation support any theory and the artificial produc- 
tion indicates only the possibilities and not necessarily the 
realities as to the origin of bitumens. 
Furthermore every case of artificial production of 
bituminous matter, whether from animal, vegetable or min- 
eral material has required a temperature much beyond the 
