382 POPULAR SCIENCE MONTHLY. 



It is apparent that nothing more than the value of a hypoth- 

 esis can be attached to these speculations. Nothing indicating 

 sublimation has been observed where the theory supposes it to 

 have taken place ; the operation of a natural chemical distilla- 

 tion is not proved by any evidence of such a process having any- 

 where taken place. The opinions of MM. Daubree, Lartet, and 

 Coquand, in favor of a chemical origin, being based upon studies 

 of the formations themselves, are regarded as being of more sub- 

 stantial value. These authors, however, are judged to have erred 

 in confounding the original formation of the substances with 

 their appearance where they are found which, in the view of the 

 author, are two very different affairs. 



A bituminous limestone of the Val de Travers, Switzerland, is 

 formed almost wholly of shells, echini, and similar fossils, held 

 together by a calcareous cement. Some of these fossils are only 

 casts, the shell having been absorbed, while the interior, other- 

 wise empty, is partly filled with a viscous bitumen, the quantity 

 of which is proportioned to the size of the shell. In the smaller 

 brachiopods there is only enough to color the inclosing rock a 

 chocolate brown ; in the larger ones it forms a lump which is 

 softened by warming. The bituminous limestone of Auvernier 

 is marked by infinitely numerous little cavities, such as are seen 

 in tufas, which are made visible by the presence of a brown sub- 

 stance, the residue of a volatilized bitumen. It also contains casts 

 or impressions of fossilized shells, and in these again are deposits 

 of brown or blackish substance the organic matter of the mol- 

 lusk, transformed into bitumen. The cavernous or breccialike 

 rock of Bevais, a few miles south of Auvernier, contains what we 

 might perhaps call glutinous inclusions cavities corresponding 

 with the internal part of the fossils, colored brown with organic 

 matter. There are also real nockets of viscous bitumen, which 

 liquefy under a slight increase of temperature. A closer exami- 

 nation of the cavity shows that it is the result of the destruction 

 of an astrsean polyp. Of the association of petroleum and fossils 

 in the United States, an observation has been recorded by M. 

 Daubree of petroleum occupying the cavities of fossils ortho- 

 ceratites, brachiopods, and corals, as well as porous parts of the 

 rock in some of the beds of the Ohio Valley ; and a statements 

 by MM. Fuchs and Launay, that " a remarkable characteristic of 

 the Canadian oil is the profusion of remains of mollusks and 

 crustaceans, with some traces of marine vegetation, which it 

 contains. This is one of the most serious facts on which an 

 organic origin is attributed to petroleum." 



Of the occurrence of these hydrocarbons, including also natu- 

 ral gas, a review of all the theories and evidences leads us to the 

 conclusion that stratified deposits of asphalt, bitumen, and petro- 



