Peckham.] 44 S [September 18. 



of petroleum are largely due to the varied forms of animal life 

 existing during the different geological epochs to which the 

 rocks belong, from which the oil primarily issues. This latter 

 idea was suggested b}^ a remark of Dr. T. S. Hunt when he 

 saj's : " their presence" (that is, the petroleums of Pennsylvania 

 and Canada) " in the lower palaeozoic rocks which contain no 

 traces of land plants, shows that they have not in all cases been 

 derived from terrestrial vegetation but may have been formed 

 from marine plants or animals ; the latter is not surprising 

 when we consider that a considerable portion of the tissues of 

 the lower marine animals is destitute of nitrogen and very simi- 

 lar in chemical constitution to the woody fibre of plants.*" 



This opinion is further strengthened and confirmed when we 

 find in rocks of tertiary age, in which fossil remains of the 

 higher marine animals are found in abundance, a petroleum com- 

 paratively rich in nitrogen, of unstable constitution and under- 

 going decomposition in a manner similar to putrefaction. Such 

 is the character of the petroleum issuing from the Miocene of 

 the coast ranges of Southern California, and from such meagre 

 accoimts as are accessible, I infer that such are the character- 

 istics of the petroleum of the Baku region on the shores of the 

 Caspian Sea, issuing from rocks which I am assured b}^ the 

 Baron Koschkull are also of Miocene age. 



Let us examine these diff'erent theories. Bischof has shown 

 very clearly and with abundant illustrations, the manner in 

 which the decompositions may be effected which produce the 

 different kinds of coals and bitumens from wood.f These illus- 

 trations have been abridged and arranged in tabular form b}' 

 Dr. Hunt, in a paper publislied in the sixth volume of the Chemi- 

 cal News.J The reactions necessary to produce petroleum in- 

 stead of coal have been further traced bj^ him in the article 

 before quoted from the American Journal. § The theoretical 

 possibility of such a decomposition requires no further proof, 

 but it should be observed that these theories are based upon the 

 results of ultimate not proximate analysis. 



If it be granted that a theoretical compound ma}' be obtained 

 from cellulose having an equal number of equivalents of carbon 

 and hydrogen, the general formula for petroleum, the fact still 

 remains that petroleum has never been observed under such 



* Cliem. News, VI. 5. t Chera. and Pliys. Geology, I. 274. 



X C'lieni. News, VI. 38. § Am. Jour. Sci. and Arts, (2) XXXV. 158. 



