PAPERS RELATING TO NATURAL HISTORY. I93^ 



Devonian, point out, I think, not only the fecundity of an ancient marine 

 Tegetation, but its result in the contemporaneous deposits of petroleum. Indeed, 

 both kinds of Tegetation have great analogy of life, if not of organism. The 

 plants of the coal, by their structure, the form of their long pointed leaves or 

 indefinitely divided fronds, were shaped for the absorption and the transfor- 

 mation from the atmosphere of the greatest amount of carbonic acid gas into 

 woody tissue. The Chlorosperms of the Palaeozoic times, with their simple 

 bladdery conformation and their green color, were undoubtedly prepared to 

 perform in the water the same functions as the coal plants performed in the 

 atmosphere. As the result of terrestrial vegetation has been, first woody 

 tissue, and then, by its decomposition, coal, so the result of marine vegetation 

 has been, first cellular tissue, filled with a kind of liquid carbon, and as the 

 carbon is unalterable, the decomposition of the plant has left it free as fluid 

 bitumen or petroleum. 



" What Chemistry Indicates on the Subject. — We cannot follow, in our day, by 

 means of the accumulated remains of Hydrophytes, the slow process of carboni- 

 zation, and compare its results at difierent stages of its development, as we can 

 by help of the remains of land plants, in the formation of peat bogs, lignites, 

 &c. This only has been observed: "When marine vegetables are thrown upon 

 bogs and mixed with terrestrial plants as compound of the peat, they do not 

 leave any trace of organism or primitive form, and the peaty matter, then of a 

 deeper black color, is a softer, more hpmogeneous compound, richer in bitumen. 

 When, detached by storms or tides, Algae are heaped in great masses on sandy 

 shores, they promptly decompose, passing first to a black, soft paste, and then 

 to a glutinous fluid of the same color, which exhales a strong disagreeable 

 odor, and penetrates the sand. Chemistry has not analyzed these matters 

 resulting from the decomposition of Hydrophytes, nor even species of marine 

 Algae ;* and therefore it is not proved that there exists a direct relation between 

 them and petroleum. Chemistry demonstrates, however, that petroleum and 

 coal are both compounds of the same elements ; and the former matter being 

 proved of vegetable origin, the second is neccessarily, by induction, referred to 

 the same f And as some substances, like iodine, which was formerly procured 

 from marine plants only, are now more abundantly obtained from petroleum 

 chemical analyses, I think, confirm in that way the relation between petroleum 

 and Hydrophytes. 



" Though chemistry is not directly interested in it, it is but right to refer here 

 to a peculiar fact which bears upon the subject. The Algae, especially the 

 gr6np of the Caulerpm, feed some of the animals of the seas, remarkable for the 



• Prof. Liebis, to whom I wrote a resume of my opinion on the subject, with the request 

 that he would point out to me the result of chemical analysis of marine plants, if there were 

 any, either in support or discredit of my ideas, kindly answered : '• That there were unhap- 

 pily no analyses of species of Pucus, or of other Hydrophytes, which could be used as 

 affording support to my views. But that my arguments, based on esact researches, were so 

 c Dnclusive, that for himself, at least, they had removed any doubt of the truth of the theory, 

 t See, on this subject, a very remarkable and most instructive paper, by Sterry Hunt, in 

 he American Journal of Science and Arts (2), pp. 156 to 171. 



