19l«] on The Romance of Petroleum 338 



the same conditions or from an exactly similar source. On the 

 whole, however, the balance of evidence appears to point to the 

 conclusion that the petroleum which we now find in the Palaeozoic 

 and Tertiary rocks is of substantially the same geological age as the 

 rocks themselves. It is, I believe, uncertain whether man existed 

 on the earth before the close of the Tertiary period, though there 

 ai3pears to be no valid reason why he should not have, but there is 

 abundant evidence of the existence of the human race in the following 

 Quaternary period. The advent of man may, therefore, have been 

 coeval with the completion of the petroliferous formations. 



The following two slides are reproduced from illustrations in 

 Pouchet's work on " The Universe," and may be considered to give 

 some idea of what the surface of the earth was like during the two 

 principal periods of the creation of petroleum. The first is an 

 imaginary view of a forest of the Carboniferous period. At this time 

 the earth had long passed the stage of being " without form and 

 void." The elementary and compound substances of which it is 

 made up had ceased to exist countless ages before in their original 

 condition of incandescent gases and vapours ; the contractile move- 

 ment of the earth had resulted in the formation of valleys on the 

 outer crust of which the condensed aqueous vapour collected as seas ; 

 and the land was covered with luxuriant vegetation. In the fore- 

 ground of the picture is a swamp which, presuming its proximity to 

 the sea-coast, may be regarded as a typical birthplace of petroleum. 

 Pouchet says of this period that the whole surface of the land was 

 covered with strange and dense forests, where proudly jeigned a 

 host of plants the representatives of which at the present day play 

 but a very humble part. These vast primeval forests, which the 

 course of ages was to annihilate, sprang up on a heated and marshy 

 soil, which surrounded the lofty trees with thick compact masses of 

 herbaceous aquatic plants, intended to play a great part in the 

 formation of coal. This rich covering of vegetation, which extended 

 from pole to pole, was sad and silent, as well as strangely monotonous. 

 Xot a single flower enlivened the foliage, not one edible fruit loaded 

 its branches. A sky, ever sombre and veiled, oppressed with heavy 

 clouds the domes of these forests. A wan and dubious light scarcely 

 made visible the dark and naked trunks ; on all sides reigned a 

 shadowy and indescribable hue of horror. The echoes remained 

 absolutely mute, and the branches without a sign of life, for no air- 

 breathing animal had as yet appeared among the savage scenes of 

 the ancient world. Of only one reptile have remains been found, 

 but in the seas were abundant fish and shelled molluscs. 



The next slide indicates the conditions which prevailed during 

 the Tertiary period, when the formation of our stores of petroleum 

 was being completed. In this epoch peaceful and luxuriant nature 

 was, as Pouchet expresses it, animated for the first time with inoffen- 

 sive mammals, some of singular forms, others of colossal size. The 



