The lowest and most level land areas show us, especially when we dig there to very great depths, nothing but horizontal layers of material more or less varied, which almost all contain innumerable products of the sea.

The appearance of the bones of quadrupeds, especially those of complete bodies in the strata, tells us either that the layer itself which carries them was in earlier times dry land or that dry land was at least formed in the immediate area.

If they [enlightened men] take any interest in examining, in the infancy of our species, the almost obliterated traces of so many nations that have become extinct, they will doubtless take a similar interest in collecting, amidst the darkness which covers the infancy of the globe, the traces of those revolutions which took place anterior to the existence of all nations.

The observer listens to nature: the experimenter questions and forces her to reveal herself.

Hence the same instant which killed the animals froze the country where they lived. This event was sudden, instantaneous, without any gradual development.

It is to them [fossils] alone that we owe the commencement of even a Theory of the Earth ... By them we are enabled to ascertain, with the utmost certainty, that our earth has not always been covered over by the same external crust, because we are thoroughly assured that the organized bodies to which these fossil remains belong must have lived upon the surface before they came to be buried, as they now are, at a great depth.

Thus it cannot be denied that the masses which today form our highest mountains were originally in a liquid state; for a long time they were covered by waters which did not sustain any life.