When the “Alliance Francaise” did me the honour of inviting me to give an address on this interesting occasion, the choice of an appropriate subject of discourse presented at first some little difficulty. On the one hand, as a representative of science in the “Alliance Franco—Britannique,” it appeared to be incumbent upon me to choose some topic of a scientific kind, and by preference one which would in some way link our two countries together in common bonds of association. On the other hand, it was obviously inadvisable that the theme should be of a technical character which would be little suited for a general audience. After some reflection I decided to present for your consideration a brief account of two remarkable volumes, both of which, dealing with geological questions, appeared in the year 1802, the one in Paris, the other in Edinburgh. Though the political sympathies which for so many generations had linked France and Scotland in a friendly alliance had fallen somewhat into abeyance by the beginning of last century, the two nations still continued to be drawn to each other in the realms of culture by a common ardour in the prosecution of science and philosophy, and by the mutual reaction which, in these great domains of human thought, they exerted on each other.