Lord WEBB SEYMOUR and I observed pudding-stone rocks, exhibiting, instances of this singular kind of fracture, near Oban, in Argyleshire, about three years ago. The phenomenon was then entirely new to us both; but I have since met with an instance of the same kind in Saussure's last work. As the fact is of so particular a kind, I shall state it in his own words: The place was on the sea shore, near the little town of Alassio, between Nice and Genoa. "En passant entre ces blocs de breche, j'admirai quelques-uns d'entr'eux, d'une grandeur considérable, et taillés en cubes, avec la plus parfaite régularité. Il y avoit ceci de remarquable, c'est que l'action de la pesanteur, qui avoit taillé ces cubes en rompant leurs couches, avoit coupé tous les cailloux des breches à fleur de la surface de la pierre, aussi nettement que si c'eût été une masse molle qu'on eût tranchée verticalement avec un rasoir. Cependant parmi ces cailloux, la plupart calcaires, il s'en trouvoit de très durs, de petrosilex, par exemple, même de jade, qui étoient tranchées tout aussi nettement que les autres."[93] [Footnote 93: Voyages aux Alpes, tom. iii. § 1731.] 186. This description is no doubt accurate, though it involves in it something of theory, viz. that the fracture was made by the weight of the stone. This may indeed be true: the operation probably belongs altogether to the surface, and is one with which the powers of the mineral regions are not directly concerned. The phenomenon, however, appears to me, on every supposition, very difficult to explain. In the specimen which I brought from Oban, the smallest pieces of stone are cut in two, as well as the largest. The consolidation and hardness of the mass are very great, and the connection of the different fragments so perfect, that it is no wonder the whole should break as one stone. But still, that the fracture should be so exactly in one plane, and without any shattering, is not a little enigmatical; if it is indeed a fracture, it must be the consequence of an immense impulse, very suddenly communicated. NOTE XII. § 43. _Elevation and inflection of the strata._ 187. The evidence of the different formation of the primary and secondary strata, and of the changes which the former have undergone, is best seen at the points where those strata come into contact with one another. Dr Hutton was not the first who observed these junctions, though the first who rightly interpreted the appearances which they exhibit. He has mentioned observations of this sort by De Luc on the confines of the Hartz; by the author of the _Tableau de la Suisse_, at the pass of Yetz; by Voight, in Thuringia; and Schreiber, at the mountain of Gardette.[94] [Footnote 94: Theory of the Earth, vol. i. p. 410 to 453.] The leading facts to be remarked, are, I. The vertical or very upright position of the primary or lower strata.