2. Observations on the same subject. By John Goodsir, Esq. 



3. Note on the Form of the Crystalline Lens. By Professor 



Forbes. Included in the former Abstract. 



4. On the Cause which has produced the Present Form 



and Condition of the Earth's Surface. By Sir George 

 Mackenzie, Bart. 

 The author first described, generally, the appearance of the loose 

 materials covering the surface; and referred to some districts in the 

 north of Scotland, especially the central one on the borders of Perth 

 and Inverness shires, as demonstrating the effects of vast currents of 

 water having passed over the surface. He also referred to the valleys 

 of the river Conan and its tributaries, in Ross-shire, as presenting an 

 epitome of all the phenomena which may be supposed to result from 

 a vast flood gradually subsiding, and taking the direction of the val- 

 leys. He then shortly alluded to the theories proposed to account 

 for the present condition of the surface, which appear to resolve them- 

 selves into the effects of a remote cause. 



It being generally admitted that the crust of the earth now ap- 

 pears broken, some portions having been elevated, and some having 

 sunk ; and that this breaking up of the strata, causing them to take 

 various positions, the broken portions being inclined at different 

 angles, some being vertical ; and that this dislocation of the strata 

 is observed everywhere ; it is obvious that a tremendous force must 

 have been exerted to produce these effects. The elevation of the 

 former ocean bottom, and the sinking of much of the former land, 

 would occasion an agitation of the waters such as would have caused 

 the waves to overtop the mountains ; and as the waves subsided cur- 

 rents would have been directed with great violence through all the 

 vaUeys, sufficient to produce all the phenomena we observe, except 

 those which may be fairly attributed to a subsequent gradual rising 

 of the land, and to partial convulsions. 



Sir George concluded by observing that, probably, Man had 

 not appeared on the earth previous to the great convulsion 

 by which the order of the strata had been so greatly disturbed ; 

 for, besides no human fossil remains having yet been found, man, 

 without such disturbance of the rocks, could not have enjoyed what 

 external nature offers to his senses, nor have discovered the minerals 

 and organic remains which have contributed so much to his wealth 

 and comfort, as well as to the noblest exercise of his mental faculties. 



