ANNUAL OF SCIENTIFIC DISCOVERY. 



wise, in a sea which washes a chalk or limestone coast, is an operation 

 requiring much less time than from outward appearances would generally be 

 supposed. Petrifying springs are notoriously not less rapid in their action. 

 Dr. Anderson quotes an interesting and apposite instance in which operations 

 are actually going on, which would be quite sufficient to account for many 

 puzzling and abnonnal appearances. It occurs on the coast of Fifeshirc, 

 between Burntislaud and Aberdour, where the overhanging cliffs are thickly 

 planted with trees and underwood, and deeply covered with a coating of 

 calcareous breccia. In many places, branches of trees are enclosed in the 

 calcareous matter, and " on the face of the rocky cliff a portion of a branch 

 may be observed entangled in the breccia, and at the same time attached to 

 its parent tree." Now, not only may a boulder containing a branch of a 

 tree be carried by the waves to a spot at a considerable distance from tho 

 place of its formation, but the breccia in which the branch is enclosed may 

 also contain in its matrix fossil shells of a bygone period, a juxtaposition 

 of old and new, which might not improbably puzzle the observer by whom 

 it was found to assign a date for its origin. 



The second division includes those cases in which human relics and works 

 of art have been found in the silt of rivers, in morasses, or in the superficial 

 soils of the earth. One of the most striking of these is the discovery of a 

 piece of pottery in the bed of the Nile, near the ancient city of Memphis, at 

 a depth of thirty feet under the lowest point of the platform on which was 

 subsequently erected the colossal statue of Ramescs II. When this case 

 was brought before the British Association, at Leeds, the inference drawn 

 from it was that the fragment must have been made at least thirteen thou- 

 sand years ago. Dr. Anderson, however, disputes this conclusion, on the 

 ground that the whole track of the Nile through Lower Egypt has been sub- 

 ject to such successive changes of level as to render any comparison between 

 the past and present rate of silt-deposit along its bed quite impossible. In 

 support of this view he cites some observations made by Dr. Buist, in a 

 paper on the " Geology of Lower Egypt," in the Bombay Journal of Science, 

 which are so interesting or apposite that we cannot do better than extract 

 them entire : 



"A principle, says Dr. Buist, that seems to have been too often lost 

 sight of in the formation of deltas, should be constantly kept before us. Xo 

 delta could ever rise permanently above the surface of the inundation at all, 

 by the agency of setting up exclusively, and unless there was an upheaval 

 of the land or subsidence of the water. At Cairo, the deposit of each flood 

 is as thin as a sheet of drawing-paper; when this accumulation goes on till it 

 has reached within a few inches of the highest inundation, it must become 

 evanescent altogether. Neither Alexandria, Cairo, Calcutta, Hyderabad in 

 Scinde, New Orleans on the delta of the Mississippi, nor any other deltoid 

 city, could ever have found a site at all, unless by upheaval; and so wi;h the 

 sites of the villages from Cairo to the sea, and the bulk of the area of the 

 delta which the Nile, even at its highest floods, now never reaches. Yet these 

 are all composed of river-mud, of exactly the same description as that now 

 being deposited. 



' If this, which is not a hypothesis, but a principle, be kept in view; and 

 if it be remembered how much more rapidly mud is precipitated in stagnant 

 than in running water, it will be at once seen that the rate at which alluvium 

 now accumulates on deltas, merely overlaid by a shallow film from the sur- 

 face of the streams, affords not the slightest grounds for drawing conclusions 



