ISO Scientific Intelligence. 



in his report on the connection "between the distribution of the existing 

 Fauna and Flora of the British Isles, published in the Memoirs of the 

 Geographical Survey of Great Britain. Which of these theories is correct, 

 or whether they can both, with some modification, be reconciled to each 

 other, I must leave for geologists to determine. The only solution which 

 suggests itself to me is, that the shores of the African continent may have 

 extended as far west as the islands in question, and that immediately on 

 the subsidence of the land, when it was barely submerged, and the con- 

 ditions not yet incompatible with the existence of littoral species of marine 

 mollusca, the volcanic action took place, elevating the lofty masses of which 

 most of these islands are composed, and that their peculiar land mollusca 

 are of more recent origin. 



Such an explanation would, I believe, be consistent with established 

 geological facts, but I merely suggest it for the consideration of those 

 who are more qualified than I can pretend to be to grapple with the vast 

 subject of the history and conditions of our planet, in times anterior to the 

 present distribution of land and water. — Macandreiv, in Proc. of Lit, 

 and Phil. Soc. of Liverpool, 1854. 



Action of Water and Air on Basalt. — Bensch having ground a quan- 

 tity of basalt to a fine powder, with water on a porphyry slab, left it for 

 some months in a beaker glass covered with paper. At the end of that 

 time it was found to have been converted into a mass so ha,rd as to require 

 a smart blow of a hammer to break it. Its fracture was similar to that of 

 the natural basalt, and the interior consisted of a black core, having a 

 waxy lustre, and surrounded by a less compact gray mass. By longer ex- 

 posure to the air, an efflorescence of carbonate of potash appeared on the 

 surface, and 1*8 per cent, was extracted by water. The specific gravity 

 of the basalt was 2'887, and after extraction of the carbonate of potash 

 the internal portion of the altered basalt had a specific gravity of 2*1588 ; 

 that of the external portion was 2*0423. There is no doubt that a hydrate 

 must have been formed in this case, and the observation may serve to throw 

 some light on the changes which take place in the weathering of rocks. — 

 Annalen der Chimie und Pharmacie, vol. xci. p. 234. 



Pleistocene Classification. — The following table of the classification of 

 the different formations of the pleistocene or glacial period of geology, is 

 constructed from Mr Smith's papers, and may help us to form an idea, or 

 rather to lose ourselves in the attempt to form an idea of the extent of 

 time necessary for its production. 



1. Elevated marine beds. Ancient beaches. 



2. Submarine forests. 



3. Alluvial beds, most likely marine, but affording as yet no 



organic remains. 



4. Upper Diluvium or Till. The most recent deposit of the Till. 



Has yielded bones of the fossil elephant, and water-worn 

 shells. " Cyprina Islandica/' " A balanus," &c. 



5. Marine beds in the Till, affording shells. Occur at Airdrie 



500 feet above the sea level. A bed of " Tellina proxima." 

 In site under No. 4, and above No. 6. 



6. Lower Diluvium, Till, or Boulder Clay. 



7. Stratified Alluvium, consisting of sands, gravels, and clays, 



without organic remains. Resting in the Clyde district, im- 

 mediately upon the upper members of the carboniferous 

 system. — Ferguson, in Proc. Lit. and Phil. Soc. of Liverpool, 

 1854. 



