153 



agent, however, appeared to have been applied in different conditions 

 from a subaerial glacier, at least as far as Scotland was concerned, 

 for the boulder clay of many districts of our country must be con- 

 sidered as the detritus of this general glaciation ; and that shewed, in 

 the author's opinion, pi'oofs of the presence of water, both in the com- 

 pactness of the clay, and in the roundedness of the boulders. Glacier 

 ice moving on a flat surface, even supposing no sea present, would 

 obviously be different from a glacier in a sloping valley, because it 

 would not undergo the same drainage of the included water. It would 

 be in a comparatively slushy condition ; and, by the way, so much 

 the more mobile. 



The latter part of the paper was devoted to a summary of ascer- 

 tained facts regarding the superficial accumulations of different coun- 

 tries. The Drift of the Silurian region, described by Sir Roderick 

 Murchison, answered to the Scottish Boulder Clay, in the local cha- 

 racter of the included blocks, and the direction in which it had moved. 

 Over and posterior to it, was the Northern Drift, so widely spread in 

 England. This probably corresponded with a second boulder clay 

 or Till, known to Scottish geologists, and which, differing in some re- 

 spects from 'the first, might be presumed to be owing to somewhat 

 different causes, or to similar agents operating under different cir- 

 cumstances, the sea being here undoubtedly concerned. The local 

 glaciers of Wales have already been shewn to be later than this drift. 

 In clays and sands below and above the second boulder clay, are found, 

 in Scotland, deposits of shells of living species, but betraying an Arctic 

 character. 



The following Gentlemen were duly elected as Ordinary 

 Fellows : — 



1. Alex. Jaues Russeix, Esq., C.S. 



2. Dr Andbew Fleming, H.E.I.C.S., Bengal. 



The following Donations to the Library were announced : — 



Journal of the Statistical Society of London. Vol. XV., Parts 1, 



2, 3. 8vo. — From the Society. 

 Journal of the Horticultural Society of London. Vol. VII., Parts 



2 & 3. 8vo. — From the Society. 



