1813.] Geological Society. 67 



GEOLOGICAL SOCIETT. 



This society was established some years ago, for the express 

 purpose of accurately investigating the geognostic structure of 

 Great Britain. The activity of the members, and the great 

 progress which they have already made, is really surprising, and 

 entitles them to a very high place in the catalogue of useful 

 institutions. At the last general election it consisted of 115 

 ordinary, and 108 honorary members ; and, as many elections 

 have been made since that period, the number of ordinary 

 members is at present considerably increased. 1 shall give a 

 short account of the papers which have been read at their diffe- 

 rent meetings during the present session, which began on Nov. 

 the 6th, 1812. 



On Friday, Nov. 6, 1S12, a letter was read from Ed. L. 

 Irton, Esq. on the sand-tubes found at Drigg, in Cumberland. 

 These tubes have been found only in a single hill of drift sand 

 on the sea-shore, about five acres in extent. They were disco- 

 vered by the drifting of the sand. They are placed nearly 

 perpendicularly, at unequal distances. One was traced 15 feet 

 deep, but how far they go is unknown. When first dug out 

 they are flexible, but soon become quite rigid. Internally they 

 have a glaze, which is perfectly vitreous. 



An account, by Dr. Macculloch, of a remarkable vein in a 

 mill-stone of blue limestone. This mill-stone was shipped from 

 Limerick, and is at present at the Royal Powder Mills at 

 Waltham Abbey. The vein is a whitish compact carbonate of 

 lime. This vein, in its present state, consists of angular frag- 

 ments having a certain parallelism, and leaving no doubt that 

 they once constituted a regular contiguous vein. By what 

 mechanism have they been brought into their present state? 



On Friday, Nov. 20, some observations on a bed of greenstone 

 near Walsall, in Staffordshire, by Arthur Aikin, Esq. were read. 

 Tins greenstone occurs in the independent coal formation, and 

 Mr. Aikin considers it as a vein branching off a dyke of green- 

 stone that occurs near it. It consists of felspar, mixed with 

 calcareous spar, and minute grains of augite and hornblende. 

 The substances below this greenstone are considerably altered, 

 when compared with their appearances in other parts of the 

 field. These are sandstone, which is indurated; shale, which 

 is deprived of its bitumen ; and coal, which is also deprived of 

 its bitumen, and more friable than in other places. These 

 changes, as they do not occur in other parts of the field, Mr. 

 Aikin considers as connected with the presence of the green- 

 stone. 



On Friday, Dee. 4, part of a paper by William Philips, Esq, 

 on the veins of Cornwall was read. Most of the metalliferous 



1 I 



