466 Royal Society. 



casional dykes of basalt, but no regular bed?, nor mountain caps 

 of that rock, are here to be found. This formation is evidently 

 of fresh-water origin, for marine exuviss do not occur in it ; but 

 the impressions of ferns, reeds, and fresh- water muscles are met 

 with in every colliery. The magnesian or Sunderland limestone 

 next succeeds, containing casts of fish, encrinites, flustrae, and 

 other productions of the ocean, but no bed of coal or coal mea- 

 sures alternate with it. 



3d. The red calcareous sandstone with masses of gypsum, 

 over which the Tees flows from the vicinity of Croftbridge, was 

 bored for coal at Dinsdale to the depth of 54 fathoms, but no 

 seam worth tvork'ntg detected. 



4th. The alum shale of the Yorkshire moorlands is covered 

 by a thin coal formation, and some of the schistose rocks ac- 

 companying the coal envelop casts of ammonites, pectinites, &c. 

 Jet coating mineralized wood in the manner of bark is also 

 found in the alum shale itself. 



5th. On the Lincolnshire coast, fragments of a black coal, 

 but resembling that of Bovey in texture, are washed on shore, to- 

 gether with an ash-gray bituminous shale containing numerous 

 sea-shells; and several beds of the same shale have been bored 

 through near Louth, in search of a seam worth working, but 

 without success. The hard chalk forming the Wolds rests im- 

 mediately on this set of strata. 



In hopes that these short memoranda may induce some of 

 your numerous correspondents to communicate additional ob- 

 rervations on a subject so nearly connected with the prospetity 

 of this kingdom, 



I remain, &c. 

 Newcastle, Dec. 17, 1815. N. J. W. 



LXXXVIIL Proceedings of Learned Societies. 



ROYAL SOCIETY. 



Nov. 30, xiNNivERSARY. — On the Copleyan medal being 

 adjudged to Dr. Brewster by the President and Council of the 

 Royal Society, it was delivered to Mr. Troughton, his proxy, 

 with a suitable address from the President. This discourse 

 proved that, however time and disease may have affected hi-s 

 corporeal powers, they have not been able to assail his mental 

 faculties, and his capacious mind still retains that native vigour 

 whi^) once carried it around the globe. Sir Joseph, in his usual 

 perspicuous manner, took a concise retrospect of the recent dis- 

 coveries in physical optics j he described with equal simplicity 



and 



