334 



2. On the Physical Geography of the Old Red Sandstone 

 Sea of the Central District of Scotland. By Henry 

 Clifton Sorby, F.G.S. Communicated by Professor 

 Balfour. 



The author endeavours to show that in the Old Ked Sandstone 

 period there extended across Scotland a branch of the sea or strait, 

 whose northern shore was somewhere in the line of the mica schist 

 rocks which extend from Aberdeen to the mouth of the Clyde, and its 

 southern in the direction of the Grey wacke rocks that run across from 

 St Abb's Head to Wigtonshire. In this, at the earlier part of the 

 period, there were considerable tidal currents ; but when the upper 

 beds were deposited, they were more or less completely absent, and 

 there were present such as were chiefly due to the action of the wind. 



He shows that there is a most intimate connection between the 

 physical geography of a sea and the currents present in it, and that 

 even their directions and characters can be ascertained from the 

 structures produced in the deposits formed under their influence ; 

 therefore, the physical geography of our ancient seas may be in- 

 ferred within certain limits. 



He applies these general principles to the facts seen in the Old 

 Red Sandstone of Scotland, and endeavours to show that the ap- 

 pearances presented indicate the effects of tidal oscillations. 



The Council announced that it had awarded the Keith Prize 

 for the Biennial Period ending April 1855, to Dr Thomas 

 Anderson for his Papers on the Crystalline Constituents of 

 Opium, and on the Products of the Destructive Distillation 

 of Animal Substances, both printed in the Transactions. 



The following Donations to the Library were annoianced : — 

 Jahresbericht iiber die Fortschritte der reinen, pharmaceutischen 



und technischen Chemie, &c. Herausg. von Liebig und 



Kopp. 1854. 8vo. — From the Editors. 

 Die Fortschritte der Physik in den Jahren, 1850, 1851, 1852. 



Dargestellt von der Physikalischen Gesellschaft zu Berlin. 8vo. 



— From the Society. 

 Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften , 



Bd. XV., Heft. 2 & 3; Bd. XVI Heft. 1. Philosophisch-Histo- 



rische Classe. 8vo. 



