564} Geological Society, 



saturate the base, a coating of the resinous salt being apt to 

 exclude a portion of it from the action of the acid. 



The alkaline salts may also be formed by digesting the 

 resin in a concentrated solution of the caustic alkali in which 

 the salt formed is but sparingly soluble. 



With the results of this examination of the saks of the re- 

 tinic acid I am by no means satisfied, though they appear to 

 leave little doubt that the true equivalent is C.^, Hj4 O3. The 

 difficulty I have found in obtaining them of a constant com- 

 position, seems to demand so much more time for perfecting 

 the investigation than the interest of the subject promises to 

 compensate for, that I have been induced to leave it for a 

 more inviting object of research. 



Durham, April, 1838. 



LXXXIV. Proceedings of Learned Societies, 



GEOLOGICAL SOCIETY. 



[Continued from p. 291.*] 



December 13, 1837.— A paper " On the Geology of the South- 

 east of Devonshire ;" by Robert Alfred Cloyne Austen, Esq., F.G.S., 

 vjras read. 



The district described in this memoir, is included within the rivers 

 Exe and Dart, and extends from the coast to the granitic region of 

 Dartmoor. 



The formations of which it consists, are first noticed, then the 

 faults, and, lastly, the probable amount of effects produced at each 

 period of disturbance. 



1. Formations. — These are considered under two heads : — 1st. ac- 

 cumulations produced by actual causes ; 2ndly, those produced by 

 causes in operation before the most recent disturbances, including 

 tertiary, secondary, transition, and igneous deposits. 



The first of these subdivisions contains a description of the shingle, 

 sand-hills, estuary deposits, and peat-bogs ; but the south-east of 

 Devonshire presents no phenomena connected with them, deserving 

 of particular notice. 



Tertiary Deposits. — ^To this class Mr. Austen assigns the {a.) 

 raised marine deposits in estuaries, and {b.) raised beaches ; (c.) the 

 accumulations of water- worn rocks in valleys ; {d.) the Bovey de- 

 posit ; (e.) ossiferous caves ; and (/.) the bed of angular chalk flints, 

 and chert on Haldon and Blackdown. 



(a.) Raised Marine Estuary Deposits are considered to exist in the 

 valleys of the Exe and the Otter, because those rivers, in their 



• We now resume our notice of papers read before the Society, which 

 has been interrupted by the Anniversary Proceedings, as detailed p. 433 

 et seq. 



