Moj/al Geological Society of Cornwall. 305 



perty in heat, which, without entering into any speculations as to the 

 nature of those principles, appear to have a repulsive character in 

 common, indicated by a tendency to diffusion and equilibrium. He 

 conceives, that while some very delicate experiments in France have 

 given indications of the actual force exerted by heat equally diffused 

 through two adjoining masses, the energy in this case is produced 

 by the accumulated repulsive power in the last particles of the good 

 conductor, the current (without meaning anything hypothetical by the 

 term,) being suddenly cut short by the resistance opposed to its pas- 

 sage by the inferior conductor. The destructive energy of electricity 

 indicative of its repulsive force is never exerted in a state of equili- 

 brium, but by the accumulation of separate repulsive energies which 

 takes place in the transition from a good to a bad conductor, or during 

 its passage through the latter. 



ROYAL GEOLOGICAL SOCIETY OF CORNWALL. 



Twentieth Annual Report of the Council. 



" The Fourth Volume of Transactions, reported at the last Meeting 

 as being in the press, has since been published j and the Council 

 have great pleasure in stating that it has attracted considerable at- 

 tention, and lias been most favourably noticed by several distinguished 

 geologists. Its leading feature, Dr. Boase's paper on the Geology of 

 the County generally, adduces many facts at variance with the pre- 

 vailing theories, and advances some peculiar notions, which have given 

 rise to much discussion, and awakened a novel interest in the inves- 

 tigations of Primary Geology. The Council, therefore, earnestly hope 

 that Dr. Boase will be induced to prosecute, in all its details, a sub- 

 ject which forms so important a part of the objects of this Society. 

 The Volume also contains much additional and curious information 

 on the recent deposits of Cornwall. 



" Mr. Henwood's progress in the survey of the mines has been re- 

 tarded by the duties of an office in the Duchy, obtained for him by 

 the application of the Society to their patron, His Most Gracious Ma- 

 jesty. He has, however, already examined the principal mining 

 districts, and made a variety of experiments on the electro* magnetism 

 of veins, and on the intensity of terrestrial magnetism : their results 

 have brought to light some additional facts, by the accumulating of 

 which alone, we may expect to arrive at any satisfactory conclusions 

 on these obscure but interesting phenomena. 



" Several donations of mineralogical and geological specimens have 

 been received by the Society during the past year, which will be par- 

 ticularized in the Curator's Report. Since Mr. Carne's list of the 

 minerals found in St. Just was published in our Second Volume, a 

 considerable number have been discovered, not before known to exist 

 there, of which he has now given a descriptive account: and the 

 Council rejoice that he is still labouring in that field which he has 

 hitherto so successfully cultivated. 



" These numerous contributions have so nearly filled the cabinets, 

 that it cannot be long before some additional accommodation will be 



Third Series. Vol. 3. No. 16. Oct. 1833. 2 R 



