398 Proceedings of the Boyal Society. 



difference in point of fact long contested between them as to the equal 

 or unequal polarizability of heat from different sources. 



3. Account of the Fossil Species of the genus Sotarmm, La- 

 marck, found in the Supercretaceous group in Italy. By 

 M. le Chev. Michelotti of Turin. Communicated by Dr 

 Traill. 



^pril 5. — Sir T. M. Brisbane, Bart., G.C.B., President, in 

 the Chair. 



1. On the Parallel Roads of Glen-Roy. with an Examination 



of Mr Darwin's Theory of their Formation, Part II. By 

 Sir T. D. Lauder, Bart. 



2. On the Visibility of rapidly revolving Lights, made in re- 



ference to the Improvement of Light-Houses. By Alan 

 Stevenson, LL.B., Civil Engineer. 



^przt 19. — The Right Hon. Lord Greenock, V.P., in the 

 Chair. The following communications were read : — 



1. On the Theory and Construction of a Seismometer — an 



Instrument for Measuring Earthquake Shocks and other 

 Concussions. By Professor Forbes. 



2. On the Circulation of the Blood, and the Difference of the 



Laws of Fluids moving in Living and Dead Tubes. Part L 

 By Sir Charles Bell. 



3fay 3. — Right Hon. Lord Greenock, V.P., in the Chair. 

 The following communications were read : — 



1. Experimental Researches on the Production of Silicon from 

 Paracyanogen. By Samuel Brown, M.D. Communi-* 

 cated by Dr Christison. 



In his paper on Paracyanogen read to this Society at an earlier pe- 

 riod of the present session^ the author announced that he considered lie 

 had succeeded in proving, that two familiar bodies^ universally believed 

 to be distinct elements, are modifications of one and tlie same elemen- 

 tary form. In the present paper, he announced that the bodies in 

 question are carbon and silicon, and gave a detailed statement of the 

 invest igaljons by which he had been led to this conclusion* 



