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June 15, 1854. 

 The EARL of ROSSE, President, in the Chair. 



The following gentlemen having paid their Fees, were admitted 

 into the Society : 



James Apjohn, M.D. 

 Edward William Brayley, Esq. 

 Alexander Bryson, M.D. 

 John Bennet Lawes, Esq. 



Charles May, Esq. 

 Captain Richard Strachey. 

 Robert Dundas Thomson, M.D. 

 Samuel Charles Whitbread, Esq. 



The following gentlemen were elected Foreign Members of the 

 Society : 



Karl Ernst von Baer. 

 Michel Chasles. 

 Fried rich Wohler. 



The following papers were read : 



I. THE BAKERIAN LECTURE. " On Osmotic Force." By 

 Professor GRAHAM, V.P.R.S. 



This name was applied to the power by which liquids are im- 

 pelled through moist membrane and other porous septa in experi- 

 ments of endosmose and exosmose. It was shown that with a solu- 

 tion of salt on one side of the porous septum and pure water on the 

 other side (the condition of the osmometer of Dutrochet when filled 

 with a saline solution and immersed in water), the passage of the 

 salt outward is entirely by diffusion, and that a thin membrane does 

 not sensibly impede that molecular process. The movement is con- 

 fined to the liquid salt particles, and does not influence the water 

 holding them in solution, which is entirely passive : it requires no 

 further explanation. The flow of water inwards, on the other hand, 



VOL. VII. K 



