48 BULLETIN OF THE 



the Eocene has almost no connection with the present, or with 

 the Pleiocene. If, tl^eu, the period specified was sufficient to 

 account for the difference between tlie pre-glacial epoch and the 

 present, a term of 850,000 years would be entirely insufficient 

 for the period that must have elapsed since the commencement 

 of the Tertiary. 



90th Meeting. June 5, 1815. 



The President in the Chair. 

 Twenty-five members and visitors present. 



Mr. E. M. Gallaudet read a paper on 



UNCONSCIOUS cerebration, 



as evinced by mnemonic action ; citing various instances of per- 

 sons, scenes, and events suddenly recalled to the mind by per- 

 ceptions of sight, hearing, or touch, without any exercise of the 

 will. 



Remarks were made by Messrs. Hilgard, Henry, TxIylge, 

 and others. 



Mr. O. T. Mason exhibited 



ARCH^OLOGICAL SPECIMENS, 



stone implements of an early age ; describing them and others, 

 and giving a history of their discovery in Porto-Rico. 



Mr Baird remarked that Mr. GtEORGE Latimer, of Porto- 

 Rico, had made a large collection of such specimens, which he 

 had bequeathed to the Smithsonian Institution after refusing 

 $12,000 for them. 



Mr. Asaph Hall made a communication on 



approximate quadratures ; 



describing the various methods which had been employed in 

 determining approximately an area comprised between a curve, 



