2^BS 



There can be little doubt that this foot is a true sucker, and 

 that the animal sustains its position by means of atmospheric 

 pressure. When the foot is raised the same appearance is pre- 

 sented as when raising a moist sheet of paper from the table 

 by a string running across its centre. 



This is the only real suctorial foot I yet have met with. 



In conclusion, I may be allowed to express a hope that, 

 when the disappointment necessarily resulting from the break- 

 ing up of a long established notion has been overcome, the 

 new theory will be found equally beautiful with the old. 



Twelfth Meeting — April 7, 1851. 

 J. B. YATES, Esq., in the Chair. 



The Society confirmed the resolution of Council, that the 

 President should re-invite the British Association to hold their 

 meeting here in 1852, or as early thereafter as possible. 



Dr. D. P. Thomson called the attention of the Society to the 

 Pendulum experiment of M. Eoucault, and explained its nature. 



He then exhibited a Mineral from Carrock Pell, which 

 Mr. P. P. Marrat had ascertained by qualitative analysis to 

 contain cerium, a metal hitherto unknown in this country. 

 He submitted a series of specimens containing cerium in diffe- 

 rent combinations, as allanite, cerite, cerine, yttrocerite, and 

 fluocerite. 



Mr. J. P. G. Smith then read a Memoir On Temperatures 

 taken helow the Surface of the Ground. These observations 

 were begun in 1848, and are being continued with thermome- 

 ters sunk in his garden. Mr. Smith has been asked to con- 



