British Association for the Advancement of Scie7ice. 27 



Changes of Level. — Mr. Smith, of Jordan Hill, made some 

 observations on the changes of level of land and sea, that have 

 last taken place, instanced by the occurrence of recent marine 

 shells and gravel at various elevations. He mentioned the shores 

 of the Sohvay Frith, and of Ayrshire, the neighborhood of Pais- 

 ley : also Portrush in the northern part of Ireland, and the late 

 observations of Mr. Lyell, in Sweden. The alluvial clay of the 

 Forth is elevated sixty feet, that of Essea one hundred and fifty 

 feet ; indeed, recent shells have been found by Mr. Gilbertson in 

 some places at an elevation of three hundred feet. On the shores 

 of the Clyde, over a deposit of erratic blocks, is a stratum of shells, 

 which contains fourteen new species not now found in the river ; 

 this is a singular occurrence, as in other parts of Great Britain the 

 erratic blocks overlie the newer Pleiocene strata, to which Mr. 

 Smith refers this stratum. 



Silica in Plants. — Prof Henslow stated, that he believed the 

 object of the author was to prove, that all plants contained more 

 or less silica ; that the silica left after burning assumed ditFerent 

 forms, according to the species of plants, and that this process 

 might probably be applied to the investigation of the species of 

 fossil plants. 



Groliathus Magnus. — A specimen of the Goliathus magnus, 

 was also exhibited. This is the largest species of insect known, 

 measuring three or four inches in length, and one and a half in 

 breadth. It is also very rare, only three specimens existing at 

 the present time in the cabinets of Europe. It was one of the 

 rarest insects known. It had been offered for sale at the price of 

 fifty guineas, and he had himself offered twenty guineas for a 

 specimen. It belonged to the extensive family of the Cetonidas. 

 This family was one of the most extensive and best known 

 groups of insects that we possessed, and afforded the best oppor- 

 tunities for acquiring ideas of general arrangement. It contained 

 six hundred species, only six of which were British. The family 

 JBuprestidfB, perhaps equalled them in numbers. 



Wood in the Sea. — The President then exhibited some wood 

 from the new pier at Southampton, that had been attacked by the 

 Limnoria terebrans. He had been applied to, by Capt. Du Cane, 

 mayor of Southampton, for his opinion as to what was the best 

 course to be pursued, as the existence of the pier was threatened 

 by these devastating animals. He had recommended, that stone 



