BRITISH ASSOCIATION. 



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were found alternating with them. He then pointed out 

 different modes in which the igneous rocks affected the beds 

 with which they were associated^ and stated that he agreed 

 with Mr. Lyell in considering, that where two beds are 

 differently affected by such contact, it was owing to dif- 

 ferences in their chemical constitution. The phenomena of 

 volcanic eruptions he attributed to the chemical action of 

 certain substances existing in the interior of the earth, either 

 amongst themselves, or by coming in contact with water. 



Sir H. De la Beche stated, that in the Silurian region there was 

 decided evidence of eruptions corresponding to the volcanic action of the 

 present day ; there were beds of volcanic ash of the same chemical com- 

 position as trap, and, when consolidated, undistinguishable from green- 

 stone, but containing organic remains ; and these deposits occurred in 

 the series mingled with solid igneous rocks, and were evidently the result 

 of the same general cause. He, therefore, contended that modern vol- 

 canic action, as it was termed, was not confined to recent periods. 



Dr. Buckland was gratified to observe the steady advancement of 

 the opinions founded by Hutton, and remarked as an act of justice, that 

 Dr. M'Culloch was the first to entertain those views as to the origin of 

 gneiss, mica slate, &c. which regarded them as rocks altered more or less 

 by heat, up to the extreme amount of alteration nearest fusion. 



Prof, Owen's Report on Fossil Mammalia, 



The first part of the Report communicated by Prof. Owen, in- 

 cluded the fossil Quadrumana^ Cheiroptera, Insectivora, Car- 

 nivora, Rodentia, Marsupialia, and Cetacea of Great Britain. 

 This enunciation alone made known the Professor remarked, 

 the surprising fact, that one order of mammalia, the Marsu- 

 pial, had now totally disappeared from the Old World, and a 

 second order, recognised as European only, by the few 

 monkies which breed on the rock of Gibraltar, had formerly 

 representatives in the land now constituting the British 

 islands. The existence of a species of Macacus has been 



