60 Proceedings of the British Association. 



the masses of ice, not being there confined between two sides of 

 a valley, their movements were in some respects different, — the 

 boulders not being connected in continuous ridges, but dispersed 

 singly over the Jura at different levels. Prof. A. conceives that at 

 a certain epoch, all the North of Europe, and also the North of Asia 

 and America, were covered with a mass of ice, in which the ele- 

 phants and other mammaha found in the frozen mud and gravel 

 of the arc.tic regions, were imbedded at the time of their destruc- 

 tion. He thinks that when this immense mass of ice began 

 quickly to melt, the currents of water that resulted, transported 

 and deposited the masses of irregular rounded boulders and gravel 

 which fill the bottoms of the valleys ; innumerable boulders hav- 

 ing at the same time been transported together with mud and 

 gravel, upon the masses of the glaciers then set afloat. Prof. A. 

 announced that these facts are explained at length in the work 

 which he has just published, ' Etudes sur les Glaciers de la Suisse,' 

 illustrated by plates. 



Mr. Jeffreys detailed an experiment he had made on a very great 

 scale, to decide the question, whether silicious matter could be 

 dissolved largely by water, or what is the same thing, by its va- 

 por. This experiment formed the subject of a pap^r, read some 

 months ago before the Royal Society, and by the experiment a 

 solution of more than 200 lbs. of silica was effected in steam, at a 

 heat exceeding that of fused cast-iron. The steam was not un- 

 der pressure, but was conducted into a large kiln used for stone 

 pottery. The silica was not only dissolved, but carried away in 

 the vapor, and some pounds weight of it were deposited from the 

 vapor, before it issued from the kiln, like ahoar frost, upon some ar- 

 ticles in the kiln, where the temperature was not above a red heat. 



The following papers were also read, but our limits permit us 

 to give only their titles. 



On the relative level of land and sea, and on the alteration of the east coast of 

 England; by Mr. Stevenson. 



On the superficial beds in the neighborhood of Glasgow ; by Mr. Smith of Jordan 

 Hill. 



On the Geology of Canada; by Capt. Baddeley. 



On the Silurian rocks of Llangollen, and on a plateau of igneous rocks on the 

 east flank of the Berwyn range; by Mr. Bowman. 



On ancient sea cliffs and needles in the cljalk of the valley of the Seine, in Nor- 

 mandy ; by Charles Lyell. 



On the geology of the island of Arran ; by A. C. Ramsay. 



On the geology of Castle Hill, Ardrossan ; by Wm. Keir. 



On the value of topographical maps and models, with a map of the county of 

 Mayo, in Ireland ; by Mr. Bald. 



