On Earthquake- Shocks felt in Great Britain^ S^c. 137 



the land have been pierced by numerous out-bursts of igneous 

 and gaseous matters, accompanied by violent oscillations and 

 breaks, whereby the chronicles of succession have been sore- 

 ly defaced, and often rendered more illegible than the most 

 carbonized of the papyri found under the lava of Vesuvius. 

 Nay, so intensely has this metamorphism operated, that obli- 

 terating all vestiges of former life, and concealing them from 

 us, we have been sorely puzzled to ascertain by what power- 

 ful physical agency such mighty changes can have been ac- 

 complished, — changes by whiah the strata have been convo- 

 luted into forms grotesque as the serpent's coil, inverted in 

 their order, or shivered into party-coloured and crystalline 

 fragments. And yet in these broken and mineralized masses, 

 as another branch of our science teaches, are found the pre- 

 cious ores, and the metals most useful to mankind. 



Such complicated relations and such changes in original 

 structure call forth the application of the highest powers of 

 physical science; andnot only involving the agency of that great 

 central heat, to which geologists have willingly referred, but 

 also invoking the aid of agents, some of them still mysterious, 

 by which electricity and magnetism are bound together in the 

 cycle of terrestrial phenomena. To few of us is it given to 

 venture with firm steps into that region ; and, though I hope 

 to live to see some of these questions answered, I am well sa- 

 tisfied to have been among you when such solid advances 

 have been made, in deciphering the mutations of the surface 

 of the earth, and in the compilation of a true history of its 

 earlier inhabitants. 



Notices of Earthquake- Shocks felt in Great Britain, and espe- 

 cially in Scotland, icith inferences suggested by these notices as 

 to the causes of the Shocks. By David Milne, Esq., F.R.S.E., 

 M.W.S., F.G.S., &;c. Communicated by the Author. 



(Continued from Yol. XXXIV. page IOC.) 



Having described in detail, the impressions produced in 

 ditferent parts of Scotland, by the shock of an earthquake felt 



