ROCK. 



foon after fought for and difcovered. — A great part of the tile foils, are precifely thofe which decompofe with the 

 mountain fituated above that which had fallen was com- greatefl rapidity, whilft thofe which are unfavourable to ve- 

 pofed of earth and (tones, not difpofed in beds, but con- getation refill, for ages, the effects of atmofpheric influence. 



fufedly heaped together. I thus perceived that the moun 

 tain had been fubject to fimilar falls, which had left the 

 large rock that fell this year without a fupport, and with 

 a confiderable projection. This rock was compofed of 

 horizontal beds, of which the lower were of flate, or rather 

 of fragile fchiftofe flone of little confiltency, while the two 

 beds beneath thefe were of marble like that of Porto Venere, 

 but full of fiflures, which eroded the beds. The fifth bed 

 was wholly compofed of flate in vertical plates, entirely dif- 

 united ; this bed formed all the upper part of the fallen 

 mountain. Upon the fame level fummit were three lakes, 

 the waters of which penetrated conftantly through the fif- 

 fures of the beds of rock, and decompofed their fupports. 

 The fnow, which had fallen in Savoy in greater abundance 

 than had ever been feen in the memory of man, increafed 

 the effect, and the united waters occafioncd the fall of three 

 million cubic fathoms of rock, a mafs fufficient to form 

 a large mountain." 



On the 2d of September 1806, at five in the evening, 

 the Knippenhoul rock, which formed the fummit of mount 

 Rofenberg, was on a fudden detached from its fituation ; 

 and at the fame time part of the mountain, about 280 feet 

 thick on the eaft fide, and feveral feet thick on the weft, 



It can fcarcely be denied that this beneficent provifion of 

 the Author of nature, is ordained to repair the conftant wafte 

 and change which are taking place on the furface. 



" Nee fpecies fua cuique manet, rerumque novatrix 

 Ex aliis alias reparat natura figuras." Ovid. 



The formation of rocks, or the procefs by which they ac- 

 quired their prefent form and confidence, may, perhaps, 

 ever remain a fubject of uncertain fpeculation, as no ana- 

 logous formations are now taking place, except in one clafs 

 of rocks, the volcanic. 



Some geologifts contend that all the folid materials in the 

 mineral kingdom were once in a ftate of aqueous folution, 

 from which rocks and itrata were formed, partly by chemical 

 precipitation, and partly by fediment ; the lower cryftalline 

 rocks being entirely chemical products, the intermediate or 

 tranlition partly chemical and partly mechanical depofitions; 

 and the upper rocks and ftrata principally mechanical, or 

 formed of fediment or the fragments of former rocks. It has 

 been objected to this hypothefis, that neither the elementary 

 fubltances, nor the compounds of which rocks are formed, are 

 foluble in water. In reply to this it has been contended, that 

 though the fubilances called elementary are infoluble, in all 



gave way, and fell into the valley which feparates the lake probability there was a time when they exiited in amorefimpL 



uncombined ftate; and that the more Ample elements werconce 

 foluble in water, though the prefent fubftances called ele- 

 mentary are not fo ; in the fame manner as very foluble fub- 

 ftances are known to become nearly infoluble by chemical 

 union with each other, of which we have an inftance in the 

 tartareous acid and potafh, which are both very foluble, but 

 when united in certain proportions, they form a fait that 

 can only be dillolved in twenty times its weight of water. 

 According to thefe geologifts, the quantity of water which 

 once covered the whole globe mull have been much greater 

 than at prefent ; but in what manner it has been diminifhed 

 they do not attempt to explain. 



Other geologifts fuppofe that mofl of the rocks, whether 

 ftratified or not, were formed of the fand, or fediment, wafhed 

 down from former continents, and that they have acquired 

 their prefent llructure and hardnefs from the action of a 

 central fire, which they believe to exift conftantly in our 

 planet, but which is called into greater activity at certain 

 periods by laws with which we are unacquainted. Accord- 

 ing to the fyftem of thefe philofophcrs, the prefent conti- 

 nents were raifed from the bottom of the ocean by the action 

 of the fame fire, and the rocks of bafalt and porphyry were 

 forced through, and fpread over, the furface in a ftate of 

 fufion, like currents of lava from active volcanoes. It mufl 

 be admitted, that the only inftances we have of the formation 

 of rocks, in our own times, are from the agency of fire ; and 

 that lonie of the lavas prefent the cryftalline internal llruc- 

 ture, or contain imbedded cryftals as perfect as thofe found 

 in primary rocks. It is foreign to the purpofe of this article 

 to difcufs the probabilities of thofe two theories which have 

 acquired the names of the Neptunian and Plutonian, for an 

 account of which, fee Eahtii. The defcent of Itony 

 mafles from the atmofphere, (bmetimea oi great fixe and 

 weight, is now fully proved ; and the formation of thefe 

 flones, bom the concretion ot gafeOUB matt) r, may probably 

 throw fome light ultimately on the moll abltrufe queftions in 

 geology, and lead to new, and more correct, views of the 

 nature of our planet. Perhaps the different primary beds 

 of ftone, that environ the globe, wire formed by fimilar 

 concretions from an atmofphere of vail extent. Of one 



thing 



of Zug from that of Lauwertz. One part of the moua 

 tain fell into the lake of Lauwertz, which caufed fuch an 

 agitation in the waters of the lake, that they overthrew a 

 number of houfes, chapels, mills, &c. along the northern 

 fhore. Upwards of 1000 perfons were the victims of this 

 calamity. A fociety of thirteen travellers were on the 

 road from Arth to Schwetz ; nine who walked firfl perifhed, 

 the other four efcaped. In this convulfion enormous pieces 

 of rock were carried through the air to prodigious diftances. 

 The lake of Lauwertz has loft about a quarter of its ex- 

 tent. That rich plain, before fo beautiful, now prefents a 

 mountain of 100 feet in height, ii league in length, and 

 as much in breadth. The villages of Goldau and Rothen, 

 confiding of 1 15 houfes; that of Bulingen, of 1 26; and that 

 of Kufiock, have totally difappcared. Of Lauwertz, which 

 had 25 houfes, there remain ten buildings, all much damaged. 

 Twenty years previoufly, general Pfyfler predicted this 

 cataftrophe, from the knowledge he had of the nature 

 of the mountain. A profefibr of Schwitz faid, that 

 above Spietsfleu there was a lake of water which had un- 

 dermined the rock for feveral years, and that below there 

 was a cavern of great depth, where the waters were in- 

 gulphed. The quantity of water which had fallen during 

 the preceding years haftened the cataftrophe, and the rains 

 of fome preceding weeks decided it. On the iotli, eight 

 hundred perfons were employed in digging for the bodies of 

 thofe who were deftroyed by the falling of the mountain. 

 In forming a channel to draw off the waters, between thirty 

 "id forty labourers were fwallowed up by a torrent of 

 muddy water which broke in upon them fuddenly. Annual 

 Regrfter, 1806, page 449. 



In the mountainous parts of North Wales, Cumberland, 

 and Weftmoreland, fimilar effects, on a diminutive fcale, 

 are taking place ; and the fcattered mafles of rock, fpread 

 widely over the fides and feet of the hills, prove that they 

 have once had a greater elevation. 



By the decay of rocks and mountains, new and pro- 

 ductive foils are formed to renovate the furface of the globe, 

 and fit it for the fupport of vegetable and animal life ; and it 

 has been remarked that thole rocks which form the moll fer. 



12 



