288 COSMOS. 



We have now passed through the whole series of forma- 

 tions comprised in the geological portion of the present work, 

 proceeding from the oldest erupted rock and the most ancient 

 sedimentary formations to the alluvial land on which are 

 scattered those large masses of rock, the causes of whose 

 general distribution have been so long and variously dis- 

 cussed, and which are, in my opinion, to be ascribed rather 

 to the penetration and violent outpouring of pent-up waters 

 by the elevation of mountain-chains, than to the motion of 

 floating blocks of ice.* 1 The most ancient structures of the 

 transition formation with which we are acquainted are slate 

 and greywacke, which contain some remains of sea weeds 

 from the siluriaii or cambrian sea. On what did these so- 

 called most ancient formations rest, if gneiss and mica schist 

 must be regarded as changed sedimentary strata? Dare we 

 hazard a conjecture on that which cannot be an object of 

 actual geognostic observation? According to an ancient 

 Indian myth, the earth is borne up by an elephant, who in his 

 turn is supported by a gigantic tortoise, in order that he may 

 not fall ; but it is not permitted to the credulous Brahmins to 

 inquire on what the tortoise rests. We venture here upon a 

 somewhat similar problem, and are prepared to meet with 

 opposition in our endeavours to arrive at its solution. In the 

 first formation of the planets, as we stated in the astronomical 

 portion of this work, it is probable that nebulous rings revolv- 

 ing round the sun were agglomerated into spheroids, and 

 consolidated by a gradual condensation proceeding from the 

 exterior towards the centre. What we term the ancient 

 siluriau strata are thus only the upper portions of the solid 

 crust of the earth. The erupted rocks which have broken 

 through and upheaved these strata, have been elevated from 

 depths that are wholly inaccessible to our research; they 

 must, therefore, have existed under the silurian strata, and 

 been composed of the same association of minerals which we 

 term granite, augite, and quartzose porphyry, when they are 

 made known to us by eruption through the surface. Basing 

 our inquiries on analogy, we may assume that the substances 

 which fill up deep fissures and traverse the sedimentary strata, 



* Leopold von Buch, in the AWiandl. der Alcad. der Wissensch. zu 



Berlin, 1814-15, s. 161; and in Poggend., Annalen, bd. ix. s. 575; 



1 Elie de Beaumont, in the Annales des Sciences Naturelks, t. xix. p. 60. 



