220 THEORY of the EARTH. 



Andes *, there mall be found one cockle-fhell, or piece of coral, 

 it muft be concluded, that this bed of ftone had been original- 

 ly formed at the bottom of the fea, as much as another bed 

 which is evidently compofed almofl altogether of cockle-fhells 

 and coral. If one bed of limeftone is thus found to have been 

 of a marine origin, every concomitant bed of the fame kind 

 muft be alfo concluded to have been formed in the fame man- 

 ner. 



WE thus mall find the greateft part of the calcareous mafles 

 upon this globe to have originated from marine calcareous bo- 

 dies ; for whether we examine marbles, limeftones, or fuch fo- 

 lid mafles as are perfectly changed from the ftate of earth, and 

 are become compact and hard, or whether we examine the foft, 

 earthy, chalky or marly ftrata, of which fo much of this earth 

 is compofed, we ftill find evident proofs, that thofe beds had 

 their origin from materials depofited at the bottom of the fea ; 

 and that they have the calcareous fubftance which they contain, 

 from the fame fource as the marbles or the limeftones, 



2^/y, IN thofe calcareous ftrata, which are evidently of ma- 

 rine origin, there are many parts that are of a fparry ftru<5lure, 

 that is to fay, the original texture of thofe beds, in fuch places, 

 has been diflblved, and a new ftructure has been aflumed, 

 which is peculiar to a certain ftate of the calcareous earth. 

 This change is produced by cryftallization, in confequence of 

 a previous ftate of fluidity, which has fo difpofed the concreting 

 parts, as to allow them to aflume a regular ihape and ftruclure 

 proper to that fubftance. A body, whofe external form has 



been 



* " CETTE fbmmite elevee de 984 toifes au deffas de notre lac, et par confequent de 

 " 1172 au deilus de la mer, eft remarquable en ce que 1'on y voit des fragmens d'hultres 



" petrifies. Cette montagne eft dominee par un rocher efcarpe, qui s'il neft pas in- 



" acceflible, eft du moins d'un bien difficile acces} il paroit prefqu'entierement compose 

 " de coquillages petrifies, renfermes dans un roc calcaire, ou marbre groflier noiratre. 

 " Les fragmens qui s'en detachent, et que 1'on rencontre en montant a la Croix de fer, 

 " font remplis de turb.inites de differences efp.eces." M. DE SAUSSURE, Voyage dans .let 

 Jlpes, p. 394. 



