FREE BOOKS

Author's List




PREV.   NEXT  
|<   164   165   166   167   168   169   170   171   172   173   174   175   176   177   178   179   180   181   182   183   184   185   186   187   188  
189   190   191   192   193   194   195   196   197   198   199   200   201   202   203   204   205   206   207   208   209   210   211   212   213   >>   >|  
ns stalactiques dont elles s'ornent. Quelques-unes de ces grottes ne peuvent etre attribuees qu'a quelque bouleversement des couches; d'autres semblent devoir leur origine a l'ecoulement des sources souterraines qui ont amolli, ronge et charrie une partie de la roche qui en etoit susceptible. "En s'eloignant de la chaine, on voit les couches calcaires s'aplanir assez rapidement, prendre une position horizontale, et devenir abondantes en toute forte de coquillages, de madrepores, et d'autres depouilles marines. Telles on les voit par-tout dans les vallees les plus basses qui se trouvent aux pieds des montagnes (comme aux environs de la riviere d'Oufa); telles aussi, elles occupent tout l'etendue de la grande Russie, tant en collines qu'en plat pays; solides tantot et comme semees de productions marines; tantot toutes composees de coquilles et madrepores brisees, et de ce gravier calcaire qui se trouve toujours sur les parages ou la mer abonde en pareilles productions; tantot, enfin, dissoutes en craie et en marines, et souvent entremelees de couches de gravier et de cailloux roules." How valuable for science to have naturalists who can distinguish properly what they see, and describe intelligibly that which they distinguish. In this description of the strata, from the chain of mountains here considered as primitive, to the plains of Russia, which are supposed to be of a tertiary formation, our naturalist presents us with another species of strata, which he has distinguished, on the one hand, in relation to the mountains at present in question, and on the other, with regard to the strata in the plains, concerning which there is at present no question at all. Now, let us see how these three things are so connected in their nature, as to form properly the contiguous links of the same chain. The primary and tertiary masses are bodies perfectly disconnected; and, without a medium by which they might be approached, they would be considered as things differing in all respects, consequently as having their origins of as opposite a nature as are their appearances. But the nature and formation of those bodies are not left in this obscurity; for, the secondary masses, which are interposed, participate so precisely of what is truly opposite and characteristic in the primary and tertiary masses, that it requires nothing more than to see this distinction of things in its true light, to be persuaded, that in those three differen
PREV.   NEXT  
|<   164   165   166   167   168   169   170   171   172   173   174   175   176   177   178   179   180   181   182   183   184   185   186   187   188  
189   190   191   192   193   194   195   196   197   198   199   200   201   202   203   204   205   206   207   208   209   210   211   212   213   >>   >|  



Top keywords:

strata

 

masses

 
marines
 

tertiary

 

things

 

nature

 

tantot

 
couches
 

question

 

present


productions

 

gravier

 

distinguish

 
properly
 
mountains
 

formation

 

plains

 
considered
 

madrepores

 

bodies


opposite
 

autres

 
primary
 

supposed

 

Russia

 

primitive

 

requires

 

obscurity

 

secondary

 
respects

differing

 

presents

 

naturalist

 
persuaded
 

description

 
appearances
 
origins
 

distinction

 

differen

 
medium

participate

 
precisely
 
contiguous
 

perfectly

 

disconnected

 

connected

 

characteristic

 
distinguished
 
approached
 

relation