226 CONTRIBUTIONS 



De la Beche very justly remarks, that " all the exam- 

 ples hitherto produced of deposits that can be fairly traced 

 to existing springs, are relatively unimportant," " though 

 they may lead us to understand how great geological de- 

 posits may, chemically, have taken place, as the cabinet 

 experiments of the chemist teach us the laws which go- 

 vern nature on the large scale."* 



We have, in the Geological Description of the Environs of 

 Paris, by Brogniart, p. 274, some account of the Freshwater 

 Formations, posterior to the Calcaire Grossier, which ex- 

 ist in Europe. They are found in Spain, France, Eng- 

 land, Switzerland, Germany, Hungary and Italy. These, 

 however, are more ancient than the deposit at Syracuse. 

 It is necessarry to bear in mind that these deposits are en- 

 tirely distinct from that which Brogniart calls " calcaire 

 lacustre inferieur," which lies immediately over the Cal- 

 caire Grossier, in the Paris basin, contains extinct species, 

 and forms there a most important stratum of the series. 



We have an example of the strata of an age contem- 

 poraneous with that of Syracuse, in the valley of Elsa, in 

 Tuscany. Here, Mr Lyell says, " we meet with fresh 

 water marls and travertins full of shells, belonging to 

 species which now live in the lakes and rivers of Italy ."f 

 He tells us also, that valleys, several hundred feet deep, 

 have been excavated through lacustrine beds. 



In the Geological Transactions, volume second, the 

 same author mentions other calcareous deposits, which 



* Geological Manual, p. 138. 



t Principles of Geology, vol. 3, p. 137. 



