Foreign Literature and Science. 381 



account of Travels through part of the United States and 

 Canada, in 1818 and 1819, intended chiefly to illustrate 

 subjects connected with the Moral, Literary, and Religious 

 condition of the country. 



Those who enjoyed the pleasure of Mr. Duncan's 

 acquaintance, while travelling in this country, will expect 

 much from his intelligence and candor, and we confidently 

 believe they will not be disappointed. — Ed* 



3. Fossil Vegetables. — We have received from Mr. Adol- 

 phus Brongniart of Paris, a work "Sur la classification et la 

 distribution des Vegetaux Fossiles" — illustrated by litho- 

 graphic plates. It is an elaborate and valuable work and an 

 analytical notice of it by Dr. J. G. Percival will appear in 

 our next number. — Editor. 



Communicated by Dr. Jeremiah Van Rensselaer. 



4. Fresh water formations. — From the new edition of 

 Cuvier's work on Organic Remains, it appears that the fresh 

 water formations of Paris and Rome are precisely similar : 

 presenting the following order of succession from below up- 

 wards. 



1. A compact limestone analogous to the Jura limestone, 

 or even perhaps to chalk — rarely containing petrifactions. 



2. The coarse sandstone formation, composed at its low- 

 est part of bluish argillaceous marl, with shells, and towards 

 its upper part of reddish sandy limestone, and sometimes 

 of marine sandstone. 



3. The volcanic breccia, in all its modifications, lying 

 above this formation. 



4. The fresh water formation. 



Messrs. Brongniart and Brocchi, who have examined to- 

 gether these formations, conclude that there are two kinds 

 of fresh water formations, very distinguishable by external 

 characters, which indicate their difference of origin. The 

 one produced by solution and precipitation, more or less 

 pure and crystalline, has issued from the interior of the 

 earth with the waters which have carried them to the sur- 

 face of the soil. They may be formed at all elevations 

 where similar waters may have issued, and the height at 



