18 



It is the opinion of some, that the increase and ex- 

 tent of alluvial formations or deposites, depends more 

 or less on the extent which a river or stream passes 

 through a secondary, or transition district ; inasmuch 

 as the substances which compose these two districts 

 are more liable to decomposition,* consequently liable 

 to be carried away, by the meltings of snows and hea- 

 vy rains, into the smaller streams, and from thence into 

 rivers, and deposited at their mouths. But this will 

 not hold good, 



The Connecticut river, and I believe some others 

 in the eastern states, runs through both ; particularly 

 the secondary formation, for a considerable distance, 

 and yet there is but a very small extent of alluvial for- 

 mation at its mouth. 



The same may be said of the Susquehanna and Po- 

 tomac rivers, each of which runs through both primi- 

 tive and transition formation ; yet it is a matter of 

 doubt, if we judge from appearances, whether there is 

 one foot more of alluvial formation at their influx into 

 the Chesapeake bay, than there was a thousand years 

 ago. 



An other opinion is, that alluvial formations are, in 

 some cases, occasioned by the retreat of the ocean, 

 which, it is believed by many, is constantly retreating, 

 and of course becoming less. 



Henry, (in his Travels iu Canada,) says in his re- 

 marks on the subsidence of the waters in that region.. 



* See Chapter 10th. 



