258 On Salt Marsh. 



and storms add to the depository, until this alluvion rises 

 above low water mark ; and being then more or less un- 

 der the influence of the sun and atmosphere, it gives 

 birth to docks, reeds, grasses and mosses, of various sub- 

 stances and properties, according to the quantity of heat 

 or moisture, or to the operation of some other agents in 

 nature. This herbage arrests the particles of mud float- 

 ing over and through it, when the tide is high enough to 

 cover the flats, and detains such portions as have suffi- 

 cient gravity and adherence to resist the impetus of the 

 current : hence, in some places, the mud-flat enlarges its 

 dimensions, in width and height, till the height is that of 

 high water mark ; and, in other situations, the force of 

 water, in more rapid transit, carries away, at a single tide, 

 whatever had been left the preceding one ; such force be- 

 ing just sufficient to allow the shoal to rise to a certain 

 height, and no higher : this may account for the lowness 

 of the Pea Patch and Reedy Island, at the head of Dela- 

 ware bay ; while the opposite marshes, on either shore, 

 are raised to the level of ordinary high tides. 



The wild grasses have never been properly classed ; 

 and for want of a nomenclature, as well as from a la- 

 mented deficiency of science, I am unable to represent 

 the several aquatic plants ; but as grasses and soils are 

 so intimate, I must note some of the most predomi- 

 nant of those, that my account of these may be intelligi- 

 ble. I shall not attempt to assign a reason for the differ- 

 ence of vegetables that grow on salt marsh, from those 

 which spring from fresh mud, barely stating that there 

 is a difference, and that the grasses of the former are 

 much more abundant, and in their natural state more use- 

 ful, as they afford tolerable pasture for cattle. The great- 



