252 COMPUTATION OF AGE [CHAP. XXXIV. 



freshwater are seen extending, from the various 

 mouths, in the flood-season, into the Gulf ; and still 

 more, the destruction of the banks and bars of mud 

 and sand caused by the tide scouring out the chan 

 nels when the river is low *, and the strength of 

 the marine current, running ten miles an hour, and 

 the stories of anchors and heavy ballast cast up by 

 the breakers high and dry on the shifting shoals 

 near the extremity of the delta, make me doubt 

 whether the larger part of that impalpable mud, 

 which constitutes the bulk of the solid matter car 

 ried into the sea by the Mississippi, is not lost alto 

 gether, so far as the progress of the delta is concerned. 

 So impalpable is the sediment, and so slowly does it 

 sink, that a glass of water, taken from the Missis 

 sippi, may remain motionless for three weeks, and 

 yet all the earthy matter will not have reached the 

 bottom. If particles so minute are carried by the 

 current, setting for a great portion of the year from 

 west to east, across the mouth of the river, into the 

 Gulf Stream, and so into the Atlantic, they might 

 easily travel to the banks of Newfoundland before 

 sinking to the bottom ; and some of them, which left 

 the head waters of the Missouri in the 49th degree 

 of north latitude, may, after having gone southwards 

 to the Gulf, and then northwards to the Great Banks, 

 have found no resting-place before they had wan 

 dered for a distance as far as from the pole to the 

 equator, and returned to the very latitude from 

 which they set out. Were it not for the peculiar 



* See ante, p. 154. 



