FACTS AND INFERENCES. 297 



been imported into England, and zealously patronized. But, how 

 could this alternate submersion of the strata, in salt water and fresh, 

 take place, without destroying their conformity? Convulsions of 

 such magnitude as to expel the sea, and introduce a fresh-water 

 lake, and again destroy the lake, and restore the sea, could not have 

 occurred, without violently agitating and breaking the strata, so that 

 there could be no conformity or parallelism between beds thus de- 

 posited. Is it possible, that, after depositing the alum shale and the 

 dogger, the sea, in this quarter, gave way to a mighty lake, which 

 formed our coal strata; that this lake was, in its turn, expelled, the 

 sea returning to form the blue limestone; that the fresh-water again 

 prevailed, but after leaving the crow-stone beds as monuments of its 

 prowess, finally quitted the field, allowing old ocean to resume his 

 pristine sway ; — and that, during this dreadful struggle for the as- 

 cendancy, the operations of both agents proceeded in unison, so as 

 to leave no vestiges of the direful contest, not a trace of such mighty 

 revolutions? Some of the methods employed by the authors of this 

 hypothesis to bolster it up, betray a disposition to set up theory 

 against fact. In one of their supposed fresh-water formations, marine 

 shells of the genus cerithium were discovered. What then ? Must the 

 hypothesis be abandoned? By no means: — the sea-faring straggler, 

 being found in such company, is to be deemed a landsman, a new 

 fresh-water shell, and is therefore dubbed apotamides!* We wonder 

 that its presence was not rather imputed to the pranks of some mis- 

 chievous sea-gulls, who might amuse themselves in picking up shells 

 from the sea shore, and dropping them in the fresh-water lake ! 

 There is reason to suspect, that a great number of the supposed 

 fresh-water shells of these authors, are in reality marine shells; it 

 being difficult, in many cases, to distinguish between them. \ 



* Geological Transactions, II. p. 230, Note, 

 t It appears from llie experiments of M. Beudant, that some fresh-water shells may live 

 ill salt water, and vice versa. See Philosophical Magazine, Vol. XLVIII. p. 223. 



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