-59 



Again (page 230), he repeats the same common cause, 

 retraite et reserrement; in one case, the effect of desicca^ 

 tion; in the other, of refroidksement . 



I Avill not detain the reader, by shewing the folly of 

 lumping two causes for the same effect, so totally difi'e- 

 rent from each other, as desiccation and contraction: the 

 one arising from evaporation; the other from that pro- 

 perty, which all solid bodies seem to have, of expanding, 

 and contracting, with heat and cold. Nor Avill I dwell 

 on the utter insufficiency of either cause, to produce our 

 exquisitely neat and regular pillars, and especially their 

 highly finished articulations. 



It is to Mr. Desmarest's total ignorance of the facts, 

 attending this fossil, I call the attention of the reader: 

 for each cause, to which , he ascribes the formation of 

 basalt pillars, necessarily supposes intervals between them. 

 Every one knoAvs, that, on desiccation, cracks and inter- 

 vals are produced : and Mr. Desmarest himself (page 222), 

 explaining the formation of basalt prisms, by the other 

 process, contraction in cooling, says, " leur faces sont le 

 " resultat des fentes verticaks." 



But, unfortunately for Mr. Desmarest's credit, in basalt, ' 

 there are no intervals, no fentes, between the prisms, or 

 pillars: all are united together, into one solid mass, sepa- 

 rable from each other; but it is by external causes alone, 

 that they are actually separated. It is true, the pillars, in 

 our fapades, sometimes exhibit very small intervals, between 

 which, as Sir Torbern Bergman says, the point of a knife 



can 



