47^. 



and diforder, as he himfelf defcribes ? and how comes it that his lava 

 (which muft have been in an high ftate of fluidity, to admit its paflage 

 through fuch narrow crevices^ ftops in every fingle infbnce when it 

 reaches the furface, without fpreading along it when its confinement 

 was at an end ? 



The next topic I fliall mention, feems to me of itfelf decifive againft 

 Dr. Mutton's theory ; I mean, columnar bafalt, which he never once no- 

 tices. This is the more extraordinary, as he feems to have feized as his 

 piivate property, all the varieties of bafalt, calling it uncrupted lava, 

 fufed in his own fubmarine laboratory. He complains of the Velcanifis 

 for invading this property, and gives marks and tokens by which his 

 unerupted lavas (bafalts) may be at once diftinguiflied from their 

 erupted lavas, the obvious product of volcanos. 



Still, however, columnar bafalt, the moft curious and important part 

 of his property (as having of late excited fo much attention} efcapes 

 him ; no doubt it would have embarrail'ed him to account for the 

 fteady vertical pofition which thcfe pillars retain in moft places, after 

 the fubverlion and jumble of his ftrata, which he fo particularly de- 

 fcribes. There are, I know, in other countries, inftances where thefe 

 columns deviate conCderably from perpendicularity; with us (where 

 fuch colonades are without number) the deviations are few and 

 trifling ; and even on thefe occalions, though the pillars are de- 

 ranged, the ftratum is undiilurbed ; for 1 cannot call the depreflions 

 that occur in a few places, a difturbance, Cnce the ptrmanent and de- 

 prefled ftrata, continue to preferve a fteady parallelifm to each other. 



Mr. Playfair is more particular on the fubjeft of bafalt than Dr, 

 Hutton, and, as ufual, more clear ; but each of them, feparately, gives 

 fuch an account of this foflii,. its departmeat in the operations of 

 nature, and its arrangement when expofed to our view, as excites 

 my aftonifliment. It has been my misfortune already to differ often 

 from them, both as to fafts, and opinions ; but when they come to 

 treat of bafalt, my contradidions muft be much more decided ; for 



though 



