48 



ments, and evidence, which Auvergne aflbrds, to enable him 

 to estabUsh his discovery, that columnar basalt is a volcanic 

 production, formed in currents of lava as they cooled. 



Fortunately, however, for science, and, I may say, for 

 truth, Mr. Desmarest is not the only naturalist who has 

 visited Auvergne, and published an account of its natural 

 history. Mr. Guetard, a professed mineralogist, twice made 

 a tour of Auvergne; and, Avith an interval of eight years, 

 twice he published his observations, in the same Trans- 

 actions with Mr. Desmarest. Should, therefore, any contra- 

 dictions occur between these two gentlemen, the reader 

 must decide between them as he best can: and, the bet- 

 ter to enable him, I remind, him, that, while Mr. Gue- 

 tard seems to have no other views, but what are purely 

 scientific; Mr. Desmarest has discovered his intention, of 

 making natural history subservient to his purposes. 



The Volcanic Theory, as laid down, and maintained, by 

 Mr. Desmarest, I have shewn before, turns entirely on one 

 question, to wit, whether what he pronounces to be cur- 

 rents of lava, actually floAved from any volcano ? I, there- 

 fore, in comparing Mr. Guetard's account of the same 

 country with his, shall limit myself merely to such facts 

 and observations, as promise to throw light on this 

 question. 



Mr. Guetard visited Auvergne in 1752, and again in 

 1760. He piques himself on discovering this country to 

 have been, at a remote period, ravaged by subterraneous 

 fires and eruptions. His attention seems much fixed on 



volcanic 



