n 



His doubts he expresses thus, in his second letter to 

 Mr. St. Fond, trom Lisbon. He says, " can a mountain be 

 " called volcanic, Avhich is not conic, has no crater, is 

 " grouped with other mountains of a different species, 

 " which form, together, but one mass ? Can we say, that a 

 " volcano has burned in a country, where we find neither 

 " scoria, pumices, cinders, or puzzolana?" 



I must confess, Mr. Dolomieu assigns good reasons to 

 justify his doubts; which, however, he surmounts gradually; 

 for he tells us, he thinks, the difficulty may be got over, if 

 Ave concede to him, that the agitation of the waves destroyed 

 all other stones, except the basalts. 



At length, in his fourth letter, he pronounces himself 

 satisfied these mountains are volcanic, provid-ed his postu- 

 lates be granted to him; which are, " that there have been 

 " four revolutions, in this part of the globe; that the vol- 

 " canos were anterior to the last alluvion, and posterior ttf 

 " another sejour of the sea, which deposited the calcareous 

 " sti'ata, upon which these lavas are placed." 



Mr. St. Fond is just as ready as his friend, to make use of 

 revolutions, submersions, and deluges, to help him to get over 

 the difficulties, Avhich his favourite theory has to encounter. 

 He found, at Chamarelle, in Vivarais, what he calls a cur- 

 rent of lava, attended by many circumstances, incompatible 

 with the state of fluidity he ascribes to it. For instance: 



This lava has not only been able to penetrate the hardest 

 calcareous rocks, 7nais encore d'y circuler, tantot dans une sens, 

 tantot dans une autre; to cut, transversely, strata of consider- 

 able 



