118 HISTORY OF MEXICO. 



to that continent. All other fyftems are fubjecl: to heavy 

 difficulties; even this is not without fome, but they are 

 not altogether insurmountable. The greateft confifts in 

 the apparent improbability of an earthquake fo great as 

 to fink a fpace of land of more than one thoufand five 

 hundred miles, which, according to our fuppofition, was 

 that which united Africa to America, and funk it fo 

 much as to the depth obferved in fome of the places of 

 that fea. But we do not afcribe that ftupcndous revo- 

 lution to one fmgle fhock, as there are in the bowels of 

 the earth fuch extenfive mattes of combuftible matter, 

 the inflammation of one could eafily communicate to 

 others, (in the fame manner as GafTendus explains the 

 propagation of lightning) and the violent concuffion of 

 the air, contained within thofe natural mines, could at 

 once fhake, agitate, and overwhelm a fpace of land of 

 two or three thoufand miles. This is not impoffible, 

 nor improbable, nor is hiftory unfurniflied with exam- 

 ples of it. The earthquake which was felt in Canada, 

 in the year 1663, overwhelmed a chain of mountains of 

 freeflone more than three hundred miles long, the whole 

 of that immenfe tract remaining changed into a plain. 

 How great then muft the convulfion have been which 

 was occafioned by thofe extraordinary and memorable 

 earthquakes, mentioned in the hiftories of America, 

 when the world was thought to have been coming to an 

 end ! 



It may be objected to our fyflcm, that if beafls pann- 

 ed by land from the one continent to the other, it is 

 not eafy to divine the caufe why fome fpecies pafTed 

 there without leaving a fmgle individual in the old con- 

 tinent ; and, on the contrary, that fome entire fpecies 

 fliould remain in the old continent, and not a fmgle in- 

 dividual of them pafs to America. Why, for example, 



did 



