4S 



The following is the series of phenomena re- 

 marked on the northern coasts of Cumana, 

 Nueva Barcelona, and Caraccas ; and presumed 

 to be connected with the causes, that produce 

 earthquakes and eruptions of lava. We shall 



may contain strata of coal, with primitive porphyries." We 

 have just described earthquakes in lands entirely granitic, in 

 vast regions where, as on the banks of the Oroonoko, no other 

 formation, primitive or secondary, rests on the granite. We 

 shall soon see, that boiling springs gush out, as if by prefe- 

 rence, from granite and gneiss; and that the trachytes, or 

 trap-porphyries of the Andes, far from belonging to the 

 formation of red sandstone, or to those Jlcetzporphyries which 

 Messrs. Steffens and Freiesleben have so well described, issue 

 in the midst of volcanic lands from mica-slate and gneiss. The 

 nature and disposition of the strata in the interior of the 

 Earth, especially in primitive formations, appear to me but 

 little favourable to the hypothesis of a great pile, the action 

 of which occasions shocks at the surface of the Globe, and 

 causes (by the chemical action of the electro-motive apparatus) 

 in brine springs and thermal waters so surprising a constancy 

 in their mixture and specific gravity. (Geogn. Aufi. f p. 322 

 and 335). A person who has lived a long time, like me, in 

 the Cordillera of the Andes, who has heard these explosions 

 propagated through the interior of the Globe, who has seen 

 those enormous effects of the heaving up of the earth, those 

 swollen masses, which, bursting, throw out immense quantities 

 of water, mud, and vapours, finds it difficult not to admit the 

 existence of cavities, of communications between the oxidated 

 part of the Globe, and that part which abounds in metalloids, 

 in sulphurets of silex, and other substances not oxidated* 

 See above, chap, ii, vol. i, p. 256; and chap, iv, vol. % 

 p. 237. 



