II 



Volcanos and Earthquakes. 351 



also be produced by gaseous exhalations in the interior of the 

 globe. At least in many accounts of earthquakes, mention is 

 made of the exhalation of gases from rents, produced by 

 them,* and the smell of sulphuric acid and of sulphurous va- 

 pours, which indicate the presence of sulphuretted hydrogen.f 

 These last may have occasioned also the destruction of the fish 

 in the sea, and in lakes, during earthquakes ; many instances of 

 which are known. The bursting forth of flames from the earth 

 and from the sea, which is so often mentioned,J also indicates 

 the presence of inflammable gases. However, although this is 

 corroborated by the fire-damp in mines, the disengagement 

 of sulphuretted hydrogen while boring artesian wells, and 

 the not uncommon exhalations of inflammable gas from the 

 earth, yet it is difficult to account for their inflammation. 

 This difficulty would disappear, if observation had found flames 

 only to occur in really volcanic districts. || But at any rate, 



* Von Humboldt, Reise, t. i. p. 499. Von Hoff in Poggend. Ann. t. vii. 

 p. 292, t. ix. p. 593, t. xxv. p. 76. V. Humboldt believes indeed, that 

 during most earthquakes, nothing arises from the earth ; but there are 

 on the contrary, proofs that gases are often gradually evolved from the 

 ground before and after the shocks. The uneasiness of small animals, or 

 those whose organs of respiration are rather feeble, before and after earth- 

 quakes, lead us to infer this. Le Gentil (Nouveau Voyage autour du Monde? 

 t. i. p. 172) has already obsei-\ed, that animals living in holes, as rats, mice, 

 reptiles, &c., commonly quit their abodes shortly before earthquakes. Cro- 

 codiles quit their pools in the Llanos, and remove to the continent, Rdat. 

 Hist. t. v. p. 57. Von Humboldt moreover relates that dogs, goats, and par- 

 ticularly hogs, which have a keen smell, and turn up the ground, are sud- 

 denly affected, and a great number of these latter animals have been found 

 suffocated during the earthquakes in Peni. 



+ Von Humboldt, ibid. t. i. p. 484, and t. ii. p. 73. Von Hoff, ibid. t. xii. 

 p. 567, t. xviii. p. 46. See also Philos. Trans, t. xlix. p. 415. 



J Von Humboldt, ibid. Gehler's Physikal. Wiirterbuch, new edit., t. iii* 

 p. 804. Also during the earthquake of Lisbon (Philos. Trans, ibid.) and on the 

 island of Matschian (Hist, de la Conquete des MoUuques, t, iii.p. 318) the 

 bursting forth of flames is reported to have taken place. 



II Von Humboldt mentions flames which rise from time to time out of two 



extensive caverns in the ravine of the Cuchimno. This phenomenon was 



accompanied, during the last great earthquake at Cuinami, with a continued 



. hollow subterranean noise. These flames are more especially to be seen 



during the rainy season. 



