INFLAMMABLE EXHALATIONS. 67 



disengagement of hydrogen.* When travellers, who ore not 

 acquainted with natural inflammable gases, are shown the 

 Cueva del Serrito de Monai, the people of the country love 

 to frighten them by setting fire to the gaseous combination 

 which is constantly accumulated in the upper part of the 

 cavern. M^y we attribute the insalubrity of the atmosphere 

 to the same causes as those which operate in the plains be- 

 tween Tivoli and Home, viz., disengagements of sulphuretted 

 hydrogen ?f Possibly, also, the mountainous lands, near 

 the llanos of Monai, may have a baneful influence on the 

 surrounding plains. The south-easterly winds may convey 

 to them the putrid exhalations that rise from the ravine 

 of Villegas, and from La Sienega de Cabra, between Carora 

 and Carache. I am desirous of collecting every circum- 

 stance having a relation to the salubrity of the air ; for, in a 

 matter so obscure, it is only by the comparison of a great num- 

 ber of phenomena, that we can hope to discover the truth. 



The barren yet feverish savannahs, extending from Ear- 

 quesimeto to the eastern shore of the lake of Maracaybo, are 

 partly covered with cactus; but the good silvester-cochineal, 

 known by the vague name of grana de Carora, comes from a 

 more temperate region, between Carora and Truxillo, and 



* What is that luminous phenomenon known under the name of the 

 Lantern (farol) of Maracaybo, which is perceived every night toward the 

 seaside as well as in the inland parts, at Merida for example, where M. 

 Palacios observed it during two years? The distance, greater than 40 

 leagues, at which the light is observed, has led to the siipposition that it 

 might be owing to the effects of a thunderstorm, or of electrical explo- 

 sions which might daily take place in a pass in the mountains. It is 

 asserted that, on approaching the farol, the rolling of thunder is heard. 

 Others vaguely allege that it is an air-volcano, and that asphaltic soils, 

 like those of Mena, cause these inflammable exhalations which are so 

 constant in their appearance. The phenomenon is observed on a moun- 

 tainous and uninhabited spot, on the borders of the Rio Cutatumbo, near 

 its junction with the Rio Sulia. The situation of the farol is such that, 

 being nearly in the meridian of the opening (boca) of the lake of Mara- 

 caybo, navigators are guided by it as by a lighthouse. 



t Don Carlos del Pozo has discovered in this district, at the bottom of 

 the Quebrada de Moroturo, a stratum of clayey earth, black, strongly 

 soiling the fingers, emitting a powerful smell of sulphur, and inflaming 

 spontaneously when slightly moistened and exposed for a long time to 

 the rays of the tropical sun. The detonation of this muddy substance if 

 rery violent. 



* 5fi 



