222 COSMOS. 



equally eruptive, black trachyte of the volcano of Tungu- 

 ragua covering a greenish mica-schist containing garnet near 

 the rope-bridge of Penipe. As sulphur has hitherto been 

 found in Europe, not in the primitive rocks as they were 

 formerly called, but only in the tertiary limestone, in gypsum, 

 in conglomerates and in true volcanic rocks, its occurrence 

 in the Azufral de Quindiu (4^ N. lat.) is the more remark- 

 able, as it is repeated to the south of the equator between 

 Quito and Cuenca, on the northern slope of the Paramo del 

 Assuay. In the Azufral of the Cerro Cuello (2 13' S. lat.). 

 again in mica-schist, at an elevation of 7980 feet, I met 

 with a vast bed of quartz, 79 in which the sulphur is dissemi- 

 nated abundantly in scattered masses. At the time of my 

 journey the fragments of sulphur measured only 6 8 inches, 

 but they were formerly found of as much as 3 4 feet in 

 diameter. Even a naphtha spring rises visibly from mica- 

 schist in the sea-bottom in the gulf of Cariaco near Cumana. 

 There the naphtha gives a yellow colour to the surface of the 

 sea to a distance of more than a thousand feet, and I found 

 that its odour was diffused as far as the interior of the pen- 

 insula of Araya. 80 



" 9 With regard to the elevation of Alausi (near Ticsan) on the Cerro 

 Cuello, see the " Nivellement barome'trique, No. 206," in my Observ. 

 Astron. vol. i, p. 311. 



80 " The existence of a naphtha spring issuing at the bottom of the sea 

 from a mica-schist, rich in garnets, and diffusing, according to the ex- 

 pression of the historian of, the Conquista, Oviedo, a " resinous, aromatic, 

 and medicinal liquid," is an extremely remarkable fact. All those 

 hitherto known belong to secondary mountains ; and this mode of stra- 

 tification appeared to favour the idea that all the mineral bitumens (Hat- 

 chett, Transact. Linncean Society, 1798, p. 129) were due to the destruc- 

 tion of vegetable and animal matters, or to the ignition of coal. The 

 phenomenon of the Gulf of Cariaco acquires fresh importance, if we 

 bear in mind that the same so-called primitive stratum contains subter- 

 ranean fires, that the odour of petroleum is experienced from time to 

 time at the edge of ignited craters (for example, in the eruption of 

 Vesuvius in 1805, when the volcano threw up scoria?), and that most of 

 the very hot springs of South America issue from granite (las Trin- 

 cheras, near Portocabello), gneiss and micaceous schist. More to the 

 eastward of the meridian of Cumana, in descending from the Sierra de 

 Meapire, we first came to the hollow ground (tierra hueca), which, 

 during the great earthquakes of 1766, threw up asphalte enveloped in 

 viscous petroleum ; and afterwards, beyond this ground, to an infinity 

 of hydrosulphurous hot springs (Humboldt, Relation Historique, t, i, 

 pp. 136, 344, 347, and 447). 



