290 Mr. Bennet on the Island of Tenenffe. 



which constitute the central chain of the island, and which stretch 

 out as headlands like those of las Horcas and San Ursula, 



I never found in situ those masses of columnar basaltic rock that 

 are so common in the island of Madeira : but in the valley cf las 

 EsperanzaSy in the chain of hills to the north-eastward of the town 

 of Santa Cruz, they lie scattered about in considerable numbers, 

 and M. Escolar told me that he had seen strata of them to a con- 

 siderable extent, exhibiting with precision the columnar basaltic 

 form ; the modern lavas of the peak are all basaltic, that 

 of 1704 is decidedly so, as well as that of 1798, though not 

 exhibiting any prismatic form. Prisms of basaltic lava are yet 

 found on the peak : I picked up one, though there are no strata of 

 them to be met with. The metals are rare, and afford but little 

 variety : specular and micaceous iron, black and grey manganese 

 are all that have hitherto been discovered. The salts that are s.o 

 common on Vesuvius, are here seldom met with. Augite is also 

 rare, and mica and leucite, though carefully sought after, have 

 hitherto not been found. 



In that part of the island between Laguna and Tacaronte, where 

 there are few streams of lava, the soil is evidently volcanic. I 

 examined many of the clods that were turned up by the plough, and 

 found them all alike : they contained much strong clay, with 

 crystals of feldspar, olivine, and specular iron. Dr. Gillan, who 

 accompanied Mr. Barrow and Sir G. Staunton, has advanced an 

 opinion, that between Laguna and Matan%os there are no signs 

 of volcanic formation. That the currents of lava occur but seldom 

 is most true ; but the mountains in the vicinity of Laguna are all 

 volcanic, and one has a visible crater ; besides, the assertion would 

 prove too much ; for it would go to maintain that the Campagna 

 Felice, as well as the plains of Catania, were not created by the 



