NATURAL HIST DRY. 



609 



cold at this time was intense, the 

 wind keen and strong, and the 

 thermometer sunk to 32 degrees. 

 After a short though rapid ascent 

 we reached the summit of the se- 

 cond stage of the mountain, we pass- 

 ed over a small plain of white pu- 

 mice on which were spread masses 

 of lava, and at length arrived at the 

 foot of the cone. This divison of 

 the mountain forms what is gene- 

 rally termed the Peak of Teneriffe. 

 It resembles the present crater of 

 Vesuvius ; with this difference, 

 however, that while the surface of 

 that mountain is composed of a 

 black cinder or ash, the superfices 

 of this appears to be a deposit of 

 pumice of a white colour, of sco- 

 ria and of lava, with here and there 

 considerable masses that were pro- 

 bably thrown out when the volca- 

 no was in action. Towards the 

 north-west, on the right hand of our 

 ascent, there is a small current of 

 lava, showing itself above the pu- 

 mice, the composition of which is 

 Kimilar to that at the bottom, 

 though of a redder tinge ; it is 

 broken on the surface, and is in a 

 rapid state of decomposition. Nu- 

 merous small cavities on the side of 

 the mountain emitted vapour with 

 considerable heat. Here begins, 

 in my opinion, the only fatiguing 

 part of the ascent : the steepness 

 of the cone is excessive ; at each 

 step our feet sunk into the ash, and 

 large masses of pumice and lava 

 rolled down from above : we were 

 all bruised, and our feet and legs 

 were cut, but none materially hurt. 

 At last we surmounted all difficul- 

 ties, and seated ourselves on the 

 highest ridge of the mountain. — 

 This uppermost region does not 

 appear to contain in superficies 

 more than an acre and an half : it is 



composed of a lava similar to that 

 on its sides, though decomposed 

 and changed white or grey by the 

 action of the sulphurous acid ; this 

 acre and an half is itself a small 

 crater, the walls of which are the 

 different points on which we sat, 

 and are plainly visible from below. 

 Within, the lava is in the most ra- 

 pid state of decomposition ; losing 

 its brown colour and siiade of red, 

 and acquiring a whitish grey al- 

 most the colour of chalk; large 

 masses of sulphur are depositing, 

 which are crystalized in minute 

 though distinct forms; there is also 

 a coating of alum produced by the 

 union of the sulphurous acid with 

 the argil of the lava ; the surface 

 is hot to the feet, and the guides 

 said it was dangerous to remain 

 long in one spot ; as it was, some 

 of us sunk to our knees in the hot 

 deposit of sulphur: upon striking 

 the ground with the feet, the sound 

 is hollow, similar to what is pro- 

 duced by the same impulsion on the 

 craters of Vesuvius and Solfaterra. 

 I estimate the depth of the crater 

 to be, from the highest ridge to the 

 bottom, about 200 feet, forming 

 an easy and gradual descent, the 

 whole being in a state of rapid de- 

 composition, and charged with 

 sulphur, large masses of which are 

 every where depositing. I searched 

 in vain for any of the arseniats so 

 common on Vesuvius, nor could I 

 find those siliceous stalactites re- 

 sembling strung pearls, which are 

 met with in the island of Ischia, 

 in the crater of the Solfaterra, and 

 in the Maremma of Tuscany. The 

 sulphur is pure and fine, and is 

 sold for a considerable price at Oro- 

 tava. We were not able to go all 

 round the walls or exterior sum- 

 mit of the crater, and hence could 



