VAPOROUS ERUPTIONS. 
72 
Alps or that mass of pebbly stones which wo find at the lower 
extremity of the glaciers. ' At the peak the lava, broken into 
sharp pieces, leaves hollows, in whieh we risked filling up to 
our waists. Unfortunately the listlessness of our guides 
contributed to increase the’ difficulty of this ascent. Unlike 
the guides of the valley of Chamouni, or the nimble-footed 
Guanchcs, who could, it is asserted, seize the rabbit or wild 
goat in its course, our Canarian guides were models sf the 
phlegmatic. They had wished to persuade us on the preced- 
in" evening not to go beyond the station of the rocks. 
Every ten minutes they sat down to rest themselves, and 
when unobserved they threw away the specimens of obsidian 
and pumice-stone, which we had carefully collected. We 
discovered at length that none of them had ever visited the 
summit of the volcano. 
After three hours’ walking, we reached, at the extremity 
of the Malpays, a small plain, called La Eambleta, from the 
centre of which the Piton, or Sugar-loaf, takes its rise. On 
the side toward Orotava the mountain resembles those pyra- 
mids with steps that are seen at Eayoutn and in Mexico ; 
for the elevated plains of Eetama and Eambleta form two 
tiers, the first of which is four times higher than the 
second. If we suppose the total height of the Peak to be 
1904- toises, the ltambleta is 1S20 toises above the level of 
the sea. Here are found those spiracles, which are called 
by the natives the Nostrils of the Peak (Nances del Pico). 
Watery and heated vapours issue at intervals from several 
crevices in the ground, and the thermometer rose to 43'2° ; 
M. Labillardiere had found the temperature of these vapours, 
eight years before us, 53‘7°; a difference which does not 
perhaps prove so much a diminution of activity in the vol- 
cano, as a local change in the heating of its internal sur 
face. The vapours have no smell, and seem to be pure water. 
A short time before the great eruption of Mount Vesuvius, 
in 1805, M. Gav-Lussac and myself had observed that water, 
under the form of vapour, in the interior of the crater, did 
not redden paper which had been dipped in syrup of violets. 
I cannot, however, admit the bold hypothesis, according 
to which the Nostrils of the Peak are to be considered as 
the vents of an immense apparatus of distillation, the lower 
i art of which is situated below the level of the sea Since 
