174 



pet that surrounds the crater. We plunged the 

 thermometer into them, and saw it rise rapidly 

 to 68 and 75 degrees. It no doubt indicated 

 a higher temperature, but we could not observe 

 the instrument till we had drawn it up, lest we 

 should burn our hands. M. Cordier found se- 

 veral crevices, the heat of which was that of 

 boiling water. It might be thought, that these 

 vapours, which are emitted in gusts, contain 

 muriatic or sulphurous acid ; but when con- 

 densed, they have no particular taste ; and ex- 

 periments, which several naturalists * have made 

 with reagents, prove, that the chimneys of the 

 Peak exhale only pure water. This phenome- 

 non, analogous to what I observed in the crater 

 of Jorullo, deserves the more attention, as mu- 

 riatic acid abounds in the greater part of vol- 

 canoes, and as Mr. Vauquelin has discovered it 

 even in the porphyritic lavas of Sarcouy in Au- 

 vergne. 



I sketched on the spot a view of the interior 

 edge of the crater, as it presented itself in the 

 descent by the eastern break. Nothing is more 

 striking than the manner, in which these strata 

 of lavas are piled on one another, exhibiting the 

 sinuosities of the calcareous rock of the higher 

 Alp&. These enormous ledges, sometimes hori- 

 zontal, at others inclined and undulating, remind 



* Voyage de La Perouse, t. iii, p. 2. 

 + Picturesque Atlas, Mio, PI. 54. 



