part of the year, that which falls upon theſe orifices is ſoon melted by the heat. The ſides of theſe holes are adorned with beautiful cryſtals of ſulphur, moſtly of the form of needles, and ſome of them arranged into very regular figures. The action of the ſulphuric acid combined with the water, effects ſuch a change upon the volcanic products of this place, that at firſt ſight one might miſtake them for very white argillaceous earth, that has acquired a high degree of ductility from the moiſture conſtantly iſſuing from the above-mentioned apertures. It is in this kind of earth that the ſulphuric cryſtals which I have ſpoken of are found.
The decompoſition of the ſulphur, and the volcanic products, form an aluminous ſalt that covers the ground in needles, which have very little coheſion with each other.
The thermometer, when placed in the ſhade at the height of about three feet from the ſurface of the ground at the ſummit of the peak, roſe in a quarter of an hour to 15° above 0. No ſenſible variation was obſerved upon changing its diſtance from the earth, even by ſix or eight feet, which gives us reaſon to believe, that the internal heat of the ground in this place, though ſo very great, has little influence upon the temperature of the atmoſphere. Beſides, the air of the atmoſphere
might
