Advancing still farther into the cavern, another phenomenon presented itself, for which we were unable to account at first. Every now and then we observed a gush of vapour or smoke (we could not tell which) issue from the further extremity of the rock on the left, spreading itself over the walls of the cavern, and ascending towards the crevice in the dome. It looked like an explosion of steam; but the roar of the torrent would have prevented us from hearing any noise, if such had occurred. We soon found, however, that it was occasioned by the rush of vapour from the cavern in which the thermal source is situated, every time the door was opened for the ingress or egress of visitors to and from this natural vapour-bath. At such moments the whole scene is so truly Tartarean, that had Virgil and Dante been acquainted with it, they need not have strained their imaginations in portraying the ideal abodes of fallen angels, infernal gods, and departed spirits, but painted a HADES from Nature, with all the advantage of truth and reality in its favour. Our ingress occupied nearly half an hour, when we found ourselves at the extremity of the parapet, on a jutting ledge of rock, and where the cavern assumed an unusually sombre complexion, in consequence of the cliffs actually uniting, or nearly so, at the summit of the dome. Here, too, the TAMINA struggled, roared, and foamed through the narrow, dark, and rugged gorge with tremendous impetuosity and deafening noise, the sounds being echoed and reverberated a thousand times by the fractured angles and projections of the cavern. We were now at the source of the THERMÆ. Ascending some steps cut out of the rock, we came to a door, which opened, and instantly enveloped us in tepid steam. We entered a grotto in the solid marble, but of what dimensions we could form no estimate, since it was dark as midnight, and full of dense and fervid vapour. We were quickly in an universal perspiration. The guides hurried us forward into another grotto, still deeper in the rock, where the steam was suffocating, and where we exuded at every pore. It was as dark as pitch. An owl would not have been able to see an eagle within a foot of its saucer eyes. We were told to stoop and stretch out our hands. We did so, and immersed them in the boiling—or, at least, the gurgling, source of the PFEFFERS. We even quaffed at this fountain of Hygeia. Often had we slept in damp linen, while travelling through Holland, Germany, and Switzerland. We had now, by way of variety, a waking set of integuments saturated with moisture _ab interno_, as well as _ab externo_, to such an extent, that I believe each of us would have weighed at least half a stone more at our exit than on our entrance into this stew-pan of the Grison Alps.