Jackechan's wife and child were still very unwell, and, as the child was supposed to be dying, the doctor was sent for. He proceeded to cure it by laying it on the ground, muttering a charm and patting it on the head; after which he put his mouth close to its chest and shouted to bring the devil out: he then turned it on its face and repeated the same process. The child's health mended next day, and it was shortly out of danger.
About ten o'clock at night Casimiro returned with his horses, which had strayed a considerable distance on the road back to Geylum. The next day a long march of twenty miles brought us to an encampment on the western verge of a broad plain, watered by a brooklet. During the hunt the first Patagonian hares, or cavies, were caught. These little animals live in burrows, but are generally out feeding or sleeping in the grass during the day. They are excessively swift for perhaps a mile, but, like the foxes of this country, soon get tired. The chase of these small deer afforded an agreeable relief to the monotony of the journey. As soon as we entered a plain or valley where they abounded, as they always were found in numbers where the pasture was good, all hurried off to 'stop the earths,' i.e. close up the burrows with bushes; but the cunning little beasts often evaded us by slipping into a burrow overlooked by the earth stoppers. It required considerable skill to bring them down with the bolas, as, if only caught round the legs or body, they disentangled themselves quickly, but a blow on the head proved at once fatal. They are good eating, though the flesh is somewhat dry when roasted. Their skins are made up into mantles, but are of little value, as the hair soon comes off.
About a mile below the encampment, where the sandy plain narrowed and sloped down to a low-lying grassy valley, a singular phenomenon presented itself. The morning after our arrival, when going out to look for the horses, a furious easterly gale whirled the dust aloft in dense clouds, and, to my great surprise, the sand, which was driven into our faces, was as hot as when the fire so nearly encircled us. Almost blinded in forcing our way through this curtain of driving sand, we rode right into a hollow, where the earth appeared to be on fire; as the horses plunged through the heated surface the hair was burnt off their fetlocks, and they were nearly maddened with fright, so that it was a difficult feat for the riders without saddles or stirrups to keep their seats. Once I was somewhere near my horse's ears, but, more by good luck than good management, just escaped being thrown as it were into the fire. After the gale had partially moderated, I proceeded to inspect this place, and found that, although not, as I at first thought, absolutely on fire, the ground was smoking as if from internal combustion. The surface presented a crust of baked yellow clay, which, yielding to the horses' feet, disclosed a black subsoil; there was no flame, but a thin white vapour issued from the ground. When I incautiously ventured a step on the treacherous crust it gave way, but I managed to extricate myself with no further damage than burning my potro boots. The Indians stated that the fire had been originally caused some years previously by their having kindled the pasture higher up the valley, and that the ground had been burning ever since. It was impossible to discover whether there was any subjacent bed of combustible matter which might thus have been ignited; but, as there are hot wells and springs in the same range not many miles distant to the south-east, it seems more probably due to volcanic agency. The principal hot spring was described as a circular basin of about six feet in diameter, the water, of a temperature not so hot as to scald the hand, bubbling up through numerous holes in a clay bottom. In many of the surrounding hills there are lava and pumice of not extremely ancient formation; some of the hills have also an appearance of having been at a recent period the outlets of eruptive forces, which have scattered large shattered masses of rock over the sides of the extinct craters.