to the constant fires which the dry nature of that plant causes to spread in a most destructive manner. A person who paid attention to the subject might easily tell how many years had elapsed since the forest was cut down in any particular place, by observing the height of the fern. In the first year, after its cultivation for potatoes has been discontinued, the fern springs up to ten, or even thirteen feet in height, gradually dwindles down to six inches, and at last vanishes altogether: it is then replaced by a short wiry grass, growing in small tufts, about a foot apart, with nothing between, and presenting the most desolate appearance.
Coteropo, the village where I encamped, at the south-east end of the lake, is a small place surrounded by boiling springs. The whole side of the mountain at the back is enveloped with steam, escaping from innumerable crevices in the soil. The bushes of Veronica and fern-plants grow close to these places, and do not seem to be affected by the heat, unless they are absolutely touched by the boiling water. The portion of land on the side of the mountain where the springs are most numerous is about two miles square, and a great part of it is so covered with springs that nothing grows on it, and it looks as bare as a ploughed field. There are a great many other places on the lake where there are hot-water springs, but not so extensive as at this place. I found here, that the action of the hot water, which was nearly tasteless, (although the vapour smelt of sulphuric acid,) converted the compact black lava into clay of different colours; some of it being quite white, other parts mottled with red and yellow. The stones which overhung the hot places were half converted, while the others were as hard and fresh as if they had been only formed yesterday; the lava is hard, black, compact with white grains, strongly resembling greenstone in general appearance and weight. I physicked some
