Shortly before we arrived at this place, we observed to the south a ragged cloud of dark reddishbrown colour. The poor cottagers in vain attempted by lighting fires, by shouts, and by waving branches to avert the attack. Before sucking they are quite thin, but afterwards they become round and bloated with blood, and in this state are easily crushed. When placed on a table, and though surrounded by people, if a finger was presented, the bold insect would immediately protrude its sucker, make a charge, and if allowed, draw blood. No pain was caused by the wound. It was curious to watch its body during the act of sucking, as in less than ten minutes it changed from being as flat as a wafer to a globular form. The prosperity of the place has much declined of late years. To my mind the town had a stupid, forlorn aspect. We had to cross a long and most sterile traversia of fifteen leagues. As we had ridden all day without a drop of water, both our mules and selves were very thirsty, and we looked out anxiously for the stream which flows down this valley. I stayed here and at some neighbouring mines during the two succeeding days. The geology of the surrounding country is very curious. I was gratified in a very extraordinary manner. These were petrified trees, eleven being silicified, and from thirty to forty converted into coarselycrystallized white calcareous spar. They were abruptly broken off, the upright stumps projecting a few feet above the ground. The trunks measured from three to five feet each in circumference. They stood a little way apart from each other, but the whole formed one group. I saw that they had sprung from a volcanic soil which had been raised above the level of the sea, and that subsequently this dry land, with its upright trees, had been let down into the depths of the ocean. As all these rivers have a rapid and short course, and are formed by the melting of the snow, the hour of the day makes a considerable difference in their volume.