If the water-spout had passed over fresh-water lakes or rivers, frogs might be drawn up instead of fish, and let fall in the same manner. But I will relate to you another circumstance, which may have been imputed to a descent of fish from the clouds. I told you in the first part of this book respecting the alluvions, or torrents of mud, which make their way after an eruption down the sides of Mount Vesuvius. In some of the great volcanoes of South America, these alluvions have not to be formed in the regular way, but mud of the consistence of pap is ejected from the craters themselves in amazing quantities. This mud is supplied by subterranean waters connected with the volcanic channel, and it often contains myriads of little fishes of the kind called _Pimelodes Cyclopum_: they are generally about four inches long, and they exist in such vast numbers, that their putrifying has before now bred a pestilence in the neighbourhood of the Volcano. There are plenty of the same fish in the contiguous streams. What renders the circumstance so wonderful, is their being raised up to the level of 8 or 9000 feet, and then thrown out from the crater with very little injury. [Illustration: PLATE XVIII. SPECTRE OF THE BROCKEN] CHAPTER VII. THE SPECTRE OF THE BROCKEN. I am going to tell you respecting some of the appearances produced by clouds which reflect like mirrors; and by those changes in the atmosphere which turn aside, in an irregular manner, the rays of light, which, as they pass from an object to the eye which is looking at it, excite the sensation called vision. One of the most remarkable of these, has long been known by the name of "The Spectre of the Brocken." The Brocken is the loftiest summit of the Hartz Mountains, in Germany; it is said to be 3,300 feet above the level of the sea, and to command the prospect of a tract of land which is inhabited by more than five millions of people. It appears that clouds, from some cause or other, which perhaps we shall never perfectly know, are wont at times to collect on the neighbouring heights, and reflect a very distinct shadow of great size of whatever object may be on the summit of the Brocken, when the sun is rising and casts his beams horizontally. The best account of this wonderful spectacle, is given by the Abbe Hauy, who visited it in 1797, and I shall give you his own statement.