Dr. Weissenborn has given the following interesting statements:--“In the year 1818, I was fortunate enough to get a fine view of the ignes fatui operating on an extensive scale. I was then at Schnepfenthal, in the duchy of Gotha; and in a clear November night, between eleven and twelve o’clock, when I had just undressed, the bright moonshine allured me to the window, to survey the expanse of boggy meadows, which spread two or three English miles in length, a quarter-of-a-mile from the foot of the hillock on which the house in which I then was, is standing. Through the first third of the meadows there was a winding rivulet, of the breadth of seven or eight feet, which then turns off into an artificial bed, whilst the old bed continues in the direction of the meadows, which are bounded on one side by a range of brushwood, and on the other by cultivated grounds, with marshy dells here and there. My intimate acquaintance with the locality, together with the bright moonshine, enabled me to discover every object round the meadow-ground, sufficiently well to judge of the position and direction of the luminous phenomena, the display of which I saw as soon as I had posted myself at the window. I perceived a number of reddish yellow flames on different parts of the expanse of almost level ground. I descried, perhaps, no more than six at a time, but dying away and appearing in other places so rapidly, that it was impossible to count them; but I should say, on a rough calculation, there were about twenty or twenty-five within a second. Some were small and burned dimly; others flashed with a bright flame, in a direction almost parallel with the ground, and coinciding with that of the wind, which was rather brisk. After having for some time looked with amazement at the brilliant scene, as a whole, I tried to study its details, and soon found that the flames which were nearest originated in a quagmire, the position of which I knew exactly, by a solitary cluster of willows; and I could trace a succession of flashes from that spot to a certain point of the margin of the wood across the rivulet and meadow. The distance of the two points from each other was more than half-a-mile, and the flames travelled over it, perhaps, in less than a second. The first flash was not always observed in the immediate neighbourhood of the quagmire; but the succession of flames lay always in the same straight line, and in the direction of the wind; whilst other sets were observed, though not with the same distinctness, in the more distant parts of the meadow-ground.