the weather never utterly deranged, its balance lost irrecoverably ?"

The complicated nature of the elements, which enter into the constitution of the atmosphere, renders it difficult, perhaps impossible, to give a distinct answer to these interesting questions, by pointing to the precise law which regulates and controls these elements. Mr. Whewell refers to the very peculiar adjustments which were requisite, and are actually discoverable, in the comparatively simple problem of the solar system, by which its motions have their cycles, and its perturbations their limits and period; and, from this analogy, he conjectures, with much probability, that could the investigation be followed out, it would land us in a similar result. However this may be, it cannot but be regarded as a mark of the interference of an intelligent and beneficent mind, that the intensity of those tremendous forces which are employed in our atmosphere should be so adjusted, as not only to preserve the permanence of the system, but also to be adapted to the existence and comfort of the animal creation.

In adverting to the general properties of that wonderful fluid which envelopes our globe as with a mantle, the distinguished philosopher from whom we have already quoted, makes the beautiful observations, with which we close this paper.

"If the atmosphere be considered as a vast machine, it is difficult to form any just conception of the profound skill and comprehensiveness of design which it displays. It diffuses and tempers the heat of different climates; for this purpose it performs a circulation occupying the whole range from the pole to the equator; and, while it is doing this, it executes many smaller circuits between the sea and the land. At the same time, it is the means of forming clouds and rain; and, for this purpose, a perpetual circulation of the watery part of the atmosphere goes on between its lower and upper regions. Besides this complication of circuits, it exercises a more irregular agency in the occasional winds which blow from all quarters, tending perpetually to restore the equilibrium

of heat and moisture. But this incessant and multiplied activity discharges only a part of the functions of the air. It is, moreover, the most important and universal material of the growth and sustenance of plants and animals; and is, for this purpose, every where present, and almost uniform in its quantity. With all its local motion, it has also the office of a medium of communication between intelligent creatures, which office it performs by another set of motions, entirely different both from the circulation and occasional movements already mentioned; these different kinds of motions not interfering materially with each other; and this last purpose, so remote from the others in its nature, it answers in a manner so perfect and so easy, that we cannot imagine that the object could have been more completely attained, if this had been the sole purpose for which the atmosphere had been created. With all these qualities, this extraordinary part of our terrestrial system is scarcely ever in the way; and when we have occasion to do so, we put forth our hand and push it aside, without being aware of its being

ONE of the curious atmospheric phenomena of winter, the nature of which is not well understood, and still less its use in the economy of Providence, is that shining vapor which generally makes its appearance in moist weather, in marshy ground, known to the Romans by the name of ignis fatuus, and called, at this day, 'Will-o'the-Wisp,'' Jack-with-the-lantern,' and a variety of other names, all of them indicating the superstitious feeling with which it is associated in the minds of the vulgar. This paper shall be chiefly occupied with some accounts

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that have been published of the various appearances which the phenomenon assumes. The first I shall quote, is that of a writer in a public journal, who subscribes himself A Farmer,' and expresses himself with such amusing simplicity, in describing some of the ordinary vagaries of this reputed sprite, that the homeliness of the style requires no apology.

"I was riding through a wet boggy part of the road, that lies between my house and the mill, when a little sleety shower, with a strong blast of wind, came suddenly upon me, and made it so very dark, that I could scarcely see my old mare's white head. I began to consider with myself, whether it would be better to turn my back to the storm, and wait till it was past, or take my chance of letting my horse find its own way, when I saw something bright, dancing in the air before me. You may be sure I was startled a little at this; for the rain was pouring so fast, and the wind was blowing so strong, that no ordinary fire could stand it; so I whipt up my horse to get out of the way as fast as I could; but to go fast was out of the question, with such an old mare, such a bad road, and so heavy a burden; and, besides, I soon found that it served me in no stead, for the light still kept waving before my eyes; so I thought it would be best to go slowly, and try if I could find out what it was.

"You may think how surprised I was, when I discovered, that the top of my whiplash was all in a flame. I had at first almost thrown it out of my hand in my fright; but, on second thoughts, I did not like to do that, for fear of losing it, as it was nearly new, and a present from my uncle John. I therefore whisked it about in my hand, and whipped my horse with it, thinking to make the flame go out; but, though it turned dim for a few minutes, it soon became brighter than ever. Just at this time, I heard the sound of a foot before me; and, when I looked, I saw very distinctly the marks of footsteps all on fire, close beside me; but it was so dark, I could not see whether any person was there or not. Soon afterward, I got upon better road, and my poor mare, who was herself frightened, jogged faster on; so I saw

no more of it. I am happy to tell you, that I got home without a broken neck, and found all well there, which was more than I expected; for I verily believed it was a dead light, or an elf candle, or some other bad omen.”* M. Boccari mentions, that a light of this kind appeared to a gentleman of his acquaintance, as he was travelling in the neighborhood of Bologna, in Italy, where it is very common. It moved constantly before him for about a mile, and gave a better light than a torch that was carried by his servant. Sometimes it rose,and sometimes sunk, but hovered commonly about six feet from the ground. Sometimes it appeared like waves, and, at other times, seemed to drop sparks of fire. It was little affected by the wind; but, during a shower of rain, it became brighter.

A very remarkable account of a will-o'-the-wisp, is given by Dr. Shaw, in his Travels in the Holy Land. It appeared in one of the valleys of Mount Ephraim, and attended him and his company for more than an hour. Sometimes it would seem globular, or in the shape of the flame of a candle. At other times, it would spread to such a degree as to involve the whole company in a pale inoffensive light, then contract itself, and suddenly disappear; but, in less than a minute, would appear again. Sometimes, running swiftly along, it would expand itself, at certain intervals, over more than two or three acres of the adjacent mountains. The atmosphere, from the beginning of the evening, had been remarkably thick and hazy; and the dew, as they felt it on the bridles of their horses, was clammy and unctuous.

In the Appendix to Dr. Priestley's third volume of Experiments and Observations on Air, M. Waltire gives an account of some very remarkable ignes fatui which he observed, about five miles from Birmingham, on the 12th December, 1776, before daylight in the morning. A great many of these lights were playing in a neighboring field, in different directions; from some of which, there suddenly sprang up bright branches of light, something

* Dumfries Courier, 20th December, 1809.

resembling the explosion of a rocket, that contained many brilliant stars; and the hedge, with the trees on each side of the hedge, was illuminated. This appearance continued but a few seconds, and then the willo'-the-wisps played as before. M. Waltire was not near enough to observe if the apparent explosions were attended by any report.

From these and other facts which have been recorded, and indeed from the familiar occurrences of the winter months, it appears, that the ignis fatuus belongs to a class of phenomena which prove that light and heat, though so intimately connected, may exist separately; or, to speak more correctly, that the peculiar substance, whatever it may be, in which these qualities inhere, contains sometimes the one in a latent state, and sometimes the other. This, is only another remarkable property of that most wonderful substance which seems to pervade universal nature, and to combine the various phenomena of electricity, of galvanism, and probably also of magnetism, along with those of light and heat, sometimes in a quiescent, and sometimes in a highly active state.

The phenomena of light without heat, are not so frequently the subject of observation as those of heat without light; but various wellknown, and indeed familiar, instances of the latter do occur. Of this kind is the light of the glowworm; of fire-flies; of the Medusa tribe, which are diffused so plentifully over the surface of the sea, in tropical regions; of other marine productions; of the scales of fish; and of animal and vegetable substances in the process of putrefaction. Nor must we forget the beams of the moon, which, so far from exhibiting the presence of heat, are even said by some to be slightly chilling.

An attempt, more ingenious, I think, than successful, has been made to connect the light of the ignis fatuus with the phenomena of falling stars, which may be shortly stated. It is supposed, that some phosphoric fluid, arising from the decomposition of animal or vegetable substances, passes into the atmosphere, and continues to float there, without mixing with the atmosphere itself;