One night, as I had taken up my quarters on the verge of a forest, and had got seated in my cradle, which you know was among the thick branches of some huge tree, I saw a light glancing among the trees. I came down from my roosting place, almost in an instant, and went towards it, hoping there was a village near; for I was sadly in want of a better rope to fasten myself with; and the Indians of these villages make some very ingenious ones, by twisting together the long fibres of the leaves of the cocoa-tree.
Well, as I said, I followed the light, but where, do you think? Why out of the forest, to be sure, but into something worse than a forest. I found myself, ere I was aware of the nature of my guide, up to my knees in a quagmire: and what was more mortifying still, I was not much nearer the light than when I set out.
I began now to suspect what it was. It was evidently one of those things to which they give the name of ignis fatuus, or will-o’-the-wisp. They are seen, as you know, (and as I might have known had my wits been about me) in low swampy places, peeping and dodging about. They are supposed to be gaseous; but perhaps you do not all of you know what gaseous means; and I am hardly philosopher or chemist enough to tell you.
The atmosphere or air which we breathe is composed of two ingredients, or gases, as the chemists call them. One is oxygen. This is the supporter of life and flame, for if it could be taken out of the air we could not breathe again, and every candle and lamp would be extinguished in a moment. The other is nitrogen or azote, which destroys life.
I told you the air we breathe was made up of these two airs or gases; and it is. But many other gases sometimes float in it. One of these is hydrogen. It is produced in various ways, and is one of the most inflammable substances in the world. Now electricity, (or lightning, for it is the same thing) which is a subtle or penetrating fluid, always exists in the atmosphere, and has at all times power to ignite (set on fire) a vapor so inflammable as hydrogen, if it happens to come in contact with it. Now, again, as this hydrogen gas is most readily produced by the decomposition of water, and combines or mixes with various other matters arising from decaying vegetation, putrifying animal substances, in low and marshy swamps, a tiny spark is sufficient to ignite these combined gases, and thus set off the Will-o’-the-Wisps.
THE AEROLITES.
Stones falling—Where they come from—Arrival at the river Orinoco.
Well, I extricated myself from the quagmire and returned,—though not without some difficulty, I had wandered so far, to my roosting place. The next morning as I was preparing to descend the tree, the sky being clear, and the sun shining, I was alarmed by a hissing noise in the air; and looking quickly around, I was just in time to see an immense mass of something, I could not tell what, falling from above, with a loud noise, and crushing in its fall, the branches of a lofty tamarind tree.
Hastening to the spot, I found, to my surprise, an enormous piece of metal, quite hot, which had fallen with such force that it lay half buried in the swampy ground.
I stood lost in wonder. When I was a boy, I had often picked up lumps of metal on the Wiltshire Downs, in England, but though told they were aerolites, I did not at that time believe a word of it. “Can the thin pure air,” thought I then, “form such hard bodies? Or can there be great iron mountains, and forges, and blacksmiths, and every thing of that sort, up in the air?”