METE oit irrE Tars term, derived from the Greek .Marwecc, is here preferably adopted, as the shortest and most convenient appellation of a stony or metallic substance, which falls from the air, and whose descent is, generally, preceded or accompanied by a fiery meteor.
That stony, and even metalline bodies, have repeat edly impinged upon the earth's surface, and from great elevations, is a physical position from which no con siderate and candid logician can any longer withhold his assent. The object of the ensuing pages, there fore, is not so much to prove the reality of such a phe nomenon, as to supply our readers with a summary, but continuous review of its history, or, in other words, with a transcript of its modifications, and of the lead ing observations and reasonings to which it has given rise, thus approximating the results of various and dis persed documents, and reducing within a desirable compass the groundwork of future inquiry and dis cussion. We may, at the same time, confidently ven ture to indulge the reasonable expectation, that our exposition of facts and observations will suffice to con vince those who have not heretofore examined the na ture of the evidence on which it rests, that the pheno menon in question is neither doubtful nor chimerical, hut entitled to all the credibility which can attach to hu man testimony.
In our present state of knowledge, we can feel no hesitation in ascribing a meteoric origin to certain de tached masses of native iron, nbt merely because tradi tion accords with our opinion, but principally because the circumstance of their fall has been, in one instance at least, duly authenticated, and because their chemi cal constitution is, in some important particulars, ana logous to that of undoubted meteorites. According to the discoveries of Proust and Klaproth, for example, native iron, reputed meteoric, differs from that which occurs in a fossil state, by the presence of nickel. Of the two pieces of Siberian iron in the Grevillian col lection, one exhibits a cellular and ramified texture, analogous to that of some very light and porous vol canic slags. An attentive examination, moreover, re veals impressions or cavities of greater or less depth, and in some of which there remains a transparent sub stance, of a yellowish-green hue. The iron itself is very malleable, and may be cut with a knife, or flat tened under the hammer. The other specimen is more solid and compact, but so blended and incorporated with the yellowish-green matter, that if the whole of the latter were subtracted, the remainder would consist of iron in the metallic state, and would present the same cellular appearance as the preceding. The stony
portions of the composition usually assume the form of small nodules, generally of an irregular outline, but sometimes nearly globular, with a smooth, shining, and vitreous surface, and, both in aspect and proper ties, approaching to olivine. "I cannot help observ ing," says the Count de Bournon, " that there appears to exist a very interesting analogy between these trans parent nodules and the globules I described as making part of the stones said to have fallen on the earth." The native iron from Bohemia, like the larger speci men from Siberia, is compact, and contains nodules, but not so numerous. They are, besides, quite opaque, and very much resemble the globules in atmospheric stones. This iron contains nearly 5 per cent. of nickel ; and between 5 and 6 per cent. of the same metal seems to exist in a piece of native iron, brought from Senegal.
In like manner, we shall offer no apology for includ ing in our chronological recital the mention of pulveru lent or coloured showers, since the products of some of them seem to indicate a similar origin, and since, in several instances, their fall has even accompanied that of concrete masses. The colouring matter of alleged showers, however, has sometimes been found to be of a vegetable or animal nature, so that cases of this de scription are to be admitted with caution. Thus, the crimson snow, described by Captain Ross, in his ac count of his recent voyage to Baffin's Bay, is supposed by Dr. Wollaston to owe its complexion to some vege table production, and Mr. Bauer fancies that he has detected in it the existence of a nondescript Uredo, which he, very appropriately, designates nivalis. With the exception of such instances, however, the black and reddish dusts, to which we shall have occasion to refer, may, perhaps, be regarded as replacing the grey and earthly portions of the friable meteoric stones. Nor is it improbable that the vitreous [natter which accom panies the masses of native iron, may he the same por tions completely fused, and that the dusts, meteorites, and ferruginous masses may have undergone different degrees of heat, which would account for their different modifications and appearances. Certain it is, that even sand was mingled in the Siena shower of stones, thus pointing to an intimate connection between silex in the loose and in the consolidated state, and thus justifying our insertion of the few examples of atmospheric sand that have come within our knowledge.