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the sea * ; but in particular the new distant luminous phenomenon observed by M. Schroter +, will appear the more favourable to this hypothesis, as we have reason to suppose that there are pro. cesses carried on in our atmosphere with which we are as little ac. quainted as with those carried on in the interior parts of the earth.
15. The time of their duration was very different: that observed by De Genssance continued half an hour; at other times their du. ration has seldom been above a minute. Few or none of them, however, have been observed from the commencement of their ap. pearance till the time when they disappeared.
16. Many of them in their course threw out sparks, and the greater part of them were seen to divide themselves into several, sometimes larger, sometimes smaller parts, before they entirely disappeared. This division also seems to oppose the hypothesis of a track of inflammable air set on fire I, which Dr. Chladni has sufficiently refuted on other grounds.
17. This bursting into pieces was for the most part accompanied with a rumbling noise like thunder, or a sudden report. This was observed to be the case in regard to 27 of the 50 abovementioned; and
very often two or more reports have been heard in succession, without the large ball being divided into smaller ones, and without these being still farther shattered. But as these reports were heard at a very great distance Ś, and as many which did not appear to be more remote, but nearer, have burst without any report; a question arises, whether we are to consider, as Dr. Chladni does, this violent bursting as peculiar to all these phænomena?
18. Several, after bursting, seemed to dissolve into smoke ll, and, according to the observation made by Celsius in the month of March, 1731, a visible smoking stripe seemed to be previously in. flamed. The greater part of them, however, after exploding, left no visible traces behind.
Brydone in the Philosoph. Transactions, vol. Ixiii. part I. p. 167. + Gothaisches Magazin, vol. xi. part 1. p. 86.
Gehlers Phys. Wörterbuch, art. Feuerkugel.
Allgem. Historie der Reisen, vol. ix. p. 564 ; and Philosoph. Transactions, vol.iii. part I. p. 163.
De Bonon. Scient. Institut. Coinment vol i. p. 285; Philosoph. Transac. tions, vol. xli. part 2. p. 870, vol. xlii. p. 1 ; and Hist. de l'Acad. des Sciences, Paris, 1753, p. 73.
19. In some cases, after their disappearance, a sulphurous smell was perceived *, like that perceived after lightning has fallen, and which gave occasion to Muschenbroek's hypothesis of an accumulation of sulphurous inflammable vapours that arise from volcanoes and subterranean pits, and being driven together by the winds form clouds, that by some accident or other are set on fire; but whicb, however, can as little be reconciled with their general prodigious height, as Silberschlag's oily and slimy vapours.
20. As scoriaceous masses have frequently been either actually seen to fall at the time of the disappearance of these phænomena, or have been found soon after on the surface of the earth; and as it is sufficiently proved by various accounts that stones have fallen from the atmosphere, Dr. Chladni concludes that both these phænomena are connected; but this can be determined only by future accurate observations.
[Good's Lucretius. Thomson's Chemistry.
Aërolites, or Meteoric Stones.
1. General History and Observations. It is now well known, aud admitted without hesitation, that a variety of stony bodies are frequently falling from the atmosphere, in every quarter of the world, and in every instance of similar com. position, and connected with the fiery meteors we have just con. templated. It is not many years ago, however, that the fact was generally discredited by every one. Yet it is by no means a discovery of modern times, having been almost as fully known to the philosophers of Greece as it is at present to the philosophers of Europe at large.
“ What,” observes a writer who is well acquainted with their opinions, “ will the unlearned reader say, when he finds that even the meteoric stones, or those which are now traced to have fallen from the heavens, and are at this moment, for the first time as is
* Breslauer Sammlungen, i. p. 157 ; Philosoph. Transactions, vol. 1. p.299; 2nd Goth. Magazin, vol. xi, part 2mp. 112,
commonly supposed, exciting attention in the philosophic world, are not a new discovery, and were known to mankind upwards of four hundred years before the birth of our Saviour; were as differently accounted for by the sages of that early æra as they are in our owu day; and their fall capable of being foretold by some of them, and especially by Anaxagoras, who predicted the descent of a very large stone that fell accordingly on the banks of the Argos in Thrace. This fact and prediction are recorded by Plioy ii. 68, and Diogenes and Laertius, in Vit. Anaxag. ii. 10. Aristo. tle, in his first book of Meteorics, supposes these stones to be car-, ried upwards from the earth in the course of a violent tempest. In modern times they are said by many philosophers to fall from the moon. Anaxagoras contended that they feil from the sun : and bence his disciple Euripides denominates the sun χρυσισν Κωλον, , “ a golden-glebe*."
But though, observes Dr. Thomson, several well authenticated accounts of the fall of such stones had been from time to time published, little credit was given to them; nor did they indeed attract the attention of philosophers, till Dr. Chladni published a dissertation on the subject, in 1794. Two years after, Mr. King published a still more complete collection of examples, both ancient and mo. dern; many of them supported by such evidence that it was im. possible to reject it. These two dissertations excited considerable attention : but the opinion, that stones bad really fallen from the atmosphere, was considered as so extraordinary, and so contrary to what we know of the constitution of the air, that most people hesi. tated, or refused their assent. Meanwhile Mr. Howard took a different method of investigating the subject. He not only collected all the recent and well authenticated accounts of the fall of stony bodies, and examined the evidence of their truth, but pro. cured specimens of the stones which were said to have fallen in different places, compared them together, and subjected them to a chemical analysis. The result was, that all these stony bodies differ completely from every other known stone; that they all resemble each other, and that they are all composed of the same ingredients. His dissertation on the subject was published in the Philosophical Transactions for 1802. The proofs which this admirable disserta.
* Good's Notes to his Translation of Lucretius, book iii. c. 239, page 414.
tion contains, that the stony bodies in question really fell from the atmosphere, are quite irresistible. Indeed their external charac. ters and chemical analysis would alone decide the point : For it is quite inconceivable that in India, England, France, Germany, and Italy, in climates and in soils exceedingly different from each other, stones should have been pointed out which differed from every other mineral in the countries where they were found, and which exactly resembled one another, provided those bad not had the same origio. The chemical analysis of Howard was soon after repeated and verified by Vauquelin and Klaporth +.
1. Most of the stones which have fallen from the atmosphere have been preceded by the appearance of luminous bodies or me. teors, These meteots burst with an explosion, and then the shower of stones falls to the earth. Sometiines the stones continue luminous till they sink into the earth ; but most commonly their luminousness disappears at the time of the explosion. These meteors move in a direction nearly horizontal, and they seem to approach the earth before they explode. The following Table, drawn up by Mr. Izarn, exhibits a collection of the best authenticated instances of the falling of stones from the atmospbere hitherto ob. served, together with the time when they fell, and the persons ou whose evidence the fact rests I.
. Ann. de Chim. xlv, 225. + Phil. Mag. xv. 182. Ibid. xvi. 298.