A E R
A E R
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steatite. A portion of the entire stone beinganalysed by Vauquelin afforded46. silex15. magnesia2. lime
38. oxide of iron2. oxide of nickel
103.
9. On the 26th of April,’ 1803, about oneo’clock in the afternoon, the air being calm andonly a few clouds floating in the sky, a brilliantmeteor was observed moving rapidly from S.to N. in the vicinity of the town of l’Aigle ,in Normandy . In a few seconds afterwardsthere was heard at l’Aigle , and all around tothe distance of even 90 miles radius, a violentexplosion which lasted five or six minutes : thiswas succeeded by three or four bursts like thedischarge of cannon, and by a number ofsmaller explosions like musket firing, the wholebeing terminated by a noise like the roll of aprodigious drum. These sounds evidently pro-ceeded from a small cloud which appeared tobe nearly stationary during the whole time,and the vapours of which it was composedwere thrown out on all sides during each ex-plosion. The inhabitants of the district imme-diately under the cloud were also alarmed bythe hissing noise as of stones discharged fromslings, and at the same time a multitude ofmasses of solid matter were observed to fall tothe ground. The area upon which these stonesfell is an irregular ellipse about 7 miles longby 3 miles wide; the largest stones were foundat the S. Eastern extremity of this space, thesmallest ones at the opposite extremity, whilethe middle-sized occupied the middle of thearea. The size of the stones varied from 181bs.to a quarter of an ounce: their number couldnot be ascertained, but they certainly amountedto some thousands. They were so hot whenthey fell as to burn those who attempted totake them up, their odour was sulphureous, orrather like that arising from the discharge ofgunpowder. In their external characters, andas far as can be judged from a coarse analysisof them by M. Sage, they bear a close analogyto those which have been already described.
10. On the 15th of March, 1806, b a loudexplosion with a roll like thunder was heardat Valence Dept. Du Gard, and immediatelyafterwards a stone weighing about 4 lbs. wasobserved to fall; in its descent it broke a
a Journ. de Phys. 1803.
branch of a fig-tree and buried itself a fewinches in the soil, (at the same time anotherstone of the weight of eight or nine lbs. wasobserved to fall in the adjacent district of St.Etienne). This aerolite differs greatly in ap-pearance from all those that have been hithei toobserved. It is bl?.ck throughout its wholesubstance, and is composed of slightly adheringfriable lamellae ■, when rubbed on paper it leavesa grey trace not unlike that of plumbago : itacquires a kind of bituminous polish by friction,and by bruising in a mortar it is reduced tothin flat plates instead of powder. Whenheated it exhales a slightly bituminous odour.Its specific gravity is 1.94. Certain small gra-nular portions of the stone were found to beattracted by the magnet. When calcined incontact with air its colour soon changed fromblack to red, without losing any weight; butwhen ignited in a small retort it remainedblack, gave Out a little carbonic acid, and lostabout 17 per cent, of its weight, which pro-bably was water, which its porous structureenables it readily to absorb. By ebullition with,muriatic acid it affords a very small quantityof sulphuretted hydrogen. It has been analysed,by Vauquelin with the following result:
38. sub-oxide of iron.
30. silex14. magnesia2. oxide of nickel2. oxide of manganese2. oxide of chrome2.5 carbonaceous matter
90.5
9.5 sulphur, water, and loss
An analysis of the same substance has beenpublished by Thenard, who found in it thesame ingredients as those already mentioned,,but in somewhat different proportions. Mr.Howard’s analyses of the aerolites related above,,were not calculated to detect the presence eitherof manganese or of chrome; as far thereforeas certainly appears, the loose texture of thisstone and the presence of a little carbonaceous,matter are the principal circumstances in whichit differs from the other meteoric stones. Ifat the period of its formation or explosion ithad been subjected to a high degree of hert,.the iron and other metds would have been-deoxygenated at the expence of. the carbon,and this would probably have also induced agreater compactner > oi structure, in which case: