METEORS AND METEORITES. 



549 



eral other meteorites, with notes on meteoric 

 irons. In the same journal, for March, 1865, 

 an interesting resume is given of investigations 

 respecting the meteor and meteorites of Or- 

 gueil, the latter falling near the village of that 

 name, in France, ou the evening of May 14, 

 18G4; and in the number for September, 1865, 

 a description and analysis, by Prof. J. L. Smith, 

 of Louisville, of a meteorite from Arkansas. 

 (See METEORIC IEON, CYC., 1861.) 



Composition of Meteorites. By a very mi- 

 nute analysis of the Chili meteorite, Prof. Joy 

 finds in this, in 100 parts, Fe, 48.298 ; Ni, 5.298 ; 

 Co, 0.838; Mn, 0.375; Cu, 0.040; S, 2.693; 

 P, 0.115; Si0 3 , 20.689; MuO, 0.976; Cr,O 3 , 

 0.477; NiO. CoO, 0.073; FeO, 10.417; CaO, 

 1.548; Al a Oa, 3.772; MgO, 4.278; SnO a , 0.189 

 total, 100.076 ; and he deduces the miner- 

 alogical composition of the meteorite, as, Nickel 

 iron (with Co, Mn, and Cu),'48.689 ; sulphide 

 of iron, FeS, 7.405 ; chrome iron, Cr 2 O 3 FeO, 

 0.701 ; Schreibersite (Fe, Ni, and P), 1.563 ; 

 olivine, 11.677; Labradorite, 29.852; tin-stone, 

 SuO ; , 0.189. In the meteorite of Bishopville, 

 S. C., 1843, M. Rammelsberg finds silica, alumi- 

 na, sesqui oxide of iron with some MnjOo, mag- 

 nesia, and lime, besides a small loss, probably 

 of alkalies. For the composition of the whole 

 Orgueil meteorite, M. Pisani grVes, SiO s , 26.08 ; 

 MgO, 17.00; FeO, 6.96; MnO, 0.36; CaO, 

 1.85 ; NaO, 2.26 ; KO, 0.19; A1,O 3 , 0.90; with 

 chromic iron, 0.49 ; magnetic iron, 12.03 ; nick- 

 eliferous sulphide of iron, 16.97; water, and 

 supposed organic substances, 14.91, total, 100. 



The last-named meteorite was examined also 

 by other chemists, among whom MM. Cloez 

 and Wohler conclude that a black amorphous 

 substance contained to the amount of 6 per 

 cent, in it is a true organic substance a kind 

 .of humus, -consisting of carbon, hydrogen, and 

 oxygen in proportions quite similar to those 

 occurring in lignite and peat. This fact, if 

 it be such, is somewhat startling, in view of 

 the conclusion drawn from it, that, from what- 

 ever portion of space this meteor may have 

 come, organic matter, and hence living organ- 

 isms, must probably there have had an exist- 

 ence. Note in Reader, February 11, 1865. 



Thus ifc still remains true, that the meteoric 

 stones which reach the earth and have been 

 examined reveal in their composition only such 

 elements as have long been known as entering 

 into the earth's solid and liquid mass and its 

 atmosphere; though some differences present 

 themselves in the forms of combination entered 

 into by those elements. Indeed, very many 

 terrestrial chemical elements, both among such 

 as are abundant, and among such as are very 

 rare and till recently unknown, have not yet 

 been detected in any meteorites analyzed. 



Structure of Meteorites. Mr. Sorby, in the 

 first of the papers by him already referred to, 

 applies to the case of meteorites the principles 

 he had before developed in his study of terres- 

 trial rocks (Quarterly Jour. Geolog. Soc., 1858, 

 vol. xiv). Thus, he had shown that the pres- 



ence in crystals of fluid-, glass-, stone-, and 

 gas-cavities, respectively, enable us to deter- 

 mine in a very satisfactory manner under 

 what conditions the crystals were formed. 

 The olivine of meteorites, like that of lavas, 

 contains excellent glass-cavities, proving that 

 the material was at one time in a state of fu- 

 sion ; and the former, also* gas-cavities, indicat- 

 ing the presence of some gas or vapor (Par- 

 nallee, etc.). The vitreous substance, found 

 both within and without the cavities, is of a 

 claret-brown color, with the structure and 

 optical properties of artificial glasses. Some 

 isolated portions of meteors have also a struc- 

 ture very similar to that of stony lavas, the 

 crystals having evidently formed during solidi- 

 fication and where found. In others, the mass 

 is one apparently of broken fragments after- 

 wards compacted by mechanical and chemical 

 actions (L'Aigle), the structure here resembling 

 that of consolidated volcanic ashes. The par- 

 ticles in some cases indicate a breaking-up 

 after cooling from fusion; in others, being 

 globular, a breaking-up while in the fused or 

 semi-fused condition (Parnallee, etc.). Thus, 

 in certain peculiarities of physical structure, 

 meteorites are connected with volcanic rocks, 

 while in others they differ most characteristi- 

 cally. 



In the second of his papers referred to, Mr. 

 Sorby proceeds from the conclusions he had 

 reached in the first, regarding it as proved that 

 the material of meteorites has been to some ex- 

 tent fused, in some part, at least, compacted 

 from minute detached particles, and in other 

 portions showing evidence of having been con- 

 densed from a state of vapor ; while, at the 

 same time, he declares it extremely improbable 

 that masses so constituted have ever been por- 

 tions of the moon or of a planet. In accord- 

 ance with the observed facts of structure, he 

 traces hypothetically a history of the formation 

 of such masses, from the time in which their 

 materials must have existed in a vaporous con- 

 dition, as the black lines of the spectrum prove 

 that certain metals now do in the atmosphere 

 of the sun, down through their aggregation 

 into a sort of cometary cloud, to that of a fused 

 and crystallizing mass, broken and comminuted 

 by movements pervading it, and later com- 

 pacted again, and under the influence of heat 

 undergoing a sort of metamorphism. The 

 view presented may be regarded as a modified 

 form of the nebular hypothesis. The relative 

 amounts of metallic constituents in meteorites 

 would appear to have increased with lapse of 

 time : various iron-compounds, in particular, 

 appeal* as if having entered and been condensed 

 within them, from the vaporous state ; though 

 some irons may have separated from the general 

 mass through difference in specific gravity. 

 Meteorites are thus, probably, records of the 

 existence in planetary space of physical condi- 

 tions more or less similar to those now confined 

 to the immediate neighborhood of the sun, and 

 at a period indefinitely more remote than that 



