COMPOSITION AND STRUCTURE OF METEORITES 37 



begins. In many instances, the enstatites of a chondrule extend out 

 into the ground mass with which they are intergrown. As noted, the 

 Hvittis stone is a crystalline chondrite; this might suggest either a 

 crystallization of the chondrule in situ or a case of secondary enlarge- 

 ment. In writing of the Shelbume stone, a gray chondrite, however, 

 he says,^' 



Each individual chondrule represents a structure of cooling and crystallization 

 from a molten state, and as their structure shows an intimate relation to the 

 boundary of the chondrule it must be supposed that each, at the time of its 

 solidification, was a separate unit. Because chondrules of the same chemical 

 composition have a different structure, they must have been formed under differ- 

 ent physical conditions. Since such a variety of conditions can not have existed 

 in the narrow space in which the different structures now are met with, the 

 chondrules must have accumulated after solidification. 



Such a condition is well shown in Figure 2, Plate 18, from the stone 

 of Cedar, Tex. Meunier ^^ basing an opinion apparently upon the 

 theoretic work of M. Faye, suggests the probability of the chondrules 

 resulting from the sudden condensation of a cyclonic vapor. 



II parait difficile de ne pas admettre que les chondres sont aux roches de pre- 

 cipitation gazeuse ce que les drag^es de Carlsbad et le fer en grains sont aux 

 roches de precipitant aqueus * * * Conformement a la terminologie dont 

 font usage les paleontologistes h propos du vent fossile, du soleil fossile, de la 

 pluie fossile, on serait tent^ de les qualifier de cyclones photospheriques fossiles. 



This is conceivable, to the present writer, only in the case of 

 radiate enstatite or monosomatic forms. 



Brezina, to whom is so largely due the building up of the magnifi- 

 cent collection at Vienna, concludes a review *^ of the subject with the 

 statement: 



Durch die vorangefuhrten Beobachtungen konnen wohl die alteren An- 

 schauungsweisen als beseitigt betrachtet werden, und wir konnen wohl mit 

 Bestimmtheit die Meteoriten als gestore tiber hastete Krystallbildungen in 

 einem einzigen gemengten Magma bezeichen. 



This apparently includes both the ground mass and its chqndrules. 



Hussak, basing an opinion on experimental work by himself and 

 Dolter ^^ suggests that chondritic meteorites, like that of Uberaba, 

 Brazil (a crystalline chondrite), originate through the long continued 

 immersion of meteoric stones in a nickel-iron magma, and are to be 

 regarded as true volcanic ejectmenta, 



Ich mochte demnach die Meteorsteine durch ultrabasische Eruptivgesteine 

 vergleichen und die Bildung der Chondren wie der Triimmerstructur und der 

 schwarzen Adern als eine magmatische Eirnwirkung vor der Ejerktion ansehen. 



'« Trans. Royal Astr. Soc, Canada, 1904. 



«o C. R. Paris Acad. Sci., vol. 90, 1883, p. 808. 



" Die Meteoritensammlung, etc., 1885. 



'2 Neues Jahrb. fur Min., etc., vol. 1, 1884, pp. 18-43. They immersed fragments of an "olivinefels" 

 for many hours in a slowly cooling melt of nephelin basalt. The stone was strongly attacked and the 

 outer portions, in close contact with the melt, shattered and corroded, the olivine granules becoming filled 

 with embayments and enclosures of a secondary colorless glass, all strongly suggestive of meteoric 

 chondrules. 



