I 88 STUDIES EOT? STUDENTS 



however, would seem to indicate that division planes were lack- 

 ing in the masses from which they have separated. 



SYNTHETIC EXPERIMENTS IN THE REPRODUCTION OF STRUCTURAL 



DETAILS 



Fouque and Levy have succeeded in reproducing, so far as 

 the component minerals were concerned, mineral aggregates 

 corresponding to several types of meteorites. Among meteor- 

 ites not containing feldspar, aggregates were produced corres- 

 ponding to the meteorite of Rittersgriin, which is made up of 

 chrysolite, enstatite, a magnesian pyroxene, and iron. Among 

 meteorites containing feldspar, aggregates were produced cor- 

 responding to those of the class known as Eukrites, which are 

 made up of anorthite, enstatite, and pyroxene, and of the class 

 made up of anorthite, enstatite, and chrysolite. These were all 

 produced by cooling from fusion, different mixtures of silica, 

 alumina, magnesia, carbonate of lime and iron oxide. The chief 

 difference noted by these authors between these products and 

 meteorites of corresponding chemical composition is one of 

 structure. The artificial products were of a marked granitoid 

 texture, while most meteorites have as strongly brecciated or 

 tuffaceous character. It is also true that the iron in the arti- 

 ficial products was in the form of oxide. This could, however, 

 easily be reduced to the metallic state by exposing the mass to 

 the action of reducing gas at a red heat for two hours. Previous 

 to the experiments of Fouque and Levy stone meteorites of sev- 

 eral types had been fused by Daubree and the resulting cooled 

 products examined. The products resembled the original 

 masses in some respects, but in many respects differed. Thus 

 chrysolite and enstatite separated in a sort of liquation, the 

 chrysolite forming a thin layer above, while the enstatite crys- 

 tallized below in the form of long needles. Moreover the 

 iron grains took spherical forms rather than the irregular ones 

 which characterize meteorites. Daubree therefore concluded 

 that the mode of formation of meteorites differed from purely 

 igneous fusion. The needles of enstatite artificially obtained 



