ART. 21 OEIGIN" OF METAL IN METEORITES MEREILL 7 



view of the Researches of F. Flacle.^^ The metal in this case, it will 

 be remembered, is shown to have been reduced from magnetic pyrites. 

 That, however, in the meteorite it was not derived from the sulphide 

 is shown apparently by the fact that the latter is the later formed 

 mineral of the two. 



Objection to such a possible source might be raised on account of 

 the large amount of chloride demanded to produce the 10 per cent 

 and upward of metal contained by the average stone. (Lawrencite, 

 FeCl2=Fe 40.1 per cent, CI 55.9 per cent.) Could it be allowed, 

 however, it would be an aid ,in accounting for the enormous quanti- 

 ties of sodium chloride in seawater and locked up in the rocks of the 

 earth's crust- 



EXPLANATION OF PLATES 



Plate 1 



Tig. 1. Anthony (Kans.) stone. (1) Troilite; (2) nickel-iron. Dark, nearly 

 black areas, silicates. 



2. Dark inclosure in Cumberland Falls stone. Small white dots and 



stringers (1) are metal. Dark areas, silicates. 



3. Admire (Kans.), pallasite. (1) Nickel-iron, (2) schreibersite, (3) 



troilite. Dark areas, olivine. 



4. Four Corners (N. Mex.), iron. (1) Nickel-iron, (2) granular admixture 



of silicates and metal. 



Plate 2 



Upper. Polished slice of Admire pallasite, showing clastic structure and shat- 

 tered condition of olivines. Natural size. 



I^owEK. Polished slice of Estheiville mesosiderite, showing shrinkage cavities 

 black, metal white, silicates dark gray. Enlarged about four diam- 

 eters. 1 Silicate ; 2 metal ; 3 cavities. 



Plate 3 



Upper. Structure of Mount Joy meteroric iron — a coarse kamacite octaliedrite — 



after fusion. 

 Lower. Structure of Canon Diablo iron — a coarse octahedrite — after fusion. 



" Das Biihleisen hat alle Bigenschaften eiues extreiir niedrig gekohlten Schmiedeeisen, 

 is iufolge dessen ausserordentlich zahe und dcbnbar, aber nur schwer mit der Ge.stein- 

 schneldemaschine oder mit der Sage zuzerkleinern. (Senkenbergia, vol. 2, Heft 5, Aug. 

 15, 1920.) 



o 



