from MazapiL Mexico. 61 



In its crvsalline structure (see fig. 2, exact natural size), it 

 closely resembles the iron of Rovvton. since it exhibits lines at 

 nearly I'ight angles (cubic) in the Widmanstatten figures. It 

 is also similar to the iron of Juncal, and of La Caille, and very 

 probal)ly, if it was cut in other directions, a more marked re- 

 semblance could be seen, especially in the twinning lamellae and 

 cubic structure. 



The bands of iron-nickel in the Maznpil iron average one milli- 

 metre bi'oad. In J^rezina's classification it belongs among the 

 the Tlolosiderites, in his '' Trenton-gruppe (Omtr) " of *' mit- 

 telei-e lamellen." It does not contain much plessite, but is mostly 

 kaniacite, and the bands present a shimmer at different angles, 

 thus showing uniform crystallization. 



Mr. 0. W. Fluntington has lately shown* "that the features 

 of the Widmanstatten figures are due to the elimination of 

 incompa table niateiial during the process of crystallization," 

 and that '* these met^eoric masses show cleavages parallel to the 

 planes of all the three fundamental forms of the isometric or 

 iTgular system, i. e., the octahedi'on, the cube, and the dodeca- 

 liedron ;" and further that he " is strengthened in the opinion 

 that the ]n-ocess of crystallization must have been very slow." 



Whei'e tlie surface-crust of the Maza])il iron has been accident- 

 ally detached, it shows, without etching, the Widmanstitttian 

 figures. 



Troilite (ferrous-snlphide) and Schreibersite (nickel-iron-phos- 

 phide) have been identified on the surfaces prepared for etching. 

 Cai-bon (as graphite) is disseminated throughout the mass be- 

 tween the lamellae, and as nodules of considerable size extruding 

 from the surface. Eleven of them can be counted on one 

 side, one of nearly an inch in diameter. This graphite is veiT 

 hard and seemingly^ amorphous ; scattered through it is troilite 

 in thin plates as a mechanical mixture. Of quite excep- 

 tional occurrence is the ])resence in this iron of such quantities 

 of carbon ; and it is noteworthy that the speciroscope showed 

 this element as present in the Biclid meteors of Nov. 27, 1885. 

 The illustration (plate 1), which is three-fourths natural size, 



* Proceedings of the American Academy of Arts and Sciences, May 12, 



1886. 



