﻿Huntington — Crystalline Structure of Iron Meteorites. 303 



First. That many of the masses of meteoric iron in our col- 

 lections are cleavage crystals, broken off probably by the im- 

 pact of the mass against the atmosphere. 



Secondly. That these masses show cleavages parallel to the 

 planes of all the three fundamental forms of the isometric or 

 regular system, namely, the octahedron, the cube, and the do- 

 decahedron. 



Thirdly. That the Widmanstattian figures and Neumann 

 lines are sections of planes of crystalline growth parallel to the 

 same three fundamental forms of the isometric system. 



Fourthly. That on different sections of meteorites Widman- 

 stattian figures and Neumann lines can be exhibited in every 

 gradation, from the broadest bands to the finest markings, with 

 no break where a natural line of division can be drawn. 



Fifthly. That the features of the Widmanstattian figures are 

 due to the eliminations of incompatible material during the 

 process of crystallization. 



This investigation throws no new light upon the origin of 

 meteorites, except so far as it strengthens the opinion that the 

 process of crystallization must have been extremely slow. The 

 occurrence of large masses of native iron occluding hydrogen 

 gas, and containing nickel, cobalt, phosphorus, sulphur, etc., 

 implies a combination of conditions which the spectroscope in- 

 dicates as actually realized in oar own sun and in other suns 

 among the 'fixed stars, and the most probable theory seems to 

 be that these masses were thrown off from such a sun, and that 

 they very slowly cooled, while revolving in a zone of intense 

 heat 



In this paper we have not taken into consideration a number 

 of iron masses, whose meteoric origin has been generally ac- 

 cepted, which show no Widmanstattian figures and not even 

 any Neumann lines. A considerable proportion of these are 

 certainly not meteoric. In the Harvard cabinet there are two 

 specimens, labelled respectively Campbell County, Tennessee, 

 and Hominy Creek, North Carolina, which are evidently noth- 

 ing but cast-iron, and a third, labelled Tarapaca Hemalga, 

 Chili, which is probably of similar material. We could find 

 on the specimens of this class in the Harvard collection no dis- 

 tinct evidences of crystallization ; but also we could find no 

 features incompatible with that unity of structure which it has 

 been the chief object of this paper to illustrate. 



