166 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



cipally in two directions, which include between them an angle of 55°. The wavy lines are much broader (0.04 to 0.05 

 mm.) and, at least in the portions not disturbed, almost follow the longer diagonal of the rhombus formed by the sharp 

 lines (measuring angles of 38, 17 to 30, and 25°). The wavy lines frequently are situated with their ends upon a line 

 system inclined at an angle of 55°. In two places a considerable disturbance slightly bends the sharp lines and has a 

 similar though more considerable effect upon the wavy lines. The elongated islet of iron in the middle beneath appears 

 to be turned toward the iron particles beyond the schreibersite at an angle of about 8°. The two sharp and the wavy 

 line systems seem to show closely compacted line systems, the first of which is inclined perpendicular to the section 

 surface, the latter very level with it. 



Besides these structural lines still another structural element is visible. First of all a vein, which runs in a double 

 curve from the middle above to the uppermost point of the schreibersite, then extends toward the upper left branch of 

 the schreibersite crystal, penetrates this at a slight angle of deviation, and, parallel with the downward curved portion 

 of the branch, a piece runs into the large bay. This vein is fine grained and spotted but does not lie in a granular 

 groundmass. Another phenomenon is the occasional granulation running entirely independent of the Neumann lines 

 which it penetrates. The abundant layers of rhabdite, here uniformly fine and short, are for the most part surrounded 

 by grains of nickel-iron 0.05 to 0.3 mm. in size, which frequently are confined to the immediate neighborhood of the 

 needles and are then situated like berries on a branch. Also, lengthwise of a giant rhabdite, or of the individual faces 

 of large schreibersites, as well as of finer irregular cracks, a small fine-grained zone occurs, but the entire granular 

 portions compose a very small part of the total section surface. 



The greater portion of the nickel-iron of No. Ill is scattered in irregular sharply defined grains — roundish, longish, 

 bent, and jagged — every portion of which has the same strongly oriented sheen. The diameter of the grains is between 

 0.2 and 1.5 mm., and the form is in general the more irregular the greater the dimensions. In some places particles of 

 a very fine-grained structure predominate with characteristic oriented sheen in which, however, are found large grains, 

 singly or in groups, with different sheen. As in No. VI, so here also a row of brightly glistening grains lies directly 

 along the giant rhabdite, where they stand out sharply. Under the microscope these grains appear in part spotted and 

 then less glistening, and in part full of compact lattice-like etching lines, and then with lively oriented sheen. Here 

 and there — especially where particles of nickel-iron become inclosed by branching schreibersite or interjected between 

 neighboring larger schreibersite — lie isolated grains with a smooth etched surface, and the groundmass then shows 

 Neumann lines, which are unmistakable, although their development is much less complete than in No. I. 



Independent of the grains is a network of fine, irregularly meandering cracks, occasionally breaking through the 

 former, therefore of later origin. They appear even after weak etching, provided the granular structure does not make 

 itself perceptible, and are to be regarded as a segregation phenomenon. 



Very noteworthy is the already mentioned fine-grained, microscopically compact-appearing portion which traverses 

 the entire plate, and which appears as a vein 1 to 3 mm. in breadth, which is sharply marked off by a small border 

 zone filled with dark dust-like particles. It penetrates one of the giant rhabdites, which appears to be displaced about 

 2 mm. 



The following analyses of Masses I, III, and V are given: 



1. Mass I, Dr. R. Knauer and E. Cohen. 



2. Mass III, Dr. O. Hildebrand and E. Cohen. 



3. Mass III, Dr. R. Knauer. 



4. Mass V, J. E. Whitfield. 



a gives the total composition, 6 the composition of the nickel-iron after abstraction of accessory material, c the 

 mineralogical composition of the masses. 



la 2a 3a 4a 



Fe 95.41 95.18 95.14 95.02 



4 - 32 l 4.82 I 4U 



0. 69J 1 0.40 



0. 01 



0. 04 0. 05 



0. 07 0. 16 



0. 20 0. 29 0. 32 

 0. 06 Trace. 



0.00 



100.40 100.50 100.37 100.01 



26 36 45 



95. 22 95. 60 95. 86 



4.021 | 3.62 



0.65) 1 0.36 



0. 00 0. 01 



0. 04 0. 05 



0. 07 0. 16 



100.00 100.00 100.00 100.00 



