276 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



If a weakly etched section be observed with the unaided eye, it will be seen that the nickel-iron is composed of 

 irregular grains 0.25 to 0.75 mm. in size, of which the larger number also show a shimmering reflection, as well as thin, 

 long lamellae and small, brightly glistening rhabdites. If a stronger magnifying power be used, tiny lumpy eminences 

 appear in very large numbers, which hinders the recognition of the finer structure of the above-mentioned grains. 



The little lumps are oval to round. In the former case, they have a diameter of 0.01 to 0.02 mm.; in the latter 

 case they attain a similar thickness and a length of 0.04 mm. They lie close together and are quite evenly distributed, 

 so that the interspaces as a rule are only 0.02 to 0.05 mm. in size and vary but slightly from these dimensions; the 

 etched section is therefore regualrly compacted and fine grained. Only in the neighborhood of the lamellae and the 

 rhabdite do the lumps diminish in number, and when the former cluster together in larger numbers the lumps dis- 

 appear entirely in their immediate neighborhood. On such places a smooth etching zone appears distinct from the 

 rest of the iron mass. These tiny formations suggest somewhat crystals of schreibersite or cohenite, which are not so 

 readily affected by etching as nickel-iron. However, they can not be isolated by dilute hydrochloric acid nor by 

 copper ammonium chloride, and the quantity of phosphorus and carbon found is far from sufficient for such an inter- 

 pretation. Alloys rich in nickel, moreover, according to the results of the analysis, are not present. 



The above-mentioned lamellae attain a length of 13 mm. and a thickness of 0.02 mm.; they are apparently irregu- 

 larly oriented, and when they occur scattered everywhere, they still readily mass themselves in greater numbers in 

 some places. By treating the nickel-iron with dilute hydrochloric acid they still are not isolated ; smallj deep grooves 

 quickly appear, but the residue contains no flakes. On the other hand, after dissolving in copper ammonium chloride, 

 there remain, besides carbonaceous substances, tin-white, very brittle, thin scales, which, after dissolving in aqua 

 regia, give a strong phosphorus reaction, so that without doubt scales of schreibersite are present . They are distinguished 

 from similar occurrences by less thickness and more frequent occurrence. 



Rhabdite occurs in considerable quantity and is sometimes found isolated, sometimes in small groups. In the 

 latter case, the rhabdites are sometimes oriented perpendicular to one another, so as to form a fine network with rec- 

 tangular meshes; the majority are, however, irregularly arranged. In one place small needlets arrange themselves 

 around the end of a larger needle, so as to form a very beautiful star-shaped group. The rhabdite attains a length of 

 3 mm. and a thickness of 0.25 mm., but as a rule falls well within these dimensions and is for the most part of a com- 

 pact form. Schreibersite can be isolated from them. A few spots occur consisting of quite irregular particles of schrei- 

 bersite of about 1 mm. in size, closely filled with tiny dark grains; they resemble those which lie in such large num- 

 bers in the nickel-iron. 



Graphite and troilite nodules occur only in isolation and of small size. A graphite nodule 10 mm. long and 5 mm. 

 wide is still present entire; a second nodule of about the same size and of a pear-shaped form has fallen out in the cut- 

 ting of the plate or section, except for a small remainder clinging to the wall of the cavity. After these come a few 

 small elongated particles (8 to 9 mm. long, 1 to 2 mm. wide). The troilite forms round particles of a few millimeters 

 in size, a few of which are entirely or partially bordered with schreibersite. 



In the four sections examined all the graphite and troilite nodules as well as most of the schreibersite lamellae lie 

 in proximity to the original surface of the meteorite, while the central portion contains rhabdite almost exclusively. 

 It may be noted in this connection that iron sulphide is also found separated on the surface of pig iron rich in sulphur. 



As the sections of the two ends of the billet-shaped mass have been separated from one another as far as possible 

 before now, and as the section surfaces together measuring 160 sq. cm. show exactly the same character, it may be 

 assumed that the meteorite has the same structure throughout. Nothing of any importance can be gathered from the 

 alteration zone near the fusion crust. 



The insoluble residue contains a small quantity of grains which, when entirely separated have a diameter as great 

 as 0.1 mm., but for the most part are of only 0.02 to 0.03 mm. and sometimes very much smaller. By far the greater 

 number belong to the colorless grains with high cleavage exponents and sometimes stronger, sometimes weaker double 

 refraction, which have been found hitherto in every meteoric iron which has been investigated in this direction. 

 Many of them harbor numerous tiny opaque inclusions. Quartzlike grains having the same index of refraction as Can- 

 ada balsam are much less numerous here than usual. A few, small, columnar microlites, rounded at the ends, with 

 very strong relief and very lively interference colors, resemble in a high degree many zircon microlites of terrestrial 

 rocks. In addition to these there are isolated blue, pleochroic obliquely extinguishing columnar fragments, brown 

 grains having a double cleavage, as well as splinters, each one of which according to its position is either cinnamon- 

 brown or almost black and appears comparable with tourmaline in respect to coloring and absorption. The inter- 

 mingled opaque particles are more probably slow burning carbon than chromium, since a chrome reaction was not 

 obtained. 



Analysis (Sjostrom), specific gravity by Leick, 7.7083: 



Pe Ni Co Cu C O P CI 



94. 30 5. 57 0. 64 trace 0. 02 0. 05 0. 18 0. 01 =100. 77 



Mineralogical composition: 



Nickel-iron 98. 70 



Schreibersite 1. 16 



Troilite 0. 12 



Lawrencite 0. 02 



100. 00 



