METEORITES OF NORTH AMERICA. 131 



100.93 100.05 100.08 100.07 98.70 



Of the above blocks only Hacienia St. Rosa and the Butcher iron have been sufficiently described to make certain 

 their relation to the hexahedrites, but Fletcher's consideration of the subject leaves no doubt that they originated 

 from one fall, while the data of Hamilton and Shepard on the one hand and of Butcher on the other, in many points — 

 especially in the matter of the estimated weight, the distance from the place of discovery to Santa Rosa, and in the 

 description of the neighborhood — differ not unessentially from one another. Santa Rosa is to be especially considered 

 as the place of discovery since, according to Hamilton, Yeatch, and Butcher, masses of iron have repeatedly been 

 brought to the town since the year 1837. 



The following data refer solely to the Butcher iron. 



The Butcher iron shows distinct hexahedral cleavage and etching lines which are of equal distinctness, but of very 

 various length. Some systems may be followed over an entire section surface of 20 cm., while others attain only a 

 length of 5 mm. or fall for the most part considerably under these limits. Moreover the distribution is different. Upon 

 one part of the etched surface both sorts are to be found, the shorter especially being very abundant and lying close 

 together; here occur at the same time, in considerable number and uniformly distributed, etching pits and rhabdites 

 which produce an unusually lively, oriented luster. Upon other parts of the etched surface, and penetrating the former 

 in very irregular finger-like areas, are long etching lines massed together in bundles. The short twin lamellae are 

 wanting, as well as etch pittings and rhabdite, and the luster is a dull satin gloss, but, as it seems, of the same orienta- 

 tion as that of the other portion of the etched surface ; that is, the reflection is strongest in each case in the same position 

 with reference to the light. Nevertheless the two portions are sharply distinguished from one another in consequence 

 of very different luster. The extremely fine rhabdites are mostly under 1 mm. in length but occasionally reach 4 mm. 

 They run parallel to each other in two directions. In the proper position with reference to incident light they appear 

 as extremely fine, glistening streaks. Where they occur together with short twin lamellae, within the dull portions, 

 both are surrounded by a small bright area whose luster coincides, in respect to strength and orientation, with that of 

 the principal part of the nickel iron, so that here small dark specks lie in a dark field. The same is true of the troilite 

 which, as a rule, is bordered by fine schreibersite and frequently contains plates of daubreelite. The Butcher irons 

 are distinguished among all meteoric irons by the abundance of the latter mineral (daubreelite), scarcely a single piece,, 

 even of the smallest dimensions of the irons, being entirely free from it. 



The Butcher irons take an extremely weak permanent magnetism and behave therefore like soft iron, which also 

 occasionally shows traces of coercive force . Whether this is a consequence of artificial heating, as I formerly conjectured, 

 may be left undecided. The specific magnetism was determined by Leick as 0.0S5 absolute units per gram. 



By dissolving a large piece (160 grams) in very dilute muriatic acid grains of chromite and silicate were observed 

 among the subsidiary constituents, but both in very small masses. The dimensions of the isolated rhabdites agree 

 quite closely with those of Walker County, although they may be a trifle greater in diameter. Most of them are between 

 0.003 and 0.013 mm. thick, the observed boundaries (0.0015 mm. and 0.035 mm.) being only seldom attained. If now 

 a large part, in fact apparently the largest portion obtained by isolation on account of the ready divisibility, be broken 

 at right angles to the longitudinal dimension the thinner needles are in general the longer. Yet many crystals bounded 

 at both ends by pyramid faces have a length of only 0.05 to 0.07 mm. Two pyramids, one sharper and the other more 

 obtuse, are at times accompanied by the base. A few crystals are differently formed at both ends so as to suggest 

 hemimorphism, and sometimes the pyramid faces appear to be incomplete in number. This recalls the observation 

 of Hlawatsch, who described thin rhabdite needles from a furnace product with only two pyramid faces on the ends, 

 so that he regarded the crystals as hemihedral. 



Analysis (Cohen): 



Fe Ni Co Cr P Insoluble 



94.82 5.62 0.60 trace 0.29 0.06 =101.39 



Specific gravity, 7.8678. 

 Mineralogical composition. 



Nickel iron 98. 344 



Rhabdite 1. 615 



Daubreelite 0. 027 



Carbon 0. 011 



Chromite and silicate grains 0. 003 



100.00 



