METEORITE COLLECTION—HANDBOOK AND CATALOGUE. 19 
The association of iron and nickelin the form of an alloy was 
long thought to be a peculiarity of meteoric bodies, but at least two 
terrestrial minerals are now known, which are constituted of such an 
alloy. One of these, awaruite (361), contains 67% of nickel to 31% 
of iron, the other, josephinite (367), 60% of nickel to 23% of iron. 
The iron found in large masses on Disco Island and other parts 
of West Greenland also resembles the derosiderites very closely in 
composition, since it contains from 1 to 6% of nickel and small per- 
centages of phosphorus and carbon. | 
These occurrences are so isolated, however, that in general, masses 
of iron alloyed with nickel, when found upon the earth’s surface, may 
be regarded as being probably of. meteoric origin, especially if they 
also exhibit a crust and pitted surface like that described, and etch- 
ing figures such as will be mentioned later. 
Other elements commonly occurring in the aerosiderites, though 
in much smaller quantities, are copper, cobalt, manganese, phosphorus, 
sulphur and carbon. 
The phosphorus is usually combined with iron in the form of 
schreibersite, the sulphur with iron as troilite, while the carbon may 
be either free in a graphitic form or as minute diamonds, or com- 
bined with iron. 
The proportions of the different elements as they commonly oc- 
cur in the derosiderites are illustrated by the following analyses of 
some of those represented in the collection :— 
Fe. Ni. Co, Ca. Pe 
DR PRIAMUC Ay, 0's scat o's aces Beye tae 40> 0440 OTS X..63 = 100.46 
ROD UR ee (Sel aoe ode Osa. ee we.s, OVS er. LOW. 
(a)reisases Co; Mo;:.... (95) 89.12 10.02 0.26 0.0L 0.12 = 99.538 
(4) Grand Rapids, Mich. (116) 88.71 10.69 ea Vie. U.20  G.00e 5. 00> -=9auoe 
(5) Glorieta Mt., N. M. (122) 87.93 11.15 0.33 .... 0.36 = 99.77 
Gpeeteotoix CO. Wis (825) 89.78 - 7.65 1.33 tr. -0.51C tv. Snfr. = 99.2% 
The specific gravity of the meteoric irons ranges between 5.75 
and 8.31, nearly all lying between 7.5 and 7.0. oa 
Most meteoric irons present a distinct crystalline structure, the 
features of which are brought out by etching a polished surface with 
acids. There then appear upon the surface, bands or lines intersect- 
ing one another at various angles, according to the direction of the 
section. These are enclosed in a more or less unindividualized 
ground mass. 
(1) Taylor, Am. J.Sc. Vol. 22 p. 374, 1856; (2) Duflos and Fischer, Pogg. Ann. Vol. 72, pp. 170, 475, 18- 
47; (3) J. L. Smith, Am. J. Sc. 3rd series, Vol. 13, p. 213, 1877; (4) Riggs, ibid, Vol. 30, p. 312, 1885; (5) 
Mackintosh, ibid, Vol. 30, p. 238, 1885; (6) D. Fisher, ibid, Vol. 34, p. 381, 1887. For further analyses 
see Lithological Studies by M. E. Wadsworth, Mem. Mus. Comp. Zool., Harvard Coll., Vol. XI, Part 
I, Oct. 1884. 
