32 FIELD MUSEUM OF NATURAL HISTORY 
magnesium silicate, chrysolite. The distribution of this silicate 
is irregukir, some parts of the masses being wholly metal. 
Of the Canyon Diablo meteorite nine individuals and five 
sections are shown. The largest of the individuals weighs 
1013 lbs., and is one of the largest ever obtained from the lo- 
cality. The next smaller individual shown, weighing 265 lbs. 
is remarkable for the perforation about one inch in diameter 
passing entirely through it. Of the sections, several are etched 
and show the characteristic figures of the meteorite. These 
figures are broad and irregular. The small projecting particles, 
about the size of a grain of wheat, are cohenite, a carbide of iron 
little attacked by the acid used in etching and hence standing 
in relief. In addition are seen larger nodules of oval form which 
are sulphide of iron, often surrounded by graphite or cohenite. 
Of the Toluca meteorites sixteen individuals and seven sec- 
tions are shown. The largest individual weighs 90 lbs. An- 
other individual shows shaping for use as a hammer. Such use 
of these meteorites was frequent in early times. The etched 
sections show the typical figures of this meteorite, with laminae 
about 2 mm. in width and of a regular network pattern. 
In the wall cases are shown the smaller specimens of the col- 
lection, also casts of meteorites. The casts are placed in the bays, 
the meteorites on the shelves above. In the two cases first in 
order from the entrance from Hall 61, beginning at the left, are 
shown the specimens of stone meteorites or aerolites. These 
specimens are in part individuals and in part fragments. They 
are arranged in chronological order passing from left to right. 
Specimens of about one hundred and fifty falls are shown . These 
include 660 individuals of the Forest City, Iowa, fall, about 
twenty individuals of Pultusk, Poland, and large masses from 
Farmington, Kansas, Saline, Kansas, Homestead, Iowa, Bluff, 
Texas, Estacado, Texas, etc. The rare carbonaceous meteor- 
ites are well represented by specimens from Orgueil and Alais, 
France, and Mighei, Russia. 
Following the stone meteorites are shown the iron-stone 
meteorites, of which about twenty-five distinct falls are repre- 
sented. These contain more iron than the stone meteorites and 
thus pass toward the iron meteorites. The iron varies in quan- 
tity from coarse flakes or nodules scattered among the stony 
minerals to sponge-like masses in which the stony portions are 
held. Complete individuals of the Crab Orchard, Tennessee, 
