No. 382.] REVIEWS OF RECENT LITERATURE. 815 
Meteorites.!— The writer believes that the iron meteorites, known 
as siderites, are of the same nature as the small specks of iron 
that occur in nearly all the stony meteorites ; that they represent. 
the product of a slower crystallization of the meteoric mass under 
specially favorable, and therefore rarely occurring, conditions; that 
this explains the fact that stony meteorites are of much more frequent 
occurrence than siderites. Moreover, he believes that a meteor con- 
taining these iron concretions is more subject to rupture by explosion 
on reaching our atmosphere, the nodules forming points of weakness; 
and that therefore the iron nodules are generally freed from their 
stony matrix before falling, and may arrive at the earth’s surface 
at a distance from the lighter constituents. The Estherville fall is 
quoted as a good example of such a case. He further points out 
that meteorites with a deeply pitted surface are coarsely crystalline, 
and contain relatively large troilite nodules, the pits being probably 
due to the tearing away of portions of the mass along the easy 
fracture planes of the large crystal individuals, whereas in the masses 
with finer texture such fracture would be less likely, and a smooth 
surface would be formed. 
The siderites secured by Mr. Ward? while in Australia in 1896 are 
from the following localities : (1) 200 miles southeast of Roebourne 
in northwest Australia, weight 191} lbs.; (2) ro miles south of 
Ballinoo, West Australia, weight 93 lbs.; (3) three miles north of 
Mungindi P. O., New South Wales, two masses of 62 and 51 lbs.; 
(4) Mooranoppin, West Australia, weight 2} Ibs. All four irons are 
octahedral in structure, No. 3 being remarkable for the ease with 
which Widmanstatten etching figures of great clearness and beauty 
may be developed. 
The siderite described by Preston was found in the prairie seven 
miles south of San Angelo, Tom Green County, Texas. Its weight 
was 194 lbs., and the structure noticeably octahedral, a broken sur- 
face exhibiting large cleavage faces. It showed a few troilite nodules 
and veins of a lustrous graphitic-looking mineral. Its composition, 
together with that of three of the Australian irons, is shown in the 
following table of analyses by Mariner & Hoskins, Chicago, Ill. : 
1 Preston, H. L. On Iron Meteorites as Nodular Structures in Stony Meteor- 
ites. Am. Journ. Sci., vol. clv (1898), p- 
2 Ward, H. A. Four New pee deo “Meteorites. bid., p. 135. Preston, 
H. L. San Angelo Meteorite. bíd., p: 269. 
