133 
1861.] Report on the Shallca, Sfc. Meteorites. 
delicate fossil-remains. The polished section shews the whole sub- 
stance to be a nearly homogenous compound of single granules very 
different in form, some of circular, others of angular section, varying 
in colour from dark smoke-grey, to nearly greyish white : the largest 
among them not above -jV inch in diameter. Metallic iron, and a 
yellowish sulphuret of iron, in atoms too minute to admit of speci- 
fic determination, are distributed in very minute particles and rather 
inconstant proportion through the whole substance. A stratum of 
magnetic pyrites, of the colour characteristic of this mineral species, 
runs vein-like through the whole of the fine-grained loose substance ; 
it forms a lamina of about 2 inches in length f inch in breadth, and 
about -Jj inch thick, growing gradually thinner towards both ends. 
The presence of such a lamella of heterogenous substance offers a 
strong argument in favour of its formation having taken place amidst 
a larger mass (as it were, a massive rock), while the whole incor- 
porated into a larger body went through several stages of evolution, 
and especially a pressure took place perpendicularly to the fissure, 
while the now filled in crevice was in course of formation ; the whole 
mass simultaneously contracting itself in a direction perpendiculai to 
the place of the laminae, and so causing a separation of particles, and 
consequently a vacuum, subsequently filled with crystalline magnetic 
pyrites. 
The crust is opaque, greyish-black, with a brownish tint. The 
specimen in question shews more of the interior than of the cortical 
substance, being probably a fragment of a larger meteorite ol pei- 
haps above 20 lbs. in weight. The thickness of the crust is not 
above of an inch. 
Specific weight 3.737. 
The Pegu meteorite may well find its appropriate place in Baron 
Reichenbach’s group 2. (Meteorites with dark globules interspers- 
ed with others of lighter colour) next to the meteorites of Luce, 
Nanjemoy, Aussun, Benares, Tipperary, Cereseto, Weston, &c. 
The original weight of the fragment kindly transmitted by Mr. 
Oldham, was 1 lb. % ounces. Friable and creviced as it was, a cutting 
into two pieces became unavoidable, the smaller fragments being 
reserved for chemical analysis. Three fragments of 9:(, 4,^ and 
ounces in weight, are ready for delivery to the Imperial Museum ; 
s 2 
