METEORITES OF NORTH AMERICA. 325 



powdered, not very finely, and separated into two parts by the magnet; 40 grams were obedient to the magnet; 25 

 of which were taken for examination. The same quantity was taken of the unmagnetical portion. 

 The unmagnetical portion yielded : 



Si0 2 A1 2 O S MgO CaO FeO NiO S 

 14.90 0.05 2.60 0.45 6.15 0.80 1.27 =26.22 



The magnetic portion yielded: 



FeO NiO SiO 2 S 

 24.00 1.25 3.46 trace =28.71 



A further account of the meteorite was given by Silliman 2 in the same article, as follows: 



An excellent specimen, for which we are indebted to Dr. Samuel D. Carver, weighs 4 pounds 5 ounces. Its dimen- 

 sions are 7 by 3 by 4 inches: its form is that of an irregular ovoidal protuberance nearly flat where it was detached from 

 the larger mass and bounded by irregular curves in the other parts of the surface. In all parts, except where it has 

 been fractured, it is covered by the usual black vitreous coating which, in this case especially when it is viewed by a 

 magnifier, has more luster than is common. This coating is severed by innumerable cracks running in every direction 

 and communicating with each other so as to divide the surface into polygons resembling honeycomb or madrepore, and 

 no undivided portion of the surface exceeds half an inch in diameter. 



This circumstance is much less apparent upon the aerolites of Weston (1807), L'Aigle (1803), and Stannern in Moravia 

 ( 1808) ; it appears to have arisen from the rapid cooling of the external vitreous crust after intense ignition. It is impos- 

 sible to doubt that this crust is a result of great and sudden heat. In the Maryland aerolite it is not quite so thick as 

 the back of a common penknife and, as in that of Weston and Stannern, it is separated by a well-defined line from the 

 mass of the stone beneath. The mass of the stone is, on the fractured surface, of a light ash-gray color, or perhaps more 

 properly of a grayish- white; it is very uniform in its appearance and not marked by that strong contrast of dark and 

 light gray spots which is so conspicuous in the Weston meteorolite. The fractured surface of the Maryland stone is 

 uneven and granular, harsh and dry to the touch, and it scratches window glass decidedly, but not with great energy. 

 To the naked eye it presents very email glistening metallic points and a few minute globular or ovoidal bodies scattered 

 here and there through the mass of the stone. With a magnifier all these appearances are of course much increased. 

 The adhesion of the small parts of the stone is so feeble that it falls to pieces with a slight blow and exhibits an appear- 

 ance almost like grains of sand. The metallic parts are conspicuous but they are much less numerous than the earthy 

 portions which, when separated, are nearly white and have a pretty high vitreous luster, considerably resembling 

 porcelain. They appear as if they had undergone an incipient vitrification and as if they had been feebly agglutinated 

 by a very intense heat. I can not say that I observed in them, as M. Fleurian de Bellevue did in the aerolite of Jonzac 

 (Journ. de Phys., tome 92, p. 136), appearances of crystallization, although it is possible there may have been an incipient 

 process of that kind, especially as the small parts are translucent. The Maryland stone is highly magnetic; pieces as 

 large as peas are readily lifted by the magnet and that instrument takes up a large proportion of the smaller fragments. 

 The iron is metallic and perfectly malleable; although none of the pieces are larger than a pinhead, still they are readily 

 extended by the hammer. The iron in the crust is glazed over so that the eye does not perceive its metallic character, 

 but the file instantly brightens the innumerable points which then break through the varnish of the crust and give it 

 a brilliant metallic luster at all the points where the file has uncovered the iron. The'same is the fact with the Weston 

 stone and with that of L'Aigle, but not with that of Stannern in Moravia; specimens of all of which and of the meteoric 

 iron of Pallas, of Louisiana, and of Auvergne are now before me. The aerolites of Jonzac and of Stannern, as stated by 

 M. Bellevue, are the only ones hitherto discovered that do not contain native iron and do not affect the magnet; still 

 their analysis presents a good deal of iron which is probably in the condition of oxide. 



The iron in the metallic state is very conspicuous in the Weston stone, sometimes in pieces of 2 inches in length, 

 and both in this stone and in that of Maryland it is often brilliant like the fracture of the meteoric iron of Pallas and of 

 Louisiana. 



In the analysis of the Weston stone published in 1808 1 did not discover chrome although it was afterwards announced 

 by Mr. Warden. I have desired Mr. Chilton to reanalyze the Weston stone and he has nearly completed the labor, the 

 result of which may be given hereafter, but he writes that he has not been able to discover any chrome. I am not 

 quite sure that I discover pyrites in the Maryland aerolite, although it is mentioned by Dr. Carver in his letter in the 

 preceding volume. 



Partsch 3 described the specimen in the Vienna collection as 



Groundmass varying between light and dark gray, partly spotted with rust flecks; in part showing lighter but 

 generally darker spherical inclusions firmly intergrown. There is a considerable sprinkling of iron and pyrrhotite. 

 Crust rough and dull, broken by narrow clefts. 



Shepard 4 gave the following notes: 



Its crust resembles that of the Iowa stone (Marion) without, however, possessing its uniformity of thickness or its 

 deep black color. The proportion and mode of dissemination of the nickel-iron and of the pyrites is very similar in 

 both; but the color of the earthy mineral in the Maryland is several shades darker and more inclined to blue. The 

 iron-rust points are less frequent than in the Iowa meteorite. Like the latter it is principally composed of howardites; 

 although rounded grains of olivinoid to the amount perhaps of 15 per cent are distinguishable with the aid of the 

 microscope. 



