Notice of Prof. Clark’s Thesis on Metallic Meteorites. 7 
in my report on meteorites published in vol. vi, new series, of 
the Amer. Journal of Science and Arts, p. 404. The drawings 
in fig. 3 (as well as those of the two preceding ones) were made 
by Mr. R. Bakewell. The uncommon completeness and perfec- 
tion of form in this stone, seemed to render it worthy of being 
accurately figured. Its greatest diameter is four inches: from 
the fractured apex of the four-sided pyramid to the centre of the 
* opposite side, measures 34 inches. It weighs 2 lbs. 84 oz. 
Art. Il.—WNotice of Professor Clark's Thesis on Metallic 
8 eteorites.* 
Pror. Wa. S. Ciarx of the Scientific Department in Amherst 
College has presented a valuable contribution to the science of 
Astrolithology, in an Inaugural Dissertation on his promotion to 
the rank of Doctor of Philosophy at the University of Gottingen. 
The following extracts from the dissertation, are intended to giv 
a general view of such facts and observations as are either new, 
or at least have not been presented in the pages of this Journal. 
The color of meteoric metal varies from silver-white to dull 
gray, and the hardness from that of the hardest steel to that of 
metallic copper. The specific gravity is usually between 7 and 8, 
though rarely as low as 6. It varies exceedingly on different 
parts of the same mass. The metal is generally very malleable, 
both hot and cold ; and of course difficultly fusible. _Wohler bas 
observed that the metal of some meteorites is in a passive, an 
that of others in an active condition ; so that specimens of some 
precipitate copper from a solution of the sulphate, while those of 
others, do not. He infers from his experiments, that all meteoric 
metal is probably passive at the time of its fall, and becomes ac- 
tive after long exposure on the earth. Besides the chrysolite 
found in the masses of Krasnojarsk, Atacama, etc. ; almost micro- 
Scopic grains of a mineral harder than glass and resembling the 
Hest quartz sand, are often to be seen in the insoluble residue 
obtained by digesting pieces of meteoric metal in hydrochloric 
acid. Stromeyer made a series of experiments upon chrysolite 
of terrestrial and of meteoric origin; and came to the astonish- 
Ing conclusion, that the former usually contains nickel, while the 
latter though imbedded in nickeliferous iron, contains none. Ga 
. Rumler first discovered arsenic to belong to the meteoric ele- 
ments, while testing the Atacama chrysolite for water. When 
meteoric metal is dissolved in an acid, the solution almost inva- 
Eighty pages 8vo, with 3 lithographic plates. Printed by W. F. Kaestn sali er; 
