C. T. Jackson on Meteoric Iron from Dakota Territory. 259 
It will be noticed from the figures (in which the relative 
proportions of the planes have been preserved as nearly as 
Art, XXVII.—WMeteorie Iron from Dakota Territory—Description 
and analysis ; by CHARLES T. JAcKsSoN, M.D., of Boston. 
On the 9th of June last, I received, through Messrs. John W. 
Shaw & Co. of this city, a mass of meteoric iron from John B. 
This mass of metal was supposed by Mr. Hoffman to be some 
native alloy of silver, and it was sent here to be assayed for 
t metal. 
_ The mass in my possession weighs ten pounds ten ounces, and 
is six inches long, five inches wide, and about two inches thick, 
but is of an irregular form, the weathered or exterior surface 
being much indented, or wavy and pitted, while its opposite side 
is columnar, a natural fissure having exi between it and the 
large mass from which it was detached by the aid of a sledge 
* At least this is true of all the specimens which have fallen under my observa- 
original fig Tavistock crystals by Brooke, (Brande’s Quar- 
tion, but in the of the y 
terly Journal, xvi, 274, and Dana’s Manual ag. Mineralogy, ii, 424,) not only the basal 
plane O but also a second set of octabedr 3 } are represented. 
in general quite Hebron crystals and is very dif- 
ferent form we have given above. The d bl 
to be explained by the ing characters of the matrix in which the crystals occur 
at that locality, and it ee under certain conditions, the mineral has a tend- 
eney to the prismatic form which is only more fully developed i imens 
from Hebron. & 
