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140 On Crystallized Native Terrestrial Iron, &c. 
Essore in France, where, during the trituration of a gunpowder, of 
this description, although it was conducted with all possible care, an 
explosion killed several persons. 
Fulminating mercury, and fulminating silver are still more irritable, 
and the latter, when thoroughly dry, will not permit even the weight 
of a knife blade to rest upon it, without inducing a violent explosion ; 
in a quantity equal to a common musket charge of gunpowder, it 
would, probably, be always fatal.* ; 
7. It is not therefore theoretically improbable, that the heat ne- 
cessary to the action of the oxygen upon the combustibles in gun- 
powder, may be evolved by pressure, and the particles may also be 
brought within the distance of effectual attraction, by the blow ap- 
plied in ramming down, and thus it is possible, that the action may 
come on, even when there is no spark.f May not some of the pre- 
mature explosions of cannon and other fire arms be attributed to simi- 
lar causes, especially when the piece is hot, in consequence of pre- 
vious firing, although there should be no spark ? 
All these views conspire to render it highly desirable that Mr. 
Blake’s method should prove successful, and I shall be much imter- 
ested to learn the result, which, after sufficient experience, I shall 
hope that you will communicate to the public. I remain respect- 
fully, your very obedient servant. B. Siiman. 
Yale College, Sept. 17, 1829. 
Arr. XV.—On Crystallized Native Terrestrial Tron, Ferro-silicate 
of Manganese, and various other American Minerals 3 by 
Cuartes U. Sueparp, Assistant to the Professor of Chemistry; 
and Lecturer on Botany, in Yale College. 
1. Crystallized Native Terrestrial Tron. 
In looking over a suite of rock specimens collected by Prof. Olm- 
sted, with a view to illustrate the Geology of North Carolina, and 
deposited by that gentleman in the cabinet of the American Geologi- 
cal Society, my attention was arrested by two pieces of Native Iron. 
Of one of these, the larger of the two, an account is given in Prof. 
ese ne ogee eg ee 
* Thad nearly lost both my eyes in 1811, by the explosion of fulminating silver. 
which took place in consequence of gentle pressure, even when it was under fluids. 
The particulars of the accident are related in Dr. Bruce’s Journal, Vol. I 
As in the eases that tinF nd which have been cited by Mr. Blake: 
