83 On Meteoric Iron, 



the removal of portions of the external laminae during its separa- 

 tion from the original mass. The cells and cavities are perfectly 

 geometrical in shape, being either rhomboidal, tetrahedral, or in 

 the figure of four sided pyramids. Indeed, the resemblance of the 

 mass in this respect to that of an imperfectly formed crystal of 

 alum, is very striking. 



It requires the application of numerous and powerful blows to 

 disengage fragments from the specimen. The hammer slightly 

 indents the surface ; and at length loosens sections of the external 

 laminee, which may be detached by the aid of a forceps. Their 

 shape is commonly that of an acute rhomboid, considerably flat- 

 tened in its dimensions ; but they are capable of an easy division 

 into regular octahedrons and tetrahedrons, whose exactness of 

 form rivals the cleavage-crystals of fluor. Some of the plates will 

 separate into leaves nearly as thin as mica, which substance they 

 even resemble in color, (being silver-white, inclining to steel- 

 grey,) and are slightly elastic, though when twisted up, they re- 

 main as a piece of thin iron would do under the like circumstan- 

 ces. The shape of the thinnest fragments is as regular in outline 

 as the layers of the most highly crystalline fluor ; and are deli- 

 cately striated in every direction, in accordance with the octahe- 

 dral cleavages. 



Prior to the separation of any fragments, the surface of the spe- 

 cimen did not aflbrd the metallic lustre ; but was coated with a 

 thin blebby pellicle, apparently of hydrous peroxide of iron. 

 Those surfaces which have been recently developed, lose their 

 silvery grey lustre in the course of a few weeks, but without any 

 sensible attraction of moisture from the atmosphere. 



Its specific gravity varies from 6.5 to 7.5 ; indeed, one fragment 

 mounted as high as 8. This diversity of results is no doubt de- 

 pendent on the compression of the fragments, produced during 

 their separation from the specimen. 



Analysis. 

 A. Fragments of it were treated with nitro-hydrochloric acid. 

 The action was feeble until heat was applied, and afterwards less 

 striking than with metallic iron, or even with the native terrestrial 

 iron of Canaan,* (Ct.) A dark clove-brown matter remained after 

 some hours of continued digestion, troubling the transparency of 

 the solution, and forming also a distinct sediment at the bottom. 



* See this Jour. Vol. xiv, p. 183, for Prof. Shepard's notice of this iron. — Eds. 



