20. Fienp CoLtumBian MusgtumM—GEo.ocy, VOL. 1. 
Upon close examination the bands are found to be made up of a 
broad, central plate depressed below the surface, which is bounded by 
narrow ones in relief. These are shown in Figs. 1 and 2, Plate II. 
Analysis of these plates by Reichenbach has shown that the 
broader ones are made up of an alloy of nickel and iron containing a 
large percentage of iron and hence readily dissolved by the acid. 
This alloy he called kamacite, The narrow plates, made up of an 
alloy which he called ¢aenite, contain a larger percentage of nickel, 
are less readily dissolved and hence stand out in relief. The ground 
mass, to which he gave the name of Alessite, he considered as having 
a proportion of iron and nickel between the two. Recent investiga- 
tions by Davison,* however, indicate that there may be but two alloys 
present, the plessite representing simply portions of the mass where 
the bands of taenite are so closely crowded as to protect the kama- 
cite from the action of the acid. This is rendered more probable 
by observing the insensible gradations by which the finer lines, 
called by J. L. Smith Laphamite markings, pass into the ground 
mass as if there were no real division between them. See Plate If, 
Pigs 
- The angles at which the bands meet are dependent, as has been 
stated, upon the direction of the section and also upon their parallel- 
ism to the faces of either the octahedron, cube or dodecahedron, of 
the isometric system. All of these planes may occur in one meteorite 
but commonly only those of one kind appear and give to the iron a 
characteristic structure, distinguishing them as either octahedral or 
cubic. 
The varying thickness of the plates and differences in their 
angles of intersection produce a variety of figures which characterize 
irons-of different falls. See Plates I, If and III. ‘Since they were 
first described by Widmanstdtten, they are called Widmanstatten 
figures. ‘They form one of the most striking features of the metallic 
meteorites and were long thought to be peculiar to such bodies, but 
are now known to be imitated by the etching figures of steel and of 
the native iron of Greenland. They have been produced by Daubrée 
upon a mass artificially formed by fusing together iron, nickel and 
phosphides of iron and nickel. They are, therefore, rather to be con- 
sidered as indicative of the conditions under which the meteoric mass 
originated than as representing any distinct property of extra-ter- 
restrial matter, 
As examples of coarse etching figures, 2. e. those made up of 
broad bands, may be noted sections of the Toluca (16), Staunton (79), 
Robertson Co, (83) and Cation Diablo (147), irons. More delicate fig- 



FAM... SC) gra ser, Vola 42, p64. 
