W. M. Foote — Meteoric Iron from Sams Valley, Oregon. 83 



After making a plaster model, the iron was sawed at Phila- 

 delphia into four slices of the largest possible area and about 

 5 to 10 ,nm thickness, as well as two large end-pieces. Polished 

 and etched with a weak solution of nitric acid, the crystalli- 

 zation of a medium octahedrite is clearly brought out. The 

 sawing was done parallel to the plane of two of the three cubic 

 axes. The lamellae forming the octahedral units of the crys- 

 talline mass are therefore sectioned so as to meet at right angles, 

 thus affording a network of rectangular figures (fig. 4). In 

 sawing irons the plane of sawing usually intersects a plane 

 formed by two of the crystal axes ; the etching thus exhibits 

 rhomboidal and triangular figures. Both rectangular and other 

 figures are shown in the same piece by 

 etching in different planes, as in fig. 3. FlG - 3 * 



Fig 4 is an end-piece, the reverse 

 side of which is shown in fig. 1. The 

 troilite nodule, measuring 25 mm in long- 

 est diameter, is the only one met with 

 in the mass, except one already men- 

 tioned and indicated by the hole at 

 the center of the reverse side of this 

 end-piece. The two may form part of 

 a nodule between 40 and 50 mm long 

 and 20 to 25 n,m thick. In the adjoining 

 slice, 2 mm distant, the nodule is slightly 



smaller, and on the reverse of this slice, „ m 



trn.m i j 'i. i j- j rru Fig. 3. Two planes of 



5 nim beyond, it has disappeared. 1 he etching at angles of 45° to 



polished nodule bears a central inclusion one another. 



of nickel iron. 



Schreibersite is abundant in small masses, but mostly in the 

 form of broad, thin plates showing on the etched surface as 

 slender rods of about 0*1 to l mm width and 10 to 30 mm length. 

 These plates sometimes lie between the kamacite lamellae, but 

 more often cut across the squares prominently at various 

 angles. In either case they are paralleled for their entire 

 length by the typical and familiar swathing kamacite of Bre- 

 zina. The bands are about double the thickness of the normal 

 kamacite forming the crystalline mass. 



The kamacite bands are quite regular, except for those par- 

 alleling the schreibersite plates, and range mostly from 0*5 to 

 l mm diameter ; their length varies greatly, many being only 1 

 to 2 mm , while others reach 25 to 30 mm . The characteristic and 

 very thin lamellae of nickel-rich tsenite outline all of the kam- 

 acite bands, and are prominent in certain lights. The ground- 

 mass consists of abundant fields of the nickel-poor plessite. 



The chemical analysis was made by Mr* J. Edward Whit- 

 field of the firm of Booth, Garrett & Blair, Philadelphia. The 



