1891.] DAVISON—ON METEORIC IRON. 179 
after being left for some time protected from air currents under a bell 
glass. The meteorite as a mass also showed polarity. The tenite is 
found separating the plates of kamacite, and enveloping the crystals of 
plessite. Figures 3 and 4 show plates of kamacite which were in close 
contact, and when separated were found to have been joined by a little 
triangular prism of the same substance. It is attached to 4, and has 
penetrated 3 to the depth of 1.5 m.m_ The socket in 3 was lined with 
teenite. It was at first intended to analyze the plessite as a whole; but 
on examination, its fine layers were so suggestive of alternate lamellz 
of kamacite and tenite that the attempt was made to separate them, 
and to analyze each separately. 
It was found that one was brittle, the other flexible and elastic ; 
one dark with superficial oxidation, the other showing the tznite luster. 
Physically their correspondence, the one with kamacite, the other with 
taenite, was exact, and in the kamacite-like part the columnar structure 
was shown on a diminutive scale, the diameter of the rods being from 
16-13 m. m. 
Their separation then became simply a matter of patience, and 
with the aid of a watchmaker’s glass and a magnetized needle, to pick 
up the grains and flakes, most of which were too small for even delicate 
forceps to handle, there was obtained for analysis, of the part resem- 
bling kamacite, gm. 0.5261, of that resembling tenite, gm. 0.1314. 
The thickness of the kamacite was from 1-2 m.m., that of the 
teenite from ;/; to 35 In.m. 
In the plessite the kamacite-like bands were from 3} to 35 m.m 
thick ; the tenite-like bands, as nearly as could be measured, from 
zi7 to shy Mm. 
The method of analysis was the same in each case. The material 
was gone over repeatedly, piece by piece, with a watchmaker’s glass, 
and very carefully assorted and cleansed, the pieces of kamacite being 
scraped bright. It was not possible to do this to any extent with the 
kamacite-like part of plessite. It was dissolved in dilute hydrochloric 
acid by the aid of a weak galvanic current at the positive pole of the 
battery. 
The carbon thus separated was collected on a Gooch filter and 
burned. The nickel and cobalt were separated from the iron by 
digestion in ammonium hydrate, the process being repeated four times. 
The iron was weighed, and the nickel and cobalt first determined 
together by electrolysis, then separated by potassium nitrite and each 
determined separately in the same manner. : 
