54 
THE BOND SPRINGS STONY METEORITE 
mineral substance, creamy-white with a tinge of brown, but, 
on etching with a 2 per cent, solution of picric acid in alcohol, 
it is resolved into an intergrowth of kamacite ( -nickel- 
iron), taenite (y-nickel-iron), and an unidentified mineral. 
Kamacite (6-8 per cent. Ni) constitutes the bulk of the 
nickel-iron; it is isotropic, magnetic and readily scratched 
with a needle. With nitric acid it effervesces and stains 
brown, and the resulting solution gives microchemical re- 
actions for iron and nickel ; the etched surface reveals grain 
boundaries and irregular lamellae of the unidentified mineral. 
Hydrochloric acid attacks the kamacite readily, with effer- 
vescence, and turns it black. Ferric chloride rapidly stains it 
blown, and it ridis to a slightly etched surface; mercuric 
dilonde blackens the surface at once, but it rubs clean. 
Potassium cyanide and potassium hydroxide give negative 
results. 
l aenite (25-40 per cent. Ni), which is also a creamy-white 
isotropic magnetic mineral, is distinguished from the kama- 
cite by the fact that it is not etched rapidly by picric acid- 
alcohol solution nor by bromine water. Nitric acid slowly 
stains taenite brown, but does not cause effervescence. Other 
standard etching reagents give negative results, except 
mercuric chloride, which immediately blackens the taenite, 
but rubs clean. 
Some doubt attaches to the determination of taenite in this 
meteorite, because the mineral under discussion occurs in 
Plains (PI. XII, figs. 1 and 2) and not lamellae; the possi- 
bility that it is the phosphide, schreibersite, cannot be 
neglected. A small grain of the mineral regarded as taenite 
was prised out with a drill and dissolved in nitric acid; it 
yielded positive reactions for iron and nickel. The iron may 
have come from associated pyrrhotite, but it is unlikely that 
the nickel came from this source, since repeated tests for 
niclpl on grains of pyrrhotite gave negative results. The 
grain was too small to test for phosphate. 
Determination of this mineral as taenite is strengthened 
by occasional dark cores (PI. XII, fig. 1) identical with 
those observed in undoubted taenite; Yanick (12, p. 178) 
regards these cores as due to minute carbon particles, but 
Johnston and Ellsworth (9, p. 97) consider them to be dis- 
solved phosphide. 
The taenite frequently forms thin rims, 5 to 10 microns 
thick, around small areas of kamacite; similar rims are 
figured by Dunn (4) for the Rangala Meteorite. Occasionally 
