44 
THE CAROLINE STONY METEORITE 
free from oxidation. Nickel-iron visible on polished surfaces 
does not occupy more than 0 3 per cent, of their area, but this 
figure would be much greater if slices were taken from the core 
of the meteorite, instead of from the marginal zone as has been 
done to avoid undue damage to the specimen. The original 
amount of nickel-iron, however, was probably not greater than 
that of pyrrhotite. 
Nickel-iron, which appears bright white on the polished 
surface, is readily attacked by nitric acid and the solution so 
obtained gives microchemical reactions for nickel with dime- 
thylglyoxime. Etching with 2 per cent, picric acid in alcohol 
reveals the internal structure and composition of the grains ; 
kamacite is more readily attacked than taenite or schreibersite. 
Occasionally the kamacite grains enclose thin laminae which 
are less readily attacked and are presumably taenite; some 
thicker laminae consist of eutectoid mixtures of kamacite 
and taenite. Kamacite grains are often surrounded by a 
thin film of more resistant mineral (Eig. 2), probably taenite, 
but in one instance the proportions are reversed, the taenite 
rim exceeding the kamacite core in amount. In some grains 
an unattacked particle is attached to the kamacite (Fig. 4). 
Several of these chemically resistant particles were large 
enough to scratch with a needle ; all but one were malleable, 
and may be regarded as taenite ; one is brittle and is, therefore, 
schreibersite. A rare, internal, irregular intergowth with 
kamacite may also be schreibersite. 
In some grains the progress of oxidation has been arrested 
at a lamina of taenite, other grains coated with a film of 
taenite have escaped oxidation in many cases. The taenite 
film may be partially separated from the kamacite by a layer 
of limonite, and even in completely oxidized grains, there are 
occasionally traces of marginal taenite. 
An attempt was made to verify the presence of schrieber- 
site by determining the phosphorus content of the more highly 
magnetic fraction of a sample of powdered meteorite. The 
highly magnetic fraction contained particles of nickel-iron, 
and limonite, some pyrrhotite and trevorite, and small quan- 
tities of transparent minerals ; its P 2 O 5 content, determined by 
Dr. A. B. Edwards on a sample weighing 0 15 grain, was 0 47 
per cent. This percentage is higher than the average figure 
for stony meteorites, but is practically the same as that (O’ 48 
per cent. P2O5) for the fraction unattracted by the magnet. 
The close approximation of the two percentages, together 
with the great impurity of the magnetic fraction, suggests 
that the oxidized minerals include some phosphate ; and since 
