—E=_- 
% 
Ancient Vegetation of the Earth. 315 
Its powder is feebly attacked by long digestion in dilute hydro- 
chloric acid. Heated for half an hour with five times its weight 
of anhydrous carbonate of soda in a platina crucible, a light 
brown, cohering, porous mass was obtained, which was treated 
with dilute hydro-chloric acid and digested for some time; a 
bulky, heavy brown precipitate remained undissolved, which 
grew paler however towards the end of the digestion. The 
whole was thrown upon a a an abundant milky substance 
continued to the so long as water was on the filter, 
and which (considered lai with the blowpipe indications) was 
regarded as titanic acid. A portion of the hydro-chloric acid 
liquor (obtained clear by decantation) was treated with a satura- 
ted solution of sulphate of potassa without obtaining any precipi- 
tate, even after twenty four hours standing. Another portion was 
examined for silica, lime, magnesia, and alumina, but without 
detecting either = them. Iron and manganese appeared to be 
the only bases present. 
As the result of nt foregoing examination, therefore, I conclude 
that Warwickite is a fluo-titaniate of iron and manganese ; but I 
must add that my chemical trial was made upon a sample ina 
decomposing state, though it was still endued with considerable 
hardness and a faint lustre. As my cabinet at Charleston em- 
braces a large and fresh crystal, I purpose on my return to that 
city to occupy myself still farther with the elucidation of its 
chemical properties. 
New Haven, May 22d, 1838. 
Art. VI.—Considerations upon the Nature of the Vegetables that 
have covered the surface of the Earth, at different epochs of its 
~rmation ; read before the Academy of Sciences of Paris, on 
the 11th September, 1837, by Mons. Apotpur Bronenrart. 
Translated from the French, and communicated for this Journal, by R. W. Has- 
Kins,” of Buffalo, New York 
_Currosrry is one of the most distinctive faculties of the human 
mind; one of those that most clearly mark the distance between 
man and the brute creation; and for this reason it may be desig- 
_ * Mr. Haskins prefers an orthography in some cases peculiar, and retains also 
in F: idioms.—Eps. 
