a 
T. 8. Hunt—The Decay of Rocks. 205 
and evidently in part changing into honey-combed brown hem- 
atite ore.” * 
beds conformable to the other rocks.” He at the same time 
supposed that some of these ore-deposits are, like one noticed 
in Wythe County, Virginia, due to “the weathering of the 
his view is to be supplemented by the consideration 
that carbonated solutions of ferrous oxide fo 
beds of carbonate of 
latter by carbonate of iron.’ The transformation of diffused 
«amer. Philos. Soe. Proc., ix, p. 471-475. 
ret Amer, Assoc. Adv. Science, 1867, p. 114. 
6 eo ogical Survey of Penn., 1858, ii, 757. : : 
J. Ville found one liter of carbonated water at the ordinary pressure to hold 
eee at 20° O. 1°142 grams of ferrous carbonate. and at 15° C. 1°390 ie 
om i 
. 
F 
and magnesia uce the same effect though more slowly. (C. Rendus de l’'A 
des Sciences, Oct., 1881, vol. xciii, p. 443.) The present writer found recen' 
Precipitated ferrous carbonate to be temporarily much more soluble, under the : : 
rmed as above © 
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