374 
carbonate of lime from waters holding it in solution may therefore 
result from two opposite causes; an absorption of carbonic acid, 
from the atmosphere, or from some subterranean source ; and the loss 
of that part of it, which exists in excess, and which may be driven 
off by heat, or forced into other combinations, by the combined 
agency of different affinities. A farther investigation of the cir- 
cumstances on which these depositions depend, does not appear to 
be necessary, it seeming to be sufficient to have ascertained that 
water, saturated with carbonate of lime, is not only flowing over 
Various parts of the earth’s surface, but is also transuding its sub- 
stance in almost every direction. That it should therefore impreg- 
nate with its earthy particles, any substance, which like bituminized 
wood, or any decaying organic substance, might be fitted to receive 
it, appears to be highly probable : and that calcareous fossil wood 
may have been formed by such an impregnation, and under such 
circumstances, every character which it possesses, either physical or 
chemical, serves to demonstrate. 
Yours, &c. 
LETTER XXXIX. 
CALCAREOUS FOSSIL WOOD WHERE FOUND CALCAREOUS WOOD 
OP OXFORDSHIRE, DORSETSHIRE, SOMERSETSHIRE ANALYSIS 
MIXTURE OF SPAR AND BITUMEN CALCAREOUS WOOD OP NEW 
SOUTH WALES ALUMINOUS WOOD, ETC. 
It has been said, that calcareous wood is found in various parts of 
the continent, and particularly in the neighbourhood of Arundsee 
in Brandenberg ; near Joachimsthal, in Bohemia ; at Schemnitz, in 
