TO ODESSA. 367 
gation of mineralized sea-shells, used for a CI *£ P - 
material in building the cottages, of such — * — 1 
extraordinary beauty and perfection, as to uzed'sheii* 
merit more particular description. The author 
has since annually exhibited a specimen of this 
singular deposit, in the Mineralogical Lectures 
given to the University of Cambridge; and, 
since it seems to offer some evidence of a 
remarkable change sustained by animal matter 
in its decomposition, as well as a striking 
proof of the draining of the Great Oriental 
Plain by means of the Canal of Constantinople, 
he begs leave to state here, as briefly as pos- 
sible, his own observation upon this subject. 
It is an opinion of the celebrated Bournon, Observa. 
that, whenever the abode of a testaceous animal th™Odm" 
ceases to conduce to purposes of life, and is Limestone * 
abandoned by its inhabitant, it becomes pro- 
perly a mineral s ; that, for example, as a 
specimen of carbonated lime, it possesses, in an 
eminent degree, the characters and fracture of 
that substance, when indurated or crystallized. 
In proof of this, he once exhibited to the author, 
in the casual fracture of a common oyster-shell, 
the same relative position of surfaces which is 
(S) Traiti' complet dc la Chaux carbonate, &c. par Bournon, 
PP’SIO, 314. 
