TO ODESSA. 
369 
variety of limestone used for architectural pur- ci ™p. 
poses, it hardens by exposure to the atmosphere. > — - v — 
Owing to this, and also to its remarkable light- 
ness, it has become a favourite material for 
building. When examined closely, it displays, 
throughout the entire mass, no other appear- 
ance than an aggregate of small cockle-shells, all 
exactly of the same size, and perfect in their 
forms, but crumbling in the hand, and being 
coloured by the yellow or the red oxide of iron. 
The chemical analysis of this mineral is nearly 
that of the Ketton-stone ; yielding no other ingre- 
dients than lime and carbonic acid, excepting a 
very small proportion of the oxide of iron. The 
stratum whence it is dug is of considerable 
thickness, and lies several yards above the pre- 
sent level of the Black Sea. It may be noticed 
in every part of the coast, and especially within 
the port of Odessa. Similar appearances may 
be also traced the whole way from the Black Sea, 
towards the north, as far as the forty-eighth 
bne of latitude, and perhaps over all Asiatic 
1'ahtary; whence it follows, that the level of 
the waters appearing at intervals between the 
Parallels of French longitude 40 and 80 , was not 
always what it is now : and, that the period of 
J ts incipient fall may be traced to an sera subse- 
quent to that of the Scriptural Deluge, seems 
evident, not only from history, but also by 
