62 
ox THE roSSII. ELEPHANf 
The air has no^v begun to operate upon the tootli ; li 
has shrunk considerably, and is formed into longitudinal 
concentric rings. When first cut across, it was quite solid : 
this circumstance proves liow completely it had been ex- 
cluded from the action of air or water, otherwise it must 
have decayed long ago. 
I have frequently mentioned to naturalists the observa- 
tion I had made of no trace of oro;anic remains being: fotmd 
in this kind of cover; and this is the more remarkable, as 
in the coal-fields, where it rests on rock, the strata abound 
with impressions, and casts of plants and shells ; and the 
shistus at Cliftonhall abounds with delicate and beautiful 
impressions of the former. To this observation I have re^ 
ceived for answer, that probably both plants and animals- 
may have been at one time in this kind of cover, but are 
now decayed. Had this been the case^ some faint traces of 
them would have remained, and the clay would consequent- 
ly have had some of the principles of the fertihty of the 
recent alluvial covers. But this is not the case in the least 
degree. Besides, from the specimen now exhibited, its qua- 
lity of preserving organic remains is very manifest. 
There are instances, however, where I have seen large 
trees inclosed in this kind of cover by the sides of rivers : 
this is easily accounted for. Such trees have grown on the 
banks of the river ; the floods have undermined them, and 
the trees, after faUing, were overlaid by succeeding falls of 
the bank, and in such a manner as to secure them from 
either the action of air or of water. Such trees, when taken 
out, are as solid and hard as when they were growing. I 
saw an instance lately of an oak-tree taken out of a bank 
of this kind at Yester, near Haddington ; it was very black 
throughout, and so close in the texture, that it was made 
into ornamental furniture, which had the appearance of 
ebony. With this circumstance in view, I examined the 
