FOSSIL BONES. 47 
and Oolite, may be restored in the same manner. These 
remains are generally very brittle, and when imbedded 
in hard grit cannot be extracted whole: they will often 
fall to pieces on the slightest blow of the hammer or 
chisel. When of moderate size, it is best not to attempt 
their removal from the stone, but to trim the block into a 
convenient shape, and carefully chisel away the surround- 
ing part, so as to expose the essential characters of the 
bone. In all cases this is an excellent method where prac- 
ticable, for such specimens haye a double interest ; they are 
at once illustrative examples of the fossil, and of the rock 
in which it was deposited. 
But many specimens will not admit of this method; and 
with large ones it is inconvenient and undesirable, except 
where bones lie in juxtaposition. The large examples in 
Tilgate grit, (figured in the Fossils of Tilgate Forest,) were 
all extracted piecemeal from the rock: and most of the 
gigantic bones of the Iguanodon, &c. now in the British 
Museum, were originally in many hundred pieces, and were 
cemented together with glue in the manner above described ; 
I have found no other method so convenient and effective. 
When a bone is too imperfect to be united as a whole, it 
may be imbedded in Roman cement, or plaster of Paris, 
which when dry may be coloured of the prevailing tint of 
the rock. For large heavy specimens, the cement is pre- 
ferable; it is of easy application, and the fissures and cracks 
of the bones may be filled up with it, taking care first to 
cover the parts with thin hot glue, or the cement, when it 
dries, will shrink and fall out. <A thin coating of mastic 
varnish will restore the colour, and by excluding the air, 
tend to preserve the specimens. 
The teeth have generally undergone the same changes as 
the bones with which they are associated. The teeth of 
elephants or mammoths that are imbedded in loose calca- 
reous earth, like the loam and chalk rubble of Brighton 
