4*5 
on some fossil Bones. 
should have the most ; for the harder and more compact the 
earth, the better is the animal part preserved ; which is an ar- 
gument in proof of their having been the longest in a fossil 
state. From experiment and observation, the animal part is 
not allowed to putrefy, it appears only to be dissolved into a 
kind of mucus, and can be discovered by dissolving the earth 
in an acid ; when a shell is treated in this way, the animal sub- 
stance is not fibrous or laminated, as in the recent shell, but 
without tenacity, and can be washed off’ like wet dust ; in 
some, however, it has a slight appearance of flakes. 
In the shark's tooth, or glosso-petra, the enamel is composed 
of animal substance and calcareous earth, and is nearly in the 
same quantity as in the recent ; but the central part of the 
tooth has its animal substance in the state of mucus inter- 
spersed in the calcareous matter. 
In the fossil bones of sea animals, as the vertebrae of the 
whale, the animal part is in large quantity, and in two states; 
the one having some tenacity, but the other like wet dust: 
but in some of the harder bones it is more firm. 
In the fossil bones of land animals, and those which inhabit 
the waters, as the sea-horse, otter, crocodile, and turtle, the 
animal part is in considerable quantity. In the stags horns 
dug up in Great Britain and Ireland, W'hen the earth is dis- 
solved, the animal part is in considerable quantity, and very 
firm. The same observations apply to the fossil bones of the 
elephant found in England, Siberia, and other parts of the 
globe; also those of the ox kind ; but more particularly to 
their teeth, especially those from the lakes in America, in 
which the animal part has suffered very little; the inhabi- 
tants find little difference in the ivory of such tusks from the 
