SPIRIT OF GOOD BOOKS. 
323 
part of the field was occupied for sev^eral centuries as a Gallo-Roman burying 
ground. But the old sculptures rarely extend deeper than the brick-earth and 
gravel b. Some fine specimens of stone coffins (of the hard and sandy lower 
chalk) remain on the ground, the surrounding brick-earth having been exca- 
vated. Of the wooden cofllns nothing but the ironwork remains. Roman 
coins, and fragments of old pottery are found on or near the surface, and the 
new ground is, in places, strewed with human bones. The following sections 
in M. FreviUe's pits, show how distinct the line is between the disturbed and 
undisturbed ground. 
Fig. 8.— Section in the pit near the high road at St. Achenl. 
" The remaining question is whether the fossU bones may have been derived 
from an older deposit, presents a contingency requiring especial notice. That 
such a case is possible is evident from the circumstance of fossils and debris of 
various tertiary strata being found in the gravel. Still tliere are, I think, valid 
objections to this supposition. 1. The fragments of bones, although constantly 
found with their sharp angles worn and blunted, never assume a rounded 
pebble-form, or exhibit an extent of wear materially differing from or exceeding 
that to which the flint-implements have been subjected; while, as a general 
rule, the entire bones and the teeth are either not rolled at aU, or are so slightly 
so, as rarely to be in any way injured by attrition. If the bones were really 
derived from an older bed, then consequently they would in general be worn as 
much as any other materials derived from such a source, — a wear necessarily 
in excess of that of the newer portion of the gravel, — whereas, on the contrary, 
the bones are amongst the least worn substances in it. 2. Neither do the 
bones or teeth show any mineral character, nor is there any mineral substance 
adhering to them, different to that which would be imparted b_v the matrix in 
which they are now imbedded. Nor, if they had only been originally subjected 
to«their actual extent of mineral change, would they have been in a better 
condition to resist destruction by subsequent exposure and wear than they are 
now. The teeth of the Elephant are mostly much decomposed, and tend, 
without great care, to fall to pieces on exposure. Many of the bones are also 
very friable, the greater number being porous and free from any foreign matter. 
3. No older beds that could have furnished such mammalian remains, are 
known to exist in the district. 4. The delicate and fiiable shells found 
associated with the bones at St. Acheul and Menchecourt, and that couJd not 
