43i 
THE GEOLOGIST. 
bed of ferruginous clay, about a foot thick. The " black sand " is a very- 
important deposit, both on account of the thickness and the number of 
fossils it contains. It is the equivalent of the "black crag" or " glauco- 
nite crag." As this deposit has nowhere been penetrated in the excavations, 
its thickness is not known. The chief shell is the Pectuncidm variabilis. 
The " Systeme Rupelien " is solely represented by the " marne argil- 
leuse," which is found at Fort no. 8, and in the brickfields of Edeghem. 
It is a black or bronze-coloured clay, containing concretions of pyrites and 
septarife, often \xiQvw.s>img Xautilas Aturi. It also contains flint-pebbles 
and teeth of Carcharodon heterodon. 
EEYIEW. 
Essays and Observations on Natural Si story. Anatomy, Physiology, Psy- 
chology, and Geology. By John Hunter, F.R.S. Being his Posthu- 
mous Papers on those subjects, arranged and revised, with Notes, by 
Kichard Owen, F.H.S., D.C.L., Superintendent of the Natural His- 
tory Department, British Museum, etc. etc. John Van Voorst. 
The aphorism of Niebuhr, that "he who calls what has vanished back 
again into being, enjoys a bliss like that of creating," which has been 
quoted by almost every geologist from Lyell downwards, is nowhere more 
applicable than to the discovery and safe transmission to the thinking 
scientific men of the present day of the long-lost Hunterian manuscripts, 
and especially on that on G-eology, to which we shall draw our readers' 
attention. 
John Hunter, after communicating to the Royal Society of London, in 
1793, his paper "on the Fossil Bones presented to that Society by His 
Most Serene Highness the Margrave of Anspach " (' Philosophical Trans- 
actions,' vol. IxxKiv. 1794), followed up the subject by a second memoir, 
summing up the conclusions which he had deduced from his study of "Ex- 
traneous Fossils " in general. This manuscript he communicated to the 
Royal Society, with the following result : — 
" The attention of the Secretaries or Council of the Royal Society had 
been called, by some of the Fellows, to the expressions in the first paper, 
on the ' thousands of years ' required for such and such geological phe- 
nomena ; and, in the second memoir, the Secretaries found that a chrono- 
logy of the earth, widely different from the usually accepted one, was more 
directly and emphatically affirmed by the author, as essential to the ra- 
tional comprehension of the phenomena he treated of, while, at the same 
time, the adequacy of the chief or sole geological dynamic at that time 
recognised, viz. the Mosaic Deluge, to account for the presence of marine 
fossils on land, was called in question. Considerations for the repute and 
interests of the author himself may have swayed his advisers in the recom- 
mendation to him to submit the manuscript to a geological friend, before 
finally sending it in for formal acceptance and perusal before the Society. 
Major Rennell, author of some papers in the 'Philosophical Transactions' on 
' Tides and Currents,' and other geographical subjects, undertook the deli- 
cate task of submitting to Hunter the misgivings of the authorities mainly 
responsible for the publications of the Royal Society. He did it in these 
words : ' This leads me to remark that, in page 3, you have used the term 
