Notice and Review of the Religuiae Diluvianae. 323 
action, and of antediluvian animal existence, as the Euro- 
pean caverns. : 
It s well known, that the most noted of the American 
caverns occur in our western States ina limestone, probably 
of the same character as those in Europe containing bones 
These American caves also contain, as is well known 
an abundance of stalactite and stalagmite ; but wheth- 
er there exists in them all, one and only one layer of dilu- 
vial mud, we have not been able to ascertain from any 
account now before us. Many of them, however, contain 
Jarge quantities of nitre. and we know not a more probable 
hypothesis than that which imputes its origin to the decom- 
position of animal substances. If we mistake not, we dis- 
cover in the following extract of a letter from Dr. Brown, 
to the Editor of this Journal, inserted in our first Volume, 
at the 147th page, evidence of the existence of the black 
animal dust which Professor Buckland found in the cave 
at Kuhloch. 
“fam much obliged to you for recalling my attention 
to that curious subject, (nitre caves,) as it has brought te 
my recollection a fact, which I believe | omitted to men- 
tion inmy memoir, (viz.) the existence of a black substance 
in the clay under the rocks, of a bituminous appearance 
andsmell. This I remember to have seen in a rock-house, 
near the Kentucky river, where very considerable quan- 
tities of sand-rock nitre had been obtained. This substance 
‘was found in masses of a few ounces weight, and in the 
crevices of the rocks near the basis of the side walls. 
The smell is not wholly bituminous, but resembled that of 
bitumen combined with musk. I am quite unable to ac- 
count for the formation of the nitre, or the production of 
this black substance which sometimes accompanies it, both 
in Africa and America. Had I seen Mr. Barrow’s travels, 
when I noticed the bitumen, I should certainly have paid 
more attention to it. But perceiving no relation between 
the rock nitre and the masses of this substance, my exam- 
ination of it was much too superficial. I do not very well 
understand what Mr. Barrow’s means by saying, that many 
waggon loads of animal matter lay on the roof of the cay- 
erns in Africa.* Isawno such matter on the roof of the 
* The same was asserted to be the fact in regard to the European caveg 
until Mr. Buckland examined them and found it to be a deception. Holes 
