[ +°/] 
Mafies of Building-Stone 5 in Ingria , in feveral Parts 
of Bruffia, <&c. and are commonly of an immenfe 
Bignefs, to feveral Feet in Length, and proportion- 
ally thick, yet not perfect For fuch Alveoli, which 
are only Nuclei , we muft fuppofe immenfe large 
Belemnites 5 and fuch we have never heard of, fo 
with Probability we may conclude none fuch to 
exift. 
I do not doubt the Growth of this Error, of the 
Belemnites being a Part of its Alveolus , to have been 
caufed by too raih Conclufions, and too little an In- 
flght into the foflil Kingdom 5 which has propagated 
that Affertion of the Alveoli being found only in 
the Belemnites 1 which Experience daily contradicts, 
fince we find them loofe, as well as imbedded in 
many other foflil Subftances, as in Marble, Stone, 
as has been above obferved. 
Thefe are the Arguments which I allege, Sir, for 
the Improbability of the faid Opinions. I could ad- 
vance a Number of other Proofs \ but as I have 
already extended my Letter beyond a due Length, I 
beg Leave, before i conclude, only to offer feme, 
few Reafons for their being a natural Foflil, or La- 
pis fui generis . 
The very View of a Belemnites fufficiently evinces 
its mineral Origin, and fhews it evidently compofed 
of two foflil Subfiances, a Talc, and a Spar, or baf- 
tard Cryftal; whereof the former is the Bafis, and 
from which Principle I do not hefitate to attribute 
its ftriated Texture.. Moft of the talcy Bodies are 
of a fibrousT Nature, and feveral are compofed of 
Crufts inclofing each other, in the fame Manner as 
the Septa of the Ludus Helmontii , fome of the Af« 
beftos kind, the Hematites Crufts* Qf the Sta- 
lattitu 
