116 Mr Middleton on Fluorine in Recent and Fossil Bones. 
it is no argument to say, that a warehouse built like a funnel, 
and provided with all the elements of conflagration, is attend- 
ed with risk, when it is well known that a perfectly secure 
and perfectly sound fireproof building can be erected free 
from all the perils above enumerated. 
In my own mind, there is not the shadow of a doubt as to 
the security of such a structure; and I do not hesitate to 
assert, that a well-built and properly arranged fireproof 
warehouse can not only be constructed, but may be made to 
entail upon the commercial and manufacturing communities 
of this country an important and lasting benefit. 
Wma. FAIRBAIRN.* 
MANCHESTER, June 3. I844. 
On Fluorine in Recent and Fossil Bones, and the sources from 
whence it is derived. By J. MIDDLETON, Esq.t 
Having been for some time past engaged in investigations, 
not yet matured, on the absolute and relative quantities of 
fluorine in fossil bones, I was readily led to inquire into its 
presence, or otherwise, in recent bones. The high authority 
of Berzelius had indeed satisfied me on this subject; and I 
might not have felt a motive to examination for myself, had 
I not lately heard the fact doubted and disputed before the 
Chemical Society, and elsewhere, with an earnestness which 
could only proceed from conviction. The readiness with which 
the authorities of the University College acceded to my re- 
quest for materials, as well for this as for my more labo- 
rious investigations, left me no difficulty, and deserves my 
best acknowledgments. 
I easily obtained conclusive evidence of the presence of 
fluorine in the following portions of the human skeleton, the 
* From a printed Report “ On the Construction of Fireproof Build- 
ings ;’’ communicated to us by the Author. 
t Communicated to the Philosophical Magazine by the Chemical So- 
ciety, having been read May 6, 1844. On the subject of this paper, see 
the author’s previous one, p. 285, and also Dr Daubeny’s, p. 288, of pre- 
ceding volume of this Journal. 
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