sewhere endeavour to manifest when I come to shew the use of the
Air in respiration, and for the preservation of the life, nay, for the
conservation and restauration of the health and natural constitution of
mankind as well as all other aereal _animals_, as also the uses of this
principle or propriety of the Air in chymical, mechanical, and other
operations. In this place I have onely time to hint an _Hypothesis_, which,
if God permit me life and opportunity, I may elsewhere prosecute, improve
and publish. In the mean time, before I finish this Discourse, I must not
forget to acquaint the Reader, that having had the liberty granted me of
making some trials on a piece of _Lignum fossile_ shewn to the Royal
Society, by the eminently Ingenious and Learned Physician, Doctor _Ent_,
who receiv'd it for a Present from the famous _Ingenioso Cavalliero de
Pozzi_, it being one of the fairest and best pieces of _Lignum fossile_ he
had seen; Having (I say) taken a small piece of this Wood, and examin'd it,
I found it to burn in the open Air almost like other Wood, and insteed of a
resinous smoak or fume, it yielded a very bituminous one, smelling much of
that kind of sent: But that which I chiefly took notice of, was, that
cutting off a small piece of it, about the bigness of my Thumb, and
charring it in a _Crucible_ with Sand, after the manner I above prescrib'd,
I found it infinitely to abound with the smaller sort of pores, so
extreamly thick, and so regularly perforating the substance of it
long-ways, that breaking it off a-cross, I found it to look very like an
Honey-comb; but as for any of the second, or bigger kind of pores, I could
not find that it had any; so that it seems, whatever were the cause of its
production, it was not without those small kind of pores which we have
onely hitherto found in Vegetable bodies: and comparing them with the pores
which I have found in the Charcoals that I by this means made of several
other kinds of Wood, I find it resemble none so much as those of Fire, to
which it is not much unlike in grain also, and several other proprieties.

And therefore, what ever is by some, who have written of it, and
particularly by _Francisco Stelluto_, wrote a Treatise in _Italian_ of that
Subject, which was Printed at _Rome_, 1637, affirm'd that it is a certain
kind of Clay or Earth, which in tract of time is turn'd into Wood; I rather
suspect the quite contrary, that it was at first certain great Trees of Fir