*'(.&$)■■ 
f heabfence and return of the Ambient Air, as might with any 
probability have the lofs or recovery of the W oods (plendour at- 
tributed to it. For I had formerly (if! were not miftaken) found 
by feveral circumftances, which I fhill not now (fay to name. 
That a flight (fo it be an appropriated} variation of the Texture 
of this Wood, and which may feem mainly to refpeft the Pores 
(which perhaps ought to be of a determinate fhape and fize, and 
filled with a determinate matter} will have a great operation up- 
on irs fplendour. And I formerly found by other trials, that 
even confident Bodies, if foft ones, may have their Pores en- 
larged and vitiated,and their bulk, and confequently their texture 
Cat leaf): as to their pores}manifeftly enough altered by having the 
Air withdrawn from about them (whereby the Aerial particles 
within them were enabled to expand themfelves)and let in again, 
whereby, as to fenfe, they feemed pretty well reftored to their 
former ftate. But the luccefs of my endeavours either with Micro - 
[copes (through which a vivid piece of Wood will fhine by its 
own light} or otherwife, was not confiderable enough to deferve 
a particular account 5 efpecially in this Paper, where I am nos 
to venture at matter of Theory. 
Experiment VI. 
T Hiriking fit to try. Whether a [mill quantity of Air^ with- 
out being ventilated or renewed, might not fumce to 
maintain this Cold fire, though it will not that of a Live Coal, 
*©r a piece of Match, we caufed a piece of fhining Wood to be 
Hermetically fealed up in a pipe of clear and thin glafs: but 
though, carrying it into the dark, we found it haa quite loft its 
light, yet imagining that that might proceed from its having 
been over-heated (being fealed up in a Pipe not long enough to 
afford it a due diftance from the flame of the Limp we employed 
to Teal it,) we caufed two or three pieces of freih Wood, amount- 
ing all of them to the length of about two inches, to be lealecl op 
in a {lender pipe between four or five inches in length 5 which be- 
ing warily done, the Wood retained its light very well, when the 
Operation was over : And afterwards laying it by my beu-iide, 
when the Candles were earned away out of the room, 1 coim- 
