Ufpl) 
filver was driven ap again, and confequently,the Air above It was 
reftored to its former denfity; upon which the rotten Wood alfo 
recovered its light. What the greateft Expan fion of this Air was, 
we could not certainly determine, becaufe the Expansion raffed 
the external Quickfi-iver fo high, as to hinder us to fee and mea~ 
Cure it. But we gueffed, that the Air reached to about a foot or 
more from the cop of the Pipe to the furface of the Quickfilver 
near the bottom of it. But, when that rarified Air was impelled 
into its former dimenfions, we meafured ir, and found, that the 
upper part of the Tube, unpofTeft by the Quickfilver, - was about 
three inches 5 and the Wood being about an inch long, there re- 
mained two inches or fomev hat better for the Air. But this Ex- 
periment is to be repeated, when exadler Inftruments can be pro- 
cured. 
Experiment X, 
T Banking it fit to try as well. Whether Stinking Fi/1), that 
flfnes, be of the fame nature as to Lutninoufnefs with 
Rotten Wood, that fhinestoo * as, Whether the withdrawing of the 
Air will extinguilh or eclipfe the Light of a confide M bulk of 
luminous matter, as in the Experimenc$,hitherto made, we found 
k would do to a fmall one .* We took a Fifli, that we had kept, 
2nd caufed to be watched, till’cwas almoft all over Luminous - 
though much more in the Bdly and feme parts of the Head, than 
elfewhere: And having fufpended him in a conveniently fhaped 
Receiver ,we found him to give fo great a Lightest we fufpefted 
beforehand, that the withdrawing of the Air would hardly have 
its full operation upon a Body, whofe bulk was confiderablc, as 
well as its light very vivid, and which had many luminous parts 
retired to a pretty diftance from the Air. Accordingly having 
exhaufted the Receiver as much as we were wont, it appeared in- 
deed, efpecially towards the latter end of the operation, that the 
abfence or the Air did confiderably leffen, and in fome places 
eclipfe the light of thofe parts, that fbone lefs ft rongly. But the 
Belly appeared r ot much lefs luminous than before : Wherefore 
iuppofing, that upon the turning of the Stop cock the Air coming 
in much more hafhly than it could be drawn our, we fhould have 
the beft advantage to difeein, what intereft it had in the Lumi- 
Q*qq 2 noufnefs 
