filver was driven op again, and confeqaently^the Alt above it m% 
reftored to its former denfity 5 upon which the rotten Wood alfo 
recovered its light. What the greateft Expanfionof this A\: was, 
we could not certainly determine, beoufe the Expanfion raifcd 
the fx^^rWQuickfilver fo high, as to hinder us to fee and mea- 
fureit. But we guefled, that the Air reached to about a foot or 
more from the top of the Pipe to the furface of the Quickfilver 
nearthe bottom of it. Bat, when that ratified Air was impelled 
into its former dimenfions, we meafured it, and found, that the 
qpper psrt of the Ta^e, unpofTeft by the Qaickfilver, was about 
three inches \ and the Wood being about an inch long> there re- 
mained two inches orfomewhat better for the Air. But this Ex- 
periment is to be repeated, when exader laftruments can be pro- 
cured. 
'Experiment X. 
THinking it fit to try as well. Whether ^//^i&i^;^/'//^, that 
fhines, be of the fame nature as to Lumin jufnefs vyith 
Rotten Woodjihu (bines too as, Whether the withdrawing of the 
Air will extinguifli or eclipfe ;:he Light of a confiderdle bdk of 
luminous matter, as in the ExperimentSjhitherto made, we found 
it would do to a /w4^one «• We took a Fifh, that we hid kept, 
andcaufed to be watched, tiU'twas almoft all over Luminous 5 
though much more inthe.5dly andfome parts of the Head, than 
elfewhere: And having fufpended him in a conveniently ftiaped 
Receiver ^"^t found him to give fo great a Lights that we fufpedcd 
beforehand, that the withdrawing of the Air would hardly have 
its full operation upon a Body, whofe bulk was confiderable, as 
wellasits//>^? very vivid, and which had many luminous parts 
retired to a pretty diftance from the ^ir. Accordingly having 
exhaufted the Receiver as much as we were wonr, it appeared in- 
deed, efpecially towards the latter end of the operation, that the 
abfence of the ^ir did confidcrably le([eny and in fome places 
ecliffe thfc light of thofe parts, that (hone lefsftrongly. M\ii the 
^fiZjf appeared rot much lefs luminous than before : Wherefore 
fup'pofing, that upon the turning ot the St&p ceck the Air coming 
in much more haftily than it could be drawn out, we ftioald have 
thebeft advantage todifcern, whacintertft it had intheLumi- 
Q^q q 2 noufnefs 
