($84) 
We pHt In a piece of Wood bigger than the fomer (this be- 
ing above an inch long) and that (hone very vigoroufly. ^nd 
having by a few flicks quite deprived it of Light, we left it ia the 
Gxh^nilQd Receiver iox full half an hour, and then coming into 
the dark room again, we found all had not continued fo ftanch, 
but that fome fmall portion of J'x had infinuated it felf intothe 
Receiver. This we concluded to be but a fmall portion of ^ir, 
btcaufe the Wood was but vlfible to an attentive Eye. >f ad yer, 
that it was really fome A\^, which was got in, that caufcd the 
little glimmering light, which we perceived, may appear by this, 
that, it did prefently (as we expected) vanifli at the firftorfc- 
coRc (ffuck I and then the ^ir being let into the dark Receiver^ 
ihe included Wood prefently fl^one again as before ; though I 
fafpeded, I difcerned fome little diminution of its brightnefs 5 
which yet, till further Trials of the like kind, and for a longer 
time^ have been made, I dare not affirm. Before the Receiver was 
fufficiently emgtied at the beginning of the Experiment made 
with this greater piece of Wood,a fmall leak accidentally fprurg^ 
which, lettingin a little ^ir, did fodner thati we intended, recall 
^heilmoft dif-appearing Light.. 
'Experiment IV. 
'^^T^'^Here is an Experiment of affinity with the former, which 
we thought it not altogether impertinent to try. For ha- 
ving obferved on another occafion. That fometimes the Opera- 
tion, which the withdrawing the Ak hath upon a Body included 
in the Receivery proves more confiderable fomemimte^ after we 
have ceafed ^M^^mgyihrn immediatelj after thfecxercife is left 
off, I imagined, that even in fuch cafes, where the Light is not 
made wholly to dif-appear (though it be made almoft quite to 
dofo) by the emptying of the Pneumatical ghft, the fufferiflg 
ihe Body to remain a while there, though without any pumping 
(aalefsnow and then a very Lttle to remove the ^ir, that might 
have ftollea in in the mean time) the remaining Light of theBa- 
dy might probably be further impaired, if not reduced quite to 
vanilL. Tq examine this conjetee we put in a Body, that wss 
T,^i Wo }dp which had fome parts much more luminous than the 
reft. 
9 
