1ſubſtance ſubtler then it ſelf, reſiding m
it. In order to the ſatisfying my ſelf about
the firſt of theſe, I intended to let down
into the Receiver a Veſſel of Water,
wherein ſhould be immerſ'd a very ſmall
oyl'd Bladder, almoſt devoid of Air, but
ſtrongly ty'd up at the Neck with a ſtring,
and detain'd a little under Water by ſuch
a weight faſten'd to that ſtring, as ſhould
juſt be able to keep the Bladder from
ſwimming, and no more. For I ſuppoſ'd,
that if when all things were thus order'd,
the Receiver were empty'd, in caſe there
were any ſuch preſſure of the Atmoſphere
upon Water, as I was inclin'd to believe,
the Air within the Bladder, being upon the
exſuction of the Air within the Receiver,
freed from that preſſure, and being preſſ'd
onely by the ſmall weight of the in
cumbent Water, would conſiderably ex
pand it ſelf; but whil'ſt we were prepa
ring Bladders for this Experiment, there
occurr'd an eaſie way for the making at
once both the Diſcoveries I deſir'd.
it. In order to the ſatisfying my ſelf about
the firſt of theſe, I intended to let down
into the Receiver a Veſſel of Water,
wherein ſhould be immerſ'd a very ſmall
oyl'd Bladder, almoſt devoid of Air, but
ſtrongly ty'd up at the Neck with a ſtring,
and detain'd a little under Water by ſuch
a weight faſten'd to that ſtring, as ſhould
juſt be able to keep the Bladder from
ſwimming, and no more. For I ſuppoſ'd,
that if when all things were thus order'd,
the Receiver were empty'd, in caſe there
were any ſuch preſſure of the Atmoſphere
upon Water, as I was inclin'd to believe,
the Air within the Bladder, being upon the
exſuction of the Air within the Receiver,
freed from that preſſure, and being preſſ'd
onely by the ſmall weight of the in
cumbent Water, would conſiderably ex
pand it ſelf; but whil'ſt we were prepa
ring Bladders for this Experiment, there
occurr'd an eaſie way for the making at
once both the Diſcoveries I deſir'd.
Experi
ment 21.
ment 21.