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flew off, with a boiling motion, and conflderable force, 
from the furface of the water ; which, by its dilata- 
tion, arofe into the bladder. The vial was kept, in 
this moderate heat, two hours j during which time, 
the bladder became more and more diftended with 
the air, or other elaflic fubftance, expelled from the 
water ; which was obferved to acquire a muddy 
whitenefs in proportion as the elaffic fubffance was 
expelled from it. The bubbles, after about an hour 
and half, gradually leffened in number and fize ; and, 
at the end of two hours, almofl; difappeared. The 
heat was then gradually increafed for another hour ; 
at the end of which time the water in the copper 
veffel began to boil. And in this boiling heat the 
vial remained another hour 5 when it being judged 
that all the elaflic fubffance contained in the water 
was expelled from it, the vial was removed from the 
fire, after it had continued in the water bath four 
hours. From the time that the heat of the bath was 
increafed, the water in the vial grew more and more 
turbid 5 the earthy particles were formed into fmall 
maffes, which were driven about by the heat. To- 
wards the end of the operation, thefe earthy maffes 
cohered into larger flocculi; and from white became 
of a yeilowifli colour. Thefe flocculi grew larger as 
the water cooled, and flowly fubfided to the bottom 
of the vial. While the water in the vial was yet 
warm, the elaffic fubffance that had been expelled 
from it was tied up clofe in the bladder, and then 
removed from the vial. The water in the vial, be- 
ing corked up, was fuffered to ffand till perfectly 
cool. Being then examined, it was found to have 
got a taffe from the bladder j but was quite vapid, 
VoL. LV^. G g having 
