(2050) 
tbe Rcturn^f the Air, was attentively confidered by mc, prefently after 
*twas removed from the Engine whereby it was eafy to difcern, that 
both the Snails thruH: out and retrad:ed their Horns (as they are com- 
nionly called^ at pleafure,though their Bodies had in the fofter places 
pretty (lore of newly generated Bubbles flicking to them: but though 
they did not ioofe their motion near fo foon, as other Animals were in 
our Vacuum wont to do ^ yet coming to look on them after fome hours, 
they appeared raovclefs and very tumid, and at the end of 12 hours the 
inward parts of their bodies feemed to be almoft vanifhed, and they 
feemed to be but a couple of fmall fuIl-bJown Bladders • and on the let- 
ting in of the Air they immediately fo ftirunk, as if the Bladders having 
been prickM,the receding Air had left behind it nothing but skins nor 
did either of the iSnails afterwards, though kept many hours, give any 
fignsoflife. 
Upon a fuppofition that the cold, and clammy Conftitution of Snails 
might be a main caufe of their being able to endure the abfence of the 
Air fo well, I thought it worth Tryal, whether Efts and Leeches might 
not yet be piore able to continue in our Vacuum then a Snail and ac- 
cordiagly fome Experiments were made perfuant to that Curiofity ^ the 
moft fully rcgiftred whereof are thefe that follow. 
Experiment i. ,'■ 
We included in a Receiver, whofe Globular part was about the big- 
nefs of a large Orangc,one of that fort of Animals, that they vulgarly 
\ cd^l\Efts I having withdrawn,but not follicitoufly, the Air, and fecured 
;the veffel againft the unpermitted return of it, we kept him there about 
'^8 hours, during all which time he continued alive, but appeared fomc- 
what fwelled in his belly his under-chap moving the very firft night, 
but not the day and night foIlowing.By opening the Receiver at length 
under water^we perceived,that about half the Air had been drawn out. As 
foon as the water was impelled into the Glafs, the Animal , that was be- 
fore duji and torpid, feemcd,by very nimble and extravagant motions, 
to be ftrangely revived, ■\' Y} 
' Experiment 2. 
We took ^ Leech,xh2it was of a moderate bignefs,or fomewhat fhort of 
jt,and having included it together with fome water in a portable Re- 
ceiver, that was guefled to be capable of holding about 10 or 12 ounces 
of that liquor • the Air was pumped out after the lifual manner, and the 
Receiver being removed to a lightfomc place, wc obferved, as wcexpe- 
ded,that,the Leech keeping her felf under water, there emerged from 
divers parts of her Body ftore of Bubbles, fome of thera ina difperfed 
' way,but others in Rows or Files, if I may fo fpeak^that feemed to coitie 
f'rom determinate points. Though this Produdion of Bubbles lafted a 
pretty while, yet the Leech did fiot fecm to be very much difcorapofed 
by her prefent condition This done we difpofed of the Receiver, which 
was well fecured from the ingrefs of the outward Air, into a quiet place , 
where we daily vifited it once at ieaft,or oftner,as there was occafion ^ 
