iii. CONFINED IN STAGNANT AiR, 93 
takes place, when animals die in clofe veffels. 
Secondly, whether the degree of alteration is fuf. 
ficient to kill the animals; for. we know that 
every degree of diminifhed elafticity is not fatal 
to them. 
Here Sig. Cigna has laboured in a mariner 
that merits commendation. I fhall afterwards 
employ fome of his ideas. I have made 2 courfe 
of experiments, with the fame view, which hall 
be abbreviated after relating the method adopted. 
Several air-pump glafs receivers were inverted 
in a veflel of water. They opened and ‘hut a- 
bove by means of a metal ftop-cock. The.re- 
ceiver being-teft open when immerfed, a free paf- 
fage was left for the internal air to efcape above, 
in proportion as it was comprefled by the rifing 
water ; thus the remanent portion preferved the 
natural degree of denfity- as the external air ; 
which was abfolutely' neceflary for the accuracy 
of the experiment. This done, I clofed the vet. 
fel, and, to make it more fecure, pafled feveral 
folds of leather round the ftop-cock, to cut off 
all communication with the external air. I was 
certain that it could not infinuate itfelf, for the 
fame receivers were ufed as in my pneumatic ex- 
periments. ‘The animals being put in the re- 
ceivers, the diminifhed elafticity could be feen by 
‘the afcent of the water within. If the animals 
were aquatic, or amphibious, -I let them remain 
, m 
