The winged insects furnished with breathing holes, become motionless
in nitrous oxide very speedily; being however possessed of a certain
voluntary power over respiration, they sometimes recover, after having
been exposed to it for some minutes, under the action of atmospheric
air.
A butterfly was introduced into a small jar, filled with pure nitrous
oxide, over mercury, He struggled a little during the first two or
three seconds; in about seven seconds, his legs became convulsed, and
his wings were wrapt round his body; in about half a minute he was
senseless; taken out after six minutes, he did not recover.
Another butterfly introduced into hydrogene, became convulsed in about
a quarter of a minute, was senseless in twenty seconds, and taken out
after five minutes, did not revive.
A large drone, after being in nitrous oxide for a minute and a quarter,
was taken out senseless. After being for some time exposed to the
atmosphere, he began to move, and at last rose on his wings. For some
time, however, he was unable to fly in a straight line; and often
after describing circles in the air, fell to the ground as if giddy.
A large fly, became motionless in nitrous oxide after being convulsed,
in about half a minute. Another was rendered senseless in hydrogene, in
less than a quarter of a minute.
A fly introduced into hydrocarbonate, dropt immediately senseless;
taken out after about a quarter of a minute, he recovered; but like the
fly that had lived after exposure to nitrous oxide, was for some time
vertiginous.
Flies live much longer under water, alcohol, or oil, than in
non-respirable gases, or gases incapable of supporting life. A certain
quantity of air always continues attached in the fluid to the fine
hairs surrounding their breathing holes, sufficient to support life for
a short time.
Snails and earth-worms, live in nitrous oxide a long while, they die in
it however, much sooner than in water or hydrogene; probably from the
same causes as the amphibious animals.