i had to google that. we call it either laughing gas or noz here. It's nitrous oxide, the same shit they use in whipped cream to make pressure on the inside so the cream comes shooting out.
if you inhale it and hold it in for like 30 seconds, you get lightheaded as fuck and you laugh your head off for a minute or two. it doesn't last long and has gotten the nickname of "hippy crack" because hippies love it, but since it lasts such a little time, they tend to buy a fucking lot. you'll see them sold at illegal parties for £1 or £2 per balloon.
and I VOTE
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