What exactly was dennis hopper (frank) huffing out of that oxygen mask in blue velvet?

I never saw Blue Velvet, but I have blue velvet in my pantsWhat exactly was dennis hopper (frank) huffing out of that oxygen mask in blue velvet?
Great question! I always wondered what it was...but i was only 16ish when i first saw it so my knowledge of stuff you huffed was pretty limited. I can only imagine (know that my knowledge of huffable stuff has increased in 20 years) that it must be something like nitrous-oxide. Awesome wacky disturbing groovy movie though.What exactly was dennis hopper (frank) huffing out of that oxygen mask in blue velvet?
why do you care
Yes, nitrous oxide.
Don't you look at me, f***! Don't you f***ing look at me!
I would guess nitrous or nitrate, and he is old enough to be your father, which I can't figure out how that has anything at all do to with the question
OH PLEEEEEEEEEASE!!!





HE IS OLD ENOUGH TO BE MY FATHER!





COME ON GIRL~~~
I think it was laughing gas but coul not find any source for this