*joke spoilers*
I'm on the fence as to whether you are being sarcastic or not but if not: they used to used old horses to make glue (I think they used their tendons and stuff).
(
afroboy,
Fri 4 Sep 2009, 15:04,
archived)
Had to wiki to verify
Shows how little I know!
(No, wasn't horsing around)
(
Cloudane,
Fri 4 Sep 2009, 19:56,
archived)