From sci.chem Mon Dec  2 12:44:56 1996
From: maxh@ldd.net (Max Hendrix)

And yet another one I had mercifully forgotten:  in my undergraduate
organic lab we were making nitrobenzene (which of course isn't done
anymore).  Mixture of conc. nitric and sulfuric acids in a roundbottom
flask, with a one-hole stopper and long glass tube to carry nasty
fumes above our heads (we had an overhead vent for the entire lab).
Remove stopper, add small quantity of benzene, replace stopper, swirl,
repeat after a few moments.

The clue-impaired individual of the class didn't understand the
purpose of the glass tube.  So he had it shoved all the way to the
bottom of the flask.  When benzene was added and the stopper replaced,
acid mixture naturally began squirting out the top of the glass tube.
Mr. One-brain-cell-working-really-hard started whirling around
screaming "Help, help" while holding the flask, thereby squirting
acids around the lab for all to enjoy.

Happy ending:  no one was seriously injured and the student changed is
major to art or some other subject appropriate for the
brain-activity-challenged.

Max Hendrix