Better dying through chemistry: certain and humane way to execute prisoners

[William Gigantus]

Within one minute, you go into a peaceful deep sleep.

Within five minutes, you go into that bittersweet nothingness.

"Good night, sweet prince." - William Shakespeare

"See you on the other side." - Ozzy Osbourne

Inert gas asphyxiation
http://en.wikipedia.org/wiki/Inert_gas_asphyxiation

An occasional cause of accidental death in humans, inert gas
asphyxiation has also been used as a suicide method, and has been
advocated by proponents of euthanasia (using helium or nitrogen in a
device called a suicide bag). Nitrogen asphyxiation has been suggested
as a more humane way to carry out capital punishment, but so far this
use of inert gas has not been attempted by any country, state or
territory. (Except Germany)