[thackney]

HAZARDS OF NITROGEN ASPHYXIATION
http://www.csb.gov/assets/1/19/SB-Nitrogen-6-11-031.pdf
U.S. Chemical Safety and Hazard Investigation Board

Every year people are killed by breathing “air” that contains too little oxygen. Because 78 percent of the air we breathe is nitrogen gas, many people assume that nitrogen is not harmful. However, nitrogen is safe to breathe only when mixed with the appropriate amount of oxygen.

These two gases cannot be detected by the sense of smell. A nitrogen enriched environment, which depletes oxygen, can be detected only with special instruments. If the concentration of nitrogen is too high (and oxygen too low), the body becomes oxygen deprived and asphyxiation occurs....

Breathing an oxygen deficient atmosphere can have serious and immediate effects, including unconsciousness after only one or two breaths. The exposed person has no warning and cannot sense that the oxygen level is too low....

More info at the link

[driftdiver]

I’ve been drunk on Nitrogen.

[moovova]

I’m guessing expanding gases from “activated” gunpowder forcing a 45 slug down a gun barrel and into the convict’s brain...would work even faster.