Do some research on N2O.... it is not a flammable gas, and the government classifications will confirm that for you. Gasoline is injected through the nozzles along with n2o to help ensure that the mixture is not too lean.... You probably saw the gasoline ignite. I realize that this is getting way off topic, and I apologize, but nitrous oxide is not flammable "by itself."
I simply do not like misinformation, and I can speak confidently in this area because I sell n2o out of my shop in Sun Prairie, WI, and utilize it on two of my vehicles. I tried to light some this morning just to humor those of you who believe otherwise....
Sorry, n2o does not ignite.