ok tell me that edison faced the problem regarding the oxygen gas due to the absence of which the filament can;t glow. so tell me that there is also no gas present inside a bulb so then how it continues to glow.
the problem that edison ran into (in my understanding - I could be completely wrong) is that in the presence of oxygen, the filament would oxidize and break/burn. It was the lack of oxygen which allowed the filament to last for an extended period of time.
Edison's bulbs were pumped down to a hard vacuum to preserve the filament. Modern bulbs are full of argon gas. I had assumed that the salty water was for an electrochemical cell to produce current. If not, what about the salt water is going to make the bulb glow?