Tonight my school had like a special chem. thing sponsored by the National chem. Association or, whatever. We had the chance to bring a bottle, or a bunch of bottles, and coat the inside with silver.
Basically, we were supposed to wash the inside out with nitric acid. Then pour the acid out and rinse with water. Then pour in hot water to heat the glass up. After some time, we were to pour the hot water out and pour in some silver-nitrate and splash it around. This would coat the inside with silver, and make the outside look like like a mirror. It was pretty cool.
Now, on to my question. For my bottle, I decided to bring in a Capt. Morgan Parrot Bay Coconut Flavored Rum bottle. I Followed instructions pretty much to the letter. Got a rubber stopper, poured in some Nitric acid, closed the stopper, and started to swoosh it around. Fore everyone else's bottle, nothing interesting happened.
However in my bottle, apparently the nitric acid started to react with the alcohol left over from the rum and turn yellow. Also, a really thick yellowish-orangeish-brownish gas started to form and filled the entire bottle.
I decided to not do the silver thing, since the toxic-looking brown gas made it look much cooler. So, I just kept the rubber stopper in, and took it back to my dorm. Once I got home, for a safety measure, I covered the stopper and rim of the bottle with epoxy.
My question is, does anyone know what this brown gas is? 
I assume it is poisonous/toxic since it looks a lot like Nitrogen Dioxide (NO2). I will try to find someone with a digital camera to take a pic and post it. However, the gas itself looks something like this:
Thanks, I appreciate if anyone could help me out here.