Re: The New York City gas smell the other day - Natural gas doesn't smell bad, if at all. There's a chemical added to stink it up; otherwise, you wouldn't know your home was about to explode. It's called mercaptan. Back in the day, when I was in high school in a much more innocent era, my friend, the high school genius, would order various chemicals for 'experiments'*. One time he acquired some mercaptan. There's something you don't want to ever get near. Whew! A little goes a looooooooooooooooooooooooooooooong way!
* = blowing stuff up. In today's world there'd be FBI down on his smart head. He later went on to get his Ph.D. in Physics and work on esoteric stuff. Sad to say, cancer claimed him at a young age.
I remember one day Jim was mixing some nasty explosive that you had to keep wet or the friction of simply mixing it would set it off - he was very carefully stirring a peanut butter jar full of the stuff while we watched over his shoulder. A little had dried on the lip and his stirrer hit it. Snap and spark! Jim gently put the jar down and then shook while his deodorant failed. Guardian angels are real.