Sulphur dioxide and something else

When I was in year 8 in secondary school I can remember an experiment that we did involving sulphur that produced almost white plumes of smoke which the teacher encouraged us to smell and it smelt like rotten eggs.

I cannot remember what this gas was called though. I KNOW it wasnt "sulphur dioxide" because I can remember in year 10 we did an experiment where we produced sulphur dioxide which appear to be a white gas......remembering the experiment we did in year 8 I decided to take a huge whiff of this stuff....My sinuses immediately responded by "closing rapidly" and my head shook very violently. I went bright red and had to rush to the toilet as my nose and eyes were burning. I ended up being checked over by the nurse to see if I was okay.

anyway........so thats how I KNOW the rotten egg one we did definately WASNT sulphur dioxide. So what was it ?

Was that methane. It is just a guess

Rotten egg smell is hydrogen sulphide. This is an extremely pungent gas and also quite deadly - though not in the concentrations/durations you would experience in a school lab experiment.
I don't recall the exact numbers, but something of the order of twenty or forty parts per million will kill you in reasonably short order. As long as you can smell it you are OK. At higher concentrations - I think around 10 ppm it kills your sense of smell, so you think it has gone away. It is also insidious enough to penetrate burst eardrums and get to you that way, even if you are wearing a gas mask.
Nice substance.!!

Well yeah. But sniffing up a load of sulphur dioxide doesnt do much good either. TRUST ME !!!!!!

Hydrogen sulphide. thats the one. my memoery really WILL kill me at some point im sure !! lol