Re: Ratio of rubbing alcohol:water to set a shirt on fire but it does not burn?

Usually, I use a 50% solution of methanol.The trick works because the 
volatile alcohol catches on fire just above the rest of the liquid. More 
and more fuel (alcohol) is drawn out of the liquid as it burns, leaving 
behind  water which keeps the t-shirt or money wet and unaffected by the 
fire. If you want to use rubbing alcohol (70% isopropyl alcohol),add 40 mL 
of water to every 100 mL of rubbing alcohol. That way you'll get 70 parts 
of pure alcohol out of approximately every 100+40 parts of solution. I 
say "approximately" because the volumes of alcohol and water are not 
exactly additive due to something called H-bonding. 
Do you see how much science there is behind even the simplest of tricks!?

Enrico Uva