Party trick with cigarette tin foil

I imagine it's a chemical reaction between the metallic elements of the foil and the enzymes in his saliva that produces the heat? Not a chemistry whiz but that's the best I can come up with...........

A coworker of mine suggested that you're creating a current in the foil that slowly changes to heat from the resistance of the foil. I'd be interested in hearing the answer.

Would'nt you need two different metallic elements to act as cathode and anode in this cae though?

Hmmmmm..... He might have amalgam fillings or gold or stainless caps. But then he'd have to tolerate an AWFUL taste in his mouth - and it might be worth it for the gag. 8^)

there would only be an awful taste if he contacted the foil with the fillings. No current would flow (like in a battery alone) if there is no electrical contact between the metals. The answer to this does lie in dissimilar metals, i think. I would imagine that there is some sort of gold/copper coating over a tin base, and the saliva acts as an electrolyte.

The thought I had was to generate heat through resistive heating of the foil. The foil itself (at least here in the colonies) is a thin aluminum foil on a paper base. Reading the original post, though, I'll have to rethink this - the lump in the hand gets warm after a minute or two. Of course, he may have a loose or concealed filling or other metal that waws wrapped up with the foil. Saliva is a good enough electrolyte for this.

Are you sure it is the foil only and there is not a coin slipped in the center? I think nickel would work best, but it is not the lightest and most inconspicuous addition. The thought of a loose filling makes me cringe.

he uses a little caustic soda on his fingers (battery acid) rubs it until it dissolves then grabs the moist tinfoil squeezes it then a chemical reaction will occur.

I have seen this trick from a co-worker now having taken the answer to his grave. He always dampened the foil with water from his drinking glass at the table. This makes me know that he has a caustic residue on his fingers that activates as he folds and smooths out the tinfoil. I have never tried caustic soda but that may be the answer. I have tried baking soda and many other things at a lab where I worked and none of them produced this reaction. It was definitly not hypnotic suggestion because he never told you it was to get hot. He just said to squeeze it in the palm of your hand and it WOULD get hot.

Yes! This same thing was done to me at a gathering, An older guy with a white beard, his name was Bill on the Hill. Anyways I heard that he had done this to a friend and so when I saw him next I asked him to please show me this trick.

At first he acted as though it was only for particular times. But he then soon after did. But only after I stopped paying direct attention did I notice him ripping up a piece of cigarette tin foil and he pealed off the paper from it and folded it in to a 1cm x 1cm square. Then I noticed that he quickly licked his finger tips and then pinched the folded square piece of tin foil and then firmly placed it on the center of my palm and said this one is for you, as I looked down from him to my hand I started to hear what sounded kinda like a quiet sizzling sound and then it began to get so hot that I could not bear it any further and dropped it, it then was cool after when I picked it up. I know for sure that this was not caustic soda as I have worked with this chemical for years and it stings more and more and you have to wash it off quickly. This was with out a doubt heat. He would not let me know this secret either. I have tried to replicate this but have not a clue how.

Please help fellow travelers!

As an Apprentice at Austin Rover in Longbridge, Birmingham, a fellow apprentice would (on demand) take a piece of silver foil (from kitkat wrapper or lunch box), wet one side of it, with water or spit or even Cola, then fold it in half and rub it between his fingers, then fold again and continually rub it between finger and thumb, then fold again and when it was about 1cm square would put it on the back of your hand. He didn't say anything but the piece of tin foil would get hotter and hotter and if you didn't drop it, you ended up with your skin getting burnt. I even saw hairy hands where the foil would burn the hair and drop onto the skin.

There was NO CHEMICALS used, he did this on demand, several times over the course of a couple of years. No special solution on his hands, no mercury, just any tin foil and any liquid. It was obviously caused by the friction as he rubbed the foil with the wet surface inside, but we all tried to copy him and not one of us could ever do it.

He did promise to show me how in 3 years time, but by this time I was travelling the World and I didn't come back for 12 years.... Wish I knew how to do this, wish I could find the guy now to ask, but I'm also glad he didn't show others how to do it!!!!