> Coleman started marketing their camp fuel in the sixties, with the promotional claim that it was much cleaner burning than "white gas." �I had a boat motor back then that called for using white gas. �Motor fuel then contained tetraethyl lead, which would leave a lead deposit in the generator and burner of a stove or lantern, and would foul the mantle of a lantern. �Coleman fuel is from the naptha run from the refinery. �That is a little lighter than the fraction that is labeled gasoline. �Though premium gasoline in those days was generally called "ethyl," regular grade also contained the additive, starting I think in after WWII. �Before then, tetraethyl lead was in premium only. �The tetraethyl lead reduces volatility, thereby reducing burn rate, and so inhibiting preignition, same as other additives now.
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> BTW, does anyone know why lantern mantles contain thorium? �I remember in junior high school a science instructor using a mantle to demonstrate a geiger counter.
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http://en.wikipedia.org/wiki/Gas_mantle

That sure was a fascinating read, thanks for bringing it up!