Where does the candle wax go?
Illustration by Slug Signorino
Where do you think it goes? It burns, just like the logs in a fireplace. You evidently have the idea that candle wax is only there to hold the wick upright. On the contrary, the wax is the fuel for the flame, the wick being merely the conduit, drawing melted wax up by capillary attraction. Rapid oxidation (burning, for you civilians) scrambles the constituent elements of the wax and they recombine to produce, among other things, carbon dioxide and water vapor, which drift off into the void.
Many people find the fact that burning produces water surprising. They shouldn’t. The great British scientist Michael Faraday used to do an annual lecture on the “chemical history of a candle” in which he would hold a flask full of ice above a candle flame. After a short time the flask would be covered with droplets of water, most of it newly manufactured by the burning candle. They say Faraday used to pack the house for this demonstration. How fortunate to live in age when you didn’t have to compete with music videos.
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