URINE, THOUGH distained by modern society, was once surprisingly useful stuff. Street-facing laundries in ancient Rome had pissoirs attached to them, to encourage passers-by in need of relief to provide, free of charge, a raw material which was then fermented into a degreasing agent. Urine also found employment as a mordant, to assist in the dying of cloth- Scottish tweed was once notorious for smelling of the stuff when it got wet. And urine was, too, a source of potassium nitrate, one of the ingredients of gunpowder. Now, Chen Wei-Shan of Wageningen University, in the Netherlands, thinks he has found yet another use for urine-and one relevant to today's needs rather than yesterday's. He plans to employ it to create heat without fire from waste wood.
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