Electricity might not grow on trees, but it is freely available in the air -- provided you know how to catch it. Such is the contention presented by Dr. Francesco Galembeck of Brazil's University of Campinas at the 240th annual American Chemical Society shindig. He and his crew have shown how tiny particles of silica and aluminum phosphate become electrically charged when water vapor is passed over them. This aims to prove two things: firstly, that airborne water droplets do carry an electric charge, and secondly, that metals can be used to collect that charge. De
