Dr. Richard Meagher, a professor of genetics at the University of Georgia, genetically engineered the trees to extract mercury from the soil, store it without being harmed, convert it to a less toxic form of mercury and release it into the air. It was one of two dozen proposals Dr. Meagher has submitted to various agencies over two decades for engineering trees to soak up chemicals from contaminated soil. For years, no one would pay him to try. »I got called a charlatan,« he said. »People didn’t believe a plant could do this.« He will begin to assess the experiment’s success this fall. But his is not the only such experiment with trees.