Dr. Ray Crist's life has come full circle. His boyhood fascination with nature on a Pennsylvania farm eventually led to his pivotal role in the birth of the atomic age. Now, at age 101, Crist is still coaxing nature to reveal its secrets.

"I'm just trying to understand the nature of things, that's all," Crist says. "A basic driving force is my curiosity."

It's that overriding curiosity that prompts Crist to head for his laboratory at 7:30 every morning. He typically works in the lab on the campus of Pennsylvania's Messiah College until almost 6 pm. "Going in to work satisfies my curiosity," he explains. Crist has been working at the lab for the humble salary of one dollar since 1963. "If I had been paid a full salary, I wouldn't have been able to follow my own personal interests," he says. Crist clearly likes to blaze his own trail. And what a trail it's been!

After earning a degree in chemistry from Dickinson College in 1920, Crist moved to Columbia University, where he earned his doctorate in chemistry in 1926. He then went to Europe on a fellowship. While in Berlin and Munich in the late 1930s, Crist became acquainted with some of the foremost scientific minds of the day, including Nobel Prize winners Albert Einstein and Harold Urey.

From 1941 to 1945, he was one of a select group of scientists recruited for the Manhattan Project, the program that successfully developed the first atomic bomb. Crist and his colleagues developed a technique for separating and recovering active isotopes of uranium, essential for fueling the bomb's potent chain reaction. Crist holds the patent for a chemical mechanism to trigger the bomb's lethal chain reaction. Still, he says, "I haven't yet found out whether it was used, and I'm grateful not to know. I don't want to know."

After teaching at Columbia for 19 years, Crist moved to West Virginia, where he headed Union Carbide's Institute for Basic Research. "I couldn't have had a better job," Crist recalls. Yet Crist grew increasingly concerned about the environmental effects of industrial society. He was disturbed by the accidents that spilled chemicals into the environment. Then he had an idea-what if Nature itself could help with the cleanup?

In 1963, he left Union Carbide to pursue this investigation fulltime. He returned to his Pennsylvania roots, first at Dickinson College, then at Messiah College.

Dozens of scientific journal articles later, Crist is still hard at work. His latest project involves a powdery substance known as lignin, a byproduct of the wood pulp used to make paper. For years, lignin was considered a useless waste product. But Crist found that lignin is able to absorb toxic metals, just like a sponge soaks up water. Crist is working with a South Carolina paper company to develop a solid sheet of lignin that will absorb contaminants from polluted waters. He eventually hopes to market the product commercially.

Crist also believes in looking at the bright side - literally. When macular degeneration severely degraded his vision, Crist helped a colleague develop glasses with prisms that amplify the light and make maximum use of his peripheral vision. He is again able read his lab instruments. "That makes the big difference," he says.

Crist believes his inspiration comes from staying busy. "If you sit around and do nothing, you don't get any ideas. So you have to get out and do something," Crist says. "If you think about it, it will stimulate your mind, just like a plant-it sprouts and grows. Things start small, but they end up big. I just pay attention to what Nature is telling me."