Ruth was an environmentalist long before anyone took environmental concerns seriously. As a freshwater ecologist, her research on water pollution set the stage for the modern ecological movement.
She became an adviser to two presidents, helped Congress draft environmental legislation, taught at the University of Pennsylvania, wrote extensively in her field and won many honors.
She died yesterday at age 105.
She was living at the Hill at Whitemarsh, a retirement community in Lafayette Hill. She formerly lived in Chestnut Hill.
Even after attaining the century mark, Ruth barely slowed down. She was a familiar sight at the academy, with which she had been associated since 1933. She maintained an office there and continued working on her series of books on rivers.
She enjoyed eating lunch in the museum cafe, where she sat anonymously among excited schoolchildren visiting for the day and anxious to look at dinosaurs.
Her 100th birthday was celebrated with a gala at the academy, and tributes poured in from around the world, including from former Vice President Al Gore.
Harvard University biologist Edward O. Wilson once called Ruth America's foremost authority on its river systems.
"She is a pioneer environmental activist, one of America's premier women science leaders," he said, "and has been a major influence in stimulating multiple generations of scientists."
Academy president and chief executive George W. Gephart Jr. said Ruth will be missed "by generations of students, scientists, staff and colleagues around the world - but her legacy lives on."
Ruth received the National Medal of Science for her work in developing methods to monitor water pollution and to understand its effects on aquatic organisms. She is credited, along with Rachel Carson (Silent Spring) with being responsible for drawing public attention to the health of the environment.
She was an adviser to President Lyndon B. Johnson on water pollution and President Ronald Reagan on acid rain. In the 1960s, she worked with Congress on legislation that led to the Clean Water Act.
Ruth specialized in determining the health of bodies of fresh water by examining the chemistry of the water, and evaluating the number, kinds and health of the plants, insects, fish and other organisms living there.
She was studying pollution's effect on streams long before Rachel Carson shook up society with her famous book predicting the death of the environment.
Ruth invented the Catherwood diatometer, which allows scientists to collect a type of algae called diatoms growing in a body of water. The study of diatom growths is a way for monitoring environmental conditions, and is used in testing water quality.
In the 1950s, the Atomic Energy Commission asked Ruth to assess the ecological status of Georgia's Savannah River near the DuPont Co.'s nuclear power plant. She became the first woman and the first environmentalist to serve on the DuPont board of directors.
When Ruth was a kid growing up in Kansas City, Mo., she became fascinated with creepy-crawly things that many girls her age might have considered icky.
"I collected everything: worms and mushrooms and plants and bugs and rocks," she once told an interviewer. At age 7, her naturalist father gave her a microscope. That did it. She was hooked on the exploration of the environment.
Ruth Patrick was born in Topeka, Kan., and received a bachelor of science degree from Coker College in South Carolina in 1929. She went on to earn a master's degree and later, in 1934, a Ph.D. in botany from the University of Virginia.
She joined the Academy of Natural Sciences as an assistant curator in 1933. She later became chairwoman of the Limnology Department and curator of limnology (the study of inland waters). The department became the Patrick Center for Environmental Research in 1983.
Ruth received numerous honors over the years, and was the author of more than 200 scientific papers and books, including the five-book series The Rivers of the United States.
She had been married to the late Charles Hodge IV and the late Philadelphia lawyer Lewis Van Dusen Jr. She is survived by a son, Charles Hodge V, several stepchildren and grandchildren.
Services: Were being arranged.