I don't remember ever hearing of Ruth Patrick before I read her obituary the other day, but I wish I had known her. She was one of the earliest researchers in water quality, studying diatoms in lakes, and revealing the importance of biodiversity. The idea that biological diversity reflects environmental stresses even bears her name, the “Patrick Principle.” She worked when being a woman scientist and an environmentalist were both rare and sometimes suspect, starting her career in the 1930s. I should really know her name, since one of her publications was “Groundwater Contamination in the United States”, published in 1987. RIP, Dr. Patrick.