Tyndall, << TIHN duhl, >> John (1820-1893), was a British physicist and natural philosopher. He is known for his experiments on the scattering of light of different colors by small particles. The bluish appearance of a light beam passing through something like a soap solution is called the Tyndall effect. Tyndall also did work in the biological sciences. In 1876—more than 50 years before the discovery of penicillin—he described the action of a Penicillium mold in slowing the growth of bacteria. Tyndall was born on Aug. 2, 1820, in Leighlin Bridge, Ireland. He became superintendent of the Royal Institution in 1867. Tyndall often gave public lectures and had a special interest in clarifying concepts of physics for nonscientists. He died on Dec. 4, 1893.
