Walter W. Stewart (scientist)

Walter W. Stewart (born c. 1945) is an American biomedical scientist who worked at the National Institute of Health in Bethesda, Maryland. Working at the National Institute of Arthritis, Metabolism and Digestive Diseases, he invented Lucifer yellow, a fluorescent dye used for visualizing cells under microscope, in 1979. In 1971, he had also isolated and worked out the chemical structure of tabtoxin, or wildfire toxin, an antibiotic precursor from the bacterium Pseudomonas syringae. He is most popularly known for his efforts in maintaining scientific integrity by fighting against important cases of malpractices. He accompanied James Randi in debunking homeopathic experiment perpetrated by French immunologist Jacques Benveniste in an incidence known as the Benveniste affair in 1988.