Michel Eugène Chevreul was a French chemist whose work influenced several areas in science, medicine, and art. His early work with animal fats revolutionized the manufacture of soap and of candles and led to his isolation of the heptadecanoic, stearic, and oleic fatty acids. In the medical field, he was first to demonstrate that diabetics excrete glucose in the urine and to isolate creatine. He lived to 102 and was a pioneer in the field of gerontology. His theories of color "provided the scientific basis for Impressionist and Neo-Impressionist painting." He is one of the 72 French scientists, mathematicians, and engineers whose names are inscribed on the Eiffel Tower; of those 72, Chevreul was one of only two who were still alive when Gustave Eiffel planted the French Tricolor on the top of the tower on 31 March 1889.