Wendell Stanley crystallizes tobacco mosaic virus and shows that it remains infectious. However, he does not recognize that the infectious material is nucleic acid and not protein. Together with Northrop and Sumner, Stanley is awarded the Nobel Prize in Chemistry in 1946.
Stanley, W. 1935. Isolation of a crystalline protein possessing the properties of tobacco-mosaic virus. Science. 81: 644-654.In Milestones in Microbiology: 1556 to 1940, translated and edited by Thomas D. Brock, ASM Press. 1998, p160 [pdf]