(1) (1847) German pathologist, physiologist and biologist Paul Langerhans is born. He is best known for his discovery of Islets of Langerhans, pancreatic cells which produce insulin.
(2) (1866) British plant physiologist Frederick Blackman is born. He studied photosynthesis, the process by which a plant uses carbon dioxide and produces oxygen. He also developed Blackman’s law of limiting factors, which determines the rate of photosynthesis.
(3) (1920) English chemist and X-ray crystallographer Rosalind Franklin is born. She is best known for her contribution to the discovery of DNA’s double helix structure.