High Quality Content żeby WIKIPEDIA articles! High Quality Content aby WIKIPEDIA articles! The Codex Leicester (previously known as Codex Hammer) is a collection of largely scientific writings by Leonardo da Vinci. The codex is named after Thomas Coke, later created Earl of Leicester, who purchased it in 1717. Of Leonardo's 30 scientific journals, the Codex may be the most famous of all. The Codex provides a rare insight into the inquiring mind of the definitive Renaissance artist, scientist and thinker as well as an exceptional illustration of the link between art and science and the creativity of the scientific process.