It is named after Thomas Coke, the Earl of Leicester, who purchased the codex in 1717. 1. Contents: The codex primarily focuses on Leonardo's observations and theories related to water, geology, astronomy, and the properties of light. It contains a series of notes, drawings, and diagrams exploring various scientific phenomena. 2. Manuscript: The codex is written in Leonardo's characteristic mirror writing, which means the text is reversed and can only be read by holding it up to a mirror. This was likely done to protect his ideas from being easily understood by others. 3. Water Studies: A significant portion of the codex is dedicated to Leonardo's studies on water, including observations on its movement, waves, and eddies. He also explores topics like hydraulic engineering, river erosion, and the formation of whirlpools. 4. Geology and Paleontology: Leonardo's interest in geology is evident in the codex, where he examines the formation of fossils, the structure of rocks, and the effects of erosion. He also speculates on the origins of marine fossils found on mountains.

5. Astronomy and Cosmology: The Leicester Codex contains Leonardo's thoughts on celestial bodies, including the moon's surface, the nature of light and shadow during eclipses, and his understanding of the Earth's place in the universe. 6. Artistic Connections: While primarily focused on scientific subjects, Leonardo often intertwined his artistic skills with his scientific observations. The codex includes sketches of machinery, anatomical studies, and even a few artistic compositions. 7. Ownership: After being owned by the Earl of Leicester, the codex changed hands several times over the years. In 1994, it was acquired by Bill Gates, the co-founder of Microsoft, who later digitized the codex and made it available online. The Leicester Codex provides valuable insights into Leonardo da Vinci's scientific mind and his multidisciplinary approach to understanding the world. It is considered one of the most important scientific manuscripts from the Renaissance period.