From The Art and Popular Culture Encyclopedia
The Codex Atlanticus (Atlantic Codex) is an important, twelve-volume, bound set of drawings and writings by Leonardo da Vinci, the largest such set; its name indicates its atlas-like breadth. It comprises 1,119 pages dating from 1478 to 1519, the contents covering a great variety of subjects, from flight to weaponry to musical instruments and from mathematics to botany. This codex was gathered by the sculptor Pompeo Leoni, son of Leone Leoni, in the late 16th c., although Leoni dismembered some Leonardo notebooks in its formation. It is currently preserved at the Biblioteca Ambrosiana, Milan.
The codex was restored and rebound by the Basilian monks working in the Laboratory for the Restoration of Ancient Books and Manuscripts of the Exarchic Greek Abbey of St. Mary of Grottaferrata over the course of 1968 to 1972.
In April 2006, Carmen Bambach of the Metropolitan Museum of Art, New York discovered an extensive invasion of molds of various colors, including black, red, and purple, along with swelling of pages. Monsignor Gianfranco Ravasi, then the head of the Ambrosian Library, now head of the pontifical Council for Culture at the Vatican, alerted the Italian conservation institute, the Opificio delle Pietre Dure, in Florence. In October 2008, it was determined that the colors found on the pages weren't the product of mold, but instead caused by mercury salts added to protect the Codex from mold. Moreover, the staining appears to be not on the codex but on later cartonage.