Michelangelo
With the completion of the "David" came another commission. In early 1504 Leonardo da Vinci had been commissioned to paint "The Battle of Anghiara" in the council chamber of the Palazzo Vecchio, depicting the battle between Florence and Milan in 1440. Michelangelo was then commissioned to paint the "Battle of Cascina". The two paintings are very different: Leonardo depicts soldiers fighting on horseback, while Michelangelo has soldiers being ambushed as they bathe in the river. Neither work was completed and both were lost forever when the chamber was refurbished. Both works were much admired, and copies remain of them, Leonardo's work having been copied by Rubens and Michelangelo's by Bastiano da Sangallo.
Separation of Light from Darkness
Of note is that in an article published in the "Journal of the American Medical Association" in October 1990, Frank Meshberger, an obstetrician-gynecologist from Indiana, explained that Michelangelo similarly concealed an image of the brain in the shroud surrounding God in the "Creation of Adam". Since Michelangelo painted the "Creation of Adam" and the "Separation of Light from Darkness", along with two other Genesis panels, as a single thematic unit between the winter of 1511 and October 1512, it is possible that these four central panels have an underlying anatomical motif. Indeed, Garabed Eknoyan, a nephrologist from Baylor College of Medicine, proposed in an article published in "Kidney International" in March 2000 that Michelangelo concealed an image of a kidney in the "Separation of Land and Water", the third panel in the Genesis series. Michelangelo was particularly interested in kidney function because he suffered from kidney stones throughout his adult life and documented this interest in his letters and poems, according to Eknoyan.