How bodies fill the air with their images
Optics: each body is present throughout the air opposite it, proved by mirrors set face to face
A short optical argument written in Leonardo's mirror-script, with a couple of lines struck through and a small circle sketched in the margin. Leonardo holds that every body infuses the surrounding air with its own likeness or 'species', so that the whole and the parts of a body's image appear throughout the whole and the parts of the opposing air. He concludes that each body is therefore present, wholly and in part, in the bodies opposite it, as two mirrors placed facing one another demonstrate.
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Every body's image pervades the opposing air, shown by opposed mirrors
Leonardo states that all bodies have their likeness and image infused and mingled within them, so that this image appears throughout the air opposite the body, and the air's own image appears upon the body's surfaces. From this he argues that each body is present, wholly and in part, within the bodies opposite it, citing two mirrors set face to face as proof.