Reflected colour and the mirror analogy of the voice
How white bodies take on the colour before them, and how an image-or a voice-fills the whole mirror
Leonardo argues that any colorless body takes on the color of whatever is placed before it: a white surface lit through red appears red, and a white wall is tinted by the objects that face it. He then draws the mirror a-b, where object c is present at once throughout the whole glass yet entire at each part, so that viewers at m and f each see the reflection along their own line of sight, at t and at e. The reflection of the voice, he notes, obeys the same law of equal obliquity as the mirror. He closes with the everyday proof of the sun reflected in a river, which seems to walk along with you however far you go.
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A colorless body is tinted by the color set before it
Any colorless body becomes colored, wholly or in part, by the color placed before it. Experience shows it: a reflecting body is tinted by the color that faces it, and a white surface lit by red will appear red, whether shiny or opaque. A white wall shares in the color of its object.
An image fills the whole mirror yet is entire at each part
With mirror a-b and object c, since c sees every part of the mirror, every part of the mirror sees c; so c is present throughout the mirror and whole at each part. A viewer at f sees object d at part e of the mirror, and a viewer at m sees it at t, each along a straight line.
The sun in the river walks along with you
Walking along a riverbank and seeing the sun reflected in the water, however far you go the sun seems to move along with you, because it is present throughout the reflecting surface and whole at each part.