Reflected Light, and Shadows Lost at a Distance
A face lit by candle and air shows two colors; distant shadows dissolve into luminous air
Text page continuing the Treatise's account of light and color: objects reflect the light they receive, as the moon and stars send back the sun's light, while darkness clothes whatever it encloses. A chapter shows that a body almost never keeps its true color — a face lit on one side by daylight and on the other by candle-flame plainly appears in two colors, and a white strip lit through three openings (sun, fire, air) takes three colors. Further short chapters explain that shadows are lost over distance because the luminous air between eye and object tints them, and introduce the widening and narrowing of shadows on curved bodies.
On this page
A body lit by two sources shows two colors
A face set in a dark place and lit on one side by a ray of daylight and on the other by a lit candle will without doubt appear in two colors. If a white strip is placed in darkness and given light through three openings — from the sun, from the fire, and from the air — that strip will be of three colors.
Distant shadows dissolve into the luminous air
Shadows are lost over a long distance, because the great quantity of luminous air found between the eye and the thing seen tints the shadows of that thing with its own color.
Objects reflect the light they receive, as moon and stars do
All objects placed before a luminous body partake of its light and reflect it onto other objects, as is seen with the moon and the stars, which send back to us the light given them by the sun; and darkness does the same, clothing in its obscurity whatever it encloses.