Yes. A ray of light, as well as containing elementary rays that produce colours under refraction, contains also chemical rays, and heat rays.
542. How do we know that light and heat are separate elements?
Because we have heat rays, as from dark hot iron, from various chemical actions, and from friction, which are unattended by the development of light. And we have light, or luminosity, such as that of phosophoresence, which is unaccompanied by any appreciable degree of heat.
But, besides this confirmation, further proof is afforded by the fact, that in passing rays of solar light through media that are transparent to heat, but not to light, the heat rays may be separated from the luminous rays, and vice versa.
Black glass, and black mica, which are nearly opaque to light, are transparent to heat to the extent of ninety degrees out of a hundred. While pale green glass, coloured by oxide of copper, and covered with a coating of water, or a thin coating of alum, will be perfectly transparent to light, but will be almost quite opaque to heat. These remarks apply, in a greater or less degree, to various other substances.
543. In what respects are light and heat similar?
Both heat and light have been referred to minute vibratory motions which occur, under exciting causes, in a very subtile elastic medium.
They are both united in the sun's rays.
They are both subject to laws of absorption, radiation, reflection, and refraction.
They are both essential to life, whether animal or vegetable.