Calorescence

Calorescence, a term given by Tyndall to the change of the invisible dark heat rays into luminous heat rays. A beam of light may be passed through a solution of iodine in bisulphide of carbon, so as to filter off all but the dark heat rays, which will pass through unaltered. These may be concentrated to a focus by a lens and made to incandesce a piece of platinum placed there. The platinum will then give out bright heat rays, thus effecting the transformation of non-luminous to luminous heat, which means increasing the frequency of vibration of the ether-waves.