photophobia (fotofobia)

[= F. photo phobic It. fotofobia, photophobic (fo-to-foʼbik), a. [ One form consists of a thin mirror of silvered mica which receives the vibrations from the person speaking, and upon which a beam of light falls at the same time. This light is reflected to the receiving-point at a distance. There it falls upon a concave mirror, and is brought to a focus upon a selenium-cell. The variation in the light produces a corresponding variation in the electrical resistance of the selenium, and this reproduces the spoken words in a telephone connected with it. In the earlier papers describing it [the radiophone] and the experiments which led to its invention it is called photophone , because at that time the effects were supposed to be wholly due to light. Afterwards, in order to avoid ambiguity, Bell changed the name to radiophone, and suggested that, to distinguish between instruments depending on the different kinds of radiation, the names photophone , thermophone, ., should be employed. Encyc . Brit . , XXIII. 130.