Phos"phu*ret`ed (?), a. (Chem.) Impregnated, or combined, with
phosphorus. [Obsoles.] [Written also phosphuretted.]
Phosphureted hydrogen. (Chem.) See Phosphine.
Pho"tic (?), a. [Gr. fw^s, fwto`s, light.] (Physiol.) Relating to the
production of light by the lower animals.
Pho"tics (?), n. (Physics) The science of light; -- a general term
sometimes employed when optics is restricted to light as a producing
vision. Knight.
Pho"to (?), n.; pl. Photos (&?;). A contraction of Photograph.
[Colloq.]
Pho"to- (?). A combining form from Gr. fw^s, fwto`s, light; as,
photography, phototype, photometer.
Pho`to*bi*ot"ic (?), a. [Photo- + biotic.] (Biol.) Requiring light to
live; incapable of living without light; as, photobiotic plant cells.
Pho`to*chem"ic*al (?), a. [Photo- + chemical.] (Chem.) Of or pertaining
to chemical action of light, or produced by it; as, the photochemical
changes of the visual purple of the retina.
Pho`to*chem"is*try (?), n. [Photo- + chemistry.] (Chem.) The branch of
chemistry which relates to the effect of light in producing chemical
changes, as in photography.
{ Pho`to*chro"mic (?), Pho`to*chro*mat"ic (?), } a. Of or pertaining to
photochromy; produced by photochromy.
Pho*toch"ro*my (?), n. [Photo- + Gr. &?; color.] The art or process of
reproducing colors by photography.
Pho"to*drome (?), n. [Photo- + Gr. &?; to run.] (Physics) An apparatus
consisting of a large wheel with spokes, which when turning very
rapidly is illuminated by momentary flashes of light passing through
slits in a rotating disk. By properly timing the succession of flashes
the wheel is made to appear to be motionless, or to rotate more or less
slowly in either direction.
Pho`to-e*lec"tric (?), a. [Photo- + electric.] Acting by the operation
of both light and electricity; -- said of apparatus for producing
pictures by electric light.
Pho`to-e*lec"tro*type (?), n. (Print.) An electrotype plate formed in a
mold made by photographing on prepared gelatine, etc.
Pho`to-en*grav"ing (?), n. [Photo- + engraving.] The process of
obtaining an etched or engraved plate from the photographic image, to
be used in printing; also, a picture produced by such a process.
Pho`to-ep"i*nas`ty (?), n. [See Photo-, and Epinastic.] (Bot.) A
disproportionately rapid growth of the upper surface of dorsiventral
organs, such as leaves, through the stimulus of exposure to light.
Encyc. Brit.
Pho`to*gal`va*nog"ra*phy (?), n. [Photo- + galvanography.] The art or
process of making photo-electrotypes. Sir D. Brewster.
Pho"to*gen (?), n. [Photo- + - gen.] (Chem.) A light hydrocarbon oil
resembling kerosene. It is obtained by distilling coal, paraffin, etc.,
and is used as a lubricant, illuminant, etc. [Written also photogene.]