PHLOGOPITE 



263 



PHOTOGRAPHY 



Phlogopite, (flS'go-pu, [Gk. phlox, flame; 

 ops, appearance.] A mineral of the mica 

 group, common in metamorphic limestone. 



Phlogiston, (flo - gis ' ton). [Gr. phlogistos, 

 burnt.] An hypothetical subtle substance, 

 formerly supposed to be present in all com- 

 bustible substances, and to evaporate when 

 they were heated. 



Phloretic acid, (flo're-tik). [Phloridzin.]= 

 CgHioOs: a crystalline acid substance ob- 

 tained from phloridzin, found in bark of the 

 roots of apple trees, &c. 



Phloretin, (flo're-tm). (Thloridzin, q.v.]= 

 CigH^O: a resinous matter obtained from 

 phloridzin. 



Phloridzin, (flo'rid-zin). [Gr. phloios, bark; 

 rhiza, root.]=Phlorizin=C 2 iH 2 4O 10 2H 2 O: a 

 substance found in the bark of the apple and 

 cherry trees, &c., from which sugar may be 

 obtained. 



Phlorol, (flo'rol). An oil, highly refractive of 

 light, found in phloretate of calcium. 



Phlox- worts, (floks). [Gk. phlox, flame. ]= 

 Polemoniacese, q.v. 



Phoca, (fo'ka). (Phoke, the Greek name.]= 

 Seal: a marine carnivorous Mammalian ani- 

 mal, the type of Phocidae. P. ursinaSea.- 

 bear. 



Phocsena, (fo-se'na). [Gk. phokaina, porpoise.] 

 = Porpoise: a marine animal belonging to 

 Cetacea. 



Phocidae, (fo'si-de). [Phoca, q.v.; Gk. eidos, 

 form.] Marine animals belonging to Pinni- 

 ped ia. v. Carnivora. 



Phoenicopterous, ( fe-ni-kop ' ter-us ). [Gk. 

 phoinix, purple-red ;p(ero/i, wing.] Flamingo: 

 a wading bird, with long legs and neck and 

 large beak, belonging to Anatidse. 



Phoenix, ( fe'niks ). [ Phoinix, the Greek 

 name.] 1. An unimportant southern con- 

 stellation. 2. Date tree: a variety of the 

 palm tree. 



Pholadomyae, (f5-lad-om'i-e). [Gk. pholas, 

 lying hid.] A mollusc, abundant in oolite, 

 one species being still extant. 



Pholidophorus, (fol-i-dofo-rus). [Gk. pholis, 

 scale; phoreo, I bear.] A ganoid fish, known 

 by fossil remains, found in Lias rocks. 



Phonautograph, (fo-naw'td-graf ). [Gk. phone, 

 sound; autos, self; grapho, I write.] An 

 apparatus for registering the number and 

 extent of vibrations in sound. 



Phonolite, (fo'no-llt). [Gr. phone, sound; lithos, 

 stone. ]=Clinkstone, q.v. 



Phormium, (for'mi-um). [Gr. phormos, mat.] 

 New Zealand flax: a plant belonging to Lili- 

 aceas. 



Phormosoma, (for-mo-s5'ma). [Gr. phormos, 

 mat; soma, body.] A sea-urchin. P. pla- 

 centa: first discovered in 1869 in Atlantic, N. 

 of Scotland. 



Phosgene gas, (fos'jen). [Gr. phos, light; gen- 

 nao, I produce. ]=COCl2=Carbonic oxydi- 

 chloride: a colourless suffocating gas. 



Phospham, (fos'fam).=HN 2 P=Phosphide of 

 nitrogen and hydrogen: an amorphous sub- 

 stance. 



Phosphate (fos'fat). A compound of phos- 

 phoric acid and a base. P. of lime: one of the 



essential constituents of bone. P. of soda 

 and 7)imoHia=Microcosmic salt. 



Phosphenes,(fos'fenz). [Gk.phos, light; phaino, 

 I appear.] Luminous images produced in 

 darkness by pressure upon the eye-ball. 



Phosphides, (fos'fidz). [Phosphorus, q.v.] 

 Compounds of phosphorus with other ele- 

 mentary substances. P. of hydrogen, if 

 liquid, takes fire spontaneously when in con- 

 tact with oxygen. 



Phosphites, (fos'flts). [Phosphorus, q.v.] 

 Compounds of phosphorous acid and bases. 



Phosphonitryle, (fos-fd-m'tril). [Phosphorus 

 and Nitrile, g.v.]=PNO=Biphosphamide: a 

 white amorphous substance. 



Phosphorescence, (fos-for-es'sens). [Gk. phos, 

 light; phoreo, I bear.] The emission of light 

 (as in phosphorus, the glow-worm, &c.) with- 

 out combustion, especially after exposure to 

 light. 



Phosphoric, (fos-for'ik). [Phosphorus, q.v.] 

 P. acidI. Ortho-P. A.: ordinary P. A.= 

 HsPO^: combines with 3 equivalents of a 

 base. 2. Meta-P. <4.=HPO 3 ; combines with 

 1 equivalent of a base. 3. Pyro-P. A.= 

 K^PaC^; combines with 4 equivalents of a 

 base. P. anhydride=P^.O5: a white floccu- 

 lerit powder. P. cAioride=PC! 5 =Perchloride 

 of phosphorus. 



Phosphorite (fos'for-It). [Phosphorus, q.v.]= 

 Native bone phosphate: a variety of apatite. 



Phosphoroscope, (fos-for / 6-skop). [Phosphores- 

 cence, q.v.; Gk. skopeo, I show.] An appara- 

 tus to show the phorphorescence of bodies, 

 such as uranium compounds, that emit light 

 but for a very short period. 



Phosphorous, (fos'for-us). [Phosphorus, q.v.] 

 =P. acid=Dyhydric phosphite. P. anhy- 

 dride = P 2 O 3 . P. chloride = PC1 3 = Ter- 

 chloride of phosphorus: a volatile fuming 

 colourless liquid. 



Phosphorus (fos'for-us). [Gk. phos, light; 

 phoros, bearing.] P'": a waxy, semi-trans- 

 parent, very inflammable substance, which 

 is luminous in the dark, and is found in 

 several forms. Amorphous P. =Red P. : oxi- 

 dises but very slowly, and burns only at 

 500 F. Vitreous P. ^Ordinary P. P. group 

 of elements: phosphorus, arsenicum, and anti- 

 mony; all forming alkaline compounds with 

 hydrogen, and acid compounds Avith oxygen. 



Phosphuretted- hydrogen = H 3 P = Phosphor- 

 ous trihydride : a colourless very inflam- 

 mable foetid gas, which usually takes fire 

 spontaneously when in contact with oxygen, 

 owing to the presence of liquid phosphide of 

 hydrogen. 



Photoelectric microscope. A microscope illu- 

 minated by the electric light, so that the 

 image can be thrown, greatly magnified, on 

 a screen in a darkened room. 



Photogen, (fo'to-jen). [Gk. phos, light; gen- 

 nao, I produce. ]=Paraffin oil, q.v. 



Photograms, ( fo'to-gramz ). [ Gk. phos, 

 light; gramma, writing.] Light- writings 

 Photograph, but used especially for photo- 

 graphic records, such as of variations of 

 temperature, &c. 



Photography, ( fd-tog'ra-fi ). [ Gk. phos, 



