GLOSSARY. 



14] 



chest, between the walls of the 

 cavity and its contents. 



Pneumatol'ogy (Gr. nvev/jLa, pneu'ma, 

 air ; ^0705, log'os, a discourse). 

 The doctrine of the properties of 

 airs or gases. 



Pneu'mo- (Gr. irvev/juuv, pneumon, a 

 lung). A prefix in compound words, 

 implying connection with, or relation 

 to lungs. 



Pneumogas'tric (Gr. irvev/j-wv, pneu- 

 mon, the lungs ; yaarrip, gaster, 

 the stomach). Belonging to the 

 lungs and stomach ; applied to a 

 nerve which supplies these organs. 



Pneumonic (Gr. irvevfj.<i}v, pneumon, 

 a lung). Belonging to the lungs. 



Pneumo'nia (Gr. irvevnwv, pneumon, 

 a lung). Inflammation of the 

 lungs. 



Po'acites (Gr. 71-00, poa, grass). In 

 geology, the generic term for all 

 fossil monocotyledonous leaves, 

 having the veins parallel, simple, 

 and equal, and not connected trans- 

 versely. 



Podag'ra (Gr. TTOVS, pous, a foot ; ay pa, 

 agra, a seizing). The gout. 



Pod'ocarp (Gr. novs, pous, a foot ; 

 Kapiros, Jcar'pos, fruit). The stem 

 supporting the fruit. 



Podophthalma'ria (Gr. TTOVS, pous, a 

 foot ; 6<p0a\fj.os, ophthal'mos, an 

 eye). A group of Crustacea, having 

 the eyes placed on moveable 

 peduncles or stalks. 



Pod'osperm (Gr. vovs, pous, a foot ; 

 (TTrepjita, sper'ma, a seed). In botany, 

 the little bud connecting an ovule 

 with its placenta. 



Poe'cilopods (Gr. TTOIKI\OS, poi'kilos, 

 varied ; TTOVS, pous, afoot). Crusta- 

 ceous animals having the fore-feet 

 adapted either for swimming or 

 seizing. 



Polar (Lat.poZ'fts, a pole). Belonging 

 to one of the poles of the earth ; or 

 to the magnetic pole. 



Polar Circles. Two small circles of 

 the earth, parallel to the equator, 

 and surrounding the poles, north 

 and south. 



Polarlscope (Lat. pola'ris, belonging 

 to a pole ; Gr. crKoirew, slcop'eo, I 

 view). An optical instrument for 



observing the phenomena of the 

 polarisation of light. 



Polarity (Lat. pot' us, a pole). The 

 property by which the particles of 

 many bodies arrange themselves in 

 fixed directions to given poles. 



Polariza'tion (Lat. pol'us, a pole). 

 The act of giving polarity to a body. 



Polarization of Light. The process 

 by which a ray of light acquires new 

 properties when submitted, under 

 peculiar conditions, to reflection or 

 refraction. 



Pole (Gr. iro\os, pol'os, an axis or 

 pole). The extremity of the axis 

 of a spherical body, or of a straight 

 line passing through the centre of 

 such a body. Each pole is 90 

 degrees distant from any part of 

 the equatorial circumference. Mag- 

 netic poles are two poles in a load- 

 stone corresponding to the poles of 

 the earth. The poles of a Voltaic 

 battery are the ends of the wires 

 that connect its opposite ends. 



Polem'ic (Gr. TroAe^oy, pol'emos, war). 

 Controversial : disputative. 



Pollen (Lat. fine flour or dust). The 

 fine dust on the anther of flowers. 



Poly- (Gr. TroAuy, pol'us, much). A 

 prefix in compound words, signify- 

 ing much or many. 



Polyadel'phia (Gr. iro\vs, pol'us, 

 many ; a8e\(t)os,adel'phos, a brother). 

 A name given to a class of plants 

 in the Liunsean system, in which 

 the stamens are collected into several 

 parcels. 



Polyan'dria (Gr. TTO\VS, pol'us, many ; 

 av-rjp, aner, a male). A name given 

 to a class of plants in the Linnsean 

 system, having twenty or more 

 stamens on the receptacle. 



Pol'ybasic (Gr. iro\vs, pol'us, many ; 

 /3a<ns, bas'is, a base). A term 

 applied to acids which require two 

 or more equivalents of a base for 

 neutralisation. 



Polycar'pous (Gr. TroAvy, pol'us, 

 many ; Kapiros, Jcar'pos, fruit). 

 Having many fruit. 



Polychromatic (Gr. TTO\VS, pol'us, 

 many ; ;gxo;ua, chroma, colour). 

 Having many colours ; showing a 

 play of colours. 



