POEPHAGA 



270 



POLYCYSTINA 



Poiuter Dog. 



ing moss-like herbs belonging to Ru tales; 

 exogens that approximate to endogens. 



Poephaga, (po-efa-ga). [Gk. poa, grass; phago, 

 I eat. ] A division of Marsupialia, represented 

 by the kangaroo. 



Poikilopleuron, (poi-kil-o-plo'ron). [Gk. poi- 

 kilos, coloured; pleura, side.] An extinct 

 reptile belonging to Dinosanria, q.v. 



Point. The extreme end of a line, which 

 marks its position without having any space. 

 Boiling P.: the temperature at which a given 

 liquid boils. Freezing P.; the temperature 

 at which a given liquid freezes. 



Pointer. A variety of 

 thedog, used in shoot- 

 ing for his power of 

 finding game. 



Pointers, Two stars, 

 Merak and Dubhe, in 

 Ursaa Majoris, the 

 line through which 

 points to Polaris. 



Poison (poi'zon). [The French word.] Any 

 substance which tends, when mixed with the 

 blood, to destroy life. 



Poisonous snakes. Ophiophagus, Naja, Da- 

 boia, Trimeresuri, &c. 



Polar, (polar). [Polaris, the Latin word.] 

 Relating to the N. or S. Pole, or to the poles 

 of a magnet, &c. P. 6ar=Ursus maritimus: 

 a carnivorous variety of the bear. P. clock : 

 apparatus attached to a sun-dial, in the 

 northern regions, for the purpose of point- 

 ing out the time; the action of it depends on 

 the polarisation of light. P. distance: the 

 distance of a star, <tc., from the celestial 

 pole, measured along the celestial meridian. 

 P. lights, v. Aurora Borealia and Aurora Aus- 

 tralia. 



Polaris, (po-la'ris). [L. Stella polaris, star of 

 the pole.] A star very near the north pole 

 of the heavens, and therefore called the Pole- 

 star, q.v. 



Polarisation, (po-lar-i-zu'shnn). [Polar, q.v.] 

 P. of light; a conversion of an ordinary ray, 

 which vibrates in every plane perpendicular 

 to its direction, into one which vibrates in 

 one plane only, and cannot be doubly re- 

 fracted; in double refraction the ordinary 

 and extraordinary ray are each polarised, but 

 in different planes. Angle of P. : for glass, 

 about 55 with the normal ; for water, about 

 52; for diamond, about 68. 



Polariscope, (po-lar'i-skop). [Polar, q.v. ; Gk. 

 skopeo, 1 see.] An apparatus for detecting 

 polarised light. 



Polariser, (po-lar-i'zer). [Polarisation, q.v.] 

 An apparatus for polarising a ray of light. 



Polarity, (po-larl-ti). [Polar, q.v.] The pro- 

 perty of pointing, or being referred, to oppo- 

 site poles, as in a magnet, polarised light, &c. 



Pole, (pol). [1. Pol, the A.-S. word; 2. L. 

 polus, the end of an axis.] l.=Perch: a 

 measure of length =5^ yards. Square P.= 

 30J yards. 2. v. Poles. 



Poles, (polz). [ i'. Pole, 2.] 1. Of a magnet: 

 the free ends, which attract more strongly 

 than any other pai't, one called north, the 

 other south. 2, Of a galvanic battery, one 



Pole-Cat 



called positive, the other negative; the ex- 

 tremities where the electric action is ap- 



Pole-cat. = Mustela 



torius : a weasel - lke 



animal. 

 Pole - star. The star 



nearest the N. pole of, 



the heavens; nowr=a' 



Ursae Miuovis, in 60CO 



A.D.=y Draconis. 

 Polemoniaceae, (pol-e-mo-ni-a'se-e). [Polemo- 



nium, q.v.] = Phlox-worts : herbs, chiefly 



American, belonging to Solanales. 

 Polemonium, (pol-e-mo'ni-um). [Polemonion, 



the Greek name. ]= Jacob's ladder = Greek 



Valerian: a plant, the type of Polymoniaceae, 



q.v. 

 Pollards, (pol'lardz). [Pott, head.] Trees of 



which the upper portions have been cut off. 

 Pollen, (pol'len). [L. pollen, fine flour.] A 



fertilising powder contained in the anthers 



of flowering plants, v. Stamen. 

 Pollex, (pol'leks). [The Latin word. ]= Thumb, 



q.v. 

 Pollux, (polluks). [Classical] 1. A bright 



star in Gemini, once red, now orange. 2. A 



mineral, about one-third of which is caesium. 

 Poly-, (poll). [Gk. polys, many.] A prefix 



implying many. 

 Polyadelphous, (pol-i-a-del'fus). [Gk. polys, 



many; adelphos, brother.] A term applied 



to plants of which the stamens are united by 



the filaments, v. Stamen. 

 Polyads, ( poll-adz ). [Gk. polys, many.]= 



Polyatomic elements: triads, tetrads, hexads, 



&c., q.v. 

 Polyandrous, ( pol-i-an'drus). 



many ; finer, man.] P. 



plants: those having the 



stamens numerous, i.e., 



more than twenty to each 



flower. 

 Polyanthus, ( pol-i-an'th u s ). 



[Gk. polys, many; anthos, 



flower.] An herb; a variety 



<if the primrose. 

 Polyatomic, (pol-i-a-tomlk). [Poly and Atomic, 



q.v.] Term used for elements or radicles 



which have an equivalency greater than one. 

 Polybasic, (pol-i-ba'sik). [Gk. Poly and Basic, 



q.v.]= Poly atomic, q.v. P. acicte=Acid salts. 



v. Salts. 

 Polychroite, (pol-i-kro'it). [Gk. polys, many; 



chroia, colour.] The colouring matter of 



saffron, v. Saffranin. 

 Polychromatic acid, (pol-i-kro-mat'ik). [Gk. 



polys, many; chroma, colour. ]= Aloe tic acid, 



q.v. 

 Polychrome, (pol'i-krom). [Gk. polys, many; 



chroma, colour. ]=Esculin: a crystalline sub- 

 stance obtained from horse-chestnut bark, 



named from the variety of colour when seen 



by reflected light. 

 Polychromy, ( pol'i -kro-mi). [Gr. polys, many; 



chroma, colour.] Variety of colour, especially 



as applied to buildings or statuary. 

 Polycystina, (pol-i-sis-ti'na). [Gk. polys, roany; 



kystis, bladder.] Microscopic, siliceous, forar 



[Gk. polys, 



Polyaudroua. 



