EXPONENT 



124 



FALCATE 



duced. Chloride of Nitrogen, Dynamite, 

 Gun-cotton, Gunpowder, Iodide of Nitrogen, 

 Mercuric fulminate, Nitro-glycerine=Glouo- 

 ine, Perchloric ether, Silver fulminate. 



Exponent, (eks-po'nent). [L. expono, I set 

 out. ] I ndex : used in arithmetic and algebra 

 to denote the power to which a quantity is 

 to be raised: e.g., 42=4 X 4. m=the product 

 of m multiplied n.l times by m=mxmxm 

 (n times). Here 2 and n are exponents. 



Exsiccator, (eks-ik'a-tor). [L. exsicco, I dry.] 

 A drying apparatus, formed by the use of 

 substances, such as chloride of calcium, 

 which readily absorb moisture. 



Exstipulate, (eks-stip'u-lat). v. Stipule. 



Extra-current. An induced galvanic current: 

 in the same direction as the principal current 

 when contact is made; in the reverse direc- 

 tion when it is broken. 



Extrados, (eks-tra'dos). [The French word.] 

 The outer curve of an arch or of a vault. 



Extraordinary ray. One of the two rays 

 resulting from double refraction, q.v. 



Exuviae, (eks-u'vi-e). [The Latin word.] Any 

 things that are cast off as useless, as skins and 

 shells of some animals. 



Eyas, (i'as). [Fr. niais, from the nest.] A 

 hawk too young to leave its nest. 



Eye, (i). [Eage, A.-S. word.] 1. The organ 



of sight, by means of which light affects the 



optic nerve. 2. In potatoes, a bud, a point 



of growth. 

 Eyeball. A tough spheroid of connective 



tissue, the front of which is transparent. 

 Eyebolt, A bolt or bar having an eye at one 



end. 

 Eyebright, (i'brit). [Eye and Bright. ]=Euph- 



rasia, q.v.: named from having been used 



medicinally for the eyes. 

 Eyeglass=Spectacles. 

 Eyelashes, Hairs fringing the eye. 

 Eye lens. The lens of a compound eyepiece, 



which in use is nearest to the eye. 

 Eyelids. Folds of skin which can be drawn 



over the eye. 

 Eyemuscles. Those by which the eyeball is 



moved. 

 Eyepiece. The simple or compound lens, in 



any optical apparatus, to which the eye is 



applied. 

 Eyetooth=Canine-tooth: a conical tooth next 



to the incisors. 

 Eyot, (i'ot). [A.-S. ey, island. ]= Ait: a small 



river island. 

 Eyrie, (a'ri or I'ri). The nest of a bird of prey, 



especially of an eagle. 



F. 



Fabaceae, ( fa-ba'se-e ). [L. faba, bean. ]= 

 Leguminous plants: herbs, shrubs, and large 

 trees, with papilionaceous corolla and legu- 

 minous fruit, belonging to Resales. 



Fab ago, (fa-ba'go). [L. faba, a bean.] A 

 plant belonging to Fabaceae. 



Faboidea,(fa-boi'de-a). [L. /a&a,bean ;Gk.iefos, 

 form.] Fossil remains of leguminous plants. 



Facade, (fa-sad'). [The French word.] The 

 front of a build- ,.^ji_i: - ^-^=^-=^_^=_ , 

 ing,especially the 

 principal front. 



Face,(fas).[ Facie*, 

 the Latin word.] 

 The front of the 

 head, including 

 the special organs 

 of sight and smell 

 the mouth, fore- 

 head, &c. F. 

 wheel : a wheel 

 having cogs or Facade, 



pins on its face. 



Facial nerves, (fa'shi-al). [Face, q.v.] The 

 seventh pair of cerebral nerves, belonging to 

 the face muscles. 



Factors, (fak'torz). [L. factor, maker.] The 

 numbers which, when multiplied together, 

 produce a given number are the factors of 

 that number. Ex. : 4 and 8 are factors of 32; 

 3 and 7 are the factors of 21, <fec. 



Faculae, (fak'u-le). [L. f acute, small torch.] 

 Brilliant ridges and plains upon the photo- 

 sphere of the sun; probably mountains or 

 heaped-up matter, cf. Maculae. 



Faeces, (fe'sgz). [L./a>z,dregs.]=Excrement 

 q.v. 



Fseniculum, (fC-nik'u-lum). [The Latin name.] 

 = Fennel, q.v. 



Fagine, (fa'jin). [Fagus, q.v.] A narcotic 

 obtained from beech nuts. 



Fagopyrum, (fa-go-pi'rum). [Gk. phayo, I eat; 

 pyros, wheat.] A plant belonging to Poly- 

 gonaceae; also called Polygonum Fagopyrum. 

 F. escwien<um=Buckwheat, q.v. 



Fagus, (fa'gus). [Gk. phago, to eat.]=Beech, 

 q.v. : a large tree belonging to Corylaceae. 



Fahlerz, (fa'lerz). [The German name.]= 

 Grey copper ore; also called Fahlore. Silver 

 F. : a copper ore containing silver. 



Fahlunite, (fah'lu-mt). [Fahlun, in Sweden.] 

 A mineral, chiefly silicate of magnesia and 

 alnminia. Hard P.=Iolite. 



Fahrenheit's scale, (fa'ren-hit). [Fahrenheit, 

 the inventor.] Of thermometer: in which 

 the freezing point of water is 32, and the 

 boiling point 212, the distance between 

 being divided into ISO equal parts; in com- 

 mon use in England, cf. Centigrade and 

 Reaumur scales. 



Fairing, (fa'ring). A corrective process in 

 shipbuilding, by which errors in the plans are 

 detected before the building is commenced. 



Fairy, (fa'ri). [Y.f eerie, fairy-like.] Used as 

 a common name for some animals of especi- 

 ally graceful form. F. martin=Himudo 

 ariel: Australian. F. s7iri7Jip=Cbii'ocephalus 

 diaphanus. 



Falcate, (fal'kat). [L. fate, sickle.] Sickle- 

 shaped. 



