Chap. IV- The Anatomy of a HOKSV.. 47 



open, having no Covering, and is divided by the Cs fqua-^ 

 mojum into two Pipes ; one of v.'hich tends to the Coihua^ 

 the other into the Labyrinth. 



The Labyrinth^ which is the fecond Ca- a-i. r i • .l 

 vity, by Its feveral Turnings and Wind- 

 ings, w^hich are fomewhat circular, modulates the St)und3 

 in fuch Manner as they may be leifurely communicated to 

 te Auditory Nerve, which is difperfed thro' the Mem- 

 brane that inverts this Cavity. There is, befides the two 

 Windows which open into this Cavity, one Perforation 

 which opens out of it into the inner Cavity calPd the Co- 

 chlea, into which the Air palles, after it has been agita- 

 ted in this Cavity and the Concha, Befides thcfe, there ars 

 four other fmall Holes for the Ingrefs of the nervous Fibres 

 that are inferted on the Membrane, which cloaths it. 



The Cochlea, which is the third and in- <j-j^^ Cochlea • 

 nermoft Cavity, is fo caird from theRefem- 

 hlarrce it hath to a Snail's Shell, efpecially in its fpiral 

 Windings ; Jt is far lefs than either of the former, but in- 

 vefted, as the others are, with a thin Membrane, into which 

 alfo the ilender Fibres of the Auditory Nerve do enter. 

 This Cavity is fiU'd with the internal inbred Air, as well as 

 the former, by which the Eccho is made to (the Impulfeof 

 the internal Air upon the Tympanum : And the Auditory 

 Nerve being expanded upon the Membrane, which lines all 

 thofe Cavities, it is fuddenly affected therewith, whereby it 

 comes to be communicated to the Original of the Nerves, 

 where all Sounds are diftinguifh'd, 



§ VI. Of the Nofe and Mouth, 



As the Ear is made up of Parts, whereof '^he Nofe. 

 fomc are External, and fome Internal ; fo 

 the Nofe is alfo compofed of the like Parts. 



The external Parts of the Nofe are made up of Skin, 

 Mufcles, Bones, Cartilages, and Veflels of all Sorts. 



The Skin is extremely thin, and without , „ 

 Fat, and adheres fo faft to the Mufcles and '^ 

 grifly Part, that it can hardly be feparated from them. 



The Bones, which make up its Cavities^ are fome of 

 them common to it and the Forehead, and fome of them 

 proper to the N-ofe only. The Griftles are in Number Eve, 

 \-vhich fhall be treated of hereafter with the Bones. 



The 



