Chap. IV. The Amto'my <?/ ^ H O Pv S E, 47 



open, having no Coveringj and is divided by the Oi /qua- 

 mofum into two Pipes i one of which tends to the CockUa^ 

 the other intb^ the Labyrinth. 



The Labyrinth^ which is the fecond Ca- ^^^ Laljrinth 

 vity, by its leveral Turnings and Wind- 

 ings, which are fomewhat circular, modulates the Sounds 

 in fuch Manner as they may be leifurely communicated to 

 the 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 call'd the Co' 

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

 ted in this Cavity and the Comha. Befides thefe, there are 

 four other fmall Holes for the Ingrefs of the nervous Fibres 

 that are inferted on the Membrane, which deaths it. 



The Cochlea^ which is the third and in- q-j Cochlea 

 nermoft Cavity, is fo cali'd from theRefem- 

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

 Windings ; it is far leis than either of the former, but ii>- 

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

 alfo the llender Fibres of the Auditory Nerve do enter. 

 This Cavity is fill'd v\4th the internal inbred Air, as well as 

 the former, by which the Eccho is made to [the Impulfe of 

 the internal Air upon the Tympanum : And the Auditory 

 Nerve being expanded upon the Membrane, which hnes 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 7/je liofe, 

 fome 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 Skinj 

 Mufcles, Bones, Cartilages, and Vefl'els of all Sorts. 



The Skin is extremely thin, and without , _ 

 Fat, and adheres fo fall to the Mufcles and 

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



The Bones, which make up its Cavities, are forae of 

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

 proper to the Nofe only. The Griflles are in Number live, 

 \';hich fnali be treated of hereafter with the Bones. 



Th« 



