Page:Cyclopaedia, Chambers - Volume 1.djvu/627

 EAR

The two Meatus 1 s are fituate at the Sides of the Cavity ; the one opening into the Palate, called AqugduBus, not only on Account of its Form, but becaufe it may ferve for the Difcharge of any heterogeneous Matters: By other Authors it is call'd from its Difcoverer, Tuba Euflachiana. Tis by Means hereof, rhat Perfons, thick of hearing, affift the Senfc, by opening their Mouths. The other is shorter and bigger, opening into the Sinus in the Mamillary Procefs.

The two Apertures, or Fenejlr<f, of the Tympanum, are in the Surface of the Os petrojmn, which is oppofite to the Membrane of the Tympanum. The firft, called Feneflra Ovalis, by Reafon of its Figure, is iltuate a little higher than the other, and receives the Bafis of the Stages. The orher call'd Rotunda, notwithstanding its Figure, is oval like the former, and clofed by a thin, dry, tranfparent Mem- brane, refembling that of the Tympanum.

The laft Thing to be confider'd in the Cavity of the Tympanum, is a fine' Chord which runs over the inner Sur- face of the Membrane 5 called Chorda Tympani. Anatomifts have long diputed, whether it was an Artery, a Vein, a IN ltyc, or the Tendon of one of the Mufcles of the Malleus ; But 'tis now difcover'd to be a Branch of the fifth Pair ot Nerves, which meets the 'Portia dura of the Auditory Nerve.

The two Fenejlrtf abovemention'd, open into a Cavity dug out of the Os petrofum, called the Labyrinth, as being pcrplex'd with divers detours and Meanders. In this Cavity is iuppofed to be contain'd the innate Air. It is divided into unee Parts 5 the firft. called the Vejlible, by Reafon it leads into the other two : In it are oblerv'd nine Apertures, or Forui/iina. The fecond, comprehends three round Canals, diipofed in a femicircular Form, and thence call'd Canales Semicirculares. The third is the Cochlea, which confifts ot two Parts, viz. a fpiral Semi-oval Canal 5 and a Lamina, form'd into a fpiral Flight. The Canal makes two Turns ■and an half round a Ne-wel, or Axis, fiill growing lefs as it afcends. The fpiral Lamina divides this Cavity into two, being faften'd by its Bafe to this Newel, and by its other Extremity, to the Surface of the Canal, oppoiite to the J^s-wel, by Means of a very fine Membrane. The Cavity of the Cochlea thus divided, forms, as it were, two winding Stair Cafes, both built on the fame Ne-wel, one over t'other, but without any Communication between them.

Lajfly, There is the Auditory Nerve, which conlifts of two Branches, or Parts, the one foft, call'd Portio moUis j and the other harder, Portio dura : The foft Part is (pent on the Organ of Hearing, being divided into five Branches, which foiin a delicate Web, that lines xh.^VeJlibulu?n,CocIolea, &c. The hard Part, palling out of the Cranium, is diftri- buted among the Parts of the External Ear, &c.

The other Vefl.els of the Internal Ear, are Arteries and Veins from the Carotieds and Jugulars.

Particular 2)cJ crip ions of each Part of the Ear above recited, fee wider the prober Articles; Tympanum, Fenestra, Malleolus, Stapes, Incus, Orbicularis, Labyrinth, Vestible, Cochlea, Cauaks Semicir- cularis, Auditory Nerve, Be.

Ihe immediate Organ of Hearing, has been generally fuppofed to be the Membrane of the Tympanum : But later Anatomifts ihew this to be a Miftake, from divers Initances wherein that Membrane has been abfolutely de- {UoyM, and broke, without the leaft Diminution of the Sence o f Hearing. _

The Parts that bid the faireft for the Prerogative are thofe which compoie the Labyrinth, viz. the Cochlea, Lamina Spiralis, Vejlible, and Semicircular Canals: The Portio mollis of the Auditory Nerve, ramified and diffufed through thefe Parts, receives the Impreffion of Sounds, and propagates it to the Brain. See Hearing.

Behind, and under, the External Ear, are a Number of large Glands, called Parotides, wherein is fcparated a great deal of Saliva, which is convey'd by the excretory Duels into the Mouth. See Parotides.

The comparative Anatomy of the Ear furniihes abun- dant Inftanccs of the Creatot's Wifdom.

In Birds, the outer Ear is of a Form proper for Flight 5 not protuberant, as that would obflruct their Progrefs, but clofe and cover'd. See Bird.

In Quadrupeds, its Form is agreeable to the Pofture and Motion of the Body, but admirably varied, according to their various Occafions : In fome, as the Hare, 'tis large, open and erect ; by which Means, that timorous, defencelefs Creature, is warn'd of the leaft Approach of Danger : In others, 'tis cover'd, to keep out noxious Bodies. In the fubterraneous Quadrupeds, who are forced to mine and dig for their Food and Habitation, as a protuberant Ear would obitruft 'em, and be liable to Injuries, their Ears are very fhort, lodged deep and backwards in the Head.

Thus Moles have no Auricle at all, but only a round Hole, between the Neck and Shoulder. Some Authors ob-

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EAR

ferve, that the Meatus, or Paffage, is clofed with a lit* Skin, which opens and flints like an Eye-lid. The Sea- Calf, and the feveral Species of Lizards and Serpents, are likewife without any External Ear. And the Tortoife- Cameleon, and Generality of Fifties, have the Paffige of the Ear quite ftop'd, or cover'd over. There is a Sort of Whale, which has the Aperture of the Ear under the. Shoulders.

Among all the Varieties in the Structure of this Organ; none, Dr. Grew obierves, are more remarkable than thofe in the Paffage into the Os fetrofum. For in an Owl, which perches on a Tree, or Beam, and hearkens after the Prey beneath her, it is produced further out above, than below, for the better Reception of the leaft Sound : Jn a Fox, which fcouts underneath the Prey at Rooft, it is for the lame Reafon produced further out below : In a Pole-Cat, which hearkens ftrait forwards, it is produced behind, fof the taking of a forward Sound : Whereas in a Hare, which is very quick of Hearing, and thinks of nothing hut beiiM puriued, it is fupplied with a bony Tube, direSed backwards, fo as to receive the fmalleft, and moil diftant Sound that comes behind her.

Schelhammer denies the Exigence of the innate Air, fo much talk d of, in the Labyrinth ; and with good Reafon; as there is a Paffage out of the Labyrinth into the Throat, thro which the innate Air might efcape. This is paft doubt : Since by flopping the Breath, and {training, we can force the External Air into the Ear, and even hear it milling in. When the Paffage is any Way ftopp'd, as by a Cold, Uc. the Hearing thereby becomes dull and obtufe : And when by ftrong Swallowing, or other Motion of the Throat, the Paffage is open'd, we perceive it by a fudden Crack, and immediately hear very clearly; the Load of feculent Air being then difcharged from the inner Ear. See Sound, Deafness, WHispERiNG-'iVace, Speaking- Trumfiet, Bellowinc-C««.

Several Naturalifts and Phyficians have held, that cutting off the Ears render'd Perfons barren, and unprolific ; which Notion was what firft occafion d the Legiilators to order the Ears of Thieves, SSc. to be cut off, left they fhould produce their like.

The Ear has its Beauties, which a good Painter ou»ht by no Means to difregard : Where it is well form'd, it'wou'd be an Injury to the Head to be hidden. Suetonius infills particularly on the Beauties of Augufius's Ears ; and JElian, defcribing the Beauties of Affafia, obferves lhe had lliort Ears. Martial ranks large Ears among the Number of Deformities. Felibien.

Among the Athenians, it was a Mark of Nobility to have the Ears bored or perforated. Among the Hebrews and Remans, it was a Mark of Servitude.

Ear, in Mufic, a kind of internal Senfe, whereby we perceive and judge of Flarmony, and muiical Sounds.

In Mufic, we feem univerfally to acknowledge fomething like a diftinft Senfe from the external one of hearing ; and call it a good Ear. And the like Diftinaion we ihould probably acknowledge in other Affairs, had we got diftinel Names to denote thofe Powers of Perception by. See Sense.

Thus, a greater Capacity of perceiving the Beauties of Painting, Architefture, iyc. is called to a fine 'Lall, Sea Tast. j

~E±&-Wax, \ „ ./Cerumen.

EA&-Ring,r oee IPendant,

Ear, is alfo applied to a long Clufter of Flowers, of Seeds, produced by certain Plants: ufually called by Bota- nifts, Sfica. See Sues. '

The Flowers and Seeds of Wheat, Rye, Barley, t$ c. grow in Ears. The fame holds of the Flowers of Lavender °(yc We fay the Stem of the Ear, i. e. its Tube or Straw • ' The Knot of the Ear : the Lobes, or Cells, wherein rhe Grains are enclofed : The Beard of the Ear, (So. we have known 80 Ears of Wheat from the fame Root.

EARL, an Englijh Title of Honour, or Degree of No- bility, next below a Marquis, and above a Vifcount, See Nobility, Marqjjis, Viscount, &c.

Earls, were anciently Attendants, or Affociates, of the King in his Councils, and Martial Expeditions; much as Comites, Counts, were of the Magistrates of Ro.ne, in Qua- lity of Deputies, to execute their Offices for them. See Count.

Hence alfo Earls are called in Latin, Comites; in French, Comtes, Counts, 6kc. The Germans call them Graves, as Langrave, Margrave, Palfgrave, iS>e. The Saxons, Eolior' men ; the Danes, Eorlas ; and the Englifi, Earls.

At firft the Title Earl always died with the Man : William the Conqueror firft made it Hereditary ; giving it in Fee to his Nobles ; and annexing it to this or that Shire or County : For the Support of the State thereof, he allot- ted the third Peny out of the Sheriffs Court, iffuing out of all Pleas of the Shire from which the Earl took his Title, But of later Days the Matter is much alter 'd,

Cc* • Earls