2. To the inward part of this admirable Organ, And here we find the moft curious and artful Provifion for every Emergency and Occafion. The auditory Paffage, in the firft place, curiously tunnelled, and artfully turned, to give Sounds an eafie Paffage, as well as a gentle Circulation and Refraction; but withal, fo as to prevent their too furious rufhing in, and assaulting the more tender parts

within.

.

And forafmuch as it is neceffary that this Paffage fhould be always open, to be upon the Watch (10), therefore to prevent the Invafion of noxious Infects, or other Animals, (who are apt to make their retreat in every little Hole,) Nature hath fecured this Paffage (11) with a bitter naufeous Excrement

(12), af

the ticking of a Watch (when no Noife is in the Streets) may be heard from fide to fide; yea, a Whisper may be fent all round the Dome. And not only in the Gallery below, but above, upon the Scaffolds, I tried, and found that a Whisper would be carried over one's Head round the top of the Arch, notwithstanding there is a large Opening in the middle of it into the upper part of the Dome.

(10) Auditus autem femper patet : ejus enim sensu etiam dormientes egemus. A quo cùm fonus eft acceptus, etiam è fomno excita mur. Flexuofum iter habet, ne quid intrare poffit, fi fimplex,& directum pateret ; provifum etiam, ut fiqua mínima beftiola conaretur irrumpere, in fordibus aurium, tanquam in visco, inhærefceret. Cicer. de Nat. Deor. L, 2. c. 57.

It deferves a particular Remark here, that in Infants in the Womb, and newly Born, the Meatus Auditorius is fhut up very clofely, partly by the Conftriction of the Paffage, and partly by a glutinous Substance, whereby the Tympanum is guarded against the Water in the Secundine, and against the Injuries of the Air as foon as the Infant is Born.

(11) It is remarkable, that in most, if not all Animals, whose Ears are tunnelled, or where the Meatus Auditorius is long enough to afford Harbour to Ear-wigs, or other Infects; that, I fay, in the Ears of fuch, Ear-wax is conftantly to be found. But in Birds, whofe Ears are covered with Feathers, and where the Tympanum lies but a little way within the Skull, no Ear-was

(12), afforded from the Glands (13) appointed for that Purpose.

From hence let us approach the most inward Parts, in which we thall fee Strokes of the moft exquifite Art. To pass over the innate Air that most Âuthors talk of (14),(because there is no fuch)the Paffage

to

is found, because none is neceffary to the Ears fo well guarded, and fo little tunnelled.

(12) The Ear wax was thought by the old Anatomists to be an Excrement of the Brain: Humor biliofus à cerebro expugnatus, the Bartholines fay of it, . 3. c. 9. But as Schelhammer well obferves, Nil abfurdius, quam cerebri excrementum hoc flature. Nam& ratio nulla fuadet, ut in cerebro fieri excrementum tale credamus -neque via patent per quas ab eo feclufum in meatum auditorium poffit inde penetrare. As to its Tafte, Cafferius gives Inftances of its being sweet in fome Creatures. But Schelhammer fays, Ego vero femper cum amaritie aliquid dulcedinis in illo deprehendi. Vid. Schel. de Audit. p. I. c. 2. §. 10. But I could never diftinguish any Sweetness in it; but think it infipid mixed with a Bitterness.

(13) Cerumina amara Arteriolis exudantia. Willis's de Anim. Brut. par. I. c. 14. In the Skin-are little Glands, which furnish a yellow and bitter Humour Monfieur Dionis's Dem. 18. An handsome Cut of thofe Glandula ceruminofa is in Dr. Drake, from Valfalva.

Pliny attributes a great Virtue to the Ear-wax; Morfus hominis inter afperrimos numeratur: medentur fordes ex auribus: ac ne quis miretur, etiam Scorpionum ictibus Serpentiumque, ftatim impoJite. Plin. Nat. Hift. . 28. c. 4. And that it hath an healing Quality, and may be accounted a good Balfom, I my self have experienced.

(14) That there is fuch a thing as the innate Air. (talked of much by moft Authors on this Subject) Schelhammer very justly, I think, denies; by reason there is a paffage into the inner Ear from the Throat, through which the innate Air may pass out, and the outward Air enter in. Par. Alt. p. 2. C. I. §. 10. When by ftopping our Breath, and Straining, we force the external Air into the Ear, it may be heard rufhing in; and if much be forced in, it may be felt alfo to beat against the Tympanum. When the Paffage to the Throat is by any means ftop'd, as by a Cold in the Head, c. the Hearing thereby becomes dull and blunt; by reafon the Communication between the outward

and

to the Palate (15), and their Uses, with divers other curious things that might be named, let us ftop a little at the Part containing the reft, namely, the Bone (16). The particular texture and hardness of which, above other Bones of the Body, is very remarkable, whereby it ferves not only as a fubftantial Guard to the Sensory, but also to oppose the Impulses of the æthereal Matter, that there may be no lofs, nor confufion in the Sound; but that it

and inward Air, are obftructed: but when by ftrong Swallowing or fuch like Motion of the Throat, the Paffage is opened, we perceive it by a sudden Smack or Crack, and we immediately hear very clearly; the load of feculent Air, being at that time. difcharged from the inner Ear.

It is a wife Provifion, that the Paffage for the Air into the Ear, is from the Throat; Ut non ftatim quivis aer externus irrumpere queat (as Schelhammer faith, Par. Ult. c. 4 §. 8.) Sed nonnihil immutati, ac temperatus, calore ex medio ventre exfpirante; imo fortaffis non facilè alius, nifi ex pulmonibus.

(15) Valfalva hath given us a more accurate Defcription of the Tuba Euftachiana, or Paffage to the Palate, than any other Author, to whom I therefore refer, De Aur. Human. c. 2. §. 16, &c.

The chief Ufe hereof he thinks is to give way to the inner Air, upon every Motion of the Membrani Tympani, the Malleus, Incus, and Stapes. This Paffage, if it be shut up, Deafness enfues. Of which he gives two Inftances: one a Gentleman, who loft his Hearing by a Polypus in the Nofe reaching to the Uvula; the other a Yeoman, labouring with an Ulcer above the left fide of the Uvula; which when he ftopt with a Tent dipped in Medicine, he loft his Hearing in the left Ear, and recovered it, as foon as the Tent was out. Ibid. c. 5. §. 10.

(16) Os [petrofum] ex quo interiores fingularum [Labyrinthi] cavitatum parietes conflati funt, album, durissimum, necnon maxime compactum. Id autem à Naturâ ita comparatum effe videtur, ut materia etherea Sonorum objectorum impreffionibus onufta, dum predietis impingitur Parietibus, nihil aut faltem ferè nihil motûs fui amittat, atque adeo illum qualem ab Object is fonoris accepit, talem communicet Spiritui animali contento intra expansiones rami mollioris Nervorum auris. Dr. Raym. Vieuffens of Montpellier, in Phil. Traní. Nr. 258.

may

Book IV. may be conveyed regularly, and intirely to the Auditory Nerves.

The next Part I fhall take notice of, may be that fine Membrane, called the Tympanum, or Membrana Tympani (17), with its inner Membrane (18); together with the four little appendant Bones (19), and the three inner Mufcles to move them, and adjuft the

(17) The Tympanum of the Ear, or as Valfalva and the Moderns, the Membrana Tympani was taken notice of as early as Hippocrates's time. In Birds, it is ftrained towards the outward Parts; in other Animals towards the Brain, or inner Parts. Monfieur Dionis faith, It is not equally fastened to the whole Circumference of the bony Circle, in which it is inchafed; for on the upper fide it hath a free disengaged Part, by which fome can give vent to the Smoak in their Mouth. Demonftr. 8. That there is fome Paf.. fage I doubt not, but I question whether Monfieur Dionis ever saw the difengaged Part he mentions. I have my self carefully fearched divers Subjects, and do not remember to have feen any fuch Paffage; and I perceive it efcaped the diligent Schelhammer's Eye. Valfalva alfo by injecting in through the Tuba Euftachiana, could not force any Liquor into the Meatus Auditorius, But yet he imagines he found the Paffage out in another place of the Drum, in fome morbid, and one found Head. Valfalv. de Aur. Hum. c. 2. §. 8. Mr. Cowper alfo affirms there is a Paffage by the upper part of the Membrane. Anat. Ap. Fig. 8.

(18) Dr. Vieuffens before named difcovered a Membrane, tenuiffime rareque admodum texture intra cavitatem Tympani; as he defcribes it. Whofe ufe he faith is, 1. Occludens Labyrinthi januam impedit ne naturalis puriffimus ac fubtiliffimus Aer intra cavitates -communicationem- -habeat cum aere craffo. 2. Labyrinthi bafin calefacit, &c. ubi fupra. Probably this double Membrane may be fuch, or after the fame manner as it is in the Tympanum of Birds: Of which fee my Obfervations in Book VII, Chap. 2. Note 4.

(19) The four little Bones being treated of by all that have concerned themselves about this Senfe of Hearing fince their difcovery, I fhall take notice of only two things concerning them. 1. The discovery of them is owing wholly to the Diligence and Sagacity of the latter Ages, of which Schelhammer gives this Account from Fallopius. Hac Officula antiquis Anatomicisig nota fuere ; primufque qui in lucem produxit [Malleum &iacum fuit Jac. Carpenfis; primus quoque procul omni dubio

anatomice

the whole Compages to the feveral purposes of Hearing, to hear all manner of Sounds, loud or languid, harth or grateful (20).

From

anatomica artis, quam Vefalius poftea perfecit, reftaurator. Tertium [Stapedem invenit ac promulgavit primus Joh. Phil ab ingraffia, Siculus, Philofophus ac Medicus doctiffimus. Quartum, Thoma Bartholin tefte, viro longè celeberrimo, Fran. Sylvio debetur Schel. ubi fupr. c. 3. §. 9. 2. Their difference in different Animals In Man, and Quadrupeds, they are four, curiously inarticulated with one another; with an external and internal Muscle to draw, or work them, in extending, or relaxing the Drum. But in Fowls the cafe is very different. His unum Officulum folum largita eft Natura, quod Collumellam forte appellaveris teres enim eft fubtiliffimum, bafi innitens latiori, rotunde. Huic adnexa eft Cartilago valde mobilis, que in Tympanum videtur terminari. Id. Ib. §. 8. In the Ears of all the Fowl that I could examine, I never found any more than one Bone and a Cartilage, making a Joynt with it, that was easily moveable. The Cartilage had generally an Epiphyfe, or two, one on each fide. The Bone was very hard and Small, having at the end of it a broad Plate, of the fame Subftance, very thin, upon which it refted, as on its Bafis. Dr. AL. Moulen in Phil. Tranf. Nr. 100.

These are the most material things I find obferved by others concerning the Ears of Fowls, and fome of them hardly, I believe, obferved before. To which I thall fubjoyn fome other things have my felf discovered, that I prefume escaped the Eyes of thofe moft curious and inquifitive Anatomifts. Of which the laft cited Book VII. Chap. 2. Note 4.

(20) Videtur quod Tympanum Auditionis inftrumentum prelimi nare, & quafi preparatorium fuerit, quod Soni impreffionem, five Species fenfibiles primo fufcipiens, eas in debita proportione, & apta conformitate, verfus Senforium, quod adhuc interius fitum eft, dirigat fimili officio fungitur refpectu Auditus, ac tunica Oculi Pul pillam conftituentes refpecta Visus; utraque Membrane Species fenfibiles refringunt, & quafi emolliunt, eafque Serforio non nifi proportionatas tradunt, cui nudo fi adveniant, teneriorem ejus crafin facilè ladant, aut obruant. Reverd Tympanum non audit, fed me hiori taniorique Auditioni confert. Si hac pars deftruatur, Senfio adhuc aliquandiu, rudi licèt modo, peragri poffit; quippe experiments olim in Cane facto, & Janitoris officio ut Tympanum rectè defungi poffit, expanfum ejus pro data occafione ftringi, aut relaxari debet, veluti nimirum Oculi Pupilla Quapropter huic Auris Tympano, non fecus ac bellico, machine, five tenia quædam appo

nuntur,