Page:Cyclopaedia, Chambers - Volume 2.djvu/76

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Reception of the Food, the Larynx raifes itfelf to com- preis it, and facilitate its Doicent.

There are five different kinds of Parts belonging to the Larynx, viz Cartilages, Mufcles, Membranes, Nerves, and Glands. Its Cartilages are the Thyroides, Cricoides, Aryta:noides, Glottis, and Epiglottis, by means of which it can eafily dilate and contract, fhut and open itfelf. Thefe form the whole Body of the Larynx, and grow dry and harden, in proportion as the Perfon grows old, whence the Larynx fonietimes appears as if it were bony. The biggeit of thefe is the Thyroid es or ficutiformis, this guards the Forepart, and has its "Name from fome fuppoied Refemblance it bears to a Shield. It is of a Concavu-convex fquare figure, the hollow part be- ing inward, and the gibbous outward, having a little Pro- minence in the middle, called Vomum Adami, asir fome of the forbidden Fruit had ftuck in Adam's Throat, and oc- cafioned that Swelling. The fecond is called Cricoides, or Annularis, from its Refemblance to a Ring which the Turks put on their Thumb for the drawing of their Sows. The forepart of this is very narrow, coming un- der the other Cartilage, but behind it is broad, thick, and ilrong, being as it were the Bails of all the others. The third and fourth are called Arytienoides, or Guttaks, from the Figure of an Ewer, which thefe two together fome what referable. At the Juncture of thefe two there is a little Cleft, or Chink, in form of a little Tongue, and for that reafon called Glottis, or Lingula. Through this Chink the Air deicends into the Lungs, and the pituitous Matter ejected by coughing in Catarrhs is let out. It fcrves alio for modulating the Voice, and is imitated in Flutes and the Pipes of Organs. Over the Glottis lies a fifth Car- tilage called the Epiglottis, which is very thin and foft, and in Non-adults almoft membranous, concave on the under Side, and convex on the upper: It defends the En- trance of the Larynx, and hinders the Liquids which in drinking flip over it into the Oefophagus, from falling in- to the Trachea. The Larynx has feven Pair of Mulcts, which ferve to move its feveral Cartilages, and tocontradt or dilate them at plealurej two Pair of them are com- mon, the other five proper: the proper arc thole which have both their Origination and Infertion into the Larynx, the common have only their Infertion there. Of the former Kind are the Crycothyroides, which moves the fcutiform, Cartilage j the Crico-arytienoides Fofticum, which ferves, by its Contraction, to draw the Arytccnoid.es Cartilage, and to open the Rima. The third is the Arytcenoides ; this ferves to bring the two Cartilages of that Name to- gether, and to fhut the Rima. The fourth is the Crico- arytienoides Laterale 5 and the fifth the Thyreo-arytrcnoi- des, which /huts the Larynx. The common Mufcles are the Sternothyroidcs, which ferve to draw down the Thyroide Cartilage, and the Hyothyroides which lift up that Cartilage. The Larynx has but too Membranes, the one external, which is a Continuation of that which covers the Trachea 5 and the other internal, which is the fame that lines the whole Mouth ; It receives two Branches of Nerves from the Recurrents, and it is moiftened by four large Glands, two fituate above called Tonfils, and two underneath call'd Thyroides.

The Larynx is of very confiderable Ufe, not only in forming and modulating the Voice, by the different Apertures of its Rima or Chink, but alfo in comprefTing the Lungs in a greater or lefs Degree by the Air : For if the internal Diameter of the Larynx had been equal to that of the Trachea, the Lungs could have undergone little or no Compreffion at all j nor, confequently, with- out the Larynx could we have reaped any Advantage from Breathing, in regard the Air would not have refilled that Force wherewith it is driven out in Expiration, nor confe- quently could the Compreffion have been made in the Lungs, which is found necelfary for the Comminution of the Globules of the Blood, and the mixing of the two Fluids, Air and Blood, together. For the Action of the Larynx in Sound, fee Glottis and Sound 5 fee alfo Epiglottis, Trachea, &c.

LASH, the Sea-Word for binding up to the Ship's fide Muskets, Butts of Water or Beer, or Pieces of Timber to make fpare Top-Mafts. When any thing is thus faftcn'd to the Ship, it is called Lajking. But the Lafiers are properly thofe Ropes only, which bind fail the Tackles, and the Breeches of the Ordnance, when they are haled, or made fait within board.

LASKING, a Sea-Term. See Veering.

LASSITUDE, among Phyficians, expreffes that We a- rinefs or Heavinefs of Members that proceeds from a diftempered State of Body, and not from Excrcife 5 either from an Increafe of Bulk, from a Diminution of proper Evacuation, or from too great a Confumption of that Fluid which is neceflary to maintain the Force and Spring of the Solids, as in Fevers and Convullions; or from a vitiated Secretion of that Juice, whereby the Fibres are

not fupplied either in due Quantity or Quality. The Remedy in the firft Cafe is Evacuation, in the latter proper Diet, or fuch Alterative Medicines as influence fuch a Secretion.

LAST, ox Left, in general fignifies the Burden, or Load of a Ship. It is alfo ufed for a certain Weight and Mea- fure, which is various in various Countries; tho in the ge- neral, the Laji is eft i mated at 4000 lib. weight. A L-ijl of Cod-Fifb, White Herrings, Meal, and A/hesfor Soap, is 12 Barrels for each 1 Of Corn or Rape-Seed 10 Quar- ters: Of Gunpowder 24 Barrels, or 2400 lib. weight; Of Red Herrings 2c Cades : Of Hides 12 Dozen : Of Lea- ther 20 Dickers: Of Pitch or Tar 14 Barrels : Of Wool 12 Sacks : Of Stock- fifh icco ; Of Flax or Feathers 1700 lib. weight.

LASTAGE, or Lejlage, according to Rafial, is a Du- ty exacted in fome Fairs and Markets to carry things bought where one will. Lajiage, fays another Author, is properly that Cuftom, which is paid for Wares fold by the Lalt. In a Law of R. 1. the fecond Lajiage is taken for the Balance or Lading of a Ship. Laftly, Lajiage is fame- times ufedfor Garbage, Rubbifh, -or fuch Filth.

LAST HEIR, is he to whom Lands come by Efcheat for want of lawful Heirs j which in many Cafes is the Lord whereof they are held, but in others the King.

LATERAL EQUATION, in Algebra, an Equation having only one Root; whereas a Quadratick hath two, and a Cubick 3 Roots, fjje. And fuch Equations can be determined and conftructed by ^the Interjection of two Right Lines, which is a Compofition of 1 -|- 1 = 2. But a Quadratick cannot be determined or confl rutted, with- out a Strait Line and a Circle cutting each other.

LATER AN, was originally the proper Name of a Man, whence it defcended to an antient Palace in Rome, and to the Buildings fince erected in its place : Particu- larly to a Church called St. $ohn of the Later an, which is the principal See of the Popedom.

Councils of the Later an are thofe held in the Bafilifquc of the Lateran : Of thefe there have been five, held in 1 1 25, 11 39, 1 1 79, 1 21 5, and 1 513.

Canon Regular of the Congregation of the Lateran, is a Congregation of Regular Canons, whereof that Church is the principal place. 'Tis pretended, there has been an Uninterrupted Succeflion of Clerks, living in common, from the Time of the Apoftles, and that a number of thefe were eftablifh'd in the Lateran in the Time of Con- fiantine. But the Canons were not introduced till the Time of Leo I. and thefe held the Church 800 Years, till the Reign of Boniface, who took it from 'em, and placed Secular Canons in their room, 150 Years after, the Re- gulars were reinftated.

A LATERE, a Latin Term ufed for the Qualification of Cardinals whom the Pope fends as Legates into foreign Courts, who are called Cardinals a latere, as being his Holinefs's Counfellors in ordinary and Affiftants. See Legate. The Guards of Princes were heretofore called Laterones, becaufe always attending at their Sides, a la- tere. JDh Cange, in his Gloffary, fays there were antiently Counts a latere, and Monitors a latere.

LATH, in Building, long, thin, narrow Slips of Wood ufed in Tyling and Walling. Thefe are divided into three kinds, with regard to the differenr Woods they are made of, viz Heart of Oak, Sap-Laths and Deal-Laths : the two laft ufed only for Ceiling and Partitioning, and the firft only for Tyling. Again, Laths are diftingui/h'd into three kinds more, with regard to their Length, viz. into 5 foot, 4 foot, and 5 foot Laths, tho the Statute allows but of two lengths, viz. thofe of 5 foot and of 3, each of which are to be an inch and half in breadth, and half an inch in thicknefs. [Thefe are what Vitrwoius calls Ambrices.

LATHE, or Leathc, a very ufeful Engine for the turn- ing of Wood, Ivory, Metals, and other Materials. The Invention ot the Lathe is very antient. Diodortts Siculus fays, the firft who ufed it was a Nephew of Daedalus, na- med Talus. Pliny afcribes it to Theodore of Samos, and mentions oneTbericlcs, who render'd himfelf very famous by his Dexterity in managing the Lathe.

With this Inftrumcnt the Antients turn'd all kinds of Vafes, many whereof they enrich'd with Figures and Or- naments in Baffo Relievo. Thus Virgil t

Lenta quibtis Torno facili fttPeraddita Iritis.

The Greek and Latin Authors make frequent mention of the Lathe, and Cicero calls the Workmen who ufed it Vaf- cular't!. 'Twas a Proverb among the Antients, to fay a thing was formed in the Lathe, to exprefs its Delicacy and Juftnefs,

The Lathe is compofed of two wooden Cheeks or Sides, parallel to the Horizon, having a Groove or Opening be- tween j perpendicular to thefe, are two other Pieces cal- led Puppets, made to Hide between the Cheeks, and to be fix'd down at any Point at pleafure. Thefe have two

Points,