Page:Cyclopaedia, Chambers - Volume 2.djvu/70

 LAC

for the Wings or other Parts of the In feels that produced the Lacca. 1'hefe little Bodies are of a beautiful Red j and when broke, make a Powder as fine as Cochineal. "Tis mofl probable thefe Cells are deilined to lodge the young Brood, as thole of the Bees ■, and that ihcfe little Carcaffes are the Embryo's of Infefls, or perhaps their Skins.

There are feveral forts of Lacca: that mention'd in the laft Article is the natural : when it is prepared, as in the former, thufe kinds of dry Cells are not feen. M. Geoffroy reckons fix or feven different Kinds •■, befides which, there arc feveral Pafts ufed by the Painters, that go by this name, or that of Laque. This Gum boil'd in Water with Acids, makes a beautiful Red Dye. The Englifi and Dutch ufe it in Scarlet.

Lemery having examined the Gum Lacca chymically, judges it to be a mean Mixture between a Gum and a Refin, more abundant in Salt than Oil.

Artificial Lacca, or Laque, is a coloured Subflancc, drawn from feveral Flowers ; as the Yellow from the Flower of the Juniper, the Red from the Poppy, and the Blue from the Iris or Violet. The Tinclures of thefe Flowers are ex- prefs'd by diililling them feveral times in Aqua Fit*, or by boiling them over a Stove- Fire in a Lixivium of Pot- Afhes and Alumn. Artificial Lacca is alio made of Bra- file boil'd in a Lixivium of the Branches of the Vine, adding a little Cochineal, Terramerita, Alumn calcin'd, and Arfenic incorporated with the Bones of the Cuttle-fifh. pulveriz'd, made up into little Cakes and dry'd. If it is to be very red, they add Juice of Citron to it ; to make it brown, they add Oil of Tartar. Dove-colour'd or Co- lombine Lacca is made with Braille of Femambom fteep'd in dillill'd Vinegar for the fpace of a month, mix'd with Alumn incorporated in the Bones of the Cuttle-fi.fh.

LACERNA, the Name of a Garment worn by the Antients. It was a kind of Cloke made of Wool, only ufed by the Men : they wore it over the Toga, and when that was not on, over the Tunica. It was at firii very fhort, but growing popular in the Roman Army, was foon lengthen'd. The Lacerxa was fcarce kno'wn in Rome till the Time of the Civil Wars and the Triumvirate. Then indeed it came into fa/hion, for the Soldiers being then frequently in the City, or at the City-Gates, the Sight became familiar to the Citizens, and they fell into the Ufe of it •■> infomuch that it became the common jDrefs of the Knights and Senators, till the Time of Falentinian and Tbeodojiv.s, when the Senators were prohibited the wearing of it in the City. The Lacerna was the fame with the Chlamys and Ein-us. Martial mentions Lacerna of ten thoufand Sefterces price. The word comes from the Greek h&w or he.yw, a Garment.

LACHRYMALIS GLAKDULA, in Anatomy, the Name of a fmall oblong Gland fituate above the Eye, near the little Canthus,whcnce proceed two or three fmall Duels which opening on the inner Surface of the Eye-lid, fil- trate a Serofity ferving to moifien the Ball of the Eye, and to facilitate its Motion. Near the larger Angle is alfo a little Eminence, in form of a Caruncle, which fome have taken for another Glandula Lachry>nalis y but by mif- take, this being no more than the Duplicature of the inner Membrane of the Eye-lids. On the fame fide, near the lefTer Angle, are two little Perforations, call'd FunBa La~ chrymalia j which are the Openings of a little membranous Bag at the Entrance of the Excretory Canal, that de- fcends into the Cavity of the Nofe, by which means the fuperfluous Moifture of the Eye is difcharged into the Nofe. On the fame fide is a very fmall Bone, one of thofe of the upper Jaw, fometimes call'd Os Lachrymale, but moreufually Os Ujiguis.

Fifiula Lachymalis is a Fiflula in the larger Angle of the Eye. It ufually happens after an Abfcefs formed in the Bag above mention'd, by means of the Serofity lodg'd there j which being retain'd too long, becomes acrimo- nious, and occafions an Ulcer which frequently degene- rates into a Fiflula.

LAOHRYMAL1A PUNCTA, in Anatomy, two little Apertures in the extreme Angles of each Eye-lid, into which an aqueo-faline pellucid Humour, fecreted from the Blood by the Glandula Lachrymali^ is convey'd, and thence carried offby the Lachrymous Canals into a little Bag in the Canal of the Nofe ; whence by a Pipe, always open, it is carried into the Cavity of the Nofe immediately un- der the lower Os Sfongiofum. Hence appears the Reafon why People in crying run attheNofe. ThisHumoiir fc- parated by the Glandula Lachrymals, ferves to moi ft en and lubricate the Ball of the Eye, f and prevent any hurtful Attrition : When it is fecreted in any great quantity, fo as to overflow the Eve-lids, it is call'd Tears.

LACHRYMATORIES were antiently fmall Earthen VefTels, wherein the Tears of the weeping Friends that furvived were repofited, and buried with the Arties and Urns of the Dead. Some of thefe are Hill feen in the Cabinets of the Curious.

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LAD

LAC LUN JE, Milk of the Moon. See M-:i:. LA CON ISM, a ftiort, brisk, fentemjeus Speech, in the. manner of the Lacedemonians, who were remarkable for the Clofenefs and Concifenefs of their way of deli- vering themfelves.

LACTATION, the giving of Suck, and the Time the Mother doth that Office to her Xoung.

LACTEAL VEINS, a kind of long (lender Tubes for the Conveyance of the Chyle from the Inteitines to the common Refervatory : They were firrt difcovered by A- Jellms an Italian Phyfician in nfii, and call'd LaBeal, from the Liquor they contain, which refembles that of Milk. Their Coats are fo thin, as to be invifible, except when diftended with Chyle or Lympha. They arife from all the Parts of the fmall Guts, and as they run from the fides of the Guts to the Glands in the Mefentery, unite and form larger Branches, called Verne Laftex frltni generis. The Mouths of thefe LaBeals, which are open into the Cavity of the Guts, from whence they receive the Chyle, are fo fmall as not to be feen by the belt Microfcope. It was neceffary they mould be fmaller than the fineft Arteries in the Body, that nothing might enter to Hop the Circulation of the Blood. The fame Extre- mity of the LaBeals has likewife communication with the Capillary Arteries of the Guts, by which they receive a Lympha that dilutes, and propels the Chyle forwards, and wa/hes the LaBeals and Glands, that they might not fur, and be obitrucfed by the Chyle's Haying in them upon falling. The other Extremity of the' LaBeals dif- charges the Chyle into the velkular Cells of the Glands difperfed up and down the Mefentery ; And from thefe arife other LaBeals of a larger fize, which carry the Chyle immediately into the Receftacttlum Chyli ; thefe are called LaBex fecundi generis. The LaBeal Veins have Valves at feveral diftances, which hinder the Chyle from returning back into the Inteftines.

It is itill doubted whether or no the Intejiina Craffli af- ford any LaBeals or not. The Impoflibility of human DiffeCtion proper for fuch an Enquiry, gives no room either to affirm or deny. But the Contents of the In- tejiina Craffa feem not likely to afford much Chyle, and therefore if there beany, 'tis probable they are very few. In Brutes, if differed at a reafonablc time after feed- ing, as two or three hours, the LaBeals appear very tu- mid and white ; and if wounded, the Chyle flows plenti- fully from 'em. But if infpeSed when the Stomach of the Animals has lain fome time empty, they appear like Lymphaticks, vifible indeed, but fill'd with a tranfparent Liquor. That the LaBeals have a Communication from the Cavities of the Inteflines, is demonflrated by their Contents, the Chyle ; but how their Pores are difpofed to receive it, has not yet been difcovered: Nor is there any way known whereby to fill the LaBeals from the Cavities of the Guts after Death. 'Tis probable then, their En- trance into the Gut is oblique, fince neither Wind nor Liquors can pafs from thence. As 'tis found thefe Pores can only receive any thing in the living State, we may be allow 'd to imagine that 'tis the Periftaltic Motion of the Guts which difpofes them in that State to receive the Chyle. And this may be done by means of the Circular and Longitudinal Fibres of the Inteftines ftill applying the Internal Coats of the Guts to their Contents, by which means its Pores abforb the Chyle from the Excremen- titious Part.

LACTEA VIA, the Milky Way. SeeGalaxy. LACUNjE, among Anatomifts the Name of certain excretory Canals. Between the flelhy Fibres of the Ure- ter and the Membrane of the Vagina in Women, is found a whitifb. glandulous Body about a finger thick, running round the Neck of the Bladder, having a great number of excretory Duels, which Graef calls Lacunx, and. which terminate in the lower part of the Orifice of the Womb, conveying thither a flimy Matter, that mixes with the Seed of the Male. See Generation.

LACUNAR, in Architecture, an arched Roof or Cicling, more efpecially the flanking or flooring above the Portico's and Piazza's.

LADANUM, or Labdanum, in Pharmacy, the Name of a Gummous or Refinous Matter ouzing out of the Leaves of a Shrub call'd Cifttts Ladanifera, which is very common in the hot Countries, and whereof there are va- rious kinds. They gather the Ladanum by means of Goats, which brouzing on the Leaves of this Shrub, re- turn to the Stable with their Beards loaden with a fat Subftance, which the Peafants rake off, with a kind of Combs made for that purpofe. This Matter they thus collect into Lumps, and, as 'tis mix'd with the Goats Hair and other Impurities, call it Ladatiitm in the Beard, or natural Ladanum. Others draw Cords over the Leaves and other Parts of the Shrub, and fcraping off what had fluck to the Cords, make up the Ladanum into little Baits. Ladanum is ufed in Phyfick to foften, digeft, attenuate

and