Page:Cyclopaedia, Chambers - Volume 1.djvu/265

 BON

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BON

Others make the Thicknefs of the Eomi? -*-, or J, or ^ of the whole Diameter ; and the Diameter of the Aper- ture -*- or y of the fame.

Bombs only differ from Hand Granadas, in that the lat- ter are much lefs, and inftead of Mortars are thrown out of the Hand 5 fee Granada. The Word Bomb comes from the Latin, Bomb us t crepitus, oxfibilus Ani, by reafonof the Noife it makes. M. Blondel, who has wrote the Art of throwing 'Bombs, obferves, that the firft Bombs were thofe thrown into the City of Wachtendmcb in Guelderland, in 1588 ; others pretend they were in ufe a Century before, viz. at the Siege of Naples by Charles VIII. in 1495.

BOMBARD, a Piece of Artillery antiently in ufe, ex- ceedingly fhort and thick, and with a very large Opening: Some alio call it Bafilic. There were fome of thefe faid to have carry'd Balls of 300 Pound Weight 5 Frciffart men- tions one of 50 Foot long. To load 'em, they made ufe of Cranes, &e. The Bombard is fuppofed to have been in ufe be- fore the Invention of Cannons, fee Cannon and Ort-nance. Some derive the Word, by Corruption, from Lombard, as fuppofing 'em firft us'd in Lcmbardy : Menage, after Voffius, derives it from the Greek Bo^/3©-, or the Latin bo'mbus, a bumbo ££? ardeo ; others from the German Bom- barden, the plural of Bomber, Balijia.

BOMBARDIER, an Engineer, or Perfon whofe Bufinefs is to take care of the firing and throwing Bombs out of Mortars : He firft drives the Fufee, then fixes the Shell, loads, and fires. See Bomb.

Bomb-Chest, is a kind of Chejl fill'd with Gunpouder, Bombs, &ic. plac'd under Ground, to tear and blow it up into the Air, with thofe who ftand upon it. Thefe Bomb- Che (Is- are frequently us'd to drive Enemies from a Poft they have feiz'd, or are about to take poffemon of; and are fet on fire by means of a Saucidge faften'd at one End. See Mine.

Bomb-ketch, is a fmall Veffel, ftrengthen'd with large Beams, for the ufe of Mortars at Sea.

BONA NOTABILIA, in Law. Where a Perfon dying has Goods, or good Debts, in another Diocefe or Jurisdic- tion within that Province, befides his Goods in the Diocefe where he dies, amounting to the Value of 5 l. at leaft, he is faid to have Bona notabilia ; in which Cafe, the Probat of his Will, Sfc belongs to the Archbiihop of that Pro- vince.

BONA PATRIA, a Jury or Aflize of Countreymen, or good Neighbours, fee Jury.

BONE, in Anatomy, a fimilar Part of the Body, white, hard and brittle, notdiftendible, and void of Senfation ; giv- ing Support, and Form to the whole Fabrick. The Bones of the Body are all cover'd with a peculiar Membrane, call'd the Periofieum, which is extremely fenfible, (fee its De- fcription and Office in its Place :) They are moft of 'em Hkewife hollow, and fill'd with an oily Subftance call'd Marrow 5 fee Marrow. Dr. Havers, defcribing the Tex- ture of the Bones*, obferves, that they confift of Lamella* or Plates lying one upon another ; and thofe, again, of Fi- bres running lengthwifc, fome to the Extremities of the Bones, others not fo far ; but none of 'em terminating there in diftinc^ Ends, as they feem to do 5 but in lieu of that continu'd tranfverfly, and as it were arch'd : The Fi- bres of one Side, meeting and uniting with thofe of the other ; and this at each Extremity. So that the Fibres are a Con- tinuation of each other ; tho not in the fame uniform Order, but in very long Ellipfes ; not all of a length, however, but in each Plate, /horter and fhorter than other.

Thefe Lamella, or Plates, are differently difpofed in dif- ferent Bones ; v. g. In thofe that have a large Cavity, they are contiguous on each fide, and very clofely united 5 in thofe again whole Cavities are fmall, or which are altogether {pongious within, many of the internal Lamina are placed at a diftance from each other, having betwixt 'em little bony Cells ; and even in Bones that have a larger Cavity, fome of thefe leffer Cells arc ufually found at each Extre- mity. In fuch Bones as have their Plates contiguous, there are Pores thro and between the Plates, befides thofe made for the Faffage of the Blood-Veffels : The firft penetrate the Lamina tranfverfly, and look from the Cavity to the external Surface of the Bone ; the fecond run longitudinally between the Plates : The firft are found in every Lamina 5 tho the nearer the Cavity, the greater the Number of Pores- but they don't lie dire&ly over one another, fo as to form any continu'd Paflage from the Cavity to the Sur- face. The fecond are feldom found but by good Glaffes : A Medullary Oil isdiffus'd, by thefe, throughout the Plates ; and to thofe, the firft kind feem only fubordinate ; ferving to bring the Oil into 'em.

The Marrow in the Cavity of the Bones, is invefted with a Membrane, wherein are included little Bags, or Lobules ; and in thefe Bags are Veficula, or glandulous Bladders ; fer- ving both for the Secretion of the Medullary Oil from the Blood, and for the Reception and Confervationof the fame. They feem to have Paflages into each other, as have alfo

i

the Bags 5 whereby the Oil has a freer Courfe to the joints and Subftance of the Bone. The ufe of the Marrow, is to oil the Subflance of the Bone, and to prevent its being too dry and brittle 5 it alfo lubricates the Articulation of the Bones, and hinders their Ends from being worn, or over- heated with Motion j and it moiftens the Ligaments by which they are ty'd to each other : in which it is affiled by the Mucilaginous Glands, found in all the Articulations of the Bones ; fee Mucilaginous.

The Bones are generally bigger at their Extremities than in the Middle; that the Articulations might be firm, and the Bones not fo eafily diflocated : But to render the Mid- dle of the Bone Itrong withal, fo as to fuftain its allotted Weight, and refill: Accidents, the Fibres are there more clofely compared together, and fupport one another : To which it may be added, that the Bone being hollow, is not fo eafily broken, as if it had been folid' and fmaller i For of two Bones of equal Length, and of equal Numbers of Fibres, the Strength of the one to the Strength of the other, will be as their Diameters. See Giant.

The Bones are join'd and connected together various Ways, according to the various Purpofes they are to ferve : Some being intended for Motion 5 others for Reft, and the Support of the incumbent Parts only. That Jointure in- tended for Motion, is call'd Artbrofis, or Articulation $ that for Reft, Sympbifis, or Coalition. Articulation is divi- ded into two Kinds, Diartbrofis and Synarthrofis 5 and each of thefe again fubdivided into feveral others, fee Ar- ticulation, Diarthrosis, 0a. Sympbifis is divided into Sutwa, Harmonia, and Gomfhafis 5 which fee. Be- fides thefe, are five other Kinds of Connexion, viz. Syffar- chofis, Syncbondrofis. Syneurofis, Syntenojis, and Synymen- fis ; which fee.

The Number of the Bones is various in various Subjects; ordinarily 'tis about 250 fviz* 61 in the Head, 67 in the Trunk, Cz in the Arms and Hands, and do in the Legs and Feet : The Variations arc in the number of the Se- fa?noidea, the Teeth, and the Sternum. See the Names of the feveral Bones in the following Table ; their Figures, and Places in the Plate, Anatomy ; and particular Defec- tions of each under their proper Heads. Os Frontis 1 VcrtebraCervicis-) TheOj Fcmoris z

— Occipitis 1 — 7)orJi 1 2 Rotula a

OffaParietalia % — Lumborum 5 Tibia 2

— Offis Sacri 6 Fibula 2

Os Coccygis 3 Ojfa Tarji 14 Scapula z — Metatarfi 10

Clavicula % — fDigitorum 28

Cofta 24

Sternum 1

Ojfa Innominate 2

HI In all

— Tcmporum

Ojjlcula Aaditus 8

Os Etbmoides 1

— Spbanoides 1

— Mali 2 — 1 Maxillare a

— Unguis 2

— Na/i 2

— Palati 2 Vomer 1

do

245

The Humerus

Maxilla Inferior 1 xftna

fDentes Incijivi 8 Radius

— Canim 4 qffa carpi

— Molares 20 _ Metacarpi Os Hyoides 1 _ FDigitorum

Befides the Ojfa Sefamoidea, which are faid to be found to the Num- ber of 48;

61 60

Dr. Havers divides the Blood- VeiTels of the Bones into Nutritious and Medullary; the one furnifhing Matter for the Nutrition, the other for the Lubrication of the Bones. The Chief of the Nutritious enter the Ends of the Bone y viz. the Arteries at one End, and the Veins at the other. The Medullary commonly enter the Sides of the Bone, and that obliquely ; but both by the fame Foramen.

The Medullary Oil is difpens'd from the Cavity where it is depofited, throughout the whole Subftance of the Bone ; paning firft thro the tranfverfe Pores of the firft internal Lamina into the longitudinal ones ; where it proceeds till it finds other tranfverfe Pores, when it alters its Courfe again, and exfudes further : Thus it paflfes alternately thro and between the Plates, till it is diffufed throughout. This is the Method of its Conveyance in Bones, the Plates whereof are contiguous : Where the Plates are at a Diftance, as in Bones that have no great Cavity, the fmall Caverns abovemention'd contain Medullary Glands ; whence the Plates have the Benefit of the Marrow without the former Method of Conveyance.

Thus are all the Bones ftock'd with Pores, £$?<;. excep- ting the Teeth $ which have this further Diftinfticn, that they have Nerves inferred into 'em : whereas in all the other Bones, the Nerves go no farther than the Periojlcum.

Befides the large Cavities in the Infide, moil Bones have fupcrficial Cavities, or Sinus's, which may be diftinguifli'd into Sulci* or Furrows, the longer fort ; and 'Pits the fhor- ter ones. On the Outfide are alfo obferv'd Prominences, whereof there are two Kinds ; the one a continu'd Part of the Bone, jetting apparently above its plane Surface, for the more commodious Infertion of the Mufcles, £<fa call'd Apo-

phyjis ;