BON 



flave corporally ; but cannot deprive him of life for any 

 offence, nor even fell him to a llranger, without firft bringing 

 him to a public trial, called a '' Palaver," before the chief- 

 men of the town ; and on fiich occafions the caufe of the 

 flaves is pWadcd by the native Mahometans, who are a fort of 

 proftflional advocates. Tlitfe indulgences indeed extend 

 only to native or dometlic flaves ; for captives tai<en in war, 

 and thofe who are obtained in traffic, may be fold at pleafure, 

 and treated as the owner thinks proper. Park's Travels 

 intoAfriea. Re"ncll's Proceedings of the African aifociation. 



BON DOUR, a town of Afuitic Turkey, in the province 

 of Natcilia, 2-1. miltS well of Ifbarteh. 



BONDRE'E, in Ornithology, the honey buzzard (fako 

 api-vorus^, ftanc's under this name in Buflbn's Hiftory of 

 Birds. The Frencli writers of the prcfcnt day alio call it 

 bondree. 



BONDUC, and Bonducella, in Botany (Plumier). 



See GuiLLANDIN.U 



BONDUCH, in the Materia Med'ica, a name by which 

 many authors have called the Molucca, Marfao, or Bczoar 

 nuts. 



BONE, in /luatomy. The bones are the moft folid parts 

 of animals, and may be regarded as the walls of a building 

 fupporting and containing the other parts. The human 

 body is compofcd of a pile of bones, the extremities of 

 which are varioufly ihaped, and adapted to each other, and 

 calculated to admit of a variety of motions. Bones appear 

 to be compofed cf a vafcuiar fiibllancc, not differing ma- 

 terially in llruilure from that of the reft of the body, ex- 

 cept that there is depolitcd in its interllices phofphat of 

 lime, which gives to the whole mafs rigidity, ftrength, and 

 a permanent figure. That Hate of the vcffeis in which they 

 fecrete, and depofit, earthy matter, occurs in diftafes of other 

 parts of the body. The nutrient veflels of arteries, mem- 

 branes, and ligaments, occnfionally depofit lime, and caufe 

 the ofTification of thofe part?. Tiie earth of bone is alio 

 depolited in fome fpecies of tum.ours, and often in confider- 

 able quantity, and in an irregular manner in the cellular lub- 

 ftance of a limb, when the bone of it is difeafcd. After this 

 general view of the fnbjeft, we proceed to give an account 

 of the ftrufture of a bone, both with refpeft to the arrange- 

 ment of its earthy particles, and with relation to its vafcuiar 

 texture. 



It is cuftomary, however, in giving an account of the 

 ftrufture of bones, firft to dcfcribe thtir original formation 

 in the fcctus ; and this is ufefui, hecaufe it demonlfrates the 

 fimplicity of the procefs, and tends to refute old and erro- 

 neous ideas refpeCtir:g it. The parts of the young foetus 

 which are afterwards to become bone,>, are merely a vafcuiar, 

 gelatinous fubllance, fcarcely dillinguifhable from the other 

 parts ; afterwards the outhne of the bone becomes evident, 

 and its fubltance is rendered white and firm, in proportion 

 to the quantity of hme depofited in it. The quantity depo- 

 fited in it, even at the lime of birth, is only fufiicient to give 

 firmnefs to the whole mafs, but not to prevent its flexibility. 

 The extremities of all the long b')nes coufill of large portions 

 of cartifige, and thefe, by degrees, become bony. This 

 change is effefted by an alteration, tirlt, in the organization 

 of the parr ; the cartilage is abforbed, the vefTcls enlarge, fo 

 as to admit of inieftion, and then they appear to have the 

 power of depofiting earthy matter, or forming bone. The 

 formation of bone begins in the centre of a cartilage, and 

 gradually extends from thence to the remote parts, fo that 

 the feparate piece of bone, formed at the extremity, rem-ains 

 to nearly the period of puberty, conjoined to the body of 

 the bone, by a cruft of cartilage. In this ftate it is techni- 

 cally termed an epiphylis. The obfervation of thefe faifls 



BON 



led formerly to the erroneous notion, that it was neceflary 

 that cartilage fhould exill, prior to the formation of bone ; 

 and that it was converted by preffure, or in fome inexplicable 

 manner, into bone. It were a walle of argument to refute 

 this opinion. We can perceive a llriking advantage that 

 rcfults from the bones of the foetus being formed as they are. 

 Their flexibility admits of the form of limbs becoming 

 adapted to the varying figure of the pelvis, through 

 which they muft pafs, and their elalticity, wiiich is powerful, 

 rellores them afterwards to their natural ihape. 



The fubjeft which full engages our attention, in examin- 

 ing the llrufture of bone, is the arrangement of the earthy 

 parts. The phofphat of lime is depolitcd by the arteries 

 in minute points or particles, and thefe being placed length- 

 wife, with refpett to each other, form fibres ; again thefe 

 fibres being placed parallel to one another, form bony plates, 

 fcales, or laminae. That bones are fibrous and lauiincus, is 

 evident from a mere infpeftion of them in the foetai ftate ; 

 that they are fo in the adult fubjeft may be demonftrated by 

 calcination, or long expofure to weather : in which cafes the 

 connefting vafcuiar fubftance is more fuddenly or flowly dif- 

 fipated, and thus the arrangement of the earthy matter is 

 rendered vifible. The earthy fibres of long bones extend 

 themfelves in a direftion parallel to the axis of the bone ; in 

 broad bones they fhoot out in every direflion, like rays from 

 a centre. In long bones the earthy matter is confolidated 

 in the circumference and fides, fo as to form thick and llrong 

 walls ; whilfl a tube or more Ipongy bony ftruilure is found 

 in their centre. In broad bones a fimilar llruflure is ob- 

 ferved ; the earthy matter is conlolidated exteriorly, fo as to 

 form denfe plates or tables ; whilft interiorly the fabric of 

 the bones is fpongy or cancellous. In the internal ipongy 

 part of bones the marrow is depolited. In the middle part 

 of long bones the wails are very thick, being compofed of a 

 great number of bony lamella, and thefe walls gradually be- 

 come extenuated as thty approach to the extremities of the 

 bone, where they are proportionally very thin. Long bones 

 are alfo flender in the middle, but at ttie fame time llrong, on 

 account of the great quantity of carthv m.atter thus confoli- 

 dated to form their walls ; whilft there is but little cavity or 

 m.eduilary ftrufture. Thefe bones expand greatly at their 

 extremities, in order to afford an extent of furface for the 

 formation of joints, and for the fupport of the weight of 

 the body. In the extremities cf long bones, though the 

 walls are thin, there yet exiils a great deal of bony matter, 

 which is depofited fo as to leave interfpaces between its 

 fibres, forming what is termed the cancellous ftrufture, or 

 lattice-work of bones. It has been therefore concluded, 

 that the quantity of earthy matter may be nearly equal in 

 each part of a bone, and give to it an equal degree of 

 ftrength ; but that it has this difference of arrangement, 

 that in the middle it is compafted fo as to form very thick 

 and denfe walls, occupying but little fpace, and leaving but 

 little internal cavity, whilll in the extremities it occupies a 

 greater fpace, and forms a lefs folid kind of fabric. It 

 would be defirable to afcertain, with fome piecifion, where 

 fimilar circumftances are to be met with in broad bones ; and 

 though no precife ndes can be given, yet this may be ad- 

 mitted as a general truth, that where a broad bone fwells out 

 into a protuberance, there we (liail find the walls or tables 

 thin, and the cancellous ftrufture abundant ; and, on the 

 contrary, where a broad bone is condenfed fo as to occupy 

 but httle fpace, there we Ihall find the tables proportionately 

 thicker, and the cancellous ftrufture lefs in quantity. 



Having thus defcribed the an-angement of the earth of 

 bones, we may next enquire into the advantages which re- 

 fult from this llrufture. The long bones are made Uender 



in 



