V E R 



V E R 



fix hours without any motion, he loft often a whole inch in 

 height. 



People who ufe liard labour fink rather lefs ia the whole 

 than thofe of fedentary lives ; and the height once loft is 

 Tieter to be recovered that day, not even by the ufe of the 

 cold batli ; but a night's lying down can alone reftore it. 

 Phil. Tranf. N° 383. p. 87. 



Thig difference in height takes place only in the human 

 fpecics, as they are the only creatures who walk ereft, and 

 throw the preffure of their whole weight upon the back- 

 bone. This gentleman mcafured horfes before and after 

 riding, and could find no difference even after the longeft 

 journeys. 



The alteration in height is much greater in young people 

 than in thofe who are more aged. It is evident from this 

 change happening to perfons when they fit, as well as when 

 they ftand, that it is brought about merely by the back- 

 bone ; and we muft admire the ftruflure of that part of the 

 body, which owes its giving way thus to its being formed 

 together in that manner, which alone could fuit it to the 

 feveral purpofes it was intended for. The thicknefs and 

 fhortnefs of the bones, with the intervening cartilages, afllfted 

 by the bony proceftes, difpofe it to a motion peculiar to it- 

 felf; whereas, had the bodies been of any confiderable 

 length, upon bending the body, the articulations muft have 

 made a large angle upon their innioft edges, and the fpinal 

 marrow would have been continually liable to be injured ; 

 and had the cartilages been entirely wanting, it would have 

 been as ufelefs as if it were but one bone, by which the 

 trunk of the body, being rendered incapable of bending, 

 muft have remained for ever in an eredt pofture. Another 

 particular, which befpeaks the utmoft wifdom and defign in 

 the contrivance of this part is, the remarkable difference 

 there is in the cartilages placed between the feveral bones of 

 the fpine. 



The vertebrse of the back require but little motion, and 

 the cartilages there are for that reafon fmall and thin, in 

 comparifon with thofe of the loins, which being very thick, 

 the loweft more tfpecially, the motion is much greater 

 there, and much better to be borne. This being the ftate 

 and difpofition of the parts during the whole fpace of time 

 in which we are ufually employed about our feveral bufi- 

 ncffes, till the time that we difpofe ourfelves to reft, the car- 

 tilages of the fpine will, by their compreftible and yielding 

 properties, become more clofc and compaft for the preflure 

 they fuftain, and confcquently the fpine, which is the only 

 liipport of the trunk of the body, will become fhorter ; but 

 when this fuperior weight ftiall be entirely removed, by 

 placing the body in an horizontal pofture, as it always is 

 when we are in bed, the compreffcd cartilages will, by their 

 natural elaftic power, begin gradually to enlarge thcmfelves, 

 till they, by degrees, recover the expanded ftate they had 

 before they gave way. 



The cartilages between the feveral vertebrae are twenty- 

 four in number, and every one of thefe i& preftcd fomewhat 

 in our daily employments, fo that when they all come to 

 expand, the aggregate of their feveral cxpanfions cannot be 

 fuppofcd lefs than about an inch. Now, if this be the dif- 

 ference occafioncd by the preffure of the common weight of 

 the body alone upon itfelf, it muft neceffarily be much 

 greater in thole perfons whofe conftant employment is to 

 carry heavy burdens. The compreflion and expanfion of the 

 cartilages in older people being lefs than in younger, is a 

 neceffary confequence of the cartilages in time of age grow- 

 ing harder, and lefs capable of comprefnon ; for they often 

 grow almoft bony in length of time : and hence it is, that 

 old people are obferved to lofe fomewhat of their former 



Vol.. XXXVII. 



height, the cartilages in them fhrinking to a fomewhat 

 fmaller compafs as they grow bony ; and this ftiortening is, 

 therefore, not imaginary, as many have believed, but real, 

 and owing to this plain caufe. Phil. Tranf. N. 383. p. 90. 

 See Cartilaoe and Spine. 



Vertebr*:, Difuije of the. See Spine. 



Vertebra, Dijlocations of. See Luxation. 



Vertebra, Fradurcs of. See Fracture. 



Vertebr* of Fiji. The vertebrse of fifh are extremely 

 different in fhape in the feveral kinds, and even vary in num- 

 ber in the different fpecies of the fame genus. The anterior 

 vertebra in fome have three apophyfes, as in the cyprini, 

 efoces, pleuronedli, &c. ; and in the clupez they have no 

 lefs than feven of thefe apophyfes, but they are (lender and 

 capillary. Artedi Ichthyol. 



VERTEBRAL Artery and Vein, m Anatomy, branches 

 of the fubclavian veffels. See Artery and Vein. 



Vertebral Canal, the canal of the fpine, which con- 

 tains the medulla fpinalis. See Spike. 



Vertebral Nerves, the nerves fent off from the medulla 

 fpinahs, and palTing out at the lateral holes of the fpine. 

 See Nerve. 



Vertebral Theca, the flieath of dura mater inclofing 

 the medulla foinahs. See Braiv. 



VERTEILLAC, in Geography, a town of France, in 

 the department of the Dordogne ; 7 miles N. of Riberac. 



VERTENEGGI, a town of Iftria ; it miles S. of 

 Capo d'Iftria. 



VERTERIS, in Ancient Geography, a town of Great 

 Britain, in the fecond route of Antonine, between Bro- 

 vonacae or Kirbythure and Lavatra: or Bowes, and in the 

 fifth route between Lavatrx and Brocavum or Brougham 

 Caftle, placed at Brugh under Stanemore. 



VERTEUIL, in Geography, a town of France, in the 

 department of the Charente ; 3 miles S. of Ruffec. — Alfo, 

 a town of France, in the department of the Lot and Ga- 

 ronne ; 6 miles N.N.E. of Tonneins. 



VERTEX, in Anatomy, the crown of the head, or that 

 uppermoft and middle part filuated between the finciput 

 and occiput. See Head. 



Hence, alfi), vertex is figurately ufed for the top of other 

 things. Thus, the vertex of a cone, pyramid, conic fcftion, 

 &c. is the point of the upper extremity of the axis, or the 

 top of the figure. 



Vertex of an Angle, is the angular point, or the point A, 

 Plate n. Geometry, Jig. 15.) in which the legs meet 

 of a Figure, is the 

 to the bafc 



Vertex of a Figure, is the vertex of the angle oppofitc 



Siicli is the point M [PlateXW. Geometry, Jig. 17.) op- 

 pofite to the bafe A B. 



Vertex of a Curve, is the point A {PlateXV. Geometry, 

 Jig. 18.) from wliich the diameter is drawn; or it is the 

 interfedtion of the iliamcter and the curve. 



Vertex of a Glafs, in Optics, the fame with the pole 

 of it. 



Vertex is alfo ufed, in AJlronomy, for the point of heaven 

 perpendicularly over our heads, called the zenith. 



Vertex, Path of the. Sec Path. 



VERTIBULUM, a word ufed by fome writers to e.x. 

 prefs the round head of a bone, which, in its articulation, is 

 infcrted into the finus, or cavity of anotli'.T bone. 



VERTICAL, in Botany, is technically ufed to cxprefs 

 the perpendicular pofition, or infertioii, of ccrtiin p.irts of 

 a plant. Vertical Leaves are fuch aa ftand fo erccl, that 

 neitlier of their furfaces can properly be caJIcJ the upper 

 or under, of which nature are all fword-fhaped leaves, folia 

 enjformia. (Sec Leaf.) But the term is ufually reftridltd 

 P to 



