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Show Of the Dura Menynx. Book III. and .is of the upper Region of the Brain, parting the Two Hemifphaeres, "who, ""1" carried the whole length of the Head, under the Sagittal Suture, and tied to the upper part of the 0f Ethmoeider. The Fourth Sinur is the molt lhort ofthem all, and tending downward, undefcendeth in a l‘traight courfe, between the Certain-um and the Cerebellar", der the Bafe of the Brain, to the Nate: and Glam "Fined/is. Having in fome manner given you a profpeét 0f the feveral Si/mr,l lhall endeavour to render you an account of their ules. I'afirumfirnfiuritm mttmri [mic obcundo defignarzmt Anatomzci, Mt 'Z/Ent‘ ab Arterioritm duéiilzm, membrimi/s (9‘ tcrebro latimntibm, fangumem bit reforil/andis vii/mt idomum, retipienter in Siam bofcc exonerarcnt. Adm ut smug/1m. dew pcrfimgtmiiir pen/o qua/e 72cm: Carla intimi corpori/r rcgz‘oni clargiamr, ittfint Ciflemx quiedzmt, magnorum amalinm ill/far, ad quot minaret wemrum rimli tonflucrcnt, flingninii copitzm regercntef : Argue to Hamil"? Titlfll z'Ila 45! (10min[ti Imjzu‘ parietir all/{gamut flirt/in»: ille Opifi'x, m' intimz temrrimiq', tercbrire. ct: iii, topic/0 intumcftemcr fanguinc, nimia dlfltntimle larermtitr, C7 Ilemitior (9v delimit; Spiritmtm Animalium wtonomia, iiitcflino flmguinis perferoidi molt exagitattz finiéiionibitiw aniline peragendit, prorfu: itiepta rel/cleretirr. +7.45, m. The proper Blood-\‘eflels + with which the Dam Mater is concerned, iif‘anmcs are either Arteries, the internal Carotides which import Blood into it, and 2"" PM the internal Jugulars to export Blood from it. . hoax. i two of As to the Arteries, . . them of the lame fide before they arrive the Bafe of the Brain, are difperled into the Dam Menynx, branching themf‘elves principally into the ConvexSurface of the Membrane; and fome of them do infinuate themfelves be. tween the Tables and Sutures of the Skull, terminating into the Pcriofieum . new"; ""1"" and Peritmnittm, the finer vails, that every way externally invefl it. And as to the Veins, they export Blood from the Membrane, and carry it into the defcendent Trunk of the Cam, and f0 into the Right Ventricle Mtnjnx. of the Heart. Boole 111. 0f the Dura lVlenynx. from thence are tranfmittcd laterally into the Firf't and Stond Simu, making little trenches crofs the Ot'cipm, (when it was tender in its firi‘t rudiment) and are from thence conveyed to the bottom of the Brain, to a common Receptacle as a kind of Lake', whence it is exonerated into the Jugulars, whichare car- tied in Two Perforations ( made fit for them) through the OJ Pctrofimz. As to the Functions of the Dun: Way/1x, they confifi in Senfe and various 5 Motions, which may be liyled Natural or Violent, the Fir-Pt, fome fancy to 31,5, . . be a kind of Syfiole or Dialiole, Analogous to that of the Heart, pi‘occed- iiialffliliin ing from its camous Fibres, irritated by the quantity ofBlood, which after_ Hea t, " ward is impelled through the Aorta into the carotide Arteries ( feared in the Dnm Menynx) which being aéted with frequent vibrations, do affect this Membrane by confequence, with alternate Motions and Relaxations, followingthefe of the Arteries, which do by their repeated pulfiitions draw the Membrane into confent, by making imprellioz s in its adjacent parts; whereupon the 'Dura Mcnymc is not aéled with a natural primary Motion, flowing from the peculiar contexture of its Fibres, but only agitated with an accidental Concuflion, externally forced by the pulfatitm ol'the Arteries. O, And before we quit the Treating ofthis Coat, it may be Worth our dif- Tlicmfns quifition, with what Senle and farther Morion it is endued 5 and to its more "Emmi acute Senfation, the molt fierce pains of the Head are configned, but after whitinanner they are produced, is not f0 ealily underliood. It is vulgarly received, that {harp Fumes7 mounting up from the Bowels of the lowcfi Apartiment,chiefly from theHflocondergWomb,and Stomach do {trikethis Membrane, torturing it with grievous pains, this may quickly be faid, but is not ['0 eaiily made out,by reafon it is difi‘icult to apprehend how thefe vapours lliould arife a ("it arm: minoitlvc gmfihr‘hfi‘ "Filin- :2]: mm" outof the lower parts of the Stomach and Gillet, and pals through the Palate, and penetrate the thick Wall of the 0: Cuneiform/z, before they can land at the Dim: Menynx, and afl'eé‘t it with importunate Senfation : But (I conceive) [1}: Tl"Meal PM" El it may be more probably afferted, that the Dam Mater may have (harp con- The Drum Mater is furnilhed ( as above defcribed) with Four eminent Cavities, and many Branches, difperfed through the Membranes, and fub- liance of the Brain, as rhofe more fpacious and venous Receptacles, and f0 many lakes, into which Veins the finallcr Rivulets difcharge their Purple Liquor, f0 that the Office (to which thefe Simu are configned) is to fervc the Veins, as f0 many greater Chancls, to reconvey Blood from the Menibranes, and feveral regions of the Brain, to the Jugulars feated below itThe upper Simtr, which by reafon of its firuation, and greatnefs,mlgl1t be truly fiyled the Firl't, but is called by the Antients the Third (WhiCh I will obferve in refpeét to Antiquity, and for diftinétion fake) received! W mm" Blood immediately from the Veins of the upper part of the Dnm Mater, and how the _ . . ' eatlilifflfu‘fi" the Elm" 5 and thence conveyeth it into the lateral Sinus, which being tienm M. ed near the Firll; Bone of the Occiput, and pafling up obliquely to the Apex m intothc um. of the Cerebellar», receiveth Blood from it, and the hinder part of the Brain, by the interpolition of the Veins. The Fourth Simtr extending it {51between the (brebmm and Cerebellar" to the Nate; and Glanduliz @iflmlih ‘0' ward the Bafe of the Brain, receiveth Blood from the inward Recefles, an all the adjacent parts of the Cerebrum and Cerebellum ‘, f0 that the Upper 3" lower, and lateral Sinus unite themfelves in one, called the 'Ihrculm i" which two crofs ways of the upper, lower, and lateral Simu do meet; an hold an intimate correfpondence with each other in this common center, an tells, arifing from the troublefome Steams of the Blood, fermenting within ' the Brain (confining on the Dura Mater ) Thefe vapours may be gathered as it were into a cloud, blowing it up with great diflcntion, offering great VIOICHCC to the curious frame of nervous Fibres, full of molt acute Scnfe: And it hath been often difcovered, the Skull having been taken off not long aiter death, that the Dam Il/[enynx hath been blown up like a Bladder, and rcndred tranfparent, as it feemed to be fwelled with much Water, contained Within it, which was afterward difcovered to proceed from Wind, making an inflation in the Membrane, which being Launced, the Swelling imme~ diately vanilhed, without the cfi‘ufion of any Liquor. And this Membrane is not only obnoxious to great pains, but alfo fufi‘er- Com‘ullli': motions of cth Convulfive motions, caufed by a quantity of inflamed Blood, running m, 1,," M:in the fubl'tance of it, producing fometimes vertiginous indifpofitions, and W" die Falling Sicknefs, caufed by a malignant quality of the Blood, and Animal Liquor, highly difaffeaing the Dun: Mater till its nervous Fibres are feverely tortured, \Vitl) Concullions, Contractions, which alfo draw the Nerves into confent, feared in the Mufcular parts, fo that the Limbs are dillorted with vio- fflt Motions, which proceed originally from the Convulfive Vibrations of t C nervous Fibres, relating to the Dum Menynx ; but I refer the Treating OFthis unkindly Senfation, and Motion ofthe Dura Menymt, to the (2le- "1g", where I intend to dilcourfe more largely of them. the feveral {beams of Blood run upward and downward into the 'Iortulm an from C HAP. |