Body than in One of Five or Six Months In a Faetus of Nine Months it almost fills the Interstice which the Lungs after the Birth begin to take up in the Upper-part of the Thorax The Thymus after the Birth gradually decreases except the Upper-part of the Cavity in the Thorax is Capacious enough for its Reception as appear'd in an Anatomical Subject I lately Dissected of Thirty Years of Age in whom the Thymus was very large I must confess I never yet met with a Subject tho never so Old in whom the Thymus was wanting In those Bodiâ—â— the Thymus is less than ordinary we find the Subclavian Glands those of the Internal Jugular Veins and the Glandule Thyraidam larger as they lately appear'd in a Boy of about Eight Years of Age. In Women the Thymus and Thyroid Glands are larger than in Men but the Subclavian Glands are less by reason the Claviculae in Women are straight and shorter than those of Men whence a much less Interstice is frain'd for entertaining those Glands I have more than once found the Lymphe-Ducts fill'd with Wax which Arise from the Thymus and empty themselves into the Upper-part of the Thoracick-Duct by Injecting that Duct by the Vesica Chyli See App. Fig. 12. D. From what has been abovesaid it appears the Thymus bears a Proportion to the Head whether in the Faetus or in Bodies before they become Adult which we conceive is in order to receive a Proportionable Quantity of Lympha deriv'd from thence And as the Subclavian Glands of Women are less than those of Men so the Thyroide Glands and Thymus are larger Hence also it appears the Thymus is a Lymphatick Gland and Varies its Magnitude according to the Quantity of the Lympha that is necessarily transmitted thro' it from the Superior Parts or as the Neighbouring Lymphatick Glands do more or less transmit their Lympha to it Besides this common Office of the Thymus whether in the Faetus or Adult it has another Use which was first suggested to Me by Injecting a Liquid into the Thoracick-Duct when finding it not only fill the Lymphe-Ducts of the Thymus but the Thymus it self was Extended with it The like Observation I since found was made by the Expert Anatomist Dr. Tyson some Time since whence I conceive the Thymus and its Lymphe-Ducts are Diverticula to the Chyle when too great a Quantity is pressing forewards towards the Subclavian Vein I know it may be Objected that the Valves of the Lymphe-Ducts oppose this contrary Course of Liquours in them but repeated Observations convince me that not only these Lymphe-Ducts of the Thymus which are large and have very few if any Valves as appears by their being Injected with Wax but those of the Loins and their Glands from whence they Arise are frequently fill'd with Chyle when no Compress is made on the Thoracick-Duct Hence it is a Milky Liquor has been commonly found in the Thymus but more frequent in that of a Pâ—tus than iâ— an Adult and that not only because the Thymus and its Lymphe-Ducts are much larger Proportionably in the former State or Faetus but the bended Position of the Thoracick-Duct of the Fetus in Vterâ— renders the Ascent of the Chyle by that Duct more liable to Regurgitate by the Lymphe-Ducts of the Thymus H H The Fore-part of the Diaphragma free'd from the Cartilaginous Endings of the Ribs and Pinn'd up THE TWENTY-SECOND TABLE Fig. 1. THE Heart with Parts of the Trunks of the great Veins and Arteries cut off A A The proper Membrane of the Heart a Portion of which is Rais'd and hangs Down B B The Left Side of the Heart adorn'd with in Coronary Vessels C ψ Part of the Right Auricle of the Heart C The Left Auricle on the Basis of the Heart D The Cone of the Heart E The Vena Cava which conveys the Refluent Blood from the whole Field of the Body into the Right Auricle of the Heart when the Heart iâ— iâ— Systole whence the Blood is again transmitted into the Right Ventricle of the Heart when it is in Diastole So that when the Auricles of the Heart are in Diastole or Relaxation they are fill'd with Blood and the Heart it self is in Systole or Contraction and Vice versa when the Heart is in Diastole the Auricles are in Systole F The Arteria Pulmonalis or Vena Arteriosa which carries the Blood from the Right Ventricle of the Heart into the Lungs G The Vena Pulmonica or Arteria Venosa which conveys the Refluent Blood from the Lungs into the Left Auricle and Ventricle of the Heart not unlike the Vena Cava c. H The Arteria Magna Arising out of the Left Ventricle which conveys the Mass of Blood from the Heart thro' the Field of the Body from whose capillary Extremities the Veins are continued as appears by a Microscope in the transparent Parts of living Animals See App. Fig. 4. and 5. Fig. 2. The Heart divested of its External Membrane and Carnous Fibres after Boyling so that the Disposition of the Subjacent Fibres may appear The way of preparing the Heart to exhibit this Disposition of its Fibres may be practis'd after the following Manner The Heart with Portions of the Trunks of the large Blood-Vessels being taken off the Blood as well within its Ventricles as Blood-Vessels being evacuated then with Tow or Pieces of Rags fill the Ventricles Auricles and large Vessels on the Basis of the Heart the Mouths of the large Blood-Vessels being stitch'd up least their Contents should be Extruded by the Contraction of the Heart in Boyling This done Boyl it according to its Bulk if it is the Heart of an Ox c. Boyl it Four or Five Hours if of a Man One or Two N. B. This Figure is Printed reverst A A Sinus plac'd between both Ventricles in which a large Trunk of one of the Coronary Arteries is convey'd B The Cochleated or Oblique descending Order of Fibres of the Left Ventricle of the Heart C The External and Oblique descending Order of Fibres of the Right Ventricle which decussate the former or Subjacent Fibres in Acute Angles D Part of the Arteria Pulmonalis E The Aorta ee The Trunks of the Coronary Arteries F The Right Auricle G The Left Fig. 3. A The Sinus above mention'd between the Ventricles B The Tortuous Disposition of the Fibres of the Right Ventricle C Those of the Left The Heart consists chiefly of divers Strata of Oblique descending Fibres the External passing more straight or less Contorted than the Internal whence it happens that the External Fibres are seen to Decussate the Internal with Acute Angles the former Arising from the Basis of the Heart at the Roots of the Blood-Vessels and End in the Cone the later Arise from the same Place and Terminate either in the ' Parietes of the Ventricles or Columnae Carneae Fig. 7. g g from which divers Tenditious Filaments are continued to the Lower-parts of the Tricuspid
and Mitral Valves D The Aorta divided between its Origin from the Heart and Valves and reclin'd to One Side hanging by its Two◠Coronary Arteries Exprest Fig. 2. e e. e e The Three Semilunary Valves of the Aorta which hinder a Return of the Blood into the Left Ventricle when the Heart is in Diastole Fig. 4. The Concourse of Fibres near the Cone of the Heart as they appear after a Transverse Section Fig. 5. Some Fasciculi of Fibres of the Left Ventricle of the Heart A B The Two Tendinous Extremities of the Oblique Fleshy Fibres Exprest Fig. 2 3. C The Fleshy Parts of the Fibres between the Two Tendons D The Collateral Fibres which appear in dividing the last mention'd Fasciculi Nor are these any other than Parts of the Fibres of the divided Fasciculus and lay Parallel to each other according to their length The Blood-Vessels and Nerves passing between these Fibres make a Reticular Appearance when divided as here Exprest Fig. 6. The Right Auricle and Part of the Basis of the Heart A A The Right Auricle expanded B B B The Three Tricuspid Valves Two of which are extended by Pinning out their Tendons deriv'd from the Columnae Carneae See Fig. 7. g g Fig. 10. A Inferior The Office of the Auricles is to receive Part of the Refluent Blood whilst the Heart is in Systole and to discharge that Blood again into the Ventricles of the Heart when it is in Diastole so that the Auricles of the Heart seem as Diverticula to the Blood in its passing into its Ventricles else a Repercussion of the Blood in the Veins would necessarily happen in the Systole of the Heart which would prevent the regular Influx of the Blood to the Ventricles Fig. 7. The Heart with its Left Ventricle Open'd A The Inside of the Vena Pulmonalis B The Aorta in like manner Open'd C C The Septum Cordis which divides the Right Ventricle from the Left D The Left Auricle intire which in Humane Bodies is very little as appears by this Figure and the Trunk of the Pulmonick Vein very large d The Trunk of the Arterìa Pulmonica cut off e e Two of the Three Semilunary Valves at the Beginning of the Arteria Magna which hinder the Reflux of the Blood when the Heart is in Diastole in which Action they are Exprest Fig. 3. e e. f f The Two Mitral Valves in the Pulmonick Vein which prevent the Blood repassing that Vessel when the Heart is in Systole g g The Carneae Columnae compos'd of Muscular Fibres deriv'd from those of the Sides of the Heart whençe divers small Tendinous Filaments do Arise and are faltned to the Inferior Limbus of the Mitral Valves by which means those Valves are drawn down towards the Cone of the Heart and prevent the Blood from passing out again that way when the Heart is in Systole I know Dr. Lower in his Accurate Book De Corde Supposes that these Mitral and Tricuspid Valves are Relax'd in the Systole of the Heart and by their Rising up stop up the Passages of the Veins But if the Structure of the Heart and these Parts are Attentively consider'd in a large Animal as in an Ox c. it will appear reasonable to conceive that these Mitral and Tricuspid Valves are rather drawn down than suffer Extrusion upwards nor need Nature have been at any trouble in making those Valves at the Orifices of the Veins any otherwise than the Reverse of the Semilunary Valves of Arteries if as the Expert Dr. Lower Supposes they are driven up and Extended like a Sail with Wind when the Heart is in Systole but by fastening those Tendinous Fibres to the Lower-parts of those Tricuspid and Mitral Valves which are of a Conical Figure seems to me to be an Argument that they cannot suffer such Extension upwards without letting some Part of the Blood repass them in the Systole of the Heart Besides there must constantly a considerable Part of the Blood remain in the Ventricles of the Heart if those Valves are so dispos'd in its Systole which I think the Dr. himself seems no where to conceive but on the contrary the Ventricles of the Heart are with great Strength adequately Comprest in it's Systole for which End the Insides of its Ventricles are compos'd of divers Fleshy Columns between which divers Intersticia necessarily Result that are elegantly Exprest in this Figure by which means the Ventricles are more exactly Closed in their Systole than they could have been had they been smooth Fig. 8. The Heart with its Right Ventricle Open'd A The Inside of the Right Auricle of the Heart as it appears when Open'd and Pinn'd out B The Left Auricle Intire C The Coronary Blood-Vessels of the Heart from these particularly from the Arteries Spring those of the Auricles and large Blood-Vessels of the Heart as the Accurate Ruysch describes them in his Anatomical Epistles Pag. 15. The Nerves of the Heart Spring from the Eighth Pair and Intercostal Nerves a particular Description of which may be found in Dr. Lower's Book De Corde and Vieussenius Nervographia D Part of the Right Ventricle of the Heart Open'd E A Portion of the Vena Arteriosa or Arteria Pulmonalis Divided and Expanded f f f The Three Valvulae Sigmoides or Semilunares which oppose the Return of the Blood from the Lungs by the Arteria Pulmonica into the Heart when it is in Diastole Fig. 9. A A The Heart cut Transversely B That Part of it next its Basis. C That next its Cone D D The Right Ventricle of the Heart E The Left F The Septum Cordis or the Partition between the Two Ventricles of the Heart G G A Stylus put thro' the Vena Cava into the Right Ventricle of the Heart H H Another passing from the same Ventricle thro' the Arteria Pulmonalis I I A Stylus in the Left Ventricle of the Heart passing out at the Arteria Magna K K Another Inserted into the same Ventricle by the Vena Pulmonica Fig. 10. A Inferior A Portion of the Columna Carnis of One of the Ventricles of the Heart cut off See Fig. 7. g g in Situ B The Tendinous Fibres deriv'd from the Fleshy Column and fastned to the Inferior Margin of One of the Tricuspid Valves A A Superior Portions of the Tricuspid Valves Fig. 11. The Coronary Blood-Vessels of the Heart as they appear on its Surface when Injected after Drying the whole Heart A A The Arteries fill'd with Mercury fix'd with Tin B B The Veins Extended with Wax Fig. 12. A Portion of the Vena Pulmonalis next the Basis of the Heart A A Parts of the Mitral Valves Pinn'd out by their Tendons Fig. 13. The Inner Surface of a Portion of the Arteria Magna cut off at the Basis of the Heart when Divided and Expanded A A A A The Three Semilunary Valves well Exprest when Pinn'd out One of them being cut thro' in its Middle in dividing the Great Artery Fig.
the Arteries of a Humane Foetus Injected with Wax and Display'd after Dissection 1 The Aorta or Arteria Magna cut from its Origin at the Orifice of the Left Ventricle of the Heart 2 The Trunk of the Great Coronal Artery of the Heart Arising from the Beginning of the Aorta the Rise of the Lesser Coronal Artery not Appearing in this Position of the Arteria Magna 3 The Canalis Arteriosus Fill'd with Wax by Injecting it into the Aorta This Arises from the Upper Part of the Trunk of the Pulmonick Artery near its Two Ramifications which pass into the Lungs and after an Oblique Descent under the Beginning of the Aorta Empties it self into the Upper Part of its Descending Trunk as here Exprest 28. Besides this Communication between the Right Ventricle of the Heart of a Foetus and Arteria Magna there is another call'd Foramen Ovale by which Part the Blood at its Entrance into the Right Ventricle passes into the Pulmonick Vein and the Left Ventricle of the Heart thence to the Aorta Hence it Appears That the Blood which Flows into the Right Ventricle of the Heart of the Foetus Passes immediately by the Canalis Arteriosus to the Arteria Magna as well as the Blood of the Left Ventricle which is Receiv'd immediately from the Vena Câ—â—a or Right Article of the Heart into the Pulmonick Vein and Left Ventricle So that the Blood in the Foetus which Runs into the Right Ventricle passes immediately to the Aorta by the Systole of the Heart as well as the Blood of the Left Ventricle Not do's any Part of the Blood of the Right Ventricle pass into the Left Or any Blood of the Left Ventricle first pass the Right as in the Adult Hence the Heart in the Foetus may be said to have but One Ventricle in Effect since the Blood which passes One do's not come into the Other before it arrives at the Aorta After the Birth when the Infant has Receiv'd Air into the Lungs and their Vesciculae remain Distended and the Ramifications of the Pulmonick Arteries and Vein consequently are more Display'd the Blood thâ—â— begins to pass their Extremities more freely than before and the Arterious Chanel at length becomes neglected as well as the Foramen Ovale the Former becoming a Ligâ—â—â—â— and the Latter Closing up The too early Occlusion of these Passages in Children often produces many Disorders as Inflammation of Divers Parts of the Head Neck and Lungsâ— in which Cases Bleeding is of great Use Of this I have met with many Inâ—â—â—nces in the Dissection of Children I have often found the Foramen Ovale open in the Adult The Canalis Arteriosus for what I have observ'd closes sooner than that Foramen 4 4 The Subclavian Arteries Arising from the Arteria Magna to which the Axillary Arteries and those of the Arms 23 23 are conâ—â—'d 5 5 The Two Carotide Arteries Arising from Aorta between the Subclavian Arteries 6 6. The Two Vertebral Arteries Arising from the Subâ—levâ—culae which pass thro' all the Transverse Processes of the Vertebrae of the Neck from whence they are freed 7 7. The Arteries which Convey Blood to the Lower Part of the Face Tongue Adjacent Muscles and Glandules 8 8. The Trunks of the Temporal Arteries Spring from the Carotides and giving Branches to the Parcâ—ide Glands 9 9. as well as the Temples 10 10. also to the Neighbouring Muscles Hairy-Scalp and Forehead 11 11. The Occipâ—tal Arteries whose Trunks pass close by the Mammiâ—oâ—â— Process and are Distributed on the Hinder Paâ—â— of the Hairy-Scalp where they are Inosculated with the Branches of the Temporal Arteries 12. Diâ—ers Arteries which carry Blood to the Fauces Gaâ—gaâ—con and Muscles of those Pâ—â—â—â— 13 13. The Contortions of the Carotid Arteries as they pass the Basis of the Skull to the Brain 14 14. Those Parts of the Carotid Arteries where they pass by each Side of the Solla Tâ—â—ica where Diâ—eâ—â— Small Branches do Arise from them and help to Compose the Rete 〈◊〉 which is more conspicuous in Quadrupedes than Men. 15 15. The Contortions of the Vertebra Arteries as they pass the Transverse Processes of the First Vendâ—â— â—â— the Neck towards the Great Foramen of the Os Occiputis I have more than once taken Notice That the Cavities of these Arteries where they are Conâ—eâ—â—ed have been Larger than their Inferior Trunks whereby the Impetus of the Blood must necessarily be very much Lessen'd as well as by their Contortions only In Quadâ—â—pedes the Angles of these Contortion of the Arteries of the Brains are more Acute which in them is the more Necessary to Lessen the Force of the Blood at their Extremities by Reason of the Horizontal Position of their Trunks 16. The Vertebral Arteries where they Ascend on the Medulla Oblongata towards the 〈◊〉 Protuberance or Poâ—a Varâ—â— 17 17. The Communicant Branches between the Carotid and Vertebral Arteries in this Subject somewhat Larger than we Commonly find them 18 18. The Ramifications of the Arteries within the Skull the Larger Trunks of which lie between the Lobes of the Brain and in its Sâ—â—â—i From the Extremities of these Arteries of the Brain are Continu'd its Veins whose Trunks vary much in their Position from the Arteries They Entring the Brain at its Basis and Distributing themselves as above noted whereas the Trunks of the Veins are Extended on the Surface of the Brain and Discharge their Blood into the Longitudinal Sâ—râ—s Nor do's the Veins of the Brain Accompany its Arteries at their Ingress as in other Parts Or the Arteries and Vein of the Dura Meter pass the same Fâ—ramen in the Basis of the Skull 19 19. The Arteries of the Larynx Thyroid Glandules and Adjacent Muscles and Parts Arising from the Subclavian Arteries 20 20. Others Arising near the Former which convey Blood to the Muscles of the Neck and Scapulâ— 21 21. The Mammariae which Arise also from the Subclavian Arteries and Descend on the Cartilages of the True Râ—bs Internally about Half an Inch distant on each Side the Or Pectoris or Sâ—rmâ—n Some Branches of these pass thro' the Pectoral as well as iâ—â—â—costal Muscles and give Blood to the Mammae where they meet with some Branches of the Intercostal Arteries to which they are Inosculated These Maminary Arteries join with the large Trunks of the Epigastricks 57 57. also by which Means the Impetus of the Blood in Integuments of the Abdomen is carry'd on with more Force the Exâ—â—â—es of the Intercostal and Lumbal Arteries do also Inosculate with each other as well as with These 22 22. The Arteries of the Muscles of the Os Humeri and some of those of the Scapulâ— 23 23. Those Parts of the Large Trunks of the Arteries of the Arms which are liable to be Wounded in Opening the Vena Basilica or Innermost of the Three Veins in the Bending of the Cubit See Fig. 1. of this Appendix between 26. and m where the Precise Progress of
and from the Mixture of these two Juices is compounded a proper Menstruum by which the Parts of the Aliment are dissolved and receive their first Transmutation within the Body In this Action which is a Dissolution of the Texture of the Alimentary Mass the Aerial Parts included in its Pores now escape from their former Prisons and being rarified distend the whole Body of the Stomach and this I take to be the true Reason why most Men have less Appetite at some distance of Time viz. when this Intumescence is made than immediately after they cease from Eating From the same Cause arise frequent Eructations great Inflation from divers Meats such as Old Pease Cabbage Roots Herbs and other Vegetables which very much disturb decay'd debilitated Stomachs I am apt to suspect the Stomachick Menstruum may excite an Intestine motion of the Particles of the Mass in Digestion which yet I do not think fit to call Fermentation fearing so bold a Term may mislead us into a False Idea of a greater Conflict than really happens The Intumescence or Dilatation of the Stomach has two Effects First to compress the Gall Bladder and Pancreas and oblige their Ductus Excretorii to spue out their Contents into the Duodenum next to retard the Refluent Blood and by this means dispose the Muscular Fibres of the Ventricle to a Contraction The Reason of this last Hint will appear by what we have offer'd concerning Muscular Motion in the Introduction to our Myotomia Reformata For the Cause of Hunger which is an observable Phaenomenon belonging to this part I conceive it to be an Irritation of the Stomach arising from a copious Quantity of this Menstruum when it wants Matter to act upon This conjecture seems more probable since it is Natural to discharge the Spittle out of the Mouth which comes into it at that Time rather than suffer it to descend into the Stomach and we may perpetually observe a depraved Appetite does follow a Vitiation of the Saliva as in Scorbutick Habits Salivations by Mercurial Medicines and such like Cases When the Mass is sufficiently prepar'd and reduced to a Pultaceous Consistence the Stomach by the help of its Muscular Fibres contracts it self and expels its Contents thro' the Pylorus into the Duodenum where the Digested Mass is mixed with the Bile and Pancreatick Juice forced to discharge it self here as was just now described which Volatilize Subtiliate and Separate the more Fluid and Fine Parts of the Aliment from the more Impure and Gross and here it is that Chylification is first made perfect Now the Bile abounding with Lixivial Salt is apt to intangle with the grosser Parts of the Chylaceous Mass and its Saline Quality not only cleanses the Cavities of the Guts from the Mucus Excreted by their Glands App. Fig. 40. to smear their Inmost Coat and defend the Ostia of the Lacteal Vessels from being injured by Extraneous Bodies which may happen to pass that way but Stimulates the Intestines in their Peristaltick Motion The Peristaltick or Wormlike Motion of the Guts being thus Accelerated by the Acrimony of the Bile the Contents of the Intestines are carried on and the Thinner and more Fluid Parts fitted for the Pores of the Lacteal Vessels is absorbed by them and the Thicker move on more slowly till by the many Stops they meet with in the Connivent Valves all the Chyle is at length absorbed and the Remains being meerly Excrementitious are only fit to be excluded by Stool This Vermicular Motion of the Guts is perform'd by the Alternate Contraction of their Longitudinal and Transverse Fibres App. Fig. 39.40 which at the same Time convey the Digested Mass thro' the Intestinal Tube and express the Chyle into the Orifices of the Lacteal Vessels adapted to receive it whose Progress from the Intestines till it is discharged into the Mass of Blood next presents it self to our Consideration By the reciprocal Action of these differing Fibres and the Apposition of the Connivent Valves Tab. 39. Fig. 2. the Chyle is forced into the Lacteal Vessels Tab. ib. Fig. 1. and hence it is we cannot make any Fluid pass from the Cavity of the Guts into the same Vessels when the Peristaltick Motion ceases A farther Use of the Contraction of these Muscular Fibres is to Accelerate the Chyle in its Progress till the Lympha derived from the Arteries of the Guts joyn with it which is done before it leaves the External Surface of the Intestines by this Addition the Chyle is diluted and assisted in its Progress towards the Mesenterick Glands in the Cells of which it is a Second Time Mixed with a Juice or Lymphatick Liquor there Secreted from the Arteries and so carried on to the Vasa Lactea secundi Generis These Vessels resembling Pipes convey the Chyle from hence all emptying themselves into the Common Receptacle or Cistern the happy Discovery of which we owe to the Observation of Mons. Pecquet It is here the Lympha returned from the Inferior Limbs and adjacent Parts is mixed with the Chyle App. Fig. 11. which not only serves to dilute but promotes its Ascent thro' the Thoracick Duct Fig. ib. to the Lest Subclavian Vein Fig. ib. where this Channel empties its Contents into the main Current of the Blood If we consider in this Duct its several Divisions and Inosculations resembling the Veins of the Testicles its numerous Valves looking from below Upwards its advantageous Situation between the Great Artery and Vertebrae of the Back together with the Ducts discharging their Refluent Lympha from the Lungs and the other Neighbouring Parts we shall find all conduce to demonstrate the utmost Art of Nature used in furthering the Steep and Perpendicular Ascent of the Chyle which Beautiful Order is Represented App. Fig. 11. and cannot but equally Create in us Delight and Admiration Having traced this Animal Juice to its Reception into the Blood with which it is at last Circulated and Assimulated we shall proceed to the Blood it self whose Circular Motion the various Artifices of Nature for adjusting the Proportions and other subordinate Contrivances the Manner and Cause of the Contraction of the Heart and Arteries Respiration with the whole Theory of the Lympha and Glandular Secretion in the Order of Nature follow The Refluent Blood in the Upper and Lower Trunk of the Vena Cava meeting in the Right Auricle of the Heart is thence expelled by its Contraction into the Right Ventricle when the Heart is in its Diastole but by its Systole or Contraction it is thence driven into the Arteria Pulmonaris from whose Capillary Vessels it passes into the Extremities of the Vena Pulmonaris and thence returning is discharged into the Left Auricle and Ventricle of the Heart From whence it is again by the Systole driven into the Aorta by whose Branches it is convey'd thro' the whole System of the Body But when it arrives in the Capillary Arteries it do's not stop there but passes into the like
of the Obliquus Descendens on the Lest Side Indented with the last mentioned Serratus H The Pectoralis in Situ on the Left Side this Muscle has a Broad Semicircular Fleshy Beginning above from near Half the Inferior Part of the Clavicula B below from the Os Pectoris L and all the Cartilaginous Endings of the Six Superior Ribs M M and from the Bony Part of the Seventh Rib it hath sometimes a distinct Fasciculus of Fleshy Fibres which I have frequently seen Confounded with the Obliquus Descendens hence it passeth Transversely over the Upper-Part of the Biceps Cubiti where it is made into a short and broad strong Tendon Inserted to the Superior and External Part of the Os Humeri above the Termination of the Deltoides I The Right Pectoral Muscle rais'd where the Decussation of its Fibres near its Insertion is well Exprest This crossing of its Fibres is a Contrivance in Nature to render its Action more Vigorous the Fibres of its Upper-Part Descending to the Lower-Part of its Implantation to the Os Humeri and those of its Lower-Part Ascend to the Superior crossing each other with Acute Angles This Muscle is call'd Adductor Humeri when it Acts it moves the Arm variously according to the Operation of its several Series of Fibres K The Serratus Minor Anticus raised from its Implantation at the Bony Parts of the Second Third Fourth and Fifth Ribs and left at its Origin at the Processus Carocoides Scapulae L The Os Pectoris or Sternum M M The Cartilaginous Endings of the Superior Ribs Connexed to the Sternum N N The Deltoides Vide Tab. 66. XX. O O The Superior Parts of the Recti Abdominis Vide Tab. 32 Fig. 1. N O c. P Part of the Coracobrachialis Vide Tab. 65. F. Q Part of the Biceps Cubiti Tab. ib. 1. THE TWENTY-FIRST TABLE SHEWS the Sternum Rais'd and the Principal Organs contain'd in the Thorax partly in View A The Inner-Face of the Sternum or Os Pectoris B B The Cartilages of the True Ribs cut from the Bony Extremities of the Ribs and left at their Connexions to the Sternum Upon these Cartilages are plac'd the Musculi Triangulares which Muscles Arise from the Inferior and Internal Part of the Sternum and after an Oblique Progress are inserted to the Bony Endings of the Fourth Fifth Sixth and sometimes Seventh and Eight Ribs These Triangular Muscles scarcely appear in Macilent Subjects as is Exprest in this Figure C The Mediastinum free'd from the Os Pectoris where in Humane Bodies it appears Double being a Continuation of the Pleura from both Sides the Internal Part of the Thorax whence it Descends and firmly Cleaves to the Pericardium dividing the Thorax into Two Cavities and the Right Lobes of the Lungs from the Left In this Progress of the Mediastinum it parts with One of its Laminae to cover the large Blood-Vessels within the Thorax A Triangular Interstice is fram'd immediately under the Sternum at the Approach of the Pleura from each Side as it Descends to compose the Mediastinum Nor is this Interstice an empty Space as it is commonly suppos'd but is interwoven with various Orders of Fibres framing Loculi or little Cells Real Columbus Lib. xi Cap. iii. Proposes the letting out of Pus collected in this Interstice by Perforating the Sternum As the Fore-part of the Mediastinum plainly appears a Continuation of the Pleura â— so its Back-part is evidently a Continuation of the same Membrane as it advances towards the Vertebrae of the Back In Dissecting a Morbid Body I found the Right Side of the Cavity of the Thorax so extended with a Serous Humor as its External Appearance especially at the Cartilaginous Endings of the True Ribs was Prominent Nor would the least Portion of the Lungs on the same Side Swim in common Water but Sunk to the Bottom of the Vessel In this Subject I could not find any Part of the Hydropick or Serous Humor in the other Side of the Thorax but the Lungs on that Side in no very ill State By this we may be assur'd that the Mediastinum adequately divides the Right Side of the Thorax from the Left The Mediastinum also supports the Pericardium leaft its Flaccidity impede the Systole of the Heart and sustains the Trunks of the Nerves of the Par Vagum in their Progress thro' the Thorax The Diaphragm is also said to be suspended by the Mediastinum leaft the Liver to whose Lower-Side it 's Connexed should become Insupportable The Mediastinum receives Arteries from the Mammary and Intercostal Branches it has Two large Veins which discharge their Blood into the Subclavian and Neighbouring Trunks Its Nerves are said to Spring from the Eighth Pair The Lymphe-Ducts of the Mediastinum pass towards the Thymus D D The Pericardium or Capsula Cordis Open'd and Pinn'd up The Pericardium Arises from the large Vessels at the Basis of the Heart and seems to be compos'd of a Continuation of the Pleura or Mediastinum It adheres to the Diaphragm below and laterally to the Mediastinum It has Blood-Vessels from the Diaphragm and Mammary-Vessels according to the Accurate Ruysch in his lately publish'd Epistles The Capillary Extremities of these Blood-Vessels are very Numerous as will appear when Injected with Mercury There are divers Lymphe-Ducts on the Pericardium which convey the Lympha to the Thoracick-Duct The Glands which are in the Pericardium and at the Basis of the Heart which separate that Humor imploy'd in Moistening the Inside of that Membrane and Surface of the Heart are not to be discover'd by the naked Eye in ordinary Dissections no more than those on the Inside of the Peritonaeum and Surface of the Intestines which afford a Humor to Lubricate those Parts but when either of these Parts are Diseased so that those Glands are Affected their Existence then is Demonstrable as appear'd in the Pericardium of an Infant I lately Dissected where the Neighbouring Parts and Pericardium its self were Apostumated In the Pericardiums of this Subject we found Two or Three Ounces of Purulent Matter in place of the Serous Humor and the External Membrane of the Heart so loosned as its Surface appear'd Villous nor did any Fat appear on the Basis of the Heart In an Adult Person who Died suddenly I found the Pericardium somewhat Thickned and no Humor contain'd in it but in Two or Three Places cleaving to the Heart especially near its Basis and the Heart it self intirely cover'd with Fat The Use of the Pericardium is to defend the Heart in its Systole from the Neighbouring Parts and to contain a Humor to Moisten the External Surface of the Heart E The Heart lying within the Pericardium F F Parts of the Lungs on both Sides the Thorax in Situ G The Thymus in Situ The Magnitude of the Thymas varies according to the Age of the Body in a Faetus Two Months after Conception it is larger in Proportion to the Bulk of the
Scutiformal Cartilage I O The Fore-part of the Cartilago Annularis made bare Fig. 6. The Back-part of the Larynx and its Muscles plac'd on it Exprest very Confusedly which together with the former Figure is Erroneously describ'd by Bidloo F F G K L M P Q Should Express the Back-part of the Cartilago Annularis cover'd with the Musculi Cricoarytenoidei Postici as it 's Represented in our Appendix N N The Musculus Arytenoideus O The Internal and Concave Part of the Epiglottis as it appears when Pinn'd up R The Posterior Edge of the Scutiformal Cartilage of the Right Side S The Membranous Part of the Wind-Pipe next the Gula. Fig. 7. The Os Hyoides or Bone of the Tongue together with the Fore-part of the the Cartilages which compose the Larynx and Part of the Aspera Arteria A The External and Convex Part of the Cartilago Scutiformis B The Internal and Concave Part of the Os Hyoides which Part of it necessarily comes in View in this Position C The Annular Cartilage D The Epiglottis Exprest with the Internal Concave Part Forewards as is truly Exhibited in the following Figure which on the contrary should have been here Represented with its External and Convext Part as in Fig. 5. F. E Part of the Aspera Arteria or Wind-Pipe F F The Glandulae Thyroideae From what I have hitherto observ'd these Glands seem to be of the same Office with the Thymus Nor do's their Colour or Compactness distinguish them from the Thymus if we consider that by their Situation on the Wind-Pipe they are perpetually in Motion by which the Motion of the Blood is very much hasten'd thro' them and the Blood-Vessels consequently Enlarg'd whence their Colour and Compactness do's Arise G G Two long Processes of the Thyroide Cartilage or Scutiformis ty'd to the Extremities of the Os Hyoides Fig. 8. The Os Hyoides and Back part of the Larâ—yx A The External Convext Part of the Os Hyoides This Bone of the Tongue appears in this preceding Figure to be compos'd of Three Bones the Middle-Bone A is joyn'd to One of the Extremities of the Two Side-Bones by a Cartilaginous Interposition call'd Sychondrosis the Two other Extremities of these Side-Bones are ty'd to the Extremities of the Two long Processes of the Thyroide Cartilage G G Fig. 7. by a Ligament which Connexion is call'd Syndesinusis B The Internal Concave-part of the Epiglottis next the Glottis C C The Arytenoidal Cartilages cover'd with the Glottis or Internal Membrane of the Oesophagus D The Cricoidal Cartilage cover'd with the Internal Membrane of the Oesophagus which composes the Glottis E E The Two Sides or Back-part of the Thyroidal Cartilage whence the Musculus Oesophageus do's Arise which Muscle in a Semi-circular Manner Invests the Back-part of the Oesophagus F F The Back-parts of the Thyroidal Glands G The Posterior-part of the Wind-Pipe where it is Membranous and receives the Fore-part of the Gula in its way to the Stomach Having View'd the Fore and Back-parts of the whole Larynx we come in the next place to Examine those Cartilages which Compose it when Separated from each other 1 The External Convext-part of the Thyroidal Cartilage 2 The Internal Concave-part of the same Cartilage In these Two Figures the Two Kinds of Processes of the Thyroidal Cartilage are Remarkable the Two Superior or long Processes are joynd with the Extremities of the Os Hyoides G G Fig. 7. the Two Inferior are fastned to the Cricoidal Cartilage Laterally 3 4 The Cricoidal Cartilage 3 the Fore-part 4 the Back-part of this Cartilage That Figure of the Right Hand towards the Figure of the Lungs and Heart Expresses the External Inferior and Back-part of the Annular Cartilage That of the Left Hand Represents the Inferior Internal and Fore-part of the Annular Cartilage 5 6 5 6 Two different Views of the Arytenoidal Cartilages which are Articulated to the Superior Part of the Cricoidal Cartilage THE TWENTY-FIFTH TABLE Fig. 1. A Portion of the Wind-Pipe cut off A B B The External Membrane of the Wind-Pipe Rais'd and Pinn'd out Fig. 2. The Muscular Fasciculi lying between the Cartilages of the Wind-Pipe Fig. 3. The Glandulous Membrane of the Wind-Pipe where divers Clusters of Glandules of a different Magnitude are Exprest Fig. 4. The Internal Membrane of the Wind-Pipe compos'd of Fibres extended according to its Length between this Internal and Longitudinal Order of Fibres and the Cartilages are plac'd another Transverse Order which pass Circularly according to the Disposition of the Cartilages These Internal Transverse Fleshy Fibres are more Numerous than the Superior Longitudinal Ones Both these Orders of Fibres are Exprest in this Figure This Disposition of the Fibres of the Internal Membrane of the Wind-Pipe is very Conspicuous in the Wind-Pipes of most Quadrupedes especially in the Larger sort as Oxen Horses c. But chiefly considering the Bulk of the Animal in a Hog in whose Wind-Pipe this Membrane appears compos'd of Strong Fleshy Fibres whence an Account may not improbably be suggested why that Animal is capable of altering the Tone of the Voice from a Base to a Treble For when these Fibres Contract the Channel of the Wind-Pipe is very much Straitned as well in its Diameter as Length whence the Tone is rendred more Acute This Constructure of the Inward Membrane of the Wind-Pipe is continued to the Beginning of the Bronchia where these Fleshy Fibres lessen and bear a Proportion to the Cavities of the Bronchia and are at length so Thinn'd as to Frame Transparent Membranes which help to compose the Vesiculae of the Lungs Fig. 5. Part of One of the Lobes of the Lungs with the Bronchia Injected with Wax to exhibit the Lobuli A Part of the Bronchial Tube cut off B B The Lobuli or distinct Clusters of the Vesiculae partly compos'd of the Extremities of the Bronchia and partly of the Blood-Vessels of the Lungs These Lobuli are not always of the same Figure some being Round others Oval some Oblong and others Variously Figur'd C C The Interstitia of the Lobuli which are Invested with the Internal Lamina of the Proper Membrane of the Lungs here Pinn'd out on which the Blood-Vessels are very Conspicuous These Interstitia or Spaces between the Lobuli Appear in the Lungs of a Foetus very plain and do not Communicate with the Vesiculae of the Lobuli but are distinguish'd from them as do's Appear by Blowing into these Interstitia which may be done with a Blow-Pipe after Wounding the External Membrane of the Lungs and you will find the Interstitia of the Lobuli very much Distended with Wind and the Vesiculae not at all Inflated Nor on the Contrary will these Interstitia be any ways Inflated by Blowing into the Bronchia tho' the Vesiculae and Lobuli are very much Extended D D The Branches of the Pulmonick Vein and Artery on each Side the Bronchia See Fig. 10. A B. Fig. 6. Part of the Bronchia with divers
Parts proper for its further Elaborations Respiration or Breathing is a double Action i. e. Inspiration or Receiving of Air into the Lungs and Expiration or Expelling it again The whole is done by means of Widening and Straitning the Cavity of the Thorax in which the Lungs are contain'd How the Cavity of the Thorax may be Enlarged and Contracted we may easily conceive if we consider the Order of its Bony Parietes Tab. 27 and 28. and observe the Oblique Descending Position of the Ribs from the Vertebrae of the Back with their Cartilaginous Connection to the Os Pectoris and the Position and Action of the Diaphragm as is explained Tab. 52. whence it appears when the Ribs are drawn up and the Superior Convex Surface of the Diaphragm deprest towards a Plain the Included Space must necessarily be Enlarged and on the contrary very much Straitned when the Ribs are drawn down and the Upper Surface of the Diaphragm Convex towards the Lungs as it is Represented in the last mention'd Table The Elevation and Depression of the Ribs is perform'd by the Proper and Common Muscles of the Thorax The First have their Rise and Termination confined to the Parts Composing its Parietes The Other notwithstanding their Relation to other Parts yet chiefly respect This Of the Common Muscles some are Principal immediately moving This together with those Parts from which they are derived Others are Auxiliary which by moving the Contiguous Bodies Contribute to the better performing the Grand Motion Thus the Elevation of the Shoulder-Blades is required in violent Respirations without which the Musculi Serrati Tab. 20. which spring from the Scapulae Tab. 29. V. W. could not Act hence it happens that Respiration is Interrupted when the Arms are in Action by reason the Scapulae at that time engage all their Muscles especially the Serrati T. 20. to render them Stable and the Extension of the Vertebrae of the Neck becomes necessary to the end the Musculi Scaleni Tab. 18. B B. may Raise the Upper Ribs The Proper Muscles of the Thorax are the Intercostales Externi and Interni Tab. 26. Fig. 1. the Triangulares Tab. and Fig. ead the Serrati Superiores and Inferiores Postici Tab. 28. The Principal Common Muscles are the Scaleni Tab. 18. the Subclavii Tab. 20. the Serrati Majores Minores Antici Tab. ead and the Sacrolumbales Tab. 29. The Auxiliary Muscles are such as Raise the Scapulae and draw them Backwards and those which Extend the whole Spine The Cavity of the Thorax being dilated in the manner above mention'd the Ambient Air necessarily rushes thro' the Aspera Arteria and Bronchia into the Vesiculae of the Lungs whereby their whole Substance becomes Distended and this we call Inspiration In Expiration the Air contain'd in the Vesiculae of the Lungs is Excluded in this Action the Lungs are not meerly Passive as in the Former but the Elasticity of the Ligaments of their Bronchia draw their Small Cartilages over each other and Conduce to the Expulsion of the Air contain'd in their Vesiculae This Alternate Diastole and Systole of the Lungs and Thorax bears an Analogy to a Pair of Bellows whose Two Boards being drawn from each other the Ambient Air necessarily rushes in between them and Fills the Internal Space enlarg'd by the Deduction of their Sides which Air is again Expell'd from thence by Approaching them towards each other The Inducements the Author of Nature had to Frame this Pulmonary Organ are many by this the Aerial Particles pass to the Mass of Blood which Rarifie Subtilize and render it fit for those Elaborations it afterwards undergoes By these the Tenacious Serum of the Blood is Attenuated and the whole Mass rendred fit for Motion the Effects of which are Evident in those Rhumatick Asthmas and other Cases which Oblige some to leave this Town for a Clearer Air. The Lungs are the Intermediate Passage between the Two Ventricles of the Heart whereby the whole Mass of Blood passes thro' their Large Blood-Vessels in an equal Rapidity and Quantity with that of all other Parts of the Body besides and do by this means discharge the Blood of a great Quantity of its Serum by Halitus in Expiration wherefore the Accurate Dr. Tyson Reckons them among the Number of Glands This Alternate Action in which Respiration consists is Necessary to the End the Blood may pass the Lungs whose Vesiculae if they were constantly Distended by the Inspired Air the Extremities of the Pulmonick Blood-Vessels would be Comprest and on the contrary if these Vesiculae were Collaps'd as after Expiration their Blood-Vessels would be consequently Corrugated but by this Vicissitude they become Permeable and the Blood easily passes their Extremities We have Traced the Aliment from its First Reception till it is Elaborated into Blood and pursued in its Motion and Circulation thro' its several Channels We ought next to take a View of the several Liquors or Fluids separated from it in its Tour. All Animal Juices except the Chyle are separated from the Arterial Blood which common Material in its Percolation in the Brain and Nerves yield the Contents of their Fibres in the Glands of the Mouth and Throat the Saliva in the Mammae the Milk in the Kidneys the Urine in the Testes Sperm not to name the Sweat Mucilage of the Joints c. and thro' the Universal Body a Copious Quantity of Lympha which is not applied to any distinct Use in the Animal Oeconomy but is all discharg'd into the Great Cystern or Receptacle of the Chyle and Subclavian Vein and so Refunded into the Refluent Blood The Doctrine of Secretions is the last and only remaining Part of those Natural Functions which are directed to the Preservation and Subsisting of the Individual For the Nature and Properties of these Liquors their Use and Office and the peculiar Structure adapted for the Percolation of one and excluding the rest we must remit the Reader to the Description of the Organs themselves contenting our selves here with the Theory of the Origin of the Lympha and Secretion in General The Knowledge of this Animal-liquor call'd Lympha and the Ducts which Convey it is owing to the Industry and Searches of this present Age. But whether Rudbeck Bartholine or our Countrey-man Dr. Iolive ought to carry the Honour of the Discovery I shall not pretend to decide But the Rise Course and other particular Circumstances needful to inform us of their Use and the Design of Nature in the Fabrication of these Ducts has not been hitherto at least fully Demonstrated Some have pretended to derive these Ducts from the Nerves others from the Membranes or Tendinous Parts of the Muscles but these are Impertinencies scarce worth a serious Refutation The diligent Melpighius in his Epistle to the Royal-SocÃety is follicitous in enquiring whether they are not Excretory-ducts to Export the Juice Secreted in the Conglobate Glands since there is none of these Glands so inconsiderable to be
Lobuli of One of the Lobes of the Lungs Dr. Willis who has given a Figure of these Lobuli after the Manner as they are here Represented says that by filling the Bronchia with a Liquid these Lobuli may be separated from each other I must confess I have more than once Attempted to Divide these Lobuli but could not be satisfied of their Appearance like this Figure The External Surface of the Lobuli in the Foetus Appear Angular and are in a Cubical manner plac'd by each other A The Inside of the Bronchia where the Holes for divers of its Ramifications which pass out of it and the Straight Progress of the Fibres of its Internal Membrane do Appear B B The Bronchia divided into lesser Branches to which the Lobuli are Fastned C C The Lobuli which may be more or less Divided and are compos'd of the Vesiculae The Vesiculae as above hinted are Fram'd by the Extremities of the Bronchia and the Pulmonick Blood-Vessels N. B. The Lobuli in this Figure may be observ'd to have the Extremities of the Blood-Vessels Branch'd on Them Each Vesicula also has One of the Extremities of the Pulmonick Veins and Arteries Branch'd on it and without doubt Conformable to the Extremities of the Blood-Vessels of other Parts those Vessels also are continued Channels on the Vesiculae of the Lungs Here the Art of Nature is very Extraordinary in Framing the Extremities of these Blood-Vessels of the Lungs so very small and confining their vast Number in so narrow a Compass as the Body of the Lungs for these Pulmonick Blood-Vessels Correspond to those of the whole Field of the Body in constantly ' Discharging the Blood thro' them as well as thro' the Heart whilst Life with perfect Health is maintain'd And notwithstanding One Half of the Lungs is compleatly Vitiated as I have more than once found in Dissecting Morbid Bodies yet nevertheless the Circulation of the Blood has been still carried on for some time Tho' in this Case Respiration must not only be very Quick and Attended with no small Difficulty on frequent Occasions but the Heart must also Labour very much to drive the Blood on Fig. 7. A Portion of the External Surface of the Lungs cut from them when Dri'd after Inflation A A The External Membrane B B The Lamellae of the External Membrane which pass between the Vesiculae and compose the Lobuli between which the Interstitia necessarily Result C D The Lobuli compos'd of the Vesiculae which are here well Exprest Fig. 8. The Aspera Arteria or Wind-Pipe together with the Bronchus or Ramifications of it free'd from the Lungs A A The Fore-part of the Wind-Pipe B B The Division of the Wind-Pipe into Two Branches and afterwards into more call'd Bronchus C C The Larger Branches of the Bronchus D D The Lesser from whose Extremities the Vesiculae are Pull'd off E E The Semicircular Cartilages of the Wind-Pipe F G H The Cartilages of the Bronchia of Various Figures and Sizes some of which are Circular F F others Semicircular Triangular G Quadrangular c. H. These Cartilages of the Bronchus are not Connexed to each other like those of the Wind-Pipe it self but the Lower-parts of the Superior receive the Upper-parts of the Inferior not unlike the Crustaceous Coverings of the Locusts or Tail of a Lobster so that in Inspiration the Bronchus may be Coextended with the Tumified Lungs for these Ligaments between the Cartilages of the Bronchus have an Elastick Power of Restitution not unlike that strong Ligament plac'd on the Spines of the Vertebrae of the Necks of Quadrupedes by which means the Superior Parts of the Lower Cartilages of the Bronchus are drawn under the Inferior Parts of the Upper in Expiration But in Inspiration the Ligaments are Extended and the Inferior Cartilages are with-drawn from under the Superior and to this Action in Expiration the Longitudinal Fibres of the Wind-Pipe which pass into the Bronchus do concur to Contract them In Inspiration the Weight of the Superincumbent Air is sufficient to Extend the Bronchus and consequently the Lungs when the Cavity of the Thorax is Widen'd by the Muscles which Draw the Bibs up Fig. 9. A small Portion of the Lungs whose Bronchial Branch is fill'd with Injected Quick-Silver A The Bronchial Branch on both Sides of which the Pulmonick Blood-Vessels Appear Fig. 10. Part of the Largest Branches of the Bronchus free'd from One of the Lungs together with the Pulmonick Blood-Vessels and Lobes Injected with Wax A A The Pulmonick Vein B B The Artery fill'd with different Colour'd Wax Besides freeing the Bronchia as in Fig. 8. there is another way of Demonstrating their Ramifications by pouring of Melted Tin into them which may be Practis'd in the following Manner Cut off one Side of the Humane Lungs at the Division of the Trachea B B Fig. 8. and with the Feather End of a Goose-Quill so wipe the Inside of the Bronchia by often thrusting it into their Various Ramifications that at length it no longer comes out wet with the Mucus they have in them The Insides of the Bronchia being thus throughly Dri'd with a Feather In like Manner Anoint them with Linseed Oyl This done Tye the Mouth of the Divided Trachea to a Tin or Iron Tunnel This Tunnel must be so plac'd that the Lungs may hang Pendulous and Free but least their Flaccidity should too much Compress the Bronchia it 's convenient to pass divers Threads thro' the External Parts of the Lungs and so Fasten them to the Floor and other convenient Places that the Lungs may be Extended thereby In doing of which be sure you do not distort the Lungs from a direct Pendulous Position but that the large Trunk of the Bronchia remains Perpendicular to the Tunnel This done Melt Block-Tin and pour it into the Tunnel in doing of which stand at some Distance least the Conflict which arises from the hot Metal in its meeting with the remaining Moisture in the Bronchus scatters it on your Hands or Face c. N. B. If the Metal is made very hot it will so Scorch the First Passages of the Bronchia as to Contract them and thereby Obstruct the rest Nor must it want Fluidity least its passing into the smaller Branches is thereby Hindred The Bronchus being thus Injected in the Lungs lay them in Water Nine or Ten Days till they begin to Putrifie then Boyl the whole Lungs off the Block-Tin and you may expect to see it much fuller of Branches than it 's Exprest in the 11 th Figure Fig. 11. Represents the Ramifications of the Bronchia in Block-Tin as above Describ'd THE TWENTY-SIXTH TABLE Fig. 1. THE upper Part of the Body lying in a Supine Posture with the Os Pectoris or Sternum rais'd together with the Cartilages of the Ribs which are connexed to it so that the Cavity of the Thorax after its Viscera are remov'd comes in view A A A The Cavity of the Thorax invested with the