The Economy of the Animal Kingdom, Considered Anatomically, Physically, and Philosophically

By Emanuel Swedenborg, late Member of the House of Nobles in the Royal Diet of Sweden; Assessor of the Royal Metallic College of Sweden; Fellow of the Royal Academy of Sciences of Upsala, and of the Royal Academy of Sciences of Stockholm; Corresponding Member of the Imperial Academy of Sciences of St. Petersburg.

Translated from the Latin by the Rev. Augustus Clissold, M.A.

Paucis natus est. Qui populum aetatis sucae: multa annorum millia, multa populorum supervenient: ad illa respice, etiamsi omnibus tecum viventibus silentium ... [aliqua causa] indixerit: venient, qui sine offensa, sine gratia judicent. (SENECA, Epist. 79.)

Contents of First Volume (Part I.)

Introduction 1

Chapter I. The Composition and Genuine Essence of the Blood. 29

Chapter II. The Arteries and Veins, their Tunics, and the Circulation of the Blood. 116

Chapter III. On the Formation of the Chick in the Egg, and on the Arteries, Veins, and Rudiments of the Heart. 241

Chapter IV. On the Circulation of the Blood in the Foetus; and on the Foramen Ovale and Ductus Arteriosus belonging to the Heart in Embryos and Infants. 316

Chapter V. The Heart of the Turtle. 372

Chapter VI. The peculiar Arteries and Veins of the Heart, and the Coronary Vessels. 387

Chapter VII. The Motion of the Adult Heart. 460

Contents Of Volume Two (Part II.)

Chapter I. On the Motion of the Brain; showing that its Animation is coincident with the Respiration of the Lungs. 653

Chapter II. The Cortical Substance of the Brain specifically. 721

Chapter III. The Human Soul. 860

Index of Authors, List of Unverified Citations, Bibliographical Notices of Authors 1020

Appendix

1020. BIBLIOGRAPHICAL NOTICES OF AUTHORS CITED IN "THE ECONOMY OF THE ANIMAL KINGDOM".

THE remarks prefixed to the corresponding "Notices" in the "Animal Kingdom," Vol. II., p. 698, may be repeated here. When an author is mentioned in those "Notices," his name alone is given in the present account, with a reference to the "Animal Kingdom;" or such of his works as come under our plan, and are cited in the "Economy" and not in the "Animal Kingdom," are specified.

ARISTOTLE, "the chief philosopher of the Gentiles" (Swedenborg, Econ. A. K., Vol. II., p. 240), born at Stagira, B. C. 884, died at Chalcis, B. C. 822. The edition of Aristotle made use of in the present translation, is that of Du Val, 4 vols., folio, Paris, 1654. The annexed bibliographical account is borrowed from the article "Aristotle" (by F. A. Trendelenburg, translated by George Long), in the "Biographical Dictionary of the Society for the Diffusion of Useful Knowledge."

"The following are the most important editions of all the works of Aristotle:

"The Editio Princeps, which has the value of a MS., is the Aldine, called Aldina Major, printed at Venice, by Aldus Manutins, 1496, 1498, 5 vols. fol. It is well printed, and was scarce even in the time of Erasmus. Certain small variations show that this edition was printed twice (Dr. Postolaka, in the Zeitschrift Wiener Jahrboecher, 1831, 26 Heft). The edition of Basle contains the emendations of Simon Grynaenus, and the preface of Erasmus; Basle, 1631, fol. The second Basle edition belongs to the year 1639; and the third, on which both Conrad Gesner and Grynceus were employed, to 1650. The Aldina Minor was edited by J. B. Camotius, whence it is else called Camotiana, Venice, 155-163, 6 vols. 8 vo.

"The Frankfort edition by F. Sylburg has some critical notes and indexes; it is well printed, and justly valued; Frankfort, 1684, 1587, 11 vols. 4 to. The edition of Isaac Cassaubon, besides some various readings and emendations printed on the margin, contains the Latin translation by several hands; Lyons, 1690, fol., Geneva, 1605, fol. The edition of Du Val contains the Latin version; Paris, 1619 and 1629, 2 vols. fol.; 1639, 4 vols. fol. Du Val was physician and councillor to Louis XIII. of France. He has added a view of the Peripatetic philosophy, and of the writings of Aristotle. The edition of Buhle contains valuable literary notices in the first volume; but it was never finished. Only five volumes 8 vo. appeared; Deux Ponts, 1791-1800.

"The most important edition for the text of Aristotle is that of Immanuel Bekker or of the Berlin Academy, Berlin, 1831, 1836, 4 vols., 4 to. The first two volumes contain the text, which is established on the collation of numerous manuscripts, but no use has been made of those older readings which may be derived from the Greek commentators on Aristotle. The third volume contains the Latin translations of the works of Aristotle. The fourth volume is entitled 'Scholia in Aristotelem. Collegit Christianus Augustus Brandis, edidit Academia Regia Borussica, 1836, 4 to.:' it contains excerpts from the commentaries on Aristotle, chiefly Greek, printed and unprinted, and is very useful for the understanding of the text. A fifth part, which is to be a continuation of the Scholia, is still expected.

" ... Further information on the editions of Aristotle, and of his several works, may be found in Buhle's edition, vol. i., p. 210, and company.; Hoffman's Lexicon Bibliographicum; and Aristotle, De Anima, by Trendelenburg, Jena, 1833, Preface, p. 17, and company."

For particulars respecting the life and philosophy of Aristotle, the reader is referred to the above mentioned authority, or to the article "Aristotle" in Smith's "Dictionary of Greek and Roman Biography and Mythology."

BAGLIVI, GEORGE, an Italian physician, born in 1668, according to Haller at Ragusa, according to Nicholas Comnenus, at Lecce, a town of Otranto, in the kingdom of Naples, died at Rome in 1706, or 1707.

I. His "Dissertatio de Experimentis per infusoriam in vivis animalibus," was published with his work, "De Praxi Medica," 8 vo., Rome, 1696; 8 vo., Lyons, 1699; in English, 4 to., 1703; 8 vo., 1723.

II. "Specimen quatuor Librorum de Fibra Motrice et Morbosa" 4 to., Perousa, 1700; 4 to., Paris, 1700; 12 mo., Rome, 1702; 8 vo., Utrecht, 1703; 8 vo., London, 1703; 8 vo., Basle, 1703; Altorf, 1703.

III. "Dissertationes varii Argumenti," 8 vo., Leyden, 1707; 8 vo., 1710. The complete works of Baglivi were also published, viz., "Opera Omnia Medico practica et Anatomica," 4 to., Lyons, 1704, 1710, 1716, 1746; Paris, 1711; Antwerp, 1716; Basic, 1737; Leyden, 1744; Venice, 1738, 1764; and by Pinel, with notes, corrections, and a preface, 2 vols. 8 vo., 1788. Baglivi is esteemed the father of modern "solidism," which in general attributes the primary morbid affections of the body to the solids rather than to the fluids. It appears, however, that be did not intend to banish the humoral pathology (fluidism) from medicine, but to counterbalance it, and prevent its undue application. Some of the positions on which his solidism is grounded appear to be questionable as axioms of physics. Thus he says: "Solido major, quam fluido, vis inest et resistentia." (De Fibr. Motr., lib. i., cap. vii.) and again: "Evidenter patet corpus solidum continuum, partibus duris et resistentibus compositum esse magis aptum conservadi propagandique motum sibi impressum, quam moles fluida clausa intra canales, et composita minimis contiguis, mollibus," and company. (Ibid., cap. ix.) These statements are hardly countenanced by the tenor of modern art and science. In general the works of Baglivi display great powers of observation and grasp of mind. He discarded the hypotheses prevalent in his age, and betook himself to the writings of Hippocrates, "the Romulus of physicians, who speaks in the language of nature, and not of man." (De Praxi Medicoe, lib. i., cap. i., mon. iv.) He was also a diligent student and close follower of Lord Bacon, whose style of writing he imitated with great erectness in his works. And he coincided with Bacon in adopting the aphoristic manner of delivering the sciences (as Hippocrates had also done), in preference to the methodical. (Ibid., lib. i., cap. ix.) His observations on the dura mater as a moving power in the brain and the body, and the experiments which he instituted to bear out his views, occasionally brought him near the verge of that grand peculiarity of Swedenborg's theory, the alternate animation of the Grain.

BAHTHOLIN, THOMAS. (Animal Kingdom, Vol. II., p, 699.)

BELLINI, LAURENCE, an Italian physician and anatomist, born at Florence in 1643; died at the same place in 1704. "Opuscula Aliquot ad Archibald. Pitcairn, de Motu Cordis," 4 to., Pistoya, 1695; 4 to., Leyden, 1696, 1714, 1737.

BIDLOO, GODFREY. (Animal Kingdom, Vol. II., p. 600.)

BOERHAAVE, HERMANN. (Animal Kingdom, Vol. II., p. 600.) "Aphorismi de Cognoscendis et Curandis Morbis, in usum Doctrinae Domesticae," 12 mo., Leyden, 1709, 1716, 1728, 1734, 1742; 12 mo., Paris, 1720, 1726, 1728, 1747; 12 mo., Louvain, 1751; in English by J. Delacoste, M. D., 8 vo, London, 1716.

CALDESI, J. BAPTISTA, a native of Arezzo in Tuscany. His book on the Turtle and Tortoise, "Osservazioni anatomiche intorno alle Tartarughe marittime, d'Acqua dolce, et Terrestri;" 4 to., Florence, 1687, is described by Haller as an excellent work, entirely based upon facts: and the same authority says that it would not be easy to name another animal, of the anatomy of which we possess an equally good account.

COLUMBUS, REALDUS, an Italian anatomist of the 16th century, born at Cremona in the Duchy of Milan, died about 1677. His work, "De Re Anatomica libri xv.," was published at Venice, fol., 1869; 8 vo., Paris, 1662, 1172; 8 vo., Frankfort, 1590, 1593, 1699 (the two latter editions enriched with anatomical observations by J. Posthius); also 8 vo., Leyden, 1667. Realdus Columbus was a pupil of Vesslius, and according to Haller was among the first who described the alternate dilatation and constriction of the brain; but which he says are coincident with the motions of the heart.

EUSTACHIUS, BARTHOLOMAEUS. (Animal Kingdom, Vol. IL, p. 601.)

FANTONI, JOHN. (Animal Kingdom,V01. II., p. 602.) His Epistle to Pacchioni, which is so often quoted by Swedenborg in the present work, is printed in the various editions of Pacchioni's "Opera:" in the Translation we have made use of Ed. 4, Rome, 1741. See Pacchioni.

GROTIUS, HUGO, or HUGO DE GROOT, one of the most celebrated of Dutch writers, born at Delft in Holland in 1583, died at Restock in Mecklenburg in 1645. His work, "De Veritate Religionis Christianae," was published at Leyden, 8 vo., 1627 and 1629: with the author's Notes, 8 vo., Paris, 1640; 12 mo., Leyden, 1640; Paris, 1660; with an arabic version by Pocock, 8 vo., Oxford, 1660; 12 mo., 1678; 12 mo., Amsterdam, 1662, 1669; 8 vo., Ibid., Elzevir, 1674; also 8 vo., 1709; 2 vols. 8 vo., Jena, 1726. This work has been translated into nearly all the European languages, as well as into arabic and Persian: and many times into English, in which it has gone through numerous editions.

GULIELMINUS, DOMINICUS (GUGLIELMINI DOMINICO). An Italian writer on mathematics end medicine, born at Bologna in 1665, died at Padua in 1710. "De Sanguinis Natura et Constitione exercitatio physico-medica," 8 vo., Venice, 1701; 8 vo., Utrecht, 1704: also in the author's "Opera Omnia," 2 vols. Ho., Geneva, 1719 and 1740, edited by Morgagni, who appended to his edition an account of the author's life.

HARVEY, WILLIAM, an English physician, and the discoverer of the circulation of the blood, born at Folkstone, in Kent, in 1578, died in 1658.

I. "Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus," 4 to., Frankfort, 1628; 4 to., Leyden, 1639 and 1647; 12 mo., Padua, 1643; fol., Amsterdam, 1645; 4 to., Leyden, 1647; 12 mo., Rotterdam, 1648, 1661, and 1671; fol., Geneva, 1685; 12 mo., Glasgow, 1751, and in Manget's "Bibliotheca Anatomica." In English, 8 vo., London, 1653.

II. "Exercitationes de Generatione Animalium," and company., 4 to., London, 1651; 12 rno., Amsterdam, 1651 and 1662; 12 mo., Padua, 1666; 12 mo., the Hague, 1680; and in Manget's "Bibliotheca Anatomica." In English, 8 vo., London, 1683.

III. "Opera Omnia," 2 vols. 4 to., Leyden, 1737: best edition, by the London College of Physicians, with Life of the Author in Latin, by Dr. Lawrence, 2 vols. 4 to., London, 1766. In speaking of Harvey, Haller observes, that "out of that very England, in which hitherto anatomy had scarcely an existence, a new light of the art arose, whose name is only second in medicine to that of Hippocrates."

HEISTER, LAURENCE. (Animal Kingdom, Vol. II., p. 602.)

LANCISI, JOANNES MARIA. (Animal Kingdom, Vol. II., p. 603.) His "Epistola de Gangliis Nervorum" was published with Morgagni's "Adversaria Anatomica V." according to Haller, Lancisi maintains that the ganglia serve as cerebella to the voluntary motions.

LEEUWENHOEK, ANTONY VON. (Animal Kingdom, Vol. II., p. 603.)

LITTRE, ALEXIS, a French anatomist, born at Cordes in 1658, died in 1725. Littre is the author of no separate work, although he was a laborious cultivator of the sciences, and his whole life was absorbed in their pursuit. His papers were published at intervals in the "Hist. de l'Acad. Roy. des Sciences de Paris," from 1691, but principally from 1700 to 1720. Those on the foetus and the foetal circulation are contained in the above Transactions for the years 1700, 1701, 1709.

LOWER, RICHARD, an English physician and anatomist, born in Cornwall in the early part of the 17th century, died in 1690 or 1691. His "Tractatus de Corde, item de Motu et Colore Sanguinis, et chyli in eum transitu," was published in London, 8 vo., 1669, and again in 1680; 8 vo., Amsterdam and Leyden, 1708, 1722, 1728, 1740, 1749; and in Manget's "Bibliotheca Anatomica." This is the author's chief work.

MALPIGHI, MARCELLUS. (Animal Kingdom, Vol. II., p. 604.) "Appendix De Ovo Incubate," Bologna, 1672; London, ; and in the author's "Opera Omnia." Haller states that the descriptions in this tract are somewhat more accurate than those in its predecessor, "De Formations pulli in ovo," and company. (See a note in the Economy of the Animal Kingdom, Vol. I., p. 209.)

MAGNET, JOHN JAMES. (Animal Kingdom, Vol. II., p.604.) Manget's "Theatrum Anatomicum" and "Bibliotheca Anatomica" assume an importance for the translators of Swedenborg's physiological works and manuscripts, from the fact that the latter has often borrowed his citations of the anatomists from these compilations, and not from the original sources. And this accounts for certain interpolations, omissions, and company, with which Swedenborg appeared to be chargeable. It is to be observed that Manget's works are not remarkable for correctness.

MERY, JOHN, a French surgeon and anatomist, born at Vatan in 1645, died in 1722. "Nouveau Systems de la Circulation du sang par le trou ovale dens le fetus humain, avec les responses aux objections de MM. Duverney, Tauvry, Verheyen, Sylvestre, et Bussiere." 12 mo., Paris, 1700.

MORGAGNI, JOHN BAPTISTA. (Animal Kingdom, Vol. II., p. 604.)

MUNNICKS, JOHN, a Dutch physician and anatomist, born at Utrecht in 1662, died in 1711. "De Re Antomica liber," 8 vo., Utrecht, 1697; in Dutch, Amsterdam, 1740. This is a short but well written work, and contains many original observations.

NEEDHAM, WALTER, an English physician, died in 1691. "Disquisitio Anatomica de Formato Foetu," 8 vo., London, 1667; 12 mo., Amsterdam, 1668; and in Manget's " Bibliotheca Anatomica."

NUCK, ANTONY. (Animal Kingdom, Vol. II., p. 605.) "Observationes et Experiments Chirurgica," 8 vo., Leyden, 1692, 1696, 1714, 1733; 8 vo., Jena, 1698; with his "Sialographia" and "Adenographia," 12 mo., Lyons, 1722; and in his "Opera Omnia," 2 vols., Leyden, 1733.

PACCHIONI, ANTONY, an Italian physician, born at Reggio, in the Duchy of Modena, in 1664, died at Rome in 1726. His works consist of a number of short dissertations, principally upon the anatomy and physiology of the dura mater. These were collected and published; viz., "Opera," Ed. 4, 4 to., Rome, 1741.

REVERHORST, MAURICE VAN. (Animal Kingdom, Vol. II., p. 606.)

RIDLEY, HENRY, an English anatomist.

I. "The Anatomy of the Brain, containing its mechanism and physiology," 8 vo., London, 1695; in Latin, by M. E. Ettmuller, and (1706) in the L'Eph. Net. Our.," dec. iii., app.; and in Manget's "Bibliotheca Anatomica;" also at Leyden, 8 vo., 1725, under the title, "Anatomia Cerebri complectens ejus mechanismum et physiologism."

II. There is a paper of Ridley's in the "Philosophical Transactions," n. 287, detailing a case of vivisection, in which the systolic motion of the brain was observed to be continued and even increased after the division of the dura mater.

RUYSCH, FREDERIC. (Animal Kingdom, Vol. II., p. 605.)

STENO, NICHOLAS, a celebrated Danish anatomist, born at Copenhagen in 1638, died at Swerin, in the Duchy of Mecklenburg, in 1686. Haller speaks very favorably of Steno's paper in T. Bartholin's "Acta Hafniensia," detailing his experiments in living animals upon the motion of the heart, and styles the experiments, "Optima et utilissima." This paper was reprinted in Manget's "Bibliotheca Anatomica." Steno was pupil to Bartholin and great uncle to Winslow. In 1669 he embraced the Catholic religion, and towards the close of his life became an ecclesiastic and missionary, and was made a bishop by the Pope.

SWAMMERDAM, JOHN (Animal Kingdom, Vol. II., p. 606.)

VALLISNERI, ANTONIO, "Considerazioni ed Esperienze intoro al creduto cervello di Bue impierito, vivente ancor l'animale, presentato dal' Sig. Verney all' Academia Real di Parigi," Padua, 1710.

VALSALVA, ANTONY MARIA, an Italian physician and anatomist, born at Imola, in Romagna, in 1666, died at Bologna in 1723. His work, "De Aure Humana," was published at Bologna, 4 to., 1704; 4 to., Utrecht, 1707; and Ed. 4, "A. M. Valsalvae Opera, hoc est, de Aure Humana et Dissertationes Anatomicae, cum additionibus J. B. Morgagni," 4 to., Venice, 1740; 4 to., Utrecht, 1707, 1717; Geneva, 1716. Haller describes Valsalva as an unwearied and laborious inquirer.

VERHEYEN, PHILIP. (Animal Kingdom, Vol. II., p. 606.)

VIEUSSENS, RAYMOND. (Ibid., p. 607.)

WEPFER, JOHN JAMES, a Swiss physician, born at Schaffhansen in 1620, died in 1695.

I. "Observationes Anatomicae ex cadaveribus eorum quos sustuilit apoplexia, cum exercitatione de ejus loco adfecto," 8 vo., Schaffhausen, 1668, 1676 (the latter edition enlarged by new cases); 8 vo., Amsterdam, 1681, 1724 (the latter edition again enriched with eleven new cases); 8 vo., Leyden, 1734; Venice, 1759.

II. "Historia Anatomica de puella sine Cerebro nata," 8 vo., Schaffhausen, 1665; and in "Eph. Nat. Cur.," dec. i., an. 8., obs. 129; reprinted also in Magnet's "Theatrum Anatomicum." According to Haller, Wepfer stands in the first rank as an inquirer in the whole circle of the medical sciences. And Eloy says, that he was not of the number of those anatomists who have no other power than their eyes; but that he possessed the skill to fathom the causes of things, and to elicit truths from phenomena.

WILLIS, THOMAS. (Animal Kingdom, Vol. II., p. 607.)

WINSLOW, JACQUES BENIGNE. (Ibid., p. 608.)

WOLFF, WOLF, or WOLFIUS, CHRISTIAN, a German philosopher, born at Breslau in Silesia in 1679, died at Halle in Saxony in 1784.

I. "Philosophia prima sive Ontologia, methodo scientifica pertractata, qua omnis cognitionis humanae explicantur," Ed. 2, 4 to., Frankfort end Leipsic, 1736.

II. "Cosmologia generalis, methodo scientifica pertractata, qua ad solidam, inprimis Dei atque naturae, cognitionem via sternitur," 4 to., Frankfort and Leipsic, 1731, Ed. 2, 1737.

III. "Psychologia Rationalis: qua ea, quae de Anima Humana in dubia experientiae fide innotescunt, per essentiam et naturam animae explicantur," 4 to., Frankfort, 1734 and 1740. Swedenborg became acquainted with the "Ontology" and "Cosmology" of Wolff after writing his "Principia," in the last paragraph of which he says, that he had formed and written his theory two years before he saw those works; but that they greatly confirmed him in it; and he admits important obligations to them in the revision of his Treatise; adding that whoever will take the pains to compare his work with those of Wolff, will see that his special principles, in their application to the world and the series of which it consists, are almost exactly coincident with the metaphysical and general axioms of Wolff. And again he says in one of his posthumous works: " July 10, 1733, ... I have seen the 'General Cosmology' of Wolff, who aims to establish the nature of the elements on metaphysical principles alone; this work rests upon very sound foundations. (Itinerarium: sectio prima, p. 21, 8 vo., Tobingen, 1840.) And in a Manuscript preserved in the Royal Academy of Sciences of Stockholm, we find the following, which appears to be a draught of the paragraph before alluded to, but containing additional particulars:

"Comparison of the 'Ontology' and 'General Cosmology' of Christian Wolff, with my 'Principia.'

"I wish to institute a comparison between my 'Principia' and the rules of metaphysics, with a view of enabling me in some measure to judge of the foundations upon which my philosophy and theory repose; and whether their parts are geometrically and metaphysically true, or the contrary. There is no better source for this test, then the 'Cosmology' of the learned Christian Wolff, who may justly be styled a true philosopher, since he has drawn out the principles of a true philosophy with unwearied care, scrutiny, end elaboration, and teaches them metaphysically and in the most regular order, and at the same time scientifically and by experiment. Let us see then whether there be consent between us, or any dissent. In rational philosophy Wolff treats admirably of the mode of philosophizing. 'The liberty of philosophizing,' says he, 'should be allowed to those who philosophize in a philosophical manner; and from this concession, no danger need be apprehended either for religion, virtue, or the state.' again he says: 'Without liberty in philosophy, progress in knowledge is impossible.' And further: 'a place must be granted in philosophy to philosophical hypotheses, inasmuch as they prepare the way for discovering the real truth.' And again: 'If any one philosophize in a philosophical manner, he has no need to refute opposite opinions.'"

The Biographers of Swedenborg state that he corresponded with Christian Wolff. It is certain that much of the terminology of Wolff is to be found in the "Economy" and "Animal Kingdom;" and perhaps an investigation of Wolff's books would in some cases conduct us to approximate definitions of Swedenborg's terms.

116. CHAPTER II. THE ARTERIES AND VEINS, THEIR TUNICS, AND THE CIRCULATION OF THE BLOOD.

VERHEYEN. "The tunics of the larger arteries are four in number; but the parietes of the minute branches are so thin that they appear to be composed rather of a single tunic than of four.... The external tunic of the arteries ... has nervous twigs ramifying and winding over it in different directions, and is covered by an extremely dense and as it were retiform texture of vessels of every description, but the chief of which are blood vessels; as is best shown in the bodies of those who have recently died without loss of blood. To this retiform or vascular tunic succeeds a second, which is properly termed the glandular tunic, because it is beset throughout by minute whitish glands. This second tunic is very thick, and may be readily separated into several layers, and exhibits also in the larger arterial trunks a number of small vessels. The third tunic, reckoning from without, is muscular or fibrous, consisting of annular fibres set thickly together. These fleshy and motive fibres surrounding the arterial tube, are not disposed in a thin and single series, as in the venous coat, but aggregated and superimposed one upon another, so as to constitute a membrane of considerable thickness. The fourth and internal tunic is the thinnest, end is almost entirely membranous, or if you prefer the term, nervous. Its fibrillae extending longitudinally, out the annular fibres of the preceding tunic at right angles. In the neighborhood of the heart these fibres are thicker and as it were fleshy.. ..

"The tunics of the veins are almost of the same structure with those of the arteries, but thinner, and arranged in a different order. Thus the membranous tunic, formed of various fibres running lengthwise, is the first; but its fibres do not lie parallel, as in the fourth arterial tunic, but often intersect each other. The second tunic is vascular, like the first tunic of the artery. The third is glandular, like the second of the artery. The fourth and inmost tunic, like the third tunic of the artery, consists of annular fibres, but thinner, and arranged in a very simple series....

"The vena portae has thicker coats, so as to appear in a measure to be an intermediate between the other veins and the arteries....

"The veins are much larger and more capacious than the arteries.... Nevertheless a much greater quantity of blood flows through the arteries than through the veins, if you except that part of the vena cava that lies between the insertion of the [thoracic or] chyliferous duct, and the right ventricle of the heart. In dead subjects almost all the blood is found collected in the veins, while the arteries are usually empty.... In the cavity of the veins, at different intervals, there are certain very thin, light pellicles, called valves, which at one extremity, namely, toward the smaller twigs, are continuous with the interior venous coat, while at the other [namely, toward the heart] their edges are free....They are frequently found near the divisions of the veins, or the junction of the branches; and sometimes are single, sometimes in pairs, sometimes in triplets, and company. The latter are placed anteriorly and posteriorly with respect to the body, while the former [or the single] have a lateral position; or vice versa. (Corp. Hum. Anat., lib. i., tr. i., cap. iv., p. 13, 15; Bruxell., 1710.)

"If the crural vessels be exposed and tied (for instance, in a living dog), the vein swells up in its narrower part, that is to say, on the side of the ligature farthest from the heart, while the part that is broader and nearest to the heart collapses. The contrary happens with the arteries.

"As it is the office of the venous twigs to receive the blood from the little arteries, so we find that these two sets of vessels constantly either accompany or meet each other: but the larger venous branches are sometimes bound up with the arteries, and sometimes separate from them and indeed not unfrequently the veins mount up over the arteries.... Moreover, not only are blood vessels of different kinds connected with each other, but also blood vessels of the same kind; frequently, that is to say, veins with veins, and arteries with arteries; so much so, indeed, that there are scarcely any considerable twigs running from the same trunk to the same region, but after their division again unite, at any rate by minute anastomoses. Most anatomists have hitherto considered such anastomoses to be confined to the regions of the head and uterus;... but they are beautifully seen externally in the skin of a foetus of six or seven months. (Ibid., p. 12, 13.)

"The circulatory motion or circulation of the blood is as follows. The blood passes from the trunk of the vena cave, and from certain of its branches, into the right ventricle of the heart, in part immediately, in part mediately through the right auricle. From the right ventricle it is expelled by the contraction of the heart into the pulmonary artery, by the little branches of which, distributed through the lungs, it is conveyed into the twigs of the pulmonary vein, and passes along the trunk of this vein to the left cavity of the heart, in part immediately, and in part mediately through the left auricle. From the left ventricle it is expelled by the contraction of the heart into the aorta, and by the ramifications of this vessel is distributed all over the body. That portion of the blood that is neither converted into solid substance, nor into any other matter extraneous to the circulation, passes from the little branches of the aorta into the little branches of the veins, and at length comes back through the trunk of the vena cava to the right ventricle of the heart, from which it started....

"If an artery of a dog be tied, and punctured with a lancet above the ligature on the side next the heart, provided the animal be healthy, the blood will spirt out in a strong jet to the height of several cubits; and if the artery be left open for any length of time, the dog will die from loss of blood. If, however, the puncture be made on the other side of the ligature, very little if any blood will escape. But if a vein be punctured, the contrary will happen: on the side of the ligature next the heart no blood will escape, while on the other side a copious stream will be emitted, although not with such force as when the blood escapee from the arteries....

"The sagacious and penetrating Leeuwenhoek endeavors to prove (Epist. 67) that the blood does not flow more rapidly through the large vessels than through the small. To demonstrate this position he constructed two tubes, and made them communicate with each other by means of smaller tubes, so that all together formed a continuous pipe. He does, in fact, prove that the liquid sent through one of the larger tubes moves with equal rapidity through the other. With respect to the smaller tubes, it is evident, that unless collectively they are of a calibre not inferior to that of the larger tube, the liquid must run through them more rapidly then through the larger....The same most curious inquirer watched through a microscope the circulation of the blood in an eel (Epist. 67), and found it so rapid, that in the space of one hour it amounted to a distance of 288 inches ... or 24 feet.... [From this] he concludes, that in a man the blood circulates from the heart to the extremities of the feet and back again, only twice and two thirds in an hour. And that in the same time it completes four times and a little more than one third of the whole circle, through the extremities of the fingers; eight times to the extremities of the head;... and that within the hour, 14 times the quantity of blood in the body is forced from the heart," and company. (Ibid., lib. ii., tr. iv., cap. iv., p. 263, 269.)