order in which the several parts appear in the chick. He states that the punctum saliens or fœtal heart is the first organ to be seen, and explains that the nutrition of the chick is not only effected by yelk conveyed directly into the midgut, as Aristotle taught, but also by absorption from yelk and white by the umbilical (omphalomescraic) veins; on the fourth day of incubation appear two masses (which he oddly names vermiculus), one of which develops into three vesicles, to form the cerebrum, cerebellum, and eyes, the other into the breastbone and thorax; on the sixth or seventh day come the viscera, and lastly, the feathers and other external parts. Harvey points out how nearly this order of development in the chick agrees with what he had observed in mammalian and particularly in human embryos. He notes the bifid apex of the fœtal heart in man and the equal thickness of the ventricles, the soft cartilages which represent the future bones, the large amount of liquor amnii and absence of placenta which characterize the fœtus in the third month; in the fourth the position of the testes in the abdomen, and the uterus with its Fallopian tubes resembling the uterus bicornis of the sheep; the large thymus; the cæcum, small as in the adult, not forming a second stomach as in the pig, the horse, and the hare; the lobulated kidneys, like those of the seal ("vitulo," sc. marino) and porpoise, and the large suprarenal veins, not much smaller than those of the kidneys (li.–lvi.). He failed, however, to trace the connexion of the urachus with the bladder. In the following chapters (Ixiii.–Ixxii.) he describes the process of generation in the fallow deer or the roe. After again insisting that all animals arise from ova, that a "conception" is an internal egg and an egg an extruded conception, he goes on to describe the uterus of the doe, the process of impregnation, and the subsequent development of the fœtus and its membranes, the punctum saliens, the cotyledons of the placenta, and the "uterine milk," to which Professor Turner has lately recalled attention. The treatise concludes with detached notes on the placenta, parturition, and allied subjects.
Harvey's other Writings and Medical Practice.—The remaining writings of Harvey which are extant are unimportant. A complete list of them will be found below, together with the titles of those which we know to be lost. Of these the most important were probably that on respiration, and the records of post-mortem examinations. From the following passage (De Partu, p. 550) it seems that he had a notion of respiration being connected rather with the production of animal heat than, as then generally supposed, with the cooling of the blood. "Hæc qui diligenter perpenderit, naturamque aeris diligenter introspexerit, facile opinor fatebitur eundem nec refrigerationis gratia nec in pabulum animalibus concedi. Hæc autem obiter duntaxat de respiratione diximus, proprio loco de eadem forsitan copiosius disceptaturi."
Of Harvey as a practising physician we know very little. Aubrey tell us that "he paid his visits on horse-back with a footcloth, his man following on foot, as the fashion then was." He adds—"Though all of his profession would allow him to be an excellent anatomist, I never heard any that admired his therapeutic way. I knew several practitioners that would not have given threepence for one of his bills" (the apothecaries used to collect physicians prescriptions and sell or publish them to their own profit), "and that a man could hardly tell by his bill what he did aim at." However this may have been,—and rational therapeutics was impossible when the foundation-stone of physiology had only just been laid,—we know that Harvey was an active practitioner, performing such important surgical operations as the removal of a breast, and he turned his obstetric experience to account in his book on generation. Some good practical precepts as to the conduct of labour are quoted by Willoughby, a contemporary. He also took notes of the anatomy of disease; these unfortunately perished with his other manuscripts. Otherwise we might regard him as a forerunner of Morgagni; for Harvey saw that pathology is but a branch of physiology, and like it must depend first on accurate anatomy. He speaks strongly to this purpose in his first epistle to Riolanus: "Sicut enim sanorum et boni habitus corporum dissectio plurimum ad philosophiam et rectam physiologiam facit, ita corporum morbosorum et cachecticorum inspectio potissimum ad pathologiam philosophicam." The only specimen we have of his observations in morbid anatomy is his account of the post-mortem examination made by order of the king on the body of the famous Thomas Parr, who died in 1635, at the reputed age of 152. Harvey insists on the value of physiological truths for their own sake, independently of their immediate utility; but he himself gives us an interesting example of the practical application of his theory of the circulation in the cure of a large tumour by tying the arteries which supplied it with blood (De Generat., Exerc. xix.).
The following is believed to be a complete list of all the known writings of Harvey, published and unpublished:—
Exercitatio Anatomica de Motu Cordis et Sanguinis, 4to, Frankfort-on-the Maine, 1628; Exercitationes duœ Anatomicœ de Circulatione Sanguinis, ad Johannem Riolanum, filium, Parisicnsem, Cambridge, 1649; Exercitationes de Generatione Animalium, quibus accedunt quœdam de Partu, de Membranis ac Humoribus Uteri, et de Conceptione, 4to, Lond., 1651; Anatomia Thomœ Parr, first published in the treatise of Dr John Betts, De Ortu et Natura Sanguinis, 8vo, Lond., 1669. Letters:—(1) to Caspar Hoffmann of Nuremberg, May 1636; (2) to Schlegel of Hamburg, April 1651; (3) three to Giovanni Nardi of Florence, July 1651, Dec. 1653, and Nov. 1655; (4) two to Dr Morrison of Paris, May 1652; (5) two to Dr Horst of Darmstadt, Feb. 1654-5 and July 1655; (6) to Dr Vlackveld of Haarlem, May 1657. His letters to Hoffman and Schlegel are on the circulation; those to Morrison, Horst, and Vlackveld refer to the discovery of the lacteals; the two to Nardi are short letters of friendship. All these letters were published by Sir George Ent in his collected works (Leyden, 1687). Of two MS. letters, one on official business to the secretary Dorchester was printed by Dr Aveling, with a facsimile of the crabbed handwriting (Memorials of Harvey, 1875), and the other, about a patient, appears in Dr Willis's Life of Harvey, 1878. Prœlectiones anatomiœ universalis per me Gul. Harveium medicum Londinensem, anat. et chir. professorem, an: dom. 1616, œtat. 37,—MS. notes of his Lumleian lectures in Latin,—are in the British Museum library; they are almost illegible, but were partly deciphered and a photograph of one of the pages taken by Dr Sieveking; for an account of them see his Harveian Lecture for 1877. A second MS. has been discovered in the British Museum, entitled Gulielmus Harveius de Musculis, Motu Locali, &c., and an account of it was published by Dr George Paget (Notice of an unpublished MS. of Harvey, Lond., 1850). The following treatises, or notes towards them, were lost either in the pillaging of Harvey's house, or perhaps in the fire of London, which destroyed the old College of Physicians:—A Treatise on Respiration, promised, and probably at least in part completed (pp. 82, 550, ed. 1766); Observationes de usu Licnis; Observeratones de motu locali, perhaps identical with the above-mentioned manuscript; Tractatum physiologicum; Anatomia medicalis (apparently notes of morbid anatomy); De Generatione Insectorum. The fine 4to edition of Harvey's Works, published by the Royal College of Physicians in 1766, was superintended by Dr Mark Akenside; it contains the two treatises, the account of the post-mortem examination of old Parr, and the six letters enumerated above. A translation of this volume by Dr Willis, with Harvey's will, was published by the Sydenham Society, 8vo, Lond., 1849.
The following are the principal biographies of Harvey:—in Aubrey's Letters of Eminent Persons, &c. (vol. ii., Lond., 1813), first published in 1685, the only contemporary account; in Bayle's Dictionnaire Historique et Critique, 1698 and 1720 (Eng. ed., 1738); in the Biographia Britannica, and in Aitken's Biographical Memoirs; the Latin Life by Dr Lawrence, prefixed to the college edition of Harvey's Works in 1766; memoir in Lives of British Physicians, Lond., 1830; a Life by Dr Robert Willis, founded on that by Lawrence, and prefixed to his English edition of Harvey in 1847; the much enlarged Life by the same author, published in 1878; the biography by Dr Munk in the Roll of the College of Physicians, 2d ed., vol. i., 1879.
The literature which has arisen on the great discovery of Harvey, on his methods and his merits, would fill a library. The most important contemporary writings have been mentioned above. The following list gives some of the most remarkable in modern times:—the article in Bayle's dictionary quoted above; Anatomical Lectures, by Wm. Hunter, M.D., 1784; Sprengell, Geschichte der Arzncikunde, Halle, 1800, vol. iv.; Flourens, Histoire de la Circulation, 1854; Lewes, Physiology of Common Life, 1859, vol. i. pp. 291–345; Ceradini, La Scoperta della Circolazione del Sangue, Milan, 1876; Tollin, Die Entdeckung des Blutkreislaufs durch Michael Servet, Jena, 1876; Kirchner, Die Entdeckung des Blutkreislaufs, Berlin, 1878; Willis, in his Life of Harvey; Wharton Jones, "Lecture on the Circulation of the Blood," Lancet for Oct. 25 and Nov. 1, 1879; and the Harveian Orations, especially those by Dr Sieveking, Dr Guy, and Prof. Rolleston. (P. H. P.-S.)