teries; Georg Wirsung discovered (1642) the pancreatic duct; Pecquet made known (1651) his discovery that the lacteals pour their contents into the receptaculum chyli, and that the thoracic duct (previously observed by Eustachius) leads thence to the left subclavian vein; the lymphatic vessels were noted by the Cambridge student George Joyliffe in 1652, and, about the same time, Rudbeck traced the connection of the lymphatics of the liver and intestines with the receptaculum chyli and thoracic duct. Before the death of Harvey, Wharton discovered the duct that bears his name, and Glisson gave an accurate description of the capsule of the liver.

Willis was aided in the preparation of his "Cerebri Anatome" (1664) by Sir Christopher Wren and by Richard Lower, who in his "Tractatus De Corde" furthered the work of Harvey by definitely applying the new science of physics to explain the mechanism of the heart. Robert Hooke (the first microscopist to observe the cellular structure of plants) by experiments in artificial respiration (1667) proved that life may be maintained without muscular movement so long as the lungs are supplied with fresh air; and John Mayow in the following year demonstrated that in respiration only part of the air is taken up by the lungs, and that the gas which supports life is identical with that which supports combustion.

In the meantime the influence of Galileo and Harvey had advanced the cause of physiological research in Italy. Much of the progress centers about the name of Ferdinand II of Tuscany, whose brother Leopold de' Medici improved the thermoscope of Galileo and was the first president of the Accademia del Cimento, founded at Florence in 1657. To the University of Pisa, Ferdinand called Borelli, Malpighi, Bellini, and Stensen. For Borelli, the disciple of Galileo, physiology was a part of physics. He recognized that the action of a muscle is a mere contraction of its length, due to the fibers, or muscle substance proper, and not to the tendon. He estimated in pounds the force of the muscles of the jaw and heart. The motion of the heart differs from that of the arm or leg in being nonvolitional; it may be automatic, or caused by some organic necessity. The heart is like a wine-press, and, by propelling the blood into the arteries, causes them to distend. The arteries, then contracting, force the blood into their ramifications. By means of the microscope Malpighi, distinguished in embryology, pathology, and histology, observed (1661) the capillaries in the lung, mesentery, etc., of the frog, as well as in the lung of the tortoise. He thus found that the blood is always contained in vessels, and does not escape from the arterioles to be taken up by the venuoles. These observations

were confirmed by Leeuwenhoek (1668), by the Irish scientist William Molyneux (1683), and others. In 1665 Malpighi observed the red blood corpuscles, but in this discovery he had been anticipated by Swammerdam. Bellini's study of the minute structure of the kidneys and Malpighi's histological examination of the spleen, liver, brain cortex, lungs, tongue, skin, etc., as well as of the kidneys, became the basis of a more definite knowledge of the physiological action of these parts. The correlation of structure and function was the dominant idea of these investigators. Stenson, the discoverer of the duct of the parotid gland, furthered the investigations of Borelli in reference to the mechanism of the muscles.

It seems almost like a travesty of the mechanical theory of physiological action that in a later generation it was taught, not only that the heart and vessels resemble waterworks and that the chest is like bellows, but that the glands may be compared to sieves, the teeth to scissors, and the stomach to a flask.

REFERENCES

Brooks, W. K.: William Harvey as an Embryologist, Johns Hopkins Hospital Bulletin, 1897, VIII, pp. 167-74.

Curtis, John G.: Harvey's Views on the Use and Circulation of the Blood. Columbia University Press, 1915. 194 pp. Foster, Sir Michael: Lectures on the History of Physiology. Cambridge University Press, 1901. 310 pp.

Haldane, Elizabeth S.: Descartes, his Life and Times. London, 1905. 398 pp.

Mitchell, Weir S.: The Early History of Instrumental Precision in Medicine, 2d Congress of Am. Physicians and Surgeons, 1891, pp. 159-81.

Some Recently Discovered Letters of William Harvey. Philadelphia, 1912. 59 pp.

Tierney, M. A.: The History and Antiquities of the Castle and Town of Arundel. London, 1834, 2 vols. 772 pp. (pagination continuous).

Moore, Norman: "William Harvey," The Dictionary of National Biography.

Power, D'Arcy: William Harvey. London, 1897. 283 pp. (Bibliographical appendix.)

Willis, Robert: The Works of William Harvey. Translated from the Latin with a Life of the Author. London, The Sydenham Society, 1847. 624 pp.

CHAPTER VII

SCIENCE AND PRACTICE: SYDENHAM,

BOERHAAVE

Is it possible to be a great physician without an intimate knowledge of up-to-date science? Should the focus of a doctor's attention be something else than anatomy, histology, physiology, embryology, bacteriology, chemistry, etc.? The lives of Thomas Sydenham and Hermann Boerhaave give us occasion to consider these questions.

Sydenham's early life served to develop his practical, rather than his theoretical, tendencies. Born of a family of Puritan gentry at Wynford Eagle, Dorsetshire, September, 1624, he went in 1642 to Oxford, where his eldest brother William - soon to gain distinction as one of Cromwell's officers and councillors -was already in residence. Thomas was enrolled in May at Magdalen Hall, the recognized center of Oxford Puritanism, but he was compelled within a few months, or weeks, to quit the University on account of the impending struggle between the King and the Parliament. He returned to his home in Dorset, where the Sydenham family became, in the bitter local warfare that followed, the leaders of the Parliamentary forces. The father