The Evolution of Modern Medicine [72]
distributed to the body at large, and its several parts, in the same manner as it is sent through the lungs, impelled by the right ventricle into the pulmonary artery, and that it then passed through the veins and along the vena cava, and so round to the left ventricle in the manner already indicated."[29]
[29] Ibid. p. 49.
The experiments dealing with the transmission of blood in the veins are very accurate, and he uses the old experiment that Fabricius had employed to show the valves, to demonstrate that the blood in the veins flows towards the heart. For the first time a proper explanation of the action of the valves is given. Harvey had no appreciation of how the arteries and veins communicated with each other. Galen, you may remember, recognized that there were anastomoses, but Harvey preferred the idea of filtration.
The "De Motu Cordis" constitutes a unique piece of work in the history of medicine. Nothing of the same type had appeared before. It is a thoroughly sensible, scientific study of a definite problem, the solution of which was arrived at through the combination of accurate observation and ingenious experiment. Much misunderstanding has arisen in connection with Harvey's discovery of the circulation of the blood. He did not discover that the blood moved,--that was known to Aristotle and to Galen, from both of whom I have given quotations which indicate clearly that they knew of its movement,--but at the time of Harvey not a single anatomist had escaped from the domination of Galen's views. Both Servetus and Colombo knew of the pulmonary circulation, which was described by the former in very accurate terms. Cesalpinus, a great name in anatomy and botany, for whom is claimed the discovery of the circulation, only expressed the accepted doctrines in the following oft-quoted phrase:
"We will now consider how the attraction of aliment and the process of nutrition takes place in plants; for in animals we see the aliment brought through the veins to the heart, as to a laboratory of innate heat, and, after receiving there its final perfection, distributed through the arteries to the body at large, by the agency of the spirits produced from this same aliment in the heart."[30] There is nothing in this but Galen's view, and Cesalpinus believed, as did all his contemporaries, that the blood was distributed through the body by the vena cava and its branches for the nourishment of all its parts.[*] To those who have any doubts as to Harvey's position in this matter I would recommend the reading of the "De Motu Cordis" itself, then the various passages relating to the circulation from Aristotle to Vesalius. Many of these can be found in the admirable works of Dalton, Flourens, Richet and Curtis.[31] In my Harveian Oration for 1906[32] I have dealt specially with the reception of the new views, and have shown how long it was before the reverence for Galen allowed of their acceptance. The University of Paris opposed the circulation of the blood for more than half a century after the appearance of the "De Motu Cordis."
[30] De Plantis, Lib I, cap. 2.
[*] Cesalpinus has also a definite statement of the circlewise process.--Ed.
[31] J. C. Dalton Doctrines of the Circulation, Philadelphia, 1884; Flourens Histoire de la decouverte de la circulation du sang, 2d ed., Paris, 1857; Charles Richet Harvey, la circulation du sang, Paris, 1879; John G. Curtis Harvey's views on the use of Circulation, etc., New York, 1916.
[32] Osler An Alabama Student and Other Biographical Essays, Oxford, 1908, p. 295.
To summarize--until the seventeenth century there were believed to be two closed systems in the circulation, (1) the natural, containing venous blood, had its origin in the liver from which, as from a fountain, the blood continually ebbed and flowed for the nourishment of the body; (2) the vital, containing another blood and the spirits, ebbed and flowed from the heart, distributing heat and life to all parts. Like a bellows the lungs fanned and cooled this vital blood. Here and there we find glimmering
[29] Ibid. p. 49.
The experiments dealing with the transmission of blood in the veins are very accurate, and he uses the old experiment that Fabricius had employed to show the valves, to demonstrate that the blood in the veins flows towards the heart. For the first time a proper explanation of the action of the valves is given. Harvey had no appreciation of how the arteries and veins communicated with each other. Galen, you may remember, recognized that there were anastomoses, but Harvey preferred the idea of filtration.
The "De Motu Cordis" constitutes a unique piece of work in the history of medicine. Nothing of the same type had appeared before. It is a thoroughly sensible, scientific study of a definite problem, the solution of which was arrived at through the combination of accurate observation and ingenious experiment. Much misunderstanding has arisen in connection with Harvey's discovery of the circulation of the blood. He did not discover that the blood moved,--that was known to Aristotle and to Galen, from both of whom I have given quotations which indicate clearly that they knew of its movement,--but at the time of Harvey not a single anatomist had escaped from the domination of Galen's views. Both Servetus and Colombo knew of the pulmonary circulation, which was described by the former in very accurate terms. Cesalpinus, a great name in anatomy and botany, for whom is claimed the discovery of the circulation, only expressed the accepted doctrines in the following oft-quoted phrase:
"We will now consider how the attraction of aliment and the process of nutrition takes place in plants; for in animals we see the aliment brought through the veins to the heart, as to a laboratory of innate heat, and, after receiving there its final perfection, distributed through the arteries to the body at large, by the agency of the spirits produced from this same aliment in the heart."[30] There is nothing in this but Galen's view, and Cesalpinus believed, as did all his contemporaries, that the blood was distributed through the body by the vena cava and its branches for the nourishment of all its parts.[*] To those who have any doubts as to Harvey's position in this matter I would recommend the reading of the "De Motu Cordis" itself, then the various passages relating to the circulation from Aristotle to Vesalius. Many of these can be found in the admirable works of Dalton, Flourens, Richet and Curtis.[31] In my Harveian Oration for 1906[32] I have dealt specially with the reception of the new views, and have shown how long it was before the reverence for Galen allowed of their acceptance. The University of Paris opposed the circulation of the blood for more than half a century after the appearance of the "De Motu Cordis."
[30] De Plantis, Lib I, cap. 2.
[*] Cesalpinus has also a definite statement of the circlewise process.--Ed.
[31] J. C. Dalton Doctrines of the Circulation, Philadelphia, 1884; Flourens Histoire de la decouverte de la circulation du sang, 2d ed., Paris, 1857; Charles Richet Harvey, la circulation du sang, Paris, 1879; John G. Curtis Harvey's views on the use of Circulation, etc., New York, 1916.
[32] Osler An Alabama Student and Other Biographical Essays, Oxford, 1908, p. 295.
To summarize--until the seventeenth century there were believed to be two closed systems in the circulation, (1) the natural, containing venous blood, had its origin in the liver from which, as from a fountain, the blood continually ebbed and flowed for the nourishment of the body; (2) the vital, containing another blood and the spirits, ebbed and flowed from the heart, distributing heat and life to all parts. Like a bellows the lungs fanned and cooled this vital blood. Here and there we find glimmering