Richard lower, of England, was one of the greatest pioneers in the field of cardiorespiratory physiology. Lower is regarded as the physician who played a critical role by the depth of his experimentations in establishing the function of the lungs.
He published his celebrated book "Tractatus de corde" in 1669. Lower's work is the most important contribution to the study of the physiology after Harvey's De motu Cordis which was published in 1628. The Tractatus is composed of 5 sections:
1) The position and structure of the heart
2) The movement of the heart
3) The movement and color of the blood
4) The transfusion of blood from one animal to another
5) The chyle, its passage into the blood , and its transformation into blood
Lower confirmed the heart was a muscular organ and carefully studied myocardial anatomy and structure and demonstrated for the first time the complex organization of myocardial fibers. The spiral course of myocardial fibers was accurately illustrated in his book. He also studied cardiac valves and described with precision their function during cardiac cycle. Using injection techniques during dissection, he was able to demonstrate the existence of intercoronary arterial anatomoses. These anatomic observations were based on the dissection of human and animal hearts.
Tractatus de corde is also the first book dealing with cardiovascular diseases.
Cardiac diseases were divided into four categories: Those due to structural anomalies of the heart, those due to arteries, those due to blood, and finally those due to spirits flowing to the heart.
Lower described a case of pericardial effusion and one of the first postmortem cases of constrictive pericarditis. He also reported one of the first accounts of heart failure.
The color of the blood is the subject of the second part of his treatise and following a series of experiments he concluded that "the red color of the blood is entirely due to the penetration of particles of air into the blood...it is extremely probable that the blood takes in air in its course through the lungs, and owes its bright color entirely to the admixture of air." In the original Latin version, he referred to these particles as "spiritus aeris nitrosus." Based on his experimental observations, Lower strongly rejected the common belief that the red color of the arterial blood was related to the heat generated in the heart during systole and that the dark color of the venous blood resulted from the loss of heat during circulation.
Richard Lower was a pioneer in the field of blood transfusion and performed the first transfusion from animal to animal in 1665. He also performed several cases of blood transfusion from animals to human in 1667. Lower declared "while Harvey first taught that the blood by its circulation within its own vessels ensures life to the body, we also revealed that it could be transferred outside the confine of its own body for the health of a second." Lower provided illustrations in his monograph to demonstrate the tubes that he used for transfusion (plate 7 of the Tractatus).
Finally, Lower performed anatomic studies of the thoracic duct in animals and established for the first time the exact path for the drainage of lymph into the circulation. The plate six in the Tractatus shows the digital compression of the thoracic duct which results in the dilatation of the mesenteric lymphatic vessels. It also illustrates the connection between the duct and the subclavian vein.
Franklin KJ. The work of Richard Lower (1631-1691). Proc Royal Soc Med 1932;25(1):113-118
Hoff EC, Hoff PM. The life and times of Richard Lower, physiologist and physician (1631-1691). Bull Hist Med 1936;3:517-535
Franklin KJ. A facsimile edition of Tractatus de corde item de motu & colore sanguinis et chyli in eum tansitu. London and Oxford ,Oxford University Press,1932
Fye WB. Profiles in Cardiology: Richard Lower. Clin Cardiol 1993;16:757-758