Portrait of Paolo Mascagni. Courtesy of the National Library of Medicine, History of Medicine Division. This portrait is in the public domain in the U.S., PD-US.
Housed in the P.I. Nixon Medical Historical Library’s Special Collections is Paolo Mascagni’s 1787 Vasorum lymphaticorum corporis humani historia et ichnographia. Recognized as a landmark in anatomical illustration, this large folio edition contains 41 brilliantly executed copperplates, faithfully representing the details of the lymphatic system. Even with the benefit of modern technology, researchers find it difficult to attain the perfection of his work. As a professor of anatomy at the University of Siena, Paolo Mascagni (1755-1815) devoted himself to the advancement of anatomical knowledge. In 1771, when he became prosector, a person who dissects cadavers for the illustration of anatomical lectures, he concentrated his investigative efforts on the lymphatic system.
Why is his work considered perfect and so hard to duplicate? Because of the level of accuracy and detail Mascagni was able to attain in replicating the intricacy and complexity of the lymphatic system of the human body. Using mercury as a contrast medium, Mascagni developed new research methods leading to highly accurate dissection results. He did this using a tubular needle bent at a right angle at one end and tapered to an extremely fine point. Mercury was then injected into the body’s peripheral lymphatic networks and flowed through whatever part of the lymphatic system that was under study. Following the mercury injection with careful dissection, Mascagni obtained magnificent preparations of those networks.
The Significance of Mascagni’s Work
Vasorum Lymphaticorum was ground-breaking and opened the way for continued progress in our understanding of the anatomy and physiology of the human body. He did not limit himself to studying the anatomy of the lymphatic system alone but also studied its physiology and pathology, and emphasized the vital role it plays in maintaining the body’s well-being. He sought to gain a more comprehensive understanding of the lymphatic networks and advance anatomical knowledge. And he accomplished just that. Using his method of research, Mascagni observed, named, and described nearly all the lymph glands and vessels of the human body. Demonstrating that arterial and venous lymphatics did not exist, this work challenged accepted views of Mascagni’s contemporaries. Mascagni disproved the theory that the lymphatics originated from the terminal arteries and continued in the veins through various, very fine tubules. Rather, Mascagni concluded that the lymphatic system originates from all the internal and external cavities and surfaces of the body, and is directly related to the function of absorption. Through his research, he also discovered and described lymphatic vessels in regions of the body where they had not previously been known to exist.
Mascagni also refuted the belief that there was an anastomosis, or connection, between the lymphatics and the veins. Except at the point where the thoracic duct and the thoracic vein merge into the venous system, there is no connection between the two systems. However, his research demonstrated that there is a link between the lymph and serous vessels. He determined that all the lymphatics pass through one or more lymph nodes during their course and provided excellent illustrations to document this fact by means of colored injections.
~Trinaé Weldy, Special Collections Intern
For more information on the P.I. Nixon Medical Historical Library, contact Lisa Matye Finnie, Special Collections Librarian, at email@example.com or 210-567-2406.
References and Additional Information:
Eimas, Richard. “The Great Anatomy of Paolo Mascagni.” The University of Iowa Libraries Special Collections and University Archives. The University of Iowa Libraries, Apr 1983. Web. 17 Mar 2014. <http://www.lib.uiowa.edu/scua/bai/eimas.htm>.
“Paolo Mascagni.” Anatomia Universa. The University of Iowa Libraries, 1996-2006. Web. 17 Mar 2014. <http://sdrc.lib.uiowa.edu/exhibits/imaging/mascagni/index.html>.