Gasparo Aselli

Gasparo Aselli spent the most of his short life in Milan where he had acquired citizen’s right and practised medicine. He was protochirurgus to the royal army in the cisalpine wars, and was made an honorary citizen of Milan in recognition of his outstanding services as a physician. He was also for many years professor of surgery and anatomy at Padua.

The discovery for which he is remembered occurred in Padua on July 23, 1622, during vivisection of a living dog that had been recently fed. On opening the abdomen, he noticed whitish cords that exuded a creamlike liquid “like milk”. Upon careful repetition of the experiment, he described these new vessels as venae albae et lacteae ("white and lacteal veins"). He described them in De lactibus sive lacteis venis, published posthumously in 1627, just before the De motu cordis of the English physician William Harvey, who appears to have been unaware of Aselli's work. Erroneously Aselli maintained the Galenic view, according to which these "milk veins" transport intestinal lymphatic material to the liver, the traditional central organ, in which blood was produced. His discovery was completed by the Swedish anatomist Olof Rudbeck (1630-1702), who in 1650 demonstrated the passage of the lymphatic vessels of the mesentery into the ductus thoracicus.

Three days later Aselli was able to demonstrate his discovery in a new experiment to his friends, the famous physicians Alessandro Tadini (1580-1661) and Ludovico Settala (1552-1633). After Aselli’s premature death in 1626 these two published a paper on his discovery.

Previously Bartolomeo Eustachius had recognized the thoracic duct in the horse and even detected some of its valves. His work on this structure was forgotten until Aselli’s description of the lacteals. Jean Pecquet (1622-1674) discovered the thoracic duct in dogs and its relation to the lacteals. Using a dog that was digesting, he described the thoracic duct, its entry into the subclavian veins, and the receptaculum chyli or chyle reservoirs. The chyle reservoir had been sought after since Aselli’s discovery of the chyliferous vessels in the dog.

We thank Patrick Jucker-Kupper, Switzerland, for information submitted.

• De lactibus sive lacteis venis, quarto vasorum meseraicorum genere novo invento, dissertatio, qua sententiae anatomicae multae, vel perperam receptae convelluntur, vel parum perceptae illustrantur etc. Morte praeventus ut ederetur curarunt Alexander Tadinus et Senator Septalius physici de Coll. Nob. Mediol. Etc.
  Published posthumously by Alessandro Tadini and Ludovico Settala. Mediolani, apud Io. B. Bidellium, 1627.
  Later editions in Leyden, 1641.
  Also published with the works of Adrian Spigel in Amsterdam 1645.
  In Geneva 1685, in the Bibliotheca anatomica edited by Daniel Leclerc (1652-1728) and Jean-Jacques Manget (1652-1742).
  Also included in a 1647 edition of William Harvey’s De motu cordis. Reprinted in Leipzig, 1968, Milan, 1972.
  The first edition is typographically rather special, as it includes the first anatomical plates printed in colours – four chiaroscuro woodcuts, 16” x 10”. In later editions these have been replaced by much smaller copperplates. Works by others:
• Bertolomeo Eustachi:
  Opuscula anatomica. Venetis, V. Luchinus, 1564.
  Eustachius recognized the thoracic duct in the horse and even detected some of its valves. His work on this structure was forgotten until Aselli's description of the lacteals.
• Jean Pecquet (1622-1674):
  Experimenta nova anatomica, quibus incognitum chyli receptaculum, et ab eo per thoracem in ramos usque subclavis vasa lactea deteguntur.
  Parisiis, Apud Sebastianum Cramoisy et Gabrielem Cramoisy, 1651.
  Pecquet discovered the thoracic duct in dogs and its relation to the lacteals. Using a dog that was digesting, he described the thoracic duct, its entry into the subclavian veins, and the receptaculum chyli or chyle reservoir. The chyle reservoir had been sought after since Aselli's discovery of the chyliferous vessels (lacteals) in the dog. English Translation, London, 1653. Biographical and bibliographical:
• August Hirsch (1817-1894), publisher:
  Biographisches Lexikon der hervorragenden Ärzte aller Zeiten und Völker.
  2nd edition. Berlin, Urban & Schwarzenberg, 1929.
  First published in 6 volumes 1884-1888. 3rd edition, München 1962.
• Jeremy M. Norman, editor:
  Morton’s Medical Bibliography. An annotated Check-list of Texts Illustrating the History of Medicine (Garrison and Morton).
  Fifth edition. Scolar Press, 1991.