(b. Minden, Germany, 1598; d. Padua, Italy, 30 August 1649), anatomy, botany.
Vesling’s reputation rests on his excellent powers of observation. Nothing certain is known about his parents, although it appears that the Catholic family fled to Vienna to escape religious persecution. All the biographers agree that Vesling attended secondary school and studied medicine in Venice, but his name is not found among the registration records of the university. Since Vesling stated that Everhardius Vorstius of Leiden was his teacher, an examination of the records of the university reveals that Johannes Wesling of Minden enrolled as a student at Leiden at age twenty on 15 November 1619. Vorstius had studied at German and Italian universities, including Bologna, and was especially interested in botany as well as in medicine. Vesling, too, had a predilection for botany, and he also went to Bologna, presumably on Vorstius’ advice. Vesling named Fabrizio Bartoletti as his teacher in Italy. Bartoletti, who moved from Bologna to Mantua after 1675, instilled in Vesling an enthusiasm for anatomy and surgery.
The next documented fact that we have concerning Vesling’s career dates from the winter of 1627-1628. He performed, in the presence of Venetian physicians, an anatomical demonstration that earned him the right to practice in the areas controlled by Venice. His teaching was so highly esteemed that even Paduan students came to hear him. The Venetian government unfairly refused to reimburse Vesling for the expenses he incurred in conducting his demonstrations. This was probably done in an attempt to drive him from the city in order to protect the much older Paduan professor Caimo from the competition of his youger colleague. For the same reason, Vesling was directed to serve as physician to the partician Alvise Cornaro during the latter’s term as Venetian representative in Cairo. The two men left for Egypt at the beginning of August 1628. Vesling studied the flora of the country with great interest. In many cases his observations were more accurate than those previously made by Prospero Alpini, and his book on the subject is also better illustrated than the latter’s. Of particular interest are his comments on the coffee plant.
All of Vesling’s biographers assign an earlier date to his trip to Egypt, despite the fact that Haller long ago published the correct information on the basis of letters Vesling sent to Wilhem Fabry (Hildanus Fabricius). Only Adelmann cites this refernce and mentions that a date contained in Vesling’s working notes makes it certain that he was still in Egypt on 7 May 1632. On that day Vesling repeated his investigations of the development of the chick embryo in artificially hatched eggs. The results of these embryological studies are very fully discussed by Adelmann, and the reader should consult his account for details. The place names that Vesling mentions in his writings show that he was familiar with only a small part of Egypt, that between Rashid (Rosetta) and Memphis. He traveled to Palestine only once, on which occasion he became a knight of the Order of the Holy Sepulcher in Jerusalem.
Because of his stay in Egypt, Vesling escaped the epidemic of plague that ravaged northern Italy in 1629-1631. During the epidemic students avoided Padua, and the chair of anatomy was vacant for a year. On 30 December 1632 Vesling was appointed professor of anatomy and surgery, and at the beginning of 1633 he returned from Egypt. Veiling proved to be a very able teacher and enilvened his lectures with drawings that the he himself had prepared and that were later used in his Syntagma anatomicum. This textbook, characterized by a concise style, went through many editions and was translated style, went through many editions and was translated into several languages. Of particular scientific value are his descriptions and illustrations of the chyle vessels (lacteals) and his assertion that four is the normal number of pulmonary veins emptying into the left auricle of the heart. Further, he was the first to see the ductus thoracicus, but he did not mention the discovery until 1649, in a letter to Thomas Bartholin.
In 1638 Veiling ceased lecturing on surgery and turned instead to botany. Under his direction the botanical garden in Padua was renovated, as several plant catalogues of the period show. IN 1648 Vesling was given a leave of absence that allowed him to undertake a second botanical expedition. He went to Crete but returned ill, and he died soon after. In accordance with his wishes he was buried in the cloister of the church of St. Anthony in Padua. Vesling’s posthumous papers contain much remarkable material that he would undoubtedly have formulated in more precise terms. Among the more notable things to be found in these papers (which were published by Thomas Bartholin) is a correction of his intial findings concerning the sexual organs of the viper and the scent glands of the snakes.
I. Original Works. Vesling’s most important anatomical work is Syntagma anatomicum, publicis dissectionibus in auditorium usum diligenter aptatum (Padua, 1641). Along with many Latin editions, this work appeared in Dutch, German, and English translations—the last under the title The Anatomy of the Body of Man, N Culpeper, trans. (London, 1653).
Vesling’s most important work in botany is De plantis aegyptiis observationibus et notae ad Prosperum Alpinum, cum additamenta aliarum eiusdem regionis (Padua, 1638). Vesling’s embryological and comparative anatomical investigations were published by Thomas Bartholin as De pullitione Aegyptiorum et aliae observationes anatomica et epistolae medicae posthumae (Copenhagen, 1664).
II. Secondary Literature, Two biographical accounts are Arturo Castiglioni, in Enciclopedia Italiana, XXXV (1937), p. 218; and A. Fracesco La Cave, in Castalia (Milan, 1948). For an assessment of Vesling’s contribution to the history of embryology see Howard B. Adelmann, Marcello Malpighi and the Evolution of Embryology (Ithaca, N. Y., 1966). Vesling’s comparative anatomical studies are discussed in F. C. Cole, A History of Comparative Anatomy (London, 1944).