Conrad Gessner (/ˈɡɛsnər/; Latin: Conradus Gesnerus;[a] 26 March 1516 – 13 December 1565) was a Swiss physician, naturalist, bibliographer, and philologist.

Born into a poor family in Zürich, Switzerland, his father and teachers quickly realised his talents and supported him through university, where he studied classical languages, theology and medicine.

[3] In school, he impressed his teachers so much that a few of them helped sponsor him so that he could further his education, including arranging a scholarship for him to attend university in France to study theology (1532–1533) at the age of 17.

In 1535, religious unrest drove him back to Zürich, where he made what some considered an imprudent marriage at the age of 19, of a woman from another poor family who had no dowry.

[3][4] Throughout his life Gessner was interested in natural history, and collected specimens and descriptions of wildlife through travel and extensive correspondence with other friends and scholars.

[5][6] Gessner's approach to research consisted of four main components: observation, dissection, travel to distant lands, and accurate description.

[7] Conrad Gessner was a Renaissance polymath, a physician, philosopher, encyclopaedist, bibliographer, philologist, natural historian and illustrator.

[2] In 1537, at the age of 21, his publication of a Graecolatin dictionary led to his sponsors obtained for him the professorship of Greek at the newly founded academy of Lausanne (then belonging to Bern).

After three years of teaching at Lausanne, Gessner was able to travel to the medical school at the University of Montpellier, where he received his doctoral degree (1541) from Basel.

In 1541 he prefixed to his treatise on milk and milk products, Libellus de lacte et operibus lactariis[9] a letter addressed to his friend Jacob Avienus (Vogel)[10][b] of Glarus on the wonders to be found among the mountains, declaring his love for them, and his firm resolve to climb at least one mountain every year, not only to collect flowers, but in order to exercise his body.

[8][4] Gessner is credited with a number of the first descriptions of species in Europe, both animals such as the brown rat (Rattus norvegicus), guinea pig (Cavia porcellus)[13] and turkey (Meleagris),[14] as well as plants such as the tulip (Tulipa gesneriana).

This was a revision of an original work by the Italian cleric, Varinus Phavorinus or Guarino of Favera (d. 1537), Magnum ac perutile dictionarium (1523).

Gessner's great zoological work, Historia animalium,[22] is a 4,500-page encyclopedia of animals that appeared in Zürich in 4 volumes between 1551 and 1558: quadrupeds, amphibians, birds, and fishes.

In Historia animalium Gessner combines data from old sources, such as the Old Testament, Aristotle, Pliny, folklore, and medieval bestiaries, adding his own observations.

The book unlike many works of its time was illustrated with hand-colored woodcuts drawn from personal observations by Gessner and his colleagues.

Besides any plant or animal's potential advantage to people, Gessner was interested in learning about them because of the moral lessons they could teach and the divine truths they might tell.

[36] Over his lifetime, Gessner amassed a considerable collection of plants and seeds and made extensive notes and wood engravings.

The scale and scientific rigour of these were unusual for the time, and Gessner was a skilled artist, producing detailed drawings of specific plant parts that illustrated their characteristics, with extensive marginal notation discussing their growth form and habitation.

In fact, Catholic booksellers in Venice protested the Inquisition's blanket ban on Gessner's books, and some of his work was eventually allowed after it had been "cleaned" of its doctrinal errors.

In the words of science writer Anna Pavord, "He was a one-man search engine, a 16th-century Google with the added bonus of critical evaluation.

[36] In 1576 George Baker published a translation of the Evonymus of Conrad Gessner under the title of The Newe Jewell of Health, wherein is contained the most excellent Secretes of Physicke and Philosophie divided into fower bookes.

The society's annual publication, the Neujahrsblatt der Naturforschenden Gesellschaft in Zürich was devoted to a biography of Gessner in 1966, to celebrate the 400th anniversary of his death.