He studied medicine in
Paris under
Guichard Joseph Duverney (1648–1730), in
Montpellier under
Raymond Vieussens (1635–1713) and received his medical degree in 1681 at
Basel. Later, he returned to Schaffhausen in order to practice medicine. Here, he performed research with
Johann Jakob Wepfer (1620–1695), and Wepfer's son-in-law
Johann Conrad Brunner (1653–1727). in 1677 Peyer published
Exercitatio anatomico-medica de glandulis intestinorum earumque usu et affectionibus, in which he describes the eponymous
Peyer's patches. These anatomical structures are aggregated
lymphatic nodules found in the lining of the
small intestine. He was also the author of an influential work on
veterinary medicine titled
Merycologia sive de Ruminantibus et Ruminatione Commentariae. ==References==