Odds and quads

They were donated to the institution by Frederick A. Coller, who was chairman of surgery at Michigan between 1930 and 1957. He was renowned not only as a gifted medic, but also as a scholar of the history of medicine.

The amulets were previously owned by Campbell Bonner, a professor of Greek language and literature at Michigan who collected these examples in Syria and Egypt and from dealers in Greece and England.

In Studies in Magical Amulets: Chiefly Graeco-Egyptian (1950), Dr Bonner describes an amulet as "any object which by its contact or close proximity to the person who owns it, or to any possession of his, exerts power for his good, either by keeping evil from him and his property or by endowing him with positive advantages".

The carvings on these examples range from depictions of Anubis - the jackal-headed god associated with the afterlife - to Ouroboros, a serpent eating its own tail, and a reaper cutting stalks of grain.

Send suggestions for this series on the treasures, oddities and curiosities owned by universities across the world to: matthew.reisz@ tsleducation.com.