At the Osler Library, you can find a plethora of rare books on medicine. Among the rows of shelves, there are treasures such as the “De humani corporis fabrica libri septem” (1543) by Vesalius (worth 500 000 USD), but there are also hidden gems. One of them is the book “Aristotle’s Master-Pieces or Every Woman’s Book! Displaying all the Secrets of Nature as Exhibited in the Creation of Man”. At first glance, it seems fairly unremarkable; its cover is tattered, its pages are pages stained - it’s clear that the book has been heavily used.