Algorithmus.
Algorithmus is a mathematics treatise by Prosdocimus de Beldemandis, who died in 1428, held in a medical library collection and shown here through two bookplates. The pictures are small printed ex libris labels: one a plain Yale Medical Library crest with an open Hebrew-lettered book and motto, the other an ornate engraved frame with heraldic shield, skull, laurel, caduceus, and a signed name space, which a designer could draw on for bookplate framing, heraldic borders, and engraved label layouts.
