The Bartholin family dominated Danish medical and anatomical science for three generations. Thomas Bartholin (1616 – 1680), like his father, Caspar, was Professor of Medicine at the University of Copenhagen.

Thomas Bartholin and his father were both interested in the unicorn, particularly in the fabled medical properties of its horn.

This book, De Unicornu Observationes Novae (New observations on the unicorn), is partially an essay on the likelihood of the existence of unicorns, drawing on available evidence.

Bartholin includes historical, mythological and religious sources, as well as an examination of known one-horned animals, such as the rhinoceros, the narwhal, the rhinoceros beetle and the hawk moth caterpillar.

Interestingly, Bartholin seems to conclude that the unicorn may exist – not as a magical creature, but as just another of the world’s fascinating animals.

Thomas Bartholin’s contributions to medical publishing includes the first full description of the human lymphatic system and the description of a condition known as Bartholin–Patau syndrome, a chromosomal abnormality causing multiple disabilities.

He was also the first to scientifically describe the method of refrigeration anaesthesia – a process of using intense cold to anaesthetise a specific are of the body.

The Research Library’s copy of De Unicornu Observationes Novae is bound in vellum – a smooth, tanned animal skin (often calf). The illustrations are early copper engravings, with some woodcut decorative devices. Like most scientific works of the period, the text is in Latin.

De Unicornu was published in Padua in Northern Italy. Ours is one of fewer than ten known copies held in libraries worldwide, making it another one of the many fascinating and unexpected items held in the Museum's rare book collection.