Harry Potter and the Philosopher’s Stone turned 20 years old on June 26th, 2017, and perhaps the most appropriate place to celebrate the first score of the Harry Potter franchise is in a library.

How to Pass Your O.W.L.s at Hogwarts: A Prep Course” is a curated collection of 40 images within The New York Academy of Medicine’s 33,000 rare book collection. (The organization’s main book catalog includes nearly 550,000 books.) The collection is available to view online, showcasing things like dragons from Ambroise Paré’s 1607 Les oeuvres d'Ambroise Paré: Sixieme Edition and the 1707 hieroglyphics attributed to Nicholas Flamel in the alchemical text, Medicina Practica, or the Practical Physician.

But, of course, electronics don’t function on Hogwarts’ campus (despite the many Hogwarts RPG characters strolling around with “charmed” CD players and cameras in internet-days-gone-by), and there’s only one student that comes to mind who would study in the early days of summer. So I disguised myself as Hermione Granger and went to visit NYAM’s rare books library.

The first thing to note is that the prep course covers five of the seven core subjects taught at Hogwarts, and two additional subjects: Herbology, Defense Against the Dark Arts, History of Magic, Potions, Transfiguration, Care of Magical Creatures, and Divination.

You’ll be greeted at the door by a softball-sized cow bezoar from 1862. The goat’s bezoar is a fine antidote to most poisons, as any first-year Potions student could tell you. In person, the churned hairs are so smoothed by the stomachs of the cow that it looks like an antiquated but fashionable clip-on bun.

Start, as J.K. Rowling did, with the Philosopher’s Stone. The books curated for the Transfiguration course focus largely on alchemical texts from the 17th and 18th centuries, and include hieroglyphics attributed three centuries post-mortem to Nicholas Flamel.

The legend of Flamel’s alchemical ambitions began almost two full centuries after his death, when Livre des figures hiéroglyphiques (1612) was published under his name. According to the legend, the scribe traveled to Spain to translate a 21-page text he’d purchased and with no luck, began to return home. He happened upon a sage. The sage recognized the text as a key to alchemy, and so Flamel and his wife dedicated their lives to decrypting it, eventually developing a success Philosopher’s Stone and the Elixir of Life.

The Twelve Keys of Basil Valentine are compiled in Jean-Jacques Manget's Bibliotheca Curiosa (1702), and display a rich set of images suitable for any Ancient Runes student. Rare books curator Anne Garner (a great deal more helpful than Madam Pince) pointed out that the roses in the final image indicate a successful completion, but other illustrations could likely only be translated with the insider knowledge of a secret society member.

The course selection for Care of Magical Creatures will feel familiar: in it are depictions of unicorns, dragons, phoenixes, three-headed dogs, and mermaids. Unicorn horns are foretold to have healing properties in Conrad Gesner’s 1563 Historia Animalium, although there’s no mention of drinking their blood. Curious.

centaurs, basilisks, and mandrakes

More magical creatures appear in their appropriate sections: centaurs in a 1667 tome are under Divinations; a 1640’s basilisk appears in Defense Against the Dark Arts; and both male and female-presenting mandrakes are shown in the Herbology books. The books chosen for course study of History of Magic reveal some less fantastical tales: witch hunting.

Jean Bodin's Demonomanie was originally published in France in 1580; the edition in the collection is from 1593. The book denounces sorcery, including the works of Cornelius Agrippa (have you gotten his card in your chocolate frogs yet?), and is considered the most influential manual on witch hunting in France in the 16th century. It sits next to della Porta’s Natural Magic (1658), which theorizes that women accused of witchcraft after claiming they could fly had only experienced hallucinogens while making herbal remedies. della Porta offers several of his own herbal remedies, including some mandrake to help one sleep, or a lot of mandrake to make one go crazy for a day. In the 17th century, Bodin referred to della Porta as a “Neapolitan sorcerer,” but today, their books are displayed side by side.

Fans won’t be surprised by the level of thoughtfulness and research that went into the mythos of the seven books’ literary world, but there may be no better way to appreciate the series than to uncover the work that created them, nestled in centuries-old volumes.