J. Rowling - Short Stories From Hogwarts of Power, Politics and Pesky Poltergeists

Quintus Horatius Flaccus was one of the greatest Roman Poets, more commonly known as Horace. He gave Slughorn two of his Christian names. The name ‘Slughorn’ derives from the (Scots) Gaelic for ‘war cry’: sluagh-ghairm, which later gave rise to ‘slughorn’, a battle trumpet. I loved the word for its look and sound, but also for its many associations. The original Gaelic suggests a hidden ferocity, whereas the corrupted word seems to allude to the feeler of the Arion distinctus (or common land slug), which works well for such a seemingly sedentary, placid man. ‘Horn’ also hints at his trumpeting of famous names and illustrious associations.

Horace Slughorn was one of the most gifted Potion makers that Hogwarts had ever seen. Like Severus Snape, he had the power to bottle fame, brew glory, and even stopper death, but what makes a truly talented Potions master? According to J.K. Rowling, you need more than just a cauldron and the right ingredients to whip up a winning concoction.

It is often asked whether a Muggle could create a magic potion, given a Potions book and the right ingredients. The answer, unfortunately, is no. There is always some element of wandwork necessary to make a potion (merely adding dead flies and asphodel to a pot hanging over a fire will give you nothing but nasty-tasting, not to mention poisonous, soup).

Some potions duplicate the effects of spells and charms, but a few (for instance, the Polyjuice Potion and Felix Felicis) have effects impossible to achieve any other way. Generally speaking, witches and wizards favour whichever method they find easiest, or most satisfying, to produce their chosen end.

Potions are not for the impatient, but their effects are usually difficult to undo by any but another skilled potioneer. This branch of magic carries a certain mystique and therefore status. There is also the dark cachet of handling substances that are highly dangerous. The popular idea of a Potions expert within the wizarding community is of a brooding, slow-burning personality: Snape, in fact, conforms perfectly to the stereotype.

Chemistry was my least favourite subject at school, and I gave it up as soon as I could. Naturally, when I was trying to decide which subject Harry’s arch-enemy, Severus Snape, should teach, it had to be the wizarding equivalent. This makes it all the stranger that I found Snape’s introduction to his subject quite compelling (‘I can teach you to bottle fame, brew glory, even stopper death…’), apparently part of me found Potions quite as interesting as Snape did; and indeed I always enjoyed creating potions in the books, and researching ingredients for them.

Many of the components of the various draughts and libations that Harry creates for Snape exist (or were once believed to exist) and have (or were believed to have) the properties I gave them. Dittany, for instance, really does have healing properties (it is an anti-inflammatory, although I would not advise Splinching yourself to test it); a bezoar really is a mass taken from the intestines of an animal, and it really was once believed that drinking water in which a bezoar was placed could cure you of poisoning.

You can hunt down dittany or find a bezoar in the real world, but you’d be hard pressed to track down a Bicorn horn – one of the key ingredients in Polyjuice Potion. This appearance-altering potion is undeniably powerful, whether used for good or evil; but what is the meaning behind each of the ingredients in the mixture, and why is Hermione’s ability to brew it as a second-year student so remarkable?

The Polyjuice Potion, which is a complex and time-consuming concoction, is best left to highly skilled witches and wizards. It enables the consumer to assume the physical appearance of another person, as long as they have first procured part of that individual’s body to add to the brew (this may be anything – toenail clippings, dandruff or worse – but it is most usual to use hair). The idea that a witch or wizard might make evil use of parts of the body is an ancient one, and exists in the folklore and superstitions of many cultures.

The effect of the potion is only temporary, and depending on how well it has been brewed, may last anything from between ten minutes and twelve hours. You can change age, sex and race by taking the Polyjuice Potion, but not species.

The fact that Hermione is able to make a competent Polyjuice Potion at the age of twelve is testimony to her outstanding magical ability, because it is a potion that many adult witches and wizards fear to attempt.

I remember creating the full list of ingredients for the Polyjuice Potion. Each one was carefully selected. Lacewing flies (the first part of the name suggested an intertwining or binding together of two identities); leeches (to suck the essence out of one and into the other); horn of a Bicorn (the idea of duality); knotgrass (another hint of being tied to another person); fluxweed (the mutability of the body as it changed into another) and Boomslang skin (a shedded outer body and a new inner).

The name Polyjuice was supposed to make several allusions. ‘Poly’, meaning ‘many’, gave the idea that the potion could turn you into lots of different people; but ‘Polyjuice’ is also very near ‘Polydeuces’, who was a twin in Greek mythology.

If you’re going to cook up a goblet full of Polyjuice, or any other vile-tasting but powerful brew, you’re going to need a cauldron. Here’s a little history of this vital piece of magical equipment.

Cauldrons were once used by Muggles and wizards alike, being large metal cooking pots that could be suspended over fires. In time, magical and non-magical people alike moved on to stoves; saucepans became more convenient and cauldrons became the sole province of witches and wizards, who continued to brew potions in them. A naked flame is essential for the making of potions, which makes cauldrons the most practical pot of all.

All cauldrons are enchanted to make them lighter to carry, as they are most commonly made of pewter or iron. Modern inventions include the self-stirring and collapsible varieties of cauldron, and pots of precious metal are also available for the specialist, or the show-off.

Cauldrons have had a magical association for centuries. They appear in hundreds of years’ worth of pictures of witches, and are also supposed to be where leprechauns keep treasure. Many folk and fairy tales make mention of cauldrons with special powers, but in the Harry Potter books they are a fairly mundane tool. I did consider making Helga Hufflepuff’s hallow a cauldron, but there was something slightly comical and incongruous about having such a large and heavy Horcrux; I wanted the objects Harry had to find to be smaller and more portable. However, a cauldron appears both in the four mythical jewels of Ireland (its magical power was that nobody ever went away from it unsatisfied) and in the legend of The Thirteen Treasures of Britain (the cauldron of Dyrnwch the giant would cook meat for brave men, but not for cowards).