What's the meaning of the weird ingredients in “Double Trouble”?

This selection is from the third film in the Harry Potter franchise, HP and the Prisoner of Azkaban. It’s performed by the Frog Choir, a group of Hogwarts students who don’t appear in any of the actual books but whom J. K. Rowling really loved when she saw them in the movie. They perform at the welcoming feast that begins the new school term and each carries a toad, one of which croaks during the song. (Why aren’t they called the Toad Choir? I don’t know.) The music is, of course, by John Williams. Isn’t everything?

But that’s all I have to say about the film. Will I lose my readers if I say that I saw none of the Harry Potter movies and read only the first three books in the series? I hope not. I loved, loved, loved the first HP book, as I’m always entranced by origins/setup/identity stories. The fantasy/magic/spells stuff? Not so much. So I’m going to concentrate on the words of the song, which of course come from Shakespeare’s play Macbeth and are spoken by three witches, characters who show up in a couple of scenes. They serve as agents of foreshadowing, telling the title character that he will be king of Scotland and then using their cauldron with its weird ingredients to call up visions of the future. In my former incarnation as a high school English teacher I taught Macbeth to ninth graders. Not as difficult as it may sound, since Macbeth is Shakespeare’s shortest play and full of action. Certain scenes and references are at least somewhat commonly known outside the classroom: Lady Macbeth’s sleepwalking scene in which she tries to rub the blood of the murdered King Duncan from her hands (Out, damned spot! Out I say!”), Macbeth’s scene in which he says he’s now a permanent insomniac (“Methought I heard a voice cry, ‘Sleep no more!’”), and the banquet scene in which the ghost of the murdered Banquo appears to Macbeth (“Never shake thy gory locks at me!”).

(As a side note on the last reference, we used to have a Chihuahua who had a habit of snarling if you tried to take something away from her; we’d say, ”Never curl thy hairy lip at me!” Ah, I do miss dear little Lupita.)

Okay. Back to Shakespeare. While not everybody has heard of Banquo or Lady Macbeth, virtually everyone has heard of the three witches, and especially of the brew that they’re stirring up as Macbeth approaches them over the “blasted heath,” whatever that is. You’d think that after teaching this play, and viewing several versions on film, and seeing at least two different live performances (one at the Shakespeare Folger Library in downtown Washington D.C. with special effects by Teller of the magician duo Penn and Teller) that I’d know just about all there is to know about the play, but I don’t remember ever actively researching the witches and their brew before now. So here’s a sampling of what I’ve found out:

First, Shakespeare’s source material had Macbeth being greeted by fairies or nymphs instead of by witches. He changed these beings to witches. What’s eerie about cute little fairies? The witches are much more atmospheric, and Shakespeare really has fun with his descriptions. When we first meet them in Act I we are told that they have “skinny lips” and, although they seem to be women, they also have “beards,” obviously a reference to those pesky chin hairs that seem to crop up with age. But they really come into their own in their second appearance, at the beginning of Act IV, where they have their famous cauldron scene. Here’s where the wording comes for the song, which includes only a small sampling of the actual ingredients listed. These also include a poisonous toad, parts of a shark, a tiger’s entrails, and baboon’s blood. It may seem very farfetched that there could really be such an assemblage of materials, but medieval medicine often used extremely strange ingredients. For instance, the song mentions “witches’ mummy,” and, while it may strain your credulity to think it, actual mummies (the best being the Egyptian ones) were crumbled up and ingested for various ailments. The French king Francis I (who lived at roughly the same time as Shakespeare) carried around ground-up mummy in a pouch, just in case he was wounded while hunting. Medieval and Renaissance Europe was sort of obsessed with mummies and their supposed magical or medicinal powers. So the witches’ brew has at least one ingredient that really was used. Other items may have been herbs that were given code names to keep ingredients of potions secret, or simply because the herbs bore a resemblance to an animal’s body part: “tongue of dog” and “adder’s fork” are both known plants.

Getting into the whole history of witch-hunting and the tragic executions that followed, both in Europe and America, is beyond the scope of this post. What seems clear is that there were certainly woman, often elderly, who were known as brewers of potions. Some of these mixtures were legitimately medicinal; if you couldn’t afford to go to an apothecary’s shop in town, you might visit a local herbalist and get her to give you something to help you with your aches and pains. It seems clear that at least some of these herbalists trafficked in less-wholesome products, though, including poisons and love potions. It was against the law for anyone to sell poison. (Remember that scene in Romeo and Juliet scene in which Romeo buys poison to kill himself because he thinks Juliet is dead, offering a huge sum of money to the apothecary, who first objects, saying that Mantua’s law forbids it, but finally says, “My poverty, but not my will, consents”?) Also, keep in mind that Macbeth is set in Scotland, with all of its intriguing Celtic traditions. We may find the witches rather funny today, but the audience at the time would almost certainly have been seriously creeped out. (That is, if they were paying attention, what with all the talking, flirting, and orange-eating that would have been going on during the play as it was originally performed in the Globe Theater.)

Here’s the song as it’s performed in the film. Scroll down below to find the entire text from the play:

First Witch:
Round about the cauldron go;
In the poison’d entrails throw.
Toad, that under cold stone
Days and nights has thirty-one
Swelter’d venom sleeping got,
Boil thou first i’ the charmed pot.

All
Double, double, toil and trouble;
Fire burn, and cauldron bubble.

Second Witch
Fillet of a fenny snake,
In the cauldron boil and bake;
Eye of newt and toe of frog,
Wool of bat and tongue of dog,
Adder’s fork and blind-worm’s sting,
Lizard’s leg and howlet’s wing,
For a charm of powerful trouble,
Like a hell-broth boil and bubble.

All
Double, double, toil and trouble;
Fire burn and cauldron bubble.

Third Witch
Scale of dragon, tooth of wolf,
Witches’ mummy, maw and gulf
Of the ravin’d salt-sea shark,
Root of hemlock digg’d i’ the dark,
Liver of blaspheming Jew,
Gall of goat, and slips of yew
Silver’d in the moon’s eclipse,
Nose of Turk and Tartar’s lips,
Finger of birth-strangled babe (30)
Ditch-deliver’d by a drab,
Make the gruel thick and slab:
Add thereto a tiger’s chaudron,
For the ingredients of our cauldron.

All
Double, double, toil and trouble;
Fire burn and cauldron bubble.

Second Witch
Cool it with a baboon’s blood,
Then the charm is firm and good.

And if you’d like an exhaustive breakdown of the medical properties of the foregoing, you can read this article: “More than ‘toil and trouble’: Macbeth and Medicine”