— The Significance of Blood in Medicine and Literature —

In Rowling’s first novel, Harry Potter and the Philosopher’s Stone, the reader is introduced to Nicolas Flamel and the legendary Philosopher’s Stone. While Flamel was a historical figure known for his forays into alchemy (the study of how to turn lead into gold) the mythical Philosopher’s Stone was said to be the substance that could actually transform base metals into precious gold. But instead of discussing the Stone in the context of alchemy, Rowling focuses on a less familiar supposed use for it — its ability to produce the “Elixir of Life,” a potion that has the power to bestow immortality upon its drinker.4 By emphasizing this aspect of the Stone, Rowling conveys to the reader a profound message about human existence and death, both subjects of intense fascination and speculation for people in the Middle Ages, when death was poorly understood, and which remain so today. Since immortality is tied with the maintenance of blood flow, Rowling’s incorporation of the Philosopher’s Stone links her novels to historical views of blood.

The body’s red fluid, which Starr calls the “Elixir of Life” in Blood: An Epic History of Medicine and Commerce and which Porter deems as “the source of vitality” in Blood and Guts: A Short History of Medicine, is the very essence of life. Such a view, exemplified by the old English saying, “the life of the body is the blood,” dates back to before the birth of Christ5 and helps explain why many popular remedies from the medieval period in Europe centered around blood, including bloodletting, purging, and inducing bowel movements with laxatives, cures that belonged collectively to a medical philosophy known as humoral thinking. Originating in Ancient Greece, humoral medicine posited that the body was composed of four humors, phlegm, choler, bile, and blood. Each humor was associated with a bodily function: phlegm with sweating and crying, blood with energy and vitality, choler with the digestive process, and bile with any major malady that did not fall under the other three categories. People believed that if any one substance were present in excess, or too scarce, that the humoral balance would be thrown off, resulting in illness and diminished spirits.6

To combat these imbalances, physicians employed a wide range of remedies. For example, if a person experienced digestion problems, the doctor used laxatives to purge excess choler. If a patient’s phlegm was out of balance, physicians typically induced vomiting, and if blood was causing the illness, bloodletting practices were employed, usually with leeches or by opening veins in the arms, necks, or legs.7

Rowling explores this humoral concept of blood as a revitalizing substance in Harry Potter and the Philosopher’s Stone. Towards the end of the novel, there is an eerie scene in which Harry and his friends enter the Forbidden Forest to save a dying unicorn. Unfortunately, they discover that they are too late when a “cloaked figure (reaches) the unicorn, (lowers) its head over the wound in the animal’s side, and (begins) to drink its blood.”8 Harry remains oblivious to the significance of this act until Firenze, a centaur, tells him that, “‘the blood of a unicorn will keep you alive, even if you are an inch from death ...’”9 This scene is the first time Rowling emphasizes the importance of blood. Her graphic deployment of the unicorn’s silver blood as an agent for immortality underscores the absolute necessity of blood for continued life.

In addition to its reputation as a vital life humor in the Middle Ages, blood played a major role in the debate on the origin and nature of souls. One theory, known as vitalism, suggested that blood carried the organism’s essence, or the temperament with which a particular animal was associated. People thought that a stag’s blood contained the traits of courage and longevity because stags were often seen as brave, long-living animals.10 Similarly, human characteristics such as intelligence, kindness, and sloth were also carried through the bloodstream. Therefore, it is extremely significant that Harry and James Potter both produce stag Patronuses in the novels. (A Patronus is an advanced piece of magic that is conjured by a witch or wizard for protection in the face of darkness. Each Patronus is unique to its conjurer and always takes the form of an animal that possesses characteristics similar to his or hers.)11 Harry and his father, James, both embody the spirit of bravery, but James dies before he is able to significantly shape Harry’s courageous personality. The assumption is that the essence of Harry’s courage once resided in James’ blood and was passed from father to son as a hereditary trait, an idea that stems directly from the theory of vitalism.

Blood is an extremely important aspect of Rowling’s Harry Potter series. It connects son with deceased father and offers precious immortality and revitalization to those who come in contact with it. And although one will likely never encounter unicorn blood, nor will blood ever literally be an “Elixir of Life,” it will undoubtedly always be considered one of the most precious and prized earthly commodities.

— Herbs and Plants —

Herbs and magical plants are prominent players in the Harry Potter novels. They form the basis for various potions, those that save lives, those that kill, and others that alter one’s states of being between the extremes of life and death. In Harry Potter and the Philosopher’s Stone, Professor Snape tells his Potions students that he can “bottle fame, brew glory, and stopper death.”12 In Harry Potter and the Chamber of Secrets, Harry, Ron, and Hermione encounter Moste Potente Potions, a book from which the three friends find a recipe for Polyjuice Potion, which can transform a person’s likeness to be exactly that of another person’s. Hermione notes that it is the most complicated potion she has ever seen, for it involves using very rare ingredients: “Lacewing flies, leeches, fluxweed knotgrass ... powdered horn of a Bicorn ... (and) Shredded skin of a Boomslang.”13

The second book also advises the mandrake root when for when one is petrified into stone by the Basilisk’s averted stare. In Harry Potter and the Half-Blood Prince, Professor Slughorn presents the students with vials of Polyjuice Potion, Amortensia, the most powerful love potion ever invented, and Felix Felicis, known as “Liquid Luck.” During their seven years at Hogwarts, Harry and his friends also encounter potions such as the Sleeping Draught and the Forgetfulness Potion as well as magical substances and potions with ingredients such as essence of dittany, wormwood, asphodel, and dried nettle.

The significance of medicinal plants in Harry’s wizarding world reflects the importance of herbs in the medical world. In medieval England, folk recipes often involved various leaves, roots, and barks that were combined into potent remedial mixtures to treat a wide array of diseases and discomforts such as stomach pain, head pain, leprosy, and madness. Nicholas Culpeper wrote in 1653 that dead nettle could “make the head merry, drive away melancholy, and quicken the spirits.”14 Moreover, many herbal folk remedies were so effective that they are still quite popular today; pharmaceutical companies, major representatives of modern science, rely heavily on the chemical compounds found in various medicinal plants that were once used in ancient and medieval times. For example, wormwood was an ingredient used to guard against the Devil or drive away psychological madness,15 and today, it is used sparingly as an antiseptic, anaesthetic, insect repellent, digestive, and treatment for worms.16 Poppy is another example of an enduring medicinal herb, popular in Tudor England to make “syrup of poppy,” that could be used to sooth a restless child or to treat a toothache.17 Today, the poppy plant is used for similar purposes; it is a major ingredient in the manufacturing of codeine and morphine, two drugs that are commonly used as painkillers. 

This section will focus on herbs and plants that are related in some way to Rowling’s Harry Potter novels, some are named directly, others might be used as substitutes for magical elements.

In Harry Potter and the Philosopher’s Stone, Professor Snape mentions several herbs and potions ingredients, including dried nettle, asphodel, valerian, wormwood, and monkshood (or wolfsbane). Dried nettle is used at Hogwarts to make the Boil-cure Potion, which, appropriate to its name, cures boils. But in the real world of botanical medicine, nettle (there are several types) is used for other purposes. Young nettles (mature nettles are poisonous to humans) were brewed in beers and teas to keep the bowels open, the pores closed, and the blood clean, and their seeds were often soaked in vinegar and applied to the scalp to treat dandruff. Nettles were also used to treat anemia and counter the detrimental effects of heavy menstrual periods because they were rich in iron and able to effectively staunch excessive bleeding. Dead nettle, as mentioned previously, was used to cure madness and depression, and stinging nettle, the most commonly used nettle species, was often employed in the treatment of arthritis. These particular remedies required the patient to “beat the aching parts with stinging nettles,” thereby reducing pain and swelling.18 Medieval physicians did not know the exact mechanisms by which stinging nettles relieved inflammation. Modern research shows that although the nettle’s fine needles inject formic acid and histamine into the skin upon contact, causing swelling at the point of contact, a wellplaced rubbing of the plant can actually draw inflammation away from areas of chronic joint swelling because the nettle also contains anti-inflammatory polysaccharides.19

Like nettle, Asphodel is mentioned only briefly by Professor Snape, but Harry Potter readers know that it is an ingredient in the Draught of Living Death, the wizarding world’s most powerful sleeping potion. The plant is not used in contemporary medicine (although it is sometimes used to make glue and Asphodel bread), but medieval physicians employed its properties in the treatment of swollen stomachs and abdominal discomfort:

Asphodel was also used as a cooling agent, a diuretic, an antispasmodic, and a pain reliever for the legs and the liver:

Presumably, since asphodel is no longer used for medicinal purposes, these remedies were ineffective despite their endorsement by medieval physicians.

Another ingredient in the Draught of Living Death is the valerian root, but unlike asphodel, valerian is still used in today as a component in medicines to deal with insomnia, stress, muscle tension, and anxiety. Contemporary researchers have theorized that the plant either acts directly on the amygdala, the part of the brain that controls emotional response, or on the parasympathetic nervous system, which slows heart rate and increases sedation. Rowling’s careful attention to the history of herbal medicine is evident when she included the valerian root in the recipe for quickly-induced slumber.

Medieval uses for valerian were not so different from its modern ones. After a 16th-century Italian nobleman claimed valerian cured his epilepsy, medieval Europe associated the plant with neurological ailments, and physicians began prescribing it as treatments for chronic headaches, epilepsy, hysterics, and other problems of the nervous system. This effectiveness in healing diseases of the brain then grew to encompass other sorts of illnesses. Nicholas Culpeper noted in 1653 that the plant could help cure croup, the plague, and wounds, and John Pechey wrote in 1694 that it could induce vomiting and bowel movements. Valerian was also used to heal small wounds, for it was often a central ingredient in medieval healing salves.22

Another integral component of Rowling’s Draught of Living Death is wormwood. As mentioned previously, wormwood is used very sparingly in modern medicine because it contains an addictive chemical called thujone. But in medieval medicine around the world, the plant was thought to cure many types of diseases. Nicholas Culpeper noted in 1653 that, “The seed of (sea) wormwood is usually given to children for worms,”23 and the caretakers of Chelsea Physic Garden in London write that sweet wormwood was a “traditional Chinese cure for malaria.”24 The plant was also an ingredient in health tonics, insect repellents, and treatments for fleas and lice as well as a drug to treat various common diseases. John Pechey wrote in 1694 that wormwood could strengthen the stomach and help cure “jaundice, dropsy, fever, and ... ‘Tumors of the Kernels of the Throat.’”25 Furthermore, medieval laypersons associated wormwood with magic and witchcraft, believing that “a wreath made from it and thrown into a Midsummer Eve’s fire would protect the thrower for an entire year.”26

The final herb on Snape’s list is monkshood, or wolfsbane. In Harry Potter and the Prisoner of Azakaban, monkshood is an ingredient in the Wolfsbane Potion, which helps to relieve the symptoms of being a werewolf. Professor Snape makes the potion once a month to ensure that werewolf-professor Lupin turns into a tame wolf during his transformation period. However, Rowling only included monkshood in her books as a play on the words wolfsbane and werewolf, for monkshood is actually a highly poisonous plant with toxins that can inhibit respiratory function and cause asphyxiation. One medieval physician learned this fact through experience after he tried to use the plant as a counterpoison and discovered that its effects were the same, if not worse, than those of the original toxin:

Not surprisingly, there are no records in folk medicine of successful attempts to cure disease with this plant, although people did employ its poison as a part of ancient methods of euthanasia. Furthermore, it seems that medieval people only successfully used monkshood for killing prey by poisoning arrows and darts with the juice of the monkshood flower. Today, monkshood is used only sparingly in the most dire cases (as an external applicant for rheumatic joint and nerve pain).28

Perhaps the most significant plant in Rowling’s novels is the mandrake, for it plays a central role in Harry Potter and the Chamber of Secrets. In the book, the mandrake is used to make a Mandrake Restorative Draught; as Hermione says during Herbology class, the “Mandrake, or Mandragora, is a powerful restorative ... It is used to return people who have been transfigured or cursed, to their original state.”29 In reality, the mandrake is poisonous in large doses because it contains strongly hallucinogenic chemicals known as hyoscyamines. But despite this poisonous element, the mandrake and its hyoscyamines are still ingredients in the most common modern pre-operative sedative drugs, and other varieties of the mandragora plant, such as the American mandrake, are used for contemporary cancer treatments and skin growths.30 In a restorative sense, Rowling was correct in attributing powerful physical recoveries to the mandrake plant.

Given the limits of their understanding of the chemical components of the mandrake, medieval physicians were incredibly creative with their utilization of the plant. A document from the 12th century records six major illnesses that were curable by the mandrake — sleep-preventing headaches, earaches, severe attacks of gout, epilepsy, muscle cramps and contractions, and head colds. The herbal writes that to cure headaches, “a salve is made with the juice and applied to the forehead as a plaster, ‘when the pain in the head is soon relieved, and sleep will come again quickly.’”31 For earaches, mandrake juice is mixed with oil and poured into the ears, and for gout, the root is ground into a powder, mixed with wine, and administered for seven consecutive days. Epilepsy and muscle cramps are cured in a similar fashion: the root is ground into powder and added to various liquids that are then either imbibed if one is epileptic, or smeared on the affected area if one is suffering from muscle aches. The sixth ailment listed in the herbal, the head cold, is treated in a very different fashion from the other five ailments: it simply requires the patient to own a bit of mandrake root in order to experience relief.32 Other ancient sources mentioned that the mandrake could expel phlegm and bile, treat inflammation and eye pain, anaesthetize, and induce menstruation, but that it would cause death if it were consumed in large amounts.33

The mandrake has always been an interesting plant because its shape has led people to view it as strangely anthropomorphic. Legends spoke of a deadly plant with roots that grew in human form, a plant that issued a fatal shriek when ripped from the ground. Rowling addresses this legend when Hermione tells the class that, “‘the cry of the Mandrake is fatal to anyone who hears it,”34 and when the students re-pot the young mandrake plants in class:

— Conclusion —

As this journey through the Harry Potter series has shown, medieval medicine and folklore have been far more influential on the Western world than many people realize, both in the realm of the arts and the sciences. Folk legends are the basis for many modern beliefs about witchcraft, which are now described in contemporary literature, art, and film; and medicinal practices in the Middle Ages, whether they were effective or not, formed an important foundation for the advancement of science, technology, and modern medicine. Furthermore, studying such historical periods in the development of medicine can be incredibly enlightening to researchers who search for potent cures of diseases such as cancer and malaria. After all, wormwood was an age-old cure for the symptoms of malaria, and scientists recently discovered that it is in fact effective in treating certain cases of malaria. Therefore, we must not cease the endeavors upon which we have already embarked: to continue learning about the history of medicine and the impact that medieval medicine has had on the development of social and scientific culture. §