Toxicology in the Middle Ages and Renaissance

Philip Wexler

• Publisher: Academic Press
• Year: 2017
• ISBN:
  9780128095591
• Topic: Medicine
• Subtopic: Toxicology

Toxicology in the Middle Ages and Renaissance provides an authoritative and fascinating exploration into the use of toxins and poisons in the Middle Ages and Renaissance. Part of the History of Toxicology and Environmental Health series, this volume is a follow-up, chronologically, to the first two volumes which explored toxicology in antiquity.

The book approximately covers the 1100s through the 1600s, delving into different aspects of toxicology, such as the contributions of scientific scholars of the time, sensational poisoners and poisoning cases, as well as myths. Historical figures, such as the Borgias and Catherine de Medici are discussed. Toxicologists, students, medical researchers, and those interested in the history of science will find insightful and relevant material in this volume.

• Provides the historical background for understanding modern toxicology
• Illustrates the ways previous civilizations learned to distinguish safe from hazardous substances, how to avoid them, and how to use them against enemies
• Explores the way famous historical figures used toxins

Chapter 1

Poison and Its Dose

Paracelsus on Toxicology

Urs Leo Gantenbein, University of Zurich, Zurich, Switzerland

Abstract

The Swiss physician, natural philosopher, and radical church reformer Theophrastus Bombast of Hohenheim, called Paracelsus (1493/94–1541), was a reformer of medicine. He formulated the famous four pillars of medicine: natural philosophy, astronomy, alchemy, and medical ethics. Alchemy was a means to refine raw substances in order to separate the poisonous parts from the medically effective constituents. He further used alchemical terminology for the explanation of physiological and pathological bodily processes. According to Paracelsus, nutritional poisons were one of the major causes of disease. In his tract on the miner’s diseases, he gave clinical pictures of the intoxications by arsenical compounds and other inorganic substances. Paracelsus coined the famous saying that all the things are poisons, and that the degree of toxicity is only caused by the dose.

Keywords

Paracelsus; alchemy; arsenic; mercury; intoxication; Renaissance; medicine

1.1 The Four Pillars of Medicine

The adage, “The dose makes the poison,” is perhaps the most famous quote in the history of toxicology. It was coined by the Swiss physician, natural philosopher, and radical church reformer Theophrastus Bombast of Hohenheim, called Paracelsus (1493/94–1541). Being an enigmatic and independent Renaissance thinker, he was long misunderstood and a subject of controversy, in part even to this day. Paracelsus intended nothing less than to completely reform medicine which in his day was founded on mere book learning and the rigid medical doctrines of the ancients. As brilliant as his mind was, so was his character difficult and unrelenting, especially when confronted with dissent, which often was the case. As a result of orthodox physicians’ opposition, his life was one of the endless wanderings throughout Europe with local authorities reluctant to provide him license to stay at a place longer than a few months. Paracelsus reached the climax of his career in Basle, Switzerland, where in 1527 he was appointed town physician and professor at the university. He announced plans to revise the ancient doctrines, to advocate for the importance of practical experience in medical matters, and to establish a new framework of medicine and surgery in books he would write himself. In just a few months, he presented an extensive series of lectures covering pharmacology, medicine, and surgery. After an ideological clash with his students and a legal dispute with his superiors, he was forced to flee from the town, a blow which he never recovered from.

Following this fracas, he composed many other works among which his two famous theoretical writings were the Paragranum (1529) and the Opus Paramirum (1531) [1]. The former contains the concept of the Four Pillars of Medicine as philosophy, astronomy, alchemy, and virtue (ETW 8-14).[2]. Although natural philosophy, as understood in this scheme, describes the principles and substances found in nature applied to medical therapy, astronomy elucidates the secret bonds between heaven and earth, leaning on the neo-Platonic conception that the stars are celestial ideas which influence and determine everyday occurrences. Through his acquaintance with mining and metallurgy, Paracelsus became knowledgeable in Medieval alchemy. From this, he appropriated the principle of “separatio puri ab impuro” (S 4:115, 132) [3], the separation of the pure essence from an otherwise toxic substance, and applied it to the preparation of effective remedies [4]. In this sense, Paracelsus writes in the Paragranum:

Who is there who would deny that in all good things poison also resides? Everyone must acknowledge this. This being the case, the question I ask is: must one then not separate the poison from what is good, taking the good and leaving what is bad? Of course one must. (ETW 247)

Extending additionally the alchemical motto of “probing in the fire” (ETW 311) to clinical experience, alchemy became the very basis of Paracelsus’ medical revolution. Other than the common doctors who used mixtures of mostly unprocessed raw substances, he enriched the remedy treasure with alchemically prepared and thus detoxified mineral drugs. Finally, the fourth pillar, virtue, represents medical ethics, a subject in which Paracelsus was far ahead of his time [5]. Stressing empathy he said, “the greatest foundation of medicine is love” (S 7:369) and “where is no love there is no art” (S 8:263). He was opposed to forsaking the sick in hopeless cases but rather argued for compassion because “mercifulness is the teacher of the physicians” (S 8:264).

The second one of the above-mentioned theoretical works, the Opus Paramirum, contains among many other things the medical application of the three basic philosophical principles of Paracelsian alchemy—mercury, sulfur, and salt. First introduced by Paracelsus in the Basle lectures and not to be confused with the corresponding chemical substances, this trinity comprises the fundamental constituents of all organic and inorganic matter [6]. When a substance is observed in the alchemical furnace, mercury stands for the liquid and volatile or part, sulfur represents the oily and combustible part. Salt, on the other hand, is untouched by fire and remains as a fixed principle in the laboratory vessel. Using wood as an example, Paracelsus states, “Let it burn: that which burns is sulphur. What smokes is mercurius. What turns to ash [is] sal” (ETW 319). Later, in the Opus Paramirum, Paracelsus reinterpreted the three principles as physiological processes in a bodily alchemy, seeing the functioning of the body in terms of sublimation, distillation, circulation, heating, and cooling (S 11:188). Using this theory, Paracelsus explained disease as a malfunction of the three principles. Thereby, he had nothing less in mind but to replace the ancient theory of the four humors—blood, phlegm, yellow, and black bile. With all these new ideas, Paracelsus was shaking the very foundations of contemporary medicine. It is therefore not surprising that he was confronted with massive opposition. As a result of general disrepute, from the enormous collection of manuscripts written by Paracelsus, which will fill up to 30 volumes when completely edited [7], only a minor fraction was printed during his lifetime (Fig. 1.1).

Figure 1.1 Portrait of Paracelsus—U.S. National Library of Medicine, Bethesda, MD, United States.

1.2 Poison and the Alchemist in the Stomach

Another important work of Paracelsus relates to his various concepts of poison, namely, the Volumen medicinae Paramirum, which is not identical with the later Opus Paramirum. Sketchy and rather inconsistent, it comprises probably an early work written before the Basle period. It contains the etiological theory of the Five Entia as the causes of disease, with which Paracelsus has gained a certain fame [8]. Roughly summarizing, the ens astrale signifies the pathogenic influences of the stars, the ens venale stands for the poison contained in the food and the air, and the action of the ens naturale corresponds to the malfunctioning of the body itself. Resembling a force like a spirit “born out from our thoughts without matter in the living body” (S 1:216), the ens spirituale could represent psychosomatic disorders and the influence of witchcraft, both based on imagination. Finally, in ens deale, disease is understood as a punishment from God. Andrew Weeks argues that Paracelsus could have derived the five entia from the five different suspected explanations for the ravaging plague epidemics of his times. Indeed, the contemporary plague tracts discussed as possible causes, astronomic events, miasmatic theories with poisonous vapors in the air, humors and natural catastrophes, magic and imagination, and divine punishment [9].

Even the ens astrale acts by poison, namely, the “vapors of the planets harm us” (S 1:185), and the poisoned stars “stain the air with their poison, so where the poison arrives, there will be diseases springing up according to the stars’ qualities” (S 1:184). In asserting the importance of poisons in the development of illness, he stated that the stars are even more powerful and outwit the earthly poisons:

No physician should be astonished that there are not so many poisons on earth, but be aware that there are even more are in the stars. And every physician should be aware that no illness comes without poison, because in poison lies the very beginning of every illness. (S 1:185)

In describing the ens venale or ens veneni, as he also called it, Paracelsus declares that the body is not naturally contaminated with toxins, but can, in fact, be poisoned by taking food. This is so because everything contains an essence and a poison. “Essence is what preserves the human being, poison is what brings him sickness” (S 1:195). So when eating, human beings are automatically subject to poison:

A human being must eat and drink, because the body which houses his life requires it and cannot do without it. Thus the human being is forced to take his own poison, and illness and death, by eating and drinking. (S 1:191)

However, nature knows how to manage this predicament. Drawing a parallel to the alchemical reactions, he observed in his laboratory, Paracelsus imagined that in the human body, there must be a similar assimilating and transforming principle. This “inner alchemist” or “archaeus” (S 11:188), as he later called it, skillfully separates the poison from the food and eliminates the waste from the body:

Now remember … while poison may and does harm us, we have got an alchemist in us, installed and given us by the Creator, who shall separate the poison from the good so that we may not receive any disadvantage. (S 1:193)

Human beings and the animals have different inner alchemists with their own capacities to neutralize various poisons. For example, the alchemist of the peacock, which resembles no other animal, is subtle and allows this bird to eat snakes, scorpions, and newts without harm. The alchemist of the ostrich separates iron and the one of the salamander even transmutes fire, but the keenest inner alchemist belongs to the pig which may even ingest human and other animal excrements and extract nourishment from it (S 1:192). Depending on the nature of the poison in question, it is driven out through various openings of the body—the pores of the skin, the nose, the ears, the eyes, the mouth, and via urine and excrement (S 1:199). The alchemist resides in a specific location of the body, namely, in the stomach which naturally resembles a retort which one might find in an alchemist’s laboratory. This is where foods are cooked and disentangled. The alchemist transforms the good parts into an essence, and this tincture permeates or “tinges” the whole body in order to produce blood and flesh. When for some reason the alchemist fails in his task, then the precarious food remains in the stomach and is subject to putrefaction, eventually leading to disease:

He [the inner alchemist] separates the bad part from the good, he transmutes the good into a tincture, he tinges the body that it may live … that it may become blood and flesh. This alchemist resides in the stomach which is the instrument in which he cooks and works. (S 1:194)

When the alchemist fails, so that the poison is not be properly separated from the good according to the rules, there is a joint putrefaction of the poison and the good, followed by digestion. This is what results in human disease, because all illnesses obtained by human beings from ens veneni arise from a rotted digestion … when digestion has failed and the alchemist is not perfect in his instrument, from which corruption follows, and this is the mother of all diseases … because corruption empoisons the body. (S 1:195)

These quotations amply demonstrate that Paracelsus was eager to find an explanation for the apparently assimilating and excreting processes of the human body. He found the answer from the realm he was accustomed to, i.e., the theory and practice of alchemy with its theories of refining crude materials. Although Paracelsus was not the first to apply alchemy to pharmacology and medicine, he was the first to significantly expand this theory and promote it to a broader audience. In this sense, he anticipated chemical therapeutics, and his efforts to explain vital processes in chemical terms could be considered a precursor of present-day biochemistry.

1.3 Noxious Mineral Vapors and the Miner’s Disease

A great many alchemists lived in the vicinity of mining sites [10] and Paracelsus himself had a great interest in mining. The would-be alchemist would do well to travel to mountains and their mines, because “where the minerals lie there are the artists [of alchemy]” (S 11:...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• List of Contributors
• Preface
• Acknowledgments
• About the Editor
• Chapter 1. Poison and Its Dose: Paracelsus on Toxicology
• Chapter 2. The Golden Age of Medieval Islamic Toxicology
• Chapter 3. Maimonides’ Book on Poisons and the Protection Against Lethal Drugs
• Chapter 4. Pietro d’Abano, De venenis: Reintroducing Greek Toxicology into Late Medieval Medicine
• Chapter 5. The Case Against the Borgias: Motive, Opportunity, and Means
• Chapter 6. Aqua Tofana
• Chapter 7. Poisons and the Prince: Toxicology and Statecraft at the Medici Grand Ducal Court
• Chapter 8. Georgius Agricola, a Pioneer in the Toxic Hazards of Mining, and His Influence
• Chapter 9. Jan Baptist Van Helmont and the Medical–Alchemical Perspectives of Poison
• Chapter 10. Origin of Myths Related to Curative, Antidotal and Other Medicinal Properties of Animal “Horns” in the Middle Ages
• Chapter 11. Animal Stones and the Dark Age of Bezoars
• Chapter 12. Fossil Sharks’ Teeth as Alexipharmics
• Chapter 13. Catherine La Voisin: Poisons and Magic at the Royal Court of Louis XIV
• Chapter 14. A Late Medieval Criminal Prosecution for Poisoning: The Failed Murder Trial of Margarida de Portu (1396)
• Chapter 15. Animal Venoms in the Middle Ages
• Chapter 16. Medical Literature on Poison, c. 1300–1600
• Index