Toxicology in the Middle Ages and Renaissance

By Philip Wexler

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

• Language: English
• Publisher: Academic Press
• Release date: Mar 13, 2017
• ISBN: 9780128095591

Book preview

Francis/Routledge).

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