In Search for Symbolic Qualities of Iron: The Metal of Life

Iron, classically known as the Metal of Mars, has been universally perceived as the symbol of human strength, obstinacy, fortitude, honor, courage, sharpness (of body and mind), tenacity, and confidence in power. Legendary personalities like the knight Götz von Berlichingen (the one with prosthetic iron hands) or Margaret Thatcher (the iron lady) epitomized the metal properties in human character. However, it was in Rudyard Kipling’s poem “Cold Iron” that a pugnacious Baron elevates iron to a supreme level by proclaiming “cold iron asmaster of them all” (leaving gold for the mistress and silver for the maid). Ironically, the Baron’s strong belief in iron supremacy leads him to wage war against the King, but ends up defeated and humiliated. Although pardoned despite of betraying the King, he rather adheres to his original “iron master” creed to be sentenced with “iron out of Calvary is master of them all.” It is a question of interpretation whether or not the poem conveys a theological message or a metaphor for a feigned feeling of supremacy, its recurrent use by “siderophiles” as a symbol of iron’s preponderance in living organisms is perplexing (Beutler, 2002; Sheftel et al., 2012). Shouldn’t a more benevolent “master iron” icon be adopted to represent iron as the metal of life? We learn from history that a symbolism based on genuine iron master qualities was proposed more than a quarter of a millennium ago (Rodríguez Marín, 1925; Lasso de la Vega y Cortezo, 1988; Beutler, 2002; Sheftel et al., 2012; Beecher, 2015; Olmedilla y Puig, 2015). It was in 1574, in the town of Seville, the gateway to the recently discovered and conquered New World, where El Señor Doctor Nicolás Monardes (1493/1508?-1588) made public an essay entitled “Dialogue about the grandeur of iron” (which excels over other metals and is in highest demand to human service and of great medicinal qualities) (Monardes, 1549/1574) (Figure 1). The essay appears as a separate section in the Medicinal History of Plants Imported from the New World published together with two (previously published) sections and a new appended one (Monardes, 1549/1574)1. The author is a graduate in Arts and Philosophy (and later in Medicine) from the famous Universidad de Alcalá de Henares, who excelled in the practice and writing of Medicine, Botany, and Alchemy. His contributions earned him honorary titles such as “Father of Spanish Pharmacology” and “Discoverer of Fluorescence.” His associations with colonial traders of medicinal plants and minerals were instrumental in his scientific career as a botanist and in his medical practice. However, commercial misfortunes with overseas traders led him to declare bankruptcy and hide for a decade in a monastery, before managing to repay his creditors and to openly resume his medical practice and scientific endeavors. Monardes collected, studied, cataloged, and grew in his own garden some rare plants from which he made extracts that were applied to patients. He practiced medicine using classical books as well as novel information gathered from the American natives as guidelines. On the basis of Galenic medical reasoning