The Book of Theriac was unknown in the Latin West but many other translations of Arab, then Greek, treatises assured the success of this universal panacea. During the early Middle Ages, medicine was essentially empirical and abounded with recipes, antidotaries and lists of simple medicines. Books circulated in which different recipes for theriac could be found, including the gigantic Natural History by Pliny the Elder, on the basis of which a medical compilation was drawn up in the fourth century titled Medicina Plinii.

Similarly, works essentially dealing with pharmacopoeia, such as the Compositiones medicamentorum by Scribonius Largus, whose recipes for theriac were taken up in the compendium of remedies composed in the fifth century by Marcellus Empiricus from Bordeaux. However, given the current state of research, it is difficult to know whether theriac was then known by physicians and even less if it was used. It seems that it was from the eleventh century that theriac began to occupy a place of importance in the therapeutic arsenal of Western medicine, and this under a dual influence. On one hand derived from the first Latin translations of Arab medical treatises, and on the other from the thriving trade between the ports of Italy and the countries of the East. The introduction of Arab medicine – and by means of this intermediary also of Greek medicine – occurred in southern Italy in the eleventh century through the translations of Constantine the African.

Having become a monk at Monte Cassino, this man who was born in what is today Tunisia translated into Latin works that exercised considerable influence, including the Isagoge and the Pantegni, given deliberately Hellenised titles. The first includes extensive fragments of the Kitāb al-masā’il fī l-ṭibb by Ḥunayn ibn Isḥāq; the second most of the Kitāb kāmil al- ṣinā’a al-ṭibbiyya by al-Majūsī. This latter author, who was known in the West by the name Haly Abbas (his complete name was ‘Alī ibn al-‘Abbās al-Majūsī), had organised his magisterial encyclopaedia in two large parts: the_ Theorica_ and the_ Practica. The Practica_ in Constantine’s version often diverges from the Arabic original. For example, the tenth and last book, which deals with compound medicines and later circulated separately under the name Antidotary, had been enriched with additions taken from other treatises.

Nonetheless, it seems, subject to a collation that has yet to be made, that the first seven or eight chapters on the subject of electuaries, amongst which theriac, are fairly faithful representations of the work of al-Majūsī. In any case, the contents passed into the_ Great Antidotary_ compiled at Salerno around 1100. A shorter version was drawn up some years later, probably before 1160, with the title Antidotarium Nicolai. This work contains a large number of prescriptions and ingredients taken from the tenth book of the Pantegni. The recipe for Andromachus’ theriac is included. The Antidotarium Nicolai enjoyed widespread success in the Middle Ages, being translated or adapted into vernacular languages, and there is every reason to believe that it was via this intermediary that the theriac of Andromachus knew such renown throughout the Latin West.

Numerous ingredients unknown in the West were used in the composition of theriac. To make the compound meant procuring rare products, or “spices”, as the condimentary, tinctorial and pharmaceutical products imported from the East were called. Whereas Mediterranean trade flourished before the Crusades, the formation of Latin states after the capture of Jerusalem in 1099 further encouraged the activities of Italian merchants in the Mediterranean. Venice in particular built up a huge and active commercial network.

The importation of spices from the Orient was a huge business and allowed the Serenissima to produce its own theriac, one that enjoyed an especially good reputation. Its formulation followed the instructions given in the Antidotarium Nicolai. Packed in boxes made of tin or lead stamped with the symbol of the Republic, it was sold right across Europe. From the thirteenth century and the time of the setting up of medical faculties in universities, other cities began to fabricate their own theriac under the control of doctors. The theriac of Montpellier was particularly renowned due to the selection of its ingredients and the care taken in its preparation. The formulas handed down to us by authors who worked in this city during the early decades of the fourteenth century – such as Petrus Cellarius and Bernard de Gordon – closely follow the recipe given in the Antidotarium Nicolai. Later, when Galen’s treatises on theriac were translated into Latin – De theriaca ad Pisonem and De theriaca ad Pamphilianum in the fourteenth century, then the two books in De antidotis two centuries later – the works on pharmacopoeia of the modern era more closely followed the composition known as_ Andromachus’ theriac_, as given by the Greek scholar.

Thus there was no unique formula: those writers who have described theriac have left lists that differ from one another in terms of both the number and nature of the drugs. Whilst comparison of the various recipes is a heavy research task, it is possible that two reasons explain the multiple variations: the authorities to whom the authors refer and the need to find substitutes with similar properties for drugs that were difficult to procure in the West. To replace rare and costly drugs, herbalists and pharmacists did not hesitate to use succedanea, and the formulas of the modern era propose medicinal plants of local provenance in place of “ultramarines”. Falsifications were common and constantly denounced by the authorities.

Diverse measures, such as public preparations, were imposed by physicians; thus the Faculté de médicine in Paris monitored the corporate body of apothecaries from 1271, and, as was customary, in 1422 it assembled all the herbalists of the city to make them swear an oath that, amongst other things, “they shall not replace any medicine with another in any recipe without the agreement of the master who ordered it, and that they shall only follow the recipe of the master; if they do not have the herb or medicine prescribed, they shall refer the question to the master so that he shall supply it.”

Over and above the empirical approach, the Latin savants also took up the medical and philosophical line of the Arab authors on the subject of the manner in which theriac acted. The translation of Avicenna’s Canon in the twelfth century by Gerard of Cremona stimulated considerable theoretical considerations also outside circles of physicians. For instance, Robert Grosseteste (died in 1253), whose works covered more theology, philosophy and physics than medicine, made explicit reference to theriac. In the seventh book of his commentary on Aristotle’s Physics, he cites Avicenna’s Canon on the question of the methods with which medicines act, which was one of the Arab author’s most original contributions to the debate.

The methods are divided into two categories: acting either through their primary qualities, such as cold, heat, dryness and moistness, or by means of an inherent property that the physician-philosopher calls “specific form”. To explain Avicenna’s notion of “specific form”, Robert Grosseteste cites the example of a lodestone that has the property of attracting iron, and theriac that has the property of reinvigorating the heart and thus of fortifying the health. However, the property inherent to a medicine’s specific form can only be observed through experience: knowledge of a medicine’s primary qualities is not enough for specific form to be deduced logically, and thus experimentation is necessary. The debate over theriac was particularly lively in Montpellier during the period 1290-1340. Several manuscripts were drawn up in reaction to Avveroës’ treatise, of which a Latin version circulated from 1280 or so (though its author and exact date are unknown). Although the tone was more empirical amongst some authors, for example, Arnaud de Villeneuve and Bernard de Gordon, and more scholastic amongst others, such as William of Brescia, these works too adopted the notion of “specific form” to explain the active principle of theriac.

They examined the nature of the preparation, discussed its specific usages and concluded, in agreement with Avveroës, though they were also happy to criticise him, that it is a new treatment for an individual in good health. Thus, the pharmacological speculations of medieval savants justified the place of importance accorded to theriac. But here again, studies are lacking to elucidate the balance between the two approaches: on the one hand, an empirical (if not magical) recourse to a universal panacea, and, on the other, an enquiry into the active principle of a preparation that today would fall under the heading of polypharmacy.

Theriac became the most famous preparation in the Western pharmacopoeia. The pharmacist Pierre Maginet wrote in 1623, “Compared with all our other compositions, theriac is the sun among the planets, fire among the elements, gold among the metals, cedar among the trees”. In 1688 a work called Thériaque d’Andromaque, dispensée et achevée publiquement par Moyse Charas appeared in Paris. Charas, who was a doctor and pharmacist, at length described the preparation that he had made in two stages, in 1667 and 1669. In spite of the criticism following Paracelsus by supporters of medicines of chemical origin, theriac was fabricated and recommended until the nineteenth century.

As late as 1884 it was still mentioned in the Codex, the compendium of medicines and pharmaceutical preparations approved by the Faculté de médecine that all French pharmacists were obliged to procure and to which they were required to conform. In the 1908 edition it disappeared with this brief comment: “Having held such a great and longlasting place in pharmacy and therapeutics, it has left the domain of history to be relegated to that of legend”.

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