Читать книгу The Greatest Benefit to Mankind: A Medical History of Humanity - Roy Porter - Страница 32

The eastern Mediterranean experienced turmoil of its own. Prolonged warfare between the Byzantine (Roman) and Persian empires caused chaos; within Byzantium, ethnic tensions between Greeks, Semites, Persians, Armenians and Slavs were exacerbated by vitriolic doctrinal splits amongst Christian sects. The heroic military efforts of Justinian (r. 524–65) to recover the western Roman Empire and his ruinous building ambitions caused further upheaval. The appearance of bubonic plague in 541 heralded two hundred years of devastating outbreaks. The Greek heritage grew less assured. Learned medicine continued in large cities, especially Alexandria, but most doctors were increasingly working in isolation, and religion assumed a dominant role in everyday life. The scene was set for Islam.

Muhammad (570–632) was a member of the tribe of Quraysh who ruled Mecca. He began life as a poor orphan but rose to become a wealthy merchant. When he was about forty, he received a call, and the Qur’an (Koran) was revealed to him in visions. He gradually assumed the mantle of the last of the prophets in a long line beginning with Adam and Noah. In 622 an assassination plot against the Muslims in Mecca led him to flee to Medina where he commanded a growing following.

By the time of his death, practically all of Arabia had been won over for Islam, and a century later his adherents had conquered half of Byzantine Asia, all of Persia, Egypt, the Maghreb (North Africa) and Spain, where Cordova became capital of the western caliphate, the Baghdad of the West, the source of Hispano – Arabian culture, together with Seville and Toledo, which peaked in the twelfth century, and later still Granada. Unlike Christianity, Islam was not a proselytizing faith which saw itself as superseding earlier ones, and the Qur’an granted Christians and Jews special status as ‘People of the Book’ (ahl al-Kitab), adherents of the other scripture-based faiths. Before the papacy launched the Crusades, Christians, Jews, Muslims and others rubbed along well together. What brought some unity to the Arab empire was not religion but a common language.

The pre-Islamic Near and Middle East possessed a popular medicine akin to that of the Mediterranean. Materia medica included plants and herbs familiar to Greek medicine, though certain remedies were distinct. Truffle juice was applied to eye disorders, clarified butter was used against fever, dates were prescribed for children’s maladies, while camel’s urine toned up the system. Cupping, cautery and leeches were employed for blood-letting; wounds were disinfected with alkali-rich saltwort, and ashes were applied to stanch bleeding. Knowledge of internal organs was meagre, and surgery was basic.

Interwoven with these practices were animist beliefs. Ill health was widely attributed to spirits. To restore well-being, the sick had to outwit them or recruit the protection of superior magical powers. The forces responsible for ill health were the jinn and the evil eye (al-’ayn), a glance believed to harm those upon whom it fell. The jinn (plural :jinni, whence genie) was a lesser spirit interfering with human beings; one could see, bargain with and even kill jinni, and they could bring good luck as well as bad. Healthwise, however, their activity was harmful, and they were held particularly to blame for fevers, madness and children’s diseases.

Avoidance of sickness thus demanded practical and magical precautions to ward off evil spirits. There were incantations against ailments like leg ulcers and night-blindness, and charms guaranteed a safe delivery for pregnant women. Popular observances countered unwelcome visitations from spirits: thus a boy suffering from a blistered lip would beg for food and then toss any offerings to the dogs; as the blister had originally been attracted by his eating food, it would be drawn to the scraps and so transferred to the dogs. Practical medicine was everyone’s business, but those who, like bleeders and cuppers, possessed particular skills were paid for their services, while the magical side of traditional medicine was performed by diviners, seers and charmers.

Initially the rise of Islam posed no threat to this traditional lore. The Qur’an has almost nothing to say about medicine, apart from advice to the faithful to wash for prayer and praise for the healing powers of honey. Scripture accepted the jinn, and Islam raised no objection to the indigenous medicine of conquered provinces; formal learning, including medicine, continued in the (Christian) Jacobite and Nestorian monasteries of Syria and Mesopotamia.

The seventh and eighth centuries, however, brought the transformation of Islam from a simple monotheistic creed to a formal faith, laying down theological orthodoxy. Popular medicine became mired in controversy because of its animistic bent, and many traditional practices were condemned. Conflict was sharpened by the fact that, in the centuries after the Prophet’s death (632), discussion of issues tended to be dominated by claims that Muhammad or his companions must have pronounced on the matter. Such pious dicta grew into a distinct corpus called hadith, the sayings of the Prophet. Old-style healers also began to claim Muhammad’s support: traditions alleged to be from the Prophet told, for example, that ‘the evil eye is real’; that there was medicinal power in his saliva; and that the water of the well of Zamzam in Mecca had healing properties. Being God’s word, the Qur’an too must have great powers. Hence, to assist a woman in labour, certain verses should be written on a slate, cleaned off, and the water given her to drink. The parallels with Christian healing are plain.

As Islam developed, traditional medicine was called into question. One major dilemma was plague. Early views had attributed epidemics to the jinn. This explanation was displaced by beliefs setting pestilence within the monotheistic framework of an Allah who was the ordainer of all things (including disease), yet was just and merciful. Though with the growth of Islam, many folkloric practices were attacked, medicine itself was not called into question, since Islam taught that ‘God sends down no malady without also sending down with it a cure.’

It is often held that a distinctive Arab – Islamic medicine dates from the time of the Prophet and stems from a hospital (bimaristan: Persian for house for the sick) and academy at Jundishapur, near Susa in southern Persia. Jundishapur was certainly a meeting-place for Arab, Greek, Syriac and Jewish intellectuals, but there is no evidence that any medical academy existed there. Only in the early ninth century did Arab – Islamic learned medicine take shape. The first phase of this revival lay in a major translation movement, arising during the reign of Harun al-Rashid (r. 786–809) and gaining impetus in the caliphate of his son, al-Ma’mum (r. 813–33). It was stimulated by a socioeconomic atmosphere favourable to the pursuit of scholarship, a perceived need among both Muslims and Christians for access in Arabic to ancient medicine, and the ready availability of the relevant texts.

Crucial in this ‘age of translations’ was the establishment in Baghdad, capital of the Islamic empire under the Abbasid caliphs, of the Bayt al-Hikma (832), a centre where scholars assembled texts and translated into Arabic a broad range of non-Islamic works. The initial translation work was dominated by Christians, thanks to their skills in Greek and Syriac. The main figure was Hunayn ibn Ishaq (d. 873), later known in the West as Johannitius, a Nestorian Christian from the southern Iraqi town of al-Hira. Hunayn, who travelled to the Byzantine empire in search of Galenic treatises and was said to wander the streets of Baghdad reciting Homer in Greek, was amazingly prolific. With his pupils, he translated 129 works of Galen into Arabic (and others into Syriac), providing the Arabic world with more Galenic texts than survive today in Greek.

Encouraged by official patronage, the translation drive proceeded rapidly. Hundreds of Greek texts were rendered into accurate and elegant Arabic; works in Syriac and Sanskrit were also translated, reflecting the cosmopolitanism of ninth-century Baghdad. The impact was enormous, not least in view of the hundreds of ancient texts saved in Arabic for posterity. The favoured author was Galen, and he thereby became the father figure for Arabic medicine. Even the Hippocratic Corpus was known primarily through his commentaries.

Continuing into the early eleventh century, the translation movement revived learned medicine, made Arabic a tongue for original scholarship, and gave Islamic culture access to a galaxy of learning. The early translators also launched an original medical literature of their own. Hunayn authored essays on ophthalmology, known as his Kitab al-’ashr maqalat fi l-’ayn [Book of the Ten Treatises on the Eye]. His Medical Questions and Answers, a student text book, adopted the threefold scheme of discussing first the natural organisation of the body, then neutral factors, and finally unnatural (or contra-natural) disease – a handling reproduced by all Arabic writers in the Galenic tradition. By the late ninth century medical men had access to a stock of ancient texts in superior Arabic translations and an expanding corpus of original scholarship glossing Greek works.

This in turn created a need for fresh syntheses, leading to the supreme achievement of Arab – Islamic medicine, the medical compendia. The first was the Firdaws al-hikma [Paradise of Wisdom] by ’Ali ibn Rabban al-Tabari (c. 850), in which the author, an Islamic convert, sought to collect a summa of medical erudition worthy for presentation to the Caliph al-Mutawakkil. His sources were Arabic and Persian translations of ancient classics, and his citations included not only Hippocrates, Galen and Dioscorides but Persian and Indian writers (this Indian element was soon, however, eclipsed by the Greek tradition).

Persia produced one of the greatest Muslim physicians and philosophers, Muhammad ibn Zakariya al-Razi, known in the West as Rhazes (865–925), author of some 200 treatises. In his youth (anecdotes tell us) al-Razi studied and practised medicine at the bimaristan of Baghdad. He later returned to Rayy, near Teheran, as head of its hospital, at the invitation of Persia’s ruler, Mansur ibn Ishaq; al-Razi dedicated to him Al-Kitab al-mansuri fi’l-tibb [The Mansurian Book of Medicine], a manual in ten books. The first six ran through such concerns as anatomy, physiology and materia medica, while the last four dealt with clinical matters: diagnosis, therapy, surgery and pathology, discussing diseases from head to foot. His separate work, al-Tibb al-ruhani [Spiritual Physic] handled diseases of the soul within a discussion of philosophy. Having won fame in Rayy, al-Razi went to Baghdad to take charge of its new al-Mu’tadidi Hospital. He spent his declining years in Rayy suffering from glaucoma, before becoming blind.

Al-Razi developed a medical philosophy. In the first chapter (‘On the Excellence and Praise of Reason’) of al-Tibb al-ruhani, he asserted that reason (al-’aql) was the ultimate authority which ‘should govern, and not be governed; should control, and not be controlled; should lead, and not be led’. He condemned slavish authority, devoting a large book, Fi’l-Shukuk ’ala Jalinus [Doubts about Galen], to criticism of precepts in Galen, beginning with al-Burhan [Demonstration], and ending with his large work, Fi’l-Nabd [On the Pulse]. In his introduction to Fi’l-Shukuk, he nevertheless declared himself Galen’s disciple; but since the art of healing was a form of philosophy, it could neither renounce criticism nor benefit from worshipping the dead. Extolling the progress of scientific knowledge, he wrote in Fi Mihnat al-tabib [On Examining Physicians and on Appointing Them] that ‘he who studies the works of the Ancients, gains the experience of their labour as if he himself had lived thousands of years spent on investigation.’ Nevertheless ‘all that is written in books is worth much less than the experience of a wise doctor.’

Al-Razi’s best-known work, al-Hawi fi’l-tibb [Continens, or Comprehensive Book of Medicine], was a commonplace book of detailed notes and transcribed bits of texts, beginning with diseases of the head and working down. Devoted to specific subjects, these files were gradually filled with jottings; the result was a kind of filing system, organized by subject though lacking overall form. Al-Razi incorporated case histories from earlier sources, notably Galen, but he also registered his own cases, recording the patient’s name, age, sex and occupation. Clinical observations of his own illnesses are also preserved: notes on how he had treated throat inflammation by gargling with strong vinegar; elsewhere he wrote about his swollen right testicle (emetics helped recovery). From these notes, al-Razi took the material for books such as al-Qulani [Cholic] and al-Jadari wa’l-hasba [Smallpox and Measles]. Hitherto all exanthemata (infections causing rashes) had tended to be lumped together; al-Razi was the first to distinguish them as separate diseases: ‘The physical signs of measles are nearly the same as those of smallpox, but nausea and inflammation are more severe, though the pains in the back are less. The rash of measles usually appears at once, but the rash of smallpox spot after spot.’ It is intriguing to find measles regarded as the more severe.

Al-Razi had many asides on medical practice: noblemen, he judged, echoing Galen, were entitled to special consideration in prescribing; for them unpleasant tasting drugs should be made palatable. But he did not neglect the poor, for whom he wrote his Man la yahduruh al-tabib [Who has no Physician to Attend Him]. Khawass al-ashya’ [Properties of Things] included the role of alchemy in medicine and the secret recipes and remedies of nature. Experience must be the touchstone of truth:

since many wicked people tell lies with regard to such properties, and we do not possess decisive means to distinguish the truth of rightful men from the false testimony of liars – save only actual experience – it will be useful not to leave these claims scattered but to collect and write them all. We shall not accept any property as authentic unless it has been examined and tried.

Al-Razi won renown, and his medical works later enjoyed ascendancy in the Latin West. In 1279 al-Hawi fi’l-tibb was Latinized under the title of Continens by the Sicilian Jew Faraj ibn Salim (Farragut), and printed five times between 1488 and 1542. His al-Mansuri fi’l-tibb [Liber ad Almansorem] and his al-Tibb al-muluki [Liber regius] were also popular. His work was in turn mentioned by Abu Rayhan ibn Ahmad al-Biruni (Al-Biruni, 973–c. 1050), who wrote on a variety of subjects: astronomy and astrology, mathematics, geography, history, philosophy and religion, mechanics, mineralogy and medicine. As well as editing al-Razi, he translated much of Galen’s otherwise lost Commentary on the Hippocratic Oath.

The Arabic medical compendium culminated in two works of the tenth and eleventh centuries. ’Ali ibn al’-Abbas al-Majusi (Haly Abbas, d. late tenth century) was a native of al-Ahwaz in southern Persia, but little is known about his life. Following al-Razi’s example, he divided his Kamil al-sina’a al-tibbiya [The Complete Medical Art] into two sections, on theoretical and on practical medicine, each including ten treatises on specialized topics, and his introduction surveyed the development of medicine up to his own times. Well-organized, practical, and devoting greater attention than al-Razi to anatomy and surgery, it secured al-Majusi’s medical reputation, winning a place second only to Ibn Sina’s Qanun.

The talents of Abu Ali al-Husayn ibn ’Abdallah ibn Sina (Avicenna, 980–1037) were evident from early youth. A Persian tax-collector’s son, he could, it is piously recorded, recite the Qur’an at the age of ten and was practising medicine by sixteen. If somewhat mythologized, Ibn Sina represents the pinnacle of the Galenic ideal of the philosopher – physician in Islam: he was the first scholar to create a complete philosophical synthesis in Arabic.

In a wandering life driven by burning intellectual curiosity, Ibn Sina held positions as a jurist, a teacher of philosophy, an administrator, and as physician to various courts. His autobiography boasts that his writing was done on horseback during military campaigns, in hiding, in prison and even after drinking bouts. The outcome was two hundred and seventy tides which include two monumental encyclopaedias, one on science (Kitab al-Shifa) and one on medicine (Kitab al-Qanun).

The Kitab al-Qanun [Canon, or The Medical Code] arranges in its million words the whole of medical science: the legacies of Hippocrates, Galen, Dioscorides and the late Alexandrian physicians, enriched by the works of Arab predecessors. It consists of five books arranged by subject, with subdivisions and summaries. Book I deals with general principles, starting with the theory of the elements, humours and temperaments and moving on to anatomy, physiology, hygiene, aetiology, symptoms and treatment of diseases. Book II is on materia medica, describing the physical properties of simple drugs, and how to collect and preserve them (a separate section lists 760 drugs alphabetically). Book III deals with specific diseases, classified from head to heel, together with the aetiology, symptoms, diagnosis, prognosis and treatment of each. Anatomy is also discussed. Book IV is concerned with diseases, such as fevers, affecting the whole body; it also covers ulcers, abscesses, swellings, pustules, fractures and injuries, as well as poisons, and there is even a section on anorexia and obesity. Book V describes compound drugs – theriacs, electuaries, emetics, pessaries, liniments, and so on – together with their medicinal uses.

In addition to the Canon, Ibn Sina wrote about forty works on medical subjects. The best known is Urjuza fi’l-tibb [A Medical Poem], a summary of the principles of medicine in verse as a mnemonic aid to students. But it was the Qanun that became the authoritative text on medicine for centuries, both in Islam, where it remains influential, and in Latin Christendom, earning him such tides as the ‘Galen of Islam’. His pre-eminent standing in the Latin West is symbolized by Dante’s ennobling him between Hippocrates and Galen.

Critics have alleged that al-Razi’s and Ibn Sina’s work stifled independent thought. Certainly the Canon was taught and annotated, but some of the commentaries were highly critical, notably that of the Andalusian physician, Ibn Rushd (Averroës, 1126–98). Criticism of its anatomy section also gave rise to the description by Ibn al-Nafis (d. 1288) of the pulmonary (lesser) circulation, nearly three hundred years before Servetus and Realdo Colombo (see below).

All these great compendia originated in Persia, but texts were also produced elsewhere, including the work of Abu’l-Qasim Khalaf ibn Abbas al-Zahrawi (Albucasis, 936–1013). Born in Cordova, al-Zahrawi was author of a medical compendium entitled Al-Tasrif li-man ’ajaza ’an al-ta’lif [The Recourse of Him Who Cannot Compose (a Medical Work of His Own)]. Some 1500 pages in length, and divided into thirty treatises, it offers information on topics elsewhere neglected, including surgery, midwifery and child-rearing, and detailed accounts of bleeding, cupping and cautery. Treatise 30, the most celebrated, deals with surgery, describing operations for the stone, cauterization of wounds, sutures, obstetrical and dental procedures, setting fractures and dislocations, procedures for opening abscesses and eye surgery, to say nothing of 200 illustrations of medical and dental instruments, many of which he designed himself. This surgical treatise won enormous acclaim in the Latin West.

Albucasis gave a definitive account of cautery, which was central to Arabic surgical practice, being used to open abscesses, burn skin tumours and haemorrhoids, cleanse wounds, and stanch blood flow. Like bloodletting, it was also performed in the treatment of internal diseases, and Albucasis advised the cauterizing iron for almost every ailment, including epilepsy, stroke and melancholy. Apart from him, it is unlikely that the Arabic surgical authors ever practised surgery themselves.

Also Spanish-born was Abu-l-Walid Muhammad ibn Ahmad ibn Muhammad ibn Rushd (d. 1198), latinized as Averroës. Physician, philosopher and jurist, Ibn Rushd is known in the West for his classic commentaries on Aristotle. Coming from a long line of lawyers, he served as a judge in Cordova and Seville and also as physician to the ruling Almohad family – though he later came under attack for his views, leading to exile and the burning of his philosophical works. His major medical text is the encyclopaedic al-Kulliyat [The Book of General Principles], written between 1153 and 1169. Consisting of seven books dealing with anatomy, health, pathology, symptoms, dietetics and drugs, hygiene and therapeutics, it was conceived as a companion to al-Taisir, written by his colleague, Ibn Zuhr (Avenzoar, c. 1091–1162), which dealt with specific diseases. Together they constituted a comprehensive medical treatise, becoming familiar in the West through their Hebrew and Latin translations [Colliget], and printed together in Venice in 1482. On physiological issues he preferred Aristotelian explanations over Galen’s, but he was not a slavish follower, and both the Colliget and the Commentaries show independent thinking.

Rabbi Moshe ben Maimun (1135–1204: Moses Maimonides or Abu ’Imran ibn ’Ubdaidalla Musa ibn Maimun) was another scholar who testifies to the intellectual pre-eminence of Spain at this time. The ascendancy of a fanatic Muslim ruling group forced the Jewish Maimonides, like Averroës, to flee Cordova in 1148, and he spent the next ten years in exile. In 1158, he settled in Fez, but moved on a few years later to Cairo where he stayed until his death. His medical practice earned him celebrity; in 1174 he was appointed court physician to Saladin, sultan of Egypt and Syria, and he became the head of the Jewish community in Egypt.

Paralleling the Islamic intellectuals of his day, Maimonides was a polymath, combining philosophy, logic, theology, astronomy and medicine. Apart from his major fourteen-volume religious work, the Mishneh Torah, which is in Hebrew, his books were written in Arabic. His ten medical works, all surviving, mostly in Arabic but some only in Hebrew translation, include the Extracts from Galen, a collection of Galen’s writings, and a Commentary on the Hippocratic Aphorisms. His Medical Aphorisms is of particular interest because of its criticism of Galen for preferring Aristotelian over biblical cosmology. He emphasized the duties of physicians: ‘may I never see in the patient anything but a fellow creature in pain.’

There are various treatises on individual topics (on haemorrhoids, asthma, poisons and their antidotes, and so forth), but Maimonides’ most famous medical book was his Regimen of Health – short, much reproduced, often translated, and full of solid advice:

How can a person heal his intestines if they are slightly constipated? If he is a young boy, he should eat salty foods, cooked and spiced with olive oil, fish brine and salt, without bread, every morning; or he should drink the liquid of boiled spinach or cabbage in olive oil and fish brine and salt. If he is an old man, he should drink honey mixed with warm water in the morning and wait approximately four hours, and then he should eat his meal. He should do this for one day or three or four days if it is necessary, until his intestines soften.

While not adding anything original to Graeco – Arabic medicine, Maimonides’ considerable literary output earned him respect, and, like other contemporaries, he was widely cited by leading European authorities such as Henri de Mondeville, Arnald of Villanova and Guy de Chauliac.

An original aspect of Arab – Islamic medicine was its contribution to pharmacology. The lands overrun by Arab warriors yielded an abundance of plants, animals and minerals; hence, whereas Dioscorides’ materia medica had included less than a thousand plants, animals and minerals, that of Ibn al-Baytar (d. 1248) astonishingly listed over 3000 items, including 800 botanical drugs, 145 mineral drugs, and 130 animal drugs. The medical formulary of al-Kindi (Yaqub ibn-Ishaq al-Kindi, c. 800–870) served as a source for Arabic treatises on pharmacology, botany, zoology and mineralogy. His writings contained many Persian, Indian or Oriental drugs unknown to the Greeks, including camphor, cassia, senna, nutmegs and mace, tamarind and manna.

In the eleventh century, al-Biruni described more than a thousand simples in his Kitab al-Saydanah fi al Tibb [Book of Pharmacy in the Healing Art]. The Minhaj al-Dukkan via Dustur al-’yan [Handbook for the Apothecary Shop], written in Cairo in 1259 by the Jewish pharmacist Abu al-Muna Kohen al-’Attar, was much more than a mere formulary of the materia medica. Intended to provide instruction for his son, it included drug synonyms, recipes for syrups, remedies to aid digestion, fumigations and liniments and pharmaceutical weights – and also covered the duties and shop practices of the pharmacist.

The word ‘drug’ is of Arabic origin, as are alcohol (it then referred to a sulphurous powder), alkali, syrup, sugar, jujube and spinach; and many new drugs were introduced by the Arabs – benzoin, camphor, myrrh, musk, laudanum, naphtha, senna and alcohol. From the time of the ‘father’ of Arabic alchemy, Jabir ibn Hayyan (Jebir or Geber), who lived in the tenth century, they developed the alchemical techniques of crystallization, filtration, distillation and sublimation, alongside investigations into the properties of things contained in a ‘secrets of nature’ tradition paralleling that in the West. They created the first pharmacies, which also served as rendezvous for the exchange and discussion of information.

Overall, the value of Arab contributions to medicine lies not in their novelty but in the thoroughness with which they preserved and systematized existing knowledge. Great effort was devoted to its dissemination and medical texts were repeatedly copied. Over 5000 medical manuscripts in Arabic, Turkish, and Persian survive in libraries in Turkey alone, with more than fifty copies of Ibn Sina’s Qanun, and still more transcripts of the many later commentaries on it. And though the era of the great Arabic medical compendia ended with the Qanun, such works long continued as foci of scholarly attention, commentaries in turn becoming the bases for super-commentaries, such as that of ’Ala’ al-Din ibn al-Nafis (1200–88).

Growing up in Damascus, Ibn al-Nafis studied at the famous Nuri hospital there. As with so many Arabic physicians, his interests were wide: medicine, logic, grammar and theology; he also wrote numerous commentaries on Hippocrates and Ibn Sina. His Mujiz al-Qanun, an epitome of Ibn Sina’s Canon, was vastly popular, but the work for which he is best known today is the commentary on the anatomy of Ibn Sina, the Sharh Tashrih al-Qanun, since one passage contains the first description of the pulmonary circulation.

Contrary to the Galenic description of the passage of blood from the right ventricle directly through ‘invisible pores’ to the left ventricle, Ibn al-Nafis states that no blood could pass through the interventricular septum, ‘the substance of the heart there being impermeable … therefore, the blood must pass only through the lungs’. He thus proposed for the first time the pulmonary circuit of the blood:

This is the right cavity of the two cavities of the heart. When the blood in this cavity has become thin, it must be transferred into the left cavity, where the pneuma is generated. But there is no passage between these two cavities; the substance of the heart there seems impermeable. It neither contains a visible passage, as some people have thought, nor does it contain an invisible passage which would permit the passage of blood, as Galen thought.… It must, therefore, be that when the blood has become thin, it is passed into the arterial vein [pulmonary artery] to the lung, in order to be dispersed inside the substance of the lung, and to mix with the air. The finest parts of the lung are then strained, passing into the venous artery [pulmonary vein] reaching the left of the two cavities of the heart.

His description, however, seems to have fallen into obscurity. A similar description of the pulmonary circuit appeared in 1553 by the Spaniard Michael Servetus, and then in 1559 by the Italian, Realdo Colombo, but there is no evidence that either had access to his work.