Showing posts with label Avicenna. Show all posts
Showing posts with label Avicenna. Show all posts

Tuesday, December 5, 2023

Medieval Germ Theory?

It was Ignaz Semmelweis in the 1840s in Vienna who noticed a link between illness (and death) and unsanitary conditions, specifically a link between women dying during childbirth who were aided by people who also were performing autopsies. He spent years trying to implement a universal handwashing policy. He did not know what was causing the deaths, but he saw a link to something.

Figuring out the cause of disease was a goal for anyone practicing medicine from the beginning of the discipline. Long before germ theory was developed, the miasma theory was proposed by Hippocrates (c. 460 – c. 370 BC): that some form of "bad air" or even "bad water" arising from rotting matter caused diseases like the Black Death, cholera, and other infections. This was an important move away from the theory of supernatural causes of illness. (There was also the idea of an imbalance in the body's natural humors.) The miasma theory allowed infection to pass through a population because of the environment, not from personal contact.

To counter bad air, you would naturally want "good air."  medical faculty of the University of Paris, writing in 1348 to explain the causes of the Black Death, said "The present epidemic or pest comes directly from air corrupted in its substance" and recommends incense which "hampers putrefaction of the air, and removes the stench of the air and the corruption [caused by] the stench."

Earlier, however, there were counters to the miasma theory.

The Classical Era and Middle Ages did have theories of person-to-person contact. Thucydides (c.460BCE - c.400CE) believed that the plague of Athens was being spread by personal contact. Galen (129 - c.200CE) referred to "seeds of plague" in the air. Isidore of Seville also mentioned "plague-bearing seeds." Avicenna (c.980-1037) was widely studied, and he linked the miasma theory with personal contact, believing an ill person could infect others by transmitting the "bad air" through breathing. His example was tuberculosis, and he believed that disease could also be transmitted through dirt and water, anticipating Semmelweis by 800 years.

Recent posts have mentioned Bologna as an important center for medical study, so it is not surprising that it was a professor of Bologna, Tommaso del Garbo (c. 1305–1370), who in 1345 promoted Galen's "seeds of plague" idea in his works

It took Girolamo Fracastoro in 1546, however, to publish De Contagione et Contagiosis Morbis ("On Contagion and Contagious Diseases"), three volumes on different diseases and their avoidance and treatment. He believed that there were particles that could travel through the air or by direct contact.

The idea that these "seeds of disease" were living things (what we call "germs") and traveling from one person to another was not being entertained, simply because there was a long-standing theory that living matter could arise spontaneously from putrefaction, and no one believed in invisible living things floating in the air. The belief that life could spring from rotting organic matter hindered understanding of bacteria already existing in the air around us. As it turns out, there were plenty of examples of Spontaneous Generation; let's talk about those tomorrow.

Friday, October 27, 2023

Causes of the Bubonic Plague

The Bubonic Plague's first appearance in medieval Europe from 1348-1351, and it was terrifying. At least one-quarter to one-third of the population died in those few years; entire villages were depopulated, and no country was untouched.

King Philip VI of France asked the University of Paris to determine the cause. Forty-nine members of the medical staff studied the matter and wrote the Paris Concilium.

They produced more than one theory of why humans were suffering from it, while maintaining that the plague was too mysterious for human beings to ever truly understand the origin. They drew from the available authorities: Avicenna's work on pestilential fever, Aristotle's Meteorology on weather phenomena and putrefaction, Hippocrates' Epidemics on astrology in medicine.

Their theories:

—The Concilium followed Aristotle's idea that a conjunction of Jupiter and Saturn was disastrous. Albertus Magnus believed a conjunction of Jupiter and Mars would bring plague. A conjunction of Saturn, Jupiter, and Mars took place in 1345 right after solar and lunar eclipses, under the sign of Aquarius, compounding the disastrous effects of the planets. Jupiter was sanguine, hot and wet—the worst combination that would lead to putrefaction.

—Another possible cause was poisonous gases released during earthquakes. Disadvantageous conjunctions of constellations produced winds that distributed gases rising from rotting carcasses in swamps. The poisonous vapors would be inhaled and go straight to the heart (they thought the heart was the organ of respiration), and then cause the body's vital organs to rot from the inside.

—There was also the possibility of God's punishment for man's wickedness.

Of course, there was no reason to believe that these causes were mutually exclusive.

The plague was devastating, and also didn't end in 1351. It remained endemic to Europe, as I'll discuss next time.

Thursday, October 26, 2023

A Few Medical Firsts

Gentile da Foligno was a physician who learned his art at Padua and Bologna and then became a teacher—quite a wealthy one, as it happens. At the University of Perugia in Siena he made 60 gold florins per year (1322 - 1324). He then went back to his origin at the request of the Lord of Padua, Ubertino I da Carrara.

Besides teaching, he produced several medical treatises. One was a massive and widely copied commentary covering the Canon of Medicine by Avicenna. The Nuremberg Chronicle of 1493 referred to him as Subtilissimus rimator verborum Avicenne, "that most subtle investigator of Avicenna's teachings"; the illustration above shows Gentile learning "at the feet of Avicenna."

He is said to have performed the first medical dissection in centuries. Even the Romans, for all their search for knowledge, did not approve of cutting open the deceased. Examining the insides of the human body was necessary for starting to learn how organs work; for example, how liquids flow through the body.

Foligno wrote a commentary on urine and suggested that the blood passes through "porous tubules" (per poros euritides) in the kidneys, which strain it and pass the urine to the bladder. He was also the first to suggest that a fast pulse rate led to higher urine output (as a faster metabolism would). He also believed there was a correlation between the heart and the color of urine. A Journal of Nephrology article says he may have been the first cardionephrologist in history.

He also wrote a popular treatise on the Black Death, and recommended theriac for its treatment. Unfortunately, theriac preparation was complex and time-consuming, so there may not have been enough of it to go around. Not that it would have helped: presumably Foligno would have had access to some; however, he died of the plague at its start, on 18 June 1348.

To cure the plague, you would probably want to know what caused it, and that was a puzzle. Tomorrow I'll tell you of the Paris Consilium, who believed they had the answer.

Friday, March 29, 2019

The Theory of Impetus

1582 woodcut demonstrating
impetus with artillery
Impetus is the force or energy with which a body started to move. The term itself entered the English language in the 17th century, but the concept was studied long before that.

Aristotle thought that, for an object in motion to continue to move, it must have a continuous force behind it. John Philoponus in the 6th century thought rather that the initial force was necessary and did not need anything else, but that the initial force would therefore be only temporary; hence an object in motion's observed tendency to slow and stop. Avicenna in the 11th century agreed with him, calling the phenomenon "projectile motion."

In the 12th century, an Islamic philosopher, Hibat Allah Abu'l-Barakat al-Baghdaadi, recognized (finally!) that the motive force diminishes with distance from the mover.

Jean Buridan, writing in French in the 14th century, called this force "impetus" (from Latin impetere, "to assail"), and even expressed it mathematically: impetus = weight x velocity. Even he, however, treated impetus as if it were momentum. Modern physics distinguishes the two thusly: impetus is the initial force behind a moving object, momentum is "the quantity of motion of a moving body." It seems universally understood by anyone who has ever thrown a ball that Aristotle's option of a continuous motivating force is simply quaint.

Buridan understood that there was resistance (such as the air) that caused the impetus to fade. There was a case, however, in which impetus did not have resistance. God, when putting the celestial spheres in motion, did so in a way that created infinite impetus so that they would (obviously!) never stop moving.

To which the medieval world replied: Thank Heavens.

Monday, December 17, 2018

Rabies

Rabies, from the Latin rabies which means "madness," has been noticed for a long time. The Codex of Eshnunna (c.1930BCE), found on two cuneiform tablets and pre-dating the Code of Hammurabi, declares the owner of a dog who shows signs of rabies is to be fined if the dog bites someone. Aristotle in 300 BCE described rabies as a disease that can be transmitted from a dog to the dog's victim. Excess salivation was a sign that a dog owner should take care to prevent the dog from biting someone. Rabies was known to Avicenna, who explained its symptoms, method of transmission, and treatment.

Treatment almost always failed until the modern era. There were reported cases of people surviving before modern methods of treatment, but not until Louis Pasteur and Émile Roux developed their vaccine in 1885 was there an effective way to prevent the spread.

But the Middle Ages had a solution: St. Hubert's Key.

St. Hubert, or Hubertus, was the patron saint of hunters and hunting, and therefore of hunting dogs, and therefore of rabid dogs. St. Hubert's Key was an example of a sacramental, which is the church's word for an amulet or talisman. Whereas an amulet or talisman were supposed to have magical properties, a sacramental's effectiveness depended on the faith of the user.

St. Hubert's Key was a piece of iron: either a nail or a cross or cone. They were given out by the monks of the Benedictine abbey where Hubert's remains were, as tokens to go to folk who could not make the pilgrimage to the abbey. These items were hung on the wall of your house for protection against disease.

How did this cure rabies? The piece of iron would be heated and placed on the site of the bite by a priest. The practice is recorded in the 1870s in the Ardennes region (where Hubert was active while alive) of branding a dog with St. Hubert’s Key to guard him from rabies.

Tuesday, July 29, 2014

The Abbasid Caliphate

The Abbasid Caliphate has only been mentioned so far as a target of the Assassins, but deserves more attention. Descended from Muhammad's uncle Abbas, the caliphate took power from the Umayyad caliphate and ruled from 750 until its conquest by Mongols in 1258.

That means that the Abbasid Caliphate was "in charge" during many of the Islamic interaction with Europe mentioned in this blog:


Besides math and philosophy, the Abbasid Caliphate was at the forefront of technology, adopting the use of Chinese paper-making techniques and gunpowder. Arabs developed the sextant, windmills for industrial use, and kerosene from petroleum.

The Abbasid's first capital was Kufa, on the banks of the Euphrates, but they shortly chose a different city, whose only shortcoming was that it did not exist.

On 30 July, 762, that would change; but that's a story for tomorrow.

Tuesday, April 30, 2013

A Pain in the Ass

(I apologize if the title—or the topic—is too crude for some.)

The poor fellow to the right (the one half showing) is suffering from an anal fistula, described thusly:
... a small channel that can develop between the end of the bowel and the skin near the anus.
... can cause bleeding and discharge when passing stools - and can be painful. ...
In some cases, an anal fistula causes persistent drainage. In other cases, where the outside of the channel opening closes, the result may be recurrent anal abscesses. The only cure for an anal fistula is surgery. [WebMD]
Nowadays it is called a "pilonidal cyst." At the very least, inconvenient; in many cases, extremely painful, especially when sitting down.

At a time when many men spent long stretches of time bouncing on horseback, these fistula-in-ano (to give it the Latin phrase) were debilitating. Fortunately, soldiers of Edward III's time had a solution in the skill of John of Gaunt's favorite physician and surgeon.

John Arderne (1307-1392) left us very little information about his early life. It seems he was a surgeon in Nottinghamshire. During the Hundred Years War, he probably traveled with the army; his writing suggests a well-traveled man with wide experience of the world as well as medical practices.

He produced the definitive work on treating this particular medical problem. His writing describes the cause and the treatment, and describes the surgical instruments needed for his procedures. He also shows knowledge of Galen & Guy de Chauliac, Avicenna, and Dioscorides.

Arderne was ahead of his time in some ways. He advised opium to dull pain during surgery, and the code of conduct proper for a physician. In the matter of fees, he was fine with charging a rich patient whatever the traffic would bear, but felt that the poor should be treated for free. He was also a great believer in cleanliness, and in not fussing with a wound once treated, but allowing the healing process to proceed untampered with.

That is not to say that he was "modern." He also subscribed to the belief that parts of the body were aligned with astrological signs, and that the time of the year could influence the efficacy of surgery on parts of the body.

Tuesday, December 18, 2012

Avicenna

In 1527, when the healer and alchemist Paracelsus wanted to display his contempt for tradition, he burned a book in the town square in Basle, where he had been appointed to the university by the town council. That book, allegedly, was The Canon of Medicine by Avicenna. Paracelsus had gone too far in rejecting what was still considered a fundamental work in western medicine. He was ejected from his post at the University, and from the town itself. Avicenna was too respected, even 500 years after he wrote his books.

Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā, called by the West Avicenna (c.980-1037), was mentioned here in the context of medicine. About 40 of the 240 surviving texts that he wrote (of a total of about 450!) deal with medicine. The encyclopedic Book of Healing and the Canon became standard textbooks for centuries.

The Canon assembled the best known medical knowledge to date, including Galen (129-c.200 CE) and Hippocrates (c.460-c.370 BCE) and adding a great deal of information that seems new to Avicenna. For instance:
The 'Qanun' is an immense encyclopedia of medicine. It contains some of the most illuminating thoughts pertaining to distinction of mediastinitis from pleurisy; contagious nature of phthisis*; distribution of diseases by water and soil; careful description of skin troubles; of sexual diseases and perversions; of nervous ailments. [George Sarton, Introduction to the History of Science]
Another reason why Paracelsus would want to burn Avicenna: Paracelsus was advertising his reputation as an alchemist, and believed that with salt, sulphur and mercury you should be able to produce anything. Avicenna, however, was completely opposed to the idea of alchemy, rejecting the notion that man could improve on Nature.

One could still work with Nature, however. Besides dealing with disease and injury (such as explaining how to judge how much healthy tissue could be removed during an amputation or the removal of cancerous tumors), Avicenna promoted restoring health, not just treating disease. He believed in the importance of physical exercise, of a good diet, and of a healthful environment.

Among other innovations, he lays the groundwork for modern ophthalmology, even suggesting that the optic nerves cross over each other. He laid out careful ground rules for the preparation, administration, and testing of drugs.

It has been called "one of the most significant intellectual phenomena of all times."** The Canon of Medicine is an essential part of any curriculum that studies the history of medicine.

*tuberculosis
**Swiss tuberculosis expert, Arnold Klebs

Monday, December 10, 2012

Jacob Anatoli

Daily Medieval has frequently mentioned the importance of Arabic texts in the transmission of knowledge to Western Europe. Arabic, however, was not a commonly known language, and Arabs did not have a strong presence in Western Europe. Arabic culture often brushed up against Latin culture in the southern Mediterranean, as mentioned Salerno, or when a scholar such as Michael Scot made it a point to learn Arabic. Scot probably had help in the form of Jacob Anatoli.

Jacob ben Abba Mari ben Simson Anatoli (c.1194-1256) grew up in southern France, and gained such a reputation for scholarship that he was invited to Naples by Frederick II, who gathered several other academics to his court, such as Scot and Fibonacci. Anatoli became known for his translations of Arabic texts into Hebrew, and he very likely aided Michael Scot in his Arabic translations. Roger Bacon explains that Scot was aided by a Jew named Andreas, and some scholars believe "Andreas" to be a misunderstanding of "Anatoli."

Of his non-translations, the greatest work is the Malmad ha-Talmidim (the title is a pun, being interpreted either "Teacher of the Students" or "Goad to the Students"). The Malmad shows a wide range of knowledge, incorporating the Old Testament and Jewish commentators, but also the New Testament, Aristotle, Plato, and Averroes. His egalitarian approach to Christian and Muslim matters was refreshing, but Judaism still had special status; he wrote "the Greeks had chosen wisdom as their pursuit; the Romans, power; and the Jews, religiousness." He tells us that a non-Jew who seeks religious Truth should be respected by Judaism and not mocked.

Anatoli extended this intellectual courtesy to Frederick II, incorporating remarks by the emperor in his works. He also mentions a Christian whom Anatoli considers a second master (after Anatoli's own mentor, Samuel ibn Tibbon); this "master" has been equated to Michael Scot.

As for his Arabic translations, Anatoli's crucial contribution was exposing the West to the work of Averroes, one of two Arab scholars (the other was the medical expert Avicenna) whose work is considered fundamental to the Middle Ages.We'll look at Averroes tomorrow.

Tuesday, December 4, 2012

Pre-Inertia

Expositio & questiones manuscript
Jean Buridan (c.1300-c.1361) was a University of Paris scholar who was not afraid to tackle some of the big scientific and philosophical issues of the day. That meant, in some cases, taking a critical look at one of the most revered figures in science and philosophy, Aristotle. Buridan, like William of Ockham (c.1288-c.1348),  believed in the observable reality around him, and believed that observation of the world was the key to understanding it. Challenging Aristotle could be risky, but as more and more scholars observed the world around them, they realized that Aristotle's theories needed amendment. He wrote Expositio & questiones (Expoition and questions) to analyze Aristotle's work.

For example, Aristotle believed that an object set in motion—let's say, a rock thrown by a human hand—continues to move after it has left the hand because there must be some continuous external force exerted on it. He theorized that, in the same way a hand swished through water creates little eddies and swirls in the water around it, so the rock's movement is continued by eddies and currents of the air. If there were no movement in the medium that helped carry the rock forward, he believed, the rock would stop its forward course (and presumable drop the the ground). The currents eventually faded, allowing the rock to end its forward flight.

Buridan was not satisfied with this. Building on the work of others (such as John Philoponus and Avicenna, both of whom deserve their own entries some day), he believed that there must be a property in the rock itself that accounts for its action once it has left the motive force of the hand. He called this property of the object impetus (from Latin impetere, literally "to rush toward, to attack").

The property or quality of impetus was clearly changeable. To hurl a heavy rock required you to give it more impetus than to hurl a pebble. Also, impetus was obviously used up over time, allowing the rock to cease its movement and fall. He also explained that a falling object gained impetus the longer it fell (are you paying attention, Galileo?). Unlike Aristotle, who believed that the medium of air in which the object moves helps it along, Buridan saw the air as resistance, causing the object to use up its impetus.

He expanded this theory by looking up. A question had bothered some philosophers for ages: why don't the planets slow down? Will they move forever? Buridan extrapolated his theory to say that a thrown rock in a vacuum would experience no resistance and its impetus would last indefinitely. If the planets were moving in a vacuum...

Well, actually, he couldn't go that far. He agreed with Aristotle that a vacuum couldn't exist in space, since there was no container to keep matter from rushing into the empty area. If above our atmosphere were filled with quintessence, however, Aristotle's "fifth element" that was pure, unchangeable, and frictionless, then the impetus imparted to the planets by whatever initial agency would continue to move forever! The idea of an eternal universe was supportable by science!

Monday, July 23, 2012

Great Surgeon

The history of medicine includes many brave and progressive thinkers who were not willing to follow the herd or be content with what was already known. One such in the Middle Ages was Guy de Chauliac. Born about 1300, he studied at a university in Montpellier known for its expertise in medicine. After becoming a Master of Medicine and Surgery around 1325, he went to Bologna for further study. His reputation became such that he was invited to Avignon to be personal physician to Pope Clement VI, then Pope Innocent VI and Pope Urban V. The papal connection gave him access to a library that included the texts of the Greek physician Galen in their original; most of Europe knew Galen through less accurate Latin translations.

He possibly saved Clement's life during the spread of the Black Death, when he advised the pope to stay near blazing fires. Although many physicians fled Avignon at the arrival of the Plague, Chauliac stayed to study the disease and treat people. He determined that it was contagious, but couldn't figure out the method of contagion. Still, he advised bloodletting, a healthy diet, and exposure to pure air (hence the fires, which would have serendipitously served to keep fleas away). He also realized that there were two diseases involved because of different sets of symptoms: the initial Bubonic Plague, and the follow-up Pneumonic Plague which found its foothold in the weakened population and killed much more swiftly. Chauliac spoke out strongly against those who blamed the Jews for the Plague, explaining that scientifically it made no sense to consider them at fault.

Tools for withdrawing an arrow.
His value to the rest of the world and history was the writing of Chirurgia magna (Great [book of] Surgery) in 1363. Its seven volumes covered every imaginable medical topic of the day: intubation, surgery, disease, anesthesia, hernia, cataracts, ulcers, bloodletting, cauterization of wounds, and the use of special instruments (some of which he designed himself, such as an elaborate contraption for withdrawing an arrow from flesh). Chauliac drew on the past, quoting Galen (129-c.200) and Avicenna (Abu Ali al-Husayn ibn Abd Allah ibn Sina, c.980-1037). He placed great emphasis on learning anatomy, saying that "A surgeon who does not know his anatomy is like a blind man carving a log."

Chauliac was not always accurate. He believed, for instance, that pus was an important part of the healing process and should be left alone. Nevertheless, his Chirurgia became a standard text for the next three centuries, translated into several European languages. Unfortunately for future generations, anti-Islam sentiment caused many translators to leave out knowledge from Islamic scholars, resulting in a less complete and less accurate work. Still, he has been labeled the "Father of Modern Surgery," and his great work was the standard text until the 17th century.