1768: Bosier de Sauvages classifies asthma

Francois Boissier de Sauvages (1706-1767)

One of the key figures in the early days of nosology was the French physician and nosologist Francois Boissier de Sauvages (1706-1767). He worked with the disease classification system created by Thomas Sydenham, and divided diseases into ten categories based on symptoms in his 1763 book, "Nosologie Methodique (diagnostic methods)."  (1)(2)

De Sauvages, like Sydenham, was from the vitalist school of medicine in Montpellier. It is Sauvages who is often given credit for making vitalism popular among the medical community in the 17th century.

Vitalism was an ancient system of medicine that was started by the ancient Greeks (if not earlier) and perhaps first described through the writings of Hippocrates and Aristotle.  It was a belief that a vital spirit, or a soul, was responsible for maintaining the balance of health and sickness.

They believed that the vital spirit within the body was determined by the opposing humours within the body: black bile, yellow bile, phlegm, and blood.  As noted earlier in this history, even the Chinese had a system regarding the balance of substances in the body, such as Qi.  So systems of vitalism, of sorts, existed from an earliest moments of civilization.

Vitalism was revitalized, so to speak, by George Ernest Stahl (1660-1734).  He believed a significant difference between living organisms and inorganic bodies was that living organisms possess a vital spirit.  This view was worded well by the authors of Encyclopedia Britannica:

From his observation that organic bodies decompose rapidly after life ceases, while inorganic bodies remain chemically stable, he concluded that the strong corruptibility of organic matter must result from its material nature (that is, chemical composition) and that there was an immaterial reason that kept a living body from its natural decomposition. Stahl identified this reason with the principle of life, which he sometimes called “natura” (nature) and sometimes “anima” (soul). This natural reason of anima was the source of the remarkable self-healing power of the organism, and when misled, such as by emotions, it produced illnesses. This double character of the vital principle made it the foundation of physiology and pathology, and it dictated that physicians should work to facilitate or restore its healing power based on attentive observation. (6)

Stahl, like most vitalists, understood that the body was a complex system, but he rejected the idea that it was purely mechanical, (6) or consisted of a system of "pulleys and levers" that worked together to maintain health. He did not believe that health could be explained by physical or mechanical means. (5)

Stahl believed it was this soul, or anima, or vital spirit, that made the difference between living organisms like human beings and inanimate objects. The vital spirit was the vital principle of life, health, and healing. (6)

Following the beliefs of Stahl and his vital principle were Sydenham and then Sauvages.

Dr. John Charles Thorowgood, in 1879, said during a lecture on asthma to the Medical Society at London, that by the mid 17th century physicians started to take notice of the periodicity of asthma, or the fact that asthmatics tend to go long periods between episodes. (3, page 5)

Thorowgood said that Sauvages, In his 1768 book Genera Morborum, defined  asthma as "Difficultas spirandi periodice recurrens, chronica (difficult breathing that recurs periodically and is chronic)."  (3, page 5)

In 1879, Francis Ramadge said Sauvages used the term suspirium (sigh) instead of the term asthma.    However, Ramadge said that Sauvages made the same error as the ancients "by giving to asthma a sense almost as extensive as that which belongs to dyspnoea. (4, page 5)

References:

1. "Francois Boissier de Sauvages," encyclopedia.com, http://www.britannica.com/EBchecked/topic/525610/Francois-Boissier-de-Sauvages, accessed 10/12/13
2. "Francois Boissier de Sauvages," neuroportraits.eu, http://neuroportraits.eu/portrait/fran%C3%A7ois-boissier-de-sauvages, accessed 10/12/13
3. Thorowgood, John Charles, "The Lettsomian Lectures delivered at the medical society at London, 1879, on on bronchial asthma: its causes, pathology and treatment," 1879, London, Bailliere, Tindall, & Cox
4. Ramadge, Francis Hopkins, "Asthma, its species and complications," 1835, London, Longman, Rees, Orme, Brown, Green, and Longman
5. "Vitalism," Dictionary.com, http://www.merriam-webster.com/dictionary/vitalism, accessed 10/12/13
6. "George Ernst Stahl," encyclopedia britannica.com, http://www.britannica.com/EBchecked/topic/562520/Georg-Ernst-Stahl, accessed 10/12/13

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1750: Purpose of air, breathing is learned

Stephen Hales (1677-1761) 

So we are now in the year 1750 sitting among a group of fellow students at the University of Glasgow. The topic for today, says our instructor in his usual monotone manor, is the purpose of air.

He reminds us that in 1553, Michael Servetus was the first to speculate that it was the lungs that caused dark blood to become bright red, and not the heart.

In 1640, he says, William Harvey was the first to describe the systemic circulation of the blood through the vessels of the body.

In 1667, Joachim Becher published a book, "Physical Education," in which he said the four classic elements of fire, earth, air and water were no longer relevant, and replaced them with three earth forms: terra lapidea, terra fluida, and terra pinguis.  He believed terra pinguis was responsible for combustion and rusting.

Joseph Black (1728-1799)

In 1697 George Ernst Stahl changed this theory slightly and used the term phligoston (Greek term for burning up) to describe a material or principle of fire (not the fire itself) that was released into the air during combustion.  When a substance was burned, the combustible components of the burned material were released into the air, thus causing it to become impure.

This theory, says our instructor, is the generally accepted theory of today. However, it must be known that another theory, that substances are formed from atoms, that is beginning to be more generally accepted in our time.  However, before we get to that discussion let's continue our history.

In 1668, John Mayow was the first to speculate that the purpose of the lungs was not to cool the heart, but for the exchange of gases.  He believed a substance in the air -- nitro-aerial gas -- was inhaled into the lungs, and when it entered the blood stream the blood turned from a dark color to a bright red.  This, he speculated, was why venous blood was dark and arterial blood red.

He also speculated that a vapor produced by the blood was exhaled by the lungs. He did not know that nitro-aerial gas was oxygen, and he did not know that the substance produced by the blood and exhaled by the lungs was carbon dioxide. He may have made these discoveries had he not died at the young age of 35, before any of his works were published.

In 1727 and 1733 Stephen Hales published the results of experiments on air and respiration where he proved that there is no circulatory system in trees like there is in humans and animals.  (2, page 193)

So, by 1750, our present year, investigators had determined that one of these gases was fixed air that was exhaled by the lungs, and the other was a vapor that was inhaled by the lungs.

One of the students in our class is Joesph Black.  He would go on to become the first to recognize that this gas was burned off during the exhalation phase of respiration.   He discovered it "was deadly to animals, and could distinguish a flame." (1) (2, page 193-194)

References:

1. "Carbon Dioxide,"  Scienceclariied.com, http://www.scienceclarified.com/Ca-Ch/Carbon-Dioxide.html#b, observed the site on May 4, 2012 (this information is available at a variety of sources, although I chose to give sciencedaily.com credit)
2. Magner, Lois N., "History of Life Sciences," 2002, 3rd edition, New York, Marcel Dekker

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