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Manuel Varela: Who Was Antoine Lavoisier?

Sep 1, 2017 by

An Interview with Manuel Varela: Who Was Antoine Lavoisier?

Michael F. Shaughnessy –

1) The name Antoine Lavoisier is linked with a great many ideas, theories and important aspects as we shall see. What do we know about his childhood?

The investigator Antoine Laurent de Lavoisier, is known amongst the present chemists as the principle founder of the modern field of science called chemistry. Lavoisier was born on the 26th of August in the year 1743 in Paris, France, to parents Jean Antoine (his father) and Jeanne Emilie Punctis Lavoisier (his mother). Antoine’s father was a prominent attorney, and his mother was herself the sole daughter of a wealthy attorney. The immediate Lavoisier family was known to be wealthy and bourgeois members of France’s powerful nobility and aristocracy.

His mother Emilie died when Antoine was only 5 years of age, leaving a rather sizeable sum of money as an inheritance.  He was then sent to live with his doting aunt, Marie Marguerite Constance Punctis (Aunt Constance), and his grandmother Punctis from his mother’s side of the family, during this time onward. Some sources say that his widower father and kids lived together in the same household as his aunt and grandmother.  Young Antoine had a younger sister, Marie Marguerite Emilie, who was born during the year 1745 and later died at the age of 15 years, bringing the close-knit family even closer together.

Antoine’s devoted Aunt Constance, who never married, passed away later in 1781.  She left the grand bulk of her own rather enormous wealth to Antoine, whom she had essentially raised ever since his mother had died. Additionally, his grandmother Punctis died in 1768 and left Lavoisier another hefty sum for his inheritance.

2) Apparently, when he went to College Mazarin, the procedure in terms of education then was some Professor came in and lectured- and then some grad or doctoral student would conduct some experiment proving what the grand old Professor said- but what happened with Lavoisier?

In 1754, when the child Lavoisier was approximately 11 years old, his father had enrolled him (Antoine) in the prestigious College de Quatre Nations, founded by Cardinal Mazarin, also referred to as the Mazarin College, where he was provided an education in the liberal arts and sciences, focusing primarily on the languages because, at the time, the young Lavoisier had initially wanted to become a writer. A short while later, when Lavoisier had changed his primary interests to those of the sciences, he nonetheless went into the study of law, receiving his undergraduate degree and law license in 1764, at the age of 21 years.

While it has been alleged that Lavoisier was greatly influenced by several of his professors while in college, such as by Prof. Abbe la Caille (astronomy & math), who had discovered the arc of the meridian around the Cape of Good Hope, by Prof. Guillaume-François Rouelle (chemistry), by Prof. Bernard de Jussieu (botany), and especially by Prof. Etienne Condillac (chemistry), he (Lavoisier) was, at the same time, not easily persuaded by the professors’ proclamations during their lectures.

During this period at Mazarin, the professors’ lectures were often accompanied by an actual experimental demonstration of the proclaimed concepts, often conducted by a graduate student or a doctoral candidate, also known as a ‘demonstrator’ of the lectured concepts. Occasionally, a demonstrator’s public ‘demonstration’ was in stark contradiction to the stated ‘facts’ put forth by the great Professor, and Lavoisier was known to have wisely and acutely been aware of the inconsistent nature of these lectured concepts versus the laboratory demonstrations.

Apparently, many of his fellow students merely took their notes obediently, seemingly unaware of these disparities. Lavoisier saw the need for careful experimental analysis and constant reevaluation of the commonly accepted notions held by his generation, especially when dealing with the concepts of alchemy. Lavoisier often had hope for successive generations in the acceptance the new ideas emerging from his own work.

3) Apparently, he was first involved in literature, then agriculture- what were his contributions to that field?

Lavoisier was made aware of a serious agricultural problem occurring in France and elsewhere in Europe and the New World pertaining to a disease known as the ergot poisoning, or ergotism. Although unknown to Lavoisier and his contemporaries at the time, certain grain crops, especially rye, may be contaminated with a fungus, now known by its scientific name Claviceps purpurea, producing a rye blight.

The fungus produces a toxin, a derivative of ergoline-based molecules, that conveys upon their unsuspecting victims rather startling symptoms, like extreme pain in the extremities—patients reported that their hands and feet felt like they were on fire—plus, hallucinations and physical uncontrollable convulsions, among other non-specific signs and symptoms.

The ergot poisoning was known historically in the Middle Ages as the so-called “Holy Fire” and later as the “St. Anthony’s Fire” because, as it has been recorded, if the patients made a pilgrimage to the church of St. Anthony’s, they would find relief that was considered nothing short of miraculous.

Historians and scientists have speculated that the monks at St. Anthony’s fed their pilgrims rye bread that was not contaminated with the fungus.

It’s been further postulated that the ergot poisoning also played in role in conferring behavior reminiscent of having been bewitched in those individuals who had been accused of practicing witchcraft in Salem, Massachusetts, during the 1660s.

Lavoisier became a member and secretary of a Royal Commission dealing largely with agricultural issues in France. Lavoisier was known to have spent a great deal of his time (about 10 years) and money to study and develop new farming practices devoted to not only improving crop yield but also to minimizing crop losses due to the ergot fungus and the rye blight. Lavoisier noted an association between unusually wet and rainy seasons with the onset of the rye blight and the ergotism.

Lavoisier was involved in the filing of a report addressing the rye blight issue.  In the Royal Commission’s report, Lavoisier provided an overview of certain farming practices that might possibly be implemented in order to solve the rye blight problem.  Lavoisier suggested that other crops be farmed, such as those less susceptible to the ergot.  He noted, however, that because the farmers were terribly poverty-stricken as a result of heavy taxing and unusually high rent rates, the potentially useful farming practices would necessarily be unrealistic. Thus, reform was essentially impossible.

4) Okay–key word—phlogiston — why is this important and why linked to Lavoisier?

During Lavoisier’s time, it was widely believed that fire released a substance called phlogiston, contained within combustible materials. Lavoisier conducted experiments aimed at measuring the substances released during combustion.  First, Lavoisier set the metal tin on fire and measured the weight of the resulting ash produced; he noticed the tin ash weighed more than the unburned tin!  This was an unexpected result because it meant that during the fire the tin was picking up something, rather than losing something, like the putative phlogiston, perhaps.

Next, Lavoisier repeated his combustion experiments but with the element phosphorous and found essentially the same sort of results, namely, that the burned phosphorus was heavier than it had been prior to the setting of it on fire.

Then, Lavoisier tried his combustion experiments with mercury.  Again, Lavoisier found that the burned substances were heavier after being burned than they had been prior to being set on fire, suggesting that the combusted mercury material was actually picking up substances, rather than releasing them, like the so-called phlogiston theory had so eloquently predicted.

Lavoisier’s work went totally against the widely held phlogiston concept—in a word, he became an ardent ‘antiphlogist.’

5) Air consists, (and correct me if I am wrong) of oxygen and nitrogen. Why is this important in the big scheme of things- and how does it relate to Lavoisier?

You are certainly correct about the essentially non-polluted elemental composition of the Earth’s atmospheric nature. The elements oxygen and nitrogen played a large part in the studies of Lavoisier.

Following up on his phlogiston experiments, Lavoisier found that combusted materials that he had set on fire were picking up oxygen and very likely nitrogen after the burning processes.

He measured the volume of the so-called ‘dephlogisticated’ air around the combusted materials using a large bell-shaped jar. The air volume had been reduced during the combustion process, suggesting that something from the air was being picked up by the burned materials. At first, Lavoisier called one of the new substances ‘azote’ which we now know to be the element nitrogen.

At first, critics of Lavoisier’s antiphlogiston work maintained, albeit incorrectly, that the reduced air volume was indicative of and represented by the phlogiston. Favorable to Lavoisier’s antiphlogiston work was the then recent discovery and purification of the element called oxygen by Joseph Priestley and Carl Wilhelm Scheele in 1774.

Using tin and mercury for his experiments, Lavoisier burned these metals as before, except that he then used a tightly sealed glass container while permitting the burned elements to become oxidized. Upon measuring the weight of the sealed vessel, he found no difference in amounts before and after their burning.  However, when Lavoisier opened the sealed container, he made the astute observation of air rushing into the newly opened combustion vessels. Lavoisier reasoned that a vacuum had been generated in the sealed vessel, probably as a result of the burned material picking up a substance from the air, leaving behind the vacuum.

Lavoisier deduced that, instead of phlogiston becoming liberated by combustion, a substance was taken up.  This substance he later found to be present in acids. Therefore, in 1778, Lavoisier called this absorbed substance oxygéne, meaning “generator of an acid,” or what we now know to be the element oxygen.

This discovery was to have a profound effect on the history and the progress within the field of chemistry.  His work meant that during combustion, oxygen was taken up into the equations involving the chemistry of fire. The work essentially changed the entire direction of the investigations pertaining to the chemistry discipline.

6) Heat, and combustion—why are these two words key to Lavoisier’s thinking about chemistry?

In Lavoisier’s experiments, he had carefully controlled the amount of heat needed to initiate the combustion process during the burning of his experimental materials. For example, in his mercury experiments, Lavoisier heated mercury contained within a large bell-shaped jar apparatus, turning the mercury into a reddish colored ash heap. The reddish ash heap weighed more than it had before while the air had less volume. He had found that the leftover air was nitrogen.

Next, he repeated his mercury-heating experiment, except that this time he used the red ash heap as a starting material and raised the amount of heat to even higher levels than he had previously. This time, however, he had regenerated the mercury and at the similar weight that it had been before, demonstrating the reversibility of the process. This reversibility should have been impossible, at least according to the phlogiston theory, which had quite clearly stated that the chemical reactions cannot be reversed.

These experiments conducted by Lavoisier essentially had the effect of forever discrediting the phlogiston hypothesis, thus paving the way for progress to occur in the burgeoning field of chemistry.  This work was incredibly important when, for instance, Pasteur later proclaimed that living beings could also conduct chemistry during the respiration process.

During the process of wine fermentation, Lavoisier found that sugar was converted to bicarbonate gas and to ethanol, a chemical compound he called the ‘spirit of wine.’ Lavoisier hypothesized that fermentation and the process of putrefaction occurred by similar modes.  He showed the involvement of carbon dioxide in the course of respiration.

He also clearly delineated the nature of the so-called ‘fixed air,’ which had been studied by Joseph Black, as carbon dioxide. These studies were to be critical to the development of both organic chemistry and later of biochemistry.

7) Now, I have to tell you- for years of my life in school- I stared at that Periodic Table of the Elements in various classes. Was Lavoisier somewhat initially involved in that big Table?

As you no doubt know, and were quite likely taught as you stared at The Table, the periodic table of the elements was meant to include only those substances which cannot themselves be broken down any further. Although, in modern times, we now know that these elements representing the atoms can indeed be further broken down into sub-atomic particles, like quarks and muons, etc.

Lavoisier had several important contributions regarding the formulation of periodic table of the elements.

First, in studying water in 1783, Lavoisier found that it was not elemental in his strictest sense of the word, as he found that water consisted of oxygen, plus some other substance, which he had named as hydrogen. Prior to this discovery, Henry Cavendish had called this hydrogen gas an ‘inflammable air.’ Lavoisier had burned Cavendish’s inflammable air in the presence of oxygen and found water consisted of hydrogen and oxygen.

Regarding other elements, Lavoisier has been credited with astutely predicting, in 1878, the presence of silicon as an element. Additionally, he is credited with having discovered the element sulfur. He was known to have burned sulfur and to have combined it with oxygen. Further, it has been reported that he coined the name carbon to this important element. Interestingly, the elements carbon, hydrogen and oxygen are all present in carbohydrates.

He was reported to have written the very first list of the elements. In 1789, after his death, his grand book was published, due largely through the efforts of his widow, Marie-Anne Lavoisier.  The book was titled ‘Elementary Treatise of Chemistry’ in which Lavoisier simply began making a listing of the various pure substances, the elements. Within the book, Lavoisier called this list a ‘Table of Simple Substances.’ Some historians of chemistry consider this book to constitute one of the first, if not the first, of the modern chemistry textbooks.

8) Elementary chemical nomenclature is attributed to him and a few colleagues- what is the story here?

Lavoisier had apparently made the suggestion that while the so-called simple non-decomposable substances be referred to as elements, the combination of any given elements, however, should be henceforth called compounds.  Thus, the term chemical compounds owes its origin to Lavoisier and is commonly used to this day.

Furthermore, he said that if a substance was known to undergo a chemical reaction with oxygen, the substance should be referred to as having been ‘oxidized,’ calling the new chemical variation an ‘oxide.’ Thus Lavoisier is recognized has having an important and long-lasting influence upon the nomenclature nature within the study of the chemical substances.

9) Conservation of matter in a specific chemical equation- why was this important?

Prior to Lavoisier’s involvement with the phlogiston hypothesis, the principle of the conservation of matter had been put forth by Mikhail Lomonosov in 1756.  Lavoisier’s experimental studies with the anti-phlogiston work was completely in line with the law of matter conservation in that the overall weights of both starting and ending materials remained largely unchanged.

The so-called law of conservation of matter is vitally important not only for chemicals, as noted in Lavoisier’s studies, but also critical when considering energy. The mass conservation principle is widely applicable to the fields of chemistry, physics, engineering, mechanics, etc. Lastly, the work of Lavoisier in this area began transition from the end of alchemy as we know it to the start of modern chemistry, as it exists today.

10) Sadly, for whatever reason, like so many in France at the time, he faced the guillotine. What happened?

Unknown to him, the path to the guillotine started early on for Lavoisier.

First, as a result of the inheritances from his devoted Aunt and his Grandmother Punctis, Antoine became an independently wealthy individual, leaving him plenty of free time to pursue intellectual interests when he became an adult. It also provided needed funding to perform many of his important experiments. Unfortunately, however, it also provided a secure means for other new and rather dubious investments, one being an investment in a notorious tax-collecting firm.  It is reported, however, that Lavoisier had indeed tried to institute tax true reform measures that were meant to actually help the poor, but to no avail.

During the period of the French Revolution, all of the supremely hated tax collectors and anyone even remotely associated with tax collecting, such as Lavoisier, and his father-in-law, were themselves collected (arrested) by the revolutionaries, given a highly questionable and obviously unfair, but speedy trial, all based on trumped up charges, and were summarily condemned to death.

It is also told that part of his demise centered on his refusal to allow admittance of Jean-Paul Marat to the French Academy of Sciences, a slight that Marat never forgot and was later to exploit in an effort to destroy Lavoisier. Thus, his minor business association, in addition to being a bona fide member of the aristocracy, of course, were also to constitute another important motive for the prosecution of Lavoisier.  His many scientific contributions were summarily rejected and deemed insufficient by his persecutors for any sort of hope of redemption. Sadly, on the day of the execution of Lavoisier by guillotine on the 8th of May in the year 1794, he was apparently first made to stand and watch the beheading of his beloved father-in-law, just before undergoing the execution himself.

11) His wife carried on his work after his death. Any ideas about her contributions?

In 1771, when Lavoisier was already 28 years old, he married the then 13 year old Marie-Anne Pierrette Paulze, the daughter of one of his senior tax-collecting business associates. His new wife, Madame Lavoisier, was reported to have had an educational background in the sciences and was well studied in the arts and languages.

The story is told that the marriage of Lavoisier to the very young Marie-Anne was actually a favor to her father, a senior business partner of the tax collecting firm, La Ferme Generale, of which Lavoisier was an investor.  Apparently, the 40-year old Count d’Amerval had proposed to young Marie-Anne and made it clear that if she refused, her father would be fired from the tax-collecting firm. Thus, in order to have a convenient excuse for refusing the Count’s proposal, Lavoisier and Marie-Anne quickly got married. The ‘ruse’ apparently worked, and the Count was put off.

The newlyweds, however, were devoted to each other for the rest of his life, and she proved to be a strong supporter and advocate for Antoine and of his career in particular.

Prior to his death, Madame Lavoisier had been continually at his side, able to ‘talk shop’ with Lavoisier on a routine basis.  She translated journal articles from English to French for him to read. She participated in the actual experimental research as his laboratory assistant. She was even to elegantly produce many of the illustrative engravings featured so prominently in his publications, her illustrations forever archived within the important scientific literature in chemistry.

After his untimely death, Madame Lavoisier, who was spared the guillotine during the French Revolution, continued on with the work of her late husband. She made every effort to retrieve her husband’s laboratory notes and books which had been confiscated during his prosecution. She was able to assure continued publications of later printings for his works, ensuring their permanent archival in the published literature.  She also worked on and published his memoirs.  She hosted many gatherings in which prominent investigators of the day were invited to present and discuss new scientific contributions in the newly established field of modern chemistry.

Madame Lavoisier lived for many years after the death of her beloved husband Antoine in 1794.  Marie-Anne died on the 10 of February in the year 1836 at 78 years of age.

12) I think as a closing comment, I will quote Joseph Lagrange who said “It took but a moment to sever that head, though a hundred years perhaps will be unable to replace it.” Lavoisier was known as the Father of Modern Chemistry? Has anyone replaced him?

I think that the quotation you to which you refer and which is rightly attributed to Lagrange, is a noticeably profound one, and I believe it is most certainly an apropos observation. Lavoisier was so prominent in the fledgling subject of modern chemistry with so many amazing discoveries it is difficult to comprehend what other additional great contributions he might have been able to make, had he not been quite unfairly executed at such an early age.

Many great scientists have made their greatest contributions to science in their later years. I believe that in terms of playing such an important role in the transition from alchemy, a dubious and defunct area, to the field of modern chemistry, a widely accepted and extremely important scientific discipline today, Lavoisier certainly has no equal.

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