2. What was phlogiston? Based on what theoretical and experimental bases did Lavoisier reject it?
According to Bowler’s Making Modern Science, A Historical Survey, the theory of phlogiston was first stated by Johann Joachim Becher in 1667. In 1703, Georg Ernst Stahl, a professor of medicine and chemistry at Halle, proposed a variant of the theory in which he renamed Becher’s terra pinguis to phlogiston theory and it was in this form that the theory had it influence.
Phlogiston was a fire-like substance without color, odor, taste or mass that every combustible substance was in part composed of, and it was released during combustion (Bowler 56). A substance rich in phlogiston was said to be phlogisticated and once they were burned, they became dephlogisticated and back to their true form, the calx (residual substance in form of fine powder). In general, substances that burned in air were said to be phlogisticated. After trying various experiments of combustion of substances in enclosed space, it became clear that combustion ceased once in an enclosed space. This was evidence enough that air was only capable of absorbing a certain amount of phlogiston, and once air became entirely phlogisticated, it would no longer support combustion, nor could it support life of any kind since its purpose in the respiration process was to remove phlogiston from the body; thus, a calx would never be formed. In conclusion, according to the phlogiston theory, phlogiston’s role in combustion is opposite to the role of oxygen in combustion.
The phlogiston theory and the use of phlogiston in the vocabulary of many chemists remained dominant until French chemist Antoinne-Laurent Lavoisier disproved it with his caloric theory of combustion (Bowler 56). In his theory, Lavoisier showed that combustion requires a gaseous substance that has weight and that its weight can be measured. In his experiments with phosphorous and sulfur, both of which burned readily in air, Lavoisier showed that they both gained weight by combining with air. Using lead calx, Lavoisier was also able to capture a large amount of air that according to phlogiston theory was liberated when the calx was heated. These results hadn’t been explained by phlogiston theory. Even though Lavoisier had come to a realization that combustion involved air, he was still puzzled by the exact composition of air, which was not understood then. It was until 1774 when Lavoisier met with the English natural philosopher and phlogistonist Joseph Priestly, who had experimented with a mercury calx and collected a gas, which supported the burning of a candle and the respiration process of a rat (Bowler 63-66).
In Lavoisier’s Memoir in Combustion in General, the author emphasizes the importance of organizing experimental data to form new theories. Specifically, he encourages hypothesis testing and trial-and-error to better understand the laws of nature. Lavoisier apply these principles to his own theory by outlining the observations from combustion and calcification, and by hypothesizing the properities of “pure air” and “the matter of fire”.
... middle of paper ... ... We can trace the origins of modern scientific trends back to Greek primal establishment. From the simplistic Socratic approach of ‘Who am I?’
"Paul David Buell." Max Planck Institute for the History of Science. Max Planck Institute, n.d. Web.
He began writing about his hypothesis/ idea in 1864-65, and published the results in 1866. It was not until 1900 that his published findings were
We scurried to the garage, carrying paper and other “burnables.” Matches were always better than lighters for experiments such as these. For our first experiment, we ignited napkins and paper, but the excitement quickly fizzled. Having lost our initial adrenalin rush, we began to search for more dangerous “flammables.
Antoine Laurent Lavoisier is considered to be the father modern day chemistry. He had a mighty impact on the way the world views chemistry today. From identifying elements to discover...
Bernhard Tauchnitz, 1908 -. Google Play Books. Web. The Web.
Book XII of the Metaphysics opens with a clear statement of its goal in the first line of Chapter One: to explore substances as well as their causes and principles. With this idea in mind, Chapter One delineates the three different kinds of substances: eternal, sensible substances; perishable, sensible substances; and immovable substances. The sensible substances are in the realm of natural sci...
In 1789, French chemist Antoine-Laurent de Lavoisier (1743-93) separated 33 substances he considered elements -including light (now know not to exist as an element) and a liquid called ‘Caloric’ (now known not to exist) (Chemical Heritage Foundation, n.d.)- into metals, non-metals and ‘earths’ (Linstead, 2012, p. 115-116).
To begin, a major shift in scientific thinking arrived with the dawn of the printing press and the new-found accessibility of knowledge. "Alchemy was from its origins a secret art;" (Roberts 66) secrecy was an absolute necessity in early science when a powerful recipe or method had been discovered, as such knowledge was a valuable commodit...
The next era is the end of the 17th century- mid 19th century also known as “traditional chemistry”. In the 1700’s, Johann J. Beecher discovered a substance called phlogiston. When substances burn, phlogiston is supposedly added from the air to flame the object that’s burning. Charles Coulcomb the ...
From the unit of chemistry in grade ten science, the students have learned many things from different types of elements in the chart all the way to how each element impacts the daily life each student or even adult lives in. Some of the things I as a student have learned include how to draw the different elements in a bohr rutherford diagram, balancing chemical equations, types of chemical reactions, and even information about the different types of acids and bases. Although there were many other things in the unit, these four definately helped me learn about chemistry in a more in-depth way, as well as teaching me something very new since these were some things a few of the students had never done in the previous years. Learning this in the classroom has really opened my eyes to the world in which we live in today, many times I leave the house on a cold day and as I look upon the cold water becoming ice or even the snow falling down, I know how it is happening, why it is happening, and I can even picture the molecules solidifying as we had seen in class with many different diagrams.
Bruce Mattson. “Henry Cavendish 1731-1810”. History of Gas Chemistry. Updated September 25, 2001. Retrieved December 1, 2011
Rowlinson, J.S. “James Joule, William Thomson and the Concept of a Perfect Gas.” The Royal
Of all the scientists to emerge from the nineteenth and twentieth centuries there is one whose name is known by almost all living people. While most of these do not understand this mans work, everyone knows that his impact on the world is astonishing.