Weight gain of metals in calcination as a general fact (Guyton de Morveau)
An experimental proof that not only lead and tin but every metal gains weight on calcination. Earlier this was taken as a convenient rule but not as a general law.
The series of accurate weighings was carried out in 1772 by the Dijon lawyer and chemist Louis-Bernard Guyton de Morveau. He tried to explain the gain within phlogiston theory: phlogiston is lighter than all other substances, air included, so a metal containing phlogiston weighs less than its calx; nobody accepted this explanation.
The fact itself, proved by a phlogistonist, became one of the impulses for Lavoisier's investigations of combustion and calcination in the same year 1772. Guyton later wrote that the work done to perfect the phlogiston system had insensibly prepared its ruin, and in 1787 he himself went over to Lavoisier's side.
Why this date
exact: the Dissertation sur le phlogistique, the first essay of the volume Digressions académiques (Dijon, 1772); according to Guerlac (DSB) the book appeared early in 1772, in any case before June. The experiments continued the work of Chardenon of the Dijon Academy, who died in 1769.
What it grew from
-
Phlogiston theory (Becher, Stahl)
influenced · Confidence: high
Guyton's weighings were made within the phlogiston programme: he continued the work of the phlogistonist Chardenon and explained the weight gain he found by phlogiston being lighter than air, so the question was posed and answered in the terms of Stahl's theory.
Link sources
- Blumenthal G., Ladyman J. «The development of problems within the phlogiston theories, 1766-1791», Foundations of Chemistry 19 (2017) Verified 20 Sep 2026
Following on from Chardenon's work and the associated controversies, Guyton (1772) was the first to show clearly that weight gain during calcination was a general phenomenon.
- Blumenthal G., Ladyman J. «The development of problems within the phlogiston theories, 1766-1791», Foundations of Chemistry 19 (2017) Verified 20 Sep 2026
Guyton produced the revised proposal that the addition of phlogiston to a metallic calx made the metal lighter, because it was specifically lighter than air, but this explanation was no more workable than Chardenon's and was not adopted.
- Smeaton W. A. «Guyton de Morveau, Louis Bernard», Dictionary of Scientific Biography (via Encyclopedia.com) (1972) Verified 20 Sep 2026
In order to explain why a metal containing phlogiston weighs less than its calx, he modified Chardenon's theory, believing that phlogiston was specifically lighter than all other substances.
- Blumenthal G., Ladyman J. «Theory comparison and choice in chemistry, 1766-1791», Foundations of Chemistry 20(3) (2018) Verified 20 Sep 2026
the work which had been done to try to perfect the system of phlogiston had insensibly prepared its ruin
"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.
- Blumenthal G., Ladyman J. «The development of problems within the phlogiston theories, 1766-1791», Foundations of Chemistry 19 (2017) Verified 20 Sep 2026
What grew out of it
-
Oxygen theory of combustion and "Réflexions sur le phlogistique"
influenced · Confidence: high
Guyton's book, which appeared before June 1772 and proved the generality of the weight gain in calcination, was, according to Guerlac and Smeaton, one of the factors that led Lavoisier to take up combustion and calcination; Lavoisier saw at once that the fixation of air might be the cause.
Dispute: Guerlac's reconstruction (1961), in which Guyton's book triggers Lavoisier's experiments of 1772, was revisited by Perrin (BJHS 22, 1989, Document, Text and Myth: Lavoisier's Crucial Year Revisited) on the basis of Lavoisier's drafts and sealed notes; moreover, the absorption of air in calcination was asserted independently by Bayen (Blumenthal, Ladyman 2017). Guyton himself explained the weight gain by phlogiston, while the oxygen theory rests on Lavoisier's own experiments with phosphorus, sulfur and lead, and Guyton's result only posed the question.
Link sources
- Guerlac H. «Lavoisier, Antoine-Laurent», Dictionary of Scientific Biography (via Encyclopedia.com) (1973) Verified 20 Sep 2026
Early in 1772, at all events before June of that year, there appeared a book by the provincial lawyer and chemist Louis Bernard Guyton de Morveau, which conclusively proved that the well-known gain in weight of lead and tin when they are calcined is not a peculiarity of those metals.
- Guerlac H. «Lavoisier, Antoine-Laurent», Dictionary of Scientific Biography (via Encyclopedia.com) (1973) Verified 20 Sep 2026
Guyton sought to explain these results by invoking a fanciful variation of the phlogistic hypothesis, but Lavoisier saw at once that the fixation of air might be the cause.
- Smeaton W. A. «Guyton de Morveau, Louis Bernard», Dictionary of Scientific Biography (1972) Verified 20 Sep 2026
The experimental part of Guyton's essay, however, was influence for his proof of the gain in weight was one of the factors that led Lavoisier to investigate combustion and calcination.
"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.
Further reading
Not evidence: these carry no quotation and support nothing we wrote. They are books and scans to read next.
- Guerlac H. «Lavoisier, Antoine-Laurent», Dictionary of Scientific Biography (via Encyclopedia.com) (1973) Verified 20 Sep 2026
Node sources
- Smeaton W. A. «Guyton de Morveau, Louis Bernard», Dictionary of Scientific Biography (via Encyclopedia.com) (1972) Verified 20 Sep 2026
His results were published in 'Dissertation sur le phlogistique,' the first essay in a volume entitled Digressions académiques (1772).
- Smeaton W. A. «Guyton de Morveau, Louis Bernard», Dictionary of Scientific Biography (via Encyclopedia.com) (1972) Verified 20 Sep 2026
Guyton pointed out that no one had, in fact, proved that every metal invariably gains weight. This he now did, in a careful and accurate piece of quantitative work.
- Smeaton W. A. «Guyton de Morveau, Louis Bernard», Dictionary of Scientific Biography (via Encyclopedia.com) (1972) Verified 20 Sep 2026
In order to explain why a metal containing phlogiston weighs less than its calx, he modified Chardenon's theory, believing that phlogiston was specifically lighter than all other substances.
- Guerlac H. «Lavoisier, Antoine-Laurent», Dictionary of Scientific Biography (via Encyclopedia.com) (1973) Verified 20 Sep 2026
Early in 1772, at all events before June of that year, there appeared a book by the provincial lawyer and chemist Louis Bernard Guyton de Morveau, which conclusively proved that the well-known gain in weight of lead and tin when they are calcined is not a peculiarity of those metals.
- Blumenthal G., Ladyman J. «The development of problems within the phlogiston theories, 1766-1791», Foundations of Chemistry 19 (2017) Verified 20 Sep 2026
Guyton (1772) was the first to show clearly that weight gain during calcination was a general phenomenon.
- Blumenthal G., Ladyman J. «The development of problems within the phlogiston theories, 1766-1791», Foundations of Chemistry 19 (2017) Verified 20 Sep 2026
Guyton produced the revised proposal that the addition of phlogiston to a metallic calx made the metal lighter, because it was specifically lighter than air, but this explanation was no more workable than Chardenon's and was not adopted.
- Blumenthal G., Ladyman J. «Theory comparison and choice in chemistry, 1766-1791», Foundations of Chemistry 20(3) (2018) Verified 20 Sep 2026
the work which had been done to try to perfect the system of phlogiston had insensibly prepared its ruin
"Verified" means that on that day the quotation was found at the address given, word for word. No date means we have not been able to open the source yet, not that the quotation is wrong.
Further reading
Not evidence: these carry no quotation and support nothing we wrote. They are books and scans to read next.
- Guyton de Morveau L. B. «Digressions académiques, ou essais sur quelques sujets de physique, de chymie et d'histoire naturelle», Dijon: Frantin (1772)