Editing Mikhail Lomonosov (section)

===Physics===
[[File:Ekaterina II and Lomonosov.jpg|thumb|[[Catherine the Great|Catherine II of Russia]] visits Mikhail Lomonosov in 1764. 1884 painting by Ivan Feodorov.]]
In 1756, Lomonosov tried to replicate [[Robert Boyle]]'s experiment of 1673.{{sfn|Menshutkin|1952|p=120}} He concluded that the commonly accepted [[phlogiston theory]] was false. Anticipating the discoveries of [[Antoine Lavoisier]], he wrote in his diary: "Today I made an experiment in hermetic glass vessels in order to determine whether the mass of metals increases from the action of pure heat. The experiments – of which I append the record in 13 pages – demonstrated that the famous Robert Boyle was deluded, for without access of air from outside the mass of the burnt metal remains the same."

That is the [[Conservation of mass|Law of Mass Conservation]] in [[chemical reaction]], which is well-known today as "in a chemical reaction, the mass of reactants is equal to the mass of the products." Lomonosov, together with Lavoisier, is regarded as the one who discovered the law of mass conservation.<ref>{{Cite journal | volume = 10 | issue = 3 | pages = 119–127 | last = Pomper | first = Philip | title = Lomonosov and the Discovery of the Law of the Conservation of Matter in Chemical Transformations | journal = Ambix | date = October 1962| doi = 10.1179/amb.1962.10.3.119 }}</ref>

He stated that all matter is composed of corpuscles – molecules that are "collections" of elements – atoms. In his dissertation "Elements of Mathematical Chemistry" (1741, unfinished), the scientist gives the following definition: "An element is a part of a body that does not consist of any other smaller and different bodies ... corpuscle is a collection of elements forming one small mass."<ref>{{Cite book |url=https://archive.org/details/mikhailvasilevic017733mbp |first=Mikhail Vasil'evich |last=Lomonosov |title=Mikhail Vasil'evich Lomonosov on the Corpuscular Theory |translator-first=Henry M. |translator-last=Leicester |publisher=Harvard University Press |year=1959 |location=Cambridge, Massachusetts |pages=[https://archive.org/details/mikhailvasilevic017733mbp/page/n71 56]–57}}</ref> In a later study (1748), he uses the term "atom" instead of "element", and "particula" (particle) or "molecule" instead of "corpuscle."

He regarded heat as a form of motion, suggested the [[wave theory]] of light, contributed to the formulation of the [[kinetic theory of gases]], and stated the idea of [[Conservation of mass|conservation of matter]] in the following words: "All changes in nature are such that inasmuch is taken from one object insomuch is added to another. So, if the amount of matter decreases in one place, it increases elsewhere. This universal law of nature embraces laws of motion as well, for an object moving others by its own force in fact imparts to another object the force it loses" (first articulated in a letter to [[Leonhard Euler]] dated 5 July 1748, rephrased and published in Lomonosov's dissertation "Reflexion on the solidity and fluidity of bodies," 1760).<ref>{{cite book |last1=Pismen |first1=Len |title=The Swings of Science: From Complexity to Simplicity and Back |date=2018 |publisher=Springer |isbn=978-3-319-99777-3 |page=41 |url=https://books.google.com/books?id=Rvx9DwAAQBAJ&pg=PA41}}</ref>