<P> In the middle of the eighteenth century, Mikhail Lomonosov, a Russian scientist, postulated his corpusculo - kinetic theory of heat, which rejected the idea of a caloric . Through the results of empirical studies, Lomonosov came to the conclusion that heat was not transferred through the particles of the caloric fluid . </P> <P> In 1798, Count Rumford (Benjamin Thompson) performed measurements of the frictional heat generated in boring cannons, and developed the idea that heat is a form of kinetic energy; his measurements refuted caloric theory, but were imprecise enough to leave room for doubt . </P> <P> The mechanical equivalence principle was first stated in its modern form by the German surgeon Julius Robert von Mayer in 1842 . Mayer reached his conclusion on a voyage to the Dutch East Indies, where he found that his patients' blood was a deeper red because they were consuming less oxygen, and therefore less energy, to maintain their body temperature in the hotter climate . He discovered that heat and mechanical work were both forms of energy and in 1845, after improving his knowledge of physics, he published a monograph that stated a quantitative relationship between them . </P> <P> Meanwhile, in 1843, James Prescott Joule independently discovered the mechanical equivalent in a series of experiments . In the most famous, now called the "Joule apparatus", a descending weight attached to a string caused a paddle immersed in water to rotate . He showed that the gravitational potential energy lost by the weight in descending was equal to the internal energy gained by the water through friction with the paddle . </P>

Who devised the law of conservation of energy