Mayer, Julius Robert von

Mayer, Julius Robert von,

1814–78, German physician and physicist, studied medicine at Tübingen, Munich, and Paris. From a consideration of the generation of animal heat, he was led to determine the general relationship between heat and work. This resulted in his announcement in 1842, independently of J. P. JouleJoule, James Prescott
, 1818–89, English physicist. His scientific researches began in his youth when he invented an electromagnetic engine. Joule made valuable contributions to the fields of heat, electricity, and thermodynamics.
..... Click the link for more information.
, of the mechanical equivalence of heat, a consequence of the law of conservation of energy. In 1845 he gave a still more general statement of this law. Controversy arose, however, as to the priority of the discovery, and it was only years later that he received due credit for his contribution.


See study by R. B. Lindsay (1973).

Mayer, Julius Robert Von


Born Nov. 25, 1814, in Heilbronn; died there Mar. 20, 1878. German physician and physicist.

Mayer was the son of a pharmacist. He graduated from the medical faculty of the University of Tubingen in 1838. In 1839 he worked at clinics in Paris. In 1840-41 he was physician on a Dutch vessel bound for Batavia (Java). Mayer noticed a change in the color of the venous blood in his patients during their stay in the tropics and concluded, on the basis of his observations, that there is a relationship between food consumption and the formation of heat in the body. In 1841 he sent his first article, “On the Quantitative and Qualitative Determination of Force,” to J. C. Poggendorff, the editor of Annalen der Physik. The article, which took a position similar in meaning to the law of the conservation of energy, was not printed.

Mayer gave a more complete presentation of his viewpoints in the article “Remarks on the Forces of Inanimate Nature,” which was published in 1842. In the book Organic Movement in Relation to Metabolism, published in 1845, Mayer clearly formulated the law of the conservation of energy and theoretically calculated the numerical value of the mechanical equivalent of heat. According to Mayer, motion, heat, electricity, and other phenomena are qualitatively different forms offerees” (his term for energy), which are convertible at equal quantitative ratios. He also considered the application of the law to processes occurring in living organisms, asserting that plants are accumulators of solar energy on earth and that in all other organisms there is only a conversion of matter and forces (and not a creation).

Mayer’s concepts were not understood by his contemporaries. Because of this and because of persecution arising out of disputes over priority in the discovery of the law of the conservation of energy, Mayer attempted suicide in 1850. The true value of Mayer’s works was first recognized by G. Helmholtz.


In Russian translation:
Zakon sokhraneniia i prevrashcheniia energii. Chetyre issledovaniia, 1841-1851 Edited by A. A. Maksimov. Moscow-Leningrad, 1933.


Robert Mayer und das Energieprinzip. 1842-1942. Gedekschrift zur 100 Wiederkehr der Entdeckung des Energieprinzips. Vienna, 1942. (Contains a bibliography of works and references.)


Mentioned in ?