Vocation : Science : Physics

Théodose Achille Louis Vicomte du Moncel or Théodore du Moncel (6 March 1821 – 16 February 1884) was a prominent French physicist and advocate of the use of electricity. He invented many electrical devices and wrote several books. He was also a proficient artist, making high-quality prints of scientific and cultural interest.He also worked as a popularizer of knowledge on electricity.
In 1879, he founded the journal La lumière électrique.
He is one of the founders of the Société Nationale des Sciences Naturelles et Mathématiques of Cherbourg and was a member of the French Academy of Sciences.He was conseiller général of the Manche département (1861–1870) (Canton of Cherbourg-Octeville-Sud-Ouest).

Georges Lochak (12 February 1930 – 4 February 2021) was a French physicist known for his work on magnetic monopoles.

Antonino Lo Surdo (4 February 1880 in Syracuse – 7 June 1949 in Rome) was an Italian physicist. He was appointed as professor of physics at the Istituto di Fisica in Rome in 1919; upon the death of Orso Mario Corbino in 1937, he became the director. Lo Surdo studied terrestrial physics, including seismology and geophysics; the 1908 Messina earthquake caused the death of his parents and other close relatives, except his brother. He contributed to the foundation of the Istituto Nazionale di Geofisica under the auspices of the Consiglio Nazionale delle Ricerche, when its president was Guglielmo Marconi.
His name is remembered for the discovery (made independently by Johannes Stark) in 1913 of the effect on an electric field on the emission spectrum of a gas. This physical phenomenon is called the Stark-Lo Surdo effect in Italy (and is generally known outside Italy simply as the Stark effect). The discovery of the effect was a remarkably important contribution to the development of the quantum theory. Lo Surdo's discovery of the effect led Antonio Garbasso to introduce quantum theory into the Italian universities.

Louis Georges Gouy (February 19, 1854 – January 27, 1926) was a French physicist. He is the namesake of the Gouy balance, the Gouy–Chapman electric double layer model (which is a relatively successful albeit limited model that describes the electrical double-layer which finds applications in vast areas of studies from physical chemistry to biophysics) and the Gouy phase.
Gouy was born at Vals-les-Bains, Ardèche in 1854. He became a correspondent of the Académie des sciences in 1901, and a member in 1913.

Paul-Quentin Desains (12 July 1817 – 3 May 1885) was a French physicist.
He was born at Saint-Quentin, Aisne, France. He studied literature at the Collège des Bons-Enfants in his native town and then entered the Lycée Louis-le-Grand in Paris. Here he distinguished himself, taking the first prize in physics. In 1835 he entered the science section of the Ecole Normale where his brother Edouard had preceded him. He made the acquaintance there of La Provostaye who was at the time a surveillant and who became his lifelong friend and his associate in his researches. After completing his course, he accepted a professorship in 1839 at Caen, and in 1841 returned to Paris where he received similar appointments, first at the Lycée St-Louis and later at the Lycée Condorcet, where he succeeded La Provostaye who was forced to retire on account of ill-health. His growing reputation won for him in 1853 the chair of physics at the Sorbonne which he held for thirty-two years.
Between 1858 and 1861 he made many observations in connexion with terrestrial magnetism. His most important contributions to physics, however, were his researches on radiant heat made in conjunction with La Provostaye. The two physicists concluded that radiant heat, like light, was a disturbance set up in what was then called the ether and propagated in all directions by transverse waves. They showed in a series of "Mémoires" published in the Annales de Chimie et de Physique that it manifests the characteristic phenomena of reflection, refraction, and polarization, as well as of emission and absorption. They also made a study of the latent heat of fusion of ice, and a careful investigation of the range of applicability of the Dulong-Petit law representing the law of cooling.
He also worked in connexion with the establishment and development of laboratory instruction in physics. When the Ecole pratique des hautes études was founded in 1869 he was commissioned to organize the physical laboratory. During the Siege of Paris (1870–1871), he succeeded after many difficulties in establishing electrical communication with d'Alméida who was outside the lines. The exposure he underwent brought on rheumatism which greatly weakened his constitution. He died in Paris. Desains published a Traité de Physique (Paris, 1855) and numerous articles, chiefly with La Provostaye.

Émile Hilaire Amagat (2 January 1841 in Saint-Satur – 15 February 1915) was a French physicist. His doctoral thesis, published in 1872, expanded on the work of Thomas Andrews, and included plots of the isotherms of carbon dioxide at high pressures. Amagat published a paper in 1877 that contradicted the current understanding at the time, concluding that the coefficient of compressibility of fluids decreased with increasing pressure. He continued to publish data on isotherms for a number of different gases between 1879 and 1882, and invented the hydraulic manometer, which was able to withstand up to 3200 atmospheres, as opposed to 400 atmospheres using a glass apparatus. In 1880 he published his law of partial volumes, now known as Amagat's law.
For his studies, he developed many original piezometer devices. His originality went so far as to use the depth of a mine shaft being drilled to reach high pressures of 430 atmospheres in order to study the equations of state of certain gases. His expertise led him to collaborate with the physicist Peter Tait in the development of a piezometer suitable for measuring the compressibility of liquids.Amagat was elected a member of the French Academy of Sciences on 9 June 1902. A unit of number density, amagat, was named after him. He was elected a foreign member of the Royal Society of London in 1897.The French Academy of Sciences gave him the posthumous award of the Prix Jean Reynaud for 1915.

Balthasar van der Pol (27 January 1889 – 6 October 1959) was a Dutch physicist.

Cornelis Jacobus (Cor) Gorter (14 August 1907, Utrecht – 30 March 1980, Leiden) was a Dutch experimental and theoretical physicist. Among other work, he discovered paramagnetic relaxation and was a pioneer in low temperature physics.