Foreign Members of the Royal Society

Pierre-Joseph van Beneden FRS FRSE FGS FZS (19 December 1809 – 8 January 1894) was a Belgian zoologist and paleontologist.

Charles Eugene Barrois (21 August 1851 – 5 November 1939) was a French geologist and palaeontologist.

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.

Joseph Louis François Bertrand (French pronunciation: [ʒozɛf lwi fʁɑ̃swa bɛʁtʁɑ̃]; 11 March 1822 – 5 April 1900) was a French mathematician whose work emphasized number theory, differential geometry, probability theory, economics and thermodynamics.

Jean-Victor Poncelet (French pronunciation: [ʒɑ̃ viktɔʁ pɔ̃slɛ]; 1 July 1788 – 22 December 1867) was a French engineer and mathematician who served most notably as the Commanding General of the École Polytechnique. He is considered a reviver of projective geometry, and his work Traité des propriétés projectives des figures is considered the first definitive text on the subject since Gérard Desargues' work on it in the 17th century. He later wrote an introduction to it: Applications d'analyse et de géométrie.As a mathematician, his most notable work was in projective geometry, although an early collaboration with Charles Julien Brianchon provided a significant contribution to Feuerbach's theorem. He also made discoveries about projective harmonic conjugates; relating these to the poles and polar lines associated with conic sections. He developed the concept of parallel lines meeting at a point at infinity and defined the circular points at infinity that are on every circle of the plane. These discoveries led to the principle of duality, and the principle of continuity and also aided in the development of complex numbers.As a military engineer, he served in Napoleon's campaign against the Russian Empire in 1812, in which he was captured and held prisoner until 1814. Later, he served as a professor of mechanics at the École d'application in his home town of Metz, during which time he published Introduction à la mécanique industrielle, a work he is famous for, and improved the design of turbines and water wheels. In 1837, a tenured 'Chaire de mécanique physique et expérimentale' was specially created for him at the Sorbonne (the University of Paris). In 1848, he became the commanding general of his alma mater, the École Polytechnique. He is honoured by having his name listed among notable French engineers and scientists displayed around the first stage of the Eiffel tower.

Jean Servais Stas (21 August 1813 – 13 December 1891) was a Belgian analytical chemist who co-discovered the atomic weight of carbon.

Édouard Brézin (French: [bʁezɛ̃]; born 1 December 1938 Paris) is a French theoretical physicist. He is professor at Université Paris 6, working at the laboratory for theoretical physics (LPT) of the École Normale Supérieure since 1986.

Elias Magnus Fries (15 August 1794 – 8 February 1878) was a Swedish mycologist and botanist. He is sometimes called the "Linnaeus of Mycology". In his works he described and assigned botanical names to hundreds of fungus and lichen species, many of which remain authoritative today.

Gabriel Auguste Daubrée MIF FRS FRSE (25 June 1814 – 29 May 1896) was a French geologist, best known for applying experimental methods to structural geology. He served as the director of the École des Mines as well as the president of the French Academy of Sciences.

Henry Louis Le Chatelier (French pronunciation: [ɑ̃ʁi lwi lə ʃɑtəlje]; 8 October 1850 – 17 September 1936) was a French chemist of the late 19th and early 20th centuries. He devised Le Chatelier's principle, used by chemists and chemical engineers to predict the effect a changing condition has on a system in chemical equilibrium.