Foreign associates of the National Academy of Sciences

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

Xavier Le Pichon (born 18 June 1937 in Qui Nhơn, French protectorate of Annam (later South Vietnam and today Vietnam)) is a French geophysicist. Among many other contributions, he is known for his comprehensive model of plate tectonics (1968), helping create the field of plate tectonics. In 1968 he combined the kinematic ideas of W. J. Morgan, D. McKenzie and R. L. Parker with the large data sets collected by Lamont, and especially with the respective magnetic profiles, to show that Plate Tectonics could accurately describe the evolution of the major ocean basins. He is professor at the Collège de France, holder of the Chair of Geodynamics (1986–2008). He is a lifelong devout Catholic, and has come to think of caring attention to others' weakness as an essential quality that allowed humanity to evolve. He lives with his wife and has five children and eleven grandchildren.

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.

Jean Jouzel (born 5 March 1947) is a French glaciologist and climatologist. He has mainly worked on the reconstruction of past climate derived from the study of the Antarctic and Greenland ice.

Catherine Jeanne Cesarsky (born Catherine Jeanne Gattegno on 24 February 1943) is an Argentine and French astronomer, known for her research activities in astrophysics and for her leadership in astronomy and atomic energy. She is the current chairperson of the Square Kilometre Array's governing body, SKAO Council. She was the first female president of the International Astronomical Union (2006-2009) and the first female director general of the European Southern Observatory (1999-2007).

Edoardo Amaldi (5 September 1908 – 5 December 1989) was an Italian physicist. He coined the term "neutrino" in conversations with Enrico Fermi distinguishing it from the heavier "neutron". He has been described as "one of the leading nuclear physicists of the twentieth century." He was involved in the anti-nuclear peace movement.

Ludwig Franz Benedikt Biermann (March 13, 1907 in Hamm – January 12, 1986 in München) was a German astronomer, obtaining his Ph.D. from Göttingen University in 1932.He made important contributions to astrophysics and plasma physics, discovering the Biermann battery. He predicted the existence of the solar wind which in 1947 he dubbed "solar corpuscular radiation".
He was a visiting scholar at the Institute for Advanced Study in the fall of 1961. He won the Bruce Medal in 1967 and the Gold Medal of the Royal Astronomical Society in 1974.
Asteroid 73640 Biermann is named in his honor.

August Friedrich Leopold Weismann FRS (For), HonFRSE, LLD (17 January 1834 – 5 November 1914) was a German evolutionary biologist. Fellow German Ernst Mayr ranked him as the second most notable evolutionary theorist of the 19th century, after Charles Darwin. Weismann became the Director of the Zoological Institute and the first Professor of Zoology at Freiburg.
His main contribution involved germ plasm theory, at one time also known as Weismannism, according to which inheritance (in a multicellular animal) only takes place by means of the germ cells—the gametes such as egg cells and sperm cells. Other cells of the body—somatic cells—do not function as agents of heredity. The effect is one-way: germ cells produce somatic cells and are not affected by anything the somatic cells learn or therefore any ability an individual acquires during its life. Genetic information cannot pass from soma to germ plasm and on to the next generation. Biologists refer to this concept as the Weismann barrier. This idea, if true, rules out the inheritance of acquired characteristics as proposed by Jean-Baptiste Lamarck. However, a careful reading of Weismann's work over the span of his entire career shows that he had more nuanced views, insisting, like Darwin, that a variable environment was necessary to cause variation in the hereditary material.The idea of the Weismann barrier is central to the modern synthesis of the early 20th century, though scholars do not express it today in the same terms. In Weismann's opinion the largely random process of mutation, which must occur in the gametes (or stem cells that make them) is the only source of change for natural selection to work on. Weismann became one of the first biologists to deny Lamarckism entirely. Weismann's ideas preceded the rediscovery of Gregor Mendel's work, and though Weismann was cagey about accepting Mendelism, younger workers soon made the connection.
Weismann is much admired today. Ernst Mayr judged him to be the most important evolutionary thinker between Darwin and the evolutionary synthesis around 1930–1940, and "one of the great biologists of all time".

Antoine François Alfred Lacroix (4 February 1863 – 12 March 1948) was a French mineralogist and geologist. He was born in Mâcon, Saône-et-Loire.

Marie Ennemond Camille Jordan (French: [ʒɔʁdɑ̃]; 5 January 1838 – 22 January 1922) was a French mathematician, known both for his foundational work in group theory and for his influential Cours d'analyse.