Decipium was the proposed name for a new chemical element isolated by Marc Delafontaine from the mineral samarskite. He published his discovery in 1878 and later published a follow-up paper in 1881. [1] [2] [3]
Decipium was considered to be in the cerium group of rare earths. [4]
In 1880 spectral analysis proved that decipium had a high samarium content. It is now believed that Delafontaine's decipium sample was a mixture of samarium with traces of other rare earth elements. [5]
Samarium is a chemical element with symbol Sm and atomic number 62. It is a moderately hard silvery metal that slowly oxidizes in air. Being a typical member of the lanthanide series, samarium usually has the oxidation state +3. Compounds of samarium(II) are also known, most notably the monoxide SmO, monochalcogenides SmS, SmSe and SmTe, as well as samarium(II) iodide.
Paul-Émile Lecoq de Boisbaudran, also called François Lecoq de Boisbaudran, was a French chemist known for his discoveries of the chemical elements gallium, samarium and dysprosium. He developed methods for separation and purification of the rare earth elements and was one of the pioneers of the science of spectroscopy.
Marie Ennemond Camille Jordan was a French mathematician, known both for his foundational work in group theory and for his influential Cours d'analyse.
The year 1878 in science and technology involved many significant events, listed below.
Jacques-Louis Soret was a Swiss chemist and spectroscopist. He studied both spectroscopy and electrolysis. He held the chairs of chemistry (1873-1887) and medical physics (1887-1890) at the University of Geneva.
Georges-Henri Halphen was a French mathematician. He was known for his work in geometry, particularly in enumerative geometry and the singularity theory of algebraic curves, in algebraic geometry. He also worked on invariant theory and projective differential geometry.
Eugène-Anatole Demarçay was a French chemist who designed an apparatus to produce a spark using an induction coil and used it to generate the spectra of rare earth elements which he examined using spectroscopy, thus detecting the element europium in 1896, and isolated it as the oxide europia in 1901. He helped Marie Curie to confirm the existence of another new element, radium, in 1898.
Luíz Cruls or Luís Cruls or Louis Ferdinand Cruls was a Belgian-Brazilian astronomer and geodesist. He was Director of the Brazilian National Observatory from 1881 to 1908, led the commission charged with the survey and selection of a future site for the capital of Brazil in the Central Plateau, and was co-discoverer of the Great Comet of 1882. Cruls was also an active proponent of efforts to accurately measure solar parallax and towards that end led a Brazilian team in their observations of 1882 Transit of Venus in Punta Arenas, Chile.
Holmium(III) oxide, or holmium oxide is a chemical compound of a rare-earth element holmium and oxygen with the formula Ho2O3. Together with dysprosium(III) oxide (Dy2O3), holmium oxide is one of the most powerfully paramagnetic substances known. The oxide, also called holmia, occurs as a component of the related erbium oxide mineral called erbia. Typically, the oxides of the trivalent lanthanides coexist in nature, and separation of these components requires specialized methods. Holmium oxide is used in making specialty colored glasses. Glass containing holmium oxide and holmium oxide solutions have a series of sharp optical absorption peaks in the visible spectral range. They are therefore traditionally used as a convenient calibration standard for optical spectrophotometers.
The Prix Pierre Guzman was the name given to two prizes, one astronomical and one medical. Both were established by the will of Anne Emilie Clara Goguet, wife of Marc Guzman, and named after her son Pierre Guzman.
Comptes rendus de l'Académie des Sciences, or simply Comptes rendus, is a French scientific journal that has been published since 1835. It is the proceedings of the French Academy of Sciences. It is currently split into seven sections, published on behalf of the Academy by Elsevier: Mathématique, Mécanique, Physique, Géoscience, Palévol, Chimie, and Biologies.
In physical optics, the Cotton–Mouton effect is the birefringence in a liquid in the presence of a constant transverse magnetic field. It is a similar but stronger effect than the Voigt effect. The electric analog is the Kerr effect.
Paul-Auguste-Ernest Laugier was a French astronomer, one of two French astronomers referred to as M. Laugier.
Georges Julien Giraud was a French mathematician, working in potential theory, partial differential equations, singular integrals and singular integral equations: he is mainly known for his solution of the regular oblique derivative problem and also for his extension to n–dimensional singular integral equations of the concept of symbol of a singular integral, previously introduced by Solomon Mikhlin.
The Lalande Prize was an award for scientific advances in astronomy, given from 1802 until 1970 by the French Academy of Sciences.
The Valz Prize(Prix Valz) was awarded by the French Academy of Sciences, from 1877 through 1970, to honor advances in astronomy.
Léon César Autonne was a French engineer and mathematician, specializing in algebraic geometry, differential equations, and linear algebra.
Wang Dezhao or Ouang Te-Tchao was a Chinese physicist who was known for his research in atmospheric electricity and underwater acoustics. Under the direction of Paul Langevin, he helped the French improve sonar at the beginning of World War II and after his return to China, Wang was considered as the founder of national defense water acoustics in China.
Étienne Halphen was a French mathematician. He was known for his work in geometry, on probability distributions and information theory.
Frédéric Alphonse Musculus, born on July 16, 1829, in Soultz-sous-Forêts and died on May 26, 1888, in Strasbourg, was a French chemist.