(b. Brooklyn, New York, 31 January 1881; d. Falmouth, Massachusetts, 16 August 1957),
Irving Langmuir was the third of four children (all sons) of Charles Langmuir, a New York insurance excutive of Scots ancestry, and Sadie Comings Langmuir, the daughter of a professor of anatomy and a descendant, on her mother’s side, of the early English settlers who arrived in America on the Mayflower. Irving Langmuir alternately attended schools in New York and in Paris, where his father headed the European agencies of the New York Life Insurance Company. Irving was in his last year at the Pratt Institute’s manual training high school in New York and in Paris, where his father headed the European agencies of the New York Life Insurance Company. Irving was in his last year at the Pratt Institute’s manual training high school in Brooklyn in 1898 when his father unexpectedly died at the age of fifty-four of pneumonia contracted during a winter transatlantic crossing. His mother lived to be eighty-seven. Fortunately, Charles Langmuir had provided well for his family, and Irving was able to enter Columbia University. Although deeply interested in science, he chose the more exacting curriculum of the School of Mines. “The course was strosng in chemistry,” he said later. “It had more physics than the chemical course, and more mathematics than the course in physics-and I wanted all three.” He received the degree of metallurgical engineer (equivalent to bachelor of science) in 1903 and decided to enter on a course of postgraduate study in Germany. He hesitated between Leipzig and Göttingen and chose the latter, where he worked under Walther Nernst on the dissociation of various gases by a glowing platinum wire, research that became the topic of his 1906 doctoral dissertation. The decision for Göttingen very likely had a profound influence on Langmuir’s career, for not ony was Nernst deeply engaged in the work on thermodynamics that was to earn him the Nobel Prize in 1920, but he was also favorably inclined toward applied research. Nernst had devised a new type of electric lamp that became a great commercial success, in a sense presaging Langmuir’s own career in industrial research. At Leipzig, would probably have come under the influence of wilhelm Ostwald and might not have become interested in the problems of molecular and atomic structure that underlie much of his mature work, since Ostwald had little faith n that approach
Armed with a doctorate from Göttingen, Langmuir returned to America and for a time taught chemistry at Stevens Institute of Technology in Hoboken, New Jersey, but eh position gave little scope to his talents. After a summer job at the new research laboratory that the General Electric Company had established in 1901 in Schenectady, new York, he gratefully accepted an offer to stay there permanently. He remained there for forty-one years until his retirement in 1950 and continued as a consultant.
Langmuir’s scientific work was extremely varied. During overlapping periods he made major contributions in at least seven fields: Chemical reactions at high temperatures and low pressures (1906-1921); thermal effects in gases (1911-1936); atomic structure (1919-1921); thermionic emission and surfaces in vacuum (1913-1937); chemical forces in solids, liquids, and surfce films (1916-1943); electrical discharges in gases (1923-1932) and atmospheric science (1938-1955). Much of his work led to technological developments of wide and lasting importance.
His work on chemical reactions at high temperatures and low pressures derived from his dissertation under Nernst, who wanted to understand the equilibrium conditions governing the formation of nitric oxide from air in the vicinity of a hot wire. The scope of the investigation presently came to include other gaseous equilibria. Langmuir was fascinated by the simplicity of the experimental setup, which resembled an incandescent light bulb. The electric lamp of the day was a relatively inefficient device containing a fragile carbon filament and was everely limited in lifetime and power. (Electric street lights used arc lamps.) Tantalum and tungsten filaments were being tried but did not last much longer even in the best available vacuum. Langmuir’s first task at General Electric wa to find the reason for the short life, which proved to be residual gases adhering to the glass envelope and other impurities. This research ultimately led to the recognition that filling the lamp with inert gases (a nitrogen-argon mixture worked best) greatly increased both lifetime and efficiency, a discovery that revolutionized the electric-lamp industry. The same studies led to the discovery and understanding of the formation of atomic hydrogen from molecular hydrogen and to a series of other results in the fields of heat transfer and low-pressure phenomena.
Continuing experiments on hot tungsten filaments in various gases, Langmuir turned to a study of heat losses and evaporation from hot filaments. He found that the laws governing the evaporation of tungsten into nitrogen resembled those of heat convection: thin wires lost as much tungsten per unit area as thick wires, but the latter were more efficient, a contraction that led to the adoption of a lamp filament made from a thin wire tightly coiled into a helix. He also estimated the heat of dissociation of hydrogen and observed various properties of atomic hydrogen, including its adsorption on cold glass walls. The heating effects produced by the recombination of atomic hydrogen later led Langmuir to invent the atomic-hydrogen welding torch, in which an arc between tungsten electrodes in hydrogen produces hydrogen atoms that create heat when they recombine on the metal to be welded.
Of all his major contributions, Langmuir’s sortie into atomic structure occupied him for the shortest period (1919-1921). Building upon the ideas of G. N. Lewis, Langmuir suggested a modification in the model of the atom proposed by his idol, Niels Bohr. Although the Lewis-Langmuir theory, called the “octet theory” of chemical valence, ultimately yielded to the quantum-mechanical concepts of chemical bonds, it proved to be astonishingly successful from a practical viewpoint, explaining a great variety of chemial phenomena by essentially classical methods. At this time, Langmuir apparently made a deliberate decision to concentrate his efforts on fields in which such classical methods were likely to yield new results and recognized that atomic structure was not one of them.
Concurrently with these efforts, he was engaged in investigations of thermionic emission and of surfaces in vacuum, two fields that proved of tremendous fundamental and practical importance. Elucidating the phenomenon of space charge (the cloud of charged particles that maintains itself in the interelectrode space) he independently derived for electrons the relationship established previously for ions by C. D. Child. Now known as the Child-Langmui spacecharge equation, the relationship shows that the current between the electrodes is proportinal to the voltage raised to the 3/2 power, regardless of the shapes of the electrodes. This law, which underlies the design of a great variety of electron tubes and other devices, was elaborated by Langmuir and his co-workers for several geometrical configurations. At the same time, Langmuir observed that certain admixtures such as thoria, an oxide of thorium (ThO2), greatly enhanced thermionic emission from tungsten, a result that he correctly ascribed to an effective lowering of the work function atoms to the surface of the tungsten filament. His other studies in this field related to the changes in emission and in ionization produced by the presence of cesium, and were also destined to become of technological importance. A development of more immediate import was his invention of a condensation pump, which produces a good vacuum very quickly with the help of a refrigerant such as liquid nitrogen. This device rapidly came into widespread industrial and laboratory use and continued to dominate the field for decades.
The largest single topic to occupy Langmuir’s attention was surface chemistry—the study of chemical forces at interfaces between different substances. He evolved a new concept of adsorption, according to which every molecule striking a surface remains in contact for a time before evaporating, so that a firmly held monolayer is formed. He developed a multitude of experimental techniques for studying surface films on liquids. Turning to solids, he developed the Langmuir adsorption isotherm, an expression for the fraction of surface covered by the absorbed layer as a function of pressure and the temperature-dependent rates of surface condensation and evaporation. He also characterized the catalytic effect of an adsorbing surface by considering the chemical reaction as occurring in the film, a concept that served to explain many phenomena of surface kinetics that had not been previously understood. It was largely in recognition of this work that Langmuir was awarded the Nobel Prize in chemistry in 1932.
Possibly of even greater lasting significance was his work relating to electric discharges in gases, which derived from an interest in mercury-arc and other gaseous devices used in the control of heavy alternating currents. This effort led to a large body of experimental and analytical research concerned with electron-ion interactions, ionization, oscillations, and other aspects of a space-charge-free ionized gas, the richly complex and inherently unstable medium for which he coined the term “plasma” Subsquent work in such fields as electron physics, magnetohydrodynamics (MHD), and the control of thermonuclear fusion depends heavily on the basic results on plasma first reported in the papers of Langmuir and his associates. In these papers, the concept of electron “temperature” was introduced as well as a method of measuring both it and the ion density by a special electrode, now called the Langmuir probe.
The major field that occupied Langmuir into his retirement years was atmospheric science. Following a lifelong preoccupation with the weather (he was a great outdoorsman, a capable sailor, and an enthusiastic amateur flyer), he studied such phenomena as the regular formation of streaks of seaweed on the wind-blown surface of the sea (windrows), the formation of liquid particles of various sizes in air, and the nucleation of ice crystals in supercooled clouds by “seeding” with solid carbon dioxide particles. This last work, which was based on a discovery of Langmuir’s associate V. J. Schaefer, led to the beginnings of artificial weather control, although early efforts at producing rain and diverting storms were marred by much scientific and public controversy regarding the efficacy of cloud seeding.
Langmuir was the first eminent scientist employed by an industrial laboratory to be honored by a Nobel Prize—an aspect of his career that had an impact on the worldwide development of scientific research and that lent a certain cachet to such endeavors. Forward-looking industries everywhere began to appreciate the importance of undirected basic research of a sort previously restricted to universities.
Langmuir’s mature life was serene. At the age of thirty-one he married Marion Mersereau of Schenectady; they adopted two children, Kenneth and Barbara. He was close to his brothers and to his many nephews and nieces, several of whom also achieved distinction in scientific fields. Langmuir’s elder brother Arthur was a successful industrial chemist, a fact that doubtless influenced young Irving’s choice of a career. Moreover, Arthur’s enthusiasm for science transmitted itself to Irving through their exceptionally close relationship. Langmuir’s interests extended to such diverse fields as the Boy Scout movement, aviation, and music—he was a personal friend of Charles Lindbergh and of the conductor and sound-recording innovator Leopold Stokowski. He also concerned himself with problems of public policy such as the conservation of wilderness areas and control of atomic energy. In 1935 he stood for the city council of Schenectady, N. Y., but failed to be elected. He participated actively in America’s scientific war efforts during both world wars: in antisubmarine defense and nitrate production during the first, and in aircraft de-icing and smoke-screen research (both outgrowths of his interest in meteorology) during the second. He worked best with small teams of collaborators. Outstanding among them was Dr. Katherine Blodgett, with whom he worked closely for over thirty years.
In addition to the Nobel Prize, Langmuir received many other honors, among them the Hughes Medal of the Royal Society (1918), the American Rumford Medal (1920), the American Chemical Society’s Nichols Medal (1920) and Gibbs Medal (1930), the Franklin Medal (1934), and both Faraday Medals: that of the Chemical Society (1938) and of the Institution of Electrical Engineers (1943). He was granted fifteen honorary degrees. He was a member of the National Academy and a foreign member of the Royal Society and of other bodies. Mount Langmuir in Alaska is named after him, and in 1970 a residential college at the State University of New York at Stony Brook was named Irving Langmuir College in his honor.
I. Original Works. Langmuir received 63 patents and published over 200 papers and reports between 1906 and 1956. Virtually all his papers appear in the 12-vol. memorial edition of The Collected Works of Irving Langmuir, C. G. Smits, ed. (London-New York, 1960-1962), which is devoted to the following topics: 1. Low-Pressure Phenomena, 2. Heat Transfer-Incadescent Tungsten, 3. Therimionic Phenomena, 4. Electrical Discharge, 5. Plasma and Oscillations, 6. Structure of Matter, 7. Protein Structures, 8. Properties of Matter, 9. Surface Phenomena, 10. Atmospheric Phnomena, 11. Cloud Nucleation, 12. The Man and the Scientist. Scatteredc throughout are memorial esays by scintists who knew him, including a book-length biography by Albert Rosenfeld, “The Quintessence of Irving Langmuir” in vol. XII, pt. 1, also published separately (New York-Oxford, 1966). In addition to a complete list of Langmuir’s own papers, it contains an extensive bibliography of writing about him. Langmuir was also authour of Phenomena, Atoms and Molecules (New York, 1950).
II. Secondary Literature. Tributes are by Sir Hugh Taylor in Biographical Memoris of Fellows fo the Royal Society, 4 (1958), 167-184; A. W. Hull in Nature, 181 (1958), 148; W. R. Whitney in Yearbook. American Philosophical Society (1957), 129-133; and Katherine B. Blodgett in Vacuum, 5 (1957), 1-3.
The chemist Irving Langmuir (1881-1957) was one of the best of the industrial scientists in the United States who helped establish scientific research as a necessary industrial activity.
Irving Langmuir was born in Brooklyn, N. Y., where his father was in the insurance business. When he was 11 years old, his family moved to France, where he attended elementary school for a time. In 1895 he returned to the United States and attended high school in New York City. In 1903 he took a degree in metallurgical engineering from the Columbia University School of Mines. Like many scientists of his generation, he went to Germany for postgraduate work; he took a doctorate from the University of Göttingen in 1906. Returning to the United States, he became an instructor of chemistry at the Stevens Institute of Technology in New Jersey.
In 1909 Langmuir went to work for the General Electric Company in Schenectady, N. Y. He remained there until his retirement in 1950 and continued as a consultant until his death in 1957. General Electric was one of the first large manufacturing firms in the United States to invest in industrial research, and Langmuir soon became one of the laboratory's brightest stars. Indeed, an associate once said of him, "Langmuir is the nearest thing to a thinking machine that I know—you put in the facts and out roll the conclusions." However, he was also an energetic hiker and mountain climber, as well as an enthusiastic private pilot.
During his years at General Electric, Langmuir was responsible for the research that led to the gas-filled incandescent lamp, the high-vacuum power tube, and atomic hydrogen welding, among other advances. He worked for many years on electron emissions and gaseous discharges, and he also developed experimental techniques for the study of proteins that were widely copied by biochemists and biophysicists. His most famous research dealt with oil films on water and opened up the new field of surface chemistry. In 1932 he was awarded the Nobel Prize in chemistry. As a result of his work for the military during and after World War II, he supported the idea of weather modification by seeding clouds with dry ice or silver iodide to produce rain and snow.
There is no first-rate biography of Langmuir, although he is the subject of several works: John Clarence Hylander, Irving Langmuir: American Scientist (1935); Bernard Jaffe, Irving Langmuir: Crucibles—The Story of Chemistry (1948); and Albert Rosenfeld, The Quintessence of Irving Langmuir (1966). A sketch of his life is in Eduard Farber, Nobel Prize Winners in Chemistry, 1901-1950 (1953). Also valuable are John T. Broderick, Forty Years with General Electric (1929), and especially Kendall Birr, Pioneering in Industrial Research: The Story of the General Electric Research Laboratory (1957). For one aspect of Langmuir's work see Arthur A. Bright, The Electric-Lamp Industry (1949). □
American chemical physicist who was awarded the 1932 Nobel Prize for Chemistry for work on surface chemistry. From studies of surface films on liquids Langmuir deduced approximate molecular sizes and shapes, and his studies of gas absorption at solid surfaces led to the Langmuir absorption isotherm. He also developed a shared-electron theory of chemical bonds. While at General Electric (1919-1950) Langmuir developed many devices, including an improved light bulb, enhanced vacuum pump, and hydrogen welding torch.