The American chemist, Linus Carl Pauling (1901-1994), was twice the recipient of a Nobel Prize. He clarified much that was obscure in the determination of the exact tri-dimensional shapes of molecules, revealed the nature of the chemical bond, helped to create the field of molecular biology, proposed the concept and coined the term "molecular disease;" founded the science of ortho-molecular medicine, and was an activist for peace.

Linus Carl Pauling was born in Portland, Oregon, on February 28, 1901. He was the first of three children born to Herman Henry William Pauling and Lucy Isabelle "Belle" (Darling) Pauling. His father was a druggist who struggled to make a living for his family. With his business failing, Herman Pauling moved the family to Oswego, seven miles south of Portland, in 1903. But, he was no more successful in Oswego and moved the family to Salem in 1904, to Condon (in northern Oregon) in 1905, and back to Portland in 1909. In 1910 his father died of a perforated ulcer, leaving his mother to care for the three young Pauling children.

As a child, Pauling read continuously and, at one point, his father wrote to the local newspaper asking for readers to suggest additional books that would keep his young son occupied. His interest in science was apparently stimulated by his friend, Lloyd Jeffress, during his grammar school years at Sunnyside Grammar School. Jeffress kept a small chemistry laboratory in a corner of his bedroom where he performed simple experiments. Pauling was intrigued by these experiments and decided to become a chemical engineer.

During his high school years, Pauling continued to pursue his interest in chemistry. He was able to obtain much of the equipment and materials he needed for his experiments from the abandoned Oregon Iron and Steel Company in Oswego. His grandfather was a night watchman at a nearby plant and Pauling was able to "borrow" the items he needed for his own chemical studies. Pauling would have graduated from Portland's Washington High School in 1917 except for an unexpected turn of events. He had failed to take the necessary courses in American History required for graduation and, therefore, did not receive his diploma. The school corrected this error 45 years later when it awarded Pauling his high school diploma--after he had been awarded two Nobel Prizes.

In the fall of 1917 Pauling entered Oregon Agricultural College (OAC), now Oregon State University, in Corvallis. He was eager to pursue his study of chemical-engineering and signed up for a full load of classes. But finances soon presented a serious problem. His mother was unable to pay family bills at home and, as a result, Pauling regularly worked 40 or more hours a week in addition to studying and attending classes. By the end of his sophomore year, he could not afford to stay in school and decided to take a year off and help his mother by working in Portland. At the last minute, OAC offered him a job teaching quantitative analysis, a course he had completed as a student just a few months earlier. The $100-a-month job allowed him to return to OAC and continue his education.

During his junior and senior years, Pauling learned about the work of Gilbert Newton Lewis and Irving Langmuir on the electronic structure of atoms and the way atoms combine with each other to form molecules. He became interested in how the physical and chemical properties of substances are related to the structure of the atoms and molecules of which they are composed and decided to make this topic the focus of his own research.

During his senior year, he met Ava Helen Miller while teaching chemistry in a home-economics class. They were married June 17, 1923, and later had four children: Linus Jr., born in 1925; Peter Jeffress, born in 1931; Linda Helen, born in 1932; and Edward Crellin, born in 1937.

Pauling received his bachelor's degree from OAC on June 5, 1922 and began attending the California Institute of Technology (Cal Tech) in Pasadena the following fall. He received his doctorate summa cum laude in chemistry (with minors in physics and mathematics) on June 12, 1925. During his graduate studies, he was assigned to work with Roscoe Gilley Dickinson on the X-ray analysis of crystal structures. His first paper, published in the Journal of the American Chemical Society (JACS) in 1923, was a direct result of this work. Pauling's entire scientific life is connected with Cal Tech and he would publish six more papers on the structure of other minerals before graduation.

After graduation, Pauling decided to travel to Europe and study in the new field of quantum mechanics with Arnold Sommerfeld in Munich, Niels Bohr in Copenhagen, and Erwin Schrodinger in Zurich. The science of quantum mechanics was less than a decade old and based on the revolutionary concept that particles can sometimes have wave-like properties, and waves can sometimes best be described as if they consisted of mass-less particles. He had been introduced to quantum mechanics while at OAC and was eager to see how this new way of looking at matter and energy could be applied to his own area of interest. After two years in Europe, he and Ava left Zurich and returned to Cal Tech.

Pauling was appointed to Cal Tech's faculty of theoretical chemistry in the fall of 1927 as an assistant professor and would stay on there until his leave as a full professor of chemistry in 1963. In addition, from 1937 to 1958, he headed the Gates and Crellin Chemical Laboratories.

The central theme of Pauling's work was always the understanding of the properties of chemical substances in relation to their structure. He began by determining the crystal structure of various inorganic compounds and complexes with a view to deriving from these the principles governing the structure of molecules. He went on to the prediction of the chemical and physical properties of atoms and ions based upon theoretical considerations. In 1928 Pauling introduced rules relating to the stability of complex ionic crystals which greatly facilitated structural studies.

Pauling spent the summer of 1930 traveling around Europe visiting the laboratories of Laurence Bragg in Manchester, Herman Ludwigshafen and Sommerfeld in Munich. In Ludwigshafen, Pauling learned about the use of electron diffraction techniques to analyze crystalline materials. Over the next 25 years, Pauling and his colleagues would use this technique to determine the molecular structure of more than 225 substances.

Using what he had learned over the summer, Pauling and R.B. Corey began studying the structure of amino acids and small peptides. They postulated that polypeptide chains, especially those derived from fibrous proteins, form spirals of a particular configuration--this was the alpha helix. On April 6, 1931, Pauling published the first major paper on this topic ("The Nature of the Chemical Bond") and was awarded the American Chemical Society's Langmuir Prize for "the most noteworthy work in pure science done by a man 30 years of age or less."

This was a bold proposal for the newly appointed full professor to make. But it has been repeatedly confirmed since, and is now known to apply also to significant portions of the polypeptide chains in the so-called "globular proteins." Pauling would write six more papers on the same topic, continually refining his work.

In some ways, the 1930s mark the pinnacle of Pauling's career as a chemist. During that decade he was able to apply the principles of quantum mechanics to solve a number of important problems in chemical theory.

In 1939 Pauling published his book The Nature of the Chemical Bond and the Structure of Molecules and Crystals. This book has been considered by many as one of the most important works in the history of chemistry. The ideas presented in the book and related papers are the primary basis upon which Pauling was awarded the Nobel Prize for Chemistry in 1954.

In the mid-1930s Pauling was looking for new fields to explore and soon found his interest turning to the structure of biological molecules. This was a surprising choice for Pauling, because earlier in his career he had mentioned that he wasn't interested in studying biological molecules. The interest of the newly-formed department of biology at Cal Tech in hemoglobin was derived from the discovery by Pauling and C.D. Coryell in 1936 of a change in the magnetic properties of hemoglobin upon oxygenation. These studies, although they dealt mainly with heme structure, led to an interest in the globin portion of the molecule. This finally culminated in the 1949 proposal that humans may manufacture more than one kind of adult hemoglobin. Sickle-cell anemia was shown to be due to the presence of a type of hemoglobin which tends to aggregate and crystallize under conditions of reduced oxygen, with distortion and malfunctioning of the red blood cell. This was the first documented instance of a "molecular" disorder, a discovery of major import to medicine, biochemistry, genetics, and anthropology.

The 1940s were a decade of significant change in Pauling's life. He had never been especially political and, in fact, had only voted in one presidential election prior to World War II. But in this decade he quickly began to immerse himself in political issues. One important factor in this change was the influence of his wife, who had long been active in a number of social and political causes. Another factor was probably the war itself. As a result of his own wartime research on explosives as a principal investigator for the Office of Scientific Research and the National Defense Research Commission, Pauling became more concerned about the potential destructiveness of future wars. As a result, he decided while on a 1947 trip to Europe that he would raise the issue of world peace in every speech he made in the future, no matter what the topic.

From that point on, Pauling's interests turned from scientific to political topics. He devoted more time to speaking out on political issues, and the majority of his published papers dealt with political, rather than scientific, topics. In 1957, with the help of his wife and many others, he organized a petition calling for an end to nuclear bomb testing. In January of the following year, he presented this petition at the United Nations with over 11,000 signatures from scientists all over the world. In 1958 he published his views on the military threat facing the world in his book No More War!

His views annoyed many in the scientific and political communities and he was often punished for these views. In 1952 the U.S. State Department denied him a passport to attend an important scientific convention in England because his anti-communist statements were not "strong enough." Only after his fourth try did he succeed in receiving a "limited passport." In 1960 he was called before the Internal Security Committee of the U.S. Senate to explain his antiwar activities. But neither popular nor professional disapproval could keep Pauling from protesting, writing, speaking, and organizing conferences against the world's continuing militarism. In recognition of these efforts, Pauling was awarded the 1963 Nobel Prize for Peace.

In 1966 Pauling again found a new field to explore: the possible therapeutic effects of vitamin C. Pauling was introduced to the potential value of vitamin C in preventing colds by biochemist Irwin Stone. He soon became intensely interested in the topic and summarized his views in the 1970 book Vitamin C and The Common Cold.

In 1974 Pauling testified before the U.S. Senate Subcommittee on Health on food supplement legislation. He advocated controls over vitamins but did not want to classify them as drugs. In 1986 he published How To Live Longer and Feel Better, and in 1990, along with Daisaku Ikeda Seimei, he published In Quest of the Century of Life --Science and Peace and Health.

Pauling's views on vitamin C have received relatively modest support in the scientific community. Many colleagues tend to feel that the evidence supporting the therapeutic effects of vitamin C is weak or nonexistent, though research on the topic continues. Other scientists are more convinced by Pauling's argument. He is regarded by some as the founder of the science of ortho-molecular medicine, a field based on the concept that substances normally present in the body (such as vitamin C) can be used to prevent disease and illness.

Pauling's long association with Cal Tech ended in 1963, at least partly because of his active work in the peace movement. He "retired" to become a research professor in the physical and biological sciences at the Center for the Study of Democratic Institutions in Santa Barbara, California. He went on to teach chemistry at the University of California in San Diego and Stanford University in Palo Alto. In 1972 he founded, along with Arthur B. Robinson and Keene Dimick, the Institute of Orthomolecular Medicine as a non-profit California organization to engage in scientific research. Later, it was re-named the Linus Pauling Institute of Science and Medicine.

Pauling received many awards during his successful career. He was a member of the National Academy of Sciences and of the Royal Society, from which he received the Davy Medal in 1947; the American College of Physicians presented him with its Phillips Memorial Award in 1956; and in the same year he received the Avogadro Medal from the Italian Academy of Sciences.

On August 19, 1994 Pauling died of cancer at his ranch outside Big Sur, California. After his death, research continued on every aspect of his earlier discoveries, especially his theory on vitamin C and its effects on disease and the human body. His career exemplified the highly productive results that clear theory along with daring experimental approaches and a courageous imagination can bring.

Further Reading

• Short biographies of Pauling are in Eduard Farber, Nobel Prize Winners in Chemistry, 1901-1961 (rev. ed. 1963), and Nobel Foundation, Chemistry: Including Presentation Speeches and Laureates's Biographies (1964). A personal reminiscence of Pauling and his scientific work is in James Dewey Watson, The Double Helix: A Personal Account of the Discovery of the Structure of DNA (1968). Pauling's efforts for peace and disarmament are recounted in detail in Mortimer Lipsky, Quest for Peace: The Story of the Nobel Award (1966).
• Other biographies of Pauling appear in Anthony Serafini Linus Pauling: A Man and His Science (1989) and Ted George Goertzel Linus Pauling: A Life In Science and Politics (1995). Probably the best source for information on Pauling is maintained by the Oregon State University Library with its Ava Helen and Linus Pauling Papers, which were donated in 1986 by Pauling himself and are available on-line at www.orst.edu.