Pauling and the Rockefeller Foundation

 

Rockefeller Foundation administrator Warren Weaver.

Rockefeller Foundation administrator Warren Weaver.

We are … particularly gratified that the Institute has found it possible to make a substantial contribution which will enable you to direct a larger proportion of our aid to the study of the substances of fundamental biological importance.”
– Warren Weaver to Linus Pauling, December 27, 1934.

It is obvious from much of his scientific work that Linus Pauling possessed a brilliant and uncanny ability to think across and between disciplines. Pauling was also a pragmatic and often business-like researcher who understood the necessity of securing financial support for his projects. The long and fruitful relationship Pauling maintained with the Rockefeller Foundation – and, in particular, a Rockefeller administrator named Warren Weaver – made possible much of Pauling’s most groundbreaking work on hemoglobin and structural chemistry. The full force of this intellectually-fruitful relationship reveals both the importance of interdisciplinarity in scientific work as well as the essential nature of active and timely funding.

Pauling received his first grant from the Rockefeller Foundation in 1932 for a program of research in structural chemistry. Shortly thereafter, in the fall of 1933, Pauling applied for and later received a three-year grant from the Foundation to support his experimental researches.  Pauling’s proposal was bolstered by his recent work in electron and X-ray diffraction, and held great promise of continued theoretical development in the study of the electronic structures of molecules.

In 1934 Pauling received more funding from the Rockefeller Foundation, this time in support of his hemoglobin research. He proposed to study hemoglobin in part because he understood that a great deal of general interest lay in the biomedical application of theoretical chemistry.

It is also clear that Pauling was, at least to a degree, shifting his research focus to match the lines of inquiry that the Foundation was interested in funding. In 1986, Pauling would note

…I’d had one elementary course in organic chemistry and no biochemistry. Didn’t know much about these things. I was getting support from the Rockefeller Foundation. Warren Weaver said to me, “Well it’s alright. We’ve been giving you some money to determine the structure of the sulfide minerals. But the Rockefeller Foundation isn’t really interested in the sulfide minerals. We’re interested in biological molecules and life.” So I said, “Well, I’d like to study the magnetic properties of hemoglobin and see whether the oxygen molecule loses its paramagnetism when it combines with the hemoglobin molecule.” So they said, “Alright, we’ll give you more money.”

And so it was, more or less, that Pauling’s hemoglobin work received Rockefeller support on the order of $70,000 per year circa 1940.

Listen: Pauling discusses the roots of his relationship with the Rockefeller Foundation

Pauling not only sought and gained special assistance from Rockefeller funds, but Rockefeller personnel also contributed to the development of his hemoglobin work throughout the 1930s. Alfred E. Mirsky, a professor in cell biology at the Rockefeller Institute for Medical Research, was one of the first individuals with whom Pauling discussed potential hemoglobin research. Pauling quickly developed a personal friendship with Mirsky and clearly held his colleague in very high regard as a scientist. In a 1944 letter recommending Mirsky for a position at the Carnegie Institution of Washington, Pauling wrote

I do not know any one who is so keenly interested in the development of the field of science involving the applications of chemistry and physics to borderline problems of biology, and especially of genetics, and who has such a penetrating understanding of the work which has been done. I find that every conversation which I have with Dr. Mirsky gives me some valuable idea. He has a masterly ability to coordinate results into a significant whole.

 

Alfred E. Mirsky

Alfred E. Mirsky

Indeed, over the years Pauling gave a number of lectures at the Rockefeller Institute and continued to benefit from a wide array of academic and personal relationships that began with the Foundation. The Foundation also continued to fund Pauling’s work well into the 1950s, contributing mightily to the “big science” phenomenon that helped define academic research following World War II.

The Rockefeller Foundation was pioneering in its recognition of the importance of supporting interdisciplinary work; in particular, it actively sought to foster research between biology and chemistry. In many ways, Pauling with the prototype scientist that the Foundation was looking to support. Looking back, few can deny the impact that this partnership made on the history of twentieth century science.

For more information on Pauling’s relationship with the Rockefeller Foundation, see the website It’s in the Blood! A Documentary History of Linus Pauling, Hemoglobin, Sickle Cell Anemia. We also strongly recommend the book The Molecular Vision of Life: Caltech, the Rockefeller Foundation, and the Rise of the New Biology (1993), written by the late Dr. Lily Kay.

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Pauling’s Methodology: X-ray Crystallography

X-ray apparatus at Linus Pauling's desk, Gates Laboratory, California Institute of Technology. 1925.

X-ray apparatus at Linus Pauling's desk, Gates Laboratory, California Institute of Technology. 1925.

I was very fortunate in having A.A. Noyes suggest to me, or tell me, that I was to work with Roscoe Dickinson on x-ray crystallography, determination of the structure of crystals by x-ray diffraction. This technique gave for the first time detailed information about how atoms are related to other atoms in a crystal and how far apart they are from the other atoms.
Linus Pauling, 1988.

As a graduate student, well before Pauling began to research hemoglobin in earnest, he spent a great deal of his time using the technique of X-ray crystallography to determine the crystalline structure of a number of inorganic compounds. Pauling recalled that at that time X-ray crystallography “was a new technique, ten years old when I began. Quite a number of structures had been determined but there was a tremendous field open, a tremendous amount of work that could be done.”

Listen: Pauling discusses the importance of X-ray crystallography to his early structural chemistry research

The young Pauling obviously reveled in the excitement of being able to use a new and powerful technology. “We have a pretty extensive collection of apparatus” he once wrote to William Lawrence Bragg, the senior author of a 1922 textbook that started Pauling on X-ray crystallographic research. Any one of Bragg’s student’s, Pauling remarked, “no matter how physical his training,” need not “be frightened at coming to a chemical laboratory” so well-stocked with mechanical apparatus.

Initially Pauling used the technique of X-ray diffraction to determine the structures of fairly simple inorganic compounds, but later, as his own expertise grew and as he discovered new sources of funding, Pauling oriented this new technology toward complex organic compounds, including hemoglobin.

What was ultimately important to Pauling was not what X-ray crystallography could tell him about the size, structure, or relative placement of atoms within a molecule, but rather, what broader theories that information could then be used to support. His growing allegiance to structural chemistry, his developing ideas about the nature of the chemical bond, and his still nascent interest in biochemical interaction were all fed by his experience of rigorously determining molecular structure through new technological methods.

Pauling’s manuscript notes concerning his early experiments with hemochromogen, for instance, indicate the wide spectrum of experimental results he had to assimilate in order to create a coherent picture of the hemoglobin molecule.

The difficulties presented by the need to combine the information he had obtained from x-diffraction with information from other kinds of experimentation, including solubility and more traditional experimental methods, are readily apparent in Pauling’s notes.  Indeed, the impressive new technology of X-ray crystallography is relegated to just one entry in a list of experimental results.

Ultimately it wasn’t the technology at Pauling’s disposal that helped him become such a successful researcher, but rather his attitude in approaching technology and his ability to use the results it gave him to construct more broadly-applicable and intellectually-powerful theories.

To learn more about Linus Pauling’s use of x-ray crystallography, see the websites Linus Pauling and the Nature of the Chemical Bond: A Documentary History and It’s in the Blood!  A Documentary History of Linus Pauling, Hemoglobin and Sickle Cell Anemia.

Thinking Structurally: The Roots of Pauling’s Hemoglobin Work

Pastel drawing of Hemoglobin at 20 angstroms, 1964. Drawing by Roger Hayward.

Pastel drawing of Hemoglobin at 20 angstroms, 1964. Drawing by Roger Hayward.

Linus Pauling is one of that select group of individuals whose lives have made a discernible impact on the contemporary world. His contributions to molecular chemistry have been substantial and fully deserving of the recognition that he received in the form of a Nobel Prize in chemistry….Pauling continued to do productive scientific work throughout his lifetime, making a second outstanding contribution in his discovery of the molecular processes involved in sickle-cell anemia. This discovery, if made by anyone who was not already the only person to receive two unshared Nobel Prizes, might well have merited a third prize in medicine.
– Ted Goertzel. “Linus Pauling: The Scientist as Crusader.” Antioch Review, 38 (1980): 371-382. 1980.

Two of Linus Pauling’s greatest scientific discoveries, his work on the nature of the chemical bond and the discovery of molecular disease, both hinged on his distinctly structural approach to scientific problems.

Having written a doctoral dissertation on the determination of the molecular structure of inorganic compounds in crystalline state, Pauling chose hemoglobin as an object of study in part because he knew that it was hemoglobin’s changing structure that allowed it to carry oxygen to the tissues of the body. While Pauling like to joke that he chose to work on blood because it was easy to obtain, the intellectual challenge of explaining the sigmoid curve of oxygen saturation in hemoglobin profoundly sparked Pauling’s scientific interest.

Later, upon learning about the disease sickle-cell anemia, Pauling came to recognize that the potentially molecular and structural basis of the disease could facilitate a deeper investigation into structural studies of the molecule. Hemoglobin, in part because of its association with the bonding and transport of iron atoms, demonstrated extremely changeable magnetic charges and suggested, even from a preliminary acquaintance, the importance of structural changes in chemical function.

By 1934, when Pauling suggested hemoglobin as the organic molecule of choice for his particular research program, he had already laid out a general plan of research that relied heavily on investigations into the structural and electrically-charged nature of organic molecules. In May of 1935, Pauling wrote in his research notebook

At this time I have analyzed the oxygen equilibrium data to make plausible the idea that in hemoglobin the four hemes are arranged at the corners of a square on one side of the globin, being interconnected along the edges of the square, and that in the hemochromogens the hemes are independent of one another; and I have outlined a general program of investigation, consisting mainly of magnetic studies and x-ray studies (anomalous dispersion, radial distribution about iron atoms).

In a way, Pauling had always been thinking structurally about the nature of the hemoglobin molecule, its ability to bind oxygen molecules and, later, its particular pathology in the case of sickle-cell anemia.

In 1937, Pauling delivered an inaugural lecture for the Sigma Xi society of Corvallis, in which he asserted both the importance and the relatively-recent arrival of structural chemistry as a discipline. For Pauling structural chemistry involved “the determination of the structures of molecules – the exact location of the atoms in space relative to one another – and the interpretation of the chemical and physical properties of substances in terms of the structure of their molecules.”

This lecture, entitled “Hemoglobin and Magnetism,” addressed the “new branch of chemistry, modern structural chemistry” through a discussion of some of Pauling’s most recent work on hemoglobin’s magnetic properties.

The Guggenheim Trip, Part III: Unexpected Colleagues

Walter Heitler, Fritz London, and Ava Helen Pauling in Europe. 1926.

Walter Heitler, Fritz London, and Ava Helen Pauling in Europe. 1926.

The paper of Heitler and London on H2 for the first time seemed to provide a basic understanding, which could be extended to other molecules. Linus Pauling at the California Institute of Technology in Pasadena soon used the valence bond method. . . . As a master salesman and showman, Linus persuaded chemists all over the world to think of typical molecular structures in terms of the valence bond method.” – Robert Mulliken. Life of a Scientist, pp. 60-61. 1989.

After Linus Pauling’s publication of “The Theoretical Prediction of the Physical Properties of Many-Electron Atoms and Ions,” he was ready for an even greater challenge – the problem of the chemical bond was a tantalizing enigma for Pauling, and he wanted more time in Europe to work on it. In the winter of 1926, he applied for an extension of his Guggenheim fellowship and with the help of a particularly complementary cover letter from Arnold Sommerfeld, Pauling was granted six more months of support.

Boosted by this news, he quickly began planning visits to Copenhagen and Zurich, both cities boasting of some of Europe’s finest research facilities. His first stop was Copenhagen, where he hoped to visit Niels Bohr’s institute and discuss ongoing research with the renowned scientist. Unfortunately, he had arrived uninvited and found it almost impossible to obtain a meeting with the physicist. Bohr, with the help of Werner Heisenberg and Erwin Schrödinger, was deeply engaged in research on the fundamentals of quantum mechanics, and was specifically attempting to root out the physical realities of the electron, in the process developing a theory which would eventually be termed the “Copenhagen Interpretation.”

Pauling did, however, did make one valuable discovery in Denmark — that of a young Dutch physicist named Samuel Goudsmit. The two men quickly became friends and began discussing the potential translation of Goudsmit’s doctoral thesis from German to English. Their work did eventually get them noticed by Bohr, who finally granted Pauling and Goudsmit an audience. Unfortunately for the pair, Bohr was neither engaging nor encouraging. Nevertheless, the two continued to work together, their cooperation eventually culminating in a 1930 text, The Structure of Line Spectra, the first book-form publication for either scientist.

In 1926 though, frustrated by his unproductive time in Copenhagen, Pauling departed, stopping briefly at Max Born’s institute in Göttingen before traveling to Zurich where other advances in quantum mechanics promised an interesting stay. Unfortunately, the man Pauling was most interested in, Erwin Schrödinger, proved to be just as unavailable as Bohr. The quantum mechanics revolution was consuming the time and thoughts of Europe’s leading physicists and Pauling, a small-fry American researcher, simply wasn’t important enough to attract the interest of men like Bohr and Schrödinger.

Fritz London

Fritz London

As a result, Pauling chose to converse and work with men of his own status in the scientific community. Fritz London and Walter Heitler, acquaintances of the Paulings, had spent the past several months working on the application of wave mechanics to the study of electron-pair bonding.

Heitler and London’s work was an outgrowth of their interest in the applications and derivations of Heisenberg’s theory of resonance, which suggested that electrons are exchanged between atoms as a result of electronic attraction. Heitler and London determined that this process, under certain conditions, could result in the creation of electron bonds by cancelling out electrostatic repulsion via the energy from electron transfer. Their work on hydrogen bonds likewise agreed with existing theories, including Wolfgang Pauli’s exclusion principle and G.N. Lewis’ shared electron bond. The Heitler-London model was well on its way to contributing to a new truth about the physics of the atom

Walter Heitler

Walter Heitler

Pauling used his time in Zurich to experiment with the Heitler-London work. While he didn’t produce a paper during his stay, the new model made a great impression on him and he returned to Caltech with a renewed sense of purpose. He was preparing to tackle the problem of atomic structure, in all its manifestations, and make history as one of the greatest minds of the twentieth century.

For more information, view our post “Linus Pauling and the Birth of Quantum Mechanics” or visit the website “Linus Pauling and the Nature of the Chemical Bond: A Documentary History.”

The Guggenheim Trip, Part II: The Growth of a Scientist

Linus Pauling, Werner Kuhn, and Wolfgang Pauli traveling by boat in Europe. 1926.

Linus Pauling, Werner Kuhn, and Wolfgang Pauli traveling by boat in Europe. 1926.

My year in Munich was very productive. I not only got a very good grasp of quantum mechanics — by attending Sommerfeld’s lectures on the subject, as well as other lectures by him and other people in the University, and also by my own study of published papers — but in addition I was able to begin attacking many problems dealing with the nature of the chemical bond by applying quantum mechanics to these problems.”
– Linus Pauling. The Chemical Bond: Structure of Dynamics, Ahmed Zewail, ed. 1992.

After his and Ava Helen’s stay in Italy, Linus Pauling was itching to return to the lab. The couple arrived in Munich in the last week of April and the first item on Pauling’s agenda was a meeting with Arnold Sommerfeld.

Sommerfeld, in association with Niels Bohr, was responsible for the Bohr-Sommerfeld model of the atom, a precursor to modern quantum mechanical ideas on atomic structure. At the time of Pauling’s European trip, Sommerfeld was serving as the director of the Institute of Theoretical Physics in Munich. He had spent the past decade building Germany’s community of physicists, nuturing many of Europe’s best scientists on a steady diet of cutting edge research. His lectures, famous by the time Pauling reached Europe, were known for their new and innovative content. As Thomas Hager, a Pauling biographer, explains, “[Sommerfeld] knew everyone in theoretical physics, had collaborated with many of them and corresponded regularly with the rest.” He knew exactly what was happening in his field and made sure his students did too.

Pauling’s first Munich meeting with Sommerfeld was something of a disappointment for the young scientist. Rather than being allowed to continue the work he had begun at Caltech, Sommerfeld chose to assign Pauling mathematical research relating to electron spin – an area that held little interest for him.

After a spell of half-hearted devotion to the electron spin problem, Pauling convinced Sommerfeld to allow him to study the motion of polar molecules. Pauling believed he could clarify portions of the Bohr-Sommerfeld model by introducing the effects of a magnetic field to the existing equations. This caught Sommerfeld’s attention and Pauling was subsequently instructed to continue his research under the stipulation that he provide Sommerfeld with the details of his work for presentation at an upcoming conference in Zurich. Pauling did so, and a few days after Sommerfeld had departed for the conference, he received an order to appear in Zurich to discuss his work.

Once at the conference, Pauling found himself surrounded by the leading physicists of Europe. Wolfgang Pauli, a young German physicist famous for his development of the revolutionary Pauli Exclusion Principle, was among those in attendance. On a whim, Pauling approached his colleague and began explaining his recent work on the Bohr-Sommerfeld model. Pauli was unimpressed. The paradox-riddled Bohr-Sommerfeld model, and Pauling’s work supporting it, was on its way out with the new ideas of quantum mechanics soon to take its place. Pauling’s research was too late to be of any value and Pauli was not shy about telling him so.

After finishing his summer vacationing with Ava Helen in Switzerland, Pauling returned to Munich for the fall semester. It was at this time that Pauling really began to prove himself, developing a reputation for his extensive knowledge and concentrated enthusiasm. Pauling’s most important accomplishment, however, was not his ability to make friends. Instead, it was gaining both the attention and the esteem of Arnold Sommerfeld. Pauling did so by discovering a mathematical error in the work of Gregor Wentzel, a protégé of Sommerfeld. The discovery and correction of this mistake garnered Pauling a great deal of respect in Sommerfeld’s eyes.

As it turned out, Pauling’s discovery of Wentzel’s error resulted in more than just Sommerfeld’s acclaim. It allowed Pauling to apply Wentzel’s work to the calculation of energy levels, which in turn provided the platform for a series of calculations on the energy values for complex atoms. This was a totally new approach to deriving atomic properties and Pauling took full advantage of his discovery, publishing his findings in a paper titled “The Theoretical Prediction of the Physical Properties of many-Electron Atoms and Ions.”

In a matter of months, Pauling had evolved from a star-struck young American to a legitimate player in the European field of quantum mechanics. Fortunately for him, his rise to scientific prominence had only just begun.

Read about Arnold Sommerfeld in “The Duelist” or learn more about this entire story on the website “Linus Pauling and the Nature of the Chemical Bond: A Documentary History.”

Linus Pauling and the Birth of Quantum Mechanics

Linus and Ava Helen Pauling in Munich, with Walter Heitler (left) and Fritz London (right), 1927.

Linus and Ava Helen Pauling in Munich, with Walter Heitler (left) and Fritz London (right), 1927.

My year in Munich was very productive. I not only got a very good grasp of quantum mechanics — by attending Sommerfeld’s lectures on the subject, as well as other lectures by him and other people in the University, and also by my own study of published papers — but in addition I was able to begin attacking many problems dealing with the nature of the chemical bond by applying quantum mechanics to these problems.”
– Linus Pauling, 1992

In the spring of 1926, funded by a Guggenheim Fellowship, Linus and Ava Helen Pauling embarked on their first trip to Europe, scientific tourists beginning a journey that would revolutionize modern chemistry and physics.

The Paulings travelled through the continent, stopping at the famed institutes of modern science in Munich, Göttingen, and Zurich, among others, and meeting with scientific giants including Arnold Sommerfeld, Max Born and Erwin Schrödinger. It was at this time that quantum mechanics, the branch of science devoted to the study of the atom’s physics, was being revolutionized by the ideas of Schrödinger and Werner Heisenberg. It wasn’t until Pauling left Germany for Switzerland however, that he was introduced to a ground-breaking idea – the combination of Schrödinger’s wave mechanics with the study of structural chemistry.

In Zurich, the German researchers Walter Heitler and Fritz London explained to Pauling the concept of “electron resonance” as developed by Heisenberg. At its core, the theory suggested that electrons could be attracted to one another, to the point where they would eventually switch back and forth between two given atoms. This exchange of electrons would, in turn, release energy, in the process drawing the two atoms together and creating a chemical bond. This revolutionary concept agreed with certain known principles of the hydrogen atom – the atom on which Heitler and London were conducting their calculations – and appeared to support the Pauli exclusion principle which, as Pauling later put it, “states that no two electrons in the universe can be in exactly the same state.”

After his return to Caltech in September of 1927, Pauling worked on several projects, including his first published book and a class on the Heitler-London work. In the process of defining his research program as a young member of the Caltech faculty, Pauling decided that, rather than continuing to dabble in theoretical physics, he would instead return to his roots in chemistry. With that, he set out to combine what he had learned in Europe with his continuing interests in structural chemistry.

He began his work on the chemical bond, figuring calculations and comparing his results to existing experimental data. He affirmed that Heitler and London’s work meshed comfortably with G. N. Lewis‘ theory of the shared electron pair and he published articles on the subject, in the process introducing many chemists to the notion of using quantum mechanics as a tool for the study of non-physics problems. In early 1928, he suggested that quantum mechanics could answer the question of carbon bonding – a revolutionary idea at the time. Unfortunately, while the preliminary mathematics were promising, the sheer mathematical computing power required did not exist for Pauling to fully solve the problem.

In 1930 M.I.T. physicist John C. Slater succeeded in simplifying Schrödinger’s mathematical description of the types of changes experienced by any quantum system over time — an important mathematical model known as the Schrödinger Wave Equation. By slightly restructuring Slater’s set of simplified equations, Pauling was able to utilize the concept of wave functions to describe new orbitals that matched the known traits of the carbon-tetrahedron bond. Not only did these new methods allow Pauling to calculate the data for basic tetrahedral bonds, they also provided stable footing for detailing the precise structures of a series of complex molecules. This was the genesis of valence-bond theory — a hugely important marriage of quantum physics and structural chemistry.

In early 1931, Pauling released a paper detailing six rules, later known as “Pauling’s Rules,” that dictated the basic principles governing the molecular structure of any given molecule. He presented his findings in the simplest language possible, avoiding complex mathematics in order to make the concepts accessible to his fellow chemists. This paper, of course, was titled “The Nature of the Chemical Bond” and would serve as the basis for his immensely popular textbook of the same name.

In 1954 Pauling won the Nobel Prize in Chemistry “For research into the nature of the chemical bond and its application to the elucidation of complex substances.” The award was granted in recognition of the work that began during his first trip to Europe and blossomed in the decade that followed. Pauling’s innovative application of quantum mechanics had resulted in his receipt of the highest possible scientific honor and the subsequent worldwide recognition of his talents.

Learn more about this story by visiting the website “Linus Pauling and the Nature of the Chemical Bond: A Documentary History.”

A Classic of Twentieth-Century Science: The Nature of the Chemical Bond

Portrait of Linus Pauling, 1930s

Portrait of Linus Pauling. 1930s.

“I have just returned from a short vacation for which the only books I took were a half-dozen detective stories and your ‘Chemical Bond’. I found yours the most exciting of the lot.”
– G.N. Lewis. Letter to Linus Pauling. August 25, 1939.

In the fall of 1930, Pauling began work on a determination of the structure of the carbon tetrahedron, implementing the simplified version of the Schrödinger wave equation as modified by John C. Slater. Pauling’s goal was to define the atomic architecture of the carbon tetrahedron, as it was understood by chemists, in terms of quantum mechanics. Success in this venture carried with it the potential to unify chemists and physicists in their understanding of molecular bonding.

Pauling worked through the fall without any major breakthroughs until finally, in December of 1930, he made the decision to remove the radial function from his equation in an attempt to simplify the mathematics of the project. Having done so, Pauling found that the resulting wave functions, (which might be thought of as mathematical models of atomic structures derived from x-ray studies of substances) when mathematically combined, resulted in four hybrid orbitals oriented at the angles of a tetrahedron. Moreover, the mathematics demonstrated that bonds strengthened as the overlap between orbitals increased.

Pauling was elated to find that all variables could be accounted for using his new mathematical method. It was immediately clear to the 29-year-old scientist that this was a major discovery. In his own words,

“I was so excited and happy, I think I stayed up all night, making, writing out, solving the equations, which were so simple that I could solve them in a few minutes. Solve one equation, get the answer, then solve another equation about the structure of octahedral complexes such as the ferrocyanide ion in potassium ferrocyanide, or square planar complexes such as in tetrachloroplatinate ion, and various other problems. I just kept getting more and more euphorious as time went by.”

In February of 1931, Pauling mailed his paper to the Journal of the American Chemical Society. Boldly titled “The Nature of the Chemical Bond: Application of results obtained from the quantum mechanics and from a theory of paramagnetic susceptibility to the structure of molecules,” Pauling’s publication was promptly recognized to be an instant classic of twentieth-century science.

The paper defined six rules for the shared electron bond and presented his findings in uncomplicated terms, allowing his colleagues to examine his research without becoming lost in the mathematics. Pauling’s write-up was distributed in J.A.C.S. only six weeks after the manuscript arrived in the journal’s offices. The incredible speed of this turn-around from manuscript to print was abetted by the fact that the paper had not been refereed, as J.A.C.S. editor Arthur Lamb could think of no individual properly-qualified to review the revolutionary content of Pauling’s work.

Pauling’s unique combination of chemistry and quantum mechanics reinforced the accumulated knowledge of both fields and, in an invaluable breakthrough, pushed researchers toward an understanding of completely new atomic structures and properties. The importance of Pauling’s discovery only grew with time — that, and the publication by Pauling of six more papers on the topic.

In 1939, Pauling collected his research into an extremely popular textbook titled The Nature of the Chemical Bond and the Structure of Molecules and Crystals: An Introduction to Modern Structural Chemistry. The text was a huge success on many levels: not only did it describe research of fundamental importance to the study of chemistry, but it did so in a lucid style that was understandable to a wide range of users. As Max Perutz would later note, The Nature of the Chemical Bond proved that “chemistry could be understood rather than being memorized.” A contemporary of Pauling’s, Dr. Charles P. Smyth, would echo this perspective in a 1939 letter, writing:

“I have been very much interested by your new book and have assigned several of the chapters for reading in connection with a graduate course. As evidence of my interest in it, I can cite the fact that it is the first scientific book which I can remember reading during the course of a fishing trip, although I have carried many with me in the past.”

It is likewise worth noting that various editions of The Nature of the Chemical Bond can still be found for sale online, nearly eighty years after its first printing and fifteen years after it’s author’s death. While some of the research presented in its pages is now outdated, the clarity and impact of its writing insures its status as one of the great scientific publications of all time.

Read the original manuscript for the first “Nature of the Chemical Bond” paper and learn much more about this important story on the website “Linus Pauling and the Nature of the Chemical Bond: A Documentary History.”