[Linus Pauling and the promise of post-war science, part 3 of 5.]
“Unsolved problems of structural chemistry.” Acceptance address for the 1947 Theodore William Richards Medal, awarded by the Northeastern Section of the American Chemical Society. Chemical and Engineering News, October 1947.
In May 1947, Linus Pauling received yet another award from a chapter of the American Chemical Society. This time it was the Theodore William Richards Medal, granted by the Northeastern section of the ACS.
Pauling chose to use the occasion to speak on “Unsolved Problems of Structural Chemistry.” At the beginning of his talk, he praised the progress that had been made in the field over the previous twenty-five years, and then speculated on the potential for advancement over the next quarter century. In his address, he sorted the discipline’s “unsolved problems” into four categories: “comic-strip science,” “some puzzling small problems,” “some larger problems,” and “some great problems.”
Pauling’s “comic-strip science” designation referred to depictions of chemistry aimed at children as well as other popular-media portrayals, including magazine advertisements. Pauling believed that many young people were first introduced to the concepts of atoms and molecules through comics, a point of entry that was often capable of instilling a reasonable understanding of basic concepts. On the other hand, advertisements for household products often hinted at the chemical properties that made the products effective, but these details were usually under-explored and not well-understood. In particular, Pauling cited pin-point carbonation – an old-fashioned process by which bubbled were added to sodas, seltzers, and other beverages – and the activation of chlorophyll in household deodorizers as two examples of chemical reactions that were taken for granted in daily life but still not adequately explained by scientists.
By “puzzling small problems,” Pauling meant to refer to ongoing research on the molecular structure of simpler molecules, for which newer methods had begun to produce greater insights. His “larger problems” were also structural in nature, but more complex and theory-based, and primarily relating to the structures of groups of substances rather than individual molecules. This category also included studies on the extent to which covalent bonds between metal atoms occur in nonmetallic compounds. Pauling’s list of “great problems” included the structure of metals and intermetallic compounds, the structure of activated complexes, and an array of questions in organic and biological chemistry, especially the structures of proteins and genes, and the relation of structure to biological specificity.
Having provided an overview of these types of problems, Pauling concluded with optimistic rhetoric that was consistent with his talks of this time:
The progress of science in recent years is bringing biology and medicine into closer and closer contact with the basic sciences, and I am confident that the next few decades will bring to us a detailed understanding of the molecular structure of biological systems, and that this understanding will help in the rapid general progress of biology and medicine.
“Chemical achievement and hope for the future.” Silliman Lecture presented at Yale University in October 1947, on the occasion of the Centennial of the Sheffield Scientific School. American Scientist, 1948.
Pauling took a similar approach to his 1947 Silliman Lecture, delivered at Yale University in the fall. In thinking about “Chemical achievement and hope for the future,” Pauling began by examining the past century of scientific achievement in the field of chemistry. This period was one characterized by transition from “an empirical and descriptive science to an exact and theoretical one.”
For Pauling, a perfect example of this transition was the study of chemical thermodynamics, a field that had developed in conjunction with improvements in the understanding of molecular structure, among other fairly recent discoveries. Pauling also pointed out that, over the last hundred years, precise atomic weights had been assigned to most of the elements, and many of those predicted by sequences in Mendeleev’s periodic table had been discovered, along with the noble gases and a subset of man-made elements.
Pauling then summarized the last century of scientific achievement in each of the sub-fields of chemistry. For inorganic chemistry, he cited an increased understanding of the molecular structure of substances, particularly those needed to synthesize silicon-based substances that behave like carbon-based ones. These compounds included synthetic diamond and rubber, both of which were extremely useful to industry.
For organic chemistry, Pauling spoke to breakthroughs in both the “art of organic chemistry” and a corresponding but previously distinct “science of organic chemistry,” and identified as the greatest achievement in the field the unification of the two. The ability to synthesize new plastics was one major tangible outcome that arose from this consolidation within the discipline.
In Pauling’s view though, the field in which the most significant breakthroughs had occurred was clearly biomedical chemistry. Over the past five decades, average life expectancy had risen some sixteen years and childhood mortality rates had plummeted by 90% in the last twenty-five years alone. Numerous maladies had been controlled or nearly eradicated, though threats in the form of polio and flu viruses remained; so too degenerative diseases like cancer and heart disease.
As he considered the possibility of future advancement in medicine, Pauling emphasized the need for research on the structural basis of physiological activity, which he considered to be the greatest problem in chemistry. Work in this area was sure to reveal new insights into the behavior of antigens, proteins, enzymes, and other immunochemical actors, with medical progress emerging quickly from there.
Pauling wound up his talk with a look ahead. In so doing, he put forth the tantalizing idea that
This discussion has been confined to the least interesting aspects of the developments of chemistry in the future…those that can be predicted, that can be foreseen on the basis of our present knowledge…The great discoveries of the future – those that will make the world different from the present world – are the discoveries that no one has yet thought about…
Inspired by Walt Whitman’s “As I lay with my head in your lap, Camerado” Pauling confessed that he knew not where the future would lead but urged science to confront it head on. “Science cannot be stopped,” he implored,
Man will gather knowledge no matter what the consequences – and we cannot predict what they will be… I know that great, interesting and valuable discoveries can be made and will be made… But I know also that still more interesting discoveries will be made that I have not the imagination to describe – and I am awaiting them, full of curiosity and enthusiasm.