Mirsky and Pauling first proposed: Mirsky and Pauling 1936. Some earlier work was done by Hsien Wu in 1931.

is composed of chains: Very significantly for Pauling’s subsequent work, the authors noted that “this chain is folded into a uniquely defined configuration, in which it is held by hydrogen bonds.” Hydrogen bonds—where the hydrogen is held jointly by two atoms, effectively creating a bridge between them—were about to become Pauling’s trademark.

obtained by the physicist William Astbury: Astbury 1936.

Pauling immersed himself in the work: Pauling described his activities at the time in a dictation given in 1982. The transcription was published by Pauling’s assistant, Dorothy Munro; Pauling 1996.

Figure 11 shows a schematic drawing: Pauling’s original piece of paper, on which he sketched the structure and then folded it, in 1948, was never discovered.