An Experimental Perfectionist

Rosalind Franklin knew exactly what she had. James Watson’s claim that he’d recognised what Franklin had failed to see in her famous photograph of DNA’s helical structure was taken at face value in part because she’d left no notes about the image. Researchers have now shown that it’s because it was a second photo, taken to correct the centering and contrast of a first—which Franklin had made extensive notes about, and had used “to calculate, for the first time, the length of each turn in the spiral—34 angstroms—and the number of bases ‘per turn of helix (if there is a helix).’” Watson’s and Crick’s Nobel-winning breakthrough might well not have happened without Franklin’s evidence. Fortune favours the prepared mind, but not all prepared minds are fortunate. More to the point, her evidence, photograph 51, wasn’t just a chance finding. It was the product of a deliberate process of refinement by a scientist who knew what she was looking at in the earlier photograph 49. Sponsel and…