PHOTO FINISH.

The structure of DNA, the molecule of life, was discovered in the early months of 1953. Nine years later, three men were jointly awarded a Nobel Prize for this achievement, which has proved to be one of the most consequential in the history of science. James Watson and Francis Crick, who worked at the Cavendish Laboratory, in Cambridge, England, came up with the famous double-helix structure. The third man honored, Maurice Wilkins, was a scientist in London; although he worked at a rival lab, he did make available to Watson and Crick some of the experimental evidence that helped them clinch their discovery. The person actually responsible for this evidence, however, was not Wilkins but an estranged colleague of his named Rosalind Franklin, who had died four years before the prize was awarded.

For a decade after her death, Rosalind Franklin remained little known beyond the world of molecular biology. Then, in 1968, Watson published "The Double Helix," his rambunctious, best-selling account of the race to solve the structure of DNA. In its pages, Rosalind Franklin becomes Rosy, a bluestocking virago who hoards her data, stubbornly misses their import, and occasionally threatens Watson and others with physical violence--but who might not be "totally uninteresting" if she "took off her glasses and did something novel with her hair."

Friends and colleagues of hers mounted a counter-offensive, which was soon joined by feminist historians of science. Why did Watson create Rosy the Witch? Out of guilt for having used her evidence, which Wilkins showed him without her knowledge. Neither Watson nor Crick ever admitted to Franklin that they had relied crucially on her research; neither so much as mentioned her in his Nobel acceptance speech. Moreover, Franklin herself had made great progress toward identifying the structure of DNA. Had she not been the rare woman laboring in a patriarchal scientific establishment that limited her opportunities and stifled her talents, the triumph might well have been hers. So her partisans have contended.

"Since Watson's book, Rosalind Franklin has become a feminist icon, the Sylvia Plath of molecular biology, the woman whose gifts were sacrificed to the greater glory of the male," Brenda Maddox writes in "Rosalind Franklin: The Dark Lady of DNA" (HarperCollins; $29.95). This mythologizing, Maddox thinks, has done Rosalind's memory a disservice. One wouldn't guess from the "doomed heroine" caricature, for instance, that Rosalind enjoyed an international reputation in three different fields of research. Nor would one guess from Watson's depiction that, far from being frumpier than the average Englishwoman, she had actually brought with her to London elements of Christian Dior's New Look that she had picked up during her years in Paris. Maddox, who has previously written lives of D. H. Lawrence and Nora Joyce, tells Rosalind's story engagingly. We get a vivid picture of her scientific prowess, the complexity of her character, and the stoicism with which she pursued her research during her final months even as she was dying of ovarian cancer. Inevitably, though, it is her part in the DNA drama which commands the most interest. Did she really play an indispensable role in the great 1953 discovery, as Maddox finally joins so many others in suggesting? Was she cheated of the credit due her because she was a woman?

Rosalind Franklin was born in London in 1920 to a prominent Anglo-Jewish family. (Her great-uncle had been installed by the British as the first High Commissioner of Palestine.) The one indulgence of her "frugal rich" parents was foreign travel; they favored vigorous mountain hiking trips--an activity that became a Wordsworthian passion for Rosalind. At sixteen, she chose science as her subject, selecting the "hard" areas of physics, mathematics, and chemistry rather than the botany and biology courses usually taken by girls. She avoided the social whirl. At the age of twenty-one, after three years of study at wartime Cambridge, she confessed to a cousin that she had never been kissed and did not know how the human ovum was fertilized. In 1945, she submitted a Ph.D. thesis on how the porosity of carbon was affected by heat, a subject she mockingly described as "the holes in coal."

In fact, Rosalind's ...