A Twist Of Fate

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A few weeks later, Crick and Watson were pretty sure they had it. DNA was a triple helix. They invited Wilkins to take a look at their model, and to their surprise, Franklin came along too. It didn't take long for everyone to realize that Watson's memory had betrayed him. The amount of water a DNA molecule had to contain was a whopping 10 times the quantity he had assumed. The structure Crick and Watson had so confidently come up with was impossible.

Their mistake had two immediate effects. First, Bragg, already fed up with Crick's impertinence, forbade the pair to work actively on DNA. Second, Franklin, previously suspicious of Crick and even more so of Watson, was convinced that the latter, at least, was a blithering idiot. Chagrined, Watson and Crick turned over their model-making kits to the King's group and urged Wilkins and Franklin to use them. Watson and Crick may have been ambitious for themselves, but they were passionate about knowing the structure of DNA. If they couldn't make the discovery, they would have to acquiesce to Wilkins' and Franklin's doing it. But the Cavendish botch job had cemented Wilkins' and Franklin's view that building models was not the way to solve the structure of DNA. They never used the kits.

Watson turned grudgingly to work on the structure of the tobacco mosaic virus, and Crick went back to hemoglobin. But no mere lab director could keep them from talking about dna between themselves. And while their blunder the first time around had been dispiriting, it didn't discourage them. After all, they had no reputations to be tarnished. And if they had come to the wrong conclusions based on incomplete information and a dumb mistake, that was just an incentive to get better information and be more careful next time.

Besides, they couldn't give up, because Pauling was now on the case for sure. He had written to Wilkins, then to Wilkins' boss, J.T. Randall, asking for copies of King's X-ray images. Both men declined. But Pauling was coming to a Royal Society meeting in May 1952; it would be tougher to refuse him in person. As Pauling was preparing to board a plane in New York, however, the U.S. government seized his passport, citing what they considered his dangerous left-wing political views. While that setback might delay Pauling, Watson and Crick knew it would not stop him.

The King's College group, meanwhile, pushed ahead with its DNA research. Franklin kept working to perfect her X-ray images. In May 1952 she took one that would prove crucially important--though until the day she died, she would never realize it. By increasing the humidity in her lab apparatus, she and graduate student Raymond Gosling discovered that DNA could assume two forms. When sufficiently moist, the molecule would stretch and get thinner, and the pictures that resulted were much sharper than anything anyone had ever seen. They called the wetter version the B form of DNA.