For doctors and chemists. Project 523 was a lifeline, according to Professor Zhou Yiqing. "By the time Project 523 had got under way, the Cultural Revolution had started and the research provided shelter for scientists facing political persecution." Tu's husband had been banished to the countryside when she was asked to get involved in Project 523. Tu's research project sought to find modern logic in ancient ways, much as the French researchers identified quinine from the bark of the cinchona tree. According to Tu, she and her team screened over 2,000 different Chinese herbs described in old texts, of which about 200 were good enough to test in mice. That's when they hit upon a plant called Artemisia annua: annual wormwood, or qinghao in Chinese. At the time, all of this work remained a Chinese military secret; some of the results were published in Chinese-language journals, but it would be well after the death of Mao Zedong until China would reveal that it had discovered a surprisingly potent new weapon against malaria.
According to Guo the lion's share of the credit rightly goes to Tu and the countless other Chinese scientists who worked on Project 523. But Oxford anthropologist Elisabeth Hsu suggests that the political climate at the time also deserves recognition. Qinghaosu might never have been discovered had it not been for Maoist China's nationalist infatuation with Chinese folk medicine. "It was thus a feature specific to institutions of the People's Republic of China that scientists, who themselves had learnt ways of appreciating traditional knowledge, worked side by side with historians of traditional medicine, who had textual learning," Hsu argues. "This was crucial for the 'discovery' of qinghao."