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Why do carnations sleep after coming into the city?
In 1908, a flower grower from Chicago in the United States went to consult a botanist. He said: "I have many beautiful carnations in the countryside, and they bloom very brightly there, but when they reach the city, they come down with sleeping sickness." The botanist thought it might be because the composition of the air in the city differed somewhat from that in the countryside. To confirm his idea, he took all kinds of gases and put them inside a glass cover, then placed blooming carnations inside, and the result showed that as long as the cover contained a few parts per million of ethylene gas, the blooming carnations would wither.