And so, by and large, until this freon was invented by Midgley, there wasn't a good gas that had the right properties to be used for a refrigerant.

因此，总的说来，直到Midgley发明氟利昂，没有一个气体,能被很好的用作制冷剂。

麻省理工公开课 - 固态化学导论课程节选