来自《耶鲁大学开放课程：1600年后西方社会的流行病 第13集 第13集》

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  But there's more to it, in Pettenkofer's epidemiology.
  佩腾科弗的流行病学理论中 更糟的是
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  Like a plant, fermentation required a number
  像植物一样 发酵需要
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  of other preconditions.
  其他的先决条件
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  It needed water; plants always need water.
  它需要水 正如植物也需要水
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  It needed a warm temperature.
  它需要一个温暖的气候
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  It needed air and porous soil in which to grow.
  还需要空气和多空的土壤让其生长
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  And it was at this point that we see why Pettenkofer's theory
  只有在这些都具备的条件下
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  is sometimes called the groundwater theory.
  佩腾科弗的地下水理论才有意义
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  Groundwater was important to his analysis because he
  地下水在他的分析中很重要
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  considered variations in the water table beneath the city to
  因为他考虑到了城市地下水的许多变量
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  be a measure of the capacity of a soil beneath the city to
  来计算城市地下土壤的容量
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  support fermentation and give rise to cholera epidemics.
  以此支持他的霍乱发酵说