In the comments of my post pining for an inter-war upper-class drinking culture, Red writes,

If they went to a public (ie private) school before the First World War – as Waugh did – it’s a fair bet that they drank beer every day, rather than tea or coffee. That’s what happened in the days before clean water was universal.

So, I wonder. Has anyone written a thesis on how the purification of potable water led to the demise of Western civilisation?