Did anyone boil drinking water before Pasteur?

Question

OK, I know it wasn't till the 1860s that Louis Pasteur demonstrated the existence of bacteria in liquids and that boiling the liquid would kill them. But did nobody before that ever work out empirically that boiling dodgy water somehow made it safe to drink? Are there any medical or scientific texts from e.g. Ancient Greece or Rome, or the Middle Ages, that say "boil your drinking water, it's safer?"

Answer 1

Observations had been made that drinking water could cause illness, so few drank water. Fermented beverages were those consumed. After the invention of the microscope, where they saw microorganisms ideas began to form as to there effect.  Koch put forth the germ theory, although others were observing and commenting on hygiene and cleanliness and its relation to health.

Answer 2

They Chinese and other eastern cultures used to do that when they made tea which is why they suffered much less from some diseases.  The Europeans made beer and added alcohol to water to make it safer.