Hippocratic medicine - in the form of the four humors was practiced in various guises for two and a half thousand years.

Parallel with this phenomenon the scientific method (as we understand it today) was also evolving and recognisable from at least the tenth century AD.

Can anybody tell me of any known instances where the scientific method was applied to, for example, the practice of bloodletting or purging, to test the validity of these practices?

Thank you for your help :-)