How the injection-19 will be studied 50 years from now:

Bloodletting
Bloodletting is the withdrawal of blood from a patient to prevent or cure illness and disease. Bloodletting, whether by a physician or by leeches, was based on an ancient system of medicine in which blood and other bodily fluids were regarded as "humours" that had to remain in proper balance to maintain health.

That used to be called settled science too.