Bloodletting

From Conservapedia

Bloodletting, (literally the partial draining of the body's blood) was for many centuries considered a tried and true remedy for certain conditions. It was recommended for fevers, inflammations, a variety of disease conditions and, ironically, for hemorrhage. Although it fell in and out of favor, it persisted into the 20th century and was even recommended by Sir William Osler in the 1923 edition his Principles and Practice of Medicine.