Support of medical research by the U.S. federal budget enjoys widespread public support today. Few people realize that the Federal government provided no funding at all for this activity before the later nineteenth century. The principal reason for this is that health and disease were understood differently from the way they are today. The body was viewed as composed of four "humors," or fluids: blood, phlegm, yellow bile, and black bile, each of which had well-known properties. When these humors became unbalanced, disease ensued, and adding or removing a particular humor was viewed as the best way to cure the patient. Bloodletting is perhaps the best known example of such medical intervention. The framers of the U.S. constitution, who shared this medical world-view, made no mention of health or medicine in that document beyond a reference to the government’s responsibility "to promote the general welfare."