ished his discovery of circulation in 1628, recognized the value of
investigating the implications of his theory. Harvey could not explain the
causes and uses of the circulation but he believed that it did not rule
out the practice of bloodletting. He claimed that

daily experience satisfies us that bloodletting has a most salutary
effect in many diseases, and is indeed the foremost among all the
general remedial means: vitiated states and plethora of blood, are
causes of a whole host of disease; and the timely evacuation of a
certain quantity of the fluid frequently delivers patients from very
dangerous diseases, and even from imminent death.[36]

The English scientist Henry Stubbe brought to the surface what would
appear to be an obvious dilemma: How could one bleed to produce local
effect if the blood circulated? Stubbe commented in 1671:

I do say, that no experienced Physician ever denied the operation of
bloodletting though since the tenet of the Circulation of the Blood
the manner how such an effect doth succeed admits of some dispute,
and is obscure. We the silly followers of Galen and the Ancients do
think it an imbecility of judgement, for any to desert an experienced
practice, because he doth not comprehend in what manner it is
effected.[37]

In the early nineteenth century the physiologist Francois Magendie
(1783-1855), who argued against bloodletting, showed that the
physiological effects of opening different veins was exactly the same, and
therefore the choice of which vein to bleed did not affect the
procedure.[38]

The first serious modern challenges to bloodletting were made in the
sixteenth and seventeenth centuries under the leadership of the German
alchemist Paracelsus and his Belgian follower, Van Helmont. The medical
chemists or iatrochemists espoused explanations for and treatments of
diseases based on chemical theories and practices. They believed that the
state of the blood could best be regulated by administering the proper
chemicals and drugs rather than by simply removing a portion of the blood.
Iatrochemistry provided a substitution in the form of medicinals to quell
the flow of blood for therapeutic purposes.[39]

The revival of Hippocratic medicine in the late seventeenth and eighteenth
centuries also led to questioning the efficacy of bloodletting. The
Hippocratic treatises, while they occasionally mentioned bloodlettin