Dark Banquet - Bill Schutt [36]
Granted, as far as circulatory system basics go, figuring out that blood and not air was carried in arteries was significant, but Galen’s deeply flawed concepts of human anatomy and physiology would have a serious and long-lasting effect on the field of medicine—especially with regard to the circulatory system. As previously mentioned, Galen’s overarching ideas on the human body were generally extensions of those proposed by the ancient Greeks, and these mistake-laden views came to completely dominate the field of medicine. Not only did Galen’s take on medicine and anatomy remain pervasive for fifteen hundred years, it remained unchallenged. According to Bill Hayes, the author of Five Quarts—A Personal and Natural History of Blood, “In the early Middle Ages, church leaders declared his work to have been divinely inspired and thus infallible.” Rather than experimenting or dissecting specimens (and thereby bringing down upon themselves the serious and often deadly wrath of the church), the disciples of “Galen the Devine” simply deferred to their long-deceased master and his stance on any given medical topic. Anything else would have been blasphemous.
How did bleeding become such a popular therapeutic tool? What was it that compelled the most learned physicians of their day to drain their patients until they were cold, blue, and unconscious?
During ancient times, bleeding was generally thought to rid the body of evil spirits. Later, once the concept of balancing humors became accepted, regularly scheduled bouts of bloodletting were prescribed in much the same way that a balanced diet and exercise are extolled today. For example, fever and headache were thought to be symptoms of excess amounts of blood (“plethoras”) and called for immediate drainage. Galen considered blood to be the most important of the four humors. (Is anyone shocked that it edged out both shades of bile and survived a late run by the cigarette smoker’s favorite—phlegm?) He used his knowledge and expertise to write a series of books that soundly trounced his critics—especially those who denounced his bloodletting techniques.
After Galen, the significance of blood as a humor gained even greater import, especially when folks determined that there was a slight problem with black bile—it didn’t exist.*51 Blood, on the other hand, was real and it could be tapped by any number of methods. Galen and his contemporaries used a metal scalpel called a phlebotom (from the Greek words for “vein” and “cut”) to make a small venous incision through which a pint or so of blood would be drained. Influential physicians drew up complex charts based on parameters like the seasons, tides, and weather to calculate the amount of bleeding to be done.†52 Similarly, Hebrew and Christian writings also prescribed the best days for bloodletting to take place.
Most historical accounts of mammalian circulation emphasize the work of William Harvey, who, in the early seventeenth century, used scientific methodology to prove that blood did not ebb and flow like the tides. Instead, the heart pumped it around the body in a pair of loops, one to the lungs and back (the pulmonary circuit), and one to supply the body and its tissues (the systemic circuit).‡53 Before Harvey’s discovery, the general belief was that disease-laden “bad blood” had a tendency to pool in the extremities where it would stagnate. Bloodletting, therefore, was a way to eliminate the bad blood. Unfortunately for George Washington (and countless other patients), physicians mistakenly thought that the often copious amounts of blood they drained would be replaced within a very few hours by new, healthy stuff. As Dr. Craik and his colleagues would never learn, this just wasn’t the case.
Beginning in the seventeenth century, bloodletting was not generally undertaken by physicians