Dark Banquet (12 page)

As opposed to our longstanding misconceptions about bats, bad information on blood and the circulatory system didn't start with the Europeans—although they were responsible for carrying this miserable banner for well over a thousand years.

The ancient Egyptians certainly had some vague ideas about the function of the circulatory system (as revealed in the Smith and Ebers papyri, dated to the seventeenth and sixteenth centuries BCE, respectively). They knew, for example, that there was a relationship between the heart and a person's pulse. Their knowledge was somewhat limited, however, by an inability to differentiate among blood vessels, nerves, tendons, and ureters (the tubes which carry urine from the kidneys to the urinary bladder). This led to confusion about substances like sperm, urine, tears, and blood, although the latter was put to some use. For example, some ancient Egyptians took the blood of a black calf or a black ox, mixed it with oil, then slathered it on top of their heads. Why? To combat graying hair, of course—a sort of Grecian Formula 44 before there were actual Greeks. Maybe that sounds ridiculous today, but the implication is that there was
something
in the blood itself that would restore blackness to the hair.

The word
blood
shows up in the Bible over four hundred times with the earliest mention coming in the Old Testament (Genesis 4:10), right after Cain has murdered his brother, Abel:
“And the Lord said, ‘What have you done? The voice of your brother's blood is crying to me from the ground.'”
Later, an even more significant passage concerning blood occurs in Genesis 9:6:
“Whoever sheds the blood of man, by man shall his blood be shed.”

Since the ancient Hebrews believed that the spirit resided in the blood, killing someone was more often referred to as spilling or shedding their blood. It was and is, arguably, the most serious thing we can do to another human. So serious, it seems, that it calls for the spilling of
more
blood from those deemed responsible.

Blood pops up (oozes up?) again in the Old Testament, in Genesis 9:3–4, as God is chatting with Noah:
“Every moving thing that lives shall be food for you; and as I give you the green plants, I give you everything. Only you shall not eat flesh with its life, that is, its blood.”
(Note: This passage follows right after God's more popular command that Noah and his sons
“be fruitful and multiply.”
)

This notion, that life itself resided in the blood, appears to have led to the requirement that animals slaughtered for food be drained of blood before being eaten.
^*47
Apparently, exsanguination spares people from eating the spirit of the animal—which presumably escapes the red puddle sometime
before
the clotting process is completed. Did I mention that this procedure also comes in handy if you're looking for a way to feed your vampire bat colony?

The Hebrews certainly weren't alone in their belief that blood was a special juice, nor were they the only ones who spent considerable time and effort spilling it for those beliefs. So important was this fluid that the offering up of blood was thought by many cultures to be the ultimate way to atone for one's sins, to pay homage to one's god or gods or to cure one's self of various ills. (Countess Báthory serves as a rather extreme example of the latter.) Generally, animals were sacrificed. Calves were popular, possibly because they were easy to lead around and their blood could cover a lot of altar surface, but in far too many cases to fathom human blood was considered to be the ultimate sacrifice—whether it was shed for atonement, revenge, the gods, or a cure.

Scientific knowledge of blood and the circulatory system was, to put it mildly, rather slow to come about. To put it less mildly, most of the early information was dead wrong, yet somehow it lingered in the field of medicine for over two thousand years. Here's how it happened.

Around 400 BCE, Hippocrates proposed (among
many
other things) that the human body contained four substances called humors: black bile, yellow bile (or choler), phlegm, and blood. When the four humors were balanced, the person remained healthy, but any humoral imbalance led to sickness, misery, and despair. Accordingly, to the ancient Greeks, it was the
volume
of blood that dictated the health of an individual.
^*48
It should come as no surprise, then, that starvation, vomiting, and bleeding were used to treat perceived excesses in humors, while other patients were instructed to gorge themselves when their humoral levels needed boosting.

As adopted by Claudius Galenus (better known in English as Galen) nearly six hundred years after Hippocrates, humoral imbalances were not only used to explain how people got sick but how they got their personalities. Too much phlegm, for example, led to a lack of emotion in the individual—a phlegmatic personality. On the other hand, too much blood led to a “sanguine” or carefree temperament. In this case, nosebleeds, hemorrhoids, and menstruation were looked upon as the body's way of restoring normal blood levels.

Earlier, while working as a physician at a gladiator school in the Turkish city of Pergamon, Galen, the son of a wealthy architect, had glimpses of internal human anatomy, referring to wounds as “windows into the body.” The thirty-two-year-old Galen moved to Rome in 160 CE, but the Roman ban on human dissection meant that he would never get to explore what was on the other side of that window. Galen was reduced to making inferences about the human condition by examining animals like macaques (a type of Old World monkey), pigs, and goats. These animals were often dissected alive and in public, and Galen's “hands-on-guts” public demonstrations made him incredibly popular. Unfortunately, although Galen's dissections set him apart from more traditional physicians (who employed a distinctly less hands-on approach), his reliance on inference, conjecture, and his own imagination often led to conclusions about the human body that were dead wrong.

Galen eventually became the personal physician of Emperor Marcus Aurelius and later his son Commodus.
^*49
Although Galen was much more interested in the central nervous system than he was in the circulatory system, he did prove, among other things, that blood, not
pneuma
(an airlike spiritual essence dreamed up by the ancient Greeks), traveled through arteries.

On the other hand, Galen had no real concept of blood circulation. He believed that blood ebbed and flowed like the tides, with venous blood originating from and returning to the liver.
^†50
Unwilling to abandon the concept of
pneuma,
Galen proclaimed that blood within the heart passed through invisible pores in the wall separating the heart's chamberlike ventricles. After mixing with the
pneuma,
the blood was then distributed to the body.

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 or surgeons (the top two rungs of the medical practitioner's ladder, respectively). Procedures such as therapeutic phlebotomy, leeching, and even minor surgeries were usually carried out by a lower class of medical personnel, the barber-surgeons (who were themselves a rung or two higher than midwives). Barber-surgeons were the descendants of the bath men who toiled in medieval bathhouses. Both had duties that included shaving, cutting hair, bleeding patients, administering enemas, and changing wound dressings. During wars, some barber-surgeons traveled with their respective armies—treating fractures and probing for bullets. They became the first military surgeons. Back home, they advertised their talents with a striped barber pole outside their establishment—the red stripes signifying blood, blue stripes were veins, and white stripes represented the gauze bandages they used to stem the bleeding. The pole itself was a symbol of the stick that patients would grip tightly as they were being bled and the ball atop the pole signified the blood collection basin (and the container they used to hold leeches).