The year is 1626, the place, London, England. The dining room of William Harvey has been cleared of the evening’s meal, the plates, cups and cutlery safely outside the room. The table has been stocked with cutting instruments, small bowls, and containers filled with quills (only some of them for writing). Save for a handful of stubborn dark spatters, the table is immaculate. A single large pig lies, lashed down and quivering on the table, a stray swine Harvey had picked up earlier in the day. He raises his knife, used only an hour ago to carve the family turkey, and begins to make his first incision. My fellow Toastmasters, and honoured guests, I present to you today a brief glimpse of the world of medicine at the beginning of the scientific revolution.
William Harvey, a physician by trade, has been inspired by the many discoveries being made in this new era of scientific inquiry, but few of these discoveries have so far concerned medical treatment. In this seventeenth century, medicine is still informed almost exclusively by the work of Galen, a second century physician. Fifteen hundred years’ worth of medical doctors have been taught by rote memorization how our bodies function, all derived from examining the corpses of monkeys and orang-utans. They never bothered to – never believed they’d need to – examine actual human bodies. They already know all there is to know: Our health is simply a matter of the balance of the Four Humours, of blood, phlegm, black and yellow bile. The solution to just about every ailment is either a bloodletting, or a purging by emetic or laxative. If a patient gets better, the practise is validated; if the patient worsens, they simply hadn’t purged enough. So the practise goes.
A physician, even one as dedicated as William Harvey, can only learn so much from a corpse. He has studied plenty of them already, but was just one man among the many gathered at the thieves’ gallows each day to collect his specimens. William Harvey wants to know more than just the names and positions of body parts. He wants to know how they work while their owner is still alive. More specifically, he wants to know about blood flow. Where does it come from? Where does it go?
Galen had hypothesized a path for blood, and made the claim that ours is an open-ended system. Food goes in; we digest it in the stomach; it gets passed to the liver, where it is converted to blood; it passes next through our bodies to the furnace of the heart; there, it is incinerated, and we breathe out the waste. This is what doctors were told, and what they knew to be true for millennia. Harvey’s investigations, however, were about to prove them wrong.
The problem with studying blood flow is that it requires a living patient from start to finish. Blood clots very quickly, and the flow of blood has a tendency to cease altogether in the absence of a beating heart. The messy work of bloodletting, of trepanation or amputation almost never falls to the doctors, themselves, who prefer to pontificate in their ivory towers, away from the dirt and filth of the real world. Poorly trained barber-surgeons are instead the prime practitioners of limb-cutting, which they perform in between clients waiting for simple hair trimmings.
William Harvey is among the first to challenge the medical establishment, and performs his vivisections himself. Lacking the support of the universities, Harvey executes his work at home, in the graceful absence of his doting wife. His skill with the knife and phenomenal powers of observation, are all put to the test as he exsanguinates his writhing client. Afterward, he removes the heart from the cooling, and now still, porcine patient, and weighs it and whatever remaining blood he can squeeze out. He traces what paths he can of the veins, and notes the direction of the valves within. Two years from now, he will publish his results in Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus (On the Motion of the Heart and Blood in Animals), and describe the reality of the human circulatory system. Decades more will pass before Galen is finally removed from the medical universities, but scientific truths are, eventually, inescapable.
[Toastmasters: The Entertaining Speaker Series. Speech #1.]