Microhistory and Early-Modern Blood Transfusion

Philosophy Is No Secret
7 min readJul 21, 2021


Holly Tucker’s book titled Blood Work (2011) opens with the death of the first president of the United States. George Washington received four rounds of bloodletting when he fell ill. His life ended after the treatment intended to cure him. After the president passed, his family declined an offer by a famous physician to attempt to revive Washington in an experiment with his organs and his blood. Dr. William Thornton planned to invite life back into the president’s body by performing a transfusion of blood from a lamb. The details of this story contain context for Tucker’s study of early blood transfusion during the age of scientific revolution.

In her prologue, Tucker cited Steven Shapin, a sociologist of science, in order to challenge the notion of scientific revolution. What was traditionally seen as the invention of scientific knowledge was reinterpreted as a particularly Eurocentric phenomenon. British and French science in early modernity really included a range of different practices.

In 1670, transfusion was outlawed by the French parliament. The ban on blood experiments came two years after a physician named Jean-Baptiste Denis surprised the world by performing the first animal-to-human transfusion. For his scientific achievement, Dr. Denis became famous. First, Denis transfused the blood from a lamb into a fifteen-year-old boy. Then, Denis performed the same “procedure” on a thirty-four-year-old man named Antoine Mauroy who was homeless and mentally ill. When Mauroy finally died, Denis was accused of murder. Human blood transfusion was banned across Europe for the next hundred and fifty years. The trial and acquittal of Dr. Denis presents a microcosm of civil society in France at an early period of cultural shift toward modernity.

Blood Work, Chapter 1: “The Doctor and the Madman”

In the first chapter of Blood Work, Dr. Denis traveled across Paris to a luxurious mansion. There lived Henri-Louis Montmor, described as a respected member of an aristocratic culture in which money and connections open doors. At Montmor’s estate, his staff prepared a room full of onlookers. A calf was strapped to a table, and Denis opened its femoral artery with a scalpel. Next, the human subject entered the room, Antoine Mauroy, a “deranged” and “homeless” man to those who knew him locally. Denis sliced a vein on his right arm to insert a metal tube from the calf. As soon as Mauroy’s vein received the flow of animal blood, he panicked. He immediately experienced fever, chills and dizziness — all symptoms of the body fighting foreign antigens from another blood group or from an animal’s blood. Mauroy, the “unwilling” subject, struggled against the chair to which he was bound until he lost consciousness.

Despite his unknown destiny, Mauroy survived the first transfusion, so the next day was planned. He even survived the second transfusion. To those fewer guests who were invited to attend the second day’s experiment, the human participant appeared unambiguously improved, he was obviously cured. The next morning, Mauroy awoke to politely request a priest. After his confession, he was described by the priest as now of sound mind. At this point, Denis and Montmor seemed to have fully succeeded in their ambition to cure Mauroy of his madness. Dr. Denis discharged him to return home to his wife. In a self-interested sense, Denis had made history. To him, the months of practicing transfusion on dogs, cows, sheep and horses actually perfected his technique. But the degree of celebrity he enjoyed would end shortly since Mauroy would soon be dead. For this, Denis faced the accusation of murder.

Blood Work, Chapter 2: “Circulation”

In the second chapter of her book, Tucker introduced William Harvey, an Englishman who, in 1628, shook the foundations of medicine when he argued that blood circulated through the body. Physicians had long followed the writings of men like Hippocrates, Galen, and Aristotle. According to Galen, blood did not circulate, but made a one-way trip. It moved from the stomach to the heart, filtered through the liver. In the second century, Galen understood the body’s health as determined by the balanced mixture of four different fluids called “humors.” Breathing was not to oxygenate blood, but to vent the heat created by the heart’s using or "burning" blood like fuel. Fever was a sign of too much blood, and bloodletting was a cure-all. The model of a heart as a fire or furnace explains why bloodletting became a standard first course of action by the Middle Ages.

Harvey refuted this model by measuring all the blood he could drain from a body. He determined it would be impossible for the body to contain as much blood the heart would need to use or “burn” in the Galen model. At a time when the medical community deferred to received wisdom and ancient writers, Harvey disdained tradition as an undue limit on scientific progress.

In the nineteenth century, bloodletting declined as evidence became the center of research and practice. Germ theory of disease was introduced by Louis Pasteur and Joseph Lister. When two thousand hospital patients were interviewed in 1835, the French doctor Pierre Charles Alexandre Louis recorded data to assess bloodletting. He did not condemn it fully, but concluded the procedure was much less useful than was commonly believed. According to Tucker, Louis' conclusion is significant because it indicated a demotion of a two thousand year universal practice to an outmoded relic by the twentieth century.

Blood Work, Chapter 3: “The Age of Vivisection”

In chapter three, Tucker writes about the seventeenth century as “the age of vivisection”—so named because of the blood experiments being performed by English and French scientists. After Harvey’s game-changing discovery of circulation, vivisections were performed to find evidence for and against it. At the time, French philosopher René Descartes reversed traditional philosophy’s thought on the body, the soul, and the life of animals. In philosophy, Descartes equated organism with machine. Although animals and humans both have bodies, he argues that animals cannot feel pain without the capacity for reason and understanding. God authored nature, so he made the animals for the humans to use.

For Tucker, it is no coincidence that Cartesian philosophy offered a convenient justification for the use of live animals. To Descartes, animals are unthinking, unfeeling creatures without souls. Although, he conceded, animals may utter words, they do not think the words before speaking. With this theory, Descartes overturned the dominant thinking since Aristotle, which asserted that animals have sense, but no intellect. For Aristotle, humans had both a sensitive soul and an intellective soul. The competing explanation from Descartes was his dualism of mind and body. The soul inhabited the body, but was not of the body. “Descartes,” Tucker writes, “evicted the soul from the body,” and in so doing, also evicted the soul from animals. Mind-body dualism meant the soul was incorporeal, not of bodily substance. Excluded from this explanation was the ancient idea that the soul resided in the blood.

The question of a corporeal soul became concrete in the criminal trial of Denis, the French physician. What was the cause of death in the case of Mauroy, where animal and human blood were mixed? Cause and effect were under deliberation as much as guilt and innocence. That, Tucker writes, was the judgement that decided the fate of Denis.

Analyzing a “Microhistory” of Scientific Knowledge

Denis' criminal trial is what Tucker calls “microhistory," which she connects with the “macrohistory” of ideas. The accusation of murder brought into question the reality of Mauroy, the scientific status of his insanity, his blood, and his destroyed body made public. The procedure took place over three hundred years before the knowledge of blood groups, and before anesthesia and antisepsis. Blood groups were unknown until 1901, when Carl Landsteiner observed how different mixtures of blood would clot. From this simple experiment, Landsteiner discovered A, B, and O types of blood, overlooking at first the AB blood group which is a scarce three percent of the population. These are the differences of life and blood. Bloodletting ceased to be a universal treatment, changing from a primary response for two thousand years to an artifact of the past. For Tucker, what returned was the theme of undesirable blood. The life of an unwilling madman was expendable enough for Denis not relative to the local cadaver market, but according to the requirements for vivisection. Scientific reason imposed its own model of life.

In the Middle Ages, philosophers explained theocratic rule by reference to the church and its valorized knowledge. Tucker tracks the substitution of one model for another. The idea that anyone could become mad ought to be as familiar as the idea that anyone could be king. It is true that everyone becomes disabled at some point in their life, but not everyone gets to be king. Accordingly, royal physicians and scientists did not act blindly, but rather selected subjects for experimentation based on the standards of a corresponding monarchist social structure. The early path of scientific experimentation followed a development from different kinds of animals to graded kinds of humans, different levels of criminals, children, and the insane. Tucker writes that "the dissection of criminals was officially sanctioned by Pope Sixtus IV in 1482." In early modern Europe, the madman was his own sort of social delinquent, another category of criminal. Any inconsistent madness threatened the universality valued by the project of scientific reason.