Elizabeth Roberts explores the creepy world of pre-19th century barbers, who "treated and extracted teeth, branded slaves, created ritual tattoos or scars, cut out gallstones and hangnails, set fractures, gave enemas, and lanced abscesses." And of course, provided your annual bloodletting:
Bleeding was done for a number of reasons, but the basis of the ideas was that by letting out the bad or morbid blood in the body, it would be replaced by fresh healthy blood. Bleeding of patients was done in many ways, including cupping and using leeches, but the most common was cutting a patient’s vein and letting the blood flow into a small basin.
As bleeding became one of the main responsibilities of the barbers, they came to signify their presence in the marketplace with a red and white striped pole, the colors reminiscent of the blood and rags used in bloodletting. This pole was usually capped with a small basin, used to symbolize the vessel with which they would collect the blood. Later, barbers placed bowls of blood in their shop windows, to indicate that they performed bloodletting services.