理发店门口的彩色柱子是用来干啥的?

During medieval times, barbers performed surgery on customers, as well as tooth extractions.
在中世纪，理发师为顾客做外科手术，并为顾客拔牙。

The original pole had a brass wash basin at the top (representing the vessel in which leeches were kept) and bottom (representing the basin that received the blood).
原来的柱子上下各有一个黄铜脸盆（上面的表示放水蛭的容器，下面的是盛血的水盆）。

The pole itself represents the staff that the patient gripped during the procedure to encourage blood flow.
杆子本身代表着手术过程中病人紧紧抓着的工作人员，以促进血液流动。

At the Council of Tours in 1163, the clergy was banned from the practice of surgery.
1163年图尔议会禁止神职人员从事外科手术。

From then, physicians were clearly separated from the surgeons and barbers.
从那时起，医生与外科医生和理发师就被清楚地区分开来。

Later, the role of the barbers was defined by the College de Saint-Côme et Saint-Damien, established by Jean Pitard in Paris circa 1210, as academic surgeons of the long robe and barber surgeons of the short robe.
后来，大约在1210年，让·皮塔德在巴黎创办的圣卡米和圣达米恩学院确定了理发师的角色，学术外科医生穿长袍，理发师穿短袍。

After the formation of the United Barber Surgeon's Company in England, a statute required the barber to use a red and white pole and the surgeon to use a red pole.
英国联合理发师外科医生公司成立后，一项法令要求理发师使用红白相间的杆子，而外科医生使用红色的杆子。

In France, surgeons used a red pole with a basin attached to identify their offices. Blue often appears on poles in the United States, possibly as a homage to its national colors.
在法国，外科医生用一根带盆的红色杆子来区分他们的办公室。美国人则常用蓝色的杆子，这可能是为了向其民族色彩致敬。

Another, more fanciful interpretation of these barber pole colors is that red represents arterial blood, blue is symbolic of venous blood, and white depicts the bandage.
另一种更奇特的解释是，红色代表动脉血，蓝色代表静脉血，白色代表绷带。