The study of hypertension is inseparable from the topic of salt. So today’s new nonsense about blood pressure is about salt. As the saying goes, “Salt is salty, vinegar is sour”, which means that we have to understand the essence of things. So let’s talk about the history of salt. The history of salt in China The ancient source of salt in China, according to the Five Thousand Year History of China (Zhang Qi Yun, 1982), there are two, namely the sea salt in Shandong and the pool salt in Shanxi. In ancient China, natural salt was called “brine”, and those processed by human beings were called “salt”. Such as the “Erya” that cloud: born that brine, life that salt. It is said that in the ancient times of the Yellow Emperor our ancestors knew how to take salt from the sea. In the 26th century BC, there was the saying that “the Changsha clan cooked the sea for salt”, whose representative was Changsha Quzi, who lived on the seashore of Jiaodong, Shandong Province, and was respected as the “Salt Father”. In the Spring and Autumn and Warring States, salt was made by boiling seawater in iron pots. Since this method of salt production was labor-intensive, time-consuming, fuel-intensive, and limited in production, salt was expensive. At the end of the Tang Dynasty, there was a man named Chen in Putian County, Fujian Province, who was wise enough to take seawater and expose salt in the garden, and said that “in case of a hot sun, a husband’s strength, can sun salt two hundred pounds. The invention of sun-dried salt is a great leap forward in the salt-making process. Today, China is the world’s largest producer of salt, sea salt produced from seawater ranks first in the world. How many types of salt are there? Salt is divided into four types: sea salt, pond salt, lake salt and well salt, depending on the source of the brine and the production process. Well salt has high purity and contains many chemical elements such as potassium, boron and iodine, making it the best salt. Sea salt is the richest in iodine, and “eating sea salt can prevent great neck disease”, but sea salt has a slightly spicy taste, which is the middle of the salt. Pool salt and lake salt have a bitter taste and are inferior to iodine. The efficacy of salt should not be underestimated “China’s salt history” (Zuo Shuzhen) that: the world’s salt industry is not preceded by China, China’s salt industry originated in the past Shennong era in the ancient sand boiled sea for salt, nearly 5,000 years ago. Literary scholar February River (Preface to “The History of Chinese Salt Culture”, 2009) believes that salt has three significant functions: ① salt is the general of food, is the life of the people ② salt is the great treasure of the country, is the foundation of the country ③ salt is a divine gift, is the white currency and give examples to illustrate the historical role of salt can enrich the country, with salt refining people. In fact, he ignored the medicinal value of salt. Tao Hongjing, a famous doctor of the Liang Dynasty, once said, “Among the five tastes, this is the only one that cannot be missing”. According to Chinese medicine, this product is salty and cold in nature. It is used to promote vomiting and water retention, to relieve heat and soften hardness, to moisten dryness and relieve constipation, and to induce the return of medicine to the meridian. It is used for chest and epigastric fullness, inconvenient bowel movements, sore throat, bleeding gums, toothache, eye opacity, and sores. What are the other good uses of salt? In the “Keju Miscellaneous Knowledge”, it was recorded that Li Ciming, a literary scholar and Guangxu scholar at the end of Qing Dynasty, had black and yellow teeth like rust, which really lost the elegance of a scholar. He used all the secret recipes, but the effect was not good. Li Ciming happened to look through the “Four Books” and found that the Song Dynasty “Taiping Sheng Hui Fang” reproduced in a “wipe teeth formula”, is the salt calcined into fine powder, and then soak one or two almonds to remove the tip of the skin, and then they are mixed together and pounded like mud, and every morning and evening each rub teeth once a day on the line. He then followed the same method, and as a result, his teeth were as white as jade in only half a year’s time. The Song Dynasty monk Wen Ying’s “Yuhu Qingxue”, there is a tooth wiping song: “pig’s tooth soap and ginger, the western country hemp Shu Di Huang. The wood law dry lotus acacia seeds, fine pungent lotus leaves to be equivalent. The salt is equal to the same burned calcination, research the final future make the most good. Wiping teeth and moustache temples black, who knows there is a magic formula in the world.” This is the earliest medicinal toothpaste in the world. This song also tells us that the use of nine Chinese herbs with salt not only strengthens the teeth and cleans them, but also darkens the beard and hair. Of course, salt can only assist in the treatment of oral diseases, and cannot replace the doctor’s guidance on the use of medicine.