Document salt is one of the substances of great significance to human survival. When the ancients in China changed from meat to grain, there was a need to eat salt, because the flesh and blood of animals contained enough salt for human consumption, while the grain itself did not. In the Paleolithic Age, which lasted for hundreds of thousands of years, human beings lived by hunting, and their bodies had already adapted to the combination of trace elements brought by meat. Around 2300 BC, in the late Neolithic period, that is, in the areas of western Shandong and eastern Henan, the ancients in China developed grain agriculture and began to live mainly on grain. In this way, the diet with salt as the basic seasoning has changed the combination of trace elements that has been adapted for a long time, which directly leads to the emergence of new diseases related to eating salt. In order to treat new diseases caused by eating salt, acupuncture came into being.

In ancient China, natural salt was called "brine", and it was called "salt" only when brine was artificially processed into solid crystals. The earliest discovery and utilization of natural salt in ancient China was in flood times, just like animals licking rock salt and salt water, which was based on physiological instinct. Records handed down in ancient China, such as "White Deer Drinking Spring", "Salt Produced in Cow's Lick Land", "Monkey's Lick Land" and "Sheep's Lick Land", all show that the ancients in China discovered the existence of salt by observing animal behavior. Among the cultural relics unearthed in Fujian in the 1950s, there were cookers, which proved that the ancients had learned to cook sea salt from 5000 BC to 3000 BC at the latest. However, the era of "cooking the sea for salt" recorded in the literature was in Shennong era (2370-2338 BC, see the encyclopedia entry "Chronology of Three Emperors and Five Emperors", the same below). Shuowen: "Su Sha cooked the sea for salt." This era is relatively late. Why did you remember to boil salt in seawater about 4300 years ago? That's because by the time of Fuxi (2400 BC-2370 BC), there were not enough animals to provide people with the source of meat in Luxi and Yudong areas where the population center of China is located today, but the blood and meat of animals contained enough salt for human consumption. In other words, if we adopt a life style with meat as the mainstay, supplemented by fruits, vegetables and grains, then people don't need to eat salt. Therefore, the Fuxi era became an era in which meat was the main thing in western Shandong and eastern Henan changed to grain. However, grains don't contain salt like meat, so there is a unique need to eat salt, so a professional salt cooking tribe like Su Sha emerged. According to the literature, Su Sha people attacked their monarch and naturalized Shennong. This is consistent with the record of Shennong's national grain, that is, eating grain and eating salt happen at the same time.

The first natural salt discovered and utilized in China is pond salt. Its origin is Shanxi, Shaanxi, Gansu and other vast northwest regions. The most famous salt ponds in Yuncheng, Shanxi Province (namely Jiechi and Hedong Salt Pond) have a long history. According to Records of the Historian, the Yellow Emperor fought against Emperor Yan in Hanquan, and was defeated by Zhuolu, and later became the city of Zhuolu. According to experts' research, "Hanquan originated in Yanchi, Xie Xian County, Shanxi Province, with Chiyou City, Chiyou Village and Zhuoze-Zhuolu". And "the bloody battle between Yan and Huang is actually caused by salt." Although we can't prove from archaeology that the battle of Yanhuang Zhuolu is essentially a battle for salt, the legend of the relationship between Chiyou and Yanchi in Xie Xian County, Shanxi Province is completely consistent with the legend of the relationship between Shennong and Su Sha, that is, the era of Shennong, Huangdi and Chiyou is the era when the western part of China changed from meat-based to grain-based areas.

Another kind of natural salt is rock salt, which is called rock salt because it is produced in Yanshan Mountain. It is produced in Nanquzi, Huan County, Gansu Province, and near Quanshi, Gansu Province. The so-called "salt mountain" actually refers to large particles of mineral salt. In addition to the main chemical component NaCIQH, its trace elements are also different due to different geology and strata, resulting in different colors such as red, purple, cyan, black and white. The main use of salt in ancient times was eating. In Zhou people's view, "salt shape" is used to entertain guests. He also said: "The king's diet is shameful, not only for salt, but also for future generations." The "shaping salt" mentioned here refers to white rock salt, which can be "carved" because of its large volume. "Salt salt" is the best kind of rock salt, which tastes salty and delicious, like water essence and tiger beads, and is also called "king salt".

In the southern minority areas, there are still legends about Salt god. The Naxi people in Yanyuan County, Sichuan Province worship the girl "Salt god". It is said that she found salt water while herding sheep, and later dug a salt well here. There is a legendary story in Cuba, which tells the story that the Japanese monarch fought against Salt god and finally settled in the "land of fish and salt". This shows that ethnic minorities pay special attention to the possession of natural salt.

The working people in ancient China had long explored the causes of salt and had preconceived ideas. They believe that the formation of salt has a lot to do with water vapor: "Water is wet and wet is salty." . This is the conclusion of long-term observation of lake salt formation. Lake salt, also known as "pool salt", is an inland salt lake (pool). Due to the influence of dry climate, crystalline salt can be naturally generated. The most famous and oldest Hedong Salt Pond in the history of China (also known as Jiechi, now the south of Yuncheng County and the northern foot of Zhongtiao Mountain) naturally produces salt through wind, sun and evaporation, which is called "Xie Yan", "Luyan" or "Hedong Salt" in history. Can you find the earliest record of "resting pool" in Shan Hai Jing? North Mountain Scenery ",in which there is a sentence of" three hundred miles south, Yue Jingshan, looking south at salt vendor Shize ". According to A Jin scholar Guo Pu, salt vendors are "salt ponds". At present, Chaerhan Salt Lake and Chaka Salt Lake in Qinghai Province are rich in this kind of pool salt, of which Chaerhan Salt Lake covers an area of 65,438 0.600 square kilometers, making it the largest salt lake in China. Pool salt has the characteristics of natural crystallization. The Jin people's "Luodu Fu" said: "Hedong Salt Pool is clean and fresh, and it is natural for nothing. "In other words, pool salt can be made naturally without boiling." Xiechi "is located in the Yellow River Basin. It is conceivable that ancient ancestors living in the Yellow River Basin came into contact with this natural pool salt very early.

One thing is certain: sea salt is cooked only after natural salt is discovered and eaten. Because cooking salt is an advanced production process, it requires certain cooking utensils, such as the "prison basin" used for cooking salt in the Han Dynasty. What materials are used to make such vessels, how to cook them, and so on, are unknown. But one thing can be summed up: the discovery and consumption of natural sea salt, pool salt, rock salt, salt spring and earth salt are the beginning of human edible salt. This should be shared by all countries in the world. Yunnan, Sichuan, where salt cooking has a long history.

Well salt appeared late and first appeared in Bashu area (now Sichuan Province) during the Warring States Period. During the Qin Dynasty, Li Bing was stationed in Shu County. While controlling water, he surveyed the distribution of underground brine and began to dig salt wells. History book: Li Bing "knows all the water veins of Guangdu Yanjing, and all the ponds of Tongguangdu Yanjing, so it is full of health." This is the earliest record of digging salt wells in ancient China.

The rock salt system is refined from mined salt ore, mostly concentrated in the northwest and southwest mountainous areas, such as Xinjiang, Ximao and Yunnan. In which generation did the production of rock salt begin? There is no historical record. The production method of rock salt, according to "water mirror note? "Jiang Shui" contains: "In Yiren County (now Yunyang County, Sichuan Province), there are stones in the soup mouth for 43 miles, which are boiled as salt. If the stone is big, it will rise, if the stone is small, it will be like a fist, and if the water is exhausted, it will become salt. " It can be seen that rock salt is obtained by boiling.

Soil salt, that is, "alkali salt", is produced in saline-alkali land, with bitter taste and poor quality. It is at the bottom of the salt family and is only used as a substitute for edible salt. It is also impossible to test when the production of soil salt began. Its production method is based on the Book of the Later Han Dynasty? "Biography of Southwest China" contains: "Wenshan has salty soil, cooked as salt, and elk, sheep, cattle and horses are all fat." It can be seen that soil salt is also obtained by boiling.