Soap is a traditional washing product widely used in every family. At present, soap is still a necessity for most people. Generally, it is a solid block, but there are also paste and liquid products. With the improvement of people's living standards, it is required not only to have the function of cleaning skin, but also to have some new functions such as beauty, sterilization and deodorization.
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The historical development of soap;
A synthetic detergent appeared in Song Dynasty, which was made of natural Gleditsia sinensis (also known as Gleditsia sinensis, hanging knife and Gleditsia sinensis) by mashing and grinding, adding spices and other things, and made into orange-sized balls for washing face and bathing body, commonly known as "soap balls". Song people's careful "Old Wulin Stories" (Volume 6) and "Little Broker" recorded that there was a businessman who specialized in "soap troupe" in Lin 'an, Kyoto in the Southern Song Dynasty.
Li Shizhen's Compendium of Materia Medica in the Ming Dynasty recorded the making method of Gleditsia sinensis: Gleditsia sinensis was born in a high mountain, with tall trees, leaves like sandalwood Gleditsia sinensis, flowering in May and June, the pod was three or four inches thick, fleshy, with several spots as big as fingers, not round, and white kernels inside, which were edible.
Picking pods in October, boiling and mashing, white flour fragrant pills, bathing the body, removing dirt and moistening, is better than Gleditsia sinensis. In addition to natural Gleditsia sinensis, plants such as Sapindus mukoraiensis have also spread among the people and become good cleaners.
In the west, it may be traced back to an ancient Greek island called Lesbos 4,000 years ago. The local people sacrificed animals to heaven. Because wood is used when burning animals, the mixture of wood ashes and animal fat will produce a soapy yellow substance. The heavy rain washed these things into the river where local women often washed their clothes. They found that their clothes were cleaner.
Although traces of using similar soap can be found from ancient Greece, a poetess named Saffo recorded these stories in history. In memory of her, people later called this process saponification, and the chemical name was soap-based production.
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