Plant essence is a kind of "qi" continuously secreted by vegetable oil cells, which is distributed in the air, enters the body through the respiratory tract and human skin epidermis, and is finally absorbed by the human body.
The permeation rate of terpenoid (Ti) olefins through skin is 100 times that of water and 1000 times that of salt. After being absorbed by human body, terpenoids have a moderate stimulating effect, which can promote the increase of immune protein, effectively regulate the balance of autonomic nerves, thus enhancing the resistance of human body, and achieving the physiological effects of antibacterial, antitumor, blood pressure lowering, anthelmintic, anti-inflammatory, diuretic, expectorant and physical fitness.
In the middle and late last century, many unique "forest hospitals" appeared in some forest areas in Europe. This kind of hospital is located in a forest with tinkling springs. No doctor, no medicine, no clinic, no ward. People take a walk and rest in the winding path of the forest and the spring water under the tree, and take the plant essence emitted by the forest as the main treatment means, which is called "forest therapy". Scientists believe that walking in dense green forests has the same effect as washing hot springs.