It is written in Classic of Tea that, "The tea drinking tradition began with Shen Nong and actively developed by the Duke of Zhou." Tea was used in ancient China. It is said that Shen Nong, the God of Medicine who tasted all herbs was poisoned by 72 different plants everyday. He relied on tea to neutralise the toxins. As for how he discovered this plant which can treat all sorts of ailments, there are many different versions.
The first version is that the God of Medicine had a transparent belly and what he ate could be clearly seen. To save the people from the torments of disease, he travelled the wilderness and tasted every herb. One day, he tasted fresh leaves of a certain plant and found that they moved up and down inside his belly as if they were inspecting something. He named it zha (check). As time went on, it became cha (tea).
The second version says the God of Medicine was poisoned by herbs and almost died under a tree. He was revived by fresh dew on the leaves which dropped into his mouth, and he discovered the great medicinal value of tea.
Yet another version says that Shen Nong was boiling water under a tree one day and some leaves fell into the pot. He drank the mixture and all ailments and toxins disappeared. He thus discovered the treatment action of tea leaves.