Question and answer 5:

Question 5:
An instance, for the basic substances: wood, fire, earth, metal, and water, how come there are absent leaves, and greenery, flowers, petroleums, stone, etc. In some ways, these five elements are used the same as the basic elements, i.e. oxygen, nitrogen, phosphorus ... that make up life? Are there any correlations between these in any readings in Chinese medicine or science, that you know?
5). Answer:
Leaves, flowers etc are included in the category of wood, and petroleum the water, the stones the earth.
Basically the five elements are enough to explain the formation of the globe. As oxygen is concerned, it's in another category, it's Qi anyway.
Please do notice, the five elements, in the original meaning, are referred not only to 5 types of substance, but rather the 5 categories, so in original Chinese it means the "five walks" or to be more exact the five categories. I think there are many readings in this aspect of theories in ancient time and now. Personally I think most of the readings are printed in Chinese not in English. But you can try to find the books written by Dr. Joseph Lee, the late British scientist who has done a lot in studying the ancient Chinese science history.