After the introductory chapter was limitless material knowledge.
In this book, there was no distinction between spirit herbs, ores, and other materials. Everything in the Book of the World was considered part of the universe.
This book had any information one needed, including information on one of the most inconspicuous grasses in the world and a handful of ordinary dirt.
Fortunately, the contents of the book were hierarchical, so it moved from a low level to a high level. The book did not explain the distinction between low level and high level, but Di Jiu guessed that it was based on the distribution of Spirit Qi, hardness, and so on.
According to the Book of the World, all matter was tangible, but different tangible matter abided by different laws, be it high level or low level.