The opening of the book sets the stage for Liebig's arguments by discussing the historical development of chemistry as a science, particularly focusing on the works of Lavoisier and the subsequent advancements in understanding chemical processes. Liebig emphasizes the previous disconnect between chemistry and the biological sciences, and he aims to bridge that gap by highlighting how a chemical perspective can elucidate the functions of living organisms. He introduces the concept of "Lebenskraft" (vital force) and outlines the importance of chemical transformations in respiration and nutrition, paving the way for a more integrated view of life sciences that relies on chemical understanding. (This is an automatically generated summary.)