About two years ago, the company Urban & Schwarzenberg approached me with the proposal to publish an encyclopedia of technical chemistry, which would consist of approximately 10 volumes and be released over the course of 3 to 4 years. Thus, after nearly two years of intensive preliminary work, the basic plan for the entire project was developed, and the organization and scope of the individual articles to be included were determined. The subject of this broadly conceived work encompasses not only the chemical bulk industry and metallurgy with its mechanical and apparatus aids but also the numerous border areas that deal with the material transformation or refinement of matter in general. In keeping with the encyclopedic nature of the work, the arrangement of the material had to be alphabetical. However, it seemed beneficial for clarity.