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