Julius was a natural scientist and teacher. He wrote his book with an educational purpose in mind. It aims to inspire teachers of chemistry to see the material world as a part of nature. For a quarter of a century, it has served this purpose in Waldorf schools. Today, this task presents itself to us as a demand of the times. It is to be hoped that Julius's work will find a wide readership beyond the realm of Waldorf education. Ernst-Michael Kranich.