A generation ago, near1y all college students who p1anned to become chemists were required to take a course in the history of their subject, but nowadays, such courses are usually not required, and in many schoo1s, are not even offered. It is argued that the subject of chemistry is expanding so rapid1y that students can hard1y master the material which fills the new text books, to say nothing of 1earning what chemists thought and did a century ago. Although this point of view has some validity, it fails to take into account the much more important fact that one cannot really understand or appreciate the present position of science un1ess he knows something of the slow and tortuous steps through which it deve10ped. His ability to he1p it move forward will be greatly enhanced by an understanding of the thinking of the chemists who built the theories which we use today. It has been tru1y said, 'He who knows on1y his own generation remains a1ways a chi1d. ' The appearance of a book which details the birth of a great development in chemistry is therefore a significant event, and one which we welcome warmly. The events which are chronieled here are now far enough behind us to allow a elear evaluation of their significance, but elose enough that there still remain a few people who knew WERNER personally, and who have preserved intimate records of his work. Thus, Prof.