It is truly wonderful to find assembled here a conference of experts-experts of the widest diversity of training and interest, yet having in common a concern for the purification and separation of materials. However, despite the existence of this very assembly, and despite the increasing number of symposia on the topic of purification, I feel that the scientific community, on the whole, has failed to recognize the importance of purification and separation of materials. I refer not only to the many researches wasted on materials whose impurities obscured the true properties and rendered the researches worthless-that is an old story-but I refer also to the need to recognize that the field of purification and separation of materials is a legitimate branch of science in its own right, a field worthy of the best that talented minds can bring to bear.