Hypertension has certainly been one of the topics most fre quently discussed at symposia, meetings, and congresses during recent years. There may be several reasons for this; three of them are obvious: firstly, the fact that a large proportion of the world's population is suffering from various forms of hypertensive disease; secondly, increasing knowledge of the pathogenesis of hypertension and of the disturbances underlying it; and, thirdly, the marked progress which has been made in antihypertensive therapy over the past fifteen years. When plans for the present symposium were being drawn up, it was felt that it should not simply bring forth just another meeting on hypertension, but should place particular emphasis on those aspects which had not been adequately discussed at previous symposia of this kind. Curiously enough, the topic which appeared to have received least attention in the past was therapy, although from the practical point of view this is by far the most important. The choice of therapy as the main theme of the whole symposium also seemed to be warranted in view of the relatively long period that had elapsed since effective antihyper tensive treatment became available; the time had in fact come now to pass judgement on the benefits as well as the shortcomings of drug treatment as available today.

International Symposia sponsored by ClBA Basle have been held once a year since 1959 in various European countries. In con trast to the many scientific meetings organised by the ClBA FOUN DATION either at its headquarters in London or occasionally abroad, the subjects dealt with at these International Symposia have con cerned problems more directly related to ClBA'S own research work in the pharmaceutical field. The various topics covered up to the present reflect the far-reaching interests and the wide spread activities that a pharmaceutical enterprise develops in quite diverse fields of chemical, biological, and medical research, and to which the ba.sic approach is an increasingly important prerequisite for the development of a new and useful therapeutic agent. Iron metabolism came into the sphere of interest in connection with CIBA'S research on antibiotics and related natural products containing iron, substances which act in their metal-free form as strong and specific chelating agents. Of course, these observations, interesting though they are, would not in themselves have justi fied a symposium. It seemed, however, useful to examine the new results from a wider perspective and to attempt to relate them to present-day knowledge of iron metabolism in general its physiology, its pathology, and therapeutic aspects. The success of a scientific symposium depends on the concep tion of the programme and the selection of the participants."