Mr. President, ladies and gentlemen: I need not say that no one here regrets more than I do that the Minister of Health, Sir Hilton Young, is unable, because of his Parliamentary duties to-day, to accept your invitation to open this Exhibition. You will agree with me that I am a very poor substitute for a Minister of the Crown, for I can only claim to have been the obedient servant of the Ministry for a great many years. I have come here, therefore, to represent the Minister, and also, if you will allow me to be so bold, to represent myself. I am here for two reasons. In the first place I had a pressing invitation from my friend and colleague, Dr. Stanley Melville, the Consulting Radiologist to the Ministry of Health; it is through him that I come to support this very admirable society, the British Institute of Radiology. But, also, I am here because I have for many years been keenly interested in the subject of radiology. It is a great pleasure to carry out the honourable task of opening your Exhibition.It has been said by some of the great leaders of science, including the President of the British Association, that our discoveries in science are so rapid and so fundamental that they have outstripped the capacity of the average man ever to appreciate or to apply them; and perhaps that truth, remarkable as I think it, has a definite application to the great subject, to the triumphs of which you and I are met here to bear witness.