When one is invited to read an article or to present some topic of professional interest before a medical society, the choice of a subject is often dependent to some extent on the character of the audience. Thus, if one wishes to announce some new or epoch-making discovery, to place on record some valuable, but hitherto unknown, therapeutic measure, to describe some novel and highly successful operation or surgical procedure for the relief or cure of some malady which had hitherto been regarded as hopeless, one is apt to select a large gathering of his professional colleagues, such as one of the great national associations or international congresses, so that the benefit of his discovery or clinical experience may quickly reach the largest number of his professional brethren and through them promptly be handed on to suffering humanity. If, on the other hand, one is anxious to obtain enlightenment on