The importance of mental diseases as a factor in the social and economic welfare of the community has not been given adequate consideration, notwithstanding the remarkable progress of modern psychiatry. Nor is this influence, unfortunately, one which can be easily estimated or accurately determined. We have, as a matter of fact, no data at hand to show the prevalence of disease, either physical or mental, with any degree of exactness even under our most elaborately organized forms of government. There is no complete information available which will enable us to determine the frequency of such important conditions as appendicitis, cardiac or renal diseases, peritonitis, septic infections, diseases of the eye, ear, skin or nervous system. It is true that there are, in the majority of states, records of contagious or readily communicable diseases which are probably fairly reliable. Aside from this, the only information at our disposal is confined to mortality statistics. This suggests a further consideration of the advisability, if not absolute necessity, of more extensive statistical studies of diseases, both mental and physical, if the welfare of the community is to be safeguarded and the future of medical science assured. Every physician should be required by law to make careful reports to the Board of Health of his state showing all medical conditions requiring treatment by him or coming to his professional notice. The value of such information to medical science would much more than compensate for the comparatively small cost of such an undertaking. Nor is this procedure more radical either in theory or practice than was the proposal to report all communicable diseases only a few years since. The data thus made available in the various states should be correlated and published by the Public Health Service.