(_c_) Next they took the amount of illness, of time off, away from work, as a measure of fatigue, and it was very definitely shown that with a diminished number of hours the number of sicknesses of all kinds, such as colds, were diminished, illustrating the point that I made a moment ago,--that accumulated fatigue diminishes our resistance to infection. (_d_) Finally, they made some physiological tests of powers of sight, quickness of answer, etc., after fatigue, and showed that a man was less keen in his senses, less capable of accurate response, after a certain number of hours' work than before, and that fatigue could to a certain extent be measured in that way. All these tests of fatigue can be applied in our lives and in the lives of people we are trying to help in social work. We have to take account of the number of hours, the possible breaks, intervals, that can be made in otherwise continuous labor. Many people can get on very well if they break the day into manageable fragments. We must also take account of the effect of fatigue in producing infectious disease, of the general look of the person, and of such little physiological lapses as I have spoken of, weakened attention, the capacity for forgetting names, and mental numbness or the sense that things are unreal. In dispensary work, when we try to give up the use of particular medicines which are useless (as contrasted with the medicines that are useful), one of the chief things to put in their place is the study of fatigue and of the methods for resting our patients. We cannot make the social work of a medical-social clinic successful unless, whenever we take away something which we know to be a fraud and an untruth, we put something else in its place. It is for that reason that I have devoted so much space to the subject of fatigue and rest. FOOTNOTE: [3] See Health of Munition Workers Committee. Final Report, _Industrial Health and Efficiency_. (London, 1918.) CHAPTER VII THE SOCIAL WORKER'S BEST ALLY--NATURE'S CURE OF DISEASE Fatigue is a matter that seems to me of particular importance in social work for two reasons: first, because it concerns the visitor's own work and the way she does it; and second, because it concerns the troubles of a large proportion of all patients. The ultimate diagnosis, if we could make it, in probably half of all the people who come to a general clinic, is fatigue of some form, falling upon the weakest organ or function.