Mental Conditions of Occupations.--While the details of manual occupations have to be learned with great care if we are to modify the conditions so as to prevent certain unfortunate effects, just as much care has to be exercised, with those not employed manually, in finding out details as to mental worries, and the various disturbances consequent upon business conditions. Many a man has not brain enough to run his business and his liver. This is the old English expression, and the liver, as the largest of the abdominal organs, is taken for the physical life generally. Many people have not vital energy enough to waste any of it on worries and then be able to complete their digestion and other physiological functions with success. The preceding mental condition is a predisposing cause of many a purely physical ailment. It used to be said that during a cabinet crisis in England, or rather just after it was over, attacks of gout were most frequent among prominent politicians. Mental influence usually kept the attacks off until the very end of the crisis. Merchants come down with pneumonia or digestive disturbances more frequently during periods of acute business depression. Physicians are attacked by pneumonia, or influenza in bad form, after they have been wearing themselves out in an epidemic and worrying about patients. Just after a mother has nursed a child through a severe ailment she herself is prone to suffer from some acute infection. Such common-place infections as boils, styes, abscesses and even the more serious osteomyelitis are likely to come at these times. It is important, then, to know as much as possible about a business man's affairs. Any one who has had a series of tuberculous patients (who were getting along quite well in spite of latent or even active lesions) disturbed by anxieties of one kind or another, knows how much worries may mean. Men will lose weight and appetite and weaken in their general condition as a consequence of some serious business incident, while all the time physical conditions are the same as they were when they were improving. And it must not be forgotten that even in those who do no physical labor, there may be physical conditions of their occupation that are important. Many a business man does his work cooped up in a small office, with insufficient ventilation, and sometimes, especially where his business is on the ground floor of a large building, with so little sunlight that his environment is quite unhygienic. The great air purifier is sunlight. Unless sunlight is admitted for hours every day to the rooms in which people live, the dust that is inevitably breathed will contain living germs, active and noxious, though had they been exposed to sunlight these germs would be harmless.