This occurs in the following manner: In response to the demand for new material created by the chemical combustion of lecithin, new oil flows down the axis cylinders of the nerve fibrils, which are arranged somewhat in the manner of lamp wicks. The average duration of the flow of this oil is about eighteen hours. When the cerebro-spinal nerves refuse to perform their function any longer, because the supply of oil is running low, fatigue and sleep ensue, and the blood descends from the brain to the intestines. Thus the cerebro-spinal system is permitted to relax and rest. In the meantime the sympathetic nervous system has taken up the task of directing the renewal of worn tissues, which draw their supply of necessary materials from the digestive canal, with a new supply of phosphatic oil. For the carrying out of these processes, which prepare the brain and spinal nerve system for the demands of another day, the magnetic blood current acts as distributor of supplies. Through the fact that this supply is directly dependent upon nutrition, three possibilities inevitably present themselves: (1) That any radical change of diet may result in an insufficient supply of the various elements necessary for the production of lecithin in the requisite quantities. (2) That strenuous and unaccustomed physical and mental exertion may involve a consumption both of nerve substance and muscular tissue, greater than the outcome of the ordinary diet is able to compensate. (3) That a protracted term of emotional strain and agitation may adversely affect both appetite and digestion while rapidly consuming the substance of the nerves. In discussing the causes of disease Julius Hensel lays great stress upon the emotions. He goes so far as to say that they "_undoubtedly occupy the first place amongst the factors causing disease_, and we must not evade the consideration of them. _We shall find that their action also amounts to an electro-chemical process._" I would not for an instant be understood to contend that the emotions alone are sufficient to explain the origin of disease--not at all. There are other factors--jointly or severally dominant--diet, occupation, changes of weather, climate, or conditions. In the matter immediately under review, however, the world-wide pandemic of "Spanish Influenza," there can remain no shadow of doubt in the mind of any unbiased observer who follows the question fairly along the lines of electro-chemical biology, but that the general emotional disturbances incident upon the war conditions of the world, combined with the chaotic dietetic position with its anxieties and privations under strenuous and unwonted physical demands, do undoubtedly afford a sound and reasonable explanation of the cataclysmal outbreak which has recently fallen upon the nations.