The whole process of life consists of an electro-chemical combustion.  This is clearly shown in the case of lecithin, which serves to control both motion and sensation.  In the presence of oxygen it burns up, forming a new chemical combination, and throwing off minute quantities of carbonic acid and water in the process. Every movement and process, both voluntary and involuntary, and every thought and emotion, depends upon oxidation, which consumes muscular tissue and nerve substance.

The greater our physical exertion the more muscular tissue must be consumed.  The higher our emotional state, the more we think or agitate ourselves, the greater must be the quantity of nerve substance burned up.  All of the substance burned up in labour, in worry and in thought, must be replaced or the flame will flicker out!

The metabolism of muscular tissue is not in question at the moment.  We are concerned here with nerve metabolism alone.

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.