ture of lymph and the
composition of nerve substances are compared. The contrast which exists
between fibrine and lymph, and the similarity of lymph to nerve fat when
taken together, justify the conclusion that the nerve substance
lecithin, was formed from lymph in the first instance.

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 pr