Let us endeavor to read the riddle rightly.  On scientific contemplation it at once becomes apparent that the symptoms as defined by Kuhnemann—­and indeed all other observers—­are confined to the regions traversed by the Vagus (wandering) or Pneumogastric nerve—­a nerve of comprehensive scope and bi-functional activity, physical and psychic and in operation, remarkably in accord with the manifestations of Influenza.

Concisely stated, the physiological function of the Vagus nerve is to regulate the process of breathing, tasting, swallowing, appetite, digestion, etc.; and the result of its failure to function would create coughing, choking, indigestion—­separately or in combination.  Its mental functions include the expression of shame, desire, disgust, grief, torture, depression and despair.

The following is its academic description: 

Vagus or Pneumogastric nerve (tenth cranial); function—­sensation and motion; originates in the floor of the fourth ventricle (the space which represents the primitive cavity of the hind-brain; it has the pons and oblongata in front, while the cerebellum lies dorsal), and is distributed through the ear, pharynx, larynx, lungs, esophagus, and stomach; possesses the following branches—­auricular, pharyngeal, superior and inferior laryngeal, cardiac, pulmonary, esophageal, gastric, hepatic, communicating, meningeal.

It is interesting to compare the scope and characteristics of the Vagus, as here defined with the details of Prof.  Kuhnemann’s diagnosis of Influenza and to draw conclusions.

In order to establish more unmistakably the symptomatic sympathetic connection between the Vagus and Influenza, it may be well to touch briefly upon the initial processes of metabolism and nerve production.

An inherent impulse in the ovum (protoplasm or egg cell) serves to separate the albuminous substance into groups of an opposite nature.  Water is chemically separated from one portion, which results in thickening the albumen from which it was extracted, while the liberated water aids in liquifying another portion of the albuminous matter.  Thus, on one side slender threads arise, termed fibrine or filaments, and on the other lymph fluid appears, which receives the particles of salts freed from the filaments during their chemical separation.  When the fibrine and lymph are organized from the protoplasm, the remaining albumen is absolutely unchanged and ready to furnish material for the growth of either.

It is the function of salts to increase the electrical tension of the lymph.  All salts possess the property of being electrically positive or negative.  The more concentrated a saline solution, the greater its electrical energy.

That the function of the lymph is to assist in the formation and nutrition of the nerves is apparent when the nature 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.