[Illustration:  Fig. 144.—­Section of Cochlea.

From A straight downwards is the direction of the central column, to which E points.  B points to the projecting ridge, almost dividing the canal of the tube into an upper compartment (D), and a lower (C).]

Insects may gain entrance to the ears and occasion annoyance, pain, and fright, perhaps leading to vomiting, even to convulsions, with nervous children.  A lighted lamp held at the entrance of the ear will often induce the offending insect to crawl out towards the light.  A few drops of warm water, sweet oil, or molasses, dropped into the ear, will help remove the intruder.

When a discharge occurs from the ears, it is not best to plug them with cotton wads.  It only keeps in what should be got rid of.  Do not go to sleep with the head on a window sill or in any position, with the ears exposed to draughts of cold or damp air.

No effort should be made to remove the ear wax unless it accumulates unduly.  The skin of the canal grows outward, and the extra wax and dust will be naturally carried out, if let alone.  Never employ any of the many articles or “drops,” advertised to cure deafness.  Neuralgic pain in the canal, usually classed as earache, may be due to decayed or improperly filled teeth.

Quinine, so generally used in its many preparations for malaria, causes a peculiar ringing or buzzing in the ears.  This is a warning that it should be taken in smaller doses, or perhaps stopped for a time.  In some cases quinine may produce temporary deafness.

The practice of snuffing up cold water into the nostrils is occasionally followed by an acute inflammation of the middle ear, some of the water finding its way through the Eustachian tube into this part of the organ of hearing.  The nasal douche, so often advised as a home remedy for nasal catarrh, should be used only with great caution, and always in accordance with detailed directions from a physician.

348.  Effect of Tobacco upon the Hearing.  The sense of hearing is often injured by the use of tobacco.  The irritating smoke filling all the inner cavity of the mouth and throat, readily finds its way up the Eustachian tube, dries the membrane, and irritates or inflames the delicate mechanism of the inner ear.  Thus may be produced a variety of serious aural disturbances, such as unnatural noises, whistling, and roaring, followed oftentimes by a partial loss of hearing.

Hearing may be impaired by the use of alcoholic beverages.  Alcohol inflames the mucous membrane of the throat, then by its nearness the lining of the Eustachian tube, and finally may injure the delicate apparatus of the internal ear.

Additional Experiments.