that the latter senses have special nerves, while Taste is compelled to fall back upon the ordinary nerves of Touch.  It is true that Taste is confined to a very small part of the surface of the body, while Touch is general.  But this only indicates a special development of the special area.  The sense of Taste also depends to a great extent upon the presence of fluids, and only substances that are soluble make their presence known through the organs and sense of Taste.

Physiologists report that the sense of Taste in some persons is so acute that one part of strychnine in one million parts of water has been distinguished.  There are certain occupations, such as that of wine-tasters, tea-tasters, etc., the followers of which manifest a degree of fineness of Taste almost incredible.

The sense of Smell is closely connected with the sense of Taste, and often acts in connection therewith, as the tiny particles of the substance in the mouth arise to the organs of Smell, by means of the opening or means of communication situated in the back part of the mouth.  Besides which the nose usually detects the odor of substances before they enter the mouth.  The sense of Smell operates by reason of the tiny particles or the object being carried to the mucous membrane of the interior of the nose, by means of the air.  The membrane, being moist, seizes and holds these particles for a moment, and the fine nervous organism reports differences and qualities and the Mind is thus informed of the nature of the object.

The sense of Smell is very highly developed among animals, who are compelled to rely upon it to a considerable extent.  And many occupations among men require the development of this sense, for instance, the tobacconist, the wine dealer, the perfumers, the chemist, etc.  It is related that in the cases of certain blind people, it has been observed that they could distinguish persons in this manner.

The sense of Hearing is a more complex one than in the case of Taste, Touch and Smell.  In the latter three the objects to be sensed must be brought in close contact with the sense-organs, while in Hearing the object may be far removed, the impressions being carried by the vibrations of the air, which are caught up and reported upon by the nervous organism of the sense of Hearing.  The internal mechanism of the ear is most wonderfully intricate and complex, and excites to wonder the person examining it.  It cannot be described here for want of space, but the student is advised to inquire into it if he has access to any library containing books on the subject.  It is a wonderful illustration of the work of the mind in building up for itself instruments with which to work—­to acquire knowledge.

The ear records vibrations in the air from 20 or 32 per second, the rate of the lowest audible note, to those of 38,000 per second, the rate of the highest audible note.  There is a great difference in individuals in regard to the fineness of the sense of Hearing.  But all may develop this sense by the application of Attention.  The animals and savages have wonderfully acute senses of Hearing developed only along the lines of distinctness, however—­on the other hand musicians have developed the sense along different lines.