Second Sight

The relations of our sense-organs to the various degrees of matter, to solids, fluids, gases, atmosphere and ether, vary in different individuals to such a wide extent as to create the greatest diversity of normal faculty. The average wool-sorter will outvie an artist in his perception of colour shades. An odour that is distinctly recognizable by one person will not be perceptible to others. In the matter of sound also the same differences of perception will be noted. On a very still night one can hear the sugar canes growing. Most people find the cry of a bat to be beyond their range. The eye cannot discern intervals of less than one-fiftieth of a second. Atmospheric vibration does not become sound until a considerable frequency is attained. Every movement we make displaces air but our sense of touch does not inform us of it, but if we stand in a sunbeam the dust particles will show that it is so. Our sense of feeling will not register above certain degrees of heat or below certain degrees o