If, instead of supposing a mathematical line to be the object, we take a _single piece_ of coloured glass, with an irregular outline, we shall have no difficulty in perceiving, from experiment, that an infinite variety of figures may be created from it alone. This system of endless changes is one of the most extraordinary properties of the Kaleidoscope. With a number of loose objects, it is impossible to reproduce any figure which we have admired. When it is once lost, centuries may elapse before the same combination returns. If the objects, however, are placed in the cell, so as to have very little motion, the same figure, or one very near it, may, without difficulty, be recalled; and if they are absolutely fixed, the same pattern will recur in every revolution of the object-plate. CHAPTER XX. ON THE APPLICATION OF THE KALEIDOSCOPE TO THE FINE AND USEFUL ARTS. If we examine the various objects of art which have exercised the skill and ingenuity of man, we shall find that they derive all their beauty from the symmetry of their form, and that one work of art excels another in proportion as it exhibits a more perfect development of this principle of beauty. Even the forms of animal, vegetable, and mineral bodies, derive their beauty from the same source. The human figure consists of two halves, one of which is the reflected image of the other; and the same symmetry of form presents itself in the shapes of almost all the various tribes of animated beings. In the structure of vegetables, the principle of symmetry is less perfectly developed. From the extreme delicacy and elasticity of its parts, a plant, regularly constructed, would have lost all its symmetry from the influence of gravitation, or from the slightest breath of wind; and therefore a symmetrical combination of parts has been effected only in its leaves and flowers. When the laws of crystallization are allowed to perform their functions uncontrolled, the beautiful geometrical forms which they create are marked with the most perfect regularity. Even their physical properties are symmetrically related to some axis or fixed line; and though all their functions are performed in utter silence and repose, yet their physiology, if we may apply that name to the actions of apparently dead matter, is not less wonderful than that which embraces the busy agencies of animal and vegetable bodies. The irregular forms which are the foundation of picturesque beauty constitute a single exception to the general law, and therefore the landscape painter is the only artist who is not professionally led to the study of that species of beauty which arises from the inversion and multiplication of simple forms.