The shapes of atoms vary; and so differences of species, and differences within the same species, arise. This variety in shape accounts, too, for the varying action and effects of atoms. Atoms in hard bodies, for example, are mainly hooked; but in liquids mainly smooth. In each thing, however, there are several kinds, which furnish that particular thing with a variety of properties. Furthermore, atoms are colourless, for in themselves they are invisible; they never come into the light, whereas colour needs light--witness the changing hues of the down on a pigeon's neck, or of a peacock's tail. Atoms are themselves without senses, though they produce things possessed of senses. To grasp the origin of species and development of animate nature, one must realise the momentous importance of the arrangement and interconnection of atoms. Wood and other rotting bodies will bring forth worms, because material particles undergo, under altered conditions, fresh permutations and combinations. One may ask, what of man? He can laugh and weep, he can discuss the composition of all things, and even inquire into the nature of those very atoms! It is true that he springs from them. Yet a man may laugh without being made of laughing atoms, and a man may reason without being made of reasonable atoms! EPICURUS AND THE GODS O thou that from gross darkness first didst lift A torch to light the path to happiness, I follow thee, thou glory of the Greeks! And in thy footsteps firmly plant my steps, Not bent so much to rival as for love To copy. Why should swallow vie with swan? Thou, father, art discoverer of things, Enriching us with all a father's lore; And, famous master, from thy written page, As bees in flowery dells sip every bloom, So hold we feast on all thy golden words-- Golden, most worthy, aye, of lasting life. Soon as thy reasoning, sprung from mind inspired, Hath loud proclaimed the mystery of things, The mind's fears flee, the bulwarks of the world Part, and I see things work throughout the void. Then Godhead is revealed in homes of calm, Which neither tempests shake nor clouds with rain Obscure, nor snow by piercing frost congealed Mars with white fall, but ever cloudless air Wraps in a smile of generous radiancy. There nature, too, supplieth every want, And nothing ever lessens peace of mind. _III.--Of Mind and Soul and Death_ Mind and soul are portions of the body. While mind is the ruling element, they are both of the nature of the body--only they are composed of exceedingly minute and subtle atoms capable of marvellous speed. Therefore, when death deprives the body of mind and soul, it does not make the body appreciably lighter. It is as if a wine had lost its scent, Or breath of some sweet perfume had escaped.