In the formation of light, and the beneficent effects it produces, the wisdom and goodness of the Almighty are conspicuously displayed. Without the beams of the sun and the influence of light, what were all the realms of this world, but an undistinguished chaos and so many dungeons of darkness? In vain should we roll our eyes around to behold, amidst the universal gloom, the flowery fields, the verdant plains, the flowing streams, the expansive ocean, the moon walking in brightness, the planets in their courses, or the innumerable host of stars. All would be lost to the eye of man, and the “blackness of darkness” would surround him for ever. And with how much wisdom has every thing been arranged in relation to the motion and minuteness of light? Were it capable of being transformed into a solid substance, and retain its present velocity, it would form the most dreadful and appalling element in nature, and produce universal terror and destruction throughout the universe. That this is not impossible, and could easily be effected by the hand of Omnipotence, appears from such substances as _phosphorus_, where light is supposed to be concentrated in a solid state. But in all its operations and effects, as it is now directed by unerring wisdom and beneficence, it exhibits itself as the most benign and delightful element connected with the constitution of the material system, diffusing splendour and felicity wherever its influence extends. CHAPTER II. ON THE REFRACTION OF LIGHT. Refraction is the turning or bending of the rays of light out of their natural course. Light, when proceeding from a luminous body--without being reflected from any opake substance or inflected by passing near one--is invariably found to proceed in straight lines without the least deviation. But if it happens to pass obliquely from one medium to another, it always leaves the direction it had before and assumes a new one. This change of direction, or _bending_ of the rays of light, is what is called _Refraction_--a term which probably had its origin from the broken appearance which a staff or a long pole exhibits, when a portion of it is immersed in water--the word, derived from the Latin _frango_, literally signifying _breaking_ or bending.