Nor is it the gratification of this sense which is the only source of enjoyment connected with it. The regular periods for repast bring around the social board those united to each other by the tenderest ties of kindred and affection. These become seasons of cheerful hilarity and relaxation, seasons of cessation from daily cares, seasons for the interchange of kind feelings and intellectual stores; and while the mere gratification of sense is one source of pleasure, to this is often added the "feast of reason and the flow of soul." The effect on the best feelings in thus assembling to participate in common blessings is scarcely ever appreciated. Did every individual of our race retire to secrecy and solitude to satisfy the cravings of nature, how much would the sum of human happiness be diminished! But thus has our benevolent Creator contrived that one source of enjoyment should serve as an occasion for introducing many more. _Hearing._ The sense of hearing is one more connected with the intellectual and moral powers of man than either taste or smell, as it is through the medium of this organ that both music and speech operate on the human mind. We can form some imperfect estimate of the amount of happiness derived from this sense by imagining the condition of mankind were they at once and forever deprived of this source of improvement and enjoyment. The voice of sympathy, friendship, and love would be hushed. The eloquence of the forum, the debates of the Legislature, the instructions of the pulpit, would cease. The music of nature--its sighing winds and dashing waters--would be stilled, and the warbling of the groves would charm no more. The sound of pipe, and harp, and solemn harmonies of voice would never again waken the soul to thrilling and nameless emotions. Where now ten thousand sounds of active life, or cheerful hum of business, or music of language and song charm and animate the soul, man would walk forth in silence and solitude. The operation of mere sound, disconnected with the ideas which are often conveyed by it, is a subject of curious speculation. Sounds differ from each other in _quality_, _pitch_, _force_, and in _length_. The difference in _tone_ may be illustrated by the sounds of a clarionet compared with the sound of a bell or of the human voice. Every instrument and every human voice has each a peculiar tone by which it is distinguished from all others. The difference in _pitch_ is shown by sounding a low and a high note in succession on an instrument. The difference in _force_ is exhibited by singing or speaking loud or soft. There are certain sounds that in themselves are either agreeable or disagreeable from their tone alone. Thus the sound of a flute is agreeable, and that of the filing of a saw is disagreeable. Sounds also are agreeable according as they succeed each other.