It would thus appear that the common charge brought against laughter, of being something babyish, or childish, or boyish--something properly appertaining to early life--is unfounded. But we of course must not be understood to speak of what is technically called giggling, which proceeds more from a looseness of the structures than from any sensation of amusement. Many young persons are continually on the giggle till their muscles strengthen; and indeed, when a company of them are met together, the affection aggravated by emulation, acquires the loudness of laughter, when it may be likened, in Scripture phrase, to the crackling of thorns. What we mean is a regular guffaw; that explosion of high spirits, and the feeling of joyous excitement, which is commonly written ha! ha! ha! This is altogether unknown in babyhood; in boyhood, it exists only in its rudiments; and it does not reach its full development till adolescence ripens into manhood. This train of thought was suggested to us a few evenings ago, by the conduct of a party of eight or ten individuals, who meet periodically for the purpose of philosophical inquiry. Their subject is a very grave one. Their object is to mould into a science that which as yet is only a vague, formless, and obscure department of knowledge; and they proceed in the most cautious manner from point to point, from axiom to axiom--debating at every step, and coming to no decision without unanimous conviction. Some are professors of the university, devoted to abstruse studies; some are clergymen; and some authors and artists. Now, at the meeting in question--which we take merely as an example, for all are alike--when the hour struck which terminates their proceedings for the evening, the jaded philosophers retired to the refreshment-room; and here a scene of remarkable contrast occurred. Instead of a single deep, low, earnest voice, alternating with a profound silence, an absolute roar of merriment began, with the suddenness of an explosion of gunpowder. Jests, bon-mots, anecdotes, barbarous plays upon words--the more atrocious the better--flew round the table; and a joyous and almost continuous ha! ha! ha! made the ceiling ring. This, we venture to say it, _was_ laughter--genuine, unmistakable laughter, proceeding from no sense of triumph, from no self-gratulation, and mingled with no bad feeling of any kind. It was a spontaneous effort of nature coming from the head as well as the heart; an unbending of the bow, a reaction from study, which study alone could occasion, and which could occur only in adult life.