Breathing, is that alternate contraction and expansion of the lungs and breast, by which animals inspire and expire the surrounding atmosphere; a process essentially necessary to the support of life. From the moment a child enters the world, the air penetrates into its lungs, which were previously filled with a watery mucus, but are then opened for tire circulation of the blood. Thus respiration, one of the primary and most important of the vital functions, commences with birth, and is incessantly active; as it cannot be interrupted for many minutes, without endangering the life of the individual.

There have, indeed.been instances of persons wantonly endeavouring to restrain the act of breathing, nay even to check the pulsation of the arteries, so as to exhibit a specimen of apparent death, for several minutes. We still remember the account of such a hazardous experiment related by a most respectable professor in the University of Edinburgh, who informed his pupils, that a man possessing the talent here alluded to, at length paid the price of his life, by remaining, in one of his exhibitions, a fatal example of his temerity.

More frequent, however, though not so immediately dangerous, are the instances in which persons, in other respects sensible, unthinkingly expose themselves to situations, where they must necessarily breathe the most vitiated and pernicious atmosphere. Such is the case in all public assemblies, which are confined in narrow limits, particularly in theatres and other places of amusement, to which numbers of spectators indiscriminately re-sort, and where each individual is obliged to respire part of the aggregate mephitic vapours of the company. Far from wishing to discourage the frequenting of those fashionable places of resort, in general, we only think it our duty to warn such invalids, as are liable to athmatic or pulmonary complaints, against a too free indulgence in these enticing amusements. Indeed, we are convinced, by numerous facts, of their deleterious influence; and if any person be disposed to doubt the propriety of this caution, let him reflect on the. dreadful effects frequently produced by shutting up 5 or 6 passengers in a stage-coach, only during a short space of time ; and he will acknowledge that our admonition is well founded. Hence we would advise those who lead a studious or sedentary life, never to continue for several hours together in a close and perhaps low apartment, where they admit the same air to re-enter the lungs, which has before been respired, and has become at length totally unfit for supplying the vital principle. Thus, they deprive themselves of the most beneficial cordial of life, namely, fresh air, and exhaust the source of vitality as much in one hour, as was perhaps destined by Nature for the support of weeks, or even months. Instead of following such an irrational practice, they ought either to remove to another atmosphere, or to open the window or door, to admit a supply of pure air, rather than to destroy themselves by an obstinate or indolent perseverance in their former habit.