of the poor in this country, are in no respect superior to many so-called savage tribes. The endeavour at once to impress on beings plunged in such degradation the duties and responsibilities of religion is almost hopeless; "the seeds of Christianity cannot germinate in such a soil, or issue in fruit in such an atmosphere." No! we must first sweep away physical impurities, give them the means of procuring the health and happiness that are compatible even with poverty, and, when we have taught them to feel that life here may be rendered a desirable and dignified state, we may induce them to anticipate and prepare for its perpetuation hereafter! Among the many objects of idolatry in the 'pantheon' of the ancient Greeks was a certain goddess of health called 'Hygeia.' She was represented holding a serpent in one hand, and in the other a bowl containing liquid. The serpent was regarded among the ancients as the symbol of prudence and foresight; the bowl and liquid may have had reference to the sustenance of the animal; and the two may be taken as symbols of the ever-watchful prudence, which is the principal element in the preservation of health! The French word 'hygiène,' which has been adopted into our language, is derived from the Greek, and is now, both in this country and on the continent, applied to a distinct branch of research which may be termed the science of health. Hygiene has for its objects an investigation of the conditions necessary to health, and the best means of realizing them. It may relate either to individuals, or to the community of which they form part; hence its division into 'private' and 'public.' In either case it is based on an intimate knowledge of the physical conditions essential to life and health; which must be studied before we can successfully apply them. Light, heat, electricity, air, water and food are the agents, the action of which is so necessary, that they are termed 'vital stimuli.' They must not be confounded with the vital principle itself. They are merely passive agents acting under the direction of an unseen force, whose nature the researches of the anatomist have failed to reveal, but whose presence is attested in every indication of life. Without a due supply of these vital stimulants the body would be unable to perform its various functions, lose its activity and vigour, and death inevitably result. Their action consists chiefly in supplying new materials, and removing those that are useless and injurious. The comparison of life to a burning lamp,-' a brief candle' as our dramatist forcibly expresses it-is, in one sense, not inapt; since the flame of life burns brightly, in proportion as conditions analogous to those requisite for combustion are fulfilled; steady, bright, and full in maturity, and as life declines, and old age draws on, growing dimmer, until at last it merely flickers in the socket. These vital stimulants act on the body and are reacted on by it; they become changed, and also induce changes in the animal system; these changes, whether chemical or physical, being determined by the controlling influence of the vital principle.' But for the interposition of this, physical agents would act upon the body, as they do when life is extinct, and as they ordinarily do upon inorganic bodies-induce decom position of the component elements, and re-union of these under new forms. "Of all the phenomena, included in that circle of actions which we designate by the general term life, this power of resisting the effects universally produced by physical agents on inorganic matter, and of bringing these very agents under subjection to a new order of laws, is one of the most essential and distinctive." Through these stimulants, the body is constantly throwing off waste, and receiving new material; thus undergoing such a constant and complete change of its particles, that, literally speaking, it is not the same body at one given point of time that it was at some time previous. Physical agents, then, act principally by renovating and contributing to the component materials of the body. It is not exactly understood in what way light and electricity act; but the former, doubtless, directly excites the various functions, and thus promotes health and development. Heat is necessary to maintain the temperature of the body, especially in infancy and old age, when the vital powers are depressed. It would seem also to enter directly into the composition of the animal structure. Atmospheric air is indispensable for the performance of the respiratory function, without which the blood could not be purified and renovated, and life would be rapidly extinguished. Water is directly necessary as one of the component parts of the tissues and organs, and indirectly for purposes of ablution, by which the important functions of the skin are effectively maintained. And lastly, food directly stimulates the body, and after pass * Southwood Smith, Philosophy of Health. ing through certain changes, becomes part of it. Man cannot live many days without it; if a due amount of wholesome nutriment be not furnished, the body is reduced to live upon itself, and becomes rapidly attenuated, weakened, and incapable of supporting its vitality. These then are the conditions essential to life and health; and, among the endless manifestations of the wisdom and goodness of the Creator, there is none more striking than the exact adaptation of animal life to the world without, and the marvellous interdependency of physical agents and the inorganic, vegetable and animal worlds. This point may be illustrated by the fact that plants not merely prepare food for man from inorganic substances, but, in the performance of their vital functions, exactly counteract the deteriorating action of animal life upon the atmosphere. I cannot dwell longer on this view of the subject, and merely observe, in passing, that each division of Nature is but a link in the great chain of Creative Design. Before considering more minutely the action of these different physical agents upon life, the influence of various modifying circumstances in individuals and communities must be noticed. Every man may be regarded as a little world in himself, moving in a distinct and proper sphere. Age, sex, temperament, hereditary predisposition, peculiar habit of body or mind, condition of life, combine to produce in every man a characteristic individuality, affording special subject for study in relation to the world without. The symptoms of health present, as has been well observed, as many shades of difference as those of disease, and demand, like the latter, peculiar treatment. These peculiarities in the individual modify, and may be modified by the influence of external agents. Every man has, at birth, certain constitutional peculiarities, consisting in a certain preponderance of the circulatory, nervous, or absorbent systems, to which, in the aggregate, the term temperament is applied. In one man the complexion is bright and florid, the chest open and ample, the respiratory movements energetically performed, the muscular system well developed, the various functions effectively discharged, in short, the whole aspect expressive of power and full health. Such a man is said to be of a 'sanguine' temperament. In another, the nervous system preponderates the brain is large and well-formed, the eye expressive; the muscular system playing a secondary part, and the different functions being under the control of energetic nervous influence. His sympathies, his susceptibility to impressions from within and without, are acute; his will is frequently impetuous; he has a large capacity for either pleasure or pain, with great latent power, which is equal to any emergency. Such a man is said to be of nervous temperament.' A third, is large, illdeveloped, with unsymmetrical limbs, and red, or flaxen hair. His surface is pale, smooth, and appears as if water, instead of blood, were circulating in the vessels; this condition being accompanied with deficiency of muscular tone, as well as of nervous and mental energy. We should speak of him as possessing a 'lymphatic temperament.' These temperaments are not, in general, so distinctly marked; one being more or less |