functions, and consequent bad health, could scarcely have been expected. But in this as in many other cases, carelessness leads to results not contemplated in the economy of nature. All the parts concerned in inhaling and exhaling air-the trachea and bronchial tubes, and cells in the lungs are delicate, and susceptible of injury from cold and humidity. Undue exposure of the person to cold and wet, sitting with damp feet, or neglecting to shift damp clothes, have often a fatal effect. Inflammation in the lungs or parts connected with them ensues; the first demonstration of which is usually catarrh, or what is called a The symptoms are coughing, pain in the throat, &c., which are significant of danger, and require to be promptly remedied. You are particularly warned against treating a cold lightly. If disregarded, it may lead to ulceration and wasting of the lungs, or pulmonary consumption-one of the most fatal diseases among young persons in England; and which, in many instances, is traceable to some apparently insignificant act of neglect years previous to the period at which it assumes a threatening aspect.

cold.

Disease in the respiratory organs, fevers, and other fatal maladies, arise, likewise, from imbibing air rendered foul by living in confined apartments. The air coming from the lungs loaded with impurities, is unfit for being again inhaled; it is, in point of fact, poisoned, and so being unsuitable for animal life, ought to escape into the general atmosphere, where there is provision for its purification. The open air, during the day, when it is mild in temperature, and happens to be not too humid, is therefore best adapted for respiration. During the night, it is less wholesome, as well as less pleasant.

The nearer the condition of air in our houses is to that of the atmosphere in an agreeable summer day in the country, the better is it adapted for health. Ordinarily, no special provision is made for supplying pure air to houses; and none is admitted except by the casual opening of doors and windows, or by

crevices in different places. The greater number of dwellings are consequently much too close, and the air in them is considerably vitiated. This is particularly the case in sleepingapartments, theatres, assembly and work rooms, churches and schools. It is in bedrooms that most harm is usually done. These are smaller than other rooms, and they are usually kept close during the night; when several persons sleep in one room, the result is most injurious.

In large, and also in some small towns, the air is rendered noxious, not only by the closeness of the streets and alleys, but by smoke and other impurities; among which are included exhalations from ill-managed drains and collections of decaying substances. Constant residence in these spots, along with a disregard of cleanliness, is known to produce disorders of various kinds; for the lungs are habitually charged with an unwholesome, at least not a perfectly pure air. Attention to ventilation is therefore one of the things which no one can disregard with impunity.

It is now well known that, as regards health, there is much virtue in sun-light, more particularly in the direct rays of the sun. Your apartments, therefore, should, if possible, face the sun, besides being open to the free action of the air.

A person in good health feels no pain anywhere, and he has a pleasure in existence. As soon as any derangement takes place, unpleasant sensations are experienced-perhaps internal pains, sickness, or headache. A notion of what is wrong is obtained by an examination of the tongue and the pulse. These two points you should understand.

The tongue is always looked at by medical men who are called in to give advice in the case of illness. The reason for their doing so is to learn the condition of the stomach. If the digestive functions are in good order, the tongue is clean and reddish in appearance; but if they be deranged from over eating or drinking, or from having taken some improper

substance or liquid into the stomach, it becomes white and furred -the upper surface of the tongue being in reality a continuation of the inner surface of the stomach. At a single glance, therefore, a medical attendant can tell whether the illness is connected with the functions of the stomach; and there is no reason why you should not be able to detect digestive derangement from the same symptoms. It might be ridiculous for you to be frequently looking at the state of the tongue; but totally to neglect this kind of examination would be equally improper. Take a look now and then at your tongue, to see whether you are pursuing a right method of living. In the ordinary circumstances of life in towns, the tongue is seldom perfectly clean; and a slight foulness is accordingly of little moment. But if you observe, from time to time, that the tongue is thickly studded with a whitish roughness up the centre, you may be certain that the stomach is seriously out of order; and you are by such symptoms admonished to be more temperate, or in some other way to alter your system of living. The morning, at rising, is the best time to examine the tongue.

The pulse is the throbbing of an artery; that which is commonly felt by medical men being situated at the wrist. They feel it with the forefingers, and reckon the number of beats by the second-hand of a watch. The rate of pulsation in a person in the prime of life, is from 65 to 75 beats in a minute. In childhood, the pulse is much quicker-from 100 to 145 beats; and in old age it again becomes slower than the medium standard.

The circulation of the blood through the system is one of the leading features in the animal economy. From the heart, the centre of the circulation, the blood is conveyed through the body by vessels called arteries, and is brought back to the same part by veins. The purpose of its thus making the circuit of the whole body, is to supply the necessary waste which takes place by perspiration and the perpetual operation of the

excretory organs. The blood is supported and restored to its nutritious state by the chyle-a juice formed in the stomach and intestines from the digested food. The lungs and the heart are organs intimately connected with the circulation; and it may be generally explained that it is by its passage through the lungs that the blood, on exposure to the air-cells, receives its bright-red colour; and that it is the action of the heart which impels the circulation to the extremities. The beating of the pulse, therefore, is merely a symptom of the heart's continued action; and hence the value of feeling and reckoning the number of throbs per minute. As long as the beats amount to about seventy in the minute, in a well-grown person, the circulation is going on properly; but when they rise much beyond that number-as to eighty or ninety, feverishness is indicated, and a remedy ought to be applied.

EXERCISE.

W

E observe that the lower animals are fond of exercise, according to their instincts and the necessities of their nature. Beasts of prey, browsing quadrupeds, dogs, birds, fishes, and other animals, respectively move about, not only in quest of food, but apparently for the gratification of rambling and exercising their muscular energy; such being essential for the preservation of their health. Children are, in the same manner, fond of active exertion; they run about, play, and indulge in boisterous vociferation-all which forms a useful exercise of their system. A love of exercise is natural in man. We

have not been created with a view to passing our lives in torpidity or idleness. Exercise is of two kinds-muscular and mental: the body requires to be exercised in its various muscles; the mental faculties need to be kept in a proper degree of activity.

Bodily Exercise.-With regard to this kind of exercise, it is observable that in proportion as any muscle or limb is exercised in its appropriate functions, it improves in strength and development. Physiologists explain this phenomenon by saying that whenever one of the organs is put in motion, a greater flow of blood and nervous energy is sent to the part, so as to supply the waste that is caused. When one state of action follows close upon another, the renovating part of the process exceeds the waste, and an increase of new substance, as well as an addition of fresh power, takes place. On the contrary, when an organ is little exercised, the process of renovation goes on languidly, and to a less extent than that of the waste, and the parts consequently become flabby, shrunken, and weak. The bones are subject to the same laws, and they increase or diminish in dimensions and solidity according as they are exercised.

Applying these principles, it is seen that much depends on the proper exercise of the limbs and other parts of our system. By habitually sitting still or reclining, we may shrivel up the lower limbs, and so weaken the muscles of the back, as to be at length unable to stand. On the contrary, by duly exercising these parts, great strength of limb and power of walking and standing may be produced. So likewise by exercising the hand or arm, these become strong and energetic. What arm, for example, is so muscular and strong as that of a blacksmith? what leg so firm and alert as that of a dancingmaster? These facts are well understood by men who go into training for feats of walking, rowing, and other varieties of exercise.