Pure atmospheric air is composed of nitrogen, oxygen and a very small proportion of carbonic acid gas. Air once breathed has lost the chief part of its oxygen, and acquired a proportionate increase of carbonic acid gas. Therefore, health requires that we breathe the same air once only.

The solid part of our bodies is continually wasting, and requires to be repaired by fresh substances. Therefore, food which is to repair the loss should be taken with due regard to the exercise and waste of the body.

The fluid parts of our bodies also wastes constantly; there is but one fluid in animals, which is water. Therefore, water only is necessary, and no artifice can produce a better drink.

The fluid of our bodies is to the solid in proportion as nine to one.

Therefore, a like proportion should prevail in the total amount of food taken.

Light exercises an important influence upon the growth and vigor of animals and plants. Therefore, our dwellings should freely admit the solar rays.

Decomposing animal and vegetable substances yield various noxious gases which enter the lungs and corrupt the blood. Therefore, all impurities should be kept away from our abodes, and every precaution be observed to secure a pure atmosphere.

Warmth is essential to all the bodily functions. Therefore, an equal bodily temperature should be maintained by exercise, by clothing or by fire.

Exercise warms, invigorates and purifies the body; clothing preserves the warmth the body generates; fire imparts warmth externally. Therefore, to obtain and preserve warmth, exercise and clothing are preferable to fire.

Mental and bodily exercise are equally essential to the general health and happiness. Therefore, labor and study should succeed each other Man will live most healthfully upon simple solids and fluids, of which a sufficient but temperate quantity should be taken. Therefore, an excessive use in strong drinks, tobacco, snuff, opium and all mere indulgences, should be avoided.

Sudden alternations of heat and cold are dangerous (especially to the young and the aged). Therefore, clothing in quality and quantity should be adapted to the alternations of night and day and of the seasons; and drinking cold water when the body is hot, and hot tea and soups when cold, are productive of many evils.