From a book written in 1858:
“Rules for the preservation of health: 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 breath the same air once only.
The solid part of our bodies are 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 part 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 vigour 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.
Fire consumes the oxygen of the air, and produces noxious gases. Therefore, the air is less pure in the presence of candles, gas, or coal fire, than otherwise, and the deterioration should be repaired by increased ventilation.
The skin is a highly-organized membrane, full of minute pores, cells, blood-vessels, and nerves; it imbibes moisture or throws it off, according to the state of the atmosphere and the temperature of the body. It also “breathes,” as to the lungs (though less actively). All the internal organs sympathise with the skin. Therefore, it should be repeatedly cleansed.
Late hours and anxious pursuits exhaust the nervous system, and produce disease and premature death. Therefore, the hours of labour and study should be short.
Mental and bodily exercise are equally essential to the general health and happiness. Therefore, labour and study should succeed each other.
Man will live most healthily upon simple solids and fluids, of which a sufficient but temperate quantity should be taken. Therefore, 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 quantity and quality, should be adapted to the alterations of night and day, and of the seasons. And, therefore, also, drinking cold water when the body is hot, and hot tea and soups when cold, are productive of many evils.
Moderation in eating and drinking, short hours of labour and study, regularity in exercise, recreation, and rest, cleanliness, equanimity of temper and equality of temperature, these are the great essentials to that which surpasses all wealth, health of mind and body.”