Heaters, ranges, stoves, and furnaces should be kept in complete order, so that no gas shall escape. Its entrance into a bedroom is often so stealthy as to stupefy the unconscious sleeper and destroy life without awakening him.
Sewer Gas.—Of all forms of vitiated air in cities, none is responsible for such serious derangement of health as that which is polluted by the air or gas from sewers and waste pipes. Some physicians and sanitarians hold that sewer air is often the direct cause of typhoid fever, scarlet fever, diphtheria, and cholera. Others maintain that the sewers and pipes furnish favorable breeding places for the germs of these diseases, which germs are carried through the air and produce their effects. The important matter is to keep the waste pipes flushed and well trapped. Some precautions against sewer gas are treated in the chapter on Dwellings.
Influence of Climate and Temperature.—Diarrhœal diseases, both of adults and children, are most frequent during hot weather. In July, August, and September there are from ten to twelve times as many cases as at other seasons of the year. Proper diet and suitable clothing will go far toward protecting the individual from the ill effects of climate and season.
The mortality from consumption and other forms of lung diseases is greatest in March and April, and least in August and September. September and October claim the greatest number of deaths from typhoid fever, followed closely by August and November. The mortality from diphtheria and croup is highest in November and December, and lowest in August and September. Of suicides, the largest number occur in May, and the fewest in February.
Hygienic Value of Winds.—Prof. Dexter, of the University of Illinois, has made a careful study of the effects of calms on the records of the public schools, the police courts, and the penitentiaries. All air movements not exceeding four miles an hour are regarded as calms. Over 497,000 observations were considered and tabulated. These show that during calm weather the absence from school on account of illness is three times as great as that during all other kinds of weather, including the very cold, wet, and windy. During calms, the criminal records show less disorder and violence, more policemen are laid off, more errors are made by clerks in banks, and more deaths are reported. This is in accordance with the principle that oxygen is the great source of mental and physical energy. When oxygen is deficient, we are less capable of action, either for good or evil. The slowly-moving air-currents of a large city are robbed of their oxygen, and vitiated by the exhalations of thousands of men and animals. A brisk wind brings in a fresh supply of vitalized air to take the place of the old, and to promote physical and mental energy. Old Boreas is a better friend than we have been wont to believe.
Nature’s Balance.—By a wise provision of nature, the carbonic acid, which is so destructive to all animal life, constitutes the chief food of plants. These absorb the carbon and give out oxygen, and in this way the animal and vegetable kingdoms tend to preserve the balance of nature. Except for this wonderful provision, the human family would be threatened with annihilation.
WATER
Water in the Human Body.—Taken as a whole, the human body consists of about seventy-one parts of water in the hundred. When we consider how large a quantity of water is given off daily, not only through the kidneys and intestines, but through perspiration, sensible and insensible, and through the vapor breathed out from the lungs, it becomes clear that the food must contain a large proportion of water to supply the daily loss.