118. Salt The most important and extensively used of the condiments is common salt. It exists in all ordinary articles of diet, but in quantities not sufficient to meet the wants of the bodily tissues. Hence it is added to many articles of food. It improves their flavor, promotes certain digestive secretions, and meets the nutritive demands of the body. The use of salt seems based upon an instinctive demand of the system for something necessary for the full performance of its functions. Food without salt, however nutritious in other respects, is taken with reluctance and digested with difficulty.
Salt has always played an important and picturesque part in the history of dietetics. Reference to its worth and necessity abounds in sacred and profane history. In ancient times, salt was the first thing placed on the table and the last removed. The place at the long table, above or below the salt, indicated rank. It was everywhere the emblem of hospitality. In parts of Africa it is so scarce that it is worth its weight in gold, and is actually used as money. Torture was inflicted upon prisoners of state in olden times by limiting the food to water and bread, without salt. So intense may this craving for salt become, that men have often risked their liberty and even their lives to obtain it.
119. Water. The most important natural beverage is pure water; in fact it is the only one required. Man has, however, from the earliest times preferred and daily used a variety of artificial drinks, among which are tea, coffee, and cocoa.
All beverages except certain strong alcoholic liquors, consist almost entirely of water. It is a large element of solid foods, and our bodies are made up to a great extent of water. Everything taken into the circulating fluids of the body, or eliminated from them, is done through the agency of water. As a solvent it is indispensable in all the activities of the body.
It has been estimated that an average-sized adult loses by means of the lungs, skin, and kidneys about eighty ounces of water every twenty-four hours. To restore this loss about four pints must be taken daily. About one pint of this is obtained from the food we eat, the remaining three pints being taken as drink. One of the best ways of supplying water to the body is by drinking it in its pure state, when its solvent properties can be completely utilized. The amount of water consumed depends largely upon the amount of work performed by the body, and upon the temperature.
Being one of the essential elements of the body, it is highly important that water should be free from harmful impurities. If it contain the germs of disease, sickness may follow its use. Without doubt the most important factor in the spread of disease is, with the exception of impure air, impure water. The chief agent in the spread of typhoid fever is impure water. So with cholera, the evidence is overwhelming that filthy water is an all-powerful agent in the spread of this terrible disease.
120. Tea, Coffee, and Cocoa. The active principle of tea is called theine; that of coffee, caffeine, and of cocoa, theobromine. They also contain an aromatic, volatile oil, to which they owe their distinctive flavor. Tea and coffee also contain an astringent called tannin, which gives the peculiar bitter taste to the infusions when steeped too long. In cocoa, the fat known as cocoa butter amounts to fifty per cent.
121. Tea. It has been estimated that one-half of the human race now use tea, either habitually or occasionally. Its use is a prolific source of indigestion, palpitation of the heart, persistent wakefulness, and of other disorders. When used at all it should be only in moderation. Persons who cannot use it without feeling its hurtful effects, should leave it alone. It should not be taken on an empty stomach, nor sipped after every mouthful of food.
122. Coffee. Coffee often disturbs the rhythm of the heart and causes palpitation. Taken at night, coffee often causes wakefulness. This effect is so well known that it is often employed to prevent sleep. Immoderate use of strong coffee may produce other toxic effects, such as muscular tremors, nervous anxiety, sick-headache, palpitation, and various uncomfortable feelings in the cardiac region. Some persons cannot drink even a small amount of tea or coffee without these unpleasant effects. These favorite beverages are unsuitable for young people.
123. Cocoa. The beverage known as cocoa comes from the seeds of the cocoa-tree, which are roasted like the coffee berries to develop the aroma. Chocolate is manufactured cocoa,—sugar and flavors being added to the prepared seeds. Chocolate is a convenient and palatable form of highly nutritious food. For those with whom tea and coffee disagree, it may be an agreeable beverage. The large quantity of fat which it contains, however, often causes it to be somewhat indigestible.