Experience and observation have universally confirmed the expediency of a heartier and more systematised diet than recently prevailed. Its utilitarian advantages are publicly recognised. Within twenty years the rations of armies, of institutions, charitable, penal, and medical, have been liberally increased. Family habits in regard to eating, since the flush times of the civil war, have greatly changed, and the large allowance of food requisite for the maintenance of a sound health can scarcely be exaggerated in any statement of its details. In the application of this accepted dogma to special and personal cases there is much, however, still left to be desired. (R. M. Hodges.)
Drinks.—There are physiological facts in relation to drinking which ought to be recalled by those who know them, and brought to the knowledge of the unskilled in medicine, because they concern the promotion of health. Thus it is essential that there should be constantly passing through the organism a flushing, as it were, of fluid, to hold in solution and wash away the products of disassimilation and waste. Those who do not recognise the fact that ¾ of the entire organism is normally composed of fluid cannot fully realise the great need which exists for a copious supply. If there be not a sufficient endosmose, the exosmose must be restricted, and effete matters, soluble in themselves, but not dissolved because of the deficiency of fluid available, will be retained. Take, for example, the uric acid; this excrementitious product requires not less than 8000 times its bulk of water at the temperature of the blood to hold it in solution; and if it be not dissolved it rapidly crystallises, with more or less disastrous consequences, as in gout, gravel, and probably many other less well-recognised troubles. We only mention this particular excrement by way of illustration. In all, it may be fairly concluded that not less than 3½ pints should be consumed by any person in the 24 hours, and when the body is bulky 4 or even 5 pints should be the average. It is, moreover, desirable that the fluid thus taken should be in the main either pure water, or water in which the simplest extracts are held in solution.
So far as the mere sensation of thirst is concerned, there can be no question that it is a mistake to drink too much or too frequently in hot weather; the fluid taken in is very rapidly thrown out again through the skin in the form of perspiration, and the outflow being promoted by this determination toward the surface, a new and increasing demand for fluid follows rapidly on the successive acts of drinking and perspiring, with the result that “thirst” is made worse by giving way to it. Meanwhile, it must not be forgotten that thirst is Nature’s call for fluid to replace that lost by cutaneous exudation in warm weather; and if the demand be not met, what may be regarded as the residual fluid of the tissues must be absorbed, or the blood will become unduly concentrated. To thirst and drink, and perspire and drink again, are the natural steps in a process by which Nature strives to maintain the integrity of those organic changes which the external heat has a tendency to impede. The natural and true policy is to supply an adequate quantity of fluid without excess. Therefore do not abstain from drinking, but drink slowly, so as to allow time for the voice of Nature to cry “Enough.” There is no drink so good as pure water. For the sake of flavour, and because the vegetable acids are useful, a dash of lemon-juice may be added with advantage. The skin should be kept fairly cool, so that a sufficient quantity of the fluid taken may pass off by the kidneys.
Sufferers from certain common forms of indigestion forget the immediate effect of loading the stomach with cold drinks. If hot drinks are sometimes debilitating to the organ of digestion, cold drinks are certainly not always bracing, but, on the contrary, are often depressing. It is especially desirable to remember this fact when the weather is more than commonly lowering to the nervous tone of the organism. Even though the fluid taken may be what is called stimulating, the consequence of its being cold is to chill the gastric organ and depress the nerve centres, whence it derives its supply of nervous force. The peculiar form of indigestion now very prevalent, in which food is retained an unreasonable time in the stomach, with the result of flatulence, and it may be of irritative reaction on the part of the nerves of the viscus, and neuralgic pain as a consequence, is in a large proportion of instances the direct effect of persistent chilling of the gastric organ by copious draughts of cold drink. It is recognised that cold drinks are dangerous in very hot weather, acting as irritants, but it is not, apparently, understood that the mischief they do as depressants may be even greater, and that this effect is to be especially dreaded when the weather is itself depressing by cheerless or unseasonable cold. (Lancet.)
Water.—When fluid taken “as drink” is itself heavily charged with solid matter, it cannot fairly be expected to so entirely rid itself of this burden in the process of digestion and absorption as to be available for solvent purposes generally, although the separation between solid and fluid ingredients of the food is doubtless fairly complete in the processes preparatory to assimilation. The aim should, nevertheless, be to supply the organic needs in this particular abundantly, and with such fluids as are not overloaded with solids, but simple and readily available as solvents. Another urgent reason for drinking freely of bland fluids is to be found in the need of diluents. This is something slightly different from mere solution. Many of the solids of the tissue waste are of a nature to irritate and even disorganise the kidney, if they be brought to that organ for excretion in too concentrated form. There is no reason to suppose that the kidneys are liable to suffer from over-work if the specific secreting power of the kidney cells be not too heavily taxed. If only the products of disassimilation be diluted, so that they can be passed through the kidney by the simple process of exosmosis, the organ will discharge its function without injury or exhaustion. As a matter of fact and experience, those who drink innocuous and unstimulating fluids freely do not suffer from kidney trouble, but are almost uniformly healthy—at least, so far as the excreting functions are concerned. It is a popular fallacy that the kidneys may and ought to be relieved by the determination of fluid to the surface of the body and perspiration. Except in cases of organic disease of the kidney, or where, as in the elimination of a special product, it is desirable to use the skin as an emunctory, the fluid diverted from the kidney is wasted so far as flushing purposes are concerned.
But if water be the drink, how shall it be drunk? The means must have regard to the end required of them. To moisten food and prepare it for digestion it is hardly necessary to say that it should be taken with a meal; a couple of tumblerfuls at dinner is not an excessive quantity for most persons. For thirst-quenching properties nothing can surpass this simplest of drinks, and all which approach it in efficacy owe their power almost entirely to it. As to temperature, there is no real ground for supposing that one should not drink a sufficiency of cold water when the body is heated by exertion. The inhabitants of hot climates have no such objection. Some tropical wells are dug so deep that the water within them, even in hot seasons, is as cool as that of a European spring. In fevers, too, the use of ice in quantities sufficient to allay thirst is a part of rational and legitimate treatment. The shock which has to be avoided in all such states is not that which cools the mucous membrane, but that of sharp chill applied to the surface of the body. Some persons, however, find it convenient and beneficial to imbibe a certain amount of warm water daily, preferably at bedtime. They find that they thus obtain a bland diluent and laxative, without even the momentary reaction which follows the introduction of a colder fluid, and softened by abstraction of its calcareous matter in the previous process of boiling. This method, which is an accommodation to jaded stomachs, has its value for such, though it is not great even for them; but it affords no noticeable advantage for those of greater tone. The use of water as an aid to excretion deserves some remark. In certain cases of renal disease it has been found to assist elimination of waste by flushing, without in any way irritating the kidneys. Every one is probably aware of its similar action on the contents of the bowel when taken on the old-fashioned but common-sense plan of drinking a glass of water regularly morning and evening, without any solid food. Whatever may be true of harmless luxuries, enough has been said to show that health, happiness, and work find stimulus enough in the unsophisticated well of nature. The quality of water may be judged by its fauna and flora. It is a standing fact that water containing neither fish nor molluscs is unfit for drinking purposes. The presence of the common watercress (Nasturtium officinale) in a stream is sufficient evidence of the potability of the water; on the other hand, always avoid the water of a stream in which the duckweed or water lentil (Lemna minor) is found.
Tea.—Warm infusion of tea has been proved to have a marked stimulant and restorative action upon the brain and nervous system, and this effect is not followed by any secondary depression. It further increases the action of the skin, and raises the number of the pulse, while it has but little effect upon urination, excepting simply as a watery diuretic. It tends to lessen the action of the bowels. Dr. Parkes found that tea is most useful as an article of diet for soldiers. The hot infusion is a patent protective against extremes both of heat and of cold; and Sir Ranald Martin proved it to be particularly valuable in great fatigue, especially in hot climates. But the habit of tea-drinking is one that grows on its victims like the similar ones of opium or alcohol. Taken in strict moderation, and with due precautions in the mode of preparation, tea is, like alcohol, a valuable stimulant; in its abuse there is also a certain analogy. There is hardly a morbid symptom which may not be traceable to tea as its cause. This is a fact that general practitioners often use to their own satisfaction and to their patient’s advantage, if it happen to be that kind of patient who does not object to make some sacrifice in order to be rid of troubles. The alkaloid which tea contains appears to be less easily absorbed than that of coffee, owing to the very large quantity of tannic acid present. The tannic acid in tea is doubtless one of the causes why it is as a drink so attractive. It is slightly astringent and clean in the mouth, and does not “cloy the palate.” Tannic acid is also one of the dangers and drawbacks of tea. It is largely present in the common teas used by the poor. The rich man who wishes to avoid an excess of tannic acid does not allow the water to stand on the tea for more than 5, or at most 8 minutes, and the resulting beverage is aromatic, not too astringent and wholesome. The poor man or poor woman allows the tea to simmer on the hob for indefinite periods, with the result that a highly astringent and unwholesome beverage is obtained. There can be no doubt that the habit of drinking excessive quantities of strong astringent tea is a not uncommon cause of that atonic dyspepsia, which seems to be the rule rather than the exception among poor women. A word in reference to the now prevalent custom of dining late, and taking an afternoon tea. “Unless cautiously arranged, it is apt to produce dyspepsia. The rule should be that the tea should precede dinner by 3 hours, and not come sooner after lunch than 3 hours, supposing the lunch to have been a good meal; and that if any tea or coffee is taken after dinner, it ought to be immediately after, so as to constitute part of the same meal, and to partake in the same process of digestion. It is most injurious to take tea or coffee 1-2 hours after dinner, or any other full meal.” (Dobell.)
Coffee.—Coffee, like tea, when used as an article of diet, especially affects the nervous system. It is a brain and nerve stimulant; in very large doses, it produces tremors. It increases the action of the skin, and it appears to have a special power in augmenting the urinary water. It increases both the force and frequency of the pulse. Unlike tea, it tends to increase the action of the bowels. Coffee has been proved to be an important article in a soldier’s dietary, as a stimulant and restorative. Like tea, it acts as a nerve-excitant, without producing subsequent depression. It is serviceable against excessive variations of cold and heat, and its efficacy in these respects has been established in Antarctic expeditions, as well as in India and other hot climates. Dr. Parkes pointed out that coffee has a special recommendation in its protective influence against malaria. While admitting that the evidence on this point was not strong, he held it to be sufficient to authorise the large use of coffee in malarious districts. Coffee should be used as an infusion. If coffee be boiled, its delicate aroma is dissipated. (Brit. Med. Jour.) Coffee has a slight value as a nutriment, and a very high value as a stimulant; when mixed with boiling milk in the form of café-au-lait it forms the ideal of breakfast foods for body workers and brain workers, and a very small quantity of black coffee taken after a full meal serves to stimulate the stomach to the necessary digestive effort, and to ward off that sleepiness which is often the attendant of satiety. Supposing all the dissolved matter to be available for the needs of the body, the dietetic value of a cup of coffee is more than twice that of a cup of tea, and if we assume that the stimulating power is due to the contained alkaloid, then quâ stimulant the cup of coffee has more than three times the value of the cup of tea. (Poore.)
Cocoa.—The theobromin of cocoa is, chemically, identical with the thein of tea, and the caffein of coffee. While tea and coffee are comparatively valueless as true foods, cocoa, by reason of the large quantity of fatty and albuminoid substances it contains, is very nourishing, and is of high dietetic value as a tissue-forming food. Compared with tea and coffee, it is a food rather than a stimulant, being akin to milk in its composition and place in the diet-scale. It is useful to sustain the weakly, and to support the strong in great exertion, as a readily assimilable and general form of nourishment. (Brit. Med. Jour.)