Whiles they behold a greater than themselves,
And therefore are they very dangerous.”
Even experience must have taught every one with what zest we sit down to enjoy the pleasures of the table, and how largely we incline to eat, when the mind is free, unburdened, and joyous, compared with the little attention we bestow on our meals when we are overwhelmed with anxiety, or have the whole energies of the mind concentrated on some important scheme. There cannot be a doubt, indeed, that the over-exertion and excitement, or absolute inertness, of mind, in which sedentary people are generally immersed, contributes greatly, along with the want of muscular exercise in the open air, to impair the tone of the digestive organs. In this way, as it is not less justly than forcibly remarked by Dr Caldwell, “dyspepsia commences perhaps as often in the brain as in the stomach. Possibly oftener. That this is true of the disease in Europe will scarcely be denied, after a fair examination of the facts connected with it. It is there almost exclusively a complaint of the studious and the scheming, who, over-tasking their brains, injure them by toil. Among the husbandmen of England, who steadily pursue their tranquil mode of life, regardless of the fluctuations of stock, the bickerings of party, the fate of political measures, and the changes of place, dyspepsia is almost a stranger.” “In the cities, the same is in a great measure true of merchants, manufacturers, and mechanics, who are engaged in a regular and well established business, which is fully understood by them, where the risk is slight and the profits sure, and no disquieting anxiety attends it. Such individuals have a good digestion, and bear the marks of it. But with literary men, officers of state, dealers in scrip, daring adventurers, and anxious and ambitious projectors of improvements, with these and every other brain-worn class of persons, the case is different. Dyspepsia is their torment, and they exhibit deep traces of it in their lean frames and hagard countenances. Yet are they much more select in their diet, both as respects quantity, quality, and cooking, than the classes to whom dyspepsia is unknown. This fact is notorious, and has been so for centuries. Nor can it be attributed, I think, to any other cause but excessive and deleterious cerebral irritation in the one case, and an exemption from it in the other; and this cause seems sufficient to solve the problem.”[58]
In denouncing active exertion of mind or body immediately after eating, as inimical to digestion, it is not meant that we should go to sleep, or indulge in absolute listlessness. A weak constitution may require something like complete repose, but a person in ordinary health may indulge in a leisurely saunter or pleasant conversation not only without injury but with positive benefit; and perhaps there is no situation in which digestion goes on so favourably as during the cheerful play of sentiment in the after-dinner small-talk of a well-assorted circle. The nervous stimulus sent to the stomach is then of the most healthful and invigorating description, and ever the dyspeptic, if on his guard against a heavy meal, forgets his woes amidst the unwonted vigour of his functions.
It is true that thousands who habitually neglect the observance of the condition here adverted to, continue to live and digest for years without appearing to suffer much from their conduct. But it is not less true that there are many more who bring wretchedness and disease upon themselves and their offspring, in the vain attempt to counteract the intentions of Nature, and that there are comparatively few even of the former so happily constituted as to escape entirely unscathed. Most frequently the evil consequences are only accumulating, and when they are summed up at the end of years, the victim finds himself more severely punished than he had ever expected to be. In this respect, the consequence resembles that arising from breathing in a vitiated atmosphere. The effect may not be perceptible for a time; but if God has ordained a pure air to be best adapted for respiration, we have the infallible authority of His omniscience for believing that one which is vitiated must be less wholesome, although His beneficence has so constituted us, that the injury resulting from it is gradual in its infliction, for the very purpose of giving us time to escape. In like manner, if bodily and mental relaxation are favourable to digestion, we have the same infallible guarantee that every departure from them must be in so far hurtful, however slowly the effect may develope itself.
CHAPTER V.
ON DRINKS.
Thirst the best guide in taking simple drinks—Thirst increased by diminution of the circulating fluids—The desire for liquids generally an indication of their propriety—Much fluid hurtful at meals—Most useful three or four hours later—The temperature of drinks is of consequence—Curious fall of temperature in the stomach from cold water—Ices hurtful after dinner—Useful in warm weather, when digestion is completed and caution used—Cold water more dangerous than ice when the body is overheated—Tepid drinks safest and most refreshing after perspiration—Kinds of drink—Water safe for every constitution—Wine, spirits, and other fermented liquors, too stimulating for general use, but beneficial in certain circumstances—Test of their utility.
On the subject of drinks two questions naturally occur. When ought we to drink? and, What ought we to drink? On both I shall offer a few very brief remarks.
In the first part of this volume I endeavoured to shew that the sensation of thirst is given to us for the express purpose of impelling us to take liquids whenever the wants of the system require them, and that, in all ordinary circumstances, we cannot have a better or a safer guide. Such is the general case; but exposed as we are to numerous deviations from the intentions of Nature in our ways of living, a few precautionary observations may not be without use.
The quantity of fluid separated from the blood and thrown out of the system, in the course of twenty-four hours, by perspiration, exhalation from the lungs, the urinary discharge, and the various other secretions, is very great; and were not the loss as regularly supplied by the ingestion of liquid, either as food or as drink, the blood would speedily become so thick as to be unfit for circulation. This actually happens in spasmodic cholera, in which the serum or watery portion of the blood passes off through the bowels with such rapidity, as to cause the entire suppression of the urinary secretion, and in which consequently, the urgency of thirst is almost always excessive. In the healthy state, however, the loss of fluid is never too rapid unless under severe exertion or exposure to a very high temperature, both being circumstances in which it is well known that thirst becomes urgent in proportion to the necessities of the frame.