its The signs of death. Death as viewed by the Physiologist, and the Christian. ble sign of death, putrefaction, has appeared. That we should wait for the appearance of this sign in all cases in which there is a shadow of doubt, I will allow. But the cases are exceedingly rare in which we cannot determine the reality of death long before this sign shows itself. Our decision is not made up, it must be observed, merely from the signs of death. All the circumstances of the case are taken into view the disease, progress, its symptoms, and the events of the last hours of the patient. With this evidence before us, we absolutely know, in all ordinary cases, that death has occurred when the respiration and the circulation have ceased. And in the exceedingly few cases in which there is any reason to doubt on that point, there is always something which will attract the attention and excite the curiosity of some one, unless there be stolid indifference and the most absolute lack of intelligence. In such cases there is always something strange-the circumstances attending the cessation of the respiration and circulation are singular, and the signs of death are not complete and in their proper order of succession. Whenever there is for these reasons any doubt as to the reality of the apparent death, the strictest watch should be maintained till the signs of commencing putrefaction appear. With this simple rule of prevention burying alive need never to occur. 610. The investigations of physiology, as you have seen, end with the death of the body. It can give us no light on the question as to what may be beyond this life. Although the physiologist studies the human structure not merely as an organization instinct with life, but also as the wonderful machinery through which a reasoning soul acts and is acted upon in this state of being, yet, as a physiologist, he knows not that the soul survives the death of the body. He knows not but that it is a mere endowment of matter, as life probably is, and so perishes in the hour of dissolution. He may indeed conjecture that such exalted faculties which are in this world susceptible of such high cultivation, instead of being destroyed with the body, are destined to still farther development in another state of existence. But what is mere conjecture to him as a Physiologist, is made fact to him as a Christian. The eye of his faith sees an immortal spirit rise from the dying body, and he realizes the truth of the sublime declaration, that "death is swallowed up of victory." Sources of our knowledge of hygiene. CHAPTER XXI. HYGIENE. 611. Ir seems appropriate that the concluding chapter of this book should be on Hygiene. After having considered the construction of the machinery of the human system and the uses which the mind makes of it, one naturally inquires what are the conditions on which the full development of this complicated machinery and its daily repair depend. 612. The principles and rules of Hygiene are to be learned from two sources. 1. They are to be learned from Physiology. As we observe the functions of the different organs, we can learn what those circumstances are which favor their due performance, and what those are which interfere with it. 2. They are to be learned, also, by observing the effects of those agencies which are known to interfere with the functions and to produce disease. An exemplification of these two modes of learning the principles of Hygiene in relation to a single point will suffice. The study of the physiology of the chest shows us that nature has, in the construction of its framework, especially provided for giving ample room to the lungs; and so we deduce a law of Hygiene, that the chest should not in any way suffer compression. This is the first mode. But the same law can be deduced by the second mode, that is, by observing the results of compression of the chest. 613. Rules of hygiene generally have but little practical influence, unless the physiological facts upon which they are based are understood. Although the evil effects of their violation may be vividly portrayed, and even illustrated, as in the case of the chest, by engravings, the impression upon the mind is by no means as thorough and practical, as when the same lesson is enforced by a clear knowledge of the functions and arrangements of the organs and the conditions necessary to their healthy action. Physiology, therefore, should be studied as preparatory to a proper appreciation of Hygiene. 614. Not only is a knowledge of Physiology essential to a proper appreciation of the rules of Hygiene, but in many Hygiene of digestion. Quantity of food to be eaten. cases they cannot be fully understood in their varied application without such a knowledge. With the very partial and superficial knowledge of Physiology that is usually communicated with Hygiene, these rules are for the most part mere arbitrary rules. And just so far as the principles on which they are based are not understood, is there a liability to mistake their application under various circum stances. 615. In considering the subject of hygiene, the natural division of Physiology, stated in § 57, should be kept in mind. There is a hygiene relating to the construction of the machinery of the body, and there is also a hygiene relating to the uses of this machinery. Besides, each organ has to a certain extent its own hygiene. And yet, as all the organs are connected more or less together in sympathetic action, there is a general hygiene of the system. I shall observe for the most part the same natural order that I followed in developing the subject of Physiology. I shall first treat of the hygiene of the construction and repair of the system— that is, the hygiene of digestion, circulation, respiration, and formation and repair. You can recur to a summary of these functions given in § 69. I shall then pass to the consideration of the hygiene of the uses of the machinery thus constructed and kept in repair. 616. Many of the points in the hygiene of the digestive organs have been already noticed in the physiology of digestion. I need say nothing more in addition to what is said there of the importance of the thorough mastication of food, and of its having a due amount of saliva mingled with it; of the evils resulting from eating too fast, from eating between meals, and from eating a great variety of food; and of the influence of exercise upon the process of digestion. There are some other points, however, that remain to be noticed. 617. No very precise rules can be given as to the quantity of food that is proper to be eaten. But a consideration of the physiological principles of digestion suggests rules that are sufficiently definite for practical purposes. There must be such an amount of food as will furnish sufficient chyle to keep the blood, the building material of the body, in proper quantity. The question arises, how we shall know what amount of food is requisite for this purpose Fortunately, the want of the system and its supply are com Mistakes as to quantity of food. Length of intervals between meals. monly quite accurately indicated by the sensations as stated in § 87. The proper hygienic rule then on this point is, that we should cease to eat when the sensations created by the want of the system are removed--that is, when the hunger is appeased, and the accompanying feeling of discomfort is succeeded by a feeling of agreeable ease. 618. But there are mistakes often made in regard to these sensations. They may be prevented from making a true report. Thus, when eating is done too rapidly, more food than is needed may be introduced into the stomach before the sensation of ease and satisfaction is experienced. It is only when suitable time is given to mastication, and the food is rather gradually introduced, that this sensation forms the proper limit of eating. Again, there is a very common mistake in substituting the feeling of fulness for the sensation alluded to, as indicating the time for ceasing to eat. Those who adopt this false rule generally make the stomach to bear as much as it can without absolute discomfort, and many daily overreach this point. The result is, that this organ soon gives out under this daily overworking; or, if the stomach be a strong one, an injurious repletion is produced in the system. Even in the latter case, the stomach at length gives out, and becomes the seat of disease. But it is astonishing how much labor, in the work of digestion, this organ will perform in some cases. 619. Too little food is sometimes taken. Poverty is commonly the cause. But sometimes it arises from false notions; as, for example, the notion that the quantity of food should be regulated by weight, or the more common notion, that we should rise from a meal with some amount of appetite remaining. The result is, that there is not a sufficient supply of chyle to meet the wants of the system. The wear and tear create a demand which is greater than the supply, and the body therefore loses its fulness and its vigor. 620. In determining the length of the intervals between the meals, we should have regard to the time required for the completion of the process of digestion, and to the wants of the system. Some articles are digested more rapidly than others, but it commonly requires from three to four hours to complete the digestion of a meal. When the system is in a state of action, its want of food, as indicated by its sensations, shows itself a little time after the completion of Regularity of meals. Quality of food. Influence of the mind on digestion the process of digestion. The interval, then, between the meals should not vary much from four hours. If it be made longer than five hours, some degree of exhaustion results; and if it be less than three hours, disturbance of the digestive process may occur, from having the digestion of one meal begin before that of the previous one is fairly finished. 621. It is important that the meals should be eaten at regular periods from day to day. For the stomach, with its times of work and of rest, naturally contracts regular habits, a disturbance of which is injurious. This obedience to habit in this organ is manifest whenever any change is made in the time of eating. 622. The question is often asked, whether such and such an article "is healthy," as if there were essentially different degrees of suitableness in different articles of diet. So far as digestion is concerned, any article is healthy to any individual whose stomach can digest it without difficulty. An article may be perfectly healthy to one, and unhealthy to another. There are sometimes wide differences in this respect, owing to unaccountable peculiarities. But even in regard to ordinary differences, the question as to the propriety of any article of food is wholly an individual question. 623. Our food should be varied in the different seasons of the year to a greater extent than is commonly done. In the warmer seasons it needs to be less stimulating, less heatproducing than in the colder seasons. The fruits, each in its season, should form regularly quite a large proportion of our food in the warmer months. If used thus, and not irregularly, as is commonly the case, they will tend to prevent, rather than induce, the complaints peculiar to that portion of the year. 624. The state of the mind has much influence on the digestive organs. This is sometimes strikingly exhibited in the loss of appetite on the sudden reception of bad news. It is also seen in the influence of continued sorrow upon the appetite and the digestion. It is not strange, then, that one of the prominent causes of dyspepsia is mental disturbance or. depression. And a cheerful mind is very properly deemed to be essential to easy and thorough digestion. 625. In order to understand fully the hygiene of respira tion, it must be borne in mind, that the great object of this function, as stated in § 131, is to bring the air into all the minute air-cells of the lungs, that it may change the blood |