Part 2 (1/2)

In every department of nature, _waste_ is invariably the result of _action_ In mechanics, we seek to reduce the waste consequent upon action to the lowest possible degree; but to prevent it entirely is beyond the power of man Every breath of wind that passes over the surface of the earth, reat toe of the bronze statue of Saint Peter at Roinal size by the successive kisses of the faithful

In _dead_ or _inanimate_ matter, the destructive influence of action is constantly forced upon our attention by every thing passing around us, and so enuity is exercised to counteract its effects that no reflecting person will dispute the universality of its operation But e observe shrubs and trees waving in the wind, and ani violent exertion, year after year, and continuing to increase in size, we _ bodies as constituting an exception to this rule On oes on in living bodies not only without intermission, but with a rapidity immeasurably beyond that which occurs in inanietable world, for instance, every leaf of a tree is incessantly pouring out so its own fruit and seed, speedily to be separated fro in a few reater than what occurs in the same lapse of ti operations are at a close

The sa as life continues, a copious exhalation frooes on without a moment's intermission, and not a ree increase the circulation, and add to the general waste In this way, during violent exertion, several ounces of the fluids of the body are sometimes thrown out by perspiration in a very few uished, all the excretions cease, and waste is limited to that which results from ordinary chemical decomposition[6]

[6] For the views presented in the preceding paragraph (as also in several that folloould acknowledge my indebtedness to Dr Andrew Coestion” Froy,” by the same author, I have already quoted These admirable works will prove an invaluable treasure to persons desirous of beco acquainted with the laws of health

So far, then, the law that waste is attendant on action applies to both dead and living bodies; but beyond this point a remarkable difference between them presents itself In the physical or inanimate world, what is once lost or worn away _is lost forever_; but _living_ bodies, whether vegetable or ani able to _repair their oaste_ and add to their own substance The possession of such a power is essential to their existence But there is a wide difference between the the respective etables and of animals, we perceive the fixity of position of the one, and the free locorows, flourishes, and dies, fixed to the sa However e around it, it must remain and submit to their influence At all hours and at all seasons, it is at home, and in direct communication with the soil from which its nourishment is extracted But it is otherith anie of locoo a distance in search of food and shelter The necessity for a constant change of place being iement became indispensable for their nutrition The method which the Creator has provided is not less admirable than simple To enable animals to move about, and at the same time to maintain a connection with their food, they are provided with a stomach In this receptacle they can store up a supply of radually elaborated during a period of time proportioned to their necessities and mode of life Animals thus _carry with them_ nourishment adequate to their wants; and the small nutritive vessels imbibe their food from the internal surface of the stomach and bowels, where it is stored up, just as the roots or nutritive vessels of vegetables do frorow The possession of a stouishi+ng characteristic of the ani to repair waste and to aded that within certain lirowth or waste proceeds with the greatest rapidity Even in vegetables this provision is distinctly observable It is also strikingly apparent in ani rapidly, or the ani much exertion and expenditure of material, an increased quantity of food is invariably required On the other hand, where no new substance is for, and where, from bodily inactivity, little loss is sustained, a co ani the sensation of hunger and thirst, the Creator has effectually provided against any inconvenience which uide in relation to both the quality and quantity of food needful for the of it, with that beneficence which distinguishes all his works He has not only provided an effectual safeguard in the sensations of hunger and thirst, but he has attached to their regulated indulgence a degree of pleasure which never fails to insure attention to their dehly-civilized coratification Their end is manifestly to proclaim that nourishment is required for the support of the systeood deal of waste is effected by perspiration and exhalation froent for ied, we eat with a relish unknown on other occasions, and afterward experience a sensation of internal co the frame, as if every individual part of the body were i of contentment and satisfaction; the very opposite of the restless discomfort and depression which come upon us, and extend over the whole system, when appetite is disappointed There is, in short, an obvious and active sy of the stomach, and those of every part of the anier is felt very keenly when the general systeent need of repair, and very moderately when no waste has been suffered

We have seen that _waste_ is every where attendant upon _action_, and that the object of nutrition is to repair waste and adestion_

All articles used for food necessarily undergo several changes before they are fitted to constitute a part of the body In the process of digestion, four different changes should be noticed More ht be specified

1 MASTICATION--The first step in the preparation of food for i nourish

Food should be thoroughly masticated before it is taken into the stomach This is necessary in order to break it up and reduce it to a sufficient degree of fineness for the efficient action of the gastric juice Besides, the action of chewing and the presence of nutrient food constitute a healthful stilands, situated in the mouth By this means, also, the food not only becomes well masticated, but has blended with it a proper amount of saliva, upon both of which conditions the healthy action of the stomach depends We have here another illustration of the beneficence of the Creator, who has kindly so arranged that the very act ofthe seat of this sensation But if we disregard these benevolent laws, and introduce unastric juice can act only upon its surface, and changes of a purely chemical nature frequently coestion can take place Hence frequently arise--and especially in children and persons of delicate constitution--pains, nausea, and acidity, consequent on the continued presence of undigested aliment in the stomach

2 CHYMIFICATION--As soon as food has been thoroughly nated with saliva, it is ready for trans part of the process of digestion, called deglutition or sing, is most easily and pleasantly performed, when the alimentary morsel has been well masticated and properly softened, not by drink, which should never be taken at this time, but by saliva When the food reaches the stomach, it is converted into a soft, pulpy e is effected is called _chyestion, and is effected iastric juice_ This powerful solvent is secreted by the gastric glands, which are excited to action by the presence of food in the stoastric secretion always bears a direct relation to the quantity of aliment required by the systeestion is sure to follow, for the sufficient reason that the gastric juice is unable to dissolve it This is true even when food has been well ly apparent when a full meal has been hastily sed, bothbeen imperfectly performed

The time usually occupied in the process of chymification, when food has been properly estion is sos'

feet soused; but it er period, as in the case of salt pork and beef, and etable

By the alternate contraction and relaxation of the muscular coat of the stomach, which is excited to action by the presence of food, a kind of churning reatly proestion; for by this ht in contact with the gastric juice as it is discharged from the internal surface of the stomach This motion continues until the contents of the stomach are converted into chyo another ie

3 CHYLIFICATION--As fast as chyme is formed, it is expelled by the contractile power of the stomach into the _duodenum_, or first intestine It there meets with the _bile_ from the liver, and with the pancreatic juice By the action of these agents, the chyme is converted into two distinct portions: a milky white fluid, called _chyle_, and a thick yellow residue This process is called _chylification_, or _chyle-_ The chyle is then taken up by the absorbent vessels, which are extensively ra of the bowels From the white color of the contents of these vessels, they have been nanifies e into one trunk, called the _thoracic duct_, which terreat vein under the clavicle or collar bone, hence called the _subclavian_ vein, just before that vein reaches the right side of the heart Here the chyle is poured into the general current of the venous blood, and,with it, is exposed to the action of the air in the lungs during respiration By this process, both the chyle and the venous blood are converted into red, arterial, or nutritive blood, which is afterward distributed by the heart through the arteries, to supply nourishe which takes place in the lungs is called _sanguification_, or _blood-_ The chyle is not prepared to ie takes place _Respiration_, then, is, in reality, _the co and vital part of the process of digestion will be consideredfroeneral nature seem called for The _nerves of the stoestible_ substances When any body that can not be digested is introduced into the stomach, distinct uneasiness is speedily excited, and an effort is soon made to expel it, either upward by the mouth or doard by the bowels It is in this way, says Dr Combe, that bile in the sto The _nerves of the bowels_, on the other hand, are constituted in relation to _digested_ food; and, consequently, when any thing escapes into theested_ state, it becomes a source of irritative excitement This accounts for the cholic pains and bowel-coh the intestinal canal of such indigestible substances as fat, husks of fruits, berries, and cherry-stones

The process of digestion, which commences in the stoists have hence sometimes called the former part of the process, or chyestion_; and the latter, or chylification, has been terestion_ The bowels have distinct coats corresponding with those of the stomach By the alternate contraction and relaxation of the muscular coat, their contents are propelled in a doard direction, soated from one end of a worm to the other It has hence been called vermicular, or _wormlike _ the order of the muscular contractions E Other ree, and induce a cathartic action of the bowels When medicines become necessary to obviate that kind of costiveness which arises from imperfect intestinal contraction, physicians usually administer rhubarb, aloes, and similar laxatives, combined with tonics But when the muscular coat of the bowels is kept in a healthy condition by a natural mode of life, and is aided by the action of the abdominal muscles, it rarely becomes necessary to administer laxative medicines

The inner or arded by physiologists as a continuation of the skin They greatly resemble each other in structure, and they are well known to syenerally the result of disorders of the digestive organs On the other hand, bowel complaints are frequently produced by a chill on the surface The ed with the double function of _excretion_ and _absorption_ By the exercise of the _former_ function,to be re with the indigestible portion of the food, forms the common excrement; while by the exercise of the _latter_ function the nutritive portion of their contents is taken up, and, as we have seen, passes into the general circulation, and contributes either to prorowth or to repair waste

4 EVACUATION--This is the fourth and last principal step in the process of digestion After the chyle is separated froestible and refuse portion of the food, which is incapable of nourishi+ng the systeh the intestinal canal In its course its bulk is considerably increased by the excretion of waste matter which has served its purposes in the syste with the innutritious and refuse part of the food, is thrown out of the body in the for retained, uneasiness is produced

Hurtful matter, also, which should pass off by evacuation, is reabsorbed, passes again into the general circulation, and is ultih the pores of the skin

This part of the process of digestion is _very iood health while this function is imperfectly performed To secure full and natural action in the intestinal canal, several principal conditions are necessary These are, first, well-digested chyme and chyle; second, a due quantity and quality of secretions fro membrane of the bowels; third, a free and full contractile power of the muscular coat, and the unrestrained action of the abdominal and respiratory muscles; and, finally, a due nervous sensibility to receive impressions and communicate the necessary stimulus The contractile power of the e of the intestinal contents froreatly aided by the constant but gentle agitation which the whole digestive apparatus receives during the act of breathing, and from exercise of every description By free and deep inhalations of air into the lungs, the diaphragm is depressed and the bowels are pushed down But when the air is thrown out fro pressed upward by the contractile power of the abdo is deeper and ives additional pressure to the bowels from above The abdoorous and extensive, and thus the motion is returned from below Persons that take little or no exercise, or who allow the chest and bowels to be confined by tight clothing, lose this natural sti from habits of costiveness These should be reenerally can be by a proper course of discipline This should have reference to both diet and exercise Such articles of food should be used as tend to keep open the bowels This should be cos and the abdominal muscles In addition to these, there should be a determination to secure a natural evacuation of the bowels at least once a day This is regarded by physiologists generally as essential to health Efforts should be continued until the habit is established Some definite period should be fixed upon for this purpose Soon after breakfast is, on enerally preferable

TIME FOR MEALS--Before passing frohts in relation to the ti It has already been observed that _three or four hours_ are generally necessary for the digestion of a sith of time is required It is also an established doctrine, based upon the results of careful examination and experiment, that _the stoestion is finished, to enable it to recover its tone before it can again enter upon the vigorous perforeneral rule, then, _five or six hours should elapse between reater time is required; if active, less ties of society will allow the principaltienerally: breakfast at 7 o'clock, dinner at half past 12, and tea at 6 Luncheons and late suppers should be avoided; for the former will always be found to interfere with the healthful perforestion, and the latter will induce restlessness, unpleasant dreams, and pain in the head ”A late supper,” says the author of the Philosophy of Health, ”generally occasions deranged and disturbed sleep; there is an effort on the part of the nerves to be quiet, while the burdened stomach makes an effort to call the efforts there is disturbance--a sort of gastric riot--during the whole night This disturbance has sometimes terminated in a fit of apoplexy and in death”

THE SKIN--This , which is spread over the surface of the body to shi+eld the parts beneath, serves also as an excreting and secreting organ By the great supply of blood which it receives, it is admirably fitted for this purpose The whole animal system, as we have seen, is in a state of transition, decay and renovation constantly succeeding each other While the stomach and alimentary canal take in new materials, the skin forms one of the principal outlets by which particles that are useless to the system are thrown out of the body

Every one knows that the skin perspires, and that checked perspiration is a powerful cause of disease and death; but few have any just notion of the extent and influence of this exhalation When the body is overheated by exercise, a copious sweat breaks out, which, by evaporation, carries off the excess of heat, and produces an agreeable feeling of coolness and refreshacity of Franklin led him to the first discovery of the use of perspiration in reducing the heat of the body, and to point out the analogy subsisting between this process and that of the evaporation of water froh porous surface, so constantly resorted to in the East and West Indies, and in other war the temperature of the air in rooms, and of wine and other drinks, her and ree of the function of exhalation But in the ordinary state of the systee quantity of waste materials by what is called _insensible perspiration_; a process which is of great importance to the preservation of health, and which is called _insensible_, because the exhalation, being in the for air, is invisible to the eye But its presence ht, by the near approach of a dry cool mirror, on the surface of which it will soon be condensed so as to become visible It is this which causes so copious deposits upon the s of a crowded school-room in cold weather A portion of these exhalations, however, proceed fros