Rural Hygiene Part 16

There are two points to be noted in an animal about to be killed, namely, whether the animal is healthy, that is, free from disease,--and whether it is in proper condition, neither too young nor too old, is well-grown and well-nourished. Among the diseases to which animals are subject, some are objectionable because of the possibility of the direct transmission of their disease to those eating the flesh, while others are objectionable because the flesh is spoiled and so causes irritation in the stomach and intestines of those eating it. Among the former diseases may be mentioned trichinosis, tuberculosis, and measles of pigs. In the latter category are animals suffering from such diseases as epidemic pneumonia, foot-and-mouth disease, Texas fever, anthrax, hog cholera, and others in which a general toxic condition of the animal's system results from the disease. Toxins are thus formed in the body which may pa.s.s to the human being eating the flesh, and in this way poisons called ptomaines are produced, resulting in so-called toxic poisoning. It is not the function of this book to describe the symptoms peculiar to each of these diseases, and it is here sufficient to say that the flesh of no animal apparently suffering from any disease should be used for food.

The unhealthy animal can usually be recognized by a casual examination, without undertaking to define the specific disease from which the animal is suffering, characterized by such an examination. When sick, according to Parkes, the coat of the animal is rough or standing, the nostrils are dry or covered with foam, the eyes are heavy, the tongue protrudes, the respiration is difficult, the movements are slow and uncertain, and the various organs of the body perform their functions abnormally. On the other hand, the healthy animal moves freely, has a bright eye and moist nostril and a clear skin, the respiration is not hurried and the breath has no unpleasant odor, the circulation is tranquil, and the appet.i.te good, thirst not excessive, and, if ruminant, when in repose, chews the cud.

There is, however, one exception to this general rule, and that is in the case of tuberculosis, since the most scientific observations have failed to trace any connection between the inception of tuberculosis in man and the eating of meat from tuberculous animals, or to show any evil effects to man from eating the flesh of cows affected in the first stages of tuberculosis. The regulations of the United States Department of Agriculture on this point are as follows:----

"All carca.s.ses affected with tuberculosis and showing emaciation shall be condemned. All other carca.s.ses affected with tuberculosis shall be condemned, except those in which the lesions are slight, calcified, or encapsulated, and are confined to certain tissues ... and excepting also those which may ... be rendered into lard or tallow."

The regulations referred to say in substance that when the lesions occur in a single part of the body, as in the neck, liver, lungs, or in certain specified combinations, the meat may be used; but that where the lesions affect more than one or two parts of the body, the carca.s.s must be rendered at a temperature of not less than 220 degrees Fahrenheit for four hours into lard or tallow.

This really means that an animal only slightly affected with tuberculosis, where the lesions are slight and are confined to the tissues of certain organs only, may be used for food. This has been decided only after very careful reading of all known facts, and is particularly important in view of the opposition to the use of milk of tuberculous cows. The tuberculin test, on which depends the determination of tuberculosis in cows, is so delicate that a very slight lesion is sufficient to cause a reaction. The lesions are so slight as in many cases to be entirely overlooked by the ordinary butcher. The United States regulations allow such a carca.s.s to be butchered and used for food after the cow has been condemned by the tuberculin test as a milk-producing animal. This does not mean, of course, that those parts of the body affected by the tuberculosis lesions shall be used, but, since these lesions are usually segregated, they can readily be cut out without reference to the rest of the body.

The other point to be noted in selecting or rejecting animals for slaughter is their general condition. This means that they should be of the proper weight,--that is, not emaciated, but with a proper amount of fat,--that the flesh should be firm and elastic and the skin supple. Nor should they be either too young or too old. A prominent example of the first error is in the sale of calves under three weeks old, known as "bob-veal," and while some sanitarians will not object to eating calves under three weeks old, the consensus of opinion is that to be fit for food a calf should be at least that age. Fortunately, it is for the interest of the butcher to hold the calf until it has arrived at a certain weight, and the stringent laws of most states prohibiting the sale of bob-veal make it dangerous and expensive for the farmer to slaughter young calves unless they are of the right age.

The most common example of the direct transmission of disease from animals to men is through the development of the parasite in a pig, known as "trichinosis." This disease is due to a minute worm scarcely visible to the naked eye which lives in the muscles of men, dogs, swine, and other animals, and also under other conditions in their intestines.

Millions of the young trichinae may live in the flesh of a pig without producing any particular difference in the appearance of the flesh.

After four or five weeks, they become incased in small white spherical capsules which later, after a year or so, become entirely calcified. In this form they live for years in the flesh of the pig and do no harm in that condition. If, however, this flesh be eaten by man without being cooked so thoroughly as to destroy the little worm (about one twenty-fifth of an inch long) which has been living in these capsules, then they become distributed around the stomach of the person eating that flesh, enter the intestines, and attach themselves to the membranes there. They grow very rapidly, and broods of from 500 to 1000 young worms are produced from each one of the entering worms, and, since there may be a quarter of a million or more in an ounce of pork, it is not surprising that the total number deposited in the intestines from a single meal of raw pork is enough to produce great distress, characterized by vomiting and diarrhea. Fortunately, the disease is not necessarily serious, since after the development of the young worms (and it is at this period when the suffering of the human patient is at its height), the worms begin to form capsules again, as in the pig, and when inclosed, are again inocuous. Professor Sedgwick says that persons in robust health may be able to survive the attack of half a million or more of these flesh worms and recover, but there is a limit to human endurance, and the numbers often contained in the muscles of man from this source are almost incredible. In some severe cases, the numbers contained in human bodies have been estimated by reliable authorities to be as high as forty to sixty millions. Not long ago, the writer was impressed with the severity of this disease by having brought to his attention an epidemic in a herd of swine caused, presumably, by feeding waste which contained rinds of Western pork, infected with trichinae and many examples may be found of regular epidemics caused by persons eating raw ham infected with this disease. Fortunately the means of prevention is very simple and implies merely the thorough cooking of the meat. If persons will avoid eating raw or underdone swine flesh in any of its varieties, no danger need be apprehended.

In general, it should be remembered that any animals dying of diseases are not fit for food, and this applies to all animals, from the largest to the smallest. Animals dying by accident, of course, are exceptions, but if diseased animals, animals dying a natural death, and animals out of condition are eliminated, the quality of food supplied from any individual farm may be approved so far as the animal itself is concerned.

_The slaughter-house._

There is, however, the further question of the sanitary condition of the slaughter-house and the care of the meat after being dressed. It may be that one gets accustomed to the sight of the filthy barns or out-houses so often used for slaughtering. Places infected with flies and other insects, overrun with rats, and the effluvia of which is easily noticeable at a distance of half a mile, are not uncommon and suggest their own condemnation. While it is not possible to directly a.s.sociate any particular disease with such a condition of the slaughter-house, yet such conditions must result in a rapid development of putrefactive bacteria, in the deposit by flies of different micro-organisms brought from the festering heaps of offal and manure in the vicinity, and must prevent the maintenance of the flesh in the clean and wholesome condition in which it may have been up to the time of hanging in such a place. A well-kept slaughter-house will have the ceilings, side walls, and part.i.tions frequently painted, or else scrubbed and washed. The floor of the building, particularly, should be made water-tight, with proper drains so that the blood shall not remain on the floor to saturate the wood and develop decay. An abundance of clean water should be provided, so that the area may be thoroughly washed as often as used, with proper drains provided for carrying away the dirty water. The ventilation of the building should be complete, and provision should be made for lifting and moving carca.s.ses without handling.

In most small slaughter-houses, the obnoxious practice prevails of maintaining a herd of swine to consume the entrails of the slaughtered animals, and a more fearsome and disgusting spectacle than a dozen lean, active hogs fighting over recently deposited entrails and wallowing up to their bellies in filth can hardly be imagined. Nor is this any fanciful picture. The writer has seen it over and over again, the income from the hogs thus fed being one of the princ.i.p.al a.s.sets of the establishment. Such hog meat is not fit for food. The refuse from the slaughter-house ought to be carried away and buried; its fertilizing value will not be lost if it be put in the garden, and the effect of the prompt removal of this refuse will be to improve the character of the entire slaughter-house.

CHAPTER XII

_FOODS AND BEVERAGES_

Before discussing the question of suitable foods for individual needs or the ill-health which is so likely to follow an unrestrained or unwise diet, it will be well to trace briefly the pa.s.sage of food through the human body, with the various changes which take place in its ma.s.s from the time it enters the mouth _until_ it is absorbed by the stomach.

_The human mechanism._

In a little book by Hough and Sedgwick ent.i.tled "The Human Mechanism,"

the authors point out that in many respects the human body is like any machine developing energy by the conversion of certain kinds of raw material. Thus, as the steam engine will use up coal in the development of mechanical energy, so the human body will absorb food and convert it into vital energy, and it is quite as important that the human body shall have its source of energy properly adjusted to its needs as that the steam engine shall be fired with coal possessing a reasonable amount of heat-producing particles.

The human body requires this supply of raw material for several different purposes. In the first place, the very fact of living uses up each minute a number of cells of various kinds in various organs. Each breath taken, each heart beat, each muscular motion, all tend to the destruction of tissue and involve its reconstruction. Violent exercise uses up cell tissue very rapidly, so much so that a football player will commonly lose from five to ten pounds in weight during a well-contested game. It is a fundamental principle of training for any athletic event involving hard exercise, that suitable food in large quant.i.ties must be provided, and a young man training for football or rowing will eat beefsteak, eggs, and other hearty food to an astonis.h.i.+ng amount, all of it going chiefly to repairing worn-out and used-up tissue.

In the second place, food is needed to supply material for growth, and so it is that a growing boy eats out of all proportion to his size, and the fact that he seems to be, as it is said, hollow clear to his feet, is only his rational endeavor to supply the material needed for his growing body.

In the third place, food must be supplied for the work to be done by the body, as distinguished from the loss of tissue due to the performance of the work, and finally, food must be provided in order to maintain the bodily temperature, a larger amount being naturally required where the difference between the temperature of the body and the outside air is very great, as in the Arctic regions.

The human body being a special kind of machine, the raw material supplied must be adapted to the needs of the machine, and while a lump of coal admirably supplies energy for a steam boiler, no one would think of feeding a lump of coal to a human being, simply because, by experience, we know that suitable energy is not thereby developed. In the matter of suitability of foods, much depends upon the local supply.

It is not to be supposed, for example, that the Eskimos eat meat and fat altogether because it is the best article of food for them, but rather because it is the only food available. It would be foolish to prescribe fresh fruit or even white bread for the Eskimos because it is out of the question for them to get such food. But, in general, it is possible for the average individual to choose his supply of raw material in accordance with the needs which his experience has pointed out and with the teachings of scientific investigators on this subject. Raw material, however, is not converted into energy by any simple operation. The human body is made capable of taking raw material of most varied kinds and transforming it into nutriment capable of being absorbed by the system and made over into cell tissue. It will be worth while to indicate the steps of this complex process.

_Digestive processes._

The mouth plays the first part in the scheme of transformation, and here two operations are performed. First the food is crushed and ground by the teeth, exactly as when, in some chemical processes, a fine grinding is essential for the subsequent transformation. In this country, this preliminary process is often sadly neglected, so much so that a distinguished investigator, named Horace Fletcher, has, within the last few years, established a school for the cultivation of the habit of chewing, with the idea that if this practice could be encouraged and at least twenty chews taken with every mouthful, the health of the individual would be vastly improved and sick persons even cured merely through this practice.

The other function of the mouth is to mix with the food the saliva which drops from small glands in the back of the mouth into the food.

The action of the saliva is partly to lubricate the food, so that it will slip down easily, and no better proof of this can be found than trying to eat a cracker rapidly without chewing. But it also acts on starch which is not digested easily unless mixed with this ferment. The action of the saliva on starch is to convert it into sugar, which is easily absorbed later on. Curiously enough, most persons would be more apt to chew a piece of meat thoroughly than to chew a piece of bread, and yet the meat contains practically no starch and therefore does not need the action of the saliva, whereas bread is chiefly made up of starch and therefore needs the saliva as an essential for digestion.

The food then pa.s.ses down into the stomach, which is a sort of storehouse, preparatory to the really important steps in digestion.

Here, the food is acted upon by another element known as gastric juice, which is supplied by small glands found in the membrane of the stomach.

The mixture of food and gastric juice is made very thorough by the continual agitation of the food, so that the ma.s.s is softened as well as thoroughly mixed. The effect of the gastric juice is to act upon that portion of food known as proteids. Examples of almost pure proteids are found in the fiber of beef and other meat, in the yolk of eggs, and in cheese. Some vegetables, such as peas, also contain large quant.i.ties, and coa.r.s.e flour and oatmeal contain considerable percentages. The effect of the gastric juice on this proteid matter is to break up the complex molecules into small molecules which then pa.s.s into solution, making the ma.s.s leaving the stomach a uniformly mixed semiliquid substance of about the consistency of thick pea soup. The food then enters the smaller intestine, at the beginning of which the juices from the pancreas are added. The pancreas is a gland which furnishes a strongly alkaline liquid neutralizing the acid of the gastric juice, so that the gastric agent, pepsin, loses its power. From this gland comes a material which can act on all kinds of food and which is by far the most important of the digestive juices.

When thoroughly mixed with the bile and pancreatic juice, the contents of the intestine are gradually absorbed, in so far as their condition allows, by the surface of that organ and are carried away by the ducts designed for that purpose to the various organs, while that part not suited for absorption is eliminated.

_Teachings of the digestive operations._

The matter of hygienic eating, therefore, consists in supplying the various organs, the mouth, the stomach, and the smaller intestine with proper food in proper quant.i.ty, so that the body itself may be properly nourished from the food supplied. A great deal of scientific investigation in this connection has been made to ascertain any relation which may exist between the different kinds of food and their availability for the body. Scientists have divided all food into four cla.s.ses, namely, proteids, carbohydrates, fats, and inorganic salts, and they have agreed on the following general statements with reference to these four cla.s.ses. Examples of almost pure proteids have already been given, and it may here be added that carbohydrates are typically shown by the starchy particles found in potatoes or wheat. Chemically, the difference consists in the fact that proteids contain nitrogen whereas carbohydrates do not. Fats are self-explanatory, and the group of inorganic salts includes such material as salt, lime, phosphates, and other minerals needed by the body but not requiring digestion.

Just what function each one of these four groups plays in the nutrition of the human body is not definitely understood, but it seems that the proteids are particularly useful in building up cell tissue, that the carbohydrates are particularly useful in providing for muscular energy, that the fats are particularly useful in keeping up the normal warmth rather more by laying on a blanket of fat over the bones than in actually consuming the food in the creation of heat. These statements are not absolute, since experiments have shown that some tissue-building can go on even if proteids are rigorously excluded from the diet, and on the other hand that muscular work, while accompanied by a large consumption of carbohydrates in the body, may come from proteids entirely. This may explain why men can live and even do a reasonable amount of work eating meat and fat altogether, as in the Arctic regions, or dry bread and fruit in other regions, the above facts being complicated by the influence of muscular exercise on the activity of the digestive system.

No principle of hygiene is better established than that men undergoing hard physical exercise need and will take care of a larger amount of coa.r.s.e food than those occupied in sedentary work. In cold weather what is required is not really more fat as food, but more food. It has been found that there is a limit to the amount of meat food which the body can absorb, and, further, that the excess is not easily disposed of, as with starchy food, and tends to load up the liver and other organs with the waste products, resulting in general disturbances of the whole body.

It is commonly known, for instance, that high-livers, as they are called, are likely to be troubled with diseases like indigestion, rheumatism, or gout,--diseases which are the result of overburdening those organs just mentioned.

_Balanced rations._

TABLE XVI

==================================+====================================== WEIGHT IN GRAMMES CONDITION +-----------+-----------+-------------- Proteid Fat Carbohydrates ----------------------------------+-----------+-----------+-------------- Child up to 1-1/2 years (average) 0.71-1.27 1.06-1.59 2.12-3.18 Child from 6 to 15 years (average) 2.47-2.82 1.30-1.76 8.82-14.10 Man (moderate work) 4.16 1.98 17.63 Woman (moderate work) 3.24 1.55 14.10 Old man 3.53 2.40 12.34 Old woman 2.82 1.76 9.18 At.w.a.ter (man, light exercise) 3.70 3.70 13.3 Chittenden (man, light exercise) 2.16 2.83 13.0 ==================================+===========+===========+==============

A well-designed food ration, therefore, will be one which will provide the body with the proper amount of food material wisely adjusted to the occupation and the digestive ability of the individual. It has been, in the past, a matter of very exact computation to determine how many ounces of proteid food, how many ounces of starchy food, and how many of fatty foods should be consumed during the day, and experiments have been made in asylums, prisons, and on companies of soldiers with a view to proving the theoretical figures.

It has always been found that an overdose of proteids results in inability to absorb the excess, and it has been a.s.sumed that a ratio of proteids to carbohydrates of one to four is approximately the proper proportion. For instance, Koenig (1888) shows the minimum daily need of food stuffs at different ages and two American authorities, At.w.a.ter and Chittenden, have also laid down standards; all three being shown in the preceding table.

The following table taken from Rough and Sedgwick's book, already referred to, gives the percentage composition of some of the more common foods:--

TABLE XVII

============+=======+=========+========+=======+======+====== Water Proteid Starch Sugar Fat Salts ------------+-------+---------+--------+-------+------+------ Bread 37 8 47 3 1 2 Wheat flour 15 11 66 4.2 2 1.7 Oatmeal 15 12.6 58 5.4 5.6 3 Rice 13 6 79 0.4 0.7 0.5 Peas 15 23 55 2 2 2 Potatoes 75 2 18 3 0.2 0.7 Milk 86 4 -- 5 4 0.8 Cheese 37 33 -- -- 24 5 Lean beef 72 19 -- -- 3 1 Fat beef 51 14 -- -- 29 1 Mutton 72 18 -- -- 5 1 Veal 63 16 -- -- 16 1 White Fish 78 18 -- -- 3 1 Salmon 77 16 -- -- 5.5 1.5 Egg 74 14 -- -- 10.5 1.5 b.u.t.ter 15 -- -- -- 83 3 ============+=======+=========+========+=======+======+======

It will be noted that meats, cheese, and such vegetables as peas are high in proteids, while certain other vegetables, as rice and white flour, are high in starch or carbohydrates. According to the table given above, a man at moderate work requires 4.1 ounces of proteids and 17.5 ounces of carbohydrates per day. If, then, the carbohydrates were to be made up entirely from potatoes, 18 per cent of which is starch and he should need 17.5 ounces, he must have 100/18 of 17.5 or 97 ounces of potatoes per day, an amount equal to about 6 pounds. If, however, with the potatoes, he should eat half a pound of bread, of which about half is carbohydrates or 8 ounces, the amount of potato necessary would be cut down, and so on with as many combinations as one might choose to make.

It is curious, however, that when different kinds of food are available, one naturally combines different articles of food, so as to make up the well-balanced daily ration, so that the different parts may have the proper proportion. For instance, b.u.t.ter is always used with bread in order to add to the proteid and starch of the bread the necessary fat.

With potatoes or rice, either b.u.t.ter or gravy or meat is always used because potatoes and rice are lacking in proteids as well as in fats which the meat supplies. Bread and cheese are well known to make up a good combination, and the table shows why: the bread furnis.h.i.+ng the starch and the cheese the proteid and fat. Eggs alone are a very poor article of diet since no starch at all is present, and therefore it is that when eggs are eaten for breakfast, as is so generally the custom to-day, either a generous helping of cereal ought to be given with the egg or else a generous supply of bread or toast ought to be included in the breakfast. Milk is generally considered an ideal article of food, and yet it contains no starch, and it is undoubtedly because of this fact that milk and bread is more palatable as well as more nutritious than milk alone.

_Human appet.i.te._

One other factor needs to be considered in this matter of selecting one's daily food, and that is the respect which must be paid to the appet.i.te. The most carefully balanced ration will fail to satisfy the ordinary human being unless it is served attractively and unless sufficient variety is provided. To be sure, soldiers in the army are furnished a carefully computed ration consisting of so much meat, either fresh or salt, so much bread, and so much vegetable food, and the variety being small, the soldier has to put up with his dislike to the same food day after day. The need of fresh vegetables has been proved by the results of a continuous diet of salty food on certain cla.s.ses of men, such as sailors.

It is well known that a failure to provide fruit or fresh vegetables results in the disease known as scurvy, for which, practically, the only cure is a changed diet. The writer has no doubt but that in many farmhouses a very similar condition, perhaps not so p.r.o.nounced, exists on account of this very lack of variety in the daily menu. He remembers to this day a week's experience in the house of a well-to-do farmer in the early spring when the winter vegetables were exhausted and before summer vegetables appeared, when the dishes offered three times a day throughout the week were salt pork in milk sauce and boiled potatoes.