The use of animal fats as food is a very ancient custom, especially among the northern tribes. This custom was once justified owing to the necessity for the consumption of a liberal amount of fats in cold countries, but in this country where our marvelous system of international transportation places at the door of every northern home the delicious fats from the olive orchards of Italy, France, and Spain, the refined oil from the cottonseed, and more than a dozen varieties of nuts, including the humble peanut, there is but little necessity for the use of animal fats except in the form of butter and cream.

Perhaps the most injurious way in which animal fats are used is in the process of frying, which is much practised in southern countries in the preparation of other food. The chemical change which takes place in fats, when treated in this manner, renders them exceedingly indigestible, and almost wholly unfit for food.

That per cent of animal fats contained in the ordinary meat diet is quite as wholesome as any other element of nutrition secured from animal sources. However, with the splendid supply of vegetable fats civilized people have to draw upon, the use of animal fats cannot be recommended in any form except that of cream and butter, and when we consider the expense of these by comparison with many pure vegetable fats, our sense of ordinary economy would bid us discard them.

The chief distinction between animal and vegetable fats is in the proportion of olein compared with stearin and palmitin. The proportion of the two latter fats is much greater in fats of domestic animals than it is in the human body; this is especially so of tallow. For this reason vegetable fats, which are of a more liquid nature, are more desirable than those of animal origin, especially where we wish to add fatty tissue to the body.

COLD STORAGE OF MEAT

A very small amount of the meat produced in this country at the present time is consumed near its place of slaughter. Cold storage plants and refrigerator cars have been constructed for the purpose of preserving meats until they can reach their destination, and to hold them awaiting market advances for the benefit of packers and tradesmen.

Meat in cold storage is slowly undergoing a form of decomposition which is evidenced by the fact that cold storage meat decays much more rapidly upon its removal from storage than do the same cuts of fresh meat.

The process of ripening meat in rooms of varying temperatures depends upon this form of decomposition. The natural enzyms of the meat, and the bacteria contained therein, digest a portion of the proteids, forming nitrogenous decomposition products, similar to the above-mentioned meat extractives. Ripened or storage meats contain a much larger per cent of this group of compounds than does fresh meat.

The high flavor and "peculiar rich taste" of ripened meats is produced by these decomposition products, while the decay of the gelatinoid or connective tissue is the primary reason for its tenderness. There are certain species of bacteria that produce more poisonous waste-products than others, and this occasionally causes the development of ptomains in storage meat.

The use of flesh as an article of food is fraught with many serious and scientific objections, but the use of cold storage or ripened animal products is to be condemned from every standpoint of hygiene. Nevertheless, if people insist upon using flesh foods, and economical conditions make it profitable to produce them far from their place of consumption, cold storage methods seem inevitable. The choice between storage meats and home-killed is, in its last analysis, a matter of selecting the lesser of two evils.

CONTAGIOUS DIS-EASES AND ANIMAL FOOD

Much has been written as to how, from dis-eased animals, human beings have contracted contagious dis-eases, especially tuberculosis. The risk of such contagion has in all probability been much exaggerated. Flesh foods are seldom taken in an uncooked form, and dis-ease germs are usually destroyed by the sterilizing process involved in cooking. The cooking process, however, must be very thorough in order to destroy dis-ease germs; that is, the heat must be sufficient to coagulate the proteids. The interior of a rare beefsteak, such as popularly demanded by the flesh-eater, has not reached this temperature, hence this form of meat should be condemned on this ground if for no other.

Perhaps the worst form of dis-ease contamination from fresh flesh food is that of trichinosis. Trichinae are worm-like creatures which have the first stage of their growth in the flesh of swine, and then become encased in a cyst or egg-like structure, which, when taken into the human digestive organs are revived, and the trichinae then bore their way through the walls of the digestive organs, completing their growth in the human muscle-tissue. Trichinosis is one of the most fatal of diseases, but fortunately is not common. Tapeworms owe their origin to a similar source. There are several species of tapeworms; some have their origin in pork, and some in beef.

FISH

Under this heading I will consider fish and other sea-creatures.

The flesh of most fish is quite free from fat, and consists almost entirely of water and proteids. It is less concentrated than the flesh of warm-blooded animals, averaging about 18 to 20 per cent proteids, and 60 to 70 per cent water. The percentage of ash in fish is also somewhat greater than in any other flesh food. The popular idea that fish is good food for the brain originated in the fact that analysis of some fish shows a considerable percentage of phosphorus, which substance Fish as brain food is also found in the brain. There is no reason to believe, however, that the liberal use of fish would develop or produce an excess of brain-tissue. Any well-balanced diet contains ample phosphorus to nourish the brain.

The true science of human nutrition lies in the knowledge of selecting, combining, and proportioning food according to age, climate, and work. When this is done, the tendency of the body is to eliminate dis-ease and to assume normal action; this accomplished, every part of the anatomy shares in the general improvement.

My theory advanced against the use of meat because of nitrogenous decomposition products, holds true with fish, though in a somewhat limited degree. The decomposition products of cold-blooded animals are not identical with those of mammals, hence their consumption as food does not add to the percentage of human waste-products so directly as do other meats.

Oysters and clams, which are generally eaten uncooked, are recommended by many authorities as valuable sources of proteid. The serious objection to their use, and especially uncooked, is the fact that they are grown in the sea-water around harbor entrances which are flooded with sewage, and hence they are likely to be contaminated with typhoid, or similar germs. The actual food value in shell-fish is quite small. They contain only about ten per cent of proteids, and are scarcely worth considering as a source of nutrition.

POULTRY AS AN ARTICLE OF FOOD

The objections that I have made against the use of the flesh of fish and mammals as an article of food may also be assessed against the use of domestic and wild fowls. There are a few special points, however, in favor of poultry as food that are worth special consideration.

The production of chickens and other domestic poultry is one of the most prolific industries in America, and is of great importance to the general public because it is capable of being carried on in communities too thickly settled for the economic production of beef and other meats.

Another point to be observed in the use of poultry as food is that, because of the ease with which every farmer and villager can keep a flock of chickens, it is possible for him to have fresh meat produced under the most sanitary and hygienic conditions, while if he uses meat as food, he will be compelled to depend upon the various meat products of unknown age and origin, secured from the general market.

Another reason why the use of poultry, from a hygienic standpoint, is less objectionable than the use of pork and beef is that the quantity consumed is usually much smaller than the amount eaten of these heavy-blooded meats.

For example: When five pounds of beefsteak is purchased in the market, the amount consumed would be almost the full weight of the purchase. If the money were invested in a five-pound chicken, a goodly portion of this weight would be lost in preparing the fowl for the table, while a still further loss would occur in the bones and in the inedible portions, so that the actual amount of flesh consumed would not be more than perhaps two pounds.

According to the old idea of economy and diet, this would be a serious argument against the use of poultry products, but as has been clearly proved in this course of lessons, the most serious criticism that can be urged against the modern bill of fare is quantity, and especially the use of meat in large quantities, so common among the American people.

The chief reason for which meat is kept upon the bill of fare of most civilized people is that of conformity to custom, surely not to that of hygiene. That form of meat, therefore, which is pleasing to the taste, and which has a tendency to reduce the quantity of flesh consumed, is a step in the right direction of true food reform.

EFFECTS OF FEEDING POULTRY

The methods of fattening poultry by shutting them in small coops or compartments, and feeding them upon soft mushy foods, is condemned by some writers on the ground that it is unnatural and harmful to the health of the fowls, and therefore the meat cannot be wholesome. In truth, this process, if not carried too far, will produce a quality of meat less harmful than that of the barnyard and ill-fed poultry. One of the greatest objections to the use of animal food, as already explained, is the presence of the unexcreted waste-products of animal metabolism. The flesh of fowls, fed and fattened in coops, contains the smallest possible quantity of waste or decomposition products, because of the limited amount of motion or exercise they are permitted to undergo. For this reason, when poultry is to be eaten, the whiter the meat the less objectionable it is as an article of food.

The marketing of poultry in an undrawn condition (without the removal of the internal organs), has been much condemned by the public, and the legislatures of some states have passed laws against this practise. This, however, is to some extent a misapplication of good intentions. When poultry is to be killed for the market by those who thoroughly understand the business, the fowls are left without food for a period of twenty-four hours. Since the digestive processes of these small animals are very rapid, this results in emptying the intestines of most of the fecal matter, which removes the principal objection to the practise. On the other hand, if the fowls are drawn at the time of killing, and several days elapse before their consumption, bacteria gain access to the interior of the carcass and cause very rapid decomposition.

It is the practise in some oriental and European countries to "hang" poultry for a few days before they are eaten. This process, as in the case of ripened meats, is simply one of partial decay. The enzymotic action taking place in the meat is arrested only by the process of cold storage. Decomposition proceeds slowly until it reaches that point when it is pronounced high-flavored and "ripened." This is very largely practised in this country at the present time. It is a custom that is instinctively condemned by everyone from the standpoint of both hygiene and aestheticism. The people should demand and force Congress to pass a law labeling all cold storage meats with the date of slaughter, and all canned meats with the date of packing.

What is true of domestic poultry is also true of all wild game. The amount of actual food contributed to the world by the slaughter of game is exceedingly small. A similar quantity of domestic food could be produced at one-tenth the cost of time and labor, without slaughtering the wild creatures of our forests. The popularity of hunting as a sport, and the idea that the flesh of all wild animals is a rare and dainty article of diet, is merely an illustration of anthropoid inheritance. It is a step backward toward savagery instead of forward toward a higher civilization.

EGGS

Eggs and milk occupy a unique place in the catalog of foods. The purpose for which they were produced in nature throws much light upon their value as food.

As will be learned from the lesson, "Evolution of Man," no living creature exists for the sole benefit of other creatures, but because once created, the inherent struggle of all living matter to survive and to reproduce itself has evolved wonderful and various adaptations. Every organic substance is primarily produced in nature for a specific purpose in the life of its species. The lumber in our houses owes its existence to the plant's struggle for sunlight, which made it necessary for the tree to possess a strong storm-withstanding stem to hold aloft its leaves above the shade of other foliage.

The leaves and the stems of grass are primarily an essential part of the life of the plant, and not food for animals. The greater part of the human food of plant origin represents in nature the nutrient material supplied by the parent plant for the early life of the seedling. All grains, nuts, fruits and roots, and tubers are merely modified forms of food material adapted to the rapid nourishment of the young plant.

The starch and the oil of seeds, the sugar of fruit, and the lesser quantities of nitrogen contained in all seeds, are in a more available form for cell-nourishment than would be the original mature portions of plant life.

Milk and eggs in the animal world occupy a position identical to that of seeds and fruit in the plant world; that is, they are created for the first nourishment of the offspring.

In the process of evolution, a fundamental distinction between birds and mammals is in the manner in which the young are nourished. The egg of the bird supplies sufficient nourishment to develop the young bird to a point where it can exist upon the ordinary food of the adult bird.

The hen's egg must contain all food material necessary to form all portions of the body of the chick, and to supply it for a time with heat and energy.

An average egg weighs two ounces; of this weight about 10 per cent is shell, 30 per cent yolk, and the remainder white. The white of the egg is composed of albumin and water. The yolk consists of globulin, egg-fat, and lecithin; this latter substance contains a considerable proportion of phosphorus, and is one of the essential contingents of brain and nerves. The egg-shell contains 13 per cent protein, 10 per cent fat, and one per cent ash.

The younger the animal, the more rapid is the growth of the animal body compared with the amount of energy expended. Milk and eggs not a balanced adult diet For this reason the percentage of nitrogen in milk and in eggs is much too great to form a balanced adult diet, and should be supplemented by articles containing larger proportions of heat-producing materials, preferably carbohydrates.

The proteid material of eggs is in a form especially adapted to the construction of new cells. For this reason it is one of the best known foods for use in cases of emaciation, where new tissue is to be added rapidly to the body. An egg contains about fourteen decigrams of nitrogen. Ten eggs, therefore, would supply an ample amount of nitrogen for the daily needs of the average body, were no nitrogen taken from other sources. In feeding patients who are convalescing from fevers or other wasting dis-eases, it is sometimes necessary to prescribe a diet of from ten to twelve eggs daily for a limited time.

The consumption of five eggs a day, when we rely wholly upon this article for animal proteids, is quite sufficient for one performing ordinary labor, when supplemented by one succulent and one tuber vegetable.

MILK

Milk and the various products made therefrom constitute one of the most important groups of food in the modern bill of fare. Milk and eggs are interdicted by some vegetarians, but aside from the sentimental feeling against the taking of any food of animal origin, there are no scientific reasons for such exclusion. Dairy products are free from many of the objections assessed against the use of flesh, and they supply a number of readily soluble, digestible, and assimilable nutrients that, in many respects (curative and remedial feeding), excel anything that can be secured from the vegetable kingdom.

The composition of cow's milk varies widely. Dairy cows, by long domestication, breeding and feeding, have been brought to a high state of specialization. Some breeds have been so trained, fed, and bred as to produce large quantities of milk. Some Holsteins have been known to produce one hundred pounds of milk per day each, which of course is many times the quantity required for the nourishment of their young. Some Jersey stock have been so bred, raised, and fed as to produce large quantities of butter; in some cases the butter-fat of especially fed Jerseys has been known to run as high as 8 or 10 per cent, whereas the normal fat content of milk is not more than 3.5 or 4 per cent.

The average composition of mixed milk from many cows runs about as follows: Water, 87 per cent; lactose or milk-sugar, 4.5 per cent; butter-fat, 3.5 per cent; ash, .7 per cent; proteids, 3.3 per cent, of which about 2.5 per cent are casein, and .8 per cent albumin.

The commercial value of milk is measured almost entirely by its content of butter-fat. This is because the public knows practically nothing about the food value, or the chemistry of milk, therefore its value is estimated upon that which can be seen, and upon that which tastes best. The chief value of milk as a food lies in the nitrogenous element it contains. Fat can be secured from many other sources.

The nutritive elements of milk from various animals vary according to the natural requirements of the young of various species.

Cow's milk contains too large a proportion of casein, and not enough milk-sugar to meet the natural requirements of the human infant. This subject, however, will be discussed at length in Lesson XVI on "Infant Feeding," Vol. V, p. 1154.

The casein in cow's milk is coagulated by the hydrochloric acid of the stomach, which forms into lumps or curds, rather difficult to digest. This can be overcome or counteracted in several ways. First, if milk is allowed to sour or clabber, the casein is coagulated by nature, which is really the first process of digestion. In this form it neither burdens the digestion nor causes the supersecretion of hydrochloric acid, which is likely to occur when sweet milk is too liberally used. Second, the sipping and thorough insalivation of milk, by taking it into the mouth with something that requires thorough mastication, insures better digestion and assimilation, and less liability to produce intestinal gas.

Milk will harmonize chemically with all non-acid fruits, cereals and nuts. Milk is in chemical harmony with meat and eggs, but all of these articles being highly nitrogenous, when taken at the same meal, the portions should be limited to the minimum.

Milk should not be combined with acid fruits, especially those of a highly acidulous character, such as lemons, limes, grapefruit, pineapples, etc. (See Lesson VIII, Vol. II, p. 314.) Neither should it be taken at the same meals with succulent plants, such as lettuce, watercress, romaine, parsley, etc.

When the stomach has long been over-burdened with food, and made the receptacle in which acid fermentation has taken place until the mucous membrane has become irritated or probably ulcerated, there is no food so acceptable as milk. For the common disorder of hyperchlorhydria, which is a term used to describe a condition of chronic sour stomach or supersecretion of hydrochloric acid, milk is one of Nature's best counteractive food nutrients. (See "Superacidity," Vol. II, p. 418.)

In cases of severe constipation or alimentary congestion, milk should be given as follows:

Omit breakfast. Begin about 9:30 taking an ordinary glassful of fresh, cool milk every twenty or thirty minutes, until about one and one-half quarts have been consumed. After two or three hours, repeat the same process until about two quarts more have been taken. With each quart of milk, from three to four heaping dessert-spoonfuls of clean, wheat bran should be taken, in thin cream or rich milk. At noon and at evening a few tablespoonfuls of coarse cereal (wheat or rye flakes), might be eaten. They should be masticated thoroughly, and eaten with nuts and a limited quantity of cream. Under this regimen I have known the most severe cases of constipation to yield readily, and the patient to make a gain in weight of half a pound daily for a period of from twenty to thirty days. If the appetite should rebel against taking milk in this quantity, the amount should be reduced, and a cupful of soaked evaporated apricots taken at night just before retiring, and in the morning, just after rising.

When milk is taken for the purpose of counteracting a congested condition of the bowels, or an irritated condition of the mucous membrane of the stomach, it should be combined with the fewest possible things—one coarse cereal only will give the best results. A large quantity of milk, three and one-half to four quarts taken daily, as above directed, will act as a laxative, while a small quantity will have a tendency toward constipation.

THE ADULTERATION OF MILK

The old method of adulterating milk with water has very largely gone out of practise, owing to the surveillance of city authorities, and the passing of laws that fix legal standards, which require milk to contain a certain percentage of fats and total solids.

The chief form of criminal tampering with milk has been the use of preservatives to prevent souring. Formaldehyde has been used very extensively for this purpose. Formaldehyde is a poison, destructive to all cell life, and has probably been the cause of more actual deaths than any other form of food adulteration.

MILK PASTEURIZATION

Pasteurization, which takes its name from Pasteur, the French bacteriologist, is merely a process of heating milk to about 170 degrees Fahrenheit for the purpose of destroying possible dis-ease germs, and the bacteria that produce fermentation. In this process the milk is not allowed to come to a boil for the reason that boiled milk is rather "dead" or distasteful, and would readily be detected by the public. It is quite evident that any method of Pasteurization, which would kill bacteria, would also cause coagulation of the protoplasm and the albumin of the milk, and render it much less nutritious, and much more difficult to digest.

If milk producers and dairymen understood the superior food and remedial value of naturally soured milk, and would exert some effort to educate the public in its use, they would soon establish a new and profitable industry, and would give the dairy business of the whole country a new commercial impetus. The souring of milk can be prevented by cleanliness, which renders Pasteurizing unnecessary. At the time of the Paris Exposition, a dairy farm in Illinois sent pure unpasteurized milk to Paris, which arrived in an unsoured condition. This was achieved by absolute cleanliness, with the cows, dairy utensils, etc.

CHEESE

Cheese consists of the coagulated casein of milk, together with the fat globules that may be mechanically retained. Cheese is made by coagulating the milk with rennet, which has been extracted from the stomach of a calf, the sugar of the milk being passed off in the whey, and lost.

Schmier Käse or cottage cheese is formed by allowing the milk to sour, and to coagulate by gradual warming. This cheese is usually made from skimmed milk, hence contains practically no fat.

The cheese of commerce is ripened in various ways. The process of ripening is due to the action of enzyms present in the milk, or to those formed by bacterial growth. Ripened cheese is considered to be more easily digested than the unripened product. The best that can be said of this process is that the ripening of cheese is perhaps the least objectionable of all processes of decomposition taking place in food proteids. The only benefit that can be claimed is one of flavor, and, in matters of flavor, the appetite for Limburger, and similar cheeses, is at least a cultivated taste that furnishes evidence neither of merit nor of nutrition.

In the manufacture of cheese, the milk, sugar, and a part of the albumin and fat are wasted, and as there are no advantages in taking the milk in this changed form, there exists no scientific reason for the use of cheese when fresh milk can be obtained.

BUTTER

Butter constitutes one of the most wholesome and palatable of all animal fats, and is probably one of the most extensively used articles of food of animal origin.

When the pure butter-fat has been separated from the casein of milk it can be kept sweet and wholesome for a length of time sufficient to transport it, and to pass it through the various links in the chain of commerce, so that it can reach the family table a long distance from its source of production. This, in addition to man's instinctive relish for dairy products, makes butter the most popular fat in the diet of civilized man.

In prescribing butter-fat, however, it is advisable to nominate fresh, unsalted, or what is commonly termed "sweet" butter. It is also advisable for the practitioner to suggest that this can be made daily, merely by whipping either sweet or soured cream with an ordinary rotary egg beater until the fat globules have separated from the whey.

Pure butter contains about 3,600 heat-calories to the pound, and therefore constitutes one of the most important and readily convertible of all winter foods.

If no other fat is used, about two ounces of butter each twenty-four hours is sufficient to give the ordinary body, under a temperature ranging from forty to sixty degrees above zero, the required amount of heat.

OLEOMARGARIN

Oleomargarin is a general term that includes all manufactured preparations of fats which imitate dairy butter.

Oleomargarin is manufactured by combining beef-fat with cottonseed-oil until a product is formed which has a melting point similar to that of butter. Lard is also used in some oleomargarin products. This combination of fats is then churned with either cream or milk and dairy butter is frequently added so as to give to the artificial product the pleasant flavor or odor of dairy butter. There is much popular prejudice against the use of oleomargarin, but when made under hygienic conditions, and by cleanly methods, it is practically as digestible, and quite as wholesome as the dairy product.