The Chemistry of Food and Nutrition - Part 3
Library

Part 3

Food Adjuncts and Drugs.--In addition to the nutrients and the small quant.i.ty of indigestible fibre of which we have already written, food generally contains small quant.i.ties of substances which are difficult to cla.s.sify, and whose action on the body is but imperfectly understood. Many of these possess pungent or strong odours and flavours. To them, various fruits, meats, etc., owe much of their characteristic differences of taste. When pure the proteids and starches are devoid of taste. Such oils and fats as are generally eaten have also but little flavour, providing they are free from rancidity and of good quality. The sugars differ from the other nutrients in possessing a more or less decided taste. The free vegetable acids also strongly affect the sense of taste, but they are only consumed in small quant.i.ties.

A drug may be defined as a substance which modifies the functions of the body or of some organ without sensibly imparting nourishment. This action may be one of stimulation or of depression. A drug is taken for its medicinal action, a food adjunct for its modifying action on food. It is impossible to give a quite satisfactory definition, or to draw sharp distinctions. For example, tea, coffee, alcohol and tobacco are sometimes placed in one group, and sometimes in another, according to opinion of their action and the definition of the terms food adjuncts, drugs and poisons. The difference of grouping often depends upon intensity rather than of kind of action. If taken frequently and not in quant.i.ty sufficient to have a markedly medicinal action, such things are generally called food adjuncts or supplementary foods, although much may be said in favour of a different view. The volatile oils of mustard, caraway, cloves, etc., are used in medicine; also the alkaloids of coffee and cocoa. Even honey is used as a mild laxative for infants; that is, as a drug. The difference between a drug and a poison is one only of degree. Some of the most esteemed drugs have to be administered in very small quant.i.ties, or they cause death; e.g., strychnine and morphine.

Cla.s.sifications are necessary for methodical study, and for a.s.sisting the memory in grasping large numbers of things which can be grouped together.

Cla.s.sifications, however, are artificial, not due to natural lines of demarkation, but according to man's knowledge and convenience; hence a group is apt to approach and finally merge into another group, although on first consideration they appeared quite distinct. The disregard of this often leads to confusion and useless discussions.

Plants, like animals, as the result of tissue change, have certain used-up or waste matters to get out of the way. Animals have special excretory organs for the purpose; waste matter remains in the flesh and blood of dead animals. In plants are found a large number of powerful volatile oils, alkaloids, bitter resins, etc. Many of these are, in all probability, excretory products of no a.s.similative value to the plant.

Certain volatile oils may attract insects, and in obtaining nectar from flowers insects a.s.sist fertilisation. Agreeable volatile oils and flavouring substances in fruits attract birds and animals. The eating of the fruits cause the seeds, which are uninjured by pa.s.sing through the digestive system, to be disseminated over wide areas to the advantage of the plant species. On the other hand, nauseous and poisonous alkaloids, oils, resins, etc., serve as a protection against the attacks of browsing animals, birds, caterpillars, snails, etc. These nauseous substances are most abundant in the bark, husk, skin and outer parts. It is commonly supposed that the food on which each animal, including man, subsists, is especially produced by Nature for the purpose. This is an error, for each species of plant and animal lives for itself alone, and protects itself, with more or less success, against destruction by its compet.i.tors and enemies. Each species of animal selects from its surroundings such food as is most suitable. Such food may not be theoretically perfect; that is, it may not contain the maximum of nourishment free from innutritious matter; but during the long period of evolution, each species of animal has become possessed of organs suited to its environment. If to such animals be given food containing less indigestible matter, or food which is more readily digested by laboratory tests made independently of the living animal, their digestive system will be thrown out of gear, become clogged up or refuse to work properly, just as the furnace of a steam boiler, made to burn coal, will act badly with wood or petroleum. Many scientific men have overlooked this fact, and have endeavoured to produce food substances for general consumption, in the most concentrated and soluble form, thinking such food would be more easily a.s.similated.

The Volatile and Essential Oils are contained in minute quant.i.ty in a very large number of animal and vegetable foods. They contribute in part to the flavour of fruits. They are the cause of the pungency and aroma of mustard, horse-radish, cloves, nutmegs, cinnamon, caraway seeds, mint, sage and other spices. Onions contain a notable quant.i.ty. When extracted the essential oils become powerful drugs. In moderate quant.i.ties they are stomachic and carminative, in larger quant.i.ties irritant and emetic.

Condiments and spices not only add flavour to food, but stimulate the secretion of gastric juice and peristaltic movement.

The Alkaloids most used are those of tea, coffee, kola-nut, cocoa, coca, tobacco and opium. Although the two last are generally smoked, they must be cla.s.sed amongst the food adjuncts. It is of little consequence whether their active principles enter the body by the mouth and saliva or the lungs; their action on the blood and nervous system is the same.

The Extractives, as they are called, comprise a number of bodies of varying nature. They especially exist in flesh and flesh extracts. Amongst these are the purins. They will be treated at greater length hereafter.

Alcohol is to some extent a true food, but its stimulant and other action quite overshadows any food value it may possess.

There are other bodies such as the resins and bitters. The active principle of Indian hemp is a resin.

There is a great difference of opinion as to the extent to which stimulants may advantageously be used. It is remarkable that amongst nearly all nations, either alcohol in some form or one of the stronger alkaloids is in common use. From this fact it is sometimes argued that stimulants must supply a physiological need. The same method of reasoning will apply with greater force to the use of condiments. Such conclusions appear to us to be scarcely warranted. If the extensive or even universal practice of a thing proves its necessity, then has there been justification, either now or in the past, for war, lying, avarice and other vices. It is strange that drugs differing so greatly in their immediate and obvious effects as, for example, alcohol and opium, or coffee and tobacco should be used. Should it he said that only some of the much used stimulants are useful, there is an end to the argument based on their universal use. There is no doubt that the use of stimulants in more than very small quant.i.ties is distinctly injurious, and it is difficult to see what physiological advantage there can be in their habitual use, to what is vaguely called a moderate extent. Sometimes they are taken for a supposed medical necessity, and where taste attracts, little evidence satisfies. Those in the habit of taking them, if honest, must confess that it is chiefly on account of the apparent enjoyment. The ill-nourished and the depressed in body and mind crave most for stimulants. A food creates energy in the body, including the nervous system, and this is the only legitimate form of stimulation. A mere stimulant does not create but draws on the reserve forces. What was latent energy--to become in the natural course gradually available--under stimulation is rapidly set free; there is consequently, subsequent depletion of energy. There may occasionally be times when a particular organ needs a temporary stimulus to increased action, notwithstanding it may suffer an after depression; but such cases are so rare that they may be left out of our present argument, and stimulants should only be used, like other powerful drugs, under medical advice. In the last 25 years the use of alcohol by the medical profession has steadily diminished, its poisonous properties having become more evident.

There is a general similarity in the effects of stimulants on the digestive and nervous systems. The most largely used stimulant is ethyl alcohol, and as its action is best known, it may be useful to name the princ.i.p.al effects. Alcohol in the form of wine and spirits, in small quant.i.ties, first stimulates the digestive organs. Large quant.i.ties inflame the stomach and stop digestion. (Beer, however, r.e.t.a.r.ds digestion, altogether out of proportion to the alcohol it contains.) Alcohol increases the action of the heart, increases the blood pressure, and causes the vessels of the whole body to dilate, especially those of the skin; hence there is a feeling of warmth. It the person previously felt cold he now feels warm. The result of the increased circulation through the various organs is that they work with greater vigour, hence the mental faculties are brightened for a time, and the muscular strength seems increased. The person usually feels the better for it, though this is not always the case; some have a headache or feel very sleepy. It has been repeatedly proved that these good results are but transitory. The heart, although at first stimulated, is more exhausted after the action of the alcohol has pa.s.sed away than it was at first. This is true of all the organs of the body which were stimulated. In consequence of the dilatation of the blood vessels of the skin, an unusual quant.i.ty of heat is lost and the body is cooled. After taking alcohol persons are less able to stand cold. When overtaken by snowstorms or subjected to excessive or prolonged cold, it has often happened that those who resorted to spirit drinking have succ.u.mbed, whilst the others have survived. Insurance statistics have conclusively shown that teetotallers are longer livers than the so-called moderate drinkers. The terrible effects on both body and mind of the excessive drinking of alcohol, or the use of other strong stimulants or narcotics, are too obvious to need allusion to here; we are only concerned with what is vaguely called their moderate use.

The stimulation produced by tea and coffee is in some respects like that of alcohol. The heart is stimulated and the blood pressure rises. The kidneys are strongly affected in those unaccustomed to the drug, but this ceases after a week or more of use. Their chief effect is on the brain and nervous system.

Many have boasted that they can take of what they call the good things of life to their full, without any bad effect, and looking over a few years, or even many years, it seems a fact. Some of us have known of such men, who have been esteemed for their joviality and good nature, who have suddenly broken down at what should have been a hearty middle life. On the other hand there are men who were badly equipped for the battle of life, with indifferent const.i.tutions, who never had the buoyancy and overflow of animal spirits, but who with care have long outlived all their formerly more robust but careless companions.

Simple versus Highly-flavoured Foods.--It is very difficult to decide to what extent condiments and flavourings should be used. These have stimulating properties, although differing from the more complex properties of alcohol and the alkaloids. The great differences in the dietetic practices of nations does not appear to be in conformity with any general rule. It varies with opportunity, climate and national temperament; though doubtless the national temperament is often due in part to the dietetic habits. Some races are content with the simplest foods, large numbers subsist chiefly on rice, others on the richer cereals, wheat, oatmeal, etc., and fruit. On the other hand there are races who enjoy stronger flavoured food, including such things as garlic, curry, pickles, pepper, strong cheese, meat extracts, rancid fats, dried and smoked fish, high game or still more decomposed flesh, offal and various disgusting things. The Greenlanders will eat with the keenest appet.i.te, the half-frozen, half-putrid head and fins of the seal, after it has been preserved under the gra.s.s of summer. In Burmah and Sumatra a mess is made by pounding together prawns, shrimps, or any cheap fish; this is frequently allowed to become partially putrid. It is largely used as a condiment for mixing with their rice. Numerous examples of this sort could be given. There is scarcely anything that it is possible to eat, but has been consumed with relish by some tribe or other. The strongest flavoured, and to our minds most disgusting foods are eaten by the least intelligent and most brutal races. It is hunger that compels the poor African bushman to eat anything he can get, and the Hottentot not only the flesh, but the entrails of cattle which die naturally, and this last he has come to think exquisite when boiled in beast-blood. All this shows a wonderful range of adaptability in the human body, but it would not be right to say that all such food is equally wholesome. The most advanced and civilised races, especially the more delicately organised of them are the most fastidious, whilst it is the most brutal, that take the most rank and strongly flavoured foods. Even amongst the civilised there are great differences.

The a.s.similative and nervous systems can be trained to tolerate injurious influences to a remarkable degree. A striking example is seen in the nausea commonly produced by the first pipe of tobacco, and the way the body may in time be persuaded, not only to tolerate many times such a quant.i.ty without manifesting any unpleasant feelings, but to receive pleasure from the drug. Opium or laudanum may be taken in gradually increasing quant.i.ties, until such a dose is taken as would at first have produced death, yet now without causing any immediate or very apparent harm. Nearly all drugs loose much of their first effect on continued use.

Not only is this so, but a sudden discontinuance of a drug may cause distress, as the body, when free from the artificial stimulation to which it has become habituated, falls into a sluggish or torpid condition. For the enjoyment of food two things are equally necessary, a healthy and keen appet.i.te and suitable food; without the first no food, however good and skilfully prepared, will give satisfaction. The sense of taste resides in certain of the papilloe of the tongue, and to a much less degree in the palate. Tastes may be cla.s.sified into sweet, bitter, acid and saline.

Sweet tastes are best appreciated by the tip, acid by the side, and bitter by the back of the tongue. Hot or pungent substances produce sensations of general feeling, which obscure any strictly gustatory sensations which may be present at the same time. To affect the taste the food must enter into solution. Like the other senses, taste may be rendered more delicate by cultivation. Flavours are really odours, and the word smell would be more appropriate. For example, what we call the taste of an onion, the flavour of fruit, etc. (independent of the sweetness or sourness of the fruit) is due to the nose.

Much has been written on the necessity of making food tasty, so as to stimulate the appet.i.te and digestion. It is urged that unless this is done food will not be eaten in sufficient quant.i.ty. Innumerable receipts (some very elaborate) have been published for this purpose. All this is supposed to increase the enjoyment of food. The Anglo-Saxon race--the race whose dietary is the most elaborate--is especially subject to digestive derangements, and without good digestion and the consequent healthy appet.i.te, no food will give full gustatory pleasure. The most wholesome food, and that which can be eaten most frequently without weariness, is mildly flavoured and simply prepared. Plain bread is an example; whereas sweet bread, currant bread, etc., though agreeable in small quant.i.ty, or as an occasional delicacy, soon palls on the appet.i.te. Rice is the poorest and mildest flavoured of the cereals, it is therefore often, perhaps generally, made more tasty by the addition of fish, curry, etc. The bulk of the Chinese live on rice, with the exception of only 3 or 4 ounces of fish per day, and they are a fine, big and strong race. The j.a.panese labourer lives on similar food. In India rice is the food most in use, though many other cereals are eaten there. Other races live chiefly on fruits. It appears that the digestive organs will perform their functions perfectly with the mildest flavoured food. There is nothing surprising in this. The strongest, most intelligent, and largest animals are those which feed on gra.s.s, herbs and fruits. Even the African lion is no match for the gorilla. The lion and tiger are capable of great strength, but they cannot put it forth for long periods as can the herbivora. Our most useful animal, the horse, can exert much more muscular energy, weight for weight, than any of the carnivora. The cost of feeding one of the herbivora is much less than that of one of the carnivora of the same weight. This is so whether we take the cost of purchasing the food; or the expenditure of time, labour and energy on the part of man or of natural forces in the production of the food. Herbs, roots, corn and fruit are produced much more abundantly and freely than the corresponding quant.i.ty of sheep, deer, etc., on which the carnivora feed.

The restlessness, craving for novelty, and love of excitement, so characteristic of the Anglo-Saxon, and to a less extent of some other European races, has its correspondence in the food of these races.

Highly-seasoned and nitrogenous foods act as a stimulant and favour spasmodic, and for a time perhaps, great intellectual and physical exertion, with a succeeding period of exhaustion. Simpler food favours long, sustained, uniform muscular strength, clearness of intellect, and contentment. Let no one misunderstand us; we do not a.s.sert that all who live on simple food have either clear intellects or are contented, because there are other factors besides food, but that such qualities are more easily retained or obtained under that condition. It is well known that the over-fed and badly fed are the most irritable and discontented Those living on a stimulating dietary consisting largely of flesh have their chief successes in feats of short duration. Simple and abstemious living individuals or races excel in laborious work requiring endurance over long periods, such as long walking, cycling, and other athletic feats and long military campaigns.

The digestive and a.s.similative organs need the food const.i.tuents of which we have written, in proper proportion and quant.i.ty, and in a fairly digestible condition. Within these very wide and comprehensive limits, the organs can be trained. Very much of the great difference in food is due to the non-essential flavouring and stimulating part, rather than to that part which is essential and nourishing. What is the best, interests but few; whilst what is at present the pleasantest, influences the many. The ego, the superphysical conscious and reasoning ent.i.ty should rule its material body, its temporary vehicle. The body, being the servant of the ego, just as a horse, dog, or other of the lower animals recognises its master, becomes a docile subject. The body can be led into good habits nearly as easily as into bad ones; often more easily, as bad habits are sometimes painfully acquired. The body being once habituated to certain movements, conditions, foods or drinks, within reasonable limits, derives pleasure therefrom and resists change. It is only when the food, etc., transgresses certain elementary principles, that the result is more or less painful. We may on scientific principles condemn flesh-foods, stimulants and elaborately prepared foods; but after ruling all this out, there is still left a very great variety of foods and methods of preparing them: hereon each individual must form his own opinion. Of the foods thus left, the same kind is not equally suitable to everyone, nor even to the same person at different periods.

A delicately balanced, fine-grained, high-toned mind and body responds to every tender influence, and is painfully jarred by that which is coa.r.s.e.

To such, fruits and delicately flavoured and easily digested foods are doubtless best and conducive to purity and clearness of thought. A coa.r.s.e-grained, badly poised, roughly working body and spirit, is non-responsive except to loud or coa.r.s.e impulses; and such a one's appet.i.te is gratified, not by simple but by coa.r.s.ely seasoned foods.

A person who is accustomed to a stimulating dietary of flesh-foods, especially if well-seasoned, finds a simple diet unsatisfying. Should such persons dine off simple vegetarian food, there is a tendency to over-eating. The less stimulating food fails to rouse the digestive organs and to appease the appet.i.te; although an ample supply of nourishment be consumed. This is the reason why so many imagine that it is necessary to eat a larger quant.i.ty of food if it be vegetable. Should a distressing fulness and flatulence result from their over-feeding, they lay the blame to the vegetarian dietary instead of to themselves. Most persons, on changing to a vegetarian dietary, commence by imitating flesh dishes in appearance and flavour and even in the names. There is the additional inducement that the food may be attractive and palatable to friends who lack sympathy with the aesthetic and humane principles of the diet. After a while many of them incline to simpler flavoured foods. They revert to the unperverted taste of childhood, for children love sweets, fruits, and mild-flavoured foods rather than savouries. One who loves savouries, as a rule, cares much less for fruits. By compounding and cooking, a very great variety of foods can be prepared, but the differences in taste are much less than is usually, supposed. The effect of seasoning instead of increasing the range, diminishes it, by dulling the finer perception of flavours. The predominating seasoning also obscures everything else. The mixture of foods produces a conglomeration of tastes in which any particular or distinct flavours are obscured, resulting in a general sameness. It is often stated that as an ordinary flesh-eater has the choice of a greater range of foods and flavours than a vegetarian, he can obtain more enjoyment, and that the latter is disagreeably restricted.

Certainly he has the choice, but does he avail himself of it to any considerable extent? No one cares to take all the different kinds of food, whether of animal or vegetable that are possible. Of edible animals but a very few kinds are eaten. A person who particularly relishes and partakes largely of flesh-foods will reject as insipid and unsatisfying many mild-flavoured foods at one end of the scale. The vegetarian may abstain from foods at the opposite end of the scale, not always from humane reasons, but because they are unpleasant. Thus there may be little to choose between the mere range of flavours that give enjoyment to each cla.s.s of persons. The sense of taste is in its character and range lower than the sense of sight and hearing. The cultivation of the taste for savouries seems to blunt the taste for fruits and the delicate foods. The gra.s.s and herbs on which the herbivora subsist, seems to our imagination of little flavour and monotonous; but they eat with every sign of enjoyment, deliberately munching their food as though to get its full flavour. In all probability they find a considerable range of flavours in the great varieties of gra.s.ses commonly found together in a pasture.

Our elaborate cooking customs entail a vast amount of labour. They necessitate the cost, trouble and dirt from having fires in great excess of that required for warmth: the extra time in preparing, mixing and attending to food which has to be cooked: and the large number of greasy and soiled utensils which have to be cleaned. Cooked savoury food is generally much nicer eaten hot, and this necessitates fires and attention just previous to the meal. We have already said that soft cooked food discourages mastication and leads to defective teeth. Our elaborate cookery is mainly due to our custom of eating so largely of flesh, whilst the eating of flesh would receive a great impetus on the discovery of the art of cooking. Flesh can only be eaten with relish and with safety when cooked. Such a large proportion of it is infected with parasites, or is otherwise diseased, that it would he dangerous to eat it raw, even were it palatable in such a state. In those countries where man eats flesh in a raw or semi-cooked form, parasitic diseases are common. There is not the least doubt that our habit of eating so much cooked food is responsible for much over-eating, hasty eating, dyspepsia and illness. In regard to the making of bread, porridge, and many other comparatively simple prepared foods, the advantages of cooking seem overwhelmingly great. With our present imperfect knowledge and conflicting opinions, it is impossible to arrive at any satisfactory conclusion, and the whole question requires careful and impartial investigation. Experiments have been made with animals, chiefly pigs, with cooked and uncooked clover, hay, corn, meal, etc. (U.S. Department of Agriculture). It was found that the food was more or less diminished in digestibility by cooking. At least 13 separate series of experiments with pigs in different part of the country have been reported. In 10 of these trials there has been a positive loss from cooking the food. The amount of food required to produce in the animal a pound gain in weight was larger when the food had been cooked than when it was given raw. In some cases, the increased quant.i.ty of food required after cooking was considerable.

Those who live on uncooked food contend that a smaller quant.i.ty of nourishment is required. As uncooked food requires more mastication and is eaten more slowly, there is a better flow of saliva and time is given for the digestive organs to be gradually brought into complete action, and finally for the appeasing of the appet.i.te. In the case of the members of the fruitarian family, whose food was uncooked, and of whom we have previously written, the quant.i.ty of nutriment taken was much less than that thought necessary, even after making full allowance for their small stature and weight.

Meat Extracts.--Justus von Liebig, the great German chemist, was the first to attempt to make these on the commercial scale. He described a method in 1847, and this not proving satisfactory, another one in 1865. He stated that the only practicable plan on a manufacturing scale, was to treat the chopped flesh with eight to ten times its weight of water, which was to be raised to 180 F. In another pa.s.sage he says it is to be boiled for half-an-hour. After straining from all the undissolved meat fibre, etc., and carefully cleansing from all fat, the decoction is to be evaporated to a soft extract; such a preparation is practically free from alb.u.min, gelatin and fat; all the nutritive principles except the saline matter having been extracted. Liebig states that 34 pounds of meat are required to produce 1 pound of extract. In 1872, he wrote "neither tea nor extract of meat are nutritive in the ordinary sense," and he went on to speak of their medicinal properties. Druit, in 1861, in describing the effect of a liquid preparation of meat, states that it exerted a rapid and stimulating action on the brain, and he proposed it as an auxiliary and partial subst.i.tute for brandy, in all case of great exhaustion or weakness attended with cerebral depression or despondency. In like manner, a feast of animal food in savages, whose customary diet was almost exclusively vegetable, has been described by travellers as producing great excitement and stimulation similar to that of intoxicating spirits. Similar effects have been observed from a copious employment of Liebig's extract. Voit a.s.serts, from the results of his experiments, that extract of meat is practically useless as a food, and other authorities are quite of the same opinion, although they may value it as a stimulant and drug. _The Extra Pharmacopaeia_, 1901, states that "Liebig's Extract or Lemco consists of creatin, creatinin, globulin and urea, with organic potash and other salts. It has been much over-estimated as a food either for invalids or healthy persons; still it is often valuable as a flavouring to add to soups, beef-tea, etc., and it is a nerve food allied to tea." Meat extracts stimulate the action of the heart and the digestive processes, but as in the case of other stimulants there is a succeeding period of depression. The _British Medical Journal_ says that the widespread belief in the universal suitability of concentrated beef-tea is frequently responsible for increasing the patient's discomfort, and is even capable in conditions of kidney inefficiency, of producing positive harm. Some of the meat bases, the leucomaines, have been found to possess marked poisonous effects on the body. The manfacturers of meat extracts continue to mislead the public by absurdly false statements of the value of their products. They a.s.sert that their extracts contain the nutritive matter of 30, 40 or 50 times their weight of fresh meat, or that one or two meat-lozenges are sufficient for a meal. One company, a.s.serts by direct statement, or imply by pictorial advertis.e.m.e.nt, that the nutritive matter in an ox can be concentrated into the bulk of a bottle of extract; and another company that a tea-cup full is equivalent in food value to an ox.

Professor Halliburton writes: "Instead of an ox in a tea-cup, the ox's urine in a tea-cup would be much nearer the fact, for the meat extract consists largely of products on the way to urea, which more nearly resemble in const.i.tution the urine than they do the flesh of the ox."

Professor Robert Bartholow has also stated that the chemical composition of beef-tea closely resembles urine, and is more an excrement.i.tious substance than a food. Those whose business it is to make a pure meat-broth, for the purpose of preparing therefrom a nutrient for experimenting with bacteria, cannot fail to recognise its similarity both in odour and colour to urine. Little consideration is needful to show the untruthfulness and the absurdity of the statements made by manufacturers as to the food value of these extracts. Fresh lean beef contains about 25 per cent. of solid nutriment and 75 per cent. of water. If lean beef be desiccated, one pound will be reduced to four ounces of perfectly dry substance; this will consist of about 80 per cent. of proteid matter and nearly 20 per cent. of fat including a little saline matter and the extractives. This is as far as it is possible to concentrate the beef. If it were possible to remove, without interfering with the nutritious const.i.tuents, the membraneous matter, the creatin, creatinine and purin bodies, we should reduce it to a little less than four ounces. It is very remarkable that the most nutritious matter of the beef, the muscle substance or proteid and the fat, are rejected in making Liebig's extract, whilst the effete or waste products are retained. In Bovril and some other preparations, some meat fibre has been added with the object of imparting a definite food value. Hence in some advertis.e.m.e.nts, now withdrawn, it was alleged that the preparations were immensely superior in nutritive value to ordinary meat extracts. The Bovril Company extensively circulated the following:--"It is hard for ladies to realise that the beef tea they make at home from the choicest fresh beef contains absolutely no nourishment and is nothing more than a slight stimulant. It is so, however, and many a patient has been starved on beef tea, whether made from fresh beef or from the meat extracts that are sold to the public. From these Bovril differs so much that one ounce of its nutritious const.i.tuents contains more real and direct nourishment than fifty ounces of ordinary meat extract." If a.n.a.lyses of meat extracts are referred to, it will be seen that the princ.i.p.al part of Bovril is the meat bases and other things common to all such extracts, and which the Company in their circular so emphatically condemn. If the meat fibre, which is the princ.i.p.al, if not the sole difference, is the only nourishing const.i.tuent, it is difficult to see the advantage over ordinary beef, which can be procured at a very small proportionate cost. Concerning this added meat fibre, C.A. Mitch.e.l.l, in "Flesh Foods," writes: "As this amounts to at most some 8 or 10 per cent., it is obvious that a large quant.i.ty of the substance would be required to obtain as much unaltered proteid as is contained in an egg. On the other hand, it has been pointed out that there is nothing to show that flesh powder suspended in meat extract is more digestible than ordinary flesh in the same fine state of division, whilst the amount of flesh bases, the princ.i.p.al stimulating agents, is correspondingly reduced." Concerning added alb.u.min and meat fibre, A.H. Allen, in "Commercial Organic a.n.a.lysis," vol. iv., writes: "The amount of these const.i.tuents present in such a quant.i.ty of meat extract as is usually, or could be, taken at a time, is too insignificant to give it any appreciable value as nutriment."

Notwithstanding such statements by a.n.a.lysts and others, Bovril is advertised to contain "the entire nourishment of prime ox-beef." The great extent of the extract of meat trade is shown by a circular issued by the Lemco and Oxo Company. They give the number of their cattle killed since 1865 as 5,550,000; stock of cattle 160,000; employees in works, farms and branches, 3,200. This is only one out of many such companies. It is a sad thing that myriads of animals should be slaughtered with all the horrible and brutalising surroundings of the slaughter-house to such a purpose--the nutritious matter being nearly all wasted. Reliance on these extracts is responsible for much sickness and death. Instead of their preventing colds, influenza, and other complaints as is professed, they predispose to them by overloading the body with waste products, taxing the excretory organs and reducing the vitality. The following a.n.a.lyses of meat extracts are by Otto Hehner:--

Gela- Albu- Meat Water. Fat. tin. min. Fibre.

Liebig Co.'s Extractum Carnis 15.26 0.34 5.18 -- 2.12 Armour's Extract of Meat 15.97 0.21 3.31 -- -- Brand & Co.'s Extractum Carnis 17.85 0.38 4.56 -- 1.81 Brand & Co.'s Meat Juice 55.48 0.10 0.69 1.00 -- Brand & Co.'s Essence of Beef 89.68 0.06 5.12 -- -- Valentine's Meat juice 55.53 0.10 0.75 0.25 -- Bovril Company's Fluid Beef 28.34 1.02 3.81 -- 5.37 Bovril for Invalids 24.34 1.07 4.56 -- 5.87

Albu- Pep- Meat moses. tones. Bases. Ash.

Liebig Co.'s Extractum Carnis 2.01 8.06 39.32 23.51 Armour's Extract of Meat 1.75 5.13 41.12 29.36 Brand & Co.'s Extractum Carnis 4.19 10.16 38.90 18.80 Brand & Co.'s Meat Juice 1.06 2.50 12.50 11.06 Brand & Co.'s Essence of Beef 0.19 0.57 3.43 1.00 Valentine's Meat juice 2.00 2.87 12.48 12.01 Bovril Company's Fluid Beef 8.38 13.18 19.38 17.67 Bovril for Invalids 5.56 6.44 34.07 16.50

Some of the "Liebig's Extract of Meat" so called, contains yeast extract; some even, is almost entirely, if not altogether made from yeast. The latter can be manufactured at a very low cost from brewers' and distillers' waste products, and there is a strong incentive for unscrupulous dealers to subst.i.tute it secretly. Artificial meat extracts prepared from yeast have the appearance and taste of meat extracts, but some, at least, have a considerably sharper flavour. In one method of manufacture common salt is added, and this renders it unfit for use in more than very small quant.i.ties as a flavouring. J. Graff has made a.n.a.lyses of ten yeast extracts, and contrasted them with meat extracts (see _a.n.a.lyst_ 1904, page 194), and says, "It will be seen that the chemical composition of yeast extract does not greatly differ from that of meat extract." Yeast extracts contain purin bodies, and are probably equally as injurious as meat extracts. Such strong and rank flavours (the odour is suggestive to us of putrefaction) should be discouraged by those who would cultivate a refined taste in food.

Flesh Bases and Waste Products.--As the result of destructive metamorphosis or the wearing out of the body, there remain certain waste products which have to be expelled as soon as is possible. Their retention and acc.u.mulation would soon produce death. A part is expelled by the lungs as carbon-dioxide, or as it is generally though less correctly termed, carbonic acid. Upon the breaking down of the complex proteid and other nitrogenous matter, the nitrogen is left in comparatively simple combinations. These effete nitrogen compounds are commonly termed flesh bases or nitrogenous extractives. They exist in small quant.i.ty in flesh meat, but are concentrated and conserved in the making of beef-tea or beef-extract. The spleen, lymphatic and other glands, and especially the liver, break these down into still simpler compounds, so that the kidneys may readily separate them from the blood, that they may pa.s.s out of the body. By far the largest part of this waste nitrogen is expelled from the bodies of men and many other mammals in the form of urea. Pure urea is an odourless transparent crystalline substance, of cooling saline taste like nitre. It is soluble in an equal volume of water, and is expelled from the body with great ease. In the herbivora the nitrogenous waste takes the form of another body called hippuric acid. The nearly solid light-coloured urinary excretion of birds and serpents consists of urates; this is uric acid in combination with alkalies. In man, in addition to the urea excreted, there is also a little hippuric and uric acid or compounds of these. Uric acid is a transparent colourless crystalline body almost insoluble in water but soluble as urates in the presence of alkalies. As deposited from urine it is of a dull red sand-like appearance, as it has a great affinity for any colouring matter that is present.

It is only possible to make a brief reference to the chief organic bases.

The xanthine bases are closely related to uric acid. Some of these occur in small quant.i.ty in the urine and animal tissues, others, such as caffeine, occur in plants. Creatine is a constant const.i.tuent of muscle substance. In fowl's flesh there is said to be 0.32 per cent., in cod-fish 0.17 per cent., and in beef 0.07 per cent. Creatinine is produced from creatine with great facility; it exists in urine. Both creatine and creatinine are readily soluble in water. A series of bases, closely allied to creatinine have been isolated from the flesh of large animals by A.

Gautier; they are known as Gautier's flesh bases. When administered to animals, these act more or less powerfully on the nerve centres, inducing sleep and in some cases causing vomiting and purging in a manner similar to the alkaloids of snake venom, but less powerfully than the ptomaines.

These bases are formed during life as a result of normal vital processes and are termed leucomaines.

Another cla.s.s of bases of an alkaloidal nature, are termed ptomaines; these differ from the leucomaines, being produced by putrefactive or bacterial agency from dead flesh. The poisoning which has occasionally resulted from the eating of sausages, pork-pies, tinned meats, etc., is due to their having contained ptomaines.

Such quant.i.ties of waste products as are produced in the healthy body are excreted with ease, but it is otherwise in certain diseases. Either specially noxious substances are produced, or the usual substances are in excessive quant.i.ty and not eliminated with sufficient rapidity; in consequence the body is poisoned. Those who eat largely of flesh, introduce into their system the excretory matter contained therein, which super-added to the excretory matter resulting from the vital processes of the body puts an unusual and unnatural strain upon the liver and kidneys.

It has been observed, that the eating of the flesh of some trapped animals has produced severe symptoms of poisoning. The pain and horror of having a limb bleeding and mangled in a most cruel steel trap, the struggles which only add to the misery, slowly being done to death during hours or even days of torture, has produced in their bodies virulent poisons. Leucomaine poisons have also been produced by the violent and prolonged exertions of an animal, fleeing from its pursuers, until its strength was completely spent. Cases are also known, where a mother nursing her infant, has given way to violent anger or other emotion, and the child at the breast has been made violently ill. We must not expect the flesh of any hunted or terrified animals to be wholesome. Animals brought in cattle ships across the Atlantic, suffer acutely. After rough weather they will often arrive in a maimed condition, some being dead. To this is added the terror and cruelty to which they are subjected whilst driven by callous drovers, often through a crowded city, to the slaughter house to which they have an instinctive dread. It is only to be expected that the dead flesh from such animals, should contain an unusually large quant.i.ty of the more poisonous flesh bases.

Purin Bodies.--The term purin has been applied to all bodies containing the nucleus C_{5}N_{4}. It comprises the xanthine group and the uric acid group of bodies. The princ.i.p.al purins are hypoxanthin, xanthin, uric acid, guanin, adenin, caffeine and theobromine. Purins in the body may either result from the wear and tear of certain cell contents, when they are called endogenous purins; or they are introduced in the food, when they are distinguished as exogenous purins. These purins are waste products and are readily converted into uric acid. The production of some uric acid by tissue change is, of course, unavoidable; but that resulting from the purins in food is under control.

An excess of uric acid is commonly a.s.sociated with gout and similar diseases. The morbid phenomena of gout are chiefly manifested in the joints and surrounding tissues. The articular cartilages become swollen, with ensuing great pain. There is an acc.u.mulation of mortar like matter about the joints. This is calcium urate (not sodium urate as is generally stated). These nodular concretions are called tophi or chalkstones.

Very many are the hypotheses which have been propounded on the cause of gout and the part played by uric acid; many have had to be discarded or greatly modified. Though much light has recently been thrown on the subject, there remains much that is obscure. The subject is one which is surrounded with great difficulties, and would not be suitable for discussion here, were it not for the following reason: Certain views on uric acid as the cause of gout and several other diseases, are at the present time being pushed to the extreme in some health journals and pamphlets. Unfortunately many of the writers have very little knowledge, either of chemistry or physiology, and treat the question as though it were a simple one that had been quite settled. Our purpose is to clear the ground to some extent, for a better understanding of its fundamentals, and to warn against dogmatism. Our remarks, however, must be brief. It is undeniable that great eaters of meat, especially if they also take liberally of alcoholic drinks, are p.r.o.ne to diseases of the liver and kidneys, about or soon after the time of middle life. Flesh meat contains relatively large quant.i.ties of purins. Purins are metabolised in the body to uric acid, about half of the uric acid produced in the body disappears as such, being disintegrated, whilst the other half remains to be excreted by the kidneys.

One view is that whilst the organs of the body can readily dispose of its endogenous uric acid, or that produced by its own tissue change, together with the small amount of uric acid derived from most foods, the organs are strained by the larger quant.i.ty introduced in flesh-food or any other food rich in purins: that there is an acc.u.mulation in the system of some of this uric acid. Vegetable foods tend to keep the blood alkaline, flesh possesses less of this property; alkalinity of the blood is thought to be favourable to the elimination of uric acid, whilst anything of an acid nature acts contrarily. Dr. Alexander Haig writes "I consider that every man who eats what is called ordinary diet with butcher's meat twice a day, and also drinks acid wine or beer, will, by the time he is 50, have acc.u.mulated 300 to 400 grains of uric acid in his tissues, and possibly much more; and about this time, owing to the large amount of uric acid in his body, he will probably be subject to attacks of some form of gout or chronic rheumatism." Dr. Haig ascribes to the presence of uric acid in the system, not only gout and rheumatism, but epilepsy, hysteria, mental and bodily depression, diseases of the liver, kidneys, brain, etc.

The opinion of the majority of eminent medical men, during recent years, is that uric acid is not a cause, but a symptom of gout, that uric acid is not an irritant to the tissues, and that it is readily excreted in the healthy subject. Some of the reasons for this latter and against the previously stated hypothesis, are as follows:--Birds very rarely suffer from gout--the nodular concretions, sometimes found about their joints and which have been ascribed to gout, are of tuberculous origin--yet their blood contains more uric acid than that of man, and the solid matter of their excretion is mainly urates. If uric acid caused gout we should expect the disease to be common in birds. It is a remarkable fact that the waste nitrogen should be excreted in the form of uric acid or urates from such widely differing cla.s.ses of animals as birds and serpents. Birds have a higher body temperature than man, they are very rapid in their movements and consume a large amount of food proportionate to their weight. They live, as it were, at high pressure. Serpents, on the other hand, have a low body temperature, they are lethargic and can live a long while without food. There is no obvious reason why some animals excrete urea and others uric acid. As uric acid is a satisfactory and unirritating form in which waste nitrogen is expelled from the body of the active alert bird, as well as from the slow moving reptile, it is surprising if a very much smaller quant.i.ty acts as a poison in man. Many physicians are convinced that uric acid is absolutely unirritating. Uratic deposits may occur to an enormous extent in gouty persons without the occurrence of any pain or paroxysms. Urates have been injected in large amounts into the bodies of animals as well as administered in their food with no toxic result whatever, or more than purely local irritation. The most careful investigations upon the excretions of persons suffering from gouty complaints, have failed to show uric acid in the excretions in excess of that in normal individuals, except during the later stage of an acute attack. There is an excess of uric acid in the blood of gouty subjects; some eminent medical men say it is in the highest degree probable, that this excess is not due to over production or deficient destruction, but to defective excretion by the kidneys. The excess may arise from failure of the uric acid to enter into combination with a suitable substance in the blood, which a.s.sists its pa.s.sage through the kidneys. Under the head of gout are cla.s.sed a number of unrelated disturbances in the gastro-intestinal tract and nutritive organs, whose sole bond of union is that they are accompanied by an excess of urates, and in well developed cases by deposits in the tissues. This is why there are so many different causes, curative treatments, theories, contradictions and vagaries in gout. There are good reasons for believing that uric acid is not in the free state in the body. In the urine it is in combination with alkalies as urates, perhaps also with some organic body.

It has been shown that the blood of the gouty is not saturated with uric acid, but can take up more, and that the alkalinity of the blood is not diminished. The excess over the normal is in many cases small; it is said to be absent in some persons, and rarely, if ever reaches the quant.i.ty found in leukaemia. Leukaemia is a disease marked by an excessive and permanent increase in the white blood corpuscles and consequent progressive anaemia. Neither does the uric acid of gout reach the quant.i.ty produced in persons whilst being fed with thymus gland (sweetbread), for medical purposes. In neither of these cases are any of the symptoms of gout present. In the urine of children, it is not unusual to find a copious precipitate of urates, yet without any observed effect on them.

The symptoms of gout point to the presence of a toxin in the blood, and it is this which produces the lesions; the deposition of urates in the joints being secondary. This poison is probably of bacterial origin, derived from decomposing faecal matter in the large intestine. This is due to faulty digestion and insufficient or defective intestinal secretions and constipation. This explains why excessive feeding, especially of proteid food, is so bad. The imperfectly digested residue of such food, when left to stagnate and become a ma.s.s of bacteria and putrefaction, gives off poisons which are absorbed in part, into the system. This bacterial poison produces headache, migraine, gouty or other symptoms. Because of the general failure of gouty persons to absorb the proper amount of nutriment from their food, they require to eat a larger quant.i.ty; this gives a further increase of faecal decomposition and thus aggravates matters. The voluminous bowel or colon of man is a legacy from remote pre-human ancestors, whose food consisted of bulky, fibrous and slowly digested vegetable matters. It was more useful then, than now that most of our food is highly cooked. About a third part of the faecal matter consists of bacteria of numerous species, though chiefly of the species known as the _bacillus coli communis_, one of the less harmful kind which is a constant inhabitant of the intestinal tract in man and animals. This species is even thought to be useful in breaking down the cellulose, which forms a part of the food of the herbivora. Flesh meat leaves a residue in which the bacteria of putrefaction find a congenial home. Poisons such as ptomaines, fatty acids and even true toxins are produced. It is believed that there exists in the colons of gouty persons, either conditions more favourable to the growth of the bacteria of putrefaction, or that they are less able to resist the effect of the poisons produced. It has generally been found that milk is a very good food for gouty patients. This seems due to its being little liable to putrefaction, the bacterial fermentation to which it is liable producing lactic acid--the souring of milk. The growth of most bacteria, particularly the putrefactive kinds are hindered or entirely stopped by acids slightly alkaline media are most favourable.

This explains how it is that milk will often stop diarrhoea.

Dr. Haig condemns pulse and some other vegetable foods, because, he says, they contain uric acid. Pulse, he states, contains twice as much as most butcher's meat. Vegetable foods, however, contain no uric acid and meat but a very small quant.i.ty. The proper term to use is purins or nucleins.

Dr. Haig has used a method of a.n.a.lysis which is quite incapable of giving correct results. Many vegetarians have accepted these figures and his deductions therefrom, and have given up the use of valuable foods in consequence. We therefore give some of the a.n.a.lyses of Dr. I. Walker Hall, from "The Purin Bodies in Food Stuffs." The determination of the purins has proved a very difficult process. Dr. Hall has devoted much time to investigating and improving the methods of others, and his figures may be accepted with confidence.

The first column of figures indicates purin bodies in parts per 1,000, the second column purin bodies in grains per pound:--

Sweet bread 10.06 70.4 Liver 2.75 19.3 Beef steak 2.07 14.5 Beef Sirloin 1.30 9.1 Ham 1.15 8.1 Chicken 1.3 9.1 Rabbit 0.97 6.3 Pork Loin 1.21 8.5 Veal loin 1.16 8.14 Mutton 0.96 6.75 Salmon 1.16 8.15 Cod 0.58 4.07 Lentils and haricots 0.64 4.16 Oatmeal 0.53 3.45 Peameal 0.39 2.54 Asparagus (cooked) 0.21 1.50 Onions 0.09 0.06 Potatoes 0.02 0.1

The following showed no traces of purins: white bread, rice, cabbage, lettuce, cauliflower and eggs. Milk showed a very small quant.i.ty, and cheese consequently must contain still less.