Popular Science Monthly/Volume 26/February 1885/Food and Feeding
|FOOD AND FEEDING.|
WHEN a man and a bear meet together casually in an American forest, it makes a great deal of difference, to the two parties concerned at least, whether the bear eats the man or the man eats the bear. We haven't the slightest difficulty in deciding afterward which of the two, in each particular case, has been the eater, and which the eaten. Here, we say, is the grizzly that ate the man; or, here is the man that smoked and dined off the hams of the grizzly. Basing our opinion upon such familiar and well-known instances, we are apt to take it for granted far too readily that between eating and being eaten, between the active and the passive voice of the verb edo, there exists necessarily a profound and impassable native antithesis. To swallow an oyster is, in our own personal histories, so very different a thing from being swallowed by a shark that we can hardly realize at first the underlying fundamental identity of eating with mere coalescence. And yet, at the very outset of the art of feeding, when the nascent animal first began to indulge in this very essential animal practice, one may fairly say that no practical difference as yet existed between the creature that ate and the creature that was eaten. After the man and the bear had finished their little meal, if one may be frankly metaphorical, it was impossible to decide whether the remaining being was the man or the bear, or which of the two had swallowed the other. The dinner having been purely mutual, the resulting animal represented both the litigants equally; just as, in cannibal New Zealand, the chief who ate up his brother chief was held naturally to inherit the goods and chattels of the vanquished and absorbed rival, whom he had thus literally and physically incorporated.
A jelly-speck, floating about at his ease in a drop of stagnant water under the field of a microscope, collides accidentally with another jelly-speck who happens to be traveling in the opposite direction across the same miniature ocean What thereupon occurs? One jelly-speck rolls itself gradually into the other, so that, instead of two, there is now one; and the united body proceeds to float away quite unconcernedly, without waiting to trouble itself for a second with the profound metaphysical question, which half of it is the original personality, and which half the devoured and digested. In these minute and very simple animals there is absolutely no division of labor between part and part; every bit of the jelly-like mass is alike head and foot and mouth and stomach. The jelly-speck has no permanent limbs, but it keeps putting forth vague arms and legs every now and then from one side or the other; and with these temporary and ever-dissolving members it crawls along merrily through its tiny drop of stagnant water. If two of the legs or arms happen to knock up casually against one another, they coalesce at once, just like two drops of water on a window-pane, or two strings of treacle slowly spreading along the surface of a plate. When the jelly-speck meets any edible thing—a bit of dead plant, a wee creature like itself, a microscopic egg—it proceeds to fold its own substance slimily around it, making, as it were, a temporary mouth for the purpose of swallowing it, and a temporary stomach for the purpose of quietly digesting and assimilating it afterward. Thus what at one moment is a foot may at the next moment become a mouth, and at the moment after that again a rudimentary stomach. The animal has no skin and no body, no outside and no inside, no distinction of parts or members, no individuality, no identity. Roll it up into one with another of its kind, and it couldn't tell you itself a minute afterward which of the two it had really been a minute before. The question of personal identity is here considerably mixed.
But as soon as we get to rather larger creatures of the same type, the antithesis between the eater and the eaten begins to assume a more definite character. The big jelly-bag approaches a good many smaller jelly-bags, microscopic plants, and other appropriate foodstuffs, and, surrounding them rapidly with its crawling arms, envelops them in its own substance, which closes behind them and gradually digests them. Everybody knows, by name at least, that revolutionary and evolutionary hero, the amoeba—the terror of theologians, the pet of professors, and the insufferable bore of the general reader. Well, this parlous and subversive little animal consists of a comparatively large mass of soft jelly, pushing forth slender lobes, like threads or fingers, from its own substance, and gliding about, by means of these tiny legs, over water-plants and other submerged surfaces. But though it can literally turn itself inside out, like a glove, it still has some faint beginnings of a mouth and stomach, for it generally takes in food and absorbs water through a particular part of its surface, where the slimy mass of its body is thinnest. Thus the amœba may be said really to eat and drink, though quite devoid of any special organs for eating or drinking.
The particular point to which I wish to draw attention here, however, is this: that even the very simplest and most primitive animals do discriminate somehow between what is eatable and what isn't. The amoeba has no eyes, no nose, no mouth, no tongue, no nerves of taste, no special means of discrimination of any kind; and yet, so long as it meets only grains of sand or bits of shell, it makes no effort in any way to swallow them; but the moment it comes across a bit of material fit for its food, it begins at once to spread its clammy fingers around the nutritious morsel. The fact is, every part of the amoeba's body apparently possesses, in a very vague form, the first beginnings of those senses which in us are specialized and confined to a single spot. And it is because of the light which the amoeba thus incidentally casts upon the nature of the specialized senses in higher animals that I have ventured once more to drag out of the private life of his native pond that already too notorious and obtrusive rhizopod.
With us lordly human beings, at the extreme opposite end in the scale of being from the microscopic jelly-specks, the art of feeding and the mechanism which provides for it have both reached a very high state of advanced perfection. We have slowly evolved a tongue and palate on the one hand, and French cooks and pâte de foie gras on the other. But while everybody knows practically how things taste to us, and which things respectively we like and dislike, comparatively few people ever recognize that the sense of taste is not merely intended as a source of gratification, but serves a useful purpose in our bodily economy, in informing us what we ought to eat and what to refuse. Paradoxical as it may sound at first to most people, nice things are, in the main, things that are good for us, and nasty things are poisonous or otherwise injurious. That we often practically find the exact contrary the case (alas!) is due, not to the provisions of nature, but to the artificial surroundings in which we live, and to the cunning way in which we flavor up unwholesome food, so as to deceive and cajole the natural palate. Yet, after all, it is a pleasant gospel that what we like is really good for us, and, when we have made some small allowances for artificial conditions, it is in the main a true one also.
The sense of taste, which in the lowest animals is diffused equally over the whole frame, is in ourselves and other higher creatures concentrated in a special part of the body, namely, the mouth, where the food about to be swallowed is chewed and otherwise prepared beforehand for the work of digestion. Now, it is, of course, quite clear that some sort of supervision must be exercised by the body over the kind of food that is going to be put into it. Common experience teaches us that prussic acid and pure opium are undesirable food-stuffs in large quantities; that raw spirits, petroleum, and red lead should be sparingly partaken of by the judicious feeder; and that even green fruit, the bitter end of cucumber, and the berries of deadly nightshade are unsatisfactory articles of diet when continuously persisted in. If, at the very outset of our digestive apparatus, we hadn't a sort of automatic premonitory adviser upon the kinds of food we ought or ought not to indulge in, we should naturally commit considerable imprudences in the way of eating and drinking—even more than we do at present. Natural selection has therefore provided us with a fairly efficient guide in this respect in the sense of taste, which is placed at the very threshold, as it were, of our digestive mechanism. It is the duty of taste to warn us against uneatable things, and to recommend to our favorable attention eatable and wholesome ones; and, on the whole, in the spite of small occasional remissness, it performs this duty with creditable success.
Taste, however, is not equally distributed over the whole surface of the tongue alike. There are three distinct regions or tracts, each of which has to perform its own special office and function. The tip of the tongue is concerned mainly with pungent and acrid tastes; the middle portion is sensitive chiefly to sweets and bitters; while the back or lower portion confines itself almost entirely to the flavors of roast meats, butter, oils, and other rich or fatty substances. There are very good reasons for this subdivision of faculties in the tongue, the object being, as it were, to make each piece of food undergo three separate examinations (like "smalls," "mods," and "greats" at Oxford), which must be successively passed before it is admitted into full participation in the human economy. The first examination, as we shall shortly see, gets rid at once of substances which would be actively and immediately destructive to the very tissues of the mouth and body; the second discriminates between poisonous and chemically harmless food-stuffs; and the third merely decides the minor question whether the particular food is likely to prove then and there wholesome or indigestible to the particular person. The sense of taste proceeds, in fact, upon the principle of gradual selection and elimination; it refuses first what is positively destructive, next what is more remotely deleterious, and finally what is only undesirable or over-luscious.
When we want to assure ourselves, by means of taste, about any unknown object—say a lump of some white stuff, which may be crystal, or glass, or alum, or borax, or quartz, or rock-salt—we put the tip of the tongue against it gingerly. If it begins to burn us, we draw it away more or less rapidly, with an accompaniment in language strictly dependent upon our personal habits and manners. The test we thus occasionally apply, even in the civilized adult state, to unknown bodies, is one that is being applied every day and all day long by children and savages. Unsophisticated humanity is constantly putting everything it sees up to its mouth in a frank spirit of experimental inquiry as to its gustatory properties. In civilized life, we find everything ready labeled and assorted for us; we comparatively seldom require to roll the contents of a suspicious bottle (in very small quantities) doubtfully upon the tongue in order to discover whether it is pale sherry or Chili vinegar, Dublin stout or mushroom ketchup. But in the savage state, from which, geologically and biologically speaking, we have only just emerged, bottles and labels do not exist. Primitive man, therefore, in his sweet simplicity, has only two modes open before him for deciding whether the things he finds are or are not strictly edible. The first thing he does is to sniff at them, and smell being, as Mr. Herbert Spencer has well put it, an anticipatory taste, generally gives him some idea of what the thing is likely to prove. The second thing he does is to pop it into his mouth, and proceed practically to examine its further characteristics.
Strictly speaking, with the tip of the tongue one can't really taste at all. If you put a small drop of honey or of oil of bitter-almonds on that part of the mouth, you will find (no doubt to your great surprise) that it produces no effect of any sort; you only taste it when it begins slowly to diffuse itself, and reaches the true tasting region in the middle distance. But, if you put a little cayenne or mustard on the same part, you will find that it bites you immediately—the experiment should be tried sparingly—while if you put it lower down in the mouth you will swallow it almost without noticing the pungency of the stimulant. The reason is, that the tip of the tongue is supplied only with nerves which are really nerves of touch, not nerves of taste proper; they belong to a totally different main branch, and they go to a different center in the brain, together with the very similar threads which supply the nerves of smell for mustard and pepper. That is why the smell and taste of these pungent substances are so much alike, as everybody must have noticed; a good sniff at a mustard-pot producing almost the same irritating effects as an incautious mouthful. As a rule, we don't accurately distinguish, it is true, between these different regions of taste in the mouth in ordinary life; but that is because we usually roll our food about instinctively, without paying much attention to the particular part affected by it. Indeed, when one is trying deliberate experiments in the subject, in order to test the varying sensitiveness of the different parts to different substances, it is necessary to keep the tongue quite dry, in order to isolate the thing you are experimenting with, and provent its spreading to all parts of the mouth together. In actual practice this result is obtained in a rather ludicrous manner—by blowing upon the tongue, between each experiment, with a pair of bellows. To such undignified expedients does the pursuit of science lead the ardent modern psychologist. Those domestic rivals of Dr. Forbes Winslow, the servants, who behold the enthusiastic investigator alternately drying his tongue in this ridiculous fashion, as if he were a blacksmith's fire, and then squeezing out a single drop of essence of pepper, vinegar, or beef-tea from a glass syringe upon the dry surface, not unnaturally arrive at the conclusion that master has gone stark-mad, and that, in their private opinion, it's the microscope and the skeleton as has done it.
Above all things, we don't want to he flayed alive. So the kinds of tastes discriminated by the tip of the tongue are the pungent, like pepper, cayenne, and mustard; the astringent, like borax and alum; the alkaline, like soda and potash; the acid, like vinegar and green fruit; and the saline, like salt and ammonia. Almost all the bodies likely to give rise to such tastes (or, more correctly, sensations of touch in the tongue) are obviously unwholesome and destructive in their character, at least when taken in large quantities. Nobody wishes to drink nitric acid by the quart. The first business of this part of the tongue is, therefore, to warn us emphatically against caustic substances and corrosive acids—against vitriol and kerosene, spirits of wine and ether, capsicums and burning leaves or roots, such as those of the common English lords-and-ladies. Things of this sort are immediately destructive to the very tissues of the tongue and palate; if taken incautiously in too large doses, they burn the skin off the roof of the mouth; and when swallowed they play havoc, of course, with our internal arrangements. It is highly advisable, therefore, to have an immediate warning of these extremely dangerous substances, at the very outset of our feeding apparatus.
This kind of taste hardly differs from touch or burning. The sensibility of the tip of the tongue is only a very slight modification of the sensibility possessed by the skin generally, and especially by the inner folds overall delicate parts of the body. We all know that common caustic burns us wherever it touches; and it burns the tongue, only in a somewhat more marked manner. Nitric or sulphuric acid attacks the fingers each after its own kind. A mustard-plaster makes us tingle almost immediately; and the action of mustard on the tongue hardly differs, except in being more instantaneous and more discriminative. Cantharides work in just the same way. If you cut a red pepper in two and rub it on your neck it will sting just as it does when put into soup (this experiment, however, is best tried upon one's younger brother; if made personally, it hardly repays the trouble and annoyance). Even vinegar and other acids, rubbed into the skin, are followed by a slight tingling; while the effect of brandy, applied, say, to the arms, is gently stimulating and pleasurable, somewhat in the same way as when normally swallowed in conjunction with the habitual seltzer. In short, most things which give rise to distinct tastes when applied to the tip of the tongue give rise to fainter sensations when applied to the skin generally. And one hardly needs to be reminded that pepper or vinegar placed (accidentally as a rule) on the inner surface of the eyelids produces a very distinct and unpleasant smart.
The fact is, the liability to be chemically affected by pungent or acid bodies is common to every part of the skin; but it is least felt where the tough outer skin is thickest, and most felt where that skin is thinnest and the nerves are most plentifully distributed near the surface. A mustard-plaster would probably fail to draw at all on one's heel or the palm of one's hand, while it is decidedly painful on one's neck or chest; and a mere speck of mustard inside the eyelid gives one positive torture for hours together. Now, the tip of the tongue is just a part of one's body specially set aside for this very object, provided with an extremely thin skin, and supplied with an immense number of nerves, on purpose so as to be easily affected by all such pungent, alkaline, or spirituous substances. Sir Wilfrid Lawson would probably conclude that it was deliberately designed by Providence to warn us against a wicked indulgence in the brandy and seltzer aforesaid.
At first sight it might seem as though there were hardly enough of such pungent and fiery things in existence to make it worth while for us to be provided with a special mechanism for guarding against them. That is true enough, no doubt, as regards our modern civilized life; though, even now, it is perhaps just as well that our children should have an internal monitor (other than conscience) to dissuade them immediately from indiscriminate indulgence in photographic chemicals, the contents of stray medicine-bottles, and the best dried West India chilies. But in an earlier period of progress, and specially in tropical countries (where the Darwinians have now decided the human race made its first début upon this or any other stage), things were very different indeed. Pungent and poisonous plants and fruits abounded on every side. We have all of us in our youth been taken in by some too cruelly waggish companion, who insisted upon making us eat the bright, glossy leaves of the common English arum, which without look pretty and juicy enough, but within are full of the concentrated essence of pungency and profanity. Well, there are hundreds of such plants, even in cold climates, to tempt the eyes and poison the veins of unsuspecting cattle or childish humanity. There is buttercup, so horribly acrid that cows carefully avoid it in their closest-cropped pastures; and yet your cow is not usually a too dainty animal. There is aconite, the deadly poison with which Dr. Lamson removed his troublesome relatives. There is baneberry, whose very name sufficiently describes its dangerous nature. There are horse-radish, and stinging rocket, and biting wall-pepper, and still smarter water-pepper, and wormwood, and nightshade, and spurge, and hemlock, and half a dozen other equally unpleasant weeds. All of these have acquired their pungent and poisonous properties, just as nettles have acquired their sting, and thistles their thorns, in order to prevent animals from browsing upon them and destroying them. And the animals in turn have acquired a very delicate sense of pungency on purpose to warn them beforehand of the existence of such dangerous and undesirable qualities in the plants which they might otherwise be tempted incautiously to swallow.
In tropical woods, where our "hairy quadrumanous ancestor" (Darwinian for the primeval monkey, from whom we are presumably descended) used playfully to disport himself, as yet unconscious of his glorious destiny as the remote progenitor of Shakespeare, Milton, and the late Mr. Peace—in tropical woods, such acrid or pungent fruits and plants are particularly common, and correspondingly annoying. The fact is, our primitive forefather and all the other monkeys are, or were, confirmed fruit-eaters. But to guard against their depredations a vast number of tropical fruits and nuts have acquired disagreeable or fiery rinds and shells, which suffice to deter the bold aggressor. It may not be nice to get your tongue burned with a root or fruit, but it is at least a great deal better than getting poisoned; and, roughly speaking, pungency in external nature exactly answers to the rough, gaudy labels which some chemists paste on bottles containing poisons. It means to say, "This fruit or leaf, if you eat it in any quantities, will kill you." That is the true explanation of capsicums, pimento, colocynth, croton-oil, the upas-tree, and the vast majority of bitter, acrid, or fiery fruits and leaves. If we had to pick up our own livelihood, as our naked ancestors had to do. from roots, seeds, and berries, we should far more readily appreciate this simple truth. We should know that a great many more plants than we now suspect are bitter or pungent, and therefore poisonous. Even in England we are familiar enough with such defenses as those possessed by the outer rind of the walnut; but the tropical cashew-nut has a rind so intensely acrid that it blisters the lips and fingers instantaneously, in the same way as cantharides would do. I believe that, on the whole, taking Nature throughout, more fruits and nuts are poisonous, or intensely bitter, or very fiery, than are sweet, luscious, and edible.
"But," says that fidgety person, the hypothetical objector (whom one always sets up for the express purpose of promptly knocking him down again), "if it be the business of the fore part of the tongue to warn us against pungent and acrid substances, how comes it that we purposely use such things as mustard, pepper, curry-powder, and vinegar?" Well, in themselves all these things are, strictly speaking, bad for us; but in small quantities they act as agreeable stimulants; and we take care in preparing most of them to get rid of the most objectionable properties. Moreover, we use them, not as foods, but merely as condiments. One drop of oil of capsicums is enough to kill a man, if taken undiluted; but in actual practice we buy it in such a very diluted form that comparatively little harm arises from using it. Still, very young children dislike all these violent stimulants, even in small quantities; they won't touch mustard, pepper, or vinegar, and they recoil at once from wine or spirits. It is only by slow degrees that we learn these unnatural tastes, as our nerves get blunted and our palates jaded; and we all know that the old Indian who can eat nothing but dry curries, deviled biscuits, anchovy paste, pepper-pot, mulligatawny soup, Worcestershire sauce, preserved ginger, hot pickles, fiery sherry, and neat cognac, is also a person with no digestion, a fragmentary liver, and very little chance of getting himself accepted by any safe and solvent insurance office. Throughout, the warning in itself is a useful one; it is we who foolishly and persistently disregard it. Alcohol, for example, tells us at once that it is bad for us; yet we manage so to dress it up with flavoring matters and dilute it with water that we overlook the fiery character of the spirit itself. But that alcohol is in itself a bad thing (when freely indulged in) has been so abundantly demonstrated in the history of mankind that it hardly needs any further proof.
The middle region of the tongue is the part with which we experience sensations of taste proper—that is to say, of sweetness and bitterness. In a healthy, natural state all sweet things are pleasant to us, and all bitters (even if combined with sherry) unpleasant. The reason for this is easy enough to understand. It carries us back at once into those primeval tropical forests where our "hairy ancestor" used to diet himself upon the fruits of the earth in due season. Now, almost all edible fruits, roots, and tubers contain sugar; and therefore the presence of sugar is, in the wild condition, as good a rough test of whether anything is good to eat as one could easily find. In fact, the argument cuts both ways: edible fruits are sweet because they are intended for man and other animals to eat; and man and other animals have a tongue pleasurably affected by sugar because sugary things in nature are for them in the highest degree edible. Our early progenitors formed their taste upon oranges, mangoes, bananas, and grapes; upon sweet-potatoes, sugar-cane, dates, and wild honey. There is scarcely anything fitted for human food in the vegetable world (and our earliest ancestors were most undoubted vegetarians) which does not contain sugar in considerable quantities. In temperate climates (where man is but a recent intruder), we have taken, it is true, to regarding wheaten bread as the staff of life; but in our native tropics enormous populations still live almost exclusively upon plantains, bananas, bread-fruit, yams, sweet-potatoes, dates, cocoanuts, melons, cassava, pineapples, and figs. Our nerves have been adapted to the circumstances of our early life as a race in tropical forests; and we still retain a marked liking for sweets of every sort. Not content with our strawberries, raspberries, gooseberries, currants, apples, pears, cherries, plums, and other northern fruits, we ransack the world for dates, figs, raisins, and oranges. Indeed, in spite of our acquired meat-eating propensities, it may be fairly said that fruits and seeds (including wheat, rice, peas, beans, and other grains and pulse) still form by far the most important element in the food-stuffs of human populations generally. But, besides the natural sweets, we have also taken to producing artificial ones. Has any housewife ever realized the alarming condition of cookery in the benighted generations before the invention of sugar? It is really almost too appalling to think about. So many things that we now look upon as all but necessaries—cakes, puddings, made dishes, confectionery, preserves, sweet biscuits, jellies, cooked fruits, tarts, and so forth—were then practically quite impossible. Fancy attempting nowadays to live a single day without sugar; no tea, no coffee, no jam, no pudding, no cake, no sweets, no hot toddy before one goes to bed; the bare idea of it is too terrible! And yet that was really the abject condition of all the civilized world up to the middle of the middle ages. Horace's punch was sugarless and lemonless; the gentle Virgil never tasted the congenial cup of afternoon tea; and Socrates went from his cradle to his grave without ever knowing the flavor of peppermint bull's-eyes. How the children managed to spend their Saturday as, or their weekly obolus, is a profound mystery. To be sure, people had honey; but honey is rare, dear, and scanty; it can never have filled one quarter the place that sugar fills in our modern affections. Try for a moment to realize drinking honey with one's whisky-and-water, or doing the year's preserving with a pot of best Narbonne, and you get at once a common measure of the difference between the two as practical sweeteners. Nowadays, we get sugar from cane and beet-root in abundance, while sugar-maples and palm trees of various sorts afford a considerable supply to remoter countries. But the childhood of the little Greeks and Romans must have been absolutely unlighted by a single ray of joy from chocolate cream or Everton taffy.
The consequence of this excessive production of sweets in modern times is, of course, that we have begun to distrust the indications afforded us by the sense of taste in this particular as to the wholesomeness of various objects. We can mix sugar with anything we like, whether it had sugar in it to begin with or otherwise; and by sweetening and flavoring we can give a false palatableness to even the worst and most indigestible rubbish, such as plaster-of-Paris, largely sold under the name of sugared almonds to the ingenuous youth of two hemispheres. But in untouched nature the test rarely or never fails. As long as fruits are unripe and unfit for human food, they are green and sour; as soon as they ripen they become soft and sweet, and usually acquire some bright color as a sort of advertisement of their edibility. In the main, bar the accidents of civilization, whatever is sweet is good to eat—nay more, is meant to be eaten; it is only our own perverse folly that makes us sometimes think all nice things bad for us, and all wholesome things nasty. In a state of nature, the exact opposite is really the case. One may observe, too, that children, who are literally young savages in more senses than one, stand nearer to the primitive feeling in this respect than grown-up people. They unaffectedly like sweets; adults, who have grown more accustomed to the artificial meat diet, don't, as a rule, care much for puddings, cakes, and made dishes. (May I venture parenthetically to add, any appearance to the contrary notwithstanding, that I am not a vegetarian, and that I am far from desiring to bring down upon my devoted head the imprecation pronounced against the rash person who would rob a poor man of his beer. It is quite possible to believe that vegetarianism was the starting-point of the race, without wishing to consider it also as the goal; just as it is quite possible to regard clothes as purely artificial products of civilization, without desiring personally to return to the charming simplicity of the garden of Eden.)
Bitter things in nature at large, on the contrary, are almost invariably poisonous. Strychnia, for example, is intensely bitter, and it is well known that life can not be supported on strychnia alone for more than a few hours. Again, colocynth and aloes are far from being wholesome food-stuffs, for a continuance; and the bitter end of cucumber does not conduce to the highest standard of good living. The bitter matter in decaying apples is highly injurious when swallowed, which it isn't likely to be by anybody who ever tastes it. Wormwood and walnut-shells contain other bitter and poisonous principles; absinthe, which is made from one of them, is a favorite slow poison with the fashionable young men of Paris, who wish to escape prematurely from "le monde où l'on s'ennuie." But prussic acid is the commonest component in all natural bitters, being found in bitter-almonds, apple-pippins, the kernels of mango-stones, and many other seeds and fruits. Indeed, one may say roughly that the object of Nature generally is to prevent the actual seeds of edible fruits from being eaten and digested; and for this purpose, while she stores the pulp with sweet juices, she incloses the seed itself in hard, stony coverings, and makes it nasty with bitter essences. Eat an orange-pip, and you will promptly observe how effectual is this arrangement. As a rule, the outer rind of nuts is bitter, and the inner kernel of edible fruits. The tongue thus warns us immediately against bitter things, as being poisonous, and prevents us, automatically, from swallowing them.
"But how is it," asks our objector again, "that so many poisons are tasteless, or even, like sugar of lead, pleasant to the palate?" The answer is (you see, we knock him down again, as usual) because these poisons are themselves for the most part artificial products; they do not occur in a state of nature, at least in man's ordinary surroundings. Almost every poisonous thing that we are really liable to meet with in the wild state we are warned against at once by the sense of taste; but of course it would be absurd to suppose that natural selection could have produced a mode of warning us against poisons which have never before occurred in human experience. One might just as well expect that it should have rendered us dynamite-proof, or have given us a skin like the hide of a rhinoceros to protect ns against the future contingency of the invention of rifles.
Sweets and bitters are really almost the only tastes proper, almost the only ones discriminated by this central and truly gustatory region of the tongue and palate. Most so-called flavorings will be found on strict examination to be nothing more than mixtures with these of certain smells or else of pungent, salty, or alkaline matters, distinguished as such by the tip of the tongue. For instance, paradoxical as it sounds to say so, cinnamon has really no taste at all, but only a smell. Nobody will ever believe this on first hearing, but nothing on earth is easier than to put it to the test. Take a small piece of cinnamon, hold your nose tightly, rather high up, between the thumb and finger, and begin chewing it. You will find that it is absolutely tasteless; you are merely chewing a perfectly insipid bit of bark. Then let go your nose, and you will find immediately that it "tastes" strongly, though in reality it is only the perfume from it that you now permit to rise into the smelling-chamber in the nose. So, again, cloves have only a pungent taste and a peculiar smell, and the same is the case more or less with almost all distinctive flavorings. When you come to find of what they are made up, they consist generally of sweets or bitters, intermixed with certain ethereal perfumes, or with pungent or acid tastes, or with both or several such together. In this way, a comparatively small number of original elements, variously combined, suffice to make up the whole enormous mass of recognizably different tastes and flavors.
The third and lowest part of the tongue and throat is the seat of those peculiar tastes to which Professor Bain, the great authority upon this important philosophical subject, has given the names of relishes and disgusts. It is here, chiefly, that we taste animal food, fats, butters, oils, and the richer class of vegetables and made dishes. If we like them, we experience a sensation which may be called a relish, and which induces one to keep rolling the morsel farther down the throat, till it passes at last beyond the region of our voluntary control. If we don't like them, we get the sensation which may be called a disgust, and which is very different from the mere unpleasantness of excessively pungent or bitter things. It is far less of an intellectual and far more of a physical and emotional feeling. We say, and say rightly, of such things that we find it hard to swallow them; a something within us (of a very tangible nature) seems to rise up bodily and protest against them. As a very good example of this experience, take one's first attempt to swallow cod-liver oil. Other things may be unpleasant or unpalatable, but things of this class are in the strictest sense nasty and disgusting.
The fact is, the lower part of the tongue is supplied with nerves in close sympathy with the digestion. If the food which has been passed by the two previous examiners is found here to be simple and digestible, it is permitted to go on unchallenged; if it is found to be too rich, too bilious, or too indigestible, a protest is promptly entered against it, and if we are wise we will immediately desist from eating any more of it. It is here that the impartial tribunal of nature pronounces definitely against roast goose, mince-pies, pâte, de foie gras, sally lunn, muffins and crumpets, and creamy puddings. It is here, too, that the slightest taint in meat, milk, or butter is immediately detected; that rancid pastry from the pastrycook's is ruthlessly exposed, and that the wiles of the fishmonger are set at naught by the judicious palate. It is the special duty, in fact, of this last examiner to discover, not whether food is positively destructive, not whether it is poisonous or deleterious in nature, but merely whether it is then and there digestible or undesirable.
As our state of health varies greatly from time to time, however, so do the warnings of this last sympathetic adviser change and flicker. Sweet things are always sweet, and bitter things always bitter; vinegar is always sour, and ginger always hot in the mouth, too, whatever our state of health or feeling; but our taste for roast loin of mutton, high game, salmon cutlets, and Gorgonzola cheese varies immensely from time to time, with the passing condition of our health and digestion. In illness, and especially in sea-sickness, one gets the distaste carried to the extreme; you may eat grapes or suck an orange in the chops of the Channel, but you do not feel warmly attached to the steward who offers you a basin of greasy ox-tail, or consoles you with promises of ham-sandwiches in half a minute. Under those too painful conditions it is the very light, fresh, and stimulating things that one can most easily swallow—champagne, soda-water, strawberries, peaches, not lobster salad, sardines on toast, green Chartreuse, or hot brandy-and-water. On the other hand, in robust health, and when hungry with exercise, you can eat fat pork with relish on a Scotch hill-side, or dine off fresh salmon three days running without inconvenience. Even a Spanish stew, with plenty of garlic in it, and floating in olive-oil, tastes positively delicious after a day's mountaineering in the Pyrenees.
The healthy popular belief, still surviving in spite of cookery, that our likes and dislikes are the best guide to what is good for us, finds its justification in this fact, that whatever is relished will prove on the average wholesome, and whatever rouses disgust will prove on the whole indigestible. Nothing can be more wrong, for example, than to make children eat fat when they don't want it. A healthy child likes fat, and eats as much of it as he can get. If a child shows signs of disgust at fat, that proves that it is of a bilious temperament, and it ought never to be forced into eating it against its will. Most of us are bilious in after-life just because we were compelled to eat rich food in childhood, which we felt instinctively was unsuitable for us. We might still be indulging with impunity in thick turtle, canvas-back ducks, deviled whitebait, meringues, and Nesselrode puddings, if we hadn't been so persistently overdosed in our earlier years with things that we didn't want and knew were indigestible.
Of course, in our existing modern cookery, very few simple and uncompounded tastes are still left to us; everything is so mixed up together that only by an effort of deliberate experiment can one discover what are the special effects of special tastes upon the tongue and palate. Salt is mixed with almost everything we eat—sal sapit omnia—and pepper or cayenne is nearly equally common. Butter is put into the peas, which have been previously adulterated by being boiled with mint; and cucumber is unknown except in conjunction with oil and vinegar. This makes it comparatively difficult for us to realize the distinctness of the elements which go to make up most tastes as we actually experience them. Moreover, a great many eatable objects have hardly any taste of their own, properly speaking, but only a feeling of softness or hardness, or glutinousness in the mouth, mainly observed in the act of chewing them. For example, plain boiled rice is almost wholly insipid; but even in its plainest form salt has usually been boiled with it, and in practice we generally eat it with sugar, preserves, curry, or some other strongly flavored condiment. Again, plain boiled tapioca and sago (in water) are as nearly tasteless as anything can be; they merely yield a feeling of gumminess; but milk, in which they are oftenest cooked, gives them a relish (in the sense here restricted), and sugar, eggs, cinnamon, or nutmeg are usually added by way of flavoring. Even turbot has hardly any taste proper, except in the glutinous skin, which has a faint relish; the epicure values it rather because of its softness, its delicacy, and its light flesh. Gelatine by itself is merely very swallowable—we must mix sugar, wine, lemon-juice, and other flavorings in order to make it into good jelly. Salt, spices, essences, vanilla, vinegar, pickles, capers, ketchups, sauces, chutneys, lime-juice, curry, and all the rest, are just our civilized expedients for adding the pleasure of pungency and acidity to naturally insipid foods, by stimulating the nerves of touch in the tongue, just as sugar is our tribute to the pure gustatory sense, and oil, butter, bacon, lard, and the various fats used in frying to the sense of relish which forms the last element in our compound taste. A boiled sole is all very well when one is just convalescent, but in robust health we demand the delights of egg and bread-crumb, which are after all only the vehicle for the appetizing grease. Plain boiled macaroni may pass muster in the unsophisticated nursery, but in the pampered dining-room it requires the aid of toasted parmesan. Good modern cookery is the practical result of centuries of experience in this direction; the final flower of ages of evolution, devoted to the equalization of flavors in all human food. Think of the generations of fruitless experiment that must have passed before mankind discovered that mint-sauce (itself a cunning compound of vinegar and sugar) ought to be eaten with leg of lamb, that roast goose required a corrective in the shape of apple, and that while a pre-established harmony existed between salmon and lobster, oysters were ordained beforehand by Nature as the proper accompaniment of boiled cod! Whenever I reflect upon such things, I become at once a good Positivist, and offer up praise in my own private chapel to the Spirit of Humanity which has slowly perfected these profound rules of good living.—Cornhill Magazine.