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 primæval 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, breadfruit, 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 foodstuffs of human populations generally.
But besides the natural sweets, we have also taken to producing artificial ones. Has any housewife ever realised 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 civilised world up to 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 realise drinking honey with one’s whiskey-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 beetroot 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 creams or Everton toffee.
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 civilisation, 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 cannot 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 encloses 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 us 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