The Physiology of Taste Part 5

The sensation of taste is a chemical operation, produced by humidity. That is to say, the savorous particles must be dissolved in some fluid, so as to be subsequently absorbed by the nervous tubes, feelers, or tendrils, which cover the interior of the gastatory apparatus.

This system, whether true or not, is sustained by physical and almost palpable proofs.

Pure water creates no sensation, because it contains no sapid particle. Dissolve, however, a grain of salt, or infuse a few drops of vinegar, and there will be sensation.

Other drinks, on the contrary, create sensation because they are neither more nor less than liquids filled with appreciable particles.

It would be in vain for the mouth to fill itself with the divided particles of an insoluble body. The tongue would feel by touch the sensation of their presence, but not that of taste.

In relation to solid and savorous bodies, it is necessary in the first place for the teeth to divide them, that the saliva and other tasting fluids to imbibe them, and that the tongue press them against the palate, so as to express a juice, which, when sufficiently saturated by the degastory tendrils, deliver to the substance the pa.s.sport it requires for admission into the stomach.

This system, which will yet receive other developments, replies without effort to the princ.i.p.al questions which may present themselves.

If we demand what is understood by sapid bodies, we reply that it is every thing that has flavor, which is soluble, and fit to be absorbed by the organ of taste.

If asked how a sapid body acts, we reply that it acts when it is reduced to such a state of dissolution that it enters the cavities made to receive it.

In a word, nothing is sapid but what is already or nearly dissolved.

FLAVORS.

The number of flavors is infinite, for every soluble body has a peculiar flavor, like none other.

Flavors are also modified by their simple, double, or multiple aggregation. It is impossible to make any description, either of the most pleasant or of the most unpleasant, of the raspberry or of colocynth. All who have tried to do so have failed.

This result should not amaze us, for being gifted with an infinite variety of simple flavors, which mixture modifies to such a number and to such a quant.i.ty, a new language would he needed to express their effects, and mountains of folios to describe them. Numerical character alone could label them.

Now, as yet, no flavor has ever been appreciated with rigorous exactness, we have been forced to be satisfied with a limited number of expressions such as SWEET, SUGARY, ACID, BITTER, and similar ones, which, when ultimately a.n.a.lyzed, are expressed by the two following AGREEABLE and DISAGREEABLE, which suffice to make us understood, and indicate the flavor of the sapid substances referred to.

Those who come after us will know more, for doubtless chemistry will reveal the causes or primitive elements of flavors.

INFLUENCE OF SMELLING ON THE TASTE.

The order I marked out for myself has insensibly led me to the moment to render to smell the rights which belong to it, and to recognise the important services it renders to taste and the application of flavors. Among the authors I have met with, I recognise none as having done full justice to it.

For my own part, I am not only persuaded that without the interposition of the organs of smell, there would be no complete degustation, and that the taste and the sense of smell form but one sense, of which the mouth is the laboratory and the nose the chimney; or to speak more exactly, that one tastes tactile substances, and the other exhalations.

This may be vigorously defended; yet as I do not wish to establish a school, I venture on it only to give my readers a subject of thought, and to show that I have carefully looked over the subject of which I write. Now I continue my demonstration of the importance of the sense of smell, if not as a const.i.tuent portion of taste, at least as a necessary adjunct.

All sapid bodies are necessarily odorous, and therefore belong as well to the empire of the one as of the other sense.

We eat nothing without seeing this, more or less plainly. The nose plays the part of sentinel, and always cries "WHO GOES THERE?"

Close the nose, and the taste is paralyzed; a thing proved by three experiments any one can make:

1. When the nasal membrane is irritated by a violent coryza (cold in the head) the taste is entirely obliterated. There is no taste in anything we swallow, yet the tongue is in its normal state.

2. If we close the nose when we eat, we are amazed to see how obscure and imperfect the sense of touch is. The most disgusting medicines thus are swallowed almost without taste.

3. The same effect is observed if, as soon as we have swallowed, instead of restoring the tongue to its usual place, it be kept detached from the palate. Thus the circulation of the air is intercepted, the organs of smell are not touched, and there is no taste.

These effects have the same cause, from the fact that the sense of smell does not co-operate with the taste. The sapid body is appreciated only on account of the juice, and not for the odorous gas which emanates from it.

a.n.a.lYSIS OF THE SENSATION OF TASTE.

Principles being thus determined, I look on it as certain that taste has given place to sensations of three different orders, viz: DIRECT, COMPLETE and REFLECTED.

Direct sensation is the first perception emanating from the intermediate organs of the mouth, during the time that the sapid body rests on the tongue.

Complete sensation is that composed of the first impression which is created when the food abandons this first position, pa.s.ses into the back of the mouth, and impresses all the organ with both taste and perfume.

Reflected sensation is the judgment which conveys to the soul the impressions transmitted to it by the organ.

Let us put this system in action by observing what takes place when a man either eats or drinks. Let a man, for instance, eat a peach, and he will first be agreeably impressed by the odor which emanates from it. He places it in his mouth, and acid and fresh flavors induce him to continue. Not, though, until he has swallowed it, does the perfume reveal itself, nor does he till then discover the peculiar flavor of every variety. Some time is necessary for any gourmet [Footnote: Any gentleman or lady, who may please, is at perfect liberty to translate the word gourmet into any other tongue. I cannot. As much may be said of gourmand.- -TRANSLATOR.] to say, "It is good, pa.s.sable, or bad. It is Chambertin, or something else."

It may then be seen that in obedience to principles and practice well understood, true amateurs sip their wine. Every mouthful thus gives them the sum total of pleasure which they would not have enjoyed had they swallowed it at once.

The same thing takes place, with however much more energy, when the taste is disagreeably affected.

Just look at the patient of some doctor who prescribes immense doses of black medicine, such as were given during the reign of Louis XIV.

The sense of smell, like a faithful counsellor, foretells its character. The eyes expand as they do at the approach of danger; disgust is on the lips and the stomach at once rebells. He is however besought to take courage, gurgles his throat with brandy, closes his nose and swallows.

As long as the odious compound fills the mouth and stuns the organ it is tolerable, but when it has been swallowed the after drops develop themselves, nauseous odors arise, and every feature of the patient expresses horror and disgust, which the fear of death alone could induce him to bear.

If the draught be on the contrary merely insipid, as for instance a gla.s.s of water, there is neither taste nor after taste. Nothing is felt, nothing is experienced, it is swallowed, and all is over.

ORDER OF THE IMPRESSIONS OF TASTE.

Taste is not so richly endowed as the hearing; the latter can appreciate and compare many sounds at once; the taste on the contrary is simple in its action; that is to say it cannot be sensible to two flavors at once.

It may though be doubled and multipled by succession, that is to say that in the act of swallowing there may be a second and even a third sensation, each of which gradually grows weaker and weaker and which are designated by the words AFTER-TASTE, perfume or fragrance. Thus when a chord is struck, one ear exercises and discharges many series of consonances, the number of which is not as yet perfectly known.

Those who eat quickly and without attention, do not discern impressions of the second degree. They belong only to a certain number of the elect, and by the means of these second sensations only can be cla.s.sed the different substances submitted to their examination.

These fugitive shadows for a long time vibrate in the organ of taste. The professors, beyond doubt, always a.s.sume an appropriate position, and when they give their opinions they always do so with expanded nostrils, and with their necks protruded far as they can go.

ENJOYMENTS DUE TO THE TASTE.

Let us now look philosophically at the pleasure and pain occasioned by taste.

The first thing we become convinced of is that man is organized so as to be far more sensible of pain than of pleasure.

In fact the imbibing of acid or bitter substances subjects us to sensations more or less painful, according to their degree. It is said that the cause of the rapid effects of hydrocyanic acid is that the pain is so great as to be unbearable by the powers of vitality.

The scale of agreeable sensations on the other hand is very limited, and if there, be a sensible difference between the insipid and that which flatters the taste, the interval is not so great between the good and the excellent. The following example proves this:--FIRST TERM a Bouilli dry and hard. SECOND TERM a piece of veal. THIRD TERM a pheasant done to a turn.

Of all the senses though with which we have been endowed by nature, the taste is the one, which all things considered, procures us the most enjoyments.