CHAPTER III.

OF THE APPETITES.

I.

IN

N taking up at this stage the consideration of the Appetites, I do not mean to assert that these entirely belong to our primitive impulses, or that in them the operation of intellect and experience is excluded. On the contrary, I am of opinion that Appetite, being a species or form of Volition, is like all our other effective forms of volition, a combination of instinct and education. But the process of acquisition is in this case simple and short; while, on the other hand, the stimulus to action, or the source of the craving, is usually one of the sensations or feelings discussed in the two previous chapters. Indeed, if we look at the craving alone, without reference to the action for appeasing it, that craving is merely what we have all along styled the volitional property of the sensation. Accordingly there is a certain convenience in passing at once from the subject just left, to advert more particularly to this special aspect of certain of the feelings therein delineated that have their chief interest in the circumstance in question.

I have observed that all painful states (the exceptions are unimportant in the present discussion), and many pleasurable states, are volitional; the one class exciting action for appeasing and terminating them, the other for continuance or increase. If a spur to action were to constitute Appetite, all our pains and a number of our pleasures would come under this designation. But the Appetites commonly recognised are a select class of the volitional sensations and feelings; and are circumscribed by the following property,-namely, that they are the cravings produced by the recurring wants and necessities of our bodily, or organic life. The taking in of nourishment, the ejection of what is formed to be thrown out,

the supply of air, the alternation of exercise and rest, the gratification and repose of the various senses, all these operations are attended to through the prompting of uneasy sensation. The avoiding of a scald, a cut, or a fall, is an energetic impulse of volition, and yet not a case of Appetite; there being no periodic or recurring want of the system in these cases. Sleep, Exercise, Repose, Thirst, Hunger, Sex, are the appetites most universally present throughout the Animal tribes.

2. The fact of periodic recurrence is in no case more strikingly exemplified than in Sleep. After a certain period of waking activity, there supervenes an intense and massive sensation, of the nature of a craving for repose. If we give way to it at once, the state of sleep creeps over us, and we pass through a few moments of luxurious repose into unconsciousness. If we are prevented from yielding to the sleepy orgasm, its character as an appetite is brought out into strong relief. The voluminous uneasiness that possesses all the muscles and organs of sense stimulates a strong resistance to the power that keeps us awake, the uneasiness and the resistance increasing with the continued refusal of the permission to sleep, until the condition becomes intolerable, or a reaction ensues, which drives off the drowsiness for some time longer.

The overpowering influence of drowsiness is best seen in infants, there being scarcely anything that will effectually appease the mental disturbance caused by it. The strong emotions that extreme pain sets loose-tears and rage-are never more closely at hand than in the sleepy condition. In a comparison of volitional states, to ascertain their respective degrees of strength, the appetite for sleep at its highest pitch would bear the palm over nearly every form of sensation.

3. The necessity of alternating Exercise with Repose, through the entire range of our active organs, brings on the like periodic cravings and deep-seated uneasiness. The fresh condition of the muscles is of itself a sufficient stimulus to action; without any conscious end, in other words, without our willing it, action commences when the body is refreshed and invigorated. If this spontaneous outburst is resisted, an

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251

intense uneasiness or craving is felt, being one of the conscious states incident to the muscular system. This craving is of the nature of all the other appetites, and increases with privation, unless, by some organic change, the fit passes over for the time. The dog chained up to his couch, the exuberancy of childhood restrained from bursting out, the bird in its cage, the prisoner in his cell, experience all the pains and desire of the active organs for exercise. On the other hand, after exercise comes an equally powerful craving and impulse to rest, which, if resisted, produces the same intense uneasiness, until a febrile reaction ensues, and disorders the indications that the system gives respecting its wants.

Under this head of Exercise and Repose I may include the more active of our senses, that is, Touch, Hearing, and Sight. These senses all embody muscular activity along with the sensation peculiar to each; and both the muscular activity and the tactile, auditory and visual sensations, lead to weariness of the parts, with a craving for rest; while after due repose they resume the fresh condition, and crave for the renewal of their excitement. But the alternation of exercise and rest of the senses is in a great measure involved in the rotation of sleeping and waking; inasmuch as the involuntary torpor of the nervous system is almost the only means of giving repose to such constantly solicited senses as Sight, Touch, and Hearing.

A similar train of remarks might be extended to the activity of the thinking organs. But in these the periodic cravings are less distinctly marked, and more frequently erroneous than in the case of muscular exercise. There is often a reluctance to engage in thought, when the brain is perfectly vigorous and able to sustain it; and on the other hand, there is in nervous temperaments a tendency to excess of mental action, uncorrected by any regular promptings to take repose.

I may further remark, what is probably familiar to most persons, that a sense of fatigue often arises soon after commencing any laborious operation, which disappears after a time, and is not connected with real exhaustion.

4 Thirst and Hunger I have already touched upon. In

describing them as Sensations, it was impossible to omit their character as cravings. A certain amount of liquid being indispensable to every function of the system, a deficiency in this element breeds a wide-spread disorder and intolerable oppression. Not in the stomach alone, but also in the skin, in the capillary circulation, and in the various secreting organs, may we infer that the want of water rouses up sensations of distress. The prompting to seek out and imbibe liquid is correspondingly great, in spite of the enfeebling influence of the state upon the activity of the frame.

'What is called thirst is, however, sometimes rather a call for the cooling influence of cold drinks, as, for instance, in the dry, hot state of the air-passages, mouth, and skin, produced in fevers by the increased temperature and diminished turgescence of the parts. Exhalation is in such cases often rather diminished, and the dryness of the surface arises from the circumstance that although blood still flows through the capillary vessels, the reciprocal action between the blood and the living tissues, which is denominated turgescence, or turgor vitalis, is depressed.'*

Hunger, unlike Thirst, is a state of the stomach as yet not exactly understood, while the feeling of inanition that also grows out of long fasting must be considered as a general feeling of the system. The urgency of hunger ought to be in accordance with the actual deficiency of nutritive material, but very frequently the case is otherwise. It is heightened by cold baths, by friction of the skin, by friction of the abdomen, and by the agitation to which the abdomen is subjected in horse exercise, as well as by muscular exertion.' It is diminished by all nauseating influences, which probably at the same time weaken the digestion. The local sensations of hunger,' says Müller, 'which are limited to the digestive organs, and appear to have their seat in the nervous vagus, are feelings of pressure, of motion, contraction, qualmishness, with borborygmi (gripings), and finally pain.'

In the case of hunger and in most of the appetites there is

* Müller, by Baly, p. 530.

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253

a double spur to the taking of food; first, the stimulus of uneasiness, and next the impulse arising out of the pleasure of eating. It is well understood that these two things are quite different, for on their difference hangs the whole art of refined cookery. Very plain food would satisfy the craving for nutrition, but there is a superadded pleasure that we have to cater for. The one is the appetite in its strictest signification, and as found in the lower animals; the other I might call a desire, because it supposes the remembrance and anticipation of a positive pleasure, like the desire for music, or for knowledge.

It is in the act of taking food and drink that we best see exemplified the activity springing out of the sensations of hunger and thirst. The actual assuaging of the uneasiness produces an intense pleasurable sensation that sets on the most vigorous movements for being continued and increased; while the moving organs themselves, beginning to be invigorated, display a spontaneous and lively energy in the cause. To bring together and make to cohere the sensation of the appeasing of hunger with the acts of sucking, swallowing, or prehension, is perhaps the earliest link of volition established in the animal system. This is the first case of action for an end, or under the prompting and guidance of a feeling, that the newly born infant is capable of. Eating is the most animated display of movement and action that a healthy carnivorous creature can present. There is something intensely kindling in the appetite of the carnivora for food, which rises to fury when the flesh is scented out and begins to be tasted.

Besides the natural craving for the elements of nutrition required by the tissues, we may acquire artificial cravings by the habitual use of certain forms of food, and certain accompaniments, as peppers, flavours, &c. Thus we have the alcoholic craving, the craving for animal food, for tea, coffee, &c. The use of these articles having given a peculiar tone to the stomach or the nerves, a want is felt when they are withheld; and according to the degree of uneasiness manifested is the difficulty of resisting them.