be allowed to count as something, inasmuch as the destruction or paralysis of certain of the centres leads to the total relaxation of those muscles.

(3.) It is not altogether irrelevant to cite the activity maintained by involuntary muscles as showing the existence of a mode of power originating with the nerve centres. Nervous influence is required for maintaining the breathing action, the circulation of the blood, the movement of the food along the alimentary canal, &c.; but this nervous action must evidently flow from the centres of its own accord. Even granting that when once commenced, the impression arising from one movement, is sufficient to stimulate the one that succeeds, which may be the case to some extent, as when the completed movement of expiration of the lungs initiates the succeeding inspiration, the difficulty would still present itself, How did the action commence at first? By what influence do we draw our first breath,* or set on the first stroke of the heart? If these activities cannot be kept up without the foreign assistance of nerve centres, they could not be commenced without such assistance, and in that case the nervous influence must precede, for we cannot suppose that a collapsed organ can originate the central stimulus that first sets it agoing.

Thus the notion of an initiative existing in the nerve centres is borne out not only by the tonicity, but by the more energetic action of the sphincters, and the analogy of the involuntary muscles. Seeing that the spinal cord and medulla oblongata are found capable of originating muscular contractions, we are entitled to suppose that the far larger masses that make up the brain may be the sources of a much more abundant and conspicuous activity than these examples afford. If the encephalic or mental centres are the source of movements by their own energy, without the aid of sensations and impressions from without, the phenomenon is likely to show

The power that commences respiration in the new-born infant is still undecided. I do not wish to foreclose this question, or to deny that external stimulants may come into play to produce the effect.

WAKENING FROM SLEEP.

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itself in them on a much larger scale. The proofs that follow are intended to be put in evidence of the existence of such movements.

(4) In wakening from sleep movement precedes sensation. If light were essential to the movements concerned in vision, it would be impossible to open the eyes. The act of wakening from sleep can hardly be considered in any other view, than as the reviving of the activity by a rush of nervous power to the muscles, FOLLOWED by the exposure of the senses to the influences of the outer world. I know of no circumstance that would go to show that sensation is the antecedent fact, in the case when the individual awakes of his own accord. The first symptom of awakening that presents itself is a general commotion of the frame, a number of spontaneous movements,-the stretching of the limbs, the opening of the eyes, the expansion of the features,-to all which succeeds the revival of the sensibility to outward things. Mysterious as the nature of sleep is in the present state of our knowledge, we are not precluded from remarking so notable a circumstance, as the priority of action to sensibility, at the moment of wakening.

But if this be a fact, we seem to prove, beyond a doubt, that the renewed action must originate with the nerve centres themselves. The first gestures must be stimulated from within, by a power lodged in the grey masses of the brain; afterwards they are linked with the gestures and movements suggested by sense and revived by intelligence and will. The higher degree of permanent tension in the waking muscles must be owing in part to the increased central force of the waking states, and in part to the stimulus of sensation. But in all cases, the share due to the centres must be considerable, although rendered difficult to estimate when mixed up with sensational stimulus. Thus the force that keeps the eye open throughout the day, must in some measure be due to the spontaneous energy that opened it at the waking moment, for that force does not necessarily cease when the other force, the stimulus of light, commences.

We are at liberty to suppose that the nourished condition

of the nerve centres, consequent on the night's repose, is the cause of that burst of spontaneous exertion which marks the moment of awakening. The antecedent of the activity in this case is, therefore, more physical than mental; and this must be the case with spontaneous energy in general. When linked with sensation and other mental conditions, the character of the activity is modified so as to render the spontaneity much less discernible.

(5.) The next proof is derived from the early movements of infancy. These I look upon as in great part due to the spontaneous action of the centres. The mobility displayed in the first stage of infant existence is known to be very great; and it continues to be shown in an exuberant degree all through childhood and early youth. This mobility can be attributed only to three causes. It may arise from the stimulus of sensation, that is, from the sights, sounds, contacts, temperature, &c., of outward things; in which case we should have a reflected or stimulated activity. It may, in the second place, be owing to emotion generated within the body, or states of consciousness growing out of the brain and the bodily processes generally, as when internal pains give rise to paroxysms, or high health to the lively movements of mere animal spirits. The effect may, lastly, be due to the spontaneous discharge of central vigour over all the active organs of the body, limbs, trunk, features, voice, &c.

The two first named influences, external sensation and inward emotion, are undoubted causes of active gesticulation and movement. But the question is, Do they explain the whole activity of early infancy and childhood? I think not, and on evidence such as the following. We can easily observe when any one is under the influence of vivid sensation; we can tell whether a child is affected by sights or sounds, or tastes, by seeing whether the attention is actually engaged upon such objects. And if the observation is carefully made, I believe it will be found, that although the gesticulations of infants are frequently excited by surrounding objects, there are times when such influence is very little felt, and when nevertheless the mobility of the frame is strongly manifested.

EXUBERANT ACTIVITY OF THE YOUNG.

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With regard to inward feelings, or emotions, the proof is not so easy; but here, too, there is a certain character belonging to emotional movements that serves to discriminate them when they occur. The movements, gestures, and cries of internal pain are well marked, and cannot be ascribed to the spontaneous energy of the centres; and highly pleasurable feeling is distinguished by the equally characteristic flow of smiles and extatic utterance. If there be times of active gesticulation and exercise that show no connexion with the sights and sounds, or other influence of the outer world, and that have no peculiar emotional character of the pleasurable or painful kind, we can ascribe them to nothing but the mere abundance and exuberance of self-acting muscular and cerebral energy, which will rise and fall with the vigour and nourishment of the general system.

The activity of young animals in general, and of animals, remarkable for their active endowments (as the insect tribe), may be cited as strongly favouring the hypothesis of spontaneity. When the kitten plays with a worsted ball, we always attribute the overflowing fulness of moving energy to the creature's own inward stimulus, to which the ball merely serves for a pretext. So an active young hound refreshed by sleep or rested by confinement pants for being let loose, not because of anything that attracts his view or kindles up his ear, but because a rush of activity courses through his members, rendering him uneasy till the confined energy has found vent in a chase or a run. We are at no loss to distinguish this kind of activity from that awakened by sensation or emotion, and the distinction is accordingly recognised in the modes of interpreting the movements and feelings of animals. When a rider speaks of his horse as 'fresh,' he implies that the natural activity is undischarged, and pressing for vent; the excitement caused by mixing in a chase or in a battle, is a totally different thing from the spontaneous vehemence of a full-fed and underworked animal.

It is customary in like manner to attribute much of the activity of early human life, neither to sensation nor to emotion, but to 'freshness,' or the current of undischarged activity.

There are moments when high health, natural vigour, and spontaneous outpouring, are the only obvious antecedents of ebullient activity. The very necessity of bodily exercise felt by every one, and most of all by the young, is a proof of the existence of a fund of energy that comes round with the day and presses to be discharged. Doubtless it may be said that this necessity may proceed from a state of the muscles, and not from the centres, that an uneasy craving rises periodically in the muscular tissue and is transmitted as a stimulus to the centres, awakening a nervous current of activity in return. Even if this were true, it would not materially alter the case we are labouring to establish, namely a tendency in the moving system to go into action without any antecedent sensation from without or emotion from within, or without any stimulus extraneous to the moving apparatus itself. But we do not see any ground for excluding the agency of the centres in the commencing stimulus of periodical active exercise. The same central energy that keeps up the muscular tonicity must be allowed to share in the self-originating muscular activity. If so the demand for exercise that comes round upon every actively constituted nature is a strong confirmation of the view we are now engaged in maintaining.

Coupling together, therefore, the initial movements of infancy, the mobility of early years generally, the observations on young and active members of the brute creation, and the craving for exercise universally manifested, we have a strong body of evidence in favour of the doctrine of spontaneous

action.

(6.) The mode of activity shown under states of excitement is in perfect consistency with the present doctrine. We find that excitement causes an unusual degree of activity, in fact an almost uncontrollable discharge of energy and power, as if the nervous centres were rendered incontinent and profuse by some temporary alteration in their nature. Whatever may be the way that the excited condition has been worked up-and there are very many ways-the character of it can be most accurately expressed by saying that there is an extraordinary discharge of active force from the brain towards the bodily