men is of the greatest possible service, and the warm bath will always be useful. Where, however, there exists a disposition to convulsions, the bath should not be prolonged far, or too frequently repeated, since under these circumstances, it may have a tendency to produce congestion in the vessels of the brain; it is here that the mustard foot bath will be productive of more decided advantage. But when any threatening malady exerts its influence upon the system, the eye of medical supervision is indispensable.

The temporary set of teeth commonly begin to be shed about the seventh or eighth year, and to be replaced by the permanent ones, which occupy the situations of the former. This change is generally accomplished without any constitutional distress. It often happens, that on the first teeth being pushed off, there is not sufficient room for their successors; and in order to prevent great deformities at this period, the mouth should be frequently inspected by a professional dentist; especially where there are threatened irregularities of growth,-where there is a deficiency of space, or where the teeth press too much upon each other.

Two important considerations must here be noticed, in order to preserve the teeth: first, for the purposes of cleanliness, they should be rubbed with a soft brush, and a little water only, night and morning; and secondly, all portions of food which have not been swallowed, should

be carefully removed after each meal; since these remaining about the teeth, often give rise to those decompositions which terminate in the loss of their healthy structure,-a loss, not only of consequence to personal appearance, and personal comfort, but also of great importance to the health and longevity of the individual.

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CHAP. VII.

DEVELOPMENT OF THE LOCO-MOTIVE FUNCTION -CAUTION AGAINST PUTTING ΑΝ INFANT EARLY UPON ITS FEET-MUSCULAR EXERTION DEPENDENT ON VOLITION DEVELOPMENT

OF THE FUNCTION OF EXPRESSION, AS CONNECTED WITH THE MUSCULAR SYSTEM-PHYSIOGNOMY-LANGUAGE, NATURAL AND AR

TIFICIAL.

THE development of the muscular power, and particularly of the loco-motive apparatus, will now form an important object of consideration. The first actions of infancy are altogether automatic, independent of the will, and characterized by no particular design; yet they serve to strengthen and increase the muscular fibre, and thus render it adequate to those voluntary exertions which it will presently be called upon to perform.

After a few months, it will be observed that many of the child's motions are subservient to volition; and that they are directly, though imperfectly (because the harmony between the will, the nervous system which conveys its notices, and the muscles which obey them, is not yet thoroughly established) employed for the attainment

of some particular object. Nurses are too apt to avail themselves of the first intimations of these feeble exertions, and to promote the action of walking; their great object of desire is to get the infant upon its legs. This process, however, should never be hastened. If a child walks before the bones are strong enough to bear the superincumbent weight, these will yield, and a greater or less degree of deformity will be the consequence; the legs will become bowed, or curvature of the spine will be occasioned; and all this for the sake of indulging the indolence of the nurse, or the less pardonable vanity of the parent. The wish and aim of both, should not be however to have the infant early upon his legs, but to procure the development of the muscular and bony systems, so as to obtain their fullest power, and to secure the greatest possible degree of gracefulness and strength. In the pursuit of this object, no artificial help should ever be given to the little pupil : it may be exercised in various ways, and when eight or nine months old, it should be placed upon the carpet and suffered to crawl about according to its will. When it has strength sufficient for other actions, it will get upon its feet, —an event, which however joyful, ought never to be urged. The consequence of leaving this process to nature, will be, that although children will not run alone till a much later period, parents will be abundantly rewarded for their patience, by the firm and graceful step, and upright forms of their offspring.

The loco-motive function is depending upon muscles, and the nerves which supply them, as the medium of communication with the brain: the muscles being incapable of action without the influence of the will; and the power of volition, not residing in the nerves themselves, but being transmitted through them from the brain. Hence their reciprocal dependence, and the necessity for their mutual integrity, in order to ensure muscular motion. There is a point in our researches beyond which we cannot advance: nature has ordained a barrier which reason cannot penetrate; and the Almighty Author of nature has fixed a limit to our intellectual pursuits, perhaps in order to humble the pride of man, and to prove to him, if he will listen to its voice, that this cannot be his final and most perfect state of existence. Thus, in the present instance, we know nothing certainly beyond the explanation which has been just given: we know not how the will transmitted through the nervous system, produces muscular motion.

The attention will not be confined, at this time, to the development of those muscles which are concerned in preserving the body upright, and whose perpetual agency alone abstracts man, the lord of the creation, from the universal law of obedience to the influence of gravitation; or to those by whose instrumentality progression is accomplished: there are other sets of muscles to be employed;-such as those by which he

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