MASTICATION.

King Country Chronicle, Volume VII, Issue 581, 2 July 1913, Page 3

MASTICATION.

The special feature of the second year of normal life, as contrasted with the first year, is the progressive development of the power of mastication. This is a matter of the utmost importance, because upon it depends the future of digestive power, health, and strength of the individual. Fortunate indeed the baby who during the first year of existence obtains his food by energetic suction (from the breast, if possible, and, failing this by means of a properly-held bottle with smallholed nipple) and who, towards the close of the year and throughout the second year, is made to do a proper amount of work on his food by active, vigorous munching and chewing. These'are tbe simple means by which we can aid the intention of nature to provide tbe growing child with maiticatory apparatus which shall not prematurely atrophy and decay, but shall last sound and good to the end of life. The amount of blood supplied to the jaw j and adjacent parts depends on the daily amount of work they are called on to do. Embedded deep under the gum a at tbe time of birth are the two embryo sets of teeth—the temporary and tbe permanent and the structure, growth, proper setting, and eruption depends on the supply of an abundant stream of rich, healthy blood throughout —the period of most active growth. One might say, "Take care of tbe two first years, and the rest will take care of themselves." This is true not .only of structure, but of function also. Proper feeding habits practised throughout the first two years will tend.to last for life. Dr Harry Campbell (one of tbe foremost authorities of the day on dietics and the practical application physiology to everyday life) says:— BREAKING UP THE FOOD

Mastication, by breaking up tbe food, enables it to be the more easily swallowed.—Soft,'moist, mushy foods, each as milk puddings and porridge, can be—often, indeed, are—swllowed without any mastication at all. On the other hand, it is difficult, if not impossible to swallow large lamps of tough food or large masses of very dry food, event though the latter is in a finely-divided state, like flour. The tough food needs first to be broken up by the teeth, and the dry food to be moistened by the saliva. If, then, we desire to give foods which compel mastication, we should choose such as are tough and dry. Those who are accustomed to bolt their food often swallow large lumps totally unmasticated, but, as Van Someren has pointed out, once tbe habit of efficient mastication has been acquired the swallowing of such masses is effectually prevented by a pharyngeal reflex, i.e. the instinct becomes so strong that a large onchewed lump cannot be swallowed. It is therefore of the utmost importance that children should learn to maßticate thoroughly as saon as they have the teeth to do it. COMMINUTING THE POOD. Mastication, by comminuting the food, brings it into intimate contact witd the digestive juices.—All raw vegetable food, tbe luscious fruits excepted, requires mastication in order to disintegrate the cellulose and allow the digestive juices to act upon the imprisoned nutriment; but this is not necessary in the case of cooked vegetable foods. Some of these, however, do, on account of their density, call for thorough chewing, as, for example, jtodgy padding and new potatoes also new bread, which, unlike the more crumbly stale bread, is apt to elude the teeth and pass into the stomach in the form of sold impermeable masses. Similarly, it is oecause cauliflower and minced spinach are more finely divided than new potato and cabbage that the) are more digestible. If. now we turn to animal food, we notice that while in the raw state it is readily digestible after little or no previous mastication, it may be rendered indigestible by being cooked, as in the familiar case of hard boiled egg or overdone meat and putting these facta to gether, the deduction is that the relative digestibility of animal and of vegetable foods alike depends more upon physical consistence than upon chemical composition. Thus it is chiefly on account of their density that veal, pork, lobster, and cheese are indigestible. There is nothing in these to prevent digestion but since its two chief constituents are welded together in an impermeable mass, it may, if unmasticated, remain undigested for the physical reason. A plain, wholesome cheese, well masticated or intimately mixed with other foods—e.g., with macaroni most people can digest without difficulty. Ido not, of course, deny the influence of the chemical factor. Such substances as goose-fat may set up violent irritation pigeon taken several days in succession is apt to disagree some there are, again, ' who cannot tolerate eggs in any form and numerous other dietetic idiosyncrasies axe met with; bat, making due allowance for any chemical influence, there can, I think be little doubt that the digestibility of the more common articles of diet, whether animal or vegetable, depends in the main upon their physical constitution—that, in fact, they all tend to be equally digestible if reduced to the sae degree of comminution. This, if tru*, is, I need scarcely say, a fact of the greatest importance, for it amounts to this: that wo may often allow to those with vary weak digestion! food* generally debarred ai Indigestible, protided only that they are thoroughly comminuted, either by mafltteotoo or by other 810000. '