This leads us to notice another point of analogy in this case, which is, the necessity of adapting the food to the age and capacities of those who are to receive it.--There is in the mental, as well as in the physical nourishment provided for our race, milk for the weak, as well as meat for the strong; and it is necessary in both cases that the kind and the quantity be carefully attended to. In the case of the strong, there is less danger; because, with regard both to the mental and bodily food, Nature has so ordered matters, that the food which is best adapted for the weak, will also nourish the strong; but the food adapted for the strong is never suitable, and is often poisonous to the weak. There must therefore be, in all cases where the young are concerned, as careful a selection of the mental food, as there is of the food for the body; and the parent or teacher should, in all cases, present only such subjects, and such ideas to his pupils, as the state of their faculties, or the progress of their knowledge, enables them to understand and apply. Another striking point of analogy between mental and bodily nourishment, is to be found in the effects of repletion, when too great a quantity of food is communicated at one time.--As the increase of a child's bodily strength does not depend upon the mere quantity of food forced into his stomach, but upon that portion only which is healthfully digested and assimilated; so in like manner, the amount of a child's knowledge will not correspond to the number of ideas forced upon his attention by the teacher, but to those only which have been reiterated by the mind, and committed by that process to the keeping of the memory. In both cases, the evil of repletion is two-fold; there is the waste of food and of labour, while the strength and the growth of the child, instead of being promoted, are retarded and diminished. The physical appetite gains strength, by moderate exercise; but it is palled and weakened by every instance of repletion. The desire for food is never for any length of time at rest, so long as the stomach is kept in proper tone by moderate and frequent feeding; and the quantity of food which a healthy child will in these circumstances consume, is often surprising. But whenever the stomach is gorged, then restlessness, uneasiness, and not unfrequently disease, are the consequences. The digestive powers are weakened, the tone of the stomach is relaxed, and, instead of the healthful craving for food which should occur at the proper interval, the appetite is destroyed, and food of every kind is nauseated.--Exactly similar is the case with the mental appetite. The natural curiosity of children, or, in other words, their desire of information, before it is checked or overloaded by mismanagement, is almost insatiable; and the astonishing amount of knowledge which they usually acquire between the ages of one and three years, while under the guidance of Nature, has been formerly alluded to.