We have seen that, where waste is great and growth active, an abundant supply of food is required, and that, in accordance with this relation, it is in such circumstances that the desire for food is most keenly felt. Generally speaking, appetite is a safe guide as to quantity; but, in following its dictates, we must take special care neither to eat so fast as to prevent it from giving timely intimation that we have had enough, nor to confound the mere gratification of _taste_, or the yearning of a vacant mind, with the natural craving of unsatisfied want. Dr Beaumont’s remarks on this subject are characterized by so much soundness of judgment, that no apology can be required for soliciting the attention of the reader to the following very pertinent extract from his work. “There is no subject of dietetic economy,” says Dr Beaumont, “about which people err so much, as that which relates to _quantity_. The medical profession, too, has been accessory to this error, in giving directions to dyspeptics to eat until a sense of satiety is felt. Now, this feeling, so essential to be rightly understood, never supervenes until the invalid has eaten too much, if he have an appetite, which seldom fails him. Those even who are not otherwise predisposed to the complaint, frequently induce a diseased state of the digestive organs by too free indulgence of the appetite. Of this fact, the medical profession are, generally, not sufficiently aware. Those who lead sedentary lives, and whose circumstances will permit of what is called free living, are peculiarly obnoxious to these complaints. By paying particular attention to their sensations during the ingestion of their meals, these complaints may be avoided. There appears to be a sense of perfect intelligence conveyed from the stomach to the encephalic centre, which, in health, invariably dictates what quantity of aliment (responding to the sense of hunger and its due satisfaction) is naturally required for the purposes of life; and which, if noticed and properly attended to, would prove the most salutary monitor of health, and effectual preventive of disease. It is not the sense of _satiety_, for this is beyond the point of _healthful_ indulgence, and is Nature’s earliest indication of an _abuse_ and _overburden_ of her powers to replenish the system. It occurs immediately previous to this, and may be known by the pleasurable sensation of _perfect satisfaction, ease, and quiescence of body and mind_. It is when the stomach says _enough_, and is distinguished from satiety by the difference of the sensations,--the former feeling _enough_--the latter _too much_. The first is produced by the timely reception into the stomach of proper aliment, in exact proportion to the requirements of Nature, for the perfect digestion of which a definite quantity of gastric juice is furnished by the proper gastric apparatus. But to effect this most agreeable of all sensations and conditions--the real Elysian satisfaction of