Owing to the marked individuality which man exhibits in the selection of his food, and to the intimate relationship subsisting between food and the organism it nourishes, it is impossible to arrange the alimental substances in the strict order of their nutritive values. You can bring a horse to the water, but you cannot compel him to drink it; you can swallow any kind of food you please, but you cannot force your stomach to digest it. It is, therefore, vain to tell a man that a certain kind of food is shown by chemical analysis to be nutritious, when his stomach tells him unmistakeably that it is poisonous, and refuses to digest it. In the matter of dietetics Nature is a safer guide than the chemist. Many substances, when viewed only in the light shed upon them by chemical analysis, appear to be rich in the elements of nutrition, yet when they are introduced into the stomachs of certain individuals, they disarrange the digestive organs, and sometimes cause the whole system to go out of order. Every day we see exemplified the truth of the proverb, that "one man's meat is another man's poison." There are persons who relish and readily digest fat pork, and yet they cannot eat a single egg with impunity; others enjoy and easily assimilate eggs, but their stomachs cannot tolerate a particle of fat bacon. It is not merely the composition of an aliment and its adaptability to the organism which determine its nutritive value--its digestibility and flavor are points which affect it. There are few people in these countries who are disposed to quarrel with beef; but no one would prefer the leg of an elderly milch cow to the sirloin of a well-fed three-year-old bullock: yet if our selection were to be determined by the analysis of the two kinds of beef, we would be just as likely to prefer the one as the other. No doubt the relative tenderness of meats may be ascertained by experiments conducted _outside_ the body; but tenderness is not in every case synonymous with easy digestibility. Veal contains more soluble albumen, and is, consequently, far more tender than beef; yet, as every one knows, it is less digestible. It is curious that maturity renders the flesh of some animals more digestible, and that of others less digestible. Flavor has something to do with these differences. Beef is richer than veal in the agreeably flavorous osmazome, and the flesh of the kid is destitute of the disagreeable odour of the fully-developed goat. The superiority of wild-fowl over the domesticated birds is solely owing to the finer flavor of their flesh.