Although the digestibility and flavor of meat (and of every other kind of food) affect its nutritive value, these points are in general of far less importance than its composition. Potatoes are not so nutritious as peas, because they contain a smaller amount of fat and flesh-formers; but they are more digestible. Fish contains less solid matter than flesh, and is less nutritious, yet a cut of turbot will be, in general, more easily digested than an equal weight of old beef. The fact is, that digestibility and flavor are only of great importance to dyspeptic persons. In the healthy digestive organs a pound weight of (dry) food of inferior flavor and slow digestibility will be just as useful as the same weight of well-flavored and easily assimilable aliment, provided all other conditions be alike. If the food be eaten with a relish, and tolerated by the stomach, its digestibility will not, except in extreme cases, affect in a very sensible degree its nutritiveness. Were one question in animal nutrition satisfactorily answered, it would then be comparatively easy to arrange aliments in the order of their nutritive value. That question is--What are the proper relative proportions of the fat-forming and flesh-forming constituents of our food? It is constantly urged, that the food of the Irish peasantry contains an excess of the fat-forming materials in relation to the muscle-forming substances; and the remedy suggested is, that their staple article of food--potatoes--should be supplemented with flesh, peas, and such like substances, in which, it is supposed, the elements of nutrition are more fairly balanced. In potatoes, the proportion of fat-formers (calculated as fat) is about five times as much as that of the flesh-formers; but these principles exist in the same relative proportions in the fat bacon with which the potato-eater loves to supplement his bulky food. In bread we find the proportion of fat-formers to be only 2-1/2 times as much as that of the flesh-formers, whilst, according to Lawes and Gilbert, the edible portion of the carcass of a fat sheep contains 6-1/2 times as much fat as nitrogenous (flesh-forming) compounds. It is evident, then, that meat such as, for example, the beef recently imported from Monte Video, from which the fatty elements of nutrition are almost completely absent, cannot be a suitable adjunct to a farinaceous food.