Imagine two merchants, each of whom has but a hundred dollars. Both merchants are therefore equally rich in capital. But there is the following difference between them: the one goes to the country twice a week and buys cattle and brings it to market, where he sells it again. By doing this he realizes every time five dollars on his capital. The other establishes a notion-store, buys himself a hundred dollars' worth of goods, which he sells in a month, and thereby gains twenty-five dollars. Now, which of these two fares the better? The notion-dealer, who with his hundred dollars has earned twenty-five dollars, or the cattle-dealer, who gained but five? Most assuredly the cattle-dealer. For while the other has twenty-five dollars to live on, the cattle-dealer has eight times five, or forty dollars. Whence does this come? In a month the notion-dealer turns over his capital but once, while the cattle-dealer turns his eight times. The same holds good with the Irishman and the Englishman. Both have the same quantity of blood; it is their capital, and the same for both. But the renewal is not the same. The Englishman works vigorously and eats vigorously. When he works, he spends his capital, his blood; by every blow of the hammer particles of his body are wasted; the activity of his body is great and his appetite is great. He invests his capital again and again in rapid succession, and he takes it in just as rapidly and fares well with it. The poor, unhappy Irishman, however, spends his blood but very slowly; he does not work; he eats potatoes, which, taken alone, are bad food; thus, he invests his capital very slowly and takes it in again very slowly; and though the capital is in both cases the same, its slow renewal is the cause of the Irishman's being miserable, dull, and lazy, while the Englishman is sound in body and soul. Therefore the blood alone is not all, but its rapid consumption and renewal is the most important object. CHAPTER II. DIGESTION. In the preceding article we said that the rapid conversion and waste of the blood is the main point in nutrition. In the examination of food, only such articles ought to be pronounced good and healthy, as are capable of _rapidly_ replacing the blood lost by work and vital activity. It follows from this, that our chemists do not do enough, when they examine the food and determine its worth merely according to its contents; articles of food must be studied also in reference to the rapidity and ease with which they may be converted into blood. An article that contains little of what the blood needs, but which converts that little rapidly and easily into blood, is much preferable to food which contains many of the constituent parts of the blood, but turns into blood very slowly and with difficulty. An example will illustrate this better: