VII.

The need of varied food is apparent to the casual observer, and it is well proven in the immortal work of Cabanis. "The experience of civilized life has shown," says Professor Horsford, in his admirable pamphlet on the marching ration of armies, "that the human organism requires, to maintain it in health, both organic and inorganic food.

"Of the organic, it needs nitrogenous food for the support of the vital tissues for work; and saccharine, or oleaginous food, for warmth. Of the inorganic, it needs phosphates for the bones, brain, muscles, and blood; and salt for its influence on the circulation and the secretions, and for various purposes where soda is required for a base; and doubtless both phosphates and salt for many offices as yet imperfectly understood. 'A man may be starved by depriving him of phosphates and salt, just as effectively as by depriving him of albumen or oil.' (Dalton's Physiology.)

"The salts of potassa, magnesia, and iron, of manganese, silica, and fluorine, are always present, and perform services of greater or less obvious moment in the animal economy. These organic and inorganic substances are essential, but they are not all that are needed. Man, especially when compelled to exhausting labor, requires beverages and condiments. He wants coffee, or tea, or cocoa; or, in the absence of these, he may feel a craving for wine or spirits. He wants salt, pepper, and vinegar. To preserve a sound body, then, there are required organic and inorganic food, beverages, and condiments."

"A mixed food," says another writer, "which varies from time to time, seems to be essential; and there can be no doubt that the changes which physicians have recognized in the nature of the predominating diseases, from century to century, are connected with changes which have taken place in the nature of the diet. Excess of oil, albumen, and starch produce liability to arthritic, bilious, and rheumatic affections; a deficiency of oleaginous materials, scrofula, &c."