158 ECONOMY OF HUMAN DIET. 



Those articles of food in which the nitrogenous compounds 

 predominate, are especially fitted for the maintenance of the 

 solid fabric of the body ; whilst those in which the carbon- 

 aceous compounds are in largest excess, are those which are 

 most effective as supplying materials for the combustive pro- 

 cess. Conspicuous among the former are the various kinds 

 of animal flesh, as also the white of eggs ; whilst among the 

 latter the most noticeable are bacon and butter, rice and 

 potatoes, the former consisting almost wholly of fat, the latter 

 being chiefly composed of starch. Of all single articles of 

 food, good wheaten bread, in which the proportion of nitro- 

 genous to carbonaceous components is about as 5.7 to 1, 

 seems to be the one best suited to the ordinary wants of 

 Man ; but this acquires much additional value from the con- 

 current use of a moderate amount of fatty matter in the form 

 of butter. 



165. If the more highly azotized forms of food be em- 

 ployed exclusively, a great excess of them must be consumed 

 to supply the carbon needed for respiration ; whilst if the 

 more carbonaceous kinds of food be used as the sole susten- 

 ance, unless the quantity ingested be large enough to afford 

 the requisite supply of azotized material for the maintenance 

 of the tissues, their nutrition must be imperfectly effected, 

 and the strength must fail Not only in the instance just 

 cited, but in a variety of others, the instincts of mankind 

 have led to such a combination of different articles of diet, 

 as includes in their appropriate proportions the albuminous, 

 the saccharine, and the oleaginous principles. Thus with 

 meat we eat potatoes ; and with the white meats which are 

 deficient in fat, we eat bacon. We use melted butter with 

 most kinds of fish, or fry them in oil ; whilst the herring, the 

 salmon, and the eel, are usually fat enough in themselves, and 

 are dressed and eaten alone. A similar adjustment is made 

 when we mix eggs and butter with sago, tapioca, and rice ; 

 when we add oil and the yolk of an egg to salad ; when we 

 boil rice with milk, and combine cheese with maccaroni. 

 Bacon and greens, and pork and pease-pudding, again, are 

 combinations founded in taste, which approve themselves to 

 the judgment; as is also the Irish dish termed kolcannon, con- 

 sisting of potatoes and cabbage, with a little bacon or fat pork. 

 So are the mixture so common in Ireland and Alsace, of butter- 



