FOOD AND DRINK 97 



11. The necessity for occasionally changing or varying the 

 diet, is seen in the fact that no single article comprises all the 

 necessary principles of food, and that the continuous use of 

 any one diet, whether salt or fresh, is followed by defective 

 nutrition and disease. There is one exception to this rule : in 

 infancy, milk alone is best calculated to support life ; for then 

 the digestive powers are incompletely developed, and the food 

 must be presented in the simplest form possible. It should 

 also be remembered that too rich diet is injurious, just as truly 

 as one that is inadequate. When the food of horses is too 

 nutritious, instinct leads them to gnaw the wood-work of their 

 mangers. 



12. Different Articles of Diet Milk. Milk is the earliest 

 nutriment of the human race, and in the selection and arrange- 

 ment of its constituents, may be regarded as a model food, no 

 other single article being capable of sustaining life so long. 

 Cow's milk holds caseine, one of the albuminoids, about five 

 parts in one hundred ; a fatty principle, when separated, known 

 as butter, about four parts ; sugar of milk four parts ; water 

 and salts eighty-seven parts. The caseine and fatty substance 

 are far more digestible in milk than after they have been sepa- 

 rated from it in the form, of cheese and butter. 



13. Since milk, in itself, is so rich an article of food, the 

 use of it as a beverage is unwise, unless the quantity of the 



on the one hand it may be freely conceded to the advocates of ' vegeta- 

 rianism,' that a well-selected vegetable diet is capable of producing, in 

 the greatest number of individuals, the highest physical development of 

 which they are capable, it may, on the other hand, be affirmed with 

 equal certainty, that the substitution of a moderate proportion of animal 

 flesh is in no way injurious ; but, so far as our evidence at present 

 extends, this seems rather to favor the highest mental development. 

 And we can scarcely avoid the conclusion that the Creator, by conferring 

 on a man a remarkable range of choice, intended to qualify him for sub- 

 sisting on those articles of diet, whether animal or vegetable, which he 

 finds most suitable to his tastes and wants." W. B. Carpenter on the 

 Principles of Physiology. 



11. Necessity for change In diet ? Continuous use of the same diet ? Exception ? Why ? 

 Too rich diet ? Horses ? 



12. Milk as a model food ? Cow's milk ? The constituents when separated ? 

 18. Milk as a beverage ? Milk sold in cities ? How to detect the cheat ? 



