660 



LECTURE XXVIII. 



it comes upon the table varies greatly. The species of animal from 'which 

 it is obtained, the amount of waste (tendons, bones, etc.), and the state of 

 nourishment of the animal, all constitute important factors. Meat con- 

 tains, besides albumin, other nitrogenous substances, such as creatin, 

 creatinin, sarkosin, xanthin, and carnin. It is not right, therefore, to 

 estimate the amount of protein present by the nitrogen content alone. 

 The composition of the flesh of fish is quite similar to that of mammals. 

 Fish is, as a rule, utilized by the human organism as well as other flesh 

 foods. 



The values given in the following table illustrate the composition of dif- 

 ferent kinds of food: 



Meat as well as milk is used in the manufacture of certain prepared 

 foods. The latter is used to make butter and cheese; the former in the 

 manufacture of sausages and other cured products. It may be said that 

 the value of flesh food from an economic standpoint is largely dependent 

 upon the amount of the product which may be utilized. With fish, for 

 example, there is a relatively large amount of waste. 



Among the vegetable foods the different kinds of grain are very impor- 

 tant; these are used in the form of meal and flour in a number of different 

 ways, especially in bread-making. They also serve, as well as potatoes, 

 for the manufacture of starch. Then again there are the large number of 

 green vegetables and fruits. As regards their nutritive value and utiliza- 

 tion in the human organism, we have found that on the whole they are not 

 utilized as completely as the flesh foods. A vegetable diet gives rise to a 

 large amount of excreta. In the case of the different grains it makes con- 

 siderable difference whether the whole grain is used in the flour, or only 

 that which has been freed from the hulls. The more of the hull there is 

 present, the less the percentage utilization. We cannot include within 

 the scope of these lectures all the different data which have been acquired 

 concerning these relations, and which are so important in considering the 

 food-supply of a people. We shall have to refer to the special works on 

 the subject. Here we only desire to point out the great importance of the 



