30 Essential Characters of Food. 



a mixed character ; third, that it possesses pro- 

 portionate bulk ; fourth, it should be regularly 

 supplied ; and lastly, the digestive organs gene- 

 rally must be in a state of healthy action. 



It is imperative that food possess nutritious 

 principles. This must be apparent from the fact 

 that from it all parts of the body are built up 

 and being constantly renovated. In order to 

 possess this property, bodies rich in nitrogen are 

 requisite, which are denominated nitrogenous, 

 azotised, nutritious, or flesh-forming compounds. 

 Examples of these are albumen, fibrine, and 

 caseine terms which would indicate different 

 substances. Chemically, however, they are alike 

 in composition, but exhibit physically different 

 appearances. 



If wheaten flour be placed under a stream of 

 cold water a sticky paste is left behind. This is 

 called gluten, and is identical in chemical com- 

 position with the flesh of man and animals. It is 

 the nitrogenous or albuminous principle of wheat 

 flour. 



If an egg be broken a glairy fluid escapes from 

 the shell, which becomes white and coagulates 

 into a solid mass when heated. This is albumen 

 gluten in another form, identical in composi- 

 tion, and is the nitrogenous principle of the egg 

 from which the flesh, feathers, claws, Sec., of the 

 bird are formed. 



If milk is taken and an acid added, a solid 

 mass of curds is speedily produced. This is 



