54: ALIMENTATION. 



Gluten obtained by washing flour under a stream of 

 water contains vegetable fibrin, vegetable albumen, and a 

 substance soluble in alcohol, called glutine. This latter sub- 

 stance is found in quantity only in wheaten flour. 



In the different articles of food belonging to the vege- 

 table kingdom, there are undoubtedly many nitrogenized 

 principles, with the distinguishing properties of which we 

 are not yet familiar. In their relations to the body as ali- 

 mentary principles, these would not possess much practical 

 interest, even if they had all been isolated and studied ; as 

 all articles of this class are apparently transformed into one 

 and the same nutritive principle, namely, the albumen of 

 the blood. 



Non-Nitrogenized Alimentary Principles. The impor- 

 tant principles belonging to this class are sugar, starch, and 

 fat. From the fact that these are supposed by some to be 

 exclusively concerned in keeping up the animal temperature 

 by the oxidation of carbon, they are frequently spoken of as 

 the carbonaceous or calorific elements of food. They are 

 sometimes called hydro-carbons. 1 



In many respects there are marked and important differ- 

 ences between the nitrogenized and non-nitrogenized articles 

 of food ; and whether or not these differences relate to the nu- 

 trition of the organism, is a question which will be considered in 

 its appropriate place. The production of animal heat, which 

 is supposed by some to be due entirely to the action of non- 

 nitrogenized substances, is closely connected with the function 

 of nutrition and all that is at present known of this general pro- 

 cess must be taken into consideration in connection with calo- 

 rification. It is certain, however, that all alimentary and proxi- 

 mate principles which contain nitrogen, excluding the inorgan- 

 ic and some crystallizable organic substances, have very differ- 



1 The name hydro-carbon is strictly applicable only to the sugars and starch, 

 which are, chemically, hydrates of carbon, containing as they do, carbon, with 

 hydrogen and oxygen in the proportions to form water. 



